Guide
Interceptor cleaning regulations: what's law and what's guidance
Updated
Two different rulebooks get mixed up here: waste law, which is binding, and pollution prevention guidance, which is not. Knowing which is which keeps you compliant without paying for imaginary obligations.
The part that is law: the waste
- Oily interceptor waste is hazardous waste. When it leaves your site it must go with a licensed waste carrier, and a consignment note must be completed and kept; gov.uk sets out the duties at gov.uk/dispose-hazardous-waste.
- Record keeping. Keep your consignment notes on file; they are the evidence trail if the regulator ever asks where the waste went.
- Check the carrier. A legitimate contractor will show carrier registration without being asked twice; carriers can register (and be checked) via gov.uk.
- Pollution itself. Letting oil reach a watercourse or ground can bring enforcement and cleanup costs regardless of any servicing schedule; the separator only protects you if it is working.
The part that is guidance: GPP 3
The Environment Agency's guidance for oil separators was PPG 3, now GPP 3 (Guidance for Pollution Prevention 3: use and design of oil separators in surface water drainage systems). It covers where separators are needed, classes of separator, alarms, and maintenance. It is guidance, not a statutory instrument: following it is the recognised way of showing you manage the risk properly, but the document itself does not create offences, and it does not set a legal emptying interval. Annual servicing and integrity checks are standard maintenance practice per manufacturer and EN-type guidance, commonly recommended.
What a compliant clean looks like on paper
- Before: contractor confirms waste carrier registration and where the waste is going.
- During: tank emptied and cleaned, condition checked, oil-level alarm tested if fitted.
- After: you hold a completed consignment note, a service record, and ideally photos or a condition note. File all three; see also how often to empty.
A quote that looks cheap but says nothing about disposal or consignment notes is not the same product as one that includes them. All figures on this site are typical 2026 quotes; get real prices from licensed contractors.