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HomeMy WebLinkAboutNC0089290_Permit Issuance_20131101North Carolina Pat McCrory Governor Ms. Christine Bralley Town Manager Town of Mocksville 171 Clement Street Mocksville, NC 27028 Dear Ms. Bralley: ,� r NCDENR Department of Environment and Division of Water Resources Water Quality Programs Thomas A. Reeder Director November 1, 2013 Natural Resources John E. Skvarla, III Secretary Subject: NPDES Permit Issuance. Permit NCO089290 Mocksville - Hugh A. Lagle WTP Davie County The Division of Water Resources (Division) personnel have reviewed and approved your application for issuance of the subject permit. Accordingly, we are forwarding the attached NPDES discharge permit. It is issued pursuant to the requirements of North Carolina General Statute 143-215.1 and the Memorandum of Agreement between North Carolina and the U.S. Environmental Protection Agency dated October 15, 2007, or as subsequently amended. There are changes to this permit from the draft permit dated August 14, 2013 : Proposed federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and specify that, if a state does not establish a system to receive such submittals, then permittees must submit DMRs electronically to the Environmental Protection Agency (EPA). The Division anticipates that these regulations will be adopted and is beginning implementation. a. The requirement to begin reporting discharge monitoring data electronically using the NC DWR's Electronic Discharge Monitoring Report (eDMR) internet application has been added to your fmal NPDES permit. [See Special Condition A (3)] For information on eDMR, registering for eDMR and obtaining an eDMR user account, please visit the following web page: ba://portal.ncdenr.org/web/wg/admin/boglipu/edmr. Please note that the address to send hard copies of DMR reports listed in the permit is slightly different from the address shown on forms previously sent to you. 1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Location: 512 N. Salisbury St Raleigh, North Carolina 27604 Phone: 919.807-63001 Fax: 919-807-6489 Internet:: www.ncwatemualh.org An Equal Oppodunit WirrnaBveAction Employer b. For information on EPA's proposed NPDES Electronic Reporting Rule, please visit the following web site: http://www2 epa gov/con lip ance/roronosed-nodes-electronic-reporting_ rule. c. A new footnote (1) has been added to Condition A.(1) regarding eDMR implementation. The other footnotes were renumbered accordingly. d. A new Special Condition A.(3) has been added to address the requirements of the eDMR program. The effective date of this permit is December 1, 2013. The limits become effective starting on December 1, 2015. The permit will expire at midnight on November 29, 2016; you must apply for renewal 6 months in advance of this date. If any parts, measurement frequencies, or sampling requirements contained in this permit are unacceptable, you have the right to an adjudicatory hearing upon written request within thirty (30) days after receiving this letter. Your request must take the form of a written petition conforming to Chapter 150B of the North Carolina General Statutes, and must be filed with the Office of Administrative Hearings, 6714 Mail Service Center, Raleigh, North Carolina 27699-6714. Unless such demand is made, this permit remains final and binding. This permit is not transferable except after notifying the Division of Water Resources. The Division may modify and re -issue, or revoke this permit. Please notice that this permit does not affect your legal obligation to obtain other permits required by the Division of Water Resources, the Division of Land Resources, the Coastal Area Management Act, or other federal or local governments. If you have questions, or if we can be of further service, please contact Jim McKay at iames.mckavCa_)ncdenr.gov or call (919) 807-6404. Sincerely, Thomas A. Reeder Enclosure: NPDES Permit FINAL NCO089290: Town of Mocksville -Hugh A. Lagle WTP cc: Winston - Salem Regional Office, Surface Water Protection with Fact Sheet - via email NPDES Unit Central Files Charles A. Willis Jr., P.E. of Willis Engineers, Inc. - via email (chuck@willisengineers.com) Permit NCO089290 STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES DIVISION OF WATER RESOURCES PERMIT TO DISCHARGE WASTEWATER UNDER THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM In compliance with the provision of North Carolina General Statute 143-215.1, other lawful standards and regulations promulgated and adopted by the North Carolina Environmental Management Commission, and the Federal Water Pollution Control Act, as amended, the Town of Mocksville is hereby authorized to discharge wastewater from a facility located at the Hugh A. Lagle WTP 771 Sanford Avenue Mocksville Davie County to receiving waters designated as UT of Bear Creek in the Yadkin River Basin in accordance with effluent limitations, monitoring requirements, and applicable conditions set forth in Parts I, H, III and IV hereof. This permit shall become effective December 1, 2013 This permit and authorization to discharge shall expire at midnight on December 31, 2016. Signed this day November 1, 2013 fi"UL- e�- '0�- T as A. Reed , Director vision of Water Resources By Authority of the Environmental Management Commission Page 1 of 6 Permit NCO089290 SUPPLEMENT TO PERMIT COVER SHEET The Town of Mocksville is hereby authorized to: 1. Continue to operate a conventional water treatment plant with a discharge of filter -backwash, sediment basin flush and untreated raw water. This conventional water treatment plant has a design potable flowrate of 2.0 MGD and a monthly average wastewater discharge of 0.0675 MGD, up to a peak of 0.081 MGD. The facility is located at Mocksville's Hugh A. Lagle WTP (771 Sanford Avenue, Mocksville) in Davie County. A wastewater treatment facility will be constructed in order to treat filter backwash and other wastewater streams. During the construction period, a 24 month compliance schedule is granted, such that during the construction of the treatment system, certain limits and conditions will not be enforced for a maximum of 24 months after the effective date of this permit. Wastewater will be treated by two 250,000 gallon flow equalization tanks that equalize flows from filter backwash and sediment basin cleaning. Solids will be allowed to settle, and the water dechlorinated with sodium thiosulfate liquid solution before discharging to an unnamed tributary of Bear Creek in the Yadkin River Basin. A continuous recording flowmeter will measure the discharge of treated wastewater. Solids will be pumped out as a sludge and land applied by a contract hauler as needed. 2. Discharge from said treatment works at the location specified on the attached map into a UT to Bear Creek, classified WS-IV waters in the Yadkin River Basin. Page 2 of 6 Permit NCO089290 Part I A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS a. During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 001. Such discharges shall be limited and monitored 1 by the Permittee as specified below: EFFLUENT CHARACTERISTICS _ LI1VtITS 2 MONITORING. REQUIREMENTS, - - ;: Monthly` Average., Daily, Maximum.. :Measurements .Fre uenc ... , .Sample Type Sample;Locatio, ; Flow 2 Continuous Recording Effluent Total Suspended Solids 30.0 m 45.0 m 2/Month Grab Effluent H 2 >_ 6.0 SU >_ 9.0 SU 2/ Month Grab Effluent Total Residual Chlorine 2,4 17 2/ Month Grab Effluent Turbidity 2/ Month Grab Effluent Turbidity Monthly Grab Up, Down Total Iron Quarterly5 Grab Effluent Total Copper Quarterly5 Grab Effluent Manganese Quarterly5 Grab Effluent Fluoride Quarterly5 Grab Effluent Total Zinc uarterl 5 Grab Effluent Aluminum Quarterly5 Grab Effluent Total Nitrogen Quarterly Grab Effluent Total Phosphorus Quarterly Grab Effluent Whole gent Toxicity Monitoring rin Monitor and Report Quarterly Grab Effluent Footnotes: 1. No later than 90 days from the effective date of this permit, begin submitting discharge monitoring reports electronically using NC DWR's eDMR application system. See Special Condition A (3). 2. Limits, including the requirement for continuous flow recording become effective December 1, 2015, or upon completion of the wastewater treatment facilities, whichever comes first. Instantaneous flow estimates and discharge duration shall be recorded until the flowmeter is operational. Upon completion of construction of wastewater treatment facilities, the Town shall notify the Winston-Salem Regional Office of DENR at (336) 771- 5000, and the Central Office of the Division of Water Resources, NPDES Permitting Unit at (919) 807-6390. All limits become effective the first of the next month. Monitoring is required beginning on the effective date of this permit. 3. Up is Upstream in Bear Creek at least 50 feet above Discharge location, Down is Downstream in Bear Creek at least 100 feet below Discharge location. 4. Limit and monitoring apply only if chlorine or chlorine derivatives are used for disinfection. The Division shall consider all effluent TRC values reported below 50 µg/ L to be in compliance with the permit. However, the Permittee shall record and submit all values reported by a North Carolina certified laboratory (including field certified), even if these values fall below 50 µg/ L. 5. Parameter should be sampled in conjunction with Quarterly Toxicity Testing. 6. Monitoring for Zinc is only required if zinc containing additives are added to water used for filter backwash. 7. Total Nitrogen (TN) = (NO2-N + NO3-N) + TKN where NO2 N and NO3-N are Nitrite and Nitrate Nitrogen, respectively and TKN is Total Kjeldahl Nitrogen. 8. Whole Effluent Toxicity Monitoring (Ceriodaphnia dubia) at 90%; March, June, September and December, refer to Special Condition A. (2.). b. All samples must be collected from a typical discharge event. c. There shall be no discharge of floating solids or visible foam in other than trace amounts. Page 3 of 6 Permit NCO089290 A. (2.) CHRONIC TOXICITY PASS/FAIL MONITORING (QUARTERLY) The permittee shall conduct quarterly chronic toxicity tests using test procedures outlined in the "North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised December 2010, or subsequent versions. The effluent concentration defined as treatment two in the procedure document is 90%. The testing shall be performed as a Ceriodaphnia dubia 7-day pass/fail test. The tests will be performed during the months of March, June, September and December. These months signify the first month of each three month toxicity testing quarter assigned to the facility. Effluent sampling for this testing must be obtained during representative effluent discharge and shall be performed at the NPDES permitted final effluent discharge below all treatment processes. All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge Monitoring Form (MR-1) for the month in which it was performed, using the parameter code TGP3B. Additionally, DWR Form AT-1 (original) is to be sent to the following address: Attention: North Carolina Division of Water Resources Environmental Sciences Section 1621 Mail Service Center Raleigh, N.C. 27699-1621 Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Section no later than 30 days after the end of the reporting period for which the report is made. Test data shall be complete and accurate and include all supporting chemical/physical measurements performed in association with the toxicity tests, as well as all dose/response data. Total residual chlorine of the effluent toxicity sample must be measured and reported if chlorine is employed for disinfection of the waste stream. Should there be no discharge of flow from the facility during a month in which toxicity monitoring is required, the permittee will complete the information located at the top of the aquatic toxicity (AT) test form indicating the facility name, permit number, pipe number, county, and the month/year of the report with the notation of "No Flow" in the comment area of the form. The report shall be submitted to the Environmental Sciences Section at the address cited above. Should the permittee fail to monitor during a month in which toxicity monitoring is required, then monthly monitoring will begin immediately. Upon submission of a valid test, this monthly test requirement will revert to quarterly in the months specified above. Should any test data from this monitoring requirement or tests performed by the North Carolina Division of Water Resources indicate potential impacts to the receiving stream, this permit may be re -opened and modified to include alternate monitoring requirements or limits. If the Permittee monitors any pollutant more frequently then required by this permit, the results of such monitoring shall be included in the calculation & reporting of the data submitted on the DMR & all AT Forms submitted. NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control organism survival, minimum control organism reproduction, and appropriate environmental controls, shall constitute an invalid test and will require immediate follow-up testing to be completed no later than the last day of the month following the month of the initial monitoring. Page 4 of 6 Permit NCO089290 A (3) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS Proposed federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and specify that, if a state does not establish a system to receive such submittals, then permittees must submit DMRs electronically to the Environmental Protection Agency (EPA). The Division anticipates that these regulations will be adopted and is beginning implementation in late 2013. NOTE: This special condition supplements or supersedes the following sections within Part H of this permit (Standard Conditions for NPDES Permits): • Section B. (11.) • Section D. (2.) • Section D. (6.) • Section E. (5.) Signatory Requirements Reporting Records Retention Monitoring Reports 1. Reporting [Supersedes Section D. (2.) and Section E. (5.) (a)1 Beginning no later than 90 days from the effective date of this permit, the permittee shall begin reporting discharge monitoring data. electronically using the NC DWR's Electronic Discharge Monitoring Report (eDMR) internet application. Monitoring results obtained during the previous month(s) shall be summarized for each month and submitted electronically using eDMR. The eDMR system allows permitted facilities to enter monitoring data and submit DMRs electronically using the internet. Until such time that the state's eDMR application is compliant with EPA's Cross -Media Electronic Reporting Regulation (CROMERR), permittees will be required to submit all discharge monitoring data to the state electronically using eDMR and will be required to complete the eDMR submission by printing, signing, and submitting one signed original and a copy of the computer printed eDMR to the following address: NC DENR / DWR / Information Processing Unit ATTENTION: Central Files / eDMR 1617 Mail Service Center Raleigh, North Carolina 27699-1617 If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility being physically located in an area where less than 10 percent of the households have broadband access, then a temporary waiver from the NPDES electronic reporting requirements may be granted and discharge monitoring data may be submitted on paper DMR forms (MR 1, 1. 1, 2, 3) or alternative forms approved by the Director. Duplicate signed copies shall be submitted to the mailing address above. Requests for temporary waivers from the NPDES electronic reporting requirements must be submitted in writing to the Division for written approval at least sixty (60) days prior to the date the facility would be required under this permit to begin using eDMR. Temporary waivers shall be valid for twelve (12) months and shall thereupon expire. At such time, DMRs shall be submitted electronically to the Division unless the permittee re -applies for and is granted a new temporary waiver by the Division. Information on eDMR and application for a temporary waiver from the NPDES electronic reporting requirements is found on the following web page: hn://portal.nedenr.or web/wq/admin/bog/ipu/edmr Regardless of the submission method, the first DMR is due on the last day of the month following the issuance of the permit or in the case of a new facility, on the last day of the month following the commencement of discharge. Page 5 of 6 Permit NC0089290 2. Signatory Requirements [Supplements Section B. (11.) (b) and supersedes Section B. (11.) (d)l All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part H, Section B. (11.)(a) or by a duly authorized representative of that person as described in Part I1, Section B. (11.)(b). A person, and not a position, must be delegated signatory authority for eDMR reporting purposes. For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user account and login credentials to access the eDMR system. For more information on North Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account, please visit the following web page: hM://portal.nedenr.or web/wg/admin/bodipu/edmr Certification. Any person submitting an electronic DMR using the state's eDMR system shall make the following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION WILL BE ACCEPTED: "I certify, under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person orpersons who manage the system, or those persons directly responsible for g6thering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fines and imprisonment for knowing violations. " 3. Records Retention [Supplements Section D. (6.)1 The permittee shall retain records of all Discharge Monitoring Reports, including eDMR submissions. These records or copies shall be maintained for a period of at least 3 years from the date of the report. This period may be extended by request of the Director at any time [40 CFR 122.41 ] . Page 6 of 6 a Bear Creek Outfall 001 .Ma TNM ILL Latitude: 35' 53' 22" Longitude: 80' 34'43" Facility NCO089290 Quad# D16NE/Mocksville Location Stream Class: WS-IV Subbasin: 03 07 06 Town Of 1VIOC1{SVllle (not to scale) HUC: 030401020603 Receiving Stream: UT to Bear Creek Hugh A. Lagle WTP Davie County Yadkin River Basin North DENR/DWR FACT SHEET FOR NPDES PERMIT DEVELOPMENT NPDES No. NCO089290 Facility Information Applicant/Facility Name: Town of Mocksville/ Hugh A. La le Water Treatment Plant Applicant Address: 171 Clement Street, Mocksville North Carolina 27028 Facility Address: 771 Sanford Avenue, Mocksville North Carolina 27028 Permitted Flow Not limited. Design capacity is up to 0.081 MGD at maximum flow. Type of Waste: Conventional filter backwash Facility/Permit Status: Existing facility, new permit Facility Classification PC I County: Davie Miscellaneous Receiving Stream: UT to Bear Creek Regional Office: Winston-Salem Stream Classification: WS IV State Grid/ USGS TooQuad: D16NE/ Mocksville 303(d) Listed? Impaired on 2012 Final List for copper and Ecological/ biological Integrity Permit Writer: Jim McKay Subbasin: 03-07-06 Date: I October 25, 2013 12 digit HUC: 030401020603 Facility Location (NTS) Drainage Area mi2): N/A Summer 7 10 cfs): 0 Winter 7Q10 (cfs): 0 30Q2 (cfs): 0 Average Flow (cfs): 0 IWC (%): 100 ca ed at 90% Primary SIC Code: 1 4941 SUMMARY: The Town of Mocksville uses a Conventional Water Treatment Plant to treat water drawn from Hunting Creek, which is impaired for low pH on the 2012 final 303(d) list. The facility is designed to provide 2.0 Million Gallons per Day of treated potable water. The backwash wastewater is estimated to be 0.081 Million Gallons per Day at peak rates. Wastewater is comprised of filter backwash and sediment basin cleaning flushes, and consists of finished treated water containing chlorine, fluoride and untreated source water. It is discharged to an Unnamed Tributary of Bear Creek in the Yadkin River Basin. In current operation, fixed speed intake pumps on Hunting Creek can cause untreated intake water to overflow the sediment basin with raw influent water. This can lead to high turbidity in the effluent of over 500 NTU. Bear Creek is not impaired for turbidity, so no limit is being placed in the permit, however, since the stream is known to have a high turbidity, monitoring of the effluent along with upstream and downstream monitoring will be required. Removal of this requirement or a reduction in turbidity sampling can be requested at permit renewal and will be based on effluent compliance with the NC WQS of 50 NTU and/ or the consistent demonstration of naturally high levels of turbidity caused by natural background levels and not the permittee's discharge. The receiving stream (Bear Creek) is classified WS-IV waters in the Yadkin River Basin. This reach is listed on the 2012 Approved 303(d) list as impaired for copper and Fair Bioclassification Ecological/ biological Integrity Fish Community. Town of Mocksville Hugh A. Lagle WTP Fact Sheet NPDES Permit. NCO089290 Page 1 of 3 This Conventional WTP has been operating without an NPDES discharge permit since 1946, and has been expanded and modified during this time frame. The goal of this permit is to bring the town into the NPDES Program, with a compliance schedule to allow the Town to construct facilities required to meet the terms of the NPDES Permit, including TRC, Flow Monitoring, Total Suspended Solids (TSS), pH, Turbidity and Whole Effluent Toxicity Monitoring (WET). Permit History: The Winston-Salem Regional Office discovered that the WTP had been operating without an NPDES discharge permit, and began working with them to understand the requirement to have a permit for discharge of filter backwash and other waste streams. The facility first applied for an NPDES Discharge permit for filter backwash discharge on November 16, 2012. An Engineering Alternatives Analysis document was attached. The EAA evaluated three options: Surface Water Discharge, Discharge to a WWTP, and Spray Irrigation/ Non -Discharge. All three were evaluated and costed out as required. The recommended alternate of surface discharge to Waters of the State was accepted as the lowest cost, environmentally acceptable alternative. A Draft NPDES permit was prepared based on the application and Engineer's report, and submitted for public notice and draft review in December of 2012. During the review period two things happened. First, the Town decided that it could not afford to construct the treatment facility as designed, and secondly, the Engineer retired from practice. The permit was put on hold until the Town located another Engineer to develop a more affordable treatment system that would meet NPDES Permit requirements. A compliance schedule of 24 months was negotiated with the Town and the consultant in order to provide time to construct treatment facilities required to meet the permit requirements. The earlier draft permit was modified to allow for a 2-year compliance schedule before limits were enforced. Monitoring for all required parameters will begin on the permit effective date. The permit expiration date per the Basin plan would be April 30, 2014, which would not be sufficient time to complete construction and produce data for review. A permit life of three years was chosen to allow 24 months construction and 12 months of operational data for renewal. This puts the permit out of synch. with the Basin Plan, so it is recommended that the first renewal be for the expiration to be on April 30, 2019 to be back on the Basin Schedule. This will provide a little less than two and one-half years for this first renewal permit. PermittingStrategy: trate : Permitting Strategies for Conventional Water Treatment Plants and Zero Flow streams are followed for this facility. Limits for TSS, pH and TRC are taken from the WTP Permitting Strategy for Conventional Water Treatment Plants. Monitoring for Turbidity is required for the effluent and instream (Up and Downstream of the discharge point). If data shows that the discharge has the possibility of affecting instream turbidity, the renewal should add a Turbidity Limit in accordance with current Permitting Strategy. Facility Description: The existing WTP has several fixed speed pumps of various capacities, with an intake in Hunting Creek. Raw water is pumped to the WTP where it is flow metered and dosed with chlorine, caustic, phosphate, fluoride and a polyaluminum chloride flocculant. There are two 45,000 gallon settling tanks with a chemical mixer, and one 112,000 gallon settling tank with a chemical mixer. The water enters a settling tank and solids allowed to settle out. Clear water is decanted out and filtered, then stored in a 1.0 MG clearwell for finished water. The finished water is flow metered and pumped to the Town's Distribution System. Filters are backwashed with finished water, and discharged to an unnamed tributary to Bear Creek. Settling tank rinsewater and uncontrolled untreated raw water are also discharged to the UT. The Town proposes to construct two 250,000 gallon concrete storage and settling tanks for filter backwash and sedimentation basin flush, with floating decanting systems to drain clear water from the solids. An 8 inch Parshall Flume will measure discharge flow rate, which will be continuously recorded and totalized. A dechlorination system will be provided, using liquid sodium thiosulfate. The treated wastewater will discharge to a UT to Bear Creek. Solids will be removed by a contractor for disposal Town of Mocksville Hugh A. Lagle WTP Fact Sheet NPDES Permit NCO089290 Page 2 of 3 offsite. Existing facilities will be repaired/ upgraded to improve flocculation and sedimentation basin operation. The plant has various raw water pumps available with different flowrates that can be selected. By choosing the right pump, and controlling the plant throughput to match the raw water feed rate, the operators are able to minimize overflow and discharge of untreated water to the wastewater disposal system. Whole Effluent Toxicity Testing: Chronic toxicity testing using Ceriodaphnia dubia at 90 % will be required per the permitting strategies for Conventional WTPs and for zero flow streams. Basis For Limits: Limits in the permit for Total Dissolved Solids (TDS), pH and Total Residual Chlorine (TRC) are based on North Carolina water quality standards [15A NCAC 2B .0200]. Electronic Reporting of Data: In accordance with recent EPA requirements for Electronic Reporting of Data, a new special condition A (3) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS was added to the final permit regarding electronic submittal of data required by the permit. The permittee was advised of this by email one week prior to issuance of the permit. PROPOSED SCHEDULE FOR PERMIT ISSUANCE: Draft Permit to Public Notice: September 2013 (est.) Permit Scheduled to Issue: November 1, 2013 (est.) Permit Effective Date: December 1, 2013 (est.) 2-year Compliance Schedule ends: December 1, 2015 (est.) Permit Expiration Date: November 30, 2016 (est.) First Renewal Expiration Date: April 30, 2019 (Basin Schedule) STATE CONTACT: If you have any questions on any of the above information or on the attached permit, please contact Jim McKay at (919) 807-6404, or by email at James.McKay@ncdenr.gov. M "1-' % DATE: t (i- 3/ 2. a13 REGIONAL OFFICE COMMENT: (USE EXTRA SHEETS IF NEEDED) NAM NPDES SUPERVISOR COMMENT: Town of Mocksville Hugh A. Lagle WTP Fact Sheet NPDES Permit NCO089290 Page 3 of 3 VCE1NRR North Carolina Department of Environment and Natural Resources i Division of Water Resources Water Quality Programs Pat McCrory Thomas A. Reeder John E. Sltvarla, III Governor Director Secretary j September 11, 2013 MEMORANDUM To: Lisa Edwards NC DENR / DWR/ Regional Engineer Winston-Salein Regional Office From: Jim McKay Com lex NPDES Permitting 8 Subject: Review of proposed NPDES Permit NCO089290 Hugh A. Lagle WTP, Davie County. Please indicate below your agency's position or viewpoint on the draft permit and return this form by October 18, 2013. If you have any questions on the draft permit, please contact me at telephone number (919) 807-6404, or via e-mail at James.McKay@iicdcni-.gov. ncdcni•.gov. ! RESPONSE: (Check one) Concur with the issuance of this permit provided the facility is operated and maintained properly, the stated effluent limits are rnct 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 niet: i Opposes the issuance of the above pcnnit, based on reasons stated below, or attached: ' 1II 1 Signed' - Date:_ i 1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Location: 512 N. Sallsbury St. Raleigh, North Carolina 27604 Phone. 94-807.63001 Fax: 91 M7.6489 i Internet: mvw.nmateraualilxom i An Equal OpportunitylArfirmative Won Erralever NORTH CAROLINA FORSYTH COUNTY AFFIDAVIT OF PUBLICATION Before the undersigned, a Notary Public of said County and State, duly commissioned, qualified, and authorized by law to administer oaths, personally appeared D.H. Stanfield, who being duly sworn, deposes and says: that he is Controller of the Winston-Salem Journal, engaged in the publishing of a newspaper known as the Winston-Salem Journal, published, issued and entered as second class mail in the City of Winston-Salem, in said County and State: that he is authorized to make this affidavit and sworn statement: that the notice or other legal advertisement, a true copy of which is attached hereto, was published in the Winston-Salem Journal on the following dates: September 14, 2013 and that the said newspaper in which such notice, paper document, or legal advertisement was published was, at the time of each and every such publication, a newspaper meeting all the requirements and qualifications of Section 1-597 of the General Statutes of North Carolina and was a qualified newspaper within the meaning of Section 1-597 of the General Statutes of North Carolina. This 17th day of September, 2013 (signature ofper )making affidavit) Sworn to and subscribed before me, this 17th day of Sep ber, 2013 Nota ublic My Commission expires: September 28, 2015 EmYasKIMALEY JOHNSON NOTARY PUBLIC FORSYTH COUNTY p ______.. E OF NORTH AR Lill Zol MISSION EXPIRE PUBLIC NOTICE North Carolina Environmental Management Commission/NPDrS Unit 1617 Mail Service Center Raleigh, NC 276SS-1617 Notice of Intent to Issue a NPDES Wastewater Permit WSJ: September 14, 2013 From: Mckay, James Sent: Thursday, January 03, 2013 1:18 PM To: 'Christine Bralley' Cc: Geoff Beane Subject: RE: Pending NPDES permit Ms. Bralley: A compliance schedule allows for time to modify a facility in order to comply with new permit requirements that the existing facility cannot meet. Usually they are used when permitting requirements are changed for an existing WWTP, but are also used in situations like yours where a new discharge permit is issued to an existing facility that was not designed to meet the latest requirements. Usually a compliance schedule requires the subject parameter be measured and reported, but limits are not enforced during the compliance schedule. Once the schedule is completed, then enforcement of the limits begins. The two items required for your permit can have combined, or separate compliance schedules, depending on time required for each to be implemented. The compliance schedule has to be written into the permit, using actual dates for the compliance date when limits would apply. Once the compliance schedule is finalized, I will send a revised draft for your review. Jim McKay, Environmental Engineer NC DENR / Division of Water Quality / Surface Water Protection Section Point Source Branch 1617 Mail Service Center, Raleigh, NC 27699-1617 919/807-6404 (work); 919/807-6489 (fax) **Please note, my email address has changed to James.McKay@ncdenr.gov E-mail correspondence to and from this address may be subject to the North Carolina Public Records law and may be disclosed to third parties. From: Christine Bralley rmailto:cbrallev@mocksvillenc.govl Sent: Thursday, January 03, 2013 12:56 PM To: Mckay, James Cc: Geoff Beane Subject: FW: Pending NPDES permit Mr. McKay, Thank you for the information you have provided. As you are aware from the application the town would very much like to proceed with the most cost effective means of disposal of the water plant wastewater discharge, which would be into the receiving stream. We are very much interested in the details of a compliance schedule and are making plans for the dechlorination and flowmeter. I will be back in contact with you within the next few days. Regards, Christine W. Bralley Town Manager Mocksville, NC — "Time Well Spent" file://EANC00892901RE Pending NPDES permit reply.htm 336-753-6701 From: Mckay, James [mailto:iames.mckay@ncdenr.govl Sent: Mon 12/31/2012 11:02 AM To: Geoff Beane Subject: RE: Pending NPDES permit Geoff: I called your plant this morning and was told that you would be in at noon today. I will try to call you back this afternoon. In the meantime: 1. The permit draft was based on the application and information supplied by your consultant. It was based on the upgrade being completed. Since the plant modifications have not been made, I can modify the draft permit based on your current facility. 2. Dechlorination will have to be installed, even if the modifications are not installed. I can give a compliance schedule to allow you time to arrange funding, design/ procure/ install dechlorination equipment before the TRC limit applies. How much time would you need? Normally we allow 6 months for this, as it is usually a simple process. 3. A flowmeter will be required for measuring and recording the effluent from the facility. A compliance schedule can also be granted to allow time to install a flowmeter, if needed before the requirement is in effect. You must estimate and report effluent flowrate and duration (quantity, in units of MGD) in the interim. 4. Do you have any data on current turbidity of the effluent from your plant? If so, please email it to me for review. If the current plant effluent has turbidity over 50 NTU, a turbidity limit must be applied to the permit. If not, then turbidity monitoring without a limit will remain for this permit cycle. Jim McKay, Environmental Engineer NC DENR / Division of Water Quality / Surface Water Protection Section Point Source Branch 1617 Mail Service Center, Raleigh, NC 27699-1617 919/807-6404 (work); 919/807-6489 (fax) "Please note, my email address has changed to James.McKay@ncdenr.gov E-mail correspondence to and from this address may be subject to the North Carolina Public Records law, and may be disclosed to third parties. From: Geoff Beane [mailto: abeane a,mocksvillenc.govl Sent: Friday, December 28, 2012 5:13 PM To: Christine Bralley Cc: Mckay, James Subject: Pending NPDES permit In regards to the draft NPDES permit, according to the permit the wastewater is to be treated by two 180,000 gallon equalization tanks. We have no such structures in place. Without these tanks I believe we will not be in compliance with the permit criteria. The plant does not have the recommended 4 hours detention time and as a result we have a good bit of carry over floc that settles in the filter. Our filter run times are usually 22-28 hours. This unsettled floc would be discharged in the normal wash cycle We also have to pump the water from hunting creek to the plant. We use two pumps but even at best operation we overflow at least 50,000-100,000 gallons per day, due to filter turbidity compliance and filter washing, the basin fills up and overflows. We currently have no way to prevent this. Hunting creek is pretty volatile with turbidity increases. this sometimes results in the loss of treatment at the plant. The filters are placed on rewash to pull water from the basin until treatment is restored. That wastewater too is discharged through the sample piping as the filter washwater. That can add to file://EANC00892901RE Pending NPDES permit reply.htm the amount of water discharged. It is an old plant it is uncertain if any leaks are adding to the current wastewater amount. We have no flow meter in place currently to monitor this process. As part of the upgrade package that was supposed to include the equalization tanks, there was supposed to be installed variable speed pumps and drive units at the creek intake to better control the raw flow. In closing I stress without the wastewater tanks or lagoons in place I fear we cannot achieve compliance with the pending permit. Sincerely, Geoff Beane Town of Mocksville WTP-ORC W 336-751-2635 C 336-345-5636 file://E:INC00892901RE Pending NPDES permit reply.htm Mckay, James From: Mckay, James Sent: Wednesday, January 02, 2013 8:43 AM To: 'Geoff Beane' Cc: Basinger, Corey Subject: RE: Pending NPDES permit Geoff: Our office was closed shortly after 2:00 Monday and everyone was sent home, so I was not able to reply to your email. Has the upgrade been delayed, or canceled? EPA is very sensitized to turbidity in -stream, especially when a turbidity impaired receiving stream is impacted by turbidity coming from a discharge to it. Luckily, Bear Creek is impaired for copper and biological integrity, but not for turbidity. We will have to require you to monitor and report turbidity in your discharge, but no limits at this time. You should be able to continue operating as you have been, but the Regional Office staff may be checking on turbidity more often to keep an eye on it. Hopefully you will be completing the planned upgrades to the facility in the near future to address the turbidity issues. The dechlorination and flow meter must be installed in a timely manner. Like I said earlier, I can give a compliance schedule to allow time to complete these two, but the schedule will have to be met, or penalties may be issued for noncompliance. Once we have agreed on the compliance schedule, I will make the necessary changes to the permit draft and send a revised copy to you. Please send me all questions and comments. Beat regards, Jim McKay, Environmental Engineer NC DENR / Division of Water Quality / Surface Water Protection Section Point Source Branch 1617 Mail Service Center, Raleigh, NC 27699-1617 919/807-6404 (work); 919/807-6489 (fax) "Please note, my email address has changed to James.McKay@ncdenr.gov E-mail correspondence to and from this address may be subject to the North Carolina Public Records law and may be disclosed to third parties. From: Geoff Beane[mailto:gbeane@mocksvillenc.gov] Sent: Monday, December 31, 2012 2:44 PM To: Mckay, James Subject: RE: Pending NPDES permit Hi, Mr. McKay: Thanks for your quick reply. I will have to firm some things up with our town manager as to the when's regarding the dechlor system and flow meter. Should have an answer by the end of the week. No data has ever been collected regarding the turbidity of the waste effluent. When we wash filters, basins and have plant upsets this turbidity I would expect to be over 50 ntu. Sometimes our raw turbidity can exceed 500 ntu after a rain event. Most the time what is coming out of the waste line is overflowed settled water. Also pending the permit how are basin washes to proceed? Thanks Geoff Beane Town of Mocksville WTP-ORC W 336-751-2635 C 336-345-5636 From: Mckay, James rmailto:james.mckayancdenr.go_v] Sent: Mon 12/31/2012 11:02 AM To: Geoff Beane Subject: RE: Pending NPDES permit Geoff: I called your plant this morning and was told that you would be in at noon today. I will try to call you back this afternoon. In the meantime: 1. The permit draft was based on the application and information supplied by your consultant. It was based on the upgrade being completed. Since the plant modifications have not been made, I can modify the draft permit based on your current facility. 2. Dechlorination will have to be installed, even if the modifications are not installed. I can give a compliance schedule to allow you time to arrange funding, design/ procure/ install dechlorination equipment before the TRC limit applies. How much time would you need? Normally we allow 6 months for this, as it is usually a simple process. 3. A flowmeter will be required for measuring and recording the effluent from the facility. A compliance schedule can also be granted to allow time to install a flowmeter, if needed before the requirement is in effect. You must estimate and report effluent flowrate and duration (quantity, in units of MGD) in the interim. 4. Do you have any data on current turbidity of the effluent from your plant? If so, please email it to me for review. If the current plant effluent has turbidity over 50 NTU, a turbidity limit must be applied to the permit. If not, then turbidity monitoring without a limit will remain for this permit cycle. Jim McKay, Environmental Engineer NC DENR / Division of Water Quality / Surface Water Protection Section Point Source Branch 1617 Mail Service Center, Raleigh, NC 27699-1617 919/807-6404 (work); 919/807-6489 (fax) "Please note, my email address has changed to James.McKay@ncdenr.gov E-mail correspondence to and from this address may be subject to the North Carolina Public Records law and may be disclosed to third parties. From: Geoff Beane [mailto: b�Omocksvillenc.gov] Sent: Friday, December 28, 2012 5:13 PM To: Christine Bralley Cc: Mckay, James Subject: Pending NPDES permit In regards to the draft NPDES permit, according to the permit the wastewater is to be treated by two 180,000 gallon equalization tanks. We have no such structures in place. Without these tanks I believe we will not be in compliance with the permit criteria. The plant does not have the recommended 4 hours detention time and as a result we have a good bit of carry over floc that settles in the filter. Our filter run times are usually 22-28 hours. This unsettled floc would be discharged in the normal wash cycle We also have to pump the water from hunting creek to the plant. We use two pumps but even at best operation we overflow at least 50,000-100,000 gallons per day, due to filter turbidity compliance and filter washing, the basin fills up and overflows. We currently have no way to prevent this. Hunting creek is pretty volatile with turbidity increases. this sometimes results in the loss of treatment at the plant. The filters are placed on rewash to pull water from the basin until treatment is restored. That wastewater too is discharged through the sample piping as the filter washwater. That can add to the amount of water discharged. It is an old plant it is uncertain if any leaks are adding to the current wastewater amount. We have no flow meter in place currently to monitor this process. As part of the upgrade package that was supposed to include the equalization tanks, there was supposed to be installed variable speed pumps and drive units at the creek intake to better control the raw flow. In closing I stress without the wastewater tanks or lagoons in place I fear we cannot achieve compliance with the pending permit. Sincerely, Geoff Beane Town of Mocksville WTP-ORC W 336-751-2635 C 336-345-5636 AT#LAB NCDENR North Carolina Department of Environment and Natural Resources Division of Water Quality Beverly Eaves Perdue Charles Wakild, P. E. Dee Freeman Governor Director Secretary December 19, 2012 MEMORANDUM To: Lisa Edwards NC DENR / DWR/ Regional Engineer Winston-Salem Regional Office From: Jim McKay Complex NPDES Permitting Subject: Review of proposed NPDES Permit NCO089290 Hugh A. Lagle WTP, Davie County. Please indicate below your agency's position or viewpoint on the draft permit and return this form by January 19, 2013. If you have any questions on the draft permit, please contact me at telephone number (919) 807-6404, or via e-mail at James.McKay@ncdenr.gov. RESPONSE: (Check one) Concur with the issuance of this permit provided the facility is operated and maintained properly, the stated F_x] 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: F-1 Opposes the issuance of the above permit, based on reasons stated below, or attached: Signed `°°` P Date: 1-23-13 1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Location: 512 N. Salisbury St. Raleigh. North Carolina 27604 Phone: 919-807-63001 FAX: 919-807-6489 Internet www.ncwaterauality.org An Equal Opportunity 1 Affirmative Action Employer Nose Carolina �turally NORTH CAROLINA FORSYTH COUNTY AFFIDAVIT OF PUBLICATION Before the undersigned, a Notary Public of said County and State, duly commissioned, qualified, and authorized by law to administer oaths, personally appeared D.H. Stanfield, who being duly sworn, deposes and says: that he is Controller of the Winston-Salem Journal, engaged in the publishing of a newspaper known as the Winston-Salem Journal, published, issued and entered as second class mail in the City of Winston-Salem, in said County and State: that he is authorized to make this affidavit and sworn statement: that the notice or other legal advertisement, a true copy of which is attached hereto, was published in the Winston-Salem Journal on the following dates: December 21, 2012 and that the said newspaper in which such notice, paper document, or legal advertisement was published was, at the time of each and every such publication, a newspaper meeting all the requirements and qualifications of Section 1-597 of the General Statutes of North Carolina and was a qualified newspaper within the meaning of Section 1-597 of the General Statutes of North Carolina. This 21st day of December, 2012tQ (signature ofperson mapnk affidavit) Sworn to and subscribed before me, this 21 st day of December, 2012 .Lh cr NotaJ Public My Commission expires: September 28, 2015 LMY KIMALEY JOHNSON NOTARY PUBLIC FORSYTH COUNTY STATE OF NORTH CAR I OMMISSION EXPIRE PUBLIC NOTICE North Carolina Environmental Management Commission/NPDES Unit 1617 Mail Service Center Raleigh, NC 27699-1617 Notice of Intern to Issue a NPDES Wastewater Permit lorth Carolina Environmental Manag Ission proposes to issue a NPDES wa charge permit to the Persons) listed requests to DWQ at the a persons may visit the D Street, Raleigh, NC to rei Additional information on notice may be found on of ncdenr.org/web/wq/swp/l by calling (919) 807-6390. quested issuance of perm ter Treatment Plant in Di ted discharge is treated It ter to a UT to Bull Creek, Ya Par, or ksville re - or Its Wa- is permit- wastewa- WSJ: December 21, 2012 Mckay, James From: Basinger, Corey Sent: Tuesday, December 11, 2012 3:06 PM To: Mckay, James Subject: RE: Draft NPDES Permit for Mocksville WTP Jim, The draft looks good. Proceed to public notice. Many thanks. Corey W. Corey Basinger Regional Supervisor Surface Water Protection Section Winston-Salem Regional Office Division of Water Quality Email: corey.basineer@ncdenr.eov Phone: (336) 771-5000 Fax (336) 771-4630 E-mail correspondence to and from this address may be subject to the North Carolina Public Records Caw and may be disclosed to third parties. From: Mckay, James Sent: Tuesday, December 11, 2012 2:58 PM To: Basinger, Corey Subject: Draft NPDES Permit for Mocksville WTP Corey, Attached is the draft for the Mocksville WTP permit. It should go out to public notice Wednesday of next week. If there are some things that I need to change before that, please let me know. Otherwise, please send any questions or comments to me. Jim McKay, Environmental Engineer NC DENR / Division of Water Quality / Surface Water Protection Section Point Source Branch 1617 Mail Service Center, Raleigh, NC 27699-1617 919/807-6404 (work); 919/807-6489 (fax) "Please note, my email address has changed to James.McKay@ncdenr.gov E-mail correspondence to and from this address may be subject to the North Carolina Public Records law and may be disclosed to third parties. DR. F. W. SLATE Mayor Commissioners: WILL MARKLIN, Mayor Pro Tem RICHARD BROADWAY LASH GAITHER SANFORD, JR. ROB TAYLOR AMY VAUGHAN-JONES July 3, 2013 J0Wri o/ Mr. Jim McKay NCDENR — Division of Water Quality Surface Water Protection Section Point Source Branch 1617 Mail Service Center Raleigh, North Carolina 27699-1617 INCORPORATED 1839 CHRISTINE W. BRALLEY // Town Manager ocGZ4vi e 171 S. CLEMENT STREET MOCKSVILLE, NC 27028 Subject: Town of Mocksville Hugh A. Lagle Water Treatment Plant Proposed NPDES Permit No. NC 0089290 Dear Mr. McKay: HENRY P. VAN HOY II Town Attorney Thank you for your guidance in helping the Town of Mocksville secure a NPDES Permit for the wash water discharge from our Water Treatment Plant. As you know the wash water from the Hugh A. Lagle Plant discharges directly to an unnamed tributary of Bear Creek and does not yet have an NPDES Permit associated with it. We have reviewed the Draft Permit provided to us in December of 2012 and generally agree to the requirements therein; however the Draft Permit indicates wash water is treated in two equalization basins followed by dechlorination and flow monitoring. The Town has not yet constructed these facilities and we therefore request the State grant additional time for us to design, permit and build these facilities prior to compliance with the NPDES Permit. We request the State provide twenty-four months for this process to allow us adequate time to comply with the Permit. The facilities we proposed to build are currently being evaluated. We have engaged Willis Engineers, Inc. of Charlotte for this evaluation. They have prepared the attached Technical Memorandum describing several options for our consideration. The Town has elected to build two concrete tanks and other facilities as described in the Technical Memorandum. We therefore request the NPDES Permit reflect those facilities. We trust this update is adequate for your needs. Should you need any additional information please feel free to contact me or Chuck Willis at Willis Engineers (704.338.4668). Sincerely, Christine,W. Bralley Town Manager PHONE: (336) 753-6700 • FAX: (336) 751-9187 www.mocksvillene.org Town of Mocksville, North Carolina Hugh A. Lagle Water Treatment Plant Wash Water Disposal Prepared By: Charles A. Willis, Jr. P.E., BCEE Willis Engineers (F-0114) 10700 Sikes Place, Suite 230 Charlotte, NC 28270 Date: July 1, 2013 Table of Contents 1. Overview 2. Background 3. Treatment Process Improvements 4. Storage Basin Options 5. Regulatory Requirements 6. Financial Options 7. Recommendations Attachments 1- Overview Technical Memorandum ',,1�1951SISIIjI,, ,,•%`.��►cARoz .• • E !p •. 9 a SEAL 41 �7710 , d. • C1 ii • Wien pJzy zaIS As requested, Willis Engineers has investigated options for wash water disposal at the Hugh A. Lagle Water Treatment Plant. We understand the Plant has served the Town well for many years, but has never been equipped with wash water disposal facilities other than a direct discharge to a tributary of Bear Creek. Under State and Federal regulations, the Town is required to have a National Pollutant Discharge Elimination System (NPDES) Permit for the discharge of wash water from the Plant. Our evaluation is intended to identify several options for wash water disposal facilities sufficient to comply with regulatory requirements, assist the Town in negotiating an appropriate NPDES Permit, and define the future efforts necessary to construct the wash water facilities. The results of our evaluation and recommendations are included herein. 2 - Background The NPDES program in North Carolina is administered by the NC Department of Environment and Natural Resources— Division of Water Quality (DWQ). Under this program all point -source discharges of wastewater are required to obtain an NPDES Permit, setting forth limits on the quantity and character of wastewater to be discharged. For most water treatment plant W�I�SENGINEERS 1 Town of Mocksville, North Carolina Hugh A. Lagie Water Treatment Plant Wash Water Disposal Technical Memorandum operations, only limited treatment is required in order to comply with normal Permit limits. This treatment usually consists of some form of settling to remove suspended material and dechlorination. At that point typical water treatment plant wash water has little, if any, impact on a receiving water course. At the Mocksville Water Treatment Plant we would expect an NPDES Permit would require daily flow monitoring and include limits for suspended solids, total residual chlorine and regular monitoring of several other constituents. The State has previously provided a Draft NPDES Permit including these requirements; however, the Draft Permit assumed that adequate treatment facilities were already in place. The Town therefore could not accept the Permit as proposed. The Lagle Water Treatment Plant has the capacity to produce 2.0 million gallons per day (MGD) and currently operates between 0.8 and 1.2 MGD. Sources of wash water at the Plant include backwash from filters, drains from sampling locations and other typical functions. In addition to these normal daily discharges, the Plant staff will periodically drain the sedimentation basins for cleaning resulting in a discharge of 250,000 gallons. These activities only scheduled several times a year, nonetheless sufficient capacity should be made available for receiving this amount of drainage. In addition to the normal backwash functions, the Plant also has experienced some difficultly with maintaining flow control within the treatment process. Currently the raw water pumps located at Hunting Creek convey water to the Plant at a fixed rate. Flow through the Plant is controlled by rate -of -flow control valves at each filter. When the raw water pumping rate exceeds treatment rate, excess water is diverted to the overflow drains and is discharged. All of the water draining from the Plant exits through a common drain and discharges to a ditch in the northwest corner of the property which is tributary to Bear Creek. 3 —Treatment Process Improvements The primary facility necessary to handle wash water from the Plant will be some form of storage basin. This basin would allow for flow equalization, settling solids and decanting clear water for discharge. An adequate storage basin, in combination with chemical addition for dechlorination, should be sufficient to meet the anticipated NDPES Permit limits. Options for the storage facilities are discussed in Section 4. The staff has also expressed interest in reducing the total quantity of flow discharged through the drainage system, primarily by reducing basin overflow. One option that was investigated includes the addition of a rate -of -flow control valve on the raw water line entering the Plant. W11181SENGINEERS Town of Mocksville, North Carolina Hugh A. Lagle Water Treatment Plant Wash Water Disposal Technical Memorandum This valve would allow the Plant staff to control the raw water rate to match the filters, thereby reducing overflows and the quantity of wash water produced. Although this idea has merit, we are concerned that the addition of a raw water rate -of -flow valve will increase the operating pressure on the raw water lines. These pipelines are made of asbestos cement and have never been subjected to any significant pressure in the vicinity of the Water Treatment Plant. Control of the flow in this manner may create an increased risk of a line breakage. The Plant staff has also experimented with controlling filter flow rates to more closely match raw water pumping rates. In recent months they been very successful in managing the flow rate of the Plant to minimize the quantity of excess wash water produced. This management strategy is far safer and can be accomplished without any major capital improvements. We . would recommend replacing an existing valve on the raw water line that is difficult to operate. This would allow for easier modulation and flow control by the operation staff. The nature of the settled water at the Lagle Water Treatment Plant is somewhat unique. In most treatment facilities raw water is combined with coagulant and other chemicals such that suspended matter (turbidity) flocculates and settles to the bottom of the sedimentation basins. At the Lagle Water Treatment Plant a substantial amount of this material tends to float to the surface, creating a scum layer across the top of the sedimentation basins that is difficult to remove. A portion of this floating scum is carried away when the sedimentation basins overflow during the backwash process, but nearly half of the basin is not equipped with an overflow drain. in the downstream sections of Sedimentation Basins 1 and 2, floating sediment accumulates and creates a thick earth mat floating on top of the water (Photo 1). The condition is not as bad in Sedimentation Basin 3 (Photo 2). The floating sediment may be partial attributed to poor mixing and flocculation. The original baffle style flocculation serving basins 1 and 2 have deteriorated and should be renovated (Photo 3). Although improved mixing and flocculation would likely help, testing tends to indicate it would not entirely eliminate floating scum. It is therefore advisable to provide additional scum removal. Several options are available including additional overflow pipes or a rotating weir assembly that could be utilized during the backwash cycle to periodically remove the accumulated scum. Prior to discharge, wash water will need to be dechlorinated. Fortunately, dechlorination can easily be accomplished using one of several sulfur -based chemicals, either in gaseous or liquid form. Given the size of the Plant, we recommend using liquid sodium bisulfite or sodium thiosulfate. These chemicals can be purchased in barrels or "totes" and dispensed with a simple chemical dosing pump. W11I15ENGINEERS 3 Town of Mocksville, North Carolina Hugh A. Lagle Water Treatment Plant Wash Water Disposal 4 - Storage Basin Options Technical Memorandum The main component of the wash water disposal system will be the construction of storage basins suitable for holding wash water and equalizing discharge flows. These basins should be large enough to accommodate at least several days flow and provide for adequate storage of sediment between cleanings. Several options for this facility have been evaluated including construction of earthen storage basins or concrete tanks. The overall construction costs of these facilities are similar, as demonstrated on the attached Basis of Design and Cost Estimate. Previous proposals have included construction of several circular concrete tanks with the idea that mechanical equipment could be provided to allow for removal of sludge, dewatering and disposal. Unfortunately, this type of facility is fairly expensive to build and operate. If the Town builds concrete tanks, it may wish to undertake the project in multiple phases. The first phase would include the concrete tanks, with mechanical dewatering equipment added at a later date. Construction of concrete storage tanks would include two circular 250,000 gallon tanks equipped with piping to allow water to be discharged to either basin. A floating decanter would be provided on a flexible hose in each basin to allow staff to withdrawal clear water from the top of the storage facility. As sludge accumulates, the basin could be drained and the sludge removed for dewatering by a contract operator. The general arrangement of the facilities is shown on the attached Figure 1. The estimated costs of undertaking the improvements using concrete storage basins would be approximately $614,000. Another option would be to construct earthen storage basins. These basins would be somewhat larger, with each basin having a volume of approximately 400,000 gallons. The topography of the site is difficult for the construction of earthen basins; therefore, it would be advisable to construct these facilities closer to Sanford Avenue and utilize a pumping station. These shallow basins will allow for increased settling time and use a similar decanter arrangement as provided in the concrete basin. The advantage of the earthen basins is that the sludge removal could be accomplished utilizing traditional construction equipment, possibly undertaken by Town staff, thereby reducing the overall operating costs. The general arrangement of these facilities is shown on the attached Figure 1.Construction costs for these facilities would be approximately $595,000. Another advantage to undertaking earthen basin storage is that a portion of the facilities could be constructed by Town staff or a local grading contractor. Town staff has expressed interest in undertaking this option and estimates that a substantial cost savings could be realized utilizing Town forces. The disadvantage to this option is that an additional pumping station would be 1111MENGINEERS Town of Mocksville, North Carolina Hugh A. I.agle Water Treatment Plant Wash Water Disposal Technical Memorandum required to convey drainage to the earthen storage basins. This work would likely require the services of a specialized contractor with experience in constructing pumping stations. 5 -- Regulatory Requirements The Town has had conversation with DWQ representatives who have indicated the willingness to issue a NPDES Permit with substantial time available for compliance. In our conversation with DWQ they concur that a two-year timeframe for compliance would be satisfactory which should allow sufficient time for construction of the proposed facilities. They have also indicated that Permit limits would likely include 30 mg/I Total Suspended Solids and 17 JLg/I Total Residual Chlorine. Both of these limits should be achievable using either storage option outlined above. In addition to the NPDES Permit, the Town will need approval for construction of the new facilities from the Division of Water Resources and Division of land Quality. These approvals are fairly routine and could only be undertaken after issuance of the NPDES Permit and completion of detailed construction documents. 6 - financial Options The construction of the proposed facilities will require a significant capital investment which may be beyond the immediate capabilities of the Town. Unfortunately, grant funds for such work are scarce in the current economy. Several options for low or no interest financingmay be available should the Town wish to pursue them. If the Town is to undertake a portion of the work utilizing Town forces, it is unlikely that these loan mechanisms would be available for the entire project. The work would likely need to be divided into multiple contracts with loan packages arranged only for those services provided by outside contractors. 7 - Recommendations We recommend the Town comply with NPDES requirements by entering into a Permit as issued by DWQ. The Permit could be issued with sufficient time for construction of the facilities with an anticipated completion date of two years. In order to undertake these improvements the Town will first need to decide which type of facility will be constructed and undertake its detailed design. Either concrete tanks or earthen storage basins would be acceptable and the decision is primarily based on how much Town labor would be acceptable in the construction and operation of these facilities. W�IYSENGINEEAS Town of Mocksville, North Carolina Hugh A. Lagle Water Treatment Plant Wash Water Disposal Photo 1— Sedimentation Basin #2 pit ... Photo 2—Sedimentation Basin #3 Technical Memorandum UUIIIISENGINEERS Town of Mocksville, North Carolina Hugh A. Lagle Water Treatment Plant Wash Water Disposal Photo 3 — Baffled Flocculator Technical Memorandum WIIIISENGINEERS Town of Mocksville Wash Water Disposal Existing Facility Improvements Piping Flocculation Sedimentation Basins Dechlorination Chemical Feed Method Wash Water Storage Type Number and Size Volume (each) Piping & Valves Inlet Piping Outlet Piping Flow Monitoring Size and Type Sampling Controls Preliminary Cost Estimate Existing Facility Improvements Dechlorination Facilities Grading and Driveways Back Wash Tanks Piping and Valves Floating Decanters and Hoses Flow Monitoring and Sampling Site Work and Fencing Electrical Service Subtotal Construction Contingencies (10%) Technical Services (15%) Total Estimated Project Cost Concrete Tank Option Basis of Design & Cost Estimate Raw water valve replacement Baffle replacement Slimmers, rotating weirs and piping Sodium Bisulfite or Sodium Thlosulfate Peristaltic feed pumps, manual controls Cast -in -place concrete tanks Two, 60-ft diameter, 12-ft SWD 250,000 gal 200 If of 12-in, isolation valves 250 If of 8-in and 12-in, floating decanters 8-in Parshall Flume Grab sample point Continuous flow recording, totalizer $35,000 10,000 120,000 226,000 40,000 10,000 20,000 10,000 15,000 $485,000 $614,000 Willis Engineers 1984.001 (20) July 2013 Town of Mocksville Earthen Basin Option Wash Water Disposal Basis of Design & Cost Estimate Basis of Design Existing Facility Improvements Piping Raw water valve replacement Flocculation Baffle replacement Sedimentation Basins Skimmers, rotating weirs and piping Dechlorination Chemical Sodium Bisulfite or Sodium Thiosulfate Feed Method Peristaltic feed pumps, manual controls Wash Water Pump Station Size and Type 10-ft diameter, 20-ft deep, precast concrete Pump Type (s) Low -head vertical turbine or submersible Pump Capacities One @ 200 gpm, two @ 2500 gpm Wash Water Storage Type Earthen Basin, unlined Number and Size Two, 140-ft by 100-ft, 5 ft deep Volume (each) 400,000 gal Piping & Valves Inlet Piping 200 If of 12-1n, isolation valves Outlet Piping 250 If of 8-in and 12-in, floating decanters Flow Monitoring Size and Type 8-in Parshall Flume Sampling Grab sample point Controls Continuous flow recording, totalizer Preliminary Cost Estimate Existing Facility Improvements $35,000 Dechlorination Facilities 10,000 Back Wash Pump Station 220,000 Earthen Basin 80,000 Piping and Valves 40,000 Floating Decanters and Hoses 10,000 Flow Monitoring and Sampling 20,000 Site Work and Fencing 10,000 Temporary Dewatering Area 20,000 Electrical Service 25.000 Subtotal $470,000 Construction Contingencies (10%) 47,000 Technical Services (15%) Total Estimated Project Cost $595,000 Willis Engineers 1984.001 (20) July 2013 /V ||PROPOSED GRAMEL ~- ~-~'-Otto - -'-_'--_-_-/ 740 750 740 WASH WX ER SCHARGE I WAStl WITERI " T f I 750 PUM FLOW MONITORING E)aSMG WASH AND SAMPLING WATER DRAIN 1 -0 ma PROVIDE DECHLORINATION WATER CLEARWELL IN EXISTING UTILITY BLDG..,, FLOATING DECANTER WITH FLEXIBLE DRAIN CL el WATER EBrr em TEMPORARY DEWATERING AREA WITH PRECAST PROPOSED GRAVEL 59ALMNO WALL ACCESS ROAD- - - Folto Or- sw vi SITE PLAN a G� CAMr X� AS PRELIMINARY DRAWING TOWN OF MOCKSVILLE WASH WATER DISPOSAL BASEVARDWO am w AMA NOT FOR CONSTRUCTION MMS5ENGwas WATER TREATMENT PLANT EARTHEN BASIN OPTION 2 === ON AME 2013 0 120 240 SCALE: 1"=120' CONTOURS AT 10' TRIBUTARY Tp BEAR CREEK 0 PROP DISCHARGE r I �I PROP. WASTE WATER TANKS nCLEARWELL.-�* n PLN-WP DISCHARGE LOCATION\OVR 120A GREY ENGINEERING, INC. Civil Design and Surveying P.O. Box 9 Mocksville, N.C. 27028 greyengineering.com (336)751-2110 DRAWN BY: G. BULLARD I PROJ. NO.: 102.195.13E DESIGN BY: DATE: 11/28/12 0 RD.ado F _ 1 1 I TOWN OF MOCKSVILLE PROPOSED DISCHARGE LOCATION EXHIBIT 1 TO DRY DITCH ABOVE TRIBUTARY of aceAnalyfical wwwpacelabs.oam July 09, 2012 Town Of Mocksville Town Of Mocksville 771 Sanford Avenue Mocksville, NC 27028 RE: Project: VW11'Testing 06/21/12 Pace Project No.: 92122087 Pace Analytical Services, Inc. 6701 Conference Drive Raleigh, NC 27607 (919)834-4998 Dear Town Mocksville: Enclosed are the analytical results for sample(s) received by the laboratory on June 21, 2012. The results relate only to the samples included in this report. Analyses were performed at the Pace Analytical Services location indicated on the sample analyte page for analysis unless otherwise footnoted. If you have any questions concerning this report, please feel free to contact me. Sincerely, Terri Page terri.page@pacelabs..com Project Manager Enclosures REPORT OF LABORATORY ANALYSIS Page 1 of 5 This report shall not be reproduced, except in full, without the written consent of Pace Analytical Services, Inc.. " Pace Analytical Services, Inc. /� / 1 Jr ac, laf �/f r 't l 6701 Conference Drive wwwpBCeJa`� Raleigh, NC 27607 (919)834-4998 CERTIFICATIONS Project: VWV Testing 06/21/12 Pace Project No.: 92122087 Asheville Certification IDs 2225 Riverside Dr., Asheville, NC 28804 South Carolina Certification #: 99030001 Florida/NELAP Certification #: E87648 Virginia Certification #: 00072 Massachusetts Certification #: M-NC030 West Virginia Certification #: 356 North Carolina Drinking Water Certification #: 37712 VirginaNELAP Certification * 460147 North Carolina Wastewater Certification #: 40 Eden Certification IDs 205 East Meadow Road Suite A, Eden, NC 27288 Virginia Drinking Water Certification #: 00424 North Carolina Drinking Water Certification #: 37738 VirginiaAfELAP Certification #: 460025 North Carolina Wastewater Certification #: 633 REPORT OF LABORATORY ANALYSIS This report shall not be reproduced, except in full, without the written consent of Pace Analytical Services, Inc.. Page 2of5 aceAnalytical www.pacelabs.com SAMPLE ANALYTE COUNT Project: WW Testing 06/21/12 Pace Project No.: 92122087 Pace Analytical Services, Inc. 6701 Conference Drive Raleigh, NC 27607 (919)834-4998 Analytes Lab ID Sample ID Method Analysts Reported Laboratory 92122087001 Source EPA 9040 KPP I PASI-E EPA 200.7 JMW 12 PASI-A EPA 7470 SHI3 1 PASI-A 40CFR PART 432.2 EWS 1 PASI-A EPA 351.2 JDA 1 PASI-A EPA 353.2 DMN 1 PASI-A EPA 365.1 JDA 1 PASI-A REPORT OF LABORATORY ANALYSIS This report shall not be reproduced, except in full, without the written consent of Pace Analytical Services, Inc.. Page 3 of 5 aCieAnalyiical wwwpacelab&corn ANALYTICAL RESULTS Project: VWV Testing 06/21/12 Pace Project No.: 92122087 Sample: Source Lab ID: 92122087001 Collected: 06/21/12 06:00 Parameters Results Units Report Limit DF Qualifiers pH 7.4 Std. Units 0.10 1 H6 Antimony ND mg/L 0.0050 1 Arsenic ND mg/L 0.0050 1 Barium 0.028 mg/L 0.0050 1 Beryllium ND mg/L 0.0010 1 Cadmium ND mg/L 0.0010 1 Chromium ND mg/L 0.0050 1 Iron 0.79 mg/L 0.050 1 Manganese 0.074 mg/L 0.0050 1 Nickel ND mg/L 0.0050 1 Sodium ND mg/L 5.0 1 Thallium ND mg/L 0.010 1 Selenium ND mg/L 0.010 1 Mercury ND mg/L 0.00020 1 Nitrogen 1.8 mg/L 0.70 1 Nitrogen, Kjeldahl, Total 0.61 mg/L 0.50 1 Nitrogen, NO2 plus NO3 1.2 mg/L 0.020 1 Phosphorus 0.10 mg/L 0.050 1 Date: 07/091201210:44 AM REPORT OF LABORATORY ANALYSIS This report shall not be reproduced, except in full, without the written consent of Pace Analytical Services, Inc.. Pace Analytical Services, Inc. 6701 Conference Drive Raleigh, NC 27607 (919)834-4998 Page 4 of 5 ace"Iyflcal www. fraoeta,Ds.00m QUALIFIERS Project: VWV Testing 06/21/12 Pace Project No.: 92122087 DEFINITIONS Pace Analytical Services, Inc. 6701 Conference Drive Raleigh, NC 27607 (919)834-4998 DF - Dilution Factor, if reported, represents the factor applied to the reported data due to changes in sample preparation, dilution of the sample aliquot, or moisture content. ND - Not Detected at or above adjusted reporting limit. J - Estimated concentration above the adjusted method detection limit and below the adjusted reporting limit. MDL -Adjusted Method Detection Limit. PRL - Pace Reporting Limit. RL - Reporting Limit. S - Surrogate 1,2-Diphenylhydrazine (8270 listed analyte) decomposes toAzobenzene. Consistent with EPA guidelines, unrounded data are displayed and have been used to calculate % recovery and RPD values. LCS(D) - Laboratory Control Sample (Duplicate) MS(D) - Matrix Spike (Duplicate) DUP - Sample Duplicate RPD - Relative Percent Difference NC - Not Calculable. SG - Silica Gel - Clean -Up U - Indicates the compound was analyzed for, but not detected. N-Nitrosodiphenylamine decomposes and cannot be separated from Diphenylamine using Method 8270. The result reported for each analyte is a combined concentration. Acid preservation may not be appropriate for 2-Chloroethylvinyl ether, Styrene, and Vinyl chloride. LABORATORIES PASI-A Pace Analytical Services - Asheville PASI-E Pace Analytical Services - Eden ANALYTE QUALIFIERS H6 Analysis initiated outside of the 15 minute EPA recommended holding time. M1 Matrix spike recovery exceeded OC limits. Batch accepted based on laboratory control sample (LCS) recovery. M6 Matrix spike and Matrix spike duplicate recovery not evaluated against control limits due to sample dilution. Date: 07/09/201210:44 AM REPORT OF LABORATORY ANALYSIS Page 5 of 5 This report shall not be reproduced, except in full, without the written consent of Pace Analytical Services, Inc..