Evaluating the Effectiveness of Regulatory Stormwater Monitoring Protocols on Groundwater Quality in Urbanized Karst Regions

Non-point pollution from stormwater runoff is one of the greatest threats to water quality in the United States today, particularly in urban karst settings. In these settings, the use of karst features and injection wells for stormwater management results in virtually untreated water being directed into the karst aquifer. Currently, no policies exist specifically to provide water quality protections to karst environments. This study utilized a combination of karst stormwater quality data, along with survey data collected from MS4 Phase II communities, and an analysis of current federal, local, and state water quality regulations, to assess the need for karst-specific water quality regulations. Water quality data indicate that significant levels of contamination are mobilized during storm events, and often are directed into the karst system via Class V injection wells. Survey data collected from MS4 stakeholders in the karst regions of Kentucky indicate stakeholders are generally unable to explain local karst regulations or the steps taken to develop them. This confusion comes in part from insufficient progress on evaluation criteria available for the MS4 Minimum Control Measures (MCMs). Karst waters are often placed into the legal “gray zone” due in part to differences in definitions of key terms in state and federal regulations. This study recommends the development of regulations specific to karst waters at the state and federal levels through either the adaptation of existing or creation of new policies, which place an emphasis on the integration of water quality monitoring and karst education