Rainwater Harvesting

With today’s emphasis on preserving the environment, not to mention the spiralling cost of utility bills, the idea of ”rainwater harvesting” has suddenly been lifted out of the ”wacky” and into the mainstream arena.

Rainwater harvesting works by collecting the rain which falls onto roofs, then stores it in an underground tank where it is filtered, ready for use in non-drinking situations such as for flushing toilets, filling the washing machine or supplying an outside tap. When it is required, the water is then pumped to the point of use, saving the householder from having to use their chargeable, metered mains water

AA Biotech can help in obtaining planning permission on sensitive development sites where planning authorities may be looking for innovative elements to be incorporated in the building. Some developments are receiving planning permission with restrictions on the rate of surface water disposal from site, which can also be helped by the installation of a good management system.

AA Biotech can provide the complete solution for rainwater management problems:

• Site survey to establish requirements.
• Design of tailored system to maximise use and savings.
• Supply and installation of complete underground system.
• Commissioning of internal plumbing and electrical installation.

Domestic

In a domestic situation, up to 55% of the total water requirements can be serviced by rainwater including toilet flushing, washing machines, not forgetting that rainwater is naturally a “soft” water and can therefore substantially reduce the amount of detergents required. External uses such as car washing and garden watering can also be catered for.

A typical 4 bedroom detached house built with a direct rainwater harvesting system feeding the 3 WC’s, washing machine and external tap for car washing and garden irrigation will have a payback period of less than 3 years. After that, ongoing savings will be made.

Commercial

In a commercial application, up to 85% of the total water requirements can be serviced by rainwater including office buildings, factories, schools and hotels. All have a high demand for toilet and urinal flushing and other uses such as wash down areas and industrial processing.

A large, well known, dairy company has recently had a rainwater harvesting system installed on a new plant. The rainwater from the main building was directed to several large underground storage tanks and re-used back in the building for wash down purposes. The savings against the cost of using mains water has resulted in a payback period of less than 1 year, against the cost of installation.