2.7.24. Pottsburg Creek

2.7.24.1. About Pottsburg Creek

Figure 2.58
Figure 2.59 The Pottsburg Creek Tributary (WBID 2265B).
  • East of the St. Johns River at the Butler Blvd./I-95 interchange
  • Primary Land Use: Residential
  • Current TMDL reports: Fecal coliform with BMAP (2010)
  • Verified Impaired 2016 (final): Iron (med)
  • WBID Area: 9.1 sq. mi.
  • Beneficial Use: Class III F (Recreational – Freshwater)

2.7.24.2. Data sources

Result data were downloaded from the FL STORET website (DEP 2010e) and filtered based on the stations (DEP 2010f) in the Pottsburg Creek WBID 2265B (DEP 2014d) shown above. The filtered dataset was used to generate Table 2.25.

2.7.24.3. Discussion

Water quality data for Pottsburg Creek are shown in Table 2.25. Average phosphorus levels were higher than the recently updated WQC (DEP 2015d; DEP 2016e; DEP 2016k); however, average dissolved oxygen and chlorophyll-a were within limits. Fecal coliform data in Table 2.21 (1999-2012) indicates that the average is well above the WQC and fecal coliform levels in this residential tributary were identified as impaired in 2004. Consequently, a TMDL for fecal coliform was published (Rhew 2009c).

A BMAP for Pottsburg Creek (DEP 2010a) was legally adopted in August 2010. It describes sources of fecal coliform in the watershed, and completed and ongoing activities conducted by state and local agencies that are anticipated to reduce fecal coliform loading in the tributary. The Pottsburg Creek watershed contains one permitted point source for industrial wastewater, as well as numerous outfalls for stormwater discharge. A sewer system serves 33% of households in the watershed. WSEA estimates that there are 1,585 on-site sewage treatment and disposal systems (septic systems) in use. COJ has constructed three wet detention projects and has worked with WSEA to add new sewer lines in order to eliminate 354 septic systems. Annual Progress Reports for this BMAP have been published annually since 2011, listing repairs, inspections, evaluations, and other improvements conducted by JEA, the Duval County Health Department, COJ, and FDOT. In the 2016 Annual Progress Report, 34% of Pottsburg Creek fecal coliform measurements over a 7.5 year period ending June 30, 2016 exceeded the water quality criterion (400 CFU/100 mL) (DEP 2017a). Pottsburg Creek remains impaired for fecal coliform, and the size of the exceedances has increased since implementation of the BMAP; the median exceedance increased from 800 CFU/100 mL in the TMDL report to 1,532 CFU/100 mL in the first phase of the BMAP (2010-2014) (DEP 2016b). There are 24 projects either planned or currently underway by COJ, JEA, and FDOT to address the BMAP in the Pottsburg Creek watershed (DEP 2017a).

Table 2.25 Water quality data for Pottsburg Creek.
Concentration
ParameterWater Quality Criteria (SW)LowAverageHighSamplesSampling Period
Dissolved Oxygen (mg/L)34% sat. (~3.0)0.345.3810.531961999 - 2013
Total Nitrogen (mg/L)<1.54‡0.340.941.83881999 - 2013
Total Phosphorus (mg/L)<0.12‡00.140.431011999 - 2013
Chlorophyll-a (μg/L)<20‡0.436.4339502002 - 2013
Arsenic (μg/L)≤500.731.653.3262005 - 2007
Cadmium (μg/L)≤0.30.012.1651.3552002 - 2007
Copper (μg/L)≤9.30.023.7350702002 - 2007
Lead (μg/L)≤3.206.3250672002 - 2007
Nickel (μg/L)≤5204.5250702002 - 2007
Silver (μg/L)≤0.070.010.030.04222007
Zinc (μg/L)≤1200.047.1650702002 - 2007
Fecal Coliform (log #/100 mL)<2.6‡12.485.21961999 - 2012
Turbidity (NTU)<290.17.3372821999 - 2013
Note: Hardness-dependent freshwater criteria for cadmium, copper, lead, nickel, and zinc were generated based on a hardness concentration of 100 mg/L.
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.