Agenda - Council - 07/28/2015 - Laserfiche WebLink

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• Potential for impacts of groundwater pumping on surface water features and ecosystems - Surface waters in the community may be directly connected to regional groundwater system • Significant vulnerability to contamination - A vulnerable Drinking Water Supply Management Area has been designated within the community - A Special Well and Boring Construction Area has been designated within the community - Travel time from land surface to bedrock aquifers is estimated to be less than 50 years • Significant uncertainty about aquifer productivity and extent - Parts of the community may not be represented by a Minnesota Department of Health aqui- fer test - Parts of the community may not be represented by a Minnesota Department of Natural Re- sources observation well The Metropolitan Council's Local Planning Handbook contains interactive maps of all of these issues, and they are also summarized in Chapter 5 of this Master Water Supply Plan. The following actions are recommended: • Acknowledge the issues above in local water suppy plans and water appropriation permit applica- tions, including a plan to monitor. • Explore and support water demand (water conservation) programs such as incentives, ordinances, education and outreach, rates and other approaches. The Metropoliatn Council Water Conserva- tion Toolbox can support these efforts. • Before requesting water appropriations, water users in this areas should evaluate the need to ad- dress water conflict and well interference including a) an inventory of all active domestic and public water supply wells near proposed well locations and b) an anlysis of existing water level/water withdraw) data to identify where future drawdowns could affect domestic wells. • Due to the potential for significant decline in aquifer levels, before requesting water appropriations, conduct a basic evaluation of the likelihood for significant decline in water levels (i.e. exceeding 50% drawdown in available head in confined aquifers or continued decline in unconfined aquifers). The analysis should be determined in consultation with DNR and can vary from a graphical com- parison of water levels to local groundwater flow modeling. If this analysis suggests future declines are likely to be unacceptable, a management plan should be developed and include additional water level and pumping rate monitoring, triggers and actions to protect aquifer levels, a schedule for periodic analysis of data to identify the need for action to mitigate impacts, and a schedule for periodic and timely reporting to DNR. • Due to the risk of impacting surface waters by groundwater pumping, consult with DNR to review existing information about groundwater withdrawals, water level, surface water flow, climate, and projected withdrawals and wells to predict the likelihood of a connection between aquifer with- drawals and surface water features. If a connection is likely, a management plan should be devel- oped and include aquifer testing, monitoring water levels and pumping rates and surface water flow, triggers and actions to protect aquifer levels, a schedule for periodic analysis of data to iden- tify the need for action to mitigate impacts, and a schedule for periodic and timely reporting to DNR. • Due to the risk of contamination, consult with MDH about local actions to prevent the spread of contamination. The community's source water protection plan should include measure to mitigate public health risks due to potential contamination sources, which may include cooperating with MDH to increase monitoring of contaminants regulated under the Safe Drinking Water Act. Where significant contamination exists, MDH will continue enhanced monitoring, and public water suppli- ers may need to implement treatment processes to meet Safe Drinking Water Act requirements and manage pumping to better control the extent and magnitude of the contaminant plume. WATER SUPPLY MASTER WATER SUPPLY PROFILES PLAN- Draft June 2015