Which condition would limit or prevent land application of the sludges?

• A. Low moisture content
• B. High pH
• C. Low organic content
• D. High metal concentrations

Answer: (D)

When evaluating land application, the key concern is whether the sludge meets pollutant limits to protect soil, crops, and water quality. Metals in the sludge are tightly regulated because they can accumulate in soil over time, be taken up by plants, and potentially contaminate groundwater. If metal concentrations exceed allowable standards, the sludge cannot be applied to land and must be disposed of by other means.

The other factors—low moisture content, high pH, and low organic content—affect handling, nutrient content, or soil amendment value, but they do not inherently trigger the regulatory barriers that metals do. Thus, high metal concentrations most directly limit or prevent land application.