HiPAF tank repurposed for wastewater upgrade

The national trend for pubs to orientate their businesses around food or even convert to restaurants can mean an upgrade in onsite sewage treatment is required. This was the case at a popular Toby Carvery in Stonebridge, Coventry, which has seen the number of diners eating in the restaurant rise substantially over the years.

Over 1,000 covers are served most days and additional wastewater treatment was required to ensure compliance at a site originally designed for 300. The location of the restaurant next to a busy motorway junction near Birmingham Airport makes it impossible to connect the site to mains sewerage so the existing HiPAF unit needed to be replaced by a much larger system.

Watling Hope is the main contractor for new sewage treatment plants for all sites belonging to Mitchells & Butlers which owns Toby Carvery. Working in close partnership it was decided to keep costs down by repurposing the existing  HiPAF packaged treatment unit (off mains drainage) to create an underground primary settlement tank. Two additional units were then connected in series to provide a new HiPAF – high performance aerated filter - biozone and conical final settlement tank.

The installation was necessary to ensure the site meets daily demand of 34.3m³ and peak flow of 1.19l/sec. The environmental consent for discharge to the nearby river is 20mg/l biological oxygen demand, 30mg/l suspended solids and 20mg/l ammonia.

Diners unaffected

Installation took two weeks and the restaurant stayed in operation throughout with diners unaffected. Wastewater was stored in the newly created settlement tank and tankered off-site as required during the works.

Dominic Hamblin​, technical manager said, “The Toby Carvery at Stonebridge reflects a wider trend as former pub premises change the focus of business to food. The resulting increase in flows and loads means an upgrade in wastewater treatment is often required.

“This was a routine job for us, but we were able to deliver best value for money for the client by reusing the existing HiPAF tank in an intelligent way. Our modular systems are designed for maximum flexibility and can adapt to our clients’ needs as they respond to changing market conditions.

“This innovation shows the advantage of working with a supplier that has technical expertise and the customer’s best interest at the heart of its specification process.”

Mike Palin, chairman of Watling Hope said, “We’ve have installed hundreds of HiPAF plants. The technical support is brilliant and the product is brilliant.

“On this occasion they identified a significant cost saving for the client in repurposing the existing HiPAF. This meant less civils work, fewer truck journeys and less waste for disposal.”

Mitchells & Butlers’s area building manager, Martin Lyons said, “As a business, we manage our water, energy and waste in a way which is cost effective to the business and reduces our impact on the environment. The idea of repurposing of the HiPAF wastewater treatment plant was inspired and is exactly the kind of sustainability initiative we expect from our supply chain partners.”