Radon Levels & Zone Map in Passaic County, NJ
Direct Answer for basement and lowest-level tests: Passaic County sits in the gray zone. The map helps, but your own reading matters more than the countywide signal.
Treat the map as a hint, not the answer
Zone 2 is the gray area. A real reading is what decides whether you retest, track, or price mitigation.
Official tier data shows local radon potential, not a county pCi/L average.
2.0-3.9 pCi/L usually means retest or track. 4.0+ is where EPA action and quote planning start to matter.
No reading: test first. Borderline results often need retest or long-term tracking.
Official County Evidence
Passaic County evidence before the next step
Passaic County, NJ has more than the EPA map: NJ DEP exposes municipality radon potential tiers, with 12.5% Tier 1 and 68.8% Tier 1 or Tier 2 municipalities.
Source window
Processed county verdict
Processed verdict
Mixed radon-potential area
Tier-backed confidence - 62/100
Primary result
Tier 2 dominant
n/a in-state
4.0+ signal
12.5% Tier 1
n/a in-state
High-end signal
Tier 1 present
n/a in-state
County-specific verdict
Passaic County, NJ is judged from NJ municipal radon tiers, not a county average.
Passaic County is a confirmation case because the NJ DEP table shows 12.5% Tier 1 and 68.8% Tier 1 or Tier 2 municipalities. A borderline result deserves a follow-up test before being dismissed.
Real-estate use
Buyer or seller use: use the county signal to justify a test contingency or retest, then reserve credits for confirmed 4.0+ home results.
Passaic County has mixed NJ tier signals, so the county page should push a home test rather than implying the map settles the answer.
Choose Next StepTesting priority answer
Is Passaic County a higher-priority radon testing county?
Passaic County is not shown from a county average table here; it is judged from NJ DEP municipal tier distribution. Treat Tier 1/Tier 2 concentration as a test-priority signal, then let the home result decide mitigation.
Pick the situation that matches you
You should not need to read the whole guide before clicking one of these. Start with the lane that matches your current stage, then come back for the deeper reference only if you still need it.
Jump into a prefilled Passaic County action plan based on the result you already have, instead of starting from a generic cost page.
I have not tested yet
Do not price mitigation blind. Get the first number, then decide whether you need monitoring, quotes, or nothing at all.
My result is 2.0-3.9
Usually retest or track first. If the reading keeps showing up, use the local action plan to decide whether pricing makes sense.
My result is 4.0+
This is the EPA action line. Use the local cost page before calling contractors so you know the likely scope, timing, and budget.
I am buying or selling
Turn the reading into a credit or repair number before negotiation starts. This is the faster path than arguing from a generic article.
Already tested once and just want to watch the number trend?
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County Evidence Snapshot
Passaic County testing context
Passaic County is a gray-zone county: the EPA map is useful context, but the local housing profile and your own home test decide the next step.
EPA map signal
Zone 2
County-level predicted indoor screening range, not a home-level test result.
Housing base
184,830
52th percentile among 21 NJ counties with data.
Older housing share
20.8%
10th percentile in-state; older homes often need clearer test placement decisions.
Median home value
$413,500
Used as context for whether mitigation is a small maintenance item or a negotiation issue.
RadonVerdict Processed Verdict
Mixed radon-potential area
Primary result rank
n/a
Tier 2 dominant
4.0+ rank
n/a
12.5% Tier 1 at or above 4.0
High-end rank
n/a
Tier 1 present
Test volume rank
n/a
16 municipalities
How to use this county data
Data source
NJ municipal radon-potential table
NJ DEP publishes municipal radon-potential tiers, so this county is interpreted from local tier concentration rather than a county pCi/L average.
What the numbers show
Town-level radon potential
This uses the share of Tier 1 and Tier 2 municipalities. Treat it as a reason to test, not as a home reading.
Nearby comparison
Nearby comparison: compare NJ counties by Tier 1 and Tier 1-or-2 municipal share, then let the home test decide action.
How this helps
Use this when deciding whether to prioritize testing before purchase, renovation, or a retest.
What the data says
Passaic County, NJ has 2 Tier 1 municipalities, 9 Tier 2 municipalities, and 5 Tier 3 municipalities in the NJ DEP radon potential table.
12.5% of municipalities are Tier 1 and 68.8% are Tier 1 or Tier 2. This is a reason to prioritize testing, not a county average pCi/L measurement.
What to do with it
Passaic County has mixed NJ tier signals, so the county page should push a home test rather than implying the map settles the answer.
Retest trigger: a 2.0-3.9 pCi/L home result should be confirmed when local NJ tier concentration is meaningful; the tier table is a priority signal, not a home result.
Tier-backed confidence (62/100) from NJ DEP municipality-level radon potential designations; numeric county pCi/L metrics are still not normalized.
No reading yet
No reading yet: use the NJ tier signal to prioritize testing, but do not treat a tier as a home result.
2.0-3.9 result
2.0-3.9 pCi/L: retest or track; tier context can justify not dismissing a borderline result.
4.0+ result
4.0+ pCi/L: move to mitigation quotes or seller-credit planning; the home result outranks the tier map.
Source hierarchy: NJ DEP radon potential tiers are used for this county, with EPA zone and Census housing data as supporting context.
Direct Answer
What radon risk level should homeowners assume in Passaic County?
Passaic County is currently categorized as EPA Zone 2 (Moderate Risk). Test all lived-in levels and confirm with follow-up testing if elevated.
| Evidence | Value |
|---|---|
| Area | Passaic County, NJ |
| EPA Zone | Zone 2 |
| Primary Recommendation | Perform direct radon testing in the lowest livable level |
Your Radon Reading
Enter your home's measured level. The county evidence is a radon-potential tier, not a pCi/L reading.
Elevated - Consider Action
Your reading is below the US EPA action level (4.0 pCi/L), but this range still warrants follow-up testing. The World Health Organization uses 2.7 pCi/L as a tighter reference point.
If this was just a one-time snapshot, confirm it with another test or with longer tracking. If this level persists, planning mitigation is reasonable, especially for homes with frequent basement use, children, or pending real-estate transactions. Scroll down to see your estimated cost.
Understanding Radon Levels: Complete Reference
Below 2.0 pCi/L - Lower Concern, Keep Testing
Below both the EPA (4.0) and WHO (2.7) action reference levels. This usually means mitigation is not the next immediate step after a confirmed result. The average outdoor radon level is approximately 0.4 pCi/L, and there is no known risk-free indoor level. Periodic testing is still recommended because levels can change over time due to seasonal variations, changes in home ventilation, or foundation settling.
-4.0
2.0 - 4.0 pCi/L - Elevated, Consider Action
Exceeds the World Health Organization's reference level of 2.7 pCi/L but falls below the US EPA action threshold. The EPA states that homeowners should "consider fixing" homes in this range, especially if the home has a basement used as living space, if children are present, or in connection with a real estate transaction. Practical next step: run a confirmatory long-term test, then compare mitigation quotes if levels remain elevated.
-8.0
4.0 - 8.0 pCi/L - Action Recommended
Exceeds the EPA action level of 4.0 pCi/L. The EPA and Surgeon General strongly recommend mitigation within a few months. At this level, prioritize confirmatory testing and contractor planning. Standard sub-slab depressurization systems typically reduce indoor levels by 80-99%.
Above 8.0 pCi/L - Urgent Action Required
At these levels, the EPA recommends expedited mitigation - ideally within weeks, not months. Occupants should minimize time in lower-level rooms until the system is installed. Use a certified mitigator and request priority scheduling to shorten high-exposure time. Many mitigators offer priority scheduling for homes above 8.0 pCi/L.
Why Radon is Worth Monitoring in Passaic County
Passaic County falls in EPA Zone 2, where the predicted indoor screening range is between 2.0 and 4.0 pCi/L. Even when the countywide map signal sits below the EPA action level, geological variability means that some individual homes will still test above 4.0 pCi/L.
The soil composition in this area typically includes a mix of sedimentary formations that can contain moderate uranium deposits. Homes with basement or crawlspace foundations are particularly susceptible, as they provide more pathways for soil gas entry.
The World Health Organization recommends action at 2.7 pCi/L - well below the US EPA threshold. If you have children, spend significant time in below-grade rooms, or are buying/selling a home, testing is essential even in a Zone 2 area.
Radon & Health: What the Science Says
lung cancer
from radon
4.0 pCi/L
Radon is a Class A carcinogen - the same classification as asbestos and tobacco smoke. The National Academy of Sciences estimates that radon causes approximately 21,000 lung cancer deaths annually in the United States, making it the leading environmental cause of cancer death.
Unlike smoking, radon exposure is involuntary and often invisible. There is no safe level of radon - risk increases linearly with exposure. The good news: radon mitigation systems are highly effective, typically reducing indoor levels by 80-99% within hours of activation.
Source: US Environmental Protection Agency, "A Citizen's Guide to Radon" (EPA 402/K-12/002). National Academy of Sciences, Biological Effects of Ionizing Radiation (BEIR VI) Report, 1999.
Step 1: Test Your Home
Testing is the only way to know your home's radon level. Zone data tells you the regional risk, but your home could be significantly higher or lower than the countywide pattern. For most homeowners, the right first purchase is a low-cost short-term test kit.
A digital monitor is a better fit after your first result, for seasonal re-checks, or to keep tracking levels after mitigation.
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Already Know Your Level?
If your test shows 4.0 pCi/L or higher, get an itemized cost estimate specific to Passaic County - including regional labor rates and permit requirements.
Get Mitigation Cost Estimate ->NJ Radon Regulations
New Jersey requires radon testing and disclosure for all real estate transactions in Tier 1 counties under the Radon Hazard Subcode.
New Jersey requires certification for radon testers and mitigators through the NJ DEP.
How to Test for Radon in Passaic County
Buy a Test Kit
Purchase a short-term charcoal test kit online or from a local hardware store. Cost: $15-$30. Place it in the lowest livable level of your home.
Wait 2-7 Days
Keep doors and windows closed (except normal entry/exit) during the test period. Avoid running whole-house fans. Mail the kit to the lab provided.
Read Your Results
If results are below 4.0 pCi/L, re-test every 2 years or use a monitor for ongoing tracking. If above 4.0, use our cost calculator to see mitigation options.
Related Radon Resources for Passaic County
Explore Other NJ Counties
Official State Resource
New Jersey radon program and rules
Use the state program link to verify local radon guidance, disclosure language, and contractor credential expectations before you act on an estimate.
Disclosure rule tracked
New Jersey requires radon testing and disclosure for all real estate transactions in Tier 1 counties under the Radon Hazard Subcode.
State licensing required
New Jersey requires certification for radon testers and mitigators through the NJ DEP.
Sources & Methodology
Radon zone classifications for Passaic County are sourced from the EPA's Map of Radon Zones, which uses geological surveys, indoor radon measurements, and soil permeability data to assign each county a risk tier.
Disclaimer: Zone data represents county-level screening ranges and cannot predict the radon level in any specific home. Testing is the only reliable method to determine your home's radon concentration. This content is for informational purposes and is not medical advice.
Content review: Source-level retrieval dates
Editorial and Data Transparency
- Author
- RadonVerdict Data Team (Public Data and Cost Modeling)
- Content Review
- Source-level dates shown below
- Data Retrieved At
- 2026-02-24
Primary Sources
- EPA Map of Radon Zones (retrieved 2026-02-21)
- EPA A Citizen's Guide to Radon (retrieved 2026-05-05)
- CDC Environmental Public Health Tracking - Radon Testing (retrieved 2026-05-05)
- Official NJ radon program
- US Census Bureau, 2018-2022 American Community Survey 5-Year Estimates (retrieved 2026-02-24)