12 Northumbrian Water Limited
Overall Water Quality supplied by Northumbrian Water Limited in 2001
- A total of 206,954 tests were carried out by Northumbrian Water Limited in 2001.
- Of these tests, 99.91% complied with the Regulations.
Company Information
Amount of Water Supplied: 760 Ml/d
Consumers Supplied: 2.6 million
Areas of Supply: North east of England
Water Composition: 95% from rivers and reservoirs
5% from boreholes and aquifers
Treatment Works: 36
Service Reservoirs: 245
Km of Mains: 16,687
Water Supply Zones: 112Water 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 167,772 tests on samples taken in its 112 water supply zones. The table below includes only the parameters that breached the standard; all other parameters were fully compliant with the standards. 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 7,402 37 0.50 0 Faecal coliforms 7,402 2 0.03 0 Colour 7,398 2 0.03 2 Turbidity 7,399 6 0.08 0 Taste 943 2 0.21 0 Aluminium 3,481 2 0.06 0 Iron 3,481 46 1.32 41 Manganese 3,481 8 0.23 6 Lead * 1,716 12 0.70 4 PAH 498 1 0.20 0 Trihalomethanes 842 5 0.59 5 Carbophenothion 1,486 1 0.07 0 Propyzamide 1,643 22 1.34 0 Potassium 456 1 0.22 0 Sulphate 524 3 0.57 0
* Breaches of this standard for lead are already covered by a Regulatory Programme of Work submitted by the Company under Regulation 41 of the 2000 Regulations.Treatment works
- Of the Company's 36 treatment works, 34 (94%) complied fully with the relevant standards. Failures of the standards at two works were considered trivial. 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 all of the Company's 245 service reservoirs, coliforms were absent from at least 95% of samples. Failures of the faecal coliform standard at four service reservoirs were considered trivial. There has been a significant decrease over the last three years in the number of samples from service reservoirs in which faecal coliforms were detected. All other differences were not considered significant.
Cryptosporidium
- The Company carried out a total of 3,380 tests on samples taken from nine sites. Very low numbers of oocysts were detected in 14 (0.41%) samples taken from six sites. All results were 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 Inspection of Cryptosporidium analysis laboratory
April Audit trails of ten samples
October Review of policies and procedures on contaminated land
October Audit of procedures for compliance with Regulation 25
October Inspection of one water treatment works and one service reservoir
September/October Review of plumbosolvency treatment and control programmes of work November Review of progress with the distribution system undertaking November Audit of all Cryptosporidium sampling sites Various dates during the year
Thirteen recommendations were made in respect of action required to avoid the risk of a breach of a regulatory duty. These recommendations were in relation to the audit trails, incident notification, the inspection of the treatment works and service reservoir, and the audit of the Cryptosporidium laboratory.
Four recommendations for improvements were made in respect of the distribution undertaking and plumbosolvency treatment for lead.
Incidents
- The Inspectorate regarded 21 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.
- Twenty of the incidents have been assessed by the Inspectorate. Each was of short duration and the Company has taken appropriate remedial action. Six recommendations were made to the Company mainly regarding operations and sampling.
- During the 2001 reporting period, assessment was also completed for one incident which occurred in 2000. o One incident assessment from 2001 remains under consideration.
Nature of incident
No.of incidents
Assessment completed by DWI
Areas affectedSupply of discoloured water
15
Yes
Wallsend (January); Fulwell (March);
Yarm (April); Wallsend (April); Berwick (April);
Fawdon (May); Darlington (June); Prudhoe
(July); Middlesbrough (July); Cramlington
(August ); Gateshead (August); Billingham
(August); Darlington (September);
Eaglescliffe (October); Newcastle
(November)
Fontburn (August)
Disinfection failure
1
Yes
Murton (June)
Boil water advice
2
Yes
West Denton (July); Halton Le Gate (September)
Vandalis
1
Yes
Rainten (October)
Pesticide breache
1
Yes
Tyneside (December
Improvement Programmes
- Two remedial programmes were due for completion during 2001. These were to complete the installation of a failsafe disinfection system at Murton Water Treatment Works, and to complete remedial work at Swarland Service Reservoir for coliforms. Both programmes of work were completed on schedule.
- The ongoing distribution system improvement programme has been progressing satisfactorily. During 2000 and 2001, 732 km of mains have been renovated. The Company is required to renovate a further 3,952 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 trihalomethanes at five 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 11 sites. Five of these programmes were completed during 2001, three further programmes due for completion during 2001 were delayed as a result of the impact of the Foot and Mouth Disease Outbreak. Progress with delivery of the remaining programmes is monitored by the Inspectorate, and has been 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 Individual pesticides Reg 3(3)(c) Three supply zones supplied by Whittle Dean WTW Undertaking pending
table 12.1 Northumbrian Water Limited
MICROBIOLOGICAL QUALITY OF WATER LEAVING TREATMENT WORKS2001 2000 1999 Number of water treatment works 36 41 45 Works with no sampling shortfall 35 39 45 COLIFORMS Total number of determinations 6,898 7,027 7,387 - number containing coliforms 2 6 13 - % containing coliforms <0.1 <0.1 0.2 Treatment works with coliforms detected 2 5 10 - % of all works 5.6 12.2 22.2 FAECAL COLIFORMS Total number of determinations 6,898 7,027 7,387 - number containing faecal coliforms 1 2 6 - % containing faecal coliforms <0.1 <0.1 <0.1 Treatment works with faecal coliforms detected 1 2 5 - % of all works 2.8 4.9 11.1
table 12.2 Northumbrian Water Limited
MICROBIOLOGICAL QUALITY OF WATER IN SERVICE RESERVOIRS2001 2000 1999 Number of service reservoirs 245 249 249 Service reservoirs with no sampling shortfall 242 248 248 COLIFORMS Total number of determinations 12,693 12,646 12,833 - number containing coliforms 26 29 41 - % containing coliforms 0.2 0.2 0.3 Service reservoirs with coliforms detected 25 22 37 Service reservoirs with coliforms detected in more than 5% of samples 0 1 0 - % of all service reservoirs 0.0 0.4 0.0 FAECAL COLIFORMS Total number of determinations 12,693 12,646 12,833 - number containing faecal coliforms 4 15 12 - % containing faecal coliforms <0.1 0.1 <0.1 Service reservoirs with faecal coliforms detected 4 11 11 - % of all service reservoirs 1.6 4.4 4.4
table 12.3 Northumbrian Water 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 (112 in 2001)* Total Contravening PCV Non-compliant No. % CBU CBU E Number in: 2001 2001 2000 1999 Coliforms 7,402 37 0.5 0 0 0 0 0 0 Faecal coliforms 7,402 2 <0.1 0 0 0 2 5 0 Colour 7,398 2 <0.1 2 1 0 1 5 2 Turbidity 7,399 6 <0.1 0 22 0 5 4 4 Odour 943 0 0.0 0 0 0 0 1 2 Taste 943 2 0.2 0 0 0 2 1 1 Hydrogen ion 7,399 0 0.0 0 0 0 0 0 0 Nitrate 990 0 0.0 0 0 0 0 0 0 Nitrite 990 0 0.0 0 0 0 0 0 0 Aluminium 3,481 2 <0.1 0 18 0 2 5 2 Iron 3,481 46 1.3 41 87 0 32 35 43 Manganese 3,481 8 0.2 6 48 0 8 10 14 Lead 1,716 12 0.7 4 34 0 11 12 13 PAH 498 1 0.2 0 0 0 1 1 0 Trihalomethanes 842 5 0.6 5 33 0 1 1 3 Total pesticides 1,661 0 0.0 0 0 0 0 0 1 Carbophenothion 1,486 1 <0.1 0 0 0 1 0 0 Chlortoluron 1,641 0 0 0 0 0 0 1 1 2,4-D 1,637 0 0.0 0 0 0 0 0 1 Isoproturon 1,641 0 0.0 0 0 0 0 0 22 MCPA 1,643 0 0 0 0 0 0 24 22 Propyzamide 1,643 22 1.3 0 0 0 22 0 0 Other Pesticeds 79,695 0 0.0 0 0 0 0 0 0 Potassium 456 1 0.2 0 0 0 1 0 0 Sulphate 524 3 0.6 0 0 0 2 0 0 All others 21,380 0 0.0 0 0 0 0 0 0 TOTAL 167,772 150 <0.1 58 - - - - - *111 zones in 2000; 111 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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