City issues release on odor issue from biosolids application

By City of McPherson
January 29, 2015

Recently several McPherson citizens have commented on a foul odor noticed in parts of town, primarily in the south eastern area. This odor is the result of the city’s annual process where wastewater biosolids (aka stabilized sludge) are spread on local farm ground owned by the city. These fields are located northeast and southeast of the intersection of Centennial Drive and Iron Horse Road.

Over the course of a year, the city of McPherson generates approximately 325 dry tons of biosolids as a byproduct of treating and cleaning almost 600 million gallons of the city’s wastewater each year. These solids are processed at the wastewater treatment facility, where they are organically broken down and stabilized. They are dried to about the same consistency as moist potting soil. Additionally, the biosolids are treated to kill/remove pathogenic bacteria that could pose a health hazard to people. Once the biosolids meet all KDHE and EPA health and safety requirements, they are transported and stored in a covered, concrete lined holding structure located near these fields. In order for the soil to receive the maximum benefit, the biosolids are spread on the fields in December or January. The actual spreading takes approximately 3 to 4 days and was just completed last week.

Unfortunately, the treatment process cannot remove all of the odors. These odors may persist until the biosolids are almost completely dry. Due to rain, snow, and temperatures this time of year, the drying process can take a while.

The city tries its best to minimize this inconvenience. We assure you there are no biological hazards to the public from this odor.