R2022-73 Resolution Authorizing a Professional Engineering Services Agreement with INTERA Inc. for Vulcan Pit, Rhodes Landfill and Source Water Protection Plan, City Project 2022-22

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Exhibit A Vulcan Pit Improvements, Rhodes Landfill Review and Source Water Protection Plan, City Project 2022-22 Task 1. Former Vulcan Pit Improvements to facilitate the use of the former Vulcan Pit (Pit) as a raw water source were recommended in INTERA's 2019 Alternative Water Supply Report (Report) to the City. INTERA will perform the following tasks to assess the available water quantity and to design, permit, and bid the construction of the recommended infrastructure improvements. Task 1a— Water Quantity Assessment The amount of water available from the former Vulcan Pit will be calculated with a new bathymetric survey and a recharge estimate.As 22 years have passed since the last survey of the Pit(Bainbridge-Gee-Milanski and Associates,2000), INTERA will subcontract with Aquatic Control (Canton, IL) to perform a modern, digital bathymetry survey. This data will be used to develop a new volumetric model of the Pit. INTERA will also estimate groundwater recharge to the Vulcan Pit. To aid in doing so, a stilling well will be installed in the Pit and instrumented to track changes in the water elevation in the Pit. The record of the Pit stages will be correlated with river elevation data collected by the U.S. Geological Survey just downstream at the U.S. Route 48 river crossing. These data, along with hydrologic calculations, will assist in an evaluation of groundwater recharge to the Pit. Both the bathymetric survey and the recharge study will be used to evaluate the volume of potential short-term drought supply that can be obtained from the Vulcan Pit. Task 2b—Engineering Design As described in the 2019 Report, INTERA will prepare engineering design plans and technical specifications for use in permitting, bidding, and constructing approximately 3,000 feet of 14-inch pipeline from the Pit to the raw water intake pipeline. The project includes a horizontal directionally installed river crossing and pump, electrical, and control improvements for operation of the system.This task will not begin until after an assessment of Pit volume is available from the bathymetry conducted in Task 1a. The construction cost was estimated to be approximately$1 million (INTERA, 2019). This estimate is not based on design and includes contingencies. A more refined construction cost estimate will be provided at the 60% design stage. With this estimate the City can confirm its intent to proceed. Last Revised;4/4/2022