25 Yorkshire Water Services Limited
Overall Water Quality supplied by Yorkshire Water Services Limited in 2001
- A total of 265,024 tests were carried out by Yorkshire Water Services Limited in 2001.
- Of these tests, 99.91% complied with the Regulations.
Company Information
Amount of Water Supplied: 1,304 Ml/d
Consumers Supplied: 4.71 million
Areas of Supply: Yorkshire
Water Composition: 78% from rivers and reservoirs
22% from boreholes and aquifers
Treatment Works: 109
Service Reservoirs: 418
Km of Mains: 31,000
Water Supply Zones: 205Water Quality in Water Supply Zones, at Treatment Works, and in Service Reservoirs
Water supply zones
- To be wholesome, water must comply with the standards set out in the Regulations. The Company carried out a total of 201,903 tests on samples taken in its 205 water supply zones. The table below includes only the parameters that breached the standard; all other parameters were fully compliant. A list of these parameters and their significance 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. These undertakings required remedial work to be carried out to ensure compliance with the individual standard.
Parameter Total samples taken Samples not meeting the standard Percentage Number of failures already covered by undertakings Total coliforms 12,563 45 0.36 0 Faecal coliforms 12,563 1 0.01 0 Colour 12,562 1 0.01 0 Turbidity 12,561 9 0.07 7 Nitrate 1,863 2 0.11 0 Nitrite 1,897 20 1.05 0 Aluminium 6,509 4 0.06 2 Iron 6,509 49 0.75 46 Manganese 6,509 13 0.20 13 Lead 1,699 2 0.12 0 Trihalomethanes 921 4 0.43 0 Total pesticides 1,062 4 0.38 4 Isoproturon 1,042 8 0.77 8 MCPA 1,035 1 0.10 0 Mecoprop 1,044 11 1.05 8
Treatment works
- Of the Company's 109 treatment works, 106 (97%) complied fully with the relevant standards. Failures of the standards at three works were considered trivial, or unlikely to recur as a result of remedial action taken, or being taken, by the Company. Differences over the last three years in the number of treatment works, and samples from treatment works, in which coliforms or faecal coliforms were detected were not considered significant.
Service reservoirs
- At 417 (99.8%) of the Company's 418 service reservoirs, coliforms were absent from at least 95% of samples. The Company de-commissioned the service reservoir which failed the standard, in October 2001. Failures of the faecal coliform standard at eight service reservoirs were considered trivial or unlikely to recur. Differences over the last three years in the number of service reservoirs, and samples from service reservoirs, in which coliforms or faecal coliforms were detected were not considered significant.
Cryptosporidium
- The Company carried out a total of 2,746 tests on samples taken from 10 sites. Very low numbers of oocysts were detected in 34 (1.24%) samples taken from seven sites. All results were well below the treatment standard and there were no associated outbreaks of cryptosporidiosis.
Company Audit and Inspection
- The Company was inspected or audited by the Inspectorate or its appointed consultants on a number of occasions during 2001. Where relevant, report summaries are available in the 'Business and Technical' section of the web site under 'Audit and Inspection'.
Audit or Inspection Date Audit of incident notification procedures
February Review of progress with the distribution system undertaking
October/November Audit trails of ten samples
December and ongoing Review of policies and procedures on contaminated land
December Audit of procedures for compliance with Regulation 25
December Audit of sampling programme
December Inspection of one service reservoir
December Inspection of one water treatment works
December Review of plumbosolvency treatment and control programmes of work
December Audit of Cryptosporidium sampling sites
Various dates during the year
- Ten recommendations were made in respect of action required to avoid the risk of a breach of a regulatory duty. These recommendations were mainly in relation to points arising from the audit trails and were principally concerned with laboratory methods. o Six recommendations for improvements were made in respect of progress with the distribution system undertaking and plumbosolvency treatment for lead.
Incidents
- The Inspectorate regarded 12 of the events notified during 2001 by the Company as incidents. For further details on the classification of incidents see Chapter C, 'Events affecting Water Quality', in Part 3.
- Nine of the incidents have been assessed by the Inspectorate. Each was of short duration and the Company has taken appropriate remedial action. Ten recommendations were made to the Company mainly regarding procedures.
- During the reporting period for 2001, assessments were completed for six incidents that occurred during 2000. Also during 2001, assessments were completed for two incidents that occurred in 1999 and for one incident that occurred in 2000, for which the Company received formal cautions. The Company received a further formal caution for another incident that occurred in 1999. A total of 13 recommendations were made to the Company mainly regarding procedures.
- Three incidents from 2001 remain under consideration. Final assessments are also outstanding for seven incidents that occurred in 1999 and two that occurred in 2000.
Nature of incident
No.of incidents
Assessment completed by DWI
Areas affectedSupply of discoloured water
4
Yes
Bessacar, Doncaster (March); Shadwell, Leeds and Bradford (June); Cottingley (October)
3
No
Sandygate, Sheffield
and Sheffield 10 (June);
Harrogate (November)Microbiological contamination of
supplies in
distribution system
1
Yes
Hornsea (August)
Cryptosporidium oocysts
in treated water
1
Yes
Gandale, N. Yorkshire (December)
Failure of
disinfection systems
1
Yes
East Ness (March)
Other incidents not affecting water
quality
2
Yes
Halifax (October); Thwing (December)
Prosecutions
- The Inspectorate initiated a prosecution against Yorkshire Water Services Limited relating to a discoloured water incident that occurred in 1999 and affected parts of Thornton and Denholme. The Company pleaded guilty to supplying water unfit for human consumption and asked for a second discoloured water incident, which also occurred in 1999 and affected parts of Pudsey, to be taken into consideration. Further information can be found in Chapter C, 'Events affecting Water Quality', in Part 3.
Improvement Programmes
- Four remedial programmes of work were due for completion during 2001. One related to colour and aluminium failures at Rudland Stock water treatment works; one related to hydrogen ion failures at Lowne water treatment works; and two related to hydrogen ion failures in the distribution system. All were completed on schedule.
- The Inspectorate is currently discussing with the Company progress made to date with its ongoing distribution system improvement programme. Although the programme was severely affected by the impact of the Foot and Mouth Disease Outbreak and by other reasons beyond the Company's control, most of the targets for the year were met. During 2000 and 2001, 867 km of mains have been renovated. The Company is required to renovate a further 4,519 km of mains by March 2010.
- The Company has improvement programmes to meet the new and revised standards set down in the new Water Supply (Water Quality) Regulations 2000, which will come into force on 25 December 2003. These relate to THMs at four sites and bromate at two sites, plus additional work required to meet the new standard for lead. The Company also has programmes of work to reduce any potential risk from Cryptosporidium oocysts at seven sites, one of which was completed during 2001. Progress with delivery of the programmes is monitored by the Inspectorate and has been satisfactory.
Enforcement Action
- No enforcement action was considered for the Company as a result of the Inspectorate's activities during 2001.
- An inset appointment allows a water company to supply water to customers in a specified geographical area outside its normal area of supply.
- There have been a limited number of appointments made to date and most have been between the existing water companies. Reference is made to these in the relevant company sections.
l A total of 490 tests were carried out by Albion Water Limited in 2001.
Water Quality in Water Supply Zones, at Treatment Works, and in Service Reservoirs
- To be wholesome, water must comply with the standards set out in the Regulations. The Company carried out a total of 490 tests on samples taken in its water supply zone. The table below includes only the parameters that breached the standard; all other parameters were fully compliant. A list of these parameters and their significance 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. These undertakings required remedial works to be carried out to ensure compliance with the individual standard.
Treatment works
- The Company has no treatment works.
Service reservoirs
- The Company has no service reservoirs.
Company Audit and Inspection
- The Company was inspected or audited by the Inspectorate on one occasion in 2001. Where relevant, report summaries are available in the 'Business and Technical' section of the web site under 'Audit and Inspection'.
table 25.1 Yorkshire Water Services Limited
MICROBIOLOGICAL QUALITY OF WATER LEAVING TREATMENT WORKS2001 2000* 1999* Number of water treatment works 109 121 127 Works with no sampling shortfall 109 120 127 COLIFORMS Total number of determinations 10,336 12,024 14,061 - number containing coliforms 4 6 11 - % containing coliforms <0.1 <0.1 <0.1 Treatment works with coliforms detected 3 5 10 - % of all works 2.8 4.1 7.9 FAECAL COLIFORMS Total number of determinations 10,336 12,024 14,062 - number containing faecal coliforms 3 3 3 - % containing faecal coliforms <0.1 <0.1 <0.1 Treatment works with faecal coliforms detected 2 2 3 - % of all works 1.8 1.7 2.4
table 25.2 Yorkshire Water Services Limited
MICROBIOLOGICAL QUALITY OF WATER IN SERVICE RESERVOIRS2001 2000* 1999* Number of service reservoirs 418 432 421 Service reservoirs with no sampling shortfall 417 432 419 COLIFORMS Total number of determinations 21,224 21,162 20,862 - number containing coliforms 39 27 37 - % containing coliforms 0.2 0.1 0.2 Service reservoirs with coliforms detected 35 25 31 Service reservoirs with coliforms detected in more than 5% of samples 1 0 2 - % of all service reservoirs 0.2 0.0 0.5 FAECAL COLIFORMS Total number of determinations 21,225 21,162 20,826 - number containing faecal coliforms 8 10 6 - % containing faecal coliforms <0.1 <0.1 <0.1 Service reservoirs with faecal coliforms detected 8 9 6 - % of all service reservoirs 1.9 2.1 1.4
table 25.3 Yorkshire Water Services Limited
WATER QUALITY IN SUPPLY ZONESColumns 'CBU' show, for determinations, contraventions covered by undertakings and, for zones, the total number of zones covered by undertakings in 2001. Column 'E' shows the number of zones for which new enforcement action is under consideration as a result of contraventions of the PCV in 2001. PARAMETER DETERMINATIONS in 2001 ZONES (205 in 2001)+ Total Contravening PCV Non-compliant No. % CBU CBU E Number in: 2001 2001 2000* 1999* Coliforms 12,563 45 0.4 0 0 0 0 1 1 Faecal coliforms 12,563 1 0.0 0 0 0 1 8 11 Colour 12,562 1 0.0 0 0 0 1 3 1 Turbidity 12,561 9 0.1 7 122 0 9 5 20 Odour 1,617 0 0.0 0 0 0 0 0 0 Taste 1,613 0 0.0 0 0 0 0 0 0 Hydrogen ion 12,559 0 0.0 0 7 0 0 10 7 Nitrate 1,863 2 0.1 0 0 0 2 0 3 Nitrite 1,897 20 1.1 0 0 0 5 8 7 Aluminium 6,509 4 0.1 2 63 0 4 11 13 Iron 6,509 49 0.8 46 177 0 42 58 54 Manganese 6,509 13 0.2 13 117 0 13 19 32 Lead 1,699 2 0.1 0 0 0 2 3 7 PAH 867 0 0.0 0 0 0 0 9 8 Trihalomethanes 921 4 0.4 0 0 0 1 3 3 Total pesticides 1,062 4 0.4 4 4 0 4 0 0 Isoproturon 1,042 8 0.8 8 4 0 4 4 4 MCPA 1,035 1 0.1 0 4 0 1 0 0 Mecoprop 1,044 11 1.1 8 4 0 7 0 4 Other Pesticides 78,944 0 0.0 0 4 0 0 0 0 Oxidizability 207 0 0.0 0 0 0 0 0 1 All others 25,757 0 0.0 0 0 0 0 0 0 TOTAL 201,903 174 <0.1 88 - - - - - *214 zones in 2000; 209 zones in 1999 +Figures relate to aggregated Yorkshire Water Services and York Waterworks Plc figures although combined operating licence applies from 01/04/2000 only. [ Previous ] [ Contents ] [ Next ]
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Drinking Water Inspectorate,
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Telephone : 020 7944 5956 - Facsimile : 020 7944 5969
E-mail: dwi.enquiries@defra.gsi.gov.uk
Published 10 July 2002
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