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Albert Frei and Sons, Inc. Page 4 Hatchery Pit- M-2014-043 January 7, 2019 4.) Please evaluate the effectiveness of the design of the clay liner and revise the design as necessary. Attached is a copy of the Hatchery Pit Phase 2 Slope Liner design prepared by Deere & Ault. Their evaluation and design have a sloping liner so it closely matches the slope of the ground water table at the time the property was drilled in 2013. The high point is 5083.3, approximately 300 feet south of the northeast corner and slopes to 5077.3 on the northwest corner of Stage 2 and 5077.6 on the Southwest corner of Stage 2. This places the top of the slurry wall approximately 3.5 feet above the average ground water elevation. The bottom of the french drain pipe is installed at a maximum elevation of 5079.4 and slopes to 5073.2 on the northwest corner of Phase 2 and 5073.6 on the Southwest corner of Phase 2. The french drain will maintain the height of the groundwater table at 2013 elevations. The higher liner top will provide adequate height to prevent ground water from entering the filled area when reclamation is complete. 5.) Given the possible revision to the clay liner design, the location and elevation of the French drain may need to be updated, please evaluate. Please provide a design of the French drain, this should include: a. Sizing information of the drain and a demonstration the size will be adequate. Deere & Ault determined that a 12 inch pipe will be adequate to convey the ground water around the fill. Their plans show the typical french drain trench detail on plat page 13 of 13. Albert Frei and Sons, Inc. has decided to use 14 inch perforated pipe and 12 inch solid drain pipe as a factor of safety. b. Please indicate how the drain will be maintained. Most French drains the Division has observed have standpipes at regular intervals along the drain to provide access for maintenance. The plans call for installing 8 manholes along the french drain approximately every 300 feet that will provide access to the drain for inspection and clean out if necessary. Details are shown in the Deere & Ault design Plat, page 13 of 13 and the approximate locations are shown on pages 8 of 13. c Please provide a profile for the pipe and demonstrate how it will positively drain. This information is shown in the Deere & Ault report on Plat pages 8 of 13 thru 12 of 13. As designed the pipe will a 0.5% slope from the high point to the outlets.