What is BS 7181 – Specification for storage cisterns about? 
Storage cisterns are primarily used to store water for domestic and consumptive purposes in households or buildings. Cisterns are typically found in areas where a potable water source is not available in the community, the area yields low well water capacity, or the groundwater quality is poor.
BS 7181 specifies the performance requirements for cisterns up to 500 L actual capacity designed for the storage of water for domestic purposes.
The main objective of BS 7181 is to provide best industry guidance for storage cisterns to ensure they are fit for providing clean and safe water for domestic use and consumption.
Note: Flushing cisterns are outside the scope of BS 7181.
Who is BS 7181 - Specification for storage cisterns for?  
BS 7181 on specification for storage cisterns is relevant to: 
- Anyone involved in manufacturing, designing, installing, maintenance and commissioning of storage cisterns
- Quality control and testing personnel 
- Local bodies
- Regulatory authorities
Why should you use BS 7181 - Specification of storage cisterns?  
Cisterns are large tanks that store rainwater collected from impervious surfaces for domestic uses or for consumption. To ensure that the play a positive role in supplying clean water, it is vital that best industry specifications for storage cisterns be considered.
In this regard, BS 7181 provides guidance on appropriate materials, design and construction considerations along with testing and marking requirements.
BS 7181 specifies additional performance requirements for cisterns and associated fittings to assist in safeguarding against waste and contamination. The fittings include cistern covers, screen air inlets, screened warning pipe and vent pipe entry devices.
BS 7181 also deals with insulation to safeguard cisterns against freezing or warming termination assemblies and it provides methods of test for the assessment of the ingress of particles and insects and for the performance of thermal insulation.
As a result, compliance with BS 7181 guidance can determine whether or not storage cisterns are fit for purpose and if they are capable of safeguarding the integrity of stored water for domestic purposes.
