## U.S. Environmental Protection Agency Applicability Determination Index

Control Number: M990012

Category: MACT EPA Office: Region 9 Date: 09/30/1999 Title: Control Devices and Venting Recipient: Wayne Morgan Author: Duane James

Subparts: Part 63, S, Pulp and Paper Production

References: 63.2 63.6(e)(3)(A)

Abstract:

Q: Does venting apply to the individual sources at each step of the process or only to venting from the total closed-vent system?
A: Venting applies to the total closed-vent system. Thus, venting is allowed only from the system as a whole, and not from individual sources.
Q: If the control device is operative and problems occur in the closed-vent collection system, does this time count against the 4% allowance or is this a violation of the NESHAP?
A: Whether the time counts against the 4% allowance or is a violation of the NESHAP depends on the Startup, Shutdown and Malfunction (SSM) plan. Problems that are avoidable through proper operation and maintenance, including bypasses that are not addressed in the SSM plan, would be violations.
Q: Must the control device (Recovery Furnace) be inoperative (non-functional) in order for HVLC gas streams to legitimately bypass the control system?
A: Yes. The control device must by inoperative/nonfunctional for the HVLC gas streams tobypass the control.
Q: Is a pressure/vacuum valve on a liquor storage tank that vents to the atmosphere considered a leak or defect in the ductwork, piping or enclosure and therefore subject to the 5/15 day time limit for repair or correction once detected?
A: The 5/15 day schedule applies upon detection of a leaking or broken seal. However, uncontrolled venting from an affected source detected after the compliance date and not accounted for in the Title V permit constitutes a violation not covered by the enclosure leak or defect provisions.
Q: Is a storage tank that vents through its pressure/vacuum valve for a 30 day period as a result of an incident other than a startup considered a malfunction or is it instead a NESHAP violation?
A: A venting resulting from an incident other than a startup is predictable and does not fit the definition of malfunction. Thus, it is a violation of the NESHAP.

Letter:

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX 75 Hawthorne Street San Francisco, CA 94105
September 30, 1999
Wayne Morgan Air Pollution Control Officer North Coast Unified Air Quality Management District 2300 Myrtle Avenue Eureka, CA 95501
Re: Clarification of NESHAP for Pulp and Paper Mills
Dear Mr. Morgan,
This letter is in response to your June 15, 1999 letter addressed to Stephen Shedd of EPA's Emissions Standards Division which sought assistance in interpreting the provisions of the National Emissions Standards for Hazardous Air Pollutants (NESHAPs) for Pulp and Paper Mills (40 CFR part 63, subpart S) as they apply to a Louisiana-Pacific (LP) kraft pulp mill in your District. Your letter was forwarded to EPA's Region IX Office for resolution. We hope the information provided below will help the District resolve any issues that may be hampering the District's efforts to process the LP pulp mill's Title V permit and will clarify the intent of EPA's Office of Air Quality Planning and Standards when it issued this regulationand defined Maximum Achievable Control Technology for this source category.
Since the LP mill was required to install equipment to capture and incinerate High Volume Low Concentration (HVLC) gas streams, we will assume that the mill is a new kraft mill which must meet the NESHAPs requirements for new sources. Furthermore, we will assume that the mill's liquor storage tanks are for weak black liquor. The NESHAP does not require control of strong black liquor storage tanks because most hazardous air pollutants are considered to have been removed from strong black liquor by other controls.
Question 1: Does venting apply to the individual sources at each step of the process or only to venting from the total closed vent system?

The NESHAP does not establish excess emission times for condensate collection. Excess emission times apply to control devices into which the closed collection system vents. Venting is allowed only from the total closed vent system, not the individual sources.
Question 2a: If the control device is operative and problems occur in the closed-vent collection system (i.e., air-preheater to recovery is plugged), dictating a by-pass to the main stack, does the time involved in this example count against the 4% allowance or is this a violation of the NESHAP?
Whether the time involved in your example counts against the 4% allowance or is a violation of the NESHAP depends on what has been defined as a malfunction under the Startup, Shutdown and Malfunction (SSM) plan. Problems that should be avoided through proper operation and maintenance, including bypasses that are not addressed in the SSM plan, would be violations of the NESHAP. Note that malfunction as defined in 40 CFR Sec. 63.2 is "any sudden, infrequent and not reasonably preventable failure." "Failures that are caused in part by poor maintenance or careless operation are not malfunctions."
Question 2b: Must the control device (Recovery Furnace) be inoperative (nonfunctional) in order for HVLC gas streams to legitimately bypass the control system?
Yes, the control device must by inoperative/nonfunctional for the HVLC gas streams to bypass the control system. Per 40 CFR Sec. 63.6(e)(3)(A), facilities are still obliged under their SSM plans to make a good faith effort to control emissions and to operate "in a manner consistent with good air pollution control practices for minimizing emissions at least to the levels required by all relevant standards."
Question 3: Does EPA interpret, under the NESHAP, pressure/vacuum valves on liquor storage tanks that vent to the atmosphere as a leak or defect in the ductwork, piping or enclosure which is subject to the 5/15 days for repairing and correcting it once detected?
Once a facility and the delegated agency have determined which sources will be controlled, the facility should have a clear understanding of where the emission points are in each system. Vents should be controlled as part of the facility's compliance strategy. The 5/15 day schedule would apply to a leaking seal, one that is broken. However, uncontrolledventing from an affected source that is detected after the compliance date and that is not accounted for in the Title V permit would constitute a violation and not fit the enclosure leak or defect provisions.
Question 4: If a storage tank were to vent through its pressure/vacuum valve for a 30 day period (constantly on some days and intermittently on other days) and is not a result of startup or shutdown, would you consider these to qualify as a malfunction or should it be considered as a violation of the NESHAP?

The District should refer to the definition of malfunction contained in 40 CFR Sec. 63.2. It appears as though the venting, as described above, is predictable and would not fit the definition of malfunction. This should be considered a violation of the NESHAP.
We hope this letter throughly addressed your concerns. If you have additional questions regarding the Pulp and Paper NESHAP or require further clarification, please contact Yvonne Fong of EPA's Region IX Office at (415) 744-1199.
Sincerely,

Duane James Acting Chief, Enforcement Office