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HomeMy WebLinkAboutNC0004979_Engineer's Certification_20050817Raleigh, NC 27699-1617 . RE: Engineer's Certification Allen Ash Pond — NPDES No. NC0004979 Allen Steam Station Belmont, North Carolina Shield Project No. 1030040-02 As of the date of this letter, Duke Power has substantially completed construction on the Chemical Injection Facility (CIF) for the Allen Ash Basin. As outlined in the Authorization to Construct*(ATC) Number 004979AO1 the work consists of: • Construction of three primary settling cells • Construction of treatment channel . • Construction of chemical injection system • Construction of final settling/flocculation cell At this time the project has been completed in such a manner as to allow operation of the CIF as intended. Construction on several features of the ash pond continues. Specifically, two of the three planned primary settling cells have been completed. This arrangement will allow several years of ash settling capacity while the third cell is . coinpleted. Also the main pond area will be used for final settling/flocculation until construction is completed on the final settling/flocculation cell. The ongoing activities do not prevent the CIF from operating as designed. Attached is the Engineer's Certification for the construction of the Chemical Injection Facility located at the above site. Construction of this facility was in general accordance with the plans and specifications and the Authorization to Construct issued Tune 21, 2004. Sincerely SHIE D ENGINE RING, INC. _ o ert L. i zin Keith A. An on Director of Wastewater Services Principal En me 5 � _ 1I260 Attachment=�G1F1�°c ,�''O HAProjects\2003\1030040-02 Duke - Allen\Engineer's Certification. doc , � i„ie1f4041 5 4301 Taggart Creek Road Charlotte, NC 28208 www.shieldengineering.com n Telephone 704.394.6913 Fax 704.394.6968 Allen Steam Station • Permit No. NCO004979 Page 4 Engineer's Certification I, I<Ei rA A , A w'TW s,rj Y , as a duly registered Professional Engineer in the State of North Carolina, having been authorized to observe (periodically, weekly, full time) the construction of the project, A L L F- i✓ s- -/-&A m 5 —,A 7-i 0 �✓, A Eb m a N 7- 1✓C for the Project Name Location Permittee hereby states that, to the best of my abilities, due care and diligence was.used in the following: • Construction of three primary settling cells • Construction of treatment channel • Construction of chemical injection system • Construction of final settling/flocculation cell Once. construction under this ATC has been completed and an Engineer's:Certificate has been submitted, the permittee is authorized to operate the units listed above, with permitted limits as specified in the NPDES permit issued May 17, 2002. The Division of Water Quality approves this project in terms of compliance with NPDES limits; we defer to Duke Energy and their consultants for approval of distribution system, adequate mechanical design, structural integrity, etc. of the.entire physical chemical treatment system. 1 Signature Registration No. 1 Z 60 Date " I % - 00 Mail this Certification to the NPDES Unit D4�4F�ssto�{9y ENR/DWQ 1617 Mail Service Center 11260 i Raleigh, NC 27699-1617 ' r �a�t .,.'Q• A..�•``,. 4 , June 21, 2004 Mr. Michael A. Ruhe, Manager Environmental Support Duke Power 526 South Church Street Charlotte, NC 28202-1802 Michael F. Easley, Governor State of North Carolina William G. Ross, Jr., Secretary Department of Environment and Natural Resources Alan W. Klimek, P.E., Director Division of Water Quality Subject: Authorization to Construct Permit Issuance ATC Number 004979A01 Allen Steam Station NPDES Permit NC0004979 Gaston County Dear Mr. Ruhe: A request for an Authorization to Construct (ATC) was received by the Division and final plans and specifications for this project have been reviewed and found to be satisfactory. Authorization is hereby granted for construction of a physical chemical treatment system at Allen Steam Station. Specifically, this ATC allows: • Construction of three primary settling cells • Construction of treatment channel • Construction of chemical injection system • Construction of final settling/flocculation cell Once construction under this ATC has been completed and an Engineer's Certificate has been submitted, the permittee is authorized to operate the units listed above, with permitted limits as specified in the NPDES permit issued May 17, 2002. The Division of Water Quality approves this project in terms of compliance with NPDES limits; we defer to Duke Energy and their consultants for approval of distribution system, adequate mechanical design, structural integrity, etc. of the entire physical chemical treatment system. This Authorization to Construct is issued in accordance with NPDES Permit No. NC0004979 issued May 17, 2002, and shall be subject to revocation unless the treatment system is constructed in accordance with the conditions and limitations specified in the permit. The sludge generated from these treatment facilities must be disposed of in accordancewith G.S. 143-215.1 and in a manner approved by the North Carolina Division of Water Quality. In the event that the facilities fail to perform satisfactorily, including the creation of nuisance conditions, the Permittee shall take immediate corrective action, including those as may be required by this Division, such as the construction of additional or replacement wastewater treatment or disposal facilities. The Mooresville Regional Office, telephone number (704) 663 - 1699, shall be notified at YVOLUI Yuamy (919) 733 7015 1617 Mail Service Center Allen Steam Station Permit No. NC0004979 Page 2 least forty-eight (48) hours in advance of operation of the installed facilities so that an in-place inspection can be made. Such notification to the regional supervisor shall be made during the normal office hours from 8:00 a.m. until 5:00 p.m. on Monday through Friday, excluding State Holidays. Upon classification of the facility by the Certification Commission, the Permittee shall employ a certified water pollution control treatment system operator to be in responsible charge (ORC) of the water pollution control treatment system. The operator must hold a certificate of the type and grade at least equivalent to or greater than the classification assigned to the water pollution control treatment system by the Certification Commission. The Permittee must also employ a certified back-up operator of the appropriate type and grade to comply with the conditions of Title 15A, Chapter 8G, .0202. The ORC of the facility must visit each Class I facility at least weekly and each Class II, III, and IV facility at least daily, excluding weekends and holidays, and must properly manage and document daily operation and maintenance of the facility and must comply with all other conditions outlined in Title 15A, Chapter 8G, .0204. Once the facility is classified, the Permittee must submit a letter to the Certification Commission which designates the operator in responsible charge within: (A) Sixty calendar days prior to wastewater being introduced into a new system or (B) within 120 calendar days of the following, (i) after receiving notification of a change in the classification of the system requiring the designation of a new ORC and back-up ORC or (ii) a vacancy in the position of ORC or back-up ORC. A copy of the approved plans and specifications shall be maintained on file by the Permittee for the life of the facility. The Operational Agreement between the Permittee and the Environmental Management Commission is incorporated herein by reference and is a condition of this Permit. Noncompliance with the terms of the Operational Agreement shall subject the Permittee to all sanctions provided by -G: S: 4-4-3-2+5.6-foriel-ation--ef or-€ailure--to-aet-iii-aeeordance with--the-terms-and-conditions-of this Permit. Failure to abide by the requirements contained in this Authorization to Construct may subject the Permittee to an enforcement action by the Division of Water Quality in accordance with North Carolina General Statute 143-215.6A to 143-215.6C. The issuance of this Authorization to Construct does not preclude the Permittee from complying with any and all statutes, rules, regulations, or ordinances which may be imposed by other government agencies (local, state, and federal) which have jurisdiction. Upon completion of construction and prior to operation of this permitted facility, a certification must be received from a professional engineer certifying that the permitted facility has been installed in accordance with the NPDES Permit, this Authorization to Construct and the approved plans and specifications. Mail the Certification to the NPDES Unit, Division of Water Quality, 1617 Mail Service Center, Raleigh, NC 27699-1617. Allen Steam Station Permit No. NC0004979 Page 3 One (1) set of approved plans and specifications is being forwarded to you. If you have any questions or need additional information, please contact Mr. Sergei Chernikov, Ph.D., telephone number (919) 733-5083, extension 594. Sincerely, Alan W. Klimek, P.E. cc: Central Files _NPDES_Unit,-Permit File Mooresville Regional Office, Water Quality Duke Power® A Duke Energy Company. March 24, 2004 Mr. David Goodrich NPDES Unit Supervisor Division of Water Quality North Carolina Department of Natural Resources 1617 Mail Service Center Raleigh, NC 27699-1617 Subject: Allen Steam Station NPDES Permit NC0004979 Request for Authorization to Construct Dear Mr. Goodrich: DUKE POWER 526 South Church Street Charlotte, NC 28202-1802 toT 9 Z HVW f Duke Power appreciates your cooperation and approval to extend a pilot test for selenium reduction through April 2004 while the necessary plans and specifications needed to request an Authorization to Construct (ATC) a modification of the permitted treatment system could be prepared and submitted for approval. Attached are three copies of the proposed plans for addition of a chemical injection system based on our on-going pilot test.. Operation of the pilot treatment system continues to confirm that the addition of ferric sulfate to maintain compliance with the NPDES permit selenium limit is an effective control method. Upon your review and approval of the requested ATC, Duke anticipates that construction and initial operation of the chemical injection system will take approximately six months. Thus, Duke Power requests permission to continue to use the current addition system until modifications can be implemented per approved ATC plans by your NPDES Permitting Unit. The pilot treatment system is currently approved to add up to 100 gallons of ferric sulfate per 5.0 MGD of wastewater. If you need to discuss further information, please contact Ron Lewis (980) 373-5710 or me (980) 373-3231. Sincerely, Michael A. Ruhe, Manager Enviromnental Support Attachment www.dukepower.com ATC SUMMARY SCOPE Allen Steam Station ATC No. 004979A01 Catawba River, WS -IV Catawba River Basin Gaston County The scope of the project includes construction of the physical chemical treatment system. This system will treat 18-24 MGD sluice water to reduce the TSS and Se to below the NPDES compliance limits by physical and chemical treatment processes. Raw primary ash sluice will be settled in settling/sedimentation basins or cells then conveyed past the chemical injection system form treatment. After chemical injection, the secondary sluice flows to a secondary settling basin and then it is discharged to the main pond. REVIEW SUMMARY Executive Summary The Allen Steam Station (Duke Energy) is a coal fired steam electric plant in Gaston County. The facility has been experiencing problems meeting pH and Se limits specified in the NPDES permit. Proposed project should address existing issues. Applicant: Mr. Michael A. Ruhe, Manager Environmental Support Duke Power 526 South Church Street Charlotte, NC 28202-1802 Application/Plans Prepared by: Shield Engineering, Inc. 4301 Taggart Creek Road Charlotte, NC 27560 Significant Dates: Received: 03/26/04 Acknowledged: 04/16/04 RO comments: 05/10/04 Reviewed: 05/21/04 Project Location: Gaston County Facility status: Existing Wastewater source: Coal fired steam electric plant. Funding Source: private Estimated Project Schedule: To start construct immediately upon receiving the ATC Page 1 Submissions: • Letter of Transmittal • Engineering Plans / Specs • Description of the Treatment System Regional Office comments: Pending a final technical review and approval by the NPDES Unit, it is recommended that an ATC be issued as requested. Review Notes: The project has been reviewed at the ATC review in early June 2004, no significant deficiencies were found. Duke Power proposes to use ferric sulfate to reduce concentration of selenium in wastewater. The co- precipitation of Se with iron oxides/hydroxides is most efficient under pH 3.5-5.5 and sulfuric acid will be used to control pH during treatment. Pilot studies conducted on site demonstrated that concentration of Se in wastewater can be reduced to 3 ug/L, which is significantly below current permit level of 31 ug/L. Specifications: Flow Primary Settling Influent Suspended Solids pH range Selenium level Final settling Ferric sulfate tanks Sulfuric acid tank 18-24 MGD 1 — 2 hour minimum 5,000-10,000 mg/L 7-10 31 µg/L or higher 1 hour minimum 2 x 8,000 gallons 8,000 gallons Page 2 To: Permits and Engineering Unit Water Quality Section Attention: Mark McIntire SOC PRIORITY PROJECT: No Date: May 5, 2004 AUTHORIZATION TO CONSTRUCT NPDES PERMIT County: Gaston MRO No.: 04-34 Permit No. NC0004979 PART I - GENERAL INFORMATION 1. Facility and address: Allen Steam Station % Duke Energy, Inc. EC11E 526 South Church Street Charlotte, NC 28202-1802 r M AY 1 0 2004 -� i � � 1 :�? S ;0 E 2. Date of on-site investigation (if conducted): No site visit was conducted. 3. Report prepared by: Michael L. Parker, Environmental Engineer II 4. Persons contacted and telephone number: Ron Lewis, (704) 904-3275 5. Verified discharge point(s), list for all discharge points: outfall 001 outfall 002 outfall 003 outfall 004 Latitude: 350 11' 23" 350 10' 30" 350 11' 24" 350 11' 15" Longitude: 81 ° 00' 45" 81 ° 00' 23" 81 ° 00' 46" 81 ° 00'22" Attach a USGS map extract and indicate treatment facility site and discharge point on map. USGS Quad No.: G 14 NE 6. Site size and expansion area consistent with application? Yes. There is sufficient area available for the construction of the proposed WWT facilities. 7. Topography (relationship to flood plain included): The site is not located within the 100 - year flood plain of the receiving waters. 8. Location of nearest dwelling: None within 1000± feet of the site. Page Two PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS 1. Existing treatment facility a. Current permitted capacity: Flows are intermittent in nature. b. Date(s) and construction activities allowed by previous ATCs issued in the previous two years: No ATCs issued to this facility within the past two years. C. Actual treatment capacity of the current facility (design volume in MGD): Outfall 001 Outfall 002 Outfall 003 Outfall 004 784.8 11.6 6.3 8.0 d. Description of existing or substantially constructed WWT facilities: outfall 001 - there are no existing WWT facilities; outfall 002 - permittee operates a septic tank/sand filter WWT treatment system for treatment of all domestic wastewater. The effluent from the septic tank/sand filter then enters an earthen (ash) settling basin with pH adjustment prior to discharge; outfall 003 - There are no existing WWT facilities; outfall 004 - There are no existing WWT facilities. The permittee also operates a raw water treatment system involving sedimentation, filter back wash, and demineralization. Discharges from the various raw water treatment processes (as well as any residuals generated) are sent to the ash basin. The raw water is not used for drinking, but rather in -plant process use. 2. Type of proposed treatment facility: The applicant proposes to construct a chemical injection system for treatment of pollutants that will not settle out in the existing ash basin settling cells. This system will involve the division of a portion of the existing fly ash basin into a series of three (3) primary settling cells. During any given period of time, each cell will be alternated during plant operation with one receiving the primary sluice wastewater flow while the other two operate in a drying or excavation mode (ash removal). From the primary settling cells, the wastewater will flow through what is being referred to as a "treatment channel" where any chemical injection that may be necessary will occur. In this channel, a portion of the flow will be analyzed for pH, and if necessary, ferric sulfate and/or sulfuric acid will be added as needed for pH control and to augment precipitation of other constituents of concern (primarily selenium). From the treatment channel, the wastewater will flow into a final settling or flocculation cell. This cell will help capture any solids that may not be removed in either the primary cells or the treatment channel. Overflow from this cell will then flow across a vegetated ash delta prior to discharge to the main ash pond. Duke also plans to install the capability of bypassing the main ash pond should effluent quality not require the additional polishing that the main ash basin would provide or should conditions in the main ash pond be detrimental to effluent quality (such as an algae bloom). Page Three 3. Residuals handling and utilization/disposal scheme: Ash is removed as needed from the ash basin, stockpiled for drying, and then reused in accordance with the terms and conditions of Duke Power's Ash Reuse permit. 4. Treatment plant classification: Class I 5. SIC Code(s): 4911 Wastewater code(s): 68, 66 Main Treatment Unit code: 50002 6. Important SOC/JOC or compliance schedule dates: This facility is neither under an SOC nor is one being considered at this time. PART III - EVALUATION AND RECOMMENDATIONS The applicant, Duke Energy, Inc. (Duke), has requested the issuance of an ATC for the construction and modification of the existing ash treatment and disposal system at Duke's Allen Steam Station. These modifications are necessary in order for Duke to maintain compliance with the company's NPDES permit. Specifically, Duke has experienced difficulty in complying with pH and selenium limitations. In July 2003, Duke was granted approval to conduct a pilot study where flow modifications to the existing ash basin allowed Duke to maintain compliance with the permit limitation for selenium while allowing Duke staff to collect operational data that will help them implement a permanent solution. In October 2003, Duke requested an extension of the pilot study in order to finalize the data they had acculmulated, and begin the process of designing a permanent solution. This Office granted an extension of the pilot study for an additional six (6) months ending April 30, 2004. Since the actual request for the ATC was not received by the Division until March 26, 2004, Duke requested and received (by email) an extension of the pilot study until such time as the Division issues.the ATC. Pending a final technical review and approval by the NPDES Unit, it is recommended that an ATC be issued as requested. . Signature of Report Preparer s/� Water Quality Reginal Supervisor Date hAatc\atc04\a11en.atc Duke Power Company Electric System Support 13339 Hagers Ferry Road Huntelsoille, NC28078-7929 DUKE POWER July 22, 1996 A. Preston Howard, Jr., P.E. North Carolina Department of Environment, Health and Natural Resources Division of Environmental Management Permits and Engineering Unit P.O. Box 29355 Raleigh, North Carolina 27626-0535 Subject: Duke Power Company- Allen Steam Station Wastewater Treatment Facility Certification Authorization to Construct NPDES Permit No. NC0004979 File No: ENV -0309 Dear Mr. Howard: In accordance with the requirements outlined in your March 20, 1995 letter to Ms. Jennifer Rudisill of Duke Power Company, attached is the Engineering Certification for installation of the oil/water separator system at the subject facility. A Model DP -4 separator (by the same manufacturer) was used in lieu of the Model DP -8. This modification was made to more economically treat the actual system flow rate conditions. The Mooresville Regional Office will be notified at least 48 hours in advance of system operation as required. If you have any questions or require additional information, please contact me at (704) 875-5934. Sincerely, Christopher D. Hallman, Senior Engineer Environmental Division Attachment CC' D.E.M. Sullivan Pnw i (it: n:o/ded lxw)er D.L. Scruggsyu4lewsk-i,�,,. Permit No. NC0004979 Authorization to Construct Duke Power - Allen Steam Station March 20, 1995 Page 3 Enf4ineer's Certification I, as I du&er�iodicry Professional Engineer in the State of North Carolina, havi g been authorized to obse�eweekly, full time) the construction of the ro'ect, / n. 5-&. ��.� Grou u, er B o t J� � �e,-t;.,. c� m ►,� , /J . L • for the Project Name Location r Permittee hereby state that, to the best o my abilities, due care and diligence was used in the observation of the construction such that the construction tion was observed to be built within substantial compliance and intent of the approved plans and specifications. Signature �fi� aU • ��... Registration No. 125 8 4 . Date �CARO °'•. 0•,OFEs5rp�q :9 ••�. t` SEAS Z S 12584 Q Z.. °•.�.PH E R D�•��.•o a...... 'o. NCO0044979 tion: -to Construct 7ower - Allen Steam Station 20, 1995 duly Carolina, hav' g been authorized o observe eriodicall�weeklysfull time) the construction of iheNorth project, Project Name —Be' m 0^+— C- . for the Location Permittee hereby state that, to the best of my abilities, due care and diligence was used in the observation of the construction such that the construction was observed to be built wit intent of the approved plans and specifications. hin substantial compliance and Signature Registration No. /25 8 Date �/ 9 6 CAS �O:.oFEss���..: •. :Q SEAL Z 12,984 Q . pNER D The Division of Water Quality hereby acknowledges receipt and acceptancc of this Engineers Certification Ql N5 :°:� "' x 10/26/01 15:29 V704 382 6240 DPCO ENV ENGR Z004 Author: "Parker, Michael" <TS19W48@mr0.ehnr.state.nc.us> at INTERNET Date: 4/29/96 2:23 PM Priority: Normal TO: Michael E Kowalewski at DPCGSD01 subject: RE:Certificate of Completion Permit No 0004979AC ------------------------------------ Message Contents ------------------------------------ Date: Mon, 29 Apr 96 13:36:06 EST From: "Michael E Kowalewski".<mekowale@dpcmail_dukepower_com> To: tsl9w48®mro.ehnr.state.nc.us. Subject: RE:Certificate of Completion Permit No 0004979AC Mike, Received a letter from Raleigh inquiring about permit no 0004979AC and why no certification has been received. The project is still under construction and is currently scheduled for completion by the end of June 1996. The letter directs us to contact the Mooresville Office if the facility has not been completed and provide an expected completion date. Are you the right person for this? Do you need any further information? Please acknowledge receipt. Mike Kowalewski(MEKOWALEQDPCMAIL.DUKEPOWER.COM) Mike: Response received. I'll make a copy of this for the file. No further action necessary. Thanks. M. Parker - MRO State of North Carolina Department of Environment, Health and Natural Resources 4 • 0 Division of Environmental Management James B. Hunt, Jr., Governor Jonathan B. Howes, Secretary E H N A. Preston Howard, Jr., P.E., Director March 20, 1995 Ms. Jennifer A. Rudisill Duke Power Company Generation Services Dept. 13339 Hagers Ferry Road Huntersville, NC 28078-7929 Subject: Permit No. NC0004979 Authorization to Construct Allen Steam Station Groundwater Remediation Gaston County Dear Ms. Rudisill: A letter of request for an Authorization to Construct was received on November 30, 1994 by the Division and final plans and specifications for the subject project have been reviewed and found to be satisfactory. Authorization is hereby granted for the construction of #DP -8 oil -water separator with discharge of treated wastewater into the Catawba and South Fork Catawba Rivers. This Authorization to Construct is issued in accordance with Part III, Paragraph A of NPDES Permit No. NC0004979 issued March 9, 1995 and shall be subject to revocation unless the wastewater treatment facilities are constructed in accordance with the conditions and limitations specified. in Permit No. NC0004979. The sludge generated from these treatment facilities must be disposed of in accordance with G.S. 143-215.1 and in a manner approved by the North Carolina Division of Environmental Management. In the event that the facilities fail to perform satisfactorily, including the creation of nuisance conditions, the Permittee shall take immediate corrective action, including those as may be required by this Division, such as the construction of additional or replacement wastewater treatment or disposal facilities. The Mooresville Regional Office, telephone number (704) 663-1699 shall be notified at least forty- eight (48) hours in advance of operation of the installed facilities so that an. in-place inspection can be made. Such notification to the regional supervisor shall be made during the normal office hours from 8:00 a.m. until 5:00 p.m. on Monday through Friday, excluding State Holidays. Upon completion of construction and prior to operation of this permitted facility, a certification must be received from a professional engineer certifying that the permitted facility has been installed in accordance with the NPDES Permit, this Authorization to Construct and the approved plans and specifications. Mail the Certification to the Permits and Engineering Unit, P.O. Box 29535, Raleigh, NC 27626-0535. P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone 919-733-5083 FAX 919-733-9919 An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post -consumer paper Permit No. NC0004979 Authorization to Construct Duke Power - Allen Steam Station March 20, 1995 Page 2 A copy of the approved plans and life of the facility. shall be maintained on file by the Permittee for the Failure to abide by the requireme' is contained in this Authorization to Construct may subject the Permittee to an enforcement action by t e Division of Environmental Management in accordance with North Carolina General Statute 143-215. A to 143-215.6C. The issuance of this Authorizatioo to Construct does not preclude the Permittee from complying with any and all statutes, rules, regulatio s, or ordinances which may be imposed by other government agencies (local, state, and federal) which 4ave jurisdiction. One (1) set of approved plans questions or need additional information, 5083, extension 537. d specifications is being forwarded to you. If you have any please contact Jeanette Powell at telephone number (919) 733 - Sincerely, reston i�wwr , Jr., P.E. cc: Gaston County Health Department Mooresville Regional Office, Water Quality Training and Certification Unit Facilities Assessment Unit DIVISION OF ENVIRObD=AL MANAGEMENT March 27, 1981 Mr. S. B. Hager, Chief 14ineer Dine Power Company P. 0. Box 33189 Charlotte, North Carolina 28242 SUB=Ts Permit No. MC0004979 Authorization to Construct Duke Power Company Ash Settling Basin - Stage IV Gaston County Dear Mr. Eagers c 17,, The final plans sud specifications for the subject project have been reviewed and found to be satisfactory. Authorization is hereby granted for the construction of Stage W ash settling and storage facilities consisting of increasing the total area from 111 acres to 180 acres by raising the dam height to serve Duke Power Company's Allen Steam Station, This Authorization to Construct shall be subject to revocation unless the wastewater treatment facilities are constructed in accordance with the conditions and limitations specified in Permit leo. NC0004979. One (1) set of approved plans is being forwarded to you. Sincerely yours, SiZ,7-2d by L.. F'. �art P. Helms ing Director eel Gaston County Aealth Department Mr. Richard Peace/ Mr. R. S. Taylor/ Mooresville Regional Office Manager 10/26/01 15:28 • fl ' 704 382 6240 DPCO ENV ENGR Ms. Coleen Sullins Permits and Engineering Unit -• ---� - ---- North Carolina Department oof Environment, Health and Natural Resources P.O. Box 29535 - Raleigh, NC 27626-0535 Subject: Authorization to Construct . Allen Steam Station NPDES #NC0004979 File: AS -704.15 Dear Ms. Sullins: Duke Power Company requests an authorization to construct for installation of an oil -water separator at Allen Steam Station in Gaston County. Included with this request are five (5) copies of the plans and the required fee of $200.00. The oil - water separator would be used as part of a current groundwater remediation program as outlined in a letter sent September 29, 1993. In a letter from your office dated June 21, 1994, we were informed that this discharge would have to be included in the NPDES permit prior to our receiving the ATC. The draft of the NPDES permit we received on October 31 of this year identifies the effluent from the oil -water separator as a source to the basin 'and . includes monitoring requirements for benzene, toluene and MTBE. As we understand from conversations with. -Mr. Sean Gods of your office, we may apply for the ATC concurrent with the NPDES permit renewal process.. As outlined in the September correspondence, we are currently removing free product (#2 fuel oil) from the contaminated site at Plant Allen and disposing of it with other used oil, collected on-site according to the. appropriate regulations. We would like to install an oil -water separator, the Hydro -Flo Technologies DP -8, that would separate the free product and the groundwater at a maximum rate of 20 gpm. Please see the.attached drawings for specifics. The groundwater would then be routed to the ash basin via a sump system. Please note that these plans are PMtedon tecrJedpaW 0002 Dake Poorer Company Generation Services Department 13339 Hagers Any Road Hrmtersville, NC 28078-7929 DUKEPOWER;`�Is:�+:`fir.},.•;ITFII�C ANDl �i • ...s.J�Ct/1 November 28, 1994.w 1. ....._r_.�...�__ � i;.;IQ 1 Ms. Coleen Sullins Permits and Engineering Unit -• ---� - ---- North Carolina Department oof Environment, Health and Natural Resources P.O. Box 29535 - Raleigh, NC 27626-0535 Subject: Authorization to Construct . Allen Steam Station NPDES #NC0004979 File: AS -704.15 Dear Ms. Sullins: Duke Power Company requests an authorization to construct for installation of an oil -water separator at Allen Steam Station in Gaston County. Included with this request are five (5) copies of the plans and the required fee of $200.00. The oil - water separator would be used as part of a current groundwater remediation program as outlined in a letter sent September 29, 1993. In a letter from your office dated June 21, 1994, we were informed that this discharge would have to be included in the NPDES permit prior to our receiving the ATC. The draft of the NPDES permit we received on October 31 of this year identifies the effluent from the oil -water separator as a source to the basin 'and . includes monitoring requirements for benzene, toluene and MTBE. As we understand from conversations with. -Mr. Sean Gods of your office, we may apply for the ATC concurrent with the NPDES permit renewal process.. As outlined in the September correspondence, we are currently removing free product (#2 fuel oil) from the contaminated site at Plant Allen and disposing of it with other used oil, collected on-site according to the. appropriate regulations. We would like to install an oil -water separator, the Hydro -Flo Technologies DP -8, that would separate the free product and the groundwater at a maximum rate of 20 gpm. Please see the.attached drawings for specifics. The groundwater would then be routed to the ash basin via a sump system. Please note that these plans are PMtedon tecrJedpaW 0002 • 10/26/01 15:29 U704 382 6240 DPCO ENV ENGR IA 003 identical to those in the previous request dated December 20, 1993, with one small change; we would like.to.use model # DP -8 as opposed to model # DP -4 oil - water separator. The unit would be installed and the effluent routed to the ash basin after receiving both approval from you to construct the system and the new NPDES -permit. -'Duke Power is currently operating a similar unit at Lee Steam Station in South Carolina . with good results. We are currently under time constraints with the groundwater section of NCDEHNR. As such we would appreciate an expeditious response to this request. If you have any questions about the installation of the oil -water separator, please do not hesitate to contact me at (704) 875-5966 or the above address. We thank you for your assistance in resolving this issue. Sincerely: Jennifer A. Rudisill Assistant Scientist Water Protection, Environmental Division Attachments cc: Mr. Mike Parker - NCDEHNR, Mooresville Regional Office A \ 1