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ZIP report cards

How each grade works

Every ZIP report card is built from public records. This page explains how each letter is set, where the data comes from, how current it is, and what it cannot tell you. If something looks wrong for a place you know, tell us below.

Reading the letters

A ZIP covers several neighborhoods (census tracts) and sometimes several water systems. We grade each one, then show the range: “D to F” means the best part of the ZIP is a D and the worst is an F. We never average them, and missing data is left blank rather than filled with a middle grade.

  • AAmong the best 20% of U.S. neighborhoods
  • BBetter than most
  • CAbout typical
  • DWorse than most
  • FAmong the worst 20%

Those bands apply to categories compared nationally. Categories with fixed thresholds or health benchmarks say exactly what earns each letter below. A letter is a screen, not a safety verdict.

Category by category

Superfund sites nearby

Compared nationally

How close each neighborhood is to Superfund (National Priorities List) cleanup sites, weighted by distance, from EPA’s EJScreen.

  • The neighborhood’s national percentile sets the letter: A is the best 20% of U.S. neighborhoods, F the worst 20%.

Each card also names the nearest listed sites within 10 miles, with EPA’s status and a link to the site’s EPA page.

Factories and industrial sites

Compared nationally

Industrial pressure from three EPA indicators: modeled toxic air from industry (RSEI), facilities that must file chemical-accident plans (RMP), and hazardous-waste facilities (TSDF).

  • The average of the three national percentiles sets the letter, by fifths.

Cards name the facilities and chemicals behind the largest shares of modeled toxic air in the area, from EPA RSEI. Those are screening values, not measured exposure.

Oil and gas wells

Fixed thresholds

Oil and gas wells within 5 miles of each neighborhood’s center, and EPA emergency responses within 10 miles.

  • A: no wells and no EPA responses nearby.
  • C: 2 or more wells. D: 5 or more active wells.
  • F: 5 or more unplugged orphaned wells, or 25 or more wells including an orphaned one.
  • B: anything in between.

Parks and nature nearby

Fixed tiers

Access to nature: nearby parks and protected land, and how much of the surrounding land is natural rather than built or farmed.

  • A nature-connection tier sets the letter, from Restorative (A) to Deprived (F).

A park close by can still come with a low grade where most land around it is paved or built.

Air quality

Compared nationally

Fine particles (PM2.5): each neighborhood’s own five-year average, from satellite-derived estimates calibrated to ground monitors.

  • Neighborhoods are ranked against every U.S. neighborhood; the letter is the fifth it falls in.
  • Each card also shows the WHO health guideline (5 µg/m³) and the EPA annual legal standard (9 µg/m³).

Where a neighborhood has no satellite value, the county series is used and labeled county-wide. Ozone is shown for context and does not set the letter.

Drinking water quality

Health benchmarks

Lab results for each public water system that serves the ZIP, compared with health goals (mostly California’s Public Health Goals) and shown next to EPA legal limits.

  • Non-cancer hazard index: under 1 is A, 3 B, 9 C, 30 D, 30 or more F.
  • Lifetime cancer risk: under 3 in a million is A, 3 in 100,000 B, 3 in 10,000 C, 3 in 1,000 D, higher F.
  • The letter is the worse of the two. Systems with too little testing get no grade.

Cards list every contaminant above its health goal, with test counts, dates, which labs reported it, and a flag when a lab could not test down to the goal.

Pesticide use

Compared nationally

Agricultural pesticide use: USGS county estimates, weighted by how much farmland surrounds each neighborhood, per resident.

  • Ranked against national deciles; the letter is the fifth it falls in.

USGS county estimates currently end around 2018.

Neighborhood health status

Compared nationally

How common nine chronic conditions are, from CDC PLACES estimates: heart disease, diabetes, cancer, stroke, asthma, COPD, depression, obesity and high blood pressure.

  • The average national percentile of the nine sets the letter, by fifths.

These rates reflect many causes, including income and access to care. They do not show that pollution caused them.

Past wildfire impacts

Fixed thresholds

Past wildfires recorded near each neighborhood.

  • F: inside a recorded fire footprint. D: nearest fire within 10 miles.
  • C: within 75 miles. B: farther. A: none recorded in range.

A record of the past, not a forecast. Smoke from distant fires is not included.

Past flood impacts

Fixed thresholds

Past flood events surveyed with high-water marks near each neighborhood.

  • F: inside a recorded flood footprint. D: nearest event within 10 miles.
  • C: within 75 miles. B: farther. A: none recorded in range.

This is not a FEMA flood zone. Check your address on FEMA’s flood map before buying or insuring a home.

Noise levels

Health benchmarks

Modeled day–evening–night noise from roads, rail, aircraft and other activity at each neighborhood’s center.

  • Each source is compared with its WHO guideline (roads 53 dB, rail 54 dB, aircraft 45 dB). The further the loudest source is over its guideline, the lower the letter.
  • CONUS transportation and activity noise modelPollutionProfile (model), from U.S. DOT and FAA data · noise/2026-08-26-v1 · data through 2025

Radiation signals

Screening band

A screening band from geology (radon potential, natural gamma radiation) and known radiation sites.

  • Well below typical is A; typical is C; well above typical is F.

It cannot tell you your home’s radon level. Radon varies house to house; a home test costs about $15–30.

  • Radiation screening bandPollutionProfile (screening model), from USGS, DOE and USACE data · radiation/2026-09-02-v1 · data 2005–2026

How current the data is

Public datasets are published on different schedules, some years after the measurements. Each card shows the years behind its numbers. The most recent year each category draws on:

CategoryMain sourcesLatest data year
Superfund sites nearbyU.S. Environmental Protection Agency2024
Factories and industrial sitesU.S. Environmental Protection Agency2022
Oil and gas wellsFracTracker Alliance; U.S. Geological Survey; U.S. Environmental Protection Agency2022
Parks and nature nearbyU.S. Geological Surveynot recorded
Air qualityAtmospheric Composition Analysis Group, Washington University in St. Louis; Meng, Li, Martin, van Donkelaar, Hystad and Brauer; U.S. Environmental Protection Agency2025
Drinking water qualityU.S. Environmental Protection Agency; State drinking-water programs; California Office of Environmental Health Hazard Assessment2025
Pesticide useU.S. Geological Survey2018
Neighborhood health statusU.S. Centers for Disease Control and Prevention2022
Past wildfire impactsNational Interagency Fire Center2025
Past flood impactsU.S. Geological Survey2025
Noise levelsPollutionProfile2025
Radiation signalsPollutionProfile2026

What this cannot tell you

  • It does not measure anything in your body or your home. These are records about places.
  • It cannot say that a place caused an illness. It shows which findings are worth a closer look.
  • A ZIP grade describes a range of neighborhoods. Your block can be better or worse than the card shows.
  • Distances are measured from the center of each neighborhood, and to the center of each site.
  • Health goals are stricter than legal limits on purpose. Water can meet every EPA legal limit and still exceed a health goal; the cards show both.

Report a problem

If a site, facility, water system or number looks wrong for a place you know, tell us. We check every report against the source data and fix what is wrong in the next build. Utilities and facility operators are welcome to send documentation.

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