Serving roughly 277,740 people in Los Angeles County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
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Results for GSWC - SOUTHWEST
1 water provider directly on file, serving roughly 277,740 people in Los Angeles County, California.
Quick answer: GSWC - SOUTHWEST has no violations on file and no single reading stands out against its peers (601 other providers in this area). It serves roughly 277,740 people, and the full breakdown below reflects everything EPA and California have on record for it.
Lead Summary
Lithium
Iron
Manganese
Bromide
Fluoride
Nitrate
Combined Uranium
Gross Alpha Particle Activity
Turbidity
Utility GSWC - SOUTHWESTPopulation served 277,740Owner Private
No violations on file
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2022
Iron
Detected: 520 UG/L (ppb)
9/15/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Manganese
Detected: 25 UG/L (ppb)
10/6/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Combined Uranium
Detected: 1.4 PCI/L
2/3/2025
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Fluoride
Detected: 0.41 MG/L (ppm)
7/9/2025
Often added deliberately for dental health; can also occur naturally.
Nitrate
Detected: 0.27 MG/L (ppm)
3/17/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Gross Alpha Particle Activity
Detected: 2.63 PCI/L
3/17/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 44.6 µg/L (ppb)
3/10/2025
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
VOCs (Volatile Organic Compounds)
Industrial solvents and fuel-related chemicals that evaporate easily
Bromide
Detected: 0.81 MG/L (ppm)
1/6/2025
Other
Additional substances tested that don't fit neatly into the categories above
Turbidity
Detected: 0.2 NTU
10/27/2025
A measure of water cloudiness from suspended particles.
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.