Septic Tanks and Sewage Treatment Installation

Sewage Treatment Plant Installation Services 

At Tank Services, we pride ourselves on providing a complete installation package, from conducting a site survey to having the building inspector sign off on the installation. We can quote for new sewage treatment plants and replacements when upgrading from a septic tank.  Our installation engineers will perform every aspect of the work using modern tanks that meet Environment Agency effluent quality. This protects the environment and ensures you have the correct paperwork to prove your installation is documented and approved when it’s time to sell your property.

Sewage Treatment Plant and Septic Tanks

Many buildings simply don’t have access to the main sewer system and need a Septic Treatment Tank. Usually, these structures are in remote areas where the infrastructure is unavailable. A property not connected to mains sewage drains will most likely have or require a cesspool, septic tank or sewage treatment plant. This is very common in remote and rural locations. These cheap-to-run systems have no connection to the public sewerage system. We call this off-main drainage.

3 Types of Sewage Tank

Basically, there are 3 types of tanks offering different levels of waste treatment.

1. A Cesspool is a simple holding tank. Cesspools have no sewage treatment. They hold the waste until it is emptied via a vacuum tanker Sewage treatment plant cut-awaybefore the tank fills. High running costs due to the frequency of tank purges are the biggest downsides for these systems. They keep 100% of the waste within the tank, therefore they require no soak-away or drainage.  Not recommended if a treatment plant can be installed.  Cesspool holding tanks are common for temporary solutions such as welfare units for site use, catering vans, festivals and campsites.

2. Septic Tanks are designed to provide primary crude sewage water treatment. It retains solids and allows them to settle out in a primary settlement chamber. Here they are partially broken down by biological action so that only the remaining liquor (normally called effluent) is then sufficiently treated. The Effluent can then soak from the septic system into the ground in an underground soak-away system. There the oxygen and bacteria in the earth will provide further biological treatment.


3. Sewage Treatment Plants are designed to treat the waste much cleaner within the tank. Treated wastewater is up to 97% clean and can drain into a watercourse, stream, ditch or soak-away system. We achieve this by introducing more oxygen and/or mechanical devices to anaerobically digest the waste. This allows for fast biological decomposing to take place. To achieve this on larger installations, they use a system of several tanks forming a wastewater treatment plant. Each is specifically designed to process waste sewage using different methods.

Treatment Process

Some systems have separate chambers with different treatment processes. Initially, they pass the waste through a settlement tank, separating the clarified water from the solid matter. The Solid Mass then begins to biodegrade. An Aeration Chamber is the secondary treatment process combining mobile Filter Media and an Air Bubble Diffuser.  This encourages bacteria to break down the waste in a biological reaction. Then, a final effluent tank chamber allows the remaining small solids to sink to the bottom. The Clarified Effluent can then naturally drain from the plant via displacement, allowing the earth to further treat it.

Soak-away systems

Sewage treatment systems and septic tanks will require a well-designed and installed soak-away system. This allows the final discharge from the tank to soak away into the ground for further biological treatment.  A poorly designed and installed soak-away will likely cause more problems than the tank.  Therefore, getting the soak-away correct is vital to installing the complete system.  A percolation test should be carried out to assess the ground’s ability to absorb the waste tank output.  

Septic Tank Emptying

All septic tanks and sewage treatment plants will require periodic ‘de-sludging’ or emptying per the manufacturer’s recommendations. This is done with a vacuum tanker service. Usually done annually (but check with the tank manufacturer). We recommend Rob Beale Ltd for the Wiltshire area.

These systems are within the binding rules of environmental agencies. However, if you are unsure, you should call us on 01722 714514 or Contact Us via email.