Middle St. Johns - Florida Department of Environmental Protection

154
Water Quality Assessment Report: Middle St. Johns
Table 4.2 (contined)
Planning
Unit
Econlockhatchee
River
Econlockhatchee
River
Econlockhatchee
River
Econlockhatchee
River
Econlockhatchee
River
WBID
Waterbody
Segment
3023 Crane
Strand
3023A
3023A
3023A
3024A
Lake
Baldwin
Outfall
Lake
Baldwin
Outfall
Lake
Baldwin
Outfall
Trib. to
Little Econ.
River
Waterbody
Type
Stream
Stream
Stream
Stream
1998
303(d)
Parameters
of Concern
Parameters
Identified
Using
the 2002
Impaired
Surface
Waters Rule
Total
Coliform
Bacteria
Fecal
Coliform
Bacteria
Nutrients
(Chlorophyll
a)
Total
Coliform
Bacteria
Priority for
TMDL
Development *
Projected
Year for TMDL
Development *
Comments
High 2004 Planning period: 14/38
values exceed criterion;
verified period: 10/20 values
exceed criterion. Coliform
median 810 colonies/100 ml,
range 40–16,300 colonies/
100 ml. No more than 2
values per month.
Medium 2008 Planning period: 19/36
values exceed criterion;
verified period: 12/21 values
exceed criterion. Coliform
median 510 colonies/100 ml,
range 30–4,100 colonies/
100 ml. No more than 2
values per month.
Medium 2008 Colimitation of N and P based
on a TN/TP median of 21
(63 values) during the planning
and a median of 30 (37
values) during the verified
period. Planning period: 1
Chlorophyll a annual mean
exceeded 20 μg/L (1998); verified
period: 1 Chlorophyll
a annual mean exceeded
20 μg/L (1998). 38 TN values,
median 1.12 mg/L. 38 TP
values, median 0.04 mg/L.
Medium 2008 Planning period: 14/35
values exceed criterion;
verified period: 9/21 values
exceed criterion. Coliform
median 1,480 colonies/
100 ml, range 80–8,000
colonies/100 ml. No more
than 2 values per month.
Stream DO Medium 2008 Planning period: 12/30
values below DO criterion;
verified period: 7/20 values
below DO criterion. DO met
verification threshold of IWR,
and N is the causative pollutant.
TN median = 2.73 mg/L.
58 DO values, mean 5.63
mg/L, median 5.58 mg/L,
range 3–12.9 mg/L.