UK Drinking Water Inspectorate Information

Information Letters

Drinking Water Inspectorate: Information Letter 19/2000 - 1 September 2000

To: Board Level Contacts of Water and Sewerage Companies and Water Companies in England and Wales

Dear Sir or Madam

RADIOACTIVITY AND DRINKING WATER SUPPLIES

Purpose

1. The purpose of this letter is to gather information about the monitoring for:

radioactivity in drinking water supplies to inform the United Kingdom’s policy for negotiations under the provisions of Article 12 of the new EC Directive 98/83/EC on the quality of water intended for human consumption (“the Directive”) on the monitoring requirements for radioactivity; and

radon and its daughter products, polonium-210 and lead-210 to inform the UK’s negotiating position should the Commission come forward with proposals under Article 11(1) of the Directive for standards or indicator values for these parameters.

Background

2. The Directive contains the following indicator parameter values which are not mandatory standards, but have to be set for monitoring purposes and if a value is exceeded remedial action has to be taken only if there is a risk to public health:

Tritium - 100 Bq/l

Total indicative dose - 0.10 mSv/year (excludes tritium, potassium-40, radon and radon decay products).

3. The Directive notes that:

monitoring frequencies, methods and locations will be adopted in accordance with the Committee procedure laid down in Article 12. The Commission is required to submit proposals by 25 June 2000 and these proposals shall take into account, inter alia, appropriate monitoring programmes under existing legislation; and

monitoring for tritium or radioactivity to establish the total indicative dose need not be carried out if, on the basis of other monitoring, a Member State is satisfied that the values are well below the parametric values. A Member State making use of this provision must communicate its reasons, including the results of other monitoring, to the Commission.

4. The Commission has not yet put proposals on monitoring for radioactivity before the Article 12 Committee. A group of experts appointed by the Scientific and Technical Committee under Article 31 of the Treaty establishing the European Atomic Energy Community has prepared advice for the Commission on monitoring for radioactivity. The draft of the advice proposed, in summary, the following:

monitoring of gross alpha and gross beta activities as initial screening parameters for total indicative dose. If these activities are less than 0.1 Bq/l and 1.0 Bq/l respectively (the World Health Organisation’s screening values), no further investigation is needed; and

if either activity exceeds its respective screening value, appropriate specific radionuclide analysis would be carried out and the total indicative dose calculated.

5. The Commission has invited Member States to comment on the draft of the advice from the group of experts. The Department of the Environment, Transport and the Regions (DETR) following advice from the Inspectorate, has recently submitted comments on the draft to the Commission. These comments took account of the views of Water UK and its group on radioactivity in drinking water. The Inspectorate understands that following consideration of the comments from Member States, the Commission is likely to put proposals before a meeting of the Article 12 Committee, provisionally scheduled for 17 November 2000. The Inspectorate will consult water companies on the Commission’s proposals when received through Water UK and its group on radioactivity in drinking water. In the meantime, the Inspectorate wishes to establish what monitoring for radioactivity has been carried out in the past and with what results so as to inform the UK’s negotiating position for the Article 12 Committee.

6. The Inspectorate is also aware that the expert group referred to in paragraph 4 above has been preparing a draft Commission recommendation on the protection of the public against exposure to radon in domestic water supplies. It is likely that this recommendation could feed into the review of Annex 1 (standards and indicator values) of the Directive that the Commission is required to carry out every five years. The Inspectorate understands that the draft recommendation is likely to contain the following:

Member States should set a reference level for radon for water supplied as part of a commercial or public activity for consideration as to whether remedial action is needed to protect public health. Remedial action should not be required if the concentration of radon is less than 100 Bq/l.

Measurements of radon concentrations should be required if there is specific reason to suspect, based on results of representative surveys or other reliable information, that the reference level (100 Bq/l?) might be exceeded.

Measurements of the radon daughter products polonium-210 and lead-210 should also be required if there is specific reason to suspect their presence and reference concentrations of 0.1 Bq/l and 0.2 Bq/l respectively should be used for consideration of whether remedial action is needed to protect human health.

7. Therefore it would also be useful for the Inspectorate to receive information on the monitoring that water companies have carried out in the past for radon, polonium-210 and lead-210 to inform the UK’s negotiating position should the Commission come forward with proposals for standards or indicator values for these parameters.

Information required from water companies

8. Water companies should provide the following information for each water treatment works currently operating for which it has any monitoring data for radioactivity since 1 January 1990 or earlier if the data is relevant. This data could be from analyses of the water source or the treated water:

name of treatment works

whether groundwater (GW), lowland river (LR) water or upland surface (US) water

whether analysis is of samples from water source, treated water or both

for each of the following radioactivity measurements if applicable:

gross alpha activity (Bq/l)

gross beta activity (Bq/l) (including potassium-40)

potassium-40 (mBq/l) or total potassium mg/l (specify)

tritium (Bq/l)

radon (Bq/l)

polonium-210 (mBq/l)

lead-210 (mBq/l)

any other relevant radionuclide (mBq/l)

the following data:

total number of samples analysed

minimum concentration

maximum concentration

average concentration (arithmetic mean, using zero for less than limit of detection)

the period during which the samples were taken.

9. It will not be necessary for water companies to include the results of the DETR Programme on Chemical and Radiochemical Analysis of Water Sources used for Public Drinking Water Supplied in England and Wales as the Inspectorate receives the results directly from the Environment Agency who administer the programme.

10. Water companies should submit their monitoring data in the form of the attached annex A by Friday 13 October 2000. (An Excel version will be e-mailed on request). If a water company has no relevant data it should submit a nil return. The Inspectorate will be writing to other organisations who might have carried out monitoring of public supplies for radioactivity and asking them to provide similar information.

Enquiries

11. Enquiries on this letter should be addressed to Owen Hydes (020 7944 5960). The Excel version can be obtained from his Secretary, Elsa Redman (020 7944 5961).

12. Copies of this letter are being sent to Pamela Taylor, Chief Executive, Water UK; Rodney Anderson, Water Supply and Regulation Division, Department of the Environment, Transport and Regions; Bob Macey, Environment Division, The National Assembly for Wales; Tim Hooton, Water Services Unit, Scottish Executive; Randal Scott, Drinking Water Inspectorate for Northern Ireland; Rowena Tye, Office of Water Services.

13. Please acknowledge receipt of this letter using the enclosed slip and envelope.

Yours faithfully

Michael Rouse

Chief Inspector

Drinking Water Inspectorate

Annex A

Answer Total No.
of samples minimum
concentration arithmetic mean
concentration maximum
concentration period of
sampling
(year-year)

Name of WTW

Source of water
(GW, LR, US)

Analysis of
source water (ü)

Analysis of
treated water (ü)

Analysis of
both (ü)

Gross alpha activity (Bq/l)

Gross beta activity (Bq/l)

Potassium-40 (mBq/l)

Total potassium (mg/l)

Tritium (Bq/l)

Radon (Bq/l)

Polonium-210 (mBq/l)

Lead-210 (mBq/l)

other radionuclide (mBq/l)
(specify)

other radionuclide (mBq/l)
(specify)

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Drinking Water Inspectorate,
Floor 2/A1, Ashdown House, 123 Victoria Street, London, SW1E 6DE
Telephone : 020 7944 5956 - Facsimile : 020 7944 5969
E-mail: dwi_enquiries@detr.gov.uk

Published 1 September 2000 Updated 11 July 2001
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	Answer	Total No. of samples	minimum concentration	arithmetic mean concentration	maximum concentration	period of sampling (year-year)
Name of WTW
Source of water (GW, LR, US)
Analysis of source water (ü)
Analysis of treated water (ü)
Analysis of both (ü)
Gross alpha activity (Bq/l)
Gross beta activity (Bq/l)
Potassium-40 (mBq/l)
Total potassium (mg/l)
Tritium (Bq/l)
Radon (Bq/l)
Polonium-210 (mBq/l)
Lead-210 (mBq/l)
other radionuclide (mBq/l) (specify)
other radionuclide (mBq/l) (specify)