C. Events Affecting Water Quality
Investigating events that affect drinking water quality
Learning lessons and preventing events from recurring
Taking the necessary action against water companies
Water Companies Are Required To Report All Water Quality Problems To The Inspectorate
The Water Undertakers (Information) Direction 1998 (the "Information Direction") requires water companies to inform the Inspectorate of all events that have affected or are likely to affect drinking water quality.
Companies are required to notify the Inspectorate as soon as possible of any events which, in their opinion, meet any of the criteria prescribed in the Information Direction.
DWI Information Letter 13/99 provides further guidance on those criteria.
Notified events must be confirmed in writing within 72 hours and a full report must be provided within one month for all incidents.
Companies are also encouraged to notify the Inspectorate of events not meeting the prescribed criteria but which could impact on water quality or cause concern to consumers.
Water quality events are classified according to the following definitions:
Event
Any occurrence which by its nature is required to be notified under the Information Direction. It is not possible to provide an exhaustive list of situations that are regarded as events. Water companies have to use their judgement in any particular set of circumstances.
Incident
A sub-set of events defined by the Inspectorate to include:
a non-trivial and unexpected breach of Part II of the Regulations; or
a breach of Part VI of the Regulations; or
an unusual deterioration in water quality; or
a significant risk to the health of consumers; or
adverse water quality changes perceived by consumers as significant; or
a cause for significant media interest.
Non-incident
All other event notifications not classified as incidents.
Full text of the Water Undertakers (Information) Direction 1998 and DWI Information Letter 13/99 can be found on the web site under ‘Information Direction’ and ‘Information Letters’.
DWI Inspectors Assess Every Event And If Required Take Action Against Water Companies
The Assessment - Inspectors assess the water company’s report to determine:
what caused the problem and whether or not it was avoidable;
what the company did in response and how it handled the incident;
what lessons can be learned to prevent similar incidents in the future;
if there were any breaches of enforceable regulations; and
whether the company supplied water that was unfit for human consumption.
The Outcome - This table summarises the typical outcomes of assessments based on the severity of the problem and the actions taken as a result.
Outcome of Assessment Action Taken No breaches of regulations.
Company acted appropriately in response to the problem.Letter of assessment is sent to the company, and, where appropriate copied to the National Assembly for Wales, relevant local and district health authorities and to OFWAT. Breaches of regulations and/or deficiencies in response. Letter of assessment to the company, including recommendations for action which the company must take to address problems which the incident exposed. The National Assembly for Wales (where appropriate), relevant local and district health authorities and OFWAT are informed of the outcome. Significant or repeated breaches of enforceable regulations. Enforcement action initiated against the company. A legal process to ensure that the company takes all necessary action to prevent further breaches. The National Assembly for Wales (where appropriate), relevant local and district health authorities and OFWAT are informed of the outcome. Supply of water unfit for human consumption as a result of either deficiencies in the company’s response or failings in its actions. Initiation of either prosecution proceedings against the company or the issue of a formal caution for a criminal offence. The National Assembly for Wales (where appropriate), relevant local and district health authorities and OFWAT are informed of the outcome.
More detail on the assessment process including a flow diagram which illustrates the process and timescale in which incidents and non-incidents are managed by water companies and the DWI respectively is available on this web site.
Details Of Events Notified And Assessments During 2000
Brief descriptions of all incidents are given in the relevant individual company sections in Part 2 of this report. A total of 139 incidents, which affected the quality of water supplied to approximately 2.6 million consumers, were notified to the Inspectorate during 2000. The period during which water quality was actually or potentially compromised ranged from a few hours to several days. In addition, 290 notifications were made which were classified as non-incidents.
As at 31 March 2001, a total of 58 (37 from 2000 and 21 pre-2000) assessments were outstanding. If prosecution proceedings are to be initiated, the assessment of an incident will not be completed until the prosecution proceedings have been concluded.
The following table summarises the Inspectorate’s position on 31 March 2001 in assessing the incidents and non-incidents notified under the Information Direction.
Incidents Notified in 2000:
Non-Incidents Notified in 2000:139
290Total Number of Events in 2000 429
2000 Events Assessed: 392 No action required:
Recommendations:
Enforcement Action:
Caution:
Prosecutions:335
53
3
1
0Pre- 2000 Events Assessed in 2000: 54 No action required:
Recommendations:
Enforcement Action:
Caution:
Prosecutions:8
32
0
7
7Total Number of Assessments Completed in 2000 446
2000 Assessments Outstanding:
Pre-2000 Assessments Outstanding:37
21Total Number of Assessments Outstanding 58
Incidents are categorised by the nature, origin and effect of the problem. The chart below provides a breakdown and a four-year comparison (1997 - 2000) of incident categories.
The number of notifications made to the Inspectorate that have been considered as incidents has fallen for the first time since 1997. This is because companies have improved their procedures and practices.
The number of notifications not regarded as incidents has risen to 290. This is due in part to improved arrangements for, and guidance on, the reporting of significant events.
It should be noted that following completion of assessment by the Inspectorate, a few of the events initially classified as incidents might be re-classified as non-incidents, and vice versa.
Companies Prosecuted or Cautioned for Supplying Water Unfit for Human Consumption
The Inspectorate completed successful prosecutions against three water companies during the report period relating to seven incidents that occurred in 1998 and 1999. It also issued formal cautions to four companies relating to a further seven incidents which occurred between 1997 and 2000. Brief details of prosecutions and cautions are contained in the tables below.
In addition, there is currently one case pending court for Yorkshire Water.
PROSECUTIONS Date of Incident Date of Court Case Company Incident Details Fine Costs 21.04.98 06.10.00 North West Water Wallasey - Discolouration of supplies following planned work on the distribution system. Three other cases: St Helens (September 1998); Eccles (October 1998); and Rainford (February 1999) taken into consideration. £12,000 £10,471 13.01.99 13.10.00 North West Water Nantwich - Contamination of water supplies with hydrocarbons following recycling of contaminated surface water to the wash water recovery system at Hurleston treatment works. Two other cases:Cheadle Hulme (October 1998); and Macclesfield (January 1999) taken into consideration. £20,000 £7,100 08.05.98 08.12.00 Yorkshire Water Sheepscar area of Leeds - Discolouration of supplies resulting from disturbance of mains sediment caused by flow changes during planned work. £21,000 £125,599 (combined costs) 11.06.98 08.12.00 Yorkshire Water Drighlington - Discolouration following overnight tests carried out on the distribution system by the Company. £28,000 02.07.98 08.12.00 Yorkshire Water Idle Hill area of Bradford - Discolouration following the return to supply of Idle Hill service reservoir which had been out of supply for several years. £20,000 05.11.98 08.12.00 Yorkshire Water Marton cum Grafton and Boroughbridge - Discolouration following operational problems at Marton Treatment Works following planned work on the raw water main. The Company pleaded not guilty to charges relating to three other incidents that occurred in 1997 and 1998 but the trial judge ordered that these should remain on the file. £50,000 01.08.98 12.03.01 Mid Kent Water Hadlow - Discolouration of supplies as a result of poor supervision of a mains refurbishing scheme being carried out as part of the Company’s distribution system undertaking. £12,000 £43,077
FORMAL CAUTIONS Date of Incident Date of Caution Company Incident Details 31.07.97 10.04.00 Sutton & East Surrey Water Morden - Discolouration of supplies following planned work on the distribution system. 12.05.99 04.05.00 North West Water Oldham - Contamination of water supplies with diesel oil during planned work on the distribution system carried out during adverse weather conditions. 26.08.99 03.05.00 Wessex Water Market Lavington - Supply of discoloured water following operational problems at the water treatment works. 11.05.98 15.06.00 North West Water Whitworth - Contamination of the water supplies with PAHs during planned refurbishment of the distribution system. 21.03.00 07.08.00 Three Vallleys Water Foster Street Booster - Discolouration of supplies following planned valve operations. 15.01.98 15.08.00 North West Water Rochdale - Discolouration of supplies following repairs to a burst main. 31.01.98 21.09.00 North West Water Ormskirk - Discolouration of supplies following the emptying of a service reservoir.
The following table gives the number of prosecutions and cautions that have taken place following DWI's investigation of incidents, which were concluded between 1997 and 2000. It also shows the number of cases pending court and the number of incidents that are still under consideration as at 31 March 2001. In studying the table it is important to take into account the following:
the number of incidents occurring can be expected to be proportional to the size of the water company and particularly the length of the distribution system;
companies with no incidents in these categories are not included in the table;
many are minor events affecting a small number of consumers;
many of the events occur for reasons outside the control of water companies, e.g. a burst main;
prosecution cases take at least a year to get to Court so they do not necessarily reflect the position today.
Water Company Incidents and Prosecutions 1997 - 2000 Water Company Population Supplied KM of Mains No of Incidents Notified in Year Prosecutions (Cautions) Completed in Year Cases Pending Court at 31/03/01 Incidents Still Under Investigation as at 31/03/01
1997 1998 1999 2000 1997 1998 1999 2000
Anglian 4,000,000 35,233 9 13 16 18 - - 2 - - 3 Bournemouth and W Hants 431,000 2,800 0 1 0 0 - - - - - - Dee Valley 257,100 1,953 1 1 1 0 - - - - - - Dwr Cymru 2,800,000 24,900 13 10 9 11 3 3 - - - 5 Essex & Suffolk 1,700,000 8,370 4 2 5 4 - - - - - 2 Folkestone & Dover 160,000 1,068 0 0 0 2 - - - - - - Hartlepool 91,000 513 0 0 0 1 - - - - - - Mid Kent 563,300 4,167 0 2 4 0 - - - 1 - 2 North Surrey 480,000 2,500 1 0 0 0 - - - - - - North West 6,800,000 42,200 12 34 27 16 - 1 2 3 (4) - 3 Northumbrian 2,600,000 16,515 14 13 12 11 - 1 - (1) - 1 Portsmouth 647,000 3,200 1 1 4 1 - - - - - 2 Severn Trent 7,356,000 41,000 5 9 20 19 - 1 1 - - 4 South East 1,400,000 9,554 3 3 4 7 - 1 2 - - - South Staffs 1,200,000 5,738 2 0 1 3 - - - - - 1 South West 1,500,000 15,000 8 3 4 7 1* - 2 - - 1 Southern 2,220,000 13,302 1 2 2 3 - - - - - - Sutton & East Surrey 634,000 3,374 2 1 2 0 - 1 - (1) - - Tendring 145,000 930 1 1 1 0 - - - - - - Thames 7,500,000 31,500 4 9 13 7 - - 1 - - 6 Three Valleys 2,400,000 11,000 2 1 10 9 - - - (1) - - Wessex 1,200,000 10,800 4 3 4 4 - (1) - (1) - - Yorkshire 4,710,000 30,000 15 15 27 16 - 1 (1) - 4 1 18 TOTAL 50,794,400 315,617 102 124 166 139 4 (0) 9 (2) 10 (0) 8 (8) 1 48
* The Company was acquitted of all charges.
More detail on incident investigation, prosecution policy and action taken to date can be found on this web site.
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Drinking Water Inspectorate,
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Published 11 July 2001
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