[Federal Register Volume 62, Number 48 (Wednesday, March 12, 1997)]
[Rules and Regulations]
[Pages 11724-11731]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-6215]
[[Page 11723]]
_______________________________________________________________________
Part IX
Environmental Protection Agency
_______________________________________________________________________
40 CFR Part 132
Revisions to the Polychlorinated Biphenyl Criteria for Human Health and
Wildlife for the Water Quality Guidance for the Great Lakes System;
Final Rule
Federal Register / Vol. 62, No. 48 / Wednesday, March 12, 1997 /
Rules and Regulations
[[Page 11724]]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 132
[FRL-5708-8]
RIN 2040-AC94
Final Revisions to the Polychlorinated Biphenyl Criteria for
Human Health and Wildlife for the Water Quality Guidance for the Great
Lakes System
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: EPA is publishing final revisions to the polychlorinated
biphenyl (PCB) ambient water quality criteria for human health and
wildlife for the final Water Quality Guidance for the Great Lakes
System that was published in March 1995 (the 1995 Guidance). The final
revisions are limited to the method for calculating a composite
baseline bioaccumulation factor (BAF) for PCBs and the method for
calculating a composite octanol-water partition coefficient (Kow)
for PCBs. After reviewing all public comments, EPA concluded that the
approach it proposed in October 1996 for calculating a composite
baseline BAF, using the second alternative proposed for calculating a
composite Kow, for PCBs would be preferable to the approach used
in the 1995 Guidance because it would more appropriately relate the
concentrations of the PCB congeners in tissue to the concentrations of
the PCB congeners in water. Consequently, EPA is today revising the
human health cancer criterion for PCBs from 3.9E-6 ug/L to 6.7E-6 ug/L,
and the wildlife criterion for PCBs from 7.4E-5 ug/L to 1.2E-4 ug/L.
EPA believes that these revisions more accurately represent the
numerical limits necessary to protect human health and wildlife in the
Great Lakes System.
EFFECTIVE DATE: March 12, 1997.
ADDRESSES: The public docket for this rulemaking, including the
proposal, public comments in response to the proposal, other major
supporting documents, and the index to the docket are available for
inspection and copying at U.S. EPA Region 5, 77 West Jackson Blvd.,
Chicago, IL 60604 by appointment only. Appointments may be made by
calling Mary Willis Jackson (telephone 312-886-3717).
FOR FURTHER INFORMATION CONTACT: Mark Morris (4301), U.S. EPA, 401 M
Street, SW, Washington, D.C. 20460 (202-260-0312).
SUPPLEMENTARY INFORMATION:
I. Introduction
A. Potentially Affected Entities
Entities potentially affected by this final rule are those
discharging pollutants to waters of the United States in the Great
Lakes System. Potentially affected categories and entities include:
------------------------------------------------------------------------
Examples of potentially affected
Category entities
------------------------------------------------------------------------
Industry.............................. Industries discharging PCBs to
waters in the Great Lakes
System as defined in 40 CFR
132.2.
Municipalities........................ Publicly-owned treatment works
discharging PCBs to waters of
the Great Lakes System as
defined in 40 CFR 132.2.
------------------------------------------------------------------------
This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be affected by this
final rule. This table lists the types of entities that EPA is now
aware could potentially be affected by this action. To determine
whether your facility may be affected by this final rule, you should
examine the definition of ``Great Lakes System'' in 40 CFR 132.2 and
examine 40 CFR 132.2 which describes the purpose of water quality
standards such as those established in this rule. If you have any
questions regarding the applicability of this action to a particular
entity, consult the person listed in the preceding FOR FURTHER
INFORMATION CONTACT section.
B. Great Lakes Water Quality Guidance
In March 1995, EPA promulgated the final Water Quality Guidance for
the Great Lakes System (the 1995 Guidance) required under section
118(c)(2) of the Clean Water Act, 33 U.S.C. 1268(c)(2). See 60 FR
15366-425 (March 23, 1995). The ambient water quality criteria (AWQC)
included in the 1995 Guidance to protect human health and wildlife set
maximum ambient concentrations for harmful pollutants to be met in all
waters in the Great Lakes System unless site-specific criteria are
derived and approved. See 40 CFR Part 132, Tables 3 and 4. Great Lakes
States and Tribes must adopt criteria consistent with EPA's criteria by
March of 1997. CWA section 118(c)(2). If any State or Tribe fails to
meet that deadline, EPA must promulgate criteria that will apply in
that State's or Tribe's jurisdiction. Id. Once the criteria take
effect, permits for discharges of such pollutants into the Great Lakes
System must include limits as necessary to attain the criteria.
EPA promulgated human health and wildlife criteria for a class of
closely related toxic pollutants known as polychlorinated biphenyls
(PCBs). The PCB criteria for human health and wildlife incorporate
bioaccumulation factors (BAFs) which reflect the fact that PCBs magnify
at several steps in aquatic food chains, so that humans and wildlife
that eat fish from the Great Lakes may be exposed to PCB concentrations
many times higher than the PCB concentration in the waters of the
Lakes. Different members of the class of PCBs (called ``congeners'')
have different potentials to bioaccumulate. In the 1995 Guidance, EPA
derived a single baseline BAF for PCBs for each trophic level by
computing a weighted geometric mean baseline BAF from the baseline BAFs
for each trophic level for approximately 50 PCB congeners.
Based on issues raised as part of a lawsuit on the 1995 Guidance,
in 1996 EPA proposed a different approach for calculating a single BAF
for the class of PCBs. EPA also decided to call this single BAF a
``composite baseline BAF.'' The new approach also required EPA to
calculate a composite Kow for PCBs. EPA proposed two different
approaches for this calculation. EPA, however, presented calculations
of revised BAFs and revised ambient water quality criteria based on
only one of the two Kow alternatives. For a more complete
discussion of the 1995 Guidance and the revised approach in the 1996
proposal, refer to 60 FR 15366 (March 23, 1995) and 61 FR 54748
(October 22, 1996).
After considering all comments, EPA has decided to follow the
proposed approach. EPA selected the second of the two alternatives to
calculating a composite Kow. As a result, the numerical values for
the final BAFs and the final criteria differ very slightly from those
that EPA presented in the proposal. The discussion below explains the
reasons for the changes.
II. Background
The BAFs in the 1995 Guidance relate the concentration of a
chemical measured in water to the concentration of the same chemical
measured in fish tissue. Under the methodology for the 1995 Guidance,
the calculation of a BAF that is to be used for calculating AWQC for a
non-polar organic chemical involves three steps for each trophic level.
First, EPA obtains a ``total'' BAF based on the total concentrations of
the chemical in the water and in the aquatic biota, based on field
measurements. Second, EPA converts this initial total BAF into a
``baseline'' BAF that reflects the amount of lipid (fat) in the aquatic
biota that was assessed and the amount
[[Page 11725]]
of freely dissolved chemical that was estimated in the water. This
permits better extrapolation of data from one species to another and
from one water body to another. Third, EPA computes a final ``total''
BAF based on the total concentration of the chemical in the water and
the organisms at the site to be protected. In this notice, EPA will
refer to the first ``total'' BAF as the ``initial total'' BAF, and the
final as the ``final total'' BAF. The initial and final total BAFs
generally differ because they usually apply to different bodies of
water.
An important factor in the calculation of the baseline BAF and both
total BAFs for a chemical is the Kow for that chemical. The
Kow is a measure of the affinity of a chemical to partition
between octanol and water and is used as an estimate of the
partitioning between the lipids (fatty tissues) of an aquatic organism
and water. The higher the Kow, all other factors being constant,
the greater the affinity of the chemical to concentrate in fish tissue.
Each chemical has a Kow value. The Kow value for a chemical
is usually reported as the log Kow for the chemical. When
calculating total and baseline BAFs for a chemical, the chemical-
specific Kow is used to estimate the freely dissolved fraction of
the chemical in the water.
When this methodology is used to derive human health and wildlife
AWQC for a class of chemicals, the normal ``single'' values for
baseline and total BAFs for an individual chemical are replaced by
composite baseline and composite total BAFs for the class to simplify
the equations. Using a composite value in a calculation for the class
gives the same result as summing the results of calculations for each
member of the class. When calculating a composite baseline BAF or a
composite total BAF for all of the chemicals in a class at a trophic
level, it is necessary to use a composite Kow. This composite
Kow is used to estimate the composite freely dissolved fraction of
the class of chemicals in the Great Lakes waters.
EPA based the PCB BAFs in the 1995 Guidance on a field study
conducted in the Great Lakes by Oliver and Niimi (1988). The study
collected data on numerous PCB congeners, and EPA calculated a separate
baseline BAF for each congener using separate, congener-specific
Kows. EPA, however, needed to calculate composite baseline BAFs
and composite total BAFs representing all congeners at a trophic level
in order to calculate AWQC for human health and wildlife, because there
is a single ``cancer potency factor'' which is used for evaluating
human health cancer risk for all PCBs. Similarly, for wildlife, there
is a single toxicity factor which is used in the derivation of the
wildlife criterion. Consequently, composite baseline and total BAFs
were needed in order to be consistent with the toxicity data available
to derive human health and wildlife criteria.
In the 1995 Guidance, EPA calculated a composite baseline BAF for
PCBs for trophic level 3 and a composite baseline BAF for trophic level
4 by computing a weighted geometric mean of the baseline BAFs for
individual PCB congeners at each trophic level. The weighted geometric
mean baseline BAF was 55,281,000 for trophic level 3 and 116,553,000
for trophic level 4. As explained above, when calculating a composite
baseline BAF for PCBs, EPA must also use a composite Kow. In the
1995 Guidance, EPA calculated a weighted geometric mean Kow of
3,885,000 (mean log Kow of 6.589) by weighting the log Kows
for the individual PCB congeners by the concentrations of the PCB
congeners in fish. The weighted mean log Kow of 6.589 was then
used to estimate the freely dissolved fraction of the PCB congeners in
the study of Oliver and Niimi (1988). The log Kows for the
individual PCB congeners used in the final Guidance came from Hawker
and Connell (1988).
Using the composite baseline BAF for each trophic level and the
weighted mean log Kow of 6.589, EPA calculated composite final
total BAFs of 520,900 for trophic level 3 and 1,871,000 for trophic
level 4 for use in calculating human health criteria. The PCB human
health cancer criterion calculated using these BAFs was 3.9E-6 ug/L.
For wildlife, the composite final total BAFs were 1,850,000 for trophic
level 3 and 6,224,000 for trophic level 4. The PCB wildlife criterion
derived using these BAFs was 7.4E-5 ug/L.
Various industries and trade associations challenged the human
health and wildlife criteria for PCBs. AISI v. EPA, D.C. Cir. No.95-
1348 and consolidated cases. Among the issues they raised was the
calculation of the composite baseline BAF as the weighted geometric
mean for PCBs. The AISI petitioners alleged that the equation was
mathematically inappropriate for a variety of reasons. As a result of
this challenge, EPA re-examined the basis for the calculation of the
composite baseline BAF as the weighted geometric mean. For a more
complete discussion of bioaccumulation and the approach used in the
1995 Guidance, refer to 58 FR 20803 (April 16, 1993), and the Procedure
to Determine Bioaccumulation Factors (``TSD for BAFs'')(EPA-820-B-95-
005).
III. Revised Method for Calculating Composite Baseline BAFs for
PCBs
A. The Proposed Approach
On October 22, 1996, EPA proposed a revised approach for
calculating the composite baseline BAF for PCBs for each trophic level.
The revised approach uses the sum of all concentrations of PCB
congeners in tissue and the sum of all concentrations of PCB congeners
in the ambient water, as reported in Oliver and Niimi (1988), to
calculate a composite initial total BAF for PCBs at each trophic level.
This approach is equivalent to using a weighted arithmetic mean of all
the measured initial total BAFs from the PCB congeners, where the
weights are the concentrations of the PCB congeners in water. EPA
believes this approach is consistent with the definition of
bioaccumulation factor and appropriately relates the sum of the
concentrations of the PCB congeners in tissue to the sum of the
concentrations of the PCB congeners in water. EPA further believes that
this approach will provide an accurate composite initial total BAF for
the class of PCBs.
As part of the October 22, 1996 proposal, EPA also proposed to
revise its approach for calculating the composite Kow used in the
calculation of the composite baseline and total BAFs. EPA proposed two
alternatives: the first alternative used the median log Kow of the
PCB congeners to derive a composite Kow; the second used the sum
of the concentrations of the Kows for all congeners together with
the sum of all of the freely dissolved concentrations of the congeners
in water. For a more complete discussion of the revised approach for
calculating composite BAFs and Kows, refer to 61 FR 54748 (October
22, 1996).
B. Comments on the Proposed Approach
EPA received three comments on the proposal. Two commenters opposed
the revised approach for calculating composite BAFs for PCBs. One of
the commenters who opposed the proposal argued that the revised
approach yielded less stringent criteria for PCBs and that this action
was contradictory to the principle of zero discharge, and inconsistent
with what the public had been told about the 1995 Guidance methodology
being a superior method yielding more stringent criteria. This
commenter also argued that the resulting higher criteria would allow
backsliding for pollution prevention scenarios currently established
and
[[Page 11726]]
operating for existing permitted discharges of PCBs. The other
commenter who opposed the proposal was concerned that data (congener
specific Kows, tissue and water PCB concentrations) used in the
revised approach were taken from reports that were published a decade
ago and that more recent data on the behavior of PCBs in the
environment, their activity as carcinogenic promoters, and the tendency
of ``weathered'' PCBs to be more toxic than the parent compounds, have
not been considered. This commenter argued that the revised approach
did not provide as much protection against the tendency for PCBs to
become more toxic over time. In addition, the commenter argued that, if
EPA were to revise the 1995 approach, it should not use the median
value because the median ignores extremely high or low values,
disregards population trends, and does not weigh skewness, which is a
characteristic of the PCBs. In fact, the commenter recommended that EPA
compute and use a BAF at the 90 percent confidence level. Finally, the
commenter also noted that, since a higher Kow also affects the
amount of pollutant that is freely dissolved, the change in the
Kow value has a large impact on the final criterion. For these
reasons the commenter argued that the 1995 approach, which produces the
lowest composite Kow was preferable. However, the commenter
concluded that, if EPA revised its approach, it should use the second
of the two alternatives proposed, because it produces a lower Kow
than the first alternative.
Finally, one commenter supported the revised approach stating that
the proposed modifications to the equation used to calculate the
composite BAFs for PCBs are scientifically and mathematically
appropriate. However, the commenter further stated that it disagrees
with many other issues arising from the 1995 Guidance and EPA's
derivation of BAFs for PCBs, which are issues outside the scope of this
rulemaking.
C. Response to Comments
EPA appreciates those who provided comments on this rulemaking. In
regard to the first comment, EPA disagrees that it has misinformed the
public concerning either the 1995 Guidance methodology or the 1996
revised methodology. EPA also disagrees with the prediction that the
revised criteria will result in backsliding. Although the revised
criteria are less stringent than the 1995 criteria, they are not less
stringent than the PCB criteria currently in effect in the Great Lakes
States. Currently, the range of water quality criteria being
implemented in the Great Lakes Basin to protect human health from PCBs
is 0.1 to 0.00008 ug/L. EPA's revised methodology produces a human
health criterion for PCBs that is about 10 to 10,000 times more
stringent than those currently being implemented. For the protection of
wildlife the disparity is even more dramatic because many of the Great
Lakes States do not have criteria for PCBs to protect wildlife. For the
three Great Lakes States that do have criteria for PCBs to protect
wildlife, EPA's revised approach produces a wildlife criterion that is
approximately 10 to 1,000 times more stringent than those currently
being implemented. Given this information, EPA does not believe that
permit limits for PCBs based on criteria for human health and wildlife
produced by the revised methodology will result in less protection or
backsliding. Further, EPA interprets the concept of zero discharge in
the Great Lakes Agreement as a goal toward which it is working. The
revised PCB criteria, which are still more stringent than criteria
currently in effect in the Great Lakes States, are a reasonable and
substantial step toward that goal.
EPA also disagrees with the comment that asserts that EPA should
chose an approach to calculating a composite Kow that leads to a
more conservative PCB criterion because the current criteria may not
sufficiently take into account the effects of ``weathering'' or data
from new studies suggesting that PCBs might cause reproductive and
developmental toxicity effects. EPA believes that the BAF should
estimate bioaccumulation as accurately as possible. EPA believes it is
more appropriate to account for the commenter's concerns--if
warranted--by adjusting its estimate of PCB's toxicity. Further, EPA
believes that it has adequately accounted for weathering. PCBs were
first introduced into the Great Lakes Basin in the 1930s. Researchers
in the Great Lakes have spent a significant amount of time gathering
data and studying the fate and effects of PCBs in this system. Given
the length of time some of the PCBs have resided in the Great Lakes
Basin, any increased toxicity due to ``weathering'' would be reflected
in the data collected in 1986. Therefore, EPA does not agree that it
needs to retain the 1995 approach to ensure protection against the
possible impacts of weathering.
EPA agrees that some recent data indicate that PCBs, particularly
co-planar PCBs, might cause reproductive and developmental toxicity
through processes such as endocrine disruption. Because concentrations
associated with such potential adverse effects are under evaluation,
EPA can not yet predict whether such effects might occur at
concentrations above or below those associated with the cancer risks
modeled by the 1995 Guidance. EPA does not believe that it has enough
information concerning these additional, potential effects to revise
the criteria at this time. As stated in the 1995 Guidance, EPA is
committed to improving the science supporting its methodologies and
criteria, and will continue to evaluate and revise them in future
rulemakings in light of new information, as appropriate.
EPA agrees with the comment that the median Kow of the PCB
congeners should not be used as the composite Kow and that the
second alternative set forth in the proposal is more appropriate. EPA
also agrees with some of the limitations identified by the commenter
that are associated with using a median. However, EPA's reason for
adopting the second alternative to calculate a composite Kow as
part of this final rule is not because it introduces, as the commenter
suggests, a more protective value, but because EPA believes that the
second alternative more accurately reflects how PCBs behave in the
Great Lakes System. The second alternative provides the same result as
would be obtained by performing the relevant calculations for each
congener and then summing the results.
D. Final Action
As described above, the approach for this final rule uses the sum
of the concentrations of all PCB congeners in tissue and the sum of the
concentrations of all PCB congeners in the ambient water to calculate a
composite initial total BAF for PCBs at each trophic level. The
approach also uses individual PCB congener Kow to calculate the
composite Kow. The calculations of the composite baseline BAFs for
PCBs, the composite final total BAFs to be used in the calculation of
AWQC for wildlife and human health, and the PCB criteria for wildlife
and humans using the new PCB BAFs are presented below. EPA is not
revising the data used in the calculation of the composite BAFs or
composite Kows or other aspects related to the derivation of the
human health and wildlife criteria for PCBs. The fish tissue data,
water column data, and log Kow values used to calculate the new
composite BAFs and composite Kow are identical to those used in
the 1996 proposal.
[[Page 11727]]
1. Calculation of Composite Baseline BAFs for PCBs
The equation used to calculate a baseline BAF for an individual
chemical for each individual trophic level in this final rule is the
same as was used in the 1995 Guidance and the 1996 proposal (61 FR
54748). The equation to calculate a baseline BAF when a field-measured
BAF is available for a chemical, as is the case with PCBs, is (each of
the three components for calculating a baseline BAF is discussed
below):
[GRAPHIC] [TIFF OMITTED] TR12MR97.078
Where:
Measured BAFtT = BAF based on total concentration in tissue
and water (i.e., a total BAF).
fl = fraction of the tissue that is lipid.
ffd = fraction of the total chemical in the ambient water that is
freely dissolved.
By comparison, the equation for calculating a composite baseline BAF
is:
[GRAPHIC] [TIFF OMITTED] TR12MR97.079
a. Composite Initial Total BAF
To calculate a composite initial total BAF for trophic level 4, the
data needed are the total concentration of the chemical in the tissue
of a trophic level 4 species and the total concentration of the
chemical in ambient water at the site of sampling. The trophic level 4
species used in the 1995 Guidance, the 1996 proposal and this final
rule are salmonids. To calculate a composite initial total BAF for
trophic level 3, the data needed are the total concentration of the
chemical in the tissue of a trophic level 3 species and the total
concentration of the chemical in ambient water at the site of sampling.
The trophic level 3 species used in the 1995 Guidance, the 1996
proposal and this final rule are sculpins and alewives. The average of
the values for the sculpins and alewives is used to represent the
trophic level 3 values. The equation to calculate a composite total BAF
is:
[GRAPHIC] [TIFF OMITTED] TR12MR97.080
For trophic level 4, the total concentration of PCB congeners in
fish tissue (salmonids) is 4057.3 ng/g and the total concentration of
PCB congeners in ambient water is 1006.1 pg/L. For trophic level 3, the
average of the total concentrations of PCB congeners in tissue from
sculpins and alewife is 1393.15 ng/g. These values were derived in the
1996 proposal from Oliver and Niimi (1988).
[GRAPHIC] [TIFF OMITTED] TR12MR97.081
The resulting composite initial total BAF is 4,033,000 for trophic
level 4 and 1,385,000 for trophic level 3 (rounded to four significant
figures as discussed on page G-2 of the TSD for BAFs).
b. Composite Fraction Freely Dissolved
To estimate the fraction of PCBs that are freely dissolved in the
ambient water requires information on the particulate organic carbon
(POC) and dissolved organic carbon (DOC) in the ambient water where the
samples were collected and the Kow of the chemical. As in the 1995
Guidance and the 1996 proposal, the equation for calculating the
fraction freely dissolved for an individual chemical is:
[GRAPHIC] [TIFF OMITTED] TR12MR97.082
Where:
POC=concentration of particulate organic carbon (kg/L).
DOC=concentration of dissolved organic carbon (kg/L).
Kow=n-octanol water partition coefficient for the chemical.
[[Page 11728]]
By comparison, to calculate a composite fraction freely dissolved for a
group of chemicals, the equation is:
[GRAPHIC] [TIFF OMITTED] TR12MR97.083
The log Kows used for the individual PCB congeners come from
Hawker and Connell (1988), which were included in the 1996 proposal. To
calculate the composite Kow, as explained above, EPA will not
employ the first alternative that uses the median log Kow from the
log Kows presented in Table 1 of the 1996 proposal (61 FR 54752),
but will instead use the second alternative for calculating a composite
Kow. As proposed, the formula for calculating the second
alternative composite Kow is:
Where:
[GRAPHIC] [TIFF OMITTED] TR12MR97.084
Where:
i=1, 2, * * * n congeners.
Ctw=total concentration of the congener in water.
Cfdw=freely dissolved concentration of the congener in water.
The second alternative for calculating the composite Kow was
derived algebraically from the following definition of the fraction
freely dissolved, ffd, for a single congener, as given in the 1995
Guidance and the 1996 proposal :
[GRAPHIC] [TIFF OMITTED] TR12MR97.085
In the second alternative for the composite Kow, the ratio of
the sum of the total concentrations of all of the congeners in water
over the sum of the freely dissolved concentrations of all of the
congeners in water is substituted for the ratio of the total over
freely dissolved concentration of a single congener in water. Using the
data provided in Table 1 of the 1996 proposal, these equations yield a
composite Kow of 2,189,000 (rounded to four significant figures).
[GRAPHIC] [TIFF OMITTED] TR12MR97.086
This differs slightly from the composite Kow value of
2,238,721 derived in the proposal using the median log Kow
approach.
In the 1995 Guidance and the 1996 proposal, the POC value used was
0.0 kg/L and the DOC value used was 2.0 x 10-6 kg/L for the study
of Oliver and Niimi (1988). In this final rule, EPA is not changing
these values. Using these values and the revised composite Kow
value of 2,189,000 the composite fraction freely dissolved in this
final rule is 0.6955, as shown below:
[GRAPHIC] [TIFF OMITTED] TR12MR97.087
Again, this differs slightly from the fraction freely dissolved
presented in the 1996 proposal. The difference stems from the use of
the second alternative for calculating a composite Kow.
c. Fraction Lipid
In addition, EPA is not changing the fraction lipid content of the
salmonids (0.11) or sculpin (0.08) or alewife (0.07) that were used in
the 1995 Guidance and the 1996 proposal for the study of Oliver and
Niimi (1988). The average fraction lipid for sculpin and alewife is
0.075.
d. Composite Baseline BAF
Based on the information presented above and using the equation for
calculating composite baseline BAFs, EPA calculates for this final rule
a new composite baseline BAF for PCBs for trophic level 4 of 52,720,000
and a new composite baseline BAF for PCBs for trophic level 3 of
26,550,000 (rounded to four significant figures). Composite Baseline
BAF TL4
[GRAPHIC] [TIFF OMITTED] TR12MR97.088
[[Page 11729]]
2. Calculation of Composite Final Total BAFs for Use in AWQC
The data required to calculate a composite final total BAF for use
in deriving a AWQC for PCBs are the composite baseline BAF, the
fraction lipid of the aquatic species consumed by the population of
interest whether that is humans or wildlife and the composite fraction
freely dissolved in the ambient water for the area of interest.
Composite Total BAF for AWQC = [(Composite Baseline BAF)(Fraction Lipid
of Aquatic Species Consumed) + 1](Composite ffd)
a. Composite Baseline BAF
The new composite baseline BAFs derived above in section III.D will
be used: 52,720,000 for trophic level 4 and 26,550,000 for trophic
level 3.
b. Composite Freely Dissolved Fraction
The equation for calculating the composite freely dissolved
fraction is presented above. EPA is using the same values for POC and
DOC used in the 1995 Guidance and the 1996 proposal (4.0 x 10-8
kg/L for POC and 2.0 x 10-6 kg/L for DOC). These values represent
POC and DOC concentrations in Lake Superior and were used to calculate
all of the final total BAFs that were used to derive the AWQC in the
1995 Guidance. Both the composite Kow and the composite freely
dissolved fraction must be calculated using the Lake Superior values
for POC and DOC. The relative total concentrations of the PCB congeners
in Lake Superior will be assumed to be the same as in Oliver and Niimi
(1988). The resulting composite Kow is 2,107,000 and the composite
ffd is 0.6642 (both rounded to four significant figures).
[GRAPHIC] [TIFF OMITTED] TR12MR97.089
[GRAPHIC] [TIFF OMITTED] TR12MR97.090
The freely dissolved fraction of 0.6642 differs slightly from the
value of 0.6505 presented in the 1996 proposal. The difference is due
to the change in the method for calculating the composite Kow.
c. Lipid Fraction
EPA is not changing the lipid values used in the 1995 Guidance and
the 1996 proposal. The lipid fraction of the aquatic species consumed
by humans in the Great Lakes region is 1.82 for trophic level 3 and
3.10 for trophic level 4. For wildlife, the lipid fraction for trophic
level 3 is 6.46 and for trophic level 4 is 10.31.
d. Composite Final Total BAFs for Calculating AWQC
Using the above values for the composite baseline BAFs, composite
freely dissolved fraction for Lake Superior and fraction lipid, EPA
today is promulgating the following composite final total BAFs (rounded
to four significant figures) to be used in deriving the human health
and wildlife AWQC for PCBs:
Human Health BAF for Trophic Level 4 = [(52,720,000)(0.0310) +1] 0.6642
= 1,086,000
Human Health BAF for Trophic Level 3 = [(26,550,000)(0.0182) +1] 0.6642
= 321,000
Wildlife BAF for Trophic Level 4 = [(52,720,000)(0.1031) +1] 0.6642 =
3,610,000
Wildlife BAF for Trophic Level 3 = [(26,550,000)(0.0646) +1] 0.6642 =
1,139,000
3. Human Health Cancer Criteria
Based on the BAFs presented above, EPA today is revising the human
health cancer criteria for PCBs in Table 3 of the 1995 Guidance from
3.9E-6 g/L to 6.7E-6 g/L. The equations used to
calculate the human health cancer criteria for PCBs in this final rule
are the same as were used in the 1995 Guidance and the 1996 proposal
(61 FR 54753).
4. Wildlife Criterion
For wildlife, EPA today is revising the PCB criterion from 7.4E-5
g/L to 1.2E-4 g/L based on using the BAFs presented
above. The equations used to calculate the wildlife criterion for PCBs
in this final rule are the same as were used in the 1995 Guidance and
the 1996 proposal (61 FR 54754).
IV. Effective Date
Section 553(d)(3) of the Administrative Procedure Act requires
Federal agencies to publish final rules at least 30 days before they
take effect unless they find that they have ``good cause'' to waive the
notice requirement. EPA finds that it has good cause to waive the 30-
day notice requirement for these revisions to the PCB criteria. EPA
needs to make this rule effective as soon as possible to maximize the
ability of the States and Tribes to use the new criteria in their
Guidance submissions that are due in March 23, 1997. Also, in this case
an immediate effective date does not conflict with the goal of the
notice requirement (giving the public the opportunity to adjust
behavior before the rule imposes penalties). The revised criteria will
not affect any member of the public until they are adopted by a Great
Lakes State or Tribe (or promulgated by EPA where a State or Tribe
fails to submit adequate criteria). EPA anticipates that these
processes will take at least 30 days, so that the public will receive
adequate notice of the revised requirements before they become binding.
V. Executive Order 12866
Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA
must determine whether the regulatory action is ``significant'' and
therefore subject to
[[Page 11730]]
Office of Management and Budget (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 or
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.
Pursuant to the terms of Executive Order 12866, it has been
determined that this final rule is not a ``significant regulatory
action'' and is therefore not subject to OMB review.
VI. Submission to Congress and the General Accounting Office
Under 5 U.S.C. 801(a)(1)(A) as added by the Small Business
Regulatory Enforcement Fairness Act of 1996, EPA submitted a report
containing this rule and other required information to the U.S. Senate,
the U.S. House of Representatives and the Comptroller General of the
General Accounting Office prior to publication of the rule in today's
Federal Register. This rule is not a ``major rule'' as defined by 5
U.S.C. 804(2).
VII. Regulatory Flexibility Act as Amended by the Small Business
Regulatory Enforcement Fairness Act of 1996
The Regulatory Flexibility Act (RFA) provides that, whenever an
agency promulgates a final rule under 5 U.S.C. 553, after being
required to publish a general notice of proposed rulemaking, an agency
must prepare a final regulatory flexibility analysis unless the head of
the agency certifies that the proposed rule will not have a significant
economic impact on a substantial number of small entities. 5 U.S.C. 604
& 605.
Under the CWA, EPA's promulgation of water quality standards
establishes standards that the States implement through the National
Pollutant Discharge Elimination System (NPDES) permit process. The
States have discretion in deciding how to meet the water quality
standards and in developing discharge limits as needed to meet the
standards. While State implementation of federally-promulgated water
quality standards may result in new or revised discharge limits being
placed on small entities, the standards themselves do not apply to any
discharger, including small entities.
Today's rule imposes obligations on the Great Lakes States but, as
explained above, does not itself establish any requirements that are
applicable to small entities. As a result of EPA's action here, the
Great Lakes States will need to ensure that permits they issue include
any limitations on discharges necessary to comply with the criteria in
today's rule. Until actions are taken to implement the 1995 Guidance,
there will be no economic effect of the 1995 Guidance on any entities,
large or small. States and Tribes must both adopt their own criteria
and implement them before impacts are felt. The implementation
regulations provide States and Tribes with a variety of flexible
alternatives which can affect the burden felt by any small entity as a
result of State or Tribal action to implement this final rule,
including total maximum daily load (TMDL) calculations and waste load
allocations (WLAs). Impacts will not be felt until States and Tribes
select and put in place implementation measures.
The RFA requires analysis of the impacts of a rule on the small
entities subject to the rules' requirements. See United States
Distribution Companies v. FERC, 88 F.3d 1105, 1170 (D.C. Cir. 1996).
Today's rule establishes no requirements applicable to small entities,
and so is not susceptible to regulatory flexibility analysis as
prescribed by the RFA. (``[N]o [regulatory flexibility] analysis is
necessary when an agency determines that the rule will not have a
significant economic impact on a substantial number of small entities
that are subject to the requirements of the rule,''' United
Distribution at 1170, quoting Mid-Tex Elec. Co-op v. FERC, 773 F.2d
327, 342 (D.C. Cir. 1985) (emphasis added by United Distribution
court).) The Agency is thus certifying that today's rule will not have
a significant economic impact on a substantial number of small
entities, within the meaning of the RFA.
Furthermore, today's final rule results in human health cancer
criteria and wildlife criteria less stringent than those currently in
the 1995 Guidance. If States or Tribes adopt criteria consistent with
today's final rule, they should reduce any adverse economic impact that
might have been imposed by State or Tribal adoption of the 1995
criteria. Consequently, the economic effect of today's final rule
relative to the 1995 Guidance should be positive. Any adverse economic
impact on small entities associated with measures taken to implement
the current provisions of the 1995 Guidance should be reduced by
adoption of the final revisions.
VIII. Unfunded Mandates Reform Act
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and Tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``Federal Mandates'' that
may result in expenditures to State, local, and Tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
one year. Before promulgating an EPA rule for which a written statement
is needed, section 205 of the UMRA generally requires EPA to identify
and consider a reasonable number of regulatory alternatives and adopt
the least costly, most cost-effective or least burdensome alternative
that achieves the objectives of the rule. The provisions of section 205
do not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted.
Before EPA establishes any regulatory requirements that may
significantly or uniquely affect small governments, including Tribal
governments, it must have developed under section 203 of the UMRA a
small government agency plan. The plan must provide for notifying
potentially affected small governments, enabling officials of the
affected small governments to have meaningful and timely input in the
development of EPA regulatory proposals with significant Federal
intergovernmental mandates, and informing, educating, and advising
small governments on compliance with the regulatory requirements.
As noted above, this final rule is limited to the method for
deriving a composite BAF for PCBs and for deriving a composite Kow
for PCBs, which will result in human health cancer criteria and
wildlife criteria for PCBs less stringent than those currently in the
1995 Guidance. If States or Tribes adopt criteria consistent with
today's final rule, they will reduce any adverse economic impact that
might have been imposed by State or Tribal adoption of
[[Page 11731]]
the 1995 criteria. Consequently, EPA has determined that this final
rule contains no regulatory requirements that might significantly or
uniquely affect small governments. EPA has also determined that this
final rule does not contain a Federal mandate that may result in
expenditures of $100 million or more for State, local, and Tribal
governments, in the aggregate, or the private sector in any one year.
Thus, today's final rule is not subject to the requirements of sections
202 and 205 of the UMRA.
IX. Paperwork Reduction Act
There are no information collection requirements in this final rule
and therefore there is no need to obtain OMB approval under the
Paperwork Reduction Act, 44 U.S.C. 3501 et seq.
X. References
Great Lakes Water Quality Technical Support Document for the
Procedure to Determine Bioaccumulation Factors (EPA-820-B-95-005). NITS
Number: PB95187290. ERIC Number: D049.
Great Lakes Water Quality Initiative Criteria Documents for the
Protection of Human Health (EPA-820-B-95-006). NITS Number: PB95187308.
ERIC Number: D050.
Great Lakes Water Quality Initiative Criteria Documents for
Protection of Wildlife: DDT; Mercury; 2,3,7,8-TCDD; PCBs (EPA-820-B-95-
008). NITS Number: PB95187324. ERIC Number: D052.
Hawker D.W. and D.W Connell. 1988. Octanol-Water Partition
Coefficients of Polychlorinated Biphenyl Congeners. Environ. Sci.
Technol., 22(4):382-387.
Oliver, B.G. and A.J Niimi. 1988. Trophodynamic Analysis of
Polychlorinated Biphenyl Congeners and Other Chlorinated Hydrocarbons
in the Lake Ontario Ecosystem. Environ. Sci. Technol., 22(4):388-397.
U.S. Environmental Protection Agency. Water Quality Guidance for
the Great Lakes System and Correction; Proposed Rules. Vol. 58, No.72.
April 16, 1993. pp.20802-21047.
U.S. Environmental Protection Agency. Water Quality Guidance for
the Great Lakes System; Notice of Data Availability. Vol. 59. August
30, 1994. pp.44678-44685.
U.S. Environmental Protection Agency. Final Water Quality Guidance
for the Great Lakes System; Final Rule. Vol. 60, No.56. March 23, 1995.
pp.15366-15425.
U.S. Environmental Protection Agency. Proposed Revisions to the
Polychlorinated Biphenyl Criteria for Human Health and Wildlife for the
Water Quality Guidance for the Great Lakes System; Proposed Rule. Vol.
61, No.205. October 22, 1996. pp.54748-54756.
List of Subjects in 40 CFR Part 132
Environmental protection, Administrative practice and procedure,
Great Lakes, Indians--lands, Intergovernmental relations, Reporting and
recordkeeping requirements, Water pollution control.
Dated: March 6, 1997.
Carol M. Browner,
Administrator.
For the reasons set out in the preamble title 40, chapter I of the
Code of Federal Regulations is amended as follows:
PART 132--WATER QUALITY GUIDANCE FOR THE GREAT LAKES SYSTEM
1. The authority citation for Part 132 continues to read as
follows:
Authority: 33 U.S.C. 1251 et seq.
2. Table 3 to Part 132 is amended by revising the entry for
PCBs(class) to read as follows:
Table 3.--Water Quality Criteria for Protection of Human Health
----------------------------------------------------------------------------------------------------------------
HNV (ug/L) HCV (ug/L)
Chemical -----------------------------------------------------------------------------
Drinking Nondrinking Drinking Nondrinking
----------------------------------------------------------------------------------------------------------------
* * * * * *
*
PCBs(class)....................... .............. .............. 6.7E-6 6.7E-6
* * * * * *
*
----------------------------------------------------------------------------------------------------------------
3. Table 4 to Part 132 is amended by revising the entry for
PCBs(class) to read as follows:
Table 4.--Water Quality Criteria for Protection of Wildlife
------------------------------------------------------------------------
Chemical Criteria (ug/L)
------------------------------------------------------------------------
* * * * *
PCBs(class)................................ 1.2E-4
* * * * *
------------------------------------------------------------------------
[FR Doc. 97-6215 Filed 3-11-97; 8:45 am]
BILLING CODE 6560-50-P
