Lodi Water Quality: PFAS and Forever Chemicals
Lodi Water Quality: PFAS and Forever Chemicals Deep Dive
LodiEye Investigation • March 2026
A comprehensive examination of PFAS contamination, water quality
monitoring, treatment plans, and regional context for Lodi's drinking water supply
Executive Summary
Lodi's drinking water meets all state and federal regulatory standards with no violations over nearly a decade, yet several contaminants — including PFAS “forever chemicals,” legacy pesticides, and industrial solvents — have been detected at levels that, while legal, exceed more stringent public health goals set by California health experts.
Key Finding: Well 14 recorded PFOS levels averaging 5.6 parts per trillion (ppt) — 1.3 times the federal limit of 4 ppt — with seven different PFAS chemicals detected across three locations in Lodi's water system. The city is advancing granular activated carbon (GAC) treatment to address this contamination.
Lodi is not alone. San Joaquin County cities including Stockton, Manteca, and Ripon are all grappling with PFAS contamination in groundwater wells, part of a broader pattern of “forever chemical” pollution affecting California's agricultural regions far from traditional industrial sources.
Understanding Lodi's Water Sources
The City of Lodi operates a dual-source water supply system serving approximately 68,000 residents:
- Groundwater Wells (~55%): Approximately 28 active wells drawing from underground aquifers
- Surface Water Treatment Facility (~45%): Completed in 2012, using membrane filtration and chlorination to treat imported surface water
This blending strategy helps dilute localized contamination, but groundwater wells remain vulnerable to legacy agricultural chemicals (DBCP), industrial solvents (PCE/TCE), naturally occurring arsenic, and emerging PFAS contamination.
The surface water plant produces water with no detections of DBCP and generally fewer contaminant concerns compared to groundwater sources. However, the city relies heavily on wells, making groundwater quality a critical public health priority.
Contaminants of Concern
PFAS: The Emerging Crisis
What are PFAS? Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals used since the 1940s in non-stick cookware, waterproof fabrics, food packaging, firefighting foam, and pesticides. They're called “forever chemicals” because they don't break down in the environment and accumulate in human bodies over time.
Health Risks: Studies link long-term PFAS exposure to:
- Developmental effects in fetuses and infants
- Increased cancer risk (kidney, testicular, thyroid)
- Liver, kidney, and immune system damage
- Thyroid disorders and reproductive problems
Lodi's PFAS Status (2022–2024 Data)
| Chemical | Detection Location | Level Detected | Federal MCL | Status |
|---|---|---|---|---|
| PFOS | Well 14 | 5.6 ppt (avg) | 4 ppt | Above federal limit |
| PFOA | Well 14 | 4.1 ppt | 4 ppt | At federal limit |
| PFHxS | 3 locations | Detected | 10 ppt | Below limit |
| Total PFAS | 3 wells | 7 chemicals | Various | Multiple detections |
Water Plant Superintendent Travis Kars confirmed the city is advancing granular activated carbon (GAC) treatment for Well 14, the primary PFAS-affected source.
Where is PFAS Coming From?
UC Berkeley researchers and the Community Water Center have identified potential sources in San Joaquin Valley agricultural regions:
- Biosolids Application: Treated wastewater sludge spread on farmland as fertilizer contains PFAS from household and industrial sources
- PFAS-Containing Pesticides: Certain agricultural chemicals contain forever chemicals that leach into groundwater
- Industrial Legacy: Historical manufacturing, chrome plating, and other industrial activities
- Firefighting Foam: Airports and emergency response training sites using AFFF (aqueous film-forming foam)
The discovery of PFAS in rural wells far from traditional industrial contamination sites suggests agricultural pathways may be a significant — and previously underestimated — source of forever chemical pollution.
DBCP: The Pesticide That Won't Go Away
Background: Dibromochloropropane (DBCP) was used extensively in California vineyards from the 1950s through 1977 to control nematodes (microscopic worms) that damage grape roots. It was banned after being linked to male sterility in agricultural workers and cancer in laboratory animals.
- 3 of 25 wells still show DBCP detections (up to 100 ppt; MCL is 200 ppt)
- 9 wells equipped with GAC filters to treat DBCP contamination
- Declining trend over past decade as legacy contamination slowly dissipates
DBCP concentrations are highest in wells near former vineyard areas, reflecting Lodi's agricultural heritage. While levels remain below the legal limit, they exceed the Public Health Goal of 3 ppt — a health-based advisory level set without regard to treatment costs.
PCE/TCE: Industrial Solvent Contamination
Background: Perchloroethylene (PCE) and trichloroethylene (TCE) are chlorinated solvents historically used in dry cleaning, metal degreasing, and industrial manufacturing. They're known carcinogens that persist in groundwater for decades.
- Groundwater plume in north and central Lodi from historical industrial activity
- Well 12 taken offline in 2024 due to PCE detection
- Well 6R undergoing treatment capacity upgrade; PCE no longer expected in active sources after completion
- Active remediation ongoing with responsible parties since the 1990s
Arsenic: A Natural Hazard
Background: Arsenic occurs naturally in California's Central Valley geology, leaching from rocks and sediments into groundwater. It's a known carcinogen linked to skin, bladder, and lung cancer at high exposures.
- Detected in 19 of approximately 25 active wells
- Range: Non-detect to 8.1 ppb (MCL is 10 ppb; average 4 ppb)
- Public Health Goal: 0.004 ppb (essentially zero risk)
- All wells remain below the enforceable limit, but levels substantially exceed the health-based goal
Bringing arsenic to PHG levels would require reverse osmosis (RO) treatment at an estimated annualized cost of $5.4–$18.2 million per year ($185–$623 per customer annually) — costs the city has deemed prohibitive.
Complete Contaminant Summary
| Contaminant | Wells Affected | Range Detected | MCL | Public Health Goal | Source |
|---|---|---|---|---|---|
| Hexavalent Chromium | 14 wells | ND–5.2 ppb | 10 ppb | 0.02 ppb | Industrial / natural |
| Uranium | 14 wells | ND–8.17 pCi/L | 20 pCi/L | 0.43 pCi/L | Naturally occurring |
| Gross Alpha | 6 wells | ND–15.7 pCi/L | 15 pCi/L | 0 pCi/L | Natural radioactivity |
| Combined Radium | 2 wells | ND–0.273 pCi/L | 5 pCi/L | 0.05 pCi/L | Natural radioactivity |
Regional Context: San Joaquin County's PFAS Problem
Lodi is not facing this crisis alone. Recent EPA testing reveals widespread PFAS contamination across San Joaquin County water systems:
Comparative PFAS Detections (2023–2025)
| Water System | PFAS Chemicals Detected | Highest Level vs. Federal Limit | Locations Affected |
|---|---|---|---|
| Lodi (City of) | 7 chemicals | PFOS: 1.3x over limit (5.6 ppt) | 3 wells |
| Stockton (City of) | 1 chemical | PFOS: 1.2x over limit (4.8 ppt) | 2 wells |
| Stockton (Cal Water) | 1 chemical | 1.3x over limit | 2 locations |
| Brookside Acres | 6 chemicals | PFOS: 3.2x over limit | 3 wells |
| Manteca | 4 chemicals | PFOA: 1.5x over limit | 5 wells |
| Ripon | 3 chemicals | PFOS: 3x over limit | 1 well |
Key Regional Observations
- Widespread Geographic Distribution: PFAS contamination spans urban Stockton, agricultural Lodi and Manteca, and smaller communities like Ripon — suggesting valley-wide groundwater impacts
- Multiple Chemical Detections: Systems aren't just detecting one PFAS compound; they're finding cocktails of 3–7 different forever chemicals at individual wells
- Exceedances Common: Most systems have at least one well with PFAS levels above the 4 ppt federal standard for PFOA/PFOS
- Rural Vulnerability: The highest contamination levels are in smaller, rural systems (Brookside Acres, Ripon) that may have fewer resources to implement treatment
The San Joaquin Valley Pattern
UC Berkeley researchers conducting independent sampling in the San Joaquin Valley found PFAS at 100% of tested locations — 20 sites including 10 private domestic wells and 10 public water systems. One private well recorded 96 ppt total PFAS, including 32 ppt PFOS (8 times the federal limit).
Agricultural Pathway Hypothesis
Researchers suspect biosolids — treated sewage sludge from urban wastewater treatment plants — spread on farmland as fertilizer may be a primary vector. Los Angeles County historically shipped biosolids to Kern County agricultural operations. Solano County tested soil where biosolids had been applied and found PFAS at every location tested, including areas where biosolids had not historically been used — suggesting environmental persistence and migration.
San Joaquin County's intensive agricultural production, combined with decades of biosolids application and PFAS-containing pesticide use, created conditions for widespread groundwater contamination far from traditional industrial sources.
Who's Monitoring Lodi's Water?
Primary Agencies
City of Lodi Public Works / Water Division
Operates all municipal wells and the surface water treatment facility. Conducts routine water quality testing (thousands of tests annually). Publishes annual Consumer Confidence Reports (CCRs) by June 1 each year.
Contact: (209) 333-6740 • www.lodi.gov/water
California State Water Resources Control Board (Division of Drinking Water)
Sets drinking water standards and advisory levels. Conducts enforcement and compliance monitoring. Launched statewide PFAS well testing program in 2019 (~4,000 wells). Provides PFAS testing at no cost to disadvantaged communities.
U.S. Environmental Protection Agency (EPA)
Sets federal Maximum Contaminant Levels (MCLs). Established PFOA/PFOS limit of 4 ppt each (April 2024). Requires public water systems to begin PFAS monitoring by 2027, achieve compliance by 2029.
Safe Drinking Water Hotline: (800) 426-4791
California EPA / OEHHA
Sets non-enforceable Public Health Goals (PHGs) based purely on health science. PHGs represent “no known or expected risk” levels. Used by water systems to assess health protective targets beyond legal requirements.
Independent Researchers
UC Berkeley and Community Water Center conduct independent PFAS sampling in San Joaquin Valley. Planning community meetings to discuss findings with affected residents. Advocating for expanded testing and stricter regulations.
Testing Frequency and Protocols
Lodi collected 3,152 distribution system samples from 2022–2024 with zero coliform violations — demonstrating effective disinfection and system integrity.
| Contaminant | Testing Frequency | Sample Type |
|---|---|---|
| Bacteria (Coliform/E. coli) | Monthly | Distribution system |
| PFAS | Quarterly or annually | Individual wells |
| DBCP / PCE / TCE | Quarterly (affected wells); annually (others) | Individual wells |
| Arsenic, Uranium, Radium | Annually or every 3 years | Individual wells |
| Disinfection Byproducts | Quarterly | Distribution system |
| Lead and Copper | Every 3 years (50 homes) | Customer taps |
10-Year Water Quality Trends
Declining: Legacy Agricultural Contamination
DBCP (Pesticide) — ↓ Declining
2012–2019: Detected in 6–8 wells regularly. 2020–2024: Now detected in only 3 wells. GAC treatment and natural attenuation are reducing levels. Continued slow decline expected over next decade.
Stable: Industrial and Natural Contaminants
PCE/TCE (Solvents) — → Stable
Persistent plume in north/central Lodi since the 1990s. Active remediation prevents expansion. Well 12 decommissioned in 2024; Well 6R upgrade should eliminate detections in active sources.
Arsenic — → Stable
Consistently detected in 18–19 wells across all reporting periods. Geologic source means it will not improve without costly RO treatment. All levels remain below MCLs.
Rising Concern: Forever Chemicals
PFAS — ↑ Increasing Detections
2019: California begins systematic statewide well testing. 2020–2023: Initial detections at Lodi wells. 2024: Federal MCLs established (4 ppt for PFOA/PFOS). 2025: Well 14 confirmed above federal limit; GAC treatment planned. Expect more wells to show PFAS as monitoring intensifies.
Regulatory Uncertainty: The EPA has indicated it may extend PFOA/PFOS compliance deadlines to 2031 and rescind MCLs for PFHxS, GenX, and PFNA. However, California issued its own advisory levels for PFHxS and PFHxA in October 2025, signaling the state may maintain stricter standards regardless of federal rollbacks.
Lodi's PFAS Treatment Plan
Current Strategy: Granular Activated Carbon (GAC)
Water Plant Superintendent Travis Kars confirmed during a September 2025 City Council meeting that Lodi is advancing GAC treatment for Well 14, leveraging the city's extensive experience with this technology.
Why GAC?
- Proven technology: California DPH recognizes GAC as Best Available Technology (BAT) for volatile organic compounds
- Most effective for long-chain PFAS like PFOS (Lodi's primary concern)
- Existing expertise: Lodi already operates GAC systems on multiple wells for DBCP and 1,2,3-TCP removal
How GAC Works
- Contaminated groundwater flows through vessels filled with activated carbon
- PFAS molecules adsorb (stick) to the carbon surface as water passes through
- Treated water exits with PFAS concentrations reduced to below detection limits
- Carbon must be replaced periodically as adsorption capacity is exhausted
- Spent carbon requires proper disposal or regeneration due to concentrated PFAS content
Existing GAC Infrastructure
Lodi has a strong foundation for PFAS treatment expansion:
- 4 PF 12-520 GAC systems designed by AqueoUS Vets, each with 3.2 million gallon/day capacity
- Wells 27 and 28 already equipped for 1,2,3-TCP removal
- 7 additional wells have GAC filters for DBCP treatment
- Operational experience with carbon change-outs, maintenance, and monitoring
Treatment Limitations
| Factor | Details |
|---|---|
| Long-chain PFAS (PFOS, PFOA) | Very effective removal (>95%) |
| Short-chain PFAS (PFBS, PFHxA) | Less effective; may require ion-exchange resin |
| Carbon Replacement | PFAS-laden carbon requires more frequent change-outs than carbon used for pesticides |
| Disposal | Spent GAC is hazardous waste requiring special handling |
| Monitoring | Increased testing frequency to verify treatment effectiveness |
Funding Opportunities
California SB 454 (PFAS Mitigation Fund)
Introduced in 2025–26 legislative session. Creates state fund for grants, loans, and technical assistance. Covers treatment infrastructure, monitoring, and PFAS waste disposal. Status: Pending legislative approval.
California PFAS Phase 2 Settlement
Statewide settlement supporting PFAS remediation. Available to public water systems for compliance with federal standards. Helps offset costs not recovered from PFAS manufacturers.
Drinking Water State Revolving Fund (DWSRF)
2025–26 intended use plan includes PFAS wellhead treatment projects. Low-interest loans and potential grant funding administered by State Water Resources Control Board.
Manufacturer Liability Litigation
California Water Service and other utilities have filed lawsuits against PFAS manufacturers (3M, DuPont, etc.). Outcomes pending but could result in significant cost recovery for ratepayers.
Estimated Timeline
| Phase | Duration | Target |
|---|---|---|
| Design and permitting | 6–12 months | Well 14 GAC system |
| Construction and installation | 6–9 months | Vessel placement and piping |
| Startup and optimization | 2–4 months | Performance verification |
| Total estimated | 18–24 months | Full operation |
Federal compliance deadlines: Systems must begin PFAS monitoring by 2027 and achieve compliance by 2029, with a possible extension to 2031 under consideration.
Can Home Water Filters Remove PFAS?
Yes — but not all filters are effective. Two technologies reliably remove PFAS from drinking water:
Reverse Osmosis (RO) Systems
How it works: Water is forced through a semi-permeable membrane that blocks PFAS molecules while allowing water to pass. Removes 94–100% of PFAS, plus arsenic, uranium, nitrates, and most other contaminants.
Types: Under-sink (higher flow), countertop (portable, no plumbing needed), or whole-house (most expensive).
Limitations: Produces wastewater (2–4 gallons per gallon produced), removes beneficial minerals, requires periodic filter replacement, and higher upfront cost ($400–$5,000+).
Activated Carbon Filters
How it works: Water flows through carbon media that adsorbs PFAS molecules. Removes 70–99.5% of PFAS depending on compound and filter quality.
Types: Pitcher filters (convenient, low cost), faucet-mount (moderate cost), or under-sink carbon block (higher capacity).
Limitations: Less effective than RO for short-chain PFAS. Requires frequent replacement for PFAS (every 2–3 months vs. 6 months for other contaminants). Performance varies significantly by brand.
Recommended PFAS Filters (2026)
| Filter | Type | PFAS Removal | Price Range | Best For |
|---|---|---|---|---|
| AquaTru Carafe/Classic | Countertop RO | $130–$400 | Renters; no installation | |
| Waterdrop G3 P800 | Under-sink RO | $500–$800 | Homeowners; comprehensive | |
| Clearly Filtered Pitcher | Pitcher (carbon) | $80–$100 | Budget-conscious | |
| Culligan ZeroWater | Pitcher | $30–$50 | Most affordable entry point | |
| RKIN Zero Installation | Countertop RO | ~$400 | Apartment dwellers; portable |
Certifications to Look For
- NSF/ANSI Standard 58 (RO systems) or Standard 53 (carbon filters)
- Tested specifically for PFOA/PFOS removal (not just generic “contaminant removal”)
- Independent third-party testing (not just manufacturer claims)
Filters That DON'T Remove PFAS
- Standard Brita/PUR pitchers (unless specifically certified for PFAS)
- Refrigerator filters (most are not PFAS-rated)
- Faucet aerators and shower filters
- UV light systems (kill bacteria but don't remove chemicals)
- Water softeners (remove hardness minerals only)
- Basic sediment filters
What Can Lodi Residents Do?
Immediate Actions
Know Your Water Source
- Check your water bill or call City of Lodi Public Works: (209) 333-6740
- Request which wells serve your neighborhood
- Review the 2024 Consumer Confidence Report at www.lodi.gov/water
Consider Point-of-Use Treatment
- Install a certified RO or carbon filter at kitchen tap if concerned about PFAS
- Focus on drinking and cooking water (5–10 gallons/day) rather than expensive whole-house treatment
- Budget $100–$800 for system + $50–$150/year for replacement filters
Reduce PFAS Exposure from Other Sources
- Avoid non-stick cookware (use cast iron or stainless steel)
- Choose products without “stain-resistant” or “water-resistant” treatments
- Avoid microwave popcorn bags and grease-resistant food packaging
- Check cosmetics and personal care products for PFAS ingredients
Long-Term Advocacy
- Stay Informed: Attend City Council meetings when water quality is discussed (typically September for PHG report). Sign up for city water quality alerts at www.lodi.gov
- Support Funding: Contact state legislators to support SB 454 (PFAS Mitigation Fund). Advocate for federal infrastructure funding for water treatment.
- Hold Polluters Accountable: Support litigation against PFAS manufacturers. Advocate for bans on PFAS in pesticides and consumer products.
- Participate in Public Comment: When the city releases plans for Well 14 GAC treatment, attend public hearings. Provide input on priorities for treatment expansion.
The Bigger Picture
Lodi's PFAS contamination is a microcosm of a statewide crisis. More than 825,000 Californians spanning nearly 400 water systems lack access to clean, reliable drinking water due to contamination from nitrates, heavy metals, pesticides — and now PFAS.
The San Joaquin Valley's intensive agricultural economy has created a legacy of groundwater contamination that disproportionately impacts farmworkers and communities of color. Private wells serving these communities are “particularly vulnerable” because they tend to be shallower, unregulated, and serving lower-income households with fewer resources for treatment.
California faces critical policy decisions: whether to maintain stricter PFAS standards than the federal government (early signs suggest yes), whether biosolids application should be banned near groundwater recharge areas, whether PFAS should be prohibited in pesticides and consumer products, and how treatment costs should be distributed among ratepayers, polluters, and state taxpayers.
For Lodi residents, these statewide debates have direct local consequences. The city's decisions about treatment expansion, monitoring intensity, and rate structures will shape water quality and affordability for decades to come.
Bottom Line: Lodi's water is legally safe to drink — but “legal” and “optimal for health” are not the same thing. The detection of PFOS above federal limits at Well 14 demands urgent action, and city officials are responding with GAC treatment plans. Transparency, proactive treatment, and sustained public engagement will determine whether Lodi's water quality improves in the decade ahead.
LodiEye will continue monitoring this issue and reporting updates as the city advances PFAS treatment and expands testing.
References & Resources
City of Lodi
- City of Lodi – Water Quality
- City of Lodi – Consumer Confidence Report
- City of Lodi – Public Health Goals Report (2022–2024)
- City of Lodi – Water Supply
- Public Works / Water Division: (209) 333-6740
- Emergency Line: (209) 333-6767
State Agencies
- California Water Boards – PFAS Information
- California Division of Drinking Water – File a Complaint
- California SB 454 – PFAS Mitigation Fund Bill Text
- Division of Drinking Water: (916) 449-5577
Federal Agencies
- U.S. EPA – PFAS Information
- U.S. EPA – Your Drinking Water
- Safe Drinking Water Hotline: (800) 426-4791
Research & News Sources
- HealthBeat – PFAS Pollute Wells in Rural California (Dec 2024)
- KFF Health News – Forever Chemicals Taint Rural California Water (Dec 2024)
- CalMatters – New Forever Chemicals Standards (Apr 2024)
- AqueoUS Vets – Lodi GAC Project Profile
- Water Filter Guru – Best PFAS Filters (2026)
Testing Your Water
- State-Certified Laboratories
- San Joaquin County Environmental Health (Private Well Testing): (209) 468-3420
Community Organizations
- Community Water Center • (559) 733-0219
- Clean Water Action
- Environmental Working Group – Tap Water Database
Have a Tip?
Have information about water quality issues in Lodi? Contact Lodi411/LodiEye at info@lodi411.com