Appendix F: Case Study: How North Carolina 811 Uses DIRT to Reduce Damages

By Louis Panzer, Executive Director, North Carolina 811

North Carolina 811 (NC 811) began taking a deep dive into damages and related data in 2013 with the creation of the Supermega Spreadsheet (^Mega). The purpose of ^Mega is to consolidate data shared with the center, through DIRT via a Virtual Private DIRT (VPD) and Data Grants, with other internally collected data, such as positive responses, ticket volumes and first-time caller surveys. The data is pulled together and sorted by the state’s 100 counties to further identify where positive change and challenges exist.

The DIRT data is only the beginning when a state is investigating trends and root causes. Once NC 811 began working from a statistical research position, the importance of validation became evident. One means of validation includes analysis of data from the automated positive response system. One call centers maintain important internal data and have the ability to scrub out specific member information. This allows for a glimpse into such things as on-time locates and work commencing before a ticket is legally valid.

DIRT data provides the base upon which further surveys and research is built. Additional excavator surveys have been used to gauge satisfaction with the process as a whole. This included the 811 notification interaction, on-time locates and accuracy of marks, as well as if a damage occurred. Survey data contributed to research papers co-written with Dr. Al-Bayati, an assistant professor at Lawrence Technological University, and published in ASCE Journal of Construction Engineering and Management. To access the research papers scroll down to the https://www.nc811.org/education-department.html. “Library” section on this page:

Over the past seven years, NC 811 has refined the ^Mega. Even after the law changed in 2014 requiring excavators to report damages to NC 811, a need was identified to reconcile counts between DIRT data shared with NC 811 and the data shown in annual DIRT Reports and online dashboards. CGA staff were extremely helpful through the reconciliation process, and NC 811 recommends any state interested in performing similar statistical analysis to begin with that resource.

During the year, NC 811 shares damage data with the 49 Utility Coordinating Committees across the state, highlighting the specific data for each county. Although the data is limited, it allows communication about trends and provides the ability to compare year-over-year performance within a county, the types of damaged facilities and the types of work being performed when a damage occurs.

While we applaud the CGA DIRT initiatives, NC 811 has identified the following concerns based on its use of the data: 1)

2) Validation of DIRT data with a state’s internal data and surveys is critical in order to reduce bias and to improve confidence in root cause findings. It is critical to improve the DQI for DIRT events. The type of work performed when a damage occurs is arguably the single most important guide to targeted education.

3) “Normalization” of the one call ticket volume is vitally important for comparison between state damage-per-thousand ticket ratios. This refers to finding a method to compare individual state laws and procedures when determining ticket distance and life-of-ticket to arrive at a more consistent denominator in the formula (damages reported/ (number of tickets/1000)).

In conclusion, NC 811 believes that combining DIRT damage data with individual state data and research helps fill in the gaps and filter out any biases that could potentially be introduced. It is also critical that all stakeholders contribute their data into DIRT to help provide a balanced picture of root causes. Finally, raising the DIRT DQI will improve confidence and assist one call centers to better focus education where it is needed most.

More information can be found here: https://www.nc811.org/incident-analysis.html.