[Federal Register Volume 59, Number 2 (Tuesday, January 4, 1994)]
[Rules and Regulations]
[Pages 458-469]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 93-32032]
[[Page Unknown]]
[Federal Register: January 4, 1994]
_______________________________________________________________________
Part V
Environmental Protection Agency
_______________________________________________________________________
40 CFR Parts 260 and 261
Hazardous Waste Management System; Identification and Listing of
Hazardous Waste; Wastes From Wood Surface Protection; Final Rule
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 260 and 261
[FRL-4804-9]
Hazardous Waste Management System; Identification and Listing of
Hazardous Waste; Wastes From Wood Surface Protection
AGENCY: Environmental Protection Agency.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The U.S. Environmental Protection Agency (EPA) is issuing a
final hazardous waste listing determination for wastes generated from
the use of chlorophenolic formulations in wood surface protection
processes. Upon reviewing the public comments received on its proposal
of April 27, 1993, the Agency has decided not to list wastes from the
use of chlorophenolic formulations in wood surface protection
processes. As a result of this determination, EPA is not mandating in
this rule any specific operating or information collection requirements
for owners/operators of wood surface protection plants. If, however,
use of chlorophenolic formulations resumes in the future, the Agency
would very likely re-evaluate this decision not to list. This rule also
finalizes the proposed amendment of SW-846 (``Test Methods for
Evaluating Solid Waste, Physical/Chemical Methods'') to include Method
4010 (Immunoassay Test for the Presence of Pentachlorophenol). In
addition, the Agency is adding the following four chemicals to 40 CFR
part 261, Appendix VIII: Sodium and potassium salts of
pentachlorophenol and tetrachlorophenol.
EFFECTIVE DATE: January 4, 1994.
ADDRESSES: The official record for this rulemaking is identified as
Docket Number F-93-F33F-FFFFF and is located in the EPA RCRA Docket,
room M2616, 401 M Street, SW., Washington, DC 20460. The public must
make an appointment to review docket materials by calling (202) 260-
9327. The docket is open from 9 a.m. to 4 p.m., Monday through Friday,
excluding holidays. The public may copy up to 100 pages from the docket
at no cost. Additional copies cost $0.15 per page.
FOR FURTHER INFORMATION CONTACT: For general information, contact the
RCRA/Superfund Hotline at (800) 424-9346 (toll-free) or (703) 920-9810
in the Washington, DC metropolitan area. The TDD hotline number is
(800) 553-7672 or (703) 486-3323. For technical information on specific
aspects of this rulemaking, contact Mr. David J. Carver at (202) 260-
6775, Office of Solid Waste (Mailcode 5304), U.S. EPA, 401 M Street,
SW., Washington, DC 20460. For technical information relating to the
amendment of SW-846, contact Ms. Gail Hansen at (202) 260-4761, Office
of Solid Waste (Mailcode 5304), at the same address provided above.
SUPPLEMENTARY INFORMATION: The contents of today's preamble are listed
in the following outline:
I. Legal Authority
II. Background & Summary
III. Overview of the Proposed Rule
IV. Summary of Public Comments and Responses
A. General Comments
B. Comments Regarding Risk Assessment
V. Overview of the Final Rule
A. Basis for the Determination Not to List As Hazardous Wastes
From Wood Surface Protection Operations
B. Operating Requirements for Surface Protection Plants
C. Addition of Chemicals to Appendix VIII of 40 CFR part 261
VI. Amendment of SW-846 (Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods)
VII. Pollution Prevention and Waste Minimization
VIII. Analysis of Potential Costs and Benefits
A. Executive Order Requirements
B. Description of Costs and Benefits of this Rule
IX. State Authority
X. Regulatory Flexibility Analysis
XI. Paperwork Reduction Act
I. Legal Authority
These regulations are being promulgated under the authority of
sections 2002(a) and 3001(b) and (e)(1) of the Solid Waste Disposal
Act, as amended, 42 U.S.C. 6912(a), 6921(b) and (e)(1), and 6922
(commonly referred to as RCRA).
II. Background & Summary
A. Background
Under section 3001(e) of RCRA, as amended by the Hazardous and
Solid Waste Amendments of 1984 (HSWA), EPA is required to make a
hazardous waste listing determination for wastes containing chlorinated
dioxins and dibenzofurans. As part of this mandate, the Agency began an
investigation in 1988 of dioxin-containing wastes from wood preserving
and wood surface protection processes. Three categories of wastes from
wood preserving processes were listed as hazardous wastes in 1990,
(F032, F034, and F035, see 55 FR 50450). A final listing determination
for wood surface protection process wastes were deferred due to lack of
data (53 FR 53282). In 1991, the Agency began a separate study of the
surface protection industry in an effort to obtain sufficient
information upon which to base a hazardous waste listing determination.
The Agency, upon obtaining and evaluating information, published a
proposed rule on April 27, 1993 which proposed a concentration-based
hazardous waste listing option and requested comment on an alternative
option not to list these wastes as hazardous (58 FR 25707). Details of
the options can be found in the following section to this preamble. A
detailed summary of all Agency actions related to wood surface
protection wastes was provided in the April 27, 1993 proposal (58 FR
25707). The reader is encouraged to consult that document for more
information on the wood surface protection rulemaking history.
In accordance with a proposed consent decree signed by EPA and the
Environmental Defense Fund (EDF) in EDF v. Browner (U.S. District Court
for the District of Columbia, case no. 89-0591), the Agency has agreed
to make a final listing determination for chlorophenolic wastes from
wood surface protection processes by December 31, 1993.
B. Summary of the Wood Surface Protection Regulation
After considerable review and study of the rulemaking docket for
this action, including comments received on the proposal, the Agency
has determined that listing as hazardous wastes from surface protection
operations is unnecessary and will not yield the benefits intended by a
hazardous waste listing under the RCRA program. This section summarizes
elements of the proposed rule of April 27, 1993 (58 FR 25707), and
details the conclusions reached in developing this final rule. The
reader is cautioned that although some of the highlights brought up in
the proposed rule are described below, the majority of information on
the industry itself as well as the detailed risk assessment on which
the initial proposed rule was based is found in the preamble and
background documents to the proposed rule. The information contained in
this final rule is primarily concerned with developments subsequent to
the proposed rule. This rule describes, in detail, the Agency's
justification for not listing wastes from surface protection processes
that use chlorophenolic formulations. In addition, it summarizes the
Agency's response to comments received on the proposal.
III. Overview of the Proposed Rule
The April 27, 1993 proposal discussed and requested comment on each
of the following:
(1) Proposing a concentration-based hazardous waste listing for
certain wood surface protection wastes,
(2) Proposing various testing, analysis, recordkeeping requirements
and management standards for wood surface protection plants,
(3) Adding six hazardous constituents to appendix VIII of 40 CFR
part 261,
(4) Amending of appendix VII of 40 CFR part 261 by adding F033 and
the hazardous constituents found in the wastes,
(5) Modifying the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) list of hazardous substances
to reflect the newly proposed listing,
(6) Amending SW-846 (``Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods'') to include Method 4010 (Immunoassay Test
for the Presence of Pentachlorophenol), and
(7) An alternative option not listing chlorophenolic wastes as
hazardous.
The Agency proposed to list as hazardous at 40 CFR 261.31 only
those wastes from wood surface protection processes using a formulation
with a pentachlorophenate concentration greater than 0.1 ppm. Under
this proposed option, surface protection operations using formulations
with pentachlorophenate concentrations equal to or less than 0.1 ppm
would not generate F033 listed wastes. The Agency proposed this
concentration-based listing because it had information which suggested
that many surface protectors who previously used chlorophenolics did
not sufficiently clean out equipment prior to abandoning the use of
chlorophenolics. Because of this, many formulations from past users of
chlorophenolics exhibit ``cross-contamination,'' the contamination of
current formulations by dioxins and chlorophenolic compounds from old
formulations. The rule proposed the following hazardous waste listing
description for the F033 waste code and included the following specific
waste streams from process operations:
F033:Process residuals, wastewaters that come into contact with
protectant, discarded spent formulation, and protectant drippage
from wood surface protection processes at plants that use surface
protection chemicals having an in-process formulation concentration
of pentachlorophenate (expressed as pentachlorophenol during
analysis) exceeding 0.1 ppm. (T)
Along with this option, various testing and recordkeeping
requirements were proposed. For an owner/operator to demonstrate that
he/she is not generating F033 wastes, EPA proposed formulation testing
requirements for all surface protection plants. All owner/operators of
wood surface protection plants would be required to test their
formulation to determine the concentration of pentachlorophenate if the
owner/operators wanted to avoid generating F033 wastes. If the analysis
showed a concentration at or below 0.1 ppm, the owner/operator would be
required to sign a certification to that effect and maintain records on
site related to the testing procedure. This testing proposed an
analysis using a method listed within the EPA's Test Methods for
Evaluating Solid Waste, Physical/Chemical Methods (SW-846). The Agency
proposed to add Method 4010 to SW-846. Method 4010 is an immunoassay
test for the presence of pentachlorophenol, which determines whether a
sample is above or below a set limit (such as the 0.1 ppm concentration
level proposed).
Under the proposal, if analysis showed that a facility's
formulation contains pentachlorophenate at levels exceeding 0.1 ppm,
then the wastes generated from surface protection at that facility
would be F033 wastes and the owner/operator would be subject to
additional operating requirements proposed as subpart T of parts 264
and 265. For details on the specific operating requirements, the reader
should refer to the proposed notice (58 FR 25706).
A number of the constituents of concern that are present in wastes
generated from wood surface protection processes which use
chlorophenolic formulations do not appear on the list of hazardous
constituents at 40 CFR part 261, appendix VIII. The Agency proposed to
add six hazardous constituents to appendix VIII: sodium
pentachlorophenate, potassium pentachlorophenate, the sodium salt of
2,3,4,6-tetrachlorophenol, the potassium salt of 2,3,4,6-
tetrachlorophenol, octachlorodibenzo-p-dioxin (OCDD) and
octachlorodibenzofuran (OCDF).
Sodium and potassium pentachlorophenate are the sodium and
potassium salts of pentachlorophenol. These salts were proposed for
addition to appendix VIII of 40 CFR part 261 since, as a result of
gastric secretions following ingestion, the sodium and potassium salts
of pentachlorophenol and 2,3,4,6-tetrachlorophenol are readily
converted to the corresponding phenols by acidification. Therefore, the
sodium and potassium salts are reasonably expected to elicit the same
health effects as the corresponding phenols. For this reason, the
Agency proposed to add these four compounds to the list of hazardous
constituents in appendix VIII of 40 CFR part 261.
The Agency also requested comment on an option not to list as
hazardous wastes generated from surface protection processes. The
Agency included the so-called ``no-list'' option in the proposal
because the future generation of chlorophenolic wastes is expected to
diminish rapidly to zero and because the results of risk analyses show
that the risks from the dominant exposure pathways are relatively
modest, assuming the widespread use of chlorophenolic formulations does
not resume. The Agency believed at the time of the proposal that
reintroduction of chlorophenolic formulations into the market place in
the future was not likely to occur. EPA also noted that the Agency
would always have the option of reconsidering the listing determination
should chlorophenolic surface protection formulations be reintroduced
in the future.
IV. Summary of Public Comments and Responses
Comments received on the proposed rule are placed under two
separate headings for purposes of this summary. The first addresses the
more general comments associated with the proposal, including those
relating to: (1) General implementation issues of a listing for wastes
generated by the wood surface protection industry; (2) technical
approaches discussed in the proposal relating to data sampling
methodologies; and (3) various engineering assumptions on which the
proposed listing was based. The second part of this section describes
the Agency's response to comments dealing with the risk assessment
methodology used to support the listing determination for these wastes.
A. General Comments
Several comments were submitted on the proposed listing of F033
wastes. Four commenters supported the listing in general and two
commenters supported the concentration-based approach in particular.
Three commenters opposed the proposed listing and urged EPA to rely on
its authority under FIFRA to control the risks posed by chlorophenolic
formulations. One commenter supported an outright ban on the use of
chlorophenolics for wood surface treatment.
Two commenters warned that listing F033 wastes would hinder
remediation efforts at contaminated wood surface protection sites. The
Agency agrees with the commenters' point that a hazardous waste listing
may provide a disincentive for owner/operators of surface protection
plants to initiate voluntary remediation efforts. The regulation of
potentially large amounts of contaminated soil as listed hazardous
waste could delay the start of cleanup due to the administrative and
economic realities of regulatory compliance.
Three commenters expressed concern over the possibly perceived
interchangeability of the proposed 0.1 ppm concentration level and the
Toxicity Characteristic (TC) regulatory level for pentachlorophenol.
Although the Agency is not finalizing the F033 hazardous waste listing,
EPA nevertheless wants to make clear that the concentration level
proposed in the F033 listing description was not intended as a
regulatory level for any purpose other than defining a waste as F033.
The current regulatory level for pentachlorophenol that defines a waste
as hazardous under the TC (100 mg/L) would not have been affected by
this rulemaking in any way had the F033 listing been promulgated today.
Levels set for the TC are obtained by running models which simulate
acidic landfill conditions. For the proposed listing, the proposed 0.1
ppm level was calculated using a Maximum Contaminant Level (MCL) of
0.001 ppm and a risk analysis using the Agency's Multi-med model.
Multi-med simulates groundwater contamination from specific sources,
and for this proposal, it incorporated variables which are specific to
sawmill conditions. The Agency's analysis approximated the dilution of
pentachlorophenate from the time the waste contacts the ground to when
it reaches a ground water well. The Agency did not arrive at the 0.1
ppm level by applying a dilution attenuation factor (DAF) of 100 (as
the Agency has done in other circumstances) to the MCL. Indeed, the
Agency did not take a position in the proposal about the use of DAFs in
calculating acceptable risk levels for any constituents. A detailed
discussion of the Agency's modeling assumptions and actual parameters
used to generate risk approximations can be found in the docket for the
proposed rule.
One commenter expressed reservations regarding the decontamination
procedures promulgated previously for wood preserving equipment (55 FR
50482-50483, December 6, 1990). The Agency is aware that equipment
cleaning will not always prevent cross-contamination. However, it will
certainly reduce the amount of contamination that would occur if no
equipment cleaning took place. Although the Agency is not finalizing
the proposed F033 hazardous waste listing, EPA encourages owner/
operators of surface protection plants to clean or replace any surface-
treating equipment that was used previously with chlorophenolic
formulations upon a switch to non-chlorophenolic chemicals and properly
dispose of the wastes in an environmentally sound manner. Furthermore,
the Agency has obtained information which shows that some new
substitute products are more effective if residual chlorophenolic
contamination is removed. Hence, removing sludge and cleaning equipment
from previous chlorophenolic use will not only be more environmentally
sound, but may also enhance the new products effectiveness. Methodology
on recommended cleaning and operating practices for surface protectors
will be published in the near future by the Agency in a pollution
prevention and waste minimization guidance document.
One commenter suggested that the proposed operating standards for
surface protection plants be codified in part 262 as opposed to parts
264/265. The commenter reasoned that most surface protection plants are
only generators and do not function as treatment, storage, and disposal
facilities (TSDFs). However, since the F033 hazardous waste listing is
not being promulgated, this issue is moot and there is no need for
special generator requirements.
Several commenters had specific concerns about the applicability of
the proposed F033 listing. Since the Agency is not finalizing the
proposed F033 listing, these concerns are also moot. However, where
appropriate, answers specific to each of these comments have been
addressed in the background document of this final rule.
One commenter questioned the representativeness of the Agency's
data on cross-contamination. The commenter stated that because sites
were not randomly selected, there is no true sample representation of
the surface protector population. EPA did not choose sampling sites
based on their statistical representativeness. Rather, the sites were
selected as appropriate from what the Agency considered to be typical
operating plants. The Agency visited more than 15 surface protection
sites in the Nation (both large and small plants). From the information
obtained from these plant tours and interviews, the Agency developed a
view of what it considered typical from an engineering standpoint (e.g.
size of equipment, production scale, presence of containment systems,
size of storage yards, amount of drippage, etc). The sites sampled need
not represent the entire surface protection industry in terms of the
process used and the degree of cross-contamination present to allow the
Agency to demonstrate that wastes from current and previous use of
chlorophenolics at surface protection sites were contaminated with the
constituents of concern. These sites were chosen from information
obtained by a questionnaire sent out under the Agency's 3007 RCRA
authority.
B. Comments Regarding Risk Assessment
Five commenters responded to the risk assessment presented in the
proposed rule. One commenter stated that the EPA incorrectly converted
units of measurement in the record sampling data used for the risk
assessment causing the overestimation of incremental risk for the fish/
shellfish consumption and soil ingestion pathways by a 1,000-fold. The
EPA agrees with the commenter. The dioxin concentrations in the
formulation at one of the affected facilities (Aquasco, MD) were
reported in the wrong units, causing a 1,000-fold error to be
incorporated into the risk estimates for the fish and shellfish
ingestion and soil ingestion scenarios. When this error is corrected,
the TCDD-TEQ dioxin levels used as the source concentration (the
concentration of formulation dripping onto the ground) for affected
facilities (cross-contamination from past use of chlorophenolic
formulations) and used in the lifetime individual risk estimates for
the soil ingestion scenario and fish and shellfish ingestion scenario
were reduced by a 1,000-fold. The lifetime individual risk values using
the corrected data are presented in Table 1.
Table 1.--Individual Risk From Cross-Contamination From Past Usage of
Chlorophenolic Formulations From Fish and Shellfish Ingestion
------------------------------------------------------------------------
Recreational fishers General population
-----------------------------------------------
Population Central Central
tendency High end tendency High end
------------------------------------------------------------------------
Constituent:
2,3,4,7,8-TCDD 2E-12 3E-11 8E-13 1E-11
TEQ\1\.
------------------------------------------------------------------------
\1\Excess lifetime cancer risk.
The estimated risk to any one individual using the corrected values
are 1,000-fold lower than the risk estimated in the proposed rule from
cross-contamination due to past use. In this case for the typically
exposed individual in the general population, the incremental risk of
developing cancer is a chance of 0.8 in a trillion (8E-13); in the
recreational fisher person, the risk of developing cancer is increased
by only 2E-12. The estimated incremental population risk is also
reduced, after correction, approximately by a 1,000-fold, to 0.0002
cases/70 years for the anticipated increase in the development of
cancer as a result of exposure to ingestion of fish/shellfish
contaminated with wastes from the use of chlorophenolic formulations
for wood surface protection. Chart 1 in Section V Part A of this final
rule shows the original values reported in the April 27, 1993 proposed
notice.
The soil ingestion scenarios also were based on the storage yard
soil concentrations. The soil ingestion scenario assumed that children
ages 1 to 6 could come into contact with the contaminated soil at the
sawmill sites because sawmill sites could be converted to rural
residential land use and the child's play area could be located on the
area previously used as a storage yard area. The lifetime individual
risks, using the corrected formulation concentration values for dioxin,
associated with the soil ingestion scenario for cross-contamination
from past users of chlorophenolic formulations are presented in Table
2.
Table 2.--Individual Risk From Cross-Contamination From Past Usage of
Chlorophenolic Formulations From Direct Soil Ingestion
------------------------------------------------------------------------
Storage yard
-----------------------------
Source Central
tendency High end
------------------------------------------------------------------------
Constituent:
2,3,7,8-TCDD TEQ\1\................... 7E-10 2E-9
------------------------------------------------------------------------
\1\Upper bound excess lifetime cancer risk.
The estimates presented in Table 2 show that the incremental risks from
direct soil ingestion by children are below what the Agency considers a
level of concern. A child exposed to storage yard soils cross-
contaminated by past users of chlorophenolics under typical conditions
(consumption of 0.1 gram of soil/day for 160 days/year for six years)
would be subject to an increased cancer risk of 7E-10 over a lifetime,
or a chance of 0.7 in a billion. The estimated incremental population
risk is also reduced approximately 1,000-fold (to 4E-7 cases per year
over a 70-year period) for the anticipated increase in the development
of cancer as a result of exposure to direct ingestion of soil
contaminated with wastes from the use of cross-contaminated
formulations for wood surface protection.
One commenter remarked that the EPA failed to specifically address
the incremental risks to subsistence fisher persons from consumption of
fish/shellfish contaminated from the use of chlorophenolic formulations
for wood surface protection. EPA agrees that the risks to highly
exposed sub-populations should be considered. The fish ingestion
scenarios developed for the proposed rule considered exposure to a
general population and recreational fisher at the outflow of a drainage
area containing surface protection facilities.
EPA used the analysis for the high end recreational fisher to
approximate the risk to the subsistence fisher. Recent data show that
the high end ingestion rate for a subsistence fisher is greater than
for a recreational fisher by a factor of approximately 2. Therefore,
the incremental risk for a subsistence fisher would not exceed a level
of concern, since the projected risk to recreational fishers is much
less than 10-6.
The analysis of risks from fish consumption assumes that all fish
in the drainage basin are contaminated. The estimates of PCDDs and
PCDFs in fish tissue are based on sediment concentrations of these
constituents. The sediment concentrations are estimated based on the
erosion of contaminated soils from sawmill sites in a river or stream
basin and subsequent dilution of contaminant levels by the erosion of
uncontaminated soils from the corresponding drainage basin.
The projected risk levels increase as the size of the drainage area
decreases, due to the relatively lower amounts of uncontaminated soil
in smaller drainage basins. EPA performed an analysis which shows that,
even with all exposure parameters set at values which would maximize
the overall estimate of exposure, in order to reach a risk level of
10-6, the drainage area would need to be 8,000 hectares or less,
which is smaller than the smallest drainage area in the country. The
average drainage area is 440,000 hectares, and the lower fifth
percentile of the size distribution is 109,000 hectares.
With regard to the fish/shellfish ingestion scenario, one commenter
maintained that the fish/shellfish ingestion scenario should have been
performed on a site-specific basis (i.e. EPA should have used
parameters seen at individual sites), because not all sawmills are
located on streams with commercial fisheries. The EPA chose the fish/
shellfish ingestion scenario to be protective of the recreational
fisher persons and the general population. The risk analysis was
structured so that the hydrologic cataloguing unit (or watershed) was
the basic unit of analysis to ensure that the contaminated sediment
would be associated with a body of water large enough to support fish
hatcheries and recreational fisher persons. When these assumptions were
used in the fish/shellfish ingestion scenario using corrected values
for dioxin found in formulation for PCDDs and PCDFs, the incremental
risk to individuals with high-end exposures remains well below
1 x 10-6.
With regard to the Universal Soil Loss Equation (USLE), one
commenter asserted that the equation is overly conservative for
estimating soil erosion from surface protection sites. This equation
models the amount of soil which is dumped into a drainage area
containing fish. For a more detailed description of the model, the
reader is referred to background document of the proposed rule. The EPA
believes that, although this may be a conservative approach, it is the
best method currently available. It has been used to support other EPA
rulemakings and guidance documents. The most notable example being the
Assessment of Risks from Exposure of Humans, Terrestrial and Avian
Wildlife, and Aquatic Life to Dioxins and Furans, from Disposal and Use
of Sludge from Bleached Kraft and Sulfite Pulp and Paper Mills.\1\ Even
using these conservative assumptions, the incremental risks from cross-
contamination at these sites are not at a level of concern.
---------------------------------------------------------------------------
\1\Environmental Protection Agency, 1990. Assessment of Risks
from Exposure of Humans, Terrestrial and Avian Wildlife to Dioxins
and Furans, from Disposal and Use of Sludge from Bleached Kraft and
Sulfite Pulp and Paper Mills. Prepared for the Office of Toxic
Substances. Washington, DC by Abt Association, Inc. under contract
nos. 68-02-4283, Task 3-02, and 68-D9-0169, Task 1-15. EPA 560/5-90-
13. July, 1990.
---------------------------------------------------------------------------
One commenter suggested that the population risks attributable to
the contaminated fish/shellfish ingestion scenario were too high
because the entire U.S. population was considered to be exposed. EPA
disagrees and believes it is appropriate to consider the consumption
rate of the entire population in estimating risk to the general
population from this exposure pathway. However, an adjustment of 0.4
was made to the diet fraction to account for the fact that not all fish
are contaminated. Thus, only some percentage of the population would be
affected by the contaminated fish. As discussed in the Risk Assessment
Background Document for the proposed rule, the 0.4 diet fraction was
derived by estimating the percentage of rivers and streams (i.e.,
cataloguing units) that have at least one sawmill. A second adjustment
was made in the calculation of population risk to account for the
percentage of sawmills that operate surface protection processes (about
30% of the entire number of sawmills nationally). Population risk for
the fish/shellfish ingestion scenario has been recalculated for the
final rule using the corrected incremental storage yard soil TCDD-TEQ
concentrations. The corrected estimate of incremental population risk
from cross-contamination is three orders of magnitude lower than the
risk originally stated in the proposed rule. The corrected number of
cancer cases expected in 70 years is now 0.0002.
One commenter asserted that the soil ingestion scenario was overly
conservative because all of the soil consumption was attributed to
contaminated storage yard soil and no consumption of ``indoor dust''
was considered. EPA considered only the consumption of storage yard
soil in order to be protective of human health. The range of soil
ingestion rates for average children aged 1 through 6 is presented in
the EPA's Exposure Factors Handbook (1990) as 0.2 to 0.8 grams per day.
These estimated values were determined from the clay content of fecal
samples taken from children in this age group and thus represent
consumption of soil. However, the percent of this consumption that is
attributed to house dust is unknown, as is the contaminant
concentration in the house dust. The EPA has recalculated the soil
ingestion scenario using the corrected incremental TCDD-TEQ
concentrations obtained from the formulation sample. The incremental
risk estimated is below 1E-6, using the conservative assumptions. The
Agency's risk levels are particularly protective with the use of these
conservative assumptions, thereby further lending support to the
Agency's decision not to list these wastes.
One commenter stated that children are unlikely to consume sediment
at the same rate that they consume soil. The Agency agrees, but notes
that sediment consumption by children was not considered as an exposure
pathway in the proposed rule. The Agency does not feel that this
exposure pathway is a significant one in making a determination whether
or not to list chlorophenolic wastes since the exposure areas of
concern are relatively small and any land conversion which could take
place would most likely require soil testing prior to land development.
One commenter stated that the assumptions used to estimate the
exposed population in the soil ingestion population risk scenario
greatly overestimate the number of exposed children. EPA believes that
the scenario may be conservative, but not implausible. The scenario
assumes that all sawmill sites are converted to rural residential land
use, that the children's play areas are located on the site of the
former storage yards, and that the homes are resold to new families
with young children every 25 years. These assumptions include a low
population density in these areas. It would take only a limited number
of sites to be converted to suburban housing or to daycare or school
facilities to cause a substantial increase in the exposed population.
The incremental population risk estimated using the corrected
incremental value for the storage yard soil TCDD-TEQ concentration is
4E-7 cases in 70 years, three orders of magnitude lower than that in
the proposed rule.
One commenter maintained that the soil ingestion scenario was
questionable because Superfund liabilities, state laws, and lender
requirements make land use changes unlikely without site cleanup
activities. The EPA agrees that, in some states, land transfers and
subsequent land use changes would be unlikely to occur without cleanup.
However, not all states are equally diligent in requiring site
investigations at the time of property transfer, making the types of
land use changes described in the soil ingestion scenario plausible.
Because of this, EPA believes it is entirely appropriate to assess risk
via the soil ingestion pathway, notwithstanding any risk management
decisions that may be made at some future time to address the risk.
Two commenters believed that some of the values used as input
parameters to the ground-water model (i.e. recharge rate, regional
conductivity, and average depth to water) were too conservative and
that more appropriate input parameters should be used in this MULTIMED
model. One commenter believed that the Agency had used DRASTIC (a name
given to a modelling program used to evaluate the potential which may
exist resulting from groundwater pollution) to perform its groundwater
modeling. First, the EPA did not use the DRASTIC model in this
rulemaking effort; it used the MULTIMED model developed by the Agency
to perform groundwater models. The Agency did, however, use some soil
and hydrogeologic information (on hydrogeologic regions and subregions
collected by Aller et al. (1988)) which is used when applying the
DRASTIC model. With regard to the parameters felt by the commenter to
be too conservative, the EPA supports the values used in the proposed
rule (58 FR at 25706 of April 27, 1993). This hydrogeologic information
includes many of the input parameters required to run the MULTIMED
model, and includes such parameters as depth to water, soil type and
hydraulic conductivity, net recharge, aquifer hydraulic conductivity.
The EPA selected hydrogeologic subregions in the northwest and
southeast United States, excluding subregions where sawmills were not
likely to be sited (e.g., mountain slopes or flanks). Since the
parameter value ranges presented in Aller et al. (1988) are based on
compilations of literature values and expert opinion, the values should
be viewed as bounding ranges, and are not sufficiently statistically
rigorous to estimate true means or parameter distributions. For the
average case, ``typical'' parameter values were obtained by examining
the ranges of values in Aller et al. (1988) for the selected subregions
only and selecting values representing the central tendency of the
reported ranges. Similarly, high-end values were selected to represent
the high end of the exposure distribution, using the higher end of the
range of parameter values deemed likely to occur by Aller et al.
(1988). EPA recognizes that there are limitations to this approach,
largely associated with the non-statistical nature of the data. The
Agency believes, however, that this data source is the best available
at this time for regional and subregional estimates of the
hydrogeologic properties necessary to estimate exposures through the
ground-water pathway.
Two commenters felt that the Agency's use of input parameter values
used for well location and well intake point were too conservative. EPA
derived the horizontal distance to wells from the responses reported in
the RCRA's 3007 Industry Questionnaires. Because information was not
obtained on the well type or construction, all wells described in the
questionnaire were assumed to be possible sources of drinking water and
were assumed to be screened to the top of the aquifer, that is, well
water was assumed to be drawn off the top of the aquifer where organics
are assumed to exist in greater concentrations than when water is drawn
from the middle of the aquifer. These assumptions are consistent with
similar conservative assumptions used to develop other RCRA
regulations, such as the Toxicity Characteristic (55 FR 11798, March
29, 1990).
Two commenters contended that neither biodegradation or chemical
degradation rates were considered in the ground-water modeling of
pentachlorophenol contamination. These commenters submitted studies
showing that biological and chemical degradation of PCP can occur and
that adequate biological and chemical degradation rates are available
or can be estimated from these studies. EPA has reviewed these studies
and agrees that they do indicate that biological and chemical
degradation of PCP can occur. The information submitted by the
commenters are results from laboratory studies, reporting the results
from controlled experiments. However, EPA does not agree that there is
sufficient information on unassisted field degradation rates, the
geochemical factors that affect degradation, or their spatial
variability from site-to-site or region-to-region to model degradation
in the field at generic or prototypical sites for regulatory purposes.
Moreover, the existence of metabolites that would confirm the
occurrence of biodegradation in the field has not been firmly
established. Therefore, EPA does not believe the data warrant an
assumption that biodegradation does occur at significant rates at most
sites. In addition, the toxicities of potential degradation products
have not been characterized. Therefore, the EPA does not believe it is
appropriate to consider these mechanisms in this rulemaking.
One commenter suggested that it would be more appropriate to
calculate the average peak concentration of pentachlorophenate in
groundwater used to reflect a 9-year exposure duration by producing a
breakthrough curve of annual concentrations at a well using the
MULTIMED model and calculate a series of 9-year or 10-year moving
averages. The moving averages would be sorted in descending order and a
paper plot prepared. A preferred percentile value could then be
selected as the concentration of concern. EPA believes the current
method of calculating 10-year time-weighted averages by averaging two
5-year concentrations (including the maximum concentration and the
highest adjacent 5-year value calculated from each model run) is an
appropriate approach for estimating lifetime individual risk and the
Agency selected this approach to be conservative and protective of
human health. The 30-year exposure duration scenario uses a time-
weighted 30-year average concentration that includes the maximum
concentration. Population risk estimates aggregated over 70 years were
based on a time-weighted 70-year average concentration that includes
the maximum concentration.
One commenter believed that the source concentration used by EPA
for PCP in the ground-water ingestion scenario was too high because PCP
is no longer in use and, thus, the infiltration to ground water would
be reduced. The commenter suggested that source reduction also would
occur from erosion of surface soil containing PCP, before it is leached
and enters the ground water. EPA addressed the fact that PCP is no
longer in use at most facilities in its baseline risk estimates in the
proposed rule, which have been revised in the final rule based on
comments received to reflect source concentrations and pulse durations
(estimated time in which pentachlorophenate is expected to be present
in substitute wood surface protection product from time of changeover)
more representative of the cross-contamination scenario. While surface
runoff and erosion may reduce the amount of PCP available for leaching
to ground water, EPA has assumed, for the purpose of its analysis, that
any reductions are negligible. The EPA adopted this conservative
assumption mainly because of lack of data necessary to quantify such a
loss and its effects on ground-water concentrations. Furthermore, EPA
does not believe that surface water and erosion will significantly
reduce source leachate concentrations. As formulation drips onto the
soil it will rapidly penetrate the soil until the soil is saturated.
Subsequent rain events may wash off contaminated surface soil, but will
not erode deeper soil horizons where most of the contaminant mass
resides. Thus, EPA does not consider this assumption to be overly
conservative.
One commenter noted that the results of the ground-water analysis
were not supported by actual resource damage data. The Agency does not
expect, nor does it feel that it is needed, that ground water PCP
concentrations predicted by MULTIMED would agree precisely with the
resource damage data. The resource damage incidents presented in the
background document are intended to illustrate that ground-water
contamination from PCP does occur at sawmill facilities, and are not
intended as validation points for exposure modeling. Resource damage
data were obtained from monitoring and other wells that happened to be
in place at a facility when the sampling was conducted. There are a
number of possible reasons why sampling data from the resource damage
incidents may not reflect well-water concentrations predicted by the
model, in particular the location of the wells with regard to plume
centerline and ground-water flow direction, and the timing of peak
plume concentrations at the wells.
The latter point is especially important because, depending on
patterns of past PCP use and the well location, the peak concentration
in the plume may not have reached or may have passed the well(s)
sampled. In these resource damage cases, sufficient information was not
available to determine the placement and design of these wells with
respect to the site's hydrogeology or possible plume locations and
travel time. Thus, it is not possible to use these data points for
validation of model results. However, it should be noted that the
model-estimated ground-water PCP concentrations in the final rule are
similar to those reported from resource damage incidents. When the
revised average source concentration was used in the ground-water
model, the estimated concentrations for PCP in ground water (average =
0 .005 mg/L; high-end = 288 mg/L) are in a reasonable agreement with
the values reported in the resource damage accounts (<0.001 to="" 45="" mg/="" l).="" one="" commenter="" disagreed="" with="" the="" use="" of="" multimed="" in="" that="" it="" was="" not="" as="" ``robust''="" or="" well-tested="" as="" the="" monte="" carlo-based="" epacml="" model="" used="" for="" the="" tc="" rule.="" another="" commenter="" recommends="" the="" use="" of="" the="" monte="" carlo="" approach="" for="" all="" input="" parameters="" in="" the="" modeling="" effort.="" first,="" it="" is="" important="" to="" note="" that="" the="" multimed="" ground-water="" model="" is="" the="" same="" model="" as="" used="" in="" epacml="" except="" for="" the="" manner="" in="" which="" input="" parameters="" are="" specified.="" epacml="" can="" only="" be="" run="" in="" a="" probabilistic,="" monte="" carlo="" mode,="" while="" multimed="" allows="" monte="" carlo="" runs="" as="" well="" as="" for="" individual="" input="" parameters="" to="" be="" specified="" and="" fixed.="" the="" ground-water="" flow="" and="" transport="" model="" components="" are="" the="" same="" for="" multimed="" and="" epacml.="" second,="" the="" agency="" did="" not="" pursue="" a="" probabilistic,="" monte="" carlo-="" based="" approach="" when="" developing="" input="" parameters="" for="" this="" modeling="" effort="" due="" to="" the="" fact="" that="" using="" this="" sophisticated="" technique="" requires="" knowledge="" and="" proper="" specification="" of="" input="" parameter="" distributions,="" and="" variable="" independence="" or="" proper="" specification="" of="" joint="" probability="" parameter="" distributions.="" when="" these="" requirements="" cannot="" be="" met,="" the="" monte="" carlo="" approach="" will="" not="" provide="" better="" estimates="" than="" a="" scenario-="" based="" approach.="" epa="" has="" adopted="" a="" scenario-based="" regional="" modeling="" approach="" that="" uses="" input="" parameters="" developed="" for="" regions="" of="" the="" u.s.="" where="" sawmills="" are="" more="" prevalent.="" in="" this="" approach,="" epa="" uses="" average="" and="" high-end="" values="" for="" estimating="" model="" input="" parameters="" on="" a="" regional="" basis="" because="" information="" does="" not="" exist="" on="" the="" actual="" means="" and="" distributions="" of="" these="" parameters="" for="" the="" regions="" modeled.="" the="" agency="" believes="" that="" this="" approach="" is="" an="" appropriate="" one="" and,="" furthermore,="" that="" the="" resulting="" model="" estimates="" bracket="" or="" bound="" the="" uncertainty="" associated="" with="" the="" model="" input="" parameters.="" two="" commenters="" questioned="" the="" use="" of="" cancer="" as="" the="" endpoint="" of="" concern="" for="" 2,3,7,8-tcdd.="" epa="" disagrees.="" the="" cancer="" endpoint="" for="" tcdd="" was="" selected="" because="" it="" is="" the="" most="" sensitive="" endpoint="" for="" which="" qualitative="" dose="" response="" data="" are="" available.="" 2,3,7,8-tcdd="" has="" been="" demonstrated="" to="" be="" a="" potent="" carcinogen="" in="" animals="" and="" has="" been="" classified="" as="" a="" b2="" (potential="" human)="" carcinogen.="" recently="" published="" epidemiological="" studies="" of="" occupationally="" exposed="" individuals="" report="" significant="" increases="" in="" cancer="" mortality.="" 2,3,7,8-tcdd="" also="" has="" potent="" reproductive="" and="" teratogenic="" endpoints="" and="" enough="" data="" exist="" to="" estimate="" a="" reference="" dose="" (rfd)="" based="" on="" these="" alternative="" short-term="" effects.="" (for="" a="" detailed="" discussion="" of="" this="" information,="" and="" for="" references="" to="" studies="" supporting="" these="" conclusions,="" the="" reader="" is="" referred="" to="" the="" background="" document="" of="" the="" proposed="" rule.)="" however,="" if="" health-based="" levels="" (hbls)="" are="" calculated="" using="" the="" reproductive="" effect="" rfd,="" the="" exposure="" level="" is="" an="" order="" of="" magnitude="" higher="" than="" the="" level="" calculated="" using="" the="" carcinogen="" slope="" factor="" (csf).="" thus,="" if="" the="" cancer="" end-point="" is="" used="" as="" the="" basis="" for="" calculating="" a="" permissible="" exposure="" level,="" it="" also="" will="" be="" protective="" against="" short-term="" exposures="" such="" as="" those="" associated="" with="" reproductive="" effects.="" the="" issue="" of="" 2,3,7,8-tcdd="" toxicity="" is="" being="" reassessed="" by="" epa="" (outside="" the="" framework="" of="" this="" rulemaking)="" and="" all="" endpoints="" are="" being="" considered.="" tcdd="" has="" been="" observed="" to="" express="" a="" wide="" variety="" of="" effects="" including="" teratogenesis,="" reproductive="" effects,="" and="" suppression="" of="" the="" immune="" system="" function="" in="" many="" species.="" mechanistic="" approaches="" to="" understanding="" and="" identifying="" toxic="" effects="" levels="" are="" also="" being="" considered.="" until="" the="" reassessment="" process="" has="" been="" completed,="" the="" epa="" will="" continue="" to="" use="" the="" current="" carcinogenicity="" endpoint="" csf="" value="" that="" has="" been="" accepted="" as="" the="" basis="" for="" the="" mcl.="" two="" commenters="" noted="" limitations="" associated="" with="" the="" use="" of="" the="" toxicity="" equivalence="" factors="" (tef's)="" methodology.="" they="" argued="" that="" the="" tef="" methodology="" should="" not="" be="" used="" to="" justify="" the="" addition="" of="" appendix="" viii="" in="" the="" absence="" of="" valid="" toxicological="" studies="" that="" demonstrate="" actual="" health="" effects="" associated="" with="" exposure="" to="" these="" compounds.="" one="" commenter="" questioned="" the="" proposal="" to="" add="" octachlorodibenzo-p-dioxin="" (ocdd)="" and="" octachlorodibenzofuran="" (ocdf)="" to="" 40="" cfr="" part="" 261,="" appendix="" viii.="" the="" commenters="" stated="" that="" neither="" compound="" has="" been="" shown="" to="" produce="" toxic,="" carcinogenic,="" mutagenic="" or="" teratogenic="" effects="" on="" humans="" or="" other="" life="" forms.="" the="" agency="" has="" decided="" not="" to="" add,="" at="" this="" time,="" ocdd="" and="" ocdf="" to="" appendix="" viii="" of="" 40="" cfr="" part="" 261.="" although="" the="" original="" basis="" for="" including="" these="" congeners="" on="" appendix="" viii="" remains="" valid="" (details="" of="" which="" can="" be="" found="" in="" the="" background="" document="" supporting="" this="" final="" rulemaking),="" the="" agency="" is="" investigating="" further="" the="" information="" submitted="" by="" the="" commenters="" regarding="" the="" effects="" of="" ocdd="" and="" ocdf="" reported="" in="" the="" couture,="" elwell,="" and="" birnbaum="" study="" used="" to="" support="" the="" decisions="" made="" in="" the="" ``interim="" procedures="" for="" estimating="" risks="" associated="" with="" exposures="" of="" mixtures="" of="" chlorinated="" dibenzo-p-dioxins="" and="" dibenzofurans="" and="" the="" 1989="" update''.="" ocdd="" and="" ocdf="" are="" the="" most="" prevalent="" of="" the="" pcdd="" and="" pcdf="" congeners="" accounting="" for="" approximately="" 85="" percent="" of="" the="" total="" cdd="" and="" cdf="" present="" in="" five="" of="" the="" six="" storage="" yard="" soil="" samples.="" ocdd="" has="" been="" shown="" to="" exhibit="" ``dioxin-like''="" toxicity="" in="" male="" rats="" when="" administered="" in="" small="" doses="" in="" a="" sub-chronic="" toxicity="" study.\2\="" these="" findings="" have="" been="" confirmed="" by="" a="" second="" sub-chronic="" study="" conducted="" in="" female="" rats.\3\="" ocdd="" and="" ocdf="" have="" not="" exhibited="" toxicity="" in="" short="" term="" studies;="" however,="" acute="" exposure="" is="" not="" the="" only="" concern="" of="" epa.="" the="" agency="" is="" currently="" re-="" evaluating="" its="" original="" assessment="" of="" risks="" from="" dioxin.="" at="" this="" point,="" the="" agency="" wishes="" to="" conclude="" its="" on-going="" reassessment="" before="" adding="" ocdd="" and="" ocdf="" to="" appendix="" viii="" of="" 40="" cfr="" part="" 261.="" ---------------------------------------------------------------------------="" \2\couture,="" l.a.,="" m.="" r.="" elwell,="" and="" l.="" s.="" birnbaum.="" dioxin-like="" effects="" observed="" in="" male="" rats="" following="" exposure="" to="" octachlorodibenzo-p-dioxin="" (ocdd)="" during="" a="" 13-week="" study.="" toxicology="" and="" applied="" pharmacology,="" vol.="" 93,="" pp="" 31-46,="" 1988.="" \3\hermelinger,="" n.,="" n.="" poiger,="" and="" c.="" schlatter.="" results="" of="" a="" 9-="" month="" feeding="" study="" with="" ocdd="" and="" ocdf="" in="" rats,="" organohalogen="" compounds,="" vol.="" 1,="" 1990,="" pp.="" 221-224.="" ---------------------------------------------------------------------------="" one="" commenter="" questioned="" the="" conclusion="" that="" soil="" contamination="" presents="" no="" risk="" to="" wildlife.="" the="" epa="" recognizes="" that="" concentrations="" that="" are="" protective="" of="" human="" health="" may="" not="" necessarily="" always="" be="" protective="" of="" wildlife.="" however,="" in="" view="" of="" the="" relatively="" small="" areas="" occupied="" by="" sawmills="" and="" the="" low="" concentration="" of="" tcdd-teq="" in="" storage="" yard="" soil="" from="" cross="" contamination,="" the="" epa="" believes="" the="" incremental="" risks="" to="" wildlife="" will="" be="" below="" a="" level="" of="" concern.="" v.="" overview="" of="" the="" final="" rule="" this="" final="" rule="" makes="" final="" the="" agency's="" hazardous="" waste="" listing="" determination="" for="" chlorophenolic="" wastes="" generated="" at="" wood="" surface="" protection="" plants.="" epa="" believes="" that="" listing="" as="" hazardous="" chlorophenolic="" wastes="" from="" surface="" protection="" operations="" is="" unnecessary="" for="" reasons="" described="" in="" part="" a="" of="" this="" preamble.="" this="" document="" also="" amends="" sw-846="" (test="" methods="" for="" evaluating="" solid="" waste,="" physical/chemical="" methods)="" by="" adding="" method="" 4010="" (immunoassay="" test="" for="" the="" presence="" of="" pentachlorophenol).="" this="" action="" is="" discussed="" in="" section="" vi="" of="" this="" preamble.="" this="" final="" rule="" also="" adds="" four="" chemicals="" to="" the="" list="" of="" hazardous="" constituents="" at="" 40="" cfr="" part="" 261,="" appendix="" viii.="" these="" four="" chemicals="" are:="" (1)="" sodium="" pentachlorophenate,="" (2)="" potassium="" pentachlorophenate,="" (3)="" sodium="" tetrachlorophenate,="" and="" (4)="" potassium="" tetrachlorophenate.="" a="" discussion="" of="" this="" action="" is="" found="" in="" part="" c="" of="" this="" section.="" a.="" basis="" for="" the="" determination="" not="" to="" list="" as="" hazardous="" wastes="" from="" wood="" surface="" protection="" operations="" as="" discussed="" in="" the="" proposed="" rule,="" in="" making="" a="" hazardous="" waste="" listing="" determination,="" the="" agency="" applies="" a="" ``weight-of-evidence''="" approach.="" in="" doing="" this,="" the="" agency="" examines="" the="" risks="" associated="" with="" all="" potential="" human="" health="" and="" environmental="" exposure="" pathways,="" analyzes="" trends="" in="" the="" current="" industry,="" researches="" past="" damage="" incidents,="" as="" well="" as="" other="" factors="" found="" in="" 40="" cfr="" 261.11.="" upon="" reviewing="" and="" responding="" to="" comments="" received="" on="" the="" proposed="" rule,="" the="" agency="" has="" decided="" not="" to="" list="" as="" hazardous="" wastes="" from="" the="" use="" of="" chlorophenolic="" formulations="" in="" the="" wood="" surface="" protection="" industry="" for="" several="" reasons.="" first,="" chlorophenolic="" formulations="" are="" no="" longer="" being="" produced="" in="" the="" united="" states="" and="" the="" agency="" believes="" it="" is="" very="" unlikely="" they="" will="" be="" produced="" in="" the="" future.="" the="" only="" remaining="" producer="" of="" chlorophenolics="" in="" the="" u.s.,="" chapman="" chemicals,="" stopped="" production="" in="" january="" of="" 1992="" and="" sometime="" later="" applied="" for="" voluntary="" cancellation="" of="" its="" fifra="" product="" registration.="" a="" notice="" describing="" this="" action="" was="" published="" in="" the="" federal="" register="" on="" june="" 3,="" 1992="" (57="" fr="" 23401),="" and="" a="" final="" cancellation="" order="" was="" sent="" to="" chapman="" chemicals="" with="" an="" effective="" date="" of="" september="" 14,="" 1992.="" this="" cancellation="" notice="" applies="" to="" the="" following="" products="" produced="" by="" chapman="" chemicals:="" permatox="" 181,="" 10s,="" and="" 101,="" and="" mitrol="" g-st.="" any="" manufacturer="" wishing="" to="" resume="" production="" of="" chlorophenolics="" would="" have="" to="" obtain="" a="" new="" fifra="" registration="" before="" these="" chemicals="" could="" be="" re-introduced="" and="" made="" available="" for="" use="" in="" wood="" surface="" protection.="" currently,="" there="" remains="" only="" one="" known="" user="" of="" chlorophenolics="" in="" the="" u.s.="" out="" of="" an="" estimated="" 1000="" previous="" users="" and="" the="" remaining="" plant's="" existing="" stock="" is="" believed="" to="" be="" very="" limited.="" a="" major="" element="" in="" the="" decision="" not="" to="" list="" as="" hazardous="" chlorophenolic="" wastes="" generated="" from="" the="" surface="" protection="" industry="" is="" the="" fact="" that="" use="" of="" chlorophenolic="" formulations="" has="" ceased.="" epa="" believes="" it="" is="" highly="" unlikely="" that="" a="" manufacturer="" will="" seek="" reregistration="" for="" this="" product="" for="" many="" reasons,="" including="" the="" availability="" of="" effective="" substitute="" products="" and="" the="" potentially="" high="" financial="" and="" administrative="" burdens="" imposed="" by="" the="" fifra="" registration="" process.="" additional="" justification="" to="" support="" non-future="" production="" is="" the="" fact="" that="" european="" countries="" do="" not="" want="" to="" accept="" dioxin-="" containing="" wood="" products="" which="" have="" affected="" large="" export="" mills="" who="" will="" not="" use="" chlorophenolic="" formulations="" in="" the="" future="" in="" part="" for="" this="" reason.="" use="" of="" chlorophenolics="" for="" surface="" protection="" has="" declined="" steadily="" (even="" without="" the="" influence="" of="" rcra)="" from="" over="" 1,000="" users="" to="" one="" user="" over="" the="" past="" decade.="" should="" a="" new="" registration="" of="" this="" product="" be="" sought,="" epa="" will="" consider="" this="" surface="" protection="" risk="" analysis="" for="" full="" strength="" application="" when="" determining="" whether="" a="" new="" listing="" determination="" under="" rcra="" should="" be="" initiated.="" currently,="" the="" agency="" is="" aware="" of="" nine="" available="" substitute="" products="" currently="" being="" used="" by="" surface="" protectors="" in="" place="" of="" chlorophenolics.="" the="" substitute="" products="" are="" for="" a="" large="" part="" satisfactory="" to="" their="" users="" (as="" mentioned="" on="" various="" site="" trips),="" and="" the="" agency="" does="" not="" feel="" as="" though="" a="" switch="" back="" to="" chlorophenolics="" is="" likely.="" a="" second="" reason="" why="" the="" agency="" has="" decided="" not="" to="" list="" these="" wastes="" is="" because="" the="" risk="" to="" human="" health="" and="" the="" environment="" from="" on-going="" operations="" which="" previously="" used="" chlorophenolics="" is="" shown="" to="" tail="" off="" quickly="" because="" chlorophenolic="" concentrations="" diminish="" to="" a="" near="" zero="" concentration="" within="" a="" short="" period="" of="" time="" following="" switchover="" to="" an="" alternate="" product.="" the="" agency="" has="" determined="" that="" the="" use="" of="" full-="" strength="" chlorophenolic="" formulations="" generates="" wastes="" that="" result="" in="" unacceptable="" risk="" to="" human="" health="" and="" the="" environment.="" as="" before="" mentioned,="" should="" the="" use="" of="" chlorophenolics="" for="" surface="" protection="" applications="" resume,="" for="" any="" reason,="" the="" agency="" will="" most="" likely="" re-="" evaluate="" its="" current="" position.="" however,="" dealing="" with="" the="" current="" situation,="" there="" remains="" only="" one="" known="" user="" of="" chlorophenolics="" with="" a="" limited="" supply="" remaining.="" although="" the="" agency="" believes="" the="" use="" of="" full-strength="" chlorophenolics="" will="" be="" phased="" out="" in="" the="" very="" near="" future,="" there="" was="" concern="" at="" the="" time="" of="" proposal="" that="" there="" may="" be="" unacceptable="" risks="" posed="" by="" the="" use="" of="" substitute="" products="" that="" become="" cross-contaminated="" from="" previous="" chlorophenolic="" use.="" particularly,="" the="" proposal="" cited="" possible="" ground="" water="" risks="" of="" 2="" x="">-4 for individuals and a
broad but very low potential exposure risk due to surface run-off
contributing to dioxin levels in fish. The Agency received several
comments addressing these potential impacts. In response to these
comments, the Agency conducted additional ground-water modeling using
new pulse assumptions developed from commenter-submitted information.
The Agency developed what it believed to be better pulse assumptions in
an effort to determine how long pentachlorophenate will be present in
on-going operations which have switched over from its past use. This
new data was obtained from performing mass balance iterations using
typical tank volumes found at both large and small facilities. These
mathematical calculations showed that cross-contamination from previous
use of chlorophenolics will be present in a substitute products for
only two to six years from the time a plant stops using
chlorophenolics. The Agency found that the highest estimated risk to an
individual from drinking ground water for nine years at peak
concentrations in the two- or six-year pulse resulting from cross
contamination, is significantly diminished and the broad effect on
dioxin levels in fish is reduced by several orders of magnitude. This
new analysis shows that the risks associated with cross-contamination
do not justify a hazardous waste listing to capture cross-contaminated
wastes. In the proposed rule, EPA addressed the fact that PCP is no
longer in use at most facilities in its baseline risk estimates, which
have been revised in the final rule to reflect source concentrations
and pulse durations more representative of the cross-contamination,
incremental-risk scenario. Chart 1 below compares the incremental risks
from cross-contaminated wastes as calculated for the proposed rule to
the values obtained using the new approach.
Chart 1.--Incremental Risks\1\ Due to Cross Contaminated Wastes
----------------------------------------------------------------------------------------------------------------
Significant
Constituent threat pathway Central tendency High end Population risk
----------------------------------------------------------------------------------------------------------------
Proposed in NPRM. Pentachlorophenate Ground water.... 5 x 10-7........ 2 x 10-4........ .005
(assumed 30 year
pulse).
Dioxin fish and Soil............ 18 x 10-10 4 x 10-7, rec 0.2
shellfish (general fisher.
consumption (general population).
population and
recreational fisher).
Dioxin soil ingestion Soil............ 7 x 10-7........ 2 x 10-5........ .0004
Revised.......... Pentachlorophenate (2 Ground water.... 6 x 10-7........ 2 x 10-5........ .007
year pulse, for
large facilities).
Pentachlorophenate (6 Ground water.... 2 x 10-6........ 6 x 10-5........ 0.02
year pulse, for
small facilities).
Dioxin fish & Soil............ 2 x 10-12....... 3 x 10-11....... NR
shellfish
consumption
(recreational
fisher).
Dioxin fish & Soil............ 8 x 10-13....... 1 x 10-11....... .0002
shellfish
consumption (general
pop.).
Dioxin soil ingestion Soil............ 7 x 10-10....... 2 x 10-9........ 4 x 10-7
----------------------------------------------------------------------------------------------------------------
\1\Excess lifetime cancer risk.
As shown in Chart 1, population risk is lower than that presented
in the proposal for both fish/shellfish consumption and the soil
ingestion pathway, due to a unit conversion error in expressing dioxin
concentration. The dioxin concentrations in the formulation at one of
the affected facilities (Aquasco, MD) were reported using incorrect
units, causing a 1,000-fold error to be incorporated into the risk
estimates for the fish and shellfish ingestion and soil ingestion
scenarios. When this error was corrected, the TCDD-TEQ levels used as
the source concentration for affected facilities (cross-contamination
from past use of chlorophenolic formulations) and used in the lifetime
individual risk estimates for the soil/fish and shellfish ingestion
scenarios also were reduced 1,000-fold.
The incremental population risk was revised for the ground-water
scenario from an original 0.005 value to between 0.007 and 0.02 cancer
cases. This range of 0.007 to 0.02 cancer cases was obtained because
two different modelling scenarios were run to generate the extremes of
this range. One model run used input parameters which would simulate
decay for a small production plant. The input information was obtained
from a mass balance iteration which showed that it would take a small
plant approximately 6 years to decrease cross-contamination levels to
near zero; likewise, the second model used input parameters for large
facilities which predicted a two year decline to near zero levels of
cross-contamination. The details of the mass balance approach and the
resulting change in population risk can be found in the background
document for this final rule. The Agency believes that these revised
risk levels do not warrant a hazardous waste listing.
Based on the above two main factors (i.e. (1) chlorophenolic
production stoppage and subsequent chlorophenolic use decline and (2)
revised risk due to cross contamination), the Agency looked closely at
any potential environmental benefits that may accrue from a hazardous
waste listing. Given the market trend, the Agency cannot identify any
tangible benefits to be gained from listing wastes generated from the
use of chlorophenolic formulations for wood surface protection.
Environmental damages caused by previous use of chlorophenolics have
already occurred. A listing of these wastes cannot mitigate past
damages nor can it force the clean-up of these damages. Such potential
jurisdiction exists under current programs. Authority under CERCLA and
RCRA 3007 exists even if a decision is made not to list as is the case
for this final rule.
Damage to the environment of this magnitude from previous use of
chlorophenolic formulations within this industry are not expected to
occur in the future unless use of full-strength chlorophenolics
resumes. Furthermore, sampling data collected at surface protection
sites indicate that dioxin concentrations in storage yards (the largest
area of a plant) are below 1 ppb. The heavier contamination that occurs
in the process area is confined to a small area and likely will not
migrate off-site to environmental receptors. Therefore, the Agency
finds that the risks posed by this residual contamination are limited
and that a hazardous waste listing would likely simply result in these
limited areas of contamination being left in place and not produce an
environmental benefit. Thus the effect on past contamination does not
justify a hazardous waste listing.
B. Operating Requirements for Surface Protection Plants
Because the Agency is not listing F033 wastes, the operating
standards for surface protection plants proposed in the April 27, 1993
notice are not applicable and, thus, are not being finalized.
Furthermore, surface protection plants are not required to follow any
specific waste management requirements regarding previous use of
chlorophenolics as a result of this rule.
C. Addition of Chemicals to Appendix VIII of 40 CFR Part 261
Although this final rule does not list any wastes from wood surface
protection processes as hazardous, the Agency believes that certain
constituents contained in these wastes warrant inclusion in appendix
VIII of part 261. 40 CFR 261.11 provides that ``[s]ubstances will be
listed on appendix VIII only if they have been shown in scientific
studies to have toxic, carcinogenic, mutagenic or teratogenic effects
on humans or other life forms.'' In the April 27 notice, EPA proposed
to add six hazardous constituents of concern found in surface
protection wastes to appendix VIII of 40 CFR part 261. Based on the
information gathered during this listing investigation, the following
four are being added to the list: sodium pentachlorophenate, potassium
pentachlorophenate, the sodium salt of 2,3,4,6-tetrachlorophenol, and
the potassium salt of 2,3,4,6-tetrachlorophenol. The Agency presented
information in the proposed rule and supporting background documents on
the adverse effects of these compounds. For those reasons, EPA is
finalizing the addition of four of these constituents to appendix VIII
of part 261. The Agency is not at this time finalizing the addition of
OCDD and OCDF to Appendix VIII. As mentioned before, the Agency is
investigating further the information submitted by the commenters
regarding the effects of OCDD and OCDF reported in the Couture, Elwell,
and Birnbaum study used to support the decisions made in the ``Interim
Procedures for Estimating Risks Associated with Exposures of Mixtures
of Chlorinated Dibenzo-p-dioxins and Dibenzofurans and the 1989
Update''.
VI. Amendment of SW-846 (Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods)
In the notice of proposed rulemaking, the Agency proposed to add
Method 4010 (Immunoassay Test for the Presence of Pentachlorophenate)
to the Second and Third Editions of SW-846. The purpose behind this
proposal was to aid owners/operators of wood surface protection plants
with the proposed formulation testing requirement.
With respect to requiring the use of SW-846 methods for testing for
the presence of pentachlorophenate in wood surface protection ``in-
process'' formulation, the issue is moot since EPA is not listing any
wood surface protection wastes as hazardous. Nonetheless, EPA believes
that although no comments were received on Method 4010, Method 4010 is
an appropriate method, in general, for testing for the presence of
pentachlorophenate or pentachlorophenol and can, therefore, be used in
other applications other than for wood surface protection formulation
testing. The Agency is, therefore, adding Method 4010 to the Third
Edition of SW-846 as Update IIA. We are not adding Method 4010 to the
Second Edition of SW-846 since the Third Edition has replaced the
Second Edition on August 31, 1993 for use in mandatory applications (58
FR 46040). Method 4010, including its protocol and documentation
supporting this action can be found in the docket for this rulemaking.
See the ``For Further Information'' Section in front of this preamble
for the EPA contact person for further information or with questions on
Method 4010.
VII. Pollution Prevention and Waste Minimization
The Agency is preparing a separate guidance manual recommending
voluntary pollution prevention and waste minimization techniques for
the lumber industry. Since it has studied the surface protection
industry in making a listing determination for wastes generated from
the use of chlorophenolic formulations, EPA has gained a broad
perspective on the best ways to reduce wastes generated by this wood
surface protection industry. The ideas gained from the study are
presented in this manual. Some recommended strategies for pollution
prevention in the surface protection industry are described in this
section. Further information can be found in the manual.
The ultimate goal of pollution prevention is to reduce present and
future threats to human health and the environment. Pollution
prevention (also referred to as source reduction) is the use of
materials, processes, or practices that reduce or eliminate the
quantity and/or toxicity of wastes at the source of generation.
Pollution prevention is the first step in a hierarchy of options for
reducing the generation of waste. The first recommended pollution
prevention option is to replace chemical treatment with another type of
treatment to achieve surface protection. One alternate is to dry the
wood to reduce water content (high water content leads to sapstain).
The Agency is aware that this option may not be economically viable for
a smaller mill. If such a system cannot be feasibly employed, it would
be preferable for a user of chlorophenolic-containing formulations to
switch to an alternate formulation.
Other pollution prevention strategies for use within the surface
protection industry include: (1) Providing local and general
ventilation within the cutting process area to reduce dust that can
accumulate on wood; (2) blowing wood with air to reduce the amount of
sawdust on wood prior to surface protection; and (3) using drainage
collection devices like gutters on rooftops to keep precipitation away
from process wastes. The pollution prevention practices described here
can be critical to reduce the amount of waste generated. Although the
Agency is not listing these chlorophenolic wood surface protection
wastes, the pollution prevention practices described in the guidance
manual are applicable to any waste generating process. For wastes that
cannot be reduced at the source, generators may consider recycling as
the next best option.
VIII. Analysis of Potential Costs and Benefits
A. Executive Order Requirements
Executive Order 12866
Under Executive Order 12866, (58 FR 51735 (October 4, 1993)) the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order. The order defines ``significant regulatory action'' as
one that is likely to result in a rule that may:
(1) Have an annual effect on the economy of $100 million or more
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or state, local, or tribal governments or
communities;
(2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof; or
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
It has been determined that this rule is not a ``significant
regulatory action'' under the terms of Executive Order 12866 and is
therefore not subject to OMB review. Nevertheless, the Agency prepared
an abbreviated RIA or ``Economic Assessment'' (EA) in order to examine
costs and benefits likely to occur as a result of that action.
B. Description of Costs and Benefits of This Rule
Because the Agency has decided not to list wastes generated from
the use of chlorophenolic formulations in surface protection
operations, no specific action is required under this Rule. Facilities,
however, may choose to take some remedial action as a result of
publicity surrounding this action. A detailed analysis of work
performed is described in the background document for this final rule.
IX. State Authority
Under section 3006 of RCRA, EPA may authorize qualified States to
administer and enforce the RCRA program within the State. (See 40 CFR
part 271 for the standards and requirements for authorization.)
Following authorization, EPA retains enforcement authority under
sections 3007, 3008, 3013, and 7003 of RCRA, although authorized States
have primary enforcement responsibility.
Before the Hazardous and Solid Waste Amendments of 1984 (HSWA)
amended RCRA, a State with final authorization administered its
hazardous waste program entirely in lieu of the Federal program in that
State. The Federal requirements no longer applied in the authorized
State, and EPA could not issue permits for any plants located in the
State with permitting authorization. When new, more stringent Federal
requirements were promulgated or enacted, the State was obligated to
enact equivalent authority within specified time frames. New Federal
requirements did not take effect in an authorized State until the State
adopted the requirements as State law.
By contrast, under section 3006(g) of RCRA, 42 U.S.C. 6926(g), new
requirements and prohibitions imposed by the HSWA take effect in
authorized States at the same time that they take effect in non-
authorized States. EPA is directed to implement those requirements and
prohibitions in authorized States, including the issuance of permits,
until the State is granted authorization to do so. While States must
still adopt HSWA-related provisions as State law to retain final
authorization, the Federal HSWA requirements apply in authorized States
in the interim.
Although this final rule does not list, as hazardous,
chlorophenolic wastes from the wood surface protection industry, it
does add four constituents to appendix VIII of 40 CFR part 261. These
additions will not be effective in authorized States since the
requirements are not being imposed pursuant to HSWA. These requirements
will be effective only in those States that do not have final
authorization. In authorized States, these requirements will not be
applicable until the States revise their programs to adopt equivalent
requirements under State law.
Section 271.21(e)(2) of EPA's state authorization regulations (40
CFR part 271) requires that States with final authorization must modify
their programs to reflect Federal program changes and submit the
modifications to EPA for approval. The deadline by which the States
must modify their programs to adopt this proposed regulation, if it is
adopted as a final rule, will be determined by the date of promulgation
of a final rule in accordance with Sec. 271.21(e)(2). If the proposal
is adopted as a final rule, Table 1 at 40 CFR 271.1 will be amended
accordingly. Once EPA approves the modification, the State requirements
become RCRA Subtitle C requirements.
States with authorized RCRA programs already may have regulations
similar to what is being finalized in this rule. These State
regulations have not been assessed against the Federal regulations
being proposed today to determine whether they meet the tests for
authorization. Thus, a State would not be authorized to implement these
regulations as RCRA requirements until State program modifications are
submitted to EPA and approved, pursuant to 40 CFR 271.21. Of course,
States with existing regulations that are not less stringent than
current Federal regulations may continue to administer and enforce
their regulations as a matter of State law.
It should be noted that authorized States are required to modify
their programs only when EPA promulgates Federal standards that are
more stringent or broader in scope than existing Federal standards.
Section 3009 of RCRA allows States to impose standards more stringent
than those in the Federal program. For those Federal program changes
that are less stringent or reduce the scope of the Federal program,
States are not required to modify their programs. (See 40 CFR
271.1(i).) This proposed rule, if finalized, is neither less stringent
than nor a reduction in the scope of the current Federal program and,
therefore, states would be required to modify their programs to retain
authorization to implement and enforce these regulations.
X. Regulatory Flexibility Analysis
This final rule amends the hazardous waste regulations by adding
four chemicals to appendix VIII of 40 CFR part 261 and amending SW-846
by adding Method 4010. These are impacts with negligible effects to
small entities. Therefore, there is no need to consider its impacts on
small entities by preparing a Regulatory Flexibility Analysis.
XI. Paperwork Reduction Act
This rule does not contain any information collection requirements
subject to OMB review under the Paperwork Reduction Act of 1980, 44
U.S.C. 3501 et seq.
List of Subjects
40 CFR Part 260
Environmental protection, Administrative practice and procedure,
Confidential business information, Hazardous waste.
40 CFR Part 261
Hazardous materials, Waste treatment and disposal, Recycling.
Dated: December 23, 1993.
Carol M. Browner,
Administrator.
For the reasons set out in the preamble, chapter I of title 40 of
the Code of Federal Regulations is amended as follows:
PART 260--HAZARDOUS WASTE MANAGEMENT SYSTEM: GENERAL
1. The authority citation for part 260 continues to read as
follows:
Authority: 42 U.S.C. 6905, 6912(a), 6921-6927, 6930, 6934, 6935,
6937, 6938, 6939, and 6974.
2. Section 260.11 is amended by revising the ``Test Methods for
Evaluating Solid Waste, Physical/Chemical Methods'' reference in
paragraph (a) to read as follows:
Sec. 260.11 References.
(a) * * *
``Test Methods for Evaluating Solid Waste, Physical/Chemical
Methods,'' EPA Publication SW-846 (Third Edition (November, 1986), as
amended by Updates I, II and IIA). The Third Edition of SW-846 and
Updates I, II, and IIA (document number 955-001-00000-1) are available
from the Superintendent of Documents, U.S. Government Printing Office,
Washington, DC 20402, (202) 783-3238.
* * * * *
PART 261--IDENTIFICATION AND LISTING OF HAZARDOUS WASTE
3. The authority citation for part 261 continues to read as
follows:
Authority: 42 U.S.C. 6905, 6912(a), 6921, 6922, and 6938.
4. Appendix VIII of part 261 is amended by adding the following
hazardous constituents in alphabetical order by common name to read as
follows:
Appendix VIII to Part 261--Hazardous Constituents
------------------------------------------------------------------------
Chemical abstracts Chemical Hazardous
Common name name abstracts No. waste No.
------------------------------------------------------------------------
* * * * * * *
Potassium Pentachlorophenol, 7778736...... None
pentachlorophenate. potassium salt.
* * * * * * *
Sodium Pentachlorophenol, 131522....... None
pentachlorophenate. sodium salt.
* * * * * * *
2,3,4,6- same................ 53535276..... None
tetrachlorophenol,
potassium salt.
2,3,4,6- same................ 25567559..... None
tetrachlorophenol,
sodium salt.
* * * * * * *
------------------------------------------------------------------------
* * * * *
[FR Doc. 93-32032 Filed 12-30-93; 8:45 am]
BILLING CODE 6560-50-P
