Dyserth Sewage Treatment Works (STW) is a medium sized trickling filter works. Under the Water Framework Directive (WFD), the site had 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, MMB (Welsh Water’s delivery partner) installed a FilterClear® plant with ferric dosing upstream of primary settlement. Provision was made for a 2nd point ferric dose into a static mixer upstream of the FilterClear® plant, but
this has not been necessary.
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:||Dyserth STW|
|Main Contractor:||Mott MacDonald Bentley|
|Project Scope:||Design, supply
• 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
Design, procurement, manufacture, installation and commissioning of Bluewater Bio’s proprietary FilterClear® 3V1260 plant. Fully automated and instrumented tertiary filtration system for total phosphorus removal.
FilterClear® delivered: Mar 2020
Installation time ~ 2 weeks
Commissioning time ~ 2 weeks
Compliant by: July 2020
Client organisation: Welsh Water
Contact person: Richard Matthews
Dyserth STW Process Parameters
|Average Flow||1,021 m3/d|
|Maximum Flow||2,506 m3/d (29 l/s)|
|Design Influent TSS conc.|
(incl. allowance for chemical dosing)
|28 mg/L (average)
46 mg/L (98%ile)
|Effluent TP consent||0.5 mg/L (average)|
|Effluent Fe consent||4 mg/L (95%ile)|