CLEARMASTERS
The short version
What usually goes wrong with a treatment plant?
Most treatment plant problems come down to air, sludge or overload. If the blower stops, the bacteria die and the plant smells. If it’s overdue desludging, solids carry through and the outlet turns cloudy. And chemicals, rainwater or extra people can upset the balance. An alarm or a silent blower needs attention quickly; most other problems can be put right with a service.
Interactive
Treatment plant fault finder
Tick everything you’ve noticed. The diagram highlights where the problem probably is.
Alarms
What does my treatment plant alarm mean?
Plants differ, but most alarms fall into one of three groups.
Air alarm
The plant has detected low air pressure: the blower has failed, a diaphragm has split or an air pipe has come off. The most common alarm we attend.
High-level alarm
The water is higher than it should be: a pump has stopped, a float has stuck, or the outlet or drainage field is blocked.
Power or fault alarm
The supply has been lost, or the panel has detected a fault with the blower or a pump. Some alarms have a battery so they can sound in a power cut.
If you have a separate pump station as well, our guide to pump station alarms explains those panels.
The most common fault
The blower: the heart of the plant
The blower (or air pump) runs all day, every day, pushing air into the biozone so the bacteria can break the sewage down. It’s the part that works hardest, and the part that fails most often.
Signs it’s failing: it goes quiet, starts rattling or buzzing, the air alarm comes on, or the plant starts to smell. Inside, worn diaphragms are the usual culprit, and they’re a routine part to replace at a service.
Our engineers carry common blowers and diaphragms on the van, so many blower faults are fixed on the first visit.
Effluent quality
What should the water from a treatment plant look like?
Healthy
- Fairly clear, perhaps slightly tinted
- Little or no smell
- No solids, paper or sludge
- Gentle bubbling in the biozone
Needs attention
- Grey, cloudy or milky
- A sewage or rotten-egg smell
- Bits of solids or paper
- Black or septic-looking liquid in the plant
Poor effluent can pollute a ditch or clog a drainage field, and the general binding rules require you to keep the plant in good working order.
Unusual use
Holidays, power cuts and quiet spells
Going away
Leave the plant switched on. The bacteria need air to survive, and switching off can kill them and damage moving parts. A plant copes well with a quiet spell.
Power cuts
The blower and pumps stop, so treatment pauses. A short cut rarely matters. Afterwards, check the blower is running and the alarm has cleared.
Holiday lets and guests
Lots of people for a short time can overload a plant. Make sure it was sized for the maximum number of people, and spread out laundry.
After a course of strong medication
Long courses of some medicines can affect the bacteria. If the plant seems to struggle, mention it at the next service.
Prevention
What a treatment plant service includes
Air supply
Blower output, diaphragms, air filter and pipework checked.
Biozone
Even aeration, healthy bacteria and diffusers clear.
Pumps and alarms
Air-lifts, pumps, floats and the alarm tested.
Effluent and sludge
Outlet quality checked and sludge levels measured, with desludging when it’s due.
Most makers recommend a service at least once a year. We desludge plants with our own tankers, and you get a waste transfer note every time.
All the main makes
Treatment plants we service and repair
Questions answered
Treatment plant problem FAQs
Why is my sewage treatment plant alarm going off?
Most treatment plant alarms mean either the air supply has failed, usually the blower, or the water level has risen too high because a pump, float or outlet has a problem. Cut your water use, check the power, note which light is on and call a service engineer.
My treatment plant blower has stopped. Is that urgent?
Yes. Without air, the bacteria that treat the sewage start to die within hours, and the plant begins to smell and discharge poorly treated water. Check it has power, and if it does, call us to repair or replace the blower.
Why is the water coming out of my treatment plant cloudy?
Cloudy or grey effluent usually means the plant is not treating properly. Common causes are a failed blower, overdue desludging, chemicals killing the bacteria, overloading or blocked diffusers. A service will find the cause.
Why is there foam on my treatment plant?
Some foam is normal for a few weeks after a plant is started up or emptied. Lasting foam usually points to too much detergent, heavy use of cleaning products or an imbalance in the bacteria, and is worth getting checked.
Can I turn my treatment plant off when I go away?
No. Leave it running. The bacteria need a constant air supply to survive, and switching off can kill them and damage moving parts.
How often should a treatment plant be serviced?
Most manufacturers recommend a service at least once a year, plus desludging when the sludge builds up, usually about once a year depending on the plant and how many people use it. Follow the manufacturer’s guidance for your model.
What happens to my treatment plant in a power cut?
The blower and any pumps stop, so treatment pauses. A short power cut is rarely a problem. After a long one, check everything has restarted, and if the alarm stays on, call us.
Do you service all makes of treatment plant?
We service and repair all the main makes, including Klargester, Conder, Marsh, Graf, Tricell and WPL, and carry common parts such as blowers and diaphragms on our vans.
Got a different question? Call 03333 233566 or send us a message.