EVERETT — The alleged source of a noxious odor that has plagued Marysville much of the summer, the Cedar Grove Composting Plant will submit a detailed study of its operations to the local clean air authority by the end of the month.

A supervising inspector for the Puget Sound Clean Air Agency, Mario Pedroza said the organization, which has the authority to enforce clean air laws locally, ticketed Cedar Grove twice last month in connection with alleged smells leaving the Smith Island plant.

In response, according to Pedroza, in a letter to the Puget Sound agency, Cedar Grove officials proposed investigating several areas of their operation. Pedroza said the clean air authority accepted the proposed study, but also added to the list of items to be looked at.

Cedar Grove Vice President Gerry Bartlett confirmed his company has agreed to study approximately seven areas of their operation. He described the Sept. 30 deadline for completion of the study as self-imposed by the company.

According to Bartlett, once the study is complete, officials of both Cedar Grove and the clean air group will discuss and negotiate what, if any changes, need to be made at the Everett facility.

“This has been a very cooperative process,” Bartlett said.

Early this summer, the clean air authority began investigating the source of an odor that led to complaints from both local residents and city officials, including Mayor Dennis Kendall.

Pedroza first issued Cedar Grove a written warning regarding alleged odors coming from the plant on July 9. At the time that warning was issued, literally following his nose, Pedroza said he was able to trace the smell reaching Marysville to the Cedar Grove plant on three occasions, including July 9.

Since then, because of specific complaints allegedly traced directly back to the composting plant, the Puget Sound authority was able to go a step further and hand out full-blown citations to Cedar Grove. Still, Pedroza added the number of odor complaints reaching the clean air group have dropped.

Since hitting a high in the early summer, Pedroza said the number of calls regarding the smell fell to about 25 or 30 last month.

“That is down, but the complaints are still there,” he said.

Pedroza said the tickets were linked to Cedar Grove’s grinding operation and the screening of its finished product. Bartlett has said the company accepts yard and food wastes that are converted into compost in a process that takes a total of about 120 days and includes mixing and grinding the waste materials. The grinding operation as well as the screening measures taken by the company are two obvious areas Pedroza said Cedar Grove has agreed to study.

Additionally, the clean air authority wants the firm to look at the materials it accepts, the materials it rejects, how the accepted items are mixed and how those materials are moved around the facility, among other issues.

This is not the first time the clean air authority has investigated Cedar Grove. Pedroza confirmed the agency had conducted an investigation into a Cedar Grove operation in Maple Valley near Tacoma. In the past, he has said that investigation resulted in “significant” monetary fines against the firm, but exact figures were not available. According to Pedroza, the agency can level fines reaching a maximum of $15,000 a day.

“It hasn’t reached that step yet,” he said recently in regard to the situation with the Everett Cedar Grove plant. Pedroza added that fines, if they happen at all, aren’t likely at least until after Cedar Grove completes the study now underway. Even once that happens, Pedroza believes the firm will have until roughly the end of the year to make any operational modifications ultimately suggested by the Puget Sound group.

Of course, Cedar Grove also has a legal right to challenge any findings against them.

In the meantime, Pedroza said the clean air authority will continue to monitor the operation on Smith Island.