b'Appendix B - Our Groundwater StoryPart 2Groundwater StudiesMichigan State University (MSU) was hired in 2012 to conduct thedown from the surface from recharging back into the bedrock aquifer.comprehensive, two-part groundwater study for Ottawa County. An initial Phase I groundwater assessment was completed by MSU in 2013.TheSecondly, the bedrock aquifer, known as the Marshall Formation, is naturally-rich in assessment validated the anecdotal reports:in certain areas of our bedrocksodium chloride.Consequently, as water levels decrease, the concentration of sodium aquifer, water levels have been gradually declining over the last 20 years,chloride increases in the water that is being pumped from the aquifer system. and sodium chloride levels are rising above recommended standards for drinking water (250 mg/L) and agricultural irrigation (70 mg/L). A Phase II study began in 2014 by MSU to assess how the Countys groundwater supply will be impacted as demand for water increases into the future.This study utilized The primary reasons for thewater-demand projections for the years 2020, 2025, and 2035 based on anticipated declining water levels andgrowth trends countywide.The study results, nalized by MSU in March 2018, provide increasing sodium chloridecommunity ofcials with the information needed to develop a sustainable action plan concentrations are two-fold.First,for effectively and collaboratively managing our groundwater resources.water in the deep bedrock aquifer is not being replenished as quickly as it is being withdrawn for water consumption. This is occurring mainly because of the unique geology underneath Ottawa County.A substantial layer of impermeable clay material sits atop the deep bedrock aquifer nearly 100 footFigure a, above, illustrates the increasing amount of groundwater that is being pumped from the bedrock aquifer, especially in the central portion of the County.below the land surface.This naturally occurring clay layerDid You Know.prevents water that percolatesThe full scientic study results can be found in the Phase I and Phase II Reports, available online at miottawa.org/groundwater58print plan.13.indd 58 2/19/2020 12:13:57 PM'