Serving roughly 86,458 people in San Diego County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
🏠Local Expertise
Results for OLIVENHAIN MWD
1 water provider directly on file, serving roughly 86,458 people in San Diego County, California.
Quick answer: OLIVENHAIN MWD has no violations on file. One reading is worth knowing about: Bromodichloromethane was measured at 18.3UG/L, among the highest of the 414 providers on file in this area. It's the most notable figure in this system's record among its 414 local peers.
Lead Summary
Lithium
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromoform
Bromodichloromethane
Dibromochloromethane
Dichloroaceticacid
Trichloroaceticacid
Dibromoaceticacid
Copper, Free
Langelier Index (Source Temp.)
Magnesium
Potassium
Silica
Sodium
Calcium
Alkalinity, Bicarbonate
Hardness, Total (ASCACO3)
Carbon, Total
TDS
Chloride
Sulfate
Fluoride
Gross Alpha Particle Activity
pH
Boron, Total
Vanadium, Total
Chromium, Hex
Perchlorate
Nickel
Chromium
Barium
Arsenic
Chlorate
Selenium
Conductivity (at 25°C)
Utility OLIVENHAIN MWDPopulation served 86,458Owner Local government
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)
12/31/2025
Copper, Free
Detected: 100 UG/L (ppb)
7/23/2025
Vanadium, Total
Detected: 2.8 UG/L (ppb)
4/23/2025
Chromium, Hex
Detected: 0.03 UG/L (ppb)
4/23/2025
Nickel
Detected: 2.5 UG/L (ppb)
4/23/2025
Chromium
Detected: 2.5 UG/L (ppb)
4/23/2025
Occurs in two forms — trivalent (an essential nutrient in trace amounts) and hexavalent (linked to increased cancer risk).
Barium
Detected: 88 UG/L (ppb)
4/23/2025
Arsenic
Detected: 2 UG/L (ppb)
4/23/2025
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Selenium
Detected: 2 UG/L (ppb)
4/23/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 20.5 UG/L (ppb)
7/2/2025
TTHM
Detected: 55.53 UG/L (ppb)
7/2/2025
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.
Chloroform
Detected: 18.48 UG/L (ppb)
7/2/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 3.72 UG/L (ppb)
7/2/2025
Bromodichloromethane
Detected: 18.3 UG/L (ppb)
7/2/2025
Dibromochloromethane
Detected: 15.03 UG/L (ppb)
7/2/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Chloride
Detected: 96 MG/L (ppm)
4/23/2025
Sulfate
Detected: 140 MG/L (ppm)
4/23/2025
Fluoride
Detected: 0.77 MG/L (ppm)
10/7/2025
Often added deliberately for dental health; can also occur naturally.
Boron, Total
Detected: 130 UG/L (ppb)
4/23/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 19 MG/L (ppm)
4/23/2025
Potassium
Detected: 4.1 MG/L (ppm)
4/23/2025
Sodium
Detected: 79 MG/L (ppm)
4/23/2025
Calcium
Detected: 50 MG/L (ppm)
4/23/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 200 MG/L (ppm)
4/23/2025
Gross Alpha Particle Activity
Detected: 5.67 PCI/L
4/23/2025
pH
Detected: 8.2 PH
4/23/2025
A measure of how acidic or basic the water is (7 is neutral). Affects taste and plumbing, not a direct health measure.
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 36.3 µg/L (ppb)
12/2/2024
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: 100 MG/L (ppm)
4/23/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 11.5 UG/L (ppb)
7/2/2025
Trichloroaceticacid
Detected: 5 UG/L (ppb)
7/2/2025
Dibromoaceticacid
Detected: 4 UG/L (ppb)
7/2/2025
Langelier Index (Source Temp.)
Detected: 0.45 LANG
4/23/2025
Silica
Detected: 7.4 MG/L (ppm)
4/23/2025
Carbon, Total
Detected: 2.6 MG/L (ppm)
10/7/2025
TDS
Detected: 470 MG/L (ppm)
4/23/2025
Perchlorate
Detected: 0.99 UG/L (ppb)
5/15/2025
Can occur naturally or from industrial/military sources; may interfere with thyroid function at elevated levels.
Chlorate
Detected: 140 UG/L (ppb)
4/23/2025
Conductivity (at 25°C)
Detected: 800 UMHO/CM
4/23/2025
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.