Summary
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In 2024, the city of Collinsville began posting a notice on its public works page recommending that residents filter their tap water before drinking or cooking with it. Most homeowners in the area haven’t seen it. The story behind that recommendation is worth knowing, especially if you live anywhere in the Metro East.
What PFAS are, and why they matter
PFAS stands for per- and polyfluoroalkyl substances, a family of about 15,000 different man-made chemicals that have been in use since the 1940s. The carbon-fluorine bond that makes them so useful is also what makes them a problem. Once these compounds enter the environment, they stay. Once they enter the body, they accumulate over time.
Where PFAS commonly show up:
- Non-stick cookware and bakeware
- Waterproof and stain-resistant fabrics
- Fast-food packaging and microwave popcorn bags
- Firefighting foam used at airports and military installations
- Industrial waste streams from manufacturing facilities
What peer-reviewed research has linked PFOA and PFOS exposure to:
- Thyroid disease
- Certain cancers, particularly kidney and testicular
- Reduced vaccine response in children
- Developmental effects during pregnancy
- Elevated cholesterol levels
PFAS have no taste, no smell, and no visible appearance in water. Testing is the only way to know they are present.
Where Collinsville stands today
In April 2024, the U.S. EPA finalized the first national drinking water standards for PFAS, setting a legal limit (called a Maximum Contaminant Level, or MCL) of 4 parts per trillion for both PFOA and PFOS.
For perspective: 4 parts per trillion is roughly four drops of water spread across twenty Olympic-sized swimming pools. The fact that the EPA set the limit this low says something about how persistent and biologically active these compounds are at very small concentrations.
Testing in Collinsville’s municipal supply detected PFAS above that limit. The city published a public notice recommending point-of-use filtration for drinking and cooking water, and as of September 2025, levels were still being monitored.
Collinsville is not alone. Here is what local detection looks like across the region:
| Water System | PFAS Status | Action Taken |
| Collinsville | Above 4 ppt MCL | Public notice, filtration recommended |
| Edwardsville | PFOA at 8.4 ng/L in raw well water | IL EPA Right-to-Know notice (April 2025) |
| Dupo, IL | PFOS above 4 ppt MCL | IL EPA notice (early 2026) |
| Missouri American Water | Non-detect (UCMR5 testing) | No action required |
| City of St. Louis | Non-detect (UCMR5 testing) | No action required |
This issue spans the region, and the reason is hydrology. Collinsville and Edwardsville both draw from the American Bottoms aquifer system. When contamination shows up in one part of that aquifer, it tends to show up across it. Communities like Troy, Maryville, and Glen Carbon sit within the same regional water context.
The Missouri side of the river is showing a different picture so far. Whether that holds long-term is an open question, but at present the contamination pattern is concentrated on the Illinois side. (Information drawn from the Illinois EPA PFAS Statewide Health Advisory and individual utility notices including the City of Edwardsville’s PFAS information page.)
Why municipal solutions take years
The EPA’s 2024 rule originally required water utilities to come into compliance by 2029. In 2025, the agency extended that deadline to 2031, citing the cost and complexity of treatment upgrades.
What this means in practice: Even a well-funded utility on a fast track is looking at five or more years between detection and a permanent fix.
Removing PFAS at the municipal scale takes major infrastructure investment. The federal government has made roughly $9 billion in funding available, but the work itself moves through a long sequence:
- Source assessment and pilot testing to identify the right treatment for the specific contamination profile
- Engineering and design of treatment system additions, often requiring new buildings and equipment
- Permitting and procurement at state and federal levels
- Construction and integration with existing treatment infrastructure
- Validation testing and full-scale operation
Each stage takes time. In the meantime, the city is doing what it can: testing, disclosing, and recommending that residents filter their water at home.
What works at home, and what doesn’t
Common household water treatment options vary widely in their effectiveness against PFAS. Here is a quick reference:
| Method | Effective for PFAS? | What to know |
| Boiling | No | Heat does not break PFAS down. Boiling concentrates them as water evaporates. |
| Standard pitcher filter | Usually no | Look for NSF/ANSI 53 certification specifically for PFOA and PFOS. |
| Refrigerator filter | Usually no | Most are not certified for PFAS removal. Check the label. |
| Whole-house carbon | Partial | Effective if sized correctly and serviced on schedule. Better suited to shower water than to drinking water. |
| Reverse osmosis (RO) | Yes | EPA-recognized as effective. Filters at the molecular level. |
For drinking and cooking water, a reverse osmosis system installed at the kitchen sink is the most reliable point-of-use option. The RO membrane physically blocks PFAS molecules along with lead, chromium-6, and most other contaminants of concern.
A few common questions about PFAS safety
Is the water safe to shower in? Skin absorption of PFAS is considered a much smaller exposure pathway than ingestion. The bigger concern with shower water in the Metro East is chlorine, which is added during municipal treatment and can affect skin and hair over time. A whole-house dechlorinator handles that side.
Can I just buy bottled water instead? You can, though it adds up quickly. A family of four drinking the recommended daily amount goes through roughly 60 bottles a day. There is also no consistent regulation requiring bottled water companies to test for or report PFAS, so the assurance is not always greater than what comes from a properly filtered tap.
How often does an RO filter need to be changed? Pre-filters and post-filters typically last six to twelve months depending on water quality. The RO membrane itself usually lasts two to five years. A reputable installer will set you up on a service schedule and let you know when changes are due.
How do I find out what’s actually in my water? A water test is the only way to know for certain. We offer a free 20-minute in-home test for residents in Collinsville, Edwardsville, Troy, Maryville, Glen Carbon, and surrounding communities. Results are shared on the spot.
The PFAS situation in Metro East drinking water is the kind that resolves slowly at the municipal level. At the household level, with the right system in place, it becomes a much smaller problem. If you want to know where your home stands, you can book a free water test or call (618) 693-9870.