South Carolina Code of Regulations › Chapter 61 - DEPARTMENT OF HEALTH AND ENVIRONMENTAL CONTROL › Subchapter 61-79 - Hazardous Waste Management Regulations › Part 61-79.266 - STANDARDS FOR THE MANAGEMENT OF SPECIFIC HAZARDOUS WASTES AND SPECIFIC TYPES OF HAZARDOUS WASTE MANAGEMENT FACILITIES › Appendix 61-79.266.IX - Methods Manual for Compliance With the BIF Regulations Burning Hazardous Waste in Boilers and Industrial Furnaces › Section 61-79.266.10.0 - ALTERNATIVE METHODOLOGY FOR IMPLEMENTING METALS CONTROLS

Current through Register Vol. 48, No. 6, June 28, 2024
10.1 Applicability
This method for controlling metals emissions applies to
					 cement kilns and other industrial furnaces operating under interim status that
					 recycle emission control residue back into the furnace.
10.2 Introduction
Under this method, cement kilns and other industrial
					 furnaces that recycle emission control residue back into the furnace must
					 comply with a kiln dust concentration limit (i.e., a collected particulate
					 matter (PM) limit) for each metal, as well as limits on the maximum feedrates
					 of each of the metals in: (1) pumpable hazardous waste; and (2) all hazardous
					 waste.
The following subsections describe how this method for
					 controlling metals emissions is to be implemented:
oSubsection10.3 discusses the basis of the method and the
					 assumptions upon which it is founded;
oSubsection10.4 provides an overview of the implementation
					 of the method;
oSubsection10.5 is a step-by-step procedure for
					 implementation of the method;
oSubsection10.6 describes the compliance procedures for
					 this method; and
oAppendix A describes the statistical calculations and
					 tests to be used in the method.
10.3 Basis
The viability of this method depends on three fundamental
					 assumptions:
(1) Variations in the
				  ratio of the metal concentration in the emitted particulate to the metal
				  concentration in the collected kiln dust (referred to as the enrichment factor
				  or EF) for any given metal at any given facility will fall within a normal
				  distribution that can be experimentally determined.
(2) The metal concentrations in the collected
				  kiln dust can be accurately and representatively measured (using procedures
				  specified in "Test Methods for Evaluating Solid Waste, Physical/Chemical
				  Methods" (SW-846), incorporated by reference in
				  40 CFR
				  260.11 ).
(3) The facility will remain in compliance
				  with the applicable particulate matter (PM) emission standard.
Given these assumptions. metal emissions can be related to
					 the measured concentrations in the collected kiln dust by the following
					 equation:
See
					 Image
Where:
ME is the metal emitted; PME is the particulate matter
					 emitted; DMC is the metal concentration in the collected kiln dust; and EF is
					 the enrichment factor, which is the ratio of the metal concentration in the
					 emitted particulate matter to the metal concentration in the collected kiln
					 dust.
This equation can be rearranged to calculate a maximum
					 allowable dust metal concentration limit (DMCL) by assuming worst-case
					 conditions that: metal emissions are at the Tier III (or Tier II) limit (see
					 40 CFR
					 266.106 ), and that particulate emissions are
					 at the particulate matter limit (PML):
Tier III Limit
lb Emitted Metal
DMCL lb Dust Metal =
hr
lb Dust
PML lb PM EF
lb Emitted Metal/lb PM)
hr
lb Dust Metal/lb Dust
The enrichment factor used in the above equation must be
					 determined experimentally from a minimum of 10 tests in which metal
					 concentrations are measured in kiln dust and stack samples taken
					 simultaneously. This approach provides a range of enrichment factors that can
					 be inserted into a statistical distribution (t-distribution) to determine
					 EF95% and EF99%.
					 EF95% is the value at which there is a 95% confidence
					 level that the enrichment factor is below this value at any given time.
					 Similarly, EF99% is the value at which there is a 99%
					 confidence level that the enrichment factor is below this value at any given
					 time. EF95 is used to calculate the "violation" dust
					 metal concentration limit (DMCL):
Tier III Limit lb Emitted Metal
Tier III Limit
lb Emitted Metal
DMCLC lb Dust Metal =
hr
(3)
lbDust
PML
lb PM EF95%
lb Emitted Metal/lb PM
hr
lb Dust Metal/lb Dust
If the kiln dust metal concentration is just above this
					 "violation" limit, and the PM emissions are at the PM emissions limit, there is
					 a 5% chance that the metal emissions are above the Tier III limit. In such a
					 case, the facility would be in violation of the metals standard.
To provide a margin of safety, a second, more conservative
					 kiln dust metal concentration limit is also used. This "conservative" dust
					 metal concentration limit (DMCLc) is calculated using a
					 "safe" enrichment factor (SEF). If EF99% is greater than
					 two times the value of EF95%, the "safe" enrichment
					 factor can be calculated using Equation 4a:
SEF>2EF95% (4a)
If EF99% is not greater than two
					 times the value of EF95%, the "safe" enrichment factor
					 can be calculated using Equation 4b:
SEF>EF99% (4b)
In cases where the enrichment factor cannot be determined
					 because the kiln dust metal concentration is nondetectable, the "safe"
					 enrichment factor is as follows:
SEF=100 (4c)
For all cases, the "conservative" dust metal concentration
					 limit is calculated using the following equation:
Tier III Limit
lb Emitted Metal
DMCLv lb Dust Metal =
hr
(5)
lb Dust
PML
lb PM SEF
lb Emitted Metal/lb PM
(hr)
(lb Dust Metal/lb Dust
If the kiln dust metal concentration at a facility is just
					 above the "conservative" limit based on that "safe" enrichment factor provided
					 in Equation 4a, and the PM emissions are at the PM emissions limit, there is a
					 5% chance that the metal emissions are above one-half the Tier III limit. If
					 the kiln dust metal concentration at the facility is just above the
					 "conservative" limit based on the "safe" enrichment factor provided in Equation
					 4b, and the PM emissions are at the PM emissions limit, there is a 1% chance
					 that the metal emissions are above the Tier III limit. In either case, the
					 facility would be unacceptably close to a violation. If this situation occurs
					 more than 5% of the time, the facility would be required to rerun the series of
					 10 tests to determine the enrichment factor. To avoid this expense, the
					 facility would be advised to reduce its metals feedrates or to take other
					 appropriate measures to maintain its kiln dust metal concentrations in
					 compliance with the "conservative" dust metal concentration limits.
In cases where the enrichment factor cannot be determined
					 because the kiln dust metal concentration is nondetectable, and thus no
					 EF95% exists, the "violation" dust metal concentration
					 limit is set at ten times the "conservative" limit:
DMCLv = 10 x
					 DMCLc (6)