Local officials said the application of sewage sludge on farmland poses a low risk for human health and city’s water supply provided that “everybody follows the protocols they’re supposed to.”
The use of sewage sludge, also referred to as “biosolids,” on farmland is in the local spotlight as state environmental regulators consider a request for a permit to create a sewage sludge-producing facility southeast of Columbus.
Biosolids are organic materials produced during the treatment of human sewage at wastewater treatment plants, according to the Indiana Department of Environmental Management.
Wastewater treatment techniques stabilize and disinfect the biosolids, which contain nutrients necessary for plant growth, including nitrogen, phosphorus, potassium, copper, zinc, calcium, magnesium and iron, according to regulators.
Evan Daily of Biocycle LLC, 3788 E. County Road 300S, has asked IDEM to allow his facility to accept dewatered biosolids for blending and use on farmland in Bartholomew, Jennings, Decatur, Jackson, Johnson and Shelby counties.
Earlier this week, three local farmers expressed concerns about the proposal during a Bartholomew County commissioners meeting. The farmers said they were worried about, among other things, potential runoff from the facility could reach their properties and a nearby creek, as well as the unpleasant odor from the operation and concerns over whether the sludge could get into the aquifer that supplies water to Columbus.
The commissioners said they do not have jurisdiction over the matter. IDEM has said that it “encourages the beneficial reuse of biosolids … in a manner that protects human health and the environment.”
Anyone who applies biosolids to farmland “must comply with federal and state land application laws and rules and obtain a permit,” according to IDEM.
Columbus City Utilities Director Roger Kelso said the risk that biosolids applied to farmland would contaminate the city’s water supply are low provided that IDEM and EPA rules are followed.
“It would be literally like (the odds of) winning the lottery if it would ever cause a problem,” Kelso said. “The probability is (so) low that it just isn’t an issue, as long as we follow our setbacks and things of that nature.”
“All sludge goes through regimen sampling analysis before we are even allowed to let it be land applied,” Kelso added. “…It’s processed sludge. It’s not raw waste.”
Kelso said he is unaware of sewage sludge on farmland causing any pollution issues with the city’s drinking water.
According to the proposal, the biosolids will be mixed when they arrive and placed in an area sectioned off by interlocking concrete blocks that allow access for sampling before land application. Once the desired amount is reached in the holding area, the blend will be sampled and tested to determine land application rate.
The structure Daily wants to build will have a concrete base with concrete walls on three sides, according to his application. The south side of the building, which will be open for truck access, will have a trench drain across the opening with a runoff holding tank. The application states the holding area for biosolids will be 85 feet wide by 100 feet long, with a holding capacity of 46,750 cubic feet.
However, the sewage sludge may emit a distinctive odor depending on the treatment process and methods used. The odorous compounds generated and detected are most often ammonia, amines and reduced sulfur-containing compounds, according to the EPA.
Meteorological conditions such as wind speed and direction, relative humidity, and temperature can impact nuisance odors, according to the agency website. The EPA states the odors do not mean that the biosolids pose harm to human health and the environment.
The application of sewage sludge on farms in Bartholomew County is not new, though it has been a subject of controversy in the past.
In 1987, residents opposed to issuing a state permit to spread liquid sludge on fields near Walesboro attended a public hearing and submitted letters alleging that the city was improperly applying sludge, dumping it in large piles or in improper weather conditions, The Republic reported at the time.
State regulators at the time said the city’s sludge disposal program was largely operating without problems. In April 1986, IDEM cited Columbus City Utilities for applying sludge to two fields not qualified for the program.
In 1999, property owners attempted to gather enough signatures on a petition to force IDEM to hold a public hearing on a proposal to build a 1.5-million-gallon sludge lagoon on a farm near Burney to mix fertilizer from sewage sludge and distribute it to area fields.
Parts of the aquifer in the county that supplies Columbus with drinking water “lacks overlying clays” and are “highly susceptible to contamination from surface sources,” according to the Indiana Department of Natural Resources.
Contaminants have been detected in the city’s water supply in the past, including PFAS, 1,4 dioxane and E. coli, though there is no evidence that the use of sewage sludge on farmland played any role.
Kelso said he is unaware of sewage sludge on farmland causing any contamination issues with the city’s drinking water. Columbus’ drinking water currently meets all state and federal regulations, according to city utilities officials.