CLEARMASTERS
bank holidays
tankers
common parts
trained teams
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Sewage or water escaping right now?
Call 03333 233577. While you wait, stop using water in the building, keep people and pets away from any overflow, and don't open tanks, chambers or pump stations.
Emergency guide
What’s happening?
Pick the problem for what to do while you wait for us, what not to do, and what our team will do when they get there.
Septic tank or cesspit overflowing
A full cesspit, or a septic tank whose outlet or drainage field has stopped taking water, will back up into the house or spill across the garden. Either way the first job is to stop more water going in.
Do this now
- Stop using water: no baths, showers, washing machine or dishwasher, and flush only when you have to
- Keep children and pets off any wet or smelly ground
- Find the lid or manhole if you can, and tell us about gates, narrow lanes or soft ground for the tanker
Don't
- Lift or climb into the tank to look inside
- Pour bleach, drain cleaner or additives in to "fix" it
What we do: We empty the tank with one of our own tankers and check the inlet and outlet while the tank is open. If a septic tank fills again within days, the drainage field or soakaway is usually the cause, and we can investigate that properly once the emergency is over.
Sewage treatment plant alarm
A treatment plant alarm usually means the air blower has failed, a pump has stopped or the water level is too high. The plant stops treating properly, and dirty water can reach the ditch or drainage field.
Do this now
- Cut your water use right down until it is sorted
- Look at the control panel or alarm box and note any lights or messages
- Find the make and model if you can (Klargester, Conder, Marsh, Graf, Tricell and so on)
Don't
- Open the lid and reach into the plant while it is running
- Switch the alarm off and forget about it: it will be back
What we do: Our engineers carry the common blowers, diaphragms and floats on the van, so many faults are fixed on the first visit. If the plant has filled with sludge, we can desludge it at the same time.
Pump station alarm
When a pump station alarm sounds, the pumps have either failed or cannot keep up, and the chamber is filling. How long you have depends on the size of the chamber and how much water is going in.
Do this now
- Cut water use in every building the station serves
- Tell us exactly what the control panel shows: which lights are on and any fault codes
- Check the panel has power and nothing has tripped at the consumer unit
Don't
- Open the chamber or lift the pumps out: pump chambers can hold dangerous gases
- Keep resetting a pump that trips straight away
What we do: If the chamber is close to overflowing, we send a tanker to empty it and buy time. Our engineers then find and repair the fault, whether that is a failed pump, a float switch or the control panel. Entering a pump chamber needs confined space training, which our teams hold.
Blocked drain or sewage backing up
Water rising in the toilet, gurgling plugholes or a manhole filling with sewage all point to a blockage further down the line. Every flush makes it worse.
Do this now
- Stop flushing and stop running taps that drain into the blocked pipe
- Lift a manhole cover only if it is safe and light enough, just to see whether it is full
- Ask the neighbours: if theirs is backing up too, the blockage may be in a shared sewer
Don't
- Keep plunging a toilet that is close to overflowing
- Use chemical drain unblockers, especially if you are on a septic tank or treatment plant
What we do: We clear blockages with high-pressure water jetting, then run a camera through if it keeps coming back, so you know whether it is roots, a collapse or a build-up of fat. If the blockage is in a public sewer, we will tell you, as that is down to your water company.
Flood water or groundwater
Storm water, a burst main or rising groundwater can fill basements, plant rooms, lift pits and excavations in a few hours, and it rarely drains away on its own.
Do this now
- If it is safe, turn off the electricity to the flooded area
- Keep people out of the water: assume it may contain sewage
- Move what you can to higher ground and clear a route for our hoses
Don't
- Walk through water near sockets or electrical equipment
- Pump contaminated water into a road gully or a neighbour's land
What we do: Our vacuum tankers lift standing water, silt and debris and take it away for proper disposal, rather than moving it somewhere else. Once it is out, we can find what caused the flooding.
Commercial emergency
For a restaurant, care home, school, farm or building site, a drainage failure can mean closing the doors. Grease traps, interceptors, gullies and holding tanks are the usual suspects.
Do this now
- Tell staff to stop using sinks, toilets or wash-down points on the affected drain
- Fence off any spill and keep the public away from it
- Have the site address, access details and a contact who will be there when we arrive
Don't
- Hose a spill into surface water drains, which usually run straight to a river
- Wait for the morning if waste is already escaping
What we do: We empty grease traps, interceptors and holding tanks, clear gullies and jet drains, and give you a waste transfer note for everything we take away. Once the site is working again, we can set up regular visits so it does not happen again.
Is it an emergency?
Call now, or book in?
If you're not sure, ring us anyway and we'll tell you honestly. Some problems need a tanker tonight; others can safely wait for a booked visit.
Call us straight away
- Sewage coming up through a toilet, shower or floor drain
- A tank, chamber or manhole overflowing onto the ground
- A pump station or treatment plant alarm that won’t clear
- Flood water inside a building or rising in a basement
- Waste escaping towards a stream, ditch or road drain
Usually fine to book
- A septic tank or cesspit that is filling but not yet overflowing
- Drains that are slow but still draining
- A treatment plant that is overdue a service but working
- A smell outside that comes and goes
- Needing a survey after a blockage has been cleared
For these, book online or call 03333 233566 in office hours.
When you ring
How an emergency call-out works
We answer, day or night
Our emergency line is answered around the clock. We'll ask what's happening, what kind of system you have and how we get access.
We tell you what’s next
We'll tell you who we're sending, whether that's a tanker, an engineer or both, and give you an honest idea of when they'll get there.
We make it safe
The crew stops the overflow, clears the blockage or gets the pumps running, and cleans up what they can.
We put it right
You'll get a waste transfer note for anything we take away, and if there's a repair to do, we'll explain it and arrange it with you.
Why Clearmasters
One team, from the tanker to the repair
We've been emptying tanks and fixing drains for 34 years. Because we run our own tankers and employ our own engineers, the people who turn up at 3am are the same people who can come back to put the cause right.
After an emergency, many customers ask us to service their treatment plant, look after their pump station or jet their drains regularly, so it doesn't happen again.
Our own tankers
2,000 to 4,000 gallon tankers with jetting kit, so one vehicle can empty a tank and clear the drain into it.
Parts on the van
Engineers carry common pumps, floats, blowers and diaphragms, so many faults are fixed on the first visit.
Confined space trained
Our teams hold confined space entry certificates for work inside chambers, tanks and wet wells.
Homes and businesses
From a single cottage septic tank to care homes, schools, farms, restaurants and building sites.
Where we cover
Emergency call-outs across the South East
Our crews work across all of these areas every day, from our base near Gatwick. Not sure if we cover you? Call and ask, or see all the places we work.
West Sussex
Horsham, Crawley, East Grinstead, Haywards Heath, Billingshurst, Chichester and more
East Sussex
Uckfield, Crowborough, Heathfield, Lewes, Hailsham, Battle and more
Kent
Sevenoaks, Edenbridge, Tunbridge Wells, Maidstone, Ashford, Canterbury and more
Hampshire
Petersfield, Alton, Winchester, Basingstoke, Fareham, Portsmouth and more
What our customers say
Checkatrade
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Scores as of September 2026
Questions answered
Emergency call-out FAQs
Is your emergency line really answered 24 hours a day?
Yes. 03333 233577 is answered 24 hours a day, 365 days a year, including weekends and bank holidays.
How quickly can you get to me?
It depends on where you are, the time and what else is happening that night, so we won’t promise a time we can’t keep. When you call, we’ll tell you honestly when we expect to reach you. Our crews work across Surrey, Sussex, Kent, Hampshire and London every day.
My septic tank is overflowing. What should I do?
Stop using water in the house straight away, keep children and pets away from the overflow and call us. Don’t open the tank or add chemicals. We’ll empty it and check whether the tank or its drainage field is the cause.
Is a pump station alarm an emergency?
Usually, yes. The alarm means the chamber is filling faster than the pumps can empty it. Cut your water use, note what the control panel shows and call us. Don’t open the chamber, as it can contain dangerous gases.
The blockage might be in a shared sewer. Who is responsible?
Pipes that serve only your property are normally your responsibility. Once a drain is shared with a neighbour or runs beyond your boundary, it is usually a public sewer and the water company’s job. If we find the blockage is in a public sewer, we’ll tell you so you can report it.
Do you handle commercial emergencies?
Yes. We attend restaurants, care homes, schools, farms, offices and building sites for overflowing grease traps, interceptors, holding tanks, pump stations, blocked drains and flooding, and give a waste transfer note for everything we remove.
What will an emergency call-out cost?
It depends on the work, the time of day and how much waste there is to remove. Ask when you call and we’ll explain how the call-out is charged.
Got a different question? Call 03333 233566 or send us a message.
Planned work and services
Fully accredited & compliant
We're independently vetted and certified so you can trust who you're letting onto your site.
SafeContractor
Health & safety pre-qualification accreditation, verifying our processes meet recognised safety standards.
RISQS
Railway Industry Supplier Qualification Scheme — approved to work safely within the rail industry supply chain.
Achilles UVDB
Utilities Vetting Database membership, confirming we meet the utilities sector's supply chain standards.
Trading Standards Approved
Vetted and approved under the local authority's trusted trader scheme for honesty and fair dealing.
NADC Member
Members of the National Association of Drainage Contractors, the UK trade body for the drainage industry.
Registered Waste Carrier
Registered with the Environment Agency, so your waste is handled and disposed of fully within the law.