A Total Maximum Daily Load (TMDL) is the
amount of a particular pollutant that a water body (stream
or river segment, lake or estuary) can receive and still
meet State water quality standards for that pollutant.
TMDLs must be developed for all water bodies
identified as not meeting water quality standards and for
which there are no ongoing actions to resolve the impairment.
This “303(d) list” is a subset of the larger
“305(b) list” of all impaired waters in Georgia,
which is updated every two years by the Georgia EPD after
public comment and approval by USEPA. The most current Georgia
305(b)/303(d) list has been published by EPD in the official
305(b) report entitled “Water Quality in Georgia 1998-1999”.
Since only a small percentage of State waters have actually
been monitored, the fact that a water body is not listed
on the 305(b)/303(d) impaired waters list does not mean
that it meets water quality standards. The 305(b) report
does contain a list of waters that have been tested and
found to meet the standards, however.
The schedule for development of TMDLs is
based on certain priority ranking factors and, in some cases,
court rulings on lawsuits filed by various environmental
groups. A Consent Decree in the Georgia TMDL lawsuit (Sierra
Club v. EPA & Hankinson) requires TMDLs to be developed
for all waters on the current 303(d) list consistent with
Georgia’s 5-year rotating basin management planning
cycle. TMDLS are developed by the Georgia EPD Water Protection
Branch or by the USEPA Region 4 Water Quality Planning and
Assessment Branch if EPD fails to do so. A list of proposed
and finalized TMDLs is posted on the USEPA Region 4 TMDL
Web site at http://www.epa.gov/region4/water/tmdl/index.htm,
but is not necessarily comprehensive. TMDL lists may also
be posted on the Georgia EPD website at http://www.ganet.org/dnr/environ/,
under Technical Guidance.
An impaired water body may have more than
one pollutant not meeting water quality standards, and a
TMDL must be developed for each of these pollutants. Computer
modeling is used to develop each TMDL, which defines the
current and proposed maximum allowable point source and
nonpoint source pollutant loadings, as well as a margin
of safety. The TMDL calculations may also identify the percent
reduction in pollutant loadings needed to meet the water
TMDL Implementation Plans
After a TMDL is finalized, an implementation
plan must be developed for initiating local, regional and
state actions that will reduce pollutant loads to levels
established by the TMDL. The Georgia Consent Decree required
the development of TMDL implementation plans for over 100
TMDLS already finalized by EPA and EPD, by April 19, 2001,
and others will follow. An implementation plan must identify
and allocate existing pollutant loadings as well as future
loadings that may result from land use and other changes
in the watershed. An implementation plan would typically
be developed by a lead organization and include active involvement
by local stakeholders and the general public. Stakeholders
may be any person or group whose activities contribute to
the pollutant loading or whose interests are affected by
the TMDL. Stakeholders could include city and county governments,
industrial wastewater and storm water dischargers, farmer
and agricultural producers, commercial forestry operators,
environmental groups, developers, various business interests
and other parties. EPD is responsible for facilitating the
TMDL implementation process. The EPD Water Protection Branch
provided funding for the 16 Georgia Regional Development
Centers (RDCs) to develop initial implementation plans for
TMDLs across the State, mostly for fecal coliform bacteria.
Implementation plans must include projected dates for meeting
water quality standards and would typically utilize existing
environmental programs, as well as new initiatives. For
example, enforcement of existing permits and local ordinances
might be a critical need in some watersheds, so the implementation
plan could include innovative ways to fund this effort.
Implementation plans might also include more stringent wastewater
or storm water discharge permit requirements, land use restrictions,
sewer hookup moratoriums and other activities that could
have a major impact on growth and development until water
quality standards are attained. The TMDL regulations also
require EPD to re-assess all National Pollutant Discharge
Elimination System (NPDES) discharge permits impacting a
water body, within 18 months of a TMDL being finalized for
that water body. The Phase II storm water regulations also
expand the authority of EPD to require new municipal and
industrial storm water discharge permits in watersheds with
TMDLs. EPD already requires watershed assessments and protection
plans for any new or increased NPDES municipal wastewater
discharge permits, in response to 303(d) and TMDL concerns.
This requirement may be extended to all NPDES municipal
wastewater discharge permits as they come up for renewal.
Whether the initial round of TMDL implementation
plans can achieve the goal of returning impaired waters
to compliance with water quality standards for their designated
uses remains to be seen. However, given the continuing litigation
over the development of TMDLs and their implementation plans
in Georgia and across the nation, the process will probably
not be quick or easy.
Sources: USEPA TMDL Web site at http://www.epa.gov/OWOW/tmdl/,
USEPA Region 4 Web site at http://www.epa.gov/region4/tmdl/index.htm.
Other Resources: Georgia EPD Web site at
http://www.georgianet.org/dnr/environ/ (click on Water Quality).
Association of State and Interstate Water Pollution Control
Administrators (ASIWPCA) at http://www.asiwpca.org/. Local
Government Environmental Assistance Program (LGEAN) at http://www.lgean.org/
Videotapes: “Water Quality in Georgia
– The Total Maximum Daily Load (TMDL) Program”
by the Georgia Water Management Campaign. Call the Association
County Commissioners of Georgia at 404-522-5022.
“Watershed Wisdom: Georgia’s
TMDL Program” by the Georgia EPD. Call the EPD TMDL
Coordinator at 404-675-1752.
Contacts: Georgia EPD Water Protection Branch
TMDL Coordinator at 404-675-1752.
Watershed Planning and Monitoring Program at 404-675-6236.
A complete copy of the Georgia EPD’s 1998-1999 Water
Quality In Georgia Report may also be obtained by calling