Madison Metro Sewerage District Nine Springs Water Treatment Plant

Project Challenges

The Madison Metropolitan Sewerage District (MMSD) Nine Springs wastewater treatment plant (WWTP) serves approximately 380,000 people in 26 communities covering 184 square miles. They proactively committed to: (1) better understand PFAS fate and transport with a focus on the role WWTPs play; (2) evaluate how representative sampling might address existing data gaps or inconsistencies in the available literature; and (3) share PFAS-related information with stakeholders.

TRC Solutions

MMSD needed a team with expertise in WWTP operations, sampling procedures, laboratory analytical methods, data/quality management, public sector collaboration, PFAS trends and practices, PFAS fate and transport, Wisconsin regulations, and conceptual site model (CSM) development. Our services and deliverables included:

Sampling and Analysis Blueprint

• Reviewed and compared published, draft, and developing analytical methodologies and screening techniques for PFAS.
• Prepared a phased sampling and analysis plan for the investigation of PFAS in influent, effluent, biosolids, and potential transformation points within the plant.

Fate and Transport Analysis

• Identified typical major- and minor-mass sources of PFAS and affected media.
• Conducted a literature review of peer-reviewed scientific papers, regulatory guidance, and fact sheets focused on fate and transport processes affecting the mass concentration; and/or chemical state of PFAS in the environment, within WWTPs, and following application of biosolids to agricultural fields.
• Prepared a detailed report and graphical CSM for the WWTP describing influent sources, treatment processes, effluents, and PFAS fate and transport.

Initial Characterization

• Prepared a project-specific health and safety plan and standard operating procedures for sampling.
• Collected representative samples of influent, effluent, biosolids, added polymers, and struvite.
• Evaluated and validated the laboratory analytical results, which reported 33 PFAS compounds utilizing the Wisconsin PFAS Method. The sample results will be used to refine the CSM, further understand fate and transport, direct future sampling and allow MMSD to pursue source reduction efforts.

Client Benefits

MMSD was able to: (1) create a new website devoted to helping consumers and businesses better understand complex PFAS topics and pollution prevention strategies with technical support from TRC; (2) refine the scope of future sampling efforts; and (3) share data-driven insights with Commissioners, regulators, and community stakeholders