Middle St. Johns - Florida Department of Environmental Protection

Water Quality Assessment Report: Middle St. Johns 465
allocated to this WBID fall within the Lake Corrine (3023B) WBID. An evaluation
of the only representative sampling station for this WBID [3023A], 21
FLORANLEZB, reveals that when conditions are analyzed for stream impairment, it
is not impaired for nutrients. As demonstrated by the data for WBID 3023A, raw
chlorophyll-a concentrations have remained under 20-ug/L for the majority of the
sampling period of analysis. Recommendation: Remove the Nutrient Impairment for
WBID 3023A from the Verified List [Orange County TMDL Analysis 5 PBS&J
100504.01 July 2003].
RESPONSE: It should be noted that Lake Corrine is currently assigned the WBID
number 3023E and Lake Barton is currently assigned WBID number 3023B and
changes to these numbering assignments are not anticipated. As noted in the
respondent’s comments however, Lake Corrine is otherwise known as Lake Baldwin
and there is perhaps some confusion about which water the Department is assessing
related to naming conventions. The following changes are recommended in this
regard, and have been incorporated in the November 5, 2003 update of the IWR
database:
Current
Assignment
Current WBID Proposed Assignment Proposed WBID
Lake Corrine 3023E Lake Baldwin 3023E
Lake Baldwin 3023A Lake Baldwin Outfall 3023A
A re-analysis of available data for segment 3023A leads the Department to concur that
segment 3023A should be reclassified as a stream and only the 20 ug/L chlorophyll
threshold should be used to assess nutrient impairment, rather than TSI. In reassessing
the segment in this manner, the Department finds that segment 3023A is verified
impaired for nutrients and should be retained on the verified list. This change is
reflected in the final IWR assessment on November 5, 2003.
13. Lake Barber (WBID 3036A1) is listed as being impaired for nutrients (TSI) based on
historic data. Annual average TSI values have not increased by 10 units over the
assessment period, and therefore, there are no data to support the conclusion that this
water body is impaired for historic nutrients (TSI). Recommendation: Remove the
Nutrient Impairment for Lake Barber from the Verified List [Orange County TMDL
Analysis 5 PBS&J 100504.01 July 2003].
RESPONSE: This water segment has been retained on the planning list based on its
location in the Orlando Ridge area. Additional investigation is needed to determine a
more appropriate TSI threshold for the lakes in this area.