Protecting Groundwater from Impacts Associated with Enhanced Infiltration of Urban Runoff - Thoughts and Ideas

Date / Time:
Wednesday, Sep 16 10:30am to 11:00am
Track / Session:
Track: Resiliency and Sustainability / Session 6

As California’s climate becomes more unpredictable and our surface water supplies grow less reliable, enhanced infiltration of stormwater and urban runoff will become common practice to restore and expand groundwater supplies. Enhanced infiltration can provide additional benefits by reducing pollutant loading and flows into surface waters and lessening the need to import water. However, infiltration of urban runoff is not risk free. The greatest threat if from contaminants in urban runoff that migrate down to the water table, impacting groundwater quality and potentially the health and welfare of end-users. In addition, minor changes to the pH and redox conditions can mobilize naturally occurring constituents such as arsenic and selenium. To address contaminants in runoff from industrial facilities, the State Water Boards Industrial General Stormwater Permit relies on Maximum Contaminant Levels (MCLs) developed to protect drinking water as the maximum threshold for infiltrating runoff from industrial facilities via dry wells. This is not unique to the IGP as MCLs have been used by other programs to protect groundwater as well. The regions are varied in how they address groundwater protection. Given the significant resources directed at capture stormwater and replenish groundwater at this time, development of a more flexible approach to protect groundwater based on several risk and vulnerability related factors would be highly beneficial. Reliance on MCLs may be: overly protective where threat and vulnerability are low, necessary where either risk or vulnerability is high such as presence of domestic (private) wells, and may not be enough if CECs are present. Any framework that would be developed must adhere to the State Water Boards antidegradation policy. This presentation is intended to be interactive. The presenters will describe potential ideas and concepts to the audience for feedback and response

Primary Speaker:
Christopher Beegan, State Water Resources Control Board
Chris Beegan has been with the State Water Boards Stormwater Planning Unit since inception in 2015. Chris’ focus areas consist of identifying and understanding barriers that limit stormwater capture and use, as well as evaluating alternative compliance strategies and the assumptions, limitations and uncertainty that could potentially affect the efficacy of these strategies. Prior to that, Chris worked in the Industrial and Construction Stormwater Unit and Ocean Standards Unit. Prior to joining State service, Chris worked in private industry for many years. Chris is a graduate of Cal State Long Beach.
Supporting Speaker 1:
Laurel Warddrip, State Water Resources Control Board
Laurel has worked for the State Water Resources Control Board since 2008 and served many years in the Industrial and Construction Stormwater Permitting program before taking on her current role as the Waste Discharge Requirement unit chief. She holds a B.S. in plant science from UC Santa Cruz and has completed American River College’s A.S. in Geographic Information Systems program.