[Code of Federal Regulations]
[Title 40, Volume 5]
[Revised as of July 1, 2008]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR58.14]

[Page 225-226]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 58_AMBIENT AIR QUALITY SURVEILLANCE--Table of Contents
 
                      Subpart B_Monitoring Network
 
Sec. 58.14  System modification.

    (a) The State, or where appropriate local, agency shall develop and 
implement a plan and schedule to modify the ambient air quality 
monitoring network that complies with the findings of the network 
assessments required every 5 years by Sec. 58.10(e). The State or local 
agency shall consult with the EPA Regional Administrator during the 
development of the schedule to modify the monitoring program, and shall 
make the plan and schedule available to the public for 30 days prior to 
submission to the EPA Regional Administrator. The final plan and 
schedule with respect to the SLAMS network are subject to the approval 
of the EPA Regional Administrator. Plans containing modifications to 
NCore Stations or PAMS Stations shall be submitted to the Administrator. 
The Regional Administrator shall provide opportunity for public comment 
and shall approve or disapprove submitted plans and schedules within 120 
days.
    (b) Nothing in this section shall preclude the State, or where 
appropriate local, agency from making modifications to the SLAMS network 
for reasons other than those resulting from the periodic network 
assessments. These modifications must be reviewed and approved by the 
Regional Administrator. Each monitoring network may make or be required 
to make changes between the 5-year assessment periods, including for 
example, site relocations or the addition of PAMS networks in bumped-up 
ozone nonattainment areas. These modifications must address changes 
invoked by a new census and changes due to changing air quality levels. 
The State, or where appropriate local, agency shall provide written 
communication describing the network changes to the Regional 
Administrator for review and approval as these changes are identified.
    (c) State, or where appropriate, local agency requests for SLAMS 
monitor station discontinuation, subject to the review of the Regional 
Administrator, will be approved if any of the following criteria are met 
and if the requirements of appendix D to this part, if any, continue to 
be met. Other requests for discontinuation may also be approved on a 
case-by-case basis if discontinuance does not compromise data collection 
needed for implementation of a NAAQS and if the requirements of appendix 
D to this part, if any, continue to be met.
    (1) Any PM2.5, O3, CO, PM10, 
SO2, Pb, or NO2 SLAMS monitor which has shown 
attainment during the previous five years, that has a probability of 
less than 10 percent of exceeding 80 percent of the applicable NAAQS 
during the next three years based on the levels, trends, and variability 
observed in the past, and which is not specifically required by an 
attainment plan or maintenance plan. In a nonattainment or maintenance 
area, if the most recent attainment or maintenance plan adopted by the 
State and approved by EPA contains a contingency measure to be triggered 
by an air quality concentration and the monitor to be discontinued is 
the only SLAMS monitor operating in the nonattainment or maintenance 
area, the monitor may not be discontinued.
    (2) Any SLAMS monitor for CO, PM10, SO2, or 
NO2 which has consistently measured lower concentrations than 
another monitor for the same pollutant in the same county (or portion of 
a county within a distinct attainment area, nonattainment area, or 
maintenance area, as applicable) during the previous five years, and 
which is not specifically required by an attainment plan or maintenance 
plan, if control measures scheduled to be implemented or discontinued 
during the next five years would apply to the areas around both monitors 
and have similar effects on measured concentrations, such that the 
retained monitor would remain the higher reading of the two monitors 
being compared.
    (3) For any pollutant, any SLAMS monitor in a county (or portion of 
a county within a distinct attainment, nonattainment, or maintenance 
area, as applicable) provided the monitor has not measured violations of 
the applicable NAAQS in the previous five years, and the approved SIP 
provides for a specific, reproducible approach to representing the air 
quality of the affected county in the absence of actual monitoring data.

[[Page 226]]

    (4) A PM2.5 SLAMS monitor which EPA has determined cannot 
be compared to the relevant NAAQS because of the siting of the monitor, 
in accordance with Sec. 58.30.
    (5) A SLAMS monitor that is designed to measure concentrations 
upwind of an urban area for purposes of characterizing transport into 
the area and that has not recorded violations of the relevant NAAQS in 
the previous five years, if discontinuation of the monitor is tied to 
start-up of another station also characterizing transport.
    (6) A SLAMS monitor not eligible for removal under any of the 
criteria in paragraphs (c)(1) through (c)(5) of this section may be 
moved to a nearby location with the same scale of representation if 
logistical problems beyond the State's control make it impossible to 
continue operation at its current site.