Water quality

We deal with some issues regarding Denbighshire's water quality and Natural Resources Wales look after others.

Click a heading to find out more about water quality issues we deal with;

Bathing Water

The monitoring of bathing water quality in Wales is co-ordinated by Natural Resources Wales (NRW). 

Find out more about bathing water quality

Public water supply

We have a duty to ensure that all public water supplies are wholesome and sufficient. We liaise with water companies during concerns over water quality.

Two Water Companies provide public water supply in Denbighshire; Dŵr Cymru Welsh Water and Dee Valley Water. Each water company has an extensive monitoring programme to make sure that the water reaching your tap is safe.

Find out about Welsh Water in your area

The Drinking Water Inspectorate (DWI) are responsible for assessing the quality of drinking water in England and Wales.

Private water supplies

Private water supplies are not provided by water companies and can include springs, boreholes, wells, streams, rivers, lakes and land drains. We are responsible for ensuring private water supplies are wholesome and sufficient for commercial and domestic properties. 

Domestic properties

We test private water supplies that provide more than 10,000 litres per day to households at least once a year. If it supplies less than this, then the supply would be tested at least once every five years.
A private water supply to a single property is tested at least once every 5 years. 

Non domestic properties

Private water supplies at non domestic properties are tested at least once a year depending on how much water is used and the amount of people using the water.

Type of supply Cost Number of visits
Providing less than
10,000 litres per day
£95.00 plus
analyses costs
Once a year
Providing more than
10,000 litres per day
£95.00 plus
analyses costs
Twice a year

Changing to a private water supply

If you are changing to a private water supply, or you are a new occupier at a property that uses one, you can download a private water supply form to let us know. The cost of testing a new water supply is £95.00 

More information

You can get more information on private water supplies by contacting us or visiting the following websites:

Water supplies at events

We are responsible to ensure and monitor that the organizer provides wholesome and sufficient water for events, when either by private distribution system of mains water or from private water supply.

The Water Health Partnership for Wales (WHPW) has published guidelines for the setup and monitoring of water supply to temporary events.

If you are proposing to plan a temporary event, please contact us and you can download the guidance 

Swimming, spa and outdoor paddling pools

We monitor the pool water quality at privately owned pools that are used by the public e.g. hotel and caravan sites and our leisure centre pools. This is to make sure that pools are a healthy, safe environment.
Samples are taken for testing from swimming and spa pools once a month while outdoor paddling pool samples are taken once a fortnight. If a sample does not reach the standards set by the Pool Water Treatment Advisory Group (PWTAG), then we would instruct the relevant people to take action.

If you are proposing a pool for use by the public, e.g. a new spa pool or hot tub, please contact us.

Please contact us if you have a query or complaint about any of the above. 

Natural Resources Wales deal with:

  • Pollution to water or land 
  • Poaching or illegal fishing 
  • Fish in distress or dead fish 
  • Watercourse blocked by vehicle or fallen tree causing risk of flooding 
  • Illegal abstraction from watercourses 
  • Unusual drop in riverflow 
  • Collapsed or badly damaged river or canal banks 
  • Septic tank registration

If you would like more information on these matters or to report an incident, you can call Natural Resources Wales on 03000 65 3000