Between December 18-20, 2018, City of Austin staff observed and investigated three separate, discrete discharges of sediment to Barton Springs Pool, directly from the Edwards Aquifer. The discharges caused unusual turbidity, but not acute, adverse impacts to the aquatic life of the pool, nor long-term harm to the water quality of Barton Springs Pool. City of Austin staff worked with the Barton Springs Edwards Aquifer Conservation District (BSEACD) to identify the source of sediment as geothermal/heat pump well drilling activity that was permitted by the BSEACD.
The wells are located in the confined zone just east of the recharge zone, about a mile from the springs, and the timing of the well-drilling activity coincided with the appearance of the urbitity at the springs and the known travel time of water in the aquifer.
The City of Austin issued a citation under Austin City Code Title 6, Chapter 5 for a pollutant discharge to a waterway.
The wells were completed and closed on Friday, December 28, 2018, under supervision from the BSEACD. The City of Austin does not anticipate any further discharges from this activity.
As of January 2019, the City and the BSEACD are working together to develop criteria to address these types of wells in the future. This type of well drilling is a new phenomenon to this area, so the impact was not anticipated. Now that it has happened once, the two entities can adjust our respective protocol to ensure more preventative practices and increased inspection and monitoring for this type of activity.