SEWER CONDITION ASSESSMENT – GIS DATABASE WITHOUT INTRODUCING PROCESSING ERRORS

The City of Phoenix (COP) has begun a program to investigate and evaluate the COP's wastewater collection system. The COP divided their system into four distinct groups. These include the Unlined Concrete Sewer System, Large Diameter Sewer System, Small Diameter Sewer System, and Lined Concrete Sewer System. In 1999, the COP hired URS to investigate and evaluate the condition of the Large Diameter Sewer System, consisting of approximately 1.37 million feet of 15-inch through 42-inch pipe not included in the Unlined Concrete Sewer System.Due to the pending Sanitary Sewer Overflow policy and Capacity, Management Operation, and Maintenance (CMOM) requirements, the COP recognized the need to manage the large amount of data a study of this magnitude will produce. The COP recognized the need to store the information gathered by the Closed Circuit Television (CCTV) investigations and the subsequent Capital Improvement Program data in a manageable and useable format. The COP chose to use the COP Water Department Geographic Information System (GIS) database as the format.In the past, information gathered by studies has been stored in the GIS database. This information has been gathered electronically, printed out for use, and then hand entered into the GIS database. This means that all information must be entered at least twice, which means that there are at least twice the opportunity for data entry errors. URS has used a direct electronic collection of data and a “hands-off” data transfer and collection of data into the COP's GIS.