New domestic sewage treatment plants – 2023 rule updates
On the 2nd of October 2023, the Environment Agency announced two new rules impacting new installers of private, domestic, sewage treatment plants and existing users who come to replace their current systems.
The new rules, number 22 and 23, came into force on the 2nd of October meaning that they must be adhered to immediately.
In this blog post, we cover what domestic sewage treatment plants are, what the new rules mean, and what products WCS Environmental Engineering can offer to help domestic customers meet new and existing rules.
What is a domestic sewage treatment plant?
If you live or work in an area without a public sewage system, you'll need a way of dealing with the wastewater your household or business produces. Traditionally, this has been the function of a septic tank, but following tighter regulation of wastewater disposal, more people are choosing to install a domestic package sewage treatment plant (STP) instead.
How does a small STP treat domestic wastewater?
Compared to septic tanks, STPs use bacteria and microorganisms to break down waste and leave you with practically clear treated wastewater that can be discharged into watercourses.
Who is a domestic STP best suited for?
Designed to treat flows from between 1 and 55 people, the Diamond range is ideal for small rural business that are off mains drainage such as glamping and camp sites, country estates, farm shops, B&Bs and garden centres, as well as individual homeowners.
What goes on in a domestic sewage plant?
First, depending on the system type, the wastewater goes into a settlement tank or directly into a biological ‘soup’ where, with the use of either forced air or a rotating disk, the microorganisms start to work. Finally, after settlement, the purified water gets sent out into the world to feed the flowers, trees, and other plants via a drainage field and local water courses.
Do the new rules from the Environment Agency apply to my existing system?
No, they will only apply when you come to replace your existing domestic STP with a new one.
What are the new rules if I am installing or replacing a domestic STP?
The new rules apply to treated wastewater that is discharged both to surface water and to ground. Rule number 22 states,
“A new discharge shall not use the same outlet as any other discharge if the combined volume of those discharges would exceed the volumetric general binding rules thresholds for groundwater or surface water.”
This cannot be done under the General Binding Rules (GBRs) and therefore a B6.5 permit application would need to be made before the work is undertaken.
Additionally, what this new rule means is that you cannot share a discharge, which is a soakaway, drainage field, or discharge point, with another system. This could be, for example, a neighbour’s tank if the combined output of wastewater from the multiple systems exceeds the daily discharge limits set in the GBRs.
The limits are five cubic meters (m3) of treated wastewater for discharges to surface water and 2m3 of treated wastewater for discharges to the ground.
Rule number 23 states,
“A new discharge shall not be made to a discharge point within 50 metres of any other exempt groundwater activity or water discharge activity.”
To add further clarity on this rule, the Environment Agency has said, if a new discharge was within 50m of an existing discharge “would be considered and the environmental risk assessed as part of the B6.5 permit application for the new discharge.”
In terms of the combined volume of an existing and the new proposed discharge the Environment Agency has said, “a permit would be required for the new discharge even if the combined volume would potentially be less than the maximum relevant discharge rate”.
What solutions can WCSEE provide to match the new and existing rules?
WCSEE offers new and existing customers the environmentally compliant Diamond domestic sewage treatment plant.
The Diamond is a compact wastewater treatment range suitable for domestic and commercial properties of one – 55 people in all ground conditions where mains drainage is unavailable.
The patented Diamond not only gives the highest quality process on the market, but also provides a discreet, efficient, and cost-effective solution for the longevity of the plant. This is achieved through WCSEE’s continued commitment to improving product design, development, and manufacturing processes and is backed by a 25-year warranty for the tank and a two-year warranty on blowers.
Topics: Wastewater Treatment
Written by Becky Belton
Becky is a highly experienced Senior Account Manager who over the past 20 years has built a large customer portfolio and trusted relationships with our independent network of expert drainage engineers in the UK and Europe. She works closely with clients to specify the Diamond and HiPAF sewage treatment plants for the off mains drainage market. In addition to nurturing existing customer relationships, Becky oversees new business opportunities for the market whilst delivering exceptional customer service.