Sewer condition assessment - GIS database without introducing processing errors
BJ Raval, AICP
GIS Southwest Inc.
8601 North Black Canyon Highway, Suite 215
Phoenix, Arizona 85021
John G. Malone II, P.E.
URS Corporation
7720 North 16 th Street, Suite 100
Phoenix, Arizona 85020
Abstract
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 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 GIS Southwest/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 needed a system to manage the
large amount of data this study would produce. The system would store the information gathered
by the Closed Circuit Television (CCTV) investigations and the subsequent Capital
Improvement Program data in a controllable format. The COP chose the COP Water Department
Geographic Information System (GIS) database. Historically, study results are stored in the GIS
database. This information is gathered and printed electronically and hand-entered into the GIS
database, resulting in many errors. GIS Southwest/URS has used an automated system for an
electronic collection of data and a inhands-offlS transfer into the COP™s GIS.
Introduction
Sanitary Sewer Evaluation Studies (SSES) have been completed by both large and small
communities across the county. SSES have historically required the capture, management, and
evaluation of a large amount of data. These data are generally stored on a database such as GIS.
Historically, the information is captured by CCTV and passed to the Engineer or evaluator using
a hard copy, paper format. The Engineer, or evaluator, would hand enter the data into a GIS-
compatible database.
Technology changes in database management have allowed the capture of the information
including: defect type, location, severity, and a still photo while in the field and directly transfer
to the GIS database. This allows the direct transfer of data without the tedious hand entering of
the data into the database. The use of a GIS database allows for the integration of traffic data,
environmental data, contour data, and physical features into the evaluation. These features can be
overlaid onto a single map using ARCINFO TM .
To our knowledge, and through our national SSES group located in Virginia Beach, Virginia,
this is the first project being completed using the seamless and paperless transfer of information
in the United States.
