Attachment.pdf

This is a technical characterization report for the Washington Suburban Sanitary Commission (WSSC) Water in Maryland detailing water treatment residuals (WTR) from the Potomac Water Filtration Plant as of October 2024. The document provides comprehensive analytical results for per- and polyfluoroalkyl substances (PFAS) compounds and physical/chemical characteristics of both passively dried WTR and digested biosolids from BioEnergy, including a 50/50 blend of these materials on a dry weight basis. The characterization data includes PFAS analyte concentrations measured in g/kg, physical characteristics such as pH and total solids percentages, primary and secondary nutrient compositions, micronutrient profiles, and 40 CFR 503 metals testing results including cadmium, chromium, copper, lead, mercury, molybdenum, nickel, and zinc concentrations.

The analytical results demonstrate the composition of treatment residuals that would be subject to the related WSSC contract solicitation for residuals hauling and management services at both the Patuxent and Potomac Water Filtration Plants. The characterization data is essential for determining appropriate handling, transportation, storage, beneficial reuse, and disposal methods for these residuals, as contractors must manage materials according to federal regulations and state requirements. The presence of measurable PFAS compounds and regulated metals in the residuals necessitates careful characterization and documentation to ensure compliance with environmental regulations and to inform potential contractors regarding the nature and properties of materials they will handle under the solicitation deadline of July 13, 2026.