Page 1 of 13

OFFICE OF CLIMATE, LICENSING, RESOURCES

& RESEARCH

INSPECTORS REPORT ON A WASTE WATER DISCHARGE LICENCE APPLICATION

To: Dara Lynott, Director

From: Yvonne English Environmental Licensing Programme

Date: 12/05/2017

RE: Application for a Waste Water Discharge Licence from Irish Water, for the agglomeration named Bridgend, Reg. No. D0532-01.

Application & Agglomeration Details

Agglomeration Name: Bridgend (See Map - Appendix 1)

County: County Donegal

Schedule of discharge licensed: Discharges from agglomerations with a population equivalent of 500 to 1,000.

Licence application received: 24 August 2011

Notices under Regulation 18(3)(b)1 issued: 3 March 2014, 3 February 2015, 8 June

2015, 2 June 2016

Information under Regulation 18(3)(b) received:

23 April 2015, 8 January 2016, 15 July 2016

Site notice check: 15 September 2011

Site Visit: 20 July 2016

Submission(s) Received: None

Design Population Equivalent: 260

Actual Population Equivalent: 763

Type of treatment: Secondary

Wastewater treatment plant (WWTP) description:

The plant consists of an extended aeration activated sludge process and willow plantation.

1 Waste Water Discharge (Authorisation) Regulations, 2007, as amended.

This report has been cleared for submission to Director/Board by Breen Higgins. Grainne Power, 12/05/2017 11:44

Page 2 of 13

1. Discharges to waters The following table outlines the main considerations in relation to discharges to waters from this agglomeration.

Table 1: Discharges to waters

Primary discharge point

Receiving water name River Skeoge

Type of receiving water Freshwater

Normal flow Winter – 175 m3/day

Summer – 27 m3/day

Maximum flow 450 m3/day

Secondary discharge point(s)

SW2

Receiving water name Willow Plantation

Normal flow Winter 0 m3/day

Summer 148 m3/day

SW3

Receiving water name River Skeoge

Type of receiving water Freshwater

Normal flow Variable. This discharge point is activated during periods of heavy rainfall when the high river levels prevent gravity discharges from the primary discharge point.

Storm water overflow(s)

Storm water overflow(s) Yes (1)

Receiving water name(s) Freshwater

The WWTP at Bridgend is currently overloaded. Due to this overloading and limited assimilative capacity in the receiving River Skeoge, in 2013, as part of an INTERREG2

project Donegal County Council established a willow plantation as part of the

treatment process for the Bridgend WWTP. A proportion of the final effluent from the WWTP irrigates a 14 hectare short rotation coppice willow plantation instead of discharging through the primary discharge point to the River Skeoge.

There are three different discharge scenarios at the Bridgend WWTP. These scenarios are illustrated in Appendix 2 of this report and are detailed below:

The first discharge scenario: All the flows enter the plant through the inlet works, are pumped forward to the extended aeration treatment process and discharge through the primary discharge point. This scenario occurs during the winter months (October to February), during heavy rainfall events when irrigation of the willow plantation is

not required and when flows in the river are high.

2 INTERREG is a series of European Territorial Cooperation programmes that aim to stimulate cross border and inter

regional cooperation in the European Union.

Page 3 of 13

There is also a stormwater overflow at the inlet works (SW004). This overflow activates when the inlet flow rate is greater than three times dry weather flow and discharges as untreated waste water through the primary discharge point.

The second discharge scenario: This discharge scenario occurs in the summer months and when the willow plantation has capacity and requires irrigation. In this

scenario all the flows enter the plant through the inlet works, are pumped forward to the extended aeration treatment process and are then pumped to a holding tank. From the holding tank the majority of the waste water is pumped through a secondary discharge point (SW002) for controlled irrigation of the willow plantation.

The remainder of the flow discharges through the primary discharge pipe.

The third discharge scenario: Occurs when the primary discharge pipeline, which is gravity fed, backs up due to high river levels. In this scenario all the flows enter the plant through the inlet works, are pumped forward to the extended aeration treatment process and are then pumped to the holding tank which has a high level

overflow facility. As this scenario will occur in periods of heavy rainfall there is no discharge to the willow plantation. The discharge of treated effluent from the holding tank is through a further secondary discharge point (SW003) to the River Skeoge.

The willow plantation consists of two parcels of land. The main plantation lies in the groundwater surface water interface in the hyporheic zone3 and the second plantation lies on slightly sloping tills and gravel, terminating at a berm directly adjacent to the Skeoge River. The willow plantation is designed to be a zero discharge system (i.e. all the flows discharged to the willow plantation are expected

to be taken up by evapotranspiration). In the case where flows to the planation are in excess of the flows which can be taken up by the willow, the excess flows in the main plantation discharge via the hyporheic zone which has hydrological connectivity with the Skeoge River and excess flows from the second plantation will discharge to the river as berm over top.

Due to the fact that there is no certainty that the waste water being used to irrigate the willow plantation will be fully used by the crop and therefore the likelihood that this waste water will eventually find its way to the River Skeoge it is recommended that the waste water being used to irrigate the willow shall also comply with

emission limit values (ELVs) sufficient to provide adequate protection to the receiving water and ensure compliance with the European Communities Environmental Objectives (Surface Water) Regulations, 2009, as amended.

Schedule A: Discharges & Discharge Monitoring of the recommended licence (RL) specifies the Emission Limit Values (ELVs) to which the discharge from the Bridgend

agglomeration must conform. Monitoring of the discharges will take place as per this schedule of the RL.

There is a large variation noted between the normal and maximum flows recorded from the primary discharge point. This variation can be attributed to the combined nature of the collection network.

2. Environmental Impact Assessment Considerations EIA Screening I have considered the requirements of Regulation 3(1) of the Waste Water Discharge

(Authorisation)(Environmental Impact Assessment) Regulations 2016 and have determined that the Agency is not required to carry out screening for Environmental

3 The Hyporheic zone is the zone below and adjacent to a streambed in which water from the open

channel exchanges with interstitial water in the bed sediments. It is the zone in which groundwater and

surface water mix.

Page 4 of 13

Impact Assessment (EIA) for this application due to the application not being an Agency initiated review and given that there is development associated with the discharge.

3. Receiving waters and impact

The following table summarises the main considerations in relation to the River Skeoge downstream of the primary discharge.

Table 2: Receiving waters

Characteristic Classification Comment

Receiving water name

River Skeoge (WFD Code: UKGBNI1NW393901002)

Designations

Lough Swilly SAC (Site Code: 002287) Lough Swilly SPA (Site Code: 004075) Lough Swilly Shellfish area

4.1 km downstream of SW001 1.3 km downstream of SW001 6.2 km downstream of SW001

Receiving water monitoring stations

Bridge east of Skeogh (at Bridgend) (EPA RS Code: RS39S010100) Bridge N. of Skeoge (EPA RS Code: RS39S010200)

Distance upstream of SW001 on River Skeoge – 300 meters Distance downstream of SW001 on River Skeoge – 1 km

Biological quality rating (Q value)

Q2-3 (2013) Bridge u/s Lough Swilly (EPA RS Code: RS39S010300)

2.2 km downstream of WWTP on River Skeoge

WFD status Poor (2010 – 2015) Good Status by 2021

The Crana Water Management Unit Action Plan (WMUAP) identifies the WWTP in

Bridgend as a point pressure on the Skeoge catchment.

The ‘notional clean river’ approach (formulated by the Office of Environmental Assessment) has been taken, whereby other sources of upstream pollution will be dealt with separately. The purpose of the mass balance calculations is to show the impact of the discharge with respect to water quality standards. The sources which

give rise to the background concentrations are outside the control of this licence. The North Western International River Basin Management Plan (2009 – 2015) provides details of recommendations and planned measures to reduce pollution in water courses. The wastewater treatment plant discharge shall not cause deterioration in the water quality status. The mass balance calculations are based on

the 95%ile flow in the receiving water, the notional clean river background concentrations, the normal effluent discharge rate and the maximum concentration of the parameter in the effluent (Table 3).

The 95%ile flow in the river at the Bridgend Waste Water treatment Plant is 0.08 m3/s.

Table 3: Mass Balance Calculations.

Parameter

Notional Clean River

Values (mg/l) Note 1

Proposed ELVs for discharge

(mg/l)

Contribution from

discharge (mg/l)

Predicted downstream concentration

(mg/l)

Relevant standard (mg/l)

BOD 0.26 25 0.6109 0.8709 2.6Note 2

Page 5 of 13

Orthophosphate 0.005

1.5 0.0369 0.0419 0.075 Note

2

Total Ammonia 0.008 3 0.0739 0.0819 0.14 Note 2

Note 1: Notional clean river values for AC based on 1/5th of the mean “High Status” standard in the European Communities Environmental Objectives (Surface Waters) Regulations 2009, as amended.

Note 2: European Communities Environmental Objectives (Surface Waters) Regulations 2009, as amended.

The European Communities Environmental Objectives (Surface Water) Regulations, 2009, as amended, set environmental quality objectives for the receiving water for

orthophosphate (0.075 mg/l), ammonia (0.14 mg/l) and BOD (2.6 mg/l). An emission limit value of 1.5 mg/l is recommended for orthophosphate, 3 mg/l for ammonia and 25 mg/l for BOD in the RL. The limits are set based on the mass balance calculations. The WWTP has activated sludge treatment which can achieve standards of 15 – 25 mg/l for BOD, 4.5 – 9 mg/l for orthophosphate and 2 – 5 mg/l

for ammonia in the discharge. Based on this information the emission limit values for BOD and ammonia in the RL are achievable.

The population equivalent of the agglomeration is below the 2,000 p.e. threshold at which the ELVs specified in Part 1 of the second schedule of the Urban Wastewater Treatment Regulations, 2001, as amended, apply.

For agglomerations under this threshold, “appropriate treatment” is required.

Article 7 of Directive 91/271/EC4 requires that urban waste water entering collection systems shall, before discharge, be subject to appropriate treatment, as defined in Article 2(9), for discharges to freshwater and estuaries from agglomerations of less

than 2,000 p.e.. The term ‘appropriate treatment’ is defined in the Directive as ‘treatment of urban waste water by any process and/or disposal system which after discharge allows the receiving waters to meet the relevant quality objectives and the relevant provisions of the Directive and of other Community Directives’.

It is considered that the treatment currently provided in this agglomeration is not

appropriate. This is due to the fact that the plant is overloaded, the quality of the effluent discharged from the WWTP, and the poor water quality status of the receiving water. The RL has set emission limit values (ELVs) 25 mg/l for cBOD, 125 mg/l for chemical oxygen demand (COD), 35 mg/l for suspended solids (SS) for the

primary discharge point and the two secondary discharge points. These limits are in accordance with UWWT Regulations, 2001, as amended, and are applicable from the date of grant of the licence.

Improvement works will be necessary to achieve the orthophosphate ELV. The ELVs for orthophosphate and ammonia will apply from 31/12/2019 on all discharge points.

This is to ensure that the Skeoge River achieves good status by 2021.

A mentioned above, due to the fact that there is no certainty that the waste water being used to irrigate the willow plantation will be fully used by the crop and therefore the likelihood that this waste water will eventually find its way to the River Skeoge it is recommended that the waste water being used to irrigate the willow

shall also comply with emission limit values (ELVs) sufficient to provide adequate protection to the receiving water and ensure compliance with the European Communities Environmental Objectives (Surface Water) Regulations, 2009, as amended.

The proposed limits are necessarily stringent in order to achieve the requirements of the European Communities Objectives (Surface Water) Regulations, 2009, as amended and are unlikely to be achieved utilising existing infrastructure.

4 Council Directive of 21 May 1991 concerning urban waste water treatment.

Page 6 of 13

Schedule C: Specified Improvement Programme of the RL requires that appropriate works be completed to ensure compliance with the emission limit values as set out in Schedule A: Discharges & Discharge Monitoring of the RL by 31/12/2019. 4. Ambient Monitoring

Schedule B: Ambient Monitoring of the RL specifies the parameters, analysis method and frequency for which ambient monitoring of the primary discharge shall be carried out. The requirements for ambient monitoring in Schedule B: Ambient Monitoring are sufficient to monitor for potential impacts on the status of the

receiving water as a result of the discharge.

5. Combined Approach The Waste Water Discharge (Authorisation) Regulations, 2007, as amended, specify that a ‘combined approach’ in relation to licensing of waste water works must be

taken, whereby the emission limits for the discharge are established on the basis of the stricter of either or both, the limits and controls required under the Urban Waste Water Treatment Regulations, 2001, as amended, and the limits determined under statute or Directive for the purpose of achieving the environmental objectives

established for surface waters, groundwater or protected areas for the water body into which the discharge is made. The RL as drafted gives effect to the principle of the Combined Approach as defined in Waste Water Discharge (Authorisation) Regulations, 2007, as amended.

6. Programme of Improvements

The WWTP in Bridgend provides secondary treatment for wastewater from the Bridgend agglomeration. However, the current WWTP is overloaded and does not perform satisfactorily. Condition 5.1 of the RL requires the licensee to prepare and submit to the Agency a programme of infrastructural improvements to maximise the

effectiveness and efficiency of the waste water works.

The conditions and emission limit values specified in the RL will ensure no deterioration in the quality of the receiving waters as a result of the discharge.

Condition 1.7 of the RL, as drafted, requires improvement works to increase the

organic and hydraulic treatment capacity of the plant. It requires that “the licensee shall maintain such available capacity within the waste water works as is necessary to ensure that there is no environmental risk posed to the receiving water environment as a result of the discharges”.

The RL, as drafted, requires that these works be completed by 31/12/2019 in order

to ensure compliance with the emission limit values as set out in Schedule A: Discharges & Discharge Monitoring of the RL.

7. Compliance with EU Directives

In considering the application, regard was had to the requirements of Regulation

6(2) of the Waste Water Discharge (Authorisation) Regulations, 2007, as amended, notably:

Page 7 of 13

Table 4: Compliance with EU Directives/Regulations

Compliance with Directives/Regulations Description and Conditions in RL

Urban Waste Water Treatment Directive [91/271/EEC]

Not compliant in 2015

Water Framework Directive [2000/60/EC] Good status to be achieved by 2021.

EC Environmental Objectives (Surface Water) Regulations 2009 (S.I. No. 272 of 2009), as amended

Schedule A of RL sets ELVs to contribute towards achieving the environmental quality objectives.

Drinking Water Abstraction Regulations Condition 4 requires risk assessment for the protection of downstream abstraction points.

Bathing Water Directive [2006/7/EC] No bathing waters present.

Dangerous Substances Directive [2006/11/EC] Condition 4 requires screening for priority substances.

Birds Directive [2009/147/EC] & Habitats Directive [92/43/EEC]

The Bridgend WWTP discharges indirectly via the Skeoge River, into the Lough Swilly

SAC5 (Site Code: 002287). The site is protected for priority habitats listed under Annex 1 of the Habitats Directive. It is also selected for protection of species listed under Annex II of the same directive. The site is {also} designated an SPA6, Lough Swilly SPA (Site Code: 004075), under the Birds Directive for the conservation of wild birds.

Appendix 3 lists the European Sites assessed, their associated qualifying interests and conservation objectives along with the assessment of the effects of the activity on the European Sites.

A screening for Appropriate Assessment was undertaken to assess, in view of best scientific knowledge and the conservation objectives of the site, if the activity individually or in combination with other plans or projects is likely to have a significant effect on any European Site. In this context, particular attention was paid

to the European Sites at Lough Swilly SAC and Lough Swilly SPA. The activity is not directly connected with or necessary to the management of any European Site and the Agency considered, for the reasons set out below, that it cannot be excluded, on the basis of objective information, that the activity,

individually or in combination with other plans or projects, will have a significant effect on any European Site and accordingly determined that an Appropriate Assessment of the activity was required, and for this reason determined to require the applicant to submit a Natura Impact Statement.

This determination is based on the following:

the quality of the effluent discharges from the agglomeration,

the Poor water quality status assigned to the receiving water (Skeoge River WFD Code: UKGBNI1NW393901002) under the Water Framework Directive; and,

The proximity of the primary discharge from the agglomeration to the European sites (Lough Swilly SPA ~ 1.3 km downstream; Lough Swilly SAC ~

4.1 km downstream).

5 SAC: Special Area of Conservation designated under the Habitats Directive, Council Directive 92/43/EEC of 21 May

1992 on the conservation of natural habitats and of wild fauna and flora. 6 SPA: Special Protection Area designated under the Birds Directive, Directive 2009/147/EC of the European

Parliament and of the Council of 30 November 2009 on the conservation of wild birds.

Page 8 of 13

An Inspector’s Appropriate Assessment has been completed and has determined, based on best scientific knowledge in the field and in accordance with the European Communities (Birds and Natural Habitats) Regulations 2011 as amended, pursuant to Article 6(3) of the Habitats Directive, that the activity, individually or in combination

with other plans or projects, will not adversely affect the integrity of any European Site, in particular Lough Swilly SAC and Lough Swilly SPA, having regard to their conservation objective’s and will not affect the preservation of these sites at favourable conservation status if carried out in accordance with this recommended

licence and the conditions attached hereto for the following reasons: Schedule A: Discharges & Discharge Monitoring of the RL specifies the ELVs

to which the discharge from the Bridgend agglomeration must conform.

These ELVs will contribute to the receiving water achieving the environmental quality standards set in the European Communities Environmental Objectives (Surface Water) Regulations 2009, (as amended), which are aimed at providing a high degree of protection to the receiving water body.

Condition 5.1 of the RL requires the submission of a programme of infrastructural improvement works to maximise the effectiveness and efficiency of the WWTP.

Condition 5.4 of the RL, as drafted, also requires the licensee to provide appropriate treatment to ensure all ELVs are met by 31/12/2019.

Condition 3.4 of the RL requires the licensee to take such measures as

necessary to ensure that no deterioration in the quality of the receiving waters shall occur as a result of the discharge.

Schedule C: Specified Improvement Programme of the licence requires improvements to be undertaken at the treatment works to ensure that the appropriate treatment is provided to ensure all ELVs are met.

In light of the foregoing reasons no reasonable scientific doubt remains as to the absence of adverse effects on the integrity of those European Sites, Lough Swilly SAC and Lough Swilly SPA.

8. Cross Office Liaison Advice and guidance issued by the Waste Water Technical Working Group (WWTWG) was followed in the assessment of this application. Advice and guidance issued by the WWTWG is prepared through a detailed cross-office co-operative process, with the concerns of all sides taken into account. The Board of the Agency has endorsed

the advice and guidance issued by the WWTWG for use by licensing inspectors in the assessment of wastewater discharge licence applications.

9. Submissions

No submissions were received in relation to this application.

10. Charges

The RL requires that the licensee shall pay to the Agency, such sum as the Agency from time to time determines is reflective of the monitoring and enforcement regime

being proposed for the agglomeration.

11. Recommendation

I recommend that a Final Licence be issued subject to the conditions and for the reasons as set out in the attached Recommended Licence.

Page 9 of 13

Signed

Yvonne English

Environmental Licensing Programme

Page 10 of 13

Appendix 1: Map showing location of Bridgend WWTP and associated primary discharge point.

Bridgend WWTP & Primary

Discharge Point

Lough Swilly SPA

Lough Swilly SAC

River Skeoge

Page 11 of 13

Appendix 2: Layout of Bridgend WWTP

Page 12 of 13

Appendix 3: Assessment of the effect(s) of discharges on European sites and proposed mitigate measures.

European Site

(site code):

Lough Swilly SAC

(002287)

Distance/ Direction from discharge(s)

The primary discharge is 4.1 km upstream of Lough Swilly SAC.

Conservation objectives:

As per NPWS (2011) Conservation objectives: Lough Swilly SAC 002287 and Lough Swilly SPA 004075. Version 1.0. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht (dated 19/07/2011).

Qualifying interests (* denotes a priority habitat)

Assessment

Habitats: Water Dependent Estuaries Coastal Lagoons* Atlantic salt meadows (Glauco-Puccinellietalia maritimae) Molinia Meadows Non-Water Dependent Old sessile oak woods with Ilex and Blechnum in the

British Isles

Species

Water Dependent Otter (Lutra lutra)

Emission to Water Discharge of effluent to water systems can lead to an altered nutrient balance (eutrophication), potential threat of toxicity, reduction in biological status and loss of habitat. Compliance with Environmental Quality Standards for surface water and groundwater will contribute to the maintenance of favourable conservation status. Conclusion: The RL specifies ELVs for the primary and secondary discharge which are set to ensure that emissions from this source will protect the quality of the receiving waters, to comply with the requirements of the European Communities Environmental Objectives (Surface Water) Regulations as amended. The ELVs specified will also contribute to the receiving waters achieving ‘good’ status as required under the Water Framework Directive. Condition 3.4 of the RL requires the licensee to take such measures as necessary to ensure that no deterioration in the quality of the receiving waters shall occur as a result of the discharge. Potential for Accidents to Arise There is the potential for accidents and emergency situations arising at a waste water works resulting in partially treated or untreated waste waters discharging to the receiving waters. Such incidents or events could lead to the breach of ELVs and the discharge of elevated levels of polluting organic matter, which would have the potential to impact on the receiving water environment. Conclusion: Condition 5.1.7 of the RL requires the licensee to identify measures to minimise any environmental damage associated with discharges or overflows from the waste water works following anticipated events or accidents/incidents. Condition 4.21 of the RL requires the licensee to provide an annual statement as to the measures taken or adopted to minimise environmental damage associated with discharges or overflows from the waste water works following anticipated events or accidents/incidents.

Page 13 of 13

European Site

(site code):

Lough Swilly SPA

(004075)

Distance from discharge(s)

The primary discharge is 1.3 km upstream of Lough Swilly SPA.

Conservation objectives:

As per NPWS (2011) Conservation objectives: Lough Swilly SAC 002287 and Lough Swilly SPA 004075. Version 1.0. National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht (dated 19/07/2011).

Qualifying interests (* denotes a priority habitat)

Assessment

Species: Water Dependent Great Crested Grebe Podiceps cristatus Grey Heron Ardea cinerea Whooper Swan Cygnus cygnus Greylag Goose Anser anser Shelduck Tadorna tadorna Wigeon Anas penelope Teal Anas crecca Mallard Anas platyrhynchos Shoveler Anas clypeata Scaup Aythya marila Goldeneye Bucephala clangula Red‐breasted Merganser Mergus serrator Coot Fulica atra Oystercatcher Haematopus ostralegus Knot Calidris canutus Dunlin Calidris alpina Curlew Numenius arquata Redshank Tringa totanus Greenshank Tringa nebularia Black‐headed Gull Chroicocephalus ridibundus Common Gull Larus canus Sandwich Tern Sterna sandvicensis Common Tern Sterna hirundo Greenland White‐fronted goose Anser albifrons flavirostris Waterbirds Habitats: Water Dependent Wetlands

Emission to Water The water dependent species listed in the Qualifying Interests Column of this table mainly feed on water based species. Any impact on water quality could have a knock on effect on their populations as a result of loss of prey species. Conclusion: The licence specifies ELVs for the primary and secondary discharge which are set to ensure that emissions from this source will protect the quality of the receiving waters, to comply with the requirements of the European Communities Environmental Objectives (Surface Water) Regulations, 2009, as amended. The ELVs specified will also contribute to the receiving waters achieving ‘good’ status as required under the Water Framework Directive. Condition 3.4 of the RL requires the licensee to take such measures as necessary to ensure that no deterioration in the quality of the receiving waters shall occur as a result of the discharge. Potential for Accidents to Arise There is the potential for accidents and emergency situations arising at a wastewater treatment works resulting in partially treated or untreated waste waters discharging to the receiving waters. Such incidents or events could lead to the breach of ELVs and the discharge of elevated levels of polluting organic matter, which would have the potential to impact on the receiving water environment. Conclusion: Condition 5.1.7 of the RL requires the licensee to identify measures to minimise any environmental damage associated with discharges or overflows from the waste water works following anticipated events or accidents/incidents. Condition 4.21 of the RL requires the licensee to provide an annual statement as to the measures taken or adopted to minimise environmental damage associated with discharges or overflows from the waste water works following anticipated events or accidents/incidents.