03-2038. Clean Water Act Section 303(d): Notice Final Agency Action Withdrawing of 1 Total Maximum Daily Load (TMDL)

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of withdrawal of 1 TMDL.

Subject: This notice announces EPA final action withdrawing of the TMDL for atrazine in the water column that EPA established pursuant to the Clean Water Act (“CWA”) section 303(d), for Louisiana subsegment 080903, Big Creek from the confluence with the Boeuf River to the headwaters (including Big Colewa Bayou). EPA is withdrawing this TMDL because the draft criteria value for atrazine used in screening the waterbody to determine whether it meets Louisiana water quality standards and for calculation of allowable load allocations was draft only and had not been through the complete public notice process and had not been finalized. In place of the draft atrazine criteria number of 12 μg/l, EPA is establishing a screening value of 36 μg/l as calculated by one possible procedure found in Louisiana water quality standards (LAC 33:IX,1113.C.6). Based on this new screening value of 36 μg/l, Big Creek is not, and was not at the time EPA established this TMDL, impaired by atrazine and should not be listed on Louisiana's current CWA section 303(d) list for atrazine. Thus, EPA is withdrawing this TMDL.

Background: EPA established this atrazine TMDL under CWA section 303(d) on February 28, 2001, to satisfy a consent decree obligation in the lawsuit styled Sierra Club v. Clifford, Civ. No. 96-0527 (E.D. La.). The Waterbody subsegment 080903, Big Creek from the confluence with the Boeuf River to the headwaters (including Big Colewa Bayou) was listed on the Louisiana section 303(d) list of impaired waters as impaired due to pesticides, under the “no toxics in toxic amounts” narrative Louisiana water quality standard (LAC 33:IX,1113.B.5).

Since the State of Louisiana does not have a numeric water quality criterion for the protection of aquatic life for atrazine, EPA derived a numeric interpretation of the State of Louisiana's narrative water quality criterion for toxic substances using EPA's Draft Criteria Document for atrazine (Ambient Aquatic Life Water Quality Criteria for Atrazine—Draft, EPA 822-D-010002, August 2001) and used that interpretation as the basis for establishing the Big Creek TMDL for atrazine.

During the comment period for this TMDL, commenters submitted information stating that under Louisiana water quality standard provisions (LAC 33:IX,1113.C.6) it was not appropriate to use a draft criterion document value and that the Louisiana procedures should be used. EPA has evaluated these comments and has concluded that using the calculation procedure found in the Louisiana water quality standards provisions is more appropriate for establishing a screening value for atrazine in this particular case. Based on its modification of the screening value used for interpretation of Louisiana's narrative water quality criterion of “no toxics in toxic amounts,” EPA concluded that the applicable water quality standard for the Big Creek is not, and was not at the time EPA established this TMDL, exceeded for atrazine in the water column.

Therefore, in the exercise of its discretion, EPA is withdrawing the Big Creek TMDL established in February 2001 for atrazine. Because Big Creek is not listed for atrazine on the Louisiana 303(d) list, LDEQ has no present obligation under the CWA to submit to EPA a TMDL for atrazine for Big Creek, nor does the CWA require EPA to maintain this TMDL. Three other TMDLs for Big Creek, DDT, carbofuran, and methyl parathion are not affected by this determination.

FOR FURTHER INFORMATION CONTACT:

Ellen Caldwell at [phone].

Dated: December 20, 2002.

Jayne Fontenot,

Acting Director, Water Quality Protection Division, Region 6.