Southwest Environmental Limited

Salisbury Sewage Works Layout

After conducting a study of Salisbury Sewage Works, in support of an Odour Impact Assessment, we thought to share the layout for the greater good. Salisbury Waste Water Treatment Works (WWtW) take Foul and a good deal of Surface Water from Salisbury and surrounding settlements.

From Wikipedia: Salisbury is a cathedral city in Wiltshire, England, with a population of 40,302,[1] at the confluence of the rivers Avon, Nadder and Bourne. The city is approximately 20 miles (32 km) from Southampton and 30 miles (48 km) from Bath.

Location of Wessex Water Sewage Treatment Works

Salisbury Sewage Treatment Works Components 

1—Biological Filters  

Bio logical filter is a bed of solid media for bacteria to attach on its surfaces. Wastewater is irrigated on the solid media . It is called a biological filter to emphasise that the filtration process is not mechanical straining of solids, but removal of organic substances by use of bacterial action.  

 2— Primary Flow Tanks  

Primary Settlement Tank (PST) The Primary Settlement or sedimentation tanks are designed to reduce the velocity of the wastewater flow, allowing heavier organic solids (called raw sludge) to settle. They are the first stage of treatment after the removal of rags and grit in the inlet works.  

3—Humus Tanks  

A tank in which settle able solids or humus is separated from the effluent flowing through it.  

4– Storm Tanks  

These provide buffer capacity in the event of a storm. A lot of rain water will flow through the plant during rainy periods, and if heavy the plant will not be able to keep up, and so sewage must be stored.   Notes: Other Items not positioned include screens, macerators, dewatering, and various pumping stations.  

Layout Plan

Please click below image to enlarge annotated layout plan.