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Introduction • Agenda • Learning Aims • Brett Martin
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Agenda
Introduction – Learning aims – Brett Martin
Section 1 – Why Harvest Rainwater? Our Demand for water
The cost of water
Population growth
Climate Change
Legislation
Section 2 – Rainwater Harvesting Systems Key components
Design & Application
Calculating storage capacity
Tank installation
Section 3 – Conclusion (Learning outcomes), Q&A
Introduction • Agenda • Learning Aims • Brett Martin
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Learning aims
• To outline the key factors which place pressure on
water resources.
• To demonstrate how RW Harvesting can contribute to providing a sustainable water resource.
• To gain a full appreciation of the legislative requirements in place to conserve water.
• To understand the options & key components associated with a RW Harvesting system.
Introduction • Agenda • Learning Aims • Brett Martin
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Brett Martin Plumbing & Drainage • Part of the Brett Martin Group of Companies
• Manufacturers of specialist plastics
• Turnover £112 million
• HQ in Co Antrim
• P&D Division HQ in Derbyshire
• Export to 70 countries
• Employ over 800 people
• Over 6 sites
Introduction • Agenda • Learning Aims • Brett Martin
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Service & Support
•Certification & Accreditation
•Expert Technical Advice
Introduction • Agenda • Learning Aims • Brett Martin
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Our demand for water
Water for life
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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150 Litres The amount of water used pppd
50% Could be supplied by
rainwater harvesting
How we use our water in the home
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Embedded Water
3400Litres pppd
2608 Litres (689 gallons) of water
to produce 3.8 Litres (1 gallon) of Beer
65% of water we consume is in our food
One slice of bread requires
40 Litres of water
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Water metering UK Average household water bill for 2012-13
Water bills will increase on Average 3.5% April 2013 – March 2014
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Water metering
30% - UK Households have a water meter
10% - Household water consumption is reduced after a meter is fitted. Surface water Rebate - If no surface water from your property enters a public sewer then you may qualify for a reduction in your sewerage charge ('surface water drainage rebate').
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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The daily cost of domestic water use
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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The Anglian Water region
£2 billion (2010-2015)
Investment to improve water services.
£588 million To meet the demand of 145000 new
homes.
6 million customers,
20% population growth in 20 years
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
One the driest regions of the country.
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Population Growth ONS data
62.2 million
UK population (2010)
Rising to 67.2 million by 2020
Reaching 70 million by 2027
In 2000 UK population was 58.8 million Are living Longer? 1 in 6 (16.4%) of the population are 65 and over
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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The surface area of England by land use
Population Growth Are we a crowded Island?
The UK population as 247 inhabitants per square kilometre.
Compared with the Netherlands 395
Belgium 341
Japan 339
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Population Growth – Housing Shortage
300,000 new homes required each year.
The industry is currently producing 100,000 new homes each year.
At the height of the market in 2007,
over 190,000 new homes were built.
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
The Future Homes Commission (October 2012) set by the RIBA
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Climate Change
‘It is too early to say whether the weather we've witnessed over the last three
years demonstrates that the climate is definitely changing,
But we have certainly seen exceptional weather with high temperatures and
droughts causing significant problems’
In stark contrast, this was then followed by the wettest April to September on
record, which resulted in many people suffering the misery of being flooded’
Dr Paul Leinster, Chief Executive of the Environment Agency – Dec 2012 Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
Climate Change – Winter floods 2014
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Climate Change – Drought
Sept 2010 to March 2012
Many parts of England experienced the driest
18 months for over 100 years
April 2012
Seven water companies in the South &
East of England imposed a ‘temporary use ban’
on 20 million customers to conserve resources.
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Climate Change – Rainfall & Floods
April – September 2012
The wettest period on record, over 4500 properties flooded.
Around 5 million people, in 2 million properties, live in flood risk areas in
England and Wales.
Floods are now on average nearly twice as
frequent as they were 100 years ago.
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Climate Change – Rainfall & Floods
Summer floods of 2007
• Over 55,000 homes & businesses were flooded.
• Estimated insurance losses at £3 billion.
Surface water flooding
Two thirds of properties flooded was
because drains & sewers were overwhelmed.
Currently 80,000 properties are at very significant risk from surface water flooding.
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Legislation – The Code for Sustainable Homes
The Code for Sustainable Homes (the Code) is an environmental assessment method
for rating and certifying the performance of new homes.
It is a national standard for use in the design and construction of new home
with a view to encouraging continuous improvement in sustainable home building.
The code covers 9 categories of sustainable design.
2 of which concern water usage & have mandatory
performance requirements.
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Code for Sustainable Homes - Category 2 – Water – Wat1 - Internal Water Use
• Aim – To reduce the consumption of potable water in the home
• To achieve Levels 5 & 6 (80 Litres p/day) rainwater or greywater recycling will be required
• By 2016 all new homes must comply to level 6
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Code for Sustainable Homes
Category 2 – Water – Wat2 – External Water Use
• Aim - To encourage the recycling of rainwater and reduce the amount of mains
potable water used for external water uses.
• The simplest method for rainwater collection is a water butt.
• A rainwater harvesting system can contribute to Wat1 & 2
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Code for Sustainable Homes
Category 4 – Surface Water Run-Off – Sur1
Aim - To design housing developments which avoid, reduce and delay the discharge of
rainfall to public sewers and watercourses.
This will protect watercourses and reduce the risk of localised flooding, pollution and other
environmental damage.
Specifying rainwater recycling as part of a sustainable drainage system (SUDS) to manage
surface water run-off.
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Code for Sustainable Homes
Category 4 – Surface Water Run-Off – Sur2 – Flood Risk
Aim - To encourage housing development in low flood risk areas, or to take measures
to reduce the impact of flooding on houses built in areas with a medium or high risk
of flooding.
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Legislation
Building Regulations Approved Document
Part G
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
G – Water Efficiency
125 Litres ppd of wholesome water
consumptions
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Legislation
Other legislation & standards to consider:-
Building Regulations Approved Document H & G
H - Drainage & Waste Disposal
BS8515:2009
The BSI rainwater harvesting code of practice
PPS25 – Planning Policy Statement 25
Development and flood Risk Practice Guide.
Environmental assessment method
best practice in sustainable design
Our demand for water -- The cost of water -- Population Growth -- Climate Change -- Legislation
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Section 2
Rainwater Harvesting Systems
• Key Components
• Storage Capacity
• Design & Application
• Tank Installation
• Maintenance
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Rainwater Harvesting Home & Garden Systems
Direct Feed System
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Rainwater Harvesting Home & Garden Systems
Gravity Feed System
• Additional cost of header tank & associated
plumbing.
• Restricted by building design
• Warm loft space temperatures;
potential breeding grown for Legionnaires.
• The benefit of a stored water supply;
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Rainwater Harvesting
Key components
• Pipework
• Filter Unit
• Calming Inlet
• Floating intake
• Pump & Control Unit
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Key components – Pipework
In accordance with BS8515 & WRAS
Pipework for non potable water (rainwater)
Recommended pipes should be Green or
Black & Green.
Blue pipework is a recognized standard used
for potable water.
Not for drinking water
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Key components – Filter Unit
• To comply with BS8515:2009
• Designed as a ‘in-tank’ or ‘pre-tank’ filter
• Stainless steel –water & weather resistant
• Removable 35 micron fine mesh filter
• 15˚ fall on flow
• 3 x 110mm inlets (160mm Channel option)
Independently tested at Newcastle University for flow efficiency.
Achieved 98% efficiency on flow rates up to 5 litres per second
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Key components
Calming Inlet
• To comply with BS8515:2009
• Fitted to drainage pipe feeding
rainwater into storage tank.
• Minimises turbulence, slows water
flow into tank
• Prevents disturbance of any sediment
at the base of the tank
• Ensures oxygenation, to discourage Algae growth Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Key components
Floating Intake
• In accordance with BS8515:2009
• Extracts the cleanest water available.
• Located approximately 100 to 150mm
below the surface of the water.
• Further filters the water.
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Key components
Submersible Pump
• Direct feed system.
• Delivers water to the point of demand.
• In the unlikely event that there is no
water in the tank:-
The system is equipped with run dry protection.
Pump will switch off to prevent burn out.
Pump should be removable for maintenance purposes
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Key components – Control Unit
Tundish – AA Air Gap Prevents ‘backflow’ & contamination
of mains water supply, meets requirements of
BS EN 13076
Float switch Should the tank run dry the float switch will drop to
provide mains water back up.
Positioned around 300mm from base of tank
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Design & Application – RWH
Low profile tank Systems
• 1500 Litre tank weighs only 62 kilos (9.5 stone)
• Can be lifted by two persons, reduces the requirement
for plant machinery.
• Easier access through properties
(through doorways)
• Lower levels of excavation.
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Design & Application – RWH
Low profile tank systems
• Multiple tank connections
• Large underground storage
• Attenuation
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
Design & Application – RWH
Commercial Systems
•Hotels
•Offices
•Leisure Facilities
•Schools
•Industrial Buildings
•Flushing Toilets
•Irrigation
•Laundry
•General Cleaning
•Vehicle Washing
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Calculating Storage Capacity
In accordance with BS8515:2009
The following factors should be identified in order
to calculate the size of the system;
• The amount & intensity of rainfall
• The size & type of collection surface
• The number & type of intended applications, both present & future
As set out in BS8515:2009 – The three approaches, simplified, intermediate &
detailed, are recommended for sizing. Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Building
Guttering &
pipework
Catchment surface
Runoff losses
Yield Co efficient 0.8
Rainfall
Filter efficiency 0.9 Storage Tank
Calculating storage capacity The intermediate approach
Roof Area –168.75m²
Annual Rainfall – 1151.9mm
(Taken from Cardiff Weather station)
Annual rainwater yield
Roof area in m² 168.75
X
Annual regional rainfall in mm 1151.9
X
Yield Coefficient % 0.8
X
Filter efficiency 0.9
= 139955.84
5% of Annual rainfall 6997.80
(18 days) litres
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Building
Guttering &
pipework
Catchment surface
Effective runoff
Rainfall
Storage Tank
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
Calculating storage capacity The intermediate approach
WC
Annual (non-potable) water demand
Daily requirement per person 75 Litres
X
Number of persons per dwelling 2
X
365 days per year
= 54750
5% Annual (non potable) water demand 2737.50
(18 days)
Do not oversize the tank!
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Tank Installation
In accordance with BS8515:2009
To ensure structural stability the following
issues should be considered.
• Avoiding flotation
• Resisting ground pressures
• Water table fluctuations
• Resisting vehicle loadings
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Polyethylene material (HDPE)
Rotationally moulded one piece mould
Lightweight material
Excellent impact resistance
High tensile strength
GRP Tanks
Brittle material.
Potential for tank to split/crack, through
tensile stress.
Susceptible to ‘creep’
Graf Tanks
German manufacture
Two piece mould
Requires on-site construction, labour
intensive.
Sealing requires testing with large
volume of water.
Tank Installation
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Tank Installation
Excavation area Height 2.55m
Width 1.56m
Depth 1.56m
Total 6.21m³
Complete Tank Volume – 2.382m³
Therefore 3.828m³ concrete required!
£100 to £150 per M³ of Concrete (depending on plant location)
Plus cost of plant & labour
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
Figures calculated on a 2000litre tank
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Tank Installation
250mm Slab Base Depth
Vehicle Loading A load bearing slab should
be constructed
Filter run off
& overflow
Concrete Surround To be poured & completed in
multiple lift (approx 300mm)
Fill tank Continue to fill tank with water
whilst backfilling
Ensure water level remains
300mm above concrete level
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Maintenance guidance in accordance with BS8515:2009
& as per manufacturers instruction.
Gutters/Downpipes - Annual inspection
Filter- Annual inspection
Storage Tank- Annual inspection
Pump & Controls (associated fittings) - Annual inspection
Wiring- Annual inspection
Pipework- Annual inspection
Storage Tank - Drained down & cleaned – every 10 years
(dependant on usage)
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Maintenance - Commissioning
• Poor installation
‘Read installation instruction’
• Ensure there is no debris in the tank or pipework.
• System should be flushed before use, open an appliance to create demand.
• Ensure there are no leaks in the pipework
Pump will continue to run, increasing water temperature, tripping mains top-up
• Pay-back period – depending on which web-site you read!
Estimated 10-15 years
Dependant on area, amount of rainfall & cost of mains water
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Design & Application – Domestic RWH Home & Garden System
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Design & Application – Agriculture RWH Garden System
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Design & Application – Agriculture RWH Garden System
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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Design & Application – Domestic
RWH Home & Garden System
Key Components -- Storage Capacity -- Design & Application -- Tank Installation -- Maintenance
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To Conclude, learning outcomes;
Harvesting rainwater can ease the pressure placed on our water
resources, caused by factors such as climate change & population
growth.
Contributing to providing a sustainable water resource with the
capabilities to satisfy legislation and the potential to save money.
Thank you, any questions?
Conclusion --- Thank you
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Brett Martin Plumbing & Drainage Email. paulwadsworth@brettmartin.com
Tel: 01246 280000
Mobile: 07900 906157
Websites: www.brettmartin.com
www.ribaproductselector.com
Conclusion --- Thank you
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We also supply:-
Grease Traps
Sewage Treatment systems
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