Local water quality
Water quality in San Marcos, California
2 public water systems · EPA data
The bottom line
EPA records for the water serving San Marcos, California show Lead, Nitrate, Fluoride. A filter independently certified to reduce those exact contaminants is the most direct fix.
What's in San Marcos's water
Contaminants EPA has recorded across San Marcos's water systems, and how many certified filters remove each.
Water systems serving San Marcos
Open a system for its full report — measured levels vs. federal limits, PFAS, and the certified filters that remove each contaminant.
Filter your San Marcos water
Match a certified filter to what's actually in your water — a filter certified for lead may do nothing for PFAS or fluoride.