Here in the UK, we are lucky that rainwater harvesting is not heavily regulated or even outlawed as it is in some US states. The regulations focus almost entirely on health aspects by keeping non-potable harvested water completely and safely separate from drinking water. The harvesting and collection mechanisms themselves are not regulated, merely the manner in which the resultant water is piped into buildings and coexists in parallel with drinking water circuits.
Who Needs To Be Familiar With The Regulations?
- Developers – understand the constraints for connecting rainwater storage systems when drafting designs
- Project managers – understand how they apply to plumbing work and what checks need to be implemented to ensure compliance
- Owner-installers – understand what you may and may not do and appreciate that the regulations are pure common sense to protect your family’s health
Is Planning Permission Required To Install A Rainwater Harvesting System?
For planning purposes, rainwater harvesting systems are considered to be rainwater recycling processes. That means “permitted development” rights apply to them. Therefore planning permission is not generally
required.Regardless of that, it makes sense to mitigate any risk by checking with your planning office. On a positive note, local authorities view the inclusion in plans and proposals of environmentally friendly features for new builds as a positive when assessing planning applications.
What Are The Relevant Regulations For UK Rainwater Harvesting?
These are the primary guidelines:
- Water Regulations Advisory Scheme (WRAS)
- BS EN 16941-1:2018 (this supersedes BS 8515:2009)
- BRE Environmental Assessment Method (BREEAM)
Water Regulations Advisory Scheme (WRAS)
These regulations cover the supply of water in general, specifically mains water, and how connections should be made to supply buildings. That includes low level features such as the types of valve and fittings that should be used to connect to the mains water supply. Preventing backflow from a non-potable source into the mains water supply is the priority, to avoid possible contamination of drinking water. It means that where the rainwater harvesting system connects to the mains water supply (e.g. as a backup sources if stored rainwater supplies become exhausted) then a physical air gap must be deployed so that non-potable water cannot be siphoned back into the drinking water supply. There are some, though currently very few, rainwater harvesting units which have gained WRAS approval.
Included in WRAS are The Water Supply (Water Fittings) Regulations 1999 (England and Wales). Scotland and N.I. have their own legislation. More information on the WRAS website, which also provides a complete list of what you need to do to achieve compliance.
BS EN 16941-1:2018 Rainwater Harvesting Systems
This is a recommended Code of Practice that sets out to deliver consistent installation standards and water quality. It covers risk management, testing and ongoing care and maintenance of rainwater harvesting systems. It also makes recommendations to systems suppliers with the aim of ensuring a very high standard of excellence for all installations.
Building Research Establishment Environmental Assessment Method (BREEAM)
This is not a legal requirement but defines a methodology for assessing sustainable construction of commercial buildings. The objective is to foster the active consideration of environmentally friendly approaches and features for new builds. See more on the BREEAM website.
Water Pipe Labeling
Harvested rainwater must be clearly labelled as non-potable, which is also known as “non-wholesome” or not suitable for drinking. It is vitally important to clearly identify pipes that convey rainwater, whether inside a building or in the ground outside. Appliances, outlets and valves on a rainwater system inside the building must be identified in accordance with WRAS Guideline IGN 9-02-5. Common examples would be a label inside the lid of a WC cistern, or on a washing machine that uses rainwater.
Professional suppliers such as Rainharvesting Systems Ltd are always happy to help with advice and reviewing designs as well as undertaking entire installations. Contact us today for a free consultation to review your proposals.