Grease traps, drains, gullies, pump stations and flood water handled for businesses, landlords and homes across Portsmouth and Southsea.
Portsmouth is unlike anywhere else we work. Most of the city sits on Portsea Island, one of the most densely built-up places in the country, with rows of Victorian terraces, a busy seafront, a naval base and a huge number of restaurants, bars and takeaways. It’s all on mains drainage, so our work here is about keeping drains, gullies and grease traps clear.
The island is flat and low, and much of it is only a few metres above sea level. Drains have very little fall, so silt and fat settle easily, and after heavy rain, especially with a high tide, water has fewer places to go. Basements, cellars and chambers can take on water, and gullies that haven’t been cleaned make it worse.
We’re SafeContractor, Achilles UVDB and RISQS approved, so we can work on contractor-vetted sites. Our crews are in Hampshire most days and we answer the phone 24 hours a day, 365 days a year.
With so many food businesses packed into the city, fat, oil and grease is one of the biggest causes of blocked drains. We empty grease traps on a schedule that suits how busy you are, outside service hours if you prefer, and leave a waste transfer note every time.
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Victorian terraces often share drains that run behind or beneath the houses, and converted flats add more connections. We clear blockages with high-pressure jetting and help you work out whether the problem is in your drain or a shared sewer.
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On flat ground, gullies that are full of silt mean flooding after heavy rain. We clean gullies and interceptors at car parks, yards and commercial sites, and can set up a regular schedule.
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When heavy rain floods a basement, cellar or chamber, our tankers can pump the water out and take it away. Afterwards we jet and survey the drains to find out whether a blockage made it worse.
Learn moreLocal knowledge
A flat, low, crowded island puts drainage under pressure.
Drains on Portsea Island are almost level. Silt and fat settle, so regular jetting on commercial sites is worth it.
In many terraces, several houses share one drain run. A blockage in a shared section is usually the water company’s, not yours.
Heavy rain at high tide can leave water with nowhere to go. Clean gullies and a working pump, if you have one, help keep basements dry.
Local to you
We cover the whole of Portsmouth, from Old Portsmouth to the mainland edge of the city.
Portsmouth · city and districts
Mainland and surrounding areas · homes and businesses we cover
If you’re anywhere in Portsmouth, call with your postcode and we’ll confirm.
Why Portsmouth customers use us
Whether it’s a grease trap in Southsea or a flooded cellar in Fratton, here’s what you can expect.
Emergency call-outs 24 hours a day, 365 days a year, with a real person answering the phone.
SafeContractor, Achilles UVDB and RISQS approved, so we can get onto managed sites and meet your contractor checks.
Tankers from 2,000 to 4,000 gallons, jet/vac combination units, CCTV survey kit and confined space teams for pump station wet wells.
A waste transfer note with every collection, and a written report after surveys and services.
Tanks, treatment plants, pump stations, grease traps and drains, all handled by one team.
We’ve been emptying tanks and servicing systems since long before most of the kit on the market existed.
Checkatrade
From 134 reviews · Read them
From 63 reviews · Read them
Scores as of September 2026
★★★★★Great service from the initial call to the guys that come out. And we’re at the house within 3-4 hours. That’s why we’ve always used them
Josh F. Google review
★★★★★We use Clearmasters regularly for our cesspool emptying and can't fault them at all. Always friendly and professional, both on the phone and the drivers. Online credit card payment which makes life easy. Highly recommend.
★★★★★Turned up on time, cleared the blockage with little fuss and the lads who turned up were professional throughout
How it works
The same simple process for every job.
Step 1
Call us or book online and tell us what’s happening. For businesses, let us know the best times to attend and where we can park.
Step 2
We send a jetting van or a jet/vac tanker, depending on the job. It helps if:
Step 3
You get a waste transfer note for anything we take away, and a written report after a survey or service. If it’s a regular job, we’ll remind you when the next one is due.
Free, no-obligation quote
Tell us what you need and we’ll come back with a price. If something’s flooding or overflowing, call us now.
Questions answered
The questions businesses, landlords and homeowners in Portsmouth ask us most.
The island is very flat, so drains have little fall and water moves slowly. That gives fat, silt and wipes time to settle and build up. Regular jetting and a well-maintained grease trap make a big difference.
Drains serving more than one property are usually the water company’s responsibility. We can find the blockage and tell you whether it’s in a shared section.
It depends on its size and how busy you are. Busy takeaways may need it every few weeks. We’ll suggest a schedule and adjust it as needed.
Yes. We can pump the water out, then jet and survey the drains to see whether a blockage or defect is contributing.
Yes. Tell us about parking when you book. We plan the vehicle and time to suit the street, and can work early or late at commercial sites.
Yes. We answer the phone 24 hours a day, 365 days a year. Call 03333 233566.
Got a different question? Call 03333 233566 or send us a message.
We're independently vetted and certified so you can trust who you're letting onto your site.
Health & safety pre-qualification accreditation, verifying our processes meet recognised safety standards.
Railway Industry Supplier Qualification Scheme — approved to work safely within the rail industry supply chain.
Utilities Vetting Database membership, confirming we meet the utilities sector's supply chain standards.
Vetted and approved under the local authority's trusted trader scheme for honesty and fair dealing.
Members of the National Association of Drainage Contractors, the UK trade body for the drainage industry.
Registered with the Environment Agency, so your waste is handled and disposed of fully within the law.
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CLEARMASTERS