Technology Transfer Network / NAAQS
Ozone Implementation

Table 4. Areas not meeting the 8-hour Carbon Monoxide National Ambient Air Quality Standard, 1997-98

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

Metropolitan Area	1997-98 Design Value⁽¹⁾ (ppm)	1997		1998
Metropolitan Area	1997-98 Design Value⁽¹⁾ (ppm)	2nd Max⁽²⁾	# Exc⁽³⁾	2nd Max ⁽²⁾	# Exc⁽³⁾
Designated CO nonattainment areas
Fairbanks, AK	12.1	12.1	3	10.2	2
Las Vegas, NV	10.1	8.1	1	10.1	2
Los Angeles- Long Beach, CA	15.0	15.0	12	11.5	13
Additional areas
Calexico, CA	16.7	16.7	12	13.3	8
Des Moines, IA	10.1	8.1	0	10.1	2
Weirton, WV	13.2	8.8	1	13.2	6
Number of areas not meeting the NAAQS	6		3		6

Notes:

1. The level of the 8-hour National Ambient Air Quality Standard for carbon monoxide is 9 parts per million (ppm) not to be exceeded more than once per year. The design value for the 8-hour CO NAAQS is the highest annual second maximum nonoverlapping 8-hour concentration during the most recent two years.

2. Annual second highest nonoverlapping 8-hour average CO concentration.

3. Number of nonoverlapping exceedances of the 8-hour CO NAAQS.

SOURCE: U.S. EPA's Aerometric Information Retrieval System (AIRS)

Table 4. Areas not meeting the 8-hour Carbon Monoxide National Ambient Air Quality Standard, 1997-98

Area Navigation