Inflow and Infiltration Analysis

The Washington Suburban Sanitary Commission (WSSC), a major bi-county water and wastewater utility serving Montgomery and Prince George’s Counties in Maryland, has issued Solicitation No. 86594 for professional services focused on Inflow and Infiltration (I/I) Analysis of its sewer collection system. This solicitation seeks a qualified Architect/Engineering firm to perform comprehensive flow monitoring, I/I source detection, hydraulic modeling, GIS mapping updates, and related technical analyses to support management of the wastewater infrastructure. The scope includes installation of flow monitoring equipment, delineation of base flow, groundwater infiltration, and peak inflow components, prioritization of subbasins for remedial investigations, calibration of hydraulic models, and preparation of detailed technical memoranda. Work is to be conducted across multiple field sites within WSSC service areas, with deliverables subject to approval by the WSSC Project Manager. Compliance with U.S. EPA flow monitoring standards, WSSC Water specifications, and applicable state and federal environmental regulations is mandated. The contract term allows for a base period plus one two-year option at WSSC’s discretion. Proposals are evaluated based on a weighted trade-off between technical merit (85%) and price (15%), with key evaluation criteria emphasizing firm experience (30%), qualifications and availability of key personnel (30%), and the technical/project approach (25%). Experience with public utilities, demonstrated capabilities in I/I analysis and hydraulic modeling, and adherence to WSSC’s technical standards are critical. Pricing proposals must demonstrate competitive labor rates without markup on equipment/materials, with a minimum 20% MBE/SLBE subcontracting goal focused on firms located within the two-county area. Submissions are due by January 20, 2026, via the WSSC’s eProcurement Portal, following a non-mandatory pre-bid meeting and a deadline for questions in early January. Contract administration includes strict insurance requirements, certification and affidavit submissions, and quality assurance protocols for deliverables and field work. The contract permits specialty work orders on a time-and-materials basis subject to WSSC project manager approval. Inspection and acceptance activities occur on-site and through administrative review at the WSSC headquarters in Laurel, Maryland. Overall, this procurement reflects WSSC’s ongoing commitment to maintaining and improving its extensive wastewater collection infrastructure through rigorous data analysis and engineering expertise.