Published June 2007
Steps Forward in Condition Assessment
By Scott E. Belz (page 44)
New tools help field teams document and record a wider range of structures in easy-to-manage digital forms linked to GIS data.
It is ever more important for public agencies to understand the condition of their infrastructure. Basic fiscal responsibility demands it, and so do federal programs and standards.
Sewer systems and components in particular can and sometimes must be accounted for and assessed under the federal Capacity Management, Operation and Maintenance (CMOM) program and Governmental Accounting Standards Board Statement 34 (GASB-34) standards.
Condition assessment requires field investigations that inventory structures and identify deficiencies. Watchwords in the process are accountability, functionality, and cost-effectiveness.
Surprisingly enough, the components most difficult to assess and document are sometimes those easiest to observe. Sophisticated sewer camera technology linked to survey reporting software loaded with standard defect codes make it easy to assess and document miles of buried wastewater pipelines and to record data on digital media.
But documentation has been much more difficult for structures on or near the surface, like manholes, catch basins and outfalls.
New technology is changing that for the better. Advanced software now enables field teams to collect condition information electronically, along with digital photographs and electronic sketches, and link them back to clients’ geographical information systems (GIS) or asset management software.
Staff can record observations on any sewer structure using a computer touch screen, stylus and digital camera. This configuration saves time, provides more complete and accurate data, and removes the inefficiency of dealing with paper maps, forms, drawings and reports.
All structures
Such software can be used to document all structures within a sanitary and storm sewer system, and it has potential for expansion to water systems.
The ideal application is flexible enough for users to customize: The reality is that most municipalities and public utilities use homegrown nomenclature for their sewer systems. In addition, every project is different. It is therefore better to let the software conform to the user’s needs than to make the user change to fit the software.
Because the software is based on GIS, projects start by downloading the community’s mapping into durable field computers with WiFi wireless connectivity. Existing assigned and labeled structure numbers are used. Communi-ties without a GIS can use CAD mapping to start using GIS technology on a limited and affordable basis.
Once the computer is loaded, staff can inspect, assess and measure any component of a structure — frame and lid, corbel, walls, bench or trough — and save the data in the field. Each component of the structure has a separate tab that details its own particular information, such as construction material, size and condition. Drop-down lists standardize choices, ensuring that all inspectors collect data in a consistent format. This makes it easy to perform quality review checks later.
Where inspectors find deficiencies, such as structural problems or inflow and infiltration (I/I) findings, they use drop-down menus to document them. They can also estimate flow rates for leaks, and assign ratings to unsound components.
Faster photos
Pipe information can be added: The software connects pipes to manholes or catch basins from user- supplied upstream and downstream data, using pipe elevations taken in the field. Structures not shown on a map, but found in the field, can be easily added to the electronic mapping. This means crews can inspect and add structures that were buried or for other reasons were not located in previous inspections.
Taking and managing photographs — until now a time-consuming process — is much easier and faster. The software is wirelessly linked to a digital camera. The system automatically embeds a structure number into each photograph and its file name, and presents the photo to the field crew for review on the spot.
Upon approving a photo, the crew saves it in the same folder as the structure being inspected. This eliminates the need to create a photo log, download and handle photos back in the office, re-name and re-number JPG photo files, and associate photos to field-collected data after the fact. Pictures can be taken from different angles and locations, and the software tracks and remembers the orientation of each one.
The software also simplifies handling of field sketches. Previously, an inspector sketched on paper, returned to the office, scanned the paper sketch, and associated the sketch to the field data. Now, inspectors can capture a sketch in one step.
The inspector uses a stylus to sketch the structure and the pipes entering or exiting, selects the structure shape (square, circular, or other), and inserts pipes, flow direction and other pertinent information. The system embeds the structure number into the sketch, saves it as a JPG file, and stores it in the structure folder. If desired, the user can print a field form that lists the information collected with the sketch.
Entering field data
The entry of other data on asset condition is similarly streamlined. Inspectors first find the structure on the electronic map. Then they inspect and record on any of several levels of detail:
• In-depth inspection covering all aspects of the structure, including pipe invert elevations.
• Cursory inspection covering basics such as building material, sizes and condition.
Crews can collect horizontal locations of structures using a global positioning system (GPS) or conventional survey methods. These locations are typically pre-loaded into the GIS layer.
The software should follow a logical order of an inspection. For example, tabs should proceed from ground surface (Frame and Lid) to the bottom of the structure (Pipe). Photos are taken, a sketch is made, and the electronic field form is saved.
Once all the data is collected, it is uploaded to a network via the Internet or through a local area network for quality assurance/quality control (QA/QC) review. Staff can review the mapping, check connectivity, and analyze and evaluate inspection information. Existing paper maps can be used to verify the existence of the structures and their locations.
Recording test results
The most advanced applications can incorporate I/I testing techniques like smoke and dye testing. For example, a smoke testing feature allows field staff to add points to an electronic map layer and locate downspouts, cleanouts or other areas that were found smoking during the test.
Crews also can document mainline dye testing results. Storm sewers or catch basins that leak into the sanitary system are recorded, along with data on the type and severity of the leak and other pertinent information. In addition, the system captures residential dye testing results, such as downspouts or area drains leaking into the sanitary sewers. Queries of this data are helpful in analyzing data and writing I/I reports.
The utility of condition assessment software can readily extend to other kinds of infrastructure: water lines and appurtenances, streets and signage, buildings, and others. In essence, the software can record any information that can be captured electronically and spatially located to a map.
With CMOM and GASB-34 compliance remaining a concern, condition assessment software will be an important tool for communities seeking accountability in reporting on the status of infrastructure.
Scott E. Belz is manager of field operations with the Water Resources Group, URS Corp., based in Cleveland, Ohio.
