NC0089109_Correspondence_20230717

Responses to the SELC Comments
Befesa Permit NCO089109
July 10, 2023
1. The Clean Water Act requires DEQ to impose technology -based effluent limits.
Response:
Development of the BPJ TBELs is extremely complicated and difficult procedure. Currently, the
DWR has no institutional capacity to develop their own BPJ BAT in according with the EPA
guidance. This effort would be enormous in nature and will require full-time commitment from
numerous existing staff members, it will also require an expertise in economics beyond what
exists in the DWR. For example, EPA has the Engineering and Analysis Division that employs
approximately 40 experts, these experts develop Effluent Guidelines. Recently, this EPA
Division spent 10 years to develop the latest update to the Power Plant Guidelines and then an
additional 5 years to make subsequent adjustments to the Final Rule.
In 2014, the DWR attempted to develop their own BPJ BAT for Duke Energy Riverbend permit
by using a very simplified procedure. SELC was critical of DWR's effort for not adhering to the
EPA guidance. Nevertheless, SELC now suggests that we use the same procedure, which they
strongly criticized previously.
Furthermore, the use of simplified procedure is not likely to withstand legal challenges because it
omits numerous important components, including economic evaluation, robust statistical
analysis, comparison with similar facilities that successfully install and operate treatment
technologies, public notification and comment period, etc.
2. Without a TBEL, DEQ should impose a WQBEL for chlorides.
Response: The need for water quality -based effluent permit limits is determined based on the
results of the reasonable potential analysis (RPA). The RPA procedure utilized by the Division
is conducted in accordance with the EPA's regulation (40 CFR 122.44(d)(1)). When the
permitting authority determines, using procedures in paragraph (d)(1)(ii) of this section, that a
discharge causes, has the reasonable potential to cause, or contributes to an in -stream excursion
above the allowable ambient concentration of a State numeric criteria within a State water
quality standard for an individual pollutant, the permit must contain effluent limits for that
pollutant. Permit limits are added only if the results of the RPA indicate the potential for
exceeding the water quality standards, and are not arbitrarily assigned. However, absence of
permit limits does not allow the facility to violate instream water quality standards.
When the RPA indicates no potential to violate water quality standards for a particular
parameter, the limit for this parameter is not implemented in the permit. This procedure is
conducted in accordance with EPA guidance, it does not violate anti -backsliding provisions of
the Clean Water Act, and has been consistently implemented for decades with the EPA approval.
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The RPA for this facility indicated that there is no need for chloride limit.
3. DEQ's Reasonable Potential Analysis Suffers from Significant Flaws.
Response: The Division conducts the RPA based on the procedures outlined in the EPA
Guidance entitled "Technical Support Document for Water Quality -based Toxics Control". This
process has been approved by EPA and withstood numerous legal challenges.
a. DEQ has not followed the steps to complete an RPA with no data.
According to DEQ, it determined that limits were not necessary for the following constituents
because "they did not demonstrate reasonable potential to exceed applicable water quality
standards/criteria": Total phenolic compounds, chromium VI, cyanide, mercury, selenium, and
silver.' But DEQ's RPA reveals that it input no data into its analysis for any of these
constituents.2 EPA's Permit Writers' Manual outlines the process for completing an RPA with no
data, but DEQ has not followed that process here, leaving its RPA conclusions unjustified.3
Similarly, DEQ concluded that limits were not necessary for thallium because it also "did not
demonstrate reasonable potential to exceed applicable water quality standards/criteria." But
DEQ's RPA reveals that it did not complete this analysis for thallium at all.' This conclusion
cannot be relied on to demonstrate that a WQBEL is not required. Completing this analysis is
particularly important given the high amount of thallium in BZM's wastewater.6
Finally, DEQ removed all monitoring requirements for aluminum "based on the RPA results,"
but there is no evidence DEQ completed an RPA for aluminum either.
Response: The statements above are false. The Division conducted the RPA based on the
information provided in the Renewal Application for all these parameters, including total
phenolic compounds, cyanide, mercury, selenium, silver, thallium, and aluminum. The only
exception was chromium VI because the applicant did not provide data for this parameter.
However, the Division conducted the RPA for total Chromium that predicted maximum
concentration of 187.2 µg/L, the RPA also indicated that the allowable concentration of
chromium VI is 1,220.3 µg/L. Hence, there is no need for chromium VI limit in the permit.
b. DEQ's assumption of zero background is demonstrably incorrect.
When completing its reasonable potential analysis, DEQ assumes that background levels of
pollutants in the receiving water are zero. This is plainly wrong for several constituents, which
undermines the RPA.
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For example, DEQ's RPA does not take BZM's stormwater runoff into account when
determining baseline coefficients.
Response: The Division has a substantial data set of ambient monitoring in different basins that
confirm correctness of the zero background concentration assumption. For example, Catawba
River Based has 173 permitted dischargers with individual NPDES permits. The Division has
been reviewing instream values for Allen Steam Station monitoring locations that are situated
near that state line and accumulate all the pollutants discharged by the 173 permittees.
The Allen permit requires monthly upstream and downstream monitoring near the ash pond
discharge. The upstream site (Station 15.9) is approximately 1 mile upstream of the discharge
and downstream location (Station 14) is approximately 1 mile downstream of the discharge.
These monitoring stations have been established through the BIP monitoring program, which
was required to maintain the 316(a) temperature variance and have been in place for decades.
The current monitored parameters are: As, Cd, Cr, Cu, Hg, Pb, Se, Zn, Br, Total Hardness as
CaCO3) and Total Dissolved Solids (TDS).
The concentrations of the following measured parameters upstream are either below detection
level (As, Cd, total Cr, Pb, Se, and Zn) or very well below water quality standards (Cu and Hg).
It is very important to emphasize that concentrations of the measured parameters downstream are
also either below detection level (As, Cd, Pb, Se, Zn) or well below water quality standards (Cu,
Hg, and TDS). The Broad River Basin where Befesa is discharging only has 44 individual NPDES
permitted dischargers and is very likely to have even higher water quality than Catawba River
Basin.
In addition, the Befesa performed fish tissue sampling for 3 fish species at upstream and
downstream locations in accordance with the plan approved by the DWR. The fish tissue
samples were analyzed for Arsenic, Cadmium, and Zinc. All the results were below the fish
tissue screening levels established by the NC DHHS. The only exception was Arsenic in one
upstream sample of redhorse tissue. This Arsenic measurement exceeded the NC DHHS
screening level. But even that sample was qualified by the laboratory as "an estimate". It also
confirms the fact that the permit is protective of the receiving stream.
The Division cannot take stormwater into account when conducting RPA because it will violate
the RPA basic assumptions. The RPA is based on the very low flow of 7Q10 and stormwater
discharges occur only during the rain events, which would correspond to the very high flow.
Therefore, stormwater discharges are not considered during the RPA.
4. DEQ must apply narrative water quality standards in its permitting decision.
Response: The DEQ applies the Whole Effluent Toxicity limits to evaluate cumulative impacts
of all pollutants. The facility has been consistently passing all WET tests during the last 5 years
with only one exception.
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5. DEQ must require BZM to disclose the amount of sulfide and surfactants in its
effluent.
Response: The Division will add the requirement to report sulfide and surfactant concentrations
during the next permit renewal.
6. DEQ should not further reduce or eliminate monitoring requirements.
Response: The proposed monitoring requirements are based on the Division's procedures and
will be sufficient to perform the EPA approved RPA during the next permitting cycle.
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