Information Letter

DWI Information Letter 10/2004

25 October 2004

To: Board Level and Day to Day Contacts of Water and Sewerage Companies in England and Wales

Dear Sir or Madam

Monitoring drinking water at establishments where water is supplied to the public

Purpose

1. The purpose of this letter is to inform water companies of the actions they need to take to ensure that England and Wales complies with the requirements of Article 6(2) of Council Directive 98/83/EC on the quality of water intended for human consumption (the Drinking Water Directive) in respect of establishments where water is supplied to the public.
   

Background

2. Article 6 of the Drinking Water Directive deals with the point of compliance. Paragraph 6(2) states inter alia that Member States shall be deemed to have fulfilled their obligations where it can be established that non-compliance with the parametric values is due to the domestic distribution system or the maintenance thereof except in premises and establishments where water is supplied to the public, such as schools, hospitals and restaurants.
   
   
3. At present there is no separate requirement for monitoring drinking water quality at premises and establishments where water is supplied to the public (public buildings). Some water companies include such establishments in their random monitoring programmes but others exclude them. The Department for Environment, Food and Rural Affairs (Defra) has given consideration to drafting Regulations specifically for monitoring drinking water in public buildings. However, in consultation with the Drinking Water Inspectorate, Defra has now decided that, in line with the policy in most other Member States, the most efficient way for such premises to be monitored is for them to be included in water companies’ random compliance monitoring programmes.
   
   
4. Research sponsored by Defra ¹ managed by the Drinking Water Inspectorate has estimated that there are about 225,000 public buildings in England and Wales. A list of premises and establishments and estimated numbers in each category is given in the Appendix to this letter. Under the requirements of the Water Supply (Water Quality) Regulations 2000 ² water companies in England and Wales currently take about 143,000 randomly selected samples in water supply zones annually. If 10% of these samples were taken from public buildings every year then the majority of the stock could be covered over a period of 18 to 20 years. The Inspectorate recognises that some adjustment to the present arrangements for random sampling will be required to achieve the projected percentage and coverage for all relevant parameters; also it is understood there is some degree of turnover amongst premises in certain categories of public buildings. This information letter sets out the process and timescales by which it is proposed to introduce these changes.
   

Monitoring drinking water supplies in public buildings

5. As a first step towards the 10% coverage target, from 1 January 2005 the Drinking Water Inspectorate requires ALL water companies to select from ALL premises and establishments (ie including public buildings) within their area of supply in their random compliance monitoring programmes for water supply zones. This should not present any technical difficulties as companies are already identifying their random sampling sites by postcodes or map reference. Companies are encouraged to develop a knowledge of the public buildings within their area of supply with a view to developing protocols for achieving an appropriate rate of coverage of samples and parameters to protect public health. When reporting the monthly compliance samples and results to the Drinking Water Inspectorate a sample taken from a public building should be identified with the public building “PB” text flag already available within the data reporting systems that companies are now using. It would be helpful if companies that have included public buildings in their sampling programmes since 1 January 2004 could retrospectively provide the Inspectorate with a separate list of those samples to enable the database to be updated with the “PB” text flags.
   
   
6. At the end of September 2005, when six months’ data from public building sampling by all companies has been collected, the Inspectorate will assess the number of samples taken, the parameters tested and the analytical results. It will then discuss the outcome of this review with the water industry so that any further guidance can be issued in time for implementation with effect from 1 January 2006.
   
   
7. Samples in public buildings should be taken at a tap normally used to supply water to the public or for food preparation purposes. As is known to water companies the principal purpose of the Drinking Water Directive is the protection of public health and this is reflected specifically in the Directive requirement for water in public buildings to meet its quality requirements irrespective of the whether any non-compliance is due to the domestic distribution system or the maintenance thereof. It is for this reason that the Drinking Water Inspectorate requires that taps in public buildings should not be disinfected prior to sampling for microbiological parameters. Research ¹ has demonstrated that this approach is unlikely to increase the number of samples contravening microbiological or other quality standards. Water companies may consider it appropriate to make this change to sampling procedures for all randomly selected samples. The Inspectorate will be proposing an amendment to the best practice document Microbiology of Drinking Water 2002 to bring it up to date in this respect.
   
   
8. The longer term need to protect and, where necessary, improve the quality of water supplies within public buildings and consumers’ premises will be addressed through the development of a comprehensive Water Safety Plan for the Quality of Water in Large Buildings. This approach is being led by the Drinking Water Inspectorate in consultation with Defra and other stakeholders, and in collaboration with the World Health Organisation. However, water companies are reminded that existing regulatory requirements need to be met. If a sample taken from a public building fails to meet the concentration or value for a microbiological, chemical or national parameter, a water company must take the action required by regulation 17 of the Water Supply (Water Quality) Regulations 2000. Similarly for a contravention of an indicator parameter, regulation 18 must be followed. If a failure is attributable to the domestic distribution system or the maintenance of that system, water companies must consider if action is required by them or the building owner under the Water Supply (Water Fittings) Regulations 1999. However should the required action against or by the public building owner fall outside of the scope of the Water Supply (Water Fittings) Regulations, this will not be the responsibility of water companies to enforce. Water companies are required by regulation 17(5) to communicate, to consumers likely to be affected by the failure, the nature of the failure and the steps required in the interest of consumers health. In the case of a public building the information should be sent to the owners and representatives of the building. In all cases the information should be copied to the Secretary of State (in practice DWI) and the local authority. As part of their general duty of care as experts in water quality, water companies will want to give thought to making their communications with building occupiers, owners and local authorities about any identified risks and remedial actions as clear and helpful as possible.
   
   
9. Water companies may have concerns that sampling from public buildings will reflect adversely on drinking water quality as measured by random sampling in water supply zones, particularly with respect to microbiological water quality. In the first six months of 2004, of 71, 844 randomly selected samples taken within zones, 297 failed the standard for total coliform bacteria, 19 failed the standard for Escherichia coli and six failed the standard for Enterococci. Again, research ¹ has indicated that the microbiological quality of drinking water in public buildings is at least as good as these results. There will be a benefit to water companies from sampling in public buildings because access is normally easier than it is for private domestic dwellings reducing the necessity for samplers to go from door to door to seek someone at home. Also, previously water companies often used fixed points in public buildings as sampling points for reasons of access and representative water quality.

Enquiries

10. Any enquiries about the letter should be addressed to David Drury (020 7082 8018, david.drury@defra.gsi.gov.uk ). I am copying this letter for information to Pamela Taylor, Chief Executive, Water UK; Richard Wood, Water Supply and Regulation Division, Department for Environment, Food and Rural Affairs; Philip Bishop, Environment Division, National Assembly for Wales; Tim Hooton, Drinking Water Quality Regulator for Scotland; Randal Scott, Drinking Water Inspectorate for Northern Ireland; Rowena Tye, Office of Water Services; and Jamie Bartram, World Health Organisation .
    
    
11. This letter is being sent electronically. Please acknowledge receipt by e-mail to dwi.informationletters@defra.gsi.gov.uk. Hard copies are not being sent, but the letter and attachment may be freely copied.
    
    

Yours sincerely

Prof Jeni Colbourne
Chief Inspector
Drinking Water Inspectorate

^1. WRc Report for Defra on Water Quality in Public Buildings 2003 (available from FWR (www.fwr.org))

^2. The Water Supply (Water Quality) Regulations 2001 in Wales

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