CLEARMASTERS
repair engineers
call-outs
after every visit
and tankers
in drainage
The basics
Why does a treatment plant need servicing?
A sewage treatment plant is part machine, part living system. Air blowers, diffusers, pumps and controls keep oxygen flowing to the bacteria that clean your wastewater, and like any machine, those parts wear out.
Servicing goes hand in hand with desludging, and if your plant is beyond repair we can install a new treatment plant. We service all the main makes, including WPL Diamond, Marsh and Rewatec (Conder).
We do this work across Surrey, West Sussex, East Sussex, Kent, Hampshire and London, with tankers and engineers in each area most days.
When they do, the bacteria struggle, treatment suffers and poorly treated effluent ends up in your drainage field or the local stream. Left long enough, you’re looking at smells, alarms, a failed drainage field or a pollution problem.
A yearly service keeps the mechanical parts working, checks the treatment is doing its job and catches small problems before they become big, expensive ones.
Inside a service
What we check on a service
Every plant is different, but these are the checks at the heart of every service. Hover over or tap the numbers to see what we look at.
- 1Air blowerWe clean or replace the air filter, check the diaphragms and make sure the housing is ventilated.
- 2Air lineChecked for kinks, splits and blockages between the blower and the tank.
- 3DiffuserWe check the bubble pattern and clean or replace a diffuser that’s blocked or scaled up.
- 4Sludge levelMeasured so we can tell you when the plant needs desludging.
- 5BiozoneThe colour, smell and mixing tell us how well the bacteria are working.
- 6Final effluentWe look at, and where needed sample, what’s leaving the plant, and check the outlet.
- 7Inlet, outlet and coversPipes checked for flow and blockages, and lids checked they’re secure and safe.
Your make of plant
Find the guide for your plant
Each manufacturer does things a little differently. Our guides explain how your plant works and what its service involves.
Klargester
BioDisc, BioTec and BioFicient plants.
Graf
Klaro and One2Clean SBR plants.
Tricel
Tricel Novo plants.
Marsh
Ensign plants and Uni:Gem conversion units.
Rewatec (Conder)
ASP activated sludge plants.
WPL
Diamond plants.
How often
How often should a treatment plant be serviced?
Domestic plants: usually once every 12 months. Some manufacturers, like Graf, recommend twice a year.
Holiday lets and shared systems: uneven or heavy use means more frequent checks are often worthwhile.
Commercial plants: usually every 3 to 6 months, depending on the load and any discharge permit.
Desludging is separate and depends on your plant and how many people use it. We’ll measure the sludge on every service and tell you when it’s due.
Signs your plant needs attention
- Bad smells around the plant or outlet
- The blower is noisy, or not running
- An alarm or warning light on
- Cloudy, grey or smelly effluent
- Drains slow or backing up
On the day
What happens on a treatment plant service
We isolate and inspect
We make the plant safe, lift the lids and check the tank, chambers and pipework for damage or wear.
We service the air system
We clean or replace the blower filter, check the diaphragms and air lines, and make sure the diffuser is bubbling properly.
We check the treatment
We look at the biozone, measure the sludge and check the effluent leaving the plant.
We test and report
We test alarms and electrics, put the lids back securely and explain what we found.
Why Clearmasters
Why choose us to service your plant?
We service treatment plants every day, and we can desludge them too, so one company can look after your plant from start to finish.
Ask us a questionAlways on hand
Planned servicing at a time that suits you, and 24/7 call-outs when something goes wrong.
Straight answers
We explain what we found in plain English, and give you honest advice on what needs doing now and what can wait.
Trained engineers
Our engineers hold current confined space entry certificates and work on treatment plants, pump stations and drainage every day.
Service and desludge together
We can arrange your desludge for the same visit, saving you time and a second call-out.
What our customers say
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Questions answered
Treatment plant servicing FAQs
How often should my treatment plant be serviced?
Most domestic plants need servicing once a year, and commercial plants every three to six months. Some manufacturers recommend more often, so we follow the guidance for your model.
What happens if I don’t service my plant?
Worn parts eventually fail. When the blower or diffuser stops working, the bacteria die off, the plant stops treating properly and you can end up with smells, a failed drainage field or a pollution problem.
Do I still need to empty my treatment plant?
Yes. Sludge builds up however well the plant is serviced and must be removed before it goes beyond the plant’s capacity. We measure it on every service.
What are the most common faults?
Blocked air filters, split diaphragms, failed blowers, blocked or scaled-up diffusers, high sludge levels and electrical faults. Most are caught early on a regular service.
Is servicing a legal requirement?
The Environment Agency’s rules say your plant must be operated in line with the manufacturer’s specification and should be regularly maintained in line with their instructions by someone competent. A regular service is the simplest way to show you’re doing that.
Can you fix problems you find during a service?
Yes. Our engineers carry most common parts, so many repairs can be done on the day. For anything bigger, we’ll quote and book it in.
Got a different question? Call 03333 233566 or send us a message. You can also read the rules on GOV.UK.
Related 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.