|
pollutant |
federal primary standard |
North Dakota standard |
|
total suspended particulates (TSP) |
75 µg/m3
annual geometric mean
260 µg/m3
24-hr. average |
60 µg/m3
annual geometric mean
250 µg/m3
maximum 24-hr. average |
settled particulates (dustfall) |
none |
15 tons/sq. mile,
maximum 3-month arithmetic mean
in residential areas
30 tons/sq. mile,
maximum 3-month arithmetic mean
in heavy industrial areas |
sulfur dioxide |
0.03 ppm (30 µg/m3)
annual arithmetic average
0.14 ppm (365 µg/m3)
24-hr. average |
60 µg/m3
(0.02 ppm) maximum annual
arithmetic mean
260 µg/m3
(0.10 ppm) maximum
24-hr. concentration
715 µg/m3
(0.24 ppm) maximum
1-hr. concentration |
reactive sulfur |
none |
0.24 mg/100 cm2/day,
maximum annual arithmetic mean
0.50 mg/100 cm2/day,
maximum for 1-month period |
suspended sulfate |
none |
4 µg/m3
12 µg/m3
maximum annual arithmetic
mean; maximum 24-hr.
concentration not to be exceeded
over 1% of the time
30 µg/m3
maximum 1-hr concentration
not to be exceeded over
1% of the time |
foliar fluoride |
none |
none |
sulfuric acid mist, sulfur trioxide, or combination |
none |
4 µg/m3
maximum annual arithmetic mean
12 µg/m3
maximum 24-hr.
concentration not
to be exceeded over
1% of the time
30 µg/m3
maximum 1-hr.
concentration not
to be exceeded over
1% of the time |
hydrogen sulfide |
none |
45 µg/m3 (0.032 ppm)
maximum half-hour concentration
not to be exceeded more than twice in any
five consecutive days
75 µg/m3 (0.054 ppm)
maximum half-hour concentration
not to be exceeded more than twice a year |
carbon monoxide |
9 ppm (10 mg/m3)
8-hr. average*
35 ppm (40 mg/m3)
1-hr. average* |
10 mg/m3 (9 ppm)
maximum 3-hr. concentration*
40 mg/m3 (35 ppm)
maximum 1-hr. concentration* |
nitrogen dioxide |
0.05 ppm (100 µg/m3)
annual arithmetic average |
100 µg/m3
(0.05 ppm) maximum
annual arithmetic mean
200 µg/m3 (0.10 ppm)
maximum 1-hr.
concentration not to be exceeded
over 1% of the time in any 3 months |
photochemical oxidants (ozone) |
0.12 ppm (235 µg/m3)
1-hr. average* |
235 µg/m3
(0.12 ppm) maximum
1-hr. concentration* |
hydrocarbons (less methane) |
24 ppm (160 µg/m3)
3-hr. concentration
(6-9 AM)* |
160 µg/m3 (0.24) ppm
maximum 3-hr.
concentration (6-9 AM)* |
lead |
1.5 µg/m3
calendar quarter average |
1.5 µg/m3
quarterly arithmetic mean |
visibility |
none |
0.4 coefficient of haze
per 100 linear feet maximum annual geometric mean
(coefficient of haze) |