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Sewage Treatment Plant Servicing in Dorking

Annual servicing, desludging and repairs for treatment plants at homes, farms and converted barns around Dorking.

Treatment plants are now a familiar sight in the countryside around Dorking. Many replaced old septic tanks that used to drain to a ditch, and plenty went in when farm buildings near Capel, Ockley and Newdigate were turned into homes. A plant cleans waste far more thoroughly than a septic tank, but only while it’s looked after.

The reason so many exist is the ground. On the Low Weald clay a drainage field often can’t cope, so a lot of plants here send their treated water to a ditch or brook instead. Under the General Binding Rules, anything discharged to a watercourse has to come from a plant that is working properly, and many of the brooks south of Dorking feed the River Mole.

Our engineers service most of the common makes. They check the air blower, pumps, float switches and controls, measure the sludge and tell you when the plant needs desludging. You get a written report after each visit to keep with your records.

What's included

Inside a treatment plant service

A thorough check of the air, the pumps, the panel and the sludge.

  • A written service record

    You get a record of the visit and our advice, handy for your files or when you sell the property.

  • Baffles and pipework

    We check the baffles, inlet and outlet are clear and undamaged, so waste moves through the chambers properly.

  • Lid and access

    The lid, seals and fixings are checked so the plant stays safe and watertight.

  • Control panel

    We check the panel, its settings and any warning lights, and make sure it’s safe.

  • Filters and media

    Where your plant has filters or media, we check they aren’t blocked or clogged.

  • Sludge levels measured

    We measure the sludge and arrange desludging when it’s due, often on the same visit.

Fixing faults and removing sludge

01
A Clearmasters service van

Ditches, brooks and the Mole

Where a plant drains to a ditch around Brockham, Betchworth or Strood Green, that water reaches the Mole within a short distance. If the plant is struggling, poorly treated effluent goes with it. Things to watch for are a cloudy or smelly outlet, grey sludge building up in the ditch, or a warning light on the control panel.

Most problems start with an overdue desludge or a worn air blower. Regular treatment plant desludging keeps the bacteria doing their job, and a yearly service catches tired parts before they stop.

Learn more
02
A Clearmasters tanker emptying a tank at a rural property

All the main makes

We service and repair the common makes found on homes and small sites, including Klargester, Conder, Marsh, Graf, Tricel and WPL Diamond. If you’re not sure what you have, a photo of the lid or the panel usually tells us.

If parts for an old plant are no longer made, we’ll explain the options honestly.

Learn more

Local to you

Treatment plant servicing around Dorking

We look after treatment plants across the Dorking area, including Brockham, Strood Green, Betchworth, Beare Green, Capel, Ockley, Newdigate, Westhumble and Ranmore Common. Many of these plants sit at converted barns or farmhouses down long drives, and our engineers are used to finding them. Tell us where yours is and we’ll plan the visit. See the full Dorking area list.

Other services in Dorking

We look after the whole system, not just one part of it.

Related services

Call 03333 233566

What our customers say

9.84/10

Checkatrade

From 134 reviews · Read them
4.9/5

Google

From 63 reviews · Read them

Scores as of October 2026

★★★★★

Reliable and efficient company who have been emptying our Klargester for many years.

Checkatrade review Checkatrade · RH4
★★★★★

I have been using Clearmasters since I moved into a house with a klargester in 2015. Since then, they have carried out all the regular visits for empties, as well as service checks. I can’t speak more highly about their level of service and professionalism. Very friendly guys, always leave the place in good order, never had an issue. Highly recommend for anyone needing a similar service.

Checkatrade review Checkatrade · RH5
★★★★★

Absolutely phenomenal service from Clearmasters. Not only did they come out and fix our drainage with a moments notice, they did it with a smile on their face and were extremely polite, helpful and knowledgable whilst doing so. After being let done by another local company, Clearmasters came to our rescue. A massive thank you to both Max and Matt. Highly, highly recommend

Checkatrade review Checkatrade · RH5
Read all our reviews

Free, no-obligation quote

Book a treatment plant service in Dorking

A few details about your plant are all we need. If the alarm is sounding, call us now.

  • Free quotes for servicing and repairs
  • Engineers carry the most common parts
  • Emergency call-outs 24/7
Emergency? 03333 233566

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Questions answered

Treatment plant servicing FAQs

My plant near Capel drains to a ditch. Is that allowed?

It can be, as long as the plant meets the General Binding Rules and works as it should. A septic tank on its own can no longer discharge to a ditch or stream. Keep your service reports safe, because they show the plant has been maintained if anyone asks, including a buyer’s surveyor.

How often should a treatment plant be serviced?

Most domestic plants should be serviced at least once a year, and some makers recommend every six months. Your plant’s manual will say, or we can tell you when we see it.

Is servicing a legal requirement?

If your plant discharges to the ground or a watercourse, the General Binding Rules say it must be maintained by someone competent in line with the manufacturer’s instructions. Regular servicing is the simplest way to show that.

Why does the outlet ditch from my plant near Brockham back up in winter?

On low ground near the Mole, the ditch a plant drains into can fill during a long wet spell. When it backs up, treated water can’t flow away freely and the plant may struggle or set off its alarm. We can check the outlet and suggest options, such as a pumped discharge, if it happens every winter.

Can you get my plant working on the same visit?

Often, yes. Our engineers carry the most common parts, such as blowers and pumps, so many repairs are done there and then. For less common parts we’ll order them and come back.

Do you service my make of plant?

We service and repair the common makes, including Klargester, Conder, Marsh, Graf, Tricel and WPL Diamond. If you’re not sure what you have, send a photo of the lid or panel when you get in touch.

Got a different question? Call 03333 233566 or send us a message.

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.

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