Her bill would have hiked maximum civil penalties from $10,000 to $37,000 per day, and criminal penalties up to $45,000, and more for repeat offenders.
In the cross hairs of the bill's restriction on incineration was medical waste handler Stericycle, which operates an incinerator in North Salt Lake. In the two decades since BFI built the plant, the Foxboro subdivision has developed around it.
Some regard the situation as a planning failure on the part of North Salt Lake city officials who rezoned this area from industrial to residential uses in 2002.
But controversy has intensified since May, when the Utah Division of Air Quality cited the company for allegedly violating emission limits for hazardous pollutants and cheating on its reporting obligations. Stericycle is formally contesting the allegations, which are the subject of a criminal probe by federal authorities, according to Amanda Smith, director of the state Department of Environmental Quality.
She recently informed lawmakers that her staff has cooperated with a Justice Department investigation and they expect to be called as witnesses if criminal charges are filed.
Against this backdrop, Robles outlined a case for keeping medical waste incineration at least five miles from schools and homes.
"Not many states have banned it completely, but they have stricter regulations than we do," Robles said. "We are one of the few states that have one of these facilities."
She said most states impose two-mile buffers, and she found it reasonable to go three miles farther. Robles' Rose Park district happens to be about five miles south of Stericyle's incinerator.
Committee members and industry representatives challenged the fairness of changing the rules on a company that is duly licensed to conduct operations where it is.
Robles agreed it wouldn't be fair, but noted that Stericycle intends to move to an uninhabited part of Tooele County and her bill wouldn't take effect until Jan. 1. She offered to amend the bill to make sure an incinerator would not have to close should someone build a house within a five-mile radius.
But her flexibility was not enough to secure the committee's support. Sen. Jim Dabakis, the lone Democrat, cast the only yea vote, after denouncing Stericycle as a "bad corporate neighbor."
Three industry groups none connected with medical waste argued the bill would set "a dangerous precedent," should the state change how it regulates an industry because residential growth crops up around it.
"Next it will be gravel pits or agricultural operations," said Todd Bingham of the Utah Manufacturers Association. "Companies will look to locate elsewhere."
Another critic argued the measure would "take away private property rights" from those who own land within five miles of an incinerator.
But Robles' supporters noted that new science has emerged regarding the risks of incineration emissions and standards should evolve to reflect these risks.
"We have enough evidence. I don't see why it's not within the purview of the state to bring regulations to keep our environment safe," Robles said.