Itchen Bank Sewage Treatment Works (STW) is a medium sized oxidation ditch site. Under the Water Framework Directive (WFD), the total phosphorus (TP) consent on site has been tightened from 0.6 mg/l
to 0.3 mg/l.
To achieve the more stringent TP consent, MWH Treatment (Severn Trent’s delivery partner) installed
a FilterClear® plant with with 1st point ferric dosing into the oxidation ditch and a 2nd point ferric dose into a static mixer upstream of the 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 Bio’s works, before being transported to site for installation on a flat concrete slab.
|Project Name:||Itchen Bank STW|
|Client:||Severn Trent Water|
|Main Contractor:||MWH Treatment|
|Project Scope:||Design, supply
• Off-site manufacture
• Consent of 0.3 mg/l TP and 4 mg/l Fe
• Rapid installation and commissioning
• No separate flocculation tank needed
Scope of Works
Design, procurement, manufacture, installation and commissioning of Bluewater Bio’s proprietary FilterClear 4V2550 plant. Fully automated and instrumented tertiary filtration system for total phosphorus removal.
FilterClear delivered: October 2020
Installation time ~ 2 weeks
Commissioning time ~ 2 weeks
Compliant by: April 2021
Client organisation: Severn Trent
Contact Person: Lewis McGregor
Itchen Bank STW Process Parameters
|Average Flow||4,207 m3/d|
|Maximum Flow||10,930 m3/d (127 l/s)|
|Design Influent TSS conc.|
(incl. allowance for chemical dosing)
|42 mg/L (average)
58 mg/L (98%ile)
|Effluent TP consent||0.3 mg/L (average)|
|Effluent Fe consent||4 mg/L (95%ile)|