City of Evanston

We are proud to present Evanston's annual water quality report, a service designed specifically for our valued water customers. The Evanston water program is dedicated to delivering the highest quality municipal water possible.

In 2017, as in previous years, your tap water has successfully met all United States Environmental Protection Agency (USEPA) and State of Illinois municipal water health standards with zero violations to report. Your water source, Lake Michigan, is not just a major commercial transportation route and recreational asset with beautiful shorelines – it's also a vital source of clean water!

Nearly half of the world's freshwater comes from Lake Michigan and the other Great Lakes. According to USEPA data, Lake Michigan's water quality has significantly improved over the past 25 years. Current regulations restrict industrial and sewage treatment plant discharges into Lake Michigan, which helps reduce contamination risks. All 63 miles of Illinois shoreline are now considered to be in excellent condition.

The Illinois EPA considers all surface water sources for community water supply to be susceptible to potential pollutants. Surface water naturally allows contaminants to enter intakes with only dilution as protection, which is why treatment is mandatory for all surface water supplies in Illinois. Evanston recognized this need long before requirements were implemented and has operated a water treatment facility for over a century!

Evanston's water intakes are positioned far enough offshore that shoreline impacts aren't typically a factor in water quality. However, during wet weather conditions, contamination potential exists due to the North Shore Channel's proximity. Additionally, the location near major shipping lanes contributes to the vulnerability of these three intakes.

Today, the Public Works Agency's Water Production Bureau staff continues Evanston's tradition of excellence by working around the clock for your health and safety. We take pride in our water and commit to providing you with the highest quality water that is humanly and technologically possible.

1. What is impervious area? Impervious area (or impervious surface) refers to any surface that prevents rainfall from soaking into the soil. This includes pavement (asphalt, concrete, etc.), rooftops, patios, sidewalks, and compacted graveled surfaces such as parking areas and driveways.
2. How are impervious surfaces determined? Impervious surfaces are measured using aerial photographs that have been processed to create scaled images allowing accurate measurements. In certain instances, field measurements or information provided on site plans may supplement data available from aerial images.
3. There are no storm sewers on or near my property. Why should I pay a fee? All properties generate stormwater runoff that requires management. Even if your property has never experienced flooding and has no nearby storm sewers, the runoff from your property must be controlled to prevent downstream pollution and flooding. This applies even when most stormwater is managed onsite; property owners must contribute to services beyond their property lines, including permit compliance, municipal separate storm sewer system (MS4) maintenance, and citywide stormwater infrastructure improvements.
4. Why not just include the stormwater program costs in our property taxes? While property taxes effectively generate revenue, creating a dedicated funding mechanism often best ensures those revenues address specific needs. A dedicated stormwater fee has the advantage of assessing costs based on impervious surface area, providing a fairer and more equitable revenue collection system than tax-based approaches.
5. There is no separate charge/dedicated fund for police, fire, roads, etc. Why do we need it for stormwater? Those services (police, fire, roads) are general services that the City provides. Stormwater is evolving into a true utility, similar to sewer, water and electricity, due to regulatory requirements and the extensive infrastructure (pipes, channels, catch basins, etc.) requiring maintenance for proper operation.
6. How do I affect stormwater runoff? If your property includes a roof, driveway, parking lot, or other impervious surfaces, you impact both the quantity and quality of stormwater runoff. Household activities like car washing and fertilizer use can also affect stormwater quality.
7. What is an ERU? An ERU (equivalent residential unit) represents the amount of impervious surface (measured in square feet) on a typical, single-family residential property.