Environmental Engineering Reference
In-Depth Information
Derivatives of the contents of toilets are not the only things that pour
from sewage treatment plants into unwanted places. Medicine residues
are signifi cantly more abundant in sewage downstream from public treat-
ment plants that handle waste from drug manufacturers.
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Apparently
some of the drug plant's product is going down the drain. The effect on
human health is not entirely known, but certainly it is not benefi cial.
Among the chemicals that survive treatment in the sewage plant are
endocrine disrupters, which affect glands and hormones that regulate
many bodily functions.
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Sewage plants are important parts of America's infrastructure, and in
2006 Democrats in Congress proposed a plan to protect sewage plants
from terrorists. Not all Republicans believed this was a serious problem,
even though Senator Lincoln Chafee of Rhode Island pointed out that
“they're going to blow up our poop.”
Pipes for Gas and Hazardous Liquids
Buried beneath the United States and offshore waters are more than 2
million miles of natural gas steel pipelines, operated by more than 3,000
companies, that transfer this energy source across the nation. Natural
gas supplies about one-quarter of our energy needs so that the mainte-
nance of this part of the infrastructure is clearly of great importance.
The location, construction, and operation of these pipelines are regulated
by either federal or state agencies, depending on whether the pipe crosses
state lines. More than seventy-fi ve full-time federal pipeline inspectors
conduct inspections from fi ve regional offi ces throughout the United
States. However, the majority of inspections are made by state inspectors
who work for state regulatory agencies.
Since 2005 there have been hundreds of gas pipeline incidents that
have killed 68 people and injured 280 others. The most recent was an
explosion and fi re that occurred in the evening of September 9, 2010, in
San Bruno, California, when a 54-year-old natural gas pipeline exploded.
Eight people were killed, 30 more were injured, 38 houses were leveled,
and many more dwellings were damaged. The cause is unclear—perhaps
corrosion, a bad weld, or a crack in the pipe.
Pipeline companies routinely inspect their pipes for corrosion and
defects using highly sophisticated pieces of equipment known as pigs:
robotic devices that are propelled down pipelines to evaluate the interior
of the pipe. Pigs can test pipe thickness and roundness, check for signs
of corrosion, and detect minute leaks and any other defect along the
interior of the pipeline that may impede the fl ow of gas or pose a poten-
