Sewage Treatment Plant Installation Guide

Sewage Treatment Plant Installation Guide

Owls Hall Environmental How To Guide

Sewage treatment plant installation doesn’t have to be a long or difficult process. If you’re aware of the legislation that applies to your situation and you have a good supplier, you shouldn’t need anything more. Owls Hall’s sewage treatment plant installation guide will give you the information required to take the first steps. Keep reading to understand the full process, or use the links below to jump to the section you’re most interested in.

When to install a sewage treatment plant

A sewage treatment plant is the most up to date way to remove sewage from properties where there is no access to mains sewage. Around 4% of properties in the UK require some form of off-mains sewage system and a plant is a good alternative to cesspits and septic tanks.

As of January 2020, new regulations from the Environment Agency state that septic tanks which discharge directly to surface water must be replaced or upgraded to a sewage treatment plant. It will also be a good idea to install a new plant if your current system is no longer fit for purpose, or if your off-mains property doesn’t already have one.

Sewage treatment plants come in a range of sizes. They can be appropriate for everything from a small house to a rural pub or even a hotel. As long as you get the right size and follow the relevant guidelines for your property, a sewage treatment plant will do the job you need it to. Use the links in our resources section at the end of the guide to make sure you can find the right information.

Relevant legislation

A number of different guidelines exist in the UK that govern sewage treatment plant installation. It is essential that you follow building regulations, notify your local council and comply with any relevant environmental rules.

In most cases, the legislation should be fairly straightforward. The best starting point is the UK government website, which contains a number of instructions and links to the relevant permit applications or guideline documents. If you live in Wales, Scotland or Northern Ireland, Guidance for Pollution Prevention 4 contains information from the Welsh, Scottish and Northern Irish environment agencies.

Do you need planning permission for a sewage treatment plant?

You might need planning permission for a sewage treatment plant. To know for sure, contact your local planning authority (LPA) and inform them of your plans. Whether you need planning permission or not, you must have building regulations approval.

If you have already installed a sewage treatment plant, you must apply for building regulations approval retroactively and must also check whether or not you need planning permission with your local council. You should also notify the council if the plant was installed before 1st January 2015, as you may need to follow further processes.

What environmental regulations apply to sewage treatment plant installation?

Sewage treatment plants discharge to either the ground or surface water. The regulations differ depending on where your plant discharges and how much you discharge. In a few cases, permits are required to ensure that the discharge meets environmental requirements.

When discharging to the ground, a permit is required in the following situations:

  • The plant discharges to a well, borehole or other deep structure
  • The discharge is more than 2 cubic metres (2,000 litres) a day
  • The plant discharges to a groundwater source protection zone (SPZ1)

Groundwater source protection zones exist around commercial water supplies and private water supplies for human consumption. There are a couple of ways to check whether or not you’re in an SPZ1.

For commercial water supplies, you can look at a map of protected zones or get in touch with the Environment Agency. For private supplies, you’ll need to check with your neighbours that your plant is not discharging to an area within 50 metres of a spring, well or borehole.

You can apply for a permit online. Be sure to read the additional ground discharge rules regardless of whether or not you need a permit.

You can only discharge to surface water if you use a small sewage treatment plant. If you’re discharging more than 5,000 litres a day, you also need to apply for a permit. As with ground discharge, additional rules apply that you need to read.

What kind of plant do you need?

The volume of the sewage treatment plant’s discharge is the most important factor to consider when purchasing a sewage treatment plant. It will also affect whether or not you need to apply for a permit. Calculations for domestic properties can be carried out with a government calculator, but commercial calculations may require Environment Agency advice.

Alongside the government calculator, Owls Hall’s own sewage treatment plant comparison guide makes it easy to see at a glance which plants might be suitable for you, based on the size of your property. Explore our sewage treatment plant shop to get more information about the different plants, including their specifications.

It may be possible to calculate the expected discharge for a sewage treatment plant with a document recommended by the government, ‘British Water: Flows and Loads – 4,’ but if you’re unsure about the requirements of your property, it is a good idea to contact the Environment Agency.

Aside from the discharge volume, looking at our commercial sewage treatment plants is a good way to get a sense of the specific plant you may need for a pub, hotel, visitor centre or other rural business.

What to look for in an installation survey

If all of the information given so far seems like a lot to take on board, don’t be alarmed. A professional sewage treatment plant installation survey will fill in a lot of the blanks for you and clarify the whole installation process.

Owls Hall can carry out installation surveys across the South East and East of England. The list below gives you an indication of what to expect from one of these surveys, and will give you a helpful reference point if you’re based elsewhere in the country.

Our survey includes:

  • The suitability of the land for the product
  • Access to the grounds
  • The type of machinery required and the number of staff we think may be required to carry out the work
  • Testing, which may need to be carried out on site
  • Current systems installed in the ground
  • Location of utility pipes and watercourses

As part of the survey, our surveyors will also be able to provide advice on the plant that we feel is best suited to your property, and can help answer any questions you may have about the other regulatory processes mentioned in the previous section of this installation guide.

Can you install the plant yourself?

We would not recommend installing a sewage treatment plant yourself. A sewage treatment plant is a big piece of equipment that needs to be installed underground and connected to your property’s drainage pipes. It is usually a multi-person job that requires specialist equipment.

There is likely to be some disruption to your property while the installation is in progress, but working with a professional team minimises the time and magnitude of that disruption. A sewage treatment plant is vital to the comfortable usage of your home, so you don’t want to be without one for too long.

Owls Hall’s installation service removes the need for any work on your part. From the survey to the finished installation, we will provide and install the best sewage treatment plant for your property. If you’re outside of our installation area, we recommend looking for a similar supplier who can take you through the whole process.