JANUARY 31 2003
Benefits. For utilities, there are two choices: (1) install and maintain CP; or
(2) periodically replace the utility when the leak failure rate becomes an operational (or
financial) burden. Properly installed and maintained cathodic protection systems
dramatically reduce life cycle costs by indefinitely extending a utility's lifetime. They
also reduce the government's potential liability from premature failure of utilities, such
as gas line explosions and jet fuel leaks. Environmental cleanup, transportation, and
disposing of contaminated soil, monitoring requirements, and other costs connected to a
"reportable" (over 3,785 liters [1,000 gallons]) leak can cost the government over one
million dollars. Notices of Violation (NOV) can carry stiff fines and penalties. CP is
essential to maintaining any metallic structure in a corrosive environment at the lowest
life cycle cost.
CP SYSTEM MAINTENANCE. System performance can be monitored by
measuring the supplied current, by measuring the potential of the structure, or (preferably)
by a combination of the two methods. Scheduled maintenance may include inspection
and adjustment of equipment items, such as current rectifiers or anodes; unscheduled
maintenance may include troubleshooting and repair of items identified as defective
during scheduled inspections, such as anode beds or electrical conductors.
CP PROGRAM ELEMENTS. A CP program includes:
Corrosion control by cathodic protection design.
Corrosion control during in-house and contracted job orders, work orders,
Use of CP to eliminate electrochemical reactions (corrosion).
Use of protective coatings to reduce CP current requirements.
Failure analysis and initiation of corrective actions on corrosion failures
caused by materials, design, construction, or the environment.
Historical records and documentation required for demonstration of
compliance and efficient operations and maintenance of CP systems.
Note: Guidance in this handbook applies to both sacrificial anode and impressed
current cathodic protection systems.