This is how water storage tanks make harvesting rain possible
Wednesday, July 05, 2017
Water storage tanks, whether above or below ground form a fundamental part of a rainwater harvesting system. The British Standard BS 8515:2009+A1:2013 Rainwater harvesting systems code of practice
defines the minimum standards for the manufacture, installation and maintenance of rainwater storage tanks and systems. The Code of Practice was set-up to give clear guidance of what the minimum accepted standards that rainwater harvesting companies have to meet. Whether for residential, commercial or industrial purposes harvesting gallons of water that falls on catchment surfaces offers three advantages.
- saves water
- saves money - alternative to mains-water supply and use and therefore saves on rising utility bills
- saves the environment - rainwater is free and if used wisely can make a positive contribution
Rainwater harvesting is about capturing and reusing rainwater for non-potable applications such as irrigation and sprinkler systems, fire protection, laundry and to flush toilets.
The British Standard BS8515:2009 (BS) defines the following minimal standards for use of water storage tanks used in rainwater harvesting -
- the design, installation, water quality, maintenance and risk management
- the amount and intensity of rainfall, size and type of roof or collection surface and the number and type of intended rainwater applications
- size of the storage tank calculated based on the formula as set out by the BS code of practise
- variables that need to be considered in the design approach to non-residential rainwater harvesting
- flow rates
- peak demand periods
- yield and demand
- filtration system to maintain clean rainwater supply that is free from debris and microbes
- care taken that water won't stagnate and contaminated water won't enter the stored water system
Standards for above and below ground water storage tanks are also set-out by the BS 8515:2009 code of practice:
- they need to be watertight with maintenance checks in place to confirm ensure tanks remains fully functional
- discourage microbial growth
- avoid stagnation
- don't allow for the conditions in which Legionella may develop
- above ground water storage tanks are sufficiently insulated to prevent the water from either freezing or warming
- has a filtration system in place at a point before rainwater enters the main body of stored water
- fitted with an overflow pipe to drain water away during periods of heavy rainfall
Water storage tanks can be found on residential, commercial or industrial properties. They are used for many different types of applications. Galvanised water storage tanks can be lined with a synthetic rubber tank liner
to keep them water tight and to preserve the tank long-term from corrosion. They are installed to supply water for the following applications:
- for the garden or turf, as in the case of sports fields and golf courses, thereby conserving water and reducing mains water usage (plus a contingency plan during periods of drought),
- fire protection - usually located close to industrial buildings
- potable water availability provided the approved type of water storage tank is used and not as part of rainwater harvesting
- domestic use by washing machines, dish washers and for flushing toilets to reduce mains water usage
- field irrigation (irrigation uses around 40% of total water consumption)
- agricultural industry - odour masking
- animal cooling system and water provision for livestock
Water storage tanks are available to order in different materials, sizes and colours depending on your choice, installation location and uses:
- Polyethylene - this is the more popular type of water storage tank as used in urban applications. The tank can be installed both underground and above ground. They are available in a wide range of sizes, with tanks being able to store from a few hundred litres of water to 50,000 litres. They can moulded into any shape, whilst also being available in many different colours.
- Galvanised steel water storage tanks - considered the most robust type and found above ground at commercial or industrial locations. Much like polyethylene tanks, they are customisable in size and shape. Additionally, they are available in either a flat or a ribbed finish. They are generally lined with a rubber tank liner to prevent corrosion and the stored water from becoming contaminated by rust. These metal water tanks can hold as much as 700,000 litres.
- Fibreglass tanks are highly durable and can withstand some of the more extreme temperatures. Since the arrival of polyethylene though, fiberglass has become a less popular choice of material due to its price.
Tanks buried under ground are made from either plastic or concrete. This type of storage tank is dependent on budget, the availability of space and ease with which the required hole can be dug.
The biggest variety of water storage tanks are found above the ground.
Is it worth installing a water storage tank? There are a number of factors determining this - it is down to life style choice, the cost savings you would make measured over a ten year period versus using mains water supplies and the cost of losing plants, crops or even livestock during a periods of drought.
Corrugated water storage tanks
are most commonly used commercially and are available to order along with uniquely fitted tank liners from Russetts Developments Ltd.
Galvanized corrugated water storage tanks
are supplied in a range of sizes to suit most needs. Along with the water storage tank components we provide a 1.0mm EPDM rubber tank liner fitted with our “Easifit” hanging system.
Water storage tank protective tank liners
RDL also supply a stitched full height one piece Geotextile matting bags, which are easily incorporated into the “Easifit” system. The protective Geotextile matting bag is installed under the tank liner providing excellent protection and prolonging the life of the tank liner.
Full set-up and fitting service is offered using our trained installers or you have the option of buying a complete kit and install yourself.