JANUARY 31 2003
of corrosion. Table 4-8 lists recommended corrective actions to prevent future leaks:
Table 4-8. Recommended Corrective Actions for Preventing Leaks
CP SYSTEM TYPE
Take appropriate action to reduce the possibility of
future leaks according to the type of corrosion found.
cathodic protection as appropriate.
Troubleshoot, repair, or adjust existing CP system.
Supplement the existing CP system until protection is
achieved, if necessary.
Conduct a corrosion survey of the system 30 days after
any repairs, adjustments, or installations.
Galvanic Anode Systems. Galvanic anode systems are typically used in
low resistivity soil, or on small or well-coated structures, or as "hot spot" protection on
unprotected structures. Galvanic anodes may be easily installed before the backfill
operation. Impressed current systems are typically used in high resistivity soil or on
large or poorly coated structures. Also, consider bonding to an existing impressed
RECORD KEEPING REQUIREMENTS. Historical records should be
maintained of all surveys and inspections for the life of the protected structure. This is
important for maintaining proof of cathodic protection and for a reference for
troubleshooting or repair of the system.
Each CP system should have a folder with the following information on
Drawings of CP system from as-builts or other sources showing the
location of all components.
Drawings of the structure protected by the system showing all casings,
foreign line crossings, test points, dielectrics, test stations or other