Sewage Treatment Plants
The Modern Way to Treat Waste
If your property isn’t connected to the main sewers, a Sewage Treatment Plant is the most effective, environmentally friendly way to handle your wastewater.
Unlike a traditional septic tank (which just separates the waste and lets the liquid soak away), a Treatment Plant is an active system. It uses electricity to power a small air pump, which encourages good bacteria to break down the sewage.
In simple terms: Think of it as a miniature wastewater treatment works sitting in your garden. It cleans the water so thoroughly that it can often be discharged directly into a local stream or ditch.

Why You Might Need One
Treatment plants are becoming the standard for off-mains drainage. You typically need one if:
- The Rules Say So: Under the ‘General Binding Rules’, old septic tanks are no longer allowed to discharge into watercourses. If yours does, you likely need to upgrade to a treatment plant to stay legal.
- You are Building a New Home: Depending on where the property is located, planning permission for new builds may require these modern systems.
- You Want to Protect the Environment: They produce much cleaner water than older systems, reducing pollution in your local soil and streams.
- Your Old System Failed: If your septic tank is smelling or backing up, upgrading to a treatment plant is a reliable, long-term fix.
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How ASL Can Help
These systems are more complex than simple tanks, so they need expert attention. We cover every stage of the process.
1. Installation – Whether you are upgrading an old tank or building a new house, we handle the full installation. We calculate the right size plant for your property, excavate the ground, install the tank and pipework and commission the system. We ensure everything complies with Building Regulations so you don’t face legal headaches later.
2. Maintenance & Servicing – Because treatment plants have mechanical parts (like pumps and air blowers), they need regular love and care. We offer annual servicing to:
- Check the motor and air blower.
- Clean the filters.
- Test the alarm systems.
- Empty the sludge (desludging) using our tankers.
3. Repairs – If you hear a buzzing alarm or notice a bad smell, something has gone wrong. We diagnose and fix common faults like broken pumps, electrical trips, or blocked outlet pipes to get the system running smoothly again.
4. Buying or Selling? – If you are selling a house with a treatment plant, your buyer will want proof it works. We provide detailed condition reports to confirm the system is compliant and well-maintained.
Common Signs of Trouble
Since these systems are mechanical, they will usually tell you when they are unhappy. Look (or listen) out for:
- Alarms: Most units have a warning light or buzzer to warn of a pump failure.
- Silence: If the gentle hum of the air blower stops, the power supply or motor may have failed.
- Smells: A working treatment plant should be virtually odourless. If it smells, it isn’t treating the waste correctly.

The Benefits to You
- Cleaner Water: The water leaving the tank is roughly 95% clean, making it safe for the environment.
- Compliance: It is the easiest way to meet modern environmental laws.
- Versatility: Because the water is cleaner, it can be discharged into streams or ditches where a septic tank cannot.
- Saleability: A modern, compliant system is a big plus point for potential buyers.
Upgrade your off-mains drainage to a cleaner, greener solution with ASL.
ASL ensures every treatment plant is installed and maintained to industry standards.
Testimonials
What Our Clients Say
“I called at 08:10 hours to report a blocked drain. A little while later, Darren rang to tell me he’d arrive in half an hour. He arrived on time and resolved the problem quickly and without fuss. He was polite and friendly throughout. Within two hours of reporting the blockage, all was well. Thank you.” Customer, Surrey
“I unreservedly recommend ASL. All the glowing reviews of ASL are true. They had to lift paving slabs to fix my drains, and I was concerned there might be unavoidable damage. I should not have worried. Liam and Richard did a superb job. Thanks, ASL” Customer, Surrey
“Darren arrived very promptly and got to work quickly. He did an excellent job and explained what he was doing. We would have no hesitation in recommending ASL Services.” Customer, Surrey
“Very efficient to book them to sort out a sewer drain blockage, and the cost was exactly what they quoted. Called before they arrived with a clear ETA. Got on with the job and sorted it out within the hour. Darren was excellent – very courteous and helpful, did more than we expected to help sort the problem out and was a font of knowledge on all things sewer-related. Given the subject matter (eeew) the whole experience with ASL was an absolute pleasure.” Customer, Surrey
“ASL recently carried out a drain repair at our house. They responded quickly to the call for help, came out and soon diagnosed the problem – tree roots blocking the drain. The remedial work on site was carried out by Lester and George – they worked hard and were very thorough. This is a long-established company that seems to know what they are doing.” Customer, Surrey
Areas we cover
Surrey, Hampshire, Berkshire, West Sussex and South West London
The ASL Limited HQ is in Guildford, but our operating area is the whole of Surrey and parts of Berkshire, Hampshire, West Sussex and South West London.

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Contact Us
Get in touch today
You can call us on 0800 181 684, email info@asllimited.co.uk or use the form below:
