Greenfield plant transforms waste into fertilizer

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Spring gardeners, lawn manicurists and nursery folk of all varieties on the hunt for cheap fertilizer this planting season need look no farther than the Greenfield's wastewater treatment facility, where there is an ample supply that will not run out anytime soon.

Stored in two open-air storage barns, numerous 12-foot-high piles of "Class A" biosolids processed from the treatment plant stand ready to be applied to area lawns, gardens and farms instead of being transported to the landfill.

The mounds look like little more than rich, dark soil. There are no flies and only the slight aroma of ammonia floats in the air.

The city has been producing the fertilizer since 2004 and has been supplying it primarily to farmers and some residential takers as well.

"We couldn't do this if people didn't take it," Greenfield Wastewater Superintendent David Scheiter told the Daily Reporter ( ).

The biosolid is initially pumped from the plant's sludge holding tanks, where aerobic and anaerobic micro-organisms start the treatment processes. The liquid material is further treated and then piped through mixers and presses that add a polymer to give the substance cohesiveness and squeeze out the water.

Fly ash, a highly alkaline residue from coal-fired power plants that has a high capacity for water absorption, is added to increase the pH level and further solidify the material, Scheiter said.

It is then heaped under the storage barns where the sun bakes it to 150 degrees for three days to finally eradicate any remaining pathogens and increase pH to the desired level.

Every batch is tested by a third-party, state-approved laboratory to make sure the fertilizer conforms to state and federal health guidelines, Scheiter said.

"This never goes out to anybody without having it tested," he said.

The Indiana Department of Environmental Management sets strict standards for biosolid fertilizers produced by municipal sewage treatment plants, and both distributors and large-scale agricultural applications require a state permit, said Amy Hartsock, IDEM public information officer.

"We want to make sure people understand that (IDEM) has extensive regulatory and safety requirements along with monitoring to ensure that the product is safe," Hartsock said.

According to the section of the Indiana Administrative Code regulating land application of biosolids, one test benchmark for fecal coliform requires that levels not exceed a "most probable number" of 1,000 per gram of solid waste.

"Ours routinely comes back testing at zero to three," Scheiter said.

Biosolid proponents, which include IDEM, Hartsock said, say the organic material boosts soil PH, decreasing the necessity of adding lime; improves water absorption and retention; and releases nutrients slowly as organic matter breaks down, providing a continuous source of food.

"The best thing about this is that it can be used to condition the soil," Scheiter said, adding that working the matter into hard, clay fields will improve soil quality over time.

And it can be used on any soil, from large agricultural applications to local lawns and gardens.

Gardeners might want to shovel the material on and then till it in, but a fertilizer or lime spreader will do just fine for local lawns, Scheiter said.

"If you put it on (the lawn) at the right time, with a little of that and a little rain, it gives it a nice kick," Scheiter said.

However, the biosolid must be used judiciously. "If you put too much on you can burn (your lawn)," he said.

Earlier this year, the city board of public works authorized the purchase of a $50,000 windrow machine to paddle and mix the material into a finer texture.

"We just wanted to provide a higher-quality product," Scheiter said.

The city charges $2 per cubic yard for the first biosolid yard and $1 for each additional yard. Quantities of 25 cubic yards or more – roughly a dump truck full, Scheiter said – are free if you bring your own truck.

Despite the low purchase price and giveaway to area agriculture, moving biosolids off the plant yard to lawns and farms also saves the city money, Scheiter said.

The city produces between 1,200 and 1,500 dry tons of the material annually and it all has to go somewhere. If farmers and residents didn't use it the city would have to pay landfill disposal fees to dump it.

"If we didn't spend money (buying) fly ash, we'd spend more money taking it to the landfill," Scheiter said.

Recycling and avoiding the landfill is one of the environmental benefits touted by IDEM, Hartsock said, and there are economic advantages above saving the carrying cost to the dump.

"We've seen higher crop yields for the farmers," Hartsock said.

Farmer Richard Buchanan heartily agreed Wednesday as he loaded a semitrailer full of biosolid at the city's treatment plant.

"We've been using this stuff every season for the past two years," said Buchanan, who farms throughout Hancock County. "We use it on everything: corn, soybeans, wheat and hay – lots of hay. It boosts it pretty good."

Buchanan said he applied the fertilizer to his wheat fields prior to the last spring snowfall, and when the snow melted, the crop immediately came out of the ground.

"This stuff is awesome," Buchanan said. "And if you use it on your lawn it's going to be amazing."

Additionally, every time Buchanan and other farmers load a big truck of biosolid, they're saving a truckload of money. A similar load of chicken manure would cost upward of $300, Buchanan said, adding that it wouldn't smell nearly as nice.

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