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HomeMy WebLinkAboutPR 21999: AN AGREEMENT WITH SCS ENGINEERS, GROUNDWATER MONITORING AT THE CITY LANDFILL City of ori rthu 111 www.PortArthurTx.gov INTEROFFICE MEMORANDUM Date: June 15, 2021 To: The Honorable Mayor and City Council Through: Ron Burton,City Manager From: Alberto Elefano,P.E.,Public Works Director RE: PR#21999:Authorizing the City Manager to enter into an agreement with SCS Engineers of Bedford, Texas for groundwater monitoring at the City Landfill in the amount of$34,400.00. Introduction: The intent of this Agenda Item is to seek the City Council's authorization for the City Manager to enter into an agreement with SCS Engineers of Bedford,Texas for groundwater monitoring at the City Landfill in the amount of$34,400.00. Background: The City of Port Arthur received a Notice of Violation (NOV) from the Texas Commission on Environmental Quality (TCEQ), dated September 3, 2020. The TCEQ noted that during the Landfill's Semi-annual Groundwater Monitoring Sampling Event, there were some exceedances that were outside of permitted parameters. Several groundwater monitoring wells tested for higher concentrations of metals in addition to higher concentrations in the soil surrounding the monitoring wells. As a result,the TCEQ has mandated that the Landfill place these specific wells and their adjoining wells in an assessment protocol to pinpoint these exceedances. SCS Engineering of Bedford,Texas has responded to the TCEQs NOV on behalf of the City and will implement and direct the new assessment protocol. Budget Impact: Funds are available from the Solid Waste Professional Services Account No. 403-50-320-5420-00-00-000. Recommendation: It is recommended that the City of Port Arthur's City Council approve PR#21999 authorizing the City Manager to enter into an agreement with SCS Engineers of Bedford, Texas for the implementation of a Groundwater Monitoring Assessment Plan at the City Landfill in the amount of$34,400.00. "Remember,we are here to serve the Citizens of Port Arthur" 444 4th Street X Port Arthur,Texas 77641-1089 X 409.983.8182 X FAX 409.983.8294 S:\Engineering\PUBLIC WORKS\PW-LANDFILL\SCS ENGINEERS\Agenda Memo SCS GW Monitoring.docx PR No.21999 06/15/2021 mje Page 1 of 3 RESOLUTION NO. A RESOLUTION AUTHORIZING THE CITY MANAGER TO ENTER INTO AN AGREEMENT WITH SCS ENGINEERS OF BEDFORD,TEXAS FOR GROUNDWATER MONITORING AT THE CITY OF PORT ARTHUR LANDFILL FOR THE AMOUNT OF $34,400.00. FUNDING IS AVAILABLE IN THE SOLID WASTE PROFESSIONAL SERVICES ACCOUNT NUMBER 403-50-320-5420-00-00-000. WHEREAS, the City of Port Arthur's Municipal Solid Waste Landfill (Landfill) received a Notice of Violation (NOV) regarding groundwater monitoring from the Texas Commission on Environmental Quality (TCEQ); and, WHEREAS, the TCEQ determined that following the Landfill's Semi-annual sampling event there were groundwater monitoring wells that had higher concentrations of metals than the Landfill Permit allowed; and WHEREAS, the TCEQ sent a letter dated September 3, 2020 addressing the violations and its recommendations for mitigation, See Exhibit A; and, WHEREAS, the TCEQ has mandated that the Landfill implement a Groundwater Monitoring Assessment Plan on the affected groundwater monitoring wells and the surrounding soil in an effort to pinpoint the exceedances; and, WHEREAS, the City currently has an existing contract with SCS Engineers of Bedford, Texas for Landfill oversite; and, WHEREAS, SCS Engineers of Bedford, Texas has responded to the NOV issued by the TCEQ on behalf of the City, See Exhibit B; and, PR No.21999 06/15/2021 mje Page 2 of 3 WHEREAS, SCS Engineers of Bedford, Texas has presented a scope of services for completing the Groundwater Monitoring Assessment Plan on the select wells in the amount of $34,400.00, see Exhibit C; and, WHEREAS, entering into this agreement with SCS Engineers of Bedford, Texas is deemed to be an appropriate action; now, therefore; BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF PORT ARTHUR: THAT, the facts and opinions in the preamble are true and correct; and, THAT, the City Council of the City of Port Arthur hereby authorizes the City Manager to enter into an agreement with SCS Engineers of Bedford, Texas in the amount of$34,400.00 to implement the Groundwater Monitoring Assessment Plan at the Landfill; and, THAT, a copy of the caption of this Resolution be spread upon the Minutes of the City Council. READ, ADOPTED AND APPROVED this the day of A.D. 2021 at a meeting of the City of Port Arthur, Texas by the following vote: Ayes: Mayor: Councilmembers: Noes: PR No. 21999 6/14/2021 mje Page 3 of 3 Thurman "Bill" Bartie Mayor ATTEST: Sherri Bellard City Secretary APPROVED AS TO FORM: APPROVED FOR ADMINISTRATION: Valecia T eno Ronald Burton City Attorney City Manager APPROVED AS FOR AVAILABILITY OF FUNDS: 0_/\ CAA Kandy K. Dai el Interim Director of Finance Alberto Elefano Director of Public Works Clifton Williams, CPPB Purchasing Manager EXHIBIT A Jon Niermann, Chairman Emily Lindley, Commissioner Bobby Janecka,Commissioner �`���� wt, ,a • Toby Baker,Executive Director TEXAS COMMISSION ON ENVIRONMENTAL QUALITY Protecting Texas by Reducing and Preventing Pollution September 3, 2020 Mr. Alberto Elefano City Engineer City of Port Arthur P.O. Box 1089 Port Arthur, Texas 77640 Re: City of Port Arthur Landfill -Jefferson County Municipal Solid Waste - Permit No. 1815A Groundwater Monitoring- First 2020 Semiannual Report and Alternative Source Demonstrations Tracking No. 25327812;RN100225390/CN600132021 Dear Mr. Elefano: This letter acknowledges that we received the first 2020 semiannual report dated July 15, 2020, for the referenced Type I facility. The report was prepared and submitted on behalf of the facility by SCS Engineers. Event Summary Event Date Event Type Monitoring Wells 1" Semiannual Detection:MW-1, MW-4, MW-5, MW-6, MW-7, MW-8, MW-18, MW-19, MW-20, MW-21, MW-22, MW-23, MW-24, April 7-9, 2020 MW-25, MW-26 Leachate Soil Sampling SSMW-1, SSMW-4, SSMW-23, SSMW-26 Please note the following highlights discussed in this report: 1. The previously submitted November 2019 event concluded with MW-1, MW-4, MW-23, and MW-26, needing an alternative source demonstration or going into assessment monitoring. The April 2020 event included a soil sampling investigation as an alternative source demonstration(ASD) for MW-1, MW-4, MW-23, and MW-26. The April 2020 soil investigation, using the Synthetic Precipitate Leaching Procedure (SPLP), compares the November 2019 and the April 2020 groundwater monitoring results with the soil sampling results. The investigation concluded: • In MW-1, barium and cobalt were found at higher concentrations in the soil than the groundwater. • In MW-4, barium and cobalt were higher in the groundwater than the soil sample results and the prediction limits. P.O.Box 13087 • Austin,Texas 78711-3087 • 512-239-1000 • tceq.texas.gov How is our customer service? tceq.texas.gov/customersurvey printed on recycled paper Mr. Alberto Elefano Page 2 September 3, 2020 • In MW-23, the barium concentration was higher in the groundwater than the soil sample results and the prediction limit. • In MW-26, the arsenic and cadmium groundwater concentrations in both events were higher than the soil sample results and exceeded their prediction limits. For copper and vanadium, the groundwater concentrations were lower than their prediction limits in the 1"2020 Semiannual event so no further discussion is required. 2. We accept the proposed ASDs for MW-1, as the soil sample SPLP concentrations are higher than the groundwater concentrations. As stated in the report, the SPLP results indicate barium and cobalt are naturally occurring in the soil on-site and is highly mobile. MW-1 will remain in detection monitoring status. An ASD is not required for copper and vanadium in MW-26. 3. We cannot accept the proposed actions to remain in detection monitoring status for barium and cobalt in MW-4,barium in MW-23, and arsenic and cadmium in MW-26 based on the soil sampling. 4. The following table highlights the constituents exceeding its prediction limit during theist 2020 semiannual event with the proposed actions recommended by the consultant(all values are in pg/L). Monitoring Prediction Event Type Well Constituent Limit Concentration Proposed Action Barium 59.48 134 ASD Cobalt 5 6.36 ASD MW-1 Remain in Cadmium 2 4.78 detection monitoring Remain in Barium 193 267 detection MW_4 monitoring Remain in Cobalt 5 13.2 detection monitoring MW-6 Barium 54.48 99.3 Previous ASD Remain in 1" MW-18 Cadmium 2 2.14 detection Semiannual monitoring MW-23 Barium 220 541 ASD Cadmium 2 4.48 ASD MW-24 Barium 82.43 177 Previous ASD Cadmium 2 8.25 Previous ASD Remain in MW-25 Cadmium 2 2.36 detection monitoring Remain in Arsenic 7 7.76 detection MW_26 monitoring Remain in Cadmium 2 2.79 detection monitoring 5. No exceedances for volatile organic compounds (VOCs)were reported from any of the sampled wells during the 1st semiannual monitoring event. 6. Four alternative source demonstrations were proposed based on statistical analysis (three for barium in MW-6, MW-23, and MW-24, and one for cadmium in MW-24), but all four Mr. Alberto Elefano Page 3 September 3, 2020 cannot be accepted based on the information provided. The ASDs indicated an interwell analysis based on a hydraulically upgradient well MW-1 but the graphs provided show an intrawell analysis. A revised ASD is required within 30 days for MW-23 to avoid assessment monitoring. 7. Additionally, your permit states that MW-1 is a downgradient/side-gradient well that is part of the point of compliance line. Please refrain from using MW-1 as an upgradient well in future ASD submittals. 8. A previously approved ASD, dated October 24, 2018, for barium in MW-6 and MW-24, and cadmium in MW-24, indicated that these constituents in these monitoring wells were affected by natural groundwater quality changes due to Hurricane Harvey potentially influencing the movement of trace elements into the groundwater. We will continue to accept this ASD as it appears current data continues to support the ASD conclusions. MW-6 and MW-24 will remain in detection monitoring status. 9. Your report indicates that you will monitor the cadmium exceedance in MW-1 and make a recommendation after the second semiannual monitoring event. Per your groundwater sampling analysis plan(GWSAP), a verification resampling event is required prior to the next semiannual monitoring event. However, since it is already time for the next semiannual monitoring event, it will act as verification resampling for cadmium in MW-1 in this instance. 10. No proposed action was mentioned for the cadmium exceedances in MW-18 and MW-25. The next semiannual monitoring event received will act as verification resampling for cadmium in MW-18 and MW-25, for the same reasons stated previously. 11. The April 2020 event is considered the verification resampling confirmation for exceedances for arsenic and cadmium in MW-26 because a verification sampling event and/or acceptable ASD was not submitted within the required timeframe after the November 2019 monitoring event. MW-26 is to be placed in assessment monitoring starting with the next groundwater monitoring event due to confirmed SSIs of arsenic and cadmium. 12. During the next semiannual monitoring event sample MW-26, as well as the immediately adjacent wells MW-1 and MW-25 on each side of the well exhibiting the SSI, for the entire list of constituents in 40 Code of Federal Regulations (CFR) Part 258 Appendix II. 13. As a reminder, verification resampling results must be submitted within 60 days of determination of an initial statistical exceedance and ASDs must be submitted within 90 days of determining an exceedance, per your GWSAP. Thank you for the submittal. If you have questions regarding this letter, please contact me at (512) 239-5090.When addressing written correspondence, please use mail code MC 124. Sincerely, '/ (4y1rWAYI ry f. VlKristen A. Hernandez, Project Manager Municipal Solid Waste Permits Section Waste Permits Division Texas Commission on Environmental Quality KAH/gg cc: Mr.James Lawrence, P.G., SCS Engineers, Bedford EXHIBIT B Environmental Consulting & Contracting SCS ENGINEERS May 19, 2021 SCS Project 16221010.00 Ms. Kristen Hernandez Texas Commission on Environmental Quality MSW Waste Permits Division, MC-124 12100 Park 35 Circle, Building F Austin, Texas 78753 Subject: Response to Texas Commission on Environmental Quality Correspondence Groundwater Monitoring - First 2020 Semi-Annual Report and Alternative Source Demonstrations, City of Port Arthur Landfill,Jefferson County RN102289390/CN600132021 Dear Ms. Hernandez: On behalf of the City of Port Arthur, SCS Engineers (SCS) is submitting a response to correspondence from the Texas Commission on Environmental Quality (TCEQ) dated September 3, 2020. The correspondence was a review of first 2020 semiannual report dated July 15, 2020. SCS's response does take in consideration the conference call SCS had with the TCEQ on May 4, 2021 to discuss the September 3, 2020 correspondence. The original TCEQ comment will be followed by SOS's response and both are noted below. A copy of the September 2020 TCEQ correspondence is provided in ATTACHMENT A. TCEQ Comment No. 1: The previously submitted November 2019 event concluded with MW-1, MW-4, MW-23, and MW-26, needing an alternative source demonstration or going into assessment monitoring. The April 2020 event included a soil sampling investigation as an alternative source demonstration (ASD) for MW- 1, MW-4, MW-23, and MW-26. The April 2020 soil investigation, using the Synthetic Precipitation Leaching Procedure (SPLP), compares the November 2019 and the April 2020 groundwater monitoring results with the soil sampling results. The investigation concluded: • In MW-1, barium and cobalt were found at higher concentrations in the soil than the groundwater. • In MW-4, barium and cobalt were higher in the groundwater than the soil sample results and the prediction limits. • In MW-23, the barium concentration was higher in the groundwater than the soil sample results and the prediction limit. Ms. Kristen Hernandez May 19, 2021 Page 2 In MW-26, the arsenic and cadmium groundwater concentrations in both events were higher than the soil sample results and exceeded their prediction limits. For copper and vanadium, the groundwater concentrations were lower than their prediction limits in the 1st 2020 Semiannual event so no further discussion is required. SCS Response: As noted in the TCEQ response, no further discussion is required. TCEQ Comment No. 2: We accept the proposed ASDs for MW-1, as the soil sample SPLP concentrations are higher than the groundwater concentrations. As stated in the report, the SPLP results indicate barium and cobalt are naturally occurring in the soil on-site and is highly mobile. MW-1 will remain in detection monitoring status.An ASD is not required for copper and vanadium in MW-26. SCS Response: The acceptance of the ASD for MW-1 is noted. However, based on comment No. 12 below, MW-1 is to be placed in assessment monitoring as a result of SSTs in MW-26. TCEQ Response No.3: We cannot accept the proposed actions to remain in detection monitoring status for barium and cobalt in MW-4, barium in MW-23, and arsenic and cadmium in MW-26 based on the soil sampling. SCS Response: SCS understands the TCEQ does not accept the proposed actions to remain in dection monitoring for barium and cobalt in MW-4, barium in MW-23, and arsenic and cadmium in MW-26. It is our understanding from a recent conversation with you and Mr. Glen Collier of SCS on May 13, 2021 that monitoring well MW-4 does not need to enter assessment monitoring at this time. TCEQ Response No.4: The following table (not provided) highlights the constituents exceeding its prediction limit during the 1st 2020 semiannual event with the proposed actions recommended by the consultant (all values are in pg/L). SCS Response: No reponse is necessary. TCEQ Response No. 5: No exceedances for volatile organic compounds (VOCs) were reported from any of the sampled wells during the 1st semiannual monitoring event. Ms. Kristen Hernandez May 19, 2021 Page 3 SCS Response: No response is necessary. TCEQ Comment No. 6 Four alternative source demonstrations were proposed based on statistical analysis (three for barium in MW-6, MW-23, and MW-24, and one for cadmium in MW-24), but all four cannot be accepted based on the information provided. The ASDs indicated an interwell analysis based on a hydraulically upgradient well MW-1 but the graphs provided show an intrawell analysis. A revised ASD is required within 30 days for MW-23 to avoid assessment monitoring. SCS Response: SCS understands that since a revised ASD was not submitted within the requested timeframe, MW- 23 will enter assessement monitoring. TCEQ Comment No. 7: Additionally, your permit states that MW-1 is a downgradient/side-gradient well that is part of the point of compliance line. Please refrain from using MW-1 as an upgradient well in future ASD submittals. SCS Response: SCS's use of MW-1 was from a hydraulically upgradient position relative to other wells and was independent of its compliance status. However, SCS will refrain from using MW-1 as an upgradient well in future ASD submittals. TCEQ Comment No.8: A previously approved ASD, dated October 24, 2018, for barium in MW-6 and MW-24, and cadmium in MW-24, indicated that these constituents in these monitoring wells were affected by natural groundwater quality changes due to Hurricane Harvey potentially influencing the movement of trace elements into the groundwater. We will continue to accept this ASD as it appears current data continues to support the ASD conclusions. MW-6 and MW-24 will remain in detection monitoring status. SCS Response: SCS understands that wells MW-6 and MW-24 were to remain in detection monitoring status. TCEQ Comment No. 9: Your report indicates that you will monitor the cadmium exceedance in MW-1 and make a recommendation after the second semiannual monitoring event. Per your groundwater sampling analysis plan (GWSAP), a verification resampling event is required prior to the next semiannual Ms. Kristen Hernandez May 19, 2021 Page 4 monitoring event. However, since it is already time for the next semiannual monitoring event, it will act as verification resampling for cadmium in MW-1 in this instance. SCS Response: The second semiannual groundwater monitoring event for 2020 was completed in February 2021. Cadmium was not detected MW-1 at or above the laboratory reporting limit of 2.0 ug/L during the event and the concentration was less than the prediction limit of 2.0 ug/L. However, barium and cobalt concentrations in MW-1 exceeded their respective Background Evaluation Report Limits (BER) during the February 2021 sampling event. SCS proposed ASDs for both constituents in our recently submitted 2020 Annual (Second Semiannual) Groundwater Monitoring Report based on the April 2020 SPLP results and declining concentrations for those constituents. SCS would have proposed that MW-1 remain in assessment monitoring, however, in comment No. 12 below, the TCEQ has requested that MW-1 be placed in assessment monitoring due to SSTs in MW-26. TCEQ Comment No. 10: No proposed action was mentioned for the cadmium exceedances in MW-18 and MW-25. The next semiannual monitoring event received will act as verification resampling for cadmium in MW-18 and MW-25, for the same reasons stated previously. SCS Response: Cadmium was not detected at or above the laboratory reporting limit of 2.0 ug/L in either MW-18 and MW-25 during the February 2021 sampling event. As a result of these verification resampling results completed in February 2021, SCS proposes that MW-18 and MW-25 remain in assessment monitoring. TCEQ Comment No. 11: The April 2020 event is considered the verification resampling confirmation for exceedances for arsenic and cadmium in MW-26 because a verification sampling event and/or acceptable ASD was not submitted within the required timeframe after the November 2019 monitoring event. MW-26 is to be placed in assessment monitoring starting with the next groundwater monitoring event due to confirmed SSTs of arsenic and cadmium. SCS Response: SCS will place MW-26 in assessment monitoring during the next groundwater sampling event to be completed in the second quarter of 2021. TCEQ Comment No. 12: During the next semiannual monitoring event sample MW-26, as well as the immediately adjacent wells MW-1 and MW-25 on each side of the well exhibiting the SSI, for the entire list of constituents in 40 Code of Federal Regulations (CFR) Part 258 Appendix II. Ms. Kristen Hernandez May 19, 2021 Page 5 SCS Response: SCS will place MW-26, as wells as MW-1 and MW-25, in assessment monitoring during the next groundwater sampling event to be completed in the second quarter of 2021. The monitoring wells will be sampled for the entire list of constituents in 40 Code of Federal Regulations (CFR) Part 258 Appendix II. TCEQ Comment No. 13: As a reminder, verification resampling results must be submitted within 60 days of determination of an initial statistical exceedance and ASDs must be submitted within 90 days of determining an exceedance, per your GWSAP. SCS Response: SCS will submit verification resampling results to the TCEQ within 60 days of of determination of an initial statistical exceedance and ASDs will be submitted within 90 days of determining an exceedance, per our GWSAP. SCS would like to request an expedited response to our letter confirming our understanding of TCEQ's expectations ahead of our next groundwater sampling scheduled for the week of June 7, 2021. Please contact Kevin Yard at 972-523-2414 or Gil Gabaldon at 817-358-6162 if you have comments regarding our responses or require additional information. Sincerely, .� 1.(rAC1�rti Kevin Yard, P.E., BCEE Gil Gabaldon, P.G. Vice President Sr. Project Professional SCS ENGINEERS SCS ENGINEERS Attachments: TCEQ Correspondence, September 3, 2020. cc: Mr. Alberto Elefano, City of Port Arthur Mr.Justin Thomas, City of Port Arthur TCEQ Region 10 Glen Collier, SCS Engineers EXHIBIT C SCS ENGINEERS Environmental Consultants & Contractors May 19, 2021 SCS Proposal No. 160027221 Mr. Alberto Elefano, P.E. Public Works Director City of Port Arthur 444 4th Street Port Arthur,Texas 77640 Subject: Proposal to Complete TCEQ Required Assessment Monitoring and Reporting, Update Background Report, and Well Development Services Port Arthur Landfill Dear Mr. Elefano: SCS Engineers (SCS) is presenting this scope of services for completing assessment monitoring for select wells noted in response to a letter dated September 3, 2020 from the Texas Commission on Environmental Quality(TCEQ). As a result of their review of SCS's First 2020 Semiannual Report and Alternative Source Demonstrations, the TCEQ requested several wells be placed in assessment monitoring. The additional services proposed in this letter are the result of further analysis and our discussions with the TCEQ on the City's behalf. The details and related costs to complete the assessment monitoring and associated reporting for two events are detailed below. Consistent with TCEQ's suggestion, SCS is including the costs to complete an update to the Background Evaluation Report for the site monitoring wells. As further discussed in Task 3, in order to reduce the likelihood of continued issues with metals in the groundwater samples, we have included the development of several wells in this scope of services. PROJECT BACKGROUND As a result of Statistically Significant Increases (SSIs)of several constituents in select wells during the April 2020 groundwater sampling event,the TCEQ has requested that monitoring wells MW-1, MW-23, MW-25, and MW-26 be placed in assessment monitoring. Monitoring wells MW-1 and MW-25 were placed in assessment monitoring because they were adjacent to well MW-26 which contained SSIs for arsenic and cadmium. SCOPE OF WORK Consistent with our currently approved scope of groundwater services, this scope of work will be completed during the two groundwater sampling events in 2021. The work is detailed below. In accordance with Subchapter J rule 330.409(d)(1), the wells noted above will also be sampled for the constituents listed in 40 CFR Part 258, Appendix II for at least two sampling events. If the concentrations of 40 CFR Part 258, Appendix II constituents are shown to be at or below background values, then, on the City's behalf, we will request the wells be placed back into detection monitoring. If any of the results are greater than background values, then additional assessment monitoring,which is not included in this scope, will be required. 12651 Briar Forest, Ste. 205, Houston,TX 77494 1281-293-8494 1901 Central Drive, Ste. 550, Bedford,TX 76021 1817-571-2288 P05192021 Port Arthur LF GWM Additional Services Proposal Mr. Alberto Elefano May 19, 2021 Page 2 Task 1 -June and November 2021 Semi-annual Assessment Groundwater Monitoring Event Field Sampling Services A qualified field technician will sample monitoring wells MW-1, MW-23, MW-25, and MW-25 for the constituents listed in 40 CFR Part 258,Appendix II for each event. The remaining monitoring wells in the network will be sampled for detection monitoring parameters as part of the previously approved scope of work. Task 2 -June and November 2021 Semi-annual Assessment Groundwater Monitoring Event Reporting Services SCS will compile the results of the assessment monitoring into the semi-annual groundwater monitoring reports along with the results of the detection monitoring. Statistical analysis of all wells will be conducted and attached to the report. The City will be consulted regarding any significant results that are observed in the course of the analysis. The draft report cover letter will be submitted to the City for review and comment prior to finalizing. Task 3—Well Development Several wells, including MW-23, MW-24, MW-25, and MW-26 have had elevated turbidity readings during prior sampling events. Elevated turbidity often affects metals concentrations due to the colloidal transportation of metals on soil particles which can affect the concentrations of metals in groundwater leading to SSIs. SCS proposes that MW-23, MW-24, MW-25, and MW-26 be developed by purging large amounts of water from each monitoring well in order to remove any sediments that have settled to the bottom the wells and may contribute to colloidal transportation and possibly elevated metals concentrations. The monitoring wells will be developed using a submersible hydro-lift pump. The wells will be surged to remove sediments from the well and within the sand pack of the wells. The purge water will be placed into drums or a tank on a trailer and transported to one of the on-site leachate tanks and transferred into the tanks. SCS assumes the purge water in the leachate tanks from the purging will be disposed of by the City's personnel or the City's contractor that transports the leachate to the City's POTW. Task 4— Update Background Evaluation Report The TCEQ previously requested that the landfill groundwater background statistics be updated on a regular basis[generally every 2 years]. This is now routinely requested by TCEQ for all Type I Municipal Solid Waste Landfills (MSWLFs). This update has the potential to benefit the landfill by incorporating additional background data (i.e., for a longer period). A more diverse [greater variation] background data set is then approved for statistical analysis. This generally results in higher statistical limits, and fewer "false positives". The Background Evaluation Report (BER)for the Port Arthur Landfill was last updated in May 2013. To incorporate additional background data, it must be demonstrated the data are "true background", unaffected by landfill impacts and therefore reflective of natural conditions. This is demonstrated by use of various statistical methods to analyze data as outlined in the TCEQ guidance published December 22, 2014. A new statistical background limit is calculated for every metals constituent,for every well. This often results in a higher statistical limit, which is beneficial to the landfill. Mr. Alberto Elefano May 19, 2021 Page 3 For this task, SCS will prepare an updated BER for submittal. The draft update will be submitted to the City for comment. City comments will be incorporated into a final draft for submittal to the City (two paper copies or e-copies as desired by the City) and TCEQ (three paper copies and an e-copy.) FEES Project fees are detailed in Table 1. Billing will be conducted on a lump sum, monthly percent complete basis. Table 1. Tabulation of Estimated Fees TASK TASK DESCRIPTION FEE ESTIMATE NUMBER 1 June and November 2021 Semi-annual Assessment Monitoring— $6,900 Field Services 2 June and November 2021 Semi-annual Detection Monitoring -- Reporting Services, and Annual Reporting $3,800 3 Well Development $8,500 4 Update Background Data Report $15,200 Total $34,400 Note: Assumes two groundwater sampling events and associated reporting will be completed. CLOSING We appreciate the opportunity to contribute to the continued success of the City's Landfill. We look forward to discussing this proposal with you at your convenience and to continuing our relationship with the City of Port Arthur. Please note that time is of the essence in that TCEQ is awaiting the response to the September letter (see attached letter, which includes a commitment by the City to conduct the assessment monitoring). If you have any questions related to this proposal, please feel free to contact Kevin Yard at(972) 523- 2414 or Gil Gabaldon at(817) 358-6162. Sincerely, Kevin D. Yard, P.E., BCEE Gil Gabaldon, P.G. Vice President Sr. Project Professional SCS ENGINEERS SCS ENGINEERS TBPE Registration No. F-3407 cc: Mr. Justin Thomas, City of Port Arthur J. Roy Murray, P.E., SCS Engineers, Houston Office Glen Collier, P.G., SCS Engineers