Drinking water

Page updated on: 04/12/2023

Drinking waters include the mains water supply and also private drinking water supplies. The mains water supply is the responsibility of Dŵr Cymru Welsh Water.

We monitor the quality of water from private supplies such as:

  • Wells
  • Boreholes
  • Streams
  • Springs
  • Rivers

A private water supply could serve just one property or it could be a large supply with a large network of pipes supplying water to many properties. To make sure that water used in the home and for producing food is of the high quality needed to protect public health, the government has set legal quality standards for all water used for drinking, washing and cooking or used in businesses which produce food or drink. These are the same standards set for mains water supplies.

The Private Water Supplies (Wales) Regulations 2017 places a duty on us to sample and risk assess all private water supplies in our area within five years, except supplies serving a single dwelling. The frequency of sampling and risk assessment is specified in the regulations.


The legislation has introduced a charging scheme for the monitoring of private water supplies. In Carmarthenshire, the charges below are for private water supply sampling and analysis, risk assessment and investigation.

Type of supply Risk assessment   Visit  Sample analysis Total cost: visit and sampling 
Large  / commercial £75 hourly rate £100 £65 plus £15.24 for microbiology sample £180.24 + VAT
Small £75 hourly rate £75 £25 £100 + VAT
Single domestic supply £75 hourly rate (if requested only) £50 £25 £75 + VAT

Requests for the sampling and analysis of supplies not covered by the regulations may also be made and are subject to the same charges.