Nearly a year after an oil tanker leaked hundreds of thousands of gallons of oil into the Delaware River, acting Gov. Richard J. Codey has signed legislation that increases the liability limits for owners and operators of vessels that discharge hazardous substances into state waterways. Last summer, investigators concluded a rusty anchor on the bottom of the river ripped the hull of the Greek tanker Athos I, causing an estimated 265,000 gallons of crude oil to pour into the Delaware. The cleanup of the spill has so far cost $176 million. The spill fouled more than 200 miles of coastline in four states, halted commercial and recreational boat traffic on the river and killed dozens of birds. While investigators have found the cause of the spill, they have not identified the anchor’s owner or determined how it ended up on bottom of the river. There are no markings to indicate its ownership.