In a nutshell, that's the problem Amherst must overcome if it ever wants to enter the organic fertilizer market with a product made from sewage-treatment plant sludge, town engineers say.
Early this year, a prototype batch of a product tentatively dubbed "AmEarth" was sold as an additive to a fertilizer wholesaler -- who sent it back after his workers complained about the smell.
The result is that, until the bugs in the process are worked out, Amherst taxpayers will see limited returns on an $8.3 million project at the town sewage plant on Tonawanda Creek.
Town Engineer Paul M. Bowers said Wednesday it could take well into next year to get the project back on track as engineers weigh a variety of technical options. When samples for analysis have to be taken over a period of several months, "it slows down how quickly we can make changes in the process," he said.
The beauty of the project that attracted the town in the first place was that it offered a way to get out from under the $1 million it was costing each year to dump 20,000 tons of wet sludge into landfills. Instead of 20,000 tons of a material that is 75 percent water and 25 percent solids, the new sludge-dewatering and drying process promised 4,000 tons of a pelletized product with 98 percent solids and 2 percent water that could be sold as a fertilizer product similar to Milorganite, which has been marketed for years by the City of Milwaukee.
But until Amherst can eliminate the odor problem, the BB-sized pellets will continue to be trucked to landfills. It won't cost $1 million like it used to, though. Because the sludge has been dried and compacted, dumping costs this year are estimated at about $500,000, Bowers said.
Amherst first ran into problems last winter.
Needing "seed" sludge to start the process in one of two huge "digesters" renovated for the project, the material obtained from another treatment plant in Western New York turned out to be bad, engineers said. Properly running digesters "stabilize" sludge -- remove the pathogens and odor.
"It may have been contaminated, it may not have been fully stabilized," Bowers said. Whatever was wrong, the "bad seed" apparently tainted the digester and it had to be cleaned, setting back the program about three months.
Then, with both digesters up and running, a new problem arose with "foaming," which continues to bedevil the project, Bowers said.
The problem is similar to what happens when warm beer is poured into a glass too fast -- you get more foam than beer.
Like in the beer glass, the foam in the Amherst digesters takes up valuable space, limiting how much sludge they can handle, engineers explained. The Amherst plant produces about 12 tons of dry sludge per day, but "we're digesting only about half because of the foaming," Bowers said.
"The upshot is we're making pellets from a combination of digested and undigested sludge," Bowers said. In other words, he said, until all the sludge can be digested properly, the odor problem will persist.
Mary Ann Jerge, a leader of the East Amherst Taxpayers Association, said that organization is concerned that the town hasn't fixed the problem, or changed project consultants by now.
"This was supposed to save us money, and instead it's costing us more. In the private sector, I don't think you'd see them waiting a year or more to fix a problem," Ms. Jerge said.
"How many more months are they going to get away with saying they're working on it? According to our information, this is not new technology; it's done all over the country. So why is it a problem here in Amherst?"