Methodology
We turn public environmental records into a first-screening report for a specific address. The goal is to show what is worth reviewing, what the source can and cannot prove, and what to ask next.
We normalize the submitted U.S. address and match it to latitude, longitude, ZIP, county, state, and census tract identifiers where available.
We check federal and public datasets for air quality, drinking-water compliance, PFAS contamination, flood zone, natural hazard, regulated facility, and Superfund signals.
Each category is interpreted with source-specific rules so one signal does not hide another. Grades are screening signals, not health or safety determinations.
The report translates findings into plain-English context, confidence notes, freshness notes, and practical questions to ask when evaluating an address.
A grade is a plain-English screening signal for a category such as air quality, drinking water, flood and natural hazard, or pollution and cleanup sites. It is designed to help you prioritize review. It is not a promise that a home is safe or unsafe.
A/B
Lower concern
No major signal in the checked public records.
C
Worth reviewing
A signal exists and deserves a closer look.
D/F
Needs attention
A stronger signal appears in public records.
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No clear data
A source was unavailable or could not match confidently.
Each category uses source-specific rules so a single outlier signal doesn't inflate or suppress others.
Based on AirNow 30-day average AQI. A = ≤50 average; B = ≤75; C = ≤100; D = ≤150; F = above 150 or frequent unhealthy days. The section also shows the county's EPA radon zone (from EPA's 1993 Map of Radon Zones) as a contextual signal — it informs the radon finding's status but does not move the AQI-based letter grade, because only a home test measures actual radon.
Based on EPA SDWIS compliance violations. A = no violations; B = monitoring/reporting issues only; C = health-based violations; D = multiple health-based or unresolved violations.
A = no detections; B = no detections, but DoD installations or PFAS Superfund sites nearby; C = detections below the 4 ppt federal MCL; D = detections present with military base nearby or PFAS Superfund site within 3 miles; F = any compound exceeds the 2024 EPA MCL (4 ppt PFOA/PFOS). UCMR 5 data required — grade is null if the water system was not matched or not required to test. Note: systems serving 3,300 or fewer people were generally not required to test under UCMR 5, so a small system with no UCMR 5 record may be untested rather than clean.
Based on FEMA NFHL flood zone and FEMA NRI risk score. A = Zone X or equivalent; B = 0.2% annual flood chance; C = Special Flood Hazard Area (Zone AE/A); D = Coastal high-hazard (Zone V/VE); null if no FEMA data available.
Based on EPA SEMS/Superfund proximity, weighed by tiered distance rings (on/adjacent, ¼ mile, ½ mile, 1 mile; 1–3 miles is context only). A = no nearby sites; B = sites only in the 1–3 mile context ring, or dense permitted-facility areas; C = EPA cleanup sites within 1 mile (or NPL in the context ring); D = National Priorities List (NPL) Superfund site within 1 mile. The section also reports underground storage tanks from EPA UST Finder (a state-reported 2018–2019 baseline) using the same rings out to 1 mile — wider than the ASTM Phase I norms of ¼ mile for USTs and ½ mile for leaking-tank (LUST) releases, deliberately, so nothing a Phase I would flag is skipped — and lead-paint-era housing share from Census ACS tract data as neighborhood context (not a test of the home). These contextual findings carry status labels but the letter grade remains Superfund-driven. Count findings also show a "typical for this county" band: the county-wide total from the same dataset, scaled by search-ring area versus county land area — a deliberately rough density estimate, labeled approximate county context, and hidden when the data isn't available.
Based on CDC PLACES census-tract health metrics. Contextual signal, not a grade of the property itself — reflects population health patterns in the surrounding area.