CLEARMASTERS
repair engineers
call-outs
after every visit
and tankers
in drainage
The basics
How does a WPL Diamond work?
The WPL Diamond is an activated sludge plant. There’s no media inside: the bacteria live freely in the liquid.
It’s a round tank with a central aeration chamber. A disc diffuser at the bottom of a draft tube pushes air and liquid upwards, keeping everything mixed and feeding the bacteria. Treated water moves into the outer clarifier, where solids settle, and clear water flows over a weir into a trough and out.
Air comes from a blower in a ventilated housing next to the tank. Some models have an integral pump chamber, for sites where the effluent can’t flow away by gravity.
How it works
How a WPL Diamond works
Hover over or tap the numbers to see what each part does.
- 1InletWastewater from the property enters the central aeration chamber.
- 2Aeration chamber and draft tubeAir from the disc diffuser rises up the draft tube, lifting the liquid and keeping it mixed.
- 3Air blower and diffuserA linear air blower in a ventilated housing. WPL recommend cleaning its filter every three months.
- 4Outer clarifierSolids settle out of the treated water, leaving it clear.
- 5Weir and troughClear water flows over the weir into a trough around the tank.
- 6OutletTreated effluent leaves the plant, by gravity or through an integral pump on some models.
What we service
What a WPL Diamond service includes
Blower
Filter cleaned, the blower checked and its housing ventilation cleared.
Diffuser and draft tube
Checking the air is lifting the liquid properly, and clearing any blockage.
Sludge level
Measured so you know how close the plant is to needing a desludge.
Clarifier and weir
Checking the outer zone is clear and the weir and trough are clean and level.
Pump chamber
On models with an integral pump, clearing and testing the pump and float.
Report
A clear record of the visit for your files.
Between services
Looking after your Diamond
Do
- Check the blower is running, ideally weekly
- Keep the blower housing vents clear
- Clean the blower filter every three months, or ask us to
- Call us if you notice a smell or a change in the blower’s sound
Don't
- Switch the blower off
- Let rainwater into the plant
- Flush wipes, sanitary products or fat
- Open the tank unless you’re trained
On the day
What happens on a WPL Diamond service
We isolate the blower
Power off before we work on anything.
We service the air system
Blower, filter, air line and diffuser.
We check the treatment
The aeration chamber, clarifier, weir and sludge level.
We report back
What we found, what we did, and when it will need desludging.
Why Clearmasters
Why choose us for your WPL plant?
The Diamond is a simple, long-lasting design when its blower is looked after. We service them across the South East and can desludge them when they need it.
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.
Visits that match WPL’s schedule
We can visit every six months, as WPL recommend.
What our customers say
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Questions answered
WPL Diamond FAQs
How often should a WPL Diamond be serviced?
WPL recommend an engineer inspects the plant every six months, with simple blower checks by the owner in between.
How often does a WPL Diamond need desludging?
WPL say to desludge when the sludge reaches about 70% of capacity, which is typically every three to five years for the domestic DMS range. Their commercial models need it more often. We measure the sludge on every service.
My blower has stopped. What should I do?
Check it hasn’t been switched off at the isolator, then call us. Without air, the bacteria start to die off within a day or two.
Does the Diamond have media inside?
No. It’s an activated sludge plant, so the bacteria live freely in the liquid rather than on media.
Is desludging part of a service?
No, desludging is done by one of our tankers and charged separately, but we can arrange it for the same visit. Your engineer will measure the sludge and tell you when it’s due.
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. If your discharge causes pollution, the first question you’ll be asked is when it was last serviced. A regular service is the simplest way to stay on the right side of the rules.
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
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Utilities Vetting Database membership, confirming we meet the utilities sector's supply chain standards.
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NADC Member
Members of the National Association of Drainage Contractors, the UK trade body for the drainage industry.
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Registered with the Environment Agency, so your waste is handled and disposed of fully within the law.