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Biosolids Land Application Information

A picture of biosolids being injected below the surface on a farm field
Environment, Great Lakes, and Energy

Biosolids Land Application Information

In Michigan, wastewater treatment plant sludge can be landfilled or incinerated or can be treated and land applied as biosolids. The graph below shows the tonnage in dry tons (dt) of each reported in Michigan.

Biosolids Metal Information

Biosolids undergo stringent monitoring for a variety of pollutants. The Part 24 Rules defines 9 pollutants and their ceiling concentrations, referred to as Table 1. Biosolids with pollutants over Table 1 ceiling concentration are not permitted to be land applied. The rules contain a second set of lower limits, referred to as Table 3. Any biosolids containing concentrations of tracked pollutants above Table 3 can be land applied as long as the concentration is not above the Table 1 ceiling concentration. Concentrations of metals above Table 3 indicate that further monitoring must occur and the biosolids generator should evaluate and eliminate sources of the pollutant.

Land applied tonnage

Not all generated tonnage leaves the facility, as some will remain onsite in storage. For a more detailed comparison of land application tonnage over the years, please refer to the graph.
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Average results expressed as a percentage of limits

On the right is a chart that compares the average pollutant levels as reported on the Discharge Monitoring Reports (DMR) expressed as a percentage of the Table 3 and Table 1 Ceiling limits. The Table 3 and Table 1 limits have been included in the graph with the pollutant label. Ex. Arsenic (41, 75) indicates that Arsenic has a Table 3 limit of 41 mg/kg dry and a Table 1 limit of 75 mg/kg dry.

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Average nutrient results

In addition to pollutants, generators use DMRs to report nutrient data as well. To the left is a graph showing the average nutrient results in biosolids.

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