Background
Wentwood Reservoir in South Wales has a Victorian control tower with 18th-century valves which needed to be removed and replaced, bringing it up to current working standards. To gain access to the base of the tower, over 500,000 m3 of water needed to be drained from the 42-acre reservoir.
The Overall Objective
Morgan Sindall was appointed by Welsh Water to carry out the upgrade, and they came to Siltbuster for a temporary water treatment solution so the silty water in the reservoir could be cleaned and discharged directly to a watercourse without causing pollution. A discharge criteria of TSS of <60mg/l and pH of between 6 and 9 had to be met.
Solution
A multistage system, capable of treating 600m3/hr was deployed, consisting of 8 HB50E lamella clarifiers, 4 MT30 mixing tanks and 2 chemical dosing containers. Sensors were used on the plant’s inlet to ensure pre-treatment chemicals (coagulant and flocculant) were only used when required. Outlet sensors measuring water quality could isolate the feed via actuated valves to prevent sediment-rich water from escaping into the environment. A GSM module sends a text message to alert users of an auto-shutdown.
