Silty Surface Water Run-Off
Background and Overall Objective
This housebuilding project in Durham, England is located on a hilly incline, specifically a 1 in 10 slope. As such, surface water run-off was travelling from the top of the hill, eroding the soil and collecting suspended solids on its way to the bottom of the site. Our client was located here and as such, the water, now laden with suspended solids, was collected in bunds. This water needed to be 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 restriction, a small submersible pump was used to transfer the waters into a Siltbuster system. Siltbuster proposed a gravity based HB20 lamella clarifier for this application. This unit offers 20m2 of treatment capacity allowing for treatment of up to 20m3/hr. This system can comfortably treat the specified flow rate, whilst keeping the footprint relatively small.
Siltbuster also proposed that a magnetic flow meter was used in this application. This ensured that the flow rate could be measured and controlled, along with a gate valve, to guarantee that the discharge consent limits were not broken, and the site could comfortably discharge water to foul sewer.
Benefits of Solution
Adam Stubbs, Technical Sales Engineer: “The HB20 has allowed the site to remove the coarse, settleable solids from the 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”.
