Program Approach and Prioritization Sample Clauses

Program Approach and Prioritization. Rehabilitation and replacement program CCTV inspections are performed as part of a comprehensive and systematic program that is closely coordinated with the system-wide sewer cleaning program. Sewers that are 15 inches in diameter and less have been divided into 218 secondary sewer basins (secondary basins). Sewers greater than 15 inches in diameter have been divided into 25 primary basins. Secondary basins are first cleaned and then inspected in priority order. The original basin cleaning and inspection priority was determined using an analysis of stoppage and spill history, miles of concrete pipe, maintenance cleaning findings, and pipe age. These factors were, and are currently, accurate indicators of sewer overflow risk from the City’s collection system. The effectiveness of this approach can be illustrated by the fact that approximately 45 percent of the collection system has been inspected, and the sewer basins that have been inspected accounted for approximately 73 percent of the City’s sewer overflows from 2000 through 2005. Secondary basin cleaning and inspection priorities are reviewed on an annual basis and modified based on analysis of best available information. The City has grouped secondary sewer basins into the five groups listed in Table 2-1: Basins 1-20 (Basin Group 1), Basins 21-50 (Basin Group 2), Basins 51-75 (Basin Group 3), Basins 76-100 (Basin Group 4), and the remaining basins. Basin Group 1 through Basin Group 4 will be planned by Year 10 of the Settlement Agreement. Table 2-1 lists each of these Basin Groups along with a total of SSOs from January 2000 through December 2005, percent of total SSOs, percent of miles in the Basin Group versus total system miles, and a calculation of the Spill Factor. For a specified time period, the Spill Factor is calculated for a group of reaches using the following formula: Basin Group Spill Factor = (SSOs from the Basin Group / SSOs from the Entire System) (Miles in the Basin Group / Miles in the Entire System) The Spill Factor can also be calculated by dividing the number of sewer overflows per 100 miles from a group of reaches by the average number of sewer overflow per 100 miles from the entire system. Table 2-1 shows that the first 75 basins that will be planned constitute 33 percent of the system and will address where 63 percent of the sewer overflows occurred over the past six years. Additionally, Table 2-1 shows that the first 100 basins planned will address deficiencies and needed impro...