EVERETT — A study aimed at getting to the root of a stink that’s plagued neighborhoods surrounding the Snohomish River delta in recent years is getting off to a slow start.

Many who complain about the stench point the finger at Cedar Grove Composting on Smith Island.

The study, being conducted by the Puget Sound Clean Air Agency, is employing electronic odor detectors — nicknamed “e-noses” — and volunteers to record data and determine if the odor is in fact coming from the composting operation or somewhere else.

The $375,000 study aimed to place six e-noses at operations in the river delta with the potential to generate odor. The hope was to recruit 20 volunteers to record their impressions over the course of a full calendar year and correlate their notes with the data from the devices.

So far, locations have been found for only three of the e-noses and only 11 volunteers have signed up. The study was supposed to have begun in November but the three monitors were installed just last month.

Still, officials with the clean air agency believe they’ll have enough data for a meaningful study, and that it can be wrapped up by November.

“We’ll still be able to perform a thorough and accurate study,” said Joanne Todd, a spokeswoman for the clean air agency.

Four of the e-noses had earlier been placed on Cedar Grove property, purchased by the company from Odotech of Montreal, Canada. Data from those devices will be used in the results, clean air officials say.

Officials with the city of Everett and the Lake Stevens Sewer District agreed to have monitors placed at their wastewater treatment plants in the delta. Another was placed at the Cemex asphalt plant on the Everett waterfront below the Legion Park overlook.

The city of Marysville and one other business declined to have the monitors placed on their property, Todd said.

Two of the three e-noses were to be placed at the Marysville wastewater plant.

Marysville opposed the study from the beginning. The city declined to participate because Odotech was selected to provide the equipment without an open bidding process though the company had previously done business with Cedar Grove, city administrator Gloria Hirashima said.

“The selection process for the e-noses we did not feel was an objective process,” she said.

Clean air agency officials said last summer that Odotech’s equipment was the most advanced on the market. According to Maryville’s research, older technology — the olfactometer — works better to detect complex odors such as those emitted by landfills or compost, Hirashima said. Clean air agency officials say they intend to find places for the remaining three monitors, though they’re not yet sure where.

“We have a high interest in getting them placed somewhere,” said Brian Renninger, an engineer for the agency.

The data from the three new e-noses is being correlated with that from the devices on Cedar Grove’s property, officials said. When that is done, the data will be put online and will be available to the public through the course of the study, Todd said.

“We promise to be transparent and straightforward,” she said.

Inspectors for the clean air agency have several times traced the stench to Cedar Grove. The company receives yard and food waste from Snohomish and King counties and grinds, cures and sells it for use in gardens.

The firm has been fined for odor violations at both its Everett location and its other plant in Maple Valley in King County. The company is also the target of four lawsuits filed recently on behalf of nearby residents in both areas.

Cedar Grove Composting is putting up $200,000 toward the study. Fines recently paid by the company for odor violations, totalling $119,000, were applied toward that amount.

The city of Seattle and King County, which send yard and food waste to Cedar Grove, are putting up $100,000 and $50,000, respectively. The Clean Air Agency is spending $25,000.

Cedar Grove officials have supported the study and said they would be willing to take any corrective action dictated by the results.

They offered only a brief comment on the latest developments.

“We are obviously interested, as a voluntary participant, in staying engaged and on top of the status of the project as it progresses,” Cedar Grove spokeswoman Susan Thoman said in an e-mail.

Bill Sheets: 425-339-3439; sheets@heraldnet.com.