Residents shouldn't smell any unpleasant odors from the pellet plant because the odor should be contained within the plant, Harris said.
However, some residents in the neighborhood as well as near 1st Urban Fiber's paper recycling plant have complained of unpleasant odors from the plant since October.
Mayor Steven T. Sager said he smelled an odor similar to "manure" on Thursday and Friday at his Dewey Avenue home, which he said he thinks was from the pellet plant.
A preliminary report by consultant Sam Cha of TRC Environmental Corp. in Windsor, Conn., states the odor most noticeable from Dec. 15 to Dec. 18 was from the pellet plant.
That odor had been detected as far away as the Venice Inn parking lot, which is about 1.2 miles from the pellet plant. An unpleasant odor from the pellet plant was noticeable in Funkstown during that time as well.
Other odors were detected from 1st Urban Fiber's wastewater treatment plant, Gold Bond Ice Cream's wastewater treatment plant and from various processes at the city's Water Pollution Control plant near the plants and adjacent streets, according to a memo from Cha.
Harris said he still doesn't know for sure that the natural enzyme is behind the unpleasant odor. Wheelabrator switched from using chemicals to the natural enzyme last March because the enzyme was less harsh on the plant's equipment and the safety regulations were less strict than with the chemicals.
Harris said he didn't hear any complaints from March to October about odors from the pellet plant nor has he heard many since the plant started operating in 1990.
The plant was built to relieve the city from dumping tons of sludge at landfills because the city's Water Pollution Control plant nearby was producing sludge faster than it could be disposed. The pellet plant also solved an odor problem caused by the old method of disposal, Sager said.
The plant sold about 90 percent of the 1,600 tons to 1,700 tons of pellets it made during the fiscal year that ended June 30, 1996, Harris said. The plant can produce 13 tons to 14 tons a day and normally operates about 4.5 days a week, 24 hours a day, he said.
During that fiscal year, the city made $4,439 in revenue from fertilizer pellet sales, said City Finance Director Al Martin. The city receives 70 percent of profits from sales, while Wheelabrator gets the remaining 30 percent.
The price of rock salt-sized pellets per ton varies from $12 per ton sold locally to $50 per ton or $60 per ton sold to Florida fertilizer companies to be used with other fertilizers on citrus crops, Harris said.