% of
Counties
Time
Designat
State
ed as Radon
EPA Test
Zone 1
Requireme
nt for
Initial
Testing
or Zone
Freque
ncy of Type of School
Re- Covered
Testing
Who New
May School
Conduc RRNC
t the Requirem
Testing ent
Mitigation
Requirement for
Radon Level ≤ 4
pCi/L
2 a
New
75.8
York
Oregon
58.3
Required
d
Required
ND
ND e
ND
Yes No No Yes No Yes
Yes No Yes Yes Yes No
Yes Yes No Yes No Yes
ND Yes No ND ND No No
ND Yes No Yes Yes No Yes
Yes No No Yes Yes Yes
Every
10 years
Every
Rhode
80
Island
Required
ND
three
years f
Tennesse
e
77.8
Encourag
e
ND
With 18
Virginia
71.6
Required
months of
occupancy
87.5
West
Required
With 12
month of
7
Every 5