Getting Drilled on 5th Avenue

What's up with the weird drilling apparatus today in the vacant lot on 5th Avenue at St John's Place in Park Slope? Paging Curbed.com! Paging! Propertyshark says it's a 20x80 vacant (duh) lot, address is 137 5th Ave, purchased in early 2004 for $500,000, zoned R6A with FAR of 3. I'd put 10:1 odds that the drilling is for soil samples to see if it's viable to build luxury condos. 3:1 on ground floor retail.