This agreement provides funding to the city of twentynine palms to implement a USGS study to support wastewater management and reclamation its project to as directed in the 2022 and 2023…

The U.S. Environmental Protection Agency (EPA) Region 9 awarded a $1.94M Cooperative Agreement to the City of Twentynine Palms under the Congressionally Mandated Projects program (CFDA 66.202) on October 1, 2025, to support comprehensive wastewater management and reclamation initiatives. The award funds a five-year hydrological and hydrochemical study conducted by the U.S. Geological Survey (USGS) California Water Science Center, extending through September 30, 2031. The study encompasses eleven coordinated tasks designed to advance understanding of groundwater processes and water availability in the Twentynine Palms area.

The deliverables include technical data collection and reporting across multiple specialized activities: review of existing geohydrologic data; baseline water quality assessment; well-bore flow logging and depth-dependent sampling; well-bore flow and transport modeling; surface geophysics surveys; installation and monitoring of multiple well sites; evaluation of nitrate loads and transformations in the unsaturated zone; estimates of septic tank discharge and nutrient flux; analysis of arsenic and fluoride contamination levels; basin recharge estimations; and comprehensive data documentation and technical reporting. These analytical outputs will provide the city with scientific information necessary to inform wastewater management decisions and groundwater protection strategies.

This agreement provides funding to the city of twentynine palms to implement a USGS study to support wastewater management and reclamation its project to as directed in the 2022 and 2023 consolidated appropriations acts or as identified in an approved technical correction if one has been approved for this project. This agreement provides full federal funding in the amount of $1,938,224. Refer to terms and conditions. Activities:the activities to be performed include the execution and implementation of a USGS hydrological and hadrochemical study project. Workplan activities consist of: review of existing geohydrologic data, establishing baseline water quality, well-bore flow logging and depth-dependent water-quality sampling, well-bore flor and transport model, surface geophysics, multiple-well monitoring site installation and data collection, nitrate lods and transformations in the unsaturated zone, estimates of septic tank discharge and nutrient flux, establishing arsenic and fluoride levels, estimates of basin recharge, data documentation, reports, and writing. Subrecipient:USGS is the subawardee and they will conduct the study for the city of twentynine palms.outcomes:the anticipated deliverables include data and reporting for each task of the work plan, tasks lusted below. Task 1 - review of existing geohydrologic data task 2 - baseline water quality task 3 - well-bore flow logging and depth-dependent water-quality sampling task 4 - well-bore flow and transport model task 5 - surface geophysics task 6 - multiple-well monitoring site installation and data collection task 7 - nitrate loads and transformations in the unsaturated zone task 8 - estimates of septic tank discharge and nutrient flux task 9 - arsenic and fluoride task 10 - estimates of basin recharge task 11 - data documentation, reports, and writing the expected outcomes include a report that will advance understanding of processes that determine water availability, by the comprehensive understanding of geological controls of water availability, and understanding human interactions with water availability. The intended beneficiaries include residents of twentynine palms and the greater community.