SAN JUAN CAPISTRANO is served by 1 water provider on file with the EPA.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
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Results for SAN JUAN CAPISTRANO, CA
1 water provider on file serving this city.
Quick answer: SAN JUAN CAPISTRANO's water has no violations on file and no single reading stands out against its peers (1 other providers in this area). It serves roughly 39,684 people, and the full breakdown below reflects everything EPA and California have on record for it.
Lead Summary
Lithium
Magnesium
Sodium
Calcium
Alkalinity, Total
Alkalinity, Bicarbonate
Hardness, Total (ASCACO3)
TDS
TTHM
Totalhaloaceticacids (HAA5)
Chloroform
Bromoform
Bromodichloromethane
Dibromochloromethane
Dichloroaceticacid
Trichloroaceticacid
Dibromoaceticacid
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2024
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
TTHM
Detected: 37 UG/L (ppb)
8/5/2025
A group of disinfection byproducts formed when chlorine reacts with organic matter. Long-term exposure above the legal limit has been linked to increased cancer risk in some studies.
Totalhaloaceticacids (HAA5)
Detected: 5.3 UG/L (ppb)
8/5/2025
Chloroform
Detected: 9.6 UG/L (ppb)
8/5/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 3.1 UG/L (ppb)
8/5/2025
Bromodichloromethane
Detected: 11 UG/L (ppb)
8/5/2025
Dibromochloromethane
Detected: 13 UG/L (ppb)
8/5/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 24 MG/L (ppm)
5/6/2025
Sodium
Detected: 93 MG/L (ppm)
5/6/2025
Calcium
Detected: 65 MG/L (ppm)
5/6/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 260 MG/L (ppm)
5/6/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 47 µg/L (ppb)
3/3/2025
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 110 MG/L (ppm)
5/6/2025
Other
Additional substances tested that don't fit neatly into the categories above
Alkalinity, Total
Detected: 110 MG/L (ppm)
5/6/2025
TDS
Detected: 600 MG/L (ppm)
5/6/2025
Dichloroaceticacid
Detected: 3 UG/L (ppb)
8/5/2025
Trichloroaceticacid
Detected: 1.1 UG/L (ppb)
8/5/2025
Dibromoaceticacid
Detected: 1.1 UG/L (ppb)
8/5/2025
Filtration considerations: General system types, not a specific product recommendation.