Biological treatment hire keeps wastewater plant compliant

A Northumbrian Water wastewater treatment plant has kept its biological treatment online and within environmental consent during an equipment upgrade with installation of two temporary T300 WCSEE Hybrid™ submerged moving-bed, fixed-film reactor from wastewater equipment specialist WCS Environmental Engineering (WCSEE).

Managers at Mickleton wastewater treatment plant (WwTP) in northern England, with a 300-population equivalent, are in the process of repairing an existing rotating biological contractor (RBC) to keep the plant within consents of 60mg/l of suspended solids and 40mg/l biological oxygen demand.

Northumbrian Water needed to carry out essential works to improve the treatment process and help ensure that the site always remained fully operational. The works involved repair and refurbishment works to the WwTP from spring 2024, taking up to five weeks to complete.

Before the works commenced, it needed to carry out vegetation clearance in preparation for the construction work, as well as setting up temporary treatment units and pumps to allow the work to be undertaken.

WCSEE was contacted by Northumbrian Water contract delivery partner Mott MacDonald Bentley (MMB) in November 2023 with the challenge of delivering the WCSEE Hybrid™ units to facilitate the refurbishment of the legacy unit which would fit inside the tight access leading to the WwTP and ensure the treatment of 2.4 l/sec.

WCSEE utility manager, Andrew Haywood said, “When WCSEE was contacted by MMB with the hire needs of Northumbrian Water, we knew we could deliver. WCSEE is a supplier capable of delivering WCSEE Hybrid™ in a 30% smaller site footprint in comparison to other Hybrid-SAF units whilst meeting environmental compliance.

“The units were delivered to site in November 2023 and were in use until April 2024.”

WCSEE Hybrid™ process cells offer the benefit that they can easily retrofit into any onsite existing vessel, regardless of shape or size. This saves on infrastructure costs, minimises disruptions, reduces waste and optimises site footprint.  

The units can achieve <0.4mg/l ammonia discharge and remove phosphorus with additional equipment. They can also be configured to provide anoxic conditions for total nitrates and meet high treatment standards for biological oxygen demand, ammonia, and soluble chemical oxygen demand. Units can be installed rapidly and put into operation immediately with fully automatic and continuous pre-set and programmed parameters.

Haywood said, “It was important for Northumbrian Water to be able to bring a unit into operation as soon as possible and WCSEE were able to meet the small site footprint and the peak flow demands. WCSEE have been dedicated partners and its hire services has provided the flexibly and adaptability needed.”

Tightening environmental standards for sewage and industrial trade effluent mean it has never been more necessary for WwTPs to have robust and reliable treatment readily available. Hiring specialist equipment for emergencies or planned refurbishment and decommissioning means water utilities have capacity to plan permanent fixes and carry out major site works and remediation in a timely way.

WCSEE supports customers throughout the hire process to keep sites in compliance and achieve full environmental protection whatever the challenge.