Step 1: The lake

Chicago's report notes that Lake Michigan is the only Great Lake entirely within the United States, and the second largest by volume, at 1,180 cubic miles of water.

Step 2: Two giant treatment plants

The City of Chicago treats the water at two plants: the Jardine Water Purification Plant — which the City calls the largest conventional water treatment plant in the world — and the Eugene Sawyer Water Purification Plant. Together they can produce about 2.1 billion gallons a day. Per Chicago's report, Jardine serves the northern parts of the city and suburbs, and Sawyer serves the southern parts.

Step 3: Tunnels, pumps, and mains

The City says its system includes 65 miles of tunnels, 12 pumping stations, and 4,300 miles of water mains, and it supplies more than five million people in Northeastern Illinois — including River Grove.

Step 4: River Grove's own system

From there, the Village of River Grove delivers the water through its own pipes and monitors chlorine levels so the water stays disinfected on the way. That's why River Grove publishes its own water quality report, with its own lead and chlorine by-product results.

Step 5: The last few feet

The final stretch — your service line, your home's pipes, solder, and faucets — is where lead most often gets in. The lake and the plant aren't the issue; the plumbing can be. River Grove's April 2026 inventory lists 1,627 lead and 218 galvanized-requiring-replacement service lines out of 2,740; 882 are non-lead.

A few numbers from Chicago's 2025 report

  • Chlorine: 1 ppm (limit 4 ppm)
  • Fluoride: 0.75 ppm, added to promote strong teeth
  • Sodium: 9.10 ppm, from naturally occurring deposits
  • PFAS: Chicago reports non-detect results in its 2014, 2020, and 2024 studies

These are Chicago system numbers. River Grove's own results, measured in its own pipes, are on the River Grove report card.

Quick questions

Where does River Grove's water come from?

Lake Michigan surface water purchased directly from the City of Chicago, stored in the Village's underground reservoir, and pumped into the distribution system.

Sources

  1. Village of River Grove 2026 Annual Consumer Confidence Report (2025 data) — Village of River Grove
  2. Suburban Customers & Regional Partnerships — City of Chicago Department of Water Management
  3. 2025 Water Quality Report — City of Chicago Department of Water Management
  4. PFAS Findings — City of Chicago Department of Water Management

This guide is general information, not medical or legal advice. River Grove Water Filtration is an independent business and is not affiliated with the Village of River Grove. Product certifications are model-specific and can change; check the current listing before you buy.