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Home My WebLink AboutRESOLUTION NO. 2023-83RESOLUTION NO. 2023-83 RESOLUTION TO ACCEPT A PROPOSAL OF SERVICES FROM INNOVATIVE GROUNDWATER SOLUTIONS, LLC FOR GROUNDWATER MODELING IN THE SILURIAN AQUIFER. WHEREAS, the Fairfax City Council intends to complete a predictive groundwater rnodel of the Silurian Aquifer to identify and optiinize locations for future Silurian wells; quantify future pumping rates for existing and proposed wells; evaluate well interference between City of Fairfax and the Big Cedar Industrial Park Silurian wells; and evaluate well interference between City of Fairfax and future City of Walford Silurian wells; and WHEREAS, Innovative Groundwater Solutions, LLC has submitted a Proposal to provide said services. NOW, THEREFORE, BE IT RESOLVED, by the City Council of the City of Fairfax, Iowa, to accept this Proposal from Innovative Groundwater Solutions, LLC as attached. BE IT FURTHER RESOLVED, by the City Council of the City of Fairfax, Iowa, that the Mayor and City Clerk are hereby authorized and directed to execute both this Resolution and the Proposal. Passed and approved this 8t�' day of August, 2023. AYES: Nurre, Daly, Pacha, and Wainwright NAYS: None ABSENT: Volk ��A'" �� Jo Am1 Beer, Mayor ATTEST: � Cy tl�ia Stimson, City Clerk/Treasurer .<�� ..II. QS ` . . `a e . i', y��; ��' ,,,• �� ` �� v "� . � � �$ �� . August 4, 2023 City of Fairfax Mayor Jo Ann Beer and/or City Council 300 80th Street Court PO Box 337 Fairfax, lowa 52228 RE: Proposal for Groundwater Modeling in the Silurian aquifer — Fairfax, lowa Mayor Beer, Thank you for the opportunity to prepare this proposal for conducting predictive groundwater modeling in the Silurian aquifer near the City of Fairfax and the proposed Big Cedar Industrial Park. The predictive groundwater model will address the following concerns: 1. Working closely with the City of Fairfax, identify and optimize potential locations for future Silurian production wells. 2. Quantify future peak and average daily pumping rates for the existing and proposed wells. 3. Evaluate the well interference between the proposed Big Cedar Industrial Park Silurian wells and the City of Fairfax Silurian wells. 4. Evaluate the well interference between future City of Walford public wells, and the City of Fairfax Silurian wells. The Silurian aquifer in southern Linn County is used by both cities, industries, and private well owners. The City of Fairfax relies on the Silurian aquifer as its sole source of water, and currently has three active wells. City well 3 was drilled in 1999, and is considered a fully completed Silurian well (open in the entire Silurian aquifer). Wells 1 and 2 were installed in 1959 and 1979 are partially completed Silurian wells (open in the upper 150 to 235 feet). A Silurian groundwater flow model was completed for Johnson and Linn counties in 2011 by the lowa Geological Survey (Gannon and others, 2011), and was updated in 2023. This model incorporates all of the higher capacity Silurian wells in Linn and Johnson counties, including the City of Fairfax. The groundwater modeling software Visual MODFLOW Flex 9.0 (2023) will be used to develop a local scale model in the Fairfax area including the proposed Big Cedar Industrial Park and the City of Walford. The following upgrades will be made to the model: Item 1. Model grid size will be reduced to approximately 2feet by 2 feet at each existing and proposed Silurian well in order to more closely evaluate future drawdowns and well interference. � �� ``� � � � � � ° \ � �, K 0' � f Item 2. Pumping rates will be updated for 2023. This information will be obtained from both the public utilities and the IDNR. Item 3. Proposed City of Fairfax production wells will be added to the model for the time period 2023 to 2043, and may be extended to 2063 at the request of the Fairfax Water Department. Future proposed pumping rates and proposed well locations will be provided by the City of Fairfax. Item 4. Proposed Big Cedar production welis will be added to the model for the time period 2023 to 2043 (possibly 2063). Future proposed pumping rates and well locations will be provided by the LRE and ISG Hydrogeologic Assessment. If available, input from Alliant Energy and the City of Cedar Rapids will be used. Item 5. if possible, proposed City of Walford production wells will be added to the model for the time period 2023 to 2043 (possibly 2063). Future proposed pumping rates will be estimated based on future population growth projections. Item 6. Recalibrate the model at the local scale using available pump test results from the City of Fairfax production wells. Adjust aquifer parameters as necessary to reduce the overall statistical error. Item 7. Once the model is recalibrated, run the model from 2023 to 2043 (possibly 2063) using the future pumping rates from items 2- 5 above. Item 8. Optimize the existing and proposed Fairfax wells by evaluating various well locations and maximizing sustainable (ong term pumping rates without the proposed Big Cedar Industrial Park wells pumping. Item 9. Evaluate the future (predictive) PWL elevations in the Fairfax production wells when the proposed Big Cedar Industrial Park wells and proposed Walford wells (if available) are pumping, and compare them to casing depths and existing pump settings in the City of Fairfax wells. Calculate the future well interference to the Fairfax wells caused by the pumping of the Big Cedar Industrial Park wells and the proposed City of Walford wells (if available). Significant well interference is defined as PWL elevations within 20 feet of pump settings or casing depths (the City may want to consider a safety factor greater than 20 feet). Various pumping rates in the proposed Big Cedar Industrial Park wells will be evaluated. Item 10. Evaluate the future (predictive) PWL elevations in private wells located between the proposed Big Cedar Industrial Park and the City of Fairfax, and compare them to casing depths and existing pump settings in the private wells. Significant well interference is defined as PWL elevations within 20 feet of pump settings or casing depths. Various pumping rates in the proposed Big Cedar Industrial Park will be evaluated. . r R,; � � , r � � �` � "`;< � _� � ` � � � � � �,. a.. ,� Item 11. Summarize the inputs, methods, and results of the modeling effort in a technical report. Optional Item. Following the completion of the new City wells in the spring of 2024, and the collection of pump test data from these new wells, the model could be updated with the results of the new pump test. The costs for well installation and the collection of pump test data will be the sole responsibility of the City of Fairfax. Innovative Groundwater Solutions, LLC will analyze the pump test data and rerun the model. Schedule Reduce the existing model grids at each existing well to 2 feet by 2 feet. — Within 30 days following the signing of the contract or proposal. Recalibrate a local scale groundwater flow model using drawdowns and pumping rates from the Fairfax public wells— Within 45 days following the signing of the contract or proposal. Update the model with future Silurian wells, future pumping rates from 2023 to 2043 (possibly 2063). Model grids will be reduced at each proposed well to 2 feet by 2 feet. — Within 60 days following the signing of the contract or proposal. Run predictive model runs from 2023 to 2043 (possibly 2063) using the available future pumping rates - Within 75 days following the signing of the contract or proposal. Results and summary report - Within 90 days following the signing of the contract or proposal. Costs 1. Items 1 through 5- 40 hours@ $100/hour 2. Item 6- 30 hours @$100/hour 3. Itern 7- 20 hours @$100/hour 4. Itein 8- 50 hours @$100/hour 5. Iteins 9 and 10 - 30 hours @$100/hour 6. Item 11 — 40 hours @$100/hour $4,000 $3,000 $2,000 $5,000 $3,000 $4,000 Total Project Cost $21,000 Optional Item Costs for Rerunning the model (Spring or Summer 2024) additiona) $5,000 � �. �;, � �'� � �, � � � � , � �� g � x ��, � Please let me know if you have any questions or comments related to this proposal. Innovative Groundwater Solutions LLC looks forward to working with you on this project. If you agree to the terms of this proposal, please sign and date the document and return to: Innovative Groundwater Solutions, L.L.C. ATTN: Mike Gannon 2118 Rosemont Drive Coralville, lowa 52241 Or email to MikeGannon-IGWS@outlook.com Sincerely, � °"'ti'►`�-'�' Mike Gannon Hydrologist 8/4/2023 �' c�,�- ��--, Jo Ann Beer, Mayor City of Fairfax References �-� <� � Date Gannon, J. M., B. Witzke, and R. Langel, 2011. GroundwaterAvailability Modeling Silurian Aquifer East-Central lowa. lowa Geological and Water Survey. Water Resources Investigation Report 5.