NUTRIENTS - Marine Pollution: What Everyone Needs to Know - page 24

systems were designed to accommodate a so-called five-year
storm—a rainfall so extreme that it is expected to occur, on
average, only twice a decade. But in 2007 alone, New York
City had three 25-year storms—storms so strong they would
be expected only four times each century. Severe storms
are likely to intensify with the forecasted climate change.
When treatment plants are swamped, the excess water spills
from overflow pipes. To avoid wastewater backing up into
homes or streets, outlets allow untreated water, including
untreated feces and industrial waste, to be released directly
into the waterways (such as the infamous Gowanus Canal in
Brooklyn). When a treatment plant releases untreated waste,
it is breaking the law. Sewage systems are frequent violators
of the Clean Water Act. In the past several years, over 9,000 of
the nation's 25,000 sewage systems—including those in major
cities—have released untreated or partly treated human
waste, chemicals, and other hazardous materials into water
bodies. The raw sewage ruins the water quality, including
at nearby bathing beaches. Hundreds of older municipali-
ties with combined sewer systems face the same water qual-
ity problems during major rainstorms; however, the cost of
replacing these systems with systems that separate wastewa-
ter from stormwater is very high. Combined sewer overflows
have become a major source of pollution, and the resulting
bacterial contamination from the sewage can become con-
centrated in shellfish, rendering them unfit for consumption.
Holding tanks and additional treatment plants have been
built to cope with the overflow, but permanently correcting
the CSO problem will take a sustained policy and many bil-
lions of dollars.
What are Concentrated Animal Feeding Operations (CAFOs)?
Concentrated Animal Feeding Operations (CAFOs) with
dense concentrations of farm animals generate tons of manure
containing nutrients; pathogens, including bacteria and