The 2024 Annual Reports for Private Water Supplies has been published by Scotland’s Drinking Water Quality Regulator.
The data submitted by local authorities for 2024 indicate that there are 23,158 private supplies in Scotland, an increase of 124 from 23,034 supplies reported for 2023. These data show that around 2.5% of the Scottish population rely on a private water supply. However, this figure is likely to underestimate the true number of individuals served, as it does not account for the large number of visitors to commercial premises including tourists, employees, and consumers of products from food premises.
Recent legislation to licence short term let properties in Scotland has led to an increase in Regulated supplies across the country, and local authorities are prioritising the administration of these additional supplies based on public health need. The increase in PWS reported in 2024 is partly due to the registration of these properties. The changing numbers make year-on-year comparisons difficult. Compliance with the statutory requirement to sample all regulated water supplies annually has improved across Scotland, rising from 65% in 2023 to 69% in 2024.
Significant performance improvements were observed in several local authority areas:
- East Ayrshire: increased markedly from 10% in 2023 to 82% in 2024
- Stirling: improved from 16% in 2023 to 62% in 2024
- Angus: rose from 55% in 2023 to 77% in 2024
These gains are largely attributed to enhanced resource allocation, with some authorities recruiting additional staff to conduct sampling and inspections, while others opted to outsource these activities to external providers. A modest improvement was also noted in Argyll and Bute Council, where compliance rose from 59% in 2023 to 66% in 2024.
Compliance with the annual sampling requirement for Regulated supplies within Perth and
Kinross Council has continued to decline, falling from 72% in 2022 to 55% in 2023, and further to 46% in 2024. This downward trend is primarily attributed to the loss of experienced personnel and ongoing challenges in recruiting suitably qualified staff to carry out sampling and inspection duties.
Most local authorities maintained performance levels consistent with previous years.
Notably, the following councils achieved 100% compliance with the annual sampling
requirement for regulated supplies:
- Aberdeen City
- East Dunbartonshire
- Falkirk
- Fife
- Inverclyde
- Midlothian
- North Lanarkshire
- West Dunbartonshire
- West Lothian
Several of these areas manage a relatively small number of supplies, which can contribute to higher compliance rates. In contrast, local authorities responsible for a larger volume of supplies, particularly those located in remote or geographically challenging areas, face additional operational complexities that can impact performance.
In 2024, as in previous years, the parameter with the highest rate of non-compliance was coliform bacteria, with 20.5% of samples failing this test. This represents a slight improvement from the 2023 failure rate of 21.2%. Coliform bacteria are naturally present in soil and the wider environment; their detection in drinking water indicates inadequate or ineffective treatment of private water supplies. E. coli was found in 10.1% of samples, which is concerning as this indicates that faecal contamination may be present.
