June 14, 2026
San Carlos, 09 Water Quality Report 2026
Unlock the full breakdown — detected levels vs. legal limits, plus what removes each one.
Full contaminant breakdown
EPA Six-Year Review compliance monitoring, 2012–2019 — the most recent national compliance dataset EPA has published. See the sections above for more recent violation and PFAS records.
| Contaminant | Avg. detected | Highest sample | Federal limit | Avg. vs. limit |
|---|---|---|---|---|
| ArsenicEPA health goal: zero | 8.35 ppb | 31.6 ppb | 10 ppb | 83% |
| Gross alpha radioactivityEPA health goal: zero | 3.29 pCi/L | 3.8 pCi/L | 15 pCi/L | 22% |
| UraniumEPA health goal: zero | 4.93 ppb | 5.66 ppb | 30 ppb | 16% |
| Nitrate | 1380 ppb | 2940 ppb | 10000 ppb | 14% |
| Fluoride | 414 ppb | 500 ppb | 4000 ppb | 10% |
| Nitrite | 100 ppb | 100 ppb | 1000 ppb | 10% |
| Total trihalomethanes (TTHMs) | 5.8 ppb | 5.8 ppb | 80 ppb | 7% |
| Barium | 70.1 ppb | 90 ppb | 2000 ppb | 4% |
| Selenium | 2 ppb | 2 ppb | 50 ppb | 4% |
Also tested, no detections: 1,1,1-Trichloroethane, 1,1,2-Trichloroethane, 1,1-Dichloroethylene, 1,2,4-Trichlorobenzene, 1,2-Dichloroethane, 1,2-Dichloropropane, 2,4,5-TP (Silvex), 2,4-D, Alachlor, Antimony, Asbestos, Atrazine, Benzene, Benzo(a)pyrene, Beryllium, Cadmium, Carbofuran, Carbon tetrachloride, Chlordane, Chlorobenzene, Chromium (total), Cyanide, DBCP, DEHA (adipate), DEHP (phthalate), Dalapon, Dichloromethane, Dinoseb, Dioxin (2,3,7,8-TCDD), Diquat, Endothall, Endrin, Ethylbenzene, Ethylene dibromide (EDB), Glyphosate, Haloacetic acids (HAA5), Heptachlor, Heptachlor epoxide, Hexachlorobenzene, Hexachlorocyclopentadiene, Lindane, Mercury (inorganic), Methoxychlor, Oxamyl, PCBs, Pentachlorophenol, Picloram, Radium (combined), Simazine, Styrene, Tetrachloroethylene (PCE), Thallium, Toluene, Toxaphene, Trichloroethylene (TCE), Vinyl chloride, Xylenes (total), cis-1,2-Dichloroethylene, o-Dichlorobenzene, p-Dichlorobenzene, trans-1,2-Dichloroethylene.
Reverse osmosis (drinking water)
The treatment category most often matched to dissolved contaminants like lead, arsenic, nitrate, fluoride, and radiological contaminants detected in this system.
Shop reverse osmosis →Whole-house carbon filtration
The treatment category most often matched to disinfection byproducts (TTHMs, haloacetic acids), chlorine taste and odor, and organic compounds detected in this system.
Shop whole-house systems →Source: U.S. EPA Six-Year Review 4 compliance monitoring data (2012–2019), the most recent nationwide compliance dataset EPA has released, reported at the water-system level. A detection is not a violation. “Avg. vs. limit” compares the average of laboratory detections to the federal MCL or action level; individual faucets can differ — household plumbing affects lead and copper, and a state-certified laboratory test of your own tap is the only way to confirm levels in your home. Treatment categories are general matches, not a certification claim for a specific product and contaminant.
Water Utility: Scua Upper Seven Mile
Population Served: 8,478 residents
Data Sources: EPA SDWIS + EPA UCMR5
Report Year: 2026
San Carlos, 09 drinking water is supplied by Scua Upper Seven Mile. All US public water systems must test drinking water and report results to the EPA under the Safe Drinking Water Act. This report summarizes health-based violations and PFAS detections recorded in federal databases to help you make informed decisions about home water filtration.
EPA Health-Based Violation History
The following contaminants exceeded EPA maximum contaminant levels (MCLs) at this utility since 2010:
| Contaminant | Violation Years | Filter Solution |
|---|---|---|
| Arsenic | 2013-2016 | Under Sink Filters |
| Coliform (Tcr) | 2012-2016 | Whole House Filters |
| Groundwater Rule | 2023-2025 | Water Filters |
| Revised Total Coliform Rule | 2017-2025 | Whole House Filters |
Source: EPA Safe Drinking Water Information System (SDWIS), updated quarterly. Health-based violations only.
PFAS "Forever Chemical" Detections
PFAS compounds were detected in this water system during EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR5) testing program (2023-2025). EPA has set maximum contaminant levels of 4 parts per trillion (ppt) for PFOA and PFOS individually.
| PFAS Compound | Level Detected | Solution |
|---|---|---|
| PFBS | 0.0479 ug/L | PFAS Filters |
Source: EPA UCMR5 occurrence data. Levels in micrograms per liter (ug/L = parts per billion). 1 ug/L = 1,000 ppt.
Should You Filter Your San Carlos Water?
Even utilities with no EPA violations may have contaminants present below legal limits but above health guidelines. The EPA sets maximum contaminant levels based on what is feasible and affordable to treat at scale -- not necessarily what carries zero health risk. Many independent health organizations recommend filtration for households with children, pregnant women, or immunocompromised individuals regardless of utility compliance status.
Protect Your San Carlos Home Water
PureWaterGuys.com carries filtration systems certified to reduce PFAS compounds like PFOA and PFOS. We ship to all 09 addresses with free expert guidance on the right system.
Shop PFAS Water Filters →Take the Water QuizFilters for Your City, Water Issues
Based on contaminants detected in this report, these systems are worth considering:
NSF-certified filters proven to remove PFAS, PFOA, PFOS, and 200+ contaminants.
Shop PFAS / Forever Chemicals Filters →
Reverse osmosis systems that reduce nitrates to safe levels.
Shop Nitrates / Nitrites Filters →
Whole-house carbon filters that eliminate chlorine taste, odor, and DBPs.
Shop Chlorine / Disinfection Byproducts Filters →
UV sterilizers and certified filtration to eliminate harmful bacteria and pathogens.
Shop Bacteria / Pathogens Filters →
Frequently Asked Questions
Is San Carlos tap water safe to drink?
Scua Upper Seven Mile is required to meet EPA federal drinking water standards. However, meeting legal standards is not the same as being contaminant-free. Trace levels of disinfection byproducts, PFAS compounds, and other regulated contaminants are common in US municipal water systems.
Does San Carlos water have PFAS?
PFAS compounds were detected in this utility's water during EPA UCMR5 monitoring. A certified PFAS filter -- such as reverse osmosis or activated carbon block -- can significantly reduce these compounds at your tap.
What water filter works best for San Carlos?
A whole-house carbon block filter removes chlorine, chloramines, and many VOCs. For PFAS, arsenic, and nitrates, a reverse osmosis under-sink system provides the highest reduction rates. Take our free 2-minute quiz to find the right system for your home and budget.
Data sourced from EPA SDWIS and UCMR5 federal databases. PureWaterGuys.com is not affiliated with any municipal water utility. Contact your utility's annual Consumer Confidence Report (CCR) for complete local data.