San Diego, California
| Contaminant | Detected | EPA limit | EWG guideline | Status |
|---|---|---|---|---|
| Total Trihalomethanes (TTHMs) | 45.6 ppb | 80 ppb | 0.8 ppb | 57× EWG |
| Haloacetic Acids (HAA5) | 28.9 ppb | 60 ppb | 0.1 ppb | 289× EWG |
| Chromium-6 (Hexavalent Chromium) | 0.35 ppb | — | 0.02 ppb | 18× EWG |
| Chloramine | 2.9 mg/L | 4 mg/L | — | — |
| Total Dissolved Solids (TDS) | 560 mg/L | — | — | — |
| Lead | 1.5 ppb | 15 ppb | 0.5 ppb | 3× EWG |
Context
San Diego imports 85-90% of its water from distant sources, making it one of the most import-dependent cities in the US. Water travels hundreds of miles and picks up minerals along the way, contributing to high TDS levels.
Chromium-6 is detected at 17.5x the EWG health guideline with no federal limit in place — a common concern across Southern California.
The Pure Water San Diego program is bringing advanced-treated recycled water online, which will diversify the supply and potentially improve quality by reducing dependence on imported Colorado River water.
Common questions
Is San Diego tap water safe to drink?
San Diego water meets EPA standards but has elevated disinfection byproducts, chromium-6 (17.5x EWG guideline), and high total dissolved solids (560 mg/L) from its imported water sources. A reverse osmosis filter dramatically improves taste and removes the key contaminants of concern.
Why does San Diego water taste bad?
San Diego's high TDS level (560 mg/L) from imported Colorado River water gives it a mineral-heavy taste that many residents find unpleasant. Chloramine disinfection adds to the taste issue. An RO system is the most effective solution — it reduces TDS by 90-95%, producing noticeably cleaner-tasting water.
San Diego's water quality reflects its heavy dependence on imported water — high TDS, elevated chromium-6, and significant disinfection byproduct levels. An RO system is particularly effective for San Diego because it addresses the high TDS (improves taste dramatically), removes chromium-6, and handles DBPs and lead.
approximately 85-90% imported water from the Colorado River and Northern California State Water Project, with a growing local supply from the Pure Water San Diego recycled water program
This data reflects system-wide testing. Your home's plumbing may add or reduce contaminants.
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