Yorkshire Water Services Limited
Overall Water Quality supplied by Yorkshire Water in 2000
A total of 273,309 tests were carried out by Yorkshire Water in 2000. Of these tests, 99.89% complied with the Regulations.
Company Information Amount of Water Supplied: 1,257 Ml/d Consumers Supplied: 4.71 million Areas of Supply: Yorkshire and North Humberside Water Composition: 78% from rivers and reservoirs
22% from boreholes and aquifersTreatment Works: 121 Service Reservoirs: 432 Km of Mains: 30,000 Water Supply Zones: 214 Water Quality in Supply Zones, at Treatment Works, and in Service Reservoirs
Water supply zones
In general, to be wholesome, water must comply with the standards set out in the Regulations. The Company carried out a total of 206,937 tests on samples taken in its 214 water supply zones. The table below includes only the parameters that breached the standard. All other parameters fully complied with the standards. Parameter meanings can be found at the beginning of this section.
- The last column indicates the number of failures in zones already covered by legally binding undertakings given by the Company to carry out remedial works to overcome the difficulty in meeting the individual standard.
Parameter
Total samples taken
Samples not meeting the standard
Percentage
Number of failures already covered by undertakings
Total coliforms
12,490
34
0.27
-
Faecal coliforms
12,490
8
0.06
-
Colour
12,391
3
0.02
1
Turbidity
12,487
8
0.06
6
Nitrite
1,983
42
2.12
-
Hydrogen ion
12,487
17
0.14
3
Aluminium
6,495
14
0.22
6
Iron
6,533
84
1.29
82
Manganese
6,496
20
0.31
18
Lead
990
3
0.30
-
PAH
957
11
1.15
6
Trihalomethanes
1,159
8
0.69
-
Isoproturon
1.093
4
0.37
4
Benzo3,4 pyrene
967
4
0.41
-
.
Treatment works
Of the Company’s 121 treatment works, 116 (96%) complied fully with the relevant standards. Failures at the remaining five treatment works were considered trivial or unlikely to recur. Differences over the last three years in the number of treatment works, and samples from treatment works, in which coliforms were detected are not considered significant. Service reservoirs
Failures of the standard for faecal coliforms at eight service reservoirs were considered trivial or unlikely to recur. Enforcement action is being considered for breaches of faecal coliform standard at one service reservoir. There have been significant decreases over the last three years in the number of service reservoirs, and samples from service reservoirs, in which total coliforms were detected. All other differences are not considered significant.
- At all of the Company's 432 service reservoirs, coliforms were absent from at least 95% of samples.
Company Audit and Inspection Link to expanded information (web site version)
- The Company was inspected or audited by DWI or its appointed consultants on six occasions in 2000. Where relevant, report summaries are available in the ‘Business and Technical’ section of DWI’s web site under ‘Audit and Inspection’.
Audit or Inspection
Date
Annual assessment of 1999 compliance data.
April / May
Audit trails of five samples
September
Audit of plumbosolvency treatment and control programs of work
November
Follow-up of response to recommendations and audit of arrangements for Cryptosporidium sampling
November
Review of procedures for operation and maintenance of the distribution network
December
Inspection of distribution system improvement programme progress.
Ongoing
A number of recommendations for improvements were made, especially in relation to analytical arrangements and Cryptosporidium sampling arrangements. Incidents
- The Inspectorate regarded 16 of the events notified during 2000 by the Company as incidents in which drinking water quality demonstrably deteriorated.
- Seven of the incidents have been assessed by DWI. Each was of relatively short duration and in all cases the Company took appropriate remedial action. Five recommendations were made to the Company, mainly regarding operations.
- During 2000 assessments were also completed for four incidents that occurred in 1999 and for the seven incidents that occurred in 1997 and 1998 that were the subject of lengthy legal proceedings (see below).
- Nine incidents from 2000 remain under consideration, together with nine from 1999.
Nature of Incident
No. of Incidents
Assessment by DWI Completed
Areas Affected
Supply of discoloured water
5
Yes
Bradford (January, March and October); Sheffield (January), Ripon (August)
6
No
Holmfirth (March); Sheffield (August and October); NE Leeds (November); Bradford (November and December)
Wholesomeness concerns relating to water treatment works
1
Yes
Oughtershaw (May)
3
No
West Stonesdale (September); Sladen Valley (October); Thornton Steward Service Reservoir (November)
Partial loss of disinfection
1
Yes
Gorpley Water Treatment Works (September)
Prosecutions
- In 1999 DWI initiated legal proceedings against Yorkshire Water in respect of seven incidents that occurred in 1997 and 1998. All involved the supply of discoloured water and affected consumers in parts of West Leeds (March 1997), parts of West Sheffield (December 1997), the Sheepscar area of Leeds (May 1998), parts of Drighlington (June 1998), parts of the Idle Hill area of Bradford (July 1998), parts of Addingham (August 1998) and parts of Marton-cum-Grafton and Boroughbridge (November 1998).
- On 5 December 2000 the Company pleaded guilty at Leeds Crown Court to offences under Section 70 of the Water Industry Act 1991 of supplying water unfit for human consumption during four of these incidents, and not guilty to charges relating to the other three incidents. For further information please see ‘Events affecting Water Quality’ in Part 3.
Improvement Programmes Carried Out by the Company
- Three remedial programmes were due for full completion during 2000 and they were completed on schedule.
- The ongoing distribution system improvement programmes due for completion in 2010, which have been implemented by the Company, have been progressing satisfactorily.
Enforcement action
- The table below indicates areas where DWI is considering, or has taken enforcement action for, breaches of regulations.
Parameter/Area
Number
Regulation Breached
Faecal coliforms
1 service reservoir
Regulation 3(7)
Hydrogen ion
3 zones
Regulation 3(3)(c)
Aluminium
2 zones
Regulation 3(3)(c)
Trihalomethanes
1 zone
Regulation 3(3)(e)
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Drinking Water Inspectorate,
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Telephone : 020 7944 5956 - Facsimile : 020 7944 5969
E-mail: dwi_enquiries@detr.gov.uk
Published 11 July 2001
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