Case study: Waste contractor brings in the Beast to transform Cornwall’s provision

The closure in April 2022 of two large Cornish disposal sites had forced local contractors into sending their vehicles long distances away to discharge their collected waste. While some liquids could be treated by South West Water, during heavy rainfall and storm events, the water company has had to keep its gates closed because capacity has been reached.

For a firm such as Pellows Waste Disposal Services, near Truro, this presented a serious problem.

“Storms and flooding from prolonged rainfall is all too common these days,” said James Martin from Pellows. “We couldn’t just stop working for long periods due to the weather, letting our customers down, or keep sending our vehicles miles and miles away to unload.”

The solution the firm decided was to act independently by treating the collected waste themselves, explained Martin.

“We had to act to protect and grow our business, so first contacted Centri-Force, who make very good decanter centrifuges. They gave us plenty of good advice.”

However, the pneumatic press (with de-stoner) that had been in operation at Pellows not only took far longer to receive incoming waste, but said Centri-Force MD Richard Montanaro, it was too small and far less sturdy, with too many areas where the process would require costly maintenance or be likely to slow or fail.

Instead they recommended using an innovative new system from SAVECO dubbed 'The Beast'. Equipped with a fully integrated 5mm screen, conveyor and compactor, all in one unit, it removes harmful debris and dewaters it prior to discharge, and can handle 200 m³/h and up to 6-8% solids as a plug and play system.

Assesses Montanaro: “It integrates very well with other parts of a plant to provide an excellent front-end pre-screen. With a centrifuge as part of a process, it has helped Pellows greatly increase productivity and take this important step to becoming a liquid waste contractor with its own treatment facility.”

Environmental wet waste is a big issue, he points out and Cornwall, with far less infrastructure and sewer connections than many counties, faces big challenges, so Pellows can now play a big part in reducing the environmental impact of septic tank liquids.

Rotating around its axis, The Beast’s cylindrical filter conveys screenings into a loading hopper placed in the centre, whilst a set of spray nozzles washes the filter during operation. A screw, placed inside the conveying pipe (with its top inside the discharge hopper), conveys the screenings towards the treatment stages, during which organic substances are washed out. Subsequently, solids are compacted and dewatered in the compacting and drainage area, before exiting through a discharge chute.

Despite septic tank contents often containing solidified calcium, rocks, stones, and sanitary products, installation of The Beast now sees Pellows’ 27-tonne artics discharge waste in less than 13 minutes, compared previously (depending on the thickness of the liquid) to 45-minutes and even up to one hour. A typical 4.5m³ tanker (1,000 gallons) that used to take over 20 minutes to empty, can now get back out on the road to collect more liquid waste after less than three minutes discharge time.

Rotating around its axis, The Beast’s cylindrical filter conveys screenings into a loading hopper placed in the centre, whilst a set of spray nozzles washes the filter during operation. A screw, placed inside the conveying pipe (with its top inside the discharge hopper), conveys the screenings towards the treatment stages, during which organic substances are washed out. Subsequently, solids are compacted and dewatered in the compacting and drainage area, before exiting through a discharge chute.

Despite septic tank contents often containing solidified calcium, rocks, stones, and sanitary products, installation of The Beast now sees Pellows’ 27-tonne artics discharge waste in less than 13 minutes, compared previously (depending on the thickness of the liquid) to 45-minutes and even up to one hour. A typical 4.5m³ tanker (1,000 gallons) that used to take over 20 minutes to empty, can now get back out on the road to collect more liquid waste after less than three minutes discharge time.

Craig Webb, SAVECO’s municipal sales engineer, commented: “Allowing effluent to be put directly through The Beast, which avoids placing further stress on an existing plant, is also a huge benefit to water companies. Liquid waste contractors and the water industry can see that by screening, washing, conveying and dewatering - all in one unit - there is a reduction in risk, and the opportunity to make big savings by removing the need for multiple pieces of equipment.”

As Pellows’ James Martin notes, the benefits include better biosolids too at the end of the process.  After South West Water, Pellows became the first company in the county with the capability to treat liquid waste for safe disposal into the foul sewer main. There is a financial gain too: payback is expected in just four months:

“Investing in The Beast is part of a major upgrade that we’ve put into place to address the big changes that have happened in Cornwall’s collection and disposal of liquid waste.”

The upgrade at Pellows, which includes a centrifuge, aeration, and larger tanks, has enabled the company – which celebrates 60 years in business next year ­ to expand its customer-base thanks to its complete in-house service. It will also provide a potential lifeline to other contractors who collect liquid waste from the holiday parks, factories, hotels and many thousands of homeowners in Cornwall that are not connected to the sewer network.