Septic tanks, cesspits and treatment plants emptied, serviced and repaired in Dorking and the villages of the Surrey Hills and the Low Weald.
Dorking sits in a gap in the North Downs, with Box Hill on one side and the wooded greensand hills around Leith Hill on the other. The town itself is on mains drainage, but the countryside around it is some of the most rural in Surrey, and a great many homes, farms and estates rely on septic tanks, cesspits and treatment plants.
Few places have such varied ground in such a short distance. The chalk of the Downs and the sandy greensand hills drain well; the Low Weald to the south, around Capel, Ockley and Newdigate, is heavy clay that holds water all winter. Hilltop cottages near Coldharbour and Abinger come with their own challenge: steep, narrow lanes that need the right size of tanker.
We look after systems right across the Dorking area, with crews here most days and phones answered 24 hours a day, 365 days a year.
We empty septic tanks and cesspits for homes, farms and estates around Dorking. On the clay towards Capel and Ockley, regular emptying protects the drainage field; on the hills, we bring a tanker that suits the lane.
Learn more
Treatment plants are common around Dorking, both in newer homes and where old tanks have been upgraded. Our engineers service them at least once a year, clean and check every part, and leave a written report.
Learn more
When an alarm sounds, a smell appears or the plant goes quiet, a blower, pump, float switch or control panel has usually failed. Our engineers carry the most common parts and can fix most faults on the first visit.
Learn more
A septic tank survey tells you what system a property has, its condition and where it discharges. If it doesn’t meet the General Binding Rules, we can install a treatment plant or a new drainage field.
Learn moreLocal knowledge
Chalk, sand and clay, all within a few miles.
Much of the countryside around Dorking is protected. Planning for new or replacement drainage can take longer, so start early.
South of the town, the clay drains slowly and drainage fields often struggle through the winter.
Hill villages like Coldharbour and Abinger need the right tanker. Tell us about access and we’ll plan for it.
Local to you
We cover Dorking and the villages of the Surrey Hills and the Low Weald.
Dorking · town and nearby
Surrounding villages · where private drainage is common
If you’re anywhere around Dorking, we cover you. Call with your postcode and we’ll give you a date.
Why Dorking customers use us
Whether it’s a cesspit at a farm near Ockley or a treatment plant at a cottage in Coldharbour, here’s what you get.
We’ve been emptying tanks and servicing systems since long before most of the kit on the market existed.
Our engineers and most of our tanker drivers hold current confined space entry certificates, and the engineers carry the most common parts.
Tankers from 2,000 to 4,000 gallons, jet/vac combination units, CCTV survey kit and confined space teams for pump station wet wells.
Regular customers get a reminder when their next empty or service is due.
A waste transfer note with every collection, and a written report after surveys and services.
Emergency call-outs 24 hours a day, 365 days a year, with a real person answering the phone.
Checkatrade
From 134 reviews · Read them
From 63 reviews · Read them
Scores as of September 2026
★★★★★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
★★★★★We have been dealing with Clearmasters for many years now. In fact over 25 years. They have always been 100% reliable, work with integrity, and have completed the clearances without any fuss. We would certainly recommend them.
How it works
Simple and the same every time.
Step 1
Call us or book online and tell us what system you have and what’s happening. If you know when it was last emptied or serviced, tell us that too.
Step 2
We book a date that suits you and send the right tanker or engineer. It helps if:
Step 3
You get a waste transfer note for anything we take away, and a written report after a survey or service. If it’s a regular job, we’ll remind you when the next one is due.
Free, no-obligation quote
Tell us what you need and we’ll come back with a price. If something’s overflowing, call us now.
Questions answered
What people around Dorking and the Surrey Hills ask us most.
Usually. We have tankers in different sizes and carry long hoses. Tell us about steep or narrow lanes and we’ll send the right vehicle.
Sometimes, especially in the Surrey Hills. The new system must also meet the Environment Agency’s rules. Check with Mole Valley District Council before work starts.
That part of the Low Weald is heavy clay, which holds water and drains slowly. Fields there are easily overwhelmed in a wet winter, especially if solids have been reaching them.
At least once a year. Most also need emptying about once a year, and we can do both on one visit.
If it discharges to a ditch or stream, it needs upgrading under the General Binding Rules. Read the rules on GOV.UK, or ask us for a survey.
Yes. Our crews work around Dorking most days and we answer the phone 24 hours a day. Call 03333 233566.
Got a different question? Call 03333 233566 or send us a message.
We're independently vetted and certified so you can trust who you're letting onto your site.
Health & safety pre-qualification accreditation, verifying our processes meet recognised safety standards.
Railway Industry Supplier Qualification Scheme — approved to work safely within the rail industry supply chain.
Utilities Vetting Database membership, confirming we meet the utilities sector's supply chain standards.
Vetted and approved under the local authority's trusted trader scheme for honesty and fair dealing.
Members of the National Association of Drainage Contractors, the UK trade body for the drainage industry.
Registered with the Environment Agency, so your waste is handled and disposed of fully within the law.
Keep the site, forms and online booking working, and protect them from spam.
Google Analytics: counts visits and shows us which pages are useful, so we can improve the site.
Meta (Facebook) pixel: measures our Facebook adverts and shows our adverts to people who've visited our site.
CLEARMASTERS