Rockford, Illinois — the state’s third-largest city with roughly 150,000 residents — has a water quality story that involves two distinct but overlapping problems: PFAS contamination from firefighting foam and industrial Superfund sites from decades of manufacturing.
Both issues are well-documented. Both are being addressed. And both deserve attention from anyone drinking the water here.
PFAS: The Contamination That Doesn’t Go Away
PFAS — per- and polyfluoroalkyl substances — are a family of thousands of synthetic chemicals used since the 1940s in everything from nonstick cookware to firefighting foam. They’re called “forever chemicals” because they don’t break down in the environment.
Rockford’s PFAS problem traces primarily to the use of aqueous film-forming foam (AFFF) at the Greater Rockford Airport and at fire training facilities. AFFF was the standard for fighting fuel fires for decades, and its use left PFAS compounds in the soil and groundwater around these sites.
The contamination was first identified through testing prompted by the EPA’s 2016 health advisory for PFOS and PFOA — two of the most studied PFAS compounds. Groundwater monitoring wells near the airport showed PFAS levels significantly above the advisory levels.
In 2024, the EPA finalized the first-ever national drinking water standards for PFAS, setting maximum contaminant levels (MCLs) at 4 parts per trillion (ppt) for PFOS and PFOA individually. That’s an extraordinarily low threshold — essentially, any detectable amount is a concern.
How Rockford’s Water Supply Is Affected
The City of Rockford draws its drinking water from a network of deep wells tapping into the sandstone aquifer system. This is important context: deep wells are generally better protected from surface contamination than shallow wells or surface water sources.
However, PFAS contamination has been detected in some monitoring wells and private wells in the area, particularly near the airport and former industrial sites. The city has taken several steps in response:
- Shut down affected wells — Wells showing PFAS contamination above health advisory levels have been taken offline
- Blending strategies — Where possible, water from wells with low-level PFAS detections is blended with clean sources to reduce overall concentrations
- Treatment planning — The city has been evaluating granular activated carbon (GAC) and ion exchange treatment systems to remove PFAS from affected wells
- Monitoring — Expanded testing across the well network to track PFAS migration
According to the city’s water quality reports and EPA data, the treated water delivered to customers has generally been below the health advisory levels. But the new 2024 MCLs set a tighter standard, and meeting those limits will require additional investment.
Superfund Sites: Rockford’s Industrial Legacy
Rockford was a manufacturing powerhouse through the 20th century, producing machine tools, fasteners, furniture, and automotive parts. That industrial history left contamination behind.
Several Superfund sites in the Rockford area affect groundwater:
Southeast Rockford Groundwater Contamination
This EPA Superfund site covers a large area of contaminated groundwater in southeastern Rockford. Volatile organic compounds (VOCs) — including trichloroethylene (TCE) and tetrachloroethylene (PCE) — from multiple industrial sources contaminated the shallow aquifer. The contamination plume extends across residential neighborhoods where private wells were affected.
EPA has conducted extensive investigation and remediation, including installing treatment systems for affected private wells and providing connections to the public water supply. But groundwater cleanup for VOCs is a slow process — these plumes can persist for decades.
Other Industrial Sites
Additional contaminated sites across Winnebago County contribute to the broader groundwater quality picture. Former dry cleaners, machine shops, and manufacturing facilities left solvent and metal contamination in soil and groundwater throughout the industrial corridors.
What EPA Data Shows
EPA ECHO compliance data for the Rockford water system shows general compliance with Safe Drinking Water Act standards. Key monitoring areas include:
- PFAS — The city has been proactive about testing and reporting. Levels in delivered water have been managed through well selection and blending, though the new federal MCLs create tighter compliance requirements
- VOCs — Deep municipal wells are largely protected from the shallow VOC plumes associated with Superfund sites. Private wells in affected areas face different risk profiles
- Nitrates — Agricultural activity in surrounding Winnebago County contributes nitrate loading to shallow groundwater. Municipal deep wells are less affected, but rural private wells should be tested
- Radium — Some deep wells in northern Illinois naturally contain radium, a radioactive element leached from sandstone aquifers. Rockford monitors for this and manages levels through blending
Private Wells: A Different Risk Profile
If you’re on a private well in the Rockford area — particularly in southeastern Rockford or near the airport — your risk profile is different from those on city water.
Private well owners are responsible for their own testing. There’s no federal requirement for ongoing monitoring of private wells. Given the known contamination in the area, testing for the following is recommended:
- PFAS — Especially if within a few miles of the airport or fire training sites
- VOCs — Particularly TCE and PCE if near known Superfund sites
- Nitrates — Common in agricultural areas
- Bacteria — Coliform and E. coli as routine safety checks
The Winnebago County Health Department can provide guidance on testing and certified laboratories.
What Residents Can Do
Whether you’re on city water or a private well, here are practical steps:
- Read the annual water quality report. The City of Rockford publishes detailed results including PFAS testing data.
- Test your water. If you’re on a private well, test annually at minimum. If on city water and concerned about lead from home plumbing, a lead test is worthwhile.
- Know your neighborhood. If you live near a Superfund site or the airport, understand the specific contaminants of concern in your area.
- Consider filtration. Activated carbon filters reduce PFAS, VOCs, and many other contaminants. Reverse osmosis provides even more comprehensive treatment.
If you’re concerned about your water quality, a certified water treatment professional can test your water and advise on solutions appropriate for the specific contaminants in your area.
The Cost of Cleanup
PFAS treatment is expensive. Granular activated carbon and ion exchange systems require significant capital investment and ongoing operational costs for media replacement. For a city the size of Rockford, treating multiple wells could cost tens of millions of dollars.
The EPA’s PFAS regulations include provisions for enforcement against polluters, and the city has pursued legal action against manufacturers of AFFF to recover remediation costs. But legal processes are slow, and the water system needs solutions now.
Federal infrastructure funding has also provided some relief. The Bipartisan Infrastructure Law allocated $9 billion specifically for PFAS remediation in drinking water systems. Illinois has been active in distributing these funds to affected communities.