Which of the following is NOT part of mound site preparation?

• A. Cut trees flush to ground leaving stumps
• B. Remove vegetation over 6 inches long by mowing
• C. Break up the top 7-8 inches perpendicular to the slope
• D. Apply chemical fertilizer to the soil surface

Answer: (D)

Preparing a mound site focuses on creating a clean, friable, cross-slope soil bed that promotes uniform infiltration and minimizes erosion. Clearing vegetation and cutting trees flush to the ground (often leaving stumps) removes roots and organic matter that could interfere with the bed’s performance. Removing vegetation over a certain length by mowing further ensures a smooth, unobstructed surface for construction. Breaking up the top layer a few inches deep, in a direction perpendicular to the slope, loosens compacted soil and increases the soil’s ability to infiltrate effluent evenly.

Applying chemical fertilizer to the soil surface isn’t part of this preparation. Fertilizer introduces nutrients that aren’t needed for building the mound bed and can lead to nutrient imbalances or leaching, potentially affecting groundwater and the treatment process. The mound bed is designed to be constructed with a stable, infiltrative soil layer, not amended with surface fertilizer.