Scottish Water has selected technology from wastewater treatment specialist WPL to deliver enhanced ammonia removal at a village treatment works.

Photo: WPL’s Hybrid-SAF™ treatment unit will deliver additional ammonia removal at Scottish Water’s Ferniegair plant

Tightening environmental consents and an increasing population has led the public utility to upgrade Ferniegair wastewater treatment works in South Lanarkshire.

The site has a tight footprint and is in close proximity to residential housing, both important factors considered early in the project design phase, which was carried out by WGM Engineering Ltd. The site serves a population equivalent (PE) of 2,000, including new housing.

WPL will provide one Hybrid-SAF™ (submerged aerated filter) treatment unit, housed in a steel above-ground container to deliver additional ammonia removal at the plant. To enable the WPL Hybrid-SAF to be gravity-fed, avoiding the need for costly and energy-intensive pumping, the unit will be positioned downstream of existing SAF units and upstream of the site’s final settlement tanks.

The Ferniegair unit will be able to treat 6.4l/s flow and provide approximately 1,000 PE of additional ammonia removal capacity. This will ensure the site maintains the Scottish Environment Protection Agency’s (SEPA) ammonia effluent requirement of 20mg/l. The agency’s regulations state the site must meet these standards at least 95% of the time.

Scottish Water project manager Richard Morris commented:

“This is an important scheme which will deliver enhanced ammonia removal at our Ferniegair treatment works. WPL is a framework supplier whose technology will have a key role in the site maintaining compliance.”

WPL’s onsite installation work will be taking place in the spring of 2021. Under its framework agreement with Scottish Water, the company has recently undertaken projects on wastewater treatment works in areas Newtown St Boswells, Canonbie and Winchburgh, all due to be commissioned in 2021.