Select Page

Stormwater Ponds in Coastal South Carolina Appendix A3 – Detailed Summary for Trace Metals, Pesticides/PCBs and PAHs in Sediments in Coastal S.C. Stormwater Ponds and Estuaries

Overview

Summaries are presented for legacy chemical contaminants concentration in sediments including trace metals, pesticides/PCBs, and PAHs. Levels reported in differing types of stormwater ponds (herein, “ponds”)  including residential, golf course, mixed land use, commercial and “pristine” undeveloped land uses. Additionally, data are presented from tidal creeks and estuarine sites measured throughout the coastal zone of South Carolina. Cumulative frequency curves plotting site location versus chemical contaminant concentrations are presented to depict the relationship between contaminant levels in retention ponds versus estuarine and tidal creek habitats. Results are also compared with existing sediment quality guidelines (ERLs/ERMs and TELs/PELs) to indicate the extent and magnitude of potential effects on estuarine organisms (%IAE).

Trace Metals

Aluminum

Aluminum (Al) concentrations in sediments from retention ponds, tidal creeks, and other coastal estuarine locations in S.C. were measured by several studies and are reported in mg/kg dry weight in retention ponds, tidal creeks, and estuaries within S.C. (Fig A3.1). Mean Al concentrations at these sites was 4,597.6 mg/kg dw, with standard deviation (SD) of ± 7,759.9 mg/Kg dw and a standard error (SE) of ± 634.0 mg/Kg dw.

Figure A3.1 Cumulative frequency plot for sediment Al concentrations in ponds and estuarine/tidal creek sites in S.C. Pond types  are classified by land use (various colors) while tidal creek sites are represented as gray symbols. This scheme is used for all figures that follow.

Comparisons of Al sediment concentrations from different retention pond types in S.C. are shown below (Table A3.1). No sediment quality guidelines on Al are available to compare the results of this analysis to use for estimating possible ecotoxicological effects in estuarine and benthic organisms.

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations9324 ± 46041,181 – 17,4914
Residential8,265.1 ± 2,746926 – 25,51210
Golf Course10,549 ± 4,134.21,006 – 26,9776
Mixed Land Use10,596 ± 3,169.71,947 – 20,0106
Commercial7,882 ± 1,7071,830 – 19,69310
ALL S.C. Tidal Creeks/Estuaries3.147.2 ± 679.10.02 – 22,488144

Table A3.1 Comparisons of measured Al sediment concentrations (mg/kg dry weight) in ponds and tidal creeks in S.C. where n = sample size.

The mean Al concentrations in residential, golf course, mixed land use, and commercial ponds were 6,469.9 ± 7,718.8 mg/kg dw. This concentration was comparable, but slightly lower, than mean Al levels measured in retention ponds in less developed locations (9,214 ± 4,604  mg/kg), as reported by Weinstein et al. (2008).  Weinstein et al. (2008) also reported that mean Al concentrations were generally very similar in residential (8,265.1 ± 2746.2 mg/kg), golf course (10,549 ± 4,134.2 mg/kg), mixed land use (10,596 ± 3,169.7 mg/Kg), and commercial ponds (7,882 +/- 1706 mg/kg).  Golf course and mixed land use ponds had slightly higher mean Al concentrations than the mean Al concentrations measured in residential and commercial land use ponds, although these differences were not statistically significant. Crawford et al. (2010) reported a mean Al concentration of 8,076 mg/kg in ponds.

Mean estuarine and tidal creek Al concentrations (3,147.16 ± 679.1 mg/kg) were 52% and 61% lower than mean Al concentrations in retention ponds reported by Weinstein et al. (2008) and Crawford et al. (2010) respectively. These results suggest that retention pond Al concentrations were quite variable. Estimating pond removal efficiencies on estuarine and tidal creek sediment concentrations is fraught with issues of tidal dilution and sediment transport, yet sediment levels represent steady state conditions with all of these dynamic processes for each estuarine and tidal creek location. Lower sediment concentrations in tidal creeks compared to ponds may thus be suggestive of the potential magnitude of pond sedimentation processes and removal efficiencies.  More detailed studies of specific NPS runoff loading into ponds are required to specifically measure pond removal efficiency and were beyond the scope of this project.  Instead, we used comparisons between ponds and tidal creeks as relative indicators of pond function in subsequent sections.

Arsenic

Arsenic (As) concentrations in sediments from tidal creeks and other coastal estuarine locations in S.C. ranged from below detection limits to 32.8 mg/kg dw. A total of 152 sites had detectable levels of As, which ranged from 0.3 – 32.8 mg/kg in tidal creeks and estuaries within S.C. There were no reported values for As in pond sediments. Mean As concentrations at these tidal creek and estuarine sites was 11.26 mg/kg (SD ± 6.14 mg/kg; SE ± 0. 50 mg/kg).  The ERL and ERM for As are 8.2 and 70 mg/kg, respectively.  The TEL and PELs are 7.24 and 17 mg/kg, respectively. More than 65.1% of the sites monitored exceeded the ERL (Fig A3.2) and 68.6% of the sites exceed the TEL; there were no ERM or PEL exceedances.  The %IAE at sites where ERL exceedances occurred ranged from 5 – 11.1%.

Arsenic is naturally occurring in phosphate sediments within the southeastern US, so that more than 25% of the sites in pristine areas of S.C. (e.g., North Inlet and ACE Basin National Estuarine Research Reserve) have ERL exceedances. Highest concentrations were generally found in tidal creeks (e.g. Murrells Inlet, Rathall, Shem and Diesel Creeks) and the Lower Savannah River.

Figure A3.2 Cumulative frequency plot for sediment As concentrations in estuarine/tidal creek sites in S.C. There were no reported studies with measured As levels reported in S.C. ponds.

Cadmium

Cadmium (Cd) concentrations in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. ranged from below detection limits to 8.30 mg/kg dw. A total of 181 samples had detectable levels of Cd, which ranged from 0.03 – 8.30 mg/kg in ponds, tidal creeks, and estuaries within S.C. Mean Cd concentrations at tidal creek and estuarine sites was 0.43 mg/kg, (SD ± 0.58 mg/kg; SE ± 0. 05 mg/kg). Mean Cd concentrations in 18 ponds in S.C. reported by Weinstein et al. (2008) was 2.04 mg/kg (SD ± 1.00 mg/kg; SE ± 0. 017 mg/kg), while Crawford et al. (2010) reported a mean Cd concentration of 8.30 mg/kg in ponds.

The ERL and ERM for Cd are 1.2 and 9.6 mg/kg, respectively.  The TEL and PPELs were 0.68 and 3.53 mg/kg, respectively.  More than 22.2% of the sites exceeded the ERL and 33.1% of the sites monitored exceeded the TEL (Fig A3.3).  Some 73% of the ERL and 56% of the TEL exceedances occurred in ponds. There were no ERM exceedances, but there were PEL exceedances at 2.2 % of the sites.  Some 75% of the ERM exceedances occurred in ponds. Based on these results, the incidence of adverse effects at sites where ERL exceedances occurred was 6.6 – 36.6%.  Generally the highest concentrations were found at ponds as depicted in Figure A3.3.

Figure A3.3. Cumulative frequency plot for sediment Cd concentrations in ponds and estuarine/tidal creek sites in S.C.

Analysis of different pond types is shown below (Table A3.2) and indicated that Cd levels in residential, golf course, mixed land use, and commercial ponds was 2.15 mg/kg dw, which was 63% higher than mean Cd levels measured in ponds in less developed locations (mean = 1.32 mg/kg). Mean Cd concentrations were generally very similar in comparisons of residential, golf course, mixed land use, and commercial ponds, ranging from 2.08 – 2.19 mg/kg as reported by Weinstein et al. (2008), while Crawford et al. (2010) reported a mean Cd concentration of 8.30 mg/kg. Mean estuarine tidal creek concentrations (0.43 ± 0.047 mg/kg) were 79 – 95% lower than those found in S.C. ponds, suggesting that ponds may remove Cd from NPS runoff.

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations1.32 ± 0.76DL – 2.684
Residential2.08 ± 0.35DL – 4.1411
Golf Course2.22 ± 0.381.61 – 2.796
Mixed Land Use2.19 ± 0.211.73 – 3.126
Commercial2.11 ± 0.62DL – 2.6210
Tidal Creeks/Estuaries0.43 ± 0.047DL – 5.50153

Table A3.2 Sediment Cd concentrations measured in ponds, tidal creeks, and estuaries in S.C. where DL = detection limit and n = number of sites.

Chromium

Chromium (Cr) concentrations in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. ranged from 4.00 – 2,873 mg/kg dw.  A total of 156 samples had detectable levels of Cr; mean Cr concentrations were 99.60 mg/kg (SD ± 278.42 mg/kg; SE ± 21.79 mg/kg).  Mean Cr concentrations at tidal creek and estuarine sites were 98.78 mg/kg (SD ± 279.18 mg/kg; SE ± 22.57 mg/kg) (Table A3.3). Mean Cr concentrations reported by Weinstein et al. (2008) was 3.08 mg/Kg, (SD ± 12.90 mg/kg; SE ± 2.15 mg/kg).  Crawford (2010) reported a mean Cr concentration of 225 mg/kg.

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations<DL<DL4
Residential11.12 ± 7.41DL – 58.0810
Golf Course<DL<DL6
Mixed Land Use<DL<DL6
Commercial<DL<DL10
All S.C. Tidal Creeks/Estuaries98.78 ± 22.574 – 2,873152
Tidal Creeks/Estuaries without Shipyard Creek*67.43 ± 3.044 – 270.2150

*Shipyard Creek = EPA Superfund Sites
Table A3.3 Sediment Cr concentrations measured in ponds, tidal creeks, and estuaries in S.C. where DL = detection limit and n = number of sites.

Analysis of different retention pond types is shown above (Table A3.3) and indicated that the mean Cr level in residential, golf course, mixed land use, and commercial ponds was 3.08 ± 2.15 mg/kg dw, which was much higher than mean Cr levels measured in ponds in less developed locations (all concentrations were below DL). Mean Cr concentrations were very different in comparisons of residential, golf course, mixed land use, and commercial ponds, as only residential ponds had Cr concentration above DL, ranging from < DL – 58.08 mg/kg as reported by Weinstein et al. (2008) for 18 different retention ponds in S.C. Crawford et al. (2010) reported a mean Cr concentration of 225 mg/kg in S.C. ponds. Mean estuarine tidal creek concentrations (98.78 ± 22.57 mg/kg for all S.C sites and 67.43 +/- 3.04 mg/kg excluding the Superfund Site at Shipyard Creek) were 95 – 97% higher than found in S.C. ponds studies by Weinstein et al. (2008) but were 56-70% lower than Cr levels reported by Crawford et al. (2010). This suggests that pond Cr concentrations were quite variable. Using Cr concentrations reported by Crawford et al. (2010), concentrations were 56 – 70% higher in comparisons of ponds with estuarine and tidal creek concentrations. This may be suggestive that ponds may remove Cr from NPS runoff.

Figure A3.4 Cumulative frequency plot for sediment Cr concentrations in ponds and estuarine/tidal creek sites in S.C.

The ERL and ERM for Cr are 81 and 370 mg/kg, respectively.  The TELs and PELs are 52.3 and 90 mg/kg, respectively. Some 25% of the sites monitored exceeded the ERL (Fig A3.4). There were ERM exceedances at 1.1% of the sites, all at tidal creek locations. There were exceedances of the TEL and PEL at 64.2 and 24% of the sites, respectively.  Based on these results, the %IAE at sites where ERM exceedances occurred was >95% (< 1% of the sites) and where there were ERL exceedances was 21.1 – 95% (30.2% of the sites). Only 3% of the ERL and TEL exceedances occurred in ponds, with the majority of ERL/TEL exceedances occurring in tidal creeks and estuarine sites (97%). There were no ERM exceedances in ponds, but there were PEL exceedances at 2.8 % of the pond sites. Highest Cr levels were generally found in tidal creeks adjoining the Superfund site at Shipyard Creek (2,873 mg/kg), which was the only site where both ERM and PEL exceedances occurred as depicted in Figure A3.4. Highest levels in ponds (225 mg/kg) were much lower than at the Superfund site.

Copper

Copper (Cu) concentrations in sediments from ponds, tidal creeks, and other estuarine locations in S.C. ranged from 1 to 288 mg/kg dw. A total of 183 samples had detectable levels of Cu. Mean Cu concentrations at these sites were 26.98 mg/kg (SD ± 33.11 mg/kg; SE ± 2.73 mg/kg).  Mean Cu concentrations at tidal creek and estuarine sites were 23.68 mg/kg (SD ± 16.10 mg/kg; SE ± 1.30 mg/kg). Mean Cu concentrations in S.C. ponds reported by Weinstein et al. (2008) were 111.76 mg/Kg (SD ±164.50 mg/kg; SE ± 27.42 mg/kg), while Crawford (2010) reported a mean Cu concentration of 288 mg/kg (Table A3.4).

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations9.72+/- 5.60<DL – 19.54
Residential154.54 +/-48.82<DL – 464.610
Golf Course89.13 +/- 25.59<DL – 160.76
Mixed Land Use15.27 +/-4.36<DL – 32.26
Commercial181.28 +/- 77.3<DL – 588.610
ALL S.C. Tidal Creeks/Estuaries23.68 +/- 1.301 – 93.7153
ALL S.C. Tidal Creeks w/o Superfund Sites*20.71 +/- 1.041 – 93.7137

*Superfund Sites = Shipyard, Diesel and Koppers Creeks

The ERL and ERM for Cu are 34 and 270 mg/kg, respectively.  The TELs and PELs are 35.7 and 197 mg/kg, respectively. Some 19.4% of the sites monitored had exceedances of the ERL (Fig A3.5). There were ERM exceedances at 3.7% of the sites. Similarly, there were exceedances of the TEL and PEL at 13.7% and 0.6% of the sites, respectively.  Based on these results the %IAE at sites where ERM exceedances occurred was >83.7% (0.6% of the sites) and where there were ERL exceedances was >29.1% – 83.7% (13.7% of the sites).

Figure A3.5 Cumulative frequency plot for sediment Cu concentrations in ponds and estuarine/tidal creek sites in S.C.

Some 91 % of the ERL and TEL exceedances occurred in ponds, with only 9% of the ERL/TEL exceedances occurring in tidal creek and estuarine sites (97%). There were no ERM exceedances, but there were PEL exceedances at 2.2 % of the sites. All (100%) of the ERM and PEL exceedances occurred in ponds. Highest concentrations were generally found in ponds where there were ERL/ERM and TEL/PEL exceedances as depicted in (Fig A3.5). Also high levels of Cu were found in highly urbanized (e.g. Vardell, Shem Creeks, and North Edisto) and Superfund Site (e.g. Shipyard, Koppers, and Diesel) impacted tidal creeks.

Analysis of different pond types as shown below (Table 4) indicated that the mean Cu level in residential, golf course, mixed land use, and commercial ponds was 111.76 mg/Kg ± 27.46, which was much higher than mean Cu levels measured in ponds in less developed locations (mean = 9.72 ± 5.60 mg/kg) as reported by Weinstein et al. (2008). Weinstein et al. (2008) also reported that mean Cu concentrations were different in comparisons of residential, golf course, mixed land use, and commercial ponds, as commercial and residential ponds had much higher mean Cu concentrations (181.28 ± 77.3 and 154.54 ± 48.2 mg/kg, respectively) than mean Cu concentrations in mixed land use ponds (15.24 ± 4.36 mg/kg). Mean Cu concentration in golf course ponds (89.13 ± 25.59 mg/kg) was intermediate between commercial /residential and mixed land use ponds. Crawford et al. (2010) reported a higher mean Cu concentration of 288 mg/kg in S.C. ponds.

Mean estuarine tidal creek concentrations (25.28 ± 22.57 mg/kg) for all S.C. sites were 77-93% lower than found in S.C. ponds as studied by Weinstein et al. (2008) and Crawford et al. (2010). These results suggest that pond Cu concentrations were quite variable but generally had concentrations that were 77 – 93% higher than in tidal creek and estuarine sites.

Iron

Iron (Fe) concentrations in sediments in 133 sites in ponds, tidal creeks, and other coastal estuarine locations in S.C. ranged from 0.42 – 320,799 mg/kg. Mean Fe concentrations at these sites averaged 5,033.6 mg/Kg dw (SD ± 29,192.3 mg/kg; SE of ± 250.9 mg/kg) (Fig A3.6).

Figure A3.6 Cumulative frequency plot for sediment Fe concentrations in ponds and estuarine/tidal creek sites in S.C.

There are no SQG’s for Fe to compare results to for estimating possible ecotoxicological effects. Analysis of sediment Fe concentrations measured in different pond types and estuarine/tidal creek sites in S.C. are shown below (Table A3.5)

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations4,471.3 ± 3,122.31013 – 13,8484
Residential4,128.3 ± 1,397.5721 – 15,049.610
Golf Course5,031.2 ± 1,850.6682.1 – 12,0616
Mixed Land Use5,831.1 ± 1,709.3520.4 – 10,832.76
Commercial4,300.5 ± 1,0351,118.4 – 11,549.310
All S.C. Tidal Creeks/Estuaries5,203.0 ± 3,384.60.42 – 320,799114

Table A3.5 Sediment Fe concentrations measured in ponds, tidal creeks, and estuaries in S.C. where n = sample size.

Statistical analysis indicated that the mean Fe concentrations in residential, golf course, mixed land use, and commercial ponds was 4,648.5 ± 4,118.4 mg/kg dw, which was comparable but slightly lower than mean Fe levels measured in ponds in less developed locations (4,471.3 mg/kg ± 3,122.3  mg/kg) as reported by Weinstein et al. (2008).  Weinstein et al. (2008) also reported that mean Fe concentrations were generally very similar in residential (mean = 4,128.3 ± 1,397.5 mg/kg), golf course (5,031.2 ± 1,805.6 mg/kg), mixed land use (mean = 5,831.1 ± 1,799.3 mg/kg), and commercial ponds (mean = 4,300.5 ± 1,035 mg/kg). Crawford reported a mean Fe concentration of 2,582 mg/kg in ponds, which was 46% lower than levels reported by Weinstein at al. (2008) (Table A3.5).

Mean S.C. tidal creek Fe concentrations were 11 – 51% higher than mean Fe concentrations in retention ponds reported by Weinstein et al. (2008) and Crawford et al. (2010) respectively. These results suggest that pond Fe concentrations were quite variable and that ponds did not appear to concentrate Fe when compared to S.C. tidal creek concentrations.

Lead

Lead (Pb) concentrations in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. ranged from DL – 343 mg/kg dw. A total of 172 sites had detectable levels of Pb, which ranged in concentration from 1.67 to 153.6 mg/kg in ponds, tidal creeks, and estuaries in S.C. Mean Pb concentrations at these sites was 28.23 mg/kg (SD ± 34.36 mg/kg; SE ± 2.62 mg/kg).

The ERL and ERM for Pb are 46.7 and 218 mg/kg, respectively. The TELs and PELs were 30.2 and 91.3 mg/kg, respectively. More than 8.7% of the sites monitored had ERL exceedances (Fig A3.7). There were no ERM exceedances at any of the sites. There were exceedances of the TELs and PEL at 23.3 and 5.2% of the sites, respectively.  Based on these results, the %IAEs at sites where there were ERL exceedances was 8 – 35.8 (9.3% of the sites).

Figure A3.7 Cumulative frequency plot for sediment Pb concentrations in ponds and estuarine/tidal creek sites in S.C.

Only 6% of the ERL and 3% of the TEL exceedances occurred in ponds, with the majority of ERL/TEL exceedances occurring in tidal creek and estuarine sites (94 – 97%).  There were no ERM exceedances in tidal creeks or ponds, and only 11% of the PEL exceedances occurred in ponds. Highest concentrations were found in ponds where there were both ERL/ERM and TEL/PEL exceedances as depicted in Figure A3.7. Also high levels of Pb were found in highly urbanized (e.g. New Market) and Superfund Site (e.g. Shipyard, Koppers, and Diesel Creeks) impacted tidal creeks.

Analysis of sediment Pb concentrations measured in different pond types and estuarine /tidal creeks are shown below (Table A3.6) and indicated that the mean Pb concentration in residential, golf course, mixed land use, and commercial ponds was 3.09 ± 0.56 mg/kg, which was very similar to mean Pb levels measured in ponds in less developed locations (3.37 ± 0.69 mg/kg) as reported by Weinstein et al. (2008).  Weinstein et al. (2008) also reported that mean Pb concentrations were very different in comparisons of residential, golf course, mixed land use, and commercial ponds, as commercial and mixed land use ponds had much higher mean Pb concentrations (5.00 ± 1.30 and 4.05 ± 1.72 mg/kg, respectively) than mean Pb concentrations in golf course ponds (0.91 ± 0.64 mg/kg). Mean Pb concentrations in residential ponds (1.82 ± 1.71 mg/kg) were intermediate between commercial, mixed land use, and golf course ponds. Mean estuarine tidal creek concentrations (29.74 +/-2.02 mg/Kg dw) for all S.C. sites were 90% higher than found in S.C. retention ponds studied by Weinstein et al. (2008), These results suggest that pond Pb concentrations were quite variable and much lower in ponds than in tidal creeks.

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations3.37 ± 0.692.17 – 5.174
Residential1.82 ± 1.71<DL – 6.4810
Golf Course0.91 ± 0.64<DL – 3.816
Mixed Land Use4.05 ± 1.72<DL – 10.746
Commercial5.00 ± 1.30<DL – 13.8110
All S.C. Tidal Creeks/Estuaries29.74 ± 2.021.67 – 153.6148

Table A3.6 Sediment Pb concentrations measured in ponds, tidal creeks, and tidal creek/estuaries in S.C. where DL = detection limit and n = number of sites.

Mercury

Mercury (Hg) concentrations in sediments from tidal creeks and other coastal estuarine locations in S.C. ranged from <DL – 0.54 mg/kg dw. There were no identified literature sources for Hg levels in pond sediments in S.C. A total of 146 sites had detectable levels of Hg which ranged in concentration from 0.01- 0.54 mg/kg in tidal creeks and estuaries in S.C. Mean Hg concentrations at these sites were 0.89 mg/kg (SD ± 0.70 mg/kg; SE ± 0.01 mg/kg).

The ERL and ERM for Hg are 0.15 and 0.71 mg/kg, respectively. The TELs and PELs were 0.174 and 0.486 mg/kg, respectively. More than 9.5% of the sites monitored had exceedances of the ERL and 4.7% of the sites exceed the TEL (Fig A3.8). There were no ERM exceedances at any of the sites. There were exceedances of the PEL at 0.7% of the sites.  Based on these results the Incidence of Adverse Effects at sites where ERL exceedances occurred was 8.3 – 23.5% (9.5% of the sites). Highest concentrations were found in highly urbanized (e.g. New Market and Vardell) tidal creeks where ERL/TEL and PEL exceedances were noted as depicted in Figure A3.8.

Figure A3.8 Cumulative frequency plot for sediment Hg concentrations in estuarine/tidal creek sites in S.C. There were no reported levels for Hg in S.C. ponds.

Nickel

Nickel (Ni) concentrations in sediments from tidal creeks and other coastal estuarine locations in S.C. ranged from 1.2 – 50.7 mg/kg dw.  There were no reported literature sources for Ni levels in pond sediments in S.C.  A total of 153 sites had detectable levels of Ni. Mean Ni concentrations at these sites were 16.93 mg/kg (SD ± 7.90 mg/kg; SE ± 0.64 mg/kg).

The ERL and ERM for Ni are 20.9 and 51.6 mg/Kg, respectively.  The TEL and PEL were 15.9 and 36.0 mg/Kg, respectively. More than 30.9% of the sites monitored had exceedances of the ERL  and 56.6% of the sites exceeded the TEL (Fig A3.9). There were no ERM exceedances at any of the sites. There were exceedances of the PEL at 1.3% of the sites.  Based on these results the %IAE at sites where ERL exceedances occurred was 1.9 – 16.7% (30.9% of the sites). No Ni concentrations were reported for retention ponds in S.C. The highest  levels of Ni were found in highly urbanized (e.g. New Market, Dill, Orange Grove, Rathall, Shem, and the Lower Savannah River) and Superfund Site (e.g. Shipyard,  Koppers, and Diesel) impacted tidal creeks (Fig A3.9).

Figure A3.9 Cumulative frequency plot for sediment Ni concentrations in ponds and estuarine/tidal creek sites in S.C. There were no reported levels for Ni in S.C. ponds.

Silver

Silver (Ag) concentrations in sediments from tidal creeks and other coastal estuarine locations in S.C. ranged from < DL-0.03 mg/kg dw.   No studies were identified which had detectable levels of Ag in S.C. ponds. A total of one tidal creek site had detectable levels of Ag (0.03 g/kg). The ERL and ERM for Ag are 1.0 and 3.70 mg/kg, respectively.  The TEL was 0.73 mg/Kg. There were no exceedances of the ERL or ERM for Ag (Fig A3.10). There were also no TEL exceedances noted. Based on these results the %IAE at sites where concentrations were < the ERL exceedances was < 2.6% (100% of the sites). This was found in a tidal creek on Kiawah Island (Kiawah River).

Figure A3.10  Cumulative frequency plot for sediment Ag concentrations in estuarine/tidal creek sites in S.C. There were no reported levels for Ag in S.C. ponds.

Zinc

Zinc (Zn) concentrations in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. ranged from <DL – 572.7mg/kg dw.  A total of 186 sites had detectable levels of Zn, which ranged in concentration from 1.96 – 733 mg/kg in ponds, tidal creeks, and estuaries within S.C. Mean Zn concentrations at these sites were 99.27 mg/kg (SD ± 91.9 mg/kg; SE ± 6.75 mg/kg).

The ERL and ERM for Zn are 150 and 410 mg/kg, respectively. The TEL and PELs were 123 and 315 mg/kg, respectively. More than 12.8% of the sites monitored had exceedances of the ERL (Fig A3.11). There were ERM exceedances at 1.6% of the sites. There were exceedances of the TEL and PEL at 21.1% and 3.2% of the sites.  Based on these results the %IEA at sites where ERM exceedances occurred was > 69.9% (1.6% of the sites) and where there were ERL exceedances was > 47- 69.8% (12.8 % of the sites).

Figure A3.11  Cumulative frequency plot for sediment Zn concentrations in ponds and estuarine/tidal creek sites in S.C.

Some 56% of the ERL and 23% of the TEL exceedances occurred in retention ponds, with the majority of ERL/TEL exceedances occurring in tidal creek and estuarine sites (44 – 77%). All (100%) of the ERM exceedances and 50% of the PEL exceedances occurred in ponds. Highest concentrations were found in ponds where there were ERM exceedances as depicted in Fig A3.11. Also high levels of Zn were found in highly urbanized (e.g. New Market and Vardell Creeks and the lower Savannah River) and Superfund Site (e.g. Shipyard and Diesel Creeks) impacted tidal creeks. Analysis of Zn concentrations measured in tidal creeks/estuaries and different retention pond types in S.C. are shown below (Table A3.7).

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations40.52 ± 2.36<DL – 89.34
Residential37.64 ± 10.89<DL – 81.4310
Golf Course30.04 ± 10.94<DL – 60.516
Mixed Land Use91.93 ± 37.652.37 – 243.596
Commercial224.00 ± 58.146.07 – 572.7010
All S.C. Tidal Creeks/Estuaries92.21 ± 5.038.60 – 422.0148

Table A3.7 Sediment Zn concentrations measured in ponds, tidal creeks, and tidal creek/estuaries in S.C. where DL = detection limit and n = number of sites.

Mean Zn concentration in residential, golf course, mixed land use, and commercial ponds was 90.59 mg/kg ± 21.90, which was much higher than mean Zn levels measured in ponds in less developed locations (40.52 ± 2.36 mg/kg) as reported by Weinstein et al. (2008). Weinstein et al. (2008) also reported that mean Zn concentrations were different in comparisons of residential, golf course, mixed land use, and commercial ponds, as commercial and mixed land use ponds had much higher mean Zn concentrations (224.0 ± 58.14 and 91.93 ± 37.65 mg/kg, respectively) than mean Pb concentrations in golf course (30.04 ± 10.94 mg/kg) and residential ponds (37.64 ± 10.89 mg/kg).

Mean estuarine tidal creek concentrations (92.21 ± 62.05 mg/kg) for all S.C. sites were similar to mean pond concentrations (90.59 ± 21.9 mg/kg) reported by Weinstein et al. (2008) for S.C. ponds. Mean tidal creek Zn concentrations were 61- 67% higher than zinc concentrations in golf course and residential ponds and were very similar to mean Zn concentrations reported in mixed land use ponds reported by Weinstein et al. (2008). Mean Zn tidal creek concentrations were 59% lower than found in S.C. commercial ponds studied by Weinstein et al. (2008) and were 87% lower than mean S.C. pond Zn levels (572 mg/kg) reported by Crawford et al. (2010). These results suggest that retention pond  Zn concentrations were quite variable, and estuaries and tidal creeks mean sediment Zn concentrations were 87% lower based upon results from mean pond concentrations reported by Crawford et al. (2010), suggesting ponds may sequester zinc.

Pesticides and PCBs

Dichloro-Diphenyl-Trichloroethane (DDT)

Dichloro-diphenyl-trichloroethane (DDT) concentrations were quantified in sediments from tidal creeks and other coastal estuarine locations in S.C. A total of 54 sites had detectable levels of DDT which ranged from 0.60 – 43.2 µg/kg dw in ponds, tidal creeks, and estuaries in S.C. (Fig A3.12).

Figure A3.12 Cumulative frequency plot for sediment DDT concentrations in ponds and estuarine/tidal creek sites in S.C. There were no reported DDT levels for ponds in S.C.

Mean concentration in tidal creeks and estuarine sites was 4.45 ± 1.26 µg/kg. No pond data were found in the literature (Table A3.8). The ERL for DDT is 0.16 µg/Kg and the ERM is 46.1 µg/Kg. Some 100% of the sites were > ERL, but there were no ERM exceedances.

Pond TypeMean ± Standard ErrorRangen
Pristine Reference LocationsN/AN/AN/A
ResidentialN/AN/AN/A
Golf CourseN/AN/AN/A
Mixed Land UseN/AN/AN/A
CommercialN/AN/AN/A
All S.C. Tidal Creeks/Estuaries4.45 +/- 1.260.60 – 43.254

Polychlorobiphenyls – PCBs

Polychlorobiphenyls (PCBs) concentrations were quantified in sediments from tidal creeks and other estuarine locations in S.C. No measured PCB concentrations were measured in ponds in S.C. A total of 54 sites had detectable levels of PCB which ranged from 3.50 – 101.50 µg/Kg in tidal creeks and estuaries (Fig A3.13).

Figure A3.13 Cumulative frequency plot for sediment PCBs concentrations in estuarine/tidal creek sites in S.C. No reported levels of PCBs were found for ponds in S.C.

The mean concentration in tidal creeks and estuarine sites was 12.68 +/- 2.46 µg/Kg dw (Table 9). The ERL for PCB is 22.7µg/Kg, and the ERM is 180. Some 11.3% of PCB concentrations exceed the ERL. There were no ERM exceedances (Figure 13).  The %IAE ranged from > 17.2-53.1% for PCBs in tidal creek and estuarine habitats in S.C.

Pond TypeMean ± Standard ErrorRangen
Pristine Reference LocationsN/AN/AN/A
ResidentialN/AN/AN/A
Golf CourseN/AN/AN/A
Mixed Land UseN/AN/AN/A
CommercialN/AN/AN/A
All S.C. Tidal Creeks/Estuaries12.68 ± 2.463.50 – 101.5054

Table A3.9 PCB concentrations were quantified in sediments from tidal creeks and other estuarine locations in S.C. where n = number of sites. No reported levels of PCBs were found for ponds in S.C.

Polycyclic Aromatic Hydrocarbons

Acenapthene

Acenapthene concentrations were quantified in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. A total of 132 sites had detectable levels of acenapthene which ranged from 3.00 – 1993.81 µg/Kg in ponds, tidal creeks, and estuaries within S.C. (Fig A3.14).

Figure A3.14 Acenapthene concentrations (µg/kg dw) were quantified in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

Mean concentration in tidal creeks and estuarine sites was 16.60 ± 5.72 µg/kg versus mean concentrations in ponds, which ranged from 91.42 ± 10.75 µg/Kg (residential ponds) to 424.81 ± 126.93 µg/Kg (commercial ponds).  Highest concentrations were found in commercial, mixed land use, and golf course ponds, which were 8 to 26 times higher than in tidal creek and estuarine habitats in S.C. (Table A3.10 and Fig A3.14). The ERL for acenapthene is 16 µg/Kg. Some 65% of the sites monitored has exceedances of the ERL. The %IAE ranged from 20-32.4%. There is no reported ERM value. There are no reported TEL and PEL values for acenapthene.

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations91.53 ± 19.7631.63 – 161.579
Residential91.42 ± 10.7550.34 – 197.7221
Golf Course191.14 ± 46.3962.15 – 588.2613
Mixed Land Use131.38 ± 13.3155.124 – 197.5913
Commercial424.81 ± 126.9354.20 – 1993.8121
All S.C. Tidal Creeks/Estuaries16.60 ± 5.723.00 – 273.0055

Table A3.10 Acenapthene concentrations were quantified in sediments from ponds, tidal creeks, and other estuarine locations in S.C. where n = number of sites.

Anthracene

Anthracene concentrations were identified in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. A total of 131 sites had detectable levels of anthracene which ranged from <DL to 1491.38 µg/kg dw in ponds, tidal creeks, and estuaries within S.C. Mean tidal creek concentrations ranged from 2.00 to 705.00 µg/kg, averaging 42.61 ± 17.16 µg/kg (Table A3.11).

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations57.92 ± 19.05<DL – 125.769
Residential15.45 ± 6.12<DL – 83.9021
Golf Course30.51 ± 9.97<DL – 130.3113
Mixed Land Use95.12 ± 48.46<DL – 491.5813
Commercial318.68 ± 96.99<DL – 1491.3821
All S.C. Tidal Creeks/Estuaries42.61 ± 17.162.00 – 705.0054

Table A3.11 Anthracene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C. where DL = detection limit and n = number of sites.

Mean ponds concentrations ranged from 15.45 ± 6.12 µg/kg (residential ponds) to 318.68 ± 96.99 µg/kg (commercial ponds). Highest concentrations were found in commercial and mixed land use ponds, which were 2 to 7 times higher than in tidal creek and estuarine habitats in S.C. The ERL and ERM for anthracene are 85.3 and 960 µg/kg, respectively. Some 20.6% of the sites monitored have exceedances of the ERL (Fig A3.15).

Figure A3.15 Anthracene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

Some 2.29% of the sites exceeded the ERM, and these sites were located at commercial ponds. The %IAE ranged from 25 – 44.2% for ERL and were > 44.2% for ERM exceedances. There are no reported TEL and PEL values for anthracene.

Acenapthylene

Acenapthylene concentrations were identified in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. A total of 132 sites had detectable levels of acenapthylene which ranged from 1 to 1783 µg/kg in ponds, tidal creeks, and estuaries within S.C. (Table A3.12).

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations364.06 ± 153.65<DL – 1178.439
Residential20.61 ± 9.7<DL – 161.9521
Golf Course9.39 ± 5.41<DL – 66.9513
Mixed Land Use48.30 ± 26.80<DL – 284.1513
Commercial21.30 ± 10.04<DL – 147.0021
All S.C. Tidal Creeks/Estuaries38.73 ±  32.131.00 – 1783.0055

Table A3.12 Acenapthylene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C. where DL = detection limit and n = number of sites.

Highest concentrations were measured in pristine reference pond locations and mixed land use ponds, which were 1 to 9 times higher than in tidal creek and estuarine habitats in S.C. The ERL for acenapthylene is 44 µg/kg. Some 1.52% of the sites monitored have exceedances of the ERL (Fig A3.16). There is no reported ERM value. The %IAE for ERL exceedances ranged from 14.3 – 17.92 %. There are no reported TEL or PEL values for acenapthylene.

Figure A3.16 Acenapthylene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

Fluorene

Fluorene concentrations were identified in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. A total of 131 sites had detectable levels of fluorene which ranged from below DL – 1,432.05 µg/kg dw in ponds, tidal creeks, and estuaries within S.C. (Fig A3.17).

Figure A3.17 Fluorene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

Highest concentrations were found in commercial, golf course, and mixed land use ponds, which were 3 to 15 times higher than in tidal creek and estuarine habitats in S.C. (Table A3.13).

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations36.99 ± 4.8227.77 – 64.809
Residential42.66 ± 4.5630.65 – 110.8021
Golf Course81.48 ± 16.1030.27 – 178.4213
Mixed Land Use49.06 ± 5.8928.76 – 103.1413
Commercial247.11 ± 88.31<DL – 1432.0521
All S.C. Tidal Creeks/Estuaries16.65 ± 7.561.00 – 386.0054

Table A3.13 Fluorene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C. where DL = detection limit and n = number of sites.

ERL and ERM for fluorene are 19 and 640 µg/kg, respectively.  Some 62.6 % of the sites monitored have exceedances of the ERL (Fig A3.17). Some 2.3% of the sites exceeded the ERM primarily at commercial pond sites. The %IAE for ERL exceedance ranged from 27.3 – 36.5% and from >36.5 for ERM exceedances. There are no reported TEL or PEL values for Fluorene.

2-Methylnapthalene

2-Methylnapthalene concentrations in sediments from ponds, tidal creeks, and other estuarine locations in S.C. ranged from <DL – 32.8 µg/kg dw. A total of 54 sites had detectable levels which ranged from 5 – 193 µg/kg in tidal creeks and estuaries in S.C. There were no reported values for ponds. The ERL for 2-methylnapthalene is 70 µg/kg. Some 7.4% of the sites monitored had exceedances of the ERL (Fig A3.18). The %IAE for ERL exceedance ranged from 12.5 – 73.3%. There were no reported TEL or PEL values for 2-methylnapthene.

Figure A3.18 2-Methylnapthalene concentrations measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

Napthalene

Napthalene concentrations were identified in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. A total of 133 sites had detectable levels of napthalene which ranged from <DL – 353.50 µg/kg dw in ponds, tidal creeks, and estuaries within S.C. Mean concentrations in tidal creeks ranged from 5.00 – 227.00 µg/kg dw, averaging 31.51 ± 5.73 µg/kg (Table A3.14 and Fig A3.19). Highest concentrations were found in golf course and mixed land use ponds, which were 2.3 to 2.5 times higher than in tidal creek and estuarine habitats in S.C.

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations1.89 ± 1.94<DL – 17.049
Residential44.72 ± 16.27<DL – 225.3321
Golf Course72.62 ± 16.504.76 – 193.2513
Mixed Land Use79.17 ± 24.1313.57 – 241.2713
Commercial11.32 ± 26.63<DL – 353.5021
All S.C. Tidal Creeks/Estuaries31.51 ± 5.735.00 – 227.0057

Table A3.14 Napthalene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C. where DL = detection limit and n = number of sites.

Figure A3.19 Napthalene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

The ERL and ERM for napthalene are 160 and 2100 µg/kg. Some 3% of the sites monitored have exceedances of the ERL (Figure 19). There were no ERM exceedances. The %IAE for ERL exceedances ranged from 11.5 – 54%. There are no reported TEL or PEL values for napthalene.

Phenathrene

Phenathrene concentrations were identified in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. A total of 150 sites had detectable levels of phenathrene which ranged from 0.3 – 32.8 µg/kg dw in ponds, tidal creeks, and estuaries within S.C. Mean phenanthrene concentrations in S.C. estuaries and tidal creeks ranged from 2.00 to 2534.00 µg/kg, averaging 97.07 ± 47.79 µg/kg (Table A3.15). Mean pond concentrations ranged from 282.58 ± 112.96 µg/kg (residential ponds) to 3701.21 ± 1110.95 µg/kg (commercial ponds) (Table A3.15).  Highest concentrations were found in commercial, golf course, and mixed land use ponds, which were 5 to 38 times higher than in tidal creek and estuarine habitats in S.C. 

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations290.82 ± 94.7611.65 – 658.349
Residential282.58 ± 112.9611.99 – 1591.1921
Golf Course528.24 ± 147.2835.59 – 1612.4213
Mixed Land Use513.74 ± 210.3739.76 – 2306.8313
Commercial3701.21 ± 1110.9519.92 – 16345.1421
All S.C. Tidal Creeks/Estuaries97.07 ± 47.792.00 – 2534.0054

Table A3.15 Phenathrene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C. where DL = detection limit and n = number of sites.

The ERL and ERM for phenathrene are 240 and 1,380 µg/kg. Some 29% of the sites monitored have exceedances of the ERL (Fig A3.20). More than 15.3% of sites exceed the ERM. The highest reported value exceeding the ERM with a concentration of 16,345.14 µg/kg is a pond classified as commercial. The %IAE for ERL exceedances ranged from 18.5 – 46.2% and for ERM exceedances were > 46.2%. The TEL and PEL values for Phenanthrene were 41.9 and 515 ug/kg. More than 55% of the sites exceeded the TEL, and 23% exceeded the PEL.

Figure A3.20 Phenathrene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C.

Benzo(a)pyrene

Benzo(a)pyrene concentrations were identified in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. A total of 140 sites had detectable levels of benzo(a)pyrene which ranged from <DL – 7,328.00 µg/kg dw in ponds, tidal creeks, and estuaries within S.C. Benzo(a) pyrene concentrations measured in estuaries and tidal creeks ranged from  5.00 to 7,328.00 and averaged 310.03 ± 128.15 µg/kg. Mean Benzo(a) pyrene concentrations measured in ponds ranged from 104.20 ± 45.51µg/kg (golf course ponds) to 1,888.37 ± 515.23 µg/kg (commercial ponds) (Table 16). Highest concentrations were found in commercial and mixed land use ponds, which were 2 to 6 times higher than in tidal creek and estuarine habitats in S.C. The ERL and ERM for benzo(a)pyrene are 430 and 2500 µg/kg. Some 22.9% of the sites monitored have exceedances of the ERL (Fig A3.21; Table A3.16).

Figure A3.21 Benzo(a)pyrene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations18.66 ± 6.77<DL – 50.709
Residential207.83 ± 98.753.16 – 1323.8721
Golf Course104.20 ± 45.513.31 – 554.9713
Mixed Land Use682.86 ± 312.765.17 – 3013.8113
Commercial1888.37 ± 515.23<DL – 7126.4921
All S.C. Tidal Creeks/Estuaries310.03 ± 128.155.00 – 7328.00063

Table A3.16 Benzo(a)pyrene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C. where DL = detection limit and n = number of sites.

Some 12.1% of the sites exceed the ERM. The % IAE for ERL exceedances ranged from 10.3 – 63%,and for ERM exceedances were >63%. The reported TEL and PEL values for benzo(a)pyrene are 31.9 and 782 ug/Kg dw, respectively. Some 52.1% of the sites exceeded the TEL, while only 17.1% of the sites exceeded the TEL.

Chrysene

Chrysene concentrations were identified in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. A total of 131 sites had detectable levels of chrysene which ranged from <DL – 3,171.00 µg/kg dw in ponds, tidal creeks, and estuaries within S.C. The concentrations in estuarine and tidal creek sites ranged from 1.00 – 3,171.00 µg/kg, averaging 172.57 ± 64.48 µg/kg (Table A3.17).

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations6.55 ± 2.63<DL – 20.919
Residential500.76 ± 177.975.31 – 2253.1821
Golf Course532.30 ± 175.978.51 – 1972.9313
Mixed Land Use728.15 ± 239.2214.15 – 2444.1313
Commercial2335.47 ± 525.65<DL – 7393.6421
All S.C. Tidal Creeks/Estuaries172.57 ± 64.481.00 – 3171.0055

Table A3.17 Chrysene concentrations (µg/kg dw) in sediments from ponds, tidal creeks, and other estuarine locations in S.C. where DL = detection limit and n = number of sites.

Mean retention pond concentrations ranged from 500.76 ± 177.97µg/Kg dw (residential ponds) to 2335.47 ± 525.65 µg/Kg dw (commercial ponds). Highest concentrations were found in commercial, golf course, residential, and mixed land use ponds, which were  2.5 – >13 times higher than in tidal creek and estuarine habitats in S.C.  The ERL and ERM for chrysene are 384 and 2800 µg/kg.   Some 31.3% of the sites monitored have exceedances of the ERL (Fig A3.22).

Figure A3.22 Chrysene concentrations (µg/kg dw) in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

Some 4.6% of sites have exceedances > the ERM.  The %IAE for ERL exceedances ranged from >19.4-45% and were > 45% for ERM exceedances. The reported TEL and PEL values for chrysene are 57.1 and 862 ug/Kg dw , respectively. Some 46.5% of the sites exceeded the TEL and 19.8% of the sites exceeded the PEL.

Di-benzo(a,h)anthracene

Dibenzo(a,h)anthracene concentrations were identified in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. A total of 136 sites had detectable levels of dibenzo(a,h)anthracene which ranged from <DL – 954.28 µg/kg dw in ponds, tidal creeks, and estuaries within S.C. Concentrations in estuarine and tidal creek sites ranged from 1.00 to 818.00 µg/kg, averaging 28.85 ± 14.87 µg/kg. Mean pond concentration ranged from 9.30 ± 4.09 µg/kg (golf courses) to 209.94 ± 60.29 µg/kg (commercial ponds) (Table A3.18).

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations1.78 ± 1.23<DL – 9.549
Residential17.00 ± 7.12<DL – 94.7721
Golf Course9.30 ± 4.09<DL – 51.2913
Mixed Land Use75.99 ± 39.79<DL – 421.3313
Commercial209.94 ± 60.29<DL – 954.2821
All S.C. Tidal Creeks/Estuaries28.85 ± 14.871.00 – 818.0059

Table A3.18 Dibenzo(a,h)anthracene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C. where DL = detection limit and n = number of sites.

Highest concentrations were found in commercial and mixed land use ponds, which were 2 to 7 times higher than in tidal creek and estuarine habitats in S.C. The ERL for dibenzo(a,h)anthracene is 261 µg/kg. Some 5.90% of the sites monitored had exceedances of the ERL (Fig A3.23).

Figure A3.23 Dibenzo(a,h)anthracene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

There were no ERM exceedances. The %IAE for ERL exceedances ranged from 11.5 – 54.5%. There are no reported TEL and PEL values for di-benz(a,h)anthracene.

Fluoranthene

Fluoranthene concentrations were identified in sediments from ponds, tidal creeks, and other estuarine locations in S.C. A total of 136 sites had detectable levels of fluoranthene which ranged from 2.66 – 37,611.95 µg/kg dw in ponds, tidal creeks, and estuaries within S.C. Concentrations in estuarine and tidal creeks sites ranged from 3.00 – 36,123.00 µg/kg dw, averaging 1,009.44 ± 623.31 µg/kg. Mean pond concentrations ranged from 445.42 ± 193.57 µg/kg (golf course) to 9,652.94 ± 2,687.53 µg/kg (commercial)  (Table A3.19).

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations53.02 ± 17.322.66 – 118.369
Residential1,056.77 ± 492.3011.16 – 6,600.5221
Golf Course445.42 ± 193.5717.19 – 2,329.4613
Mixed Land Use2,214.30 ± 997.385.42 – 9,359.2213
Commercial9,652.94 ± 2,687.539.79 –37,611.9521
All S.C. Tidal Creeks/Estuaries1,009.44 ± 623.313.00 – 36,123.0059

Table A3.19 Fluoranthene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. where n = number of sites.

Highest concentrations were found in commercial and mixed land use ponds, which were 2 to 9 times higher than in tidal creek and estuarine habitats. The ERL and ERM for fluroanthene were 600 and 5,100 µg/kg. Some 19.9% of the sites monitored have exceedances of the ERL (Fig A3.24); 14% of the sites exceed the ERM. The %IAE for ERL exceedances ranged from 20.6 to 63.6% and was > 63% for ERM exceedances. The reported TEL and PEL for fluoranthene were 111 and 2,355 ug/kg, respectively. The exceedances of the TEL was 47.1% while the exceedances of the PEL were 2.9%.

Figure A3.24 Fluoranthene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

Pyrene

Pyrene concentrations were identified in sediments from ponds, tidal creeks, and other estuarine locations in S.C. A total of 140 sites had detectable levels of pyrene which ranged from below DL – 29,361.88 µg/kg dw in ponds, tidal creeks, and estuaries within S.C. The concentrations in tidal creeks ranged from 2.00 – 27,910.00 µg/kg. The mean pond concentration ranged from 385.71 ± 175.32 µg/kg (golf course ponds) to 7,361.82 ± 2,084.15 µg/kg (commercial ponds) (Table A3.20).

Pond TypeMean ± Standard ErrorRangen
Pristine Reference Locations192.67 ± 66.38<DL – 448.369
Residential797.46 ± 386.65<DL – 5,140.3221
Golf Course385.71 ± 175.32<DL – 2,110.6813
Mixed Land Use1,871.55 ± 869.462.33 – 8,310.9513
Commercial7,361.82 ± 2,084.15<DL – 29,361.8821
All S.C. Tidal Creeks/Estuaries792.48 ± 451.492.00 – 27,910.0063

Table A3.20 Pyrene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other coastal estuarine locations in S.C. where DL = detection limit and n = number of sites.

Highest concentrations were found in commercial and mixed land use ponds, which were 2.7 to 9.2 times higher than in tidal creek and estuarine habitats in S.C. The ERL and ERM for pyrene were 665 and 2,200 µg/kg. Some 22.1% of the sites monitored had exceedances of the ERL, and some 16.4 % of the sites > ERM (Fig A3.25).

Figure A3.25 Pyrene concentrations (µg/kg dw) measured in sediments from ponds, tidal creeks, and other estuarine locations in S.C.

The %IAE for ERL exceedances ranged from 17.2 – 53.1% and were >53.1% for ERM exceedances. The TEL and PEL values for pyrene are 53 and 875 ug/kg, respectively. More than 59.3% of the sites exceeded the TEL and 20.7% of the sites exceed the PEL.