often hear the term "TMDL" in water-pollution discussions,
because many of the actions we take to reduce pollution are based
on this scientific measurement.
stands for Total Maximum Daily Load, which is the maximum daily
amount of a pollutant that a body of water can absorb without violating
water quality standards. A non-scientific definition for TMDL could
be "pollution limit."
in Delaware waters are often chemicals, such as nitrogen and phosphorus
from fertilizer runoff, but TMDLs could also be set for such other
pollutants as bacteria, sediments, or even heat --- anything that
can injure a waterway's natural health.
can come from specific "point" sources, such as sewage
treatment plants, or from "nonpoint" sources, such as
runoff from lawns, farms, parking lots and golf courses.
have so far been established for the watersheds that drain into
the Inland Bays, the Nanticoke River, the Appoquinimink River, the
Christina River, Broad Creek, Red Clay Creek and White Clay Creek.
As more than 90 percent of Delaware's waterways are considered "impaired,"
TMDLs will have to be set for many more waterways over the next
few years. The deadline for setting them is 2007.
pollution limits is just the first step toward improving water quality
--- the important next step is the development of "pollution
control strategies," which is the mission of the Tributary