Specifications include, but are not limited to: a. Greater than 6 inches DBH and less than or equal to 12 inches DBH b. Greater than 12 inches DBH and less than or equal to 18 inches DBH c. Greater than 18 inches DBH and less than or equal to 24 inches DBH d. Greater than 24 inches DBH and less than or equal to 30 inches DBH e. Greater than 30 inches DBH and less than or equal to 36 inches DBH f. Greater than 36 inches DBH and less than or equal to 42 inches DBH g. Greater than 42 inches DBH and less than or equal to 48 inches DBH h. Greater than 48 inches DBH and less than or equal to 54 inches DBH i. Greater than 54 inches DBH ; Stumps shall be ground at least six (6) inches below the existing ground level. In cases where tree stumps are located in or near an existing ditch line, additional grinding may be required to ensure that positive drainage is achieved.