Page 22 - Tennessee 811 Magazine 2021 Issue 2

According to gis-mapping.com, “In the simplest terms, GIS
is a framework that gathers, manages, and analyzes data. It’s rooted in geographic science to
help analyze and organize layers of information into visualizations using either 3D scenes or maps. Therefore, Geographic Information System
[GIS] mapping can be defined as the process of entering data layers into GIS software to create maps or 3D scenes.”
What does this have to do with safety? Just this: If you know where there
is something that might hurt you or someone else, there is a pretty good chance that you might do something to either entirely avoid that something or take steps to mitigate the risk associated with being unable to avoid whatever it is.
Some dangerous things are obvious – especially to anyone reading this. Busy highways, railroad tracks, fast moving rivers, downed power lines, the wrong side of town after dark. You get the idea.
Using GIS to collect, archive and access data enables people that build, operate, and maintain infrastructure to do their jobs as safely as possible. GIS is especially useful for keeping track of things like buried pipelines, buried electrical cable, and buried communications cable.
The largest GIS I am personally familiar with is the US DOT’s National Pipeline Mapping System (NPMS – https://www.npms.phmsa.dot.gov). The NPMS contains information regarding
nearly 1,500 companies that operate 2.8 million miles of transmission pipelines, 162 liquefied natural gas plants, 403 underground gas storage fields, 8,273 hazardous liquid breakout tanks (May 2020 data). The NPMS is more than just a map – it contains spatial and attribute history on each pipeline segment; accident and incidents associated with pipe segments; High Consequence Area (HCA) GIS data; and Unusually Sensitive Area (USA) GIS data. This information is used for many purposes: Inspection planning and analysis; Accident and incident investigations; Emergency response; Risk analysis and resource allocation; Policy analysis and engineering research; and Public Awareness, outreach and support for emergency responders and pipeline safety initiatives at all levels of government.
It is important to note, however, that the NPMS does NOT include as gathering or gas distribution pipelines OR planned pipelines (if it is not yet in the ground, it is NOT in the NPMS). Many states have publicly accessible databases that do include gas distribution lines.
It is also important to note that the accuracy in the NPMS may be as poor as plus or minus 500 feet and the geo spatial database is typically updated only once a year as part of the annual reporting process.
What is missing? All other underground utilities – electrical, water, sewer, communications, etc.
The real bottom line is that the NPMS is used primarily by PHMSA to manage
its responsibilities under the pipeline safety regulations (49 CFR Parts 190 – 199). There is public access to the NPMS so maps are available to the public and the public can identify pipeline operators and gain access
to certain other limited types of information.
That said, the NPMS is only a “hunting license.” The information in the NPMS (and the state databases) is only as good as the data that is entered. There are legacy pipelines that were installed and abandoned prior to the regulations. There are pipelines that were never subject to regulations that may still
be in use or that may have been abandoned in place.
GIS is great to try to “connect the
dots” to manage and evaluate risk but, when it comes time to start digging for whatever reason, there is no substitute for calling 811 and getting a physical locate. Even with a physical locate, it is IMPORTANT to make sure that the line of concern is the line that was located.
I don’t have the statistics but there have been situations where an abandoned line was misidentified as the active line of concern and people were injured
and property damaged when the active line was compromised. Don’t let that happen to you.
You cannot be too safe when dealing with buried utilities.
John Jacobi retired from PHMSA. For questions or comments, email: jjacobi@sbcglobal.net
by John Jacobi
GIS, Mapping and Safety
20 • Tennessee811 2021, Issue 2