AC INTERFERENCE ASSESSMENTS AND MITIGATION SOLUTIONSMESA provides AC Assessment and Remediation services for underground pipelines collocated or in close proximity of existing high voltage power lines. The upgrade to the electrical transmission infrastructure to higher current loads and the mandate to utilize common right of way has resulted in greater AC Interference to underground pipelines. AC Interference may result in a personnel and equipment safety hazard by raising step/touch voltages to dangerous levels or create risk to the underground structure by AC Corrosion.

MESA Pipeline Integrity Services can assess the AC Corrosion threat, assist with installation and monitoring of corrosion coupons, provide AC design and modeling to define the remediation requirements, and install/commission the AC Mitigation remediation.

Backed by NACE-certified corrosion professionals and a commitment to SAFETY, quality, and trouble-free execution, MESA is your turnkey provider of:aThreat AssessmentaAC Modeling and Engineering DesignaAC Interference Remediation PlanningaConstruction aCommissioningaProject Management

Assessing the threat ofAC CorrosionNACE SPO 177-2007 recommends mitigation to 15 volts AC to protect the public and operational personnel from the step/touch voltage potential hazards. AC corrosion density defines the susceptibility and risk for corrosion. While the actual corrosion mechanism remains an unknown, some general guidelines have been identified to measure the AC Corrosion risk.

Current Density Likelihood of AC Corrosion0 to 20A/m2 Unlikely

20 to 100A/m2 Unpredictable100A/m2 (9.29A/ft2) Anticipated

While there is no clear standard or recommended practice at this time, each operator has a responsibility to assess the AC Interference threat along with establishing the criterion for remediation of AC current density. This criterion for remediation represents the risk tolerance to the underground pipelines.

Headquarters4445 S. 74th E. Ave.Tulsa, OK 74145Phone: 918.627.3188Fax: 918.627.2676

Gulf Coast1415 FM 1960 EastHouston, TX 77073Phone: 281.445.8700Fax: 281.445.8880

West Coast17902 Georgetown LaneHuntington Beach, CA 92647Phone: 714.963.6202Fax: 714.963.6360

East Coast2170 Ashley Phosphate Rd.Suite 406North Charleston, SC 29406Phone: 843.628.1342Fax: 866.594.3233

Dallas/Ft. Worth12441 Business Highway 287NFt. Worth, TX 76179Phone: 817.230.4249Fax: 817.350.4537

South East1264 Timberlane Road, Suite #1Tallahassee, FL 32312Phone: 850.893.9366Fax: 850.893.9434

Mid West1208 Lunar DriveWapakoneta, OH 45895-9787Phone: 419.738.7402Fax: 918.627.2676

North West12521 Evergreen Dr., Suite AMukilteo, WA 98275Phone: 425.903.4850Fax: 425.903.4347

mesaproducts.com1.888.800.MESA (6372)

Corrosion coupon AC current density, AC modeling based upon the varying power company loads, and the geometry of the facility relationships all contribute to the initial assessment for the likelihood of AC Corrosion.

One of the first steps in the initial assessment is the mapping of the underground facilities and relationship to existing high voltage power lines. From this evaluation, key corrosion coupons with remote monitoring can be located to monitor the AC current density. For new facilities in which the power company is locating in the pipeline right of way, easement agreements with the power company should be negotiated that require the power company to pay for the study and remediation required to protect the underground facility.

AC Modeling and Engineering DesignaField Data collection; towers, heights, insulators, pipeline to centerline to tower relationship, soil resistivity profiles, photographs, power company data interface, etc.aAC modeling history and report, prediction of high voltage line impacts, graphical representations, etc. aRecommend key corrosion coupon installation and monitoring needs.

AC Interference Remediation PlanningaRemediation type and location.aProvide mapping to communicate the remediation needs.aConduct the field construction assessment to determine the required installation construction technique needs.aProvide cost estimate and proposals.

ConstructionaConstruction of AC Mitigation requirements.aMaintaining the Intent of the Design.aConstruction quality control and documentation.aProcess and procedure implementation.

CommissioningaProvide final commissioning for AC Interference mitigation implementation.aOperating and maintenance manual support.aTraining client operational training to conducting maintenance testing and surveys.aFinal data and system analysis.

Project ManagementaQualified project management resources and planning to ensure client involvement and project oversight through all phases of project management; initiating, planning, execution, monitoring and control, and closing. aWeekly written status reports including financials. aWeekly project conference calls.aManagement of scope, cost, schedule and quality.

MESA is well positioned to handle all phases of the AC assessment package. MESA is one of the largest AC Mitigation providers and performed over 500 miles of AC Interference threat assessment, and remediated over 175 pipeline right of way miles in 2013.Learn more about our capabilities at mesaproducts.com or call1.888.800.MESA (6372).

References available on request.