NJDEP tier data
Monmouth County Radon Tiers by Town (NJDEP Data)
A reference table of NJDEP 2015 radon tier assignments for Monmouth County towns this site covers, with the full state report linked for every other municipality. A tier is a town-level priority signal — the home’s own test result is what decides action.
Last reviewed July 22, 2026. Tier assignments quoted from the NJDEP 2015 Radon Tier Assignment Report (PDF).
Direct answer
In NJDEP’s 2015 tier data, Monmouth County includes both Tier 1 (high radon potential) and Tier 2 (moderate potential) municipalities. Among towns covered here, Freehold Township, Marlboro, Holmdel, Colts Neck, and Little Silver are Tier 1; Middletown, Manalapan, Red Bank, Wall, and Tinton Falls are Tier 2. NJDEP recommends testing every home regardless of tier, and EPA guidance calls for mitigation at 4.0 pCi/L or higher.
Town-by-town
Tier assignments for covered Monmouth towns.
| Town | NJDEP 2015 tier | Notes | Local page |
|---|---|---|---|
| Freehold | Tier 1 — high potential | NJDEP 2015 data lists Freehold Township as Tier 1, high radon potential; verify municipality-specific details for Freehold Borough if the address distinction matters. | Freehold page |
| Middletown | Tier 2 — moderate potential | NJDEP 2015 data lists Middletown Township as Tier 2, moderate radon potential. | Middletown page |
| Marlboro | Tier 1 — high potential | NJDEP 2015 data designates Marlboro Township as Tier 1 based on the permanent Tier 1 rules noted in the report. | Marlboro page |
| Holmdel | Tier 1 — high potential | NJDEP 2015 data lists Holmdel Township as Tier 1, high radon potential. | Holmdel page |
| Colts Neck | Tier 1 — high potential | NJDEP 2015 data lists Colts Neck Township as Tier 1, high radon potential. | Colts Neck page |
| Manalapan | Tier 2 — moderate potential | NJDEP 2015 data lists Manalapan Township as Tier 2, moderate radon potential. | Manalapan page |
| Red Bank | Tier 2 — moderate potential | NJDEP 2015 data lists Red Bank Borough as Tier 2, moderate radon potential. | Red Bank page |
| Wall | Tier 2 — moderate potential | NJDEP 2015 data lists Wall Township as Tier 2, moderate radon potential. | Wall page |
| Tinton Falls | Tier 2 — moderate potential | NJDEP 2015 data lists Tinton Falls Borough as Tier 2, moderate radon potential. | Service area |
| Little Silver | Tier 1 — high potential | NJDEP 2015 data lists Little Silver Borough as Tier 1, high radon potential. | Little Silver page |
Monmouth County has more municipalities than this table covers. For any town not listed, the tier assignment is in the full NJDEP 2015 report (PDF). Agents, inspectors, and local publications are welcome to reference this table with attribution to NJDEP as the underlying source.
How to use a tier
A tier is a reason to test, not a result.
Tier data describes how often elevated results have been found in a municipality. It cannot say whether a specific home is above or below 4.0 pCi/L — foundation type, soil contact, and construction details vary house to house. Use the tier to decide how urgently to test, then let the actual pCi/L result drive mitigation decisions.
Clear next step
Request Monmouth County radon testing or mitigation routing.
Use this for first tests, real-estate deadlines, 4.0+ pCi/L results, mitigation planning, and post-mitigation retests.
Requests are routed only where an appropriate NJ-certified provider is available.
FAQ
Common homeowner questions
What do the NJDEP radon tiers mean?
NJDEP assigns every New Jersey municipality a radon potential tier in its 2015 Radon Tier Assignment Report, based on actual indoor test results collected in each municipality. Tier 1 means high radon potential, Tier 2 moderate, and Tier 3 low. The tiers describe how often elevated results have been found locally — they are screening and prioritization data, not predictions for a specific address.
My town is Tier 2. Do I still need to test?
Yes. NJDEP recommends testing all New Jersey homes regardless of tier, because radon varies house to house within the same town — foundation type, soil contact, and construction details matter more than the municipal average. A Tier 2 town contains homes above 4.0 pCi/L, and a Tier 1 town contains homes below it. The tier is a reason to prioritize testing, never a substitute for it.
Where does this data come from?
From the New Jersey Department of Environmental Protection’s 2015 Radon Tier Assignment Report, which lists the tier for every municipality in the state. This page summarizes the assignments for a set of Monmouth County towns and links the full report for every other municipality. The tier assignments on this page are quoted from that report without modification.