Guidance

Temporary discharge of water unfit for supply from water treatment and supply assets: RPS 280

Published 17 April 2024

Applies to England

This Regulatory Position Statement (RPS) does not change your legal requirement to have and comply with a water discharge activity permit when you have a temporary discharge of out of specification water from water treatment and supply assets to surface waters. 

However, the Environment Agency will not normally take enforcement action against you if do not comply with these legal requirements provided that:

• your activity meets the description set out in this RPS
• you comply with the conditions set out in this RPS
• your activity does not cause (and is not likely to cause) pollution of the environment or harm to human health
• your activity does not cause significant adverse visible effect on the receiving water, the bed of the watercourse or any plants or animals within the watercourse
• your activity does not adversely affect the countryside or places of special interest

1. Activity this RPS applies to

This RPS applies to water which is intended, but unsuitable, for supply. These are also known as ‘out of specification waters’ that come from water treatment works (WTW) and water supply assets. Out of specification waters cannot be used in drinking water supply so have to be discharged to the surface waters.

2. Conditions you must comply with

You must:

• discharge only to surface waters as defined by paragraph 2 of Schedule 1 to Water Framework Directive Regulations 2017
• have a method statement that minimises the risk of pollution to the receiving watercourse, such as how to prevent scour or erosion and how to manage silt
• dechlorinate the discharge
• make sure the discharge is between pH 6 and pH 9
• monitor the discharge at least daily for turbidity, pH and, if applicable, total available chlorine, total iron and total aluminium
• monitor the receiving water at least daily, as far as is reasonably practicable
• include the discharge in a permitting plan agreed by the Environment Agency if the discharge has been subject to treatment, such as chemical dosing or chlorination
• keep records for 2 years that show you have complied with this RPS and make these records available to the Environment Agency on request.

You must tell the Environment Agency if:

• the pH is outside of the range 6 to 9
• the total available chlorine is greater than 0.05mg/l
• the total iron is greater than 2mg/l
• the total aluminium is greater than 1mg/l
• there are dead or distressed fish, other animals or plants in the area of the discharge
• there is appreciable deposit of solid material
• there is appreciable discolouration of the receiving water
• there is scouring of the bed or banks of the watercourse
• the discharge occurs or may occur on more than 3 consecutive days or has occurred on more than 10 days in a calendar year

You must not:

• pollute any surface waters
• discharge within or 500 metres upstream of, places of special interest unless agreed by the Environment Agency
• cause or contribute to, the failure of Environmental Quality Standards (EQS).
• cause erosion or scour of the watercourse bed or banks
• increase the spread of non-native invasive species, parasites or disease.
• cause or contribute to flooding in the downstream catchment
• carry out this activity on more than 7 consecutive days unless agreed by the Environment Agency

3. Things to note 

You must have a Water Industry Act S166 consent to discharge from a water supply asset through a pipe that’s more than 229mm in diameter if the discharge is caused by:

• construction works
• maintenance works
• repair works

As described by S165(1) of the Water Industry Act 1991.

To apply for a Water Industry Act S166 consent, email: psc-waterquality@environment-agency.gov.uk

You do not need a consent if the pipe is less than 229mm in diameter as long as you meet the requirements of section 165 (1) of the Water Industry Act.

4. When you must check back

The Environment Agency will review this RPS by 1 April 2026.

The Environment Agency can withdraw or amend this regulatory position before the review date if they consider it necessary. This includes when the activity that this RPS relates to has not changed

You will need to check back from time to time, including at and before the review date, to see if this RPS still applies or if you need to apply for an environmental permit. You can subscribe to email updates about this RPS. These will tell you if the RPS has changed and when it has been withdrawn.

This RPS remains in force until it is removed from GOV.UK or is otherwise identified as having been withdrawn.

5. If you cannot comply with this RPS

If you operate under this RPS but think you may no longer be able to comply with its conditions, you must stop the activity that this RPS relates to and tell the Environment Agency immediately.

You need to apply for a bespoke permit if you cannot comply with the conditions in this RPS.

6. Contact the Environment Agency

If you have any technical questions about this RPS email: EandB_WQ_Compliance@environment-agency.gov.uk and include ‘RPS 280’ in the subject.

General enquiries

National Customer Contact Centre
PO Box 544
Rotherham
S60 1BY

Email enquiries@environment-agency.gov.uk

Telephone 03708 506 506

Telephone from outside the UK (Monday to Friday, 8am to 6pm GMT) +44 (0) 114 282 5312

Monday to Friday, 8am to 6pm.