23 United Utilities Water Limited
Overall Water Quality supplied by United Utilities Water Limited in 2001 (previously North West Water)
- A total of 341,806 tests were carried out by United Utilities Water Limited in 2001.
- Of these tests, 99.80% complied with the Regulations.
Company Information
Amount of Water Supplied: 1,940 Ml/d
Consumers Supplied: 6.8 million
Areas of Supply: Lake District, the western Pennines, Merseyside, Greater Manchester, Lancashire, Cumbria and Cheshire
Water Composition: 92% from rivers and reservoirs
8% from boreholes and aquifers
Treatment Works: 159
Service Reservoirs: 387
Km of Mains: 42,200
Water Supply Zones: 304Water 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 253,517 tests on samples taken in its 304 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. The Company also has programmes of work in place to meet the revised lead standard.
Parameter Total samples taken Samples not meeting the standard Percentage Number of failures already covered by undertakings Total coliforms 19,157 124 0.65 6 Faecal coliforms 19,157 10 0.05 0 Turbidity 8,356 14 0.17 2 Hydrogen ion 7,738 5 0.06 0 Nitrate 4,886 5 0.10 4 Nitrite 4,888 3 0.06 0 Aluminium 10,088 13 0.13 0 Iron 10,102 161 1.59 157 Manganese 10,103 57 0.56 40 Lead 4,846 76 1.57 33 PAH 2,208 11 0.50 0 Trihalomethanes 3,918 43 1.10 35 Atrazine 1,996 1 0.05 0 MCPA 1,974 2 0.10 0 Mecoprop 1,973 5 0.25 0 2,4,5-T 1,974 1 0.05 0 Ammonium 4,888 5 0.10 0 Benzo-3,4-Pyrene 2,208 1 0.05 0 Copper 4,762 1 0.02 0 Oxidisability 572 1 0.17 0 Phosphorus 10,062 20 0.20 0 Surfactants 361 4 1.11 0 Zinc 4,760 1 0.02 0
Treatment works
- Of the Company's 159 treatment works, 120 (75%) complied fully with the relevant standards. Failures of the standards at a total of 36 works were considered trivial, or unlikely to recur as a result of remedial action taken by the Company. Enforcement action has been considered at the remaining three works. There has been a significant decrease since 2000 in the number of treatment works, and samples from treatment works, in which total coliforms were detected. All other differences were not considered significant.
Service reservoirs
- At 384 (99%) of the Company's 387 service reservoirs, coliforms were absent from at least 95% of samples. Enforcement action is under consideration for failures of the total coliform and faecal coliform standards at one service reservoir. Failures of the total coliform standard at the other two sites and failures of the faecal coliform standard at seven service reservoirs were considered trivial or unlikely to recur as a result of remedial action taken by the Company. Differences over the last three years in the number of service reservoirs, and samples from service reservoirs, in which coliforms were detected were not considered significant.
Cryptosporidium
- The Company carried out a total of 2,388 tests on samples taken from nine sites. Very low numbers of oocysts were detected in 381 (15.95%) samples taken from all nine 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 Review of procedures for operation and maintenance of the distribution network
February Audit of incident notification procedures
February Audit of arrangements for Cryptosporidium analysis
July Inspection of seven treatment works
July/August Review of progress with the distribution system undertaking
October Review of plumbosolvency treatment and control programmes of work
November Audit trails of ten samples
December Review of policies and procedures on contaminated land
December Audit of procedures for compliance with Regulation 25
December Inspection of one service reservoir
December Audit of sampling programme
December Audit of all Cryptosporidium sampling sites
Various dates during the year
- Twenty-three recommendations were made in respect of action required to avoid a risk of a breach of a regulatory duty. These recommendations were in relation to the audit trails, the treatment works inspections, and incident notification procedures. o Eight recommendations for improvements were made in respect of the plumbosolvency treatment for lead.
Incidents
- The Inspectorate regarded 18 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.
- All of the incidents have been assessed by the Inspectorate. They were of short duration and the Company has taken appropriate remedial action. Eighteen recommendations were made to the Company regarding procedures, record keeping, operations and analysis.
- During the 2001 reporting period, assessment was also completed for one incident which occurred in 2000.
- One incident from 2000 remains under consideration.
Nature of incident
No.of incidents
Assessment completed by DWI
Areas affectedSupply of discoloured water
13
Yes
Neston, Wirral (February, July and
September); Wigan (March); Liscard (March); Macclesfield (April); Stalybridge (April); Winsford (April); Glossop (August); Hyde (August); Chorley (November); Bootle (November); Huntington Works (July)
Supply of water with taste & odour
2
Yes
Hoghton WTW (February); Rainhill
(August)Loss of supplies
2
Yes
Macclesfield (April); Embleton (December)
Wholesomeness concerns
1
Yes
Hurleston WTW (May)
Improvement Programmes
- One remedial programme was due for completion during 2001, relating to coliform failures at Malpas Service Reservoir. This programme of work was completed ahead of schedule.
- The ongoing distribution system improvement programme has been progressing satisfactorily. During 2000 and 2001, 1,409 km of mains have been renovated. The Company is required to renovate a further 6,279 km of mains by 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 arsenic at 29 sites and THMs at ten sites, plus additional work required to meet the new standard for lead. The Company also submitted 16 undertakings to reduce any potential risk from Cryptosporidium oocysts in zones supplied from the Thirlmere Aqueduct. Three of these were completed during 2001. Progress with the delivery of the remaining programmes is monitored by the Inspectorate and is satisfactory.
Enforcement Action
- The table below indicates areas where, in 2001, the Inspectorate considered taking enforcement action for regulatory breaches, and where an undertaking was submitted or where the Company took appropriate action.
Parameter/Area Regulation breached Location Outcome Sampling frequency shortfall Reg 17(1) Three water treatment works Pending Sampling frequency shortfall Reg 13(1) Two water supply zones Pending Total coliforms Reg 3(7) Hodder WTW Pending Total coliforms Reg 3(7) Wybersley WTW Pending Total coliforms Reg 3(7) White Bull WTW Pending Total coliforms Reg 3(7) Barnacre WTW Pending Faecal coliforms Reg 3(7) Oldham Edge Service Reservoir Pending Manganese Reg 3(3)(c) St Helens North supply zone Pending Aluminium Reg 3(3)(c) Litherland supply zone Pending Manganese Reg 3(3)(c) Formby supply zone Pending Turbidity Reg 3(3)(c) Sutton Hall South supply zone Pending Hydrogen ion (pH) Reg 3(3)(c) Watergrove supply zone Pending Manganese Reg 3(3)(c) Preston Rural supply zone Pending
table 23.1 United Utilities
MICROBIOLOGICAL QUALITY OF WATER LEAVING TREATMENT WORKS2001 2000 1999 Number of water treatment works 159 161 176 Works with no sampling shortfall 159 156 154 COLIFORMS Total number of determinations 23,970 23,781 24,994 - number containing coliforms 56 90 42 - % containing coliforms 0.2 0.4 0.2 Treatment works with coliforms detected 39 60 32 - % of all works 24.5 37.3 18.2 FAECAL COLIFORMS Total number of determinations 23,973 23,781 24,994 - number containing faecal coliforms 12 18 8 - % containing faecal coliforms <0.1 <0.1 <0.1 Treatment works with faecal coliforms detected 12 17 7 - % of all works 7.6 10.6 4
table 23.2 United Utilities
MICROBIOLOGICAL QUALITY OF WATER IN SERVICE RESERVOIRS2001 2000 1999 Number of service reservoirs 387 387 393 Service reservoirs with no sampling shortfall 387 387 366 COLIFORMS Total number of determinations 20,173 20,35219,797 19,797 - number containing coliforms 51 53 40 - % containing coliforms 0.3 0.3 0.2 Service reservoirs with coliforms detected 42 48 39 Service reservoirs with coliforms detected in more than 5% of samples 3 1 1 - % of all service reservoirs 0.8 0.3 0.3 FAECAL COLIFORMS Total number of determinations 20,173 20,352 19,797 - number containing faecal coliforms 12 8 2 - % containing faecal coliforms <0.1 <0.1 <0.1 Service reservoirs with faecal coliforms detected 9 5 2 - % of all service reservoirs 2.3 1.3 0.5
table 23.3 United Utilities
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 (304 in 2001)* Total Contravening PCV Non-compliant No. % CBU CBU E Number in: 2001 2001 2000 1999 Coliforms 19,157 124 0.7 6 21 0 3 3 0 Faecal coliforms 19,157 10 <0.1 0 0 0 10 9 11 Colour 4,736 0 0.0 0 0 0 0 0 0 Turbidity 8,356 14 0.2 2 41 1 13 8 19 Odour 3,108 0 0.0 0 0 0 0 0 1 Taste 3,095 0 0.0 0 0 0 0 0 0 Hydrogen ion 7,738 5 <0.1 0 0 1 4 12 7 Nitrate 4,886 5 0.1 4 11 0 3 2 2 Nitrite 4,888 3 <0.1 0 0 0 3 3 5 Aluminium 10,088 13 0.1 0 0 1 12 11 18 Iron 10,102 161 1.6 157 259 0 88 108 142 Manganese 10,103 57 0.6 40 129 3 43 37 37 Lead 4,846 76 1.6 33 90 0 60 99 163 PAH 2,208 11 0.5 0 0 0 10 11 13 Trihalomethanes 3,918 43 1.1 35 133 0 24 37 12 Total pesticides 2,742 0 0 0 0 0 0 1 1 Altrazine 1,996 1 <0.1 0 0 0 1 0 0 Dichlorprop 1,974 0 0.0 0 0 0 0 0 1 Gamma-HCH 1,996 0 0.0 0 0 0 0 0 1 MCPA 1,974 2 0.1 0 0 0 2 1 0 Mecroprop 1,973 5 0.3 0 0 0 5 6 1 2,4,5-T 1,974 1 <0.1 0 0 0 1 0 0 Other pesticides 22,609 0 0.0 0 0 0 0 0 0 Ammonium 4,888 5 0.1 0 3 0 5 14 2 Benzo 3,4 Pyrene 2,208 1 <0.1 0 15 0 1 0 1 Copper 4,762 1 <0.1 0 0 0 1 1 1 Oxidizability 572 1 0.2 0 0 0 1 0 1 Phosphorus 10,062 20 0.2 0 0 0 20 4 4 Potassium 405 0 0.0 0 0 0 0 0 1 Surfactants 361 4 1.1 0 0 0 3 0 0 Zinc 4,760 1 <0.1 0 0 0 1 0 0 All others 71,875 0 0.0 0 0 0 0 0 0 TOTAL 253,517 564 0.2 277 - - - - - *305 zones in 2000; 308 zones in 1999. [ 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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