Information note on Regulation 18 (Wales)
The local authority must carry out an investigation where:
- It suspects, for any reason, that any private water supply is unwholesome.
- An indicator parameter does not comply with the concentrations or values prescribed in Part 2 or 3 of Schedule 1 of the Regulations.
If, in the event of either of the above, the local authority suspects that any private water supply presents a potential danger to human health, it must promptly take appropriate steps in accordance with regulation 17 (provision of information). This is to ensure that people likely to consume the water are (a) informed that the supply constitutes a potential danger to human health (b) where possible are informed of the nature and degree of the potential danger (c) are given advice to allow them to minimise such potential danger. This could include precautionary advice to restrict the use of the supply.
The purpose of an investigation
The purpose of an investigation is to determine the cause of the water being unwholesome, which in turn will establish the necessary subsequent steps that must be taken. These are specified in regulation 18 and will depend on the outcome of the investigation.
It is not sufficient to only resample at the point of contravention to “confirm” the sample result, as this will not determine the cause of the water being unwholesome and therefore is not an investigation as required by regulation 18.
What actions should the investigation include?
An investigation will normally (but not exclusively) be triggered by a breach of a parameter standard resulting from a regulatory sample or a sample taken privately by a supply user or owner. Although not specified in the Regulations, the local authority is advised in the first instance to determine the health significance that the result presents by consulting Public Health Wales (PHW). It may be possible to determine a health risk from one test result if the value is particularly high, or there are vulnerable consumers, to inform the rapid provision of precautionary advice such as ‘Do not drink’. A further assessment can be made with PHW when additional information has been made available by the investigation. This may include information such as historic test results, predictions of future concentrations and evidence of the source of the contamination. This process should be repeated in the event of any further breaches of parameter standards from subsequent investigatory samples, in case precautionary advice needs to be changed, or short-term controls become available.
Investigations may also be triggered by reported consumer concerns. These may be based on abnormal taste, odour or appearance, or changes within the catchment or source water, whether perceived or actual.
Steps necessary to establish the cause through an investigation are not set out in the Regulations. However, the local authority is advised to carry out a site inspection of the supply, and to undertake an investigatory sampling survey for a range of relevant parameters from various points on the supply where it is feasible. This may for example, include collection chambers and stored water tanks and points before and after treatment, including the source itself. The investigation should be risk based and consider any changes to the supply since the last risk assessment was undertaken. The local authority should however be mindful of any costs this will incur to the relevant persons.
What must the local authority do once the cause of unwholesome water has been determined?
The outcome of the investigation will determine the next steps. These are prescribed in regulation 18 and will depend on the following factors:
- Whether the cause of the unwholesome water presents a potential danger to human health.
- Whether the water is unwholesome, but not a potential danger to human health.
- Whether the cause of the unwholesome water is due to the distribution system within a domestic premises.
- Whether the unwholesome water is made available to the public, where the cause is due to the domestic distribution system.
The steps that a local authority must undertake are as follows, as applicable:
1. Where the cause is due to the distribution system within a domestic premises, irrespective of whether the water is made available to the public or not.
If the local authority is satisfied that the cause of the unwholesome water is due to the distribution system within a domestic premises (pipework and or fittings), it must:
- Promptly inform the people likely to be affected. This would normally include everyone that is consuming the water, or is likely to be consuming the water, and any other relevant persons that are likely to be affected in some way.
- Offer advice on measures necessary for the protection of human health.
The Regulations do not set out details of what constitutes a domestic distribution system. This should be considered on a case-by-case basis and is likely to depend on the ownership of any pipes and fittings on the premises. The distribution system of a domestic premises is usually considered to include the pipes and fittings within a dwelling and those to and within any other buildings, such as garages, offices, workshops and outbuildings.
2. Where the cause is due to the distribution system within a domestic premises, which is not made available to the public
No steps further to those described in section 1 above are required. Please note the following:
- Where the cause in this instance presents a potential danger to human health (for example, the presence of lead distribution pipes) regulation 18 does not require a regulation 20 notice to be served.
- Where the water is unwholesome but is not a potential danger to human health, the local authority is not required to act in accordance with section 80 of the Water Industry Act where the water is unwholesome.
3. Where the cause is due to the distribution system within a domestic premises, where the water is made available to the public
and/or
4. The cause of the unwholesome water is due to any part of the private supply that does not constitute the domestic distribution system
In addition to the steps described in section 1 above, the local authority must carry out the following steps as applicable.
If the supply presents a potential danger to human health, and the conditions in regulation 20 are satisfied, it must serve a notice in accordance with regulation 20. Failure to comply with a regulation 20 notice is an offence.
Alternatively, if the water is unwholesome, but not a potential danger to human health and appropriate remedial action has not been taken after 28 days of establishing the cause, the local authority must consider serving a notice in accordance with section 80 of the Water Industry Act 1991 to ensure that the improvements are made (unless the local authority grants an authorisation in accordance with regulation 19(2). The serving of such a notice is discretionary and the decision to do so should be made on a case-by-case risk basis. Where any relevant person fails to take any remedial steps within the specified period in the section 80 notice, the local authority may take that step itself and recover expenses reasonably incurred by this action. Failure of a relevant person to comply with a section 80 notice is not an offence.
Sampling variations
Regulation 18(6) also requires that where a parameter that is being monitored on a reduced frequency or is otherwise varied, has breached its regulatory concentration or value (PCV), the frequency of monitoring must immediately return to normal frequency following the breach. See guidance note on regulation 7.