Project Description
Sherborne Sewage Treatment Works (STW) is a medium
sized trickling filter works. In AMP7, under the Water
Framework Directive (WFD), the site has to meet a
new total phosphorus (TP) consent of 0.5 mg/l, and an
Iron consent of 4 mg/l. To achieve these new consent
standards, Wessex Water installed a FilterClear® plant.
The decision was based on a comprehensive whole life
cost (WLC) assessment of various tertiary solids removal
(TSR) plants. The FilterClear® skid was assembled and
hydraulically tested off-site at Bluewater’s works, before
being transported to site for installation on a flat
concrete slab.
The site was commissioned with two-point Ferric
dosing for P removal, and the FilterClear
performance demonstrated that the compliance
can be achieved reliably.
| Project Name: | Sherborne STW |
| Client: | Wessex Water |
| Capacity: | 108 L/s |
| Project Scope: | Design, supply & commission |
Project Highlights
- Off-site manufacture
- Consent of 0.5 mg/l TP and 4 mg/l Fe
- Rapid installation and commissioning
- No separate flocculation tank needed
Scope of Works
Project Duration
FilterClear delivered: June 2022
Installation time: ~2 weeks
Commissioning time: ~2 weeks
Client Contact
Client organisation: Wessex Water
Contact person: Andrew Gulliford (Process Manager)
Sherborne STW Process Parameters
| Average flow | 44 L/s |
| Maximum flow | 108 L/s |
| Design Influent TSS conc. (incl. chemical solids) | 49 mg/L (average) 65 mg/L (98%ile) |
| Effluent TP consent | 0.5 mg/L (average) |
| Effluent Fe consent | 4 mg/L (95%ile) |
