CLEARMASTERS
Pump, don’t dump
Every holding tank emptied at a pump-out station is sewage that stays out of the harbour. Marinas make that possible. We make sure what’s pumped ashore is taken away and treated properly.
Why it matters
What happens when a boat dumps
A sea toilet sends raw sewage straight into the water, often in the sheltered, slow-moving places where it does the most harm.
Enclosed water doesn’t flush
Marinas, creeks and estuaries are sheltered by design. Sewage discharged there doesn’t disperse the way it would in open sea, so it lingers where people sail, paddle and swim.
Bacteria in the water
Untreated sewage carries bacteria that affect bathing water and the shellfish beds many estuaries depend on.
Nutrients and oxygen
Nutrients in sewage feed algae, and breaking it down uses up the oxygen marine life needs. Harbours already under pressure feel it most.
Busy weekends, busy water
Regattas and summer weekends put hundreds of boats in the same water at once. That’s when a working pump-out matters most.
Where the message comes from: “Pump, don’t dump” is used by harbour authorities, marinas and The Green Blue, the environmental programme run by the RYA and British Marine. It asks boat owners to keep toilet waste in a holding tank and empty it at a pump-out station ashore.
The rules
Where boats can and can’t discharge sewage
There’s no single rule for every boat. It depends on where the boat is, what it is and who runs the water.
| Where | What applies |
|---|---|
| Canals and inland rivers | Discharging sewage from boats is prohibited. Boats use cassette toilets, emptied at an Elsan point, or a holding tank emptied at a pump-out station. |
| Tidal Thames | The Port of London Authority gave commercial and passenger vessels until 1 July 2024 to stop discharging sewage into the river. Its byelaws also cover houseboats and floating clubhouses. |
| Harbours and marinas | Many set their own rules, and some don’t allow sea toilets to be used in the marina at all. Check with your harbour authority. |
| Coastal waters | There’s no general UK ban for small private boats. Larger vessels, over 400 gross tonnes or carrying more than 15 people, come under the international MARPOL rules. |
| New boats | Since 2016, the Recreational Craft Directive has required new boats to have provision for a holding tank, so more boats can pump out than ever before. |
Good practice at sea: where there’s no pump-out nearby, The Green Blue advises only discharging more than 3 miles offshore, and never in marinas, near shellfish beds or where people swim.
After the pump-out
From the boat to the treatment works
A pump-out station moves the waste ashore. It still has to go somewhere, and every link in the chain has to work.
Holding tank
Toilet waste is stored on board until the boat reaches a pump-out.The riskA full tank emptied at sea or in the marina.
Pump-out station
A suction unit on the pontoon or quay empties the boat’s tank.The riskA broken or blocked unit, so boaters give up.
Tank or pump station
Waste is stored ashore or pumped on towards the sewer.The riskA full tank or failed pump on the busiest weekend.
Sewer or tanker
Either a sewer connection or a tanker takes it away.The riskWaste with nowhere to go, or no paperwork to show where it went.
Treatment works
The sewage is treated before the water is returned to the environment.The riskToilet chemicals that harm the treatment process.
That’s where we come in: we empty pump-out tanks, service the pump stations behind them and give you a waste transfer note for every load.
Interactive
Common problems at marinas and boatyards
Tap a number to see what goes wrong in each part of a typical site, and how to prevent it.
Pump-out station
Where boats empty their holding tanks. If it’s out of action, boaters are far more likely to empty at sea or in the marina.
- Wipes and debris blocking the hose or pump
- A full tank behind it, so it can’t be used
- Broken or hard-to-find stations that put people off
What to do: Keep the station working and signposted, and empty the tank behind it before it fills.
Pump-out holding tank
Many stations pump into a storage tank ashore that has to be emptied by tanker.
- Filling fast on summer weekends and regatta weeks
- No high-level alarm, so an overflow is the first warning
- Smells from waste left too long
What to do: Book emptying ahead of your busy dates, and fit or test a high-level alarm.
Pump station and sewer connection
Waterside sites are low, so waste is often pumped up to the sewer or a treatment plant.
- Wipes and fat ragging the pumps
- Floats jammed by fat on the surface
- Alarms on the busiest weekend of the year
What to do: Regular servicing and wet well cleaning. See our guide to pump station alarms.
Chemical disposal point
Where cassette toilets are emptied. The chemicals can cause problems further down the line.
- Formaldehyde-based toilet chemicals harming the bacteria in treatment plants
- Concentrated waste arriving all at once
What to do: Encourage formaldehyde-free products, and tell us where your Elsan point drains to.
Facilities block
Showers, toilets and laundry for berth holders and visitors, busiest when the marina is full.
- Wipes and sanitary products flushed
- Morning peaks in flow
- Hair and soap in shower drains
What to do: Clear “please don’t flush” signs, and planned jetting before the season.
Café, bar and clubhouse
A busy waterside kitchen sends fat and food waste into the drains.
- Fat building up in drains and the pump station
- Grease separators left too long between empties
What to do: Empty the grease separator on a schedule, and more often in summer.
Boatyard washdown
Pressure-washing hulls at haul-out washes off antifouling, weed and silt.
- Antifouling residue reaching surface water drains or the harbour
- Silt traps and interceptors left to fill up
What to do: Collect washdown water, and keep silt traps and interceptors emptied.
Bilge water and oily waste
Oily bilge water is a different waste stream from sewage and needs its own disposal route.
- Oily water pumped into a sewage pump-out
- Contaminated water left in drums around the yard
What to do: Keep oily water separate, and have it collected and disposed of properly.
Interactive
Your marina year
Tap a time of year to see what’s happening on site and what work fits best.
What we offer
How we look after marinas and boatyards
Pump-out tank emptying
Scheduled emptying of the tanks behind your pump-out stations and Elsan points, booked around your busy dates, with a waste transfer note every time.
Pump station servicing
Servicing, wet well cleaning, alarm checks and repairs for the pump stations that lift waste away from the waterside.
Treatment plants and sampling
For marinas and boatyards on private drainage: servicing, desludging and effluent sampling for your permit.
Washdown and oily water
Silt traps, interceptors and oily or contaminated water removed and disposed of properly.
Jetting and CCTV
Planned jetting of problem drain runs before they block, and camera surveys to find the cause of repeat problems.
24/7 emergency cover
One number, answered day and night. Tankers to deal with an overflow, engineers to fix the cause.
Interactive
Is your marina pump-out ready?
Making “pump, don’t dump” easy is down to the marina as much as the boater. Tick what’s already true for your site.
One contractor
Everything ashore, from the pump-out to the outfall
Around your berth holders
Visits that fit around the water
Quiet times
Mid-week and early visits, away from launches, lifts and busy weekends.
Agreed access
Routes, parking and hose runs agreed with you, clear of slipways, hoists and boat stands.
Planned around events
Regattas, open days and bank holidays noted in advance.
Briefed crews
In uniform, aware of a working yard, and the site left clean.
Paperwork on file
RAMS, insurance and training records on request, and a waste transfer note for every load.
Getting started
How it works
Site visit
We look at your pump-out, tanks, Elsan point, pump stations and washdown area, and where each one drains.
A plan for your year
Emptying and servicing booked around your season, your events and haul-out.
Visits and reports
Our own crews carry out the work. You get a written report and waste transfer notes.
Support all year
One point of contact, and our 24/7 line for overflows and alarms.
What our customers say
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Questions answered
Questions from marina and boatyard managers
What does “pump, don’t dump” mean?
It’s the message used by harbours, marinas and The Green Blue, the environmental programme run by the RYA and British Marine. It asks boat owners to keep toilet waste in a holding tank and empty it at a pump-out station ashore, rather than discharging it into the water.
Is it illegal for boats to discharge sewage?
It depends where you are. Discharging sewage from boats is prohibited on inland waterways. On the tidal Thames, the Port of London Authority required commercial and passenger vessels to stop discharging sewage by 1 July 2024. At sea there is no general UK ban for small private boats, although many harbours and marinas set their own rules. Check with your harbour or navigation authority.
Where does waste from a marina pump-out station go?
Usually into a holding tank ashore that’s emptied by tanker, or through a pump station into the public sewer or a treatment plant. If it goes to the public sewer, check with your water company that they’re happy to accept it, as they may need to give consent.
Can boat toilet chemicals cause problems?
Yes. Some toilet chemicals, particularly formaldehyde-based ones, can kill the bacteria that treatment plants and sewage works rely on, and some water companies have started restricting tankered waste that contains them. Encouraging formaldehyde-free products helps.
Can bilge water go into a pump-out station?
No. Sewage pump-out stations are for toilet waste. Oily bilge water is a different waste stream and should be collected separately. We remove oily and contaminated water and give you a waste transfer note for every load.
How often should a marina pump-out tank be emptied?
It depends on the size of the tank and how busy the marina is, and it changes through the year. A high-level alarm and a schedule booked around your busy weekends and events stop it filling up when you need it most.
Do you work with boatyards as well as marinas?
Yes. As well as pump-out tanks and pump stations, we empty silt traps and interceptors from washdown areas, remove oily and contaminated water, and look after welfare units, grease separators and private drainage on site.
What if a tank overflows or the pump station fails?
Call our 24/7 line on 03333 233566. We can send a tanker to deal with the overflow and an engineer to find and fix the fault.
Got a different question? Call 03333 233566 or send us a message.
Let’s keep your pump-out working
Tell us about your marina or boatyard: your pump-out set-up, where it drains and your busy dates. We’ll arrange a visit and plan the work around your season.
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Registered with the Environment Agency, so your waste is handled and disposed of fully within the law.