Specifications

Section 2 Existing Conditions/Affected Environment
EAA Storage Reservoirs Revised Draft PIR and EIS February 2006
2-41
assessment and determined that toxaphene, at possible action levels, is widely
distributed in the shallow soil layer within the Woerner Farm #3 area. In the
event that the FDEP affirms that potentially harmful levels of toxaphene are in
the soil, it will likely mandate additional remediation (by the responsible party)
for site closure and for issuance of a water quality certification (WQC) for
operations. However, no determination has been made and the USFWS is
presently coordinating directly with the SFWMD in order to achieve resolution
to this matter. Additionally, testing for mercury includes total mercury and
total methyl mercury, which is more likely to be accumulated in the food chain.
2.14.4 Lake Okeechobee and the EAA
Water quality data for the different system components for the Study Area are
presented in Table C-8 (Appendix C) as arithmetic means of data acquired after
2000. Since algae tend to increase water column pH during the oxygen-forming
photosynthesis process, it is common to see higher levels of dissolved oxygen
occurring in water with higher pH. Lake Okeechobee had the highest dissolved
oxygen and pH averages for the area waters. The STAs, WMAs, and EPA had
lower values, perhaps reflecting shading of surface water by emergent vegetation
that would contribute little oxygen to the water column.
Dissolved solids, as indicated by specific conductance, averaged highest in the
secondary and agricultural canals. Nutrients, solids, and ionic chemicals also
tended to have the highest concentrations in these canals. These elevated
averages may be caused in part by turbulence created during pumping activities
in these shallow canals that might re-suspend solids that had previously settled
to the bottom. Of all of the parameters shown in the above table, only specific
conductance and dissolved oxygen (DO) were found to have averages that exceed
Florida water quality standards for their respective classification. Water in the
agricultural canals averaged at 1600 uS/cm which exceeds the applicable Class
IV criterion of 1275 uS/cm. As stated above, the recorded levels may be caused
by pump-related turbulence. For both primary and secondary canals, DO
averages fell short of the Class III (minimum) criterion of 5.0 mg/l with readings
of 4.87 and 4.06, respectively. These lower levels are likely attributed to
biochemical oxygen demand (BOD) resulting from the biological response to
organic chemical laden runoff. In an effort to minimize low DO occurrences, the
detailed design and long term project operations will investigate and, if
practicable, may implement actions to minimize low DO concentrations.
The STAs, WMAs, and EPA averaged lowest for nitrogen and phosphorus forms.
Emergent plant communities in these areas appear to effectively reduce the
concentrations of nutrients in the water column. Pesticides and mercury were
found in most locations where sampling occurred.