UV Treatment Selected for Care Home Wastewater

Trevaylor Manor specialises in dementia care and is situated in the picturesque village of Gulval, two miles from the town of Penzance. As it is not connected to the public sewer, the property is served by an onsite wastewater treatment plant.

With the existing system coming to the end of its operational life, the soakaway it had historically discharged to was no longer deemed suitable. A new point of discharge, to a nearby brook, meant more stringent Environment Agency permit conditions were 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 onsite solution comprising a below-ground HiPAF - high performance aerated filter - treatment plant and UV disinfection system with a capacity of approximately 300 population equivalent (PE).

Ultraviolet light destroys microorganisms 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 robust 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, “We are pleased Trevaylor Manor has selected our technology for its new onsite treatment plant.

“The end result will be a modern, reliable and robust system that will treat effluent to the very high standards required in this environmentally sensitive location. UV disinfection will provide maximum bacteria and virus removal rates, and therefore give the highest levels of 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 in the beautiful village of Gulval. The site has very 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 are proud to be located in this beautiful part of Cornwall and take our environmental responsibilities very seriously. Our upgraded treatment plant will ensure we can continue to treat our wastewater onsite without impacting the environment.

“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’s HiPAF technology is suitable for properties from 60 up to 2,000 population equivalent (PE) where mains 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 flexible technology can manage complex site situations, including where space is an issue or where ammonia removal is a requirement.