Sacramento sits at the confluence of the Sacramento and American Rivers — two relatively clean Sierra Nevada snowmelt-fed systems that give the city a better water source than most of California. Sacramento city water goes through coagulation, sedimentation, filtration, UV disinfection, and carbon treatment before reaching taps.
The city's 2024 Consumer Confidence Report (published June 2025) states it meets all federal and state standards after testing more than 100 potential contaminants. But two things complicate that picture: PFAS levels were above the EPA's new 4 ppt MCL in some Sacramento County systems as recently as August 2024, and the groundwater underlying the broader Sacramento Valley and Central Valley — used by hundreds of thousands of people on private wells and small community systems — has serious contamination issues that surface water treatment doesn't address at all.
Sacramento City Water: The Contaminants That Exceed EWG Guidelines
Sacramento meets the legal federal and state standards. Where it gets interesting is the gap between those legal limits and EWG's health-based guidelines.
Arsenic: Sacramento's arsenic level has exceeded EWG's health-based guideline by approximately 701 times, according to EWG's tap water database. EWG's guideline is 0.004 ppb (set at a one-in-one-million cancer risk level). The EPA's legal limit is 10 ppb. Sacramento's levels are well within the federal MCL but still far above the more conservative health-based target.
Nitrates: Sacramento nitrate levels have exceeded EWG's recommended safety threshold by approximately 12 times in recent testing. Again, this remains within the EPA MCL of 10 ppm — but the EWG health guideline of 0.14 ppm reflects newer research on nitrate's relationship to colorectal cancer and thyroid disruption at sub-MCL concentrations.
Radium: Radium-226 and -228 combined has exceeded EWG's health guideline by approximately 11 times. Radium is naturally occurring in California geology. Sacramento's radium levels are within federal limits.
PFAS (August 2024): Sacramento County Water Agency testing showed PFAS levels above the EPA's new enforceable limit of 4 ppt for PFOS and PFOA as recently as August 2024. Sacramento is actively monitoring, and as of the city's 2024 CCR, is planning advanced carbon filtration and other PFAS treatment upgrades. The compliance deadline is 2031 (extended from 2029 in May 2025).
Chromium-6: Detected at levels above EWG's guideline. California has a state MCL for hexavalent chromium of 10 ppb (adopted 2024, the first in the nation). The Sacramento area has chromium-6 from both natural geology and historic industrial contamination.
Disinfection byproducts (HAA5 and TTHMs): Detected; Sacramento uses chlorine/chloramine disinfection. The Sacramento River and American River carry organic matter that reacts with disinfectants to form DBPs. Levels are below federal MCLs but above EWG guidelines.
The Central Valley Groundwater Crisis
The bigger story for the Sacramento Valley and San Joaquin Valley isn't the city's treated water — it's the groundwater used by private well owners and the hundreds of small community water systems serving rural residents throughout the valley.
A 2024 USGS study of domestic groundwater in the eastern Sacramento Valley found:
- PFAS detected in 29% of domestic groundwater resources sampled; 5% exceeded the April 2024 EPA MCLs
- Arsenic at high concentrations in wells classified as anoxic (low-oxygen), particularly in fine-grained sediments near the center of the valley — a geological pattern that drives arsenic release from aquifer sediments
- Iron exceeded aesthetic guidelines in 10% of wells; manganese in 26% — both causing staining and, in manganese's case, neurotoxic effects at higher levels
- Total coliform bacteria detected in 13% of wells; enterococci in 8% — indicating fecal contamination pathways in a significant fraction of private wells
- Nitrates at moderate concentrations in 10% of wells, concentrated in oxic wells near the valley's eastern edge where agriculture is intensive and aquifer recharge is faster
Nitrates — the agricultural footprint: The Sacramento Valley and San Joaquin Valley floor have decades of fertilizer application, dairy operations, and septic systems in rural areas. Nitrate moves through permeable soils into groundwater in oxic conditions. For private well users downgradient from agriculture, nitrate testing is essential — particularly if there are infants or pregnant women in the household.
PFAS — McClellan Air Force Base and industrial legacy: McClellan Air Force Base (now McClellan Business Park) north of Sacramento was a major Air Force installation for decades, with extensive AFFF use. The McClellan PFAS plume is among the larger groundwater contamination cases in California. Sacramento County and surrounding areas also have industrial PFAS sources from manufacturing and waste sites. The California State Water Board's GeoTracker PFAS mapping tool shows numerous Sacramento County sites with active PFAS investigation or remediation.
Chromium-6 in the San Joaquin Valley: The San Joaquin Valley (Fresno, Bakersfield, Visalia areas) has naturally occurring and industrial chromium-6 contamination in groundwater that disproportionately affects small community water systems serving farmworker communities. California adopted the first chromium-6 MCL in the nation in 2024 (10 ppb), requiring treatment upgrades for many small systems.
Sacramento Valley Source Water: What's Vulnerable
The Sacramento River and American River are classified as vulnerable to contamination from recreational use, agricultural runoff, stormwater, and upstream discharges. Sacramento's 2000 and 2001 source water assessments specifically flagged this vulnerability — and the watershed's exposure to PFAS, pharmaceuticals, and pesticides from upstream agricultural and urban areas hasn't diminished since.
The Sacramento River drains a large watershed including the Sacramento Valley's intensive agriculture. During high precipitation events, agricultural runoff containing pesticides, herbicides (particularly atrazine and similar compounds), and nitrates enters the river. Sacramento's treatment plants are designed to handle this — but source water quality variability affects treatment demands and occasionally challenges the system.
Drought and groundwater depletion: The California drought cycle has accelerated groundwater pumping throughout the Sacramento and San Joaquin Valleys under the Sustainable Groundwater Management Act (SGMA). As aquifer levels drop, wells draw from deeper, older groundwater that is often naturally higher in arsenic, uranium, and radium. This is making the groundwater contamination problem structurally worse over time.
What Sacramento City Residents Should Do
PFAS and chromium-6 concern: Sacramento's PFAS levels were above the new MCL in some County systems as recently as August 2024. Chromium-6 is detected above EWG's guideline. RO at the kitchen tap handles both.
Minimum recommendation for Sacramento city residents: A high-quality carbon block pitcher (Clearly Filtered) handles DBPs, chloramine, and many trace contaminants. For PFAS and chromium-6 specifically, RO is more thorough.
Under-sink RO for comprehensive coverage:
- APEC ROES-50 (~$215) — NSF 58; removes PFAS, chromium-6, arsenic, nitrates, radium, DBPs in one system; the right choice for Sacramento residents with PFAS or chromium-6 concern
- iSpring RCC7AK (~$219) — adds alkaline remineralization stage; good for households concerned about the demineralized taste of standard RO water
For taste and DBP reduction without full RO:
- Clearly Filtered Pitcher (~$90) — NSF certified for PFAS, lead, chloramine, DBPs, chromium-6, and 360+ contaminants; the best non-RO option for Sacramento
Countertop RO for renters:
- Bluevua RO100ROPOT-LITE Countertop RO (~$299) — no-install countertop RO; NSF certified for PFAS, nitrates, chromium-6, and more
What Central Valley Well Owners and Small System Users Should Do
Test first. The USGS data shows that 29% of eastern Sacramento Valley domestic wells have PFAS and 5% exceed the new EPA MCL. Arsenic, manganese, coliform, and nitrates are widespread. Testing before choosing a filter is essential.
Recommended test panel for Sacramento Valley / Central Valley private wells: Arsenic, nitrates, coliform (including E. coli), iron, manganese, PFAS, chromium-6, uranium, pH, hardness, TDS.
- Tap Score Advanced Well (~$200) — comprehensive panel covering metals, nitrates, bacteria, PFAS, and radiologicals; plain-language results with filter recommendations
Treatment for confirmed contaminants:
- Arsenic, nitrates, PFAS, chromium-6, uranium: Under-sink RO (APEC ROES-50 or iSpring RCC7AK)
- Bacteria: UV disinfection (VIQUA VH200) combined with sediment pre-filter
- Iron/manganese: Oxidation filtration (air injection or greensand filter) before RO
Small system users in the San Joaquin Valley (particularly farmworker communities in Fresno and Tulare counties): Many small water systems in the valley have historically struggled with chromium-6, arsenic, and nitrates above MCLs. If your water bill comes from a small water district with fewer than a few thousand connections, checking your utility's Consumer Confidence Report and testing independently is especially warranted.
→ Check Sacramento-area ZIP codes at PureCity
Resources
- Sacramento city water quality: sacramentowaterquality.com
- PFAS information: cityofsacramento.gov/utilities/water-quality/pfas
- California PFAS mapping: waterboards.ca.gov/pfas — GeoTracker PFAS Mapping Tool
- USGS eastern Sacramento Valley groundwater study (November 2024): pubs.usgs.gov/publication/ofr20241061
- EWG Tap Water Database: ewg.org/tapwater
Related Articles
- Arsenic in Drinking Water: The Well Water Risk Most People Don't Test For
- PFAS in Drinking Water: What It Is, Where It's Found, and How to Filter It
- Nitrates in Well Water: A Risk for Infants That Most Well Owners Don't Know About
- Chromium-6 in Drinking Water: What EWG's Research Means for Your Tap
- How to Test Your Well Water: What to Test For, When, and Which Services Are Worth the Money
- Best Under-Sink Reverse Osmosis Systems
Sources: City of Sacramento 2024 Consumer Confidence Report, published June 2, 2025 · USGS: Quality of Groundwater Used for Domestic Supply in the Eastern Sacramento Valley and Adjacent Foothills, November 2024 · California State Water Resources Control Board: PFAS · HomeWater: 10 Chemicals Harming Sacramento Water Quality · EWG Tap Water Database: Sacramento · King Law: Sacramento Water Contamination 2026