DISCLAIMER - Town of Claremont · 2019. 9. 17. · Spraying of planting area around FOLC shed Fence surrounding proposed FOLC Shed ... Nutgrass, Typha, Asparagus fern and Two-leaf

DISCLAIMER

Persons present at this meeting are cautioned against taking any action as a result of any Committee recommendations until such time as those recommendations have been considered by Council and the minutes of that Council meeting confirmed.

LAKE CLAREMONT ADVISORY COMMITTEE AGENDA 2 MAY, 2019

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TABLE OF CONTENTS

ITEM SUBJECT PAGE NO

1 DECLARATION OF OPENING/ANNOUNCEMENT OF VISITORS... 1

2 RECORD OF ATTENDANCE/APOLOGIES ...................................... 1

3 DISCLOSURE OF INTERESTS ......................................................... 1

4 CONFIRMATION OF MINUTES OF PREVIOUS MEETINGS ........... 1

5 BUSINESS NOT DEALT WITH FROM A PREVIOUS MEETING ...... 1

6 REPORTS OF THE CEO ................................................................... 2

6.1 LAKE CLAREMONT OPERATIONAL PLAN 2018-19 PROGRESS REPORT & DRAFT LAKE CLAREMONT OPERATIONAL PLAN 2019-20 .............................................................................................. 2

6.2 AERATION OF LAKE AND IMPROVEMENT OF WATER QUALITY ............................................................................................ 7

6.3 STREET TREE MASTER PLAN ...................................................... 12

6.4 PLANTING OF BOUNDARIES OF OFFLEAD DOG EXERCISE AREA, LAKE CLAREMONT ............................................................ 15

7 FRIENDS OF LAKE CLAREMONT ................................................. 20

8 LAKE CLAREMONT BIRD CENSUS .............................................. 21

9 COMMITTEE MEMBERS’ MOTIONS OF WHICH PREVIOUS NOTICE HAS BEEN GIVEN ............................................................ 21

10 FUTURE MEETINGS OF COMMITTEE ........................................... 21

11 DECLARATION OF CLOSURE OF MEETING ................................ 21


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LAKE CLAREMONT ADVISORY COMMITTEE

AGENDA

1 DECLARATION OF OPENING/ANNOUNCEMENT OF VISITORS

2 RECORD OF ATTENDANCE/APOLOGIES

3 DISCLOSURE OF INTERESTS

4 CONFIRMATION OF MINUTES OF PREVIOUS MEETINGS

The Minutes of the Ordinary meeting of the Lake Claremont Advisory Committee, held on 07 February 2019 be confirmed.

5 BUSINESS NOT DEALT WITH FROM A PREVIOUS MEETING

The progress of Lake Claremont Action items from previous meetings will be tabled.

https://www.claremont.wa.gov.au/MediaLibrary/TownOfClaremont/Documents/Minutes-February-07-2019-Lake-Claremont-Advisory-Committee.pdf


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6 REPORTS OF THE CEO

6.1 LAKE CLAREMONT OPERATIONAL PLAN 2018-19 PROGRESS REPORT & DRAFT LAKE CLAREMONT OPERATIONAL PLAN 2019-20

File No: PRK/00136-03

Attachments: Lake Claremont Operational Plan 2018-19 (Attachment 1)

Draft - Lake Claremont Operational Plan 2019-20 (Attachment 2)

Adopt a spot map (updated Oct 2018) (Attachment 3)

Lake Claremont Water Quality and Macroinvertebrate Assessment 2018-19 (Attachment 4)

Responsible Officer: Andrew Smith Director Infrastructure

Author: Jared Bray Supervisor Parks and Environment

Proposed Meeting Date: 02 May 2019

Purpose

The following items are to update the Lake Claremont Advisory Committee (LCAC) on activities occurring at Lake Claremont during the period February 2019 to May 2019.

Background

The Town’s officers have been involved in a number of activities which are identified in the Lake Claremont Operational Plan. The below items have been completed or are in planning for the Lake Claremont precinct:

Path pruning

Spraying of planting area around FOLC shed

Fence surrounding proposed FOLC Shed

Weed control

Turf mowing

Wetlands areas weed control

Dryland areas weed control

Sumps weed control

Weed control program general

Hand weeding (walking weeders)

Adopt a spot

Busy bees

Weed mapping


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Mulching

Litter management

Park furniture and assets

Water sampling

Sediment sampling

Macroinvertebrates spraying and sampling

Drain outflow inspections

Erosion control

Trial for Glyphosate alternative

Discussion

Path Pruning Contractors have completed pruning works in the sections along the red path from the corner opposite the FOLC shed, up to Strickland St cul-de-sac. Council officers have also completed pruning along various sections of the limestone paths and the path leading to the island. Spraying of planting area around FOLC Shed Contractors sprayed the grassed areas within the proposed planting area in late March. The Tamarix will be removed during May prior to planting. Mulching of planting area surrounding FOLC Shed The Town has mulched the planting area in readiness for 5,000 tube stock of mixed species to be planted. Fence surrounding dog exercise area Quotes have been obtained for the fencing surrounding the dog exercise area, with awarding of the contract to be approved in the coming weeks. In the interim period a petition has been received by the Council in respect to this proposed planting program, and the matter is scheduled to be reconsidered by the Council in April. Turf mowing Completed in accordance with the schedule of works with no issues to report. Weed control Wetlands areas weed control Contractors have completed spraying of weeds within the wetland areas in the March spraying round with no issues to report. No further follow-up action was required for Typha, as the initial removal was successful. Dryland Areas Weed Control Contractors have completed spraying of all dryland areas in the March spray round with no issues to report. Sumps Weed Control Contractors have completed spraying of all sumps in the March spray round with no issues to report.


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Weed Control Program General Due to low levels of rainfall, there are low weed levels in general to report. Hand Weeding (walking weeders) A core membership of four weeders continue to hand weed any areas where weeds grow in and among native plants on a Friday morning, with a focus being on the lake bed over the summer/ autumn months, targeting bushy starwort. Adopt- a- Spot Adopt- a- Spot areas confirmed by FOLC within the following areas- SE section of the Eastern buffer, SW corner of McKenzie Park and middle section of Wetland buffer South East (see attached map). Weed Mapping Mapping of more aggressive weeds such as Caltrop, Nutgrass, Typha, Asparagus fern and Two-leaf Cape tulip have been undertaken, with any new occurrences added to the database by the Bushcare and Field Officers. Areas are localised with no further spreading being identified. Mulching Contractors have completed mulching in the northern section of the lake, adjoining Alfred Rd/ planting areas, at the end of Lakeway St and surrounds, underneath the park benches situated at the NE section of the lake, underneath the gym equipment at Stirling Rd and Stirling Rd carpark and surrounds. Litter management Field and Bushcare Officers continue to remove rubbish from bush and parkland areas, with a sizable amount removed between Cresswell Park and ‘The Island’ over summer, once water levels had receded. Park furniture and assets Two noticeboards have been installed at Lapsley Rd playground area and Cresswell Park. Signage showing current location, a park overview and park facilities has also been installed at Lakeway Street, Alfred Road, Stirling Road and Lapsley Road. Deck oiling of the Stirling Road Jetty and the Bird Viewing Deck was also completed by the contractor during March and April. The Butler’s Swamp Plaque located near the Jetty has also been cleaned and re-attached. Water sampling (see attached Water Quality and Macroinvertebrate Assessment 2018-19) Key water quality issues identified at the Lake from the 2018-19 monitoring include: • High total nitrogen and phosphorus concentrations in the main Lake body

sites, particularly in summer, and summer phytoplankton; • High total nitrogen and phosphorus concentrations in the north-eastern Lake

corner, particularly in summer; • High total (and filterable reactive) phosphorus concentrations at stormwater

drain sites;


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• High concentrations of arsenic in Lake sites; • High concentrations of metals (aluminium, copper, lead and zinc) in drain

sites; • High concentrations of iron in north-eastern Lake; • Low dissolved oxygen at lake sites; • Abundant mosquito larvae near the inlet of Alfred Rd drain Macroinvertebrates sampling (see attached Water Quality and Macroinvertebrate Assessment 2018-19) A total of 19 macroinvertebrate taxa were recorded at the four Lake Claremont sites in October 2018 (Table 10-1). Macroinvertebrate richness varied between the sites, with the highest number of taxa recorded at Alfred Road Drain (16 taxa), followed by The Lookout (12), Henshaw Drain (lake) (11) and Stirling Road Central Drain (lake) (10). Total abundance was highest at the Lookout. Closer examination of the community composition of this site revealed that these high abundances were due to the presence of large numbers of three taxa: back swimmers, copepods and ostracods (> 1000 individuals recorded in the sweep). Overall, the Class Insecta was the most family rich group, followed by the Crustacea. Three taxa (dragonfly nymphs, soldier fly larvae and flat worms) were recorded in 2018 that were not recorded in 2017 (SERCUL 2017). Drain outflow inspections Completed by the Bushcare and Field Officers in March, prior to the upcoming rainfall in the winter months. Erosion control Base of the metal stairway within Lakeway Remnant Bushland continues to be monitored for signs of sand accumulating with no signs to be reported. Trial for glyphosate alternative The proposed trial has been postponed due to insufficient weed load to establish viability and generate reliable comparative information. In addition to the report on the progress of the works as contained in the 2018/19 Operational Plan, the attached Plan for 2018/19 also includes a proposed overview of works and frequencies for the 2019/20 Operational Plan. This is tabled for Committee consideration and comment (as appropriate) so that this Plan, or an amended version of this Plan can be adopted prior to the commencement of the 2019/20 financial year. Works identified in the draft 2019/20 plan have been developed to reflect contractor responsibilities and outcomes as well as staff resources and scheduling.

Past Resolutions

Ordinary Council Meeting held on 3 July 2018, Resolution 115/18 (in part):

That Council adopts the Lake Claremont Operational Plan 2018-19


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Financial and Staff Implications

Resource requirements are in accordance with existing budgetary allocation. Policy and Statutory Implications There are no policy and statutory implications.

The following documents are relevant to the Lake Claremont area.

Lake Claremont Management Plan 2016-21

Lake Claremont Operational Plan 2018-19

Communication / Consultation

Consultation to members of the community in respect to Lake Claremont has been undertaken via the Town of Claremont website www.claremont.wa.gov.au and the distribution and availability of Friends of Lake Claremont newsletters.

Strategic Community Plan

Liveability

We are an accessible community with well-maintained and managed assets. Our heritage is preserved for the enjoyment of the community.

Provide clean, usable, attractive and accessible streetscapes and public spaces.

Environmental Sustainability

We are a leader in responsibly managing the built and natural environment for the enjoyment of the community and continue to demonstrate diligent environmental practices.

Protect and conserve the natural flora and fauna of Lake Claremont and the Foreshore

Urgency

NIL

Voting Requirements

Simple majority decision required.

OFFICER RECOMMENDATION

That the Committee

1. Notes progress of the Lake Claremont Operational Plan 2018-19 items;

2. Recommends to Council its adoption of the Draft 2019-20 Lake Claremont Operational Plan.

http://www.claremont.wa.gov.au/


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6.2 AERATION OF LAKE AND IMPROVEMENT OF WATER QUALITY

File No: PRK/00123


Author: Andrew Smith Director Infrastructure


Purpose

To consider the use of aeration as a means of improvement of the water quality and oxygenation of Lake Claremont.

Background

In accordance with prior practice, Members of the Advisory Committee are regularly invited to identify matters that they would like to be included as reports to the next meeting of the Committee. At the last meeting of the Committee the Chairperson requested that an item in respect to aeration within the Lake as a means to improve both water quality and oxygenation be tabled for consideration at the next meeting of the committee. The issue of water quality at the Lake has been a recurrent issue for some time and central to much of the overall management plan developed by South East Regional Centre for Urban Landcare (SERCUL) and its quarterly reports in respect to this plan. The most recent SERCUL report provided the following comment in respect to water quality testing completed in the most recent period;

Key water quality issues identified at the Lake from the 2018-19 monitoring include:

High total nitrogen and phosphorus concentrations in the main Lake body sites, particularly in summer, and summer phytoplankton;

High total nitrogen and phosphorus concentrations in the north-eastern Lake corner, particularly in summer;

High total (and filterable reactive) phosphorus concentrations at stormwater drain sites;

High concentrations of arsenic in Lake sites;

High concentrations of metals (aluminium, copper, lead and zinc) in drain sites;

High concentrations of iron in north-eastern Lake;

Low dissolved oxygen at lake sites;

Abundant mosquito larvae near the inlet of Alfred Rd drain


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Overall, water quality results from Lake Claremont samples collected by SERCUL in 2018 were similar to those collected in the same seasons of previous years. However, higher ammonia/ammonium nitrogen concentrations were present in the main Lake body and north-eastern Lake corner in August 2018 than in winter/spring of previous years, possibly partially due to Lake sediments not drying in the preceding year as have done many years prior to this. This, in combination with the Lake being wet during summer 2019 when water levels are low, warm and concentrated with nutrients, is likely to have resulted in the phytoplankton observed (and resultant high turbidity recorded) in the main Lake body in January.

Concentrations of both total nitrogen and total phosphorus were both lower at the downstream Henshaw drain site than the upstream site when sampled in August, largely due to a reduction in organic nitrogen and particulate phosphorus between the upstream and downstream sites.

Turbidity values and metal concentrations were similar between the two sites. Although more data is required to conclusively prove the efficacy of the recently installed dry wells in improving water quality entering the Lake from Henshaw drain, these results are encouraging.

The SERCUL report also makes recommendations in respect to strategies that can be considered to improve water quality as follows;

Incorporate a form of water treatment into the Stirling Rd central drain;

Prevent planting of overly dense vegetation stands in the Lake body in the future to ensure water flow is not restricted;

Remove couch grass, Persecaria and other weeds from near the outlet of Alfred Rd drain to reduce the amount of organic debris in the water in this area;

Continue to remove any other aquatic weeds (e.g. Bacopa) from the Lake where present;

Continue with the planned planting of native trees around the Lake’s edge;

If deciduous trees are to be retained around the Lake’s edge, leaf litter falling from these trees should be removed regularly from the water body and Lake banks. Deciduous trees could also be uplifted;

The viability of installing aerators or “bubblers” to improve oxygenation of the Lake could be investigated; however the Lake may to be too shallow during the summer months to support this.

In future water quality assessments, consider: o Undertaking a “first flush” sampling event in the stormwater drainage

sites; o Collecting and analysing sediment samples for metals, nutrients and

particle size to determine whether sediments are likely to be a source of nutrients and metals to the Lake; and

o Analysing samples for dissolved organic nitrogen;


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Educate the public in the Lake Claremont catchment regarding household best practices to prevent nutrient pollution of stormwater;

Continue to coordinate road sweeping in the Lake’s catchment with maintenance activities (i.e. road or construction works) and specific events (i.e. storm events or public major events) as recommended in the Department of Environment Stormwater Management Manual for Western Australia (2004);

Continue to ensure that any accumulated pollutants (e.g. sediment and gross pollutants) are regularly removed from nodes in the stormwater network.

Discussion

Given that the use of Aerators had been identified in the most recent SERCUL report, but not in prior reports, a discussion was held with SERCUL’s Water Quality Officer, Caitlin Conway in respect to this recommendation. Caitlin advised that “whilst I mentioned aerators in the report as a possible consideration at Lake Claremont, I did think it would be likely that the Lake would be too shallow for their use to be viable (as I have stated in the report). My thought was that perhaps it might warrant further investigation given that new technologies often become available, and also I don’t know exactly how deep the lake is in the middle. I have had a look and can’t find a lot of guidance related to this topic, so I have requested information from contacts at both DBCA and DWER. Hopefully one of these departments will be able to provide some useful info. To find out definitively whether it would be viable your best bet would be to obtain advice from a consultancy such as Syrinx, but of course there would be costs involved with that. Whilst a search of the Town’s records does not indicate any content in respect to the investigation of aerators or their use at the Lake (or any other location in the Town), in early 2019 there were discussions held at officer level (generated by Councillor enquiries) in respect to the possible use of the aerators at the Lake, in an effort to try and impact upon water quality. A combination of officer advice and other published material was sourced to try and determine if aerators were able to provide solutions to the Lake water quality and what strategies there were for the management and control of botulism outbreaks as had occurred previously at the Lake. Officer advice, from the Manager of Parks and Environment provided;

Prior advice was that due to the shallow nature of the wetland and the nutrient rich sediment there is a high risk of reactivating nutrient from the mud which will lower the water quality and create the perfect conditions for botulism to occur.


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The best way to remove nutrients from the water column is to plant vegetation and then remove it once it reaches maturity. This will also improve oxygen levels.

Oxygenation works in deeper and permanent waterbodies such as rivers and lakes not shallow ephemeral wetlands.

This conclusion is supported by SERCUL who state in their most recent report;

The viability of installing aerators or “bubblers” to improve oxygenation of the Lake could be investigated; however the Lake may to be too shallow during the summer months (when algal blooms are more likely to occur) to support this.

Despite what appears to be common agreements as to the effectiveness of aerators in shallow water bodies, and therefore their practical use in Lake Claremont, there is limited information widely available to categorically prove or disprove this theory, or to illustrate the minimum amount of water required to effectively operate an aerator. As Caitlin Conway has also advised, changes to technology may provide the means by which the use of aerators which had been previously unable to be considered, may be suitable for consideration in more shallow water. It is hoped that additional information in respect to current technology and the use of aerators will be available for distribution at the Advisory Committee meeting.


Whilst there may be financial implications associated with the installation and maintenance of an aerator, the type, size, function and practical application of this type of equipment is as yet unknown.

Policy and Statutory Implications

Lake Claremont Management Plan


None proposed at this stage of this proposal.


Liveability

We are an accessible community with well maintained and managed assets. Our heritage is preserved for the enjoyment of the community.

Provide clean, usable, attractive and accessible streetscapes and public places.

Urgency

No immediate urgency identified in respect to this matter


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Voting Requirements



That the information be received.


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6.3 STREET TREE MASTER PLAN

File No: PRK/00135


Author: Andrew Smith Director Infrastructure


Purpose

To advise Committee Members in respect to the proposed review of the Town of Claremont Street Tree Master Plan, as approved at the most recent Ordinary Meeting of Council.

Background

Council at its Ordinary Meeting held on 19 March 2019 resolved (in part) that Council;

Approve the review of the Street Tree Masterplan and its presentation in draft format for further Council consideration.

This resolution came about following the proposed detailed design for the redevelopment of Davies Road being approved, and the installation of several new street trees being within newly proposed median islands. The Street Tree Master Plan whilst a useful document that provides specified trees for each tree in the Claremont district and developed through extensive community engagement and consultation, provides limited scope for variation in street tree species. As such, whilst street trees for Davies Road are prescribed within the Street Tree Master Plan, neither of the proposed species (Broad Leaf Paperbark on the west side and Narrow Leaf Peppermint Gum on the eastern side of the road) were considered to be suitable for median island planting as the growth habit of neither the Broad Leaf Paperbark nor the Narrow Leaf Peppermint Gum is considered to be suitable for the median strip location as it is more likely to impact on both vehicles and both species are more likely to adversely the road pavement as the root ball expands. In addition to issues with the street tree species approved for street planting, the report also considered issues relating to the incidence of die back within the Town and the adverse impact that this having upon street tree stock, and the replanting of many areas. In recent years there has been sufficient evidence collated to begin to suggest that the survival rates of Agonis trees in some specific locations and through repeat


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plantings over a number of years, is being adversely impacted upon by the possible presence of Dieback. This issue was first identified in 2014 when the deaths of a small number of younger Agonis trees within the Lakeway subdivision occurred. Concerned, officers commissioned soil tests were undertaken and the PH of the soil was found to be over 8.5 in some locations. This was believed to be a result of building works and builders lime impacting the soil chemistry. PH levels were subsequently monitored and adjustments were made to the soil to try and alleviate this localised problem. In 2015 and 2016 this problem arose again as further trees were lost, and initially this was thought to be due to watering regimes (as PH seemed to be stabilising to a more neutral level) and so action was undertaken to ensure adequate water was being applied and that the frequency of application was adequate. This was implemented in conjunction with soil replacement in locations where new replacement trees were planted as soils lower down the profile were also noted to have higher PH. However in some locations the trees continued to fail during 2017 and into 2018. Tissue and soil tests were carried out by a specialist in Phytophthora (dieback) resulting in positive tests being returned for the Swanbourne area including Claremont Crescent and Swanway Crescent. As a result the Town has also commenced preventative phosphate treatments of all young Agonis trees, continued soil replacement, reviewed hygiene practices such as tool sterilisation and careful selection of tree stock from reputed suppliers to eliminate new sources. Whilst this proactive response to the potential risk to these trees is appropriate, in reality it is very difficult to safeguard against the pathogen or control its spread in an open and public environment. One obvious solution to this issue is of course to alter approved or agreed plant species which are more resistant to the effects of the pathogen. Again, whilst the Masterplan seeks to guide the use of species within the district of Claremont, it does not recognise the potential issue of dieback, or the evidence that suggests this pathogen is causing considerable loss of Agonis trees around the Town.

Discussion

As a result of these issues being identified, the Council has now approved the review of the Street Tree Master Plan in the 2019/20 financial year. In the interim, the restrictions caused by the current form of the Master Plan will continue to provide limitations and officers are currently proposing further variations to ‘approved’ tree species in area of the Town to avoid the continue


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planting of Agonis Trees in areas where there have been continued unsuccessful planting.


Provision for the review of the current Street Tree Master Plan will be provided for within the 2019/20 budget.


Local Government Act 1995. Tree Promotion Policy EN304. Street Tree Policy EN305. Tree Preservation Policy EN307


The previous Masterplan was adopted following extensive community consultation and engagement. It is proposed that Council consider a similar scope of consultation dependent upon the final form of the draft Masterplan once re-presented to Council for consideration.


Liveability

We are an accessible community with well-maintained and managed assets. Our heritage is preserved for the enjoyment of the community.

Provide clean, usable, attractive and accessible streetscapes and public spaces.

Maintain and upgrade the Town's assets for seamless day to day usage.

Urgency

No urgency identified in respect to this matter

Voting Requirements



That the information be received.


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6.4 PLANTING OF BOUNDARIES OF OFFLEAD DOG EXERCISE AREA, LAKE CLAREMONT

File No: LAW/00104

Responsible Officer: Andrew Smith Director of Infrastructure

Author: Andrew Smith Director of Infrastructure

Proposed Meeting Date: 16 April 2019

Purpose

To consider and recommend appropriate plant and tree species to be installed at Lake Claremont as part of the planting of a delineation line to indicate the boundaries of the newly established dog off lead exercise area.

Background

At the Ordinary Council meeting of 16th of April, the Council considered a petition signed by 142 residents, to change the previous proposal of Council to plant a delineation line at the newly established off lead dog exercise area in Lake Claremont. This petition provided the following position;

We the undersigned respectfully request that the new off lead dog exercise area remains unsegregated for the enjoyment of all.

The letter accompanying the petition provided further clarity as to what was suggested by the use of the term segregated in which it is stated “concern has arisen over the proposed planting of bush to separate the exercise area from the non-exercise area” Council had previously at its Ordinary Meeting held on 18 December 2018 resolved (in part) to;

Approve unbudgeted expenditure of $20,000 to install the vegetation barriers relating to expended Lake Claremont Dog Exercise Area.

In accordance with this resolution Council officers had begun preparations to install these vegetation barriers on the boundaries of the off lead dog exercise area, to coincide with the beginning of the planting season. Signs were also erected on site to advise of the proposal to plant trees and groundcovers to define the dog exercise area.


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Discussion

Whilst arrangements had been made to spray the boundary line prior to planting, the petition was tabled at the Ordinary meeting of Council on the 2nd of April, one week prior to the scheduled spraying. As a result the scheduled spraying was cancelled and orders for trees and plants proposed to be planted were not issued. The type and height of vegetation proposed to be planted in this area at that time was consistent with that already existing to the north of the Reserve which had functioned as the effective demarcation of the northern boundary of the of lead dog exercise area, until the recent decision of Council to install fencing. Whilst the Council considered the petition as received on this issue, and received several submissions on the night of the Council meeting in respect to the proposal, it was resolved that the use of vegetation to ‘create’ a boundary line for the new off lead dog exercise area would proceed (with some amendments). The resolution of Council in respect to this matter was (in part) as follows;

To delineate the dog off-lead area as decided by Council on 18 December and to accommodate the request of the petitioners tabled in the meeting of 2 April 2019 , the southern and western boundary edges be marked by a line of newly planted trees. The Eastern boundary across the bottom of John and Jean Mulder Park be planted with mid-level shrubs that will act as a vegetation deterrent for off lead dogs who may be interested in going into the BBQ area and children’s playground.


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For the benefit of Members, the following plan broadly indicates the boundary of the off lead dog exercise area as previously prescribed by Council resolution;

The hatched yellow line shows the boundary line to be planted (in accordance with the recent Council resolution) whilst the red line shows the prior dog off lead exercise area. Committee Members are also reminded that Council has also recently approved the installation of landscape fencing around the northern and eastern boundary of the previous off lead dog exercise area, indicated with the red boundary. Neither the Council report of 8 December 2018 or the consequent report of 16 April 2019 considered in detail the plant species that might be suitable (or recommended) for this location, only the merit in using a vegetated line to indicate the boundary of the new off lead dog exercise area. As a result Council officers had proceeded (following the earlier resolution) on the basis that the use of species that were already prevalent in the immediate area were most likely to be most suitable.


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Consequently the proposal had progressed on the assumption of planting;

Hakea, a 2-3m small tree, and

Grevillea as the low growing shrub, generally growing to heights of 1m max With the recent review of this subject and the confirmation that the Council wishes this boundary line to be subject to planting, this also provides an opportunity to review the plant and tree species selected for this location. Whilst there have been two species already suggested for consideration, the Advisory Committee may have alternate recommendations of species types that should also be considered as part of this project. It is proposed that once a final list of suggested species has been formed, this will be distributed to Councillors for final feedback and comment prior to orders being placed. In the interim, spraying of the boundary line in preparation for planting will be undertaken.

Past Resolutions of Committee

That the Committee;

1. Notes the advertising of changes to the Dogs in Public Places Policy LV133

2. Recommends Council extend the dog exercise area at Lake Claremont with additional planting of vegetation to delineate the area.

3. Supports a request for budget allocation of $20,000 to plant and establish the necessary vegetation.

Financial and Staff Implication

Prior Council resolution provided $20,000 to install the vegetation barriers as unbudgeted expenditure to this project. This matter was included in the mid-year budget review and consequently became part of the revised 2018/19 approved budget of the Council.


Dog Act 1976 Section 31 Dogs in Public Places Policy LV133


Considerable community consultation has occurred with respect to this proposal including;

Consultation in respect to the proposed changes to the Dogs in Public Places Policy, and

Through the installation of signage indicating the proposal to install a vegetated boundary to the approved dog exercise area, as approved by prior Council resolution.


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Through this process the Council has received a considerable number of submissions, including receipt of this most recent petition.

Urgency

Due to delays in commencement of works, particularly in relation to the spraying of the area in preparation and the placement of orders of the required plant stock, there is an immediate need to resolve agreed species and place the orders.

Voting Requirements

Simple majority required.


That the Committee acknowledges and supports the use of Hakea and Grevillea as the selected species for the planting of the boundary of the newly established dog off lead exercise area at Lake Claremont.


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7 FRIENDS OF LAKE CLAREMONT

Attachments: Friends of Lake Claremont Report (Attachment 1)

Responsible Member: Nick Cook

Friends of Lake Claremont

Meeting Date: 02 May 2019


That the Committee receives the Friends of Lake Claremont update for March 2019.


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8 LAKE CLAREMONT BIRD CENSUS

9 COMMITTEE MEMBERS’ MOTIONS OF WHICH PREVIOUS NOTICE HAS BEEN GIVEN

10 FUTURE MEETINGS OF COMMITTEE

Thursday, 1 August 2019 Thursday, 7 November 2019

11 DECLARATION OF CLOSURE OF MEETING


LAKE CLAREMONT ADVISORY COMMITTEE

A T T A C H M E N T S

02 MAY 2019


6. REPORTS OF THE CEO


ATTACHMENT 1 – LAKE CLAREMONT OPERATIONAL PLAN 2018-19

Pages 2

Activity By Whom Where Frequncy per annum July August September October November December January February March April May June

Turf Management

Mowing non irrigated turf Contractor Stirling Rd Park 12 x x x x x x x x x x

Mowing irrigated turf Contractor Irrigated Turf Areas 26 x x x x x x x x x x

Broadleaf weed control Contractor Where Bindii present 1 x

Fertilising and soil tests Contractor All Parks 1 x

Reticulation inspections Contractor & In House Lake Claremont , Mulder and Stirling Road Parks 40 x x x x x x x x x x

Amend Irrigation Programs In House Lake Claremont , Mulder and Stirling Road Parks As Required

Bore Meter Reading In House Lake Claremont , Mulder and Stirling Road Parks 8 x x x x x x x x

Flow and pressure tests Contractor Lake Claremont , Mulder and Stirling Road Parks 1 x

Weed Management

Wetland Areas weed control Contractor Lake Claremont Lake Bed 1 x

Dryland Areas weed control Contractor Dryland natural areas 8 x x x x x

Verge weed control program Contractor Alfred, Strickland, Lakeway verge 8 x x x x x x

Sumps weed control program Contractor Strickland Street 2 x x

Review Weed Control Program In House Everywhere 1

Hand Weeding (Walking Weeders) Volunteers Dryland natural areas 52 x x x x x x x x x x

Hand Weeding (Adopt a spot) Volunteers Dryland natural areas 12 x x x x x x x x x x

Hand Weeding (Busy Bees) Volunteers Dryland natural areas 12 x x x x x x x x x x

Hand Weeding (Contactors) Contractor Dryland natural areas 8 x x x

Weed Mapping Contractor Dryland natural areas 8 x x x x x

Mulching Contractor & Volunteers Dryland natural areas 12 x x x x x

Litter Management

Bin Collection Contractor All parks 52 x x x x x x x x x x

Bin cleaning program Contractor All parks 1 x

Litter Clean Up In House & Volunteers All parks 52 x x x x x x x x x x

Dog poo bag replacement In House All parks 52 x x x x x x x x x x

Playground/Furniture Management

Playground weekly inspections Contractor Stirling Rd & Mulder Parks 52 x x x x x x x x x x

Playground softfall sieving Contractor Stirling Rd & Mulder Parks 4 x x x x

Playground annual audit Contractor Stirling Rd & Mulder Parks 1 x

BBQ cleaning Contractor Stirling Rd & Mulder Parks 52 x x x x x x x x x x

Deck Oiling Program Contractor Bird Observation Platform and Lake Jetty 2 x

Furniture Cleaning Contractor Stirling Rd & Mulder Parks As Required

Drink Fountains Filter Replacement Contractor Stirling Rd & Cresswell Park 2 x

Asset condition audits In House All Parks 1 x x

Water/Soil Management

Water Sampling Contractor As per Water Sampling Plan 2 x x

Macroinvertebrate Sampling Contractor As per Water Sampling Plan 2 x x

Water & Invertebrate Report Contractor As per Water Sampling Plan 1 x

Sediment Sampling & Reporting Contractor As per Sediment Sampling Plan 1

Drain Outfall Inspections In House Before major rainfall events 6 x x

Erosion Prone Area Inspections In House After major rainfall events 6 x x

NIMP Plan Review In House Golf/Scotch/Cresswell 1

Lake Claremont Operational Plan 2018-19Lake Claremont Maintanance and Capital Works Program (Updated 17 April 2019)

Activity By Whom Where Frequncy per annum July August September October November December January February March April May June

Tree/Vegetation Management

Significant Tree Inspections Contractor Ficus, Pines, Tuarts 1 x

Tree inspections In House Everywhere 52 x x x x x x x x x x

Tree works Contractor Everywhere As required

Tree Planting In House & Volunteers 1 x x

Tree pruning Contractor & In House Everywhere As Required

Tree Treatments Contractor Bee Control, Caterpillar 2 x x

View Corridor Pruning In House Northern and Eastern Buffer Areas 4 x x x

Maintain Fire Access Paths In House & Contractors Gloucester St & Alfred Road 1 x

Park path clearing program Volunteers & Contractors All Parks 12 x x x x x x x x x x

Tubestock Planting Volunteers As per attached map 1 x

Direct Seeding Contractor Trial in Ballaruk Bushland 1

Fungi Mapping In House Everywhere 2 x x x

Photopoint Monitoring Volunteers Agreed locations 1 x x

Update Species Planting Database In House Any planting lists 1 x

Revegetation Fencing Inspections In House Everywhere 1 x x

Seed Collection In House & Volunteers As required for revegetation 2 x x x x x x

Finalise Planting areas for two seasons In House & Volunteers Operational Plan 1 x

Fauna Management

Bush Bird Box Inspections In House As per map 1 x

Bat Box Inspections In House As per map 1 x

Duck Box Inspections In House As per map 1 x x

Duck Floating Nest Installation Volunteers In lake bed 1 x x

Bird Counts Volunteers Everywhere 4 x x x

Feral Animal Monitoring In House Everywhere 52 x x x x x x x x x x

Dog Patrols In House Everywhere 52 x x x x x x x x x x

Update seasonal Signage In House Swans, Turtles, Snakes, etc 4 x x x

General Management

Update Noticeboard In House Lapsley Road Playground 12 x x x x x x x x x x

Prepare Reports In House Office 6 x x x x x

Prepare Agenda In House Office 6 x x x x x

Preparing Volunteer Work Program In House Office 2 x x x x

Updating FOLC Communication Book In House & Volunteers FOLC Shed 26 x x x x x x x x x x

Capital Works Program

Revegetation fencing Contractor South West Buffer 1 x x

Henshaw Swale Realignment Contractor Lapsley Road 1 x x

Develop Self Guided Walk Contractor Off Site 1 x x

Irrigation Upgrade Contractor Lake Claremont & Mulder Park 1 x x

BBQ and Picnic Table Node Contractor Lapsley Road Playground 1 x x

Tamarix Removals and preparation for Revegetation Contractor FOLC Shed 2 x x x




ATTACHMENT 2 – DRAFT - LAKE CLAREMONT OPERATIONAL

PLAN 2019-20

Pages 2

Activity By Whom Where Frequncy per annum July August September October November December January February March April May JuneTurf Management Various

Mowing non irrigated turf Contractor Stirling Rd Park 12

Mowing irrigated turf Contractor Irrigated Turf Areas 26

Broadleaf weed control Contractor Where Bindii present 1

Fertilising and soil tests Contractor All Parks 1

Reticulation inspections Contractor & In House Lake Claremont , Mulder and Stirling Road Parks 40

Amend Irrigation Programs In House Lake Claremont , Mulder and Stirling Road Parks As Required

Bore Meter Reading In House Lake Claremont , Mulder and Stirling Road Parks 8

Flow and pressure tests Contractor Lake Claremont , Mulder and Stirling Road Parks 1

Weed Management VariousWetland Areas weed control Contractor Lake Claremont Lake Bed 1

Dryland Areas weed control Contractor Dryland natural areas 8

Verge weed control program Contractor Alfred, Strickland, Lakeway verge 8

Sumps weed control program Contractor Strickland Street 2

Review Weed Control Program In House Everywhere 1

Hand Weeding (Walking Weeders) Volunteers Dryland natural areas 52

Hand Weeding (Adopt a spot) Volunteers Dryland natural areas 12

Hand Weeding (Busy Bees) Volunteers Dryland natural areas 12

Hand Weeding (Contactors) Contractor Dryland natural areas 8

Weed Mapping In house Dryland natural areas 8

Mulching Contractor & Volunteers Dryland natural areas 12

Litter Management VariousBin Collection Contractor All parks 52

Bin cleaning program Contractor All parks 1

Litter Clean Up In House & Volunteers All parks 52

Dog poo bag replacement In House All parks 52

Playground/Furniture Management VariousPlayground weekly inspections Contractor Stirling Rd & Mulder Parks 52

Playground softfall sieving Contractor Stirling Rd & Mulder Parks 4

Playground annual audit Contractor Stirling Rd & Mulder Parks 1

BBQ cleaning Contractor Stirling Rd & Mulder Parks 52

Deck Oiling Program Contractor Bird Observation Platform and Lake Jetty 2

Furniture Cleaning Contractor Stirling Rd & Mulder Parks As Required

Drink Fountains Filter Replacement Contractor Stirling Rd & Cresswell Park 2

Asset condition audits In House All Parks 1

Water/Soil Management VariousWater Sampling Contractor As per Water Sampling Plan 2

Macroinvertebrate Sampling Contractor As per Water Sampling Plan 2

Water & Invertebrate Report Contractor As per Water Sampling Plan 1

Sediment Sampling & Reporting Contractor As per Sediment Sampling Plan 1

Drain Outfall Inspections In House Before major rainfall events 6

Erosion Prone Area Inspections In House After major rainfall events 6

NIMP Plan Review In House Golf/Scotch/Cresswell 1

Botulism inspections In House As required when water levels are low 4

Monitoring of Water for Dissolved Oxygen In House As required when water level are low 4

Service water probe contractor eco environmental 1

DRAFT ‐ Lake Claremont Operational Plan 2019‐20Lake Claremont Maintanance and Capital Works Program (Updated 17 April 2019)

Activity By Whom Where Frequncy per annum July August September October November December January February March April May JuneTree/Vegetation Management Various

Significant Tree Inspections Contractor Ficus, Pines, Tuarts 1

Tree inspections In House Everywhere 52

Tree works Contractor Everywhere As required

Tree Planting In House & Volunteers As Identified 1

Tree pruning Contractor & In House Everywhere As Required

Tree Treatments Contractor Bee Control, Caterpillar 2

View Corridor Pruning In House Northern and Eastern Buffer Areas 4

Maintain Fire Access Paths Contractor & In House Gloucester St & Alfred Road 1

Park path clearing program Contractor & Volunteers All Parks 12

Tubestock Planting Volunteers As per attached map 1

Direct Seeding Contractor Trial in Ballaruk Bushland 1

Fungi Mapping In House Everywhere 2

Photopoint Monitoring Volunteers Agreed locations 1

Update Species Planting Database In House Any planting lists 1

Revegetation Fencing Inspections In House Everywhere 1

Seed Collection In House & Volunteers As required for revegetation 2

Finalise Planting areas for two seasons In House & Volunteers Operational Plan 1

Fauna Management VariousBush Bird Box Inspections In House As per map 1

Bat Box Inspections In House As per map 1

Duck Box Inspections In house As per map 1

Duck Floating Nest Installation Volunteers In lake bed 1

Bird Counts Volunteers Everywhere 4

Feral Animal Monitoring In House Everywhere 52

Update seasonal Signage In House Swans, Turtles, Snakes, etc 4

General Management VariousUpdate Noticeboard In House Lapsley Road Playground & Cresswell Park 12

Prepare Reports In House Office 4

Prepare Agenda In House Office 6

Preparing Volunteer Work Program In House Office 2

Updating FOLC Communication Book In House & Volunteers FOLC Shed 26

Fungi Identification In house Everywhere 7

Quill item In house Office 8

Update Chemical Quantities Database Inhouse Office after each service

Suitable Plant Species Liaison for Planting Areas Inhouse & Volunteers Office 2

Preparation of Procedures Inhouse Office 2

Preparation of Task list for Field Officer Inhouse Office 12

Spot checks on Contractors‐ PPE/ Signage/Conditions Inhouse Everywhere 4

Training Inhouse Office 2

Capital Works Program VariousRevegetation fencing Contractor Planting Sites 1

Limestone Path Repairs (as required) Contractor As per map 2

Tamarix Removals and preparation for Revegetation Contractor FOLC Shed 1




ATTACHMENT 3 – ADOPT A SPOT MAP

Pages 1




ATTACHMENT 4 – LAKE CLAREMONT WATER QUALITY AND

MACROINVERTEBRATE ASSESSMENT 2018-19

Pages 72

Prepared by the South East Regional Centre for Urban Landcare Inc. (SERCUL) for the Town of Claremont

Lake Claremont Water Quality and Macroinvertebrate

Assessment 2018-19

March 2019

Lake Claremont Water Quality and Macroinvertebrate Assessment 2018-19 Page 2

Acknowledgments

This report was prepared by Caitlin Conway and Rose Weerasinghe from the South East Regional Centre for Urban Landcare Inc. (SERCUL). The Town of Claremont provided funding for SERCUL staff to prepare the sampling and analysis plan, carry out sampling and prepare this report.

Thank you to Monica Estrada (SERCUL) for assistance with the report editing.

For further information contact: Caitlin Conway Water Quality officer SERCUL 1 Horley Road Beckenham 6107 Western Australia Telephone: (08) 9458 5664 Facsimile: (08) 9458 5661 Email: [email protected] Website: www.sercul.org.au

mailto:[email protected]

http://www.sercul.org.au/


Disclaimer

SERCUL has made every effort to certify that the information described in this document is accurate, but cannot guarantee, express or imply its currency, accuracy or flawlessness as new information becomes available since the time of its writing.

Copyright notice

The Town of Claremont is the sole authorised recipient of this document. Copyright © SERCUL Inc. 2019. All rights reserved. This document is copyrighted and all rights are reserved by SERCUL and the Town of Claremont under the Australian Copyright Act 1968. The information, figures and data reported in this document are solely for the use of the aforementioned stakeholders. Except for third party material, no part of this publication may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any other language or computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical, manual or otherwise without the expressed written consent of SERCUL, 1 Horley Rd, Beckenham, Western Australia 6107. Document Control # Purpose Version Date Prepared By Reviewed By 1 Preliminary report 15/02/19 Caitlin Conway, Rose

Weerasinghe Monica Estrada

2 Final report 20/03/18 Caitlin Conway, Rose Weerasinghe

Jared Bray


Contents

ACKNOWLEDGMENTS 2 Disclaimer .............................................................................................................................................. 3 Copyright notice .................................................................................................................................... 3 CONTENTS 4 TABLES 5 FIGURES 5 EXECUTIVE SUMMARY 6 1. INTRODUCTION 8 1.1 Background of the sampling .............................................................................................. 8 1.2 Site description .................................................................................................................... 8 2. WATER QUALITY SAMPLING METHODOLOGY 10 2.1 Sampling frequency .......................................................................................................... 10 2.2 Site selection ..................................................................................................................... 10 2.3 Measurement parameters ................................................................................................. 12 2.4 Sample collection protocol............................................................................................... 12 2.5 Quality control measures ................................................................................................. 13 3. GUIDELINES FOR WATER QUALITY ASSESSMENT 14 4. PREVIOUS WATER QUALITY DATA 15 5. FIELD OBSERVATIONS 17 6. WATER PHYSICOCHEMICAL RESULTS 18 6.1 pH ........................................................................................................................................ 18 6.2 Dissolved oxygen .............................................................................................................. 19 6.3 Electrical Conductivity ...................................................................................................... 20 6.4 Turbidity ............................................................................................................................. 21 6.5 Temperature ....................................................................................................................... 22 7. WATER NUTRIENT RESULTS 23 7.1 Nitrogen .............................................................................................................................. 23 7.2 Phosphorus ........................................................................................................................ 26 8. METALS AND HARDNESS 28 8.1 Metals .................................................................................................................................. 28 8.2 Hardness ............................................................................................................................ 32 9. MACROINVERTEBRATE SAMPLING METHODOLOGY 33 9.1 Site selection ..................................................................................................................... 33 9.2 Sampling frequency .......................................................................................................... 33 9.3 Sampling protocol ............................................................................................................. 33 10. MACROINVERTEBRATE SAMPLING RESULTS 34 11. DISCUSSION AND RECOMMENDATIONS 37 11.1 Key Issues .......................................................................................................................... 37 11.2 New Henshaw drain infrastructure .................................................................................. 39


11.3 Recommendations ............................................................................................................ 39 12. REFERENCES 42

Trigger Values 46 Appendix A

Potential effects of stressors on aquatic environments 47 Appendix B

Potential sources, factors affecting toxicity and impacts of metals found in Appendix Curban stormwater 51

Field Observation Forms, ALS Chain of Custody Forms and ALS Certificates of Appendix DAnalysis 57

TABLES

Table 2-1: Details of water quality sampling locations specified by the Town of Claremont........................... 10 Table 2-2: ALS limits of reporting (LORs) for analysed parameters ................................................................. 12 Table 2-2 (continued): ALS limits of reporting (LORs) for analysed parameters .............................................. 13 Table 4-1: Summary of Lake Claremont water quality data from May 2004 to August 2016 (Town of

Claremont (unpublished)) and SERCUL 2017 water quality data ........................................................... 16 Table 8-1: Total and soluble concentrations of metals analysed in Lake Claremont water samples in 2018-19

.............................................................................................................................................................. 30 Table 10-1: Macroinvertebrate communities recorded at Lake Claremont sites in October 2018 ................... 35 Table 10-2: Mosquito dip results at Lake Claremont sites in October 2018 .................................................... 36 Table A-1: Trigger values used for comparison of Lake Claremont water quality results ................................ 46 Table A-2: Trigger values for metals (mg/L) in freshwater .............................................................................. 46 Table B-1: Effects of stressors on aquatic environments ................................................................................ 47 Table C-1: Potential sources, factors affecting impacts and impacts of metals typically found in urban

stormwater ........................................................................................................................................... 51

FIGURES

Figure 2.2-1: Map of water quality sampling locations ................................................................................... 11 Figure 6.1-1: pH values in Lake Claremont water samples in 2018-19 ............................................................ 18 Figure 6.2-1: Dissolved oxygen saturations in Lake Claremont water samples in 2018-19 .............................. 19 Figure 6.3-1: Electrical conductivity in Lake Claremont water samples in 2018-19 ......................................... 20 Figure 6.4-1: Turbidity in Lake Claremont water samples in 2018-19 ............................................................. 21 Figure 6.5-1: Water temperatures in Lake Claremont water samples in 2018-19 ........................................... 22 Figure 7.1-1: Concentrations of A) total nitrogen (TN); B) total oxidised nitrogen (NOx-N); C) nitrogen as

ammonia/ammonium (NH3/NH4+-N) (note left graph compares results to ANZECC wetlands trigger value (scale is cropped at 0.1 mg/L) and right graph compares results to adjusted trigger values for 95% protection of freshwater biota); and D) total organic nitrogen (TON) recorded in Lake Claremont water samples in 2018-19. .............................................................................................................................. 24

Figure 7.1-2: Nitrogen speciation in Lake Claremont water samples in 2018-19 ............................................. 25 Figure 7.2-1: Concentrations in Lake Claremont water samples in 2018-19 of A) total phosphorus (TP) and; B)

filterable reactive phosphorus (FRP). .................................................................................................... 26 Figure 7.2-2: Percentage of total phosphorus as filterable reactive phosphorus in Lake Claremont water

samples in 2018-19 ............................................................................................................................... 27 Figure 8.1-1: A) Total aluminium (Al); B) soluble aluminium (Al); C) total arsenic (As); D) soluble arsenic (As);

E) total copper (Cu); F) soluble copper (Cu); G) total iron (Fe); H) soluble iron (Fe); I): total lead (Pb); J) soluble lead (Pb); K) total zinc (Zn) and L: soluble zinc (Zn) concentrations (mg/L) recorded in Lake Claremont sites in 2018-19 .................................................................................................................... 31

Figure 8.2-1: Water hardness concentrations (mg/L) recorded in Lake Claremont sites in 2018-19 ................ 32


Executive Summary

The Town of Claremont commissioned the South East Regional Centre for Urban Landcare Inc. (SERCUL) to undertake this water quality and low level macroinvertebrate assessment at Lake Claremont in winter 2018 to summer 2019. As water quality data can fluctuate markedly over time, water quality data in this report should be considered a snapshot only and results interpreted with caution. Sampling was conducted in accordance with the document Sampling and analysis plan: Water quality and macroinvertebrate survey, Lake Claremont, 2018 prepared by SERCUL (2018). Water samples were collected and water physicochemical properties were measured by SERCUL staff on the 28th of August 2018 and 17th of January 2019 at the following sites at Lake Claremont: Stirling Road central drain (August only), Stirling Road central drain (lake) (January only), Henshaw drain upstream (August only), Henshaw drain downstream (August only), Henshaw drain (lake) (January only), Alfred Road drain (lake), and the Lookout. Water quality physicochemical properties were also measured and macroinvertebrate and mosquito larval sampling was conducted in the four Lake sites on the 11rd of October 2018. Key water quality issues identified at the Lake from the 2018-19 monitoring include:

• High total nitrogen and phosphorus concentrations in the main Lake body sites, particularly in summer, and summer phytoplankton;

• High total nitrogen and phosphorus concentrations in the north-eastern Lake corner, particularly in summer;

• High total (and filterable reactive) phosphorus concentrations at stormwater drain sites;

• High concentrations of arsenic in Lake sites;

• High concentrations of metals (aluminium, copper, lead and zinc) in drain sites;

• High concentrations of iron in north-eastern Lake;

• Low dissolved oxygen at lake sites;

• Abundant mosquito larvae near the inlet of Alfred Rd drain

Overall, water quality results from Lake Claremont samples collected by SERCUL in 2018 were similar to those collected in the same seasons of previous years. However, higher ammonia/ammonium nitrogen concentrations were present in the main Lake body and north-eastern Lake corner in August 2018 than in winter/spring of previous years, possibly partially due to Lake sediments not drying in the preceding year as have done many years prior to this. This, in combination with the Lake being wet during summer 2019 when water levels are low, warm and concentrated with nutrients, is likely to have resulted in the phytoplankton observed (and resultant high turbidity recorded) in the main Lake body in January. Concentrations of both total nitrogen and total phosphorus were both lower at the downstream Henshaw drain site than the upstream site when sampled in August, largely due to a reduction in organic nitrogen and particulate phosphorus between the upstream and downstream sites. Turbidity values and metal concentrations were similar between the two sites. Although more data is required to conclusively prove the efficacy of the recently installed dry wells in improving water quality entering the Lake from Henshaw drain, these results are encouraging.


A total of 19 macroinvertebrate taxa were recorded at the four Lake sites in October 2018. The macroinvertebrate taxa found in the lake were predominantly those classified with a pollution sensitivity rating of very tolerant (Waterwatch Murray 2009, Department of Environment and Education 2011). However, water mites (order Acarina), classed as sensitive, were recorded at all sites, and caddisfly larvae (order Trichoptera) were recorded at near the Stirling Rd central drain inlet. Overall mosquito breeding was considered low in the lake except at the Alfred Rd drain lake site where larvae were abundant. Recommendations made to improve water quality at the Lake include:

• Incorporate a form of water treatment into the Stirling Rd central drain;

• Prevent planting of overly dense vegetation stands in the Lake body in the future to ensure water flow is not restricted;

• Remove couch grass, Persecaria and other weeds from near the outlet of Alfred Rd drain to reduce the amount of organic debris in the water in this area;

• Continue to remove any other aquatic weeds (e.g. Bacopa) from the Lake where present;

• Continue with the planned planting of native trees around the Lake’s edge;

• If deciduous trees are to be retained around the Lake’s edge, leaf litter falling from these trees should be removed regularly from the water body and Lake banks. Deciduous trees could also be uplifted;

• The viability of installing aerators or “bubblers” to improve oxygenation of the Lake could be investigated; however the Lake may to be too shallow during the summer months to support this.

• In future water quality assessments, consider:

o Undertaking a “first flush” sampling event in the stormwater drainage sites;

o Collecting and analysing sediment samples for metals, nutrients and particle size to determine whether sediments are likely to be a source of nutrients and metals to the Lake; and

o Analysing samples for dissolved organic nitrogen;

• Turf managers within the catchment should undertake training to implement best practice fertiliser use in order to minimise nutrient input from fertilisers;

• Educate of Town of Claremont health and environmental officers in ecological control of mosquito through SERCUL’s Mozzie Wise education program;

• Educate the public in the Lake Claremont catchment regarding household best practices to prevent nutrient pollution of stormwater;

• Continue to coordinate road sweeping in the Lake’s catchment with maintenance activities (i.e. road or construction works) and specific events (i.e. storm events or public major events) as recommended in the Department of Environment Stormwater Management Manual for Western Australia (2004);

• Continue to ensure that any accumulated pollutants (e.g. sediment and gross pollutants) are regularly removed from nodes in the stormwater network.


1. Introduction

1.1 Background of the sampling

The Town of Claremont commissioned the South East Regional Centre for Urban Landcare Inc. (SERCUL) to undertake water quality sampling at designated sites in winter 2018 and summer 2019 and a low level macroinvertebrate analysis at Lake Claremont in spring 2018. Sampling was conducted in accordance with the document Sampling and analysis plan: Water quality and macroinvertebrate survey, Lake Claremont, 2018, hereafter referred to as the “SAP”, prepared by SERCUL (2018). The purpose of this sampling program was to:

• Assess the quality of water, in terms of nutrient concentrations, metal concentrations and physicochemical properties, entering into Lake Claremont from the three main stormwater drains;

• Assess the quality of the water, in terms of nutrient concentrations, metal concentrations and physicochemical properties, within the Lake;

• Compare water quality upstream and downstream of the Henshaw drain infiltration swale constructed in 2018;

• Compare water quality data to that obtained in previous years and assess potential long-term patterns;

• Provide a brief overview of macroinvertebrate diversity and abundance within the Lake; and

• Provide a brief overview of possible implications of climate change to water quality within the Lake;

• Provide general recommendations to improve water quality in the Lake.

1.2 Site description

Lake Claremont is a Conservation Category wetland situated in the suburb of Claremont, approximately 10 km south-west of Perth in Western Australia. The lake and its riparian buffer comprise an area of 20.7 hectares (Town of Claremont 2017). Land uses immediately adjacent to the lake include a golf course to the east, public recreational to the south-east and south, sports ovals to the south-west and bushland to the north-west and north. Lake Claremont is seasonal, ephemeral wetland, with groundwater and stormwater filling the lake in the winter and evaporation and a lowering groundwater table resulting in drying over spring to summer (Town of Claremont 2017). The lake is located on the south-western edge of the Gnangara groundwater mound, with groundwater flowing in south-south-westerly direction through the lake towards the Swan River (Department of Environment 2004a). The Lake is fed by three main stormwater drains: Stirling Road drain (with west, central and east components) from the south, Henshaw drain from the east, and Alfred Road drain from the north-east (Town of Claremont 2017). These drains only tend to flow during relatively high (Stirling Road drain, Henshaw drain) or extremely high (Alfred Rd drain) rainfall events, and do not flow all year round (Andrew Head personal communication). All of the stormwater drainage channels discharging into Lake Claremont incorporate some form of water treatment except the central branch of the Stirling Rd drain (Andrew Head personal communication). The Henshaw drain was upgraded in winter 2018, with three tanks installed to trap sediment and prevent it flowing into the lake. Nutrient stripping basins, which act to remove nutrients and other materials from water before it enters the lake, are present between the lake and the Scotch College playing fields to its east, and at the inlet of the Stirling Road drain into the south of the lake (Town of Claremont 2017).


Water in Lake Claremont has been generally shown in previous years to be brackish, slightly alkaline and relatively clear (Simpson 2013). Total phosphorus and filterable reactive phosphorus concentrations have generally been higher than ANZECC and ARMCANZ (2000) trigger values for wetlands in south-western Australia, and total nitrogen and ammoniacal nitrogen concentrations generally higher than, and total oxidised nitrogen concentrations generally lower than ANZECC and ARMCANZ (2000) trigger values for wetlands in south-western Australia (1.5 mg/L, 0.04 mg/L and 0.1 mg/L respectively) (Simpson 2013). Lake Claremont lies on the boundary of the Quindalup Dune (calcareous sands associated with beach ridges and parabolic dunes) and Spearwood Dune (limestone core overlain by yellow sand) geological Systems (Department of Primary Industries and Regional Development - Agriculture and Food 2016). Soils within the lake itself are mapped as Spearwood Wet in the centre (sand over limestone) (Department of Primary Industries and Regional Development - Agriculture and Food 2016). Although acid sulfate soils have been identified within the Lake these soils are considered to be presently stable (Town of Claremont 2017), as evidenced by the medium to high pH levels recorded in the Lake (Simpson 2013).

Lake Claremont was originally a seasonally drying wetland, but became permanently flooded between the 1930’s and 1950’s due to rising groundwater levels due to clearing of native vegetation (Town of Claremont 2017). In recent years in response to lowering groundwater levels it has reverted to being a mainly seasonally drying wetland, becoming dry in the summer months of most years. Previous land uses at the Lake include possible farming activities in the 1800s, market gardening from the early to mid 20th century and a landfill from 1964 to 1974 (Town of Claremont 2017).


2. Water quality sampling methodology

Water quality sampling was undertaken in accordance with the SAP prepared by SERCUL (2018) with the procedure summarised below.

2.1 Sampling frequency

Water quality sampling was conducted on the 28th of August 2018 and 17th of January 2019. Sampling in August was conducted during a rainfall event (10 mm) to allow the stormwater drainage entering the Lake to be assessed. Water physicochemical data was also collected from all Lake sites on the 11th of October to supplement the macroinvertebrate sampling.

2.2 Site selection

Table 2-1 contains details of and Figure 2.2-1 displays a map of the water quality sampling sites specified to be sampled by the Town of Claremont. Four of these sites were selected to assess water quality coming from the three main stormwater drains (Stirling Road central drain, Henshaw Drain, Alfred Rd drain) and one site (the Lookout) was selected to assess water in the Lake body. It should be noted that Henshaw Drain and Stirling Road Drain in January, and Alfred Rd Drain in both August and January, were dry. As such, on these occasions samples were collected from the Lake body immediately in front of these inlets and results are expected to be more indicative of Lake conditons than the quality of water from these inlets. Accordingly, in the water quality results reported in subsequent sections of this report, a distinction has been made between those samples collected from the inlets and those collected from the Lake body.

Table 2-1: Details of water quality sampling locations specified by the Town of Claremont

Site Name

GPS Coordinates (datum: GDA 94)

Sampling Location

Rationale for site selection

A2.1 x384544 y6461377 Stirling Road - inlet from GPT (Figure

2.2-1)

Lake inlet point

A4.1 x384592 y6461600 Henshaw Drain Lake inlet point

A4.2 x384719 y6461576 Henshaw Drain upstream

Upstream of infiltration swale

A5.1 x384590 y6462116 Alfred Road drain Lake inlet point

A7.1 x384389 y6461694 Lookout

Deeper water representative of entire water body


Figure 2.2-1: Map of water quality sampling locations


2.3 Measurement parameters

As specified by the Town of Claremont, in-situ measurements of the following physicochemical parameters were collected: • Dissolved Oxygen (DO); • Temperature; • Conductivity; and • pH. Water samples were collected in appropriate bottles for the analysis of:

• Total Phosphorus (TP);

• Filterable Reactive Phosphorus (FRP);

• Total Nitrogen (TN);

• Nitrogen as Ammonium/Ammonia (NH4+/NH3-N);

• Total Oxidised Nitrogen (NOx-N);

• Dissolved metals (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn);

• Total metals (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn); and

• Turbidity.

2.4 Sample collection protocol

In-situ measurements were taken in the surface layer of the water column, generally between the surface and a depth of 30 cm, using a pre-calibrated YSI ProPlus water quality meter with four measurement probes (temperature, conductivity, pH and dissolved oxygen). In situ measurements, as well as water depths of the lake/inlet point to the lake, weather conditions and other relevant comments were recorded on field observation forms (see Appendix D). Water samples for laboratory analysis were collected according to the SAP (2018) and sent to the Australian Laboratory Services (ALS) Environmental Laboratory in Malaga, a NATA accredited laboratory (Accreditation No: 825) for the parameters tested. Samples were accompanied by a completed Chain of Custody (COC) form detailing the invoicing and analysis requirements (see Appendix D). ALS produced laboratory reports containing the following information (see Appendix D):

• Date and time of sample analysis

• Method code and description

• All laboratory Quality Control results including analyte recovery, accepted recovery range, lab blanks, lab duplicates, lab blank spike recovery, matrix spike recovery.

Table 2-2 below outlines the limits of reporting from the ALS laboratory for each parameter.

Table 2-2: ALS limits of reporting (LORs) for analysed parameters

Measured parameter LOR

Total phosphorus 0.01 mg/L

Total nitrogen 0.1 mg/L

Filterable reactive phosphorus 0.01 mg/L

Total oxidised nitrogen 0.01 mg/L

Nitrogen as ammonia 0.01 mg/L

Turbidity 0.1 NTU

Hardness 1 mg/L


Table 2-3 (continued): ALS limits of reporting (LORs) for analysed parameters

Measured parameter LOR

Aluminium (dissolved and total) 0.01 mg/L

Arsenic (dissolved and total) 0.001 mg/L

Cadmium (dissolved and total) 0.0001 mg/L

Chromium (dissolved and total) 0.001 mg/L

Cobalt (dissolved and total) 0.001 mg/L

Copper (dissolved and total) 0.001 mg/L

Iron (dissolved and total) 0.05 mg/L

Lead (dissolved and total) 0.001 mg/L

Manganese (dissolved and total) 0.001 mg/L

Mercury (dissolved and total) 0.0001 mg/L

Nickel (dissolved and total) 0.001 mg/L

Selenium (dissolved and total) 0.01 mg/L

Zinc (dissolved and total) 0.005 mg/L

Note that for all graphs in this report, any sample recording a value less than the limit of reporting will be represented as a value equal to half the limit of reporting to allow these ‘unknown’ values to be presented graphically and to differentiate them from those samples that recorded concentrations equal to the limit of reporting.

2.5 Quality control measures

Results of duplicate samples are used to detect both natural variability of analytes in the water column being sampled and variations caused by field sampling methods. To interpret the results of a duplicate sample, the sample is compared to the standard sample and the relative percentage difference. The maximum acceptable RPD is considered to be 50%, where the concentration is greater than ten times the LOR. Example: A standard sample records a TN concentration of 1.1mg/L and the duplicate sample records a TN concentration of 0.8 mg/L. Standard TN sample (x) = 1.1 mg/L Duplicate TN sample (y) = 0.8 mg/L a = x-y = 1.1 - 0.8 = 0.3 b = (x+y)/2 = (1.1+0.8) / 2 = 1.9 / 2 = 0.95 The Relative Percentage Difference (RPD) = (a/b) x 100 = (0.3/0.95) x 100 = 31.5% 31.5% is below the limit of 50% RPD, so this is deemed an acceptable RPD between the standard and the replicate samples.

One duplicate sample was collected at Lake Claremont a randomly selected site during the September sampling event. Only one parameter (total phosphorus in August) recorded an RPD of greater than 50% (RPD=60%) between the standard and duplicate sample, however the standard sample recorded a result less than ten times the LOR and therefore this RPD is considered acceptable. As such, the level of variability present in the sampling was considered to be acceptable.


3. Guidelines for water quality assessment

It is common in these types of assessments to compare sample concentrations to recognised standards or guidelines. The National Water Quality Management Strategy: Australia and New Zealand Water Quality Guidelines for Fresh and Marine Water Quality. (ANZECC & ARMCANZ, 2000, papers 4 and 7) provides current guidance on both ecosystem and human health protection. The water quality guidelines (ANZECC & ARMCANZ 2000) provide trigger values for the following environmental values (EV): aquatic ecosystems; primary industries; recreation and aesthetics; and drinking water. Exceedance of a trigger value from the ANZECC guidelines indicates that there is the potential for an impact to occur and should therefore trigger a management response (ANZECC & ARMCANZ 2000). The rationale for the trigger values used in the ANZECC guidelines is provided in chapter 8 of the guidelines. ANZECC and ARMCANZ (2000) have devised statistically derived default trigger values for physical and chemical stressors for different types of ecosystems of southwest Australia that should not be exceeded. Nutrient concentrations and physicochemical parameter results from Lake Claremont were compared to the ‘wetlands’ ecosystem type trigger values. ANZECC and ARMCANZ (2000) have also developed “high reliability” trigger values for toxicants (including metals and ammonia) in fresh waters where sufficient “No Observed effect Concentration” (NOEC) data is available, published in chapter 3 of the guidelines. Several trigger values have been derived for each metal depending on the proportion of species for which protection is sought: 99%, 95%, 90% or 80%. Given that Lake Claremont is a Conservation Category wetland, toxicant results were compared to the guidelines for a 95% level of protection for freshwater biota where available. For the metal cobalt, a “high reliability” value is not available and therefore ANZECC and ARMCANZ recommend the use of a “low reliability” trigger value calculated by different means. For chromium, the “high reliability” trigger value is considered too high and therefore the use of an interim value for freshwater protection is recommended. For iron, ANZECC and ARMCANZ (2000) suggest the use of an interim value based upon the current Canadian guideline level (CCREM 1991).

As Lake Claremont can also be accessed by and seen by the public at several points, it is reasonable to compare the toxicant results to the National Health and Medical Research Council’s (NHMRC) Guidelines for Managing Risks in Recreational Water (2008). Trigger values for pH, dissolved oxygen, ammonia and metals are specified in these guidelines. For ammonia and metals, these guidelines recommend that trigger values for recreational use be calculated by multiplying the relevant trigger values in the NHMRC (2016) Australian Drinking Water Guidelines 6: 2011 (ADWG) by ten. This is based upon the premise that swimmers in a water body may consume 10% of drinking water consumption volumes whilst swimming. As swimming is not allowed in Lake Claremont it is very unlikely the Lake water would be ingested, and as such an exceedance of the referenced trigger level does not necessarily indicate a health risk, rather just that further consideration should be given to the situation. Table A-1 in Appendix A shows the trigger values used to compare the results of the analysed parameters.


4. Previous water quality data

The Town of Claremont has undertaken annual water quality testing and reporting for Lake Claremont in previous years. A summarised dataset encompassing Lake Claremont water quality data from May 2004 to September 2016 has been provided to SERCUL (Town of Claremont (unpublished). Data from November 2016 was also provided but as water levels were very low (approximately 15 cm) at this time this data has not been included in the summarised dataset. In this dataset, data from the north-eastern corner of the Lake and data from the rest of the Lake has been evaluated separately. This is because, as stated in the annual water quality report published by the Town of Claremont in 2015 (Simpson 2015), the water quality data obtained from the north-eastern corner of the Lake, close to Alfred Rd drain, is not considered representative of the water quality in the rest of the Lake. Data from the main lake has also been summarised separately for winter/spring and summer/autumn, however far less samples were collected in summer/autumn, as evapo-concentration of water in the lake is likely to result in vastly different results in summer and autumn when the lake is drying than in winter or spring. It is noted that data from only four sampling events held in summer/autumn at the Lake has been made available to SERCUL, perhaps as the Lake is often dry at this time of the year (Town of Claremont 2017). Data collected by SERCUL in spring and summer 2017 (SERCUL 2017) at the same sites as those sampled in 2018 (with the exception of the upstream Henshaw Drain site) has also been used for comparison purposes. A summary of the water quality information provided by the Town of Claremont and collected by SERCUL in 2017 is displayed in Table 4-1 below. For the purposes of this assessment, data collected by SERCUL in 2018 has been compared to this dataset. However due to slightly different sampling locations and sampling times over the years, statistical trends over time cannot be evaluated as part of this assessment.


Table 4-1: Summary of Lake Claremont water quality data from May 2004 to August 2016 (Town of Claremont (unpublished)) and SERCUL 2017 water quality data

Parameter

Town of Claremont data SERCUL Data

Main Lake waterbody North-eastern corner

North-eastern corner

Stirling Rd

Central Drain

Henshaw Drain

Stirling Rd Central Drain (Lake sample)

Henshaw Drain (Lake sample)

Alfred Rd Drain (Lake sample)

Lookout

May 2004 to Aug 2016 -

Winter/Spring*

May 2004 to Aug 2016 -

Summer/Autumn**

Aug 2009 to Sep 2016***

28/09/17 28/09/17 3/10/17 13/12/17 3/10/17 13/12/17 28/09/17 3/10/17 13/12/17 28/09/17 3/10/17 13/12/17

pH 8.0 (Sep 11)– 9.3 (Nov 04)

8.6 (May 16)- 8.9 (May 04 & Jan 13)

7.4 (Oct 15) – 8.5 (Jul 09)

7.05 7.89 8.55 8.12 8.22 8.38 7.5 8.06 7 8.26 8.9 8.99

Dissolved oxygen (%)

- - - 80.7 101.7 29.8 42 35 82.8 27.3 20.1 8.6 76 95.4 35.5

Electrical conductivity

(mS/cm)

1.6 (Sep 16) – 9.2 (Nov 06)

0.054 (May 16)– 10.5 (Jan 13)

1.6 (Aug 10) – 4.3 (Sep 16)

0.056 0.046 4.75 3.55 3.48 5.91 2.745 3.08 2.698 4.16 4.21 7.22

Turbidity (NTU)

0.85 (Aug 08) – 79 (Nov 06)

10.4 (May 16) -133 (Jan 13)

1.4 (Nov 14) – 48 (Jul 09)

17.8 41.2 - 20.5 - 12.2 5.1 - 3.3 5.9 - 10.7

Total nitrogen (mg/L)

0.375 (Nov 13) – 11.2 (Nov 06)

3.04 (May 16) – 23 (May 04)

1.4 (Aug 10) – 11 (Oct 15)

0.8 1.1 - 4.8 - 4 2.8 - 4.6 2.2 - 4.7

Total oxidised nitrogen (mg/L)

<0.005 (Sep 16) – 1.2 (Sep 11)

0.006 (May 16) -0.09 (May 04)

0.013 (Jul 09) – 1.5 (Sep 11)

0.11 0.06 - 0.01 - 0.01 0.64 - 0.03 0.02 - 0.01

Nitrogen as NH

4+/NH3

(mg/L)

0.007 (Sep 16) – 0.44 (Oct 15)

0.05 (May 16) – 0.13 (May 04)

0.005 (Jul 09) – 1.1 (Oct 13)

0.11 0.06 - <0.01 - <0.01 0.51 - 3.56 0.06 - 0.01

Total phosphorus

(mg/L)

0.045 (Sep 16) – 0.92 (Nov 06)

0.10 (May 16) – 0.97 (Jan 13)

0.065 (Sep 09) – 0.52 (Aug 10)

0.11 0.24 - 0.36 - 0.3 0.11 - 0.12 0.15 - 0.23

Filterable reactive

phosphate (mg/L)

0.009 (Sep 11) – 0.22 (Nov 04)

0.069 (May 16) – 0.31 (May 04)

<0.005 (Oct 13) – 0.028 (Nov 14)

0.05 0.08 - 0.1 - 0.09 0.05 - 0.05 0.12 - 0.1

* Range of means (when multiple samples collected on the same sampling event) or values (when only one sample collected per event) across 15 sampling events

** Range of means (when multiple samples collected on the same sampling event) or values (when only one sample collected per event) across four sampling events

*** Range of means (when multiple samples collected on the same sampling event) or values (when only one sample collected per event) across seven sampling

events


5. Field observations

It is important to mention field observations recorded during sampling events which can potentially link to or explain analytical results or have a potential impact on the biota of the waterbodies and/or the health of the surrounding community whom use these areas for recreational purposes. The following pertinent observations were made during the 2018 sampling period:

• In August 2018, water levels in the Lake appeared to be higher than in winter 2017;

• Slightly cloudy water was observed in Henshaw Drain upstream and downstream and Stirling Rd Drain sites in August;

• Green cloudy water, likely indicative of phytoplankton, observed at the three main Lake body sites (Stirling Rd central drain (lake), Henshaw drain (lake) and the Lookout) in January;

• Large flocks of waterbirds (mainly ducks) and bird droppings observed on the bank near Stirling Road drain on all sampling occasions;

• Lots of vegetation at the Henshaw drain (lake) site on all sampling occasions;

• Lots of vegetation at the Alfred Rd drain (lake) site, including couch grass and Persecaria, with lots of dead plant material;

• Black, anoxic smelling sediment noted in the Lake at Stirling Road drain (lake) and Henshaw drain (lake) sites when sampling in January;

• In January the Alfred Rd drain (lake) site appeared to be disconnected from the rest of the lake by a thick band of soil and vegetation (largely Baumea articulata).


6. Water physicochemical results

Refer to Table B-1 in Appendix B for a summary of the factors that can impact the following physicochemical properties of water and the ways in which changes in physicochemical properties can affect aquatic ecosystems.

6.1 pH

Water pH is a measure of the acidity or alkalinity of a water body. pH is measured on a logarithmic scale, and as such a pH of 5 is ten times more acidic than a pH of 6 and a pH of 9 is ten times more alkaline than a pH of 8. A pH value of less than 6.5 is considered acidic, between 6.5 and 8.0 is considered neutral and higher than 8.0 is considered high by the Department of Water and Environment Regulation (DWER) (Department of Water n.d.). Most samples recorded pH values within the ANZECC (2000) acceptable range for wetlands of southwestern Australia (7-8.5) (Figure 6.1-1). Samples collected from Henshaw drain (lake) and the Lookout in January, recorded pH values of 8.61 and 8.81 respectively; exceeding both the acceptable range and the NHMRC acceptable range for recreational value (6.5-8.5). One sample collected from Henshaw drain (lake) recorded a pH below the acceptable range (6.91). The pH values measured at Alfred Rd drain (lake) and the remaining three lake sites are similar to pH results recorded from 2004 to 2017 in the north-eastern corner of the Lake and the Lake body respectively (refer to Table 4-1). The high pH values recorded at the Lookout and Henshaw Drain (lake) sites in January are not of concern, as the soil type of the Lake substrate (Spearwood Wet (sand over limestone)) is alkaline and expected to result in slightly alkaline overlying waters.

Figure 6.1-1: pH values in Lake Claremont water samples in 2018-19


6.2 Dissolved oxygen

In 2018-19, all samples recorded dissolved oxygen (DO) saturations below the ANZECC acceptable range (90-120%) and most were also below the NHMRC recreational limit (>80%) (Figure 6.2-1). The lowest DO saturations recorded at Lake sites were recorded in samples collected in January, except the Henshaw drain (lake) site which recorded its lowest saturation in October. DO saturations recorded at Henshaw Drain, Henshaw Drain (lake) and the Lookout sites were somewhat lower in 2018-19 than in 2017 (Table 4-1). However it should be noted that dissolved oxygen can fluctuate greatly over a diurnal cycle as well as being strongly influenced by temperature, water level and wind conditions and this may account for some of the variation between years.

Figure 6.2-1: Dissolved oxygen saturations in Lake Claremont water samples in 2018-19


6.3 Electrical Conductivity

Electrical conductivity (EC) is the ability of water or soil to conduct an electric current. It is commonly used as a measure of salinity or total dissolved salts as solutions with high salt concentrations conduct electricity better than pure water. EC is increased when the total concentration of inorganic ions (particularly sodium, chlorides, carbonates, magnesium, calcium, potassium and sulfates) is increased. All three stormwater drain sites (Stirling Rd central drain and Henshaw drain upstream and downstream sites) had EC values less than the ANZECC lower trigger value for wetlands (0.3 mS/cm) in August, and the four lake sites (Stirling Rd central drain (lake), Henshaw drain (lake), Alfred Rd drain (lake) and the Lookout) had EC values greater than the higher trigger value (1.5 mS/cm) (Figure 6.3-1 and Table 4-1). According to DWER classifications (DoW n.d.), the two drain sites can be classified as freshwater (<0.965 mS/cm) and the four lake sites can be classified as brackish (1.953 to 8.835 mS/cm) except the January Lookout sample which was saline (>8.835 mS/cm). The EC values measured at Alfred Rd drain (lake) and the remaining three lake sites are similar to EC results recorded from 2004 to 2017 in the north-eastern corner of the Lake and the Lake body respectively (refer to Table 4-1). The high EC values at the lake sites, particularly in December when the water levels were lower and therefore the water likely more concentrated, are also expected as Lake Claremont is a naturally brackish lake as a result of its geology and its proximity to the coast. The ANZECC (2000) guidelines acknowledge that “values even higher than 1.5 mS/cm are often found in saltwater lakes and marshes” and that “higher values (>3 mS/cm) are often measured in wetlands in summer due to evaporative water loss”. The low EC values at the two drain sites are to be expected, as these drains only flow during rain and receive water from mainly impervious surfaces and therefore water from these drains is not expected to contain a high salt content.

Figure 6.3-1: Electrical conductivity in Lake Claremont water samples in 2018-19


6.4 Turbidity

Turbidity is an optical property that expresses the degree to which is light is scattered and absorbed in water and as such is essentially a measure of the water clarity (OzCoasts 2015). Turbidity can be due to coloured dissolved organic matter and suspended particulate matter, including clay, silt and organic detritus. Turbidity is expressed in nephelometric turbidity units (NTU). Turbidity in January at Stirling Rd central drain (lake), Henshaw drain (lake) and the Lookout sites had turbidity values greater than the ANZECC upper acceptable turbidity trigger value (100 NTU), with values of 171, 149 and 179 respectively (Figure 6.4-1). According to DWER classifications (DoW n.d.), these samples are classed as having “very high” turbidity (>25 NTU). All other samples recorded turbidity values except the August Alfred Rd drain (lake) recorded values higher than lower trigger value (10 NTU), with “high” turbidity (11 NTU to 25 NTU) according to DWER classifications. The January turbidity values at the three main Lake body sites (Stirling Rd drain (lake), Henshaw drain (Lake) and the Lookout) are somewhat higher than those recorded in previous years in summer/autumn months (10.4 NTU to 133 NTU), although the August values are within the range of those recorded in winter/spring in previous years (Table 4-1). These high January turbidity values are likely to be partially due to phytoplankton. The turbidity values recorded in lake samples from Alfred Rd drain (lake) are also within the range of values recorded in the north-eastern corner of the Lake in previous years.

Figure 6.4-1: Turbidity in Lake Claremont water samples in 2018-19


6.5 Temperature

Water temperatures at Lake Claremont sites ranged from 12.6°C recorded at Alfred Rd drain (lake) in August to 26°C recorded at Henshaw drain (lake site) in January. These temperatures are within an expected range for lakes and stormwater drainage in this region and are not indicative of any thermal pollution.

Figure 6.5-1: Water temperatures in Lake Claremont water samples in 2018-19


7. Water nutrient results

Refer to Table B-1 in Appendix B for a summary of the factors that can impact nutrient levels in waterbodies and the ways in which nutrients can affect aquatic ecosystems.

7.1 Nitrogen

Nitrogen can be present in multiple chemical species found in water bodies. Inorganic forms of nitrogen, which are generally more available for plant and algal growth than organic forms, include oxidised nitrogen (NOx-N) compounds nitrate (NO3

-) and nitrite (NO2-), and ammoniacal

nitrogen (NH3-N/NH4+-N) compounds ammonium (NH4+) and ammonia (NH3). Nitrogen can also

be present in dissolved and particulate organic compounds such as proteins, polypeptides, amino acids, and urea. Total nitrogen (TN) is the sum of the nitrogen present in all the above forms. Nitrogen is cycled between the above forms, as well as with nitrogen gas (N2) via physical and biological processes known collectively as the nitrogen cycle. When plants and animals die or when animals excrete their wastes, organic nitrogen in the water is converted by bacteria to ammonium/ammonia (mineralisation), then to nitrite and nitrate (nitrification). Ammonium can be converted to ammonia gas (volatilisation) in alkaline conditions and nitrate can be converted to nitrogen gas (denitrification), with the release of these gasses into the atmosphere resulting in a loss of nitrogen from the water. Processes affecting nitrogen can vary depending on weather and other conditions, as evidenced in the Lake Claremont data in 2018/19 where nitrogen results varied greatly between August and January and between stormwater sites and lake sites. In August, TN, as well as NH3/NH4+-N and NOx-N, concentrations in the three Lake Claremont stormwater drainage sites (Stirling Rd central drain and Henshaw drain upstream and downstream) were below the ANZECC trigger values for wetlands (1.5 mg/L, 0.04 mg/L and 0.1 mg/L respectively) (Figure 7.1-1-A, B, C) and less than concentrations recorded in September 2017 (Table 4-1). In contrast, both Lake sites sampled (the Lookout and Alfred Rd drain (lake)) in August recorded an exceeding TN concentration, although both concentrations were far less than concentrations recorded at these sites in January (Figure 7.1-1-A). The majority of nitrogen at both of these sites in August was present as NH3/NH4+-N (Figure 7.1-2), with NH3/NH4+-N concentrations exceeding the trigger values for both wetlands and 95% protection of freshwater biota (adjusted) (Figure 7.1-1-C). At Alfred Rd drain (lake) the August NOx-N concentration at this site also exceeded the wetlands trigger value (0.1 mg/L) (Figure 7.1-1-B). TN and NOx-N concentrations at these sites are within the ranges of concentrations recorded in the same parts of the Lake in winter/spring in previous years (Table 4-1). However the NH3/NH4+-N concentration recorded at the Lookout and Alfred Rd drain were particularly high in 2018 when compared to previous years’ data (including 2017 data) recorded in the main Lake body (0.007 mg/L – 0.44 mg/L) and north-eastern Lake (0.005 mg/L - 1.1 mg/L). In January, TN concentrations in the four lake sites (Stirling Rd central drain (lake), Henshaw drain (lake), Alfred Rd drain (lake) and the Lookout) were above the wetlands trigger value (Figure 7.1-1-A), with concentrations ranging from 6 (at Alfred Rd drain (lake)) to 13 times (at the Lookout) the trigger value. Similarly high TN concentrations have been recorded in both the main lake body (23 mg/L in May 2005 and a mean of 14.75 mg/L recorded in January 2013 (Town of Claremont pers. comm.)) and in the north-eastern Lake corner (up to 11 mg/L in winter/spring – no summer/autumn data available) on the few occasions when summer/autumn samples have been collected from the Lake in previous years, but not in December 2017 (Table 4-1).


Figure 7.1-1: Concentrations of A) total nitrogen (TN); B) total oxidised nitrogen (NOx-N); C) nitrogen as ammonia/ammonium (NH3/NH4+-N) (note left graph compares results to ANZECC wetlands trigger value (scale is cropped at 0.1 mg/L) and right graph compares results to adjusted trigger values for 95% protection of freshwater biota); and D) total organic nitrogen (TON) recorded in Lake Claremont water samples in 2018-19.

A) B)

C)

D)


Figure 7.1-2: Nitrogen speciation in Lake Claremont water samples in 2018-19

As evidenced in Figure 7.1-1 and Figure 7.1-2, most of the nitrogen in the Lookout, Stirling Rd central drain (lake) and Henshaw drain (lake) sites in January was present in organic compounds (TON) rather than inorganic forms (NH3/NH4+-N or NOx-N). These sites did not record concentrations of inorganic nitrogen forms in exceedance of trigger values for wetlands in January except for the NH3/NH4+-N concentration recorded in the Stirling Rd central drain (lake) site, which was equal to the trigger value (0.04 mg/L). In contrast, at the Alfred Rd drain (lake) site in January, approximately 75% of nitrogen present was present in inorganic compounds (mainly ammonia/ammonium) as it was in August (Figure 7.1-2). This shows that this site appears to be hydrologically isolated from the Lake water body in January, which appeared to be the case when sampling (refer to Section 5). Similarly to August, NH3/NH4+-N concentrations at Alfred Rd drain (lake) in January exceeded the trigger values for both wetlands and for 95% protection of freshwater biota (adjusted) (Figure 7.1-1-C), and were far higher than concentrations recorded both in previous years in winter/spring and in December 2017 (3.56 mg/L).


7.2 Phosphorus

Phosphorus present in water can be present in both particulate and soluble forms. Particulate phosphorus is comprised of organic material (decaying plant and animal matter); phosphorus adsorbed to particulate material and phosphorus minerals (e.g. apatite). Soluble phosphorus is approximated by filterable reactive phosphorus (FRP), which is a measure of the immediately available phosphate in the system at the time of sampling and measures the phosphates that pass through a 0.45 μm filter and respond to colorimetric tests without preliminary hydrolysis or oxidative digestions of the sample. In August, total phosphorus (TP) concentrations recorded in both the stormwater inlets to Lake Claremont (Stirling Rd central drain and Henshaw drain downstream) were less than the ANZECC wetlands trigger value (0.06 mg/L), however Henshaw drain upstream recorded an exceeding TP concentration (Figure 7.2-1-A). FRP also exceeded the ANZECC wetlands trigger value (0.03 mg/L) at both Stirling Rd central drain and Henshaw drain upstream (Figure 7.2-1-A). TP and SRP concentrations at both Stirling Rd central drain and Henshaw drain downstream were less than those recorded in September 2017 (Table 4-1). The Lookout also recorded exceeding TP and SRP concentrations in August, although concentrations of both of these parameters were within the ranges of concentrations recorded in previous years. SRP comprised 94% of TP at the Lookout in August (Figure 7.2-2). In January, TP concentrations exceeded the wetlands trigger value at all four Lake sites (Figure 7.2-1-A). At all of these sites the majority of this phosphorus was present in particulate forms, although SRP still exceeded the wetlands trigger value at all lake sites except Alfred Rd drain (lake) in January (Figure 7.2-1-B). Although TP concentrations were far greater at these sites in January 2018 than in December 2017, and at the Lookout higher than those recorded in preceding years, SRP concentrations did not vary to such a great extent between the two years and were within the range of results recorded in preceding years (Table 4-1).

Figure 7.2-1: Concentrations in Lake Claremont water samples in 2018-19 of A) total phosphorus (TP) and; B) filterable reactive phosphorus (FRP).

A) B)


Figure 7.2-2: Percentage of total phosphorus as filterable reactive phosphorus in Lake Claremont water samples in 2018-19


8. Metals and Hardness

8.1 Metals

Table C-1, Appendix C outlines the sources, water quality factors affecting impacts and the impacts to aquatic biota of all metals analysed in Lake Claremont water samples in 2018-19. It is important to note that the ANZECC and ARMCANZ (2000) trigger values for protection of freshwater biota have been based on bioavailable metal concentrations. Soluble metals are generally more bioavailable than metals bound to particles, and as such, in general, comparing soluble metal concentrations to the trigger values provides a better understanding of whether there is potential harm to biota. Total metal concentrations provide an understanding of the quantity of that metal that may become bioavailable in the future. Total and soluble concentrations of metals cadmium, chromium, cobalt, manganese, nickel, selenium and mercury were all below relevant trigger values for protection of freshwater biota and recreational values (Table 8-1). Concentrations of aluminium, arsenic, copper, iron, lead and zinc exceeded relevant trigger values at some or all sites, with results for these metals detailed below. Total and soluble aluminium concentrations at the three drain sites (Stirling Rd central drain, Henshaw drain downstream and Henshaw drain upstream) exceeded the ANZECC freshwater biota protection trigger value (0.055 mg/L), with the highest total concentration (0.96 mg/L) recorded at Henshaw drain upstream and the highest soluble aluminium concentration (0.22 mg/L) recorded at Henshaw drain downstream in August (Figure 8.1-1-A and B, Table 8-1). The three main Lake body sites (Stirling Rd central drain (lake), Henshaw drain (lake) and the Lookout) recorded exceeding total aluminium concentrations but not soluble aluminium concentrations, and Alfred Rd drain (lake) recorded acceptable concentrations of both total and soluble aluminium. Total and soluble arsenic concentrations at all Lake sites (Stirling Rd central drain (lake), Henshaw drain (lake), Alfred Rd drain (lake) and the Lookout) exceeded the ANZECC freshwater biota protection trigger value (0.024 mg/L), with the exception of the Alfred Rd drain (lake) site in August (Figure 8.1-1-C and D, Table 8-1). A significant proportion of the total arsenic in these samples was soluble, particularly at the three main Lake body sites (Stirling Rd central drain (lake), Henshaw drain (lake) and the Lookout). The Lookout recorded the highest concentrations of both total (0.45 mg/L, 19 times the trigger value) and soluble (0.42 mg/L, 18 times the trigger value) arsenic. Total and soluble arsenic concentrations at the three main lake body sites also exceeded the NHMRC recreational guideline for health value (0.07 mg/L). Total and soluble copper concentrations at the three drain sites (Stirling Rd central drain, Henshaw drain downstream and Henshaw drain upstream) exceeded the hardness adjusted ANZECC freshwater biota protection trigger value (unadjusted value 0.0014 mg/L), with the highest total copper concentration (0.018 mg/L) recorded at Stirling Rd central drain and the highest soluble copper concentration (0.008 mg/L) recorded at Henshaw drain downstream and upstream sites (Figure 8.1-1-E and F, Table 8-1). However, the four Lake sites (Stirling Rd central drain (lake), Henshaw drain (lake), Alfred Rd drain (lake) and the Lookout) recorded lower total and soluble copper concentrations that were less than adjusted trigger values. The very high hardness of the Lake water (see Section 8.2) means that any copper present is less toxic to biota than it would be in a lake with “soft” water (ANZECC and ARMCANZ 2000).

Total iron concentrations exceeded the ANZECC biota protection trigger value (0.3 mg/L) at all sites with the highest value of 5.55 mg/L recorded at Alfred Rd drain (lake) in January: the only site to record an exceeding soluble iron concentration (0.39 mg/L in both August and January) (Figure 8.1-1-G and H, Table 8-1). Soluble iron concentrations at Alfred Rd drain (lake) were the same in August and January, but total iron concentrations were substantially higher in


January, with the January result at this site also exceeding the NHMRC recreational guideline for aesthetic value (3 mg/L). Total lead concentrations recorded at the three drain sites (Stirling Rd central drain, Henshaw drain downstream and Henshaw drain upstream) exceeded the hardness adjusted ANZECC freshwater biota protection trigger values (unadjusted value 0.0034 mg/L), although the highest total concentration (0.013 mg/L) was recorded at the Stirling Rd central drain (lake) site (Figure 8.1-1-I, Table 8-1). The three main Lake body sites (Stirling Rd central drain (lake), Henshaw drain (lake) and the Lookout) recorded total lead concentrations less than adjusted trigger values, with the very high Lake hardness (see Section 8.2) meaning that lead concentrations at Stirling Rd central drain (lake) site present are unlikely to be toxic to Lake biota (ANZECC and ARMCANZ 2000). All sites recorded soluble lead concentrations less than adjusted trigger values (Figure 8.1-1-J). Total and soluble zinc concentrations recorded at the three drain sites (Stirling Rd central drain, Henshaw drain downstream and Henshaw drain upstream) exceeded the hardness adjusted ANZECC freshwater biota protection trigger values (unadjusted value 0.0092 mg/L), with the highest total concentration (0.092 mg/L) recorded at Stirling Rd central drain and highest soluble concentration (0.037 mg/L) recorded at Henshaw drain downstream (Figure 8.1-1-K and L, Table 8-1). All Lake sites (Stirling Rd central drain (lake), Henshaw drain (lake), Alfred Rd drain (lake) and the Lookout) recorded total and soluble zinc concentrations less than adjusted trigger values. The very high hardness of the Lake water (see Section 8.2) means that any zinc present is less toxic to biota than it would be in a lake with “soft” water (ANZECC and ARMCANZ 2000).


Table 8-1: Total and soluble concentrations of metals analysed in Lake Claremont water samples in 2018-19

Site

Stirling Rd central drain

Henshaw drain downstream

Henshaw drain upstream

Stirling Rd central drain (lake)

Henshaw drain (lake)

Alfred Rd drain (lake) Lookout

Parameter Trigger value(s) Date 29/08/2018 28/08/2018 28/08/2018 17/01/2019 17/01/2019 28/08/2018 17/01/2019 28/08/2018 17/01/2019

Aluminium FW: 0.055 Total 0.84 0.88 0.96 0.35 0.09 <0.01 0.03 0.1 0.14

Soluble 0.11 0.22 0.21 <0.01 <0.01 <0.01 <0.01 0.02 <0.01

Arsenic FW: 0.024

Rec (health): 0.07

Total <0.001 <0.001 0.001 0.384 0.366 0.008 0.089 0.128 0.45

Soluble <0.001 <0.001 <0.001 0.352 0.346 0.006 0.036 0.128 0.412

Cadmium FW: 0.0002* Rec (health)

Total <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001

Soluble <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001

Chromium FW: 0.0033*

Rec (health): 0.5

Total 0.003 0.003 0.003 0.002 <0.001 <0.001 <0.001 <0.001 0.001

Soluble <0.001 0.001 0.002 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Cobalt FW: 0.0028 Total <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Soluble <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Copper FW: 0.0014*

Rec (health): 20 Rec (aesthetic): 10

Total 0.018 0.016 0.014 0.004 0.001 <0.001 <0.001 <0.001 0.002

Soluble 0.007 0.008 0.008 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Lead FW: 0.0034*

Rec (health): 0.1

Total 0.006 0.005 0.009 0.013 0.003 <0.001 <0.001 0.002 0.003

Soluble <0.001 0.001 0.002 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Manganese FW: 1.9

Rec (health): 5 Rec (aesthetic): 1

Total 0.012 0.011 0.011 0.023 0.012 0.047 0.085 0.017 0.021

Soluble 0.002 0.003 0.002 0.003 0.003 0.04 0.071 0.011 0.002

Nickel FW: 0.011*

Rec (health): 0.2

Total 0.001 0.002 0.001 0.003 0.003 0.001 0.002 <0.001 0.003

Soluble <0.001 <0.001 <0.001 0.002 0.002 0.001 0.001 <0.001 0.002

Selenium FW: 0.011

Rec (health): 0.1

Total <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Soluble <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Zinc FW: 0.008

Rec (aesthetic): 30

Total 0.092 0.067 0.069 0.036 0.014 <0.005 0.006 <0.005 0.014

Soluble 0.032 0.037 0.035 0.02 0.014 <0.005 0.006 <0.005 0.014

Iron FW: 0.3

Rec (aesthetic): 30

Total 0.77 0.82 0.83 0.86 0.33 1.11 5.55 0.36 0.6

Soluble 0.06 0.12 0.12 <0.05 <0.05 0.39 0.39 0.14 <0.05

Mercury FW: 0.0006 mg/L Rec (health): 0.01

Total <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001

Soluble <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001

Hardness NA NA 22 19 28 713 705 681 528 513 724

FW ANZECC and ARMCANZ (2000) trigger values for 95% protection of freshwater biota Rec NHMRC (2008) guidelines for recreational health or aesthetic value * Unadjusted for hardness Concentration exceeds FW trigger value (or hardness adjusted FW trigger value)

Concentration exceeds both FW trigger value and recreational trigger value


Figure 8.1-1: A) Total aluminium (Al); B) soluble aluminium (Al); C) total arsenic (As); D) soluble arsenic (As); E) total copper (Cu); F) soluble copper (Cu); G) total iron (Fe); H) soluble iron (Fe); I): total lead (Pb); J) soluble lead (Pb); K) total zinc (Zn) and L: soluble zinc (Zn) concentrations (mg/L) recorded in Lake Claremont sites in 2018-19

B) A)

C) A) B) D)

E) F) H) G)

I) J) K) L)


8.2 Hardness

Total hardness, expressed as calcium carbonate (CaCO3), is the combined concentration of earth-alkali metals, predominantly magnesium (Mg2+) and calcium (Ca2+), and some strontium (Sr2+) in the water. Other metal ions (such as aluminium, iron, zinc and manganese) also contribute to water hardness. Increasing calcium and magnesium in water (hardness) is frequently associated with increases in alkalinity (as calcium and/or magnesium carbonate), and thus, pH (ANZECC and ARMCANZ 2000). Water in all samples collected from Lake Claremont Lake sites (Stirling Rd central drain (lake), Henshaw drain (lake), Alfred Rd drain (lake) and the Lookout) could be categorised as “extremely hard” (>240 mg/L) whereas water samples from all drain sites could be classified as “soft” (0 to 59 mg/L) according to DWER guidelines (DoW n.d.) (Figure 8.2-1). As the soil beneath Lake Claremont is comprised of calcareous sands, this high hardness is expected of the Lake water, whereas urban stormwater is often soft because it is largely comprised of rain flowing over impervious surfaces.

Figure 8.2-1: Water hardness concentrations (mg/L) recorded in Lake Claremont sites in 2018-19


9. Macroinvertebrate sampling methodology

9.1 Site selection

Macroinvertebrate sampling was undertaken at or close to the four water quality sampling locations (Table 2-1) in order for associations between water quality and macroinvertebrate diversity and/or abundance to be made. As such samples were collected from the following four locations:

• Within the lake close to the three drain inlets (Stirling Rd central drain, Henshaw drain and Alfred Rd drain);

• At the Lookout.

9.2 Sampling frequency

Samples were collected on the 11th of October i.e. during spring, when macroinvertebrate populations were likely to be at their peak. It should be noted that this macroinvertebrate assessment should be considered a snapshot only, as to obtain a full understanding of macroinvertebrate composition of a water body sampling should occur for at least three seasons.

9.3 Sampling protocol

At each site, samples were collected along a 10m transect using a slandered sweep net. Samples were taken back to SERCUL for identification on the same day, and as such were not preserved in alcohol prior to identification. Identification was conducted by appropriately experienced staff using a magnifying glass/microscope to the lowest practical taxonomic level using aquatic macroinvertebrate identification keys (Waterwatch Murray 2009, Davis and Christidis 1999). Total abundances were recorded. However, for ease of interpretation, only relative abundances will be shown in this report. Abundances were recorded as follows: * rare (<10 individuals/sweep); ** common (11-100 individuals/sweep); *** abundant (101-1000 individuals/sweep); and **** highly abundant (>1000 individuals/sweep). Mosquito larval counts were also conducted at each site according to the guidelines of the “constructed wetlands-sampling protocol” (Department of Health 2015). Ten dips using a slandered 350 mL ladle were conducted at each site and mosquito larvae numbers counted per dip.

Water quality physicochemical parameters, water depth and weather conditions were also recorded at each macroinvertebrate sampling site as described above. Further to this, the composition, abundance and percentage cover of any emergent, submerged and canopy vegetation was recorded at each sampling site.


10. Macroinvertebrate sampling results

A total of 19 macroinvertebrate taxa were recorded at the four Lake Claremont sites in October 2018 (Table 10-1). Macroinvertebrate richness varied between the sites, with the highest number of taxa recorded at Alfred Road Drain (16 taxa), followed by The Lookout (12), Henshaw drain (lake) (11) and Stirling Road Central Drain (lake) (10). Total abundance was highest at the Lookout. Closer examination of the community composition of this site revealed that these high abundances were due to the presence of large numbers of three taxa: back swimmers, copepods and ostracods (> 1000 individuals recorded in the sweep). Overall, the Class Insecta was the most family rich group, followed by the Crustacea. Three taxa (dragonfly nymphs, soldier fly larvae and flat worms) were recorded in 2018 that were not recorded in 2017 (SERCUL 2017). A range of functional feeding groups were present in Lake sites. Predators were the predominant macroinvertebrate community at all sites, followed by shredders. Presence of functional feeding groups and their relative importance in the overall macroinvertebrate community composition is related to food web energetics. For instance, predators can be beneficial in controlling vector mosquitos and shredders can enhance decomposition of organic material (Boets et al., 2011) and provide food for other functional feeding groups such as collectors. The macroinvertebrate taxa found in the lake were predominantly those classified with a pollution sensitivity rating of very tolerant (Waterwatch Murray 2009, Department of Environment and Education 2011). However, water mites (order Acarina), classed as sensitive, were recorded (abundant to highly abundant occurrence) at all sites, and caddisfly larvae (order Trichoptera) were recorded (rare occurrence) at Stirling Rd central drain (lake). Crustaceans, including Cladocera, Ostracoda and Copepoda were highly abundant at some locations, and although not rated for pollution sensitivity by Waterwatch Murray (2009), they have been found to be tolerant of pollution and can live in waters with low oxygen levels (Davis & Christidis 1997; McComb & Davis 1993) but sensitive to some pollutants and chemicals (Almeda et al 2013: Walsh 1978). Overall, macroinvertebrate communities at the four Lake sites were typical of disturbed wetlands i.e. they were characterised by low taxa richness and high abundances of a limited number of taxa which are belonging in to tolerant of poor water quality (Davis & Christidis 1997, McComb & Davis 1993). Vegetation composition was different amongst sites, providing different macroinvertebrate microhabitats that were reflected in the macroinvertebrate taxa found. Both the Stirling Road central drain (lake) and Henshaw drain (lake) sites had open water areas conducive to wind aeration to the habitats. Mosquito larvae were not detected in mosquito dips at these sites (Table 10-2), although mosquito larvae were encountered (rare occurrence) in sweep results. Presence of natural predators and wave action or water movement could be important factors in reducing mosquito larvae survival rates at these sites. The Stirling Road central drain (lake) site had 80% of tree cover from a mature fig tree, which would provide decaying leaf litter and twigs as habitats and food for macroinvertebrates. Caddis fly larvae were found at this site only. It is not known why ostracods were absent at only this site given that they were highly abundant in the 2017 sampling event; food or other ecological changes or possible burial of their egg bank due to sedimentation (Gleason et al. 2003, Gleason and Eulliss Jr. 1998) could be reasons for this difference. The Henshaw drain lake site had sporadic clumps of Juncus palidus, Centella asiatica, and duckweed in the water, with 90% canopy cover from an aged Eucalyptus tree.


Table 10-1: Macroinvertebrate communities recorded at Lake Claremont sites in October 2018

Common name TAXA Functional feeding group Sensitivity A2.1 A4.1 A5.1 A7.1

Amphipod (scud) Amphipoda (order) shredder * * *** ***Back swimmer Notonectidae (family) predator ** ** * ****Caddisfly larvae Trichoptera (order) predator/shredder *Copepod Copepoda (subclass) predator/scraper/shredder **** *** *** ****Damselfly nymph Odonata (order) predator * * *Dragonfly nymph Odonata (order) predator *Diving beetle larva Dytiscidae (family) predator * *Freshwater snail Gastropoda (class) scraper * ** ** **Mosquito larva Culicidae (family) predator/filter feeder * * * *Non-biting midge larva Chironomidae (family) filter feeder * ** *Ostracod (Seed shrimp) Ostracoda (subclass) filter feeder ** **** ****Flatworm Turbellaria (Class) predator/scraper *Roundworm Nematoda (phylum) collector *Leach Hirudinea (subclass) predator *Soldier fly larva Stratiomyidae (family) shredder * *Water boatman Corixidae (family) shredder/predator * *** * ***Water flea (daphnia) Cladocera (suborder) collector *** ****Water mite Acarina (order) predator/parasite **** *** *** ***Water spider Araneae (order) predator *

Polution Sensitivity Very Tolerant Tolerant Very sensitive Sensitive Not rated

Pollution sensitivity: Aquatic Macroinvertebrate ID Key, Ribbons of Blue-NRM Education, Department of Environment and Education WA, 2011.(http://education.dec.wa.gov.au/ribbons-of-blue.html)

* rare (<10 individuals/sweep);** common (11-100 individuals/sweep);*** abundant (101-1000 individuals/sweep);**** highly abundant (>1000 individuals/sweep)


The Alfred Rd drain (lake) and Lookout sites were densely covered by vegetation and had stagnant water, providing a suitable breeding habitat (i.e. able to hide from predators) for mosquito species. This may explain why mosquito larvae were found in dips at these two sites only (Alfred Rd drain (lake): 7 out of 10 dips, Lookout: 3 out of 10 dips) (Table 10-2). Overall mosquito breeding was considered low in the lake except at the Alfred Rd drain (lake) site, where native and exotic vegetation (Schoenoplectus validus, Baumea articulate, Persicaria, dense water couch) was particularly dense. The decomposition of this dense vegetation is likely to be partially responsible for the low oxygen saturations (refer to Section 6.2) and high NH4+/NH3-N concentrations at this site (refer to Section 7.1); conditions in which mosquito larvae are able to thrive in comparison to other macroinvertebrate species. This is because mosquito larvae are able to tolerate anoxic conditions due to their special breathing appendages to get oxygen from air (siphon in larvae and trumpet in pupae), and the bacteria which consume ammonium are a good food source for mosquito larvae (Thullen et al. 2001). Overall macroinvertebrate taxa and abundances recorded in 2018 were slightly different to those recorded in 2017. This can be due to slight changes of physical or ecological parameters within the wetland. Long term monitoring and moreover, sampling twice yearly (e.g. spring and autumn) over a period of years would make it possible to account for seasonal and inter annual changes in community composition, as well as account for changes due to additional disturbances related to the maintenance of these sites.

Table 10-2: Mosquito dip results at Lake Claremont sites in October 2018

Site No. of dips (out

of 10) with larvae

Average No. of larvae/dip

Stirling Rd central drain (lake) 0 0

Henshaw drain (lake) 0 0

Alfred Rd drain (lake) 7 2.6

The Lookout 3 0.5


11. Discussion and recommendations

11.1 Key Issues

The following key issues identified from the 2018-19 water quality and macroinvertebrate sampling at Lake Claremont include:

1. High total nitrogen and phosphorus in the main Lake body sites, particularly in summer, and summer phytoplankton

Nitrogen and phosphorus concentrations were high in the main Lake Body during both August and January sampling events, but were much higher in January and varied in composition between events. In August in the main Lake body (at the Lookout) a large proportion of the nitrogen was present as ammonia/ammonium, whereas in January at the three main Lake body sites (Stirling Rd central drain (lake), Henshaw drain (lake) and the Lookout) organic nitrogen comprised a very high proportion of total nitrogen. Phosphorus showed a similar pattern at these sites, with phosphorus concentrations largely soluble in August and largely particulate in January. As there appeared to be substantial phytoplankton growth in the main Lake body in January (as indicated by the very high turbidity recorded and green water appearance at these sites), this suggests that the inorganic (i.e. bioavailable) nitrogen and phosphorus present in August was used to fuel phytoplankton growth in summer.

Due to the higher Lake water levels in 2018, the Lake contained water in summer 2019 when in previous years it would have often been dry, resulting in warm, evapo-concentrated summer Lake water ideal for algal growth. On two (May 2004 and January 2013) of the few occasions the Lake has been sampled in summer/autumn, similarly high total nitrogen, total phosphorus and turbidity concentrations were recorded. The fact that the Lake has not dried since summer 2017, where it usually would each summer, may mean that less nitrogen loss has been able to occur since then, as many studies have shown sediment drying and reflooding to enhance nitrogen loss (e.g. Qiu and McComb 1996). This may partially explain the higher than usual ammonia/ammonium concentrations recorded at the Lookout in August 2018. Although nitrogen and phosphorus concentrations recorded in stormwater drains were lower than those in the lake (and nitrogen concentrations were below the wetland trigger value), as the Lake is not flushed any phosphorus entering the Lake is likely to accumulate, and nitrogen will also accumulate if it is not lost to the environment via denitrification or volatilisation. It is suspected that a high proportion of Lake nutrients may be derived from bird droppings, as evidenced by the very large waterbird (especially duck) populations observed at the Lake and copious bird droppings present on the Lake banks. Groundwater, which is known to be a significant source of water to the lake (Townley et al. 1993), could also be a source of nutrients (see below).

2. High total nitrogen and phosphorus in the north-eastern Lake corner, particularly in summer

While not as high as in the main Lake body in January, the north-eastern Lake corner (i.e. the Alfred Rd drain (lake) site) recorded high nitrogen and phosphorus concentrations in January and a high nitrogen concentration in August. In both months approximately 75% of total nitrogen was in inorganic forms, particularly ammonia/ammonium. The different water chemistry and appearance of the water in the north-eastern Lake corner, as well as the thick band of soil and vegetation between this site and the rest of the Lake in January, indicates that this site is largely disconnected from the rest of the lake, particularly in summer. The high ammonia concentrations and low oxygen in water at this site may indicate that it is a


more direct expression of the local groundwater table, which flows in a south-westerly direction from the north-eastern corner of the Lake. It is noted that there is a historical landfill approximately 1.5 km groundwater up gradient of the site and a plume of groundwater containing high levels of ammonia has been detected approximately 2 km groundwater up-gradient from the site (DWER 2019). Simpson (2015) noted a possible pattern of increasing NH4+/NH3-N concentrations over time in the north-eastern corner of the lake (i.e. near Alfred Rd drain) when considering the data in Table 4-1. While the December 2017 and January 2019 ammonia/ammonium concentrations at this site are far higher any recorded previously, as no summer/autumn data has been recorded at this site in previous years it is likely that these high concentration are indicative of seasonal effects. Evapo-concentration is likely to have partially resulted in the increase in both nitrogen and phosphorus concentrations from winter to summer, and senescence of the many plants present in this corner of the Lake (including weedy couch grass and Persecaria) in summer may also result in increased ammonia (Farnsworth-Lee et al 2000) and phosphorus concentrations.

3. High total (and filterable reactive) phosphorus concentrations at stormwater drain sites

While total phosphorus concentrations recorded in the stormwater drain sites in September were lower than those in the main Lake body, they were still in exceedance of the wetlands trigger value and thus could be improved. As the Lake is not flushed any phosphorus entering the Lake is likely to accumulate, as phosphorus is not able to be “lost” from a wetland the same way nitrogen can be in a gaseous form. It should also be noted that phosphorus (and other pollutant) concentrations in stormwater drains were likely to be higher after the “first flush” rainfall event than they were in August. The high phosphorus concentrations in the drain sites are likely to originate from a combination of sources within the drainage catchments such as fertiliser use, decomposition of plant material, dog faeces and litter.

4. High concentrations of arsenic in Lake sites

Total and soluble arsenic concentrations exceeded the trigger value for 95% protection of freshwater biota at all sites, but was particularly high (between 14 and 17 times the trigger value). This trigger value was derived from the tolerance of phytoplankton to arsenic as they are among the most sensitive organisms to arsenic, with higher trophic levels less sensitive (ANZECC and ARMCANZ 2000). As some phytoplankton play an important role in wetland food webs, the magnitude of these exceedances are concerning. Arsenic concentrations also exceeded the recreational guideline value for health, however this is based upon humans ingesting water whilst swimming, an activity that does not occur in Lake Claremont. If people are to enter Lake Claremont for any reason they should take care not to ingest any water and thoroughly wash any skin where water contact has occurred.

Arsenic could be present in Lake sediment from previous land-uses of the Lake site as market gardens and a landfill. Sediment arsenic concentrations were found to be high in 2007 when Lake sediment was sampled by the Town of Claremont (Town of Claremont 2017). Arsenic can also be released when acid sulfate soils are oxidised, however as pH levels at Lake Claremont have been stable (and relatively alkaline) in recent years this is considered an unlikely cause of the high arsenic concentrations. Arsenic concentrations in stormwater were low.

5. High concentrations of metals (aluminium, copper, lead and zinc) in drain sites

Although soluble concentrations of aluminium, copper, lead and zinc were below trigger values for protection of freshwater biota in the Lake itself (in some cases due to the high hardness of Lake water), the high concentrations of these metals in drainage could lead to


accumulation of these metals in the Lake over time. High concentrations of these metals are relatively common in stormwater drainage in the Perth area (Nice et al 2009) and can be attributed to a variety of diffuse sources common to urban environments including road sediment, runoff from metal roofs or through metal pipes, pesticides, herbicides and other household chemicals, construction runoff and litter.

6. High concentrations of iron in north-eastern Lake

Iron concentrations in exceedance of the trigger value for protection of biota are common in wetlands in the Perth region in SERCUL’s experience. However the particularly high total iron concentrations at the north-eastern lake corner could result in the formation of colloidal suspensions which can form unsightly suspended flocs, increasing turbidity, or sink to the bottom and impact benthic organisms. The high iron at this site may be due to the influence of groundwater at this site.

7. Low dissolved oxygen at lake sites

Low oxygen saturations in wetlands can result in reduced macroinvertebrate numbers and diversity, increased phosphorus release from sediments into the water column, increased ammonia concentrations due to lack of nitrification, and increased toxicity of certain metals (e.g. copper) to biota. As mosquito larvae can tolerate anoxic conditions, mosquitoes are also more likely to proliferate in low oxygen water bodies. Low oxygen saturations in waterbodies can be caused by high oxygen demand from decomposing organic material (such as deciduous leaves, aquatic plants or phytoplankton). In the north-eastern corner of the lake, several other factors including the sequestered and sheltered nature of this site, the large amount of decomposing vegetation present and the possibly greater influence of groundwater may also be contributing to low oxygen levels. It should also be noted that dissolved oxygen varies over a 24 hour period due to photosynthesis of aquatic plants and temperature changes and is often lowest at night, so dissolved oxygen saturations in the Lake at night are likely to be even lower than those recorded for this study.

8. Abundant mosquito larvae near the inlet of Alfred Rd drain

Although macroinvertebrate sampling was only undertaken on one occasion and as such considered a snapshot only, the lake near the inlet of Alfred Rd drain appears to provide a habitat for abundant mosquito larvae. This may be due to the combination of low oxygen and high ammonia: conditions which mosquito larvae are able to thrive in comparison to other macroinvertebrate species.

11.2 New Henshaw drain infrastructure

Concentrations of both total nitrogen and total phosphorus were both lower at the downstream Henshaw drain site than the upstream site when sampled in August, largely due to a reduction in organic nitrogen and particulate phosphorus between the upstream and downstream sites. Turbidity values and metal concentrations were similar between the two sites. Although more data is required to conclusively prove the efficacy of the recently installed dry wells in improving water quality entering the Lake from Henshaw drain, these results are encouraging.

11.3 Recommendations

The following are recommendations to improve water quality in Lake Claremont:

• Some form of water treatment should be incorporated into the Stirling Rd central drain, for example an infiltration bed or vegetated swale.


• It is noted that the dense vegetation present at the north-eastern area of the Lake near the outlet of Alfred Rd drain is likely to be an ideal habitat for some waterbirds such as the Black Swan and as such should be maintained. However dense vegetation stands such as this can result in a high level of organic debris in the water and subsequent low oxygen levels that can result in phosphorus release from the sediments and suboptimal conditions for biota. As such, while planting vegetation in the Lake may help to remove nutrients from the water column, if planting occurs care should be taken to ensure the planting is not dense enough to restrict water flow.

• Remove couch grass, Persecaria and other weeds from near the outlet of Alfred Rd drain to reduce the amount of organic debris in the water in this area.

• Continue to remove any other aquatic weeds (e.g. Bacopa) from the Lake where present, which may help to remove nutrients from the Lake as well as preventing the spread of such weeds.

• It is understood that more native trees will be planted around the Lake’s edge to shade the Lake with the aim of reducing water temperatures to prevent botulism outbreaks. This plan is supported by SERCUL. It is understood that the two weeping willows and an Illawarra flame tree on the lake’s edge planned to be removed are replaced with native trees.

• If deciduous trees around the Lake’s edge, such as those near the Henshaw drain and Stirling Rd drain inlets, are to be retained, leaf litter falling from these trees should be removed regularly to ensure that this litter does not contribute nutrients to the water column and create oxygen demand. Deciduous trees could also be uplifted (lower branches removed) in consultation with a certified arborist to reduce some of the leaf litter produced.

• The viability of installing aerators or “bubblers” to improve oxygenation of the Lake could be investigated; however the Lake may to be too shallow during the summer months (when algal blooms are more likely to occur) to support this.

• In future water quality assessments, consider:

a. Undertaking a sampling event in the stormwater drainage during the “first flush” of rainfall for the winter (or sometimes late autumn) season, as these events often contribute the poorest quality water to stormwater of the season. It should be noted that if this is to occur contingencies (including budget, available staff and equipment) will need to be prepared prior to this rainfall event;

b. Collecting and analysing sediment samples for metals and, nutrients and particle size analysis to determine whether sediments are likely to be a source of nutrients and metals to the Lake;

c. Analysing samples for dissolved organic nitrogen, as this can provide an indication of how much organic nitrogen is immediately available for plant and algal growth;

• Turf managers within the catchment should undertake training to implement best practice fertiliser use in order to minimise nutrient input from fertilisers.

• The understanding of the relationship between mosquito species, water quality and ecosystem health can assist in controlling mosquito populations and reduce the risk of mosquito borne viruses affecting human health. Education of Town of Claremont health and environmental officers in ecological control of mosquito through SERCUL’s Mozzie Wise education program based on Dr Rose Weerasinghe’s mosquito research is highly recommended and mosquito BMP should be incorporated into reconstructed hydraulic designs. SERCUL also offers Mozzie Wise incursions/excursions for school students to encourage awareness of mosquito breeding prevention principles at home.


• Educate the public in the Lake Claremont catchment regarding household best practices to prevent nutrient pollution of stormwater. This could include:

a. Conducting SERCUL’s Phosphorus Awareness Program incursions/excursions at local schools. This program educates both primary and high school students about how actions undertaken in the home and garden can impact the environment.

b. Sending information brochures (e.g. SERCUL’s “Fertilise Wise” brochures) to rate-payers and placing signage around water bodies and streams in public access areas providing advice regarding fertiliser practices. It is important to show images of water bodies with excessive nutrient input or eutrophic conditions such as algal blooms, excessive nuisance aquatic plant growth (duckweed coving lake surfaces), fish deaths etc. This will reinforce the impacts on our aquatic ecosystems and help the community identify when these problems are occurring.

• Continue to coordinate road sweeping in the Lake’s catchment with maintenance activities (i.e. road or construction works) and specific events (i.e. storm events or public major events) as recommended in the Department of Environment Stormwater Management Manual for Western Australia (2004). Best results can be achieved by focusing on ‘hot spots’ rather than routinely sweeping all streets;

• Continue to ensure that any accumulated pollutants (e.g. sediment and gross pollutants) are regularly removed from nodes in the stormwater network, such as the gross pollutant trap connected to the Stirling Rd central drain and the newly installed sediment trap in the Henshaw drain. Removal can be timed to occur after “first flush” and heavy rainfall events.


12. References

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Trigger Values Appendix A

Table A-1: Trigger values used for comparison of Lake Claremont water quality results

Guideline pH

(pH units) DO

(% sat)

EC (mS/c

m)

Turbidity

(NTU) TN

(mg/L) NOx-N (mg/L)

NH3-N/NH4+

-N (mg/L)

TP (mg/L)

FRP (mg/L)

Trigger values for wetlands (ANZECC and ARMCANZ 2000)

Acceptable range: 7-8.5

Acceptable range: 90-120

0.3-1.5 10-100 1.5 0.1 0.04 0.06 0.03

Trigger values for 95% level of protection (ANZECC and ARMCANZ 2000)

- - - - - - 0.91

- -

Recreational use guideline values (NHMRC 2008)

6.5-8.5 >80% - - - - 5 (aesthetic

value) - -

ALS Limit of Reporting - - - 0.1 0.1 0.01 0.01 0.01 0.01

1Not adjusted for pH

0

Table A-2: Trigger values for metals (mg/L) in freshwater

Guideline Al

As Cd Cr Co Cu Fe Pb Hg Mn Ni Se Zn Hardness

Recreational use guideline values (NHMRC 2008, NHMRC 2016)

- 0.07

(health) 0.02

(health) 0.5

5

(health) -

10 (aesthetic) 20 (health)

3 (aesthetic)

0.1 (health)

0.01 (health)

1 (aesthetic)

5 (health)

0.2 (health)

0.1 (health)

30 (aesthetic)

-

ANZECC Water quality trigger value – Freshwater 95% (2000)

0.0551

0.024 0.00022

0.00332,3,5

0.00283

0.00142

0.34

0.00342

0.0006 1.9 0.0112

0.011 0.0082

-

ALS Limit of Reporting

0.01 0.001 0.0001 0.001 0.001 0.001 0.05 0.001 0.0001 0.001 0.001 0.01 0.005 1 0

1Applicable only when pH>6.5, when pH<6.5 a low reliability interim value of 0.0008 mg/L is applicable

2Trigger values not adjusted for water hardness.

3Low reliability interim value

4Interim guideline

5 Value for Cr VI used


Potential effects of stressors on aquatic environments Appendix B

In the context of water quality, stressors can be described as chemical compounds or indicators that are naturally occurring in waterways, for which values outside of certain ranges can have multiple negative effects. Stressors often reach undesirable levels in waterways as a result of human intervention. Stressors analysed in this monitoring program included physicochemical parameters (pH, dissolved oxygen, electrical conductivity, total suspended solids and temperature), nutrients (nitrogen and phosphorus in their various forms) and hardness. Table B-1 describes the undesirable effects that these stressors can have on surface water bodies. Information informing this table has been largely obtained from the facts sheets on physical and chemical stressors present in Section 8.2.1 of ANZECC and ARMCANZ (2000) unless otherwise stated.

Table B-1: Effects of stressors on aquatic environments

Parameter Factors/sources impacting stressor levels Ecosystem impacts

pH (acidity and

alkalinity)

• Natural

• pH is determined by the balance of acidity and alkalinity present in water – water can contain a lot of acidity but if this is buffered by alkalinity a neutral pH will result

• Rainfall - (CO2) in atmosphere decreases pH of precipitation

• Algal or plant growth (photosynthesis increases pH, respiration decreases pH)

o pH often higher during the day (more photosynthesis) and lower at night (more respiration) in poorly buffered waters

• Underlying soil type (e.g. Bassendean sands – acidic (DER 2015b), limestone – alkaline)

• Influence of groundwater

• Presence of acidic tannins from vegetation – decreases pH

• Anthropogenic

• Oxidation of acid sulfate soils due to manual disturbance or anthropogenic change in water levels –acidity can enter water in contact with soil (increases acidity)

• Acidic (increases acidity) or alkaline (increases alkalinity) discharges from industry

• Acidic mining runoff or exposure of acidic rocks from mining – increases acidity

• Agricultural practices can acidify soils – increases acidity

• High or low pH can result in increased toxicity of certain metals

• High – e.g. ammonia

• Low –e.g. cyanide, aluminium

• High or low levels can have direct adverse effects on biota – different species tolerate different ranges

• → changes can result in altered compositions and/or reduced biodiversity of plants and animals

• Mosquitoes can tolerate low pH waters and can therefore become a nuisance in acidic wetlands where other macroinvertebrate predators may not survive (Calver et al 2009)


Table B-1 (continued): Effects of stressors on aquatic environments


Dissolved Oxygen

(DO)

• Natural

• Depth of waterbody (deeper waters more likely to have low oxygen levels)

• Depth of measurement - surface waters often higher, bottom often lower o Stratification (e.g. different layers of salinity) can enhance this effect

• Algal or plant growth (photosynthesis increases pH, respiration decreases pH) o DO often higher during the day (more photosynthesis) and lower at night (more

respiration)

• Decomposition of organic material – process consumes DO

• Temperature

• Salinity

• Rain and wind can introduce oxygen into water


• Anthropogenic

• Microbial breakdown of excess organic material (e.g. from grass clippings, sewage, industrial wastes or as a result of eutrophication) – decreases DO

• Oxidation of hydrocarbons, reduction of metals, microbial (bacterial and archaea) activity and nitrification – decreases DO.

• Excess algal growth can also increase DO (high levels of photosynthesis)

• Aeration through fountains and subsurface aeration - increases DO

• Low DO - directly toxic to biota

• Especially fish and molluscs

• High DO saturations can also be harmful

• Oxygen bubbles can block blood vessels in fish resulting in death (Svobodová et al 1993)

• Changes in DO result in altered redox conditions which can facilitate certain chemical reactions

• Low DO results in phosphorus release from sediments – can lead to eutrophication (Correll 1998)

• Low DO results in formation of reduced compounds, such as hydrogen sulphide, resulting in toxic effects on aquatic animals (Camargo & Alonso 2006)

• Low DO can increase toxicity of certain metals (e.g. copper) and ammonia

• Low DO levels also halt nitrogen loss from water by preventing nitrification of ammonia (Geoscience Australia 2015a)

Electrical Conductivity

(EC)

• Natural

• Communication with the ocean will increase EC

• Proximity to ocean – fine sea spray or atmospheric salt can eventuate in waterbodies

• Depth of measurement - salt water heavier than freshwater so will sink o Stratification (e.g. different layers of salinity) can enhance this effect

• Underlying geology –clays will contribute to conductivity, granite bedrock will not (USEPA 2012)


• Seasonal water level changes –increased rainfall and runoff can dilute water (decreasing EC) and evaporation concentrates ions (increasing EC)

• Anthropogenic

• Discharges from industry o E.g. sewage contamination can increase EC, oil spills can decrease EC

(USEPA 2012)

• Dryland and irrigation salinity resulting from agriculture

• High or low levels can be directly toxic to biota – different species tolerate different ranges (Hart et al 1991)

• → changes can result in altered compositions and/or reduced biodiversity of plants and animals

• Increases in EC can result in loss of leeches, flatworms and macroinvertebrates without impermeable skeletons (pulmonate gastropods) (Dunlop et al 2005) in freshwater systems




Turbidity

• Natural

• Sources include soil particles and organic material (e.g. algae, microorganisms, decaying plant and animal matter)

• Windy conditions can result in increased resuspension of bottom sediments and introduction of soil particles

• Heavy rainfall will result in increased erosion of surrounding soils and increased introduction of particles through runoff

• Soil type – claypan wetlands often have high turbidity (DEC 2012)

• Anthropogenic

• Discharges from industry from runoff and dust

• Products of vehicle wear from road run-off

• Construction and demolition operations

• Clearing of vegetation (DEC 2012)

• Introduced animals (DEC 2012)

• Deposition of suspended solids can block pipes, change flow conditions in open channels (IEA 2006), alter streambed properties and aquatic habitat for fish, smother benthic organisms, and reduce the food supply and refuge for bottom feeding organisms, macrophytes, and benthic organisms (Chetia 2014)

• High concentrations can reduce water clarity and light available to support photosynthesis → loss of submerged macrophytes (i.e. seagrasses)

• High concentrations can impair the function of fish gills

• Suspended solids can alter predator-prey relationships (e.g. could make it difficult for fish to see prey)

• Suspended solids can also provide surface area for the sorption and transport of nutrients and other pollutants (e.g. metals and bacteria)

• → often used as an "indicator" of nutrients or other pollutants

Temperature

• Natural

• Air temperature and sun exposure o Therefore time of day

• Turbidity – can increase temperature through scattering of solar radiation (Paaijmans et al 2008)

• Waterbody depth – shallow waterbodies have greater temperature variability (Department of Environment and Conservation 2012)

• Depth of measurement – surface water more variable than deep water (Department of Environment and Conservation 2012)

• Vegetation - temperatures in unvegetated water bodies will generally be higher due to lack of shade (Department of Environment and Conservation 2012)

• Anthropogenic

• Industrial discharges – can increase or decrease temperature o e.g. cooling water from power plants can increase

temperature

• Stormwater runoff from hot surfaces (e.g. roads and carparks) could increase the temperature of receiving water bodies

• Reservoirs could discharge cooler water to waterbodies.

• Increased metabolic rate of organisms with increasing temperature → increased oxygen demand (compounded by decreased oxygen solubility)

o Includes nuisance plant and algal growth

• High temperatures also reduce oxygen solubility (Wetzel 2001)

• Influences sediment redox reactions

• E.g. increased temperatures result in increased sediment phosphorus release (Lehtoranta 1995).

• Increased temperatures increase metabolic rate of bacteria and therefore mineralisation of organic matter → release of bioavailable phosphorus and nitrogen species into the water (Lehtoranta 1995)

• High temperatures increase solubility of salts

• Many chemicals exhibit between a two and four fold increase or decrease in toxicity for each 10°C rise in temperature

• Different species tolerant to different ranges → changes can result in differing biotic communities

• Fish and macro-invertebrates are ectotherms as their body temperature is controlled by the temperature of the surrounding environment (Marsh et al 2005) – as such they particularly sensitive to temperature changes

• Temperature can be a cue for spawning or migration (Queensland Government Department of Environment and Heritage Protection 2013)




Nitrogen

• Natural

• Soil type – e.g. highly mineral soils store less nitrogen → less in water • Fringing and emergent vegetation type and volume

• Seasonal conditions

• Hydrology – loss of nitrogen as N2 gas may occur more readily in certain wetland hydrology

• Sources include plant and animal decomposition, faecal material, lightning and volcanic activity

• Anthropogenic

• Fertilisers

• Sewerage

• Feed lots

• Pet droppings

• Combustion of fossil fuels

• Plant debris (e.g. from glass clippings)

• Industrial and household cleaning products (e.g. runoff from car washing)

• Ammonia/ammonium specific: o Industrial processes including the preparation of synthetic fibres (e.g.

nylons), plastics and explosives, resins, human and veterinary medicines, fuel cells, rocket fuel, dyes, metal treating operations, refrigeration, and petroleum (Commonwealth of Australia 2016f).

o Ammonia/ammonium proportion varies with pH & temperature (ammonium predominant at pH 5 to 8) → levels vary throughout day

• Some nitrogen is required for life - wetlands with very low concentrations of nitrogen and phosphorus will support little life (oligotrophic)

• High concentrations (particularly of bioavailable forms) in conjunction with high phosphorus result in nuisance growth of aquatic plants/algae/cyanobacteria (blue green algae) known as eutrophication, which can have flow-on negative effects:

• Toxic effects of cyanobacterial toxins (particularly due to cyanobacteria in fresh and brackish waters) to humans, birds and aquatic biota

• Surface growth acting as physical barrier to O2 + decomposition of excessive growth → decreased DO → harm to fish, macroinvertebrates and desirable macrophyte species

• Decreased light available to desirable macrophyte species

• Reduction in recreational amenity (phytoplankton blooms and macrophytes in wetlands and lakes) from cyanobacterial toxins and odours produced from decomposing material

• Physical blocking of waterways

• Reduction in biodiversity or change in species composition o E.g. mosquitoes (tolerant to poor water quality) can

become predominant in eutrophic waterways

• High nitrogen levels can lead to acidification of waterbodies

• High levels of ammonia are directly toxic to fish & aquatic organisms

Phosphorus

• Natural

• Decomposition of organic matter

• Weathering of rocks

• Anthropogenic

• Motor vehicle exhaust, fuels, lubricants, fertilisers, detergents, car wash products, eroded soils, and industrial wastes (IEA 2006)

• Runoff from impervious surfaces such as roads, parking lots and rooftops (especially in commercial, industrial and high-density residential areas) can potentially contribute a large portion of phosphorus to the water bodies as this water is not filtered (Department of Environment 2004b)

• Some phosphorus is required for life - wetlands with very low concentrations of phosphorus and nitrogen will support little life (oligotrophic)

• Excessive concentrations (particularly bioavailable forms (i.e. SRP)) in conjunction with high nitrogen concentrations, can result in eutrophication (see ecosystem impacts of nitrogen for more information)


Potential sources, factors affecting toxicity and impacts of metals found in Appendix Curban stormwater

The metals analysed as part of this monitoring program can be derived from a wide variety of sources, some natural and some anthropogenic. Understanding the sources of these metals can provide potential avenues for investigation if high concentrations are detected. Furthermore, if high metal concentrations are encountered, other water quality indicators and local factors may provide an indication of the severity of the impact of these concentrations. The impact of hardness on concentrations is has been quantified for some metals, but also, for example, for metals that adsorb to suspended particles, the presence of these particles may reduce the bioavailability of some (but not all) of these metals to biota, thus effectively reducing their toxicity. As metals are generally more bioavailable in soluble form, factors that increase solubility will increase their toxicity. Different functional groups of biota may also differ in their sensitivity to metals. The main impact of metals to surface waters is generally toxicity to biota, but some metals (such as iron) can have other negative environmental impacts. Table C-1 describes the potential sources, factors affecting impacts and toxic and other impacts of metals. Information regarding sources of metals is taken from The National Pollutant Inventory Australian Government Department of Environment (DoE) (2016) and information regarding factors affecting toxicity and impacts to biota are derived from ANZECC and ARMCANZ (2000) unless otherwise stated.

Table C-1: Potential sources, factors affecting impacts and impacts of metals typically found in urban stormwater

METAL SOURCES/USES FACTORS AFFECTING IMPACTS IMPACTS

Aluminium (Al)

• Natural leaching from soil and rock

• Increased in soluble groundwater concentrations under acidic conditions, therefore strongly linked to the presence of Acid Sulfate Soils (ASS) (DER 2015)

• Anthropogenic sources include industrial discharges and corrosion of products containing aluminium

• used in construction, automotive, aircraft and electrics industries, in the production of metal alloys, cooking utensils and food packaging (WHO 2010)

• Toxicity to fish and invertebrates increased at pH<5.5 and >9, with a maximum toxicity around pH 5.0-5.2

• Toxicity reduced by complexing with humic (organic) substances

• Toxicity reduced at high water hardness

• Toxicity possibly increased with increased temperature

• Toxic to biota at high concentrations

• Among aquatic plants, single celled plants most susceptible

• Fish more susceptible than aquatic macroinvertebrates

• Can affect the function of fish gills (Exley et al 1991)


Table C-1 (continued): Potential sources, factors affecting impacts and impacts of metals typically found in urban stormwater


Arsenic (As)

• Naturally present in the earth’s crust

• Can enter waterways through wind-blown dust and water run-off

• Naturally released into the environment through weathering of rocks and volcanic activity

• High arsenic concentrations in groundwater (and communicating surface waters) linked to the presence of Acid Sulfate Soils (ASS) (DER 2015)

• Mining and metal manufacturing main anthropogenic source of arsenic in Australia

• Other uses of arsenic in industry include manufacturing of food, paper products, glass products, petroleum and coal products and chemicals

• Also released from combustion of fuels and other incineration activities

• Several valencies exist in water – most common are As (III) and As (V)

• both bond with carbon to form numerous organo-arsenic compounds, some of which are very toxic (e.g. methylarsine)

• Valency state main factor affecting toxicity – As (III) most toxic form

• Toxicity of As (V) increases with increasing temperature

• As (III) removed by sulfides, As (V) by clays

• Toxic to biota

• Can bio-accumulate in some animals

• Phytoplankton is among the most sensitive organisms to both forms of arsenic

• Higher trophic levels are less sensitive to arsenic because they generally accumulate the element from food rather than the water column.

• Adult freshwater fish are generally less sensitive to arsenic

Cadmium (Cd)

• Can be found naturally in the earth's crust in various ores with other metals and compounds

• Enters waterways through settling of particles, rain, and polluted waters

• Short life in expectancy in atmosphere - not expected to travel far from source

• Produced as by-product of zinc, lead and copper extraction, and can be released into the environment from such extraction

• Fertilisers produced from phosphate ores are a source of cadmium pollution (WHO 2011)

• In natural waters is found mainly ins sediments and suspended particles (i.e. not dissolved) (WHO 2011)

• Cadmium is used in many products as an anticorrosive or in pigments in plastic, and is found in batteries, electronic components and nuclear reactors (WHO 2011)

• Other sources of cadmium include combustion, wear of tyres and brake pads, possible combustion of lubricating oils, industrial emissions, corrosion of galvanised metals and landfill leachate (IEA 2006)

• Toxicity decreases as water hardness increases

• Toxicity is lower in lower pH, and at pH>8

• Dissolved organic material reduces toxicity

• Strongly adsorbed by suspended material – as such in natural waters, cadmium is found mainly in bottom sediments and suspended particles (WHO 2011)

• Complexes with chloride and therefore is less toxic in high salinity

• Non-essential to life

• Is highly toxic and accumulates in the liver and kidneys of animals and is a known carcinogen (WHO 2011)

• In aquatic ecosystems can bio-accumulate in mussels, oysters, shrimps, lobsters and fish

• Susceptibility to cadmium can vary greatly between aquatic organisms

• Salt-water organisms are known to be more resistant to cadmium poisoning than freshwater organisms




Chromium (Cr)

• Exists naturally in low concentrations (rocks, soil, plants, animals, volcanic dust, gasses)

• Enters waterways through settling of atmospheric particles and rainfall and contaminated water and soil

• Chromium in stormwater is mostly associated with suspended solids (IEA 2006)

• Two forms: The trivalent form (Cr3+

) is mainly discharged from the metal industry where it is used for chrome plating, and the hexavalent form (Cr

6+) is

mainly discharged from tanning & painting (IEA 2006)

• Predominant form of chromium in the environment is Cr3+

• It is also used in industry to produce the following: electrical products, engine parts, fungicides, wood treatment products, ceramics, clay, paper, glass, porcelain, pharmaceuticals/medicines/medical treatment, steam & air conditioning supplies and cement products Other sources include combustion of fossil fuels, incineration of waste and sewerage sludge

• Toxicity of both forms decreases with increasing water hardness and/or alkalinity

• Cr6+

toxicity increases in freshwater at lower pH

• Cr6+

not affected by presence of suspended material, whereas Cr

3+

is readily removed from the water column with both dissolved organic matter and suspended material

• Toxicity decreases with increasing salinity and sulfate

• More toxic at high temperatures

• Chromium VI is toxic to aquatic organisms, and a carcinogen for animals & humans

• Cr3+

is far less toxic than Cr

6+

• Chromium VI may bio-accumulate to some degree

• Freshwater algae & invertebrates are more sensitive to Cr

6+ than fish,

with crustaceans particularly sensitive

Cobalt (Co)

• Found naturally in soil, dust, seawater, volcanic emissions, smoke from bush fires

• Short life in expectancy in atmosphere - not expected to travel far from source

• Automotive repair shops significant emitters of cobalt in air

• Other sources include mining/refining of nickel, copper, silver, lead and iron, and the manufacturing, use or disposal of paints, varnishes, ceramic, ink and enamels

• Adsorbs to suspended particles and sediment

• Solubility (and therefore bioavailability/toxicity) increased by complexing with organic matter

• An essential element for life but toxic at certain concentrations

• May bioaccumulate in some organisms

Copper (Cu)

• Copper compounds naturally occur in rocks, soil, water, plants, animals and humans

• Enters water from settling of atmospheric particles or dissolved in waters

• Natural sources include decaying vegetation, forest fires and sea spray

• Mining and metal manufacturing largest sources of copper emissions in Australia

• Other industrial sources include electricity supply and manufacturing of chemicals, cement, lime, plaster and concrete products, transport equipment, petroleum, coal, beverages, paper products, glass products, motor vehicles and parts, wood products, ceramic products, food and beverage products, and textiles (DoE 2016)

• Found to be related to the flow of vehicles and road network characteristics (Beasley & Kneale 2002).

• Also possible release from solid and liquid fuel combustion, lawn mowing, leaching from antifouling paint on ships and boats

• Toxicity increases when hardness, alkalinity & dissolved oxygen decrease

• Strongly attaches to organic matter and suspended material

• Levels of dissolved organic matter in freshwaters usually remove copper toxicity (except in very soft waters)

• Its toxicity in algae, invertebrates & fish generally increases as salinity decreases

• Copper and lead toxicity appear to interact in synergism

• It is a micro-nutrient and essential to life at low concentrations, toxic at higher concentrations to freshwater fish, invertebrates and plants

• Some species of algae particularly sensitive

• Negatively affects fish and macro-invertebrates in various body systems across multiple life stages

• Can bio-accumulate in aquatic organisms



METAL SOURCES/USES FACTORS AFFECTING

IMPACTS IMPACTS

Iron (Fe)

• Fourth most abundant metal in earth’s crust

• Naturally present in water in varying quantities depending upon local geology and other chemical factors

• Insoluble ferric state (Fe3+

) usually more prevalent in surface waters (ANZECC and ARMCANZ 2000)

• Soluble ferrous state (Fe2+

) present in reducing (anaerobic) waters and usually originates from groundwater (ANZECC and ARMCANZ 2000)

• Industrial production of the following iron containing products could produce anthropogenic iron pollution: pigments of paints and plastics, food colours, construction materials (WHO 2003)

• Many pipes are constructed of cast iron, steel or galvanised iron which may become sources of iron (WHO 2003)

• Solubility increases in acidic water

• Solubility higher in anaerobic waters

• Essential for both plants and animals

• Has been shown to be toxic to some macroinvertebrate species

• In aerobic waters, ferric iron can form colloidal suspensions which can either form suspended flocs or settle and harden

• may cause problems with turbidity, decreased light penetration and smothering of benthic organisms

Lead (Pb)

• Rare in nature, anthropogenic sources outweigh natural sources (ANZECC and ARMCANZ 2000)

• Lead reaches aquatic environment through rainfall, lead dust , street runoff and industrial discharges (ANZECC and ARMCANZ 2000)

• Also fires and fuel combustion

• Lead used to be used in water pipes, stained glass windows, paint and fuel and as such these products may be partially responsible for the legacy of lead in waterways

• Mining and metal manufacturing greatest industrial emitters

• Also used in production of cement, plaster, concrete, iron, steel, petroleum, coal products, paper products, glass products, metal products, motor vehicles and parts, wood products, yarn and fabric

• Toxicity increases when water hardness decreases

• Low solubility in water reduces toxicity

• Strongly adsorbed by suspended clay, humic substances and other suspended material

• Strongly complexed by dissolved organic material

• Toxicity possibly increased at low pH

• Non-essential, highly poisonous element

• Shown to affects chlorophyll synthesis in plants (e.g. Mesmar and Jaber 1991)

• Can potentially bioaccumulate but not generally present in great enough concentrations that bioaccumulation has much effect

Manganese (Mn)

• Compounds widely distributed in earth’s crust, mainly as MnO2 (ANZECC and ARMCANZ 2000)

• Commonly associated with dissolved ferrous iron and a naturally occurring constituent of groundwater (DoE 2004b)

• Can enter waterways from settling of atmospheric particles or dissolved compounds in waters

• Common constituent of mining and smelting discharges (ANZECC and ARMCANZ 2000)

• Used in steel alloys, dry cell batteries, paints, inks, glass, ceramics, fireworks and fertilisers (ANZECC and ARMCANZ 2000)

• Generally present in suspended form, but soluble at low pH and low DO

• Toxicity in brown trout shown to decrease with increasing hardness

• Vital micro-nutrient for plants and animals

• Low toxicity compared to other metals

• Not much data available regarding toxicity, chronic data only available for three taxonomic groups




Mercury

(Hg)

• Naturally occurring element found in rocks and ores

• Can enter waterways from atmospheric particles settling or deposited by rain, or through emissions in water and soil

• Natural sources of mercury in waterways include emissions from volcanoes and evaporation of water from soil

• Largest source of mercury emissions in Australia from manufacturing, mining and alumina production of non-ferrous metals

• Also can be released from burning of fossil fuels, precious metal mining, cement manufacturing, chemical manufacturing and sewerage

• Landfills and disposal of batteries, thermometers and other mercury containing products can emit mercury to land, which can eventually end up in water

• Present as inorganic Hg (II) and organomercurial compounds (such as methyl mercury) - microorganisms can convert Hg (II) to methyl mercury

• Increased toxicity with decreased hardness

• Strongly adsorbed by particles, often associated with sediments

• Strong affinity for chloride – toxicity of inorganic mercury reduced in saline waters

• Inorganic mercury relatively low toxicity and low ability to bioaccumulate

• Methyl mercury particularly toxic - can be absorbed quickly

• Can bioaccumulate in fish and their food chains

• In mercury polluted areas, larger and older fish tend to have higher levels

Nickel (Ni)

• Exists naturally in soils and rocks often with arsenic, antimony and sulfur

• Found at background concentrations in natural waters (ANZECC and ARMCANZ 2000)


• Natural sources include weathering of rocks (ANZECC and ARMCANZ 2000) and volcanoes

• Anthropogenic sources of atmospheric nickel include combustion of fossil fuels, mining and refining operations, steel production, nickel alloy production, electroplating, municipal waste incineration and nickel refineries

• Can enter water in wastewater from municipal sewage treatment plants, stormwater runoff and from groundwater near landfill sites

• Toxicity increases with decreased hardness

• Toxicity usually increases with decreased pH

• Complexed by dissolved organic material

• Less bioavailable when adsorbed to suspended material

• Toxicity increases with decreasing salinity

• Essential to life

• Moderately toxic to freshwater organisms

• Reduces growth of freshwater algae at relatively low concentrations

• Fish less sensitive to nickel, but it differs between species


Table -1 (continued): Potential sources, factors affecting impacts and impacts of metals typically found in urban stormwater

METAL SOURCES/USES FACTORS AFFECTING TOXICTY

AND IMPACTS IMPACTS

Selenium (Se)

• Occurs naturally in the environment at varying concentrations, usually combined with other compounds (such as sulphide ores of other metals)

• Commonly found in sedimentary rock formations


• Exists in water as oxyions selenate (selenium (VI)) and selenite (selenium (IV))

• Natural sources in water include weathering of rocks

• Released into the air and water from combustion of fossil fuels, smelting and refining of metals, glass and ceramics manufacturing and refuse incinerators

• Can also enter waterways from anti dandruff shampoos and application as fungicides and insecticides

• Toxicity of selenate increases with decreasing sulfate and phosphate concentrations

• Selenite uptake increases at low pH

• Toxicity ameliorated by mercury and copper

• Binding of selenium to particles does not reduce bioavailability

• Toxicity dependent on valency state – Se (IV) more toxic than Se (VI)

• Selenites readily removed form water column, but selenates can bioaccumulate in aquatic ecosystems

• Food chain uptake more significant than water uptake

Zinc (Zn)

• Exists naturally in rocks, soil, air, waters, plants and humans


• Natural sources in water include weathering of rocks

• Anthropogenic sources include mining, steel production, waste incineration, chemical waste dumps & landfills, sewage treatment plants, corrosion of galvanised structures, fertilisers and herbicides

• Urban runoff also potential source from wear of car tyres or fuel combustion

• Toxicity increases with decreasing hardness and alkalinity

• Levels of organic matter present in freshwater generally sufficient to remove zinc toxicity

• pH determines stability of these compounds

• Adsorbed by suspended material

• Toxicity generally decreases with decreasing pH when pH <8

• Uptake and toxicity decrease with increasing salinity

• Essential for life

• Labile Zn+2

most toxic form

• Bioaccumulates in freshwater animal tissues but not a major problem

caitlinconway

Typewritten text

C


Field Observation Forms, ALS Chain of Appendix DCustody Forms and ALS Certificates of Analysis

0 0.00 True

Environmental

CERTIFICATE OF ANALYSISWork Order : Page : 1 of 6EP1809987

:Amendment 1:: LaboratoryClient South East Regional Centre For Urban Landcare Environmental Division Perth

: :ContactContact Caitlin Conway Customer Services EP

:: AddressAddress 1 Horley Road

Beckenham 6107

26 Rigali Way Wangara WA Australia 6065

:Telephone 9458 5664 :Telephone +61-8-9406 1301

:Project Lake Claremont 2018-19 Date Samples Received : 29-Aug-2018 17:10

:Order number Date Analysis Commenced : 29-Aug-2018

:C-O-C number ---- Issue Date : 11-Sep-2018 18:52

Sampler : Caitlin Conway

Site : ----

Quote number : EP/761/18

6:No. of samples received

6:No. of samples analysed

This report supersedes any previous report(s) with this reference. Results apply to the sample(s) as submitted. This document shall not be reproduced, except in full.

This Certificate of Analysis contains the following information:

l General Comments

l Analytical Results

Additional information pertinent to this report will be found in the following separate attachments: Quality Control Report, QA/QC Compliance Assessment to assist with

Quality Review and Sample Receipt Notification.

SignatoriesThis document has been electronically signed by the authorized signatories below. Electronic signing is carried out in compliance with procedures specified in 21 CFR Part 11.

Signatories Accreditation CategoryPosition

Canhuang Ke Inorganics Supervisor Perth Inorganics, Wangara, WA

R I G H T S O L U T I O N S | R I G H T P A R T N E R

2 of 6:Page

Work Order :

:Client

EP1809987 Amendment 1

Lake Claremont 2018-19:Project

South East Regional Centre For Urban Landcare

General Comments

The analytical procedures used by the Environmental Division have been developed from established internationally recognized procedures such as those published by the USEPA, APHA, AS and NEPM. In house

developed procedures are employed in the absence of documented standards or by client request.

Where moisture determination has been performed, results are reported on a dry weight basis.

Where a reported less than (<) result is higher than the LOR, this may be due to primary sample extract/digestate dilution and/or insufficient sample for analysis.

Where the LOR of a reported result differs from standard LOR, this may be due to high moisture content, insufficient sample (reduced weight employed) or matrix interference.

When sampling time information is not provided by the client, sampling dates are shown without a time component. In these instances, the time component has been assumed by the laboratory for processing

purposes.

Where a result is required to meet compliance limits the associated uncertainty must be considered. Refer to the ALS Contact for details.

CAS Number = CAS registry number from database maintained by Chemical Abstracts Services. The Chemical Abstracts Service is a division of the American Chemical Society.

LOR = Limit of reporting

^ = This result is computed from individual analyte detections at or above the level of reporting

ø = ALS is not NATA accredited for these tests.

~ = Indicates an estimated value.

Key :

It is recognised that total metals (EG020T) is less than dissolved metals (EG020F) for As, Ni, Zn for samples EP1809987-004, 005. However, the difference is within experimental variation of the methods.l

Amendment (07/09/2018): This report has been amended and re-released to allow the reporting of total hardness for sample #1 to 6.l

Sodium Adsorption Ratio (where reported): Where results for Na, Ca or Mg are <LOR, a concentration at half the reported LOR is incorporated into the SAR calculation. This represents a conservative approach

for Na relative to the assumption that <LOR = zero concentration and a conservative approach for Ca & Mg relative to the assumption that <LOR is equivalent to the LOR concentration.

l

3 of 6:Page

Work Order :

:Client




Analytical Results

A7.1A5.1A4.2A4.1A2.1Client sample IDSub-Matrix: WATER

(Matrix: WATER)

28-Aug-2018 13:0628-Aug-2018 11:3228-Aug-2018 12:2428-Aug-2018 11:5629-Aug-2018 12:51Client sampling date / time

EP1809987-005EP1809987-004EP1809987-003EP1809987-002EP1809987-001UnitLORCAS NumberCompound

Result Result Result Result Result

EA045: Turbidity

18.9 21.5 15.9 3.6 14.2NTU0.1----Turbidity

EA065: Total Hardness as CaCO3

22 19 28 681 513mg/L1----Total Hardness as CaCO3

EG020F: Dissolved Metals by ICP-MS

0.11Aluminium 0.22 0.21 <0.01 0.02mg/L0.017429-90-5

<0.001Arsenic <0.001 <0.001 0.006 0.130mg/L0.0017440-38-2

<0.0001Cadmium <0.0001 <0.0001 <0.0001 <0.0001mg/L0.00017440-43-9

<0.001Chromium 0.001 0.002 <0.001 <0.001mg/L0.0017440-47-3

<0.001Cobalt <0.001 <0.001 <0.001 <0.001mg/L0.0017440-48-4

0.007Copper 0.008 0.008 <0.001 <0.001mg/L0.0017440-50-8

<0.001Lead 0.001 0.002 <0.001 <0.001mg/L0.0017439-92-1

0.002Manganese 0.003 0.002 0.040 0.011mg/L0.0017439-96-5

<0.001Nickel <0.001 <0.001 0.001 0.001mg/L0.0017440-02-0

<0.01Selenium <0.01 <0.01 <0.01 <0.01mg/L0.017782-49-2

0.032Zinc 0.037 0.035 0.005 0.007mg/L0.0057440-66-6

0.06Iron 0.12 0.12 0.39 0.14mg/L0.057439-89-6

EG020T: Total Metals by ICP-MS

0.84Aluminium 0.88 0.96 <0.01 0.10mg/L0.017429-90-5

<0.001Arsenic <0.001 0.001 0.008 0.128mg/L0.0017440-38-2

<0.0001Cadmium <0.0001 <0.0001 <0.0001 <0.0001mg/L0.00017440-43-9

0.003Chromium 0.003 0.003 <0.001 <0.001mg/L0.0017440-47-3

<0.001Cobalt <0.001 <0.001 <0.001 <0.001mg/L0.0017440-48-4

0.018Copper 0.016 0.014 <0.001 <0.001mg/L0.0017440-50-8

0.006Lead 0.005 0.009 <0.001 0.002mg/L0.0017439-92-1

0.012Manganese 0.011 0.011 0.047 0.017mg/L0.0017439-96-5

0.001Nickel 0.002 0.001 0.001 <0.001mg/L0.0017440-02-0

<0.01Selenium <0.01 <0.01 <0.01 <0.01mg/L0.017782-49-2

0.092Zinc 0.067 0.069 <0.005 <0.005mg/L0.0057440-66-6

0.77Iron 0.82 0.83 1.11 0.36mg/L0.057439-89-6

EG035F: Dissolved Mercury by FIMS

<0.0001Mercury <0.0001 <0.0001 <0.0001 <0.0001mg/L0.00017439-97-6

EG035T: Total Recoverable Mercury by FIMS

<0.0001Mercury <0.0001 <0.0001 <0.0001 <0.0001mg/L0.00017439-97-6

EK055G: Ammonia as N by Discrete Analyser

4 of 6:Page

Work Order :

:Client




Analytical Results

A7.1A5.1A4.2A4.1A2.1Client sample IDSub-Matrix: WATER

(Matrix: WATER)

28-Aug-2018 13:0628-Aug-2018 11:3228-Aug-2018 12:2428-Aug-2018 11:5629-Aug-2018 12:51Client sampling date / time

EP1809987-005EP1809987-004EP1809987-003EP1809987-002EP1809987-001UnitLORCAS NumberCompound

Result Result Result Result Result

EK055G: Ammonia as N by Discrete Analyser - Continued

0.02Ammonia as N <0.01 0.01 2.77 1.88mg/L0.017664-41-7

EK055G-NH4: Ammonium as N by DA

0.02Ammonium as N <0.01 <0.01 2.75 1.82mg/L0.0114798-03-9_N

EK057G: Nitrite as N by Discrete Analyser

0.01Nitrite as N <0.01 <0.01 0.18 0.02mg/L0.0114797-65-0

EK058G: Nitrate as N by Discrete Analyser

0.05Nitrate as N 0.03 <0.01 0.32 0.01mg/L0.0114797-55-8

EK059G: Nitrite plus Nitrate as N (NOx) by Discrete Analyser

0.06 0.03 <0.01 0.50 0.03mg/L0.01----Nitrite + Nitrate as N

EK061G: Total Kjeldahl Nitrogen By Discrete Analyser

0.5 0.5 1.0 3.7 3.5mg/L0.1----Total Kjeldahl Nitrogen as N

EK062G: Total Nitrogen as N (TKN + NOx) by Discrete Analyser

0.6^ 0.5 1.0 4.2 3.5mg/L0.1----Total Nitrogen as N

EK067G: Total Phosphorus as P by Discrete Analyser

0.07 0.10 0.15 0.04 0.17mg/L0.01----Total Phosphorus as P

EK071G: Reactive Phosphorus as P by discrete analyser

0.03Reactive Phosphorus as P 0.04 0.02 0.01 0.16mg/L0.0114265-44-2

5 of 6:Page

Work Order :

:Client




Analytical Results

----------------RepClient sample IDSub-Matrix: WATER

(Matrix: WATER)

----------------29-Aug-2018 13:00Client sampling date / time

--------------------------------EP1809987-006UnitLORCAS NumberCompound

Result ---- ---- ---- ----

EA045: Turbidity

20.4 ---- ---- ---- ----NTU0.1----Turbidity


22 ---- ---- ---- ----mg/L1----Total Hardness as CaCO3


0.12Aluminium ---- ---- ---- ----mg/L0.017429-90-5

<0.001Arsenic ---- ---- ---- ----mg/L0.0017440-38-2

<0.0001Cadmium ---- ---- ---- ----mg/L0.00017440-43-9

<0.001Chromium ---- ---- ---- ----mg/L0.0017440-47-3

<0.001Cobalt ---- ---- ---- ----mg/L0.0017440-48-4

0.006Copper ---- ---- ---- ----mg/L0.0017440-50-8

<0.001Lead ---- ---- ---- ----mg/L0.0017439-92-1

0.002Manganese ---- ---- ---- ----mg/L0.0017439-96-5

<0.001Nickel ---- ---- ---- ----mg/L0.0017440-02-0

<0.01Selenium ---- ---- ---- ----mg/L0.017782-49-2

0.038Zinc ---- ---- ---- ----mg/L0.0057440-66-6

0.06Iron ---- ---- ---- ----mg/L0.057439-89-6


0.91Aluminium ---- ---- ---- ----mg/L0.017429-90-5

0.001Arsenic ---- ---- ---- ----mg/L0.0017440-38-2

<0.0001Cadmium ---- ---- ---- ----mg/L0.00017440-43-9

0.003Chromium ---- ---- ---- ----mg/L0.0017440-47-3

<0.001Cobalt ---- ---- ---- ----mg/L0.0017440-48-4

0.019Copper ---- ---- ---- ----mg/L0.0017440-50-8

0.007Lead ---- ---- ---- ----mg/L0.0017439-92-1

0.013Manganese ---- ---- ---- ----mg/L0.0017439-96-5

0.001Nickel ---- ---- ---- ----mg/L0.0017440-02-0

<0.01Selenium ---- ---- ---- ----mg/L0.017782-49-2

0.100Zinc ---- ---- ---- ----mg/L0.0057440-66-6

0.88Iron ---- ---- ---- ----mg/L0.057439-89-6


<0.0001Mercury ---- ---- ---- ----mg/L0.00017439-97-6


<0.0001Mercury ---- ---- ---- ----mg/L0.00017439-97-6


6 of 6:Page

Work Order :

:Client




Analytical Results

----------------RepClient sample IDSub-Matrix: WATER

(Matrix: WATER)

----------------29-Aug-2018 13:00Client sampling date / time

--------------------------------EP1809987-006UnitLORCAS NumberCompound

Result ---- ---- ---- ----


0.02Ammonia as N ---- ---- ---- ----mg/L0.017664-41-7


0.02Ammonium as N ---- ---- ---- ----mg/L0.0114798-03-9_N


0.01Nitrite as N ---- ---- ---- ----mg/L0.0114797-65-0


0.06Nitrate as N ---- ---- ---- ----mg/L0.0114797-55-8


0.07 ---- ---- ---- ----mg/L0.01----Nitrite + Nitrate as N


0.6 ---- ---- ---- ----mg/L0.1----Total Kjeldahl Nitrogen as N


0.7^ ---- ---- ---- ----mg/L0.1----Total Nitrogen as N


0.13 ---- ---- ---- ----mg/L0.01----Total Phosphorus as P


0.04Reactive Phosphorus as P ---- ---- ---- ----mg/L0.0114265-44-2

0 0.00 True

Environmental

CERTIFICATE OF ANALYSISWork Order : Page : 1 of 4EP1900470

:Amendment 1:: LaboratoryClient South East Regional Centre For Urban Landcare Environmental Division Perth

: :ContactContact Caitlin Conway Customer Services EP

:: AddressAddress 1 Horley Road

Beckenham 6107

26 Rigali Way Wangara WA Australia 6065

:Telephone 9458 5664 :Telephone +61-8-9406 1301

:Project Lake Claremont 2018-19 Date Samples Received : 17-Jan-2019 17:15

:Order number Date Analysis Commenced : 18-Jan-2019

:C-O-C number ---- Issue Date : 12-Feb-2019 22:07

Sampler : Caitlin Conway

Site : ----

Quote number : EP/761/18

4:No. of samples received

4:No. of samples analysed

This report supersedes any previous report(s) with this reference. Results apply to the sample(s) as submitted. This document shall not be reproduced, except in full.

This Certificate of Analysis contains the following information:

l General Comments

l Analytical Results

Additional information pertinent to this report will be found in the following separate attachments: Quality Control Report, QA/QC Compliance Assessment to assist with

Quality Review and Sample Receipt Notification.

SignatoriesThis document has been electronically signed by the authorized signatories below. Electronic signing is carried out in compliance with procedures specified in 21 CFR Part 11.

Signatories Accreditation CategoryPosition

Canhuang Ke Inorganics Supervisor Perth Inorganics, Wangara, WA

Indra Astuty Instrument Chemist Perth Inorganics, Wangara, WA

R I G H T S O L U T I O N S | R I G H T P A R T N E R

2 of 4:Page

Work Order :

:Client




General Comments

The analytical procedures used by the Environmental Division have been developed from established internationally recognized procedures such as those published by the USEPA, APHA, AS and NEPM. In house

developed procedures are employed in the absence of documented standards or by client request.

Where moisture determination has been performed, results are reported on a dry weight basis.

Where a reported less than (<) result is higher than the LOR, this may be due to primary sample extract/digestate dilution and/or insufficient sample for analysis.

Where the LOR of a reported result differs from standard LOR, this may be due to high moisture content, insufficient sample (reduced weight employed) or matrix interference.

When sampling time information is not provided by the client, sampling dates are shown without a time component. In these instances, the time component has been assumed by the laboratory for processing

purposes.

Where a result is required to meet compliance limits the associated uncertainty must be considered. Refer to the ALS Contact for details.

CAS Number = CAS registry number from database maintained by Chemical Abstracts Services. The Chemical Abstracts Service is a division of the American Chemical Society.

LOR = Limit of reporting

^ = This result is computed from individual analyte detections at or above the level of reporting

ø = ALS is not NATA accredited for these tests.

~ = Indicates an estimated value.

Key :

It is recognised that total metals (EG020T) is less than dissolved metals (EG020F) for sample EP1900470-002, 003 for Zn. However, the difference is within experimental variation of the methods.l

Amendment (08/02/2019): This report has been amended and re-released to allow the reporting of hardness (EA065) on all samples. All other analysis results are as per the previous report.l

Sodium Adsorption Ratio (where reported): Where results for Na, Ca or Mg are <LOR, a concentration at half the reported LOR is incorporated into the SAR calculation. This represents a conservative approach

for Na relative to the assumption that <LOR = zero concentration and a conservative approach for Ca & Mg relative to the assumption that <LOR is equivalent to the LOR concentration.

l

3 of 4:Page

Work Order :

:Client




Analytical Results

----A7.1A5.1A4.1A2.1Client sample IDSub-Matrix: WATER

(Matrix: WATER)

----17-Jan-2019 10:4617-Jan-2019 12:2317-Jan-2019 11:4017-Jan-2019 10:09Client sampling date / time

--------EP1900470-004EP1900470-003EP1900470-002EP1900470-001UnitLORCAS NumberCompound

Result Result Result Result ----

EA045: Turbidity

171 149 57.4 179 ----NTU0.1----Turbidity


713 705 528 724 ----mg/L1----Total Hardness as CaCO3


<0.01Aluminium <0.01 <0.01 <0.01 ----mg/L0.017429-90-5

0.352Arsenic 0.346 0.036 0.412 ----mg/L0.0017440-38-2

<0.0001Cadmium <0.0001 <0.0001 <0.0001 ----mg/L0.00017440-43-9

<0.001Chromium <0.001 <0.001 <0.001 ----mg/L0.0017440-47-3

<0.001Cobalt <0.001 <0.001 <0.001 ----mg/L0.0017440-48-4

<0.001Copper <0.001 <0.001 <0.001 ----mg/L0.0017440-50-8

<0.001Lead <0.001 <0.001 <0.001 ----mg/L0.0017439-92-1

0.003Manganese 0.003 0.071 0.002 ----mg/L0.0017439-96-5

0.002Nickel 0.002 0.001 0.002 ----mg/L0.0017440-02-0

<0.01Selenium <0.01 <0.01 <0.01 ----mg/L0.017782-49-2

0.020Zinc 0.015 0.011 0.014 ----mg/L0.0057440-66-6

<0.05Iron <0.05 0.39 <0.05 ----mg/L0.057439-89-6


0.35Aluminium 0.09 0.03 0.14 ----mg/L0.017429-90-5

0.384Arsenic 0.366 0.089 0.450 ----mg/L0.0017440-38-2

<0.0001Cadmium <0.0001 <0.0001 <0.0001 ----mg/L0.00017440-43-9

0.002Chromium <0.001 <0.001 0.001 ----mg/L0.0017440-47-3

<0.001Cobalt <0.001 <0.001 <0.001 ----mg/L0.0017440-48-4

0.004Copper 0.001 <0.001 0.002 ----mg/L0.0017440-50-8

0.013Lead 0.003 <0.001 0.003 ----mg/L0.0017439-92-1

0.023Manganese 0.012 0.085 0.021 ----mg/L0.0017439-96-5

0.003Nickel 0.003 0.002 0.003 ----mg/L0.0017440-02-0

<0.01Selenium <0.01 <0.01 <0.01 ----mg/L0.017782-49-2

0.036Zinc 0.014 0.006 0.014 ----mg/L0.0057440-66-6

0.86Iron 0.33 5.55 0.60 ----mg/L0.057439-89-6


<0.0001Mercury <0.0001 <0.0001 <0.0001 ----mg/L0.00017439-97-6


<0.0001Mercury <0.0001 <0.0001 <0.0001 ----mg/L0.00017439-97-6


4 of 4:Page

Work Order :

:Client




Analytical Results

----A7.1A5.1A4.1A2.1Client sample IDSub-Matrix: WATER

(Matrix: WATER)

----17-Jan-2019 10:4617-Jan-2019 12:2317-Jan-2019 11:4017-Jan-2019 10:09Client sampling date / time

--------EP1900470-004EP1900470-003EP1900470-002EP1900470-001UnitLORCAS NumberCompound

Result Result Result Result ----


0.04Ammonia as N 0.01 6.75 <0.01 ----mg/L0.017664-41-7


0.04Ammonium as N <0.01 6.60 <0.01 ----mg/L0.0114798-03-9_N


<0.01Nitrite as N <0.01 <0.01 <0.01 ----mg/L0.0114797-65-0


<0.01Nitrate as N <0.01 0.01 <0.01 ----mg/L0.0114797-55-8


<0.01 <0.01 0.01 <0.01 ----mg/L0.01----Nitrite + Nitrate as N


15.8 14.6 9.0 19.5 ----mg/L0.1----Total Kjeldahl Nitrogen as N


15.8^ 14.6 9.0 19.5 ----mg/L0.1----Total Nitrogen as N


0.70 0.84 0.26 1.24 ----mg/L0.01----Total Phosphorus as P


0.14Reactive Phosphorus as P 0.13 0.02 0.16 ----mg/L0.0114265-44-2


7. FRIENDS OF LAKE CLAREMONT

ATTACHMENT 1 –

FRIENDS OF LAKE CLAREMONT REPORT (MARCH 2019)

Pages 1

Friends of Lake Claremont Ltd. Quarterly Update: March 2019

Progress - Current Grant Projects

Current grant relates to manual weed control. This will occur later in 2019

FOLC Board has approved expenditure of $9,894 to purchase 5000 native tube stock for the 2019 planting site. These funds have been raised by FOLC independent of any grants.

A schedule has been set for planting commencing in June.

Grant Applications

None current

Recurring Projects on the Ground FOLC Busy Bee – 2nd Sunday of the Month: Clean Up Australia Day Year 10 Community Service Program: Most Friday afternoons Feb. – Oct. with Scotch College and Christ Church Grammar School Students have done some bush fire fuel load reduction work and are currently working on bird nesting platforms (as requested via LCAC) Adopt a Spot: Individuals adopt a kitchen sized plot of the park to keep rubbish and weed free all year. The program continues to attract new recruits Friday Morning Weeding Group: Continuing manual weed control. The Bushy Starwort on the lake bed appears to be under control this year after significant efforts over recent years. Current membership number: 181

FOLC Events

Night Chats at the Lake – Monthly talks (4th Tuesday) with topics relating to Lake Claremont.. . Feb night chat attracted approx. 120 guests. FOLC wish to thank TOC for their assistance in facilitating permits for the event. Guided Walks:

Publicity

FOLC Newsletter: Circulated to Committee members Newspaper Articles: Website: www.friendsoflakeclaremont.org FaceBook: 932 followers

Fundraising

Other Business

Meetings with TOC: Bi-monthly operational meetings between TOC and FOLC

http://www.friendsoflakeclaremont.org/