Background

Housebuilding project in Durham, England is located on a hilly incline, specifically a 1 in 10 slope. Surface water run-off was travelling from the top of the hill, eroding the soil and collecting suspended solids on it's way to the bottom of the site. The water was being collected in bunds, and then treated and discharged to a nearby Northumbrian Water foul sewer under a permit, with a volumetric flow rate of circa 3L/s.

Solution

Because of the limited volumetric flow rate, a small submersible pump was used to transfer the water into a Siltbuster system. Siltbuster proposed a gravity based HB20 lamella clarifier for this application. This unit provides 20m2 of treatment capacity, allowing for treatment up to 20m3/hr while keeping the footprint relatively small.

Siltbuster also proposed that a magnetic flow meter was used, to ensure that the flow rate could be measured and controlled, along with a gate valve, to guarantee that the discharge consent limits were not broken.

Benefits of the solution

Adam Stubbs, Technical Sales Engineer: "The HB20 has allowed the site to remove the coarse, settleable solids from the water water allowing for clean water discharge. The unit gives the site an easy way of desludging through the hopper bottom, and it keeps the footprint small when compared to an attenuation lagoon, which would require lots of site space, digging out and reinstatement upon completion of the job."