NC0000272_Attachment B - EPA Objection Letter_20220401

Attachment B
EPA Objection Letter from James
D. Giattina (Director, EPA Water
Protection Division) to Colleen H.
Sullins (Director, NC DWQ),
February 22, 2010

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
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FEB 22 Mr
Ms. Colleen H. Sullins
Director, Division of Water Quality
North Carolina Department of Environment and
Natural Resources
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Dear Ms. Sullins:
On November 23, 2009, we received your submittal for our review of a draft National
Pollutant Discharge Elimination System (NPDES) permit for Blue Ridge Paper Products,
Permit No. NC0000272. We appreciate your efforts to continue the improvements in the quality
of the Mill's discharges to the Pigeon River through the NPDES permit process and recognize
the tremendous progress made by the Mill over the last 20 years. Your efforts have lead to
significant improvements in water quality in both the North Carolina and Tennessee portions of
the river. We also want to commend you for your decision to increase public participation in this
process by holding a public meeting on the draft permit in Tennessee.
We have had many discussions with your staff during our review of the draft permit and
resolved a number of issues. To provide more time for these collaborative discussions, we
notified you on December 10, 2009, that we would be taking the full 90-day period to complete
our review pursuant to Section IV.B.3 of the NPDES Memorandum of Agreement (MOA) with
the North Carolina Division of Water Quality (DWQ).
At this time, we have completed our review and have remaining concerns with some
provisions of the draft permit. Based on our review and consideration of issues raised at the
recent public meeting and hearing, we are providing specific objections to the draft permit,
which are explained in detail below, pursuant to Section IV.B.3 of the MOA and regulations at
Title 40 Code of Federal Regulations (CFR) § 123.44.
Specific Objection 1: Technology -Based Color Limits and Compliance Schedule
The draft permit includes an initial annual average color permit limit of 39,000 #/day and
requires a 37,000 #/day limit within four years. Although the 2001 current permit required that
DWQ conduct an analysis of mill performance and possible revision of annual average color
loading to a value in the 32,000-39,000 #/day range by March 2006, that revision did not occur.
To assess current performance, the Environmental Protection Agency (EPA) developed 95%
confidence limits for annual average color loadings using monthly average data for the period
2006-2009. EPA typically uses this type of statistical analysis to determine effluent performance
and the use of such confidence limits is consistent with effluent guidelines development. That
analysis indicates that the draft permit's annual average color limits do not fully capture current
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performance or provide a sufficient incentive for the Mill to continue to improve its
performance. These permit provisions are thus not consistent with the case -by -case Best
Professional Judgment requirements of 40 CFR §§ 125.3(c)(2) and (d)(3). The draft permit is
therefore subject to specific objection pursuant to 40 CFR §§ 123.44(c)(4), (6), and (7).
To resolve this specific objection, based on the confidence limits cited above, the permit
must require an initial annual average color permit limit of no greater than 37,900 #/day. Also, it
must require an annual average color limit no greater than the range of 32,000-36,000 #/day at
the end of the four-year compliance schedule. This is consistent with the color range
recommended by the Technology Review Workgroup (TRW) in February 2008.
Also, for the color compliance schedule cited above, the draft permit requires that the
Mill develop an implementation plan for various color reduction efforts and submit annual
reports of progress. However, the permit does not specify a date certain for submittal of that
plan, nor interim requirements and the dates for their achievement. Since the compliance
schedule exceeds one year, pursuant to 40 CFR § 122.47(a)(3), the compliance schedule must
include interim requirements and dates for their achievement. The lack of interim requirements
and dates for their achievement is subject to objection pursuant to 40 CFR §123.44(c)(7).
To address this specific objection, the permit must require the facility to submit an
implementation plan within the first year of permit issuance. The permit must also contain a
reopener clause to include interim requirements and dates for their achievement as enforceable
parts of the permit based on the submitted implementation plan. Once the implementation plan
is submitted and reviewed, the permit should be modified accordingly.
Specific Objection 2: Effluent Limit for Color; Protection of Water Quality and Status of
Variance to Narrative Color Criterion
The conditions and limits for color in the draft permit are based on the removal of the
variance to the narrative color standard for the Pigeon River, which was adopted by the State on
October 10, 2001. Thus, the color effluent limits, in the State's view, are consistent with the
State's water quality standard for color. However, the fact sheet or record supporting the draft
permit does not adequately support this determination. As background, in the absence of a
numeric translation of the narrative standard by either North Carolina or Tennessee, EPA has
historically translated the narrative standard to a numeric standard of 50 platinum cobalt units
(PCU or "color units"); North Carolina has adopted a variance from this standard that was
reflected in previous permits for the Blue Ridge facility. EPA's 50 color unit interpretation was
based on studies conducted by the National Council for Air and Stream Improvement and this
level has been met at the North Carolina/Tennessee state line in almost all measurements taken
since 2002. North Carolina adopted a variance from this standard in 2001; the terms of that
variance included the following:
"This variance shall extend for an indefinite period of time, subject to consideration
during the water quality standards triennial reviews. Any modification or termination
based thereon shall be subjected to the public hearing process required by N.C.G.S. 143-
215.3(e)."
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Therefore, until the administrative process for removal of the variance is completed, the 2001
variance remains in effect. Nevertheless, the fact sheet indicates that the variance has been
removed and does not provide an explanation as to how the procedural requirements for its
removal have been met.
Also, as mentioned above, the actions required in Section B.8 of the 2001 variance and
the 2001 permit do not appear to have been completed. That section of the variance required an
evaluation of mill performance related to color and a recommendation by DWQ of the lowest
achievable annual average and monthly average color loading effluent limitations for the mill.
This section also required that, if the analysis supported a revision to average annual color limits
in the range of 32,000 to 39,000 #/day, the revised limit was to become effective on March 1,
2006. However, the current effective annual average limitation for color is 42,000 #/day.
In addition to not completing the procedures for variance removal, DWQ also did not
include in the fact sheet a defensible scientific rationale for its determination that the draft permit
will ensure compliance with North Carolina's narrative water quality standard for color. The
fact sheet for the draft permit states that the monthly and annual average color limits are "in
accordance with the TRW recommendations." The fact sheet also states:
Based on actual instream color measured between 2002-2008, DWQ believes that
compliance with the effluent color limits established in the 2001 permit were protective
of NC's narrative water quality color standard. Only under extreme drought conditions
(below 30Q2/7Q10 flows) were instream color values reported to exceed the Prestrude
aesthetic threshold of 100 platinum cobalt units (PCU or "color units"), and NC
regulations do not consider aesthetic color standards violated by the permittee when
stream flows fall below 30Q2 design flow.
The reference to the Prestrude aesthetic threshold of 100 PCU relates to a study entitled, Color:
Misperceptions About the Aesthetics of River Color (Dr. A. M. Prestrude, July 1996) (the
"Prestrude Report"). The Prestrude Report suggests that color levels become an aesthetic
problem at 100 PCU. However, none of the studies relied upon in the Report are based on
waters that are similar to the segment of the Pigeon River near Canton. The study of ambient
color levels in the Prestrude Document included consideration of photographs of the Pigeon
River downstream of the facility discharge which were taken in or about 1988. However, the
color discharge from the facility during that time frame was approximately ten times the amount
that is currently discharged.
Further, the document also states, "From a perception standpoint, therefore, it is readily
accepted that the general population can differentiate between colors differing by approximately
50 color units. While this difference is capable of scientific quantification, more refined studies
are required to focus on what level of perceived color is objectionable in natural environments."
Thus, the Prestrude Report does not purport to establish a one -size fits all color standard that can
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be applied to different environments. EPA agrees with the Report's suggestion that more
refined, site -specific studies would be useful to determine how the narrative standard should be
interpreted or applied to specific natural environments such as the Pigeon River near Canton. 1
The terms of the 2001 variance allowed a monthly average limit of 55,000 #/day, which
was selected based on actual performance of color treatment and removal technologies that were
identified in an earlier review by the TRW. In other words, this value was selected based on the
ability of the facility to meet the limit by installing and operating color treatment and/or removal
technologies, rather than factors related to instream water quality.
The monthly average color limit proposed in the draft permit is 52,000 #/day; however,
the fact sheet does not clearly indicate whether this limit is based on what can be achieved
through application of available technologies or on protection of water quality. Due to the
absence of a numeric interpretation of the narrative color standard by the State, it is not clear
whether the State has determined that the monthly limit of 55,000 #/day, i.e., "the effluent color
limits established in the 2001 permit," or the monthly average of 52,000 #/day, as proposed in
the current draft permit, is needed to meet the narrative color standard. Using the 30Q2 flow of
the Pigeon River of 89.9 cubic feet per second at Canton, and assuming that the background
color level of the Pigeon River is 13 PCU, the current draft permit allows for a color level
downstream of the discharge of 114 PCU, and the previous 2001 monthly average permit limit of
55,000 #/day allowed an instream color level of 120 PCU. The absence of a specific numeric
interpretation of the State's narrative color standard and the ambiguity of the statements made in
the fact sheet make it difficult to determine at what PCU level the State believes ambient
conditions would be consistent with the narrative color standard. Thus, the effluent limits in the
draft permit would result in instream color levels that exceed both the "Prestrude aesthetic
threshold of 100 platinum cobalt units" and EPA's historical use of 50 PCU as a numeric
translation of the State's narrative standard. However, the fact sheet also does not adequately
explain how 114 PCU will comply with the State's narrative color standard.
The fact sheet states:
NC has generally viewed color as primarily an aesthetic issue, and the interpretation of
color as an aesthetic impact is subjective. Similar to odor issues, the number of
complaints received serves as one means to gage public perception of color impact. The
NC DWQ regional office in Asheville has received only one color complaint in recent
years.
' The Tennessee Department of Environment and Conservation reviewed the studies summarized in the Prestrude
Report and concluded that the appropriate interpretation of its narrative color standard requires that the increase of
ambient color levels in the Hiwassee River should be limited to an increment of 50 color units over levels measured
above the Bowater paper facility outfall.
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This appears to be the State's justification for the determination that the draft permit will ensure
compliance with its narrative color standard and a variance is no longer necessary. However,
while the presence or absence of complaints may be relevant, EPA does not find the counting of
complaints to be a sufficiently structured process for establishing a state water quality standard.2
EPA is not aware that the State has notified the public that the frequency of complaints is a factor
that is used in the State's interpretation or application of the narrative color standard.
As noted above, EPA has historically interpreted North Carolina's narrative color
standard for the Pigeon River to be 50 PCU. The rationale provided in the fact sheet does not
establish a scientifically defensible basis for the State's interpretation of the narrative standard or
its conclusion that the limits in the draft permit implement the State's water quality requirements
for color, as established in 15A North Carolina Administrative Code (NCAC) 2B.0211(3)(f) and
15A NCAC 2B.0206(a)(4).
In summary, EPA is concerned that the State has insufficient record support for the
conclusion that the effluent limits and conditions for color proposed in the draft permit are
protective of the State's narrative water quality color standard. The fact sheet's discussion of the
basis of the color conditions and limitations does not establish that the draft permit will comply
with the narrative color standard at all flows equal to or greater than the applicable instream
flow, i.e., 30Q2 flow, as established in its water quality standards. Therefore, the draft permit
does not comply with requirements at 40 CFR §122.44(d)(1)(vii)(A) and is subject to objection
under 40 CFR § 123.44(c)(8).
To address this specific objection, the State must revise the terms of the variance from the
North Carolina water quality standard for color for the Pigeon River to reflect the proposed
permit conditions and limits for color as referenced in Specific Objection 1 above. The
information necessary to support a variance determination appears to have already been
developed by the facility in conjunction with the TRW. Accordingly, EPA commits to timely
review and act on a request to revise and extend the variance upon the formal submittal of a
proposed variance revision by DWQ.
Recommendation For Site -Specific Study
In order to create a better record for any future effort to reinterpret the narrative color
standard, and ensure that authorized discharges are protective of the narrative standard, EPA
recommends the addition of a condition in the draft permit requiring the permittee to provide
funding for an independent study of color levels in the North Carolina segment of the Pigeon
River, or a segment of a watershed that is reasonably similar to the physical characteristics of the
Pigeon River downstream of the mill. The study should focus on the aspects of the State's
narrative color standard that are relevant to conditions and limits in the permit, and should
address assessment of color levels in ambient waters of the Pigeon River (or other watershed(s),
as specified above) when those levels are in the range of 50 to 120 PCU. The permit could also
include a reopener clause to implement the conclusions of the study if warranted.
2 EPA notes that, based on comments during the public meeting and hearing, there are citizens who believe there is a
basis to complain about ambient color in the Pigeon River.
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EPA believes that an independent, unbiased site -specific study would be useful to
determine how the State's narrative color standard should be interpreted or applied to the Pigeon
River near Canton. Such a study would be valuable in addressing uncertainties relating to the
narrative standard for color because many site -specific factors influence the overall perception of
an individual stream setting and the level of protection needed for a stream or watershed.
Evaluation of the Pigeon River downstream of the Blue Ridge mill is even more critical for
setting regulatory targets, given the color levels in the river, and the public interest in the present
permitting process for the Blue Ridge facility.
The study should be conducted with unbiased observers. For example, college students
were used in some of the studies performed by Prestrude. The results of the study could be used
by the State to address other issues related to the application of the North Carolina narrative
color standard, such as whether it would be more appropriate to establish a regulatory
requirement for the river solely based on a specific color concentration, or as an increment over
"background" color levels. We also suggest that EPA be involved in the review and approval of
the framework of the plan for conducting the study prior to initiation.
Specific Objection 3: Temperature Variance
Regarding temperature, the permit implements a Clean Water Act (CWA) § 316(a)
variance by requiring: 1) an instream monthly average of 32° C during July -September; 2) an
instream monthly average of 29° C during the rest of the year; and 3) downstream values not to
exceed upstream values by more than a monthly average of 13.9° C. ("Delta T") Compliance
with these three conditions is assessed 0.4 miles downstream from the discharge at Fiberville
Bridge.
To obtain such a variance, an applicant is required by Section 316(a) and applicable
regulations at 40 CFR Part 125, Subpart H, to demonstrate that the proposed variance assures
the protection and propagation of a balanced, indigenous population ("BIP") of shellfish, fish,
and wildlife in and on the body of water into which the discharge is made. The information
submitted with the draft permit is not sufficient to make the required demonstration. This
concern is heightened by a North Carolina Wildlife Resources Commission report indicating
that a September 2007 fish kill in the Pigeon River was, in part, due to elevated temperature. As
a result of the absence of a sufficient demonstration that the variance assures protection of a
BIP, the draft permit is subject to objection under 40 CFR §123.44(c)(7).
To resolve this objection, the permit must require completion of an updated study that
includes thermal modeling and demonstrates the protectiveness of the proposed variance; the
updated study should meet the parameters outlined in the enclosure to this letter. Further, in the
interim period before an adequate study is completed, a reduction in the Delta T limit should be
included in the permit to provide additional assurance that the BIP is protected. The current
Delta T limit was based on mill operating conditions prior to the modernization project
completed in the early 1990s, which included the installation of a mechanical draft cooling
tower. Based on daily temperature data taken at the Fiberville Bridge (River Mile 62.9) and just
above the Canton Mill (River Mile 63.8) during January 2005 to December 2009, EPA
determined average Delta T values for warm months (April through October) and cool months
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(November through March). The 95th percentile values for average Delta T for the warm and
cool periods were 7.4° C. (13.28' F.) and 8.2° C. (14.69° F.), respectively. EPA believes the
average Delta T value of 8.2° C. will be appropriate for all times of the year and could be
adjusted pending the results of the thermal modeling to be completed as part of the Section
316(a) updated study. Lastly, the permit must require the Mill to monitor and report the daily
maximum and monthly average effluent temperatures.
Specific Objection 4: Absence of Daily Maximum Dioxin Limit and Fish Tissue Monitoring
The draft permit contains a monthly average dioxin limit; however, it does not include a
daily maximum limit, as required by 40 CFR Part 122.45(d)(1). The draft permit is therefore
subject to objection pursuant to 40 CFR § 123.44(c)(7). To address this specific objection, the
permit must contain a daily maximum dioxin limit. That limit may be set at a level equal to the
monthly average limit.
Also, the draft permit contains a new provision that fish tissue monitoring for dioxin will
cease after 2009, unless DWQ determines that a public health hazard exists. EPA routinely uses
ambient fish tissue dioxin monitoring to determine whether water column impairment is
occurring and whether reasonable potential to exceed a state's numeric dioxin criterion exists.
The fish tissue levels indicating water column impairment are typically well below the levels at
which fish advisories are typically adopted. Based on North Carolina's dioxin numeric criterion
of 0.005 parts per quadrillion (ppq), the associated fish tissue value indicating impairment would
be approximately 0.025 parts per trillion (ppt). Out of the last five years of fish tissue data
collected by the facility, levels of dioxin detected in common carp at Station 4A in upper
Waterville Lake have been 1.1-1.3 ppt, with two years having estimated concentrations reported.
Assuming a linear relationship between water column concentrations and fish tissue
levels, these fish tissue concentrations would indicate a water column concentration in the range
of 0.22-0.26 ppq, thus exceeding the State's numeric criterion. In this case, direct measurement
of dioxin in fish tissue shows evidence of accumulation; reliance on effluent sampling alone
using method detection limits that cannot measure dioxin at the level of the State numeric
criterion does not provide the necessary information to make this determination.
As a result, the removal of the dioxin fish tissue monitoring requirement as proposed in
the draft permit does not ensure that sufficient data is generated to adequately represent the
monitored activity, as required by 40 CFR §§ 122.41(j)(1) and 122.48(a)-(c). Requiring
monitoring in the event of a public health hazard is not adequate to determine if water quality
standards are being met. The lack of such data also does not allow for a complete evaluation of
the reasonable potential to exceed state water quality criteria, as required by 40 CFR §
122.44(d)(1). Accordingly, the draft permit is subject to objection pursuant to 40 CFR §§
123.44(c)(5) and (7). To address this specific objection, the permit must require that the facility
conduct monitoring of fish tissue for dioxin (as was done in 2009) in the first, third, and fifth
years of the term of this permit. Annual monitoring does not appear to be warranted since fish
tissue levels have shown minor changes in recent years.
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Specific Objection 5: Absence of Turbidity Monitoring
EPA has previously requested that the State specifically document in the permit fact sheet
the manner in which reasonable potential to exceed North Carolina's Class C criterion for
turbidity was evaluated ("the receiving water shall not exceed 50 Nephelometric Turbidity Units
in streams not designated as trout waters"). To the extent that sufficient data to make that
evaluation were not available, we further requested that specific monitoring to obtain the
information be required by the permit. The draft permit and fact sheet did not address these
concerns.
Therefore, the draft permit does not ensure that the discharges authorized under the
permit are protective of North Carolina's numeric criterion for turbidity. The lack of such data
does not allow for a complete evaluation of the reasonable potential to exceed the state water
quality numeric criterion cited above, as required by 40 CFR § 122.44(d)(1), and as a result, the
draft permit does not include effluent limits that may be necessary to protect water quality. The
draft permit is therefore subject to objection under 40 CFR §§ 123.44(c)(5), (7), and (8).
To address this specific objection, the permit must require that the facility conduct
downstream turbidity monitoring at Fiberville Bridge at a minimum frequency of twice per
month during the April -October timeframe for a minimum of one year. Such monitoring must
not occur within 72 hours of a rain event. The permit must also contain a specific reopener to
enable DWQ to add an appropriate turbidity limit if reasonable potential to exceed the State's
numeric criterion is found to exist. Based on North Carolina's numeric criterion, upstream data
are not needed and should not be used to assess reasonable potential.
Specific Objection 6: Absence of Effluent Hardness Monitoring To Evaluate Zinc Toxicity
The draft permit requires quarterly zinc monitoring because DWQ determined that
reasonable potential exists to exceed North Carolina's action level of 50 ug/l based on an
assumed hardness of 50 mg/l. We are aware of a low upstream hardness value of 7.6 mg/l.
Because zinc toxicity increases at lower hardness values, any future evaluation of effluent zinc
data without concurrent effluent hardness monitoring cannot adequately assess reasonable
potential to exceed the action level.
Without concurrent effluent hardness measurements, the draft permit does not ensure that
sufficient data is generated to adequately represent the monitored activity, as required by 40 CFR
§§ 122.41(j)(1) and 122.48(a)-(c). Further, without such data, the draft permit does not allow for
a complete evaluation of the reasonable potential to exceed the hardness -based state water
quality numeric criterion for zinc, as required by 40 CFR § 122.44(d)(1), and as a result, the draft
permit does not include effluent limits that may be necessary to protect water quality. The draft
permit is therefore subject to objection under 40 CFR §§ 123.44(c)(5), (7), and (8). To address
this objection, the permit must be revised to include a requirement for quarterly effluent hardness
monitoring concurrent with the quarterly zinc monitoring.
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EPA also offers the following recommendations for your consideration:
Recommendation 1 Regarding AOX Limits
EPA also has the following comment regarding the draft permit limits for adsorbable
organic halides (AOX), which reflect a 39% increase in loadings from the 2001 permit. The
DWQ presentation at the recent public hearing and meeting indicated that the facility is #2 in the
world in terms of AOX removal. Our analysis of recent AOX effluent data confirms the
facility's performance — the typical discharge is less than 300 #/day as a monthly average. Based
on that performance, we recommend that the AOX limits in the 2001 permit be retained.
Recommendation 2 Regarding TRW
The TRW has historically performed a valuable function in assessing color reduction
efforts at the Mill and providing recommendations to DWQ. We recommend that the permit
include a provision ensuring that the TRW will assess color reduction technologies and provide
recommendations to DWQ at the end of this next permit term.
To address the specific objections above, I ask that you redraft the permit and submit a
proposed permit and a revised fact sheet to EPA for review under the provisions of Section
III.B.6 of the MOA: I also ask that you submit a summary of all public comments that have been
received and DWQ's response to them. In accordance with Section IV.B.7 of the MOA and 40
CFR § 123.44, within ninety (90) days of your receipt of this letter, DWQ or another interested
person may request that a public hearing be held, pursuant to 40 CFR §123.44(e). If no public
hearing is held, and DWQ does not resubmit a proposed permit that has been revised to meet our
specific objections within ninety (90) calendar days of receipt of this letter, exclusive authority to
issue the permit passes to EPA for one permit term. Any requests for a hearing on the objections
and the procedure for resolving any objection shall be governed by 40 CFR § 123.44, as provided
in Section IV.B.7 of the MOA.
If you have any questions, please have your staff contact Mr. Marshall Hyatt at
404-562-9304.
Enclosure
Sincerely,
ames D. Giattina
Director
Water Protection Division
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cc: Dane A. Griswold, Blue Ridge Paper Products Inc.
John S. Curry, Esq., North Carolina Environmental Management Commission
Jeffrey V. Morse, North Carolina Environmental Management Commission
Paul E. Davis, Tennessee Department of Environment and Conservation
David McKinney, Tennessee Wildlife Resources Agency
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Enclosure
Section 316(a) Report and the Study Plan for the Subsequent Permit
Blue Ridge may use existing data in completing its study and may incorporate the
existence of such data into the monitoring program plan design; however, the existing data needs
to be evaluated and presented in the context of a BIP definition that the existing record does not
adequately provide.
Section 316(a) of the CWA contains the term "BIP" but does not define it. However, 40
CFR §125.71(c) defines the term "balanced, indigenous community"1 as:
"A biotic community typically characterized by diversity, the capacity to sustain itself
through cyclic seasonal changes, presence of necessary food chain species and by a lack
of domination by pollution tolerant species. Such a community may include historically
non-native species introduced in connection with a program of wildlife management and
species whose presence or abundance results from substantial, irreversible environmental
modifications. Normally, however, such a community will not include species whose
presence is attributable to the introduction of pollutants that will be eliminated by
compliance by all sources with section 301(b)(2) of the Act: and may not include species
whose presence or abundance is attributable to alternative effluent limitations imposed
pursuant to section 316(a)."
The Environmental Appeals Board stated in its decision in In Re Dominion Energy
Brayton Point, LLC, 12 Environmental Appeals Decision (E.A.D.) 490 (2006)("Brayton Point"),
"this definition clearly envisions a consideration of more than the population of organisms
currently inhabiting the water body. In this vein, although it permits inclusion of certain
`historically non-native species' that are currently present, it explicitly excludes certain currently
present species whose presence or abundance is attributable to avoidable pollution or previously -
granted section 316(a) variances."
Page 557 of the Brayton Point E.A.D. goes on to further state that a BIP "can be the
indigenous population that existed prior to the impacts of pollutants, not solely the current
populations of organisms."
To the question of how a permittee should identify a BIP in an area that has been altered
by impacts from an existing thermal discharge, the Brayton Point E.A.D. points out that it may
be appropriate to use a nearby water body unaffected by the existing thermal discharge as a
reference area. Examination of an appropriate reference area may be applicable in this case.
The definition of "balanced, indigenous community" at 40 CFR § 125.71(c) contains
several key elements. To be consistent with the regulations, each of these key elements should
be specifically addressed in the demonstration, and the Pigeon River Section 316(a) monitoring
plan for the next permit cycle should be designed to generate information relevant to these
elements. Those elements include: (1) "a population typically characterized by diversity at all
"Balanced. indigenous community" and BIP are equivalent terms.

trophic levels;" (2) "the capacity to sustain itself through cyclic seasonal changes;" (3) "presence
of necessary food chain species;" (4) "non -domination of pollution -tolerant species;" and (5)
"indigenous." Each of these elements is discussed in more detail below:
1. "A population typically characterized by diversity at all trophic levels" means that all of the
major trophic levels present in the unaffected portion of the water body should be present in the
heat affected portions. EPA recognizes that community structure differences will occur,
however, the number of species represented in each trophic level in the unaffected portions
should be reasonably similar in the heat -affected portions of the water body. Sampling and
analysis of fish and invertebrate communities should be done such that the major trophic levels
are identified and represented by reasonably similar species distributions. Also, the study plan
should be expanded to include some observations of wildlife (i.e., water fowl, mammals,
amphibians, etc.) both upstream and immediately downstream of the discharge point that may be
impacted by the thermal discharge.
2. "The capacity to sustain itself through cyclic seasonal changes" means that any additional
thermal stress will not cause significant community instability during times of natural extremes
in environmental conditions. Community data should be collected during normal seasonal
extremes as well as during optimal seasonal conditions. Data should be compared between heat
affected and unaffected portions of the receiving water body to account for normal community
changes corresponding with a change in season.
3. "Presence of necessary food chain species" means that the necessary food webs remain intact
so that communities will be sustaining. We believe that exhaustive food web studies are not
necessary provided that invertebrate, fish and wildlife communities are otherwise healthy, i.e.,
represented by sufficiently high species diversity and abundance (appropriate for that portion of
the receiving water body) for the identified trophic levels and sustaining through normal seasonal
changes.
4. "Non -domination of pollution -tolerant species" means that in the case of a thermal effluent,
community assemblages in heat affected portions of the lake dominated by heat tolerant species
do not constitute a BIP. EPA recognizes that because all species have varying levels of thermal
tolerance, communities in the heat affected portions of the water body may possess altered
assemblages in terms of species present and abundance. All community data should be
collected, analyzed and presented to clearly demonstrate that affected communities have not
shifted to primarily heat tolerant assemblages.
5. "Indigenous" has been further clarified in the regulations: "Such a community may include
historically non-native species introduced in connection with a program of wildlife management
and species whose presence or abundance results from substantial, irreversible environmental
modifications. Normally, however, such a community will not include species whose presence is
attributable to the introduction of pollutants that will be eliminated by compliance by all sources
with section 301(b)(2) of the Act: and may not include species whose presence or abundance is
attributable to alternative effluent limitations imposed pursuant to section 316(a). " EPA
recognizes that non -indigenous species are present in most aquatic systems in the United States.
All community data should be analyzed and presented to demonstrate that community
2

assemblages in the heat affected portions of the receiving water body are not significantly
different from non -affected communities with regard to the number of non -indigenous species in
the assemblages.
In addition to the foregoing components of the BIP definition, the study plan should also
include provisions for the identification of RIS (e.g., a list of threatened, endangered, thermally
sensitive, or commercially or recreationally valuable species up- and downstream of the study
area), as contemplated in 40 CFR §125.72(b). 40 CFR §125.71(b) defines RIS as "species which
are representative, in terms of their biological needs, of a balanced, indigenous community of
shellfish, fish and wildlife in the body of water into which a discharge of heat is made."
The following EPA comments should be specifically addressed in the study plan prior to
Blue Ridge commencing sampling during the term of the next NPDES permit. The plan should:
a) include available information on wildlife in the lake areas based on
communications with North Carolina's Wildlife Management Agency. See
item 1 above.
b) include a diagram depicting the thermal plume under the worst case scenario
and address the presence or absence of a zone of passage for which fish can
travel around the thermal plume.
e) provide information of which fish collected are either heat -sensitive or
nuisance species. See item 4 above.
d) provide a list of any lake species that are endangered or threaten in accordance with
federal and state regulations.
e) analyze and present data to clearly demonstrate that affected communities
have not shifted to primarily heat tolerant assemblages.
f) include recent data or information on benthic macroinvertebrates. See item 1 above.
g)
analyze and present all data to demonstrate that community assemblages in the heat -
affected portions of the receiving water body are not significantly different from non -
affected communities with regard to the number of non -indigenous species in the
assemblages; and
h) include a thermal modeling study based on historical effluent temperatures and
operating conditions to determine appropriate permit limits for temperature.
In order to ensure that Blue Ridge's future study plan for the Pigeon River is adequate to
demonstrate that the Canton Mill should have its Section 316(a) variance renewed during the
term of its next NPDES permit, EPA requests the opportunity to review a draft Section 316(a)
plan prior to Blue Ridge commencing the study.
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