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HomeMy WebLinkAboutNC0026000_Response to additioal information_20170727rDI�CI<SON community infrastructure consultants July 27, 2017 Ms. Morella Sanchez King, PhD, PE Environmental Program Supervisor III NCDEQ-Wilmington Regional Office/Water Quality Operation Section 127 Cardinal Drive Extension Wilmington, NC 28405 RE: Compliance Evaluation of the Mercury Minimization Plan, Facility Evaluation and Corrective Action Plan - Requested Response Town of Tabor City WWTP/NPDES Permit No. NC0026000 Columbus County Dear Ms. Sanchez King: On behalf of the Town of Tabor City, we are pleased to provide this information in response to your letter dated June 8, 2017. We have compiled our response based on information provided by Municipal Engineering Service Company (MESCO), additional information from Town staff and additional information from work performed by WK Dickson staff. NCDEQ-WRO Comments/Requests with Responses 1. A priority list to accomplish the activities described in the CAP. The list should reflect coordination between the consultant companies preparing the CAP and ER. A meeting was held on February 16, 2017 between the Town, the Town's WWTP contract operator, WKD, MESCO and NCDEQ-DWI to discuss the coordination of the elements addressed in the CAP (prepared by WKD) and the project being funded by NCDEQ CWSRF (ER being prepared by MESCO). This meeting resulted in an agreement between all parties with regard to the corrective actions needed and the resulting amended Engineering Report submitted to NCDEQ-DWI and the CAP submitted to the NCDEQ-WRO reflect this. It is the Town's intent to address all of these items with the current project funded. An itemized list of the priority items to be addressed is as follows: 616 Colonnade Drive Charlotte, NC 28205 Tel. 704.334.5348 www.wkdickson.com Aviation • Water Resources • Land Development • Geomatics NCDEQ-WRO Response: Tabor City WWTP (NC0026000) July 27, 2017 Page 2 • Replace existing composite samplers with new refrigerated models. • Install automated valve to divert excess influent to surge basin based on metered influent flow. • Replace existing influent pumps with three new 50 HP pumps equipped with variable speed motors that will be controlled by VFDs. • Rehabilitate the mechanical bar screen at the current headworks structure. • Install DO probes and VFD motors for the upper treatment train. The probes will allow for proper control mechanisms which will operate VFDs in order to better control dissolved oxygen levels within the upper aeration basin and provide cost savings for Tabor City. • Dig up and expose the buried process pipe between aeration basin 1 and clarifier 1 to determine the hydraulic issues, correct any discovered deficiencies or blockage and place back in service. • Scrape and re -coat clarifier 1 with proper primer and outer coating system. • Rehabilitate the RAS pump station for treatment train 1. One RAS pump will be replaced and maintenance/general servicing will be executed on the second RAS pump. • Install influent flow meter recording station within the Lab Building to aid in operator's process control. • Reposition and replace the existing chlorine contact chamber. This new structure will utilize a dual chamber layout allowing one side to be taken off line for maintenance and cleaning efforts. • Change existing chlorine and sulfur dioxide gas feeds to safer hypochlorite and meta-bisulfite mixed liquid solution storage and feeds. • Replace 15 HP mixer in digester with new 15 HP aerator. Modify the existing decant system for the digester structure. The itemized list of planned improvements submitted to and approved by NCDEQ- DWI within the amended Engineering Report (MESCO) is attached. Note: A detailed description of all plant improvements is included on the last page of the excerpt provided by MESCO from the approved Engineering Report. 2. A tabulated schedule (based on the priority list in Item 1) with itemized corrective actions and realistic dates of implementation and completion. The schedule should include a contingency plan for lack of funding or lack of adequate funding. NCDEQ-WRO Response: Tabor City WWTP (NC0026000) July 27, 2017 Page 3 The following table outlines the schedule provided by MESCO for completing all priority items listed above: Town of Tabor City WWTP Improvements (NC002600) Project Milestone Milestone Date Engineering Report submitted to NCDEQ June 1, 2016 (actual) Engineering Report approved by NCDEQ June 30, 2017 (actual) Plans & Specifications/Permits submitted to NCDEQ October 2, 2017 (proposed) Plans & Specifications/Permits approved by NCDEQ February 1, 2018 (proposed) Receipt of Bids/Authorization to Award June 1, 2018 (proposed) Contracts Executed July 2, 2018 (proposed) Notice to Proceed July 15, 2018 (proposed) Project Completion July 15, 2019 (proposed) As previously discussed, the Town intends to undertake all priority items within this currently funded project. If bids come in above the amount of funding available for this project, the Town and MESCO will work to negotiate with the lowest qualified bidder to get as many of the itemized improvements completed. Should those negotiations be unsuccessful, the Town will work with its consultants and NCDEQ to determine if additional funds can be made available for the project and, at a last resort, the lowest priority items that can be removed from the current project and addressed in a future project. Should any itemized improvements need to be removed from the current project, the Town will prepare an additional funding application to secure funds as soon as possible and provide an update to the remaining priority items and include a proposed schedule to address them to NCDEQ-WQROS. Based on the schedule outlined above, a subsequent funding application could be submitted in September 2018. 3. Supporting documentation showing the progress and status of activities listed in Section III of the MMP. During the course of the facility evaluation, WKD worked with Town staff to determine the possible sources of mercury entering the wastewater system. The Town had previously surveyed dental offices and other commercial businesses. The main NCDEQ-WRO Response: Tabor City WWTP (NC0026000) July 27, 2017 Page 4 industrial user in Tabor City is Atlantic Corporation. Prior to finalizing the Mercury Minimization Plan, WKD staff conducted a facility investigation on January 6, 2016, met with company management and reviewed processes and MSDS sheets for all chemicals/compounds used at their facilities and provided information on materials handling/good housekeeping measures. There were no major issues found that would require more formal actions at this facility or a pre-treatment permit; however, some housekeeping and materials handling improvements were discussed and implemented. The Town will continue to monitor this facility with regard to any process/material changes that may impact mercury levels at the WWTP. Since January 2016, the Town has maintained compliance with the NPDES permit limit (12 ng/L for 12-month average). The table below details the monthly mercury sampling results for the 3 required sampling points: influent, mixed liquor suspended solids (MLSS) and effluent. A 12-month running average for these effluent samples is also included. Tabor City WWTP (NC0026000) Mercury Results 1/2016 - 6/2017 Date Influent Mercury (ng/L) MLSS Mercury (ng/L) Effluent Mercury (ng/L) 12-month Effluent Mercury Average Jan-16 800 1300 2.81 Feb-16 <200 1000 4.09 Mar-16 <200 1100 1.28 Apr-16 <200 1100 1.68 May-16 <200 1800 3.8 Jun-16 <200 1900 9.96 Jul-16 <200 1400 3.08 Aug-16 <200 <1000 6.66 Sep-16 <200 2200 7.19 Oct-16 <200 1000 1.75 Nov-16 <200 1500 2.31 Dec-16 200 2000 4.2 4.07 Jan-17 200 1700 3.41 r 4.12 Feb-17 <200 1400 2.38 r 3.98 Mar-17 <200 2100 2.37 r 4.07 Apr-17 <200 1100 1.72 r 4.07 May-17 200 4900 4.67 r 4.14 Jun-17 200 1100 3.3 r 3.59 NCDEQ-WRO Response: Tabor City WWTP (NC0026000) July 27, 2017 Page 5 The Town has added information to its website that provides information to residents and wastewater customers regarding minimizing the potential for discharging mercury into the wastewater system. The information is provided by the USEPA and outlines what routine products may contain mercury and what individuals can do to reduce impacts. This can be viewed at: www.taborcitync.org and a print screen from the Town's website is attached. 4. Supporting documentation of the I/I evaluation made (or in progress), including sewershed ranking and prioritization. Tabor City has recently received an Asset Inventory and Assessment (AIA) grant from NCDEQ-DWI. A major component of the AIA project is to complete an inspection of areas that have been identified as 'areas of concern' using CCTV inspection techniques. As a condition of the grant, a report will be prepared once these inspections are completed that will provide recommendations, prioritization and cost estimates for needed maintenance, repair and/or replacement of collection systems assets in order to further reduce inflow/infiltration. A copy of the contract with LKC Engineering, Inc. is attached. 5. An operation and maintenance plan should be on site at all times and should be updated as rehabilitation and improvements area implemented. Upon completion of the corrective actions, an operation and maintenance plan should be developed and submitted to the WQROS for approval. Upon completion of the planned improvements, MESCO will prepare and submit and Operation and Maintenance Plan for the WWTP to appropriate NCDEQ staff. NCDEQ-WRO Response: Tabor City WWTP (NC0026000) July 27, 2017 Page 6 Thank you for your continued assistance as we work collectively to improve operations at the Tabor City WWTP. We feel that the work performed by all parties has resulted in a comprehensive plan of action to ensure the Town is able to effectively and efficiently operate and maintain its WWTP and to remain in compliance with all NPDES permit conditions. We will provide updates to you as the planned project moves forward. If you have any additional questions or comments, please feel free to contact me at 843-540-1015 or amettlen@wkdickson.com. Sincerely, WK Dickson & Co., Inc. Angela G. Mettlen, Program Manager Attachments cc: Al Leonard, Town Manager - Town of Tabor City Bobby Blowe, PE- Municipal Engineering Services Company Jimmy Holland, PE - WK Dickson Tabor City WWTP NC002600 Excerpt from MESCO Approved Engineering Report flow is de -chlorinated at the effluent weir just prior to discharge into the creek. The CMU walls within the basin are crumbling and are in need of immediate repair. 10. Chlorine/De-Chlorination feed: Chlorination is provided by utilizing gaseous chlorine in 150 lb. cylinders where it is mixed with water and injected into the contact basin at the influent pipe feeding the Chlorine Contact Chamber. The de -chlorination process is provided by gaseous sulfur dioxide mixed with water and applied above the effluent weir of the chlorine contact basin The chemical storage and feed equipment is stored within two (2) FRP buildings adjacent to the chlorine contact basin. 11. Digester: The facility utilizes a concrete basin buried below grade with sloped sides. The basin currently utilizes a floating mixer to keep the waste sludge aerated prior to decant and disposal. 12. Samplers a. Influent and Effluent composite samplers: The existing sampler units are not currently refrigerated and require the operator to pack them with ice. Table 3.1.2 Description of Treatment Train Tabor City WWTP Improvements Tabor City For use with projects funded or co funded with the CWSRF, WW-HUC, WW--SRL, WW-SEL, and CDBG-I programs. Supporting Information Appendix Photo Appendix (if ER-3 ER-6 Reference* applicable): Check the box(es) that apply in accordance with Subchapter 2.1.2 of Part B of the guidance. Project is located in: a Liquid Treatment Train /1 Sludge/Solids Treatment Train Project repairs/replacements to the following unit processes: 1. Replace existing composite samplers with new refrigerated models. 2 Install divert basin based automated valve to excess influent to the surge on metered influent flow. 3. Replace existing influent pumps with three new 50 HP pumps equipped with variable be by VFD's speed motors that will controlled 4. Rehabilitate the mechanical bar screen at the current headworks structure 8 Table 3.1.2 Description of Treatment Train Tabor City WWTP Improvements Tabor City 5. Install DO probes and VFD motors for upper treatment train The probes will allow for proper control mechanisms which will operate VFD's in order to better control dissolved oxygen levels within the upper aeration basin and provide cost savings for Tabor City. 6. Dig the buried between basin 1 1 up and expose process pipe aeration and clarifier no to determine the hydraulic issues, correct any discovered deficiencies or blockage and place 7. back Scrape in service. and re -coat clarifier no. 1 with proper primer and outer coating system. 8. Rehabilitate the RAS pump station for the treatment train No. 1. One RAS pump will be / be RAS replaced and maintenance general servicing will executed on the second pump. 9. Install influent flow meter recording station within Lab Building to aid in operators process control. 10. Reposition and replace the existing chlorine contact chamber. This new structure will utilize a duel chamber layout allowing one side to be taken offline for maintenance and 11. cleaning Change efforts. existing Chlorine and Sulfur Dioxide gas feeds to safer hypochlorite and meta- bisulfite mixed liquid solution storage and feeds. 12. Replace 15 HP in Digester 15 HP Modify decant mixer with new aerator. the existing system for the Digester structure. Describe the treatment train(s) where the proposed project will occur. The proposed improvements will cover the two treatment trains and residuals management components. Size Age Condition Composite Samplers 20 Good 0 Fair Poor Influent Headworks 30 ❑ Good ❑ Fair IX Poor Aeration Basin 1 30 0 Good Fair Poor Clarifier No. 1 30 ❑ Good 1 Fair ❑ Poor Aeration Basin No. 2 20 E1 Good Fair Poor Clarifier No. 2 20 Good ❑ Fair ►1 Poor 9 Table 6 1.2 Alternatives Description Tabor City WWTP Improvements Tabor City Plant Improvements Use this table for projects funded or co funded by the CWSRF program only. Provide a description of the above the guidance. alternative in accordance with Subchapter 5.1 of Part B of Supporting Info Illation Appendix Reference* ER-3 Description Plant Improvements will include the following: -Automated Diversion Valve to Surge Basin & Replace influent pumps with three new 50 HP units equipped Headworks with VFDs. focusing bar -Rehabilitate with on existing mechanical screen -Correction of yard piping between aeration basin and clarifier in upper train -Add VFDs to floating aerators within aeration basin no. 1. DO probes will also be installed• to help operate and control the VFDs for energy savings at the facility. -Rehabilitation of clarifier on upper train. -Rehabilitate the RAS pump station for the Upper treatment train. One unit will be serviced be and rehabbed and second unit will replaced. -Install influent flow meter recording station within Lab Building to aid in process control and operations at the facility. floating in digester floating Modify decant -Replacement of mixer with aerator. the existing system for the digester structure. -Conversion of gas chlorine and de -chlorination feeds to liquid. -Replace existing chlorine contact basin with new structure Is Figure Included? '1 Yes ❑ No If Yes, Figure #• ER-3 Alternative Feasibility* 1 Feasible ❑ Infeasible Capital Cost: $2,147,910 Present Worth: $14,415,508 Water Use, Reuse, Recapture, and Conservation (CWSRF funded and co -funded projects only) Check the conservation box that most capabilities appropriately of the project. describes the water use, reuse, recapture, and The is project type not applicable to water use, reuse, recapture, and conservation. Therefore, has been no analysis completed. /1 The is scope of the project not applicable to water use, reuse, recapture, and conservation. Therefore, no analysis has been completed. The project type or project scope requires an analysis of water use, reuse, recapture, and conservation The analysis is briefly discussed below. If the third box above is checked, then check the appropriate box below and briefly qualitative discussion about the water use, reuse, recapture, and conservation abilities alternative. provide a of the 16 Tabor City WWTP NC002600 Mercury Public Education d❑ Home History Community Information Places to See Industry Contact 4— "Little Free Library" In Tabor City is OPEN!!!! Mercury Minimization: Public Outreach in Tabor City July 27, 2017 Mercury Minimization: Public Outreach in Tabor City As a result of a state-wide Total Maximum Daily Load (TMDL) approved by the US EPA on October 12, 2012, the Town's new NPDES permit for its wastewater treatment plant included the requirement for a mercury minimization plan. This plan includes targeting potential sources of mercury from commercial/industrial customers as well as public education about household sources of mercury. What is a TMDL? Simply, a TMDL is a calculated maximum limit of a pollutant that can enter a body of water and still allow it to meet water quality standards. A TMDL strategy targets specific reductions of that pollutant that are necessary and identifies ways to reduce the amount of that pollutant that enters a water body. What is an NPDES permit? A National Pollutant Discharge Elimination System (NPDES) permit is required by the Clean Water Act and controls the amounts of pollutants in treated wastewater that can be discharged in a body of water. The limits in these permits are set to protect water quality, aquatic life and human health. Where does mercury in water come from? Based on data from the US EPA and the NC Department of Environmental Quality, the majority of the mercury found in the waters of NC are from air sources. Mercury is a naturally -occurring metal; however, human activities have increased its presence. Wastewater discharges may contain some mercury but are very minor compared to the amounts of mercury found in the air. Why was a Mercury TMDL put in place in North Carolina? In very simple terms, the inorganic mercury deposited from air sources into the water and soils is converted by microorganisms to a more harmful form of mercury, methylmercury, which then can be taken up by aquatic life. It then builds up in the tissue of aquatic organisms, such as fish. Fish tissue testing across the state had been showing elevated levels of mercury resulting in a fish consumption advisory. This Mercury TMDL is a regulatory strategy to reduce the amount mercury entering the environment and thus being able to accumulate in aquatic and terrestrial plants and animals. Additional information on the NC Mercury TMDL can be found here: https://deq.nc.gov/about/divisions/water-resources/planning/modeling-assessment/special- studies/mercury-tmdl What can you do to reduce the amount of mercury released into the environment? The simplest way is to become an educated consumer. Proper disposal and handling of household items that may contain mercury can help immensely. In fact, did you know that mercury can be found in everything from appliances, batteries and light bulbs to pharmaceuticals, jewelry and skin cream? Find out more about household sources of mercury and what you can do to help reduce mercury in the environment here: https://www.epa.gov/mercury Recent News 27 14 12 19 Mercury Minimization: Public Outreach in Tabor City July, 2017 Mercury Minimization: Public Outreach in Tabor City As a result of a state-wide Total Maximum Daily Load (TMDL) approved by... Learn more "Little Free Library" In Tabor City is OPEN!!!! July, 2017 A dedication of the "Little Free Library" took place on Thursday, July 13th at the Tabor City Visitor Center!!! The library... Learn more The 30th Annual Columbus County Fourth of July Firework. Monday July 3rd June, 2017 It's almost time to celebrate the "30th Annual Columbus County Fourth of July Fireworks Celebration" which will be held on... Learn more Boat Races at Lake Tabor in June and July April, 2017 Two boat races have been scheduled at Lake Tabor. The first one is set for Saturday, June 24th and Sunday... Learn more All Events What is Tabor City doing at its wastewater treatment plant to ensure that mercury is not being released through its wastewater discharge? A Mercury Minimization Plan (MMP) has been prepared and the Town continues to monitor for mercury at various points within the treatment train at the plant, including the wastewater coming into the plant and the treated water leaving the plant. In addition, the Town has surveyed all potential commercial and industrial customers to ensure that their activities are not generating/using mercury that enter the wastewater system. If new a new industry plans to locate in Tabor City, they are required to submit data that provides a representative profile of the type of wastewater, including pollutants and their levels, that would be discharged. If there is any concern about the types and levels of pollutants, these customers would be required to pre -treat their wastewater or would not be allowed to discharge into the Town's system. Finally, the Town is monitoring its influent for mercury and can detect quickly if mercury is found. This would trigger inspections of likely sources and require immediate action by any responsible customers. This entry was posted in Uncategorized. Bookmark the permalink. 4— "Little Free Library" In Tabor City is OPEN!!!! P.O. Box 655 I I Tabor City, NC 28463 Tel: 910-653-3458 I Fax: 910-653-5969 I Email: tcpromotions@embarqmail.com Town of Tabor City © 2017 131 Tabor City WWTP NC002600 LKC Engineering Contract for I/I Evaluation AGREEMENT TO FURNISH PROFESSIONAL ENGINEERING SERVICES TOWN OF TABOR CITY, NORTH CAROLINA Asset Inventory and Assessment Grant Wastewater System This AGREEMENT made this 29th day of June, 2017, by and between the TOWN OF TABOR CITY, NORTH CAROLINA, hereinafter called the OWNER, and LKC ENGINEERING, PLLC, hereinafter called the ENGINEER. WHEREAS, the Owner intends to complete an Asset Inventory and Assessment Project (Wastewater System), as outlined in the Project Narrative within the application for funding, and outlined in the funding approval from NCDEQ Division of Water Infrastructure, hereinafter called the PROJECT; and NOW, THEREFORE, the OWNER and ENGINEER, for the consideration hereinafter named, agree as follows: The ENGINEER agrees to perform the following tasks obligated under this Agreement: SECTION I — COLLECTION SYSTEM REVIEW & REPORTING a) Engineer shall coordinate camera inspections of the collection system in areas of concern and interpret results for presentation to Town and inclusion in the Asset Management Plan and Capital Improvement Plan. Total length of review will be based on available budget and recommendations upon review with staff. b) Engineer shall utilize existing report, local knowledge, camera inspections, review of pump run times for flow monitoring and all other data to provide recommendations for maintenance, repair and/or replacement of wastewater collection lines. SECTION I1— GENERAL ENGINEERING SERVICES & OVERSIGHT a) Meet with OWNER as necessary to review and discuss aspects of the Project with the Project Team. b) Assist in reviewing mapping and system component reports for accuracy and provide input on prioritization as necessary. c) Prepare detailed estimates for repair, asset maintenance, and/or replacement as needed to accompany Capital Improvement Plan and Asset Management Plan. d) Assist in coordination of the critical asset report, with Charles R. Underwood, Inc. to insure thorough review of the assets. Town of Tabor City, NC 1 LJ Additional ENGINEERING services, if required, may be arranged for and furnished by the Engineer and separately paid for by the Owner for a price to be subsequently agreed upon if the need for these services arises. PAYMENT The OWNER agrees to pay the ENGINEER for services noted in Sections I - V above for the following not to exceed fees: I) COLLECTION SYSTEM REVIEW & REPORTING $29,000.00 II) GENERAL ENGINEERING SERVICES & OVERSIGHT $15,000.00 It is agreed by the parties hereto that the appropriate adjustments in any fixed and/or lump sum payments shall be made in the event that the physical scope of the PROJECT, time for completion, or services required are materially increased or decreased beyond that contemplated at this time. The ENGINEER shall receive progress payments based on monthly estimates as submitted to the OWNER by the ENGINEER. Should the ENGINEER be required to render "additional services" in connection with related work upon which the work scope does not apply, the ENGINEER shall receive additional compensation for such additional services at the hourly rates as specified on the fee schedule attached hereto as Exhibit "A" for the hours actually worked by the appropriate classification of employee. TERM OF SERVICE The Term of Service shall be defined as the length of time elapsed between the execution of this Agreement by all parties and the closeout of the project with the NCDEQ Division of Water infrastructure. The ENGINEER will assist the OWNER in maintaining necessary project schedules. ADDITIONAL SCOPE REQUIREMENTS The ENGINEER agrees to assist the Town as noted herein, and further outlined in the Project Narrative attached as Exhibit B. Owner shall furnish the noted services and assistance as required to insure a complete project for use by the Town and submittal to the funding agency upon completion. TERMINATION This Agreement may be terminated by either party on the basis of performance or for convenience. The terminating party shall notify the terminated party in writing a minimum of 30 days before the date of termination. Upon termination, the Engineer shall turn over all records, Town of Tabor City, NC 2 LSD files, and other pertinent information to the Owner, and the Engineer shall be fairly compensated for services provided prior to termination. The OWNER and ENGINEER hereby agree to the full performance of the covenants contained within this Agreement IN WITNESS HEREOF, they have executed this Agreement, the day and the year first above written, which is the effective date of this Agreement. LKC ENGINEERING, PLLC TOWN OF TABOR CITY By: By: Bill Lester, Jr., P.E. Town Manager Witness: Attest: Sharon McDuffie Town Clerk Town of Tabor City, NC 3