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Home My WebLink AboutParametrix 2022 Amendment # 1Jenifer Young, EP&C Division Mgr.December 21, 2022 719 2ND AVENUE, SUITE 200 | SEATTLE, WA 98104 | P 206.394.3700 September 30, 2022 Parametrix No. 555-1682-042 Mr. Richard Dickinson Mason County Department of Utilities & Waste Management 100 W Public Works Drive Shelton, WA 98584 Re: Mason County Landfill Post-Closure Services Dear Richard: Attached is our proposed scope of work and fee estimate for continued environmental monitoring services at the Mason County Landfill. The work includes providing on-call services to support terminating post-closure care. A description of the scope of work and fee estimate by task is attached as Exhibit A. The total costs are estimated at $29,507. The budget assumes the approved work plan will consist of the activities outlined in the attached scope of work. If you have any questions regarding the work performed or the project in general, please feel free to call me at (206) 394-3667. We appreciate the opportunity to provide continuing environmental services to Mason County. Sincerely, PARAMETRIX Lisa Gilbert Senior Hydrogeologist cc: Project File Mr. Richard Dickinson September 30, 2022 Page 2 EXHIBIT A – SCOPE OF WORK AND FEE ESTIMATE TASK 08 POST-CLOSURE SERVICES INTRODUCTION The Mason County Landfill closed in 1993, and the 20-year post-closure period has been completed in accordance with Chapter 173-304 WAC. WAC 173-304-407(8)(c) states that “If the jurisdictional health department finds that post-closure monitoring has established that the facility is stabilized (i.e. little or no settlement, gas production, or leachate generation), the health department may authorize the owner or operator to discontinue post-closure maintenance and monitoring activities.” The work described in the plan is intended to supplement the Post-Closure Care Status Report prepared in 2020 that evaluated the stability of the Landfill in accordance with the Ecology guidance document “Preparing for Termination of Post-Closure Activities at Landfills Closed Under Chapter 173-304 WAC”. A fee estimate by task is attached to further clarify the project requirements. This scope of work and budget assumes that the start date for this work will be October 1, 2022, and the completion date will be December 31, 2023. SCOPE OF WORK Work will be conducted to address the August 25, 2022 comments provided by the Washington Department of Ecology. Ecology recommended the following to establish a final demonstration of stabilized and protective groundwater at the Mason County Landfill:  Four additional quarters of groundwater sampling should be completed for total arsenic, iron, manganese, and zinc using an appropriate sampling methodology (such as bladder pumps or peristaltic sampling) that minimizes agitation of the water column. In accordance with Environmental Protection Act (EPA) guidance and the approved Work Plan, turbidity measurements should be collected during purging and at the time of sampling to demonstrate that turbidity in the sample is low and has stabilized. Ecology recommends allowing extra purge time for these wells before collecting the sample, ideally sampling only when turbidity has dropped below 5-10 Nephelmetric Turbidity Units (NTU) and has remained low over consecutive measurement periods.  During the final quarter of sampling, samples should be collected for Volatile Organic Compound (VOCs) in addition to total metals, using the same sampling methodology referenced above. This will demonstrate that the inertial pump sampling method did not affect detections of VOCs in groundwater.  Mason County should demonstrate that reduction-oxidation (redox) potential downgradient of the landfill and at the domestic well indicates that metals, in particular manganese, have the potential to precipitate into the formation and not negatively affect groundwater quality downgradient of the landfill. Collection of groundwater geochemical parameters such as dissolved oxygen, oxidation-reduction potential (ORP), nitrate/nitrite, and/or sulfate/sulfide may be necessary to complete this demonstration, in addition to total metals. Mr. Richard Dickinson September 30, 2022 Page 3 Subtask 01 Project Management  Prepare invoices and progress letters.  Attend two meetings with the Mason County Environmental Health District (MCEHD) and the Department of Ecology (Ecology) to discuss the work plan and findings of the study. Subtask 02 Quarterly Groundwater Monitoring The following activities will be conducted:  Remove dedicated Hydrostar pumps from wells MW-4, MW-3B, MW-8, and MW-10 and redevelop wells using a portable submersible pump. Allow wells to equilibrate for at least 48 hours prior to collecting samples.  Sample monitoring wells MW-4, MW-3B, MW-8, and MW-10 for four quarters.  Purge and sample monitoring wells using a portable bladder pump, decontaminating the pump with an alconox-water solution and distilled water rinse, changing disposable bladders between wells and using dedicated sample tubing for each well. During purging, measure field parameters (pH, conductivity, temperature, DO, ORP, turbidity). Collect samples after stabilization in accordance with EPA guidance for low- flow sampling.  Conduct laboratory analysis of samples for: total and dissolved (field filtered) metals: iron, manganese, zinc, arsenic.  During the last quarter, collect an additional sample at the domestic well from the outside hose. Conduct additional laboratory analysis of all samples for VOCs (WAC 173-351 list). Assumptions:  Well redevelopment will be conducted in one field day by two personnel.  The Hydrostar pumps can be removed from the wells to allow redevelop and sampling with bladder pumps.  The Hydrostar pumps will be placed at the landfill to be stored by Mason County.  Quarterly sampling field events will be conducted in one day by one personnel.  Samples will be submitted on a standard turnaround time Subtask 03 Reporting The findings of the quarterly groundwater monitoring will be summarized in a Technical Memorandum. The Technical Memorandum will include:  Field sampling data sheets  Laboratory analytical reports  Summary table of analytical data  Updated time-series plots for metals  Discussion of results including oxidation/reduction conditions including previously collected data for nitrate and sulfate. Mr. Richard Dickinson September 30, 2022 Page 4 Assumptions The services will be provided on a time-and-materials basis as requested by the County. Deliverables  Draft Technical Memorandum  Final Technical Memorandum Client: Mason County Project: Mason Co. LF GW Monitoring Project No: 5551682042 Aaron M. ThomKyle G. LeaseLaura B. LeeDebra M. FetherstonMargaret E. SpenceLisa A. GilbertMichael P. BradyButch R. PurgananShanon L. HarrisJean N. JohnsonScientist/Biologist IISystems Administrator ISr PlannerPublications SupervisorSr Scientist/BiologistSr HydrogeologistHydrogeologist IVDesigner IVProject Controls SpecialistSr Contract Administrator$109.28 $100.80 $187.71 $153.54 $220.96 $233.57 $155.74 $171.07 $135.62 $169.22 Task SubTask Description Labor Dollars Labor Hours 08 2023 Landfill Services $22,202.08 143 60 4 8 4 4 30 22 8 2 1 08 01 Project Management $2,556.56 15 4 6 2 2 1 08 02 Groundwater Monitoring $10,294.24 80 60 8 12 08 03 Reporting $9,351.28 48 8 4 4 16 8 8 Labor Totals:$22,202.08 143 60 4 8 4 4 30 22 8 2 1 Totals:$22,202.08 $6,556.80 $403.20 $1,501.68 $614.16 $883.84 $7,007.10 $3,426.28 $1,368.56 $271.24 $169.22 Subconsultants Analytical Resources LLC $3,850.00 Subconsultants Total:$3,850.00 Other Direct Expenses Mileage $580.00 Other Direct Costs $2,875.00 Other Direct Expenses Total:$3,455.00 Project Total $29,507.08 Burdened Rates: