2.7.14. Greenfield Creek About Greenfield Creek

Figure 2.46
Figure 2.47 Greenfield Creek (WBID 2240A/B).
  • West of the Intracoastal Waterway
  • Primary Land Use: Residential
  • Current TMDL reports: Fecal Coliform with BMAP (2010), Mercury
  • Verified Impaired 2016 (final): None
  • WBID Area: 2.9 sq. mi.
  • Beneficial Use: Class III F (Recreational – Freshwater) Data sources

Result data were downloaded from the FL STORET website (DEP 2010e) and filtered based on the stations (DEP 2010f) in Greenfield Creek WBID 2240A/B (DEP 2014d) shown above. The filtered dataset was used to generate Table 2.15. Discussion

Water quality data for Greenfield Creek are shown in Table 2.15. Average phosphorus levels were higher than the recently updated WQC (DEP 2015d; DEP 2016e; DEP 2016k) and average total nitrogen, dissolved oxygen and chlorophyll-a concentrations were within acceptable limits. (Note: the datasets for these parameters are relatively small in comparison to other parts of the basin). Dissolved oxygen had been removed from the verified impaired list (DEP 2016j) in Greenfield Creek. Recently a TMDL report (Wainwright and Hallas 2009a) was released to address fecal coliform.

The BMAP for Greenfield 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 Greenfield Creek watershed does not contain any permitted point sources for industrial wastewater. It contains the Girvin Road Landfill, which has been inactive since 1992; this landfill received not only solid waste, but sludge from the Neptune Beach Sewage Treatment Plant. The watershed also contains numerous outfalls for stormwater discharge. The sanitary sewer system serves 84% of households in the watershed. JEA reported only one sanitary sewer overflow in the watershed, which occurred in 2002 and potentially impacted surface waters. WSEA estimates that there are 177 on-site sewage treatment and disposal systems (septic systems) in use. Annual Progress Reports for this BMAP were published in 2011 (DEP 2011b), 2012 (DEP 2013b), and 2013 (DEP 2013b); they list repairs, inspections, evaluations, and other improvements conducted by JEA, the Duval County Health Department, COJ, and FDOT.

Greenfield Creek was verified impaired for mercury (DEP 2016j), but this has been addressed in the statewide mercury TMDL already in place (DEP 2013e).

Table 2.15 Water quality data for Greenfield Creek.
ParameterWater Quality Criteria (SW)LowAverageHighSamplesSampling Period
Dissolved Oxygen (mg/L)34% sat. (~3.0)2.36.0613.711311999 - 2012
Total Nitrogen (mg/L)<1.54‡0.711.333.97212007
Total Phosphorus (mg/L)<0.12‡0.040.11212007
Chlorophyll-a (μg/L)<20‡0.4314.1671212007
Arsenic (μg/L)≤50No valid data available
Cadmium (μg/L)≤0.3No valid data available
Copper (μg/L)≤9.3No valid data available
Lead (μg/L)≤3.2No valid data available
Nickel (μg/L)≤52No valid data available
Silver (μg/L)≤0.07No valid data available
Zinc (μg/L)≤120No valid data available
Fecal Coliform (log #/100 mL)<2.6‡0.62.334.021051999 - 2012
Turbidity (NTU)<290.8510.4645212007
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.