220.127.116.11. About the Sixmile Creek
- East of the St. Johns River in St. Johns County
- Primary Land Use: Forested/Wetland
- Current TMDL reports: None
- Verified Impaired 2016 (final): None
- WBID Area: 59.5 sq. mi.
- Beneficial Use: Class III F (Recreational – Freshwater)
18.104.22.168. Data sources
Result data were downloaded from the FL STORET website (DEP 2010e) and filtered based on the stations (DEP 2010f) in the Sixmile Creek WBID 2411 (DEP 2014d) shown above. The filtered dataset was used to generate Table 2.28.
Water quality data for Sixmile Creek are shown in Table 2.28. Dissolved oxygen levels in Sixmile Creek are relatively low, compared to other tributaries (Figure 2.41); however, this is likely attributed to the wetland areas surrounding the creek and therefore it is not listed as impaired (DEP 2009c). Chlorophyll-a levels have exceeded WQC in the past but recent data have shown levels are decreasing, and now the average is below the water quality criteria (20 µg/L) for freshwater streams. Silver levels are elevated, yet this has not been identified as an impairment.
Table 2.28 Water quality data for the Sixmile Creek.
|Dissolved Oxygen (mg/L)||34% sat. (~3.0)||0.58||5.26||10.82||277||1997 - 2015|
|Total Nitrogen (mg/L)||<1.54†||0.52||1.04||1.86||172||1997 - 2014|
|Total Phosphorus (mg/L)||<0.12†||0.009||0.09||0.67||355||1997 - 2014|
|Chlorophyll-a (µg/L)||<20†||0.05||11.4||93.45||219||1997 - 2015|
|Arsenic (µg/L)||≤50||0.09||2.58||22.11||109||1997 - 2011|
|Cadmium (µg/L)||≤0.3||0||0.19||3.74||110||1997 - 2011|
|Copper (µg/L)||≤9.3||0.07||2.85||170.4||156||1997 - 2011|
|Lead (µg/L)||≤3.2||0||1||8.02||126||1997 - 2011|
|Nickel (µg/L)||≤52||0||3.4||98.7||125||1997 - 2011|
|Silver (µg/L)||≤0.07||0||0.29||3.41||95||1997 - 2011|
|Zinc (µg/L)||≤120||0.27||4.83||32.72||162||1997 - 2011|
|Fecal Coliform (log #/100 mL)||<2.6†||2.18||2.18||2.18||1||2012|
|Turbidity (NTU)||<29||0.5||2.68||33.5||210||1997 - 2015|
FW = freshwater; SW = saltwater (marine). Values denoted with (*) indicate a proposed criterion, which has not yet been adopted.
Values denoted with (†) are reference values based on EPA criteria (EPA 2010b), but the water body is not regulated by this standard.