Chief Inspector's Report 2002
7 Dwr Cymru Cyfyngedig
| Overall Water Quality supplied by Dwr Cymru Cyfyngedig in 2002 | |||||||||||||||||||||||
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Water Quality at Treatment Works, in Service Reservoirs and in Water Supply Zones
To be wholesome, water must comply with the standards for the parameters set out in the Water Supply (Water Quality) Regulations 1989. In 2002, the Company carried out a total of 179,513 tests on samples taken at water treatment works, from service reservoirs and in water supply zones and of these, 99.89% complied with the relevant water quality standards set down in the Regulations. A list of the parameters, the relevant standards and their significance can be found at the beginning of this section.
Water Quality leaving Treatment works
2002 |
2001 |
2000 |
||
| Number of water treatment works | 96 |
104 |
103 |
|
| COLIFORMS | ||||
| Total number of tests | 10,595 |
11,114 |
12,973 |
|
| - | number containing coliforms | 4 |
5 |
7 |
| - | % containing coliforms | 0.04% |
0.04% |
0.05% |
| Treatment works with coliforms detected | 4 |
5 |
6 |
|
| - | % of all works with coliforms detected | 4.17% |
4.81% |
5.83% |
| FAECAL COLIFORMS | ||||
| Total number of tests | 10,597 |
11,114 |
12,973 |
|
| - | number containing faecal coliforms | 0 |
0 |
2 |
| - | % containing faecal coliforms | 0.00% |
0.00% |
0.02% |
| Treatment works with faecal coliforms detected | 0 |
0 |
2 |
|
| - | % of all works with faecal coliforms detected | 0.00% |
0.00% |
1.94% |
Failures of the coliform standard at four works in 2002 were considered trivial. There were no failures of the faecal coliform standard. Differences over the last three years in the number of treatment works, and in the number of tests carried out on samples from treatment works, in which coliforms or faecal coliforms were detected were not considered significant.
In 2002, 6,747 regulatory samples for Cryptosporidium were taken at 22 sites. Very low numbers of oocysts were detected in 260 samples from 16 sites. All results were well below the treatment standard and there were no reported outbreaks of cryptosporidiosis.
Water Quality in Service Reservoirs
2002 |
2001 |
2000 |
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| Number of service reservoirs | 544 |
553 |
552 |
|
| COLIFORMS | ||||
| Total number of tests | 27,932 |
28,441 |
29,412 |
|
| - | number containing coliforms | 21 |
38 |
66 |
| - | % containing coliforms | 0.08% |
0.13% |
0.22% |
| Service reservoirs with coliforms detected | 17 |
34 |
56 |
|
| Service reservoirs with coliforms detected | 1 |
1 |
2 |
|
| in more than 5% of tests | ||||
| - | % of all service reservoirs with coliforms detected | 0.18% |
0.18% |
0.36% |
| FAECAL COLIFORMS | ||||
| Total number of tests | 27,931 |
28,437 |
29,410 |
|
| - | number containing faecal coliforms | 3 |
7 |
12 |
| - | % containing faecal coliforms | 0.01% |
0.02% |
0.04% |
| Service reservoirs with faecal coliforms detected | 3 |
7 |
11 |
|
| - | % of all service reservoirs with faecal coliforms detected | 0.55% |
1.27% |
1.99% |
There was a failure of the coliform standard at one service reservoir. However, the Company has taken action to prevent the failure recurring. Failures of the faecal coliform standard at three service reservoirs were considered unlikely to recur following appropriate remedial action by the Company.There was a significant decrease in the last three years in the number of service reservoirs, and in the number of tests carried out on samples from service reservoirs, in which coliforms were detected. All other differences were not considered significant.
Water Quality in Water Supply Zones
The table below shows the data for the key parameters and any other parameters where there was a failure of the standard. All other parameters were fully compliant.
| Parameter | Total number of tests |
Tests not meeting the prescribed concentration or value |
Number of failures covered by Undertakings |
Number of zones not complying with the standards |
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No |
% |
2002 |
2001 |
2000 |
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| Coliforms | 8,917 |
22 |
0.25 |
0 |
0 |
0 |
0 |
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| Faecal coliforms | 8,915 |
3 |
0.03 |
0 |
3 |
3 |
3 |
|
| Colour | 800 |
0 |
0.00 |
0 |
0 |
0 |
0 |
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| Turbidity | 1,186 |
2 |
0.17 |
2 |
2 |
3 |
0 |
|
| Odour | 1,074 |
2 |
0.19 |
0 |
2 |
3 |
1 |
|
| Taste | 1,023 |
1 |
0.10 |
0 |
1 |
0 |
1 |
|
| Hydrogen ion | 1,359 |
2 |
0.15 |
0 |
1 |
3 |
2 |
|
| Nitrate | 1,744 |
0 |
0.00 |
0 |
0 |
0 |
0 |
|
| Nitrite | 1,747 |
44 |
2.52 |
0 |
7 |
26 |
29 |
|
| Aluminium | 1,050 |
0 |
0.00 |
0 |
0 |
3 |
3 |
|
| Iron | 3,871 |
46 |
1.19 |
37 |
31 |
40 |
37 |
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| Manganese | 1,313 |
2 |
0.15 |
1 |
2 |
7 |
8 |
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| Lead | 841 |
3 |
0.36 |
0 |
3 |
10 |
3 |
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| PAH | 886 |
35 |
3.95 |
24 |
18 |
21 |
24 |
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| Trihalomethanes | 682 |
1 |
0.15 |
0 |
0 |
9 |
2 |
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| Total pesticides | 2,291 |
1 |
<0.1 |
0 |
1 |
0 |
0 |
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| Atrazine | 755 |
0 |
0.00 |
0 |
0 |
2 |
0 |
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| Isoproturon | 490 |
0 |
0.00 |
0 |
0 |
3 |
0 |
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| MCPA | 623 |
0 |
0.00 |
0 |
0 |
0 |
3 |
|
| Mecoprop | 623 |
1 |
0.16 |
0 |
1 |
1 |
0 |
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| Simazine | 755 |
0 |
0.00 |
0 |
0 |
0 |
1 |
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| Other pesticides | 26,243 |
0 |
0.00 |
0 |
0 |
0 |
0 |
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| Benzo 3.4 Pyrene | 886 |
1 |
0.11 |
0 |
1 |
1 |
1 |
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| Oxidizability | 327 |
1 |
0.31 |
0 |
1 |
0 |
0 |
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| Surfactants | 314 |
0 |
0.00 |
0 |
0 |
0 |
1 |
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| All others | 26,996 |
0 |
0.00 |
0 |
0 |
0 |
0 |
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| TOTAL | 95,711 |
167 |
0.17% |
64 |
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| 171 zones in 2002, 177 zones in 2001, 183 zones in 2000 | ||||||||
The fifth column indicates the number of failures in zones already covered by legally binding undertakings given by the Company. These undertakings require remedial work to be carried out to ensure compliance with the individual standard.
The New Regulations
In 2002, the Company carried out monitoring for the six new parametric values set down in the new Water Supply (Water Quality) Regulations 2001*. These Regulations come into force on 25 December 2003. The results are shown in the table below.
| Parameter | Total number of tests |
New standard |
Tests not meeting the new standard |
| Benzene | 1,993 |
1.0 µg/l |
0 |
| Bromate | 1,997 |
10.0 µg/l |
7 |
| 1,2 dichloroethane | 1,966 |
3.0 µg/l |
0 |
| Nitrite (ex-water treatment works) | 361 |
0.1 mg/l |
0 |
| Clostridium perfringens | 1,022 |
0/100 ml |
0 |
| Enterococci | 721 |
0/100 ml |
0 |
Compliance data for 2002 has also been analysed against the revised standards and the results are shown in the following table.
| Parameter | Total number or tests |
Current Standard |
Number of tests not meeting current standard |
Revised Standard |
Number of tests not meeting revised standard |
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| Antimony | 308 |
10.0 µg/l |
0 |
5.0 µg/l |
0 |
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| Arsenic | 295 |
50.0 µg/l |
0 |
10.0 µg/l |
0 |
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| Boron | 298 |
2.0 mg/l |
0 |
1.0 mg/l |
0 |
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| Copper | 300 |
3.0 mg/l |
0 |
2.0 mg/l |
0 |
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| Lead | 841 |
50.0 µg/l |
3 |
25.0 µg/l1 |
5 |
|||
10.0 µg/l2 |
10 |
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| Nickel | 295 |
50.0 µg/l |
0 |
20.0 µg/l |
1 |
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| Nitrite (at consumers' taps) | 1,747 |
0.1 mg/l |
44 |
0.5 mg/l |
0 |
|||
| PAH | 886 |
0.2 µg/l |
35 |
0.1 µg/l |
0 |
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| Tetrachloroethene | 428 |
30.0 µg/l |
|
10.0 µg/l
|
0
|
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| Trichloroethene | 428 |
10.0 µg/l |
Details of the new and revised standards, and the reasons for the revisions where applicable, can be found in chapter J "New Regulations and Associated Programmes of Work".
* Water Supply (Water Quality) Regulations 2000 in England.
1 From 25.12.03
2 From 25.12.13
Company Audit and Inspection
The Company was inspected or audited by the Inspectorate or its appointed consultants on a number of occasions during 2002. Where relevant, report summaries are available in the 'Business and Technical' section of the Inspectorate's web site under 'Audit and Inspection'.
| Audit or Inspection | Date |
| Audit of regulatory Cryptosporidium monitoring sites | Various dates throughout the year |
| Audit of laboratory analysing for Cryptosporidium | January 2002 |
| Audit of progress with regulatory programmes of work | March 2002 |
| Audit of regulatory Cryptosporidium samplers | June 2002 |
| Review of distribution system undertaking | September 2002 |
| Audit of sampling arrangements | October 2002 |
| Audit trails of 10 test results | October 2002 |
| Inspection of one water treatment works and two service reservoirs | October 2002 |
| Review of plumbosolvency treatment and control programmes of work for lead | November 2002 |
| Audit of analytical requirements for nitrate and nitrate | November 2002 |
| Audit of response to selected consumer complaints | November 2002 |
| Inspection of in situ lining of mains at two sites | December 2002 |
A number of 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, the distribution undertaking and plumbosolvency treatment for lead, sampling procedures, treatment works and service reservoirs, regulatory programmes of work and the in situ lining of mains.
Incidents
The Inspectorate regarded 12 of the events notified during 2002 by the Company as incidents. For further details on the classification of incidents, see chapter C "Events affecting Water Quality" in Part 3.
Eleven of the incidents have been assessed by the Inspectorate. Each was of short duration and Dwr Cymru Cyfyngedig has taken appropriate remedial action. A number of recommendations were made regarding sampling and operational procedures.
During the 2002 reporting period, assessment was also completed for six incidents which occurred in 2001.
One incident assessment from 2002 remains under consideration.
| Nature of incident | No. of incidents |
Assessment completed |
Area affected |
Population potentially |
| Supply of discoloured water | 11 |
Yes |
Rhyl (January) |
16,900 |
Yes |
Rhymney Valley (February) |
4,300 |
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Yes |
Llanelli (March) |
50 |
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No |
Cray District (Swansea)/ |
13,000 |
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Bryncoch Area (Neath) |
||||
(May) |
||||
Yes |
Ystrad Mynach (July) |
7,500 |
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Yes |
Rhymney Valley Area (July) |
13,000 |
||
Yes |
Milford Haven (August) |
4,000 |
||
Yes |
Cray District (Swansea)/ |
3,000 |
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Bryncoch Area (Neath) |
||||
(September) |
||||
Yes |
Abercanaid, near Merthyr |
5,000 |
||
Tydfil (October) |
||||
Yes |
Aberystwyth (November) |
2,000 |
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Yes |
Treherbert, Mid Rhondda |
27,000 |
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(December) |
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| Failure of disinfection systems | 1 |
Yes |
Mountain Ash/Ynys Y |
1,500 |
Bwl (July) |
Enforcement Action
The table below indicates areas where, in 2002, 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 |
| Iron | Reg 3(3)(c) | Abergele Zone | Undertaking received |
| Iron | Reg 3(3)(c) | Betws Y Coed | Pending |
Undertakings and other Improvement Programmes
Water treatment works and service reservoirs
Three undertakings were due for completion during 2002. These were to install treatment at Cefni and Llanfairfechan to remove trihalomethanes and at Bontgoch to control the pH. The programmes were completed on schedule.
One Regulation 41 programme of work to meet the new and revised standards set down in the new Water Supply (Water Quality) Regulations 2001 was due for completion in 2002. This was to install treatment at Rhiwgoch to remove trihalomethanes. The programme was completed on schedule.
There were no statements of intent to reduce the risk of Cryptosporidium breaching the treatment standards due for completion during 2002.
One statement of intent for parameters other than Cryptosporidium were due for completion during 2002. The programme has been delayed due to delays in planning approval.
Distribution
The ongoing distribution system undertaking has been progressing satisfactorily. During 2002, 410 km of mains have been renovated. The Company is required to renovate a further 3,719 km of mains by March 2010.
Lead
The Company has a Regulation 41 programme of work to meet the revised standard for lead set down in the new Water Supply (Water Quality) Regulations 2001, which will come into force on 25 December 2003. Progress with the delivery of the programme is monitored by the Inspectorate and has been satisfactory.
