4-1. Attachment F - Stump Conversion Table Diameter to Volume Capacity.pdf

This is an attachment to a disaster and storm recovery services solicitation issued by the City of Liberty Hill, Texas, providing technical guidance for quantifying debris removal work. Specifically, Attachment F presents a stump conversion table that correlates stump diameter measurements to cubic yardage capacity, enabling standardized calculation of debris volumes for invoicing and project management purposes. The conversion table, derived from FEMA field studies conducted in Florida following Hurricanes Charley, Frances, Ivan, and Jeanne, applies a consistent mathematical formula that accounts for stump diameter measured two feet above ground level, a stump diameter to root ball diameter ratio of 1:3.6, and a standard root ball height of 31 inches. The table covers stump diameters ranging from 6 inches (0.3 cubic yards) to 84 inches (50.6 cubic yards), providing contractors with a reference tool to accurately quantify debris removal volumes throughout the City's storm recovery operations.

The conversion methodology utilizes a standardized formula incorporating the constant 0.7854 (one-fourth of Pi) and 46656 (the conversion factor from cubic inches to cubic yards) to ensure consistency and accuracy across all debris calculations. This attachment supports the City's solicitation for qualified contractors to perform clearing and removal of eligible debris on an as-needed basis in compliance with FEMA Publication 325, applicable State and Federal Disaster-Specific Guidance documents, and City directives. The use of this standardized conversion table facilitates transparent pricing, reduces disputes over volume measurements, and ensures that debris removal work meets federal and state regulatory standards for disaster recovery operations.