Santa Rosa to partner on feasibility study for groundwater recharge using Martha Way test well after GSA $5.3M award

Santa Rosa staff said the Santa Rosa Plain Groundwater Sustainability Agency (GSA) has been awarded $5.3 million to implement projects and studies in the Groundwater Sustainability Plan, including a feasibility study of aquifer storage and recovery that could use the city’s Martha Way test well.

Director Burke and deputy staff described the two-phase feasibility study: first rehabilitate the Martha Way monitoring/test well (cleaning and scrubbing the wellbore); second, conduct a short-duration injection test in which potable water from the city’s distribution system would be introduced, followed by pumping and continuous geophysical monitoring. Staff said the exercise is intended as a technical feasibility study — a short pilot lasting about a week — and is not a permanent conversion of the test well into a production well.

Deputy Director Peter Martin said the injected water for the test would be purchased from Sonoma Water and that the test would likely use a small tap (two-inch) from a nearby six- or eight-inch distribution main to introduce a few hundred gallons per minute for a short period. He said the pilot would include data loggers and possibly a colocated pump to assess aquifer response, possible recharge capacity and the behavior of surrounding monitoring wells.

Staff emphasized permitting and coordination requirements: the feasibility study is contingent on a permit from the San Francisco Bay Regional Water Quality Control Board (RWQCB) and the GSA obtaining a right-of-way license from the city to access the well site. Staff also said the Martha Way site has physical constraints — a small property footprint and hydrologic connections to existing production wells (Farmers Lane wells) — so the city is not planning to convert the test well into a production source at this time.

Board members asked whether water used for testing would be potable and whether the scheme could become a long-term supply. Staff confirmed the test would use potable water from the city distribution system and characterized the work as a feasibility pilot to inform potential future projects; it is not an immediate production project. Staff said the GSA must obtain the necessary permits and that the study would be designed to conclude within the available grant timeline.

Staff said the city has worked on related groundwater pilot efforts with regional partners previously and that the Martha Way test could provide valuable local information if the pilot proceeds. The board did not take formal action at the meeting; staff said they will return with updates as the study progresses and permits are obtained.