Phytotoxicology 1998 Investigation: Algoma Steel Inc. - Sault Ste. Marie Report No. SDB-075-3511-1999 February, 2000 Prepared by: Ontario Ministry of the Environment Environmental Monitoring and Reporting Branch Last Revision Date: May 2013 Cette publication hautement spécialisée n’est disponible qu’en anglais en vertu du règlement 671/92, qui en exempte l’application de la Loi sur les services en français. Pour obtenir de l’aide en français, veuillez communiquer avec le ministère de l’Environnement au 705-564-3237. For more information: Ministry of the Environment Public Information Centre Telephone: 416-325-4000 Toll free: 1-800-565-4923 Email:[email protected] www.ontario.ca/environment © Queen’s Printer for Ontario, 2013 PIBS 9483e Phytotoxicology 1998 Investigation: Algoma Steel Inc. - Sault Ste. Marie Background: Algoma Steel Incorporated is an integrated primary iron and steel producer located on the St. Mary's River in Sault Ste. Marie, Ontario. Integrated mills process iron ore in blast furnaces where coke is burned to heat the ore. As it burns, coke releases carbon monoxide which chemically reduces the ore, consisting primarily of iron oxides, to metallic iron. Limestone added to the furnace provides an additional source of carbon monoxide as well as acting as a flux to fuse with silicates in the ore. The resulting calcium silicate floats to the top of the molten iron and is drawn off as slag. A critical material in steel making is the coke. Coke consists mainly of carbon (90+%) and is produced by distilling coal. Coke provides the high heating value to smelt the iron ore and is also the source of carbon in steel. Integrated mills produce their own coke in coke ovens. The ovens are arranged in 'batteries' consisting of narrow vertical chambers. The heat to distill the coal is generated by burning gases in spaces between adjoining chambers. The volatile compounds released by the distillation are condensed to produce coal tar while the non- condensed gases are recovered and burned to distill fresh charges of coal. Polycyclic Aromatic Hydrocarbons: During coke production there are inevitable emissions of volatilized coal tar or of coal gas to the atmosphere. Major constituents of coke oven emissions are a class of organic compounds known as polycyclic aromatic hydrocarbons (PAHs). PAHs consist of three or more fused aromatic rings. Some consist only of carbon and hydrogen atoms while others have other atoms substituting carbon in the ring or function groups substituting hydrogen atoms. Consequently, it is possible to have a great diversity of PAHs. It is noteworthy that PAHs are not necessarily constituents of coal but can be formed during the coal distillation process. The boiling points of PAHs are usually high enough so that they will not persist in the atmosphere in vapour form, but will condense onto particulates which act as nuclei. Naphthalene is frequently reported to exist in the atmosphere in vapour form, despite its 218(cid:69)C boiling point. However, naphthalene sublimes and since this compound consists of only two rings it is not, strictly speaking, a polycyclic aromatic hydrocarbon. Because of the tendency of PAHs to condense onto particulates, their fate in the atmosphere in terms of dispersion and deposition characteristics, is dependant on the behaviour of the particulate nuclei. Consequently, small particles will be transported greater distances than larger particles and can theoretically contain a higher mass to volume ratio of adsorbed PAHs. However, since the greater the dispersion distance, the greater the dilution, ambient air concentrations of PAHs, either in vapour or particulate form, are invariably higher near a point source. The primary concern about PAHs is that some are considered probable human carcinogens. One of these, benzo(a)pyrene, has been the subject of considerable toxicological research and is the only PAH compound for which Ontario has an ambient air interim standard. This concentration, which is 1.1 nanograms per cubic metre per 24 hours is regularly exceeded at a MOE monitoring station located near a residential neighbourhood near the Algoma Steel complex. 1 SDB-075-3511-1999 Phytotoxicology 1998 Investigation: Algoma Steel Inc. - Sault Ste. Marie Investigation Procedures: The investigation which is the subject of this report was conducted on August 18 and 19, 1998 and consisted of collections of surface soil samples at 20 locations and tree foliage samples at 20 locations. These sampling locations were located at distances varying from about 300 to 3,800 metres from the coke ovens at the Algoma Steel complex, and covered an arc from WNW to SE of the ovens. The soil sampling locations were typically sodded lawns of residential properties or parks and school playgrounds which appeared to be undisturbed and therefore exposed to deposition of air-borne contaminants for extended periods of time. Locations near heavily travelled roads were purposely excluded to avoid influence from vehicle exhaust, particularly from diesel vehicles, since PAHs are emitted from such mobile sources. The tree foliage sites consisted of locations were there was a Norway maple tree, again away from major roads, and removed from sheltering influences of buildings or other trees. Norway maple was selected because it was the most common tree species in the investigation area and provided a receptor with consistent surface characteristics. Because of the necessity to locate suitable sites for both media, the concomitant soil and foliage sampling locations were usually not at the same property and could be as far as 400 metres apart. Figure 1 represents these locations on a map that was derived from an Ontario Base Map produced from aerial photography flown in 1978. Because this base map is 20 years old, some newly constructed streets may not be indicated. After a suitable soil sampling location was identified, the location was documented with a sketch map showing the actual sampling location with respect to permanent features such as roads and buildings. All sampling equipment that would be in contact with the sample was washed with a high-phosphate detergent, rinsed with deionized water, and then successively rinsed with acetone and hexane. The sample containers consisted of amber glass jars with aluminum foil lids. These containers were previously washed with a detergent solution followed by several dionized water rinses and were provided by the analytical laboratory. A sampling location consisted of an area about 10 metres by 10 metres within the residential lawn or park/school property. About 12 cores of soil to a depth of five centimetres were randomly removed with a soil coring device consisting of a hollow, two centimetre diameter, stainless steel tube fitted with a cutting tip. The individual cores were placed into a stainless steel bowl, dis-aggregated, homogenized and transferred to a labelled sample jar. The Norway maple foliage sampling consisted of documenting the tree location and using a tree branch pruner on extension poles to cut a branch from the side of the canopy that faced the Algoma Steel complex. About 50 leaves were removed by hand while wearing latex gloves and placed into a labelled sampling jar. All samples were forwarded to the MOE Laboratory Services Branch for determination of PAH concentrations by gas chromatography - mass spectrometry (GC-MS). 2 SDB-075-3511-1999 Phytotoxicology 1998 Investigation: Algoma Steel Inc. - Sault Ste. Marie Figure 1: Tree Foliage and Surface Soil Sampling Locations Algoma Steel, Sault Ste. Marie - August 18 & 19, 1998 Results: The results of the analysis of the foliage samples are reported in Table 1. Note that the concentrations are reported in nanograms per gram, also known as parts per billion, on a fresh weight basis. Table 2 contains the PAH concentrations in surface soil samples. These data are reported in nanograms per gram on a dry weight basis. 3 SDB-075-3511-1999 Phytotoxicology 1998 Investigation: Algoma Steel Inc. - Sault Ste. Marie Table 1: Algoma Steel Inc. - PAHs (ng/g fw) in Norway Maple Foliage - August 18, 1998 Site 1 Site 2 Site 3 Site 4 Site 5 Site 6 Site 7 Site 8 Site 9 Site 10 Naphthalene 100 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Acenaphthylene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Acenaphthene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Fluorene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Phenanthrene 60 <T 40 <T 20 <W 20 <W 20 <W 80 <T 20 <W 20 <W 20 <W 20 <W Anthracene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Fluoranthene 100 60 <T 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Pyrene 60 <T 40 <T 20 <W 20 <W 20 <W 40 <T 20 <W 20 <W 20 <W 20 <W Benzo(a)anthracene 40 <T 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Chrysene 100 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Benzo(b)fluoranthene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Benzo(k)fluoranthene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Benzo(a)pyrene 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W Indeno(1,2,3-c,d)pyrene 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W Dibenzo(a,h)anthracene 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W Benzo(g,h,i)perylene 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W Site 11 Site 12 Site 13 Site 14 Site 15 Site 16 Site 17 Site 18 Site 19 Site 20 Naphthalene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Acenaphthylene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Acenaphthene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Fluorene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Phenanthrene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Anthracene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Fluoranthene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Pyrene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Benzo(a)anthracene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Chrysene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Benzo(b)fluoranthene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Benzo(k)fluoranthene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W Benzo(a)pyrene 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W Indeno(1,2,3-c,d)pyrene 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W Dibenzo(a,h)anthracene 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W Benzo(g,h,i)perylene 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 40 <W 4 SDB-075-3511-1999 Phytotoxicology 1998 Investigation: Algoma Steel Inc. - Sault Ste. Marie Table 2: Algoma Steel Inc. - PAHs (ng/g dw) in Surface (0-5 cm) Soil - August 19, 1998 Site 1 Site 2 Site 3 Site 4 Site 5 Site 6 Site 7 Site 8 Site 9 Site 10 OTR Table B R/P Table B I/C 98 Naphthalene 280 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 75 <T 40,000 40,000 Acenaphthylene 140 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 47 <T 100,000 100,000 Acenaphthene 20 <T 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 32 <T 1,000,000 1,000,000 Fluorene 60 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 39 <T 350,000 350,000 Phenanthrene 1100 100 120 420 60 <T 80 <T 60 <T 80 <T 40 <T 180 310 40,000 40,000 Anthracene 180 20 <W 20 <W 60 <T 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 58 <T 28,000 28,000 Fluoranthene 2600 160 200 1000 140 180 120 200 120 300 560 40,000 40,000 Pyrene 2400 140 160 740 120 140 100 160 100 220 490 250,000 250,000 Benzo(a)anthracene 1300 80 <T 100 380 60 <T 80 <T 40 <T 80 <T 60 <T 100 360 40,000 40,000 Chrysene 1400 100 160 500 60 <T 80 <T 60 <T 120 60 <T 100 350 12,000 19,000 Benzo(b)fluoranthene 1400 120 120 560 80 <T 100 60 <T 120 60 <T 100 300 12,000 19,000 Benzo(k)fluoranthene 1000 80 <T 80 <T 360 60 <T 60 <T 40 <T 80 <T 60 <T 80 <T 260 12,000 19,000 Benzo(a)pyrene 1100 80 <T 120 <T 360 80 <T 80 <T 80 <T 80 <T 80 <T 80 <T 300 1,200 1,900 Indeno(1,2,3-c,d)pyrene 800 80 <T 80 <T 320 40 <W 80 <T 40 <W 80 <T 40 <W 80 <T 230 <T 40,000 40,000 Dibenzo(a,h)anthracene 320 80 <T 80 <T 160 <T 40 <W 80 <T 40 <W 80 <T 80 <T 80 <T 77 <T 1,200 1,900 Benzo(g,h,i)perylene 800 80 <T 80 <T 320 80 <T 80 <T 40 <W 80 <T 40 <W 80 <T 280 <T 40,000 40,000 Site 11 Site 12 Site 13 Site 14 Site 15 Site 16 Site 17 Site 18 Site 19 Site 20 OTR Table B R/P Table B I/C 98 Naphthalene 20 <W 20 <W 40 <T 40 <T 20 <W 20 <W 20 <W 40 <T 20 <W 60 <T 75 <T 40,000 40,000 Acenaphthylene 20 <W 20 <W 40 <T 40 <T 60 <T 20 <W 20 <W 20 <W 20 <W 80 <T 47 <T 100,000 100,000 Acenaphthene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 180 32 <T 1,000,000 1,000,000 Fluorene 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 20 <W 240 39 <T 350,000 350,000 Phenanthrene 80 <T 260 220 240 120 60 <T 120 200 80 <T 4,100 310 40,000 40,000 Anthracene 20 <W 40 <T 40 <T 40 <T 40 <T 20 <W 20 <W 40 <T 20 <W 420 58 <T 28,000 28,000 Fluoranthene 380 700 860 760 480 100 260 520 160 7,200 560 40,000 40,000 Pyrene 340 560 680 640 420 80 <T 220 440 120 5,100 490 250,000 250,000 Benzo(a)anthracene 180 260 320 240 220 40 <T 100 200 40 <T 2,300 360 40,000 40,000 Chrysene 180 260 340 320 240 40 <T 100 240 60 <T 2,500 350 12,000 19,000 Benzo(b)fluoranthene 180 320 480 440 440 60 <T 120 300 60 <T 3,000 300 12,000 19,000 Benzo(k)fluoranthene 160 220 320 280 280 40 <T 100 200 40 <T 1,900 260 12,000 19,000 Benzo(a)pyrene 160 <T 280 360 320 320 40 <W 120 <T 200 40 <W 2,200 300 1,200 1,900 Indeno(1,2,3-c,d)pyrene 120 <T 200 280 240 280 40 <W 80 <T 200 40 <W 1,600 230 <T 40,000 40,000 Dibenzo(a,h)anthracene 80 <T 120 <T 120 <T 120 <T 40 <W 40 <W 80 <T 80 <T 40 <W 640 77 <T 1,200 1,900 Benzo(g,h,i)perylene 120 <T 200 320 240 280 40 <W 80 <T 200 40 <W 1,500 280 <T 40,000 40,000 5 SDB-075-3511-1999 Phytotoxicology 1998 Investigation: Algoma Steel Inc. - Sault Ste. Marie Discussion: The data in Table 1 reveal that, as a rule, PAHs were not detected in Norway maple foliage during this investigation. Of the 20 samples analyzed, concentrations of all PAH compounds in 17 of the samples were reported to be below measurable levels of either 20 or 40 ng/g. These data are flagged with the remark '<W'. In two samples, some PAH compounds were reported at trace levels and flagged with '<T'. In the remaining sample, which was collected at Site 1, some compounds were abundant enough to be quantified, others were detected at trace concentrations, while the remainder were still below measurable levels. PAHs are not naturally present in vegetation at concentrations that can be detected by routine analyses. They are also not assimilated from the soil to any appreciable extent. Therefore, it is possible to say that, in the absence of a source, PAHs in tree foliage are below the concentrations represented by the analytical detection limits. If PAHs are detected, the presence of a source must be assumed. Site 1 is located in the residential area immediately northwest of the coke oven batteries of Algoma Steel. The distance between Site 1 and the batteries is about 200 or 300 metres. The site is also very close to the MOE air monitoring station where the interim air quality standard for B(a)P is frequently exceeded. Consequently, the presence of these compounds at detectable concentrations at Site 1 can reasonably be attributed to emissions from the coke oven batteries. However, with most of the sites reporting non-detectable PAH concentrations, it is not possible to the define the areal extent of the PAH deposition to foliage. On the basis of the data gathered in this investigation, PAH deposition can only be confirmed in the immediate vicinity of the coke ovens. The use of foliage sampling to assess PAH emissions around other sources has produced mixed results. A trial of such methodology was performed in Hamilton near the Stelco and Dofasco steel mills, and in Windsor, across the Detroit River from the Great Lakes Steel mill in Detroit. In the case in Windsor, the sampling sites were one or more kilometres from the coke ovens and foliar PAHs were not detected. In Hamilton, at one sampling location about 1,700 metres from the Dofasco coke ovens, foliar PAH concentrations were very similar those found at Site 1 near Algoma Steel. However, at other Hamilton sites at similar or greater distances from coke ovens, PAHs were not detected in the foliage samples. Foliage sampling in the vicinity of at one PAH source has occasionally been successful in delineating areal influence. This occurred in the vicinity of the UCAR Carbon plant in Welland. UCAR manufactures carbon and graphite electrodes, using coal tar pitch as a principal ingredient. Quantifiable foliar PAH concentrations occurred at several sites around this source on two occasions. However, on a third occasion is appeared that a heavy rain storm washed any accumulated PAH-containing particulates from the foliar surfaces and PAHs were not detected. To see if this could be a factor in the observations made during the Algoma investigation, Environment Canada meteorological data for Sault Ste. Marie were examined. It was noted that on August 17, 1998, i.e. the day before the foliage sampling, 6.8 mm of precipitation was recorded at the airport. On August 14, 1998, i.e four days before the foliage sampling, 2.6 mm was recorded. It is not possible to determine if these rainfalls were instrumental in washing the particulates from the foliage just prior to sampling. Should this investigation be repeated, careful 6 SDB-075-3511-1999 Phytotoxicology 1998 Investigation: Algoma Steel Inc. - Sault Ste. Marie timing would be advisable to ensure an extended dry period before sampling so that the current areal extent of PAH deposition can be determined. Table 2 represents the surface soil PAH concentrations. Assuming that atmospheric deposition is the mechanism responsible for the PAHs in soil, then these data represent the net accumulation of PAHs over the time that the soil was exposed to the deposition. It is important to note that PAHs can be degraded by microorganisms and therefore these concentrations do not necessarily represent the total PAH accumulation over the period of exposure. Another point to remember is that, in urban areas, landscaping and construction activities can disturb indigenous soil. Therefore it is important to select sampling locations that have the greatest probability of minimal disturbance. Parks, cemeteries or similar green spaces, or old residential properties (i.e. without recent construction) are usually the most suitable sites. However, there can be no assurances that any two sampling locations contain soil that has been exposed to atmospheric deposition for similar periods of time. Table 2 also contains three columns containing reference concentrations to which the investigation data can be compared. The first of these columns, titled OTR , contain statistically 98 derived values representing the highest concentrations that might reasonably be expected in locations that were not subjected to contaminant deposition from nearby point sources. These values were developed through a sampling and analysis program that determined the range of inorganic and organic chemical concentrations in soil across the province of Ontario. Appendix A discusses the Ontario Typical Range (OTR ) guidelines. 98 It should be noted that the sampling sites contributing to these guidelines were old urban parkland sites, and since some sites in the Algoma Steel investigation do not fit this category, application of these guidelines to such sites is technically inappropriate. However, for lack of OTR data for residential sites, the old urban parkland OTR values remain the only reasonable 98 alternative. The other two columns, titled Table B R/P and Table B I/C, contain the human health or ecological based Table B criteria from the Guideline for Use at Contaminated Sites in Ontario. The intended use of the Guideline is to provide a means of assessing whether soil contamination at a property produces an unacceptable risk to receptor in the normal use or occupancy of the property. Different criteria may apply depending on whether the intended use is residential or parkland (R/P), or commercial or industrial (I/C). Appendix B provides more information about the Guideline and its application. The only instance where one of the Guideline criteria is exceeded is at Site 20 where the concentration of benzo(a)pyrene is 2,200 ng/g. This is higher than both the Table B R/P and Table B (I/C) values. This case is highlighted with bold type in Table 2. The shading in Table 2 highlights cases where the OTR guideline is exceeded. There are 98 seven sites where the OTR guidelines were exceeded for several PAH compounds. These are 98 Sites 1, 4, 12, 13, 14, 15 and 20. Sites 5, 7, 10, 16 and 19 do not contain any concentrations exceeding the OTR guidelines. 98 At the remaining eight sites, Sites 2, 3, 6, 8, 9, 11, 17 and 18, only the data for dibenzo(a,h)anthracene is shaded. It should be noted that the OTR guideline for this compound 98 7 SDB-075-3511-1999 Phytotoxicology 1998 Investigation: Algoma Steel Inc. - Sault Ste. Marie is 77 <T ng/g. The flag "<T" indicates that the guideline value was less than the limit established by the analytical laboratory for unqualified data. This in turn indicates that many of the samples used to develop the guidelines contained dibenzo(a,h)anthracene at concentrations that were too low to be accurately quantified. Consequently, the OTR guideline for dibenzo(a,h)anthracene 98 should be considered an approximation and cases were the value is marginally exceeded should not be considered significant. This leaves only the first group of seven sites were PAH concentrations are unquestionably above the OTR guideline. 98 In two of these seven, specifically Sites 1 and 20, these guidelines were exceeded by a significant degree. It is notable that Site 1 is the most proximal soil site to the Algoma Steel coke ovens, and given the observed deposition of PAHs to foliage near this site, it is reasonable to infer that the coke oven emissions are responsible for these soil PAHs. However, Site 20, which actually has even higher concentrations, is considerably farther away, situated near the canal. Most of the sites that were actually closer to the coke ovens, such as Sites 2, 3, 7, 8 and 18, reported concentrations that were below the OTR guidelines. Therefore, 98 it is inappropriate to suggest that the coke ovens are responsible for the PAHs at Site 20. Given the fact that PAHs are not exclusively associated with coke ovens, the high concentrations at Site 20 may be due to other causes. To reduce the data in Table 2 to more manageable proportions and to provide a visual representation of the relative PAH concentrations at the various sampling locations, the individual PAH concentrations for each sample were summed to produce "Total" PAH concentrations. Note that the remarks '<T' and '<W' were disregarded and the totals are simple sums of the data values. Note also that these totals are only of the 16 PAHs listed. The "Total" PAH concentrations are reported in Table 3. Table 3: "Total" PAH Concentrations (ng/g dw) in Surface (0-5 cm) Soil Site 1 Site 2 Site 3 Site 4 Site 5 Site 6 Site 7 Site 8 Site 9 Site 10 "Total" PAH 14,900 1,200 1,400 5,260 920 1,140 780 1,260 840 1,500 Site 11 Site 12 Site 13 Site 14 Site 15 Site 16 Site 17 Site 18 Site 19 Site 20 "Total" PAH 2,080 3,500 4,460 4,000 3,280 680 1,480 2,920 840 33,020 These data are also represented in Figure 2 which was prepared by placing vertical bars, whose heights are directly proportional to the "Total" PAH concentrations listed in Table 3, at each respective soil sampling location symbol. 8 SDB-075-3511-1999