Utilities form an essential part of the U.S. economy by supplying gas, water, electricity, and communication. All utility companies combined spent $42.3 billion on capital goods in 1998, an increase of 9.3% from 1997. Of this total, $22.4 billion was used for structures and $19.9 billion was used for equipment. The total annual direct cost of corrosion in the utility category is estimated to be $47.9 billion, which is 34.7% of the total cost of the sector categories examined in this study. The utilities category is divided into four industry sectors: gas distribution, drinking water and sewer systems, electrical utilities, and telecommunication.

Gas Distribution

The natural gas distribution system includes 2,785,000 kilometers (1,730,000 miles) of relatively small diameter, low pressure piping, which is divided into 1,739,000 kilometers (1,080,000 miles) of distribtuion main and 1,046,000 kilometers (650,000 miles) of services. There are approximately 55 million services in the distribution system. A large percentage of the mains (57 percent) and services (46 percent) are made of steel, cast iron or copper, which are subject to corrosion; however, since the 1970s a large portion of the gas distibution main lines have been made of plastic, mostly polyethlene (PE), but sometimes polyvinyl chloride (PVC). The total annual direct cost of corrosion was estimated at approximately $5.0 billion.

Drinking Water and Sewer Systems

According to the American Waterworks Association (AWWA) industry database, there is approximately 1,483,000 kilometers (876,000 miles) of municipal water piping in the United States. This number is not exact since most water utilities do not have complete records of their piping system. The sewer system consists of approximately 16,400 publicly owned treatment facilities releasing some 155 million m3 (41 billion gallons) of wastewater per day (1995). Americans consume approximately 550 liters of drinking water per person, per day, for a total annual quanity of approximately 56.7 billion m3. The water piping transporting the treated water to Americans is subject to internal and external corrosion, resulting in pipe leaks and water main breaks. The total annual direct cost of corrosion for the nation's drinking water and sewer systems was estimated to be $36.0 billion. This cost was contributed to by the cost of replacing aging infrastructure, the cost of unaccounted for water through leaks, the cost of corrosion inhibitors, the cost of internal mortar linings, and the cost of external coatings and cathodic protection.

Electrical Utilities

The total amount of electricity sold in the United States in 1998 was 3,240 billion GWh at a cost to the consumers of $218 billion. Electricity generation plants can be divided into seven generic types: fossil fuel, nuclear, hydroelectric, cogeneration, geothermal, solar, and wind. All of the types use complex systems with many parts subject to corrosion. The total annual direct cost of corrosion in the electrical utility industry in 1998 was estimated to be $6.9 billion. The majority of electric power in the United States is generated by fossil fuel and nuclear supply systems, which contributed the largest amounts to the cost of corrosion for electrical utilities with nuclear power at $4.2 billion and fossil fuel at $1.9 billion.

Telecommunications

Telecommunication is an increasingly important part of modern society. The telecommunication infrastructure includes hardware such as electronics, computers, and data transmitters, as well as equipment shelters and the towers used to mount antennas, transmitters, and receivers. Wired communication systems include telephone and cable television systems, while wireless communication systems include items such as personal computer systems and cellular telephones. According to the U.S. Census Bureau, the total value of shipments for communications equipment in 1999 was $84 billion. An important factor to be considered for the corrosion cost is the additional cost for corrosion protection of towers and shelters, such as painting and galvanizing. In addition, corrosion of buried copper grounding beds, as well as galvanic corrosion of the grounded steel structures contribute to the cost of corrosion.

For this sector, no corrosion cost was determined because of the lack of information on this rapidly changing industry. Many components are being replaced before physically failing because they become obsolete technology in a short period of time.