Project Summary
Minworth is Severn Trent’s largest sewage treatment works serving a population equivalent of 1.75 million from Birmingham.
Average flow is 450 Ml/d (5.8 m³/s) with full flow to treatment of 1,070 Ml/d (12.4 m³/s).
As part of the AMP4 scheme an extensive programme of capital maintenance was undertaken. The liquor treatment plant was refurbished to improve the reliability and process performance.
The plant treats high strength liquors from the various dewatering and thickening processes to reduce the ammonia levels in the filtrate/centrate.
Project Scope
- Two new 11m primary settlement tanks (PST)
- PST distribution and collection chambers
- PST bridges with retractable scrapers
- Primary tank auto desludge facility
- Construction of a new inter-stage pumping station
- Decommissioning of redundant soda ash system
- New sodium hydroxide dosing package
- Enhanced chemical mixing and control system
- Replacement of the existing activated sludge plant diffusers
- Upgraded blowers control software
- Surplus activated sludge/return activated sludge flow splitting with flow measurement
- Improved personnel access
- Removed trip hazards
Added Value/Benefits
Process performance is improved, delivering the benefit of reducing ammonia load from the various sludge dewatering stages.
Primary tank bridges are fitted with retractable scrapers for safer maintenance, avoiding tank access.
Existing control panel hardware and software modified to improve functionality in auto.
New liquid chemical dosing system to replace powder unit with reliability issues
Trip hazards addressed and eliminated improving operator welfare
A large co-located office was set up in 2006 to accommodate a collaborative team of over 100 staff from Severn Trent Asset Delivery, Pick Everard and the Biwater North Midland Alliance. A key success factor in designing and constructing such a complex multi-phase project has been the face to face communication where issues can be reviewed and resolved to achieve tight deadlines. The team worked as one, drawing on the combined skills and expertise of each member to create an environment of mutual trust and respect.
The project has benefited from close working relationships with Severn Trent Operations who have explained site constraints, supported design development, prioritised asset maintenance and co-ordinated the works interface. Their positive attitude towards the construction team has been critical in achieving complex shutdowns and outages.
The Minworth Alliance won the Severn Trent Water Corporate Responsibility Award in the category of Community to honour the commitment to community involvement including charities, academic institutions, parish councils, residents, neighbours and the local economy.