Private Water Supplies - Case Study 2019/03

Multiple uses of a private water supply

Private water supplies can be used for several purposes, but they do not always fall within scope of the regulations. This case study shows just such an example at an historic water supply where the water was being used for a diverse range of uses in different buildings and the difficulties that local authorities sometimes face in interpreting the regulations due to the context in which they apply.

The supply is in an English city popular with tourists, where it forms part of a busy heritage attraction associated with Roman occupation. The water for this supply is derived from three hydraulically linked springs used historically for bathing and medicinal purposes due to its warm temperature (45̊C), although the old baths are no longer used due to amoebic contamination. Today the springs are intercepted by three boreholes, providing water at three locations in the city for several purposes, which depending on the activity at the respective location, comprise of a public activity, a commercial activity and for domestic purposes. Another use is regulated under mineral and bottled water regulations for historical reasons.

The supplies are also unusual in that the springs, which provide the source water, are owned by the local authority under an ancient Royal Charter. Furthermore, due to its multiple use, its sensitivity as a public amenity and its high profile as an internationally renowned heritage attraction, the number of stakeholders and relevant persons is diverse and numerous. With these factors in mind, the local authority contacted the Inspectorate requesting a visit to clarify and verify how and where the Private Water Supply regulations apply, given these unique arrangements. Consequently, in November 2019, the Inspectorate met with the authority and visited the sites concerned.

Two boreholes (including the Roman baths borehole) comprise one supply, which is blended. This is treated to reduce iron and manganese, chlorinated and then UV irradiated before being used at four leisure pools as a spa facility for paying patrons to bathe in the water. This is part of a commercial business. The water quality at this site is under constant scrutiny through in-house monitoring, which the local authority and spa undertake as part of the local water quality and supply agreements that have been established with several stakeholders in the interests of public health.

The local authority sought clarification as to whether the regulations were applicable at the spa, and in particular if they were required to carry out a risk assessment here as part of their regulatory duties. Bathing in the context of the regulations refers to sanitary ablutions as part of the definition of Domestic Purposes, as defined in section 218 of The Water Industry Act 1991. In this case the supply to the spa is not within scope of the private water supplies regulations because it has a capacity over 230 litres.

Water that is used exclusively for pool and spa activities is covered under different regulations. If, however the water from the private supply at these types of facilities is also provided for domestic purposes (including sanitary purposes) or it is used in food production where the product is intended for human consumption, e.g. at a café or tea room, then it would be within scope and is subject to the requirements of regulation 9. Drinking water is however made available at the spa facility and is provided from a public supply for this purpose.

The third borehole intercepts a third ancient thermal spring and provides water for bathing purposes to three exclusive en-suite bathrooms and a treatment room, in addition to three spa pools, at a separate city hotel. This supply is treated by a similar treatment setup as for the spa. The water in this instance is classified as being used for ‘domestic purposes’ in the Act since it is used for washing, bathing or showering.

Up until now the local authority had relied on information from a contracted service (weekly inhouse monitoring) to undertake routine checks and inspections of the water distribution network throughout the hotel to ensure the supply was safe. Although the local authority deemed the supply to be safe based on this information, they were advised that under Regulation 6 of the regulations they must complete a risk assessment and provide a summary of the findings of such an assessment to the Inspectorate. Those records and checks undertaken by the hotel, whilst essential and relevant, should be used as part of the overall wider assessment by the local authority, not instead of it. The local authority was advised that they have to undertake a regulatory sampling regime based around the taps located in the four rooms.

A water tasting experience is also provided in two locations at two respective water fountains (see figures 1 and 2) within the confines of the city museum and the Roman baths, the source of which comes directly from the Roman Baths borehole (which is also one of the boreholes above, part supplying the spa). Under normal circumstances this would constitute a private water supply since the water is being consumed as part of a public activity; however, in this instance the water is exempt from monitoring and all other requirements under Regulation 9, on account of it being afforded natural mineral water status, and it is instead regulated under the Natural Mineral Water, Spring Water and Bottled Drinking Water (England) (Amendment) Regulations 2018. This supply is therefore not within scope of the private water supplies regulations.

Figures 6 and 7: water fountains for the provision of public tasting opportunities.

fig 6
fig 7

The application of, and adherence to, the regulations do not always align perfectly with the supply being assessed. In this instance the water at the point of consumption is unusually warm yet samples must be cooled to around 3̊ C on being transported and stored in order to comply with sampling procedures.

The multiplicity of stakeholders and relevant persons involved; the physical and historic nature of the waters and its ownership; and the various sets of regulations which apply at different points for different reasons make this complex but interesting and informative. This is all added to the importance of an internationally recognised heritage attraction which gives it a high public profile.

Following this visit, the Inspectorate updated its guidance in its Information Notes on regulations 3 and 9 respectively with regards to water used in spas and pools. It is grateful to the local authority for sharing the complexities of these unique supplies and for bringing the need for additional guidance to its attention.