Regulatory decisions for waste management

Restarting private sewage treatment works

Careful steps need to taken before restarting a sewage treatment plant after a period of low effluent flows or shutdown.

During normal operation, a regular flow of sewage effluent keeps microorganisms alive in the biological process. The sewage treatment plant relies on the biological process to feed on and remove pollutants, treating sewage effluent to a sufficient quality prior to discharging to surface or groundwater.

Restarting the plant following the COVID-19 shutdown may overload the microorganisms. This could lead to poor quality effluent polluting the receiving environment unless careful steps are taken by the operator to prime the biological process.


In Wales, the discharge of sewage effluent to ground or surface waters is regulated under the Environmental Permitting Regulations (EPR) 2016. The discharge must meet the standards set out in an environmental permit or meet the terms of an exemption.

Operators who discharge poor quality effluent risk being in breach of their environmental permit or exemption if the discharge causes pollution of surface water or groundwater. As businesses open, the increased flows or sudden start of the treatment plant is very likely to result in poor quality effluent unless steps are taken by operators to ensure the plant can operate effectively.

Operators who are used to seasonal variations in flow and loads such as campsites, holiday villages and tourist attractions should follow their usual procedures for increasing flows to their treatment plants whilst maintain compliance with their environmental permits.

Operators who are not used to seasonal variations of low or no flows of sewage should seek expert technical advice for recommissioning their treatment plant. This may be done by contacting:

  • your usual sewage treatment plant maintenance contractor
  • the manufacturer or installer of the treatment plant
  • or a professional Sewage treatment plant maintenance engineer

As part of start up the package plant may require re-seeding with sludge from another plant. Operators will need to register a U6 waste exemption to bring in this sludge from another sewage works.

British Water have produced guidance for restarting package sewage treatment plants and a list of suitable maintenance engineers can be found on their website.

The treatment system may also have pre-treatment in the form of fat, oil and grease traps. The operator must ensure these are ready for use again when the treatment plant is operational or you may risk damaging the plant. Cleaning products should be used sparingly as the biological process in the treatment plant will be sensitive to excessive levels of chemicals.

Once a treatment plant has been restarted or flows have increased the operator must continue to monitor that it operates correctly and does not cause pollution.

If there are concerns that pollution is occurring the operator should notify their regulatory contact or call our 24-hour incident hotline.

Disposing of waste beverages

Waste beverages must not be poured down drains that lead to private sewage treatment plants or directly to surface or groundwaters because it can cause pollution.

Waste beverages should only be removed by licensed waste carriers and only disposed of at suitably permitted waste facilities. Contact the British Beer and Pub Association for advice or refer to the waste hierarchy.

Waste carrier copy cards

Due to office closures we are unable to provide waste carrier copy cards at this time.

Your reference number can be used as proof of your registration.

Waste storage limits

Following a review this regulatory decision is no longer applicable

Producer packaging obligations

Following a review this regulatory decision is no longer applicable

Signing waste documentation

Following a review this regulatory decision is no longer applicable

Technical competence

Following a review this regulatory decision is no longer applicable

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