Environmental Assessment of Sediments and Water in ... - CiteSeerX

Environmental Assessment of Sediments and Water in Bayou Grande, Pensacola, FL.

Dr. Carl J. Mohrherr Center for Environmental Diagnostics and Bioremediation University of West Florida Dr. Johan Liebens Department of Environmental Studies University of West Florida Dr. K. Ranga Rao Center for Environmental Diagnostics and Bioremediation University of West Florida

June 26, 2008

FOREWORD This study is a component of the "Assessment of Environmental Pollution and Community Health in Northwest Florida" supported by a USEPA Cooperative Agreement award X-9745502 to The University of West Florida (Project Director: Dr. K. Ranga Rao). The contents of this report are solely the responsibility of the authors and do not necessarily represent the official views of the USEPA. The study was undertaken because of the increasing concern for environmental pollution and potential impacts on human health in Northwest Florida. It was designed to assess environmental impacts of toxic pollutants in Bayou Grande. Kristal Flanders managed the spatial databases for the project and drafted the maps. Her assistance has been invaluable. Chris Carlton-Franco, Brandon Jarvis, Guy Allard, and Danielle Peterson helped with the fieldwork and some laboratory procedures.

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TABLE OF CONTENTS

I INTRODUCTION........................................................................................................... 1 II STUDY AREA .............................................................................................................. 2 II.1 Physiography.......................................................................................................................... 2 II.2 Climate.................................................................................................................................... 3 II.3 Urban Development............................................................................................................... 4 II.4 Pensacola Bay and Dredging Activity.................................................................................. 5 II.5 Historical Outline of Bayou Grande .................................................................................... 6 III POLLUTION IN BAYOU GRANDE: LITERATURE REVIEW..................................... 8 III.1 General Pollution History.................................................................................................... 8 III.2 Fecal Coliform Pollution in Bayou Grande ..................................................................... 13 III.3 Total Petroleum Hydrocarbons ........................................................................................ 14 III.4 Polycyclic Aromatic Hydrocarbons (PAHs) .................................................................... 15 III.5 Organochlorinated Compounds........................................................................................ 20 III.6 Trace Metals ....................................................................................................................... 21 IV ENVIRONMENTAL BACKGROUND OF SEDIMENT POLLUTANTS ..................... 26 IV.1 Polychlorinated Biphenyls (PCBs).................................................................................... 26 IV.2 Organochlorinated Compounds........................................................................................ 28 IV.2.1 General Notions ........................................................................................................... 28 IV.2.2 Organochlorinated Pesticides in Sediments and Biota.............................................28 IV.2.2.1 Aldrin and Dieldrin................................................................................................. 28 IV.2.2.2 Endrin ..................................................................................................................... 29 IV.2.2.3 Lindane ................................................................................................................... 30 IV.2.2.4 Chlordane................................................................................................................ 31 IV.2.2.5 DDT ........................................................................................................................ 32 IV.2.2.6 Mirex and Chlordecone .......................................................................................... 33 IV.2.2.7 Endosulfan .............................................................................................................. 36 IV.2.3 Dioxins/Furans............................................................................................................. 37 IV.2.4 Pentachlorophenol (PCP) ........................................................................................... 39 ii

IV.3 Metals................................................................................................................................... 40 IV.3.1 Mercury (Hg) ............................................................................................................... 40 IV.3.2 Lead (Pb) ...................................................................................................................... 42 IV.3.3 Cadmium (Cd) ............................................................................................................. 44 IV.3.4 Arsenic (As).................................................................................................................. 46 IV.3.5 Chromium (Cr)............................................................................................................ 47 IV.3.6 Copper (Cu) ................................................................................................................. 49 IV.3.7 Nickel (Ni)..................................................................................................................... 50 IV.3.8 Zinc (Zn)....................................................................................................................... 51 V OBJECTIVES ............................................................................................................ 53 VI METHODS................................................................................................................ 54 VII RESULTS AND DISCUSSION ................................................................................ 60 VII.1 Semivolatile Organic Compounds ................................................................................... 60 VII.1.1 Total Petroleum Hydrocarbons ................................................................................ 60 VII.1.2 Polycyclic Aromatic Hydrocarbons (PAHs)............................................................ 63 VII.1.2.1 PAHs in surface sediments.................................................................................... 63 VII.1.2.2 PAHs in the water column..................................................................................... 74 VII.1.2.3 PAHs in vibracores................................................................................................ 74 VII.1.2.4 Origins of PAHs in Bayou Grande........................................................................ 80 VII.1.2.5 Pentachlorophenol (PCP) ...................................................................................... 87 VII.2 Dioxins/furans and PCBs ................................................................................................. 88 VII.2.1 Dioxin/furan and PCB TEQ...................................................................................... 88 VII.2.2 Dioxin/furan and PCB TEQ in Bayou Grande Sediments..................................... 88 VII.2.3 Total Dioxin/Furan Mass Concentrations in Surface Sediments .......................... 92 VII.2.4 Total Dioxin/Furan Mass Concentrations in Vibracores ....................................... 93 VII.2.5 Origin of Dioxins/Furans in Bayou Grande ............................................................ 94 VII.2.6 Total PCB Concentrations in Surface Sediments ................................................... 98 VII.2.7 Total PCB Concentrations in Vibracores .............................................................. 101 VII.2.8 Origin of PCBs in Bayou Grande ........................................................................... 101 VII.2.9 Dioxin-like PCB Concentrations in Surface Sediments ....................................... 109 VII.2.10 Degradation of PAHs, PCBs, and Dioxins/ Furans in Sediments...................... 113 VII.2.11 Dioxins/Furans in Bayou Grande Sediments and Seafood Tissues ................... 120 VII.2.12 PCBs in Bayou Grande Sediments and Seafood Tissues.................................... 123 VII.3 Pesticides.......................................................................................................................... 126 VII.4 Trace Metals .................................................................................................................... 129 VII.4.1 Trace Metal Concentrations in Surface Sediments .............................................. 129 VII.4.2 Origin of Trace Metals in Surface Sediments ....................................................... 140 VII.4.3 Trace Metal Concentrations in Vibracores ........................................................... 144 VII.4.4 Trace Metal Concentrations in Water ................................................................... 147

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VIII CONCLUSIONS ................................................................................................... 150 IX REFERENCES ....................................................................................................... 153

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LIST OF FIGURES Figure 1. Location of Bayou Grande. ............................................................................................. 3 Figure 2. Bayou Grande and nearby drainage basins ..................................................................... 4 Figure 3. Dredged shipping channels in Pensacola Bay. ................................................................ 5 Figure 4. Map of Pensacola Bay, 1860s (Exploring Florida, 2008a). ............................................ 7 Figure 5. Sketch of Pensacola Navy Yard and part of Fort Pickens, 1860s (Exploring Florida, 2008b). ............................................................................................................................................ 8 Figure 6. Location of Assessment Zones at NAS. ........................................................................ 11 Figure 7. Geomeans of Enterococcus at zero rainfall for Bayou Grande..................................... 14 Figure 8. Location of sampling sites from DeBusk et al. (2002) GIS database. .......................... 18 Figure 9. General PCB structure................................................................................................... 26 Figure 10. Structure of Aldrin....................................................................................................... 29 Figure 11. Structure of Dieldrin.................................................................................................... 29 Figure 12. Structure of Endrin. ..................................................................................................... 30 Figure 13. Structure of Lindane (gamma-hexachlorocyclohexane). ............................................ 31 Figure 14. Structure of Chlordane. ............................................................................................... 31 Figure 15. Structure of DDT (di-chlorodiphenyltrichloroethane). ............................................... 32 Figure 16a. Structure of Mirex...................................................................................................... 34 Figure 16b. Structure of Chlordecone........................................................................................... 34 Figure 17. Structure of Endosulfan............................................................................................... 36 Figure 18. Chemical Structure of 2,3,7,8-dioxin (TCDD) and representative dioxin-like compounds. ................................................................................................................................... 38 Figure 19. Cycling of mercury between the atmosphere, water, sediments, and organisms (Stein et al., 1996). .................................................................................................................................. 42 Figure 20. Location of water grab samples................................................................................... 56 Figure 21. Location of vibracore sites in Bayou Grande. ............................................................. 56 Figure 22. Total petroleum hydrocarbons in sediments................................................................ 62 Figure 23. Total PAH concentration in sediments........................................................................ 71 Figure 24. Sum of 13 LMW and HMW PAHs in sediments. ....................................................... 71 Figure 25. Total naphthalenes in surface sediments. .................................................................... 81 Figure 26. Combined TEQ of dioxins/furans and PCBs............................................................... 90 Figure 27. Spatial distribution of TEQ for dioxins/furans............................................................ 91 Figure 28. Spatial distribution of TEQ for dioxin-like PCBs. ...................................................... 91 Figure 29. Total dioxin/furan mass concentrations in surface sediments..................................... 93 Figure 30. Factor loading plot for first two principal components for dioxins/furans - all profiles. ....................................................................................................................................................... 96 Figure 31. Factor loading plot for first two principal components for dioxins/furans - selected profiles. ......................................................................................................................................... 97 Figure 32. Average dioxin/furan homologue profile for GV samples.......................................... 98 Figure 33. Total PCB concentrations in surface sediments. ....................................................... 100 Figure 34. Factor loading plot for first two principal components for PCBs ............................. 104 Figure 35. Cluster analysis of PCB congener data for surface sediments. ................................. 105 Figure 36a. PCB homologue profiles for GF series samples and Aroclors. ............................... 106 Figure 36b. PCB homologue profiles for surface sediments from GV series and Aroclors....... 107

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Figure 36c. PCB homologue profiles for subsurface sediments from GV series and Aroclors. 108 Figure 37. PCB homologues in vibracore GV-1......................................................................... 115 Figure 38. PCB homologues in vibracore GV-4......................................................................... 116 Figure 39. PCB homologues in vibracore GV-11....................................................................... 116 Figure 40. Ortho, meta, and para positions on aromatic molecules............................................ 117 Figure 41. Dechlorination of dioxin/furan congeners................................................................. 120 Figure 42. Dioxins/furans in Bayou Grande seafood tissues...................................................... 121 Figure 43. Dioxins/furans in Bayou Grande crab hepatopancreas and sediment. ...................... 122 Figure 44. Dioxins/furans in Bayou Grande oysters and sediment. ........................................... 123 Figure 45. Dioxin-like PCBs in seafood tissues and sediment. .................................................. 124 Figure 46. Dioxin-like PCBs in crab hepatopancreas tissue and sediment................................. 125 Figure 47. Dioxin-like PCBs in Bayou Grande oyster tissue and sediment. .............................. 125 Figure 48. Arsenic in Bayou Grande sediments. ........................................................................ 130 Figure 49. Cadmium in Bayou Grande sediments. ..................................................................... 131 Figure 50. Chromium in Bayou Grande sediments. ................................................................... 135 Figure 51. Copper in Bayou Grande sediments. ......................................................................... 136 Figure 52. Lead in Bayou Grande sediments.............................................................................. 137 Figure 53. Mercury in Bayou Grande sediments. ....................................................................... 138 Figure 54. Nickel in Bayou Grande sediments. .......................................................................... 139 Figure 55. Zinc in Bayou Grande sediments. ............................................................................. 140 Figure 56. Factor loading plot for first three components for trace metals in surface sediments. ..................................................................................................................................................... 141 Figure 57. Spatial distribution of average standardized pollution index (ASPI) for trace metals in surface sediments .........................................................................................................................144

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LIST OF TABLES Table 1. Sources of data in environmental GIS database for Pensacola Bay System (DeBusk et al., 2002). ...................................................................................................................................... 12 Table 2. Chemical and physical requirements for JP-4, JP-5, and JP-8. ...................................... 15 Table 3. PAH SQAGs1 (μg/kg) and IARC listing ........................................................................ 16 Table 4. Existing ‘non-NAS’ Bayou Grande PAH data [ug/kg] (DeBusk et al., 2002) ............... 17 Table 5. PAHs in Bayou Grande sediments by zone of the NAS Pensacola shore (EnSafe, 2003; 2004) ............................................................................................................................................. 19 Table 6. Existing pesticide data for Bayou Grande [ug/kg] (DeBusk et al., 2002). ..................... 20 Table 7. Pesticides and PCB Aroclors in Bayou Grande sediments by zone of the NAS Pensacola shore (EnSafe, 2003; 2004)........................................................................................................... 22 Table 8. Existing total PCB data for Bayou Grande [ug/kg] (DeBusk et al., 2002)..................... 23 Table 9. Water quality standards [ug/l] for Class III marine water bodies1. ................................ 23 Table 10. Existing data for metals in sediments [mg/kg] in Bayou Grande (DeBusk et al., 2002). ....................................................................................................................................................... 24 Table 11. Metals in Bayou Grande sediments by zone of the NAS Pensacola shore................... 25 Table 12. Major PCB congener constituents of five Aroclors [%]............................................... 27 Table 13. TEF values for dioxins/furans and dioxin-like PCBs ................................................... 59 Table 14. Total petroleum hydrocarbons [mg/kg] in surface sediments. ..................................... 61 Table 15. Total petroleum hydrocarbon [mg/l] in water............................................................... 62 Table 16. Typical PAH minimal detection limit (MDL) and reporting limit (RL) and SQAGs (from sample GBc-30). ................................................................................................................. 64 Table 17. PAH concentrations [ug/kg] in sediments, GBc series................................................. 67 Table 18. PAH concentrations [ug/kg] in sediments, GF series. .................................................. 72 Table 19. PAHs and pentachlorophenol in water samples [ug/l].................................................. 75 Table 20. Total PAHs in vibracores by depth level [ug/kg]. ........................................................ 76 Table 21. Specific PAHs in Bayou Grande vibracores [ug/kg]. ................................................... 77 Table 22. Naphthalene concentrations [ug/kg] in sediments, GF series....................................... 82 Table 23. Naphthalene concentrations [ug/kg] in sediments, GBc series..................................... 83 Table 24. PAH origin indicator ratios, Yunker et al. (2002). ....................................................... 83 Table 25. PAH ratios in sediments, GF series. ............................................................................. 85 Table 26. PAH ratios in sediments, GBc series. ........................................................................... 86 Table 27. TEQ for dioxins/furans, dioxin-like PCBs, and combined total TEQ [ng/kg]. ............ 89 Table 28. Dioxin/furan mass and TEQ concentrations [ng/kg] in surface sediments. ................. 92 Table 29. Dioxin/furan mass and TEQ concentrations [ng/kg} in sediment from vibracores...... 94 Table 30. Average dioxin/furan congener composition for Bayou Grande surface sediments. ... 95 Table 31. Total PCB concentrations [ug/kg] in surface sediments............................................... 99 Table 32. Total PCB concentrations [ug/kg] for vibracores. ...................................................... 102 Table 33. Average PCB congener profile for surface sediment in Bayou Grande. .................... 103 Table 34. Dioxin-like PCB TEQ [ng/kg] and total PCB mass concentration [ug/ kg] in surface sediments..................................................................................................................................... 109 Table 35. Dioxin-like PCB congener mass concentration [ng/kg] for surface sediments. ......... 111 Table 36. Dioxin-like PCB congener TEQs [ng/kg] for surface sediments ............................... 112 Table 37. Average dioxin-like PCB mass concentration and TEQ. ........................................... 113

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Table 38. Dioxin-like PCB congener distributions [%] for seven Aroclor mixtures (modified from Frame et al., 1996). ............................................................................................................ 113 Table 39. Selected vibracore PCB, PCB TEQ, and PAH concentrations................................... 114 Table 40. TEQ-to-mass ratio for dioxins/furans in vibracore samples ....................................... 118 Table 41. TEFs for dioxin/furan congeners. ............................................................................... 119 Table 42. Dioxins/Furans in seafood tissues [ng/kg wet wt] and sediments [ng/kg dry weight]. ..................................................................................................................................................... 121 Table 43. Dioxin-Like PCBs in crab and oyster tissues [ng/kg wet wt] and sediment [ng/kg dry weight]. ....................................................................................................................................... 123 Table 44. Organochlorinated pesticide concentrations in surface sediments [ug/kg]. ............... 127 Table 45. Organochlorinated pesticide concentrations in water samples [ug/l]. ........................ 129 Table 46. Trace metals in surface sediments [mg/kg]. ............................................................... 132 Table 47. Average standardized pollution index for anthropogenic trace metals....................... 142 Table 48. Trace metals in vibracores [mg/kg]. ........................................................................... 145 Table 49. Aqueous metal concentrations in Bayou Grande [ug/l].............................................. 148 Table 50. Water parameters for Bayou Grande, February 2007................................................. 149 Table 51. Water parameters determined in laboratory................................................................ 149

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EXECUTIVE SUMMARY The PERCH (Partnership for Environmental Research and Community Health) Project component on Bayou Grande was designed to address community concerns relating to environmental health issues for this locally important water body. Bayou Grande is the largest of the three urban bayous in the Pensacola metropolitan area. Pollutants affecting the water and sediment quality of the southern half of the Bayou have been studied in reference to possible releases from the Naval Air Station (NAS) on its southern shore, but not in reference to the entire bayou system. High levels of substances of concern (SOCs) including trace metals, polycyclic aromatic hydrocarbons (PAHs), dioxins/furans and polychlorinated biphenyls (PCBs) have been found in the sediments. The State of Florida classifies Bayou Grande as a 3M body of water that is suitable for recreational uses and for the propagation of fish and wildlife. Human activities have likely affected the bayous in the area, including Bayou Grande, from the time European settlers entered the area. Initial impacts would have been caused by land clearing for agricultural and logging activities. US Naval operations in the Bayou Grande area began in the early 19th century. State of Florida scientists came to Pensacola in the 1950s to study pollution in the local bayous but focused less on Bayou Grande than on Bayous Chico and Texar. In the second half of the 20th century, however, evidence for pollution was observed in Bayou Grande due to increasing activities at NAS and increasing urbanization on the north shore of the Bayou in the Warrington area, as well as import from Pensacola Bay with which Bayou Grande connects. Among other pollutants were elevated fecal coliforms, as observed by other monitoring studies. The present study examined preexisting environmental databases and publications, some of which were incorporated into a geographic information system (GIS). The existing information was utilized in prioritizing research efforts based on perceived gaps in the information. The main gap is a scarcity of systematic information about the environmental quality of the northern half of the Bayou. Parts of the Bayou along NAS have been studied to some extent, but information about sediment quality in northern sections of the Bayou and the Bayou's northern embayment is especially scarce. The presence of aviation and maritime activities at NAS suggests that petroleum contamination may be present in the Bayou, but this has not been fully addressed by previous studies. PERCH project found high levels of dioxins/furans in nearby Bayou Chico, but dioxin/furan analysis do not appear to have been carried out in Bayou Grande, in spite of their potential health impacts. The finding of elevated dioxin/furan and PCB levels in seafood from Bayou Grande warrants a more detailed analysis of these pollutants in the Bayou’s water and sediments. In addressing these knowledge gaps, the present study is the first to systematically study a large suite of sediment pollutants for the whole Bayou and to interpret results in relation to potential human health effects. The fieldwork for the project took place from Fall 2006 to mid-summer 2007. The collected samples include: 78 sediment grab samples, collected with a ponar grab sampler; 8 water grabs, collected with a Van Dorn sampler; and 10 vibracores obtained with an in-house built vibracore system operated from a pontoon boat. The sediment grab samples consisted of two series, one series of 55 samples along the shoreline and the other of 23 samples in the channel of the Bayou

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and its main embayments, including one sample in Pensacola Bay just outside Bayou Grande that served as a reference station. Chemical analyses were performed by a contracted commercial lab according to USEPA and Florida Department of Environmental Protection standards. Physical analyses of the sediments were conducted at UWF. For total petroleum hydrocarbons (TPH) there were four detections in 23 sediment samples and three detections in eight water samples. All detected concentrations were very low and were below the reporting limit for the method. This indicates that although the potential for TPH contamination exists in Bayou Grande, the TPH levels remain low in the Bayou. Previous PERCH studies at nearby bayous (Bayous Chico and Texar) found more detections and higher concentrations of TPH. PAHs are among the most toxic components of petroleum products, and are also associated with carcinogenic effects. All 18 PAHs detected by the USEPA 8270C method were found in Bayou Grande. The highest total PAH concentrations were observed in sediments in the Yacht Basin and other embayments of the eastern portion of the main body of the Bayou. Florida sediment quality guidelines (TEL - concentrations above which adverse effects on biota are possible, and PEL - concentrations above which adverse effects on biota are probable) were exceeded in these embayments by several of the PAH species. Concentrations of most PAH species decreased abruptly with depth in the vibracores. In water, PAH concentrations were generally low. The naphthalene content of the PAHs in the sediments suggests that the PAHs may be of petroleum origin but they also exhibit characteristics consistent with other origins such as combustion and coal tar. Naphthalenes have been detected in NAS groundwater indicating that transport by contaminated groundwater to the bayou is possible. The toxicity of dioxins/furans and dioxin-like PCBs is expressed as Toxic Equivalents (TEQ). To determine the combined TEQ, all toxic dioxins/furans and dioxin-like PCBs have been assigned a Toxic Equivalency Factor (TEF) as defined by Van den Berg et al. (2006). In Bayou Grande, 17 of the 23 samples had a combined TEQ that exceeded the NOAA sediment quality guideline (AET). Seven of these samples had a TEQ almost three times the NOAA AET. The highest concentrations were found in two embayments along the southern shoreline and in an embayment of the northern shore, but exceedances occurred throughout the Bayou. Principal Component Analysis of the congener profiles of the dioxins/furans indicates multiple origins. Samples from the deeper parts of the Bayou and its embayments have a profile that is consistent with a PCP origin. PCP was not detected in the sediments and we know of no historical wood treating activities near Bayou Grande that used PCP but it is possible that treated wood with PCP has been employed along the Bayou Grande shoreline, or that PCP was used in antifouling paints for boats. Other samples have dioxin/furan congener profiles that indicate an origin from forest fires and burning of oil in industrial boilers. Samples from deeper sediment levels have a clearly different congener profile that is consistent with an origin from effluent of wastewater treatment facilities. However, we have no indication from existing literature that such effluent was released to the Bayou even though industrial wastewater was. An alternative explanation is that dechlorination of the dioxins/furans in the deeper sediments by chance created a profile similar to that of wastewater. Concentrations of dioxins/furans in the deeper sediments are only slightly below those in surface sediments.

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Homologue patterns of the PCBs in many of the surface sediment samples are similar to those of Aroclor 1260. Samples from the northern shoreline and northern embayments have homologue patterns consistent with a mixture of Aroclor 1260 and Aroclor 1254. Aroclor 1260 has been used at NAS, and 1254 is one of the most widespread Aroclors. These observations, together with the spatial distribution of the PCBs, suggest that much of Bayou Grande may be influenced by PCBs originating from NAS and that along the northern shore, near residential areas such as Warrington, PCBs from other sources have been mixed in. Dioxins/furans and PCBs in sediments can enter into the food chain and upon entering seafood are consumed by humans with probable impacts upon human health. In Bayou Grande, profiles of dioxin-like PCB congeners for crab hepatopancreas, crab muscle, and oysters are very similar to profiles for sediments. This indicates that dioxin-like PCBs are bioaccumulating in seafood in Bayou Grande and that the accumulation is proportional to the relative congener composition of the PCBs in the sediments. Comparison between profiles of dioxin/furan congeners shows similarities between profiles for sediments and oysters but not for sediments and crabs. This suggests that crabs are either selective in the specific congeners that are incorporated into their tissues or that dechlorination is occurring once the congeners are incorporated into the crab. It appears that incorporation of dioxins/furans in oysters, but not in crabs, is related to the relative proportions of the dioxin/furan congeners in the sediments. Similar observations were reported in a previous PERCH study of nearby Bayou Chico. Only five detections of organochlorinated pesticides occurred in the 23 sediment grab samples from Bayou Grande. These five detections occurred in only two samples in the mid section of the Bayou. One of the detections was for DDT and exceeded the TEL. There were more detections of organochlorinated pesticides in the 1990s. Most of these pesticides have not been applied for many years and our results suggest that the concentrations are declining in sediments of Bayou Grande. Sediment transport into and out of the Bayou can in principle reduce the concentrations of the pesticides as can abiotic degradation and biodegradation. There were no detections in the water column for any pesticides, which suggests that currently there is no transport of organochlorinated pesticides into Bayou Grande from surface sources. We tested for 10 trace metals in surface sediments from 78 sites. Selenium was detected in six samples, Cd in 32 samples, As in 53, Hg in 49, Sn in 54, Ni in 71, and Cr, Cu, Pb, and Zn were detected in all 78 samples. The respective TELs were exceeded by As, Cr, Cu, Hg and Ni; the PEL was exceeded by Cd, Pb, and Zn. Selenium and Sn do not have sediment quality guidelines. Because the metals exceed their TEL or PEL they can be assumed to have negative impacts on biota in the Bayou, but their concentrations were generally lower than in Bayous Chico and Texar, two other Pensacola bayous previously studied by PERCH. Concentrations for Hg, and to some extent Ni, are highest in the channel of the main body of the Bayou but most other metals are highest in the upper reaches of the Yacht Basin and Woolsey Bayou near NAS, and in Navy Point Bayou in Warrington. Results for the vibracore samples are consistent with those for the surface samples and show higher levels of trace metals in embayments, especially on the south side of the Bayou. At depth the concentrations are generally lower for the metals that are of anthropogenic origin, but occasionally the TEL is exceeded even at depth.

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Principal Component Analysis of the trace metal concentrations indicates that Ni and As are related to the composition of the sediment, and thus are not solely of anthropogenic origin. Another PERCH task, examining trace metal pollution of surface soils, has also found a close relationship with parent material composition for Ni content, but not for arsenic content. Arsenic, however, has a relatively high background concentration in the region and its association with sediment composition is not unexpected. Copper, Pb, Cr, and Zn appear to be of anthropogenic origin. An index that combines the standardized concentrations of these latter metals indicates that activities related to NAS are the main source of anthropogenic trace metals in Bayou Grande and that relatively unpolluted sediments are present in the Bayou near Pensacola Bay in the east and near Jones Swamp in the west. The present study was the first to assess the environmental quality of the sediments for the entire Bayou Grande systematically and with consistent methods. Many of the pollutants examined exceed regulatory guidelines, including PAHs, dioxins/furans, PCBs and trace metals. Even though these pollutants may be unlikely to directly affect humans, because of limited direct contact of people with the sediments of Bayou Grande, they do have the potential to indirectly affect humans. A case in point are the elevated levels of dioxin/furan and PCB TEQ found in some seafood by another PERCH project, and which seem to be related to sediment contamination identified in the present study. Negative effects on the living environment may be also manifested in reduced populations of some biota. Bayou Grande is the third urban bayou to be studied by PERCH in Pensacola. The three bayous in common are impacted to varying degrees by either former or current facilities undergoing federally mandated cleanup under the body of law commonly know as superfund. They are also impacted by other industries, commercial activities, and residential activities. The close proximity of NAS Pensacola to Bayou Grande has resulted in impacts to Bayou sediments. These impacts are most severe in parts of embayments that are located closest to runoff areas from the more developed regions of the NAS. In the Woolsey Bayou embayment, impact (above TEL) was observed to depths of 3 meters for PCBs. What is new in the present assessment of Bayou Grande is that there is evidence showing that the Warrington area is also impacting the Bayou. The precise nature of the impacts from both sources is not identical. For example, PAH analyses for samples taken near NAS are characterized by higher concentrations of naphthalenes than those adjacent to Warrington. Relative to the future there is some evidence that suggests that natural degradation is occurring for dioxins/furans and the more highly chlorinated PCB congeners in the deeper sediments. However, other explanations are also possible for the observed temporal changes. In any case, as sediment depth increases, total chlorination declines for dioxins/furans and PCBs. The more chlorinated persistent organic pollutants (POPs) at the surface are not as subject to anaerobic degradation and would be expected to be available to biota. Many sediment bound trace metals such as lead will likely remain bound in the sediment since degradation does not occur. It is possible that POPs and metals will be covered by sediments in the future that will hopefully be less contaminated. The most acute public health issues are related to bacteria contamination originating from fecal sources that poses health risks to recreational users of the bayou’s waters, as described in a previous study. This bacterial contamination can be remediated through the installation of appropriate sewage systems.

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I INTRODUCTION Bayou Grande, the third urban bayou to be studied by the PERCH Project, is the largest urban bayou in the Pensacola metropolitan area. Through much of its modern history, Bayou Grande has been impacted by avionic support activities and naval vessels at NAS Pensacola. These impacts have elicited environmental and human health concerns. NAS Pensacola has conducted detailed studies of its facility and immediate adjacent waters, including much of Bayou Grande’s southern shoreline. There has only been limited studies of the bayou’s basin or northern shore. The middle and eastern portions of the northern shore are urbanized with residences and commercial activities. The presence of coliform bacteria in Bayou Grande likely derives from these non-military activities. The Escambia County Department of Health has issued frequent health advisories relating to coliform bacteria contamination after rains at Navy Point in Bayou Grande. While it can be assumed that any urbanized waterway will be impacted by anthropogenic activities, there has been no systematic effort to conduct a study of the entire Bayou to verify the presence, magnitude, and origin of substances of concern (SOCs). The EPA and others estimate that approximately 10 percent of the sediments underlying our nation’s surface waters are sufficiently contaminated with toxic pollutants to pose potential risks to fish and to the humans and wildlife that consume fish and shellfish (USEPA, 1998). Contaminated sediments can affect fish and wildlife by contributing to the bioaccumulation of contaminants in the food chain. The contaminated sediments pose a threat to human health when the pollutants in the sediments bioaccumulate in aquatic organisms routinely consumed by humans. There are numerous examples of cases where fish consumption advisories or bans have been issued for Persistent Organic Pollutants (POPs) such as polychlorinated biphenyls (PCBs), mercury, and dioxins/furans because of the transfer of the pollutants into the food chain (USEPA, 1998). A related PERCH study is presently investigating the bioaccumulation of POPs and other SOCs in seafood tissues (PERCH Task A: Bioaccumulation of chemical contaminants in seafood in the Pensacola Bay region). The objectives of the current investigation are to provide sediment data on POPs such as dioxins/furans and dioxin-like PCBs in support of PERCH Task A, and to conduct analysis of other selected pollutants in Bayou Grande.

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II STUDY AREA

II.1 Physiography Bayou Grande is located in the Warrington area of Pensacola in the southwestern portion of Escambia County in the Florida Panhandle (Figure 1). It is an estuarine water body that has a total surface area of approximately 1.5 square miles (950 acres), a watershed of 10,941 acres (Hatch Mott MacDonald, 2004), and approximately 20 miles of total coastline (EnSafe, 2004). It is the largest of the three urban bayous in Pensacola and is part of the Pensacola Bay System. It still contains substantial undeveloped shoreline on its most western reaches and extends inland for approximately 5 miles into the southwestern portion of Escambia County. Its northern shoreline is bounded by civilian residences and much (approximately 8.5 miles) of the southern shore borders Naval Air Station, Pensacola (NAS) (EnSafe, 2004). The NAS property is 5,800 acres and is located approximately 5 miles southwest of the city of Pensacola. It is surrounded by water on three sides, Bayou Grande to the north, Pensacola Bay to the east, and Big Lagoon and Pensacola Bay to the south (Figure 1) (NAS Pensacola, 2001; Tetra Tech, 2003). There are extensive wetlands in the southwestern portion of Escambia County with some of these occurring within the watershed of Bayou Grande. These wetlands occur in an area roughly between the NAS and Perdido Bay (Figure 2). While close to Bayou Grande, the Jones Swamp drainage is separate and is part of the Warrington drainage that goes to Bayou Chico to the east. In fact, the drainage of the Bayou Grande area is quite complex, in part because of its young age and minimal relative relief, with some areas of the cited wetlands appearing to drain to both Perdido Bay and Big Lagoon. There is a perception that the area should be largely preserved because of its wetlands and the endangered species which live in it. This area has been of interest to real estate development since it is one of the last places in Escambia County, FL, where waterfront lots and/or large home sites are still available close to the City of Pensacola and Pensacola Naval Air Station. A major controversy over protection of some 7,000 acres to preserve the listed White Tipped Pitcher Plant has occupied a great deal of news media coverage, while land prices have risen as developments occupy more and more of the area. (Droubay et al., 1999). Protection of these areas from human encroachment has also been driven by the need to place protective buffers around NAS and its satellite installations (Droubay et al., 1999). Bayou Grande’s surrounding watershed is a most likely source for pollutants although some materials may be depositing from the atmosphere either directly into the Bayou or into its watershed. Bayou Grande at 950 acres is the largest Bayou in Pensacola but its watershed of 10,941 acres is small proportionately to the bayou’s total surface. Bayou Texar in east Pensacola, for example, has a surface area of 388 acres (Mohrherr et al., 2005) and yet has a drainage basin almost the size of Bayou Grande’s (10,479 acres). Bayou Chico at 216 acres (Mohrherr et al., 2006) has a drainage basin that is just a little smaller (9,339 acres) (Hatch Mott MacDonald, 2004). This proportionally small drainage area for Bayou Grande implies that, with all other factors being identical, pollutant loads contributed by the drainage should be lower. Airfields such as those at NAS have been shown to produce pollutants, and activities at NAS may contribute to pollution in the Bayou. It is also possible that some pollutants come from Pensacola

2

Bay and that currents transport them into the Bayou, as has apparently occurred in the past (Collard, 1991).

Figure 1. Location of Bayou Grande.

II.2 Climate The weather of Bayou Grande is wet, humid, and subtropical with an average annual temperature ranging from 50.5° Fahrenheit in the winter to 82° Fahrenheit in the summer. The average rainfall for the area is among the highest for metropolitan areas in the United States and amounts to approximately 60 inches per year, with the highest amount of rain falling in July and August. Moderate winds tend to prevail from the north during the winter and from the south during the summer (EnSafe, 1999). The area, as in the rest of the northern Gulf of Mexico, is frequently in the direct path of tropical storms and hurricanes. Some abatement of winds and flooding is afforded by Santa Rosa Island and Perdido Key. However, flooding and high wind velocities have caused severe damage during hurricanes to vulnerable structures and boats along the shoreline of Bayou Grande. In September 2004, Hurricane Ivan made landfall as a Category III hurricane about 30 miles west of Bayou Grande, and inflicted heavy damage to the structures in

3

the area, including those at NAS. Hurricane Ivan’s impact upon the sediments of Bayou Grande is unknown relative to sediment displacement and overall bathymetry.

II.3 Urban Development The western and northwestern regions of the Bayou are the least developed (Hatch Mott MacDonald, 2004). The eastern half of the southern shore has the NAS airfields, base buildings, and other developed areas. The remaining southern shore is not developed. The eastern half of the northern shore is heavily urbanized with the most densely urbanized area of the watershed being located along Navy Blvd and extending to the west along both sides (north & south) of Gulf Beach Highway until Waycross Street. Past Waycross Street most of the urbanization is to the south of Gulf Beach Highway. A significant portion of the runoff from the most heavily urbanized areas goes into Navy Point Bayou embayment. This embayment has had very high fecal bacterial counts (Snyder, 2006).

Figure 2. Bayou Grande and nearby drainage basins. The map shows that the natural drainage of the southern half of NAS does not flow towards Bayou Grande.

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II.4 Pensacola Bay and Dredging Activity It is likely that the tidal movements into and out of Pensacola Bay have been affected by dredging needed to improve shipping access to Pensacola Bay and estuaries such as Bayou Grande and Bayou Chico. Presently, the Pensacola Harbor navigation channel is used by ships of the US Navy and by commercial vessels going to the Port of Pensacola (Figure 3). The history of dredging goes back to earliest years of United States possession of Pensacola Bay. In 1825, Congress authorized the construction of a navy yard at Pensacola. Congress took this action despite being informed by the Board of Navy Commissioners a year earlier that the channel into Pensacola Bay did not provide at all times a sufficient depth of water for vessels larger than frigates of the first class due to the 21 feet depth of the pass (Pearce, 1989). As early as 1829, it became obvious to some observers that to insure future development at the yard, dredging operations to deepen the channel from the limiting 21 feet identified in the earlier French survey over the bar was needed. Over the years, dredging has deepened the entrance channel into the bay. Currently US Navy Vessels require channel depths in excess of the authorized dimensions of the Civil Works channel. Accordingly, the US Navy has funded the construction and maintenance of the Entrance and Navy Channels, which are currently maintained to the -44 and 42 foot Mean Lower Low Water (MLLW) depths, respectively. The Civil Works channels within Pensacola Bay have historically been maintained by the US Army Corps of Engineers to a depth of -33 feet MLLW (USEPA and US Army Corps of Engineers, 2005). It is likely that tides and currents have been altered and drastic changes in salinity have taken place due to the dredging but the impact on Bayou Grande or other components of the Pensacola Bay System is unknown. There are presently issues with beach erosion but the specific environmental effects of the dredging have not been studied thoroughly.

Figure 3. Dredged shipping channels in Pensacola Bay. 5

II.5 Historical Outline of Bayou Grande The first known documented contact of European colonists with Bayou Grande was in 1559 when the expedition by Don Tristan de Luna settled near what is now the Pensacola NAS. The settlement failed when it lost vital supplies after a hurricane sunk supply boats, and the survivors were not rescued until 1561. The next colonization attempt in 1698 led by Don Andres de Arriola constructed the first permanent post, Fort San Carlos, on the same site de Luna had chosen 140 years earlier. In 1719, war broke out between France and Spain. The French captured the settlement and remained in control for three years. They burned the settlement upon their retreat in 1722. It was at this time that Pensacola's historic claim of having the finest natural deep-water harbor on the Gulf Coast was made after surveys of it dating from at least 1719. In that year, the master of the Marine Academy of Toulon, France, found that it was a harbor with a bar that would admit ships with a draft of up to 21 feet. Subsequent surveys of the harbor by British cartographer George Gauld in 1764, and by Maj. James Kearney of the U.S. Topographical Engineers in 1822 corroborated the French survey of 1719 (Pearce, 1989). Following the French occupation was a Second Spanish period (1722-1763). The Spanish relocated the settlement to Santa Rosa Island because of the superior defense posture, but hurricanes destroyed the colony. The British controlled West Florida from 1763-1781 then the Spanish again claimed Pensacola for the Third Spanish period (1781-1819) which was contested by Anglo-American settlers and American troops under General Jackson (Pearce, 1989). In 1821, Pensacola was transferred to the United States. US Naval operations began on Pensacola Bay in 1825, when President John Quincy Adams and Secretary of the Navy, Samuel Southard, established “one of the best equipped naval stations in the country” (NAS Pensacola, 2001). As operations expanded between 1828 and 1835, the Navy acquired approximately 2,300 acres. Figure 4 depicts NAS as it was in about 1860 showing a detailed view of Ft. San Carlos de Barrancas and Ft. Pickens. It also shows the topography of the coast, the U.S. Navy Yard, and all other fortifications from the latest Government surveys in the 1860s (US Department of Defense, 1861). Warrington at that time was located contiguous to the NAS and not at its present location north of Bayou Grande. With the outbreak of hostilities in World War I in Europe, the Navy in 1914 expanded its role in Pensacola’s development by establishing the U.S. Naval Aeronautical Station. As the Navy expanded, so did support businesses and services, bringing more jobs and workers to the area. The military installations have been a major force in Pensacola's growth and development (Global Security, 2007). NAS has over its many years been the site of carrier based aircraft training and maintenance.

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Figure 4. Map of Pensacola Bay, 1860s (Exploring Florida, 2008a).

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III POLLUTION IN BAYOU GRANDE: LITERATURE REVIEW

III.1 General Pollution History Prior to 1860 there does not appear to have been any significant urbanization on the northern shore of Bayou Grande on the basis of a map drawn in 1860 (Figure 5) (US Department of Defense, 1861). Logging activities would have certainly occurred due to the ready water access for transport. Such activities would have resulted in some erosion. In Figure 4 Bayou Grande’s connection with Pensacola Bay appears to be mostly fronted by a sand spit that likely severely curtailed tidal exchange with Pensacola Bay except during high wind driven tides and storms. A bridge is seen crossing the Bayou in much the same position as the Navy Boulevard Bridge currently does. While not depicted on the map it is likely that there was some human habitation on the north shore along the road leading to the bridge. The naval base is shown to be situated to the south where a corner of the coast projects into Pensacola Bay. With the outbreak of hostilities in Europe related to World War I more activity occurred at NAS (Global Security, 2007).

Figure 5. Sketch of Pensacola Navy Yard and part of Fort Pickens, 1860s (Exploring Florida, 2008b). The literature for water and sediment quality in Bayou Grande is not extensive. It is likely that there was significant deterioration of water and sediment quality within the Pensacola Bay System for many years prior to it being “discovered” during the 1950’s. Bayou Grande appears 8

to have been less impacted by urbanization than is the case with the other major bayous of Pensacola. During the 1950’s when there was a general perception of environmental problems in the Pensacola Bay System, State of Florida scientists were sent to investigate environmental and health conditions in the lower Escambia River, upper Escambia Bay, Bayou Texar, and Bayou Chico (De Sylva, 1955; Murdock, 1955), but apparently not Bayou Grande. Collard (1991) in his review of the Pensacola Bay System did discuss previous studies and reports on Bayou Grande. Butler (1954) had reported that pollution in Pensacola Bay had been a problem for 50 years. Collard (1991) stated that Main Street Sewage Treatment Plant discharges (in operation since 1937) were transported into Bayous Chico and Grande. Portions of Pensacola Bay and Bayous Texar, Chico, and Grande were reported to be of poor bathing quality. Tisdale (1969), as quoted by Collard (1991), reported that NAS discharged significant amounts of oil and grease into Pensacola Bay, but suggested that tidal exchange (flushing) protected Pensacola Bay proper from excessive stress. Water quality measurements showed elevated levels of TKN (Total Kjeldahl Nitrogen), TPO-4(Total Phosphate), BOD (Biochemical Oxygen Demand), and chlorophyll-a west of the Main Street Sewage Treatment Plant and elevated levels of BOD at the mouth of Bayou Grande. Since Congress passed the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) in 1980, the Navy has actively investigated potential contamination that may have resulted from former practices at their installations. In 1988 an environmental permit was issued to NAS under the Resource Conservation and Recovery Act (RCRA). This is a standard permit issued for industrial activities that ensures that ongoing activities are environmentally sound and that spills or leaks of a hazardous waste are investigated and cleaned up (NAS Pensacola, 2003). NAS was placed on USEPA’s National Priority List (NPL) in December 1989. To identify and control environmental contamination, the Navy established the Navy Assessment and Control of Installation Pollutants, which later became part of the Navy’s Installation Restoration Program (IRP). Through these programs, 46 sites at NAS were identified as potential sources of contamination (Naval Facilities Engineering Command, 2004). Some sites are now inactive and are largely without records. Solid wastes have been disposed of primarily at two landfill areas, one site is west of the golf course at the station and the other site is north of Chevalier Field, an airfield. The Bayou Grande Shore Line was identified as Site 40 (Figure 6). Beginning in the 1930s, industrial wastes from operations at NAS were discharged directly into Pensacola Bay and Bayou Grande. This continued until 1973 when an industrial waste treatment plant began operation. Wastes included paint, solvents, mercury, radium paint, and concentrated plating wastes containing cadmium, chromium, cyanide, lead, and nickel. The plating wastes were discharged via a drainage ditch to Bayou Grande. Other areas of concern include landfills; materials disposal and storage areas; pesticide storage, handling, and disposal areas; solvent, fuel, and industrial waste pipeline leak and spill areas; radium spill areas; and fire and crash training areas (Ecology and Environment, Inc. 1989). Other activities involving hazardous substances include pesticide application, transformer storage and PCBs (USEPA, 2007). Most of these releases could have impacted Bayou Grande either through run-off, aquifer contamination, or atmospheric transport processes. The documented releases are listed and discussed in USEPA (2007) and ATSDR (2006). Other activities that can cause environmental impacts at the NAS are various housing, training, and support activities, as well as the Naval Air Rework Facility 9

(NARF), a large industrial complex for the repair and overhaul of aircraft engines and frames; the Naval Aviation Depot, which maintains and rebuilds aircraft; and the Navy Public Works Center Pensacola, which provides overall operational support for NAS. Most industrial operations have been conducted in the older portion of the base (Tetra Tech, 2003). A review of onsite releases was made by the Agency for Toxic Substances and Disease Registry (ATSDR, 2006). The ATSDR, based in Atlanta, Georgia, is a federal public health agency of the U.S. Department of Health and Human Services. The ATSDR is required by law to conduct a public health assessment at each of the sites on the National Priorities List. As part of the public health assessment process, ATSDR conducted a site visit to NAS in February 1991. The visit’s purpose was to collect information necessary to rank the site according to the potential public health hazard it represented and to identify public health issues related to environmental contamination. During the visit, ATSDR staff met base representatives, toured the installation and surrounding areas, and collected community health concerns. Through the Installation Restoration Program, the Navy identified the previously mentioned 46 sites (Figure 6) as potential sources of contamination at NAS Pensacola. ATSDR evaluated the potential for exposure to occur at each of these sites, and identified the following potential exposure situations: • Surface water in Pensacola Bay and Bayou Grande, • Sediments in Pensacola Bay and Bayou Grande, • Fish in Bayou Grande • Blue crabs in Pensacola Bay and Bayou Grande. The NAS was required by the USEPA to conduct studies that have shown that surface water runoff and groundwater are potential pathways for transport of contaminants to Pensacola Bay, Bayou Grande, and the coastal wetlands (Figure 6). The pollutants present in Bayou Grande originating from NAS fall into five basic categories (EnSafe 1995, 1997, 1998; ATSDR, 2006): 1. Inorganics, common metals and cyanide. 2. Volatile organic compounds originating from solvent used in industrial operations such as electroplating and paint stripping. 3. Semivolatile organic compounds resulting from fuel spills, asphalt, coal, and combustion. 4. Pesticides 5. PCBs Researchers at the Gulf Ecology Division of USEPA and others also initiated research upon the Bayous of the Pensacola Bay System that included a limited number of samples in Bayou Grande (Lewis et al., 2001). The available data from the non-NAS investigators were compiled into a GIS database by researchers at the Northwest Florida Water Management district (DeBusk et al., 2002). The resulting database incorporated data from FDEP, EPA, NOAA, EMAP, and EPA investigations of the 1980’s and 1990’s (Table 1). The database includes three broad categories of contaminants: heavy (trace) metals, trace organic compounds including PAHs, pesticides and PCBs, and nutrients.

10

Figure 6. Location of Assessment Zones at NAS. Blue dots represent sampling sites (from: EnSafe, 2004). 11

Table 1. Sources of data in environmental GIS database for Pensacola Bay System (DeBusk et al., 2002). • George: Master’s Thesis by S. George (1988; University of Southern Mississippi). Data from a comprehensive survey of physical sediment properties in the Pensacola Bay System includes analyses of sediment organic matter. Sampling sites were digitized from maps contained in the printed document. • Sediment Atlas: The raw data set used for the Pensacola Bay system in the Florida Coastal Sediment Contaminants Atlas (FDEP, 1994), obtained from T. Seal via electronic database. Sampling was conducted during the period 1982 through 1991, primarily in Pensacola Bay, upper Escambia Bay, and Bayous Chico and Grande. Site coordinates were provided with the data set. • EPA-Bayous: Sediment studies in bayous of the PBS, conducted by USEPA (Gulf Breeze, FL), Dr. Mike Lewis, principal investigator. Data sets comprising both published and unpublished data were obtained from studies in Bayous Texar and Chico (1993-1994). Site coordinates were provided with the data sets. • NOAA: Sediment analytical data for Pensacola Bay were transcribed from the NOAA (1997) report entitled “Magnitude and Extent of Sediment Toxicity in Four Bays of the Florida Panhandle: Pensacola, Choctawhatchee, St. Andrew and Apalachicola”. Sampling was conducted during 1993-1994 at several sites throughout the Pensacola Bay System. Site coordinates were provided with the data set. • EMAP; EPA-92; EPA-96: Three databases, in electronic format, were obtained from USEPA Region 4 offices, containing results from 1) the 1991-94 EMAP sampling, 2) the 1992 Pensacola Bay Intensive Study and 3) the 1996 Pensacola Bay Study, all conducted by the EPA Gulf Ecology Division at Gulf Breeze. Sampling stations were located throughout the Pensacola Bay System. Site coordinates were provided with the data set. The NAS sponsored studies of Bayou Grande conducted in the 1990’s have only concerned the areas of Bayou Grande that border the NAS property. These areas have been divided into four assessment zones (AZ): Assessment Zones 1, 2, 3, and 4 as illustrated in Figure 6 (EnSafe, 2003). The AZ-1 includes portions of the NAS Pensacola shoreline along Bayou Grande from a point near Soldiers Creek to Deepwater Point. Sediments within this zone are mostly fine-grained and characteristic of a low-energy tidal regime. Very few contaminant source areas were identified for this AZ. Potential sources include installation restoration program (IRP) Site 3 and Forrest Sherman Field, which lie south of the zone. AZ-2 extends from Deepwater Point to J. Kee Point and includes Redoubt Bayou. The shoreline in this area is characterized by sandy beaches with shallow, broad, sandy shelves extending out into the bayou in some areas. In these areas, fine-grained sediment is found further offshore than in AZ-1. The major contributing source to this area is IRP Site 1, potentially contributing inorganics (metals), volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), and pesticides. Wetlands that surround Site 1 discharge into this zone. A wetland known as the Southeast Drainage Ditch, conveys storm water from the eastern end of Forrest

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Sherman Field to the southern end of Redoubt Bayou. This wetland is intersected by an unnamed drainage ditch which passes the south side of Site 16, and conveys surface water from the Barrancas Cemetery area. This intersecting ditch also receives stormwater from an outfall draining the NAS Public Works Center (encompassing IRP Sites 8, 17, 22, and 24). Other wetlands that discharge into the zone include Wetlands 19, 22, 24, and 68 (Figure 6). Contaminants have been detected in some monitoring wells near the shore of this AZ (Tetra Tech, 2003) AZ-3 extends from J. Kee Point to the Navy Boulevard Bridge. Sediments in this zone are similar to those in AZ-2, with areas of sandy bottom parallel to the shoreline or extending into the bayou as sandbars. Primarily, pesticides from the NAS Pensacola Golf Course may be expected in this area. Contaminants may have been transported to this zone from Site 1 through Wetlands 3 and 4 (Figure 6). A skeet shooting range was located on the east side of Site 1. Wetland 65 also discharges into this zone. AZ-4 extends from the Navy Boulevard Bridge to the pass connecting Bayou Grande with Pensacola Bay. This area includes Woolsey Bayou, Navy Yacht Basin (Buddy’s Bayou) and portions of Bayou Grande just north of the Navy Yacht Basin. Sediments in this zone are similar to those in AZ-3, with small areas of sandy bottom along the shore. A railroad bridge was formerly in the area.

III.2 Fecal Coliform Pollution in Bayou Grande Snyder (2006) reported on chronic fecal contamination of waterways in the Pensacola Bay system and found that fecal bacteria presented a public health and environmental problem. The study was a multiyear project, carried out as part of CEDB’s activities, to identify sources of loadings of fecal contamination within the urban bayous of Pensacola. Thirty-one stations were established along the shoreline of Bayou Grande. These stations were selected to coincide with storm water drainages, perennial streams, and areas of likely groundwater discharge indicated by topography and freshwater wetland plants in salt water areas. Samples were taken at monthly intervals from December 1999 to October 2001. Bacterial counts were mostly within the acceptable range but changed drastically with rainfall (Figure 7). Rainfall tends to flush fecal bacteria out of feeder streams and other sources into Bayou Grande and often result in health advisories. The residential areas of the northern and western drainages, and not the Naval Air Station along the southern shore, appeared to be the major source areas for chronic fecal contamination. GIS analyses indicate that older residential developments using septic tanks in low-lying areas are the main source areas (Snyder, 2006). The Escambia County Health Department of Florida continues to monitor Bayou Grande.

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Figure 7. Geomeans of Enterococcus at zero rainfall for Bayou Grande. Concentrations of 35 or lesscolony forming units are considered not to pose a risk to using the waters for recreational activities. This concentration is based on a criterion from the USEPA that has officially announced a final rule for Enterococci criteria for Florida’s Coastal Recreational Waters (marine coastal waters including estuaries). This rule provides a 30-day geometric mean of 35 colony-forming units per 100 milliliters (cfu/100 ml) or less to be considered safe for swimming and water contact sports, and a single sample maximum of 104 cfu/100 ml or less at Designated Bathing Beaches (FDEP, 2007).

III.3 Total Petroleum Hydrocarbons Total petroleum hydrocarbons (TPH) may be present in Bayou Grande with the most likely origin being aviation fuels used at NAS. Common types of military aviation turbine fuels (turbojet or turbo-prop) are identified by grade designations such as JP-4, JP-5, JP-8, etc. They are among the lighter components that can be detected by the FL-PRO that has a quantitative detection for the range of hydrocarbons going from C8-C40. Jet fuels like JP-4 are composed of about 50-60% gasoline and 40-50% kerosene, are highly volatile, and contain hydrocarbons in

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the C4-C16 range. JP-4 was the primary fuel of the USAF for decades; and has been phased out in favor of JP-8. Jet fuel JP-5 is a low-volatility (C10-C19 range) jet fuel with a relatively high flash point (for shipboard safety reasons) and is designed for use in aircraft aboard Navy aircraft carriers. JP-8 was developed to be less volatile and explosive than JP-4. It is safer and has less of an environmental impact. It also contains a full military additive package including a corrosion inhibitor, anti-icing, and anti-static compounds. JP-8 is essentially commercial Jet A-1 fuel with the full military additive package. JP-8+100 is an improved JP-8 fuel with additional “fuel injector cleaner”-type additives that improves the thermal stability of JP-8. An additional difference is significantly less benzene in the environment. As seen in Table 2 aromatics by volume percent compose about 25% of all fuels. These fuels if present should be detectable by the FL-PRO that detect ranges of eight to 40 length hydrocarbon chains since aviation fuels do have hydrocarbons that exceed C-8 in length (USAF, 2006). Table 2. Chemical and physical requirements for JP-4, JP-5, and JP-8. Issuing Agency: USN USN Grade Designation: JP-4 (NATO F-40) JP-5 (NATO F-44) Fuel type: Wide-cut gasoline Kerosene type Acidity, Total (mg KOH/g) Aromatics (vol %) Sulfur, Mercaptan (wt %) Sulfur, Total (wt. %)

0.015 25 0.002 0.40

0.015 25 0.002 0.30

USAF JP-8 (NATO F-34) Kerosene type 0.015 25 0.002 0.30

III.4 Polycyclic Aromatic Hydrocarbons (PAHs) The PAHs are compounds composed of two or more aromatic (benzene) rings. PAHs may be divided into two groups, depending upon their mass: low-molecular-weight PAHs, containing two or three aromatic rings, and high-molecular-weight PAHs, containing more than three aromatic rings. PAHs can have multiple origins with oil spills and combustion products being important sources in typical urban environments. They are released into the environment by incomplete combustion and pyrolysis of organic materials such as coal, wood, fuel, garbage, tobacco, and meat. A major source of ambient PAHs is believed to be motor vehicle combustion emissions, particularly in urban areas. Motor vehicle emissions can contribute 46-90% of the mass for individual PAHs in ambient airborne particles in urban areas (Dunbar et al., 2001; Harrison et al., 1996; Nielsen, 1996). PAHs are not particularly soluble in water, but adsorb well to particulate matter, and are therefore usually concentrated in soil or attached to dust particles or marine sediments. PAHs are known to cause environmental deterioration upon accumulating in sediments, as reflected in FDEP sediment quality assessment guidelines (Table 3). Removal of PAHs from the environment occurs more rapidly for 2-ring forms than for the heavier forms via volatilization and biodegradation. Under anaerobic conditions the lighter forms will degrade under nitrate and sulfide reducing conditions and the heavier forms (4-6 rings) tend to adsorb to sediments becoming less available than the lighter 2 and 3-ring forms. The 3-ring forms due to their solubility and volatility exert more acute toxic effects (Brenner et al., 2002).

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Table 3. PAH SQAGs1 (μg/kg) and IARC listing (MacDonald, 1994). PAH Compound

TEL2 ug/kg

PEL3 ug/kg

Carcinogenic IARC4

LMW (Light Molecular Weight) PAHs Acenaphthene

6.71

88.9

No listing

Acenaphthylene

5.87

128

No listing

Anthracene

46.9

245

Not classifiable

Fluorene

21.2

144

Not classifiable

2-methylnaphthalene

20.2

201

No listing

Naphthalene

34.6

391

Possibly

Phenanthrene

86.7

544

Not classifiable

Sum LMW-PAHs5

312

1,442

No listing

HMW (Heavy Molecular Weight) PAHs Benz(a)anthracene

74.8

693

Probably

Benzo(a)pyrene

88.8

763

Probably

Chrysene

108

846

Not classifiable

Dibenzo(a,h)anthracene

6.22

135

Probably

Fluoranthene

113

1,494

Not classifiable

Pyrene

153

1,398

Not classifiable

Sum HMW-PAHs6

655

6676

No listing

Sum LMW&HMW7

1684

16,770

No listing

PAHs not assigned SQAG by FDEP Benzo(b)fluoranthene

na

na

No listing

Benzo(g,h,i)perylene

na

na

No listing

Benzo(k)fluoranthene

na

na

No listing

Indeno(1,2,3-cd)pyrene

na

na

No listing

1-Methylnaphthalene

na

na

No listing

1

: SQAGs: Sediment quality assessment guidelines adopted by the FDEP. : TEL: Threshold effects level (McDonald, 1994). Within this range, concentrations of sediment-associated contaminants are not considered to represent significant hazards to aquatic organisms. 3 : PEL: Probable effects levels (McDonald, 1994), lower limit of the range of contaminant concentrations that are usually or always associated with adverse biological effects 4 IARC: The International Agency for Research on Cancer is part of the World Health Organization. Agents with sufficient evidence of carcinogenicity in experimental animals and inadequate evidence of carcinogenicity in humans will ordinarily be placed in the category possibly carcinogenic to humans. When there is strong evidence that carcinogenesis in experimental animals is mediated by mechanisms that do operate in humans, the agent may be upgraded to probably carcinogenic to humans. The classification scheme allows for down-grading to not classifiable as to its carcinogenicity to humans if there is strong, consistent evidence that the mechanism of carcinogenicity in experimental animals does not operate in humans or is not predictive of carcinogenic risk to humans. 5 : Sum LMW-PAHs refers to FDEP TEL and PEL values determined for the sum of 7 light molecular weight PAHs 2

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6

: Sum HMW-PAHs refers to FDEP TEL and PEL values determined for the sum of 6 heavy molecular weight PAHs 7 : Sum LMW&HMW refers to the sum of the concentrations of each of the 13 low and high molecular weight PAHs having FDEP SQAG. While the mode of action of LMW and HMW PAHs is thought to differ, these substances are sometimes grouped in assessments of sediment quality. This results in a derivation of a TEL of 1,684 ug/kg and a PEL of 16,770 ug/kg. (MacDonald, 1994). The actual Total PAH from 8270C SIM analyses includes an additional 5 PAHs.

PAHs can be transported to aquatic sediments via groundwater discharge from an aquifer, via stormwater deposition, air deposition from grass and forest fires and vehicle exhaust, and petroleum product spills. PAHs tend to partition from water into sediments at ratios based on their molecular weight. Larger PAHs tend to partition preferentially into sediments with relatively small concentrations showing up in water due to their lower solubilities. After a spill on the ground the heavier of the PAHs upon entering an aquifer sink to the bottom of the aquifer to form a layer of Dense Non-Aqueous Phase Liquid (DNAPL). The lighter PAHs float on water as the Light Non-Aqueous Phase Liquid (LNAPL) layer. Lighter PAHs such as naphthalene also tend to be more soluble and enter the water column and then evaporate to the atmosphere or are transformed to alkyl forms (Van Mouwerik et al., 1998). The PAH data for Bayou Grande in the DeBusk GIS database have only two concentrations above the FDEP sediment guidelines (Table 4, Figure 8). Table 4. Existing ‘non-NAS’ Bayou Grande PAH data [ug/kg] (DeBusk et al., 2002). Site Label TEL PEL EPA17 EPA18 EPA19 PCOLA15 PCOLA16 PCOLA16 PCOLA17 PCOLA17 NOAA1 NOAA2 NOAA3 LA91SR32

TOT_LMW_PAH 312 1442 203 10 69 82 59 27 36 29 40 x 90 194

TOT_HMW_PAH 655 6676 1014 18 180 396 24 58 57 33 1 40 x 1091

LMW&HMW 1684 16770 1218 28 249 477 83 85 94 63 5 40 x 1285

NAS studies show that zone AZ-1 had all PAH concentrations within SQAGs while the other zones, especially AZ-3, had a higher percentage of concentrations that exceeded SQAGs (Table 5) (EnSafe 2003; 2004).

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Figure 8. Location of sampling sites from DeBusk et al. (2002) GIS database.

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Table 5. PAHs in Bayou Grande sediments by zone of the NAS Pensacola shore (EnSafe, 2003; 2004). Congener

1

Naphthalene 2-Methylnaphthalene 1-Methylnaphthalene Acenaphthylene Acenaphthene Fluorene Phenanthrene Anthracene Pyrene Chrysene Benz(a)anthracene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a) pyrene Indeno(1,2,3-cd) pyrene Dibenz(a,h) anthracene Fluoranthene Benzo(g,h,i) perylene

TEL 34.6 20.2 5.9 6.7 21.2 86.7 46.9 153.0 108.0 74.8

88.8

Aver1 69 94 ND4 ND ND ND ND ND 111 ND ND 120 ND 85 76

6.2

ND

113.0

107.0 85

AZ1 Det2 7/38 1/38

% Exc3 8 3

AZ2 Det 2/55 1/55

1/38

Aver 75.5 160 ND ND 33 34 104 80 163 116 103 131 110 111

1/55 1/55 7/56 1/55 17/57 13/57 13/57 21/57 9/57 16/57

1/38

110

3/38

7/38

8/38 1/38

8

% Exc 2 2

AZ3 Det 2/24

2 2 7 2 11 11 11 0 0 12

Aver 29 ND ND ND 5016 7900 1862 1440 4640 2451 2524 1419 1121 1426

% Exc 4

2/24 1/24 15/24 4/24 21/24 21/24 20/24 22/24 18/23 20/24

7/57

0

675

19/24

42

1/55

2

58

3/24

13

ND

147.0 110

21/57 10/57

16 0

2881.0 731

21/24 19/24

46

185 183

8 4 29 13 38 46 46

46

Aver is the average of all concentrations in ug/kg. Det is the number of detections/number of samples. 3 % Exc is the percentage of concentrations that exceed FDEP SQAGs. 4 NDindicates all samples were nondetect and no information was given on the number of samples taken. 2

19

AZ4 Det 2/24 2/24

Aver 58 42 ND 100 35 55 119 120 176 139 120 133 133 133

1/24 1/24 1/24 9/24 1/24 15/24 11/24 11/24 15/24 6/24 9/24

139

5/24

15/24 5/24

% Exc 8 8 4 4 4 17 4 21 21 21

17

21

III.5 Organochlorinated Compounds Organochlorinated compounds are diverse groups of compounds that include the organochlorinated pesticides, PCBs, dioxins/furans, PCP, and others. Many organochlorinated molecules and also other halogenated compounds are very persistent both in sediments and when incorporated into living organisms where they can bioaccumulate (USGS, 2005). Use of organochlorinated pesticides and PCBs was widespread beginning in the 1940s until bans and use restrictions were placed on these compounds in the 1970s and 1980s. Compounds such as chlordane, DDT and its environmental degradation products DDD and DDE, and PCBs have low solubilities in water, are strongly associated with organic carbon and fine sediment, and have long environmental half-lives (USGS, 2005). Organochlorinated compounds are included in the persistent organic pollutants (POPs) due to their high recalcitrance to the natural degradative processes. Pesticides have been applied in the Bayou Grande watershed by NAS base operations (Ensafe, 2003; 2004) and by businesses, local governments and residents for termite and pest control. Many of the commonly applied pesticides are organochlorinated pesticides. The DeBusk et al. (2002) database shows numerous detections for organochlorinated pesticides in Bayou Grande (Table 6, Figure 8). In the NAS studies of pesticides zone AZ-1 had the highest rate of non-detects compared to the other zones (Table 7). Detections of DDT related compounds were generally found in all zones of the NAS shoreline. Zone AZ-2 had the highest number of exceedances of the SQAGs (Ensafe, 2003; 2004). Table 6. Existing pesticide data for Bayou Grande [ug/kg] (DeBusk et al., 2002). SiteLabel TEL PEL EPA17 EPA18 EPA19 PCOLA15 PCOLA15 PCOLA16 PCOLA16 PCOLA17 PCOLA17 NOAA1 NOAA2 NOAA3 LA91SR32

Aldrin None None x x x x x x x x 1 0.5 x x

A-Chlord 2.26 4.79 1.17

G-Chlord 2.26 4.79 4.62

0.31 0.408 x x x x x 1 0.5 4.861 0.29

0.67 x x x x x 0.5 1 0.44

44DDD 1.22 7.81 3.6 0.14 1.62 1.477 x x x x x x 1 2.58 1.33

20

24DDD None None 0.61 0.38 8.487 2.938 x x x x x 0.5 1 0.33

44DDE 2.07 374 20.18 0.17 6.37 7.226 3.398 x 0.255 0.477 0.492 x x x 5.1

24DDE None None x x x x x x x x x x x 2.1 x

44DDT 1.19 4.77 1.73 x x x x x x x x x x 2.02 0.37

24DDT None None 1.73 0.32 x x x x x x 0.1 0.1 0.1 0.14

Table 6. Existing pesticide data for Bayou Grande [ug/kg] (DeBusk et al., 2002) - continued. SiteLabel TEL PEL EPA17 EPA18 EPA19 PCOLA15 PCOLA15 PCOLA16 PCOLA16 PCOLA17 PCOLA17 NOAA1 NOAA2 NOAA3 LA91SR32

Sum_DDT None None 27.85 0.31 8.69 17.19 6.336 x 0.255 0.477 0.492 7.6 3.1 7.8 7.27

Tot_DDT None None 3.46 0.32 x x x x x x 0.6 0.6 2.12 0.51

Dieldr 0.715 4.3 x x 2.019 0.778 x x x x 2.84 0.1 5.76

Endo None None x x x x x x 0.35 x x x x x x

Endo_II None None x 0.15 0.95 x x x x x x x x x x

Hept None None 0.11 x x x x x x x x x x x x

Hept_Epox None None 0.52 x x x x x x x x x x x x

Mirex None None x x x 22.156 14.526 10.395 10.866 16.624 13.452 0.5 0.5 0.5 x

1: Italicized underline indicates concentrations above the PEL. 2: Bold type indicates concentrations above the TEL.

For PCBs the DeBusk et al. (2002) database shows that five out of 12 samples were above the TEL, one of which was above the PEL (Table 8). Three Aroclors, Aroclor 1242, 1254, and 1260, were detected in sediments of the NAS portion of the Bayou Grande Shoreline. Aroclor 1242 was only detected in AZ 2, in 8 out 56 samples. Aroclor 1254 was detected in AZ 3 and AZ 4 in 1 out of 24 and 4 out of 23 samples respectively. Aroclor 1260 was detected in all zones in more than 50% of the samples (Ensafe 2003; 2004).

III.6 Trace Metals Trace metals have been a component of the waste stream generated by NAS (EnSafe, 2003; 2004). Many trace metals are toxic to humans and the environment and SQAGs and water quality standards (Table 9) have been established for trace metals by FDEP. The FDEP listed metals include Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Lead (Pb), Nickel (Ni), and Zinc (Zn). Of these metals mercury is considered to pose the greatest risk to human health. Data presented in the DeBusk et al. (2002) database for Bayou Grande sediments (Table 10) show that the concentrations of metals were frequently above SQAGs. Arsenic was above the TEL in 8 out 17 samples, cadmium was above the TEL for 9 out of 17 samples with 5 of these exceeding the PEL. Similar results can be observed for copper, lead, mercury, nickel, and zinc. Silver had one sample that exceeded the TEL and tributyltin had no sample that exceeded FDEP guidelines. Overall this data suggests there is definite environmental concern due to the elevated levels of trace metals in Bayou Grande sediments.

21

Table 7. Pesticides and PCB Aroclors in Bayou Grande sediments by zone of the NAS Pensacola shore (EnSafe, 2003; 2004). Analyte Aroclor-1242 Aroclor-1254 Aroclor-1260 4,4'-DDD 4,4'-DDE 4,4'-DDT Aldrin Dieldrin Endosulfan I Endosulfan II Endosulfan sulfate Endrin Endrin Alderhyde Endrin Ketone Heptachlor Heptachlor epoxide Methoxychlor Alpha-BHC AlphaChlordane beta-BHC Gamma-BHC GammaChlordane

TEL 21.6 21.6 21.6 1.22 2.07 1.19 0.715

3.3

0.32

Aver.1 ND ND 15.9 1.6 2.4 ND 0.95 1.2 ND 1.3

AZ1 Det.2

% Exc.3

AZ2 Det. 8/56

Aver. 0.82 ND 31.5 4.1 3.2 3.1 0.81 0.99 0.12 0.69

28/56 18/56 25/56 17/56 9/56 18/56 3/56 4/56

ND

0.41

ND ND

28/38 1/36 13/37 3/38 6/38

24 3 18

16

1/36

% Exc. 2

AZ3 Det.

Aver. ND 5.3 14.4 0.36 1.48 0.7 0.32 26.7 ND 0.21

1/24 13/24 3/24 10/24 10/24 1/24 4/24 5/24 1/24

1/56

0.84

0.41

9/56

1.1

0.83

1/56

ND 1.7 0.11

29 18 23 9 14

% Exc.

4/23 13/21 3/22 4/22 4/22 4/22 4/22 4/22 4/22

5/24

0.73

2/21

4/24

2.1

4/22

0.6

1/21

1/24 1/24

0.11

1/21

13 8 8 8

ND 0.81

0.76 ND

5/56

1/36

0.48

3/37

1.2

3/56

0.27

5/24

ND

ND 1.3

1/36

1.9 0.67

6/56

ND 0.61

5/24

ND 0.61

0.53

6/36

0.75

12/56

0.63

5/24

0.22

ND 1.1

6/36

0.29 0.94

2/56 15/56

ND 0.64

1/24

0.41

1/37

0.82

5/56

0.33

3/24

16

1

Aver is the average of all concentrations in ug/kg. Number of detections/number of samples. 3 % Exc is the percentage of concentrations that exceed FDEP SQAGs. 2

22

18

AZ4 Det.

Aver. ND 6.3 12.3 0.64 0.98 0.57 ND 1 ND 1.2

4

% Exc.

4 4 4 9

4

10/22

0.24 2.9

4/23

0.21

3/22

13

Table 8. Existing total PCB data for Bayou Grande [ug/kg] (DeBusk et al., 2002) SiteLabel EPA17 EPA18 EPA19 PCOLA15 PCOLA15 PCOLA16 PCOLA17 PCOLA17 NOAA1 NOAA2 NOAA3 LA91SR32

Total_PCB 249.51 2.8 48.62 70.151 16.648 1.022 2.749 0.592 53.53 16.76 16.76 53.34

1: Bold type indicates concentrations above the TEL of 21.55 ug/kg. 2: Italicized underline indicates concentrations above the PEL of 188.79 ug/kg. Table 9. Water quality standards [ug/l] for Class III marine water bodies1. Metal Marine water As (total) 8. Estuaries like Bayou Grande with pH’s ~8 could favor precipitation. In anaerobic environments and in the presence of sulfide ions, precipitation of zinc sulfide limits the mobility of zinc. Although biota appear to be a minor reservoir of zinc relative to soils and sediments, microbial decomposition of biota in water can produce ligands, such as humic acids, that can affect the mobility of zinc in the aquatic environment through zinc precipitation and adsorption. Zinc concentrations in the air are relatively low, except near industrial sources such as smelters. No estimate for the atmospheric lifetime of zinc is available at this time, but the fact that zinc is transported long distances in air indicates that its lifetime in air is at least on the order of days (ATSDR, 2005e). Zinc can accumulate in freshwater animals at 51 - 1,130 times the concentration present in the water. Microcosm studies indicate, in general, that zinc does not biomagnify through food chains (ATSDR, 2005e). Steady state zinc BCFs for 12 aquatic species range from 4 to 24,000. Crustaceans and fish can accumulate zinc from both water and food. A BCF of 1,000 was reported for both aquatic plants and fish, and a value of 10,000 was reported for aquatic invertebrates. Other investigators have also indicated that organisms associated with sediments have higher zinc concentrations than organisms living in the water column (ATSDR, 2005e).

52

V OBJECTIVES

The general goal of this PERCH project was to evaluate the presence, magnitude and potential origin of pollutants in Bayou Grande. Specifically, the project was designed to address the following objectives: • Review all accessible information related to pollution of Bayou Grande and its drainage basin to identify data gaps and areas of concern. This objective includes: o Determining historical impacts o Evaluating earlier studies o Assessing the most recent studies at NAS Pensacola • Characterize selected SOCs of water and sediments in Bayou Grande, which includes: o Determining the presence and magnitude of the SOCs o Assessing the source and mode of transport of he SOCs o Evaluating if SOCs are currently entering Bayou Grande o Appraising the rate of degradation of existing SOCs o Establishing relationships between pollution and sediment characteristics • Assess and characterize dioxins/furans and dioxin-like PCBs in sediments in Bayou Grande in support of a related PERCH Seafood Study.

53

VI METHODS Accessible information concerning the environmental conditions of Bayou Grande was compiled through an exhaustive literature search. For this effort we drew in part upon another component of the PERCH Project, the PERCH Bibliography (http://fusionmx.lib.uwf.edu/perch/index.cfm) which is a fully searchable database of bibliographical materials pertaining to the environment of Northwest Florida. A GIS database of spatially referenced data collected during the literature search was constructed by manually entering and digitally importing the data and by converting them to common spatial parameters. The purpose of the literature search was to assess what was known about the environmental quality of Bayou Grande and if it was or could be impacted by superfund sites and other potential sources of pollution. This information allowed evaluation of how the present project could further the existing knowledge. To help identify optimal locations for the sampling sites the bathymetry of the Bayou was surveyed with an echosounder and differential GPS (DGPS). Optimal sampling locations were identified by project personnel based on the bathymetry of the Bayou, the general location within the Bayou, and specific objectives of the sampling. These locations were marked on an overlay on the bathymetric map in the GIS. In the field, the GIS was used in combination with a WAAS enabled hand held GPS receiver (Garmin GPS V) to navigate to the sampling locations. The sampling was conducted from fall of 2006 to mid-summer of 2007. A total of 78 sediment grab samples, 8 water grabs, and 10 vibracores were collected (Figure 19, 20 and 21). Sediment grab samples were collected with a ponar grab from a small boat. Water grabs were collected with a Van Dorn sampler. For the vibracores three-inch decontaminated aluminum thin-walled irrigation pipe was clamped to a vibracore powered by a portable generator. The vibracore sediment was retained by a plastic core catcher at the bottom and a vacuum plug sealed the top upon retrieval of the coring pipe. Each vibracore was driven into the sediment until refusal. In the lab the cores were split lengthwise, described, and sampled at 1 meter intervals (0 meters for level A, one meter for level B, two meters for level C, and 3 meters for level D). For the sediment grab samples five local grab samples were joined at each sampling site and mixed thoroughly prior to further processing. The composited samples were placed into dedicated sampling containers and sent to the analytical laboratory the day of sampling. Sampling equipment was cleaned with soapy water, rinsed with reagent grade solvents, and two rinses of HPLC grade water. The decontaminated equipment was tested with rinsate blanks, and field splits for quality control were taken. The first sampling series, the GBc series of sediment grabs, was taken in embayments of the Bayou and along the shoreline near possible stormwater outfalls. GBc samples were analyzed for trace metals and PAH. Sample series GF was taken elsewhere in the Bayou and was analyzed for PAH, trace metals, pesticides, PCBs, total petroleum hydrocarbons, and dioxins/furans. It should be borne in mind that Ponar dredge surface grabs and the Level A (“surface level”) of the vibracores are not equivalent because the sediment depths and the homogeneity of sediments sampled differ. Ponar grab samplers like the one used in the current study do not collect deeper than 13 cm, resulting in data that reflect concentrations in the surface sediments. Vibracore samples are collected from sediments in a 3-inch diameter pipe. Sampling starts at the surface and continues down from the surface to depth of about 20 cm, or until sufficient sediment has

54

been collected for analyses. Thus, a level A vibracore sample (0 m) differs from surface grab samples relative to the depth of the sampled sediments. The surface area sampled is for a vibracore is about 46 cm2 versus about 256 cm2 for a petite ponar dredge. The dredge sample additionally consists of three to five composited samples. The smaller surface area of vibracores gives a more discrete result that is more likely to vary from the mean sediment analyte concentration due to the heterogeneous distribution of nonsoluble materials in sediments.

Figure 19. Location of sediment grab samples.

55

Figure 20. Location of water grab samples.

Figure 21. Location of vibracore sites in Bayou Grande.

56

Analytical methods followed standard procedures. Total petroleum was analyzed by the FDEP FL-PRO method. The FL-PRO analysis is designed to measure concentrations of total petroleum hydrocarbons (TPH) in water and soil/sediment in the alkane analytical range of C8-C40. The method is based on a solvent extraction and gas chromatography procedure (using a Flame Ionization Detector). Silica cleanup is a mandatory part of the procedure, designed to remove potential interferences from animal and vegetable oil and grease and biogenic terpenes. Other organic compounds, including chlorinated hydrocarbons, phenols and phthalate esters are detected and the total concentration values of TPH for the FL-PRO may include these compounds in the results. USEPA SW-846 methods were used for the following: PCBs by 1668A, dioxins/furans by 1613B, and other semivolatiles by Method 8270C. Specific PAHs (naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenz(a,h)anthracene, and benzo(g,h,i)perylene) were analyzed by USEPA SW-846 method 8270 C, with Simultaneous Ion Monitoring (SIM). This method was used to achieve detection (MDL) and reporting limits (RL) that were lower than the Florida marine sediment quality assessment guidelines (SQAGs) (MacDonald, 1994a, b). SIM is the most sensitive gas chromatography/ mass spectrometry method that is generally available for PAH detection. The target analytes are extracted by EPA method 3550 using dichloroethane (methylene chloride), separated by gas chromatography, then identified and quantitated by mass spectrometry. SIM is a method in which the detector lingers at a few selected masses for much longer than when using the typical "full scan mode", thus increasing the sensitivity of the detector to those masses and lowering both the method detection limit (MDL) and reporting limit (RL) for the analytes. Organochlorinated pesticides were analyzed by EPA Method 8081A which is a gas chromatography method that is similar to EPA Method 8082 that is used to detect PCBs. It employs fused-silica, open tubular capillary columns with electron capture detection. The 8081 analyses were run for the following pesticides: alpha-BHC, gamma-BHC (Lindane), beta-BHC, delta-BHC, heptachlor, aldrin, heptachlor epoxide, gamma-chlordane, alpha-chlordane, 4,4'DDE, endosulfan I, dieldrin, endrin, 4,4'-DDD, endosulfan II, 4,4'-DDT, endrin aldehyde, methoxychlor, endosulfan sulfate, endrin ketone, toxaphene, tetrachloro-m-xylene, decachlorobiphenyl. The EPA Method 3550 was also used for the extraction. Mercury (Hg) was determined by Method 7471A for sediments and Method 7470A for aqueous samples by cold vapor atomic absorption. For all other trace metal determinations the samples were prepared according to SW-846 Method 6010, Acid Digestion of Sediments, Sludges, and Soils. Per the method, aluminum (Al), calcium (Ca), iron (Fe), magnesium (Mg), nickel (Ni), selenium (Se), tin (Sn), cadmium (Cd), copper (Cu), zinc (Zn), arsenic (As), chromium (Cr), and lead (Pb) were prepared for graphite furnace atomic absorption spectrometry (GFAAS). The other metals were prepared for flame atomic absorption spectrometry (FLAAS). The digestates were analyzed according to Standard Method 3111 for FLAAS or USEPA Method 200.9 for GFAAS. Samples for particle size analysis were manually mixed and homogenized in the lab while being air dried. After air drying, samples were crushed with mortar and pestle to break up aggregates. Analyses were then performed by dry, Ro-tap, sieving for the sand fractions (2 mm 0.063 mm) and by the pipette method for clays (procedure 3A1 of Burt (2004)). We preferred to use the pipette method over the often employed hydrometer method because the pipette method is generally considered to be more accurate.

57

The metal, volatile, total organic carbon, and semivolatile analysis were performed by Columbia Analytical Systems of Jacksonville, FL, and their high resolution mass spectrometry laboratory in Houston, TX, performed the analyses for PCB and dioxin/furan congeners. Particle size analyses were performed at the Sediments Lab, Department of Environmental Studies, University of West Florida. To calculate a TEQ for the dioxins/furans and dioxin-like PCBs the TEF of each congener present in a mixture was multiplied by the respective mass concentration and the products were summed to represent the 2,3,7,8-TCDD TEQ of the mixture, as determined by the following equation (USEPA, 2003b):

(

)

(

TEQ ≅ Σi−n Congener i × TEF i + Congener j × TEF j

) + ....+ (Congener n × TEF n)

The TEF values used were those for humans/mammals established in 2005 by the WHO (Van den Berg et al., 2006) (Table 13). To assess the origin of dioxins/furans, dioxin-like PCBs and PCBs we statistically examined similarities in their profiles with principal component analysis (PCA) and cluster analysis. We applied a varimax rotated PCA to facilitate interpretation of the resulting components.

58

Table 13. TEF values for dioxins/furans and dioxin-like PCBs [ng/kg toxic equivalents of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)] (Van den Berg et al., 2006). Compound Chlorinated dibenzo-p-dioxins 2,3,7,8-TCDD 1,2,3,7,8-PeCDD 1,2,3,4,7,8-HxCDD 1,2,3,6,7,8-HxCDD 1,2,3,7,8,9-HxCDD 1,2,3,4,6,7,8-HpCDD OCDD Chlorinated dibenzofurans 2,3,7,8-TCDF 1,2,3,7,8-PeCDF 2,3,4,7,8-PeCDF 1,2,3,4,7,8-HxCDF 1,2,3,6,7,8-HxCDF 1,2,3,7,8,9-HxCDF 2,3,4,6,7,8-HxCDF 1,2,3,4,6,7,8-HpCDF 1,2,3,4,7,8,9-HpCDF OCDF Non-ortho–substituted PCBs 3,3',4,4'-tetraCB (PCB 77) 3,4,4',5-tetraCB (PCB 81) 3,3',4,4',5-pentaCB (PCB 126) 3,3',4,4',5,5'-hexaCB (PCB 169) Mono-ortho–substituted PCBs 2,3,3',4,4'-pentaCB (PCB 105) 2,3,4,4',5-pentaCB (PCB 114) 2,3',4,4',5-pentaCB (PCB 118) 2',3,4,4',5-pentaCB (PCB 123) 2,3,3',4,4',5-hexaCB (PCB 156) 2,3,3',4,4',5'-hexaCB (PCB 157) 2,3',4,4',5,5'-hexaCB (PCB 167) 2,3,3',4,4',5,5'-heptaCB (PCB 189)

WHO 1998 TEF

WHO 2005 TEF

1 1 0.1 0.1 0.1 0.01 0.0001

1 1 0.1 0.1 0.1 0.01 0.0003

0.1 0.05 0.5 0.1 0.1 0.1 0.1 0.01 0.01 0.0001

0.1 0.03 0.3 0.1 0.1 0.1 0.1 0.01 0.01 0.0003

0.0001 0.0001 0.1 0.01

0.0001 0.0003 0.1 0.03

0.0001 0.0005 0.0001 0.0001 0.0005 0.0005 0.00001 0.0001

0.00003 0.00003 0.00003 0.00003 0.00003 0.00003 0.00003 0.00003

59

VII RESULTS AND DISCUSSION

VII.1 Semivolatile Organic Compounds VII.1.1 Total Petroleum Hydrocarbons Bayou Grande has NAS on its southern bank. NAS is a major center for US Navy aviation activities that consumes large quantities of petroleum products that include aviation fuels, petroleum fuels, other products for vehicles and marine craft, and other diverse demands for petroleum products. NAS and also the urban activities on the northern shore of the Bayou are likely sources of spills related to fuel consumption. A likely mode of transport to the bayou of spilled petroleum product would involve stormwater and direct releases into the waters from marine activities. Contaminated aquifers are another possible source for TPH. There were four detections for TPH out of 23 analyzed sediment samples (Table 14). Three of these detections occurred in sediments located in embayments that are adjacent to the more developed areas of the watershed (Figure 22). All of the detections were below the analytical reporting limit for the analyses. The highest detection (sample GF-17, 150 mg/kg) was in Davenport Bayou that is actually not part of Bayou Grande, but is directly adjacent to it. The second highest detected level of petroleum hydrocarbons was from sample GF-2 (69 mg/kg) in the Yacht Basin of NAS, where sailing boats are moored. Detections also occurred for sample GF-19 taken from Navy Point Bayou (also adjacent to Warrington) and GF-20, which is located in the western end of the bayou that is proximal to the most undeveloped regions of Bayou Grande. In Bayous Texar and Chico, a short distance to the east of Bayou Grande, the frequency of detections and the concentrations of TPH were higher with maximum values up to 1700 mg/kg in Bayou Texar (Mohrherr et al., 2005; 2006). The method detection limit (MDL) for Bayou Grande sediment for these analyses was approximately 8-130 mg/kg. It could be argued that a lower MDL would have resulted in more detections, however the highest detected concentration of 150 mg/kg is several times less than the higher concentrations detected in Bayous Chico and Texar. These data indicate that the TPH concentrations in sediments in Bayou Grande are generally low. The presence of TPH in the water column is, however, a source for concern because oil in aquatic systems is harmful to shellfish, finfish, marine mammals and waterfowl that live near the spill. Oil spills are unsightly to the general public and are expensive to clean up. In addition, damage to fisheries places a hardship on those who make their living by fishing. The concentrations of detected TPH were relatively low in water (highest was 0.19 mg/l) and no oil slick was sighted. Detection of TPH in water occurred in three out of eight samples. Aqueous sample GW-6 (located at the mouth of Bayou Grande), GW-7 (located in the Yacht Basin), and GW 8 (located in Redoubt Bayou) had trace amounts of petroleum (Table 15, Figure 20). It is not clear where the TPH detected in the three positive aqueous samples may have come from. Samples GW-7 and GW-8 in Redoubt Bayou are adjacent to likely sources but GW-6 is actually at the interface between Bayou Grande and Pensacola Bay. The non-detect samples were taken on February 6, 2007 and the three positive samples were taken on February 14, 2007. This suggests that a release of petroleum may have occurred between these dates. On February 13th,

60

just prior to the collection of February 14th, a 3.00 cm rain event occurred. This was the first rain after a 1.4 cm rain two weeks earlier. It is possible that the rainfall created runoff that transported a land based oil release to the bayou. Since it was found in three separate sites, it is not possible to predict a precise location for such a release. Table 14. Total petroleum hydrocarbons [mg/kg] in surface sediments. Sample ID GF-1 GF-2 GF-3 GF-4 GF-5 GF-6 GF-7 GF-8 GF-9 GF-10 GF-11 GF-12 GF-13 GF-14 GF-15 GF-16 GF-17 GF-18 GF-19 GF-20 GF -21 GF -22 GF -23

TPH