MDH - Community Public Water System Flooding Guidance
4/12/2019
https://www.health.state.mn.us/communities/environment/water/com/flood.html
Community Public Water System Flooding Guidance
What to Do Now
Review Flood Resilience: A Basic Guide for Water and Wastewater Utilities (PDF) at https://www.epa.gov/sites/production/files/2015-08/documents/flood_resilience_guide.pdf
Join MnWARN, a statewide Water/Wastewater Agency Response Network
Days and Hours Before Potential Flooding
Make sure to have enough treatment chemicals on hand to allow for possible delays in access or service.
Make sure all drinking water storage tanks are full, and ask any interconnected systems to do the same to maximize flexibility in response.
Wrap and tape well caps with heavy duty plastic to help reduce the opportunity for contaminants to enter the well.
Once a well is contaminated, it can be difficult to remediate. Some systems have had to seal a well after repeated attempts to remove contamination.
Protect any electrical or communications wiring or components vulnerable to flooding.
Sandbag to prevent any breaches to vulnerable critical infrastructure.
During and After Flooding
Call the State Duty Officer at 1-800-422-0798 and say, "My drinking water system has had a [describe flooding incident]."
The State Duty Officer is a message relay service and will notify the appropriate organizations for response, including the Minnesota Department of Health Drinking Water Protection (DWP).
DWP will contact you within minutes to discuss the situation, help with technical assistance, and follow through on coordinated response actions.
Any system can request MnWARN assistance when calling the State Duty Officer.
Work to keep the distribution system pressurized.
Once a system loses pressure, it is vulnerable to contamination from intrusion of groundwater, cross-connections and backflow.
Isolate any breached infrastructure by closing valves to minimize contamination of the rest of distribution system.
As a general precaution, in coordination with DWP, you may issue a Drinking Water Advisory. If critical infrastructure is breached, you must issue a Drinking Water Advisory.
The advisory can be limited to the affected area or apply to the entire distribution system if it is vulnerable to contamination.
Once flood waters have receded, DWP will work with you to get your system back to full operation.
Once the system is fully pressurized, disinfected, and flushed, DWP will help collect water quality samples to determine when to lift a Drinking Water Advisory.
Learn more at Drinking Water Safety in Emergencies.
Questions?
Contact the Drinking Water Protection Program: health.drinkingwater@state.mn.us
or 651-201-4700