Environmental Engineering Reference
In-Depth Information
levels of dissolved oxygen, and nose-wrinkling odors. They have closed beaches, pol-
luted drinking water, hindered navigation, and damaged aquatic habitats.
here are 490 outfall pipes spread around the city's five boroughs, and the Newtown
plant has access to 55 of them. Pynn tries to keep untreated sewage away from already
severely polluted waterways—such as New-town Creek, the Gowanus Canal, and Ja-
maica Bay—reasoning that “a healthy body of water, like the Hudson, East River, or New
York Bay can handle the overflows. The water is cleaner to begin with, with more dis-
solved oxygen in it, which helps to break down the raw sewage in twenty-one days just
as well as this plant does in six hours.”
By that night in January 2010, New York had 8.3 million documented residents,
making it the nation's largest city, and, with twenty-seven thousand people per square
mile, by far its most densely populated. Such an “ultra-urban” setting has little space
for artificial runoff controls, such as catch basins and canals. Nor is there much room
to collect storm water underground, as the city's subsurface is honeycombed with tun-
nels, ducts, and pipes that convey subways, electricity, natural gas, phone lines, televi-
sion cables, steam, and water. New York's main line of defense against storm-water run-
off remains its aging sewer system.
A WAKE-UP CALL
New York was one of the first major American cities to build a sewer system. Construc-
tion began in 1849, when the city had about half a million residents. Water and sewage
conduits were made of hand-laid ceramic tile and brick, some of which remain in use.
As they age, the oldest pipes are insufficient to keep up with the city's rising demand,
and some of them are leaking. In 1856, the city's new pipes began to dump raw sewage
directly into local waterways, including Newtown Creek. It took decades, and millions
of dollars, for New York to build its current fleet of fourteen sewage plants, but the sys-
tem's Achilles' heel is the “combined” pipework.
New York is not alone with this dilemma. An estimated 4 percent of the nation's
twenty-five thousand municipal sewer systems use combined systems like those in New
York. These are mostly in older cities in the Northeast, the Great Lakes, and in the Pacif-
ic Northwest. Newer cities equip themselves with separate pipe systems to capture and
transport storm water and sewage water, to avoid CSOs.
Despite stricter laws and advances in water treatment in the 1990s, biological out-
breaks have occasionally flared up, at least in part due to sewage infiltrating drinking
supplies. In 1993, for example, both Washington, DC, and New York City were forced to
issue temporary “boil orders” for tap water, in order to kill E.coliand Cryptosporidium
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