TOTALLY ENCLOSED TREATMENT EXEMPTION APPLICABILITY TO A BAGHOUSE SYSTEM

TOTALLY ENCLOSED TREATMENT EXEMPTION APPLICABILITY TO A BAGHOUSE SYSTEM
 9432.1986(15)
 
 DEC 22 1986
 
 Mr. Frederick M. Swed, Jr.
 RMT, Inc.
 Suite 124
 1406 East Washington Ave.
 Madison, Wisconsin 53703-3009
 
 Dear Mr. Swed:
 
 Thank you for your letter of November 10 requesting guidance
 on application of the totally enclosed treatment exemption to the
 treatment prior to disposal of baghouse dust generated in the
 foundry industry. Your letter addressed a generic case in which
 an emission control baghouse system and the treatment equipment
 are directly connected to a cupola furnace through a closed system
 of ducts. The Agency does not believe that the totally enclosed
 treatment exemption applies to the system you describe, subject
 to the conditions described below.
 
 As you stated, totally enclosed treatment is defined in 40 CFR
 260.10 as (1) being directly connected to an industrial production
 process and (2) constructed and operated to prevent the release of
 hazardous waste and any constituent thereof into the environment
 during treatment. In addition, the regulatory interpretive letter
 issued July 27, 1981 to Travenol Laboratories (RIL 84) further
 clarified what constituted totally enclosed treatment.
 
 In the March 25, 1986 letter for Region 5 to Grede Foundries,
 EPA found that the specific configuration of the Grede baghouse
 did not qualify as totally enclosed because the hood collecting
 emissions was not directly connected to the cupola, only to the
 baghouse. As part of that determination, EPA stated that
 a foundry cupola qualifies as an industrial production process,
 but that the baghouse is an air pollution control device
 associated with waste treatment prior to disposal.
 
 However, our answer to Grede may have been misleading.
 Connecting the ductwork to the cupola only fulfills half of the
 totally enclosed treatment requirement. The question remains
 as to whether a system that includes a baghouse qualifies as
 totally enclosed treatment. Since baghouses do not remove 100%
 of the hazardous constituents, treatment downstream of a
 baghouse is not part of a totally enclosed treatment train.
 
 You suggested that the baghouse is part of the production
 process because the cupola cannot be operated without the baghouse.
 While you r system might require modification in order to operate
 without the baghouse, I do not believe that the baghouse is
 inherently necessary to the operation of the cupola furnace. In
 fact, prior to the development of air quality standards, cupolas
 typically operated without baghouses. Baghouses limit emissions
 from units subject to Clean Air Act standards. Therefore,
 the Agency still maintains that the baghouse is not part of a
 production process, but is associated with waste treatment.
 
 You asked whether adding the treatment reagents prior to the
 baghouse would qualify as totally enclosed treatment. Since we
 agree that the point of hazardous waste generation is typically
 the bottom of the baghouse hoppers, any processing that occurs
 prior to that point would not be treatment subject to RCRA
 requirements.
 
 You are also correct in stating that even if a production
 unit is open to the atmosphere, the unit downstream could still
 qualify as totally enclosed. As stated in a preamble to the
 261.4(c) amendment, "Except for surface impoundments and non-
 operating units, EPA did not intend to regulate... manufacturing
 process units in which hazardous wastes are generated." (45 FR
 72025, October 30, 1980) In your case, however, the production
 unit is the cupola, not the baghouse, so treatment that occurs
 downstream of the baghouse is not totally enclosed treatment.
 
 In summary although production units may not necessarily
 prevent releases of constituents to the environment, units
 downstream may still qualify for the totally enclosed treatment
 exemption. However, while cupolas are production units, bag-
 houses are not considered to be production processes. Further-
 more, baghouses release hazardous waste or constituents thereof
 to the environment during normal operation as a waste management
 method. Therefore, dust treatment downstream of a baghouse system
 directly connected to a cupola does not perform totally enclosed
 treatment under the Federal program. In addition to this Federal
 determination, of course, the States would have to be consulted
 for State hazardous waste and air quality standards that apply
 to these systems. I apologize for any inconvenience that arose from
 your reading of the EPA letter to Grede Foundries.
 
 Sincerely,
 
 Original Document signed
 
 Marcia Williams
 Director
 Office of Solid Waste
 
 cc: Hazardous Waste Branch Chief, Region V
 
 bcc: Hazardous Waste Branch Chiefs, Regions I-IV, VI-X
 RCRA/Superfund Hotline
 Irene Horner, WTB