Through the rest of this summer and fall, the compost piles in West Rifle will gradually diminish, as the material is sold off as fertilizer.
Many months of strong odors and sometimes emotional complaints to city of Rifle officials, and a state health inspection notice of violation, led the city to issue a notice to quit to Caca Loco Compost owner Jim Duke in June.
Assistant City Manager Matt Sturgeon said the city and Duke were finalizing a time frame for when the last of the material leaves the site, next to the city's regional wastewater treatment plant, but it would likely be the end of this fall.
"That's what's in the closure plan he filed with the state," Sturgeon added.
Duke said he's not sure he can sell all the material by that time.
"Even if I do, that will still leave me hundreds of thousands of dollars in debt," he added.
Most, if not all, of the approximate 10,000 cubic yards of material - biosolids from the city's nearby plant, septage, animal bedding and manure, portable toilet wastes, wood and yard wastes, paper, cardboard and food wastes - have completed the compost process, Sturgeon said.
The compost materials also included biosolids and septage from the West Glenwood Springs treatment plant, according to Sturgeon.
Several studies over the last decade have claimed people living near land fertilized with Class B biosolids suffered burning eyes and lungs, skin rashes and other symptoms of illness.
Fertilization of land with processed sewage sludge, or "biosolids," has been a common practice in Western Europe, the United States and Canada. Some local governments, according to one study, have restricted or banned the practice, after residents claimed adverse health effects.
Biosolid is sewage sludge that has undergone a certain level of treatment and is divided into two classifications. Class A biosolids undergo a high level treatment and do not show any signs of pathogens. Class B biosolids receive less treatment and have been found to contain bacterial, parasitic and viral pathogens, according to the studies.
Duke said while his operation accepted Class B biosolids, they then underwent additional treatment to the Class A standards.
The city and Duke entered into a contract to operate the site in the spring of 2011. A certificate of designation defined the operation of the 10-acre site. It could accept up to 11,000 cubic yards of materials annually, mixed in specific piles on the site, with heavy equipment used to aerate the material and help the composting process.
The Colorado Department of Public Health and Environment found several concerns with Duke's operation during a compliance assistance inspection on April 11. Some had to do with paperwork, but inspectors noted odor complaints were not adequately addressed within seven days, as the certificate requires. Other concerns focused on stormwater drainage and pad liner permeability to protect groundwater sources.
Duke expressed strong remorse for the odor problems and stopped accepting food and grease waste, two common odor sources. Duke also installed low pressure misters around the entire fence line of the site. The misters sprayed an organic solution used by hospitals to help reduce odors, he said. Atomizer fans were also placed within the site and misters sat on top of the compost piles as well.