2.7.18. McCoy Creek

2.7.18.1. About McCoy Creek

Figure 2.50
Figure 2.51 The McCoy Creek Tributary (WBID 2257).
  • West of the St. Johns River Downtown
  • Primary Land Use: Residential
  • Current TMDL reports: Fecal Coliform, Mercury
  • Verified Impaired 2016 (final): None
  • WBID Area: 5.34 sq. mi.
  • Beneficial Use: Class III F (Recreational – Freshwater)

2.7.18.2. Data sources

Result data was downloaded from the FL STORET and WIN websites (DEP 2010f; DEP 2018h) and filtered based on the stations (DEP 2010g) in McCoy Creek WBID 2257 (DEP 2014c) shown above. The filtered dataset was used to generate Table 2.19.

2.7.18.3. Discussion

Water quality data for McCoy Creek are shown in Table 2.19. The fecal coliform level, averaged over all the stations in McCoy Creek, was historically above the WQC of 400 colony-forming-units (CFU) per 100 mL. Thus, a TMDL for fecal coliform was published in 2009 (Rich-Zeisler and Kingon 2009). (Note: the data analysis in the TMDL is based on different criteria than that used in this report). Subsequently, a BMAP for McCoy Creek was legally adopted in 2010 (DEP 2010a). The last Annual Progress Report for this BMAP was published in 2016 and listed 20 active, ongoing projects underway by COJ, FDOT, and JEA and one completed project in 2016 (wet detention pond by COJ) to address the BMAP in the McCoy Creek watershed (DEP 2017c). Measurements from the past three years suggest that progress is being made.  Average fecal coliform concentrations remain above the WQC, although the average has decreased over the past three years. Roughly half of the fecal coliform measurements exceed the WQC. Additional information about fecal coliform in the tributaries can be found in Section 2.6 and Table 2.2.

Average dissolved oxygen (DO) levels are above the SSAC of 4.0 mg/L for DO in the mainstem and tributaries (DEP 2014b), and the average DO concentration increased in 2018 following a three-year period of decreases.

While ample data are available for dissolved oxygen, fecal coliform, and turbidity levels in McCoy Creek, limited data can be found in STORET for phosphorus and chlorophyll-a prior to 2018.  No recent measurements were available in WIN or STORET between 2016 and 2018 for the following parameters:

  • Arsenic
  • Lead
  • Zinc
  • Cadmium
  • Nickel
  • Copper
  • Silver

Historical water quality data for these parameters in McCoy Creek are available in previous versions of the River Report.

Table 2.19 Water quality data for McCoy Creek.

 Water QualityAverage and Number of Samples º
ParameterCriteria (FW)201620172018
Dissolved Oxygen (mg/L)≥34% sat. (≥3.0)4.09
(8 of 24 samples)
4.03
(11 of 35 samples)
4.65
(7 of 54 samples)
Total Nitrogen (mg/L)<1.54Not available0.67
(0 of 5 samples)
3.23
(1 of 10 samples)
Total Phosphorus (mg/L)<0.12Not available0.08
(0 of 2 samples)
0.15
(6 of 14 samples)
Chlorophyll-a (µg/L)<20Not available5.55
(0 of 2 samples)
7.05
(1 of 15 samples)
Fecal Coliform (CFU/100 mL)<4001800
(18 of 24 samples)
1100
(17 of 33 samples)
890
(32 of 52 samples)
Turbidity (NTU)<2910.81
(1 of 24 samples)
6.67
(0 of 35 samples)
5.22
(0 of 47 samples)
Note: Hardness-dependent freshwater criteria for cadmium, copper, lead, nickel, and zinc were generated based on a hardness concentration of 100 mg/L.
° = Number of samples below Water Quality Criteria for Dissolved Oxygen; Number of samples above Water Quality Criteria for all other parameters.
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.