[Code of Federal Regulations]
[Title 40, Volume 5]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR57.302]

[Page 140-141]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 57--PRIMARY NONFERROUS SMELTER ORDERS--Table of Contents
 
          Subpart C--Constant Controls and Related Requirements
 
Sec. 57.302  Performance level of interim constant controls.

    (a) Maximum feasible efficiency. Each NSO shall require: that the 
smelter operate its interim constant control systems at their maximum 
feasible efficiency, including the making of any improvements necessary 
to correct the effects of any serious deficiencies; that the process and 
control equipment be maintained in the way best designed to ensure such 
operation; and that process operations be scheduled and coordinated to 
facilitate treatment of process gas streams to the maximum possible 
extent. Maximum feasible efficiency shall be expressed in the NSO in the 
form of a limitation on the concentration of SO2 in the tail 
gas of each individual control system in combination with an appropriate 
averaging period, as provided below in paragraphs (b) and (c) of this 
section.
    (b) The limitation level for SO2 concentration in the 
control system tail gas. The level at which the concentration limitation 
is set shall take into account fluctuations in the strength and volume 
of process off-gases to the extent that those fluctuations affect the 
SO2 content of the tail gas and cannot be avoided by improved 
scheduling and coordination of process operations. The limitation shall 
exclude the effect of any increase in emissions caused by process or 
control equipment malfunction. The limitation shall take into account 
unavoidable catalyst deterioration in sulfuric acid plants, but may 
prescribe the frequency of catalyst screening or replacement. The NSO 
shall also prohibit the smelter owner from using dilution air to meet 
the limitation.
    (c) Averaging period. (1) The averaging period shall be derived in 
combination with the concentration limitation and shall take into 
account the same factors described in paragraph (b). The averaging 
period established under this paragraph should generally not exceed the 
following:
    (i) For sulfuric acid plants on copper smelters, 12-hour running 
average;
    (ii) For sulfuric acid plants on lead smelters, 6-hour running 
average;
    (iii) For sulfuric acid plants on zinc smelters, 2-hour running 
average;
    (iv) For dimethylaniline (DMA) scrubbing units on copper smelters, 
2-hour running average.
    (2) A different averaging period may be established if the applicant 
demonstrates that such a period is necessary in order to account for the 
factors described in paragraph (b) of this section: Provided, that the 
period is enforceable and satisfies the criteria of paragraph (a) of 
this section.
    (d) Improved performance. (1) The performance level representing 
maximum feasible efficiency for any existing control system (e.g., a 
sulfuric acid plant or a DMA scrubber) shall require the correction of 
the effects of any serious deficiencies in the system. For the purpose 
of this paragraph, at least the following problems shall constitute 
serious deficiencies in acid plants:
    (i) Heat exchangers and associated equipment inadequate to sustain 
efficient, autothermal operation at the average gas strengths and 
volumes received by the acid plant during routine process equipment 
operation;
    (ii) Failure to completely fill all available catalyst bed stages 
with sufficient catalyst;
    (iii) Inability of the gas pre-treatment system to prevent unduly 
frequent plugging or fouling (deterioration) of catalyst or other 
components of the acid plant; or
    (iv) Blower capacity inadequate to permit the treatment of the full 
volume of gas which the plant could otherwise accommodate, or in-leakage 
of air into the flues leading to the plant, to the extent that this 
inadequacy results in bypassing of gas around the plant.
    (2) Notwithstanding any contrary provisions of Sec. 57.304(c) 
(malfunction demonstration), no excess emissions (as defined in 
Sec. 57.304(a)) shall be considered to have resulted from a malfunction 
in the constant control system if the smelter owner has not upgraded 
serious deficiencies in the constant control system in compliance with 
the requirements of Sec. 57.302(d)(1), unless the smelter owner 
demonstrates under Sec. 57.304(c) that compliance with

[[Page 141]]

those requirements would not have affected the magnitude of the 
emission.
    (e) Multiple control devices. (1) At any smelter where off-gas 
streams are treated by various existing control systems (e.g., multiple 
acid plants or a DMA scrubber and an acid plant), the NSO shall require 
the use of those systems in the combination that will result in the 
maximum feasible net SO2 removal.
    (2) To the extent that compliance with this requirement is 
demonstrated by the smelter operator to result in excess emissions 
during unavoidable start up and shut down of the control systems, those 
excess emissions shall not constitute violations of the NSO.