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Buying a house with a septic tank

Does a Sewage Treatment Plant need a soakaway?

For more advice on any Septic Tank, Sewage Treatment or Soakaway query. Please call us on 0800 3101092 or via our contact form.

What is a Sewage Treatment Plant? 

Apologies for those have more advanced knowledge than others but it is important this is clear. Customers very often confuse the major types of systems used in off-grid domestic drainage.  There is a good definition on the below.

Buying a house with a Septic tank, Cesspit or sewage treatment plant

Essentially a Sewage Treatment Plant treats the effluent within a single tank. Normally using a method of compressor induced aeration. They emit near clear water. A Septic Tank is a two-tank system that merely separates most of the solids from the liquid. A Septic Tank emits raw untreated effluent. A Cesspit does not emit any effluent, it is just a big tank that collects effluent. 

What is a Soakaway?

Okay, I am going to really confuse you here. A Soakaway can never be used with any form of off-grid domestic drainage. A Soakaway by definition is just “a pit, typically filled with hardcore, into which wastewater is piped so that it drains slowly out into the surrounding soil.” This is not sufficient to comply with the Environment Agency or Building Control Guidelines. Any form of off-grid domestic drainage that discharges to the ground must do so through a Drainage Field. Please see the article below. Essentially everyone still says Soakaway but the correct terminology is Drainage Field. 

Drainage Field, size calculation and design

What is the difference between a Discharge to Ground and a Discharge to Surface Water?

If you discharge to the soil in your back garden then this is a discharge to ground. A Borehole or other deep structures are also considered to be discharges to ground.

If you discharge to a river, stream or drainage ditch or anywhere where the output is washed away by water. Then the discharge is considered to be to surface water. 

If you are unsure give us a ring. This article will also help Summary of the General Binding Rules for Septic Tanks and Sewage treatment plants.

Does a Sewage Treatment Plant need a Drainage Field?

A Sewage Treatment Plant does not necessarily need a drainage field. A Sewage Treatment Plant can discharge directly to a drainage ditch, watercourse or river. This discharge does not require a Drainage Field. Permission from the EA will only be needed if this discharge exceeds 5m squared. 

As part of a septic tank system, the soakaway treats the effluent. If discharging to ground the written rules demand you have a traditional Drainage Field which can be slightly smaller than that attached to a Septic Tank. Bizarre I know, as the effluent is already treated.  The Environment Agency allows you to pump the waste straight to streams that our children splash in during the summer but are strict when discharging to ground. Fortunately, common sense can prevail. 

With consultation with Building Control, Infiltration tunnels can be used which vastly reduce the size of discharge to ground. Infiltration tunnels also allow a much better functioning system. They also reduces the cost. In reality, most people cannot physically fit drainage fields in their garden in line with the Environment Agency’s guidelines. We can walk you through the options available here.

Want to learn more?

We have a large collection of articles containing the answer to all of your questions. Check out our Blog Page 


Our Core Services: The Sewage Treatment expert Installers

On the 1st January 2020, all Septic Tanks that discharge to a Stream, Watercourse or Drainage Ditch will become illegal and will require replacing with a Sewage Treatment Plant. Please see here for more details.

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Expert wastewater treatment engineers who specialise in Septic Tank and Soakaway replacements as well as Sewage Treatment Installations. We are based in the New Forest, Hampshire but operate across the South Coast as well as Wiltshire, Somerset, Devon, Sussex, Surrey, Oxfordshire, and Berkshire.

The Home of Septic tank and private drainage system solutions. 

Based in the New Forest, Hampshire on the border with Dorset and Wiltshire we operate an expert team of off-mains drainage specialists. This encompasses Septic Tank, Soakaway and drainage system problems, installations, blockages, and servicing. In addition, any issues relating to cesspits and sewage treatment plants.

Homeseptic offers high quality, professional advice, repairs and installation for all aspects of effluent cleansing and disposal across the south of England. Whether you’re looking for septic tank installation, sewerage treatment plants or systems, piping or soakaway solutions, Homeseptic employs only the most competent engineers in the drainage and treatment industry and knows exactly which solutions suit each property.

We only install and offer quality systems we believe in, from suppliers we know and trust.

New Forest Philosophy

As we have said Homeseptic is based in the New Forest. A great location in between the cities of Southampton, Salisbury and Bournemouth. We are a group of good friends who grew up together in the area.  Individually we all have grown tired of the way other Drainage firms are run. As a result, this is why we set up Homeseptic. If you want to know more please check out our About Page

We want to actually put the customer first and turn up to do a great job that we can be proud of. Unfortunately, this is not the case in the market, with most companies pressuring their workers to sell unnecessary works on a visit. Due to this, we offer upfront quotations with any variations discussed before we start work.

We are honest hard working professionals, which we hope you will agree with. As a result, it will certainly not turn up in flash sales vehicles and give you a load of chat and then do a terrible job. Our team will come with the job in mind and the aim of giving you the best value we can in order to facilitate a quality installation. 

We cover all of Hampshire, West Sussex, Dorset, Somerset, and Wiltshire. Please get in touch and see what you think.

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