Information Letter

DWI Information Letter 08/2005

21 June 2005

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

Dear Sir or Madam

TECHNICAL AUDIT OF WATER COMPANIES UNDER SECTION 86 OF THE WATER INDUSTRY ACT 1991: SUMMARY REPORT FOR THE VERTICAL AUDITS FOR NON MICROBIOLOGICAL PARAMETERS, 2004

Background

1. The annual inspection process has always included a number of vertical audit trails for selected parameters. In recent years the Inspectorate has refined the process to take account number of parameters audited in relation to the size of the company and also way in which the parameters are selected. For the 2004 inspection cycle, the audits were again divided into microbiological and non-microbiological parameters.
   
   
2. Dr Peter Whittle, a consultant appointed as a DWI Temporary Inspector, was commissioned to carry out the non-microbiological audits.
   
   
3. A risk based approach was taken on the number of samples to be audited, based on the relative size of the company in terms of population supplied and findings from the 2003 audits. For the smaller companies just two samples were selected for audit, increasing to a maximum of 16 samples for the larger companies. Three companies had extra samples included in their audit programme because of specific local issues.
   
   
4. Five key parameters were selected for audit. These were, in order of precedence, residual chlorine, isoproturon, lead, benzene, and hydrogen ion. Chlortoluron was substituted where isoproturon was not scheduled for the chosen sample point. Each Audit Inspector selected the samples to be audited for their companies and every effort was made to ensure that the sample selected was timely and appropriate.
   
   
5. The total number of samples audited was 215. Dr Whittle found the presentation of audit data to be generally excellent compared to previous years, and he would like to thank the companies for their efforts. In order to reduce the amount of paperwork, especially for those companies using contract laboratories, Dr Whittle offered to inspect all basic metrology records when he visited the laboratory. In practice this worked well, although not all the larger companies took up the offer.
   
   
6. Dr Whittle identified serious deficiencies in sample scheduling with a number of companies, mainly as a result of implementing the new Regulations. He considered that in general the standard of analysis had improved since his 2003 audits. However he still had concerns over the lack of quality control for residual chlorine monitoring. He also had concerns over sample stability and sample pre-treatment.

Purpose

7. Dr Whittle summarised the findings of his audits for the Inspectorate. The purpose of this letter is to share those findings with the industry. The attached summary report not only identifies recurrent themes and deficiencies, it also provides a short review of the methods of analysis and method performance. However reference to individual companies and their laboratories has been deliberately removed.
   
   
8. Dr Whittle made a total of 88 recommendations where, in his opinion, action was required to avoid a foreseeable risk of breaching a regulatory duty, and 58 suggestions on general good practice. The Inspectorate endorses Dr Whittle’s findings and recommendations.
   
   
9. Dr Whittle also made a number of recommendations to the Inspectorate in terms of follow up actions to be taken with specific companies. These will be taken account of during the 2004 round of inspections.
   
   
10. Dr Whittle also made six recommendations to the Inspectorate on areas where guidance would be beneficial or where further audits would be appropriate. The Inspectorate will be taking action on these recommendations.

Enquiries

11. Copies of this letter are being sent to Pamela Taylor, Chief Executive, Water UK; Richard Wood, Water Supply and Regulation Division, Department for Environment, Food and Rural Affairs; June Milligan, Environment Division, The National Assembly for Wales; Tim Hooton, Drinking Water Quality Regulator for Scotland; Randal Scott, Drinking Water Inspectorate for Northern Ireland; and Rowena Tye, Office of Water Services.
    
    
12. This letter is being sent electronically to Board Level contacts. Please acknowledge receipt by email to dwi.informationletters@defra.gsi.gov.uk. Hard copies are not being sent but the letter may be freely copied. Any enquiries about the letter should be addressed directly to me.

Yours sincerely

Miss C R Jackson
Deputy Chief Inspector of Drinking Water

In Word format: (243KB)

Summary Report on the 2004 Non Microbiological audit trials