responsiveness summary to public comments - US Environmental ...

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the basis that “states are not required to list water quality limited segments still requiring TMDLs
where effluent limitations required by the CWA, more stringent effluent limitations required by
local, state, or federal authority are enough to implement any water quality standard applicable to
such waterbodies”, EPA is not adding East Fork Locust Creek (WBID 608) to Missouri’s 303(d)
list.
3. EPA disagrees with the commenter’s conclusion that it is appropriate to consider the
monitored DO data and the evaluated data as describing two different waterbodies. According to
Missouri’s Water Quality Standards regulation, East Fork Locust Creek is divided into two
segments, one that is from the mouth of East Fork Locust Creek to Highway 6, and the second is
from Highway 6 to Section 12, Township 64N, Range 20 West. Three of the four sites visited by
MDNR were within the same segment. The chemical data and the biological information, with
the exception of one site were collected within the same segment, and therefore, those data can
be used together to make a decision regarding impairment.
East Honey Creek, Mercer County (WBID 555)
Comment:
1. There was disagreement with EPA’s interpretation of Missouri’s general criteria and
EPA’s listing of this water based upon minor algal growth, slightly turbid water, and slightly
elevated conductivity levels. “Slight turbidity” does not constitute a violation of Missouri’s
general criteria, rather the criteria specifies that water be free from “unsightly turbidity”.
.2 Also, the commenter inferred from the presence of darters that this waterbody is not
impaired.
EPA Response:
1. Missouri’s general criteria states that “waters shall be free from substances in
sufficient amounts to cause unsightly color or turbidity, offensive odor or prevent full
maintenance of beneficial uses.”
2. While considering the public comment, EPA located a visual/benthic field survey
sheet that had been overlooked during EPA’s initial evaluation. EPA calculated the average
tolerance value of the taxa reported at the monitoring site for this waterbody. The average
tolerance value was determined to be 6.3, which is below the CTI 6.5 cutoff value. Therefore,
based on this evaluation of the visual/benthic survey data, EPA is removing East Honey Creek
(WBID 555) from the Missouri 2002 Section 303(d) list.