Water recycling technology specialist WCS Environmental Engineering (WCSEE) has been selected by a care home in Cornwall, UK to provide on-site wastewater treatment in an environmentally sensitive location.
The property is served by an on-site wastewater treatment plant as it is not connected to the public sewer.
With the existing system coming to the end of its operational life, the soak away it historically discharged to was no longer deemed suitable. A new point of discharge to a nearby brook meant more stringent environment agency permit conditions to be stipulated, requiring enhanced levels of effluent treatment.
After close liaison with installer Jones Drainage & Groundworks and WCSEE, the care home’s owner, private care provider Swallowcourt, opted to replace the plant and add a tertiary stage of ultraviolet (UV) treatment. WCSEE has designed a custom on-site solution comprising a below-ground high performance aerated filter (HiPAF) treatment plant and UV disinfection system with a capacity of approximately 300 population equivalents (PE).
UV light destroys micro-organisms and reduces dissolved organic material, which can impact the quality of watercourses. It is considered one of the safest methods of disinfection, as it does not require use of chemicals.
A configuration of UV bulbs in a below-ground chamber, UV units connect to the outlet of the treatment plant. Effluent passes around the bulbs, with the disinfection occurring when the light comes into contact with the flows.
The technology will ensure consistent compliance with the environment agency’s discharge permit requirements, set at 20:30:10mg/l for biological oxygen demand (BOD), suspended solids and ammonia, with UV disinfection.
WCSEE technical manager Dominic Hamblin said, “The end result will be a modern, reliable and robust system that will treat effluent to standards required in this environmentally sensitive location. UV disinfection will provide maximum bacteria and virus removal rates, and give protection to local water environments.
“The combination of HiPAF treatment and UV is usually only required when the receiving waters are particularly sensitive. The advanced process gives peace of mind that effluent has undergone rigorous treatment and will meet full compliance.”
Steven Jones of Jones Drainage & Groundworks said, “This is an important project to protect the local environment. The site has tight access but because WCSEE’s HiPAF technology is modular and built off-site, we will be able to use a crane to position the units.”
Mike Tippett, Swallowcourt estates and contracts manager, said: “We have collaborated closely with WCSEE and Jones Drainage & Groundworks throughout the design process and look forward to the installation and commissioning stage, expected in early 2023.”
WCSEE HiPAF technology is suitable for properties from 60-2,000 PE where main drainage is unavailable. Modular in design, the compact units are simple to install, operate and maintain, have a small footprint and can manage variable flows and loads. The technology can manage complex site situations, including where space is an issue or where ammonia removal is a requirement.