Transcript Rainwater Harvesting CPD Seminar

Introduction • Agenda • Learning Aims • Brett Martin
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
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.
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
Service & Support
•Certification & Accreditation
•Expert Technical Advice
Our demand for water
Water for life
How we use our water in the home
150 Litres
The amount of water used per
person per day
50% Could be supplied by
rainwater harvesting
How we compare with our European neighbours
Embedded Water
3400Litres pppd
One slice of bread requires
40 Litres of water
2608 Litres (689 gallons) of water
to produce 3.8 Litres (1 gallon) of Beer
65% of water we consume is in our food
Water metering
UK Average household water bill for 2012-13
Water bills will increase on Average 3.5% April 2013 – March 2014
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').
The daily cost of domestic water use
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
A population growth of 20% in 20 years.
One the driest regions of the country.
Population Growth
ONS data
62.2 million
UK population (2010)
Rising to
by 2020
67.2 million
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
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
The surface area of England by land use
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.
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
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.
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.
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.
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 homes 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.
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
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
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.
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.
Legislation
Building Regulations Approved Document
Part G
G – Water Efficiency
125 Litres ppd of wholesome water consumptions
Legislation
Other legislation & standards to consider:BS8515:2009
The BSI rainwater harvesting code of practice
PPS25 – Planning Policy Statement 25
Development and flood Risk Practice Guide.
Building Regulations Approved Document H & G
H - Drainage & Waste Disposal
Environmental assessment method
Best practice in sustainable design
Section 2
Rainwater Harvesting Systems
•
•
•
•
Key Components
Storage Capacity
Design & Application
Tank Installation
Rainwater Harvesting
Home & Garden Systems
Direct Feed System
Rainwater Harvesting
Key components
•Pipework
•Filter Unit
•Calming Inlet
•Floating intake
•Pump & Control Unit
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.
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
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
Algai growth
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 – 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 – 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
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
Design & Application – RWH
Low Profile Systems – Tank connections
Large underground storage
Attenuation
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.
Calculating storage capacity – The intermediate approach
Development:
New Build Bungalow in
St Brides Major, S. Wales
Roof Area –168.75m²
Annual Rainfall – 1151.9mm
(Taken from Cardiff Weather station)
Calculating storage capacity – The intermediate approach
The lesser figure should be used to calculate storage capacity
Tank Installation
•
Avoiding flotation
•
Resisting ground pressures
•
Water table fluctuations
•
Resisting vehicle loadings
Tank Installation
Polyethylene material (HDPE)
Rotationally moulded one piece mould
Lightweight material
Excellent impact resistance
Tank sizes
1200 Litre
2000 Litre
3500 Litre
6000 Litre
1500 Litre LR
High tensile strength
Tank Installation
The tank is encased in concrete
Tank Installation
Vehicle Loading
A load bearing slab should
be constructed
Filter run off
& overflow
Fill tank
Continue to fill tank with water
whilst backfilling
Concrete Surround
Ensure water level remains
300mm above concrete level
To be poured & completed in
multiple lift (approx 300mm)
250mm Slab Base Depth
Design & Application – Domestic
RWH Home & Garden System
Design & Application – Agriculture
RWH Garden System
Design & Application – Agriculture
RWH Garden System
Design & Application – Domestic
RWH Home & Garden System
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 - Questions
Brett Martin Plumbing & Drainage
Email. [email protected]
Tel:
01246 280000
Mobile: 07900 906157
Websites: www.brettmartin.com
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