- Drinking Water 2024 – Summary of the Chief Inspector’s report for drinking water in Wales
- Foreword
- Water supplies and testing
- Compliance with standards
- Learning from compliance failures
- Learning from events
- Consumer contacts
- Asset health
- Water safety planning and risk assessment
- Raw water
- Poly and perfluoroalkyl substances (PFAS)
- Audit programme
- Recommendations
- Enforcement
- SEMD
- NIS
- Materials in contact with drinking water (Regulation 31)
- Research publications
- Whistleblowers
- Working with stakeholders
- Annex A – Number of tests carried out by companies
- Annex B – Compliance with standards
- Annex C – Compliance failures and events
Materials in contact with drinking water (Regulation 31)
Regulation 31 prohibits a water company from applying any substance or product to, or introduce any substance or product into water, which has not met one of the provisions in regulation 31 of the Regulations. This covers all chemicals and construction products used by water undertakers, from the source of the water, up to the point of delivery to the consumer’s premises. This is a critical duty because materials can contaminate water by taste, odour or by leaching of harmful by-products. The regulation sets out how approvals can be given to construction products and materials that do not prejudice water quality and ultimately consumer safety. During 2024, the Inspectorate continued to receive and process applications for approval of products in contact with drinking water (under regulation 31). The volume of applications processed was:
Table 18 Regulation 31 applications
| Year | Total applications | New applications | Product changes | Product reapprovals |
|---|---|---|---|---|
| 2024 | 177 | 47 | 79 | 51 |
| 2023 | 126 | 24 | 61 | 42 |
| 2022 | 145 | 32 | 62 | 51 |
| 2021 | 146 | 23 | 62 | 60 |
The Inspectorate has continued working with its IT partners to further develop the regulation 31 portal for product approvals. The system has replaced the previously used manual application forms with online, interactive application forms that will guide applicants in providing all the necessary information for an approval or product change to be considered. The online process will have the benefit of meeting accessibility standards, making them available to more people with the next phase of the project delivering and end to end process and approved products list transformed from a monthly, published PDF document to an interactive, searchable website which is updated in real-time. This will effectively become a live, online catalogue of approved products.
2024 saw a significant increase in poor product stewardship with several approved products revoked from the Secretary of State’s List with immediate effect and a prohibition issued for the use of a product with an unauthorised name change. Subsequent investigations led to further revocations in early 2025. All identified issues were as a result of unauthorised changes being made to the product.
In December 2024, approval for Puriton Pipes (DWI 56/4/1112) manufactured by Radius Systems Ltd was revoked. The company had made a late submission for reapproval and once all the relevant documents were submitted, reapproval was granted. Subsequently however, the Inspectorate was informed that the information provided was incorrect and that unauthorised changes had been made to the product. This resulted in immediate revocation of the approval and extensive liaison with the company.
A notification letter of prohibition was issued to the industry following an unauthorised name change to an approved product. As part of a rebranding process, MBCC provided suppliers with products re-labelled with a handwritten label stating the product’s new name, changing from Sikadur-CombiFlex 930 to Sikadur-CombiFlex 933 (DWI 56/4/1569), accompanied by the MBCC IFU document for MasterSeal 930 joint bandage with MasterSeal 933 adhesive (DWI 56/4/144), the product and IFU names not aligning. This was initially identified by Northumbrian Water who notified the Inspectorate and was subsequently found to be a widespread issue. The company had not completed the change process for this product which resulted in several companies having to remove the product from assets where it had been applied, with other companies forced to keep assets out of supply until the process had been completed and the name change authorised. This resulted in a significant number of meetings with company representatives to rectify the issue.
This was yet another example of both poor product stewardship by the manufacturers and complacency on behalf of water companies and contractors who failed to identify that the IFU did not match the label on the product container and the product name did not appear on the Secretary of State’s List. As a result, water companies were instructed to notify use of this product to the Inspectorate as a water quality event.
The Inspectorate does not take the decision to revoke products or prohibit the use of products lightly, however, where the requirements to maintain product approvals are not met, and constitutes a potential risk to public health
In addition, several approval holders omitted to apply for product reapprovals which resulted in an increase in expired products, and manufacturers having to undertake the process of product approval, rather than re-approval.
These incidents were extremely time consuming for the Inspectorate to resource and impacted the growing back log of applications. A list of all products approved and under consideration under regulation 31 is available on the Inspectorate’s website: https://www.dwi.gov.uk/drinking-water-products/resources-for-water-companies/approved-considered-products/
Anglian Water – Regulation 31 Case
At Northampton Magistrates Court on 15 May 2025, Anglian Water were fined a record £1.42 million following a prosecution by the Inspectorate for drinking water failures affecting around 1.3 million people.
Between June and December 2021, Anglian Water notified the Inspectorate of four water quality events due to the use of unapproved pipework and material used in several tanks in the supply of drinking water. Anglian Water Services Limited pleaded guilty to five offences under regulation 33 of the Water Supply (Water Quality) Regulations 2016 (as amended) for repeatedly introducing unapproved materials into the water supply. The investigation identified compelling and credible evidence for the following failures and findings on four separate sites and schemes.
Issues common to each event
The investigation identified compelling and credible evidence for the failures and findings below (common to all four schemes):
- Lack of control of the regulation 31 process to prevent the installation of unapproved products in a submerged environment repeatedly (strong evidence pointing to failure to control products used, backed with witness statements, contractor witness statements, photographs and Materials in Contact records).
- Poor management of contractors and supply chain/procurement arrangements (backed by witness statements, procurement and delivery records).
- Lack of regulation 31 training in place at the time of installation for engineers, water quality, or project managers (training records, witness statements).
- The coating of the pipes (in all events) deteriorated to a powder/flakes that was easily removed from the surface of the pipes. The analysis of the coatings contained controlled phthalate-based substances, some of which are banned from children’s toys, cause birth defects and cancers (evidence includes compound analysis reports, SNARLS, pictures, and witness statements).
- General compliance samples have not detected a deterioration in quality (except at Kedington, see below) – but not all relevant parameters were analysed regularly and consistently (evidence includes sampling records).
Approximately 1.3 million customers across the Anglian Water region have been impacted by these failures. The Inspectorate was critical of the wrong products being used in submerged environments, lack of controls and of the company’s management of products. The Inspectorate was also critical that an asset remained in service after it had been identified that non-approved products were being used.
- Hannington Reservoir 1A and 1B – Tank A in supply from April 2016 to December 2021. Tank B in supply to present day.
- Pitsford Storage Tank B – in supply from October 2016 to December 2021
- Diddington Reservoir – in supply from Feb 2017 to November 2021
- Kedington contact tank and balance tanks – in supply from March 2020 to May 2020
Failure to control the installation of unknown and untested materials can have consequences; this prosecution serves as a reminder that drinking water must come first as a service.