What environmental databases are included?

This page aggregates data from eight EPA databases: Safe Drinking Water (SDWIS), Superfund/NPL sites, Toxic Release Inventory (TRI), Air Quality Index (AQI), Leaking Underground Storage Tanks (LUST), NPDES water discharge permits, RCRA hazardous waste, and Brownfields.

What does the Air Quality Index (AQI) mean?

AQI is measured on a scale from 0 to 500. Values under 50 are 'Good,' 51-100 is 'Moderate,' and above 100 is 'Unhealthy for Sensitive Groups.' AQI is measured at the county level since air quality monitoring stations are sparse. Your town shares its county's AQI reading.

What is a Superfund site?

A Superfund site is a location contaminated by hazardous waste that has been placed on the EPA's National Priorities List (NPL) for long-term cleanup. These sites pose serious risks to human health and the environment. Cleanup can take decades and cost hundreds of millions of dollars.

Delafield, WI Water Quality, EPA Sites & Air Quality Data

Environmental Reporti

Air Qualityi

41Good

Water Systemsi

8community / 74 total

Water Violationsi

Active NPDESi

2/ 4 total

Air Quality — Waukesha County (2025)i

AQS

The Air Quality Index measures how clean or polluted the air is on a given day. AQI is reported at the county level. A score of 0–50 is considered good; 51–100 is moderate; above 100 may be unhealthy for sensitive groups.

Good

Median AQI

050100150200300

max 115

PM2.5 Daysi

119

Ozone Daysi

Drinking Wateri

SDWIS

Public water systems registered to serve this area. Community systems (CWS) provide water to residents year-round. Transient systems serve places like gas stations or restaurants. Violations indicate a system failed to meet federal drinking water standards.

Community Systemsi

Active Systemsi

Recent Violationsi

Transient (39)

Community (8)

Non-Transient (3)

Recent Violations (Last 5 Years)

ST JOHNS NORTHWESTERN ACADEMIES

18 violationsLatest: 2024-10-17

EPA

NASHOTAH HOUSE

3 violationsLatest: 2025-01-01

EPA

ARBORS

8 violationsLatest: 2024-10-17

EPA

Historical Violations (Over 5 Years Ago)

COUNTRY AIRE APARTMENTS 2

1 violationLatest: 1995-01-01

EPA

COUNTRY AIRE APARTMENTS 3

1 violationLatest: 1995-01-01

EPA

DELAFIELD WATERWORKS

2 violationsLatest: 2001-07-01

EPA

Wastewater & Stormwater Permits (NPDES)i

NPDES

Under the Clean Water Act, any facility that discharges wastewater or stormwater into rivers, lakes, or streams must hold an NPDES permit. "Effective" means the permit is currently active and the facility is authorized to discharge under its permit conditions.

Active Permitsi

Expired / Terminatedi

GMRI, INC2440 N. MILWAUKEE STREETMinor Discharge|EPA

BEN M ASKREN & AMY ASKRENWEST OF MAPLE AVE ADJACENT TO 601 MAPLE AVE TO THEMinor Discharge|EPA

Nearest Hazardous Waste Disposal Facilitiesi

RCRA

These are the closest licensed facilities where hazardous waste (chemicals, solvents, industrial byproducts) can be legally treated, stored, or disposed of.

SAFETY-KLEEN SYSTEMS WAUKESHA (WAU)WAUKESHA10.2 mi|EPA

Cleanup Sites (Brownfields)i

EPA Brownfields

Former industrial or commercial properties where contamination has been found. "Remedy Complete" means cleanup is finished. "Construction Complete" means cleanup infrastructure is built but monitoring continues. "In Progress" means the site is still being investigated or cleaned up.

DELAFIELD CITY HALL & LIBRARY CAMPUS507 ONEIDA STREETIn Progress|

EV Charging & Alternative Fuel Stationsi

AFDC

Publicly listed alternative fuel and EV charging stations within the municipality. Data from the U.S. Department of Energy. "Open" stations are currently available for use; "Planned" stations are approved but not yet operational.

Total Stationsi

EV Stationsi

Level 2 Portsi

Blink Network

The Grain705 Genesee StreetElectric2 L2Blink Network