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Water Quality Lookup / California / Orange County / SANTA MARGARITA WATER DISTRICT-ID9
EPA SDWIS ยท Orange County, California

SANTA MARGARITA WATER DISTRICT-ID9 Water Quality Report

Serving roughly 39,684 people in Orange County, California.

Data current as of July 2026
๐Ÿ”Straight from EPA
๐ŸงชReal Lab Results
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Results for SANTA MARGARITA WATER DISTRICT-ID9

1 water provider directly on file, serving roughly 39,684 people in Orange County, California.

Quick answer: SANTA MARGARITA WATER DISTRICT-ID9 has no violations on file. One reading is worth knowing about: Lithium was measured at 47ยตg/L, among the highest of the 167 providers on file in this area. It's the most notable figure in this system's record among its 167 local peers.
Utility SANTA MARGARITA WATER DISTRICT-ID9 Population served 39,684 Owner Local government
No violations on file
Also serves SAN JUAN CAPISTRANO

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 ยตg/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: See the table below for how whole-house carbon, under-sink reverse osmosis, and under-sink carbon systems compare against what's actually on file here. These are general system types, not a specific product recommendation.
Contaminant Whole-House Carbon Under-Sink RO Under-Sink Carbon
Total Trihalomethanes (TTHM)YesYesYes
Haloacetic Acids (HAA5)YesYesYes
ChloroformYesYesYes
Chlorine / TasteYesYesYes
Sediment / TurbidityYesYesYes
TrichloroethyleneYesYesYes
TetrachloroethyleneYesYesYes
cis-1,2-DichloroethyleneYesYesYes
1,1-DichloroethyleneYesYesYes
BromoformYesYesYes
BromodichloromethaneYesYesYes
DibromochloromethaneYesYesYes
1,1,2-TrichloroethaneYesYesYes
Vinyl ChlorideYesYesYes
Carbon TetrachlorideYesYesYes
BenzeneYesYesYes
TolueneYesYesYes
XyleneYesYesYes
Totalhaloaceticacids (HAA5)YesYesYes
LeadPartialYesPartial
ArsenicPartialYesPartial
Chromium-6 (Hexavalent)PartialYesPartial
CopperPartialYesPartial
Combined UraniumPartialYesPartial
PFOAPartialYes*Partial
PFOSPartialYes*Partial
NitratePartialYesPartial
Combined RadiumPartialYesPartial
LithiumPartialYes*Partial
Alkalinity, TotalPartialYesPartial
TDSPartialYesPartial
DichloroaceticacidPartialYesPartial
TrichloroaceticacidPartialYesPartial
DibromoaceticacidPartialYesPartial
Coliform Bacteria (indicator)NoYesNo
MagnesiumNoPartialNo
SodiumNoPartialNo
CalciumNoPartialNo
Alkalinity, BicarbonateNoNoNo
Hardness, Total (ASCACO3)NoNoNo

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What is TTHM? Understanding EPA Violation Status Is Chromium-6 Dangerous? Whole-House vs. Under-Sink Filtration Lead and Copper in Drinking Water What is PFAS? Arsenic and Uranium Explained Nitrate and Fluoride Explained Water Hardness, pH, and Turbidity What is Coliform Bacteria?