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Home My WebLink AboutNC0081671_Permit (Issuance)_20110624NPDES DOCUHENT SCANNING COVER SHEET NC0081671 Greensboro / Lake Townsend WTP NPDES Permit: Document Type: Permit Issuance Wasteload Allocation Authorization to Construct (AtC) Permit Modification Complete File - Historical Engineering Alternatives (EAA) Staff Report Instream Assessment (67b) Environmental Assessment (EA) Permit History Document Date: June 24, 2011 This document is printed on reuse paper - iariore any content on the re‘rerse side • AIM NCDENR North Carolina Department of Environment and Natural Resources Division of Water Quality Beverly Eaves Perdue Coleen H. Sullins Dee Freeman Governor Director Secretary • June 24, 2011 Mr. Allan E. Williams, P.E., Water Resources Director City of Greensboro P. O. Box 3136 Greensboro, NC 27402-3136 Subject: Issuance of NPDES Permit NC0081671 City of Greensboro — Lake Townsend WTP Guilford County Dear Mr. Williams: Division personnel have reviewed and approved your application for renewal of the subject permit. Accordingly, we are forwarding the attached NPDES discharge permit. This permit 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). This final permit includes no significant changes from the draft permit sent to you on April 13, 2011; however, its terms are significantly different from those found in the current permit. You should read the permit carefully, in order to help you maintain compliance with its terms and conditions. If any parts, measurement frequencies or sampling requirements contained in this permit are unacceptable to you, you have the right to an adjudicatory hearing upon written request within thirty (30) days following receipt of this letter. This request must be in the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of Administrative Hearings (6714 Mail Service Center, Raleigh, North Carolina 27699-6714). Unless such demand is made, this decision shall be final and binding. Please note that this permit is not transferable except after notice to the Division. The Division may require modification or revocation and reissuance of the permit. This permit does not affect the legal requirements to obtain other permits which may be required by the Division of Water Quality or permits required by the Division of Land Resources, the Coastal Area Management Act or any other Federal or Local governmental permit that may be required. 1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Location: 512 N. Salisbury St. Raleigh, North Carolina 27604 • Phone: 919-807-63001 FAX: 919-807.64921 Customer Service:1-877-623-6748 Internet: www.ncwaterquality.org An Equal Opportunity 1 Affirmative Action Employer Nose Carolina �tura!ly Mr. Alan Williams, P.E. Lake Townsend WTP Permit Renewal 2011 p. 2 If you have any questions conceming this permit, please contact Bob Sledge at telephone number (919) 807-6398, or via e-mail at bob.sledge@ncdenr.gov. y, Coleen H. Sullins cc: Central Files Winston-Salem Regional Office/Surface Water Protection Section NPDES File ec: Aquatic Toxicology Unit Barry Parsons Shamika Collins • • Permit NC0081671 STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES DIVISION OF WATER QUALITY PERMIT TO DISCHARGE WASTEWATER UNDER THE NATIONAL POLLUTANT DISCHARGE ELINIINATION 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 City of Greensboro is hereby authorized to discharge wastewater from a facility located at the Lake Townsend WTP 6268 Bryan Park Road North of Greensboro Guilford County to receiving waters designated as Reedy Fork Creek in the Cape Fear River Basin in accordance with effluent limitations, monitoring requirements, and other conditions set forth in Parts I,II,III and IVhereof. This permit shall become effective August 1, 2011. This permit and authorization to discharge shall expire at midnight on June 30, 2016. Signed this day June 24, 2011. een H. Sullins, Director ivision of Water Quality By Authority of the Environmental Management Commission • Permit NC0081671 • SUPPLEMENT TO PERMIT COVER SHEET All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked. As of this permit issuance, any previously issued permit bearing this number is no longer effective. Therefore, the exclusive authority to operate and discharge from this facility arises under the permit conditions, requirements, terms, and provisions included herein. The City of Greensboro is hereby authorized to: 1. Continue to discharge filter -backwash wastewater from a conventional water treatment plant. This facility is located at the Lake Townsend WTP, 6268 Bryan Park Road, north of Greensboro, in Guilford County. 2. Discharge from said treatment works at the location specified on the attached map into Reedy Fork Creek, classified C-NSW waters in the Cape Fear River Basin. Permit NC008 1671 Quad #: C2ONW Latitude: 36°11'22" Longitude: 79°43'55" Stream Class: C-NSW Subbasin: 03-06-02 Receiving Stream: Reedy Fork Creek NC0081671 City of Greensboro Lake Townsend WTP SCALE 1:24000 Permit NC0081671 A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS - FINAL 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 by the Permittee as specified below: EFFLUENT CHARACTERISTICS • _ LIMITS MONITORING REQUIREMENTS Monthly Average : Daily Maximum Measurement Frequency Sample Type Sample Location Flow Continuous Recording Effluent Total Suspended Solids 30.0 mg/L 45.0 mg/L Weekly Grab Effluent pH z 6.0 s.u. and <_ 9.0 s.u. Weekly Grab Effluent Total Residual Chlorine.' 17 pg/L Weekly Grab Effluent Turbidity Weekly Grab Effluent Aluminum Quarterly2 Grab Effluent Total Iron Quarterly2 Grab Effluent Total Copper Quarterly2 Grab Effluent Manganese Quarterly2 Grab Effluent Fluoride • Quarterly2 Grab Effluent Ammonia Nitrogen Quarterly2 Grab Effluent Total Phosphorous (TP) Quarterly2 Grab Effluent Total Nitrogen (TN) Quarterly2 Grab Effluent Whole Effluent Toxicity Monitoring3 Quarterly Grab Effluent Footnotes: 1. The Division shall consider all effluent TRC values reported below 50 µg/L to be in compliance with the permit. However, the Permittee shall continue to record and submit all values reported by a North Carolina certified laboratory (including field certified), even if these values fall below 50 µme- 2. Monitoring should be performed in conjunction with toxicity testing. 3. Ceriodaphnia dubia 7day pass/fail test @ 41% See Condition A. (2.) for toxicity testing requirements. Toxicity testing should be performed during the months of March, June, September and December, and sampling should coincide with sampling for parameters covered by footnote 2. All samples must be collected from a typical discharge event. There shall be no discharge of floating solids or visible foam in other than trace amounts. • • Permit NC0081671 A. (2.) CHRONIC TOXICITY MONITORING (QUARTERLY) The permittee shall conduct quarterly chronic toxicity tests using test procedures outlined in the "North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised February 1998, or subsequent versions. The effluent concentration defined as treatment two in the procedure document is 41 %. The testing shall be performed as a Ceriodaphnia dubia 7day pass/fail test. The tests will be performed during the months of March, June, September and December. Effluent sampling for this testing 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, DWQ Form AT-1 (original) is to be sent to the following address: Attention: NC DENR / DWQ / 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 Quality 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. News & Record Name Published by News & Record, Inc. Greensboro, North Carolina North Carolina, Guilford County Before the undersigned, a Notary Public of said County and State, duly commissioned, qualified and authorized by law to administer oaths, personally appeared the Publisher's Representative who being first duly sworn, deposed and says: AFFIDAVIT OF 1. That he/she is the Publisher's Representative of the Greensboro News & Record, Inc. a corporation, engaged in the publication of newspapers known as "News & Record", published, issued and entered as second class mail in the City of Greensboro in said County and State. 2. That he/she is authorized to make this affidavit and sworn statement; that the notice or other legal advertisement, a copy of which is attached hereto, was published in the News & Record on the dates listed below. 3. That the said newspaper (or newspapers) 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 of the requirements and qualifications of Section 1-597 of the General Statutes of North Ca i lina and s a q newspwithin the meaning of Section 1-59; of the General Statutes of North Carolina. Publisher's Representative Sworn to and subscribed befor - is - AP r / I , 2011 Notary Public Ad # Date Edition Class PO Ad COPY tow ` p 4NE ‘JOTAF My Comm. Exp. 6/15/2014 ‘ PUBLIC $ � -•iiiriiiitt�� NCDENR DWQ NPDES 34211420 04/20/11 News & Record 400 Lake Townsen Public NoticeNorth Carolina Environmenta Ad ID[34211420 Date 04/18/2011 Time 11:50 AM Pubis Notice North Carolina Environrrental Managerrent Corrrissbry NPDES Unit 1617 Mail Service Center Raleigh, NC 27699-1617 Notice of htent to Issue a NPD6 Wastewater Pe r rit The North Carolina Environmental Management Corm ission proposes to issue a NPDESwastewater discharge perrrittothe persons) listed below. Written corn -rents regarding the propo6ed pernit wil be accepted until 3) days afterthe pubis h date of this notice. The Director of the NC Division of Water Quality (DVVQ) may hold a pubk hearing should there be a signifiant degree of pubk interest Pbase rrei comments and'or information requests to DWQ at the abose address Interested persons rrey vsit the DWQ at 512 N. Salisbury Street, Raleigh, NC to review information on file Additional information on NPDES permts and this notice may be found on our website: http //po rtaL ncden rorg'webMgkwp/p s/npdes/calendar, or by calling (919) 807-6304 The City of Greensboro requested rerewal of perrrit NC0081671 for the Lake Townsend W[P in Guilford County, this permitted discharge 6 treated f iter-backwash wastewater to Reed Fork Creek n the Cape Fear River Basin. The City of Greensboro requested renewal of pernit NC0081426 for the N.L Mitchell W M in Guiford County, this perrrdted discharge is treated filter -backwash vsstewater to North Buffalo Creek in the Cape Fear River Basin. Guilford County Schook requested renewal of pernit NC0038164'Nathanael Greene Ebrrentary. Faciitydischarges treated wastewater to an unnarred trbutaryto North Prong Stinking QuarterCreelgCape Fear River Basin Currently BOD, amrone nitrogen, dissolved orrygen, fecal coliformand total residual chlorine are water quaky limited Quarterstone Farm HOA requested renewal of pemit NC0066966Quarterstone Farm WVVTP/Guilford County. Facility discha rges treated wastewater to Buffalo Creek/Cape Fear Riser Basin. Currently ammonia nitrogen, fecal cohforrn total nitrogen and total phosphorus are water quality lirrited . Ad shown is not actual print size FACT SHEET FOR EXPEDITED PERMIT RENEWALS This form must be completed by Permit Writers for all expedited permits which do not require full Fact Sheets. Expedited permits are generally simple 100% domestics (e.g., schools, mobile home parks, etc) that can be administratively renewed with minor changes, but can include facilities with more complex issues (Special Conditions, 303(d) listed water, toxicity testing, instream monitoring, compliance concerns). Basic Information for Ex edited Permit Renewals Permit Writer/Date Bob Sledge 4/12/2011 Permit Number NC0081761 Facility Name City of Greensboro — Lake Townsend WTP Basin Name/Sub-basin number Cape Fear River/ 03-06-02 Receiving Stream Reedy Fork Creek Stream Classification in Permit C-NSW Does permit need Daily Max NH3 limits? No - Monitoring only Does permit need TRC limits/language? Yes: Add TRC language below Does permit have toxicity testing? Added this cycle Does permit have Special Conditions? Nutrients Reopener? No Does permit have instream monitoring? No Is the stream impaired (on 303(d) list)? For what parameter? No Any obvious compliance concerns? No Any permit mods since last permit? Dechlorination Current expiration date June 30, 2011 New expiration date June 30, 2016 Comments received on Draft Permit? Yes No If Yes, discuss response with Supervisor Most Commonly Used Expedited Language: • 303(d) language for Draft/Final Cover Letters: "Please note that the receiving stream is listed as an impaired waterbody on the North Carolina 303(d) Impaired Waters List. Addressing impaired waters is a high priority with the Division, and instream data will continue to be evaluated. If there is noncompliance with permitted effluent limits and stream impairment can be attributed to your facility, then mitigative measures may be required". • TRC language for Compliance Level for Cover Letters/Effluent Sheet Footnote: "The Division shall consider all effluent TRC values reported below 50 µg/L to be in compliance with the permit. However, the Permittee shall continue to record and submit all values reported by a North Carolina certified laboratory (including field certified), even if these values fall below 50 µg/L.." BIMS Compliance Download: Queries>Reports>Violations>Monitor Report Violations>Limit Violations for Past 3 Years Reminder: Permits that are not subject to expedited renewal include the following: 1) Major Facility (municipal/industrial); 2) Minor Municipals with pretreatment program; 3) Minor Industrials subject to Fed Effluent Guidelines (lb/day limits for BOD, TSS, etc); 4) Limits based on reasonable potential analysis (metals, GW remediation organics); 5) Permitted flow > 0.5 MGD (requires full Fact Sheet); 6) permits determined by Supervisor to be outside expedited process. Note: This sheet is located on NPDES Server/CurrentVersions/Expedited Fact Sheet May2010 Sledge, Bob From: Sent: To: Cc: Subject: Attachments: Bob, Parsons, Barry [Barry.Parsons@greensboro-nc.govj Monday, March 28, 2011 2:27 PM Sledge, Bob Collins, Shameka; Drew, Steve RE: NPDES Permits: Mitchell & Lake Townsend WTPs MSDS Corrosion Inhibitor AquaPure.doc; Discharge Flows 2010.xlsx The following are some answers to your questions: 1. The backwash water is chlorinated and fluoridated. 2. We do not use a zinc compound in our corrosion inhibitor. I will attach an MSDS to this email. 3. We will be feeding ammonia and chlorine tentatively starting July 25th, 2011. 4. Attached are flow discharge values for Townsend filtration Plant and Mitchell Filtration Plant. Mitchell uses decanters and sanitary sewer. I hope this information is helpful! Thank you. Barry K Parsons, Interim Water Supply Manager Department of Water Resources City of Greensboro, NC Desk (336)-373-7643 Main (336)-373-5855 Fax: (336)-373-5834 From: Sledge, Bob fmailto:bob.sledaeCalncdenr.govl Sent: Monday, March 28, 2011 7:53 AM To: Parsons, Barry Subject NPDES Permits: Mitchell & Lake Townsend WTPs Hi Mr. Parsons, My name is Bob Sledge and I work in a compliance and permitting unit within the Division of Water Quality. I've been given the task of managing the relssuance of the wastewater discharge permits for your two facilities. The reissuing of these permits should be pretty easy, but the final results will be different from earlier permits because the Division has instituted a new strategy for permitting of discharges from conventional water treatment plants. To that end, I was hoping you could answer a few questions regarding operations at these plants. I've looked at the diagrams you provided in the renewal applications, but wanted to make sure of a few things instead of making wrong assumptions. Do these plants use finished, potable water for the backwashing of filters? Is the backwash water chlorinated and/or fluoridated? Do these facilities use zinc orthophosphate (or any other zinc compound) as a corrosion inhibitor? Do these facilities ever use chloramines as a secondary form of disinfection? It appears that each of these facilities discharge to their receiving streams just downstream of the dam release from the reservoir. Do you know if a minimum release rate has been established from the reservoirs to ensure there is a constant flow downstream? If so, can you provide me with those flow values? With your answers, I should be able to send you draft versions of the permits within the next few weeks. Thank you for your help in these matters. Bob Bob Sledge Environmental Specialist Compliance & Expedited Permits Unit NC Division of Water Quality bob.sledge@ncdenr.eov (919) 807-6398 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. Please note that email sent to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties. 2 City of Greensboro .4 North Carolina December 6, 2010 Dina Sprinkle NC DENR/DWQ/Point Source Branch 1617 Mail Service Center Raleigh, NC 27699-1617 Dear Mrs. Sprinkle: This letter is to request renewal of an existing NPDES permit. Please find enclosed a completed permit renewal package for the City of Greensboro's Lake Townsend Water Treatment Plant — NPDES permit, No. NC0081671. Since the current permit was issued, the plant has converted to ferric sulfate as the primary coagulant. If you should need any additional information, please contact Interim Water Supply Manager at 336-373-7643. Sincerely, Allan E. Williams, PE Director of Water Resources Cc: COGWR File Enclosures P.O. Box 3136 Greensboro, NC 27402-3136 www.greensboro-nc.gov (336) 373-CITY (2489) TTY# 333-6930 Name Mailing Address City State / Zip Code Telephone Number Fax Number NPDES PERMIT APPLICATION - SHORT FORM C - WTP For discharges associated with water treatment plants Mail the complete application to: N. C. Department of Environment and Natural Resources Division of Water Quality / NPDES Unit 1617 Mail Service Center, Raleigh, NC 27699-1617 NPDES Permit Number NC0081671 If you are completing this form in computer use the TAB key or the up - down arrows to move from one field to the next. To check the boxes, click your mouse on top of the box. Otherwise, please print or type. 1. Contact Information: Owner Name Facility Name Mailing Address City State / Zip Code Telephone Number Fax Number e-mail Address City of Greensboro Lake Townsend Water Treatment Plant PO Box 3136 Greensboro North Carolina 27402-3136 (336)373-7530 (336)373-7526 barry.parsons@greensboro-nc.gov 2. Location of facility producing discharge: Check here if same as above ❑ Street Address or State Road City State / Zip Code County 3. Operator Information: 6268 Bryan Park Road Brown Summit North Carolina 27214-9755 Guilford Name of the firm, consultant or other entity that operates the facility. (Note that this is not referring to the Operator in Responsible Charge or ORC) Barry Parsons 6268 Bryan Park Road n 1 jL'JIU Brown Summit 1 North Carolina 27214-9755 (336)373-7643 (336)373-7526 4. Ownership Status: Federal ❑ State ❑ 5. Type of treatment plant: Private ❑ Public El Page 1 of 3 C-WTP 03/05 NPDES PERMIT APPLICATION - SHORT FORM C - WTP For discharges associated with water treatment plants ® Conventional (Includes coagulation, flocculation, and sedimentation, usually followed by filtration and disinfection) O Ion Exchange (Sodium Cycle Cationic ion exchange) ❑ Green Sand Filter (No sodium recharge) ❑ Membrane Technology (RO, nanofiltration) Check here if the treatment process also uses a water softener 6. Description of source water(s) (i.e. groundwater, surface water) Surface Water (Lake Townsend) 7. Describe the treatment process(es) for the raw water: The treatment process is coagulation floculation using ferric sulfate as the primary coagulant entering sedimentation basins, followed by filters and then disinfected with sodium hypochlorite. 8. Describe the wastewater and the treatment process(es) for wastewater generated by the facility: Settling 9. Number of separate discharge points: 1 Outfall Identification number(s) 001 10. Frequency of discharge: Continuous ® Intermittent 0 If intermittent: Days per week discharge occurs: Duration: 11. Plant design potable flowrate 30 MGD Backwash or reject flow 772,600 MGD 12. Name of receiving stream(s) (Provide a map showing the exact location of each outfall, including latitude and longitude Reedy Fork Creek Outfall is at: N 36degrees 11.430', W 079degrees 43.855' Page 2 of 3 C-WTP 03/05 NPDES PERMIT APPLICATION - SHORT FORM C - WTP For discharges associated with water treatment plants 13. Please list all water treatment additives, including cleaning chemicals or disinfection treatments, that have the potential to be discharged. Ferric Sulfate Sodium Hypochlorite Sodium Hydroxide Hydrofluoricic Acid Calcium Hydroxide 14. Is this facility located on Indian country? (check one) Yes ❑ No Eg 15. Additional Information: ✓ Provide a schematic of flow through the facility, include flow volumes at all points in the treatment process, and point of addition of chemicals. • Solids Handling Plan 16. NEW Applicants Information needed in addition to items 1-15: • New applicants must contact a permit coordinator with the NCDENR Customer Service Center. Was the Customer Service Center contacted? ❑ Yes ❑ No • Analyses of source water collected • Engineering Alternative Analysis • Discharges from Ion Exchange and Reverse Osmosis plants shall be evaluated using a water quality model. 17. Applicant Certification I certify that I am familiar with the information contained in the application and that to the best of my knowledge and belief such information is true, complete, and accurate. Allan E. Williams, PE Water Resources Director Printed name of?erson Signing Title Signature of Applicant ), Date North Carolina General Statute 143-215.6 (b)(2) provides that: Any person who knowingly makes any false statement representation, or certification in any application, record, report, plan, or other document files or required to be maintained under Article 21 or regulations of the Environmental Management Commission implementing that Article, or who falsifies, tampers with, or knowingly renders inaccurate any recording or monitoring device or method required to be operated or maintained under Article 21 or regulations of the Environmental Management Commission implementing that Article, shall be guilty of a misdemeanor punishable by a fine not to exceed $25,000, or by imprisonment not to exceed six months, or by both. (18 U.S.C. Section 1001 provides a punishment by a fine of not more than $25,000 or imprisonment not more than 5 years, or both, for a similar offense.) Page 3 of 3 C•WTP 03/05 trY'Cfl.' 0 , aoo n 1VOW .LOMIPW.a. a.M:x.u..�..w..m. - ,wq 1 —.... 'eta` '"'• �'/I{ st I� i ` f f }` YJ F . ' —' 8C9•a { , , I . 0.3 0.6 0.9 0 0.2 0.4 0.6 Map center is UTM 17 614234E 4005972N (WGS84/NAD83) Browns Summit quadrangle Projection is UTM Zone 17 NAD83 Datum TOiA/A/SCA,g L,/3f NpcU"S ' NC 0 D 4 71 GL17r4/-L L0C47/UPI: N 3 ° f 1: 9:301 WC%'I. 49. gC5 htto://www.topozone.com/print.asp?7=17&n=4005972..00009105&e=614234.000000821... 10/12/2005 )\--G M=-8. 17 G=0.75 Waste Lagoon Backwash Water Tank Lake Townsend Water Treatment Plant Chlorine Fluoride Ammonia Finished Sample Point +—To Distribution—y-� Sotiium Hypochiorite (Chlorine) Chemical Building High Lift Pumps Caustic Bulk Storage Phosphate Bulk Storage --{>--Water to Storage r� v y 1 o Filtered E- Sample Point Lime Slurry Building Chlorine to Filters Alum Bulk Storage Fluoride Bulk Storage Alum Sedimentation Basin 2 --Raw Wator Transmission Lino ► Raw Water Sample Point Sedimentation Basin 3 1 Flocculatidn Basins f Flash Mixer Settled Sample Point Floc Sample Point PAX 18/Sulfuric Acid EarthTec Chemical Feed Points O Aluminum Sulfato (Alum) O Sodium Hypochlorlte (Chlorin) ® Sodium Hydroxide (Caustic) • Hydrofluorosilcic Acid (Fluoride) O Corrosion Inhibitor (Phosphate) • lime Slurry (lime) O Ammonia (Future) O Polyaluminum Chloride (PAX 18)lSuifuric Acid O Calcium Thiosultate 40 EarthTec r Cityof Greensboro L J North Carolina Addendum Sludge Management Plan The City of Greensboro's Lake Townsend Water Treatment Plan is a conventional surface water treatment facility permitted to treat (filter) 30 million gallons of water per day (MGD). The water produced by the facility meets all applicable State and Federal standards. The current average daily production at the facility is 21 MGD. All filter backwash and sedimentation wastewater from the facility flows to a settling lagoon on the plant site. Filter backwash flow is intermittent based on plant treatment rate and raw water quality conditions. Sedimentation wastewater flow is relatively constant with automated equipment removing dilute sludge (approximately 1% solids) to maintain full sedimentation basin volume. As wastewater flows through the settling lagoon, solids removed during the treatment process (consisting of primarily of Ferric Sulfate precipitate and the captured turbidity causing materials from the untreated raw water) settle to the bottom of the lagoon leaving a clear supernatant which meets the NPDES permit requirements. Sludge solids generated from the treatment process average approximately 1,100 dry tons per year. At 12 to 15 month intervals, the city contracts with a private sludge management firm, currently Synagro Environmental Protection and Improvement Company, to dredge and dewater the solids from the lagoon. The most recent cleaning began in October 2010 and should be completed before the end of December of 2010. All solids that are removed from the lagoon are used as either fill or cap admixture and transported to Eden Landfill (via Earthtek) in Rockingham County. P.O. Box 3136 Greensboro, NC 27402-3136 www.greensboro-nc.gov . (336) 373-CITY (2489) TTY # 333-6930