Septic tanks

What is a septic tank?

A septic tank is an underground unit made of plastic, fibreglass or concrete that connects to a property via pipes to collect and dispose of wastewater. Generally, septic tanks are the simplest and most cost-effective way to treat wastewater on small developments.

How does a septic tank work?

A septic tank collects and holds sewage, enabling solids to settle at the bottom of the tank as sludge, before being broken down in a process known as anaerobic digestion.


Wastewater from toilets, sinks, showers, baths and washing machines is collected in the septic tank and biologically treated, breaking down solids naturally before releasing the treated water into the ground.


With a natural filtration process, septic tanks separate solids, oils, grease and water. Some untreatable solids remain and require occasional emptying and cleaning to keep the septic tank running efficiently.


Septic tanks usually discharge water into a designated underground drainage field. As the effluent released by a septic tank isn’t fully treated, it cannot be discharged directly into a ditch, stream or natural watercourse.

Septic tanks for residential and commercial use

Septic tanks are suitable for any domestic or commercial setting which isn’t connected to a mains sewer, offering a cost-effective and environmentally-friendly wastewater solution.

Benefits of a septic tank

Cost-effective Septic tanks are cheaper than a full sewage treatment plant, so can be a highly cost-effective wastewater solution. Plus, as you’re treating your wastewater, you won’t have any sewage bills to pay.

Low maintenance Most modern septic tanks only require emptying and desludging once a year at the most, when waste that cannot be released builds up.

Kind to the environment Septic tanks filter water naturally, using zero chemicals, so the water released into a drainage field is kinder to the environment and wildlife.

Highly durable Providing your septic tank is fitted and maintained correctly, it can last up to 40 years, saving you money in the long-term and offering a highly durable wastewater treatment solution.

The S&S Site Services team works with thousands of customers who require an off-mains sewage solution, and we use our decades of experience to specify the right technology for each property. We only specify and install septic tanks from leading manufacturers, so you have peace of mind your equipment is 100% reliable and built to last. Our complete sewage service covers supply, installation and maintenance, or you can select a supply-only or one-off maintenance service if you prefer.

About our septic tank solutions

Our septic tanks use the latest technology and represent the most cost-effective solutions on the market.

Why choose S&S Site Services’ septic tanks?

Range of sizes – from 2800 – 4500 litres

99.63% hydraulic efficiency

Fully compliant with construction product regulations and tested to EN12566-1 Annex B.


We are confident in ensuring we deliver a service that lives up to expectation and strive to provide a successful and on-going relationship with all our clients.