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WATERWAYS AND PORTS 143

4. Cleanup of product in the case of hazardous liquid pipelines
5. Pipeline repair and back-to-service program
6. Legal issues
7. Loss in throughput.

To prevent failures, an aggressive maintenance and integrity program is
necessary.

3.9 WATERWAYS AND PORTS

The United States has more than 7750 commercial water terminals, 192 com-
mercially active lock sites with 238 chambers, and 40,000 km (25,000 miles) of
inland, intercoastal, and coastal waterways and canals (14). About 41 states, 16
state capitals, and all states east of Mississippi River are served by commercially
navigable waterways (15). Both public and private works associated with water-
ways and ports have corrosion-related problems in both freshwater and seawater
environments.
Public Works Waterway Structures operated and maintained by the US Army
Corps of Engineers include locks, dams, navigational aids, levies, and decks. A typi-
cal example of a steel-reinforced concrete dam is shown in Figure 3.12. These struc-
tures are on primarily freshwater lakes and rivers. Many freshwater public works
related to irrigation and flood control are owned, operated, and maintained by state
and local agencies such as the Tennessee Valley Authority (TVA) or the California
Aqueduct.
Public docks, piers, and bulkheads are mostly owned and maintained by port
authorities. These public agencies have structures in both freshwater and seawater;
however, most of the larger ports are in marine locations.
There are also a significant number of private terminals for loading grain and coal
owned by shipping companies and railroads. These private terminals are located in
both freshwater and marine environments. The large size of most structures at port
facilities requires that they be built with steel-reinforced concrete, steel, or a combi-
nation of both. The seawater environment is significantly more severe than river or
lake waters because of the high chloride content in the seawater.

3.9.1 Areas of Major Corrosion Impact

Reinforced concrete structures exposed to marine environments suffer premature
corrosion-induced deterioration by chloride in seawater. Corrosion is typically
found in piers and docks, bulkheads and retaining walls, mooring structures and
navigational aids.
The marine environment can have varying effects on different materials depending
on the specific zones of exposure. Atmosphere, splash, time, immersion, and sub-
soil have very different characteristics and, therefore, have different influences on