[Code of Federal Regulations]
[Title 40, Volume 2]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR51.119]

[Page 148-149]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 51--REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF 
IMPLEMENTATION PLANS--Table of Contents
 
                       Subpart G--Control Strategy
 
Sec. 51.119  Intermittent control systems.

    (a) The use of an intermittent control system (ICS) may be taken 
into account in establishing an emission limitation for a pollutant 
under a State implementation plan, provided:
    (1) The ICS was implemented before December 31, 1970, according to 
the criteria specified in Sec. 51.119(b).
    (2) The extent to which the ICS is taken into account is limited to 
reflect emission levels and associated ambient pollutant concentrations 
that would result if the ICS was the same as it was before December 31, 
1970, and was operated as specified by the operating system of the ICS 
before December 31, 1970.
    (3) The plan allows the ICS to compensate only for emissions from a 
source for which the ICS was implemented before December 31, 1970, and, 
in the event the source has been modified, only to the extent the 
emissions correspond to the maximum capacity of the source before 
December 31, 1970. For purposes of this paragraph, a source for which 
the ICS was implemented is any particular structure or equipment the 
emissions from which were subject to the ICS operating procedures.
    (4) The plan requires the continued operation of any constant 
pollution control system which was in use before December 31, 1970, or 
the equivalent of that system.
    (5) The plan clearly defines the emission limits affected by the ICS 
and the manner in which the ICS is taken into account in establishing 
those limits.
    (6) The plan contains requirements for the operation and maintenance 
of the qualifying ICS which, together with the emission limitations and 
any other necessary requirements, will assure that the national ambient 
air quality standards and any applicable prevention of significant 
deterioration increments will be attained and maintained. These 
requirements shall include, but not necessarily be limited to, the 
following:
    (i) Requirements that a source owner or operator continuously 
operate and maintain the components of the ICS specified at 
Sec. 51.119(b)(3) (ii)-(iv) in a manner which assures that the ICS is

[[Page 149]]

at least as effective as it was before December 31, 1970. The air 
quality monitors and meteorological instrumentation specified at 
Sec. 51.119(b) may be operated by a local authority or other entity 
provided the source has ready access to the data from the monitors and 
instrumentation.
    (ii) Requirements which specify the circumstances under which, the 
extent to which, and the procedures through which, emissions shall be 
curtailed through the activation of ICS.
    (iii) Requirements for recordkeeping which require the owner or 
operator of the source to keep, for periods of at least 3 years, records 
of measured ambient air quality data, meteorological information 
acquired, and production data relating to those processes affected by 
the ICS.
    (iv) Requirements for reporting which require the owner or operator 
of the source to notify the State and EPA within 30 days of a NAAQS 
violation pertaining to the pollutant affected by the ICS.
    (7) Nothing in this paragraph affects the applicability of any new 
source review requirements or new source performance standards contained 
in the Clean Air Act or 40 CFR subchapter C. Nothing in this paragraph 
precludes a State from taking an ICS into account in establishing 
emission limitations to any extent less than permitted by this 
paragraph.
    (b) An intermittent control system (ICS) may be considered 
implemented for a pollutant before December 31, 1970, if the following 
criteria are met:
    (1) The ICS must have been established and operational with respect 
to that pollutant prior to December 31, 1970, and reductions in 
emissions of that pollutant must have occurred when warranted by 
meteorological and ambient monitoring data.
    (2) The ICS must have been designed and operated to meet an air 
quality objective for that pollutant such as an air quality level or 
standard.
    (3) The ICS must, at a minimum, have included the following 
components prior to December 31, 1970:
    (i) Air quality monitors. An array of sampling stations whose 
location and type were consistent with the air quality objective and 
operation of the system.
    (ii) Meteorological instrumentation. A meteorological data 
acquisition network (may be limited to a single station) which provided 
meteorological prediction capabilities sufficient to determine the need 
for, and degree of, emission curtailments necessary to achieve the air 
quality design objective.
    (iii) Operating system. A system of established procedures for 
determining the need for curtailments and for accomplishing such 
curtailments. Documentation of this system, as required by paragraph 
(n)(4), may consist of a compendium of memoranda or comparable material 
which define the criteria and procedures for curtailments and which 
identify the type and number of personnel authorized to initiate 
curtailments.
    (iv) Meteorologist. A person, schooled in meteorology, capable of 
interpreting data obtained from the meteorological network and qualified 
to forecast meteorological incidents and their effect on ambient air 
quality. Sources may have obtained meteorological services through a 
consultant. Services of such a consultant could include sufficient 
training of source personnel for certain operational procedures, but not 
for design, of the ICS.
    (4) Documentation sufficient to support the claim that the ICS met 
the criteria listed in this paragraph must be provided. Such 
documentation may include affidavits or other documentation.