the Big Deal with TMDL's?
Waters of the State are classified by their intended
uses. Some of these uses include drinking water, swimming, boating and
canoeing, cold or warm water fishery, livestock watering, and industrial.
For example, the uses for Table Rock Lake include Livestock and Wildlife
Watering, Protection of Warm Water Aquatic Life and Human Health associated
with Fish Consumption, Whole Body Contact Recreation, and Boating and
Canoeing. If these uses can not be met due to pollution or habitat change,
then the water is listed on the 303(d) list as impaired. Once a waterbody
is placed on the 303(d) list, federal law requires the State to develop
a plan to clean up the water.
The Total Maximum Daily Load or TMDL estimates the amount
of pollution that can enter a waterbody while maintaining the intended
use of that waterbody. The TMDL is determined by examining all contributing
sources of a single pollutant (such as sediment), next, a numerical
value is calculated to establish how much pollution can be added from
each source each day, while keeping the water clean enough to maintain
the intended use. The calculation includes a margin of safety, and accounts
for seasonal variations so that the water will always meet the intended
Next for Missouri?
As of 2001, the EPA is under court order to establish TMDLs if Missouri
does not. There are 174 waters on the 1998 303(d) list of impaired waters.
Of those, 25 TMDLs have been written and approved by the EPA. Two drafts
have undergone public comment, and will be sent to EPA for approval.
That leaves 147 waterbodys that need a TMDL. In the next two years,
MDNR must complete 40 TMDLs. The remaining waterbodys must have a TMDL
in place by 2009.
The proposed 303(d) list for 2002 removes nine lakes
for atrazine and cyanazine. However, 17 lakes are being added due to
atmospheric deposition of mercury and three for Fecal Coliform. There
will be 33 lakes on the list. Creve Coeur Lake is the only lake with
an approved TMDL. Table Rock Lake is listed for both nutrients and mercury.
Lake of the Ozarks is listed for fish trauma, gas supersaturation, and
low dissolved oxygen.
What Can You Do?
Local citizens can assist the TMDL process by getting involved at the
public meetings and identifying methods for reducing pollution that
enters the waterbody. Nonpoint sources such as fertilized lawns, golf
courses, leaking septic tanks and boat sewage discharges can be addressed
by local action groups. Funding is available for education and installation
of pollution reduction practices. Each proposed TMDL is listed on the
department’s website for public notice. During that time your
comments and insight are welcome.
For more information, visit:
www.epa.gov/owow/tmdl/ or: www.dnr.state.mo.us/deq/wpcp/wpc-tmdl.htm
|What the heck
is this 303(d) list anyway?
refers to the section of the Clean Water Act which states:
303(d)(1)(A) “Each state shall identify
those waters within its boundaries for which effluent limitations
required by section 301(b)(1)(A) and 301(b)(1)(B) are not stringent
enough to implement any water quality standard applicable to such
waters. The State shall establish a priority ranking for such
waters, taking into account the severity of the pollution and
the uses to be made of such waters”
The state must determine which of its waters have problems with
water quality. Then the state has to rank those waters on a list
and address the list from the top down. The priority ranking may
be based on how bad the pollution is as well as how people are
intended to use the water.
lakes on the 2002 list are shown here
Here is DNR's interactive map with the 303(d) listed lakes
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