Septic tanks, cesspits and treatment plants in the villages, and drains, interceptors and grease traps in the town, across Andover and the north Test valley.
Andover is a busy market town with large industrial estates and distribution sites, surrounded by some of Hampshire’s most rural chalk country. In town, we clean interceptors and gullies, empty grease traps and clear drains. In the villages, from the Clatfords and Abbotts Ann to Hurstbourne Tarrant and Vernham Dean, we empty septic tanks and cesspits and service treatment plants.
The chalk here brings a problem many people don’t expect: groundwater flooding. After a very wet winter, the water table in the chalk valleys can rise right up to the surface, and streams that are usually dry, like the Bourne Rivulet, start to flow. When that happens, tanks can fill with groundwater and drainage fields stop working until levels drop.
We know how to handle that, including when it’s better not to empty a lightweight tank completely while the ground is saturated. Our crews are in Hampshire most days and we answer the phone 24 hours a day, 365 days a year.
We empty septic tanks and cesspits for homes and farms around Andover with tankers from 2,000 to 4,000 gallons. If groundwater is getting into your tank or cesspit, we’ll tell you, because emptying alone won’t solve that.
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A treatment plant needs a yearly service to keep treating water properly. Our engineers check and clean the plant, test the blower and pumps, carry the most common parts and repair it when something fails.
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Andover’s industrial estates and distribution sites have yards, loading bays and car parks that drain through interceptors and gullies. We empty and clean them with jet/vac tankers and provide waste transfer notes for your records.
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When a wet winter brings the water table up, cellars, chambers and tanks can flood. Our tankers can pump the water out and take it away, and we’ll give you honest advice about what will help and what won’t while levels are high.
Learn moreLocal knowledge
Chalk valleys behave differently in a wet winter.
In the chalk valleys north of Andover, groundwater can rise to the surface after prolonged rain and stay high for weeks. Tanks and drainage fields are affected until it drops.
Some streams here only flow in wet winters. A dry ditch in summer may be a watercourse in winter, which matters for where a tank discharges.
Yards and car parks on industrial sites should have interceptors inspected and emptied regularly, with records kept.
Local to you
We cover Andover and the villages of the north Test valley and the downs.
Andover · town and nearby
Surrounding villages · where septic tanks and cesspits are common
If you’re in or around Andover, call with your postcode and we’ll confirm.
Why Andover customers use us
Whether it’s a flooded cesspit in Hurstbourne Tarrant or an interceptor on an industrial estate, here’s what you can expect.
We’ve been emptying tanks and servicing systems since long before most of the kit on the market existed.
Tankers from 2,000 to 4,000 gallons, jet/vac combination units, CCTV survey kit and confined space teams for pump station wet wells.
SafeContractor, Achilles UVDB and RISQS approved, so we can get onto managed sites and meet your contractor checks.
Our engineers and most of our tanker drivers hold current confined space entry certificates, and the engineers carry the most common parts.
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
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Scores as of September 2026
★★★★★Came out within an hour on an emergency call out. Great service. Fast reliable reasonable prices. Highly Recommended
Peter D. Google review
★★★★★Our family have been using Clearmasters for years and are the only choice as far as we are concerned! All the staff are friendly, helpful and accommodating. Couldn’t recommend them highly enough!
★★★★★I have used Clearmasters for years. They are always on time, polite and reliable whether your need them to empty your septic tank or undertake maintenance work. I wouldn’t use anyone else. Local and the best.
How it works
The same simple process for every job.
Step 1
Call us or book online and tell us what you need. If you think groundwater is involved, tell us what you’re seeing and we’ll advise before we come out.
Step 2
We send a tanker, a jet/vac unit or a service engineer, depending on the job. 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 or flooding, call us now.
Questions answered
What homeowners, farms and businesses around Andover ask us most.
When the water table is very high, groundwater can get into cesspits and tanks through cracks and joints. Emptying gives temporary relief, but it will refill until levels drop. Once things settle, we can inspect the tank and advise on sealing or replacing it.
Not always. Some lightweight plastic tanks and treatment plants can shift or lift if they’re emptied completely while the ground around them is saturated. We’ll advise on the safest approach, which may be a partial empty.
Yes. We inspect, empty and clean interceptors and gullies, and provide waste transfer notes for your records. We can set up a planned schedule for your site.
For most households, about once a year. We’ll suggest a schedule after the first visit based on your tank size and household.
Yes. We service and repair treatment plants in villages all around Andover, and empty the sludge when it’s due.
Yes. Our crews are in Hampshire 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.
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