Which condition would most likely limit land application of sludge?

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

Answer: (A)

Land application is limited by regulated contaminant levels in the sludge, especially heavy metals. Metals persist in soil and can accumulate with repeated applications, posing risks to soil health, crops, and groundwater. Because of these long-term risks, there are strict maximum metal concentration limits for sludge used on land. If the sludge has high metal concentrations, it may exceed these regulatory thresholds and thus be barred from land application. The other conditions affect handling or short-term risk but do not pose as direct, fundamental limits as metal content does.