Pipeline Integrity & Engineering Solutions

MESA offers a complete range of pipeline integrity services, including the following:

  • Integrity project management and procedure development
  • External Corrosion Direct Assessment (ECDA)
  • Internal Corrosion Direct Assessment (ICDA)
  • Stress Corrosion Cracking Direct Assessment (SCCDA)
  • Global Position Satellite (GPS) Surveys
  • Bellhole Excavations & Inspections
  • Stray Current & Interference Analyses

ECDA Methodology

External Corrosion Direct Assessment (ECDA) is an alternate Inspection methodology approved by DOT 49 CFR Part 192 and Part 195 to assess external corrosion in determining the integrity of a pipeline system. The ECDA methodology is a four-step process requiring integration of pre-assessment data, data from multiple indirect field inspections, and data from pipe surface examinations.

Step 1: Pre-Assessment

The Pre-Assessment step utilizes historic and recent data to determine whether ECDA is feasible, identify appropriate indirect inspection survey tools, and define ECDA regions. The required data is typically available in the corrosion survey records, alignment sheets and construction records, or other customer files

Step 2: Indirect Inspection

This step utilizes above-ground inspection techniques to identify and define the severity of coating faults, diminished cathodic protection, and areas where corrosion may have occurred or may be occurring. MESA performs the following over-the-line survey inspections:

  • Close Interval Survey (CIS)
  • Direct Current Voltage Gradient (DCVG)
  • Internal Corrosion Direct Assessment (ICDA)
  • Alternating Current Voltage Gradient (ACVG)
  • Electromagnetic using Pipe Current Mapper (PCM)
  • Soil Resistivity

A minimum of two of these survey tools are used over the entire pipeline segment to provide improved detection reliability across the wide variety of conditions encountered along a pipeline right-of-way. Quality submeter Global Positioning Satellites (GPS) are utilized to integrate the multiple streams of data collected. Indications from indirect inspections are categorized according to severity. Our engineers are knowledgeable in the application of ECDA tools in the many diverse field operating conditions to which the pipeline may be subjected.

Step 3: Direct Examination

The Direct Examination step includes analyses of pre-assessment data and indirect inspection data to prioritize indications based on the likelihood and severity of external corrosion. This step includes excavation of prioritized sites for pipe surface evaluations resulting in validation or re-ranking of the prioritized indications. During the Direct Examination step, high priority areas with corrosion damage are re-evaluated for further action. The Direct Examination Step includes the following tasks:

  • Scheduling the excavations
  • Excavating the indications and collecting data at areas where corrosion activity is most likely
  • Measuring and documenting any coating damage and corrosion defects discovered

Step 4: Post-Assessment

The Post-Assessment step provides the summary and analysis of the data collected from the previous three steps to complete the Post Assessment process requirements that include, but may not be limited to:

  • Evaluation of remaining strength of the pipe segment
  • Root cause analysis
  • Re-prioritization and re-classification of indications if necessary
  • Performing remaining life calculations
  • Assessing ECDA effectiveness
  • Performing process effectiveness review
  • Performing continuous improvement review
  • Calculating reassessment interval Integrity Data Management
  • MESA’s analysis tools have the capability to integrate multiple data sets into a single database for analysis, including ILI data
  • Program aligns multiple data sources to allow single graphical and tabular presentations of merged data streams, permitting the client to see all their combined data
  • All Data Points are assigned GPS coordinates for ease of physically locating specific sites from the data presentations
  • Reports customized to meet client-specific report requirements
  • CSV, Excel or ESRI Shape file export options for importing into a Geographical Information System (GIS)


  • Remediation Plan development and management
  • Cathodic Protection: Design, Materials, Installation, Maintenance
  • Casing inspection and repair
  • Coating repair and replacement