oEPA
United SB
Environmental Protection
Agency
OHice of
Solid Waste ana
Emergency Respons*
DIRECTIVE NUMBER: 9441.19(84)
TITLE: Mineral Processing Residuals Generated by Com-
bustion Units Burning Hazardous Waste Fuel
APPROVAL DATE: 8-15-84
EFFECTIVE DATE: 8-15-84
ORIGINATING OFFICE: Office of Solid Waste
(3 FINAL
D DRAFT
LEVEL OF DRAFT
DA — Signed by AA or OAA
D 8 — Signed by Office Director
D C — Review & Comment
REFERENCE (other documents):
OS WER OS WER OS WER
VE DIRECTIVE DIRECTIVE Dl
-------
PART 261 SUBPART A - GENERAL DOC: 9441.19(84)
Key Words: Mining Waste, Cement Kiln, Burning and Blending
Regulations: 40 CFR .261.4(b)(7), 261.6, 261.3(b)/(c)/(d), 261.3(a)(2)(10)(A)
Subject: ~" Mineral Processing Residuals Generated by Combustion Units Burning
Hazardous Waste Fuel
Addressee: Conrad Simon, Director, Air and Waste Management Division
Originator: John H. Skinner, Director, Office of Solid Waste
Source Doc: #9441.19(84)
Date: 8-15-84
Summary:
A facility generates shale fines sludge as a result of the thermal expansion
of shale in two rotary kilns that are fired by listed hazardous waste fuels.
The shale fines sludge is regulated as follows:
o The sludge produced as a result of beneficiation or processing is exempt
under Subtitle C, §261.4(b)(7) which excludes solid waste from the
exploration, mining, milling, smelting, and refining of ores and
minerals, which include residuals from mineral processes, including air
emission control wastes. The use of hazardous waste fuels as the total
or partial energy source does not change the status of the waste as
beneficiation or processing waste. The exclusion, however, does not
apply to solid wastes such as spent solvents, pesticide wastes, and
discarded commercial chemical products that are not uniquely associated
with the mining and allied processing industries. If the facilty mixes
its shale fines sludge with nonexcluded listed hazardous waste, the
resulting waste is subject to the mixture rule in §261.3(b)(2).
o Similarly, cement kiln dust generated during a cement manufacturing process
that employs hazardous waste fuels as an energy source is exempt from
Subtitle C by §261.4(b)(8). However, under HSWA §204, cement kilns
burning hazardous waste in municipalities with populations greater than
500,000 must meet Part 264 incinerator standards.
o The shale fines sludge derived from the treatment of hazardous wastes
(i.e., solvents that are used as fuel) is not covered under the beneficial
reuse exemption provided by §261.6. The beneficial reuse exemption
applies to the beneficial reuse process only, and not to any wastes that
may be generated as a result of such processes. The exemption applies
solely to hazardous wastes prior to and during legitimate recycling.
o The shale fines sludge is not exempt under the wastewater exemption
contained in §261.3(a)(2)(IV(A). The provision does not apply to
sludges that are mixed or otherwise commingled with wastewater, or to
sludges that generate a wastewater through the setting of solids from
the sludge. It applies only if solvents are commingled with process
wastewater as part of routine housekeeping procedures.
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 944^l9 (84)
AIJG 15 1984
MEMORANDUM
SUBJECT: Regulatory Interpretation on Mineral Processing
Residuals Generated by Combustion Units Burning
Hazardous Waste Fuel
FROM: John H. Skinner, Director
Office of Solid Waste (WH-562)
TO: Conrad Simon, Director
Air and Waste Management Division (2AWM)
I am writing in response to your memorandum of May 25, 1984,
in which you requested a regulatory interpretation regarding mineral
processing residuals generated from the thermal expansion of shale
in rotary kilns that are fired with hazardous waste fuels. The
issue is whether these mineral processing residuals, i.e., shale
fines sludge, which would otherwise be exempt from Subtitle C of
RCRA under the mining "extraction, beneficiation, and processing"
exclusion of 40 CFR S261,4(b)(7), are subject to regulation as a
hazardous waste due to the use of listed hazardous waste as a fuel
source for the process. This letter responds to the questions
that you raised in your request, and also addresses the points
that Norlite Corporation has made in response to the Region's
complaint against them.
In response to one of your questions, we are not aware of any
explicit precedent or policy that has been established regarding
the applicability of either the mining waste exemption or the
cement kiln dust exemption where waste solvents are employed as
fuels. Therefore, we have consulted with the Office of General
Counsel and the Office of Waste Programs Enforcement in developing
the following responses.
Background
Norlite Corporation, located in Cohpes, New York, mines shale
and thermally expands it to produce a lightweight aggregate that
is used in construction products. The thermal expansion takes
place in two rotary kilns that are fired by listed hazardous waste
fuels (hazardous waste nos. F001-F005, according to Norlite) that
are purchased from waste generators and fuel blenders. Before
-------
entering the stack, the kiln gases are scrubbed with an alkaline
aqueous slurry. The shale fines captured by the scrubber are
collected in surface impoundments from which they are subsequently
dredged at a rate of 40,000 tons year. The shale fines sludge
dredgings are accumulated in waste piles at Norlite's facility.
Question It Is Noriite's shale fines sludge exempt from
regulation under Subtitle C of RCRA by virtue
of the mining waste exclusion in $261,4(b)(7)?
Answer; Yes, the waste is currently exempt.
Discussion;
Section 261.4(b)(7) provides an exemption from Subtitle C
control for "Solid wastes from the extraction, beneficiation, and
processing of ores and minerals...". In the preamble to the rule
providing this exemption, the Agency said we would interpret the
exclusion to include solid waste from the exploration, mining, -
milling, smelting, and refining of ores and minerals (see 45
Federal Register 76618-76619, November 19, 1980). This interpre-
tation includes residuals from mineral processing, including air
emission control wastes.
The process that Norlite uses involves heating shale to produce
a lightweight aggregate, thus enhancing its value. This approach
is analogous to many other thermal processes used to dry, smelt,
or otherwise upgrade an ore or mineral. Therefore, the Norlite
process would be considered beneficiation or processing, and the
wastes from, that process fall within EPA's current interpretation
of the $261.4(b){7) exclusion. The use of hazardous waste fuels
as the total or partial energy source does not, in our opinion,
change the status of the waste as beneficiation or processing
waste. EPA made it clear in the November 19, 1980, preamble that
the exclusion does.not apply to solid wastes, such as spent solvents,
pesticide wastes, and discarded commercial chemical products, that
are not uniquely associated with the mining and allied processing
industries. The solvents that we were addressing in the 1980
notice are those that might be generated as a result of equipment
maintenance or some other general plant operations, but not as a
result of extraction, beneficiation, or processing operations.
We arrive at the same conclusion for cement kiln dust waste
that may be generated during a cement manufacturing process that
employs hazardous waste fuels as an energy source. Cement kiln
dust waste is currently exempt from Subtitle C by S261,4(b)(8).
The use of hazardous waste fuels in this process would not negate
the exclusion.
We emphasize that this interpretation of the mining waste
exclusion does not necessarily exclude all solvents from regulation
-------
'under Subtitle C. As described above, wastes that are not generated
from extraction, beneficiation, or processing operations, e.g.f
spent solvents generated during equipment maintenance, are not
excluded from Subtitle C regulation. Therefore, if Norlite mixes
its shale fines sludge with nonexcluded listed hazardous waste,
the resulting waste is subject to the "mixture rule" in S261.3(b)(2).
The Office of Solid Waste is currently reviewing its 1980
interpretation of the mining waste exclusion to define more
accurately the wastes that Congress intended to exclude from Sub-
title C pending completion of the mining waste study. We will
keep you advised on the progress of the reevaluation and the
supporting studies.
Question 2; Is Norlite's shale fines sludge exempt under
the beneficial reuse exemption provided for
by $261.6?
Answer; No. Wastes resulting from a beneficial reuse
process are not covered by the $261.6 exemption.
»
Discussion;
Sections 261.3(c) and (d) state that any solid waste generated
from the treatment (which includes some recycling), storage,_or
disposal of hazardous waste, including any sludge or emission
control dust, is a hazardous waste until the generator proves
otherwise. In the case of a waste that is derived from a listed
hazardous waste, the solid waste is considered hazardous unless
and until.it is delisted in accordance with $$260.20 and 260.22.
.M
In the case of^Norlite Corporation, the shale fines sludge is
considered to be derived from the treatment of hazardous wastes,
i.e., the solvents that are used as fuel. Burning of hazardous
wastes, albeit for legitimate energy recovery, is still considered
treatment. If the shale fines sludge had not been considered a
beneficiation or processing waste under $261.4(b)(7) , and therefore
excluded from regulation, it would be classified as listed hazardous
waste.
The beneficial reuse exemption contained in §261.6 applies to
the beneficial reuse process only, and not to any wastes that may
be generated as a result of such processes. This exemption thus
applies solely to hazardous wastes prior to and during legitimate
recycling.
It should be noted that listed hazardous wastes, such as the
solvents that Norlite uses, are subject to certain transportation
and storage requirements prior to reuse. These requirements are
contained in $261.6(b). I assume that Norlite's tanks used for
storage of these listed hazardous wastes prior to firing in the
kiln are subject to these provisions. t
-------
Question 3; Is Norlite's shale fines sludge exempt under
the wastewater exemption of $261,3(a)(2)(iv)?
Answer; No, this exemption does not apply to the shale
fines sludge.
Discussion;
The wastewater exemption contained in £261.3(a)(2)(iv)(A)
applies only if solvents are commingled with process wastewater as
part of routine housekeeping procedures (e.g., minor release of
solvents during degreasing operations that would collect in the
wastewater sewer). The provision has no applicability to sludges
that are mixed or otherwise commingled with wastewater, or to
sludges that, in effect, generate a wastewater through the settling
of solids from the sludge.
You expressed concern that the mining waste and cement kiln
dust exclusions could lead to burning hazardous waste fuels with
high levels of toxic organic or metals constituents, resulting in
the generation of hazardous residues. We are presently developing
standards to regulate burning of hazardous waste in boilers and in
cement and aggregate kilns, and intend to require that these units
generally meet the same performance standards applicable to incin-
erators. The residues from burning hazardous waste in these units
may contain high levels of toxic compounds, particularly metals.
Consequently, if we find through our research that aggregate kiln
residuals or cement kiln dusts pose a substantial hazard, we will
consider eliminating their respective exemptions under Part 261,
and subjecting the wastes to regulation under Subtitle C of PCPA.
Your letter and Ncrlite's response to the Region's complaint
necessitated this lengthy response. However, it has enabled us to
develop a position on a highly complex regulatory interpretation
issue. I trust that our response can be used by the Region in
resolving the Norlite case, as well as providing advice to similar
waste fuel/mineral processors that you mentioned. John Heffelfinger
of my staff has discussed our findings on this issue with Bob-
Harris, of your office. You may contact him at FTS-3P2-7923.
For further information on the subject of burning arid blending
hazardous waste fuels and our regulatory development efforts,
please contact Bob Holloway at FTS-382-7936.
cc; Solid v;aste Branch Chiefs
Regions I-X
w/attachment (Region II Itr. dated 5/25/84)
------- |