The UK’s Environment Agency introduced new rules on sewage treatment on 1 January 2015. The general binding rules state that “You must use a small sewage treatment plant to treat the sewage if you’re discharging to a surface water such as a river or stream.”

The rules also lay out a requirement that all septic tanks discharging directly to a surface water must be replaced or upgraded to sewage treatment plants which meet the required standards. All new sewage treatment plants must be installed by 1 January 2020.

How will I be affected by the new rules on sewage treatment?

If you have a septic tank that discharges directly to a surface water, you are required to replace or upgrade your septic tank by 1 January 2020. There are four options in this scenario:

  • Upgrade your septic tank using a conversion unit (standards apply);
  • Replace your septic tank with a small sewage treatment plant;
  • Connect your discharge to a mains sewer (where available and permitted); or
  • Discharge to the ground using a drainage field infiltration system.

Permits for existing or new discharges to surface waters from septic tanks will be granted only in exceptional circumstances. If you are buying or selling a property with a septic tank, responsibility for its replacement or upgrade should be addressed between the buyer and seller as a condition of sale. Contact the Environment Agency to discuss your options if you are unsure.

How do I know if my treatment system meets the standards?

The sewage treatment system you have installed must meet the relevant British Standard which was in force at the time of its installation. For sewage treatment plants, this is BS EN 12566. If you have a drainage field installed, the relevant standard is BS 6297:2007.

You can tell if your system meets the relevant standard by checking if it has a CE mark. Alternatively, the system’s manual may have a certificate of compliance with the relevant standard. Finally, you can also check British Water’s list of approved equipment.

What size sewage treatment plant do I need?

There are several other general guidelines you must follow to ensure compliance with the new rules on sewage treatment. First, ensure that the system is installed correctly and has enough capacity. Check out our guide on how to choose the right size sewage treatment plant for advice. Next, have your system emptied regularly and maintained appropriately. Follow the manufacturer’s instructions and guidance. At a minimum, arrange to have the sludge removed (known as desludging) at least once a year by a registered waste carrier.

Where can I buy a new sewage treatment plant?

Here at Drainage Superstore, we have a wide range of sewage treatment plants available. Whether it’s for a small property, a group of houses or a large commercial premises, you can find what you need. Check out our range of sewage treatment plants from top brands Marsh, Graf, Kingspan and Tricel.

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