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HomeMy WebLinkAboutNC0004979_Fact Sheet For Permit Development_20050126NCDENR/DWQ FACT SHEET FOR NPDES PERMIT DEVELOPMENT Duke Energy Corporation - Allen Steam Station NC0004979 (1.) Facility Name_ Allen Steam Station ' (7.) Drainage Area (mi2): f ??/635 + (8.) Summer 7Q10 (cfs): 95/124 —� (2.) Permitted Flow (MGD): �j No flow limit (6.) County: Gaston (3-.) Facility Class_— I (7.) Regional Office: ;Mooresville _ (4) Pretreatment Program _ - -( N/A — _..__..__ _(8) USGS Topo Quad: — _G14NE _._._.._.__.—_.—..__._._.... (5.) Permit Status. Renewal (9.) USGS Quad Name: Belmont (1.) Receiving Stream: (2.) Sub -basin: I Catawba / South Fork Catawba Rivers E 03-08-36 ' (7.) Drainage Area (mi2): f ??/635 + (8.) Summer 7Q10 (cfs): 95/124 (3.) Stream Index Number: (9.) Winter 7Q10 (cfs):� ( 95/227 — (4.) Stream Classification: WS -IV B_ (10.) 30Q2 (cfs): J 95/309 (5.) 303(d) Status: Not listed (11.) Average Flow (cfs): 95/806 (6.) 305(b) Status: - ( (12.) IWC %: 24 (Outfall 002) 1.0 Proposed Changes Incorporated Into Permit Renewal • Change WET testing requirement from 16% effluent concentration to 24%. • Remove monitoring requirements for BOD, fecal coliform, and phosphorus. • The quarterly monitoring requirements will be removed for barium, cadmium, chromium, cyanide, naphthalene, nickel, phenols, zinc, and sulfates. None of these pollutants were presents in levels that could reasonably be expected to cause an exceedance of water quality standards. • An arsenic limit of 42 Vg/L will be added to the permit. Two values measured in 2003 were above the allowable concentration of 42 pg/L. • The facility will receive a weekly average selenium limit of 21 Pg/L. • 316(b) special condition will be added. 2.0 Summary Duke Energy's Allen Steam Station is a coal fired steam electric plant in Gaston County. Effluent Guidelines are provided in 40 CFR 423.12. The facility is also subject to the Cooling Water Intake Structure Rule (316(b) Rule) per 40 CFR 125.95. A special condition will be added expressing this requirement. The facility has four permitted outfalls in the current NPDES discharge permit, issued in September 1996. ➢ Outfall 001 is comprised of once through, non -contact condenser cooling water. The average flow through this outfall, is 626 MGD (from permit application). This outfall discharges to the South Fork Catawba River. NPDES Permit Fact Sheet — 09/27/05 Page 2 Duke Power/ Allen Steam Station , NC0004979 ➢ Outfall 002 is the ash basin discharge. In 1996 the average discharge from this outfall was 11.6 MGD, however current discharge rates average 19 MGD. This outfall discharges to the Catawba River. ➢ Outfalls 002A and 002B are intermittent discharges of emergency overflows (coal yard sump overflow and power house sump overflow, respectively). Both outfalls discharge to the Catawba River. ➢ Outfall 003 is miscellaneoup once through non -contact cooling water. This outfall discharges to the South Fork Catawba River and averages 4.5 MGD (from permit application). ➢ Outfall 004 is also miscellaneous once through non -contact cooling water. This outfall discharges to the Catawba River and averages 6.5 MGD (from permit application). w ➢ During the previous renewal, the facility received authorization to backwash an intake filter for Unit 5 condenser cooling water on an as -needed basis. The wash waters contain materials indigenous to the Catawba River such as Asiatic Clams and light debris. There is a special condition in the permit allowing for this discharge. In 1995 the facility completed construction of a Chemical Injection Facility for the ash basin. The purpose of this project was to assist with the settling of selenium and other pollutants that were not being removed from the effluent: This project consisted of the construction of three primary settling cells, a treatment channel, a chemical injection system (ferric sulfate to enhance selenium precipitation) and a final settling/flocculation cell. In the renewal application, Duke Power requested the following changes to their permit. 1. The elimination or reduction of outfall 002 monitoring requirements for the following parameters: barium, BOD, cadmium, chromium, copper, cyanide, fecal coliform, naphthalene, nickel, phenol,! phosphorus, sulfate, and zinc. 2. That the selenium limit be changed from a daily maximum limit to a monthly average limit based on an interpretation of 40 CFR 131.36. The facility also requests a continuation of the thermal limitations present in the permit. The facility has a 316(a) variance for outfall 001 and submits a yearly Balanced and Indigenous Population report in compliance with the variance. Permit modifications issued in 2003 clarify the temperature limit as being a monthly average effluent limitation, as opposed to a daily maximum limitation. As part of the permit application, Duke Power submitted EPA Forms 1, 2C, and 2F. Form 2F was filled out for two stormwater outfalls: 008 and 015. 3.0 Compliance Summary Instream Data The facility submitted the most recent Assessment of Balanced and Indigenous Populations In Lake Wylie Near Allen Steam Station report, developed in November 2004. This annual monitoring requirement began in 1990 as the result of an agreement between the Division and Duke Power to support the facility's 316(a) thermal variance. This study appears to concur with • NPDES Permit Fact Sheet — 09/27/05 Duke Power/ Allen Steam Station f Page 3 NC0004979 past studies in that Lake Wylie has a balanced indigenous fish community. No other instream monitoring is required as part of the NPDES permit. DMR Data Review DMRs were reviewed for outfalls 001, 002, 002A, 002B, 003 and 004 for the period of January 2002 through July 2005. At 001, the average flow over the review period was 581 MGD with a maximum flow of 784 MGD. The average daily temperature at this outfall was 82 T with a maximum daily temperature of 111 T. The discharge remained in compliance with its effluent limitations. Outfalls 002A and 002B have not discharged during the last permit cycle. Only flow is required to be estimated at outfall 003. The average flow estimate during the review period was 4.5 MGD. Only flow and oil and grease are required to be monitored at 004. Flow estimates during the review period averaged 6.5 MGD. O&G values averaged <5.0 mg/L with a maximum of 5.0 mg/L. The following table summarizes DMR data for non -toxicants at outfall 002. RPAs were performed for toxicants and metals (results discussed in the following section). Avera a , c 4 .. r .Maximum ...1kliruiriuin t: Flow (MGD) 18.92 34.1 0.7 BOD (m /L) <2.0 2.0 <2.0 H (s.u.) 6.8 9.3 6.1 Fecal coliform (#/100mL) <2.0 22 <2.0 TSS (m /L) 10 28 <4.0 Oil and Grease (m /L) <5 5 <5 Total Nitrogen (m /L) 0.52 0.99 0.26 Total Phosphor—us (m /L) <0.010 1 0.02 <0.010 The only violation for the above monitored parameters was for pH. In July, 2003 the facility recorded a pH value of 9.3, which exceeds its permit limit of 9.0 s.u.. Based on the above data, the facility requests removal of the monitoring requirements for BOD, fecal coliform, and phosphorus. All of those parameters had quarterly or semi-annual monitoring in the previous permit. Based on the data, it appears that effluent levels of these parameters are not sufficient to cause an adverse impact to water quality. Monitoring will be removed. RPA Analysis RPAs were performed for arsenic, barium, cadmium, chromium, copper, cyanide, iron, naphthalene, nickel, phenols, selenium, zinc, and sulfates. Since the facility does not have a permitted flow, past RPAs were conducted using the monthly average flow instead of permitted flow. That methodology was retained in this renewal. In 1996 the average flow was 11.6 MGD. Current average flows at outfall 002 are 19 MGD. NPDES Permit Fact Sheet — 09/27/05 Page 4 Duke Power/ Allen Steam Station NC0004979 The quarterly monitoring requirements will be removed for barium, cadmium, chromium, cyanide, naphthalene, nickel, phenols; zinc, and sulfates. None of these pollutants were present in levels that could reasonably be expected to cause an exceedance of water quality standards. Iron monitoring will remain in the permit due to the requirements of 40 CFR423.12. The permit limit is higher than the 1.0 mg/L recommended by 40CFR due to a past agreement between Duke Power and the Division to adjust the limit based on high levels of iron in the source water. An arsenic limit of 42 pg/L will be added to the permit. Two values measured in 2003 were above the allowable concentration of 42 Vg/L. The previous permit had a selenium limit of 31 pg/L. The facility violated this limit in July, 2003. Based on the change in IWC during this renewal, the new permit will have a selenium limit of 21 pg/L. The facility has requested that this limit be expressed as a monthly average based on EPA guidance. Duke argues that the current limit is based on a CCC for selenium of 5 ug/L and EPA directs for CCCs to be expressed as a monthly average limit. NC also has a selenium aquatic life criterion of 5.0 pg/L. According to Division policy, this criterion can be expressed as a weekly average limit. Therefore the facility shall receive a weekly average selenium limit of 21 pg/L during this renewal. 40 CFR 423.12 requires a copper limit of 1.0 mg/L. Therefore the copper limit will be retained in this renewal. e WET Test Results The IWC used for WET testing was 16% in previous permits. That value was based on an average discharge of 11.6 MGD. Currently, the discharge at outfall 002 averages 19 MGD. Therefore the WET testing requirement will be changed to reflect the 24% IWC. The Allen Steam Plant passed 21/23 chronic WET tests administered from January 2001 through July 2005. There were two total failures: one in October 2001 and another in October 2003. The facility passed two consecutive tests administered following each failure. Correspondence File History There were two daily maximum permit violations over the 2002-2005 data review period. One was for pH (reported value of 9.3 s.u.) and the other was for selenium (reported value of 40.4 pg/L). Both violations occurred during the same month (July 2003). Inspection and staff reports note that the facility is consistently well operated and maintained. 4.0 Schedule for Draft Permit to Public Notice: Permit Scheduled to Issue: If you have any questions on any of contact Toya Fields at (919) 733-508: 9/28/05 12/1/05 ie above information or on the attached permit, please extension 551. Copies of the following are attachedI to provide further information on the permit development: • Draft permit NP.DES Permit Fact Sheet — 09/27/05 Page 5 NPDES Recommendation by: Signature Date Duke Power/ Allen Steam Station NC0004979 Regional Office Comments: %�ISCG� `oG.9�la�'f• 5®uT�f �r2iL cri-� i� Gdr��l i boo Re ional Reco mendation by: Signature Date Reviewed and accepted by: Regional Supervisor: Signature ` ), / 0 C: / Date NPDES Unit Supervisor: Signature Date Whole Effluent Toxicity Testing Self -Monitoring Summary 2001 — Pass September 15, 2005 FACILITY REQUIREMENT YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP NOV DEC Duke Power -Allen 002 chr lim: 16% 2001 Pass ' — — Pass — — Pass — — Fail 164 >64' NC0004979/002 Begin:7/1/2002 Frequency:Q Jan Apr Jul Oct r + NonComp:Single 2002 >92 — — >64 — — Pass — — — — Counly: Gaston Region: MRO Subbasin: CTB34 2003 Pass — — Pass — — Pass — — Fait 452 >64 - PF: 11.6Special 2004 PAss — — Pass — — Pass — — s — 7Q10: 95.0 IWC(%) 16 Order: 2005 Pass — — Pass — -- Pass Pass Duke Power-Belew�9F- chr lin: 19% 2001 — Pass — — Pass — — Pass — — Pass — NC0024406/003 Begin:6/1/2002 Frequency Q Feb May Aug Nov + NonComp:Single 2002 — Pass — — Pass — -- >76 — — Pass — County: Stokes Region: WSRO Subbasin: ROA01 2003 — Pass — — Pass — — Pass — — Pass — PF: NA special' 2004 — Pass — — Pass — — Pass - — — Pass — ' 7QI0: 80.0 IWC(%) NA Order: 2005 — Pass — — Pass — — Duke Power -Buck Steam chr lim: 0.7% 2001 — — Pass — — Pass — — •. Pass — — Pass NC0004774/002 Begin: 10/1/2004 Frequency: Q Mar Jun Sep Dec + NonComp:Single 2002 — — >2.6 — — Pass — — Pass — — Pass County: Rowan Region: MRO Subbasin: YAD04 2003 -- — Pass — — Pass — -- Pan — — Pass PF: NA Special 2004 — — Pass — — Pass — — Pass — — Pass 7Q10: 1030 IWC(%) 0.598 Order: 2005 — — Pass — -- Pass — Duke Power-Cliffside chr lim: 7.14% 2001 -- — Pass — —. Pan — — Pass -- — Pass NC0005088/002 Begin:1/1/2005 Frequency: Q Mar Jun Sep Dec + NonComp:Single 2002 — — Pass — — >22.4 — — Pass — — - Pass County. Rutherford Region: ARO Subbasin:BRD02 2003 — — Pass -- — Pass — — Pass —, — Pass PF: Special 2004 — — Pass — — Pass — — - - Pass — — Pass 7Q10: 287 IWC(%) Order: 2005 — — Pass — — Pass — Duke Power -Dan River chr lim: 1.04% 2001 — — Pass — — Pass — — Pass •- — Pass NC0003468/002 Begin:9/1/2002 Frequency:Q Mar Jun Sep.Dec + NonComp:Single 2002 — — Pass — — Pass — — Pass — — Pass County: Rockingham Region: WSRO Subbasin: ROA03 - 2003 — — Pass — — Pass — — Pass — — Pass PF: 1.8 special 2004 — — Pass — — Pass — — Pass — — Pass 7Q10: 314.0 IWC(%) 1.04 Order: 2005 — — Pass — — Pass — Duke Power -Lincoln Turbine chr lim: 23% 2001 — — >92 — - -- >92 — _ _ >92. — — _ J Late NCO080781/001 Begin:7/1/2005 Frequency:lx/Q Jan Apr Jul Oct + NonComp:Single 2002 >92 — >92 — — >92 — 65 — Pan — — County. Lincoln Region: MRO Subbasin: CTB33 2003 — Pass — — Pass — Pass — — — — Pass PF: 0.4 Special 2004 >92 — — — >92 — — — >92 — — >92 7Q 10: 2.1 IWC(%)23 Ord.: 2005 — >92 — — — H — Duke Power -Marshall 002 chr lim: 12% 2001 — Pass — — Pass — — Pass — - Pass — NC0004987/002 Begin:6/1/2005 Frequency.Q Feb May Aug Nov + NonComp:Single 2002 — Pass — — Pass — — Pass — — Pass — County: Catawba Region: MRO Subbasin: CTB32 2003 — Pass — — Pass — — Pass — — Pass — PF: 5.3 Special 2004 — Pass —_ — Pass — — Pass — — Pass — 7Q10: 60.0 IWC(%) 12.0 Order: 2005 — Pass — — Pass — — Duke Power -McGuire 001 24hr p/f ac lim: 90% 2001 — Pass — — Pass — — Pass — — Pass — NC0024392/001 Begin: 10/1/2000 Frequency:Q + Feb May Aug Nov + NonComp:Single 2002 — Pass — — Pass •- — >100,Pass —. — Pass — County: Mecklenburg Region: MRO Subbasin: CTB32 2003 — Pass — — >100 Pass — Pass — — Pass — PF: NA Special 2004 — Pass — — Pass — — Pass — — Pass — 7Q10:80 .IWC(%)90 Order: 2005 — Pass — — Pass — — Duke Power -McGuire 002 48hr LC50 ac lim: 64% 2001 —. >100 — — >100 — — >100 — — >100 — NC0024392/002 Begin:10/1/2000 Frequency:Q + Feb May Aug Nov + NonComp:Single 2002 — >100 — — >100 — -- >100 — -- >100 — County: Mecklenburg Region: MRO Subbasin: CTB33 2003 — >100 — — Pass >100 — >100 — — >100 — PF: 0.3315 special 2004 — >100 — — >100 — — >100 — — >100 — ' 7Q10: 80.0 IWC(%) 0.64 Order: 2005 — >100 — — >100 — — Duke Power -McGuire 005 chr lim: 1.4% 2001 Pass — — Pass — — Late Pass — Pass — — NC0024392/005 Begin: 10/1/2000 Frequency: Q Jan Apr Jul Oct + NonComp:Single 2002 Pass — — ' Pass — — Pass — — Pass — — County. Mecklenburg Region: MRO Subbasin: CTB33 2003 Pass -- — Pass — — Pass — • — Pass — — PF: 0.754 Special 2004 Pass — — Pass — — Pass — — Pass — — 7QI0: 80.0 IWC(%) 1.4 Order: 2005 Pass — — Pass — — Pass / Duke Power -River Bend 002 chr lim: 10% 4: 2001 Pass •- — Pass — — Late Pass — Pass — — NC0004961/002 Begin:3/112005 Frequency:Q Jan Apr Jul Oct + NonComp:Single 2002 Late Pass — Pass — — >40 — — Pass — — County: Gaston Region: MRO Subbasin: CTB33 2003 Pass — — Pass — — Pas. — — Pass — — PF: NA Special 2004 Pass — — Pass — — Pass — — Pass — — 7Q10: 80.0 IWC(%) 10.36 Order: 2005 Pass — -- Pass — — Pass ¥ Pre 2001 Data Available LEGEND: PERM = Permit Requirement LET= Administrative Letter -Target Frequency - Monitoring frequency: Q- Quarterly; M. Monthly; BM- Bimonthly; SA- Semiannually; A- Annually; OWD- Only when discharging; D- Discontinued monitoring requirement Begin= First month required 7Q10 -Receiving stream low Bow criterion (efs) += quarterly monitoring increases to monthly upon failure or NR Months that testing must occur- ex. Jan, Apr, Jul, Oct NonComp = Current Compliance Requirement PF = Permitted Bow (MGD) IWC% = Instream waste concentration P/F= Pam/Fail test AC - Acute CHR = Chronic Data Notation: f - Fathead Minnow; • - Ceriodaphnia sp.; my - Mysid shrimp; ChV - Chronic value; P - Mortality of stated percentage at highest concentration; at - Performed by DWQ Aquatic Tox Unit; bt - Bad test Reporting Notation: —= Data not required; NR - Not reported Facility Activity Status: 1- Inactive, N -Newly Issued(To construct); H - Active but not discharging; t -More data available for month in question; = ORC signature needed 16 -L REASONABLE POTENTIAL ANALYSIS Allen Steam Station NC0004979 Time Period 2002-2005 Qw (MGD) 18.9 7Q10S (cls) 95 7Q10W (cls) 95 3002 (cls) 95 Avg. Stream Flow, QA (cls) 95 Rec'ving Stream Catawba River WWTP Class 1 IWC (%) @ 7Q10S 23.569 ® 7010W 23.569 C4130Q2 23.569 ® QA 23.569 Stream Class WS -IV B Outfall 2 Qw =18.9 MGD 'Legend., —Freshwater Discharge C = Carcinogenic NC = Non -carcinogenic A = Aesthetic 4979_rpa.xls, rpa 9/27/2005 STANDARDS & PARAMETER TYPE CRITERIA (2) POL Units REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION NC WOS/ lS FAV/ n IDA Ma Pred Cw Allowable Cw (1) Chrank Aeule Acute: WA Arsenic NC 10 ug/L 42 42 203.5 _h Cronic: 42 Two values above the allowable in2003 �r Max ptedicied ».allowable Add Ilmit r, ,,�, 'mac; `;• - Acute: WA Barium NC 1000.0 OIL 9 9 691.2 Note: n<12 Chronic: 4,243 Max predicted allow Limited data set Removemon(tonng Acute: 15 Cadmium NC 2 15 uglL 13 8 3.3 --------------- _______Chronic: 8 Chronic: Max rd td «'all owable '� `' V } Remove monIt) ng'<c�' <4, a,xr „.•r .x,,+ Acute: 1,022 Chromium NC 50 1,022 ug/L 14 1 61.62" <ts Chronic: 212 Max predicted«allowable Remove Acute: 7 Copper NC 7 AL '7.3 ug/L 79 76 117.9 ------ Chronic: _Chronic: 30 max predictetl» allowable Action level parameter � ` bmtrequired�by 40 CFR 42312 Acute: 22 Cyanide NC 5 N 22 70 ug/L 12 3 5.0 ------ _Chronic: Chronic: 21 maxpredictetl«allowable"'� y 1}4 Remove mmiitonn9 cI,"-:�� , �... ,;y `n:y%• " Acute: WA ' Mgc Iron NC 1 AL mga 52 52 2.4 Chronic: 4 Max predicted c allowable Y Acute: WA Napthalene NC 570 ugfL 19 1 13.9 Chronic: 2,418 Max predicted «allowable ,� `- Removemonitortng,� Acute: N/A Nickel NC 25 - ug/L 12 12 47.9183 Chronic: 106 Max predictetl c< allowatiley } k . '� a.� Remove riianilonng�';a��R�� t a., z.:�. r •+.�•z,.*" >=;x=3� Acute: NIA 'A Phenols A 1 N ug/L 19 0 5.0 - Chronic: 4 No detections.f ` �' ' Remove m nitonng� ���;>-,. `' �,x �� �, m, ` ;�s ��•.' Acute: 56��a Selenium NC 5 56 ug/L 80 80 58.6 Chronic: 21 Severl values above the allowabI6 in:2003 I�`-',j'�, - Retain Acute: 67 Zine NC 50 AL 67 ug/L 13 13 79.1 ' x' x + c u ,✓k_ ., _ _ __ _ _ Chronic: 212 Max rpedleted«allowable �, p - K :> Remove monitoring• „ .r „..x:,fa • „ v a Acute: WA i y sx' . ,x " " ,:. ,• Sulfates NC 250.0 mg/L 13 13 96.4 t } Chronic: 1,061 Max predicted «allowable Remove `� ` a �::�° monitonng� -x, e Exp o, oq_.t Acute: WA 0 0 WA fir• ,'� Y,. .. aal.cUu . ^ a t _ _ _ _ _ Chronic: ?mor ® Type', Acute: WA S w Chronic::rror -®,Type„� ,<. r - u -�•` c 'Legend., —Freshwater Discharge C = Carcinogenic NC = Non -carcinogenic A = Aesthetic 4979_rpa.xls, rpa 9/27/2005 WAT/c Michael F. Easley, Governor O� y QG State of North Carolina 0, William G. Ross, Jr., Secretary c Department of Environment and Natural Resources OAlan W. Klimek, P.E., Director Division of Water Quality September 28, 2005 MEMORANDUM To: Britt Setzer NC DENR / DEH / Regional Engineer Mooresville Regional Office From: Toya Fields Western NPDES Program Subject: Review of NPDES Permit NC0004979 Allen Steam Station RECD[ NEN HGOTesville Office NCL)ENR Public water Supply Please indicate below your agency's position or viewpoint on the proposed permit modification and return this form as soon as possible. If you have any questions on the proposed modification, please contact me at the telephone number or e-mail address listed at the bottom of this page. I RESPONSE: (Check one) Concur with the issuance of this permit provided the facility is operated and maintained properly, the stated effluent limits are met prior to discharge, and the discharge does not contravene the designated water quality standards. F-1 Concurs with issuance of the above permit, provided the following conditions are met: 1-1 Opposes the issuance of the above permit, based on reasons stated below, or attached: VL !'E OCT 3 2005 North Carolina Division of Water Quality toya.fields(a)ncmail.net - (919) 733-5083 x551 1617 Mail Service Center ". , , . FAX (919) 733-0719 Raleigh, North Carolina 27699-1617 On the Internet at http://h2o.enr.state.nc.us/ 10 REASONABLE POTENTIAL ANALYSIS Allen Steam Station NC0004979 Time Period 2002-2005 Qw (MGD) 18.9 7Q1OS (Cfs) 95 7Q10W (cfs) 95 3002 (cfs) 95 Avg. Stream Flow, QA (cfs) 95 Rec'ving Stream Catawba River WWTP Class I IWC(%) ®7Q10S 23.569 ® 7Q 10W 23.569 @ 3002 23.569 ® QA 23.569 Stream Class WS -IV B Outfall 2 Qw = 18.9 MGD Legend: "Freshwater Discharge C = Carcinogenic NC = Non -carcinogenic A = Aesthetic 4979_rpa.xls, rpa 9/27/2005 STANDARDS & PARAMETER TYPE CRITERIA (2) POL Units REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION Nc Wos/ %FAV/ n ADeG Mac Fred Cw Allowable Cw (1) chronic Acute Acute: WA Arsenic NC 10 ug/L 42 42 203.5 Chronic: 42 Two values above theallowable in 2003. Max predicted» allowable. Add limit Acute: WA Barium NC 1000.0 ug/L 9 9 691.2 Note: n<12 .............................................. Chronic: 4,243 Max predicted -«.allowable Limited data set I Remove monitoring Acute: 15 Cadmium NC 2 15 ug/L 13 8 3.3 _ _ _ _ _ _____________ __ _ _ Chronic: 8 Max predi(TtW «allowable. Remove monitoring Acute: 1,022 Chromium NC 50 1,022 ug/L 14 1 61.6 Chronic: 212 Max predicted << allowable Remove monitoring Acute: 7 Copper NC 7 AL 7.3 ug/L 79 76 117.9 ............... _________________ Chronic: 30 max predicted :» allowable. Action level parameter limit required by 40 CFR 423.12 - Acute: 22 Cyanide NC 5 N 22 10 ug/L 12 3 5.0 ------------ --------'---------^—'--'—'---'-- Chronic: 21 max predicted «allowable. Remove monitoring Acute: WA Iron NC 1 AL mg/l 52 52 2.4 ---------------------------------------------- _____________________________Chronic: Chronic: 4 Max predicted < allowable limit required by 40 CFR 423.12 Acute: WA Napthalene NC 570 ug/L 19 1 13.9 Chronic: 2,418 Max predicted << allowable Remove. monitoring - Acute: WA Nickel NC 25 ug/L 12 12 47.9183 Chronic: 106 Maxpredicted << allowable Remove monitoring Acute: WA Phenols A 1 N ug/L 19 0 5.0 _ _ _ __________________ _ _______ Chronic: 4 _ _____ No detections. Remove monitoring Acute: 56 Selenium NC 5 56 ug/L 80 80 58.6 ---------------------------------------------- ___________________________Chronic: Chronic: 21 Several values above the allowable. in 2003 Retain limit Acute: 67 Zinc NC 50 AL 67 ug/L 13 13 79.1 ---------------------------------------------- _________________Chronic: Chronic:212 Max rpedicted << allowable Remove monitoring Acute: WA Sulfates NC 250.0 mg/L 13 13 96.4 Chronic: 1,061 Max predicted << allowable Remove monitoring Acute: WA 0 0 WA Chronic: _rror @ Type Acute: WA 0 0 WA Chronic: -nor ® Type ----------�-------------------- Legend: "Freshwater Discharge C = Carcinogenic NC = Non -carcinogenic A = Aesthetic 4979_rpa.xls, rpa 9/27/2005 OT 1Q,4t, micnael I-. tasiey, Governor O� QG SEP 3 6 2005 State of North Carolina F William G. Ross, Jr., Secretary Co F Department of Environment and Natural Resources p„ IT, Alan W. Klimek, P.E., Director Division of Water Quality September 28, 2005 MEMORANDUM To: Britt Setter NC DENR / DEH / Regional Engineer Mooresville Regional Office From: Toya Fields Western NPDES Program Subject: Review of NPDES Permit NC0004979 Allen Steam Station `fR,•, E'LvEN SEP to, 9 20 Please indicate below your agency's position or viewpoint on the proposed permit modification and return this form as soon as possible. If you have any questions on the proposed modification, please contact me at the telephone number or e-mail address listed at the bottom of this page. I RESPONSE: (Check one) 1% Concur with the issuance of this permit provided the facility is operated and maintained properly, the stated effluent limits are met prior to discharge, and the discharge does not contravene the designated water quality standards. Concurs with issuance of the above permit, provided the following conditions are met: F-1 ❑ Opposes the issuance of the above permit, based on reasons stated below, or attached: S_ North Carolina Division of Water Quality toya.fields(Tbncmail.net - (919) 733-5083 x551 1617 Mail Service Center FAX (919) 733-0719 Raleigh, North Carolina 27699-1617 On the Internet at http://h2o.enr.state.nc.us/ To: Permits and Engineering Unit Water Quality Section Attention: Carolyn Bryant SOC PRIORITY PROJECT: No Date: January 26, 2005 NPDES STAFF REPORT AND RECOMMENDATIONS County: Gaston NPDES Permit No.: NC0004979 MRO No.: 04-135 PART I - GENERAL INFORMATION 1. Facility and address: Allen Steam Station c/o Duke Power Company 13339 Hagers Ferry Road Huntersville, N.C. 28078 2. Date of investigation: January 12, 2005 3. Report prepared by: Samar Bou-Ghazale, Environmental Engineer I 4. Person contacted and telephone number: Robert Wylie, (704) 382-4669. 5. Directions to site: From the jct. of Hwy. 7 and SR 2525 (South Point Rd.) in the Town of Belmont, travel south on SR 2525 z 2.5 miles. The entrance to the Allen Steam Plant is on the left (east) side of SR 2525. 6. Discharge point(s), List for all discharge points: - outfall 001 out&U 002 outfall002A outfall 002B Latitude: 35° 11' 23" 350 10' 30" 350 11'17" 350 11' 15" Longitude: 81* 00' 45" 81* 00' 23" 81' 00' 46" 81' 00' 22" outfall 003 outfall 004 outfall 005 Latitude: 35' 11' 24" 35' 11'15" 350 11' 24" Longitude: 81' 00' 46" 81' 00' 22" 810 00' 45" Attach a USGS Map Extract and indicate treatment plant site and discharge point on map. USGS Quad No.: G 14 NE USGS Name: Belmont, NC 7. Site size and expansion area consistent with application: Yes. There is additional area available for expansion, if necessary. a � �� r� z � � .. � t Page Two 8. Topography (relationship to flood plain included): The site was graded considerably when built, which removed existing contours. The steam plant is constructed above the high water elevation of Lake Wylie (the receiving stream). The surrounding area has gently rolling topography (slopes <1094,D). 9. Location of nearest dwelling: Approx. 1000+ feet from the steam plant site. 10. Receiving stream or affected surface waters: Catawba River (Lake Wylie) -outfalls 002, 002A, 002B, 004 & 005. South Fork Catawba River (Lake Wylie) -outfalls 001 & 003. a. Classification: Catawba River, WS -IV & B; South Fork Catawba River, WS -V. b. River Basin and Subbasin No.: Catawba 030834 C. Describe receiving stream features and pertinent downstream uses: Outfalls 002, 002A, 002B, 004 & 005 enter the main segment of the Catawba River (Lake Wylie), which is used for primary and secondary recreation and as a receiving stream for point source (NPDES) discharges both upstream and downstream of the steam plant. There are no known municipal water intakes located above or below these outfalls. Outfalls 001 & 003 enter a manmade discharge canal located west of the steam plant. This canal travels for a distance of z 1.2 miles where it enters the South Fork Catawba River (an arm of Lake Wylie). This area is also used for primary and secondary recreation and there are no known water intakes from the point of discharge to the mouth of the South Fork of the Catawba River. PART H - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS Outfall 001 002 002A 002B 003 004 005 1. a. Volume of wastewater (MGD): 626.3 20.7 N/A N/A 4.5 6.5 0.003 b. What is the current permitted capacity: No flow limit for any outfall in Permit. c. Actual treatment capacity of current facility (current design capacity): N/A d. Date(s) and construction activities allowed by previous ATCs issued in the previous two years: An Authorization to Construct for the construction of a physical chemical treatment system was issued on June 21, 2004 for the following: 1. Three primary settling cells 2. A Treatment channel 3. A Chemical injection system, and 4. A Final settling/flocculation cell The purpose of this system is to provide chemical injection for treatment of dissolved pollutants that will not settle out of the waste stream through purely Page Three Physical means. The system will treat 18-24 MGD sluice water to reduce the TSS and Selenium to below permit limits. The three primary settling cells will be used to settle the solids (only one operating at a time, while the inactive cells are being cleaned). e. Description of existing or substantially constructed VMT facilities: Outfall 001- Waste stream consists of non -contact cooling water from a system that removes heat from the condensers and other heat exchangers. Each of the 5 units at Plant Allen has two condenser cooling pumps. Outfall 002 - Ash Basin. Waste stream consist of chemicals from boiler cleaning procedure and sanitary waste from a septic tank (serving approximately 150 employee). pH adjustment (carbon dioxide, sulfuric acid, and sodium hydroxide) is available at the effluent, if needed. Other sources for wastewater entering the ash basin and discharging at outfall 002 include stormwater runoff from the coal pile area, ash sluice recirculating water system, turbine non-destructive testing, heat exchanger cleaning, condensate polishers, condensate leakage testing, yard drain sump, water treatment system, preheater washes, laboratory wastes, the power house sump (unit 5), and physical chemical treatment system (see d above). Future sources include the waste stream from a selective non -catalytic reduction system (to reduce NO emissions by approximately 30%) and a flue gas desulfurization (FGD) system (for the reduction of SO2 from the stack gas). Outfall 002A - Coal yard sump overflow. An overflow pipe directs flow directly to the Catawba River in the event that all pumps in the coal yard sump failed or redundant power supply could not be activated in a timely manner Outfall 002B - Power house sump overflow. An overflow pipe directs flow directly to the Catawba River in the event that all pumps in the yard sump failed or redundant power supply could not be activated in a timely manner. Outfall 003 - Miscellaneous equipment cooling and seal water. Discharge is to the CCW discharge canal. Outfall 004 - Equipment cooling and intake screen backwash. Outfall 005 - Asiatic clam/debris filter backwash. f. Description of proposed WWT facilities: See part II, d above. g. Possible toxic impacts to surface waters: This facility has consistently passed toxicity tests required at outfall 002. Various chemicals are used during the cleaning and maintenance of equipment (see list provided with the application package). Page Four h. Pretreatment Program (POTWs only): Not Needed. 2. Residual handling and utilization/disposal scheme: Septage from the septic tank is removed as needed by Stanley Septic Tank Services (permit# SDF-36-04). With the exception of fly ash, no other residuals generation is expected. Duke Power Company has a non -discharge Permit (WQ0003255) for the disposal of fly ash. 3. Treatment plant classification: Class I for outfall 002. Outfalls 001, 003 and 004 do not meet the minimum criteria for a class I rating. 4. SIC Code(s): 4911 Wastewater Code(s): 68, 66 MTU Code(s): 50002 PART III - OTHER PERTINENT INFORMATION 1. Is this facility being constructed with Construction Grant Funds or are any public monies involved (municipals only)? No 2. Special monitoring or limitations (including toxicity) requests: a. Permittee has requested that monitoring be either eliminated or reduced for the following parameters at outfall 002: Barium, BOD, Cadmium, Chromium, Copper, Cyanide, Fecal Coliform, Naphthalene, Nickel, Phenol, Phosphorus, Sulfate and Zinc. MRO staff can support a reduction in the monitoring frequency, however, eliminating all monitoring may not be prudent. Defer to the NPDES Unit for review and comment. b. Permittee has requested continuation of the thermal limitations that are presently in the NPDES permit. (An assessment report of balanced and indigenous populations in Lake Wylie has been submitted by Duke Power with the permit renewal). According to the submitted report, the results of data analyses for fish populations and macroinvertebrates support continuation of the existing permitted thermal limits C. Permittee requests that the current selenium limit be changed from a daily maximum limit to a monthly average limit for the following reason: 40 CFR 131.36 list the Criterion Maximum Cocentration (CMC) and the Criterion Continuous Concentration (CCC) for selenium at 20 ug/I and 5ugl1, respectively. Since the current selenium limit of 31 ug/1 is based on the CCC value of 5 ug/l, the limit should be expressed as a monthly average value. The Environmental Protection Agency's " Ambient Water Quality Criteria for Selenium -1987" document page 34 and 40 CFR 131.36 also supports this request. Defer to the NPDES Unit for review and comment. 3. Important SOC/JOC or Compliance Schedule dates: N/A 4. Alternative Analysis Evaluation: There are no practicable alternatives for the elimination of any of the existing waste streams. Page Five PART IV - EVALUATION AND RECOMMENDATIONS The permittee is requesting renewal of the subject permit. Changes requested by Duke for this renewal are discussed in Part III, No. 2 (a, b, c) above. Review and approval of these monitoring changes will be necessary by the NPDES Unit. According to Mr. Wylie, The construction of the physical chemical treatment system will be completed by the end of February 2005. Pending review and approval of the WLA and review and approval by P & E, it is recommended that the Permit be renewed as requested. Signature of Report a arer Date Water Quality Regi Supervisor ` �— Date io jr"