Severn Trent’s Blymhill wastewater treatment works in Staffordshire serves a catchment that includes Weston Park, a 17th century country house set in 1,000 acres of parkland, that hosts large outdoor events such as music festivals, concerts and fairs. Incoming flows and loads to the works can vary seasonally and depending on which events are held.
The water utility selected a WCSEE Hybrid-SAF – submerged aerated filter – unit to deliver increased tertiary ammonia removal, replacing existing temporary equipment and therefore increasing the capacity at the works to ensure that the highest loads are treated at all times.
The Hybrid-SAF is required to treat a peak flow of 7 l/s, while maintaining compliance with environmental permit requirements for ammonia of 5 mg/l during summer months.
WCSEE’s patented process technology employs a submerged moving-bed, fixed-film reactor. The unique design of the flow balancing in the primary tank means it can cope with variable flows and loads making it ideal for seasonal venues.
WCSEE utility manager Andrew Haywood said: “Treating seasonal fluctuations can be a challenge for wastewater treatment works. The sudden increases in concentration and flow can have an impact on the existing processes which may not be sized to accommodate the increases in load.
“Owing to its unique design, the WCSEE Hybrid-SAF can accommodate spikes in biological load, assisting the sewage works to perform to the required consent standards.”
John Woodward, team manager at Severn Trent Water, said: “WCSEE’s Hybrid-SAF is a technology we have successfully used many times, which is why it was selected to help us achieve strict environmental standards required at Blymhill.”
Modular in design, WCSEE’s Hybrid-SAFs are built offsite, can be transported easily and used across multiple sites as required.