United Utilities goes above and beyond to improve water quality in a Knutsford brook

United Utilities has helicoptered two new tanks into its Knutsford wastewater treatment works as part of a scheme to improve the water quality at Birkin Brook.

The water company came up with a unique solution to the access issues at its treatment works and hired a twin rotor helicopter to fly in the tanks as they were too big to fit under the low railway bridge archway located along the access road.

The tanks will be used to reduce the concentration of phosphorus in the treated effluent, which is released back into Birkin Brook, a tributary of the River Bollin.

The improvement in water quality will be achieved by dosing chemicals into the effluent as part of the treatment process and these chemicals need to be stored on site in sufficient quantities to meet the demand, which is where the new tanks come in.

Each tank is 4m diameter (12/13 ft), 3.5 m high and weighs 2.5 tonnes. They can each hold 30m cubed or 100 baths worth of liquid.

The tanks were delivered to Tatton Park and then helicoptered from there into the treatment works. Construction work on the concrete slabs, to receive the new tanks, began in July 2024 and was completed in September 2024.

Due to the restricted access into the site, United Utilities has already commissioned a new made-to-measure chemical delivery tanker that will fit through the railway bridge archway and can also be used at other hard to reach treatment works.

A spokesperson for United Utilities said: “This definitely was a construction challenge for us, but we managed to overcome it through the innovative design of the chemical dosing facility on site and a great collaborative effort between everyone involved.”

As a thank you to Tatton Park, United Utilities has donated to the Park’s education programme to help towards the funding of some its schemes including parkland education workshops and a scheme that provides financial support towards the cost of transport for schools visiting the site for an educational experience.