More than 2 million miles of underground pipelines carrying millions of gallons of crude oil, fuel and natural gas daily crisscross the U.S., and one on the nation's highest concentrations of those pipelines is in Northwest Indiana and the Illinois south suburbs.
In fact, this area south of Lake Michigan is a major hub for transportation of petroleum and natural gas all over the Northern Hemisphere and for production of petroleum products through refineries including the BP facility in Whiting and East Chicago.
The 30-inch Enbridge Energy Partners Lakehead System 6B pipeline that spilled 19,500 barrels of crude oil in the Kalamzaoo River in southwestern Michigan originates in Griffith and is just one of three types of pipelines found in this Midwest corridor.
Pipelines are denoted by what substance they carry; this also affects the size, construction and regulation of those pipelines.
* Hazardous liquid pipelines carry refined fuels such as gasoline, diesel and jet fuel.
* Gas pipelines transport natural gas and propane.
* Transmission pipelines are the larger lines that move gas and liquids around the country.
The website www.theodora.com indicates all three types of major interstate pipelines come south into Illinois from Canada and Minnesota and north from the Gulf of Mexico and Texas via Iowa, Missouri, Nebraska and Kansas. These lines cross the Indiana state line into Lake County and continue east through Porter, LaPorte and St. Joseph counties and on into Ohio and Michigan.
According to the National Pipeline Mapping System, pipelines carrying crude oil, natural gas and refined petroleum products such as gasoline are plentiful in Lake County.
The hazardous liquid pipelines and transmission pipelines are concentrated in Hammond, Munster, Dyer, Griffith and Schererville, with three major lines going east along the Indiana Toll Road, Interstate 80/94 and north of U.S. 30.
Natural gas lines transect the county west to east near I-90, on either side of U.S. 30 and along Ind. 2.
These pipelines are constructed of steel and are buried underground, between 18 inches to several feet of soil.
The pipes are fairly stable, said Robert Kramer, professor of physics and director of the Center for Energy Efficiency and Reliability at Purdue University Calumet in Hammond.
However, he said, "With subsurface pipelines, things happen."
The hot weather causes steel pipe to expand, while winter's cold contracts the metal, he said. The soil in which the pipe is buried also determines how a leak affects the environment, especially groundwater, Kramer said.
Pipeline repairs are part of regular maintenance for those who own and operate the system. On Wednesday, near Purdue Calumet's Hammond campus, a subcontractor repaired a refined products pipeline owned by Buckeye Partners LP.
A remote computerized monitoring system notified Buckeye personnel of a problem in the pipeline and the flow of fuel was stopped. Crews welded a steel sleeve to the pipeline.
