EXTRA-78483 - USA (Washington) - Drinking Water Systems Identification and Assessments Service - Deadline December 21,2026

Vendor needs to provide drinking water systems identification and assessments service to the government authority located in Washington. – Task 1. Data verification and supplementation• Verify the information in Attachment A that the contractor will rely on, and report discrepancies.• Supplement it from the public sources listed in Attachment A, and from tribal and operator records requested through agency.• Build a source data table per system: well construction, depth, screened or open interval, static water level, pumping rate and schedule, aquifer and confinement, treatment, and sampling history.• Quantify land cover and land use in each capture zone.• Check each wellhead location against aerial imagery, parcel records, and state well records. Where a source has no coordinates or the location is doubtful, estimate its location from records, state the uncertainty, and show how it affects the capture zones.• Keep a source log (source, date, search area, records returned) and deliver a data gap list per system with the handling approach for each gap.– Task 2. Hydrogeologic technical memorandum (one per Tribe)• Describe regional and local hydrogeology, aquifer properties and their sources, modeling approach,assumptions, parameter ranges, and data limitations.• Must be approved by agency before final delineations are run. agency consults the tribe. It becomes Appendix A of every report for that tribe.– Task 3. Source water delineation• Delineate analytically modeled time of travel capture zones for 6–months, 1–year, 5–years, and 10–year for every active source. Methods may include analytic element models or other analytical solutions appropriate to the aquifer, with the choice justified.• Fixed radius calculated fixed radius, and arbitrary buffers may be used only as a comparison or screening step, not as the delineation.• Run a sensitivity analysis on the parameters that control zone size (for example transmissivity or hydraulic conductivity, effective porosity, gradient, pumping rate, aquifer thickness), and present zones for a base case plus a bounded uncertainty case.– Task 4. Potential contaminant source inventory and risk ranking• Build a geospatial inventory of potential contaminant sources inside and just outside the 10–year zone, using regulatory databases, aerial imagery, and parcel records.– Task 5. Source water assessment reports • Prepare one Final Source Water Assessment Report per system following the anticipated structure.– Task 6. Maps and geographic information system (GIS) products• Deliver GIS data and maps.– Task 7. Summary and handoff• A one–page plain language summary per system suitable for a council, utility board, or community notice, delivered to agency.