Plans for a major expansion of the gradually filling Cold Canyon Landfill disposal area on Highway 227 south of San Luis Obispo are moving forward, with another hearing scheduled by the Planning Commission on Thursday, at which planners are expected to go into detail about the growth.

Corral de Piedra Land Co., which owns the site, wants to increase its “footprint” disposal area by 46 acres, up from 88 acres, and the tonnage allowed to 2,050 from 1,620 daily. It also is plugging for a new entrance and scale house one quarter mile south of the current entrance; expanded hours; and more staff — to 114 from 75.

Cold Canyon is the only landfill south of the Cuesta Grade, and it provides a disposal site for trash created by residents from Ragged Point to Nipomo, including San Luis Obispo and other cities. There are two landfills in the North County.

Cold Canyon’s operators estimate that seven years of capacity remain, and possibly less. Should they get their permit, the landfill could operate for another 25 years.

Neighbors oppose the expansion, arguing that it causes noise, odor, traffic and other problems, as well as a decline in their property values. At a hearing June 14, neighbors vented about those difficulties.

Speakers conceded that, as one said, “it (trash) has to go somewhere.” But, as another told the commission, “You must make sure we are protected from this business.”

The planning staff has imposed 119 conditions the landfill must meet before the county will grant a permit to grow. Nonetheless, commissioners said they want to hear more.

After several hours, they continued the discussion until Thursday, at which time, they said, they expect detailed answers about noise, aesthetics, and the rest of the neighbors’ concerns.

“I have about 25 questions,” said Commissioner Ken Topping.

The commission delved into several areas, one of which was the neighbors’ belief that the final life of the current landfill was limited when its permit was granted in 1991, and that the expansion proposal is therefore unlawful.

However, commissioners and the county counsel said, this is a new permit and the terms of the previous arrangement do not pertain.

Another concern, lack of code enforcement, will be met by a “compliance monitor” hired by the county but paid for by the landfill operator.

Supervising planner John Nall agreed that there has been a lack of effective code enforcement at the site, a situation he says was brought about by a previous Board of Supervisors, whose members essentially turned over the responsibility to the state, which has made infrequent visits.

The state “sends a guy once a month; that’s it,” Nall said.

Another speaker asked why trash can’t be shipped to a disposal site in Ontario, east of Los Angeles. But that would be prohibitively expensive, a local businessman who supports the expansion said, and would add to greenhouse gases.

Neither the government nor the landfill operator has sought a new site within San Luis Obispo County, as some suggested they do — another expensive option.

At the June 14 hearing, 17 people testified — 10 against the expansion and seven in favor.