2.7.4. Black Creek

2.7.4.1. About Black Creek

Figure 2.33 The Black Creek Tributary (WBID 2415A/B/C).
Figure 2.33 The Black Creek Tributary (WBID 2415A/B/C).
  • West of the St Johns River at the Clay/Duval county line
  • Primary Land Use: Forested
  • Current TMDL reports:
    Lead (2415B/C), Mercury (2415A/B/C)
  • Not included in 2016 Verified List of Impaired Waters
  • WBID Area: 15.4 sq. mi.

2.7.4.2. Data sources

Data were downloaded from the FL STORET and WIN websites (DEP 2010f; DEP 2018c) and filtered based on the stations (DEP 2010g) in Black Creek WBID 2415A/B/C (DEP 2014c) shown above. The aggregate (all three WBIDs) filtered dataset reflects water column concentrations and was used to generate Table 2.5.

2.7.4.3. Discussion

Water quality data for Black Creek are shown in Table 2.5. As compared to other tributaries in the LSJRB, Black Creek is less impacted for the majority of the assessed water quality parameters. Lead has been identified as impaired in Black Creek and a TMDL report was published in 2009 (Lewis and Mandrup-Poulsen 2009) to address this issue.  Other metals, such as copper, nickel, and silver were detected previously at higher concentrations. Water quality data from recent years had suggested that the concentrations of these metals have been reduced and controlled.  Water concentrations of the metals presented in the table below in the water remain lower than their respective WQCs, but there was an increase in the average concentrations of copper and nickel in 2018 that persisted in 2019.

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

Table 2.5 Water quality data for Black Creek.

 Water QualityAverage and Number of Samples º
ParameterCriteria (FW)201720182019
Dissolved Oxygen (mg/L)≤34% sat. (≤3.0)5.23
(0 of 8 samples)
6.18
(0 of 12 samples)
6.83
(0 of 20 samples)
Total Nitrogen (mg/L)<1.54Not availableNot available0.53
(0 of 24 samples)
Total Phosphorus (mg/L)<0.120.08
(0 of 13 samples)
0.11
(3 of 23 samples)
0.09
(3 of 21 samples)
Chlorophyll-a (µg/L)<201.68
(0 of 7 samples)
0.65
(0 of 12 samples)
1.59
(0 of 14 samples)
Arsenic (µg/L)≥500.99
(0 of 7 samples)
1.97
(0 of 12 samples)
1.25
(0 of 10 samples)
Cadmium (µg/L)≥0.30.01
(0 of 7 samples)
0.02
(0 of 12 samples)
0.05
(0 of 9 samples)
Copper (µg/L)≥9.30.85
(0 of 7 samples)
1.52
(0 of 12 samples)
1.92
(0 of 9 samples)
Lead (µg/L)≥3.20.39
(0 of 7 samples)
0.59
(0 of 12 samples)
0.37
(0 of 10 samples)
Nickel (µg/L)≥520.44
(0 of 7 samples)
1.36
(0 of 12 samples)
1.50
(0 of 10 samples)
Silver (µg/L)≥0.070.01
(0 of 7 samples)
0.04
(1 of 12 samples)
0.03
(0 of 10 samples)
Zinc (µg/L)≥1203.39
(0 of 7 samples)
9.58
(0 of 12 samples)
5.00
(0 of 10 samples)
Fecal coliform (CFU /≥400Not available20
(0 of 1 sample)
92
(0 of 4 sample)
100 mL)<292.63
(0 of 6 samples)
4.45
(0 of 12 samples)
3.85
(0 of 13 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.