
EAST PENN manufacturing co., inc.   
Metals Division

P.O.BOX 147, DEKA ROAD ● LYON STATION, PA 19536-0147
PHONE: 610-682-6361 ● FAX 610-682-1038
EMAIL: EPMSMT@EASTPENN-DEKA.COM

                                                                August 30, 2013
Charles French
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
109 T.W. Alexander Drive
Mail Code:  D243-02
Research Triangle Park, NC  27709
Dear Chuck,
I am writing with regard to the U.S. Environmental Protection Agency's ("EPA") pending administrative reconsideration of the national emission standards for hazardous air pollutants ("NESHAP") for secondary lead smelters, 77 Fed. Reg. 555 (Jan. 5, 2012).  
The purpose of the NESHAP requirement that smelters demonstrate the maintenance of negative pressure is to minimize the potential release of fugitive dust emissions.  East Penn Manufacturing Company, Inc.'s ("East Penn") has submitted a pending petition for an alternative standard, which it believes is the most environmentally-protective way that EPA could address the provisions regarding the demonstration of continuous negative pressure at its facility.  Notwithstanding that petition, in response to your request that East Penn provide input on how best to clarify certain issues that are currently subject to administrative reconsideration, East Penn would like to propose the following regulatory language.
First, EPA should revise 40 C.F.R. § 63.544(c) to read as follows:
            (c) You must construct and operate total enclosures for the sources listed in paragraph (a) of this section as specified in paragraphs (c)(1) - (3) of this section.  The total enclosure must be free of significant cracks, gaps, corrosion or other deterioration that could cause lead bearing material to be released from the primary barrier.  Measures must be in place to prevent the tracking of lead bearing material out of the unit by personnel or by equipment used in handling the material.  An area must be designated to decontaminate equipment and any rinsate must be collected and properly managed.
            (1)	You must ventilate the total enclosure continuously to ensure negative pressure values of at least 0.013 mm of mercury (0.007 inches of water); or
            (2)	You must maintain an inward flow of air through all natural draft openings.
            (3)	Where one or more sources listed in paragraphs (a)(1) through (9) of this section are located in a building that meets the definition of a total enclosure under Section 63.542 or portion of a building that meets the definition of a total enclosure under Section 63.542, the requirements of paragraphs (c)(1) or (c)(2) shall be monitored pursuant to Section 63.548(k)(1) at only one (1) leeward, one (1) windward, and one (1) additional wall each.
This revised language contains two substantive revisions from the existing language at 40 C.F.R. § 63.544(c): it adds the word "or" between subsections (c)(1) and (c)(2) and it clarifies that smelters that have numerous fugitive dust sources in a building or portion of a building need only monitor the "big box" enclosed area, rather than each separate fugitive dust source.
With regard to the first of these changes, subsection (c)(1) is not consistent with the regulatory intent that continuous negative pressure be equivalent to 200 fpm of velocity.  If negative pressure of 0.007 inches of water is continuously required for the enclosure then the natural draft openings should be at 0.007 inches of water since the measurement requirement is the pressure difference between ambient air and the pressure inside the enclosure.  To measure the pressure differential essentially a natural draft opening is created through the monitor to measure and record either the pressure or the velocity of the air flow.  Thus, it would seem that the intent now would be to add the word "or" between the two requirements.
With regard to the second of these changes, East Penn's smelting operations have incorporated total enclosure and isolation units for decades.  The design of the facility is to place the material storage area (the containment building for broken battery materials and lead bearing wastes destined for smelting) at the center of the operations since the operations of this material storage area present the greatest potential for fugitive emissions under normal operations.  This design allows several important benefits to be achieved:
	(a)	the storage area can be isolated from the balance of the facility which eliminates traffic and tracking of materials from the storage area,
	(b)	the lead bearing materials can be mechanically conveyed into and out of the containment building,
	(c)	the material flow can incorporate both the feeding of materials directly to the furnace operations and the return of materials to the room for further processing by the furnace operations, and
	(d)	the area is better suited for enclosure, since the material storage area is under negative pressure and the areas surrounding it are also under negative pressure, thus serving as a dual barrier to fugitive emissions.
The processing operations, including the battery breaker, the furnace operations, and the refinery, surround the room.  Since the areas have common walls, the potential exists when attempting to measure the negative pressure for results to be skewed by this design with different areas under negative pressure.  Moreover, specific areas are ventilated through different control devices.  Within the East Penn facility different control devices are used to effectively ventilate different sources and different areas of operation.
The way that this works in practice is most easily demonstrated by the attached drawing of the smelter building.  The areas that are required to be totally enclosed under the NESHAP are indicated and are surrounded by a bold black line, which signifies walls in the facility surrounding the areas that are under continuous negative pressure.  This revision would ensure that East Penn need not employ what could be dozens of monitors total, but instead would employ three monitors total for this totally enclosed portion of the smelter building, one each at the windward, leeward, and additional walls.
Second, EPA should revise 40 C.F.R. § 63.547(k)(1)(III) to read as follows:
            (iii)	An additional wall that is not the windward or leeward wall.
The location for the third monitor should be simply a confirmation that the operation remains under negative pressure even if there is a substantial wind shift.  Otherwise its redundancy is not required.  The monitors' readings are affected by friction losses in the external tubing and entry losses dependent upon the configuration.  Thus, it can be very difficult to locate a monitor exactly on a midpoint or on a specific area of the enclosure.  This third monitor should be able to be located at the discretion of the facility and subject to the specific configurations and layout of the facility.
Third, EPA should revise 40 C.F.R. § 63.547(k)(3) to read as follows:
            (3)	The digital differential pressure monitoring systems must be certified by the manufacturer to be capable of measuring and displaying negative pressure in the amount of 0.001 inches of water.
Accuracy of the monitors is dependent upon several issues, particularly temperature, since the measurement relates to the ideal gas law and the formula PV=nRT.
          Where P is the pressure of the gas, V is the volume of the gas, n is the amount of substance of gas (also known as number of moles), T is the temperature of the gas and R is the ideal, or universal, gas constant.
Process
Constant
Known ratio
P2
V2
T2
Isobaric process
Pressure
V2/V1
P2 = P1
V2 = V1(T2/T1)
T2 = T1(V2/V1)


T2/T1
P2 = P1
V2 = V1(T2/T1)
T2 = T1(T2/T1)






The location of the monitors and the effects of solar exposure and the temperature differential between ambient and indoor temperatures can have an effect upon the reading.  East Penn has conducted an extensive evaluation with two different monitor types.  One type measures differential pressure across a diaphragm, the other measures temperature via thermistors and converts velocity to differential pressure through an algorithm.  Both of the monitors that East Penn has evaluated express their accuracy as a percent of span or a percentage of the reading.  According to the suppliers, these numbers when converted express the differential pressure in increments of 0.001 inches of water.
Fourth, EPA should revise 40 C.F.R. § 63.547(k)(5) to read as follows:
            (5)	You must calibrate each digital differential pressure monitoring system in accordance with manufacturer's specifications.  You must not calibrate any digital differential pressure monitoring system that the manufacturer's specifications state should not be calibrated.
The intent of this subsection is to ensure that all monitors are calibrated in accordance with manufacturer specifications, but both of the monitors that East Penn has evaluated do not recommend periodic maintenance or calibration.
*	*	*
Thank you for your attention to this matter.  Please contact me if you have any questions.
Sincerely,

Richard A. Leiby
cc:	Robert N. Steinwurtzel
	Mark W. DeLaquil
	Nathan Topham



