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San Diego Tap Water Quality Report
San Diego's water has 3 contaminants above EPA MCLGs. Consider using a certified water filter for additional protection.
People Served
6,291
Health-based violations since 2020
4
SAN DIEGO MUD 1. EPA SDWA violation data as of Q2 2026 (downloaded 2026-07-09).
Latest sample on file
Nov 2025 · SAN DIEGO MUD 1
Utilities publish newer results in their annual water quality report (Consumer Confidence Report).
Is San Diego Tap Water Safe to Drink?
We recommend using a certified water filter for additional protection, especially for vulnerable populations like children, pregnant women, and those with compromised immune systems. San Diego's water has 3 contaminants above EPA health-based guidelines (MCLGs).
SAN DIEGO MUD 1, San Diego's water system, serves 6,291 people. 1 other system is listed for San Diego. Each system's results are listed under its own name, never added to SAN DIEGO MUD 1's. Water quality testing is conducted regularly and reported to the EPA. The latest sample on file for SAN DIEGO MUD 1 is from Nov 2025.
In EPA's 2023–2026 UCMR 5 testing, SAN DIEGO MUD 1 measured lithium at up to 75.9 µg/L, which EPA counts as above its health reference level of 10 µg/L. That level is a screening value EPA uses to decide what to study further, not a legal limit, and this result does not change this page's water-quality summary.
Boil water advisories are issued by water systems and state agencies, and they change from day to day. Boil water advisories in Texas
San Diego Water Service Areas
What these numbers actually mean for San Diego, TX
We read San Diego, TX’s published record and send you a short report — which findings warrant a decision, which to ignore, and what to do about it. Including when the answer is nothing.
- 3 contaminants above EPA MCLGs, 7 contaminants with an EPA health goal detected in some samples (no level on file) and 4 health-based EPA violations that began after the latest compliance result on file
- 226 results on file
- 23 PFAS compounds on record
Buying a home here? Property Water Report — $49 Emailed within one business day.
Fluoride in San Diego's water
SAN DIEGO MUD 1
PWSID TX0660003
SAN DIEGO MUD 1 reported 1.09 mg/L, at or above the 0.7 mg/L U.S. Public Health Service recommendation and below the 1.5 mg/L WHO guideline value and NTP neurodevelopment review level.
CITY OF SAN DIEGO GLOSSBRENNER UNIT
PWSID TX0660017
No fluoride level in our data for CITY OF SAN DIEGO GLOSSBRENNER UNIT. Your utility's annual water quality report (CCR) lists it.
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Recommended Water Filters for San Diego
Based on San Diego's water quality data, these NSF-certified filters are recommended to remove contaminants above EPA MCLGs.
AquaTru
Classic
NSF Certified:
Flow Rate
0.04 gpm
Daily Production
600 gpd
Highlights:
- Best overall contaminant reduction score
- Most performance certifications
- Lifetime warranty
- NSF-42, NSF-53, NSF-58, NSF-401 certified
Removes 23 contaminants:
+18 more
Molybdenum, Barium, Chlorine, Arsenic, 83+ contaminants, Calcium, Chloride, Copper, Magnesium, Nitrate, Phosphorus, Sodium, Sulfate, Total Dissolved Solids, Zinc, Total THMs, Chloroform, Nitrate (as N)
AquaTru
Carafe
NSF Certified:
Flow Rate
0.3 gpm
Daily Production
4 gpd
Highlights:
- Verified PFAS reduction
- Glass collection vessel
- Plug-and-play installation
- NSF-53, NSF-42, NSF-58, NSF-401, NSF-372 certified
Removes 17 contaminants:
+12 more
Arsenic, 83+ contaminants, Copper, Total THMs, Chloroform, Chloride, Sulfate, Nitrate (as N), Molybdenum, Barium, Strontium, Uranium
Waterdrop
G3 P600
NSF Certified:
Flow Rate
600 gpm
Daily Production
600 gpd
Highlights:
- Space-saving design
- Good contaminant reduction
- NSF-58 certified
Removes 4 contaminants:
Waterdrop
A1
NSF Certified:
Flow Rate
0.042 gpm
Daily Production
130 gpd
Highlights:
- Built-in UV sterilization
- Easy maintenance with filter change reminders
- NSF-58 certified
- Hot and cold water dispensing
Removes 12 contaminants:
+7 more
Molybdenum, Sulfate, Strontium, Phosphorus, Chlorine, Barium, Nitrate
Verify Your Water Quality with Independent Testing
With 3 contaminants above EPA MCLGs, 7 contaminants with an EPA health goal detected in some samples (no level on file) and 4 health-based EPA violations that began after the latest compliance result on file, independent laboratory testing provides a second opinion and can track changes over time.
SimpleLab
Advanced Home Water Test
$269
Comprehensive water analysis testing over 200 contaminants including bacteria, heavy metals, and chemical compounds.
Tap Score
Advanced Microplastics Test
$829
Cutting-edge testing for microplastics particles in drinking water using advanced laboratory techniques.
Tap Score
Haloacetic Acids (HAA9) Test
$275
Tests for disinfection byproducts formed when chlorine reacts with organic matter in water treatment.
With 3 contaminants above health guidelines, you may want to explore water purification options. Learn how to make distilled water at home for applications like humidifiers, CPAP machines, and baby formula.
What San Diego's water readings can explain
Utility-reported data for San Diego includes sulfate — the readings behind these common tap water questions. We publish a city-level hardness figure for San Diego, resolved from its water systems where they report one and estimated from county sampling where they do not. Each page starts with the hot-tap and cold-tap check, then shows what your own water system reported.
On a private well near San Diego? Public-water results do not apply to private wells. See Duval County well water testing and USGS risk data — modeled arsenic, nitrate, and the tests to run.
Water softener cost and installation in San Diego
San Diego's tap water measures 3.3 grains per gallon (56.1 mg/L) — soft on the USGS scale, below the range where scale is usually worth treating.
Water softener cost for 3.3 gpg water in San Diego — equipment and local installation labour for your ZIP code, with the sizing arithmetic shown in full. For the national picture first, read what a water softener costs — equipment, installation labour and ten-year ownership, each separated out. For Texas as a whole, read water softener cost in Texas — priced against the plumber wage published for the state.
Frequently Asked Questions About San Diego Tap Water
San Diego's water has 3 contaminants above EPA MCLGs. We recommend using a certified water filter for additional protection, especially for vulnerable populations like children, pregnant women, and those with compromised immune systems. EPA records 4 health-based violations for SAN DIEGO MUD 1 that began after its latest compliance result on file (Jun 2022): Maximum Contaminant Level Violation, Average (Arsenic), 4 violations, the first beginning on October 1, 2023 and the latest on April 1, 2024. Every such result predates them; its later EPA UCMR 5 results (Nov 2025) screen for unregulated contaminants and cannot show the water met this standard, so this page does not call the water safe.
Spotted something off on this page?
Residents keep our data honest.
This form corrects our data; it does not reach SAN DIEGO MUD 1. For a problem with your water now (discolored water, no water, low pressure, a leak), contact SAN DIEGO MUD 1 directly.
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