Zumwalt debris pile fire and Edwards Aquifer vulnerability

The Zumwalt debris pile fire, the longest burning fire in Bexar County, Texas history, demonstrated the potential for contamination of the Edwards Aquifer, the sole source supply of drinking water for more than 1.7 million people. This fire burned for more than 3 months and required daily emergency response from local and state agencies. The debris pile covered more than 4 acres, was approximately 80 ft. tall, and was estimated to contain more than 171,000 cubic yards of material. The Zumwalt debris pile was located over the Edwards Aquifer Transition Zone (EATZ) but in effect was over the Edwards Aquifer Recharge Zone (EARZ). In the early days of the response it became evident that there was direct communication between the debris pile and the Edwards Aquifer. The emergency response to this fire demonstrated the vulnerability of karst aquifers and how rapidly contamination can move in fractured terrain.

The potential contamination of aquifer water supplies is a concern for public health officials. Karst aquifers are particularly vulnerable. In the State of Texas private well owners have to rely upon themselves to ensure that their drinking water is free of contamination. Local water agencies must respond to events which have the potential to contaminate drinking water on a regular basis. Often they begin by locating and testing private wells in order to track contamination flow paths. The overall objective of thesis was to examine the emergency event and the data collected from the response to the Zumwalt debris pile fire. This will help shed a better understanding on how local, county, and state agencies handled this emergency event and spot light lessons learned to improve public health and safety.