NC0003425_Comments_20170221 (2)

r{ DUKE
.►, ENERGY.
February 21, 2017
Teresa Rodriquez, P.E.
NC Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Comments on the DRAFT NPDES Permit for Roxboro Steam Electric Plant
Permit No.: NC0003425
Person County
Dear Ms. Rodriquez:
Richard E. BakerJr., P.E. , P.M.P
Director of Environmental Programs
Coal Combustion Products
526 S. Church Street
Mail Code:EC13K
Charlotte, NC 28202
(704)-382-7959
Duke Energy Progress, LLC submits the following comments on the draft National Pollutant Discharge
Elimination System Permit for Roxboro Steam Electric Plant, issued for public comment by the North
Carolina Department of Environmental Quality ("NCDE(X) on January 22, 2016. Duke Energy
appreciates NCDEQ's efforts to develop the Draft Permit, which addresses novel issues associated with
surface impoundment decommissioning and modifications required to facilitate those changes.
Finalizing this wastewater permit is a critical step to advance that process by authorizing decanting and
dewatering. In addition to these general comments, Duke Energy again offers the following comments
and requests for modification and/or clarification on specific provisions of the Draft Permit:
1. On page 2 of 29, Duke Energy requests the following calrifications and modificaitons:
a. Add "extracted groundwater " as a potential contributing flow to outfall 003 and outfall
001.
b. List the retention basin (internal outfall 012) as a potential flow path for internal outfall
005 (Cooling Tower Blowdown) in addition to the ash basin and the discharge canal.
c. List the retention basin (internal outfall 012) as a potential flow path for internal outfall
008 (Domestic wastewater treatment system) in addition to the ash basin. Upon
cessation of flows to the ash basin, flows from the domestic wastewater plant will be
directed to the retention basin (internal outfall 012).
d. List the retention basin (internal outfall 012) as a potential flow path for landfill leachate
as discussed in our August 2016 NPDES application update submittal (item #7).

Page 12
2. On page 4 of 29, Duke Energy requests the sampling frequency for Acute Toxicity be designated
as "Quarterly" to align with the required frequency in condition A.(14) of the permit.
3. On page 5 of 29, Duke Energy requests revision of the footnote related to fly ash discharges to
indicate that no discharges of fly ash shall occur after November 1, 2018 as requested in Duke's
submittal from August, 2016. Also, please clarify in the footnote that this prohibition is related
to fly ash sluice water generated after November 1, 2018 only.
4. On page 5 of 29, Duke Energy requests the removal of the pH limitation from internal outfall 002
in accordance with request and documentation submitted dated October 31, 2016.
5. On page 7 of 29, Duke Energy requests the revision of the footnote related to fly ash discharges
to indicate that no discharges of fly ash shall occur after November 1, 2018 as requested in
Duke's submittal from August, 2016. Also, please clarify in the footnote that this prohibition is
related to fly ash sluice water generated after November 1, 2018 only.
6. On page 7 of 29 (Outfall 002 — dewatering), Duke Energy requests that the flow limit of 2.0 MGD
be clarified to only apply to interstitial water treated through additional physical/chemical
treatment system. Current flows from the ash basin are — 12-15 million gallons and can vary
significantly based on precipitation and stormwater flows into the basin as measured at outfall
002.
7. On page 7 of 29, Duke Energy requests that pH on the internal wastestreams be removed. EPA
has previously allowed commingling as a treatment for internal flows. Please see reference
documents previously submitted on other Duke Energy permits with this request (Attachment
1).
8. On page 8 of 29, Duke Energy requests the limits for Thallium be removed from the permit as
there is no numeric water quality criterion for Thallium in North Carolina. Please reference the
detailed request submitted by Duke Energy dated October 31, 2016 and attached to this
submittal for detail.
9. On page 10 of 29, Section A.(5), Duke Energy requests that language be added to the description
of the Cooling Tower Blowdown flow path to include the retention basin (internal outfall 012) or
the Heated Water mixing Zone.
10. On pag 11 of 29, Duke Energy notes a new limit for selenium from outfall 006. The fact sheet
indicates that this limit was inserted as the result of a single reported sample point during the
last 10 years. Duke requests that the montly average be removed. NPDES outfall 006 is
essentially a stormwater outfall with flows being generated from runoff from the coal pile and
limestone pile areas. As such, Duke requestes that the limits for selenium be modified to be

Page 13
consistent with only the "benchmark" value of 56 ug/I in stormwater permits issued to Duke by
the Department of Environmental Quality for this and other facility's. A review of the DMR data
for outfall 006 submitted by the facility confirms that discharges from this outfall are not
continuous and are primarily associated with precipitation events leading to volumes of runoff
from the coal pile. In the absence of removing the monthly average limit, Duke requests that a
compliance schedule be included in the permit to study selenium levels at outfall 006 and plan,
engineer and implement modifictions to assure compliance with the monthly average limit.
11. Duke Energy requests that pH limits for internal outfalls 008, 009, 010, 011, 012A and 012B be
removed. Please reference the detailed attached submittal dated October 31, 2016 with regard
to comments on the inclusion of pH limits on internal outfalls.
12. On page 20 of 29, Duke Energy requests the addition of the following language at the beginning
of Section A. (15) Seeps: "All previously identified seeps from this facility are contributing flows
to permitted outfalls 001 or 003. There are no seeps that discharge directly to jurisdictional
waters." Duke further requests that a list of the previously identified "seep" flows that are
tributary to outfall 003 be included in the permit as has been done for flows tributary to outfall
001. Seep flows that are tributary to outfall 003 are enumerated in paragraph 15 of the NPDES
permit application update submitted to the DEQ dated August 15, 2016.
13. On page 23 of 29, Duke requests clarifying language in condition A.(19)(b.) that temperature
readings from the afterbay release to Hyco River will be obtained from the exisiting USGS
gauging station at this location (02077303) and that malfunction of the USGS gauging station
which results in data not being recorded will not be considered a violation of the permit
requirements.
14. Duke Energy requests removal of the monthly average limit of selenium for outfall 001. Flows
from outfall 001 are similar to those from outfall 006 in that they are largely driven by
precipitation and stormwater flow through the remnant section of the East Ash Basin. There
has been no noted seepage from S10, S11 or S12 in the last two years. With that being the
operational scenario, a daily maxium value for selenium is appropriate at this location as
discussed in #10 above.
Duke Energy welcomes any further discussion on our comments or the Draft Permit. If you have any
questions, please contact Shannon Langley at 919.546.2439 or at [e-mail].
Sincerely,
Richard E. Baker Jr., P.E., P.M.P
Director of Environmental Programs - CCP
Duke Energy

Page 14
Attachments
Cc: Mr. Jon Hennessey —Roxboro Public Hearing officer
1617 Mail Service Center
Raleigh, NC 27699-1617
Bc: Jason Haynes- Roxboro Station Manager
Jim Wells, VP — Duke EHS CCP
Robert Howard — Sr. Environmental Specialist, Roxboro Station
Shannon Langley - NCRH 15
Lori Tollie — EHS CCP

Attachment I
Evaluation of Toxicological Information of
Thallium prepared by Haley and Aldrich for
DEC

Thallium Toxicity Value Review
EVALUATION OF THE TOXICITY VALUE FOR THALLIUM
1. Current Screening Provisional Toxicity Value
There is not currently an oral chronic reference dose (RfD) toxicity value for thallium established by the
United States Environmental Protection Agency (USEPA) Integrated Risk Information System (IRIS) or
from an USEPA Provisional Peer -Reviewed Toxicity Value (PPRTV) assessment. The USEPA PPRTV
document for thallium (TI) concluded that it is inappropriate to derive a provisional subchronic or
chronic provisional RfD (p-RfD) for thallium; however, USEPA states that information is available which,
although insufficient to support derivation of a provisional toxicity value under current guidelines, may
be of limited use to risk assessors (USEPA, 2012). The PPRTV document contains a separate Appendix A
that provides rationale for the derivation of a subchronic and chronic "screening provisional oral
reference dose" for thallium compounds of 0.00004 mg TI/kg-day and 0.00001 mg TI/kg-day,
respectively. Appendix A of the PPRTV document also notes that, "Users of screening toxicity values in
an appendix to a PPRTV assessment should understand that there is considerably more uncertainty
associated with the derivation of a supplemental screening toxicity value than for a value presented in
the body of the assessment (USEPA, 2012a)." The screening p-RfD is expressed in units of milligrams of
thallium per kilogram of body weight per day (mg TI/kg-day).
Due to limitations in the toxicology database and general poor quality of available studies, the USEPA
IRIS Toxicological Review of Thallium and Compounds (USEPA, 2009) also concluded that reference
doses or reference concentrations could not be derived for human health following thallium exposures.
2. Information on Human Exposure to Thallium
The conservative nature of the p-RfD can be illustrated by considering the amount of thallium ingested
daily by Americans in their diet. It is estimated by the World Health Organization (WHO) and the U.S.
Agency for Toxic Substances for and Disease Registry (ATSDR) that a 70 kilogram adult ingests
approximately 0.005 mg thallium per day in the diet, especially from consumption of home-grown fruits
and green vegetables (WHO, 1996; ATSDR, 1992). This is equivalent to a daily dose of 0.00007 mg TI/kg-
day. The USEPA supplemental p-RfD for thallium is 1E-05 mg/kg-day (0.00001 mg/kg-day). This is seven
times lower than the estimated dietary intake. In other words, use of this dose -response value to
evaluate natural dietary exposure to thallium would indicate a hazard that is unlikely to exist.
Stated another way, assuming that an average adult weighs 70 kg, and using the screening level p-RfD of
0.00001 mg/kg bw-day, it could be concluded that an adult should not consume more than 0.0007 mg
TI/day, which is well below the estimated dietary intake of 0.005 mg thallium per day in the diet.
Currently, there have not been substantial reports of toxicological effects associated with typical dietary
ingestion of TI in the general population, suggesting that the use of the "screening provisional oral
reference dose" greatly overestimates the potential risks associated with oral exposure to TI
compounds.
The 90th percentile adult urinary thallium elimination from the National Health and Nutrition
Examination Survey (NHANES) (CDC, 2016) is 0.380-0.390 micrograms per liter (ug/L) which is about
0.760-0.780 ug/day in the urine alone. This suggests that greater than 10% of Americans, and probably
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Thallium Toxicity Value Review
closer to 50% of Americans, ingest more than the screening level p-RfD. From the IRIS assessment
conducted in 2009, a reviewer stated that there is no evidence that thallium in the current U.S. diet
poses any threat, and the adoption of this screening level p-RfD would produce unnecessary concern if
the above calculation is correct. This indicates the poor quality of the existing data, and brings into
question the validity of the analysis using the available data on thallium used by USEPA (USEPA, 2009).
3. Derivation of the Current Screening Provisional Toxicity Value
Below is a summary of the data and assessment that was used by USEPA in the derivation of the oral
chronic screening level p-RfD for thallium.
3.1 HAZARL, EVALUATION/STUDY SELECTION
Note: Human or animal studies examining the carcinogenicity of thallium following oral exposure are
not available. The cancer weight -of -evidence (WOE) provided in the IRIS review (USEPA, 2009) is listed
as 'inadequate Information to Assess Carcinogenic Potential (both oral and inhalation)."
3.1.1 Human Studies
Most information on thallium toxicity in humans comes from poisonings, suicide attempts, or accidental
exposures. Symptoms observed after acute exposures to high doses of thallium in humans include
alopecia (hair loss), gastrointestinal disturbances, and neurological symptoms such as paresthesia and
neuropathy. Epidemiologic studies of either the general population or occupationally exposed groups
are limited by inadequate study design, undefined exposure parameters, and inconclusive associations
between thallium exposure and specific health effects. Therefore, USEPA (2012a) concluded in the
PPRTV document that "available human studies do not support oral RfD derivation."
3.1.2 Animal studies
Studies in animals show that oral exposure to thallium produces effects similar to those observed in
humans, most notably, alopecia. Other findings observed in animal studies include biochemical
changes, lipid peroxidation, liver and kidney damage, and histopathologic changes in the brain and
nerves. The doses at which these systemic effects were observed range from 0.2 —1.8 mg TI/kg-day
(ATSDR, 1992). Reproductive and developmental studies in animals show some evidence of adverse
effects upon oral exposure to thallium at doses of 0.08 mg TI/kg-day —1.6 mg TI/kg-day; however,
available studies have significant limitations and the same effects have not been observed in humans
(ATSDR, 1992).
Only four repeat -dose oral toxicity studies with more than one dose level are available in animals. Of
these four studies, three were not considered adequate for RfD derivation (USEPA, 2009).
3.1.3 Conclusion
The conclusion reached in the IRIS Toxicological Review (USEPA, 2009) was that the available toxicity
database for thallium contains studies that are generally of poor quality. One animal subchronic study
conducted by the Midwest Research Institute (MRI, 1988) was selected as a candidate principal study for
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Thallium Toxicity Value Review
RfD derivation but was found to include critical limitations such as high background incidence of
alopecia, lack of histopathological examination of skin tissue in low -and mid -dose groups, and
inadequate examination of objective measures of neurotoxicity, thus making it difficult to select
appropriate endpoints. On this basis, a RfD for thallium salts was not derived by IRIS (USEPA, 2012a).
3.2 BASIS FOR PROVISIONAL SCREENING ORAL CHRONIC P-RFD
As indicated above, the PPRTV assessment (USEPA, 2012a) does not derive a typical provisional toxicity
value for thallium but rather uses the limited toxicological information to develop a screening level
value.
3.2.1 Study Selection
A 90-day Good Laboratory Practice (GLP) oral gavage study in male and female rats conducted with
thallium sulfate by MRI (1988) was selected as the principal study for the screening level p-RfD. Doses
were approximately 0, 0.008, 0.04, and 0.2 mg TI/kg-day.
3.2.2 Selection of Point of ueparture
Several critical endpoints were considered, but ultimately USEPA (2009) considered only two endpoints
to be appropriate for a screening level p-RfD development:
• Hair follicle atrophy in female rats that also had alopecia; and
• Clinical observations related to animal coat, eyes, and behavior.
The clinical observation endpoint was discounted because the underlying basis for the observations is
unknown. Hair follicle atrophy was determined to be most consistent with the atrophic changes
observed in cases of human thallium poisoning and may be best indication for human response to
thallium exposure.
MRI (1998) concluded that the minor dose -related changes in the study did not affect the health status
of the treated animals and were not toxicologically significant. MRI considered the highest dose (0.2 mg
TI/kg-day) as the no -observed -effect level (NOEL). However, USEPA conducted its own analyses of the
raw data from the study to come up with different conclusions. Of the 12 high -dose females with
alopecia, 5 instances were not totally attributed to barbering behavior. Histopathologic examinations
revealed atrophy of the hair follicles in two high -dose female rats that also had alopecia. It was noted
that there were no discernable differences in either the severity or distribution pattern of alopecia
across control and treated groups (USEPA, 2009).
The high dose (0.2 mg TI/kg-day) was identified by USEPA as the LOAEL. Because histopathology of skin
tissue from the low -and mid -dose groups was not conducted, the NOAEL for this endpoint cannot be
determined with certainty. Given the low incidence of hair follicle atrophy in females in the high dose
group and absence of cases of hair follicle atrophy in male rats, USEPA (2012a) assumed that the mid -
dose could be used to approximate a NOAEL for skin histopathology.
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Thallium Toxicity Value Review
Therefore, the estimated NOAEL of 0.04 mg TI/kg-day was used as the point of departure (POD) for hair
follicle atrophy (USEPA, 2012a).
3.2.3 Uncertainty Factors
Using the NOAEL of 0.04 mg TI/kg-day for hair follicle atrophy and using an uncertainty factor (UF) of
3000, the screening level p-RfD was calculated to be 0.00001 mg TI/kg-day. Justification for the applied
OF is summarized in table below.
Table 1: Uncertainty Factors Applied by USEPA in Screening Level p-RfD Derivation
Uncertainty Factor
Justification
10
Extrapolation from laboratory animals to humans since no information is
available to characterize the toxicokinetic differences between experimental
animals and humans.
10
Variation in human susceptibility in the absence of information on the
variability of response to thallium in the human population.
10
Lack of adequate developmental toxicity studies and a two -generation
reproductive study, and additional uncertainty associated with the limited
data available on neurotoxicity.
3
Extrapolation from subchronic to chronic exposure duration. Effects on the
coat/skin as well as other clinical observations occur within weeks of exposure
to thallium (does not required chronic exposure in order to manifest).
Composite OF = 3000
Note that there are considerable and critical limitations with the principal study selected by USEPA
(2009) including:
• High background of incidence of alopecia (POD selected)
• Lack of histopathological examination of skin tissue in low -and mid -dose groups
• Inadequate examination of objective measures of neurotoxicity
4. Other Available Sources for Derivation of Toxicity Values for Thallium
The following sections describe sources consulted for information on the toxicology of thallium.
4.1 WORLD HEALTH ORGANIZATION
The World Health Organization (WHO) (1996) concluded that in the general population, environmental
exposure to thallium does not pose a health threat. The total intake has been estimated to be less than
5 ug/day with the vast majority coming from foodstuffs; drinking -water and air generally contribute very
small amounts of thallium. Concentrations of thallium in urine may be considered a relatively reliable
indicator of exposure. Exposure to thallium resulting in urine concentrations below 5 ug/liter is unlikely
to cause adverse human health effects. The estimated daily oral intake corresponding to a urinary
thallium concentration of 5 ug/liter in urine is approximately 10 ug thallium in the form of a soluble
compound. Assuming an average adult body weight of 80 kg (USEPA, 2014), this would be equivalent
to 0.000125 mg/kg-day which is a 10-fold factor above the USEPA screening level p-RfD. The WHO
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Thallium Toxicity Value Review
Task Group thus concluded that "in view of the considerable uncertainties in the evaluation, it was not
possible to recommend a health -based exposure limit. Until better information on the dose -response
relationship becomes available, it seems prudent to keep human exposures at levels that lead to urinary
concentrations of less than 5 ug/liter." In reviewing the animal studies, the WHO Task Group also noted
that, "it appears that an intake of 0.01 mg/kg-day may be associated with adverse effects. No doses
lower than this have been tested."
ATSDR
ATSDR (1992) notes, "Data on effects of intermediate duration oral exposure in animals do not reliably
identify the most sensitive target organ or the threshold for adverse effects. No data on effects of
chronic -duration oral exposure to thallium were located. Therefore, intermediate -duration and chronic -
duration oral minimum risk levels (MRLs) were not derived for thallium." Note that review of the MRI
1988 study (originally Stoltz 1986) was conducted by ASTDR but not used in the derivation of the MRL.
USEPA OFFICE OF WATER
USEPA's Maximum Contaminant Level (MCL) (USEPA, 2012b) for drinking water is 2.0 ug/L or 0.002
mg/L. The USEPA Human Health Water Quality Criteria (HHWQC) (USEPA, 2015) for thallium is 0.24 ug/L
or 0.00024 mg/L for the consumption of water and organisms from a surface water body, and is 0.47
ug/L or 0.00047 mg/L for the consumption of organisms only. These levels were derived based on the
90-day subchronic study in rats (MRI, 1988).
CALIFORNIA EPA
In California, the MCL and Public Health Goal (PHG) for thallium in drinking water are currently set at 2.0
and 0.1 ug/L, respectively (CaIEPA, 1999, 2004). The Office of Environmental Health Hazard Assessment
(OEHHA) prepared the PHG for thallium in drinking water also using the MRI (1988) study in which
alopecia was observed in both male and female rats and consistent with other reports of toxicity of
thallium in both experimental animals and in humans. OEHHA determined that the incidence of
alopecia in female rats at the highest dose of 0.25 mg/kg-day represented a biologically significant
effect. Therefore, the no -observed -effect -level (NOEL) was identified to be the administered mid -dose
level of 0.04 mg TI/kg-day. For the calculation of the PHG, a cumulative uncertainty factor of 3,000 was
incorporated to account for the use of a subchronic study, uncertainty in inter -and intra-species
extrapolation and the steep dose -response curve. Based on these uncertainty factors, OEHHA derived a
PHG for thallium in drinking water of 0.0001 mg/L (0.1 ug/L). OEHHA notes that USEPA chose to
consider the dose that resulted in alopecia and increased serum enzymes indicated of liver damage as a
NOAEL, which is why the federal values are higher than those estimated by OEHHA.
%.mjmmuiAN CUUNCIL OF MINISTERS OF THE ENVIRONMENT
The Canadian Council of Ministers of the Environment (1999) also adopted the USEPA screening level p-
RfD based on the MRI (1988) study as a provisional tolerable daily intake (TDI) for derivation of health -
based soil quality guidelines for thallium at contaminated sites in Canada.
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Thallium Toxicity Value Review
4.6 EUROPEAN UNION
No data were available on thallium or thallium compounds on the European Chemical Agency (ECHA)
Portal where the Registration, Evaluation, Authorization and Restriction of Chemical Substances (REACH)
Registration Dossiers are posted (ECHA, 2016). Thus, no derived no effect level (DNEL) is available for
thallium from this source.
4.7 OTHER
No other relevant data were located with respect to thallium toxicity since the publication of the USEPA
PPRTV assessment that could better inform the dose -response assessment and toxicity value derivation
for thallium.
5. Critique of Toxicity Value for Thallium
The current screening level p-RfD currently being used by USEPA as a toxicity value is a highly
conservative and inappropriate value for use in evaluating human health risks from oral chronic
exposure to thallium on the basis of: 1) the lack of appropriate toxicological studies on subchronic and
chronic exposures to thallium that provide relevant data and endpoints to be used in a dose -response
assessments; 2) the fact that other regulatory authorities (ATSDR, WHO) have concluded that sufficient
data on thallium does not exist and have not generated toxicity values for thallium and have placed a
low priority on development of additional toxicology data for thallium; 3) the study and POD using
alopecia as the endpoint as selected for the derivation of the screening level p-RfD by USEPA (2012a)
results in significant uncertainty to the applicability of the effects to human exposure to thallium; and 4)
the screening level p-RfD greatly overestimates the risk associated with human exposures as compared
to the typical ingestion of thallium in foods.
5.1 TOXICOLOGY DATABASE ON THALLIUM
The toxicity database for thallium in consideration of a dose -response assessment and derivation of a
toxicity value is limited. Low confidence in the screening level p-RfD is attributed to the limited
database including the lack of studies addressing the known toxic effects of thallium including
neurotoxicity, developmental toxicity, and endocrine effects, and failure of the MRI (1988) study to
identify a NOAEL of all relevant endpoints are considered. It is questionable as to whether a screening
level p-RfD should have been derived and if such an analysis is even valid knowing the database
limitations resulting in the application of such high uncertainty factors, given USEPA's own discussion of
the limitations in the PPRTV document (USEPA, 2012a).
5.2 OTHER REGULATORY SOURCES/VALUES
Most regulatory sources acknowledge the paucity of data for thallium and have not derived toxicity
values. USEPA IRS, WHO, and ATSDR have not generated oral chronic RfDs for thallium. For those that
have, the MRI (1988) study has been identified as the principal study despite the fact that it has not
been published in a peer -reviewed journal, did not provide statistical analyses, and the study did not
show a statistically significant dose -response effect for alopecia in male rats.
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Thallium Toxicity Value Review
On the Priority List of Hazardous Substances established by ATSDR last updated February 12, 2016,
thallium is listed as #275 out of 275 compounds indicating its low priority and concern for review
(http://www.atsdr.cdc.gov/SPL/). In addition, the National Toxicology Program (NTP) (2016a) has
reviewed petitions and proposals for conducting additional toxicology studies on thallium to decrease
the limitations and uncertainty with the current toxicology database but in a recent meeting on June 15,
2016, the NTP scientific board placed low priority on moving forward with these efforts.
One could infer that the low priority established by regulatory authorities on continued development
and review of the toxicology data for thallium indicates a low concern of the potential for human health
risk effects of oral exposures to thallium as compared to other compounds.
5.3 STUDY SELECTION AND POD
It has been questioned as to whether alopecia is considered an adverse event and should have been
used as the POD for the screening level p-RfD. USEPA has stated: "Whether alopecia is itself an adverse
effect merits consideration. In humans, alopecia is generally reversible upon cessation of thallium
exposure. Alopecia, however, appears to be a part of a continuum of dermal changes observed
following thallium exposure, as well as one of a spectrum of effects on target organs that include the
nervous and gastrointestinal systems. For these reasons, alopecia supported by two cases of hair follicle
atrophy is considered an adverse effect (USEPA, 2009)." USEPA (2009) acknowledged that other factors
such as caging and husbandry can cause alopecia in laboratory rodents; however, the incidence was
clearly elevated in both male and female rats over controls. Further, to the extent that alopecia was due
to barbering, research has shown that barbering in rodents can reflect a stress -evoked behavioral
response. For these reasons, some IRIS reviewers thought it was reasonable to use the alopecia as a
"biomarker" for adverse effects until additional studies are conducted to better identify adverse effects
of thallium exposures in animals and/or humans.
NTP (2016b) has also noted that the dose selection for the subchronic study was deemed inappropriate
for evaluation of alopecia since the 14-day range -finding study performed prior to the 90-day study
indicated hair follicle alterations together with decreases in body weight at a dose of 2.5 mg/kg-day of
thallium sulfate; however, a dose of ten times lower than that which effects were noted, 0.25 mg/kg-day
thallium sulfate was chosen as the high dose in the subchronic study. Further, review of the results also
show that there were challenges in distinguishing between normal hair cycling, self -barbering, and
incidences of true alopecia.
Since hair follicle histopathology and self -barbering is not a standard assessment in subchronic studies, it
is difficult to know whether what was observed in the MRI study (1988) is within the range of normal or
truly adverse. Therefore, the use of this endpoint as the POD brings considerable uncertainty to the
screening level p-RfD derived using these data.
No other studies have been identified by reviewers that could bring more certainty and validity to the
current screening level p-RfD proposed by USEPA (2012a).
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Thallium Toxicity Value Review
6. Final Assessment
Due to the significant uncertainty surrounding the study selection and uncertainty to the relevance of
adverse effects in the selected study and POD, the screening level p-RfD value as provided in Appendix A
of the USEPA PPRTV document for thallium (USEPA, 2012a) greatly overestimates potential risks
associated with exposure to TI. This is supported by other regulatory and authoritative agencies
concluding that the dataset is currently insufficient for derivation of a non -cancer value for TI. In
addition, current intakes of TI for a substantial part of the population exceed the provision screening
value with no reported adverse effects reported, which also suggests that the current value is unrealistic
for purposes of regulatory decision making.
Therefore, it seems most appropriate to establish a screening level based on the level of thallium in the
diet; clearly exposure to thallium at this level are without adverse effects. Using the information from
WHO (1996) that the estimated daily oral intake corresponding to a urinary thallium concentration of
5 ug/liter in urine is approximately 10 ug thallium in the form of a soluble compound, and assuming
an average adult body weight of 80 kg (USEPA, 2014), a RfD of 0.000125 mg/kg-day can be calculated,
which is a 10-fold factor above the USEPA screening level p-RfD. This value is still a conservative
derivation, considering that it is well below the intake of 0.01 mg/kg-day that WHO indicated was the
lowest associated with adverse effects.
7. References
1. ATSDR. 2004. Toxicological Profile for Cobalt. U.S. Department of Health and Human Services,
Public Health Service, Agency for Toxic Substances and Disease Registry. Available at:
http://www.atsdr.cdc.gov/toxprofiles/TP.asp?id=309&tid=49
2. CDC. 2016. National Health and Nutrition Examination Survey. U.S. Center for Disease Control and
Prevention. Available at: http://www.cdc.gov/nchs/nhanes/
3. CaIEPA. 1999. Public Health Goal for Thallium in Drinking Water. Office of Environmental Health
Hazard Assessment (OEHHA). Available at:
http://oehha.ca.gov/media/downloads/pesticides/report/thaIf 1.pdf
4. CaIEPA. 2004. Update of Public Health Goal (PHG)-Thallium. Office of Environmental Health Hazard
Assessment (OEHHA). Available at:
http://oehha.ca.gov/media/downloads/pesticides/report/tha111104.pdf
5. Canadian Council of Ministers of the Environment. 1999. Canadian soil quality guidelines for the
protection of environmental and human health: Thallium (1999). In: Canadian environmental quality
guidelines, 1999, Canadian Council of Ministers of the Environment, Winnipeg. Available at:
http://cegg-rcqe.ccme.ca/download/en/215
6. ECHA. 2016. ECHA Portal for Registration, Evaluation and Authorisation of Chemicals (REACH)
Registered Substances. European Chemicals Agency (ECHA). Available from:
http://echa.europa.eu/information-on-chemicals/registered-substances
November 2016 8 RICH

Thallium Toxicity Value Review
7. OEHHA. 1999. Public Health Goal for thallium in drinking water. Office of Environmental Health
Hazard Assessment, Berkeley and Sacramento, CA. Accessible at
http://www.oehha.ca.gov/water/phg/index html
8. NTP. 2016a. NTP Board of Scientific Counselors Meeting. Webinar presentation. Thallium
Compounds. June 15. See: http://ntp.niehs.nih.gov/about/org/bsc/meetings/past/index html
9. NTP. 2016b. Draft NTP Board of Scientific Counselors Meeting. NTP Research Concept: Thallium
Compounds. June 15-16. Available at:
http://ntp.niehs.nih.gov/ntp/about ntp/bsc/2016/iune/meeting%20mate rials/thallium-
compounds 508.pdf
10. USEPA. 2009. Toxicological Review of Thallium and Compounds -In Support of Summary
Information on the Integrated Risk Information System (IRIS). September. Available at:
IILuJb.iiclpuu.eua.govinceaiinsiiris aocuments/documents/toxreviews/1012tr pdf
11. USEPA. 2012a. Final Provisional Peer Reviewed Toxicity Values for Thallium and Compounds.
Superfund Health Risk Technical Support Center, National Center for Environmental Assessment,
Office of Research and Development, US Environmental Protection Agency, Cincinnati, OH.
Available at: https://hhpprtv.ornl.gov/issue papers/ThalliumSolubleSalts pdf
12. USEPA. 2012b. USEPA 2012 Edition of the Drinking Water Standards and Health Advisories, Spring
2012. U.S. Environmental Protection Agency. Available at:
http://rais.orni.gov/documents/2012 drinking water pdf
13. USEPA. 2014. Human Health Evaluation Manual, Supplemental Guidance: Update of Standard
Default Exposure Factors. OSWER 9200.1-120. February 6, 2011. U.S. Environmental Protection
Agency. Available at: http://nepis.0a.gov/Exe/ZVPDF.cgi/P100NQNA PDF?DockeV=P100NQNA PDF
14. USEPA. 2015. Human Health Ambient Water Quality Criteria. U.S. Environmental Protection
Agency. Available at: https://www.epa.gov/wgc/national-recommended-water-quality-criteria-
human-health-criteria-table
15. WHO. 1996. Thallium. Environmental Health Criteria 182. World Health Organization. Available
at: http://www.inchem.org/documents/­ehc/`­ehc/ehcl82.htm
November 2016 9 '%R'^H

Attachment 2
Reference document on internal pH limits
related to ELG's

I� 1

SCIY 1 t5Y ; CtYv HrrHI M
t . c.-mac-vv � ..•...� � r
UNITED STATES ENV IROMMENTAL PROTECTION AGENCY
WASHINGTON, H.C. 20400
Mr. Louis Canzieni
New York State
Department of Environmental
Conservation
Room 6126
Two World Trade Center
New York, NY 10047
Dear Mr. Canzianl:
This is to confirm our recent conversation regarding
effluent limitations guidelines for the steam electric power
industry (40 CFR Part 423).
In my letter of June 22, 1984 to Ms. Ursula Basch of
your office, I summarized the applicability of the steam
electric regulation pH limitat-ion as applicable to low volume
waste streams when such wastewaters are commingled with
(once -through) cooling waters. The interpretation that I
provided was not in accord with prior information and Instruc-
tions provided to EPA and State permitting authorities on
this subject.
The pH limitation per Part 423 applies at the "end -of -
pipe" discharge to surface waters when the wastewater discharge
contains low volume wastewater that is commingled' with once -
through cooling water. However, the intent of Part 423 is
also that the total suspended solids and oil and grease
limitations applicable -t.o low volume waste streams be applied
to the low*volume Waste component of such a combined discharge
prior to commingling of the Individual waste streams.
I apologize for any confusion in permit development or
delays in permit issuance that may have occurred in this
matter. If you have any further questions, please contact me
at [phone].
Sincerely,
Dennis Ruddy'
Project Dfficer
Industrial Technology Division

• I-- I-IJ A-n• 11%V1L/V1L191 AL. i MUICL IILON AtPLNL7 (�
JUN 2 2 199n
Ms. Ursula Hasch
New York State
Department of Environmental
Conservation
Roar.+ 6126
2 World TradA Center
New York, New York 10047
Dear Ms. Basch:
This is in response to, your gtipstions during cur
discussion on June 21 regarding the effluent limitations
guidelines for the steam electric industry (40 CFR Part 423).
T e pt1 limitation pplicable to low volume waste streams
is int ded t_o reguir-e"that low volume waste streams be
treated, as necessary, to comply with the pH limitation prior
to discharge. Furthermore, the basis for compliance with the
pH limitation is not buffering or dilution provided by cooling
waters or other waste streams which are commingled with low
volume wastes.
I trust that this information is responsive to your
questions. Please call me if you have any further questions.
(202-382-7165)
Sincerely,
( `"/
Dennis Ruddy
Project Officer.
Effluent Guidelines Division
i
n

AwA
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION III
6Tm AND WALNUT STREETS
PHiLADELPHIA. PENNSYLVANIA 19106
• In reply refer to
%," '
3EN21
a J. H. LONG
March 10, 1976INN•,F;,�; .,
D7E
Mr. James Long
'/K
t '.
l ..�y.'_
t
y.
Power Plant Sarvices Section
"�•,'r�d t
Philadelphia Electric Company
.o:
c1
2301 Markat Streat
Philadelphia, Pennsylvania 19101
s.t.
Dear Mr. Long:
�.
This is in response to your second
progress report subaitted February 10,
z'•'
1976 for tha Chaster Generating Station
(PA 0011614), in which you propona to d:
s
charge boiler blowdown, zeolite softener
regenerates, and evaporator blowdown u
the receiving stream without pH neutralization.
please be advised that
'
4007R Part 423.32(b)(1) requires the pH
of all discharges from power plants
(except once -through cooling water) to be
in the range of 6 - 9. Economics
were considered prior to the development
of the final guideline limitations,
therefore the expense you have cited as being associated with neutralizing Lhasa
effluent streams is not a valid argument against treatment.
A policy decision was made during the -EPA-PEA meeting in Washington, D.C.
�f
that may influence your situation with respect to neutralizing these effluent
streams. It was decided that waste- streams could be combined with cooling Ovate]
�:-
for the so $ neu a as ong as
w.
the H ran a of 6 - 9. This_poc cy iaJ not iacons s ant with guideline reguire-
:==
ments. I should s noted however, that pollutant parameters other than pH wil:
+
be —limited and mo'aitor fir to 'die comb*:(Hae3on -of apart cu ar *pasta source
category with CRMEg dater.
I trust this will enable you to complete your treatment plans. If there
are any questions, pleas@ don't hesitate to contact me at 215 597-3689.
Si�cerelp yours r
t• .
Bruce P.Smith
Delmarva-D.C. Section

Consolidated Edison Company of New York, Inc.
4 Irvin-g Place, New York, N.Y. 10003
September 21, 1984
Mr. Dennis Ruddy (WH-552)
Project Offices
Effluent Guidelines Division
U.S. Environmental Protection Agency
401 M Street-S.W.
Washington D.C. 20460
Re: pH Limits on Power Plant
Internal Waste Streams
Dear Mr. Ruddy:
-Enclosed' . for' youif -Anfors-iatign is -a '-.':copy" • of. Con..' Edison'-s
comments to' NYSDEC -concerning proposed pH -limits' and monitoring
requirements specified in the draft renewal permit for Con
Edison's Waterside Station. These comments expand upon Con
Edison's position concerning pH limits on internal waste streams,
as expressed during our August 10 meeting and detailed in previ-
ous correspondence. (In particular, see p.5, paragraph 2,
section 3 (a) (5) , section 3 (b) and section 3 (c) for new/expanded
arguments).
If you have any questions, please contact me at (212)
460-2522. We look forward to further discussions with you
concerning this issue.
Very truly �y.ours ,
Barry H. Cohen
Senior Environmental Engineer
Water & Waste Management
/gP
Attachment
cc: Mr. J. William Jordan (EN-336)
Chief
NPDES Technical Support Branch
U.S. Environmental Protection Agency ..
401 M Street S.W.
Washington D.C. 20460
I

3 , pH Reauirer:er.ts (See F." luert LiMitatior.s and Mcnitcring
Reauirec,erts , p . 2) .
DEC proposes to ma.inta it the current r_.P. 14-r:4-te.ticn (range of
6.0-9.0) for Discharge 002 and delete the current 6.0-9.0 pF
limitation for Discharge 001. DF.0 also proposes tc add ail
limitations (6.0-9.0)`cr ir_terr.al waste streams 001a
(boiler blowde=.•m), 00lb (?Waterside ':o. 1 demineralizer
regeneratier wastes), 001c (floor and equipment drainage)
and 002a (Waterside Fo.2 demireralizer regeneration wastes) .
it addition, DEC has proposed to delete p?= monitoring
requirements at Discharge 001, revise the pF ircnitor ng
freauencv _"or Discharge 002 frcm twice Greek!^ to weekl,7 and
add oI? mCn4torirg requirementsfrr waste strears OOIa
(weekly grab), 001b ane 002a (grab before each batch
discharge) and 001c (t*aice monthly) . D'EC pr­,peses 'that all
new/revised effluent limitations and mcniLoring requirements
take efrect .=,ed.iately uper. the effective date of the
renewal permit.
3

Cor. Edison's position with regard to DEC's proposed pH
requirements is sunn.a.rized below:
o Effluent limitations and/or t:onitorirg requirements for pH
in internal waste etreams 001a, 001b, OOlc, 002a or any
other internal waste stream carrot legally be imposed in
the final: permit.
o There is no environmental justificati-on for a pE 14-mit can
internal waste streams. Effluent limits on internal waste
streams are redundant and unnecessary since the current pH
1_mit of 6.0-9.0 at the point of discharge to the public
receiving water provides acequate protection: of water
cuaiity. Furthermore, a pP limit of 6.0-9.0 has beer.
deemed acceptable by DEC at the poir.t of discharge.
o The costs to achieve a pF limit of 6.0-9.0 or, internal
waste streams would be wholly disproportionate to anv
limited effluent reduction a:_d' environmental benefits to
be derived.
o Even if it wereeventually determined that pE limits may,
legall7 be imposed for waste stre2ms.-001a, OOlb, 001c and
002a (which for the reasors set' forth ir. thes-f- cements
cannot Iawfu11V be the case), in order to ochie-7e
corsistercy wit;± the limit of 6.0-9.0 at Discharge 001,
such limitations must be less stringent than a range of
6.0-9.0 (applied at the point of discharge), in order to
take fully ir_to account pR adjustment within the
discharge turnels ; and
e A covpli ance schedule to meet pF. limits on internal waste
streams reed not be provided if such limits are not
ultimateIr imposed. Even if it were e-,.entuall-%
determized that pH 1`_mits cr. irte_r_al *caste nt_reams ma;,
le€all;* be imposed, a reasonable cemplia.nce schedule must
be provided to install equipment r:ecessar;� tc achievesuch lir�itati.ors before thev become effective.
The support -cr this position is as follows:
(a) Effluent Limitaticr.s anal/or "'Critoring Pecuiremerts for of?
in Ir..terna Wa.ste Streams t . a c a or Any
Other Interr_al Waste Stream Carr_ct Legal'.^ be Impose
(1) The Clear. 1 a_ter Act 1.--m4ts the authorit;Y under Section
402 to cor.trol ling the addition of pollutants to
na,74_gable waters through point source discharges
(Sections 301 and 402 a.r.d definitions specified in
Secticr. 50'_', Paragraphs (1),(7),(11),(12) and `(16)).
Based or. those sections, e:=1uert 14-m:.t8ticr_s can only
be applied at the poirt the effluent enters the
receiving waters, except by the consent of the
permi.ttee. Therefore, the point c- discharge irtc
4

navigable waters for Discharges 001 and 002 (ard 003)
at the Statien is at the confluence of the er.d of the
discharge_ tur_r_els and the East River.
(2) EPA`s NPDES (Deccrsolidated) Regulations (40 CFR 122)
essentiall;► track the authority specified under Section.
402 and require effluent limita-ticns to be set at the
poir_t of discharge to navigable waters. Section
122.45(a) states that all permit effluent limitaticr.s
shall be established for "each outfall cr discharge
point of the permitted facil'it,r" except as otherwise
provided in Section 122.45(1). Section 122.45(i)(1)
states that !_rats on internal waste streams may be
imposed in e:-cepticnal' cases and only if limitations at
the outfall are impractical. or infeasible. Sectier.
122.45(1)(2) states that lints on internal waste
streams tray be imposed er_ly when. the Fact Sheet under
Section 46 CFP_ 124.56 sets forth the en.cepticnal
circumstances which make such limitations necessary,
such as when the final discharge -point is inaccessible,
the wastes are so diluted as to make monitoring
impracticable or the interference of pollutants at the
point of discharge "would make detection. or' analysis
impracticable. Bcth Sections 122.45•• and 124.56 are
applicable to State programs.
Based on these regulations, there car, be no exceptional
circumstance Justification for impesitior. of pH limits
ard/or monitoring regLirements an internal was to
streams unless the final. discharge point is
inaccessible for sampling. Yon.itoring (detection ar.c
analysis) for pF (unlike pollutants measured in terms
of crass or concentration, such as heavy r.Ft4'_s) is r.ct
impractical at the point of di schzree due to di lutir-r:
or interference. Based on the dietincticn bet­-;een the
nature'and monitoring of pF and other pollutants, Con
Edison has accepted inter -al limits or. other pollutants
it some cases (even thctgh we believe that such 1_imits
cannot IeFa..l1-- be it:pcsed based cr. the Clean Water Act
ar_d State Elnvirorirentel Cons er•ra,tion. Law) s_rce in
these cases we recognize the impractical t7 cf
deterr..ir.ir.g comp?ience with effluent limitations fcr
such pollutants at the ::in -al discharge (see Section 2.
of these co=er.ts) . Such impracticality, however, does
not app'_�• to pF.
t.":th regard to the euest__or, of sampling points, pH
samples for Discharges 001 are 002 are currently taker
it the discharge plume oft the dcck rather thar,
directly in the discharge tunnels, since Ph. cal
access to the tur.rels is current!?, unavailable i.e. the
discharge tunnels ter*mirate under the FDR Drive, about
60 feet from the end of the dock. However, Cer. Edison_
will create sampling access points in the Discharge 001

and 002 -discharge tunnels by ?ur_e 1, 1985, or by the
beginning of the 1985 chlorination seaser, at Waterside,
whichever is later, as part of our chlorine compliance
program (see comments cer.cerning proposed chlorine
requirements, Section_ 4(c)). There -lore, there i s no
_ustificaticr_ for internal waste stream pT? limits based
on Section 122.45.
(3) Title 8, Article 17 of the New York State Environmental
Cor:servaticr_ Law (ECL) requires permits for the
discharge of polluter.ts from any cutlet or point source
to the waters of the state (Section 17-0803). The ECL
c1eari.y, limits DEC's authority to contro?ling
pollutants at the point such effluents enter the
receivirg waters (Sections 17-0803, 17-0609 and the
definitions specified it 17-0105, paragraphs
(2),(11),(15) and (16)). This limitation is rein -forced
by the SPDES regulations implementing the. ECL (6 N:YCRR
Parts 750-757), Although we believe that the ECL
limits DEC-'s authority to impose effluent limits at the
final discharge, Ccn Edison has accepted and v ill
certirue to accept internal waste stream limits for
pollutants other than pH where we believe cemrl_.cr.ce
monitoring at the final discharge point is impractical,
the limitations are reasonable are not more strinCer.t
than required b, appropriate regulations. This is
clearly not the case ror pH.
(4) EPA Pest Practicable Technology (BPT) regulations limit
the pF of all discharges froti steam electric power
plants, except once through cooling Grater, to a ra.r.ge
of 6.0-9.0 (40 CFR 423.12(b)(1); emphasis adced).
EPA.'-- currer•t Ef fluent Limitation Guidelines fcr PH (47
FR 52303, November 19, 1982) are=der_tical to those
ccr.tained in the init=pll:r promulgated Gu? d.el ir_e,
published ir. the Federal pPQister on October 8, 1974
(39 FR 36186) . in both i e crigiral and revised
Guidelines, no PH limitations are eVplicitly placed or.
any internal we.st_e streams. Eased on the cFfinitycrs
specified in the Clear. Water Act, the EPA 14-mitation c`
6.0-9.0 would apply or.l-- at the cutlets et the
discharge tunnels to the East P.4-%7er and not to an;
r.te_-r:al waste stream.
By letter dated May 3, 1�84 (ar_tachwent to Exhihit 1) ,
Ccr. Edison fcrc;a11 requested that the L.S.
Vnvircr:mental Protection P_g?r:c- (EPA) ciari`v its BPT
a:'d internal waste_ stream regulations as they apply to
PH. At a meeting held on August 10, 1984 between'Con
Edison and EPA., the P_ee- c•- stated that it would tai;e
.bout ore torah to rev; ew the rules king record and
infcrr; Con Edison and DEC of its determination.
I C I • - .-w-. _ .r cl,00r r =t-pd December 13, 1983, DEC states

that internal waste stream monitoring is proposed for
specific low volume wastewaters since compliance with
appli catrle ?'imitations cannot be determined. at the
final discharge. For the fcllowing reasons, this
explanation dces not satisfy Federal (40 CFR 1:4.56)
and State (6 NYCPp 753.3) regulations, which require
that Fact Sheets set forth the --legal and technical
basis of proposed limitations:
(a) The Fact Sheet does not specifically address the
rationale for the proposed pH limits. In fact, it
cannot be determined _`rom the Fact Sheet to which
waste strear:s and pollutants the e:;p1 ar.ation
provided in the Fact Sheet applies;
(b) The Fact Sheet does not :pecif; whether the
proposed pH limits are based on EPA's Guidelines
for Steam Electric Power Plants or DEC's Best
Professional Judgement (BPJ) determination of Best
Practicable Technolog)7 (BPT) or Best Conventional
Technology (BCT), or any other basis;
1. tl the proposed limit is based on EPA's
Guidelines, it does :.ot specify whether DFC
interprets the 6.0-9.0 BPT pH-Iimit to appl-y to
internal waste streams (anal iF so, the reasons
for that intepretatior.) or to final discharges;
2. If the proposed limit is based or. BPJ, it does
not address the factors specified in Section. 304
of the Clear. Water Act or 40 CFI? 125.3 (See
Paragraph 3.(d) of these comments);
(c) The Fact Sheet dces not speci_`y which sections of
the Clear_ Water Act srd State Environmental
Cor, servation Law. provide DEC with the authority to
impose internal waste strepr' limits for pF. 1?cr
dces it specify the sections of EPA and 'DEC
regulations which authorize such l:r_i is ; ar.d
(d) The Fact Sheet dces not specif,T which of the
exceptional circumstances specified in 40 CFR
1212.45(1), if any, it relied or tc reach the sn�ted
cerelusior. that comp'" arce with the 6.0-9.0 pH
?._citaticr_ cannot be deterr;ined by monitoring at
the final discharge.
(b) There is Yo Environmental Justification for PH !,sits or_
Irternal t'ster Streams
The current pH limitation_ of 6.0-9.0 at Discharges 001 ar•d
002 affords adequate prctectior_ eF public receiv'_re water
eualit-r. A pH limit of 6.0-9.0 at the point of discharge
was deemed acceptable by HPA Region I! (and DEC b„ its

Section 401 Certification) in the initial discharge permit
issued by Region Il an November 30, 1974, as well as by DEC
(and Region II in its overview capacity) in the renewal
permit issued by DEC on ?uly 1, 1980. Beth the initial and
renewal permits were based on EPA's Er -fluent Guidelines
promulgated cn October 8, 1974 and were to hare included ary
more stringent water cua?ity-based--requiren..erts. Since
applicable Effluent Guidelines fqr pH have not charged since
initial permit issuance and DEC has not shown that a final
discharge pi? within the range of 6.0-9.0 has caused or wil'_
cause any adverse environmental impacts, there is no basis
for imposition of more stringent pH limitations in the
renewal permit. In addition, b:- proposing to maintain the
current 6.0-9.0 PH limitation for Discharge 002, DEC has
deemed that range acceptable at the point of discharge.
Furthermore, installation. of a waste neutralization system,
which would be required to meet the proposed limits, would
result in the addition of significart amounts of
neutralizing chemicals (acid/caustic), thereby increasing
the amount of pollutants discharged.
(c) The Cost To Achieve Inte
,` .c_ y Disproportionate To
ie to verivea
i Waste Stream
ie Effluent P.e 1
PF .Limits Is
tion Bene its
The Waterside Station. 'has two demineralization. systems,
which are housed in separate buildings. In order to achieve
the proposed pH limits For demineralizer regeneration waste
streams (001b and 002a) ,. installation of two waste
neutralization systems would be required due to the physical
layout of the facility and the relativel-v i.arge number of
regenerations performed (See SPDES Application Update for
r.
more detailed irfermation cccerrirg regereratior_ waste
streams) . Each s�Tstem would consist of 1-2 large
neutralization tanks, pumps, acid and caustic injecti.cr.
systems, instrumentation and cortro_s ar_d an elaborate
pipir_g system. Con Edison ccnservativel_y'estimates the
total capital cost of these s,'stems to be $3-` millicn, a
reasonable estimate taking into account the nature of the
facility (primaril;; steam sendcut), age of the facility, :ts
ph;?si.cal layout and space limitations, and she relatively
large number of regenerations (due to steam serdout). These
costs would increase substantially if a pK limit or: 6.0-9.0
is imposed for boiler blewdo*A-,n (001a; and 002a ir. current
permit) , wbi ch tvpi cal l y has a PH of 10-10.5 . Ir. additicr, ,
substar..tizl cperating casts (labor ar.d chemicals) would be
incurred. These capital and operating costs- would
ultiVately be bcrr_e by Con Edison's steam and electric
ratepayers.
As stated above, Con Edson believes that there is no
environmental justification for a PF limit of 6.0-9.0 or.
ir_terr.al waste streams. Such lim-; is would result in little,
4f ar.v, envirormer_tal bene{? is , which are wholly

disproportionate -to the costs that would be borne by Can
Edison and- its ratepa-ers. As specified abo,.=e, such
reeuirements would, in fact, result in the discharge of
increased atrour_t of pollutants.
(c'•) if It t?ere Eventually To Be Determined That pR Litwits Mal
Legally Be Itraesed For lrternal-Waste Streams, Such
tations rust. be Less stringent than. G.u-J.
The existing pN li.mitF of 6.0-9.0 for Discharges 001 and 002
reflect Best Practicable Control Technology Currently
Available (BPT) as defir_ed bly EPA (40 CFR 423.12(b) (1)) . By
limiting the pH cf internal waste streams to that same
range, DEC is, in effect, proposing a limit more stringent
than BPT. Section 301(b)(2)(E) of the Clean Water Act
provides for more stringent limits than BPT for pH and other
conventional pollutants by application_ of the 'Best
Conventional Pollutant Control Technolog:* ('BCT). EPA has
deferred promulgation of BCT limitations for power plants
pending promulgation of a revised BCT methodology.
Therefore, any BCT limits imposed. in a power plant permit
must be developed on a case -by -case bzsis, pursuant to
Sector. 402(a) (1) of the Clean Water Act and Article 17,
Title 8 of the State Enviror.rrental Conservation. l,aw.
The proposed internal waste stream limitatior. of 6.0-9.0
must accordingly be based or a case-bv-case determination cf
ECT by DEC. EPA regulatlor_s (40 CFR 1?5.3(c)) allow the
imposition of technology based limitations tc the extent
EPA-proum1gated effluent guidelires are ina.ppl icabie. Ir.
these cases, the permit issuing authority (DEC) is required
to apply the appropriate Factors specified ir. Secticr•. 304(b)
of the Clear. Water Act. For de,: elcptrer,t of ECT
limitations, r_1;e -factors specified in Section 304(b)(4)(B)
must be applied. These factors include "the reasonableness
or the relationship between the costs of attaining a
reduction in effluent and the effluent reduction benefits
derived, ar.d the comparison of the cost and level of
reduction of such pollutant from pLblicly owned treatment
works to the cost and level of reduction of such pollutants
-from a class of categor- of industrial source" are "the age
of equipment and Facilities involved., the process employed,
the engineering aspects of the application of various t;7pes
of control techr_iques, process changes, non -water quality'
environmental impacts (including energ;7 re-quirements) .
Co se -by -case limits must also consider the avri cpri.ate
techrclog,7 for the applicant's industrial_ categorn and any
unique factors relating to the facilit; (40 CFR
125.3(c)(2)). These Factors must be considered regardless
of the permit issuing authorit_> (40 CFR 1_25.3 (c)).
On Yovember 18, 1982, EPA proposed to revi.se 40 CFR 1.24.56
ere- 40 CFR 125.3 to explicitly specify the statutory and
--Thor rnr�rcrs that rr.'u�t be considered in setting

case -by -case, nest Professional Judgerr..ert (BPJ) limits and,
the information. that must be included in the Fact Sheet (47
YR 52072).,: The preamble to the proposed regulations states
that "Section 125.3(c)(2) already requires permit writers to,
consider -"statutory factors" in issuing RPJ permits, Eo
these changes simply clarify ar. e-xisting requirement." (47
rR 52080). The proposed regulaticnsT therefore, would make
explicit what is already required, namely the application of
the statutory factors and any other factors considered in
the determination of BPS limits and the inclusion in the
Fact Sheet of any analysis or the application of these
factors and identification or any guidance or other
documents relied upon iv. setting the Limits.
DEC has not provided Con Edison with any documentation of
its cer_sideratior, of the factors specified in Section
304(b)(4)(B) and 40 CFR 125.3(c)(2) in its development of
the proposed ECT limits for pH. Therefore, DEC cannot at
this time impose BCT limitatiors more strirger.t than BPT.
Even if it should ultimately be determined that DEC ma;
impose pH limits on internal waste streams, which for the
reasons set fcrth herein_ we submit it cannot lawfull,., em,
then such limitations roust be less stringent than 6.0-Q.0 sc
as not to be in conflict with a 6.0-9.0 limitation at the
point of discharge. Otherwise, the ir.terral limitations
would be more stringent that EPT and must be justified
taking into account the factors specified above.
(e) Even If It Were Eventually To Be -Determir?d That pH Limit
t:az Lega_l,r Be Im osed For * rnterna Taste Streams,
RM ona le Compliance Schedule Must be Provi ed
if it were to eventual!%,- be determnined that pH limits may
legally be imposed or_' internal waste streams ant such
limitations were imposed, a reasor.able schedule of
compliance would need to be provided in order to permit
procurement and installation_ cf r._ecessa.r- equipment before
such limits become effectilre.
DEC's proposed compliance deadline (ef_`ective date of the
rer.ewal Derr -it" is both arbitrary and impossible to achieve.
Although DEC has nct provided its rationale fcr the proposed
compliance deadline, we presume that ;_t was based or_ the BCT
deadline cf Jule 1, 14804 specifies' in Secticr. 301(b) (.2; (F)
of the ClP<n Water ?act, uc,�•Tever, s_r.ce DEC's proposed
limits carr_ct legally be imposed under FCT as discussed
previously, t:-:e Jul.j 1, 1984 deadline e..ces nct apply.
rl the proposed urreascr_able and impracticable ccmpliar.ce
deadline were to be eventually imposed, Con_ Edison, would
urfairly be put in the ur_terzble Position of immediatel;�
`yiclat:rg the permit. For purposes of framing the issues
'or consideration in a hearing, any permit issued b-T DEC

containing pH limits on internal waste streams should
contain a realistic compliance schedule, to be subsequently
agreed uperr, which would encompass time periods recessar;T
for the procurement and installation. of necessary equipt:ent.
(f) Mon--toripg Requirements
Monitoring requirements for pu cannot legally be imposed for
internal waste steams for the reasons stated herein. If it
were eventuall_T to be determined that pH monitoring
requirements may legally be imposed on internal wastes
streams, monitoring reauirements for those waste streams
should net be required pr--cr to a realistic comp].=ante
deadline eti entuall,T agreed uper ( see paragraph (e) abo-%Te) ,
since the limitatier.s would not be effective until that
time. We cannot currently comely with the proposed
requirement of taking grab sar^ples before each batch
discharge of demir.era.lizer regeneration. wastes (001b and
002a), since there is no provision for holding up these
wastes prior to discharge. Even if neutralization s;Tstems
are installed, this proposed requirement may be
impracticable, if the systet:s are designed for
semi -continuous operation_ in which, when the e'_`fluert is
within the set pH range, discharge may occur man; times over
a regeneraticr cycle.
In summary, effluent limitations and monitoring requirements
for pH should +not be imposed for internal waste streams for the
reasons specified above. The only pH limits that may be imposed
are the current BPT permit limitations of 6.0-9.0 at Discharges
001 and 002 (and 003). This approach would be cer_sister_t with
that recommended by DEC in its Division_ of Water Guidance
memorandum No. 04-IR-33- ("EPJ ::ethodologies - Guidance for the
Application of Rest Professional Judger:ent (BP"-,) in Dpterminir_g
S?DES Coneitions," dated April 1933), which states (Section
VIII.E.):
"T•.ith roaard to corventional pollutants, the Departmer_t
C.
will generally consider BPT 2r acceptable level of
cortrel, unless effluent guidelines or katpr quality
recess_tate more stringent control."
Since effluent guidelines mandate a pp limit of 6.0-9.0 at the
Point cf discharge and water has rot been shc-Hr. to
necessitate ar_-- trcre stringent limits, the current limits are
a.pprcpriate and should be maintained. DEC may riot impose a
particular tec!^rclogv for meeting SITES limits. Therefoie, Ccr
Edison should be free to meet those limitations by the method of
our choice.
Ever. if DEC could legally impose pH limitan-sons for internal
waste streams at this facility, a compliance schedule Tacu'_d be
required to `thieve such limitations. In addition,
not' ithstardir.g the legal argur`ents against impositicr. of pH

requirements for internal waste streams, DEC crust provide the
legal and technical basis, including any supporting
dccun,er.tatien, -for any such requirements prier to their
establishment in 2. final permit. If such rationale is e•Jpntua??�.
prc-%Tided, Cor• Edison rust be given a rea.sor.able orrc=tunity for
evaluation and submission of ccmments.