The photograph to the left is of a steel H piling embedded in concrete.  The piling provides support for a runway lighting pier at MacDill AFB, Florida.  Note the corrosion of the embedded steel in the splash zone area.  Salt eventually works its way to the metal structure beneath the concrete and begins to corrode the embedded metal.  The corrosion by product exerts pressure on the concrete and causes it to crack and spall.  The concrete, primarily in the splash zone, is eventually spalled away, exposing the metal beneath.  Cathodic protection is one recognized method to protect against this type of corrosion damage.  Cathodic protection and coatings are utilized on bridge supports, bridge beds, buildings, and other steel reinforced concrete structures exposed to salt water, or corrosive environments.

On August 19, 2000 an explosion occurred on one of three adjacent large natural gas pipelines near Carlsbad, New Mexico. El Paso Natural Gas Company operates the pipeline system. The pipelines supply consumers and electric utilities in Arizona and Southern California. Twelve people, including five children, died as a result of the explosion. The explosion left an 86 feet long crater.  Damage caused from corrosion was determined to be the cause of the failure.  This photograph was obtained from the Office of Pipeline Safety web site.  It should be noted that many of our military bases have government owned and maintained gas lines.  The Corps would not want an accident of this kind to occur on government facilities.

The photograph was obtained from the EPA’s Office of Underground Storage Tanks web site.  This Office is involved in the enforcement of federal environmental laws pertaining to corrosion control of underground storage tanks.  In this photograph, a removed underground storage tank is awaiting proper disposal.  As can be seen, product or water is leaking due to wall penetration caused by pitting.  Pitting is a localized type of corrosion cell.  Many underground fuel storage tanks, such as this, are in service on our military bases and on many of our civil works project sites.  The government must assure that corrosion prevention methods, including cathodic protection, are properly applied and maintained in order to prevent leaks, which cause damage to the environment.

This photograph is a close-up view of a severely corroded intake gate-hoisting block.  This gate does not have a cathodic protection system in place whereas the gate-hoisting block in the photograph to the right does have a cathodic protection system in place.

This photograph is also a close-up view of an intake gate-hoisting block but from a different facility than the hoisting block shown in the photograph to the left.  One significant difference in these two hoisting blocks is that the one shown in this photograph is equipped with magnesium anodes.  Proper corrosion control makes a significant difference.

This photograph offers an illustration of the adverse affects of corrosion inside a lock miter gate compartment.  This particular miter gate has not had an impressed current cathodic protection system for many years.

This is a close-up picture of a crack taken from outside a lock miter gate compartment.  Note the corrosion that can be seen all around the crack area and even down in the crack.  Cracking of structural members below the water line is a frequent occurrence and a major concern for the Corps.  Many Corps documents are devoted to examining hydraulic structures for cracks just like these. 

This photograph shows some particularly bad corrosion occurring in miter gate compartments that are normally above the water line.  The coating has not been kept in good condition thus allowing general corrosion to occur.  You can see maintenance in general has apparently not been a priority.

This is a photograph of a miter gate while the lock is dewatered.  The portion of the gate shown was repaired nine months earlier and left uncoated.  Significant corrosion took place in nine months with no corrosion prevention methods employed at all.

This is a photograph of a miter gate at Whitten Lock on the Tenn-Tom Waterway.  These gates have impressed current cathodic protection systems.  These CP systems are tested, adjusted, and maintained on a regular basis.  As a result, the gates are in excellent condition.

This is also a photograph of a miter gate on the Tenn-Tom Waterway, but a different lock than the one shown in the photograph to the left.  This photograph was taken at Rankin Lock.  Again, these gates have impressed current cathodic protection systems, which are tested, adjusted, and maintained on a regular basis.  The Tenn-Tom Waterway has a total of ten locks, all of which are equipped with impressed current cathodic protection systems, and all of these gates are in excellent condition.