Advisory committee reviews rural water-quality report, recommends board review after note on chlorides

A Sustainable Management Criteria Technical Advisory Committee meeting included a presentation of a rural water‑quality report showing recurring high levels of nitrate, chloride, total dissolved solids and detections of 1,2,3‑TCP near Greenfield City and elsewhere in the Salinas Valley.

The report showed what the presenter called "a hotter spot around the city of Greenfield" in maps compiled from multiple databases and an updated map using data since 2013. The presenter said nitrate concentrations appeared higher in more recent samples and offered a possible explanation: "the nitrate is gonna be coming from from fertilizers almost entirely," and there can be a decades‑long lag between fertilizer application and deeper aquifer detections.

Why it matters: committee members flagged public‑health and supply implications. The report identified 1,2,3‑TCP — a breakdown product of an older fumigant — as a concern because the state set a maximum contaminant level (MCL) for it in 2017 that is near analytical detection limits. The presenter said about the 123‑TCP results: "in the last couple of years, they've sampled about 200 wells in the area. These dots on the map are, the 30 or so wells where it was…