This would be the reason for the soil testing that Geckos_Rule posted about in the Waller Park Place thread that turned out to be for Endeavor's 91-93 Red River site. According to yesterday's AULCC meeting notes, this is a 30-story residential project with retail. Here's the location on Streetview:
Here's the site location from AULCC:
ftp://ftp.ci.austin.tx.us/ATD_AULCC/...ofts_PLANS.pdf