In the Secretary of State’s view Requirement G1(1) will be met if:
a. the water supplied is wholesome;
b. the pressure and ﬂow rate is sufﬁcient for the operation of sanitary appliances planned in the building;
c. the supply is reliable; and
d. the installation conveys wholesome water or softened wholesome water to the sanitary appliances and locations speciﬁed in the Requirement without waste, misuse, undue consumption or contamination of water.
The water will be wholesome if it is provided:
a. by a statutory water undertaker or a licensed water supplier; or
b. by a source complying with the Private Water Supplies Regulations 2009 (SI 2009/3101) in England or the Private Water Supplies (Wales) Regulations (SI 2010/66) in Wales.
In the Secretary of State’s view Requirement G1(2) will be met if:
a. the water supplied is either wholesome, softened wholesome or of suitable quality having regard to the risks to health;
b. the pressure and ﬂow rate is sufﬁcient for the operation of the sanitary appliances;
c. the supply is reliable; and
d. the installation conveys water to sanitary appliances and locations speciﬁed in the Requirement without waste, misuse, undue consumption or contamination of wholesome water.
1.1 Water supplied to the building by a statutory water undertaker or a licensed water supplier through an installation complying with the requirements of the Water Supply (Water Fittings) Regulations 1999 (SI 1999/1148 as amended) may be assumed to be wholesome water. The requirements in the appropriate water quality regulations are set out for ease of reference in Annex 1 to this Approved Document.
1.2 Attention is drawn to the requirements of the Water Supply (Water Fittings) Regulations 1999 (SI 1999/1148 as amended) which make provision for preventing contamination, waste, misuse, undue consumption and erroneous measurement of water supplied by a water undertaker or licensed water supplier.
1.3 Where a building is supplied with water from a source other than a water undertaker or licensed water supplier, the water shall be considered to be wholesome if it meets the criteria set out in the Private Water Supplies Regulations 2009 (SI 2009/3101) in England or the Private Water Supplies (Wales) Regulations (SI 2010/66) in Wales. The requirements in those regulations are set out for ease of reference in Annex 1 to this Approved Document.
Softened wholesome water
1.4 Wholesome water which has been treated by a water softener or a water softening processes to adjust the content of hardness minerals may have raised levels of sodium. Where the water, after this treatment, still complies with the requirements for wholesome water it is still considered to be wholesome water.
1.5 However, where it complies with all requirements for wholesome water other than its sodium content, it will be considered to be wholesome softened water. Whilst wholesome softened water may be considered suitable for most purposes it should not be provided in place of wholesome water to any place where drinking water is drawn off or to any sink provided in an area where food is prepared.
Alternative sources of water
1.6 Water treated to the high standards of wholesome water is not essential for all of the uses that water is put to in and about buildings, e.g. toilet flushing, irrigation. A variety of alternative sources are available for water. These include:
a. water abstracted from wells, springs, bore-holes or water courses;
b. harvested rainwater;
c. reclaimed greywater; and
d. reclaimed industrial process water.
1.7 The design of treatment systems for water from alternative sources should incorporate measures to minimise the impact on water quality of:
a. failure of any components;
b. failure to undertake any necessary maintenance;
c. power failure where appropriate; and
d. any other measures identified in a risk assessment.
1.8 Guidance on the marking of pipework conveying water from alternative sources can be found in the WRAS Information & Guidance Note No. 9-02-05 Marking and identification of pipework for reclaimed (greywater) systems and in BS 8515:2009 Rainwater harvesting systems – Code of Practice.
1.9 Guidance on installing, modifying and maintaining reclaimed water systems can be found in the WRAS Information and Guidance Note No. 9-02-04 Reclaimed water systems and in BS 8515:2009 Rainwater harvesting systems. Code of practice.
1.10 Information on the technical and economic feasibility of rainwater and greywater can found in MTP (2007) Rainwater and greywater: technical and economic feasibility.
1.11 Information on the specification of rainwater and greywater systems can be found in MTP (2007) Rainwater and greywater: a guide for specifiers.
1.12 Guidelines for rainwater and greywater systems, in relation to water quality standards, can be found in MTP (2007) Rainwater and greywater: review of water quality standards alternative and recommendations for the UK.
1.13 Water from alternative sources may be used in dwellings for sanitary conveniences, washing machines and irrigation, provided the appropriate risk assessment has been carried out. A risk assessment should ensure that the supply is appropriate to the situation in respect of the source of the water and the treatment of it, and not likely to cause waste, misuse, undue consumption or contamination of wholesome water.
1.14 Any system/unit used to supply dwellings with water from alternative sources should be subject to a risk assessment by the system designer and manufacturer, and appropriate testing carried out to demonstrate that any risks have been suitably addressed. A risk assessment should include consideration of the effect on water quality of system failure and failure to carry out necessary maintenance.