Now that a study shows the landfill is the main source of the odor that has sickened Nansemond Parkway-area residents for months, a city councilman says the trash authority’s handling of the issue has been less than desirable.

“It has left a bad taste in the community about the landfill,” Councilman Leroy Bennett said at Wednesday’s meeting of the Southeastern Public Service Authority board of directors. “They [residents] lost a lot of faith in SPSA because of the way it was being handled.”

The study, conducted by SCS Engineers at the behest of the authority, aimed to find the cause and concentration of the odors area residents have been complaining of since late fall. Bennett and others have accused the trash authority of being reluctant to act to reduce the odor problems.

“The odors that we smelled are characteristic of landfills,” said Bob Gardner of SCS Engineers at the Wednesday meeting.

The company conducted about 180 readings on landfill property and surrounding neighborhoods in March. Most readings were taken in the early morning and late evening hours, when residents have reported the most pungent odors. When readings showed a high level of certain chemicals, an air sample was collected and submitted for laboratory analysis.

Some air samples showed high levels of hydrogen sulfide and carbon disulfide, both gases that can be generated by rotting trash.

“The results of the analysis of one of the samples obtained at the Landfill indicate that the facility is a source of measurable [hydrogen sulfide] concentrations in the air,” states the study drafted by SCS Engineers.

The study did not turn up levels of any chemical higher than recommended exposure limits for health reasons, but levels of both gases significantly exceeded odor thresholds as determined by the Agency for Toxic Substances and Disease Registry. The odor threshold is intended to define the lowest level of a certain odor that can be detected by humans.

Gardner noted that wet weather conditions throughout the winter increased biological activity in the landfill’s Cell VI, where the authority currently is dumping trash. The increase in the rate of trash breakdown can be expected to increase odor problems unless they are controlled, Gardner said. In addition, deforestation between the landfill and nearby neighborhoods likely contributed to the odor problems in the neighborhoods.

“You had a confluence of situations that amplified it, for sure,” he said.

In February, a gas collection system was installed in Cell VI, and has been siphoning significant levels of gas, Gardner said. The installation of the system should reduce odor problems — and Bennett said he believes it already has.

“The odor has improved, I would say, 95 percent,” Bennett said. He noted, however, he still receives complaints from his constituents on occasion, and he urged the authority not to allow the problem to happen again.

“I think that will help a whole lot” toward restoring faith in SPSA, he said.