- Drinking Water 2024 – Summary of the Chief Inspector’s report for drinking water in England
- Foreword
- Water supplies and testing
- Compliance with water quality standards
- Water quality events
- Asset health and service reservoir integrity
- Consumer contacts
- Water safety planning and risk assessment
- Perfluoroalkyl and polyfluoroalkyl substances (PFAS)
- Audit programme completed by the Inspectorate
- Enforcement, transformation and recommendations
- Lead in water
- Materials in contact with drinking water (Regulation 31)
- Security and Emergencies (SEMD)
- Network Information systems (NIS)
- Research publications
- Raw water data
- Whistleblowers
- Working with stakeholders
- Annex A – Number of tests carried out by companies
- Annex B – Compliance with standards
- Annex C – Compliance failures and events
Enforcement, transformation and recommendations
The Inspectorate publishes the drinking water quality legal instruments on the website under company improvement programmes. Security (SEMD and NIS) legal instruments are considered sensitive and therefore are not published in the public domain. A summary of the legal instruments issued in 2024 is below.
| Type of legal instrument | Number of legal instruments | Companies |
|---|---|---|
| Regulation 27(4) Notice for improvements to water safety plans | 5 | Independent Water Networks (1), Leep Networks Water (1), Portsmouth Water (1), South East Water (1), Thames Water (1) |
| Regulation 28(4) Notice relating to risks identified in water safety plans | 34 | Northumbrian Water (3), Severn Trent Water (13), South East Water (3), Southern Water (6), South Staffordshire Water (1), South West Water (3), Thames Water (2), United Utilities (1), Wessex Water (1), Yorkshire Water (1) |
| Enforcement Order under section 18 of the Water Industry Act 1991 | 2 | Severn Trent Water (1), Southern Water (1) |
| Undertaking accepted under section 19(1) of the Water Industry Act 1991 for drinking water quality improvements | 2 | Castle Water (1), Wessex Water (1) |
| Undertaking accepted under section 19(1) of the Water Industry Act 1991 for SEMD improvements | 4 | Southern Water (1), South East Water (1), South West Water (1), Thames Water (1) |
| Regulation 17(1) Notice for improvements under the Network and Information Systems Regulations 2018 | 1 | Affinity Water (1) |
| Regulation 15 Notice for the provision of information under the Network and Information Systems Regulations 2018 | 2 | Affinity Water (1), South Staffordshire Water (1) |
The individual legal instruments listed above have been discussed in detail, within the quarterly Chief Inspectors reports published throughout 2024.
2024 saw the majority of our work to secure legal instruments for the delivery of improvement programmes committed to by companies during PR24, reflected in the large number of legal instruments summarised in the table below. These legal instruments enable us to monitor the progress of company plans to address drinking water quality, NIS or SEMD risks. In their PR24 determination, Ofwat have linked the price control deliverables for enhancement schemes to the DWI issued legal instruments. We shall continue to work closely with Ofwat and keep them updated throughout the AMP. This is the first time that DWI has taken a role in respect of NIS and SEMD at a price review. Our intention was to mirror, as closely as possible, our approach to drinking water quality. As such, we also issued legal instruments for these areas of activity. We were pleased with the overall positive engagement from companies in what was a new approach for all of us. We will seek to continue to guide and support companies through the lifetime of the legal instruments, whilst not losing sight that they are in place to, and our role with them, is to hold companies to account and ensure they deliver on their commitments.
| Type of legal instrument | Number of legal instruments | Companies |
|---|---|---|
| Regulation 28(4) Notice relating to risks identified in water safety plans | 78 | Anglian Water (17), Northumbrian Water (3), Portsmouth Water (4), SES Water (2), Severn Trent Water (5), South East Water (6), Southern Water (7), South Staffordshire Water (3), South West Water (14), Thames Water (4), United Utilities (7), Wessex Water (5), Yorkshire Water (1) |
| Enforcement Order under section 18 of the Water Industry Act 1991 | 2 | Thames Water (2) |
| Undertaking accepted under section 19(1) of the Water Industry Act 1991 for drinking water quality improvements | 29 | Affinity Water (2), Anglian Water (2), Northumbrian Water (2), Portsmouth Water (2), SES Water (2), Severn Trent Water (3), South East Water (2), Southern Water (2), South Staffordshire Water (2), South West Water (2), Thames Water (2), United Utilities (2), Wessex Water (2), Yorkshire Water (2) |
| Undertaking accepted under section 19(1) of the Water Industry Act 1991 for SEMD improvements | 19 | Affinity Water (2), Anglian Water (2), Northumbrian Water (1), SES Water (4), Severn Trent Water (2), South East Water (1), Southern Water (2), South Staffordshire Water (1), South West Water (1), United Utilities (1), Yorkshire Water (2) |
| Regulation 17(1) Notice for improvements under the Network and Information Systems Regulations 2018 | 15 | Affinity Water (1), Anglian Water (1), Northumbrian Water (1), Portsmouth Water (1), SES Water (1), Severn Trent Water (1), South East Water (1), Southern Water (1), South Staffordshire Water (1), South West Water (2), Thames Water (1), United Utilities (1), Wessex Water (1), Yorkshire Water (1) |
| Formal acknowledgement of a set of actions (“Acknowledged Actions”) | 10 | Portsmouth Water (1), Severn Trent Water (6), Southern Water (1), South Staffordshire Water (1), South West Water (1) |
Transformation Programmes
A key activity of the Inspectorate’s Enforcement Team is the management of the transformation programmes. The Inspectorate may initiate a transformation programme where the risk position of a company becomes elevated or is frequently realised in a specific area of operation. For example, multiple, similar drinking water quality events caused by a lack of appropriate training. Once a company is notified that we intend to place them into transformation, we seek to work collaboratively to put together a measurable programme of improvements.
A transformation programme includes a set of bespoke legal instruments to address those areas of high risk. They are generally large in scope and require a long-term, concentrated effort in order to move the risk position. Following the initial tranche of legal instruments, follow up legal instruments may be served to address issues that fall out of the initial programme.
Transformation isn’t only about completing the work under the notices, but it is about a robust and consistent effort to reduce overall risk. A large factor in this can be the attitude of company personnel, particularly those in senior leadership roles, who ultimately determine the attitude of the company.
There are currently four English water companies in transformation. A summary of the enforcement activities in 2024 and progress with transformation is given below.
Northumbrian Water
Northumbrian Water have been in Transformation since 2021, after a series of events and an increasing recommendation risk index score identified risks the company were carrying, particularly with respect to asset health.
Liaison meetings have been constructive in the main, with the company now highlighting issues earlier and they have noted that we are giving them more scrutiny than they had expected.
The management of the company’s Tanks and Service Reservoir notice has been poor. A total of five assets have been extracted out of the notice into their own individual notices, with another two currently still in draft. The lack of early planning for the difficult to isolate reservoirs and tanks does not give confidence that the notice, due to be completed by the end of March 2025, will be completed on time. One of the extracted tanks, the Gunnerton contact tank notice, was served in August 2024 but still requires dates for deliverables as a newly installed tank is required and the location is yet to be decided. This tank was only raised to the Inspectorate as an issue in the summer of 2024. The company had until the end of February 2025 to confirm delivery dates.
The company has been in transformation for three years, but have not mentioned the issues with this tank in meetings.. Most current notices are on track, but the failure of the Tanks and Service Reservoir notice has been a strong example of their poor management of legal instruments. The company is currently managing 32 legal instruments with five due for final reporting in 2025. Over the coming 12 months the company will be further scrutinised on their overall management of their legal instruments and their ambition to leave transformation.
Southern Water
Southern Water have been in Transformation since 2018. The company had begun an internal transformation programme, “Water First” prior to this, however the audits, compliance breaches and events which were still occurring required the formalisation into DWI specific transformation measures. Of the existing transformation companies, Southern Water have been in Transformation for the longest period.
New notices served during 2024 included a companywide discolouration notice, three water storage assets requiring enabling works for internal inspections, a companywide training and procedural notice aimed at network operations, and a replacement notice for the phased rebuilding of Weirwood works. Four regulation 28(4) notices were revoked in 2024, however that included the Yew Hill/West Hill notice, which was escalated to a Final Enforcement Order (FEO), Rownhams discoloration notice was replaced by the company-wide discolouration notice, the operational training notice was followed on by a network training notice and Weirwood saw a significant solution change that required a new notice. Thus, there were zero notices fully completed in the 2024 calendar year. A bulk supply metaldehyde section 19 undertaking was revoked.
Change applications submitted in 2024 resulted in one FEO, three new notices and five new versions of notices. Six change applications were rejected as the delays were deemed to have been caused by the company, or were fully within the company’s control. A list of these delayed schemes can be found below. Whilst the company does not have the most legal instruments in place, it by far applies for the most change applications. These applications almost always request to extend the dates of milestones and/or the final completion date within them. Since January 2020 an average of 1.5 change applications per month have been submitted, more than all other companies combined.
The company received its seventh FEO in August 2024. This was a result of failing to meet the requirements of the existing 28(4) notice covering Yew Hill SR and West Hill SR. These reservoir sites were unable to be removed from service for internal inspections or remedial works. Yew Hill SR had a crack along its side wall, with ingress which led to multiple failed microbiological failures since 2021. The notice had moved through a number of possible solutions, each of which pushed back the proposed inspection date. To ensure the inspection would not be delayed further, the latest change application was accepted as a FEO. The order was made on 14 August 2024, following consultation. A coliform detection from the reservoir was reported as an event in October 2024 highlighting the risk the reservoir poses to consumers in the Winchester area. The company have since fast tracked the isolation, inspection and remediation of the asset.
There have however been some green shoots starting to emerge. Following a strategic review, the Inspectorate undertook the serving of enforcement orders on the big four works (Otterbourne, Testwood, Hardham and Burham) and a new management structure was installed to provide more overarching responsibility for the sites and the multiple work streams that were required for complying with the orders. Since the enforcement orders have been in place, it has been a learning curve for the company as to what is expected in terms of evidence and reporting. In 2024 the reports submitted were vastly improved from 2023 and fewer queries and questions arose from them. Hardham and Burham works have seen a number of steps completed years ahead of the enforcement order dates.
Whilst the discolouration contacts made to the company cannot be viewed as good news, the company do appear to have pivoted from a reactive mindset to a new approach which is risk-based and outcome driven. If the solutions can remove the source of discolouration where possible, rather than simply flushing it through the system until it builds back up again, then the cause rather than the effect can be resolved.
Despite having been in Transformation for over six years, the company show few of the signs of overall improvement required to remove them from Transformation. They still suffer from large events occurring at sites covered by Legal Instruments. For example, four events occurred at Testwood in 2024. Audits still uncover a wide range of issues across the asset base and the company sit far above the expected average for their Recommendation Risk Index. The constant monthly submission of change applications outlines projects overrunning and delayed for a wide variety of reasons, mostly entirely within the control of the company. The Inspectorate will continue to apply pressure to the company until improvements are seen.
South West Water
South West Water have been in transformation since 2020 and received four transformation specific regulation 28(4) notices. These notices include Maintenance and Resilience Hazard Review, Service Reservoirs, Scientific Investigations and Cultural Change Programme.
The company has been in transformation for four years and are making positive progress with their current Legal Instruments. Regarding transformation notices, specifically the Cultural Change Programme, this concluded in January 2025 and Scientific Investigations by May 2025. The Maintenance and Resilience Hazard Review and the Service Reservoirs notices conclude in January 2027.
The company requested an extension to the existing Transformation Scientific Investigations notice. Three of the assets listed within the notice would require further works to gain access and this work would not be facilitated until further into AMP 8. The Inspectorate would not accept an extension, and three individual reactive regulation 28(4) notices were served on assets located within Dousland, Prewley and Lowermoor. A reactive section 19 SEMD undertaking was served on an asset within the Bristol region.
Transformation meetings have been constructive, and the water quality team proactively engage with Enforcement Inspectors. The company highlight issues early where possible.
South West water display a positive attitude toward the management of their legal instruments and have an ambition to leave transformation. The overall risk position of the company has decreased since the programme was initiated in 2020.
The Isles of Scilly still pose a significant water quality risk with three of the five schemes currently delayed; it is anticipated that the remaining two schemes will also become delayed. This issue is further compounded by the lack of an accredited regulation 31 laboratory to approve products in contact with drinking water, a risk the Inspectorate has talked about in these reports for many years now. The proposed solution to these five schemes depends upon regulation 31 approved products, which currently do not hold that approval. Putting an unapproved product into supply would constitute an offence under regulation 31 and therefore the company are proactively seeking a laboratory to undertake the testing requirements.
Thames Water
Thames Water entered the Transformation programme in 2018, following the identification of several deficiencies within the company’s risk assessment reports, and the realisation of these risks during site audits and the assessment of compliance and events. The transformation programme aimed to address several key areas of improvement where significant risks had been identified. The work areas included risk assessment and treatment of Cryptosporidium, management of turbidity, management of slow sand filters, training and competency of staff and risk from flooding. An initial tranche of 14 notices were served upon the company to address these risk areas, which have been followed by further notices to address other specific areas of concern. The company currently has 34 legal instruments in place, with a further three pending. Five notices are due for closure in 2025.
2024 has been a busy year for the company in terms of the management of its legal instruments. The company have submitted closure reports for several large transformation notices, which have now been assessed and revoked by the Inspectorate. The notices revoked include training and competency of staff, filter management and Cryptosporidium Hazard Review (HAZREV). In addition, the company submitted a closure report for the Data Shortfall FEO and several other notices, which have also been revoked by the Inspectorate. These are discussed in more detail in the highlights section below.
The company continue to engage with the Inspectorate, and quarterly transformation liaison meetings take place, alongside monthly catchup meetings with the Enforcement Team and the company’s Water Quality Team. The company have also invested in additional staff to improve reporting to the Inspectorate, which is seen as a welcome move and the improvement in the quality and timeliness of reports is already being realised.
The training and competency notice that was part of the initial tranche of transformation notices was successfully completed by the company in 2024 and revoked by the Inspectorate. The notice required the company to complete a critical review of competency, which found several shortcomings. Firstly, there was no standardised approach on recording competency, Secondly, the system for assessing competence was managed at a local level, resulting in varying levels of evidence. Thirdly, in terms of confidence of training, this was done via the company’s Performance Development Review Process. Fourthly, the company did not have a Licence to Operate scheme. This has now been introduced and aligned to the Industry Standard Competent Operator Scheme for all relevant business streams. The other issues identified have also been rectified. The audit strategy provided by the company for this notice showed an overall reduction in the numbers of events and failures when compared to previous years, prior to the issuing of the notice. It was also clear that the number of events and failures associated specifically with risks relating to training and competency had reduced since completing the notice. This is therefore a big achievement for the company and demonstrates tangible improvements companies can make when in Transformation.
The company also successfully closed the Cryptosporidium HAZREV notice, which was discussed in detail in the third quarterly report for 2024. It is noteworthy, however, to highlight that this notice covered 95 treatment works and was split into four sections, resulting in a complex notice to deliver. The notice remained the same version as when it was first served, without the need to be changed. Given its size and complexity, this demonstrates the company’s commitment to mitigating the risks that this notice covered.
Furthermore, the company submitted a closure report for the Data Shortfall FEO, which had been in place since January 2023, due to contraventions of regulations 6, 9, 12, 13, 14 and 17 of the Regulations. The Inspectorate assessed the information provided by the company and concluded that significant improvements had been made to the way the company approached regulatory sampling activities, including upgrades to technology and transport, additional training of staff and improvements in vehicles and resources. The Inspectorate entered consultation and subsequently revoked the FEO on 16 October 2024.
Finally, in addition to all the significant work outlined above, the company have successfully closed another five notices, demonstrating a high level of commitment to its Transformation programme.
Thames Water submitted two PR24 schemes for the Inspectorate to consider for support, for improvements in meeting the requirements of the Security and Emergency Measures Direction. The requested support was subsequently given. However, the company failed to submit section 19 undertakings to formalise the supported schemes. This was discussed in more detail in the third quarterly report from the Inspectorate, but is mentioned again here, as it represents a lowlight for the company, where the Inspectorate was left with no choice but to initiate further enforcement action. As a reminder to companies, the Inspectorate has no remit when it comes to financial matters, and will always seek compliance, using its published enforcement policies.
During an event assessment in the Guildford Water Supply Zone, deficiencies were noted in compliance with the Security and Emergency Measures Direction. The company were informed of the Inspectorate’s intention to initiate enforcement action but again declined to offer a signed section 19 undertaking. A second letter was sent by the Inspectorate, requesting a signed undertaking, and setting out that if an undertaking was not received, further enforcement in the form of an FEO would follow. The company subsequently offered a signed undertaking. Again, this serves as a reminder that the Inspectorate will always follow its published enforcement policies, to secure compliance.
Despite the positive messages regarding the original transformation programme notice progress, there have been other occasions where it has been a difficult, drawn-out process to secure legal instruments with the company. It is paramount that a company in transformation seeks to work with the Inspectorate to secure compliance. Ultimately, we are all trying to seek the same goal. Secure, wholesome drinking water supplies for consumers. The company have made real progress with their transformation programme, and its pleasing to see that measurable and substantial improvements have been made. The engagement from the company has been satisfactory, however, as discussed above, there have been issues with securing some legal instruments. The Inspectorate will always seek to work with companies to secure compliance, however, when companies undermine this process, the Inspectorate follow through and pursue further enforcement where necessary. Transformation programmes are not just about delivering a package of notices. They require real cultural change and quality dialogue at every level of the company to work with the Inspectorate to secure its success and exit the process. It is worth pointing out that the content of reports submitted to the Enforcement Team is very good, with minimal intervention required from the Inspectorate. The company should continue in this manner and work with the Inspectorate on initiation of its legal instruments in 2025 and beyond, to ultimately deliver significant improvements and risk reduction.
Delayed Legal Instruments
Delays to the delivery of projects can occur for all sorts of reasons. When notified of delays to programmes of work covered by our legal instruments, we consider they fall into two broad categories; those genuinely outside of the control of a company and those within the control of a company. Drinking water quality, security and emergency measures, or network and information systems improvement projects are important pieces of work, which should be taken seriously and delivered in a competent manner. The whole reason for their existence is the protection of wholesome drinking water supplies to consumers. Drinking water is a service that is essential for life and which must never be forgotten. We may be sympathetic regarding delays caused by matters that are genuinely outside of the company’s control and exceed a reasonable float of a project. However, we are less sympathetic to other delays and there are examples above where we have used our enforcement powers to ramp up the level of enforcement in response to unacceptable delays. The following table lists the legal instruments that were delayed as of the end of 2024.
| Company | Legal instrument | Delays |
|---|---|---|
| Northumbrian Water | Linford works | Delays in land purchase |
| Northumbrian Water | Tanks and Service Reservoirs | Five tanks outstanding beyond notice date |
| South East Water | Tanks Inspection and Cleaning | 30 tanks outstanding beyond notice date |
| South East Water | Tilford Meads Arsenic | Changes in solution and contractor issues |
| South West Water (Isles of Scilly) | Bryher Island Water Treatment Works Improvements | Delays in submitting planning application |
| South West Water (Isles of Scilly) | St Martins Island Water Treatment Works Improvements | Delays in submitting planning application |
| South West Water (Isles of Scilly) | Tresco Island Water Treatment Works Improvements | Delays in submitting planning application |
| Southern Water | AMP7 Mid Thanet Nitrate | Poor contractor management and governance |
| Southern Water | AMP7 Patcham Nitrate | Poor project management control and understanding of requirements |
Southern Water | Burpham CWT Enabling Works | Poor contractor management |
| Southern Water | Dunkirk BPT Inspection | Completion report was rejected due to outstanding issues which now need to be addressed |
| Southern Water | Hardham / Laws Aquifer Combined and Cocking High Iron | Completion report was rejected due to outstanding issues which now need to be addressed |
| Southern Water | Service Reservoir Integrity | 3 sites at risk of not meeting notice date |
Recommendations
The Inspectorate issued 836 recommendations in 2024, a significant increase on 714 in 2023 and 564 in 2022 . Recommendations are spread across the majority of companies with only some NAV companies not receiving any.
| Company code | Number of recommendations |
|---|---|
| TMS | 122 |
| SVT | 118 |
| YKS | 94 |
| SRN | 59 |
| AFW | 51 |
| ANH | 50 |
| SEW | 48 |
| UUT | 44 |
| IWN | 39 |
| SST | 35 |
| NES | 28 |
| CAM | 25 |
| SES | 24 |
| SWB | 18 |
| BRL | 17 |
| WSX | 16 |
| ESP | 14 |
| PRT | 11 |
| ALB | 7 |
| LNW | 6 |
| ICW | 5 |
| ISC | 3 |
| VWP | 2 |
| Total | 836 |
Regulatory breaches are the primary reason for making a recommendation where the company has failed to comply with the regulatory requirements which has resulted or could have resulted in a breach and a risk to wholesomeness. The Inspectorate made 112 recommendations where we felt that there was a serious breach of regulation.
A breach of regulation 27 (risk assessment) was the most common failing with 264 recommendations made, associated with shortcomings which the Inspectorate considers would have been within the company’s control and should have been proactively managed. Failings associated with disinfection and treatment resulted in 157 recommendations whilst failings associated with materials in contact with drinking water (Reg31) resulted in 30 recommendations. No one company stands out on Reg31 issues with regards to recommendations however events related to Reg31 are covered in the specific section.
| Regulations breached/likely to have breached | Number of regulatory breaches |
|---|---|
| Risk assessment (Reg 27, 28 in W) | 264 |
| Wholesomeness (Reg 4 in E&W) | 232 |
| Investigations (Regs 18 and 19 in E&W) | 175 |
| Disinfection and treatment (Reg 26, 27 in W) | 157 |
| Sampling and analysis (Reg 16 in E&W) | 64 |
| Notification (Reg 35(4); 35(6) in W) | 35 |
| Materials and products (Reg 31 in E&W) | 30 |
| Monitoring (Reg 6 in E&W, also 13,14) | 12 |
| Additional monitoring (Reg10 in E&W) | 7 |
| Number of samples (Reg 9 in E&W) | 3 |
| Water industry act | 3 |
| Information direction | 1 |
| Sampling points (Reg7 in E&W) | 1 |
| Total | 836 |