Philadelphia’s fight against bedbugs took one tiny, itchy step forward Tuesday with a City Council committee’s passage of a bill aimed at reducing the city’s vulnerability to the nasty house-guests.

The bill that advanced would hold landlords responsible for ridding rental properties of the bedbugs if the critters are discovered within 90 days of a lease’s commencement. But after the 90-day window closes, tenants would share the cost of remediation, a landlord-friendly amendment to the bill that tenant advocates and others say will make the regulation less effective.

Philadelphia is one of the only major U.S. cities that doesn’t currently use city law to guard against the critters. The city has been called the most bedbug-infested city in America. A 2014 University of Pennsylvania study found that in one South Philadelphia Zip Code, about 11% of homes had been affected.

While other cities have regulations outlining who is responsible for outbreaks in rental properties, those regulations haven’t existed here. Nor are there guidelines for reporting infestations.

A standoff between landlords and tenant advocates

The bill’s attempt to remedy that void was almost derailed by opposition from tenant advocates to the last-minute change introduced by its sponsor Mark Squilla.

Originally, the amendment, would have made tenants responsible for the cost of remediation after 30 days, as opposed to 90.

Squilla said the change would encourage tenants to take responsibility while protecting landlords from the burden of bedbugs brought into an apartment by renters.

The insertion of the amendment resulted in a tense standoff during the Council hearing, as landlord and tenant lobbyists shouted each other down in the Caucus Room across the hall from the chambers.

“You just want the responsibility solely on the landlords,” Paul Jay Cohen, a lobbyist representative the Homeowners Association of Philadelphia (HAPCO) said to a tenant advocate. “Of course you wouldn’t want it shared.”

Squilla’s bill is based on Chicago’s bedbug regulations. Laws in cities like San Francisco and Austin were consulted as well.

Landlord lobbyists pointed out that those cities have higher housing costs than Philadelphia.

“When you look at cities that have this, they have the highest rents in the country,” Marlynn Orlando, executive director of the Pennsylvania Apartment Association East.

Tenant groups fought back fiercely against the amendment.

George Gould, a lawyer with Community Legal Services who regularly lobbies for tenant rights in City Hall, argued that tenants are not experts on bedbugs and may not understand that they are dealing with an infestation until after the 30-day window is up.

Many renters also don’t necessarily read leases carefully, so they will unknowingly get stuck with the costs for bedbug remediation under the proposed amendment, he said.

“It seems like are just trying to kill the bill,” said Michelle Niedermeier, Environmental Health Program Coordinator with Penn State University’s Department of Entomology. “You have epidemiologists and entomologist in here telling you that this makes zero sense.”

Squilla appeared increasingly harried throughout the confrontation in the caucus room, which lasted long enough to put the actual hearing on hold.

Squilla has a reputation for trying to appease all interest groups on every side of an issue, and he tried to make clear that the amendment was an effort to make all sides happy—which it clearly failed to do.

“My initial thought was that if you move into a place and you know you have 30 days to report it you are going to be pretty diligent about that,” Squilla tried to explain. “But if you drag this out, they [tenants] might never do it [report bedbugs]. There has to be some line where we take responsibly as tenants.”

Tenant advocates got support from Councilmember Maria Quiñones-Sanchez, the chairperson of the committee on Licenses and Inspections, who seemed to agree that the amendment made little sense.

“Why are we giving it a date when we’ve just clarified that the bugs can come in at any time [over the course of a lease],” said Quiñones-Sanchez.

But Squilla refused to totally back down before the demands of tenant groups, instead just extending the window to 90 days.

He also amended the legislation to require that landlords and tenants share the cost of remediation after the 90-day process, instead of only having renters be responsible.

Quiñones-Sanchez voted against the bill, even after the changes.

The bill can receive its first reading before the full City Council this Thursday and could potentially reach second reading and final passage next week. But given the degree of controversy, it is likely to be held while interest groups haggle over the final language.

Another bill fought by landlords — one that required lead remediation — took more than a year to advance before being signed into law Tuesday by Mayor Jim Kenney .