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Home My WebLink AboutAllen Steam Facility - Duke Energy (4)' lDuke nergy.. September 12, 2011 Ms. Bethany A. Georgoulias 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 Allen Steam Station Permit No. NCS000546 Dear Ms. Georgoulias: DUKE ENERGY CORPORATION 526 south Church St. Charlotte, NC 28202 Mailing Address: PO Box 1006 Charlotte, NC 28201-1006 Q�c�0oe�� SEP 1 5 2011 DENR - WATER WAUTy WR"S AND STDRMIWATER BRANCH 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 Allen Steam Station and submit the following comments: a. Duke Energy agrees with the DWQ interpretation that representative outfall status be granted for SWO15 instead of SW018. b. The draft permit cover letter specifies a period of short term sampling be performed for outfalls SW002, SW007, SWO08, SW009, SWO10 and SW012; however no sampling schedule is specified in the footnotes of Part II, Section B, Tables 2 or 3. In addition, including SWO08 in this list is redundant as SWO08 is a named representative outfall. C. There are numerous stormwater outfalls on the Allen Steam Station property that are not part of industrial use areas of the site, and therefore should be excluded from the permit. These outfalls include: i. Outfall SWO01: The contributing drainage area for this outfall is located approximately 2,000 feet north of the station Powerhouse, is primarily woodlands, Y t, and contains only rail lines. Other outfalls draining rail lines at the station (such as SW007) will represent greater risk to surface waters. J www.duke-energy.com n Outfall Group SW 1� This is a group of 14 small diameter outfalls located approxi mate ly,200-feetapart along the rail lines between the station Powerhouse and the ash basin The contributing drainage areas are limited, and include only rail lines and a gravel road Other outfalls draining rail lines at the station (such as SW007) will represent greater risk to surface waters iii Outfall SW014 This outfall drains a narrow isolated strip of station property located between the coal pile and the ash landfill There are no industrial activities within this isolated area and the ,1outfall represents little risk to� surface waters IV Outfall Group SW017% This is a group of,numerous small diameter outfalls, located along both sides of the discharge canal and extending the entire length of the canal These outfalls drain only the vegetated slopes of the discharge canal embanen kmt; have limn d: contributing drainage areas, and represent little risk to surface waters V Outfall SW019 This outfall discharges stormwater runoff from a large area between the discharge canal and the station access road' The drainage area includes a soil borrow area used for landfill cover Runoff from the borrow area discharges into,a sediment basin installed as part of an active erosion control plan The remaining portions of the drainage area are wooded This outfall represents little risk to surface waters vi Outfall MOW This outfall discharges stormwater from a primarily wooded area along the FGD access road The area formally included the soil spoils area used during construction of the'FGD project The spoils area is now,stabilized and there are no other activities ongoing or planned within the area This outfall represents little risk to surface waters d Several of the stormwater outfalls at the Allen Steam Station are currently inaccessible Providing safe and secure access to these ou alis fo sampling an,"�m_dJhitoring,will be difficult and costly Currently, outfalls SW004 kSW005) §W006,SW012,' W014, SW016, SW018, 'SW019 and SW020 are inaccessible r erence attachT -supe rtmg information) In addition, sample collection�fromt eh outfalls of Group SW013 and Group SW017 is not feasible Sampling ofoutfall SW008w ipossible only at the inlet catch basin of this drainage area�,,.> e 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 In addition, benchmarks have been added for nitrogen and phosphorus Based on historical stormwater data, there is no scientific basis for inclusion of most of these p ra amet"e`rs Most of'these parameters were not detected, in the most recent stormwater samples collected from Outfalls SWO.08 and SW015 This data has bee n'subrnitted"to DWC as"part of°the-NPDES permit renewals In addition, some of these parameters are excluded from monitoring requirements at the ash basin discharge outfall in the NPDES permit based on reasonable potential analyses to exceed state water quality standards Our NPDES permit does not mandate sampling for Pb, Sb, B, P, 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 Therefore, ,most of these parameters should be removed from the permit monitoring requirements f There is no scientific justification for many of the benchmark values listed in Part II, Section B, Table 3 There should be a significantwater 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 Allen 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 g The, requirement for EPA method 1631 E low level mercury analysis stated in Part II, Section B, Table 1, Footnote 5 should be removed The quality control measures necessay 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 5) collected in this environment Contaminated -fiield-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'mtegrity-of`the data Should mercuryanalysis be required, Duke -Energy -advocates the Cold Vapor Mer curry Analytical-Method_245 1-----' - - h Part -I1, 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 I Part II, Section B, Page 6 of 111 1 st paragraph after Footnote 6 mandates a 60 d'ay separation between concurrent sampling events- This is overly restrictive and creates undo complications of establishing a "qualifying event" This restriction could be especially detrimental during periods of drought with infrequent and widely -spaced qualifying rainfall events, and could force passing on a qualifying sampling event simply - because the event fell within this 60 day window This restriction should be revised to reflect a required separation of at least 72 hours to align with`the definition of a "representative storm event" provided in the box above Table 1, page 5 of 11 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" k Part 11, 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, yParagraph 3" 1 Part II, Section B, Table 1, the footnote reference in the table after "Total Rainfall" should be changed from "Y to "6" Please contact Mark.McGary@duke-energy.com or at 704-634-7098 if you have any questions or need any additional information. Sincerely, Mark McGary, P.E. Environmental, Health & Safety Attachment Outfall SW001 10" CM P Current accessibility for sampling/monitoring: Accessible. Sample collection probability: Likely. Other comments: Outfall is in a non -industrial use area and should be omitted. �_—� rrs. ,.`<..�. `�' '1 '� ' L' �.. 5� "�� s +��e 'r..� � •,, � _ rr f,� "�,, f r :. ' � � , T'' ' �. n �� 1 � SFr I� 1 � - �� • � � �� ♦. .' , v ^ .,. � .5 1 `1 � / F•� 4 Outfall SW004 10" Cast Iron Current accessibility for sampling/monitoring: Inaccessible due to steepness of embankment and length of overhang. Sample collection probability: Possible only if a safe means of access is provided. Outfall SWOOS 18" CMP Current accessibility for sampling/monitoring: Inaccessible due to steepness of embankment and thickness of vegetation. Sample collection probability: Possible only if a safe means of access is provided. Outfall SW006 10" Cast Iron Current accessibility for sampling/monitoring: Inaccessible due to steepness of embankment and length of overhang. Sample collection probability: Possible only if a safe means of access is provided. Outfall SW007 18" CMP Current accessibility for sampling/monitoring: Normally accessible, inaccessible during high water levels. Sample collection probability: Likely during normal water levels. Outfall SW009 Concrete Ditch Current accessibility for sampling/monitoring: Accessible if grating is removed. Sample collection probability: Possible, but drainage area is of limited extent. b t •I �/ / .yi Outfall SW011 72" CMP Current accessibility for sampling/monitoring: Accessible. Sample collection probability: Likely. Outfall SW012 36" CMP Current accessibility for sampling/monitoring: Inaccessible due to partially submerged outlet. Sample collection probability: Likely, but must be collected upstream of outlet. Outfall Group SW013 Numerous 10" CMPs Current accessibility for sampling/monitoring: Generally accessible. Sample collection probability: Not feasible. Other comments: Outfalls are in a non -industrial use area and should be omitted. Outfall SW014 36" CMP Current accessibility for sampling/monitoring: Inaccessible due to steepness of embankment and heavy vegetation Sample collection probability: Not feasible. Other comments: Outfall is in a non -industrial use area and should be omitted. Outfall SWO16 36" CMP Current accessibility for sampling/monitoring: Inaccessible due to overhanging outlet. Sample collection probability: Possible only if a safe means of access is provided. Outfall Group SW017 Numerous 12" CMPs Current accessibility for sampling/n-,onitoring: Generally inaccessible. Sample collection probability: Not feasible. Other comments: Outfalls are in a non -industrial use area and should be omitted. Outfall SWO18 48" CMP Current accessibility for sampling/monitoring: Outlet currently inaccessible. Sample collection probability: Possible only if a safe means of access is provided. Not feasible during high water levels Outfall SW019 48" 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. Other comments: Outfall is in a non -industrial use area and should be omitted. Outfall SW020 48" 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. Other comments: Outfall is in a non -industrial use area and should be omitted.