121516 BFI Colonial Landfill

State environmental regulators have delayed a decision whether to allow the expansion of BFI Colonial Landfill while they try to pin down the source of foul odors that have sparked complaints from neighbors of the big dump near Sorrento.

State Department of Environmental Quality officials said Wednesday that results from a recent round of air monitoring at the landfill off La. 70 were inconclusive and did not detect air emissions that exceeded health and safety levels.

With the test results, Greg Langley, DEQ spokesman, said the agency extended the public comment period on a permit for the expansion of the landfill's storage capacity until Feb. 3.  

The agency can't make a decision on the permit until after the comment period, which had been set to end Tuesday afternoon.

"We are getting a lot of complaints, so we're still trying figure out what's going on and we don't want to move until we have some idea exactly what it is," Langley said.

He added that the air tests don't necessarily mean there aren't odors in the vicinity of the landfill but that the level of emissions is below what DEQ's monitors are designed to pick up.

He said sulfur-based compounds can produce a foul smell at very low concentrations.

"It just stinks," Langley said of sulfur compounds in general. "It's not going to kill you, but it's not very nice."

Neighbors of the 287-acre landfill and residents of nearby Sorrento have put the blame squarely on the dump. They claim something has changed in what the 43-year-old landfill has been accepting that has caused foul odors to emanate from the dump for the past year and a half.

But BFI officials, while acknowledging some odor problems in the spring that were addressed, deny that their waste stream has changed and raised doubts that the more recent noxious smells are definitively from the dump. They point out that other facilities are nearby, including another landfill next door, the Gator Landfill.

The councils of Sorrento and Ascension Parish government have adopted resolutions opposing the expansion of the BFI landfill.

A Jan. 11 DEQ summary on air testing says regulators found 17 instances of elevated hydrogen sulfide, volatile organic compounds, sulfur dioxide or indications of flammable compounds on Dec. 21 at one of the landfill neighbor's homes.

But regulators noted more than 98 percent of the data collected that day showed normal levels and indicated to inspectors that the few elevated measurements were invalid outliers. Based on the amount of flammability being reported, more of the test data should have pointed to elevated levels in other chemicals but didn't, the report says.

So, inspectors did another round of tests. Those tests from Jan. 4-6 found "very low levels" of sulfur dioxide, hydrogen sulfide and volatile organic compounds that did not exceed air quality standards. Monitors for the second round of tests were set up due north of the Colonial landfill and due north and due south of the nearby Gator Landfill.

Sulfur dioxide, hydrogen sulfide and VOCs all can produce odors. Hydrogen sulfide, which can be poisonous and flammable at very high concentrations, produces a characteristic rotten egg smell at low concentrations.

The colorless gas is a byproduct of the petrochemical industry and can come from the anaerobic breakdown of organic matter, including sewage.

Follow David J. Mitchell on Twitter, @NewsieDave.