[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 (K<INF>ow) 
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 K<INF>ow, 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 K<INF>ow 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 K<INF>ow 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 K<INF>ow. 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 K<INF>ow for that chemical. The 
K<INF>ow 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 K<INF>ow, all other factors being constant, 
the greater the affinity of the chemical to concentrate in fish tissue. 
Each chemical has a K<INF>ow value. The K<INF>ow value for a chemical 
is usually reported as the log K<INF>ow for the chemical. When 
calculating total and baseline BAFs for a chemical, the chemical-
specific K<INF>ow 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 K<INF>ow. This composite 
K<INF>ow 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 
K<INF>ows. 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 K<INF>ow. In the 
1995 Guidance, EPA calculated a weighted geometric mean K<INF>ow of 
3,885,000 (mean log K<INF>ow of 6.589) by weighting the log K<INF>ows 
for the individual PCB congeners by the concentrations of the PCB 
congeners in fish. The weighted mean log K<INF>ow 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 K<INF>ows 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 K<INF>ow 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 K<INF>ow used in the 
calculation of the composite baseline and total BAFs. EPA proposed two 
alternatives: the first alternative used the median log K<INF>ow of the 
PCB congeners to derive a composite K<INF>ow; the second used the sum 
of the concentrations of the K<INF>ows 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 K<INF>ows, 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 K<INF>ows, 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 K<INF>ow also affects the 
amount of pollutant that is freely dissolved, the change in the 
K<INF>ow value has a large impact on the final criterion. For these 
reasons the commenter argued that the 1995 approach, which produces the 
lowest composite K<INF>ow 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 K<INF>ow 
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 K<INF>ow 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 K<INF>ow of the PCB 
congeners should not be used as the composite K<INF>ow 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 K<INF>ow 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 K<INF>ow to calculate the 
composite K<INF>ow. 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 K<INF>ows 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 K<INF>ow values used to calculate the new 
composite BAFs and composite K<INF>ow 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 BAF<SUP>t<INF>T = BAF based on total concentration in tissue 
and water (i.e., a total BAF).
f<INF>l = fraction of the tissue that is lipid.
f<INF>fd = 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 K<INF>ow 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).
K<INF>ow=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 K<INF>ows used for the individual PCB congeners come from 
Hawker and Connell (1988), which were included in the 1996 proposal. To 
calculate the composite K<INF>ow, as explained above, EPA will not 
employ the first alternative that uses the median log K<INF>ow from the 
log K<INF>ows presented in Table 1 of the 1996 proposal (61 FR 54752), 
but will instead use the second alternative for calculating a composite 
K<INF>ow. As proposed, the formula for calculating the second 
alternative composite K<INF>ow is:
Where:

[GRAPHIC] [TIFF OMITTED] TR12MR97.084

Where:

i=1, 2, * * * n congeners.
C<SUP>t<INF>w=total concentration of the congener in water.
C<SUP>fd<INF>w=freely dissolved concentration of the congener in water.

The second alternative for calculating the composite K<INF>ow was 
derived algebraically from the following definition of the fraction 
freely dissolved, f<INF>fd, 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 K<INF>ow, 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 K<INF>ow of 2,189,000 (rounded to four significant figures).
[GRAPHIC] [TIFF OMITTED] TR12MR97.086

    This differs slightly from the composite K<INF>ow value of 
2,238,721 derived in the proposal using the median log K<INF>ow 
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<SUP>-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 K<INF>ow 
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 K<INF>ow.
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 f<INF>fd)
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-<SUP>8 
kg/L for POC and 2.0 x 10<SUP>-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 K<INF>ow 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 K<INF>ow is 2,107,000 and the composite 
f<INF>fd 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 K<INF>ow.
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 <greek-m>g/L to 6.7E-6 <greek-m>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 
<greek-m>g/L to 1.2E-4 <greek-m>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 K<INF>ow 
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