BS 8525-1:2010 PDF

BS 8525-1:2010 Greywater systems. Code of practice On-site collection and use of greywater is an alternative to public mains or private potable water supply. Greywater has a variety of non-potable water uses in the home, workplace and garden. As greywater systems become more popular, there is a need for standardization to protect the public and to ensure that reliable systems are designed, installed and maintained. Types of greywater systems: Greywater systems vary significantly in their complexity and size, and can be grouped according to the type of filtration or treatment they use, as follows. a) Direct reuse systems (no treatment) These systems use simple devices to collect greywater from appliances and deliver it directly to the points of use, with no treatment and minimal, or no, storage, e.g. a greywater diverter valve. b) Short retention systems These systems apply a very basic filtration or treatment technique, such as skimming debris off the surface of the collected greywater and allowing particles to settle to the bottom of the tank. They aim to avoid odour and water quality issues by ensuring that the treated greywater is not stored for an extended period. c) Basic physical/chemical systems These systems use a filter to remove debris from the collected greywater prior to storage while chemical disinfectants (e.g. chlorine or bromine) are generally used to stop bacterial growth during storage. d) Biological systems These systems use aerobic or anaerobic bacteria to digest any unwanted organic material in the collected greywater. In the case of aerobic treatment, pumps or aquatic plants can be used to aerate the water. e) Bio-mechanical systems These systems, the most advanced for d...