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Tap water and drinking water quality in San Diego, CA
WATER QUALITY REPORT

San Diego, CA tap water: what’s in it in 2026

Reviewed by Joe Letorney, 30-year water treatment expert · Former WQA Certified Water Treatment Specialist (CWS), Level VI

San Diego imports Colorado River and Northern California water — expensive, hard, and treated with chloramine across most of the county. PFAS appears in regional UCMR5 datasets.

Naval and defense industry history contributes to PFAS awareness in coastal ZIP codes. Civilian suburbs share regional sources.

Desalination supplements the blend in dry years — TDS and taste change seasonally. Re-check your report after major drought allocations shift.

See best water filters for lead removal and what filters remove PFAS.

Check water hardness in San Diego

Imported water vulnerabilityChromium-6Hard waterPFAS
78/ 88
WATERCHECKUP SAFETY SCORE
Grade: B+
Fair

WaterCheckup Safety Score — an independent index from EPA public data and our formula. Not your utility’s official water quality rating, an EPA compliance grade, or a test of water at your tap. How we score →

Same score for your ZIP — look up your ZIP for the full contaminant report
GENERALLY OK
Based on water safety score
WHAT YOU SHOULD KNOW ABOUT SAN DIEGO WATER

San Diego water currently shows no major violations in EPA monitoring data. That said, your home's internal plumbing can add lead or other contaminants after water leaves the treatment plant — especially in homes built before 1986.

Imported water vulnerability
Chromium-6
Hard water
PFAS
Public water systems in California
18,760
EPA PWSID (this report)
CA3710020
TTHMs (utility avg.)
28.1 ppb
HAA5 (utility avg.)
36.2 ppb
LEGAL DOES NOT ALWAYS MEAN SAFE

San Diegowater may meet federal EPA limits while still showing contaminants above independent health guidelines (EWG, state advisories). EPA MCLs are often set on treatment feasibility — not a "zero risk" threshold. Compare levels below to health guidelines and state/U.S. utility averages, then see which filter technologies address your profile.

CONTAMINANTS IN SAN DIEGO WATER

EPA UCMR5 PFAS plus utility/EWG averages from our contaminant bundle. Run a ZIP report for live SDWIS samples at your address.

Haloacetic Acids (HAA5)
36.2 ppb (EPA limit 60 ppb)603.3× health guidelineModerate
This utility
36.2
U.S. avg
21.6
State avg
35.0

EWG health guideline: 0.06 ppb (HAA5)

EWG Tap Water Atlas utility average (2021–2023) · U.S. utility avg (EWG Atlas sample): 21.57 ppb · CA utility avg: 35.03 ppb

Removes with: RO · Carbon

Chlorite
286.5 ppbLower concern
This utility
287
U.S. avg
286
State avg
291

Can cause anemia and nervous system effects in infants and young children at high levels.

Removes with: RO · Carbon

Chlorate
152.2 ppbLower concern
This utility
152
U.S. avg
161
State avg
121

Can impair thyroid function — most concerning during pregnancy and childhood.

Removes with: RO · Carbon

Barium
45.1 ppbLower concern
This utility
45.1
U.S. avg
43.5
State avg
50.8

EWG health guideline: 700 ppb

EWG Tap Water Atlas utility average (2021–2023) · U.S. utility avg (EWG Atlas sample): 43.45 ppb · CA utility avg: 50.81 ppb

Removes with: RO · Carbon · Ion exchange

Bromide
42.3 ppbLower concern
This utility
42.3
U.S. avg
75.6
State avg
117

EWG Tap Water Atlas utility average (2021–2023) · U.S. utility avg (EWG Atlas sample): 75.61 ppb · CA utility avg: 116.66 ppb

Removes with: RO · Carbon

Lithium
34.1 ppbLower concern
This utility
34.1
U.S. avg
23.4
State avg
16.0

EWG Tap Water Atlas utility average (2021–2023) · U.S. utility avg (EWG Atlas sample): 23.44 ppb · CA utility avg: 16.03 ppb

Removes with: RO · Carbon

Total Trihalomethanes (TTHMs)
28.1 ppb (EPA limit 80 ppb)187.3× health guidelineLower concern
This utility
28.1
U.S. avg
31.0
State avg
26.5

EWG health guideline: 0.15 ppb

EWG Tap Water Atlas utility average (2021–2023) · U.S. utility avg (EWG Atlas sample): 30.97 ppb · CA utility avg: 26.50 ppb

Removes with: RO · Carbon

Haloacetic Acids (HAA9)
18.1 ppbLower concern
This utility
18.1
U.S. avg
23.6
State avg
15.6

EWG Tap Water Atlas utility average (2021–2023) · U.S. utility avg (EWG Atlas sample): 23.64 ppb · CA utility avg: 15.58 ppb

Removes with: RO · Carbon

Dibromochloromethane
9.99 ppb99.9× health guidelineLower concern
This utility
9.99
U.S. avg
4.14
State avg
5.73

EWG health guideline: 0.1 ppb

THM component linked to cancer and harm to fetal development.

Removes with: RO · Carbon

Bromodichloromethane
7.58 ppb126.3× health guidelineLower concern
This utility
7.58
U.S. avg
6.47
State avg
5.67

EWG health guideline: 0.06 ppb

THM component linked to cancer and reproductive harm with long-term exposure.

Removes with: RO · Carbon

Chloroform
5.37 ppbLower concern
This utility
5.37
U.S. avg
17.8
State avg
12.2

EWG Tap Water Atlas utility average (2021–2023) · U.S. utility avg (EWG Atlas sample): 17.82 ppb · CA utility avg: 12.20 ppb

Removes with: RO · Carbon

Bromoform
5.18 ppbLower concern
This utility
5.18
U.S. avg
2.14
State avg
3.00

THM component with cancer risk at elevated long-term exposure.

Removes with: RO · Carbon

Molybdenum
3.6 ppbLower concern
This utility
3.60
U.S. avg
2.35
State avg
3.41

EWG Tap Water Atlas utility average (2021–2023) · U.S. utility avg (EWG Atlas sample): 2.35 ppb · CA utility avg: 3.41 ppb

Removes with: RO · Carbon

Dichloroacetic Acid
3.19 ppb15.9× health guidelineLower concern
This utility
3.19
U.S. avg
8.88
State avg
5.30

EWG health guideline: 0.2 ppb

Disinfection byproduct linked to bladder cancer and possible reproductive effects.

Removes with: RO · Carbon

Dibromoacetic Acid
2.73 ppb45.5× health guidelineLower concern
This utility
2.73
U.S. avg
1.53
State avg
1.70

EWG health guideline: 0.06 ppb

EWG Tap Water Atlas utility average (2021–2023) · U.S. utility avg (EWG Atlas sample): 1.53 ppb · CA utility avg: 1.70 ppb

Removes with: RO · Carbon

Uranium
2.07 pCi/L (EPA limit 20 pCi/L)Lower concern
This utility
2.07
U.S. avg
2.14
State avg
3.19

Radioactive — long-term exposure increases kidney toxicity and cancer risk.

Removes with: RO · Ion exchange

Bromate
1.38 ppb (EPA limit 10 ppb)Lower concern
This utility
1.38
U.S. avg
1.64
State avg
2.20

Probable human carcinogen. Kidney toxicity at high exposure.

Removes with: RO · Carbon

Trichloroacetic Acid
0.92 ppb2.3× health guidelineLower concern
This utility
0.92
U.S. avg
7.02
State avg
4.45

EWG health guideline: 0.4 ppb

Disinfection byproduct linked to bladder cancer and developmental effects at high exposure.

Removes with: RO · Carbon

U.S. and state averages from EWG Tap Water Atlas utilities in our database. For your exact tap, use a ZIP report — home plumbing can differ from utility averages.

1

San Diego imports over 85% of its water from Northern California and the Colorado River.

2

Chromium-6 has been detected in San Diego water above California's strict health goals.

3

San Diego water is very hard -- scale buildup and taste complaints are common.

4

PFAS has been found in some San Diego County water systems, particularly near military bases.

PFAS TESTING DATA — EPA UCMR5
Testing period 2023–2025 · Last updated Q1 2026
NO PFAS DETECTED
All 29 PFAS compounds tested below detection limits
Water Hardness (from UCMR5): 65 mg/L as CaCO₃ — Relatively soft

Source: EPA UCMR5 national monitoring dataset · Testing period 2023–2025 · MCL = Maximum Contaminant Level (legally enforceable limit) · Health limit = EPA health advisory threshold

🔔 Get alerts if San Diego's water data changes:
WHICH FILTER TECHNOLOGY WORKS FOR SAN DIEGO?

Reference matrix — not specific brands. NSF-certified carbon blocks, reverse osmosis (NSF 58), and ion-exchange softeners address different contaminants. Product picks below match this profile.

Contaminant
Carbon
RO
Ion exch.
Haloacetic Acids (HAA5)
Total Trihalomethanes (TTHMs)
Dibromochloromethane
Bromodichloromethane
Dichloroacetic Acid
Dibromoacetic Acid
Trichloroacetic Acid
TEST YOUR TAP OR FILTER NOW?

San Diegoutility data is a strong baseline — but lead often comes from your home's pipes, and PFAS can vary by neighborhood. Choose certified lab testing for certainty, or skip straight to NSF-certified filters matched to this profile.

STEP 1 · VERIFY AT YOUR FAUCET
Test before you buy a $300+ filter

SimpleLab Tap Score mail-in panels test PFAS, lead, nitrates, bacteria, and 100+ contaminants at your kitchen tap. Results in about a week — then pick filtration with real numbers, not guesses.

Tap Score City Test — from $89 →

Accredited labs · Best if you have old plumbing, pregnancy, or want proof before installing RO

STEP 2 · FIX IT NOW
Ready to filter based on this report?

Get NSF 58 / NSF 53 picks matched to San Diego's PFAS, lead, and disinfection byproduct profile — reviewed by a 30-year water treatment expert.

Take the 3-question filter quiz →

Best when contaminants are already flagged above and you want the right RO or pitcher today

Clean water splash — certified water filter recommendations
WHAT TO DO ABOUT IT

Based on San Diego's water profile above, here's the exact system we recommend — and why it's right for this water supply specifically.

Clean water splash — certified water filter recommendations

Certified Filter Recommendations

Matched to what's actually in your water

TOP PICKS FOR SAN DIEGO
Contaminants detected in local water
#1
Aquasana SmartFlow RO
MOST CERTIFIED
Aquasana  ·  ~$449
WQA Gold Seal + NSF 42/53/58/401. Most certifications of any under-sink RO. Removes 90+ contaminants.
WHY THIS FOR SAN DIEGO · Chosen for San Diego because PFAS contamination is detected in this system's UCMR5 data — reverse osmosis is the most effective residential technology, removing 99%+ of PFAS compounds.
#2
AquaTru Under-Sink RO
EASIEST FILTER CHANGE
AquaTru  ·  ~$375
NSF 42/53/58 certified. Quick-change filters, no tools. Compact tankless design, 4-stage filtration.
Not sure which filter is right for you? Take the 3-question quiz →
WATER SYSTEM -- EPA SDWIS
System Name
San Diego Public Public water systems
EPA PWSID
CA3710020
Population Served
1.4M
State
CA

COMMON QUESTIONS

Is San Diego tap water safe to drink in 2026?

San Diego water meets EPA legal standards, but meeting legal standards is not the same as being free of health concerns. EPA limits are set based on treatment feasibility, not always on what independent scientists consider safe. San Diego has imported water vulnerability which is a significant concern — certified filtration is strongly recommended.

Does San Diego water have PFAS?

EPA UCMR5 monitoring data for San Diego (water system CA3710001) is shown above. PFAS — sometimes called "forever chemicals" — are synthetic compounds that don't break down in the body. Only reverse osmosis systems or NSF 58-certified carbon block filters reliably remove PFAS from tap water. Standard pitcher filters do not remove PFAS.

Does San Diego water have lead?

Lead in tap water almost always comes from the pipes inside your home or building, not the treatment plant. Homes built before 1986 in San Diego are most at risk because they may have lead solder, brass fittings, or lead service lines. The EPA has no safe level for lead in children. An NSF/ANSI 53-certified filter or reverse osmosis system removes lead at the tap.

What water filter is best for San Diego?

For San Diego's water profile — imported water vulnerability, chromium-6 — a reverse osmosis system addresses the widest range of contaminants. Under-sink RO (Waterdrop G3P600, Aquasana SmartFlow) is the gold standard for homeowners. Renters can use a countertop RO like the Waterdrop K19-S Countertop RO — zero installation required. Clearly Filtered pitchers are the best non-RO option for PFAS and lead.

How do I get my San Diego water tested?

For the most accurate results for your specific tap, use a certified mail-in lab test rather than relying on city-wide data. SimpleLab Tap Score tests for 100+ contaminants including PFAS, lead, arsenic, and nitrates. Results come with a detailed health assessment and filter recommendations. City-wide EPA data like what you see above is a strong baseline, but your home's plumbing can add contaminants after the water leaves the treatment plant.

LEAD SERVICE LINE RISK
Does your street have lead pipes?

As of October 2024, all US public water systems must publish a public inventory of their lead service lines — the pipes connecting the water main to your home. Even if your public water system water tests clean at the treatment plant, lead can leach from these pipes into your tap. Homes built before 1986 are most at risk.

EPA Official Service Line Inventory →
Federal LCRR inventory data for San Diego Public Public water systems · PWSID CA3710001
💡 Homes built before 1986 may have lead solder or service lines. A filter certified NSF/ANSI 53 removes lead at the tap regardless of pipe material.
STAY INFORMED
Get San Diego water alerts

We'll notify you when new PFAS data, EPA violations, or contamination alerts drop for San Diego. One email, no spam, unsubscribe any time.

Check your specific address

City-wide data is just the start. Enter your ZIP to see your exact water system's EPA report, PFAS levels, and violation history — then get the right filter for your home.

Fix My Water — Free →

RELATED GUIDES

PFAS
Is PFAS in My Tap Water?
Lead
Best Filters for Lead Removal
Filters
What Filter Removes PFAS?
EPA
What Does an EPA Violation Mean?
Filters
Reverse Osmosis: Pros & Cons
Health
Tap Water Safety During Pregnancy
RANKINGS
Worst Water Systems in the US

COMPARE WATER QUALITY IN OTHER CITIES

Los Angeles, CA
High concern · Chromium-6 (hexavalent chromium)
San Jose, CA
High concern · Chromium-6
Long Beach, CA
High concern · Chromium-6
Bakersfield, CA
High concern · 1,2,3-TCP pesticide
Anaheim, CA
High concern · Nitrates from agriculture
Riverside, CA
High concern · Nitrates from citrus agriculture
Stockton, CA
High concern · Arsenic
Chula Vista, CA
High concern · Chromium-6
Fremont, CA
High concern · PFAS from industrial sites
Modesto, CA
High concern · 1,2,3-TCP
Glendale, CA
High concern · Chromium-6
Sacramento, CA
High concern · PFAS 41 ppt — 3 MCL violations
Browse all 50 states — all free →

Water public water system operators: Publish your official CCR on WaterCheckup free →

Reviewed by Joe Letorney, 30-year water treatment expert · Former WQA Certified Water Treatment Specialist (CWS), Level VI