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Home My WebLink AboutMarshall Steam Station (16)#41*Duke 'Energy, Carolinas July 20, 2011 Mr. Brian Lowther Division of Water Quality Stormwater Permitting Unit North Carolina Department of Environment and Natural Resources 1617 Mail Service Center Raleigh, NC 27699-1617 Subject: Duke Energy Carolinas, LLC Draft NPDES Stormwater Permit Comments Marshall Steam Station Permit No. NCS000548 Dear Mr. Lowther: GEORGE T. EVERETT, Ph.D. Director Environment and Legislative Affairs Duke Energy Carolinas, LLC 3700 Glenwood Avenue Suite 330 Raleigh, NC 27612 919-235-0955 704-906-5351 cell 919-828-5240 fax gteverett@duke-energy. com Qffl@fflowffl R JUL 2 0 2011 DIV. OF WATER QUALITY DIRECTOR'S OFFICE Duke Energy Carolinas, LLC (Duke Energy) recognizes the need to be protective of surface waters receiving stormwater runoff from our facilities, however, these efforts must be reasonable and cost effective. Duke Energy maintains that many of the requirements mandated by this permit are of little or marginal value in terms of environmental protection and therefore significant revisions are warranted. We have reviewed the subject draft stormwater permit for the Marshall Steam Station and submit the following comments: a. Duke Energy is concerned that our request for representative outfall status (ROS) was not addressed adequately in the draft permit or in the permit cover letter. In a series of discussions prior to the issuance of this draft permit, Duke Energy clearly outlined the rationale for representative outfall status as the fundamental issue at these types of facilities that have numerous individual stormwater outfalls. The permit draft cover letter (first paragraph) states that representative outfall status is being "reviewed" by DWQ and the associated response will be included in the final permit. This practice runs counter to normal permitting processes in that Duke Energy is unable to comment on any decisions regarding ROS before the permit is finalized. Stormwater outfall SWO07 is adequately representative of those drainage areas surrounding the station powerhouse where industrial activities are concentrated. SWO07 represents the greatest risk to stormwater within this group based on the relative size of the contributing drainage area, and the higher level of industrial activity occurring within the contributing drainage area. Stormwater outfall SWO03 is adequately representative of those more innocuous outlying drainage areas at the station. SWO03 represents the greatest risk to stormwater within this group based on a higher level of vehicle traffic, greater area of gravel surfacing, and occasional use of the drainage area for storage of inert materials. Consequently, we maintain that outfalls SWO07 and SWO03 are representative stormwater outfalls at the station and that representative outfall status be granted per our original request www.duke-energy.com b Most of the stormwater outfalls at Marshall Steam Station are currently inaccessible (reference attached supporting information) Providing safe and secure access to these outfalls for sampling and monitoring will be difficult and costly Currently, only outfalls SW001, SWO03 and SWO04 can be safely accessed Furthermore, four stormwater outfalls (SW001, SW002, SWO04 and SW008) have such limited and/or undefined contributing drainage areas that the likelihood of collecting a stormwater sample is remote (reference attached supporting information) Considering this, Duke Energy proposes that qualitative monitoring requirements also be limited to identified representative outfalls SWO07 and SWO03 We believe the difficulty and expense of providing safe and secure access to all inaccessible outfalls for qualitative monitoring purposes is unreasonable, ,and is not justified from �a, stormwater protection standpoint Should this not be acceptable to NCDENR, we propose that -qualitative monitoring be _ conducted at the nearest, safely accessible, location occurring upstream of each stormwater outfall These locations may be at -the inlet to -the discharging culvert, within the nearest upstream catch basin or manhole, or at the nearest accessible location along the concentrated flow channel c Part II, Section B, Table 1, Footnote 3 of the draft permit requires us to sample Outfall SWO09 (NPDES Wastewater Outfall #003), and to report the results separately as a non- stormwater discharge Duke Energy is not required to sample this outfall under the current NPDES permit because chlorine is not added to the waste stream Per item (a) above, we believe that Outfall SWO07 is adequately and conservatively representative of SWO09 Therefore, we request that the requirements for monitoring of SWO09 be removed from the permit d Part II, Section B of the draft permit mandates analytical and qualitative monitoring for a host of parameters, including 15 metals, O&G, and sulfate Based on historical stormwater and lake monitoring data, there is no scientific basis for in'c_lusion of these parameters—Many of these parameters have never been detected in historical: stormwater samples collected from Outfall SWO07 This data has been- us omitted to DWQ 6 partof-the NPDES permit renewals In addition, most of'these parameters are excluded -from -monitoring -requirements at`thi ash basin discharge outfall in the NPDES permit based on reasonable potential analyses to exceed state water quality standards Our NPDES permit does not'maridate sampling fog Ag`, -_Be, Cd, Cr, Pfj—Sb,-TI, AI—B; — COD, nor SO4 at the ash basin discharge Certainly this discharge represents the worst case impacts to surface waters in terms of mass loading associated with the facility The DWQ permit cover letter states that these parameters have been added to the permit "to investigate the pollution potential of storm water discharges " We submit that using the stormwater permit as a scientific investigation tool is inappropriate�considenng that no water quality impairments exist to support the need for data collection and monitoring Therefore, these additional parameters should be removed from the permit monitoring requirements e There is no scientific justification for many of the benchmark values listed in Part Il, Section B, Table 3 There should be a significant water quality issue, such as a 303 (d) listing, to justify the requirements for monitoring of any benchmark values in the permit These drivers do not exist for the receiving water body at Marshall Steam Station Furthermore, exceeding a benchmark value gives the appearance to third parties that a water quality standard has been exceeded We believe this is inappropriate and will cause more public concern than is intended Therefore, we request that all benchmark values be removed from the permit that do not relate to actual existing water quality issues in the receiving water body 2 The requirement for EPA method 1631 E low level mercury analysis stated in Part II, Section B, Table 1, Footnote 4 should be removed. The quality control measures necessary for ensuring quality data cannot be easily met in the conditions expected during "wet weather' sampling. Wet deposition has long been understood as a mode of transport for Hg in the atmosphere. Sampling during a storm event, in which rain is actively falling, could pose contamination issues for field blanks (also required by Footnote 4) collected in this environment. Contaminated field blanks would call into question samples collected alongside those blanks. Considering the likelihood of collecting storm water samples during active rainfall, it is very likely contaminated blanks would confound the interpretation of the mercury data and compromise the integrity of the data. Should mercury analysis be required, Duke Energy advocates the Cold Vapor Mercury Analytical Method 245.1. Part II, Section B, Table 2 comments of the draft permit requires a separate signed Annual Summary DMR copy to be submitted to the local DWQ Regional Office by March 1 of each year. Part III, Section E, Item 1 indicates that sampling results must also be submitted on the DMR forms within 30 days of obtaining the analytical results. Requiring this separate Annual Summary DMR submittal is redundant and time consuming. Therefore, we request that the requirement for submittal of the Annual Summary DMR be removed from the permit. Part III, Section E, Item 1 of the draft permit states that, in the event of no discharges occurring during the reporting period, Duke Energy is required to submit a DMR "within 30 days of the end of the three month sampling period". This sentence should read "within 30 days of the end of the six month sampling period". Part II, Section A, Paragraph 7 states that "The permittee shall provide certification in writing in accordance with Part III, Standard Conditions, Section B, Paragraph 5". This sentence should read "in accordance with Part III, Standard Conditions, Section B, Paragraph 3". Part II, Section B, Table 2, "Year 5 -- Period 1" date of "February 28, 2016" should be changed to "February 29, 2016" to reflect the leap year. Please contact Mark.McGary@duke-energy.com or at 704-634-7098 if you have any questions or need any additional information. Sinc rel , George T.42tnmental , PhD. Director, E & Legislative Affairs Attachment Cc w/aft Mr Bradley Bennett, NCDENR Mr Michael Parker, NCDENR MRO Donna Burrell Dayna Herrick John Velte Josh Quinn Mark McGary Outfall SW001 CMP Current accessibility for sampling/monitoring: Accessible. Sample collection probability: Unlikely due to limited extent of drainage area and clogging of outlet. Outfall SW002 CMP Current accessibility for sampling/monitoring: Inaccessible due to steepness of embankment and dense vegetation. Sample collection probability: Unlikely due to limited extent of drainage area, and only if a safe means of access is provided. Outfall SW003 Riprap channel Current accessibility for sampling/monitoring: Accessible. Sample collection probability: Currently impossible due to voids in existing rip rap channel. Sample collection possible if detention basin installed within channel to allow for stormwater retention. Outfall SW007 CMP Current accessibility for sampling/monitoring: Inaccessible due to submerged outlet. Sample collection probability: Possible, but must be performed at an upstream manhole. lob " - 0 lop � �� - � ,�Y' � E �� '.� - X471 a.�. •:�{ Outfall SW009 CMP Current accessibility for sampling/monitoring: Inaccessible due to steepness of embankment and dense vegetation. Sample collection probability: Possible only if a safe means of access is provided; otherwise sampling would be performed at an upstream manhole. Stormwater at this outfall is co -mingled with a continuous non -contact cooling water discharge. Outfall SW012 HDPE Pipe Current accessibility for sampling/monitoring: Inaccessible due to steepness of embankment. Sample collection probability: Possible only if a safe means of access is provided. Outfall SW022 HDPE Pipe Current accessibility for sampling/monitoring: Inaccessible due to steepness of riprap embankment. Sample collection probability: Possible only if a safe means of access is provided. Outfall SW023 HDPE Pipe Current accessibility for sampling/monitoring: Inaccessible due to unstable riprap and dense vegetation. Sample collection probability: Possible only if vegetation is cleared, and a safe means of access is provided.