Are There Any Grants for Water Treatment Systems?
Mrs Elaine Fyson asks
We aren't on mains sewage and have a large cesspit which takes all our excess water at a cost of £90 every 5 weeks. We are looking at putting in a treatment system so that we can recycle the water. Are there any government grants or otherwise available that we could apply for in order to do this?

Off-mains drainage in the UK

Around 800,000 properties in the UK sit outside the mains sewerage network. For homes not connected to mains sewerage, a private system is necessary to manage wastewater. The three main options are cesspools, septic tanks with soakaways, and sewage treatment plants.

Sewage treatment plants produce cleaner effluent than traditional septic tanks, typically removing around 95% of pollutants compared to 30% for a basic septic system. They treat waste to a higher standard before releasing it, which appeals to homeowners who want to reduce their environmental impact. However, this better performance comes at a higher installation cost.

Are grants available for installation?

There are no national grants in the UK specifically for installing domestic sewage treatment plants. However, local or regional initiatives do occasionally appear, particularly those linked to environmental improvement schemes in sensitive areas. It is worth checking with your local authority for any current programmes.

Some councils may offer planning assistance, guidance on permit applications, or information about environmental schemes that could help offset costs indirectly. The Environment Agency regulates private sewage systems in England. In Scotland, contact SEPA; in Wales, Natural Resources Wales; and in Northern Ireland, the Northern Ireland Environment Agency. Their websites may list regional schemes or exemptions relevant to your situation.

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Understanding your system options

A cesspool is the most basic option. It is simply a sealed tank that holds all waste until emptied by tanker. Cesspools do not treat waste and there is no discharge, so running costs can be high due to the need for regular waste collections, sometimes several times a year depending on household size.

Cesspools are typically installed where ground conditions prevent drainage, such as areas with heavy clay soil or a high water table. They may also suit properties with limited space or locations where environmental regulations prohibit any discharge.

Septic tanks treat sewage to a basic level. Solids settle in the tank and the liquid flows out to a soakaway, where it drains into the ground. You will still need occasional emptying, but less often than with a cesspool.

Sewage treatment plants go further. They use mechanical or biological processes to clean the effluent before discharge. The output is cleaner and can sometimes be released directly into a watercourse, subject to permits from the relevant environmental regulator.

What to check before installing

Before fitting any private drainage system, you will usually need to meet certain rules. These cover discharge quality, location and maintenance. The requirements depend on whether you are replacing an existing system or installing a new one.

For current regulations and permit requirements, check GOV.UK or contact the Environment Agency directly if you are in England. Residents in Scotland, Wales and Northern Ireland should consult their respective environmental agencies for localised guidance.