Private Water Supplies - Case Study

A complaint about a local authority not discharging its duty under the regulations


In September 2023 the Inspectorate was contacted by a private water supply consumer in England, who wished to complain that his local authority had not tested his supply in fourteen years and had never risk assessed it.

The consumer was in the process of selling his house and anxious that the sale might fall through because he was unable to evidence the wholesomeness of his supply. The consumer had requested a sample to be taken by the local authority and was concerned that should it fail the required water quality standards this could affect the pending sale. It is worth noting that even if the sample did meet the standards for the parameters tested, this alone is not necessarily reliable assurance that the supply was always safe to consume.

Supply type

The property concerned was on a supply that also fed other houses. Some of the houses have installed point of use UV systems, but some have no treatment at all. The Regulations require that such a supply must be risk assessed by the local authority, and that these must be reviewed and update by them every five years (or earlier if it considers that the existing risk assessment is inadequate). Local authorities are also required to monitor supplies of this type every five years for the parameters specified in regulation 10 and any others that the risk assessment identify as being relevant.


The Inspectorate explained that it could not investigate the matter as a formal complaint, as it had neither a statutory duty nor any powers of enforcement in this respect. Instead, he was advised to contact the authority’s ombudsman and lodge a complaint. The Inspectorate nevertheless agreed to contact the local authority on his behalf to make them aware of his dissatisfaction and to provide an opportunity for them to comment.

The Inspectorate established that some years previously the local authority had removed the supply from its record on the assumption that the properties concerned had been connected to the public mains supply. It also confirmed that this supply had not been sampled for fourteen years, or risk assessed on account of the previous property owner not replying to their attempts to contact them for information. They also confirmed that the current occupier of the property concerned had now been contacted should he wish for a sample and or a risk assessment to be undertaken.

The Inspectorate informed the authority that the requirement for supplies to be monitored and risk assessed was placed on them, and that it was not reliant on consumers to make requests of this nature by choice (unless the supply served a single dwelling only). However, the Inspectorate has found that it is a commonly made error for local authorities to incorrectly apply the sampling and risk assessment requirements based on property type (dwelling verses commercial). In this case, the property concerned was a dwelling, but it was not the only dwelling fed from the supply.

Learning points and conclusions

  • Local authorities should regularly review and then confirm any known or suspected changes to the private water supplies in their areas.
  • Where local authorities have difficulties in gaining property access or information from unresponsive owners and users, they are reminded of their powers under sections 84 and 85 of The Water Industry Act 1991 to obtain entry and information respectively.
  • Local authorities must monitor, and risk assess all shared and commercial private supplies in their area. Only those suppling a single dwelling in isolation are exempt from mandatory monitoring and risk assessments.

This case study shows that local authorities can inadvertently make themselves vulnerable to criticism if they do not fully discharge their regulatory private water supplies duties. It also shows the need for regular testing and risk assessment of private water supplies to create up to date and ongoing water quality records. Such records may be requested by solicitors on behalf of their clients, for property conveyancing purposes and their absence may impact a vendor’s ability to sell their property.

Should any local authority be unsure of its regulatory obligations, the Inspectorate provides guidance and support in the application and interpretation of the regulations on its website and takes enquiries by phone or email.