Every locate request requires time, attention, and resources. Whether your organization performs locates in-house or contracts with a third-party locator, receiving excavation notices that are nowhere near your facilities creates unnecessary work and added expense.
Some Missouri 811 member utilities using centerline-based notification areas have reported reductions in locate notifications of up to 40 percent. For a utility receiving 5,000 locate requests annually, that could mean approximately 2,000 fewer tickets to review, process, and respond to. At an estimated cost of $50 per locate request, the potential annual savings could approach $100,000 annually.
Beyond the financial savings, fewer unnecessary notifications allow utility personnel and contract locators to focus their time and attention on excavation activity that actually poses a risk to their infrastructure.
One of the most effective ways to improve notification accuracy is by using centerline-based notification area polygons.
What Are Notification Area Polygons?
Every Missouri 811 member utility has notification area polygons on file. These polygons define the geographic areas where a utility receives excavation notifications.
Many utilities use broad boundary polygons that outline an entire service territory. While this approach helps ensure all facilities are protected, it can also result in receiving tickets for excavation activity that is nowhere near actual underground infrastructure.
A more precise approach is to create notification area polygons using centerline data.
Centerline data represents the mapped location of underground facilities such as electric, natural gas, water, sewer, and communications lines. By creating a buffer around those mapped facilities, utilities can establish notification areas that more accurately reflect where infrastructure actually exists.
Many utilities use a combination of approaches. For example, a utility may use broader boundary polygons in rapidly developing areas while relying on centerline-based polygons in established areas where facility locations are well documented.
Why Use Centerline-Based Notification Areas?
When notification areas are based on centerline data, excavation notices can be routed more accurately to the utilities that actually have facilities in the area.
Benefits include:
- Fewer locate requests that do not affect your facilities
- Reduced workload for utility staff and contract locators
- More efficient use of locating resources
- Improved focus on excavation activity occurring near actual infrastructure
- Reduced labor, vehicle, fuel, and administrative costs
- Better allocation of staff time and contractor resources
Every unnecessary locate request consumes resources that could be spent elsewhere. Centerline-based notification areas help ensure your organization is dedicating its time and budget to excavation activity that truly requires a response.
Creating centerline-based notification areas is relatively straightforward.
Using GIS software, a utility can create a buffer around its facility centerlines. Buffer sizes commonly range from 20 feet to 300 feet depending on several factors, including:
- Urban versus rural locations
- Type of utility infrastructure
- Accuracy of the centerline data
- The utility’s preferred level of protection
Once the buffer polygons have been created, they can be submitted to OCC for processing.
The most common file format is a shapefile, including the following files:
- .shp
- .shx
- .dbf
- .prj
OCC can also accept:
- KML
- KMZ
- GDB files
Utilities may submit:
- A complete replacement of existing notification areas (statewide or by county), or
- Additions to existing notification areas
After submission, OCC processes the data and uploads it to IMAP, the online mapping application, where it can be reviewed and approved.
Don’t Have Buffering Capabilities?
If your utility has centerline data but does not have the ability to create buffers, OCC can help.
Simply submit your centerline files and indicate the desired buffer size. OCC can create the notification area polygons on your behalf.
This service makes it easier for utilities of all sizes to take advantage of centerline-based notification areas, even if they do not have advanced GIS resources available internally.
Keep Your Notification Areas Current
The effectiveness of centerline-based notification areas depends on keeping them up to date.
As systems expand and new facilities are installed, notification areas should be updated to ensure excavation notices continue to be routed appropriately.
How often should updates occur? The answer depends on your system and growth rate.
Utilities with little or no expansion may only need to review their notification areas annually. Utilities that regularly install new infrastructure may need to submit updates monthly, quarterly, or as changes occur.
As a best practice, Missouri 811 members should review their notification areas at least once each year to verify they accurately reflect current infrastructure. Utilities should also ensure their Mapping/GIS contact information remains current in the Missouri 811 Member Portal so mapping updates can be coordinated efficiently.
For questions about centerline data, notification area polygons, or submitting mapping files, contact:
OCC Mapping Department
mapping@occinc.com
573-636-1552
Accurate notification areas help ensure excavation notices are routed to the utilities that truly need them. The result is fewer unnecessary tickets, lower locating costs, more efficient use of resources, and better protection of Missouri’s underground infrastructure.
