Dupo
IL

Is Dupo, IL Tap Water Safe to Drink?

Dupo tap water meets federal Safe Drinking Water Act standards but 2 of 2 ZIP codes show detections above EPA health guidelines, primarily for lithium. A certified filter is recommended for households that want an additional layer of protection.

3Water systems
2ZIP codes
100%ZIPs above EPA guideline
Metro areaSt. Louis, MO-IL
Latest data2025-11-03

Where Does Dupo Get Its Water?

Water in Dupo, IL is provided by 3 public water systems: DUPO, COLUMBIA and IL AMERICAN-EAST ST LOUIS.

How Is Dupo Tap Water Treated?

Treated water is disinfected using free chlorine and calcium hypochlorite and chloramines and on-site generated disinfectant. Treatment includes conventional treatment (coagulation, flocculation, and filtration), direct filtration, post-ozone biofiltration and slow sand filtration.

What's in Dupo Tap Water?

The following contaminants were detected most frequently in Dupo public water systems. 2 of 2 ZIP codes showed detections above EPA health guidelines.

ContaminantPeak detectedEPA guidelineZIPs detectedStatus
lithium 23 µg/L 10 µg/L 2 ZIPs Above guideline
PFTrDA 0.007 µg/L — 0 ZIPs Within guideline
6:2 FTS 0.005 µg/L — 0 ZIPs Within guideline
8:2 FTS 0.005 µg/L — 0 ZIPs Within guideline
HFPO-DA 0.005 µg/L — 0 ZIPs Within guideline

Health Risk Profile for Dupo

Based on EPA monitoring data, 2 of 2 ZIP codes in Dupo have recorded detections above EPA health guidelines. Sensitive populations such as infants, pregnant individuals, and those with weakened immune systems may benefit from an additional layer of protection such as a certified point-of-use filter.

Best Filters for PFAS Water Profile

PFAS compounds are detected in this water supply. A reverse osmosis (RO) system or an activated-carbon filter specifically certified under NSF/ANSI P473 is required for reliable PFAS reduction. Standard pitcher and faucet filters without P473 certification do not remove PFAS.

Waterdrop G3P600 Reverse Osmosis System
Under-sink RO system

8-stage tankless RO system certified to NSF/ANSI 58, reduces 1,000+ contaminants including PFAS, lead, arsenic, fluoride, and nitrates.

Epic Pure XP Water Filter Pitcher
Pitcher filter

NSF-certified dual-layer filtration reduces 70+ contaminants including PFAS, lead, chlorine, microplastics, and bacteria.

See recommendations matched to your exact address: choose your ZIP code below.

Frequently Asked Questions about Dupo Tap Water

Is Dupo tap water safe to drink?

Dupo tap water meets Safe Drinking Water Act requirements but 2 of 2 ZIP codes show contaminant levels above EPA health-based guidelines. A certified point-of-use filter adds an extra layer of protection.

What contaminants are in Dupo tap water?

The most commonly detected contaminants in Dupo water systems include: lithium, PFTrDA, 6:2 FTS. See the ZIP-level reports for exact measurements and EPA guideline comparisons.

Where does Dupo get its drinking water?

Dupo receives water from 3 public water systems, including DUPO.

Do I need a water filter in Dupo?

If your ZIP code is among those with detections above EPA health guidelines, choose a filter certified for the specific contaminants shown in your ZIP report. Reverse osmosis is generally the broadest option for PFAS, lithium, and many other dissolved contaminants.

How often is Dupo tap water tested?

Public water systems in Dupo are required by the EPA to test for regulated contaminants on schedules ranging from daily (for microbials and disinfectants) to annual or triennial (for many chemical contaminants). Results are published in annual Consumer Confidence Reports (CCRs). The data on this page reflects the most recent available EPA monitoring results, with the latest sample date of 2025-11-03.

Tap water reports by ZIP in Dupo

Water utilities serving Dupo, IL

Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.

Modeled boundaries are shown with a dashed outline.

Also covers / overlaps with