Understanding Cathodic Protection: Geospatial Data Management
By Tom DeWitte and Tom Coolidge
The natural gas and hazardous liquids industries have always been dependent on knowing where they buried their assets. Like treasure hunters from the movies, industry staff are constantly looking for long-hidden things. Today's equivalent of a treasure map is an enterprise GIS, documenting the location of these buried assets. In the world of cathodic protection, mapping these hidden assets is so important that it is federal law in the United States (CFR 192.491, CFR 195.589).
Knowing that you must do something, such as map cathodic protection assets, is not the same as knowing how to do it. The purpose of this blog is to provide best practices for mapping and geospatially managing those assets. These practices ensure CP field technicians always have a reliable map to locate, understand, and inspect buried CP assets.
What Needs to be Mapped
To define best practices for mapping and managing cathodic protection data, we need to understand the relevant regulatory mapping requirements. According to the U.S. federal regulation Title 49, part 192.491 section (a): "Each operator shall maintain records or maps to show the location of cathodically protected piping, cathodic protection facilities, galvanic anodes, and neighboring structures bonded to the cathodic protection system."
Now that we know the mapping requirements, let's look at how to map these assets.
How to Map the CP Assets
How you map CP assets defines what you can do with this critical data. If all you want is a pretty map, you just need to place a bunch of points.
With a little more planning and editing, you can connect these points to the metallic pipes and assets they protect. This enables the creation of CP Zones.
Apply a little more configuration, and the placement of the CP assets can also populate the compliance inspection dates and store the inspection data. Now we have a full understanding of a cathodic protection management best practice that eliminates redundant data entry and provides a single source of truth for the organization's users. '
A Template for Cathodic Protection Data Management
Knowing how to organize this information to address the CP needs for mapping, compliance, and inspections without redundant data entry is not common knowledge. What is required is a source of knowledge that shows how to organize your CP data. That source is the Utility and Pipeline Data Model (UPDM). Esri provides this natural gas and hazardous liquids industry data model as a free download from the Esri solution site.
UPDM provides a template for organizing information on natural gas and hazardous liquids pipe systems. Included in this industry data model is the blueprint for managing cathodic protection data. This data model is an Esri-structured geodatabase. UPDM is written to be installed, and administered with Esri's standard data management tools. UPDM, a best practice geodatabase structure, shows you how to represent and map CP components.
CP Test Station
CP Rectifier
This UPDM organization of pipe system and CP system data will also provide the template for leveraging the mapped components to build and maintain CP zones. Esri intends that this next step in CP data management is implemented with ArcGIS Enterprise's ArcGIS Utility Network capabilities.
UPDM is also the template for managing compliance dates and inspections. The spring 2026 update to UPDM will include attribute rules to automatically create and maintain compliance dates, as well as a few enhancements for managing CP inspections.
Now that you know where to get your industry-specific template for managing CP, let's dig into the specifics to model the cathodic protection system.
Cathodic Protection Components in UPDM
The discrete components of a cathodic protection system modeled in UPDM have evolved over the years into a mature, comprehensive data management template. The first group of assets to look at is the devices. CP devices are components such as anodes, rectifiers, test points, decouplers, and grounding points. CP devices are modeled as point features and stored in the PipelineDevice featureclass.
These PipelineDevice features are not inline features of the pipe system. Instead, they physically sit adjacent to the pipe system. These devices are connected to the pipe system assets by wires and cables.
You can identify the location where the test lead wires connect to the pipe system using the PipelineJunction feature class, with an AssetGroup value of Wire Junction.
You can specify the location of insulators using the PipelineJunction feature class, with an AssetGroup value of Insulation Junction.
The wires and cables used to connect the CP devices to the pipe system that they are cathodically protecting are modeled as linear features. These wires and cables are classified as Test Lead Wires, CP Cables, Linear Anodes, and AC Mitigation Wires. In UPDM, they are stored in the PipelineLine featureclass.
The data modeling described so far is what you need to provide maps of where the assets are located and what type of asset they are. Now, let's look at what is necessary to leverage those mapped CP assets to build a CP Zone.
Modeling Insulating Components
A CP Zone is an electrical circuit that traverses conductive assets until it encounters an asset that does not conduct electricity. For the software to determine whether a specific asset conducts electricity, it needs to know whether the asset is conductive or insulated.
Within UPDM, the management of this property of a CP Asset is stored within a data field named: CPTraceability. This attribute has two potential values: Traceable and Not Traceable.
- Pipe system component is insulated = Not traceable
- Pipe system component is conductive = Traceable
The following UPDM featureclasses, which participate in the utility network, have the CPTraceability attribute:
- PIpelineLine
- PipelineDevice
- PipelineJunction
A Coded Value Domain named CP_Traceability is applied to this data field to ensure data quality and eliminate typos. This coded domain has the following values:
Code | Description |
1 | Traceable |
2 | Not Traceable |
Coded Value Domains for CP_Traceability
The use of this CPTraceability data field extends to all pipe system assets, fittings, valves, pipe segments, etc. Simply identifying a plastic valve as "Not Traceable" is sufficient to designate it as insulated.
Recognizing that terms such as "traceable" and "not traceable" are not the words that a CP department will associate with being conductive or insulated, we added another data field to these assets in UPDM called BondedInsulated.
The BondedInsulated data field uses the terms "bonded" and "insulated". Like CPTraceability, this data field is added to the PipelineLine, PipelineDevice, and PipelineJunction featureclasses. The BondedInsulated data field has been assigned the coded value domain: Bonded_Insulated. This coded value domain has the following values:
Code | Description |
1 | Bonded |
2 | Insulated |
Coded Value Domain for Bonded_Insulated
To avoid complication and inconsistency between these two data fields, UPDM includes an attribute rule that manages the CPTraceability data field. When an editor specifies that an asset is insulated (BondedInsulated = Insulated), the attribute rule automatically sets the CPTraceability value to “Not Traceable”. Additionally, if the asset is plastic, the CPTraceability data field is automatically set to "Not Traceable".
With this understanding of how to model whether an asset is insulated or conductive (not traceable or traceable), we need to look at a standard CP method called bonding.
Management of Bonding Lines
Bonding lines are the wires used to extend the electrical connection of the cathodic protection system. They are used to span pipeline assets that are insulated or natively non-conductive.
Example of Bonding Wire Spanning Plastic Pipe Segment
In some legacy GIS systems, managing bonding lines was tedious. Data editors were required to draw the bonding line and ensure it was connected to the metallic pipe system components at each end of the line. In the UPDM configuration, the need for geometry feature creation has been eliminated by allowing an attribute on the non-conductive pipe system asset which is being spanned to indicate that the asset has been bonded. Instead of drawing the spanning bonding line, a user simply needs to change the BondedInsulated attribute to "Bonded". This means that within the Utility Network, the spanned feature can be considered traceable.
Automating Cathodic Protection Data Management
The previously described attribute CPTraceability is the primary data field that UPDM and the utility network use to build a cathodic protection zone from the mapped assets. To maximize data quality and editor efficiency, a set of attribute rules automatically populates the CPTraceability data field.
Attribute Purpose | PipelineLine | PipelineDevice/ PipelineJunction |
Determine material type | AssetType | Material |
Determine whether bonded or insulated. | BondedInsulated | BondedInsulated |
Determine CP traceability | CPTraceability | CPTraceability |
To explain the logic embedded within the CPTraceability attribute rules, here are three scenarios:
- Scenario 1: Metallic Pipe Segment
- Asset Type = Coated Steel
- Bonded Insulated = null
- Scenario 2: Insulated Gas Valve
- Material = Steel
- Bonded Insulated = Insulated
- Scenario 3: Plastic Pipe Spanned by Bonding Line
- Asset Type = Plastic PE
- Bonded Insulated = Bonded
In each of these scenarios, the CPTraceability attribute is automatically populated by the UPDM-provided attribute rules.
- Scenario 1: Metallic Pipe Segment
- Asset Type = Coated Steel
- Bonded Insulated = null
- CP Traceability = Traceable
- Scenario 2: Insulated Gas Valve
- Material = Steel
- Bonded Insulated = Insulated
- CP Traceability = Not Traceable
- Scenario 3: Plastic Pipe Spanned by Bonding Line
- Asset Type = Plastic PE
- Bonded Insulated = Bonded
- CP Traceability = Traceable
To have the CP Traceability attribute correctly set, all the editor must do is ensure that the Material/AssetType and the BondedInsulated attributes are correctly set.
Building the CP Zone
With the CP assets now mapped and organized within the Utility and Pipeline Data Model (UPDM), and the CPTraceability data field now populated, we can build the CP Zones.
The software's logic for determining the extent of a CP zone is very simple. Start from a designated CP Test Point Station(s), then trace across the connected CP and pipe system assets, checking each asset for its CPTraceability value. If the ' 'asset's CPTraceability value is "Traceable", then continue the connected trace. When the connected trace finds an asset with a CPTraceability value set to "Not Traceable" the trace stops.
When the trace stops, the software will then gather the selected primary pipe segments to create the geometry for the CP Zone. This is stored in the Pipeline Subnet Line featureclass. Additionally, all assets selected by the trace will have the name of the CP zone written on the asset's record.
Managing Inspections
Supporting Cathodic Protection inspections is also defined within UPDM. Tables related to the PipelineDevice featureclass are intended to store the inspections captured in the field by CP technicians using an ArcGIS mobile application.
These related tables to the CP Test Station and CP Rectifier features store all the inspections. This provides a single, intuitive source of truth for CP technicians.
Managing Compliance Dates
Managing compliance dates is the last component of full cathodic protection management. It requires mapping the assets and managing inspections in ArcGIS.
Attribute rules embedded in UPDM provide the automation and logic to manage the Last Inspection Date, Next Inspection Date, and Compliance Date for each cyclically inspected CP asset.
These date fields will be part of the PipelineDevice featureclass schema in UPDM when added as part of the Spring 2026 update.
Now, when a mapper adds a new CP Test Station, the compliance dates are automatically tabulated, and the inspection date fields are automatically populated.
When the field technician performs a CP inspection, submitting the field inspection to ArcGIS automatically triggers attribute rules to update the asset's Last Inspection Date, Next Inspection Date, and Compliance Date.
Simplifying Cathodic Protection Management
If you are already using ArcGIS to meet your federal requirements for mapping CP assets, you can leverage your geospatial foundation to automate the creation of your CP zones by incorporating utility network capabilities and UPDM.
This same foundation of CP data can be used to integrate the federally required CP inspections into your ArcGIS, simplifying field users' experience documenting the inspections.
Building upon the mapping of assets and the capture of inspections, you can eliminate duplicate data entry of adding new assets to both the GIS and the compliance management system. By storing the inspection dates in ArcGIS, you will automate the maintenance of the compliance dates.
All of this provides the CP field technicians with a treasured map of information. A map that not only provides the location of the buried CP assets but also visualizes the CP zone and provides a single view into the inspection history.
That is a treasure map of value to the entire organization.
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