Portland Water District (PWD), Portland, Maine, is proactively seeking solutions for sustainable management of biosolids  in Southern Maine. In the summer of 2023, PWD issued a Request for Information (RFI) on a Biosolids Processing Facility. PWD sought information from potential vendors to explore available technologies and services for receiving and processing undigested and dewatered sludge from PWD and (potentially) the surrounding communities. Although the primary focus is volume reduction, and to produce a more “landfillable” product, alternative beneficial end uses for solids are possible.

Responses were due on August 9. The RFI specifically sought data on the fate of PFAS through processing. Working with the consulting engineer, Brown & Caldwell, PWD held a “Technology Summit” on August 1 and 2 that included over 20 vendors with various technology solutions including dewatering, thermal drying, anaerobic digestion, and pyrolysis/gasification for PFAS mitigation (11 vendors for this one).  PWD’s Director of Wastewater Operations and new NEBRA Board Member Scott Firmin compares this phase of the project to a “speed dating” event with quick introductions, short conversations, and a commitment to continue the conversation. But he said he found it very informative and an important part of the process. 

Brown & Caldwell has submitted a report which is available on PWD’s website. PWD is looking for onsite solutions but may be limited by available space. According to Firmin, if PWD looks at offsite solutions, it will likely include additional capacity beyond what is required for PWD’s long-term needs. The report scopes out different options based on various combinations of technologies. PWD’s plans are at the conceptual stage still with the report laying out numerous concepts and portfolios of technologies as well as planning-level capital cost estimates. It will not be cheap. Right now, PWD is meeting and speaking with stakeholders and potential partners to continue with the development of a biosolids solution for the area.

Following its review of the initial report, PWD intends to whittle down the list for technical solutions to continue with the planning efforts. Phase 2 is expected to start sometime in the first half of 2024. NEBRAMail will follow up on PWD’s progress. 

You can check out the slide deck from the 2024 New Egland Water Environment Association annual conference where Scott Firmin presented in Session 29 with John Ross of Brown & Caldwell on “ Working Towards a Sustainable Outlet for Maine Biosolids Through a Regional Solution” 29_AC24_SFirmin.pdf (SECURED) (newea.org). For more information on this proactive project by NEBRA Member Portland Water, see Biosolids Management | Portland Water District (pwd.org).

The Portland Water District operates four WRRFs and provides sewer collection and treatment for a larger, regional service area.  PWD’s largest WRRF is the East End Wastewater Treatment Facility with an average flow of just about 20 million gallons per day.