Exactly. As someone with experience in environmental law, I would also be willing to bet the old Kum-and-Go location at Welch and Chamberlain sits empty for awhile.
In addition to the risks and costs associated with underground storage tanks, including contaminated soil and the prospect of removing the tanks (which can cost a lot depending on the type of tanks), gas stations often have other environmental problems. It's not uncommon to find illegal antifreeze disposal, battery disposal, etc. around gas stations. Worse, there could be groundwater contamination. This is in addition to the typical risks of lead piping, asbestos, etc. that often accompany older buildings. When was that building built?
Any prospective buyer would conduct a Phase I investigation (and possibly a Phase II if warranted) to see what kind of remediation would need to be done. While Kum-and-Go is certainly liable as the past owner / operator of the property, federal environmental law would also impose liability on a new owner / operator. Thus, if there are serious environmental risks disclosed by a Phase I, even a tenant, not just a prospective buyer, could be taking on astronomical risk from the owner (which isn't easy to contract around). Unless the tenant negotiates a super deal with the owner which properly accounts for that risk from the tenant's perspective, we're unlikely to see that spot occupied for some time.
The good thing about that property is that it's in a fantastic location. Thus, there will certainly be interested buyers, but we'll only see action quickly if the environmental risks prove to be relatively clear and the price of those risks is fairly built into the negotiation. If Kum-and-Go owns the lot, I bet we'll see a new tenant / owner within 6 months to a year. If it's an individual around Ames, it's anybody's guess. It could sit empty as an eyesore for years. That, in my opinion, is sad because that corner is fundamental to campus town and to see it sit empty would detract from the atmosphere.