Sludge Hubs, Various Locations
The National Wastewater Sludge Management Plan proposes to develop a network of ‘hub’ treatment sites, optimised on a regional rather than county basis. The provision of new or upgraded sludge treatment facilities with import facilities to allow treatment of wastewater sludge on a wider regional basis will reduce sludge quantities for disposal, improve energy recovery, reduce operating costs and reduce overall energy consumption. The overall objective is to provide more efficient and effective treatment of sludge.
We carried out a feasibility study and site selection process for two of three regions (Northwest and East Midlands) to determine the feasibility of treating the potential sludge loads within each region to the required standard for land spreading. The technical options considered involved conceptual designs for anaerobic digestion in combination with pasteurisation or thermal hydrolysis. Issues assessed included capability of existing assets, import facilities, accessibility, impact on wastewater processes and discharge limits, constructability, energy efficiency and energy recovery.
Surveys to gather information, assess existing assets and to identify potential noise, odour, ecological and traffic impacts were carried out. Deliverables included asset survey reports, energy audits, energy recovery assessments and feasibility studies for each site.
In addition, a site selection process was carried out which involved a public consultation process and delivery of the associated communications materials. Site selection reports were prepared for each region to identify the emerging preferred options based on environmental and other specifically devised selection criteria.