Luận án tiến sĩ: Implications of vehicle emissions in Lake Tahoe soils and sediments (Nevada, California)

hydrocarbons PAH, other petroleum hydrocarbons PHC and phosphorus, derivedfrom engine oil, in several Lake Tahoe soils and sediments.. The PAH profile in marina sediments, road runoff lo

Implications of vehicle emissions in Lake Tahoe soils and sediments

A thesis submitted in partial fulfillment of the

requirements for the degree of Doctor of Philosophy in

Environmental Science and Health

By: Veronica Edirveerasingam

Dr Glenn C Miller/ Dissertation Advisor

August, 2006

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We recommend that the dissertation

prepared under our supervision byVERONICA EDIRVEERASINGAM

entitledImplications of vehicle emissions in Lake Tahoe soils and sediments

be accepted in partial fulfillment of therequirements for the degree of

hydrocarbons (PAH), other petroleum hydrocarbons (PHC) and phosphorus, derived

from engine oil, in several Lake Tahoe soils and sediments The PAH profile in marina

sediments, road runoff locations and from water collected immediately after running a 4

stroke engine in a tank had similar signatures, and data collected in this study offered

strong evidence that engine emissions were the primary source of these hydrocarbon

contaminants in Lake Tahoe soils and sediments Two PAH’s, fluoranthene and pyrene

were observed at relatively high concentrations, and were signature compounds in the

sediments In addition, a strong and positive correlation existed for PAH and TPH in

road runoff soils and marina sediments indicative of PAH related to vehicle emission

Phosphorus is an additive to most 4-cycle engine oils and observed at a

concentration of 700-1500 mg/L in new and used engine oils Although this source of

phosphorous is potentially significant for nutrient addition to Lake Tahoe, it comprises

only a relatively small fraction in the soils and sediments, compared to natural

concentrations The Tahoe soils examined had a total phosphorus content of 500-1000

mg/kg and an available phosphorus content of 20-100 mg/kg Assuming 0.1 % of

phosphorus content in the oil and a TPH content of 3000-5000 mg/kg in the highly

vehicle affected areas, the phosphorus contribution from engine oil is only 3-S5mg/kg

Alternatively, the hydrocarbon contaminated sediments released more phosphorus

into the water under anaerobic conditions and suggests that petroleum hydrocarbons can

drive anaerobic processes that eventually will release phosphorus This is likely an issue

in marina sediments, as well as flooded catchment basin sediments

The three catchment basins examined in the Kings beach area appeared effective

in retaining the contaminants The inlets had high TPH, and PAH concentrations in

comparison to the outlets and soil cores collected at different depths in each basin had

hydrocarbon concentrations low in the native depths and high in the layer where sediment

had accumulated PAH leaching was evaluated in basin soils and the results indicated

that only a small fraction (<0.1%) of PAH compounds would leach

I thank Dr Glenn Miller, for giving me the opportunity to work in his lab and

complete my degree Appreciation is extended to all my committee members, Dr Dale

Johnson, Dr Jerry Qualls, Dr John Sagebiel, and Dr Mark Walker for all their input and

for their valuable advice

Special thanks for my colleagues who held my hand and encouraged me to never

give up and push forward Their words were “no pain no gain” I thank the agencies that

funded this project (Tahoe Regional Planning Agency and Lahontan water Quality

Board) and to all those helping hands Janis Hall and Elizabeth Harris Gratitude is

extended to Dr Sandra Carroll, Kendra Zamzow, Cindy Hoonhout, Jim Woodrow and

Victoriya Lepak for help with the lab instruments My sincere appreciation to Mary

Miller at Desert Research Institute (DRI) for analyzing total phosphorus in soil samples

and to Dr Rick Susfalk who is also at DRI for his valuable input related to phosphorus in

Lake Tahoe soils

I thank my parents and brothers for their constant encouragement At a very

young age, they made me believe that education is important fora woman Above all, I

thank God for the opportunity that was given me

TABLE OF CONTENTS

CHAPTER 1: Polycyclic aromatic hydrocarbons profile and total

petroleum hydrocarbon loading in Lake Tahoe sediments

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Materials and methodS cece eee e eee ng nh snes ss

(a) Four stroke engine operation to examine PAH compounds

from engine emissions In WAf€T c cà e ene ene

(b) Road dust and marina sampling

(c) Sediment characterization and TOC analysIs

(d) Total petroleum hydrocarbon determination

(e) Polycyclic aromatic hydrocarbon determination

Results and discussion (a) The distribution of PAH and PHC in marina sediments and along in the road runoff areaS cà se PAH vs TPH TPH vs TOC PAH vs TOC (b) The concentration of PAH in different sieve size fractions in both marinas and road runoff locaflOns

(c) PAH profile observed in engine emission and in marina S320 2 EE EE EEE EEE EEE Ee (d) Road runoff and marina locations PAH profile

Conclusion

Literature cited

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Materials and methods c2 nh key

(a) Sampling ÏOCatIO'S ch ky

(b) Leaching experImert

(C) ANAlySiS 0 ca EEE EEE EE eee

(d) Statistical anaÏVSIS cece cece ence nh kh

Results and đISCUSSIOT c CS SH nh nena ena ng

(1) Sources of PAH and TPH to the Tahoe basin

(II) Catchment basins c {cớ

(a) Concentrations of polycyclic aromatic hydrocarbons (PAH),

total petroleum hydrocarbon (TPH), and total organic carbon

(TOC) content in the baSInS ccccc sees eases

(b) PAH compounds and TPH in different sieve fractions in Coon,

Salmon, and Hwy 28 basin nh

(IIT) Leaching of the PAH compounds in different depths

Conclusions 00.0 cece cece eeeceeecesesvesvesvesvesvesvesvesvesvesvesvesvesvesvesvenss

Literature CI{€C eee eee eee eee eee tsetse eee tsetse teens

CHAPTER 3: Phosphorus in engine oil and its availability in soils

and sediments

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Materials and methodS ng ng nh khu

(b) Phosphorus content in new and used engine oIÌs 112

(c) water extractable phosphorus in engine oIÏs 112

(d) Release of available phosphorus in sediments and soils under 113anaerobic and aerobic cOndItIO'S

Results and đISCUSSIOT nh nh nha 115

(a) Phosphorus content in new and used engine oiÌs 115

(b) Water extractable and available phosphorus in 4 stroke and 118used engine OIÏÌS ‹ ene en nen en nh kh hy

(c) Available phosphorus and petroleum hydrocarbon in soils and 122S€dIIN€TIS ence eee tees neta ene ene ng nh nh nh nen

(d) Release of bioavailable phosphorus under anaerobic and 132aerobic conditions in soils and sediments

ConcÌÏUSION eee e cece cece cece eee e eee ee eee seeeeeeeeeeeeeeeee sees 138

CHAPTER 4: Summary and Conclusions 143

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Location of the road runoff and marina samples

The quantification ion, confirmation ions, and retentiontime for each PAHs c cv

PAH concentration (ng/g) dry wt basis and TPHconcentration (mg/kg) dry wt basis in road runoff andmarina locations in Lake Tahoe sediments

Percent total organic carbon as a result of total petroleumhydrocarbon in road runoff and marina locations

Road runoff and marina TOC (%) and PAH (ng/g) dry

MANOVA showing the differences in PAH compounds

in road runoff and marina sediments when they werenormalized to fluoranthene

CHAPTER 2

Table 2.1: Less vehicle affected sampling locations in Kings 50

Table 2.2: Highly vehicle affected sampling location in Kings 51

Beach 0 cece cc eceeeeceee ences ee eeeeneeneeeeneeneenenens

Table 2.3: Soil types in the Kings Beach (Descriptions were 54

obtained from the USDA Soil conservation service andForest service in cooperation with University ofCalifornia Agricultural Experiment Station and NevadaAgricultural Experiment Station Soil Survey of theTahoe Basin area California and Nevada, March 1974)

Table 2.4: Depths used for each basin for statistical analysis 59

Table 2.5: Concentrations of total petroleum hydrocarbon (TPH) 62

mg/kg dry wt basis and polycyclic aromatichydrocarbons (PAH) ng/g dry wt basis for sites lessaffected by vehicle traŸllc ‹-

Table 2.6: Concentrations of total petroleum hydrocarbon (TPH) 63

mg/kg dry wt basis and polycyclic aromatichydrocarbons (PAH) ng/g dry wt basis for sites affected

by vehicle trafflc c {c2

Table 2.7: PAH, TPH, and TOC content of Coon basin 76

Table 2.8: PAH, TPH, and TOC content of Salmon basin 77

Table 2.9: PAH, TPH, and TOC content of Hwy 28 basin 77

Table 2.10: | PAH concentrations (ng/g) dry wt basis at different 78

depths in Coon basin cà

Table 2.11: | PAH concentrations (ng/g) dry wt basis at different 78

depths in Salmon

basin ‹ Table 2.12: | PAH concentrations (ng/g) dry wt basis at different 79

depths in Hwy 28 basin cc ene ee

Leachate results of the Coon basin at 14cm depth (n=3).

Leachate results of the Coon basin at 20cm depth (n=3)

Leachate results of the Salmon basin at 14cm depth (n=3)

Leachate results of the Salmon basin at 20cm depth (n=3)

Leachate results of the Hwy 28 basin at 12cm depth

Leachate results of the Hwy 28 basin at 20cm depthCle) re

Annual phosphorus loading budget for Lake Tahoe fromReuter et al., 2001 ccc ee ccce ch nhau

Percent total organic carbon (TOC) and total petroleumhydrocarbon (TPH) of soils from three depths in

catchment basins and marina sediments

Concentrations of elements (mg/L) found in 2 strokeengine oils, 4 stroke engine oils and used oils (analyzed

by Stavely Fluid analysis services, Sparks, NV)

Extractable total phosphorus and available phosphorusfrom I ml of new and used oils into wafer

Extractable total and available phosphorus in 49 ml ofwater (mg/L) when Iml of the following new and usedOils Were MIXEd 0 cece eet e eee eee ene

Kings Beach eee ee eee eee nena een es

Total petroleum hydrocarbon and bioavailablephosphorus from highly vehicle traveled areas

Total petroleum hydrocarbon, TOC content, andbioavailable phosphorus of the marina sediments inmg/kg dry wt basis and percentage (1%=10,000 ppm)

Percent of bioavailable phosphorus as a result of engineoil in less vehicle affected sites, sites highly affected byvehicle activity, and marInaS ‹

Eh readings of anaerobic and aerobic sediments and

Release of phosphorus under aerobic and anaerobicconditions in 11 marina sediments and 6 soils from twocatchment basInS

LIST OF FIGURES

CHAPTER 1

Figure 1.1: Pictures of some of the road runoff and marina sampling

Figure 1.2: Lake Tahoe sampling locatlons

Figure 1.3: — Polycyclic aromatic hydrocarbon (ng/g) dry wt basis vs

total petroleum hydrocarbon (mg/kg) dry wt basis inroad runoff loCatIOnS cà

Figure 1.4 Polycyclic aromatic hydrocarbon (ng/g) dry wt basis vs

total petroleum hydrocarbon (mg/kg) dry wt basis inMarina ÏOCafIOPS na

Figure 1.5: TOC (%) vs TPH (%) in marina locations except Elk

POHTI HT nh nh nh nh cà

Figure 1.6: TOC (%) vs TPH (%) in road runoff locations

Figure 1.7: Polycyclic aromatic hydrocarbon (ng/g) dry wt basis vs

percent total organic content in marina locations

Figure 1.8: — Polycyclic aromatic hydrocarbon (ng/g) dry wt basis vs

percent total organic content in road runoff sites

Figure 1.9a Sediment characterization of road runoff sites Nearly

72% of sediments are sandy coarse material and less than6% is Silty SAnd HH kg

Figure 1.9b: PAH concentration from eleven road runoff locations in

three different sieve fractions (2mm-212um, 212 75um, and <75UM) 0 cece cece eect teense eae ene ene

um-Figure Sediment characterization of marinas Nearly 80% of

1.10a: sediments are sandy coarse material and less than 2% is

Ji

Figure PAH concentration from six marina locations in three

1.10b: different sieve size fractions (2mm-212um, 212

um-75um, and <7SUm) nh si,

Sediments (n=9)with standard error bars

PAH concentrations in engine emission and marina 34sediments normalized to fuoranthene

PAH concentrations in engine emission and marina 34sediments transformed to log and normalized to

fluoranthene cọ nen

The PAH profile in road runoff and marinas in Lake 36Tahoe Mean PAH concentration (ng/g dry wt basis)

and standard error bar§ cc

PAH compounds in road runoff and marina locations 37normalized to fluoranthene Mean PAH concentration

(ng/g dry wt basis) and standard error bars

Catchment basin locations and background sampling 52sites White boxes are vehicle affected sites and green

boxes are sites less affected by vehicle traffic

Descriptions of the acronyms are given in Table 2.1 and102225 cnet nee e eee ne enon ene enennennens

Soil types in the Kings Beach area The sampling site 53consists mostly CaF, JhC and UmF soils from andesitic

sources listed in Table 2.3 Map was obtained from theUSDA Soil conservation service and Forest service incooperation with University of California AgriculturalExperiment Station and Nevada Agricultural Experiment

Figure 2.3a:

Figure 2.3b:

Figure 2.3c:

Figure 2.4:

Figure 2.5:

Figure 2.6:

Figure 2.7:

Figure 2.8:

Figure 2.9:

Figure 2.10:

Figure 2.11:

Figure 2.12:

Figure 2.13:

Figure 2.14:

Figure 2.15:

Figure 2.16:

Station Soil Survey of the Tahoe Basin area California

and Nevada, http://tahoe.usgs.gov/files/soil meta.txt

Coon basin covered with snow in WInf€f

Salmon basin in summer

Hwy 28 basin In Spring cce ccc eee eee ene eee een een es Leaching experiment

setup ‹-Total petroleum hydrocarbon vs polycyclic aromatic hydrocarbons linear regression line for less vehicle affected sampling Sifes cài Total petroleum hydrocarbon vs polycyclic aromatic hydrocarbon linear regression for sites affected by Ve€hli€Ï€S ce eee ee ene eeeneeneeneneeneeneeaeneeees PAH concentration (ng/g) dry wt basis in soils from Loch Levon and Speckled Avenue vegetation sites

PAH concentration (ng/g) dry wt basis in soils from Trout and Stealhead vegetation sItes

PAH concentration (ng/g) dry wt basis in sites 3-20m away from the road cccc cv: PAH concentration (ng/g) dry wt basis in soils from across the DaSITS nh nhu PAH concentration (ng/g) dry wt basis in three water COLlLECTOLS 0 kee cee cece ee eeseeeeeseeseeeeeeeneeneans PAH concentration in vehicle affected road sides

PAH concentration in InlefS

PAH concentration in ouftlefS

PAH concentration in and next to culverts

Soil samples collected close to lake

55

55

55

57

64

64

65

66

67

68

69

70

71

72

73

74

Total PAH (ug/g dry wt basis) and total petroleumhydrocarbon (mg/g dry wt basis) in Coon basin atdifferent depths cà.

Total petroleum hydrocarbon (mg/g) dry wt basis andpercent total organic carbon content in the Salmon basin

at different depths c cà

Total PAH (ug/g dry wt basis) and total petroleumhydrocarbon (mg/g dry wt basis) in Salmon basin atdifferent depths cà,

Total petroleum hydrocarbon (mg/g) dry wt basis andpercent total organic carbon content in the Hwy 28 basin

at different depths c cà

Total PAH (ug/g dry wt basis) and total petroleumhydrocarbon (mg/g dry wt basis) in Hwy 28 basin atdifferent depths cà v2

Coon basin total PAH (ng/g) dry wt basis at differentdepths in the three sieve SIZ€S à

Coon basin total TPH (mg/g) dry wt basis at differentdepths in the three sieve SIZ€S -

Salmon basin total PAH (ng/g) dry wt basis at differentdepths in the three sieve SIZ€S

Salmon basin total TPH (mg/g) dry wt basis at differentdepths in the three sieve SIZES

Highway 28 basin total PAH (ng/g) dry wt basis atdifferent depths in the three sieve S1Z€S

Highway 28 basin total TPH (mg/g) dry wt basis atdifferent depths in the three sieve SIZ€S

PAH compounds found in the Leachate from Coon 14cmand 20cm samples ‹

PAH compounds found in the Leachate from Highway

28 basin,12cm and 20cm samples

Total petroleum hydrocarbon (mg/kg) vs Bioavailablephosphorus (mg/kg) from less vehicle affected areas

Total petroleum hydrocarbon (mg/kg) vs Bioavailablephosphorus (mg/kg) from highly vehicle traveled

Total petroleum hydrocarbon (mg/kg) vs Bioavailablephosphorus (mg/kg) from Lake Tahoe marina sediments

Total petroleum hydrocarbon (mg/kg) and averageavailable phosphorus concentration in water (ug/L) underanaerobic and aerobic conditions

Available phosphorus and TPH concentration inanaerobic and aerobic sediments (mg/kg) dry wt basis

Polycyclic Aromatic Hydrocarbons Profile and Total Petroleum

Hydrocarbon Loading in Lake Tahoe Sediments

released during vehicle and watercraft use and are associated with sediments due to their

high octanol water partition coefficients (Koy) and low water solubility PAHs’ have

toxic, mutagenic and carcinogenic properties, and most species of aquatic biota rapidly

accumulate PAHs because of their high Koy

Significant sources of PAH into Lake Tahoe were considered to be from marine

engine exhaust as well as urban runoff Since PAHs sorb to organic matter, identifying

the concentrations in soils and sediments was found important to Lake Tahoe sediment

dwelling organisms The PAH concentration in the road runoff samples ranged from 163

ng/g dry wt basis (Highway 50) to 28,800 ng/g dry wt basis (Highway 28) This variation

was related to traffic activity Zephyr Cove and Timber Cove are marinas that had lower

PAH concentration 85-300ng/g dry wt basis The marinas with high PAH concentrations

were enclosed (i.e Elk point) and/or had high boating activity (i.e Tahoe keys Home

Owners, Tahoe Keys, and Ski Run) The PAH concentration in these marinas ranged

from 5970 -16800 ng/g dry wt basis

Fluoranthene and pyrene were the two PAH compounds observed at high

concentrations in soils and sediments When the 15 PAH compounds were normalized to

fluoranthene, no significant differences in PAH profiles were observed between the road

runoff and marinas When sediment and soil PAH signatures were compared to engine

emissions the profiles were similar for the high molecular weight compounds, but the

lower molecular weight compounds were depleted relative to fluoranthene This was

consistent with what would be expected based on solubility of each PAH compounds

Lake Tahoe is a high alpine lake known for its clear, deep waters and is uniformly

regarded as a scenic recreational resource between California and Nevada However,

increased urbanization and man made compounds have disturbed the natural ecological

systems within the Tahoe Basin, resulting in a decrease in water clarity over the past forty

years (Goldman and Byron, 1986) and an increase in pollutants due to vehicle traffic over

the past twenty years (Cliff and Cahill, Lake Tahoe water shed assessment report, 1999)

Petroleum hydrocarbons (PHC) consist of crude oil and refined petroleum (petrol

and diesel) The analytical term used when measuring PHC is total petroleum

hydrocarbon (TPH) The lighter hydrocarbons (Ca-Co) in the PHC mixture are soluble

and highly volatile and when TPH is determined on sediments, the lighter hydrocarbons

(<€¡o) are depleted and higher molecular weight fraction (>C¡o) remain, relative to the

low solubility components and persist in the soils High concentrations of TPH create

foul odors, aesthetic problems and adversely affect marine life Studies have shown that

fish exposed to petroleum in the water column and in sediments can readily take up

hydrocarbons into their liver, brain, and muscles (Varanasi et al., 1977; Malins and

Hodgins, 1981) Chapman et al., (1988) showed that gastropods exhibited reduced

activity on exposure to sub lethal concentrations of diesel

A subset of total petroleum hydrocarbon contaminants is the polycyclic aromatic

hydrocarbons (PAH), and is of concern due to their unique toxic properties These

compounds are products of incomplete combustion, primarily from internal combustion

engines, and are released into the Lake from direct marine engine exhaust and surface

runoff from vehicles

of their high log Koy Some of the known effects of PAHs include lethal and sub lethal

responses and changes in survival, growth, reproduction and metabolism, as well as

tumor formation in aquatic biota (Ziccardi et al., 2002) Studies have also reported that

high molecular weight compounds with three or more benzene rings are associated with

carcinogenic, mutagenic or teratogenic responses Low molecular weight two and three

ring PAH compounds are associated with acute (lethal) responses (Brandt et al., 2002)

PAHs associated with oil were converted into epoxy diols in fish, and these diols then

reacted with DNA and produced cancer-like tumors (Varanasi and Gmur, 1980)

PAHs are widespread contaminants and their persistence is dependent on

lipophilicity (Mackay et al., 1992) and other physical and chemical properties Under

direct UV light acenaphthylene, anthracene, fluoranthene, pyrene, and benzo(a) pyrene

are considered phototoxic because they can generate singlet oxygen and cause cell

damage (Oris et al., 1984) PAHs have low water solubility and very low vapor pressure

(Table 1.1) The PAHs listed in Table 1.1 are considered priority pollutants by U.S

Environmental Protection Agency as part of the Clean Water Act, section 301(h) EPA

TSD for 01(h)

analyzed in this study (obtained from Syracuse Research Corporation website:

Benzo(a)pyrene 252.3 <3.8x 10° 5.49 x10” 5.97 Benzo(b)fluoranthene 252.3 1.5 x 10” 5.0 x10” 6.12 Benzo(k)fluoranthene 252.3 8.0 x 107 2.0 x10” 6.12 Benzo(g.h,i)perylene 276.3 2.6x 10” 1.01x10”° 6.5§

Indeno (1,2,3-cd)pyrene 276.3 22x10” 1.0 x10" 6.58

Dibenzo(a.h)anthracene 278.4 2.5x10°-2.5 x10" 1.0x1019 6.50

in soils and sediments, half lifes increases from approximately 23 days to over 6 years.

(Environmental Health Crietria report, 1998

http://www.inchem.org/documents/ehe/ehe/ehc202.htm; Witt, 1995) In sediments and

biota, PAH’s have a strong affinity for lipophilic hydrocarbons and tend to persist in the

solid phase because of their high octanol water partition coefficients (Koy) and reduced

bioavailability The sediment particle size distribution is important to the physical

movement, chemical partitioning and biological fate of PAH’s The clay and silt

fractions contain more PAH than the sand fraction (Krein and Schorer, 2000)

PAH and petroleum hydrocarbons (PHC) related to vehicle traffic are released as

oil leaks, engine exhaust and tire wear from highly traveled roads Studies that examined

PAH compounds in gasoline and diesel in New Zealand (Ministry of Transport, Te

Manatu Waka, 2004) indicated that 75% of PAH is naphthalene, acenaphthylene, and

acenaphthene in both gasoline and diesel However, once they undergo combustion, the

exhaust contains 2-8 ring PAH from diesel emission and high molecular weight PAHs

(i.e indeno 1-2-3 [c.d] pyrene, benzo [g,h,i] perylene, and coronene) from gasoline

emission (Zielinska et al., 2004) Analyses of different tire material for PAHs indicated

that pyrene, benzo(a)anthracene, chrysene, and benzo(g.h.i)perylene, were present at

relatively high concentrations (Ministry of Transport, Te Manatu Waka, 2003)

Additionally, road dust may have PAHs from sealant materials Presently most of

highways are constructed with asphalt and, compared to coal tar sealant asphalts release

less PAHs in runoff (Mahler, et al., 2003 and 2005) PAH profiles of coal tar sealant

chrysene in abundance.

Boats and ships are sources of PAHs to sediments due to incomplete combustion

and oils leaks PAH concentrations vary dramatically from a low of 52 ng/g dry wt basis

at Chesapeake bay (Foster and Wright, 1988) and Todos Santos Bay 96 ng/g dry wt basis

(Macias-Zamora, 2002) to as high as 61000 ng/ g dry wt basis in Xiamen harbor (Hong

et , 1995) Also, concentrations in Sydney harbor (Mc Cready et al., 2000), and Kitimat

harbor (Simpson et al., 1996) were extremely high, nearly 3.8 x 10” ng/g dry wt basis.

Smaller contributions of PAH to the Tahoe Basin come from forest fires, wood

smoke and atmospheric deposition from distant sources (NRC, 1983) Data are scarce

regarding the PAH signature related to forest fires However, studies have shown that

wood smoke consists primarily naphthalene and phenanthrene, with concentrations nearly

10 to 20 times higher than anthracene, fluoranthene, and pyrene compounds (McDonald

et al., 2000) In addition, acenaphthylene, methylated naphthalenes, and methylated

phenantherenes were detected in wood smoke

Following storm events PHCs and PAHs migrate to Lake Tahoe attached to fine

sediments Our study examined road dust as a major source of these pollutants, because

it contains a combination of vehicle emissions, oil leaks, tires and road sealant materials

that have the potential to degrade water quality

Marinas are also another source of hydrocarbons into the lake In order to

determine the occurrence and distribution of PAHs, samples were collected from a wide

range of marinas with high and low boating activity Also if the PAH is from internal

combustion engines we expect that the PAH profile in the marina sediment should be

Lake Tahoe.

It was hypothesized that road runoff and marina sediments will have distinctive

PAH profiles than engine emissions Using PAH and TPH correlation we could identify

if the source is related to vehicle emission, because marinas get PAH and TPH directly

from engine emissions and a positive correlation for both PAH and TPH in marina

sediments will suggest that the source is engine emission than other sources Identifying

the PAH profile in marina sediments and plotting them against the PAH profile in road

runoff locations will positively indicate that the PAH in road runoff soils is from vehicle

emission rather than other inputs (wood smoke, forest fires, etc.) In addition, a positive

correlation for TPH and PAH in road runoff soils will suggest that the source is vehicle

emission

(a) Four stroke engine operation to examine PAH compounds from engine emissions

in water

A 4 stroke engine 9.9 hp Mercury Outboard manufactured in 1998 was operated

in a 500L test tank This tank was located at the University of Nevada Reno, Applied

Research Facility (Latitude 39° 32°69” N and Longitude 119° 48°87” W) The engine

was started followed by 5 min idling, and then speed was increased to ~5000 rpm, (90%

of full throttle) for 15min and then stopped The water was allowed to settle for 15 min

and water samples from the engine tank were collected in 1 L amber bottles and analyzed

for PAH compounds within 7 days The engine was operated for two other previous

studies in (August-November 2002; June -December 2003; and June- August 2004) that

examined the emission of PAH compounds in water from 2 stroke and 4 stroke engine

emission (Sufka, 2003) and their impact on C dubia daphnia (Carroll, 2005) The 4

stroke engine emission (n=9) PAH compounds in water was analyzed using EPA method

550.1 modified as described by Carroll (2005)

(b) Road dust and marina sampling

Sediment samples were collected in the Lake Tahoe basin 2002-2005 generally in

the spring, summer, and fall months (Figure 1.1, 1.2 and Table 1.2) A shovel and a

coring device were used and samples were placed in Zip-loc bags and stored at -20C

prior to analysis Road runoff soil samples were collected next to drainage ditches, water

collectors, and highly traveled road sites such as Highway 28 and Highway 50 Marina

sediments were collected from enclosed marinas and marinas that had direct access to the

lake (Table 1.2) The specific locations were chosen because they were close to the lake,

and were used as high boating activity areas

(c ) Sediment characterization and TOC analysis

Soil and sediment samples from road runoff and marinas were sieved using

different sieve sizes [>2mm (rocks), 2mm-212 um (Coarse sand), 212um-75um (sand),

<75um (silt)] The sieved samples were analyzed for PAH and TPH using a solvent

extraction method similar to McCready et al., 2000 Samples were extracted with a 1:1

ratio of methylene chloride: acetone and concentrated by evaporating to 2 ml with

nitrogen gas The samples extracted for PAH analysis were used for the TPH analysis

The total organic carbon (TOC) content was examined in soil and sediment samples

using a Perkin Elmer CHNS/O analyzer (PE 2400 series II)

(d) Total petroleum hydrocarbon (TPH) determination

TPH was determined in all marina sediments and Lake Tahoe road runoff

samples The TPH samples were analyzed using a HP 5890 series II gas chromatograph

equipped with a flame ionization detector (GC/FID) The carrier gas helium was set at

2.3 psi and hydrogen and air was set at 30 psi The column used was an HP-1 methyl

silicone 15m x 0.53mm x 0.25um i.d The column flow was 8.54 ml/min (73.6 cm/sec)

The initial oven temperature was set at 100 C and held for Imin, followed by temperature program at 20 C/min to 300 C and held for 15min The inlet and FID detector

temperature were set at 280C.

The TPH standards were prepared using a 4 stroke engine oil dissolved in ethyl

acetate The standard range was 0.16mg/ml-8 mg/ml and the retention time for the area

at which the bulk peak appeared for the standard was at 5-9min Ethyl acetate blanks

were placed after every 5 samples and the standards and sample peaks were subtracted

from the ethyl acetate detector response

(e) Polycyclic aromatic hydrocarbon (PAH) determination

A gas chromatograph equipped with a mass spectrometer (GC/MS Agilent Model

6890 GC with Agilent 5973 mass selective detector and Agilent 7683 autosampler) was

used for the PAH analysis A 30m long HP-5MS column with 0.25 mm i.d and 0.25um

film thickness was used Average flow velocity was 37cm/sec The carrier gas used was

ultra high purity grade helium The pressure was programmed to maintain a constant

flow of Iml/min The oven temperature program had an initial temperature of 65 C for lmin The temperature was increased at a rate of 10 C /min to 200 C and held for 2 min.

It was then increased at a rate of 8 C /min to a final temperature of 280 C and held for 10min The total run time was 36.5 min The post run temperature was 310 C and hold time was 8min The injection was splitless at 250 C and 8.91 psi with a total flow of

43.4ml/min

The GC-MS was operated in the selected ion monitoring (SIM) mode The most

abundant ion was used for quantification and two other ions were additionally used for

confirmation (Table 1.3) The standards were purchased from Accu Standard, Inc, New

Haven, CT, and prepared at concentrations ranging from 0.005 ng/ul to 5 ng/ul by

dissolving in ethyl acetate

Timber Cove road runoff

Elk Point marina Ski Run marina

Figure 1.1: Pictures of some of the road runoff and marina sampling locations

Background samples from Kings Beach area

Brockway

- Highway 28

Carnelian bay

Highway 50 Zephyr cove Elk Point

' Tahoe Keys Timber Cove

Tahoe Key Home Owners Lagoon

Figure 1.2: Lake Tahoe sampling locations

Table 1.2: Location of the road runoff and marina samples.

Road runoff sites GPS degrees, minutes, seconds

Cave Rock parking lot

Zephyr Cove parking lot

Elk Point

Kahle Drive

Edgewood

Stateline

Timber Cove Lake view intersection

Ski run Blvd intersection

Tahoe Keys parking lot

39°.10.13N, 120 °08.48 W 39°.14.37N, 120 °02.40 W 39°.10.20N, 120 °08.54 W 39°.14.21N, 120 °01.85 W 39°.14.27N, 120 °02.65 W 39°.00.4, 119 °56.85 W 39°.02.80N, 119 °56.94 W 39°.00.44N, 119 °56.85 W 38°.58.95N, 119 °56.68 W 38°.58.23N, 119 °56.16 W 38°.58.05N, 119 °56.92 W 38°.57.39N, 119 °56.90 W 38°.56.62N, 119 °58.62 W 38°.56.79N, 119 °57.30 W 38°.58.21N, 119 °59.83 W

38°.57.04N, 119 °57.55 W 38°.56.70N, 119 °58.64 W 38°.59.04N, 119 °57.38 W 39°.00.27N, 119 °57.07 W 38°.13.52N, 120 °08.89 W 39°.10.31N, 120 °08.24 W 39°.08.41N, 120 °09.21 W

Compound Quantification Confirmation ions Retention Time

Acenaphthene-d10 164 162 11.85Acenaphthylene 152 151 153 11.48Acenaphthene 154 153 152 11.92Fluorene 166 165 139 13.12

Phenanthrene —d10 188 94 80 15.39Phenanthrene 178 176 89 15.45

Anthracene-d10 188 94 80 15.52Anthracene 178 176 89 15.57Fluoranthene 202 101 200 19.43

Pyrene-d10 212 106 211 20.08Pyrene 202 101 200 20.13

Chrysene-d12 240 236 24.14Chrysene 228 226 114 24.10

p-Terphenyl-d14 244 243 122 20.97

Perylene-d12 264 263 130 28.50Benzo(a)anthracene 228 226 114 24.21Benzo(b,k)fluoranthene 252 126 250 27.30Benzo(a)pyrene 252 126 250 28.28Indeno (1,2,3-cd)pyrene 276 138 274 32.93Dibenzo(a,h)anthracene 278 139 274 33.17 Benzo(g,h,i)perylene 276 138 274 34.23

Results and Discussion

(a) The distribution of PAH and PHC along the road runoff areas and marinas

The total PAH and TPH concentration in road runoff and marina locations varied

by location (Table 1.4) The road runoff samples ranged from 163 ng/g dry wt basis

(Highway 50) to 28,800 ng/g dry wt basis (Highway 28) This variation was due to

heavy traffic activity in certain sites and parking lot use

The PAH concentration in the marinas varied depending on boating activity and

marina use Zephyr Cove and Timber Cove marinas had relatively low PAH

concentration (85-300 ng/g dry wt basis) probably because the sediment texture was

primarily coarse sand in these marinas In addition, these marinas are open marinas and

connected directly to the lake which allows moving water to deplete the marinas of the

fine grained sediments that contain the highest hydrocarbon concentrations Tahoe Keys

Home Owners, Tahoe Keys, Ski Run, and Elk Point had higher PAH concentrations

ranging from 5970-16800 ng/g dry wt basis These marinas are high boating activity

areas and enclosed and because of the latter, the PAHs are highly sorbed to the sediments

and persist

Aside from high PAH concentrations the results also indicated that almost all road

runoff sites and marinas had high petroleum hydrocarbon concentrations The Nevada

Standard for clean up and action level for hydrocarbon (TPH) contaminated soil is 100

mg/kg (Assoc Env Health and Science, 2003) The California standard for action level

is 10-1000 mg/kg dry wt basis for TPH and the clean up level is site specific All the

marinas located in the Nevada side of the Lake exceeded 100 mg/kg dry wt basis for

clean up and the action level of TPH contaminated soils Most of the marinas on the

California side of the Lake, had TPH above 1000 mg/kg the California standard for

action level However, Tahoe City and Tahoe Keys Home Owners had <1000 mg/kg dry

wt basis possibly a result of sediment removal

PAH vs TPH

The correlation for PAH and TPH was positive in road runoff (0.85) and marina

(0.74) locations (Figure 1.3 and 1.4) This correlation is important because petroleum

hydrocarbons consist of crude oil and refined petroleum (gas and diesel) and a positive

correlation of PAH vs TPH is an indication that sediments in the sampling sites contain

contaminants from vehicle emission rather than other sources such as wood smoke and

forest fires This is particularly true for marinas because marinas have the direct release

from engines and PAHs are trapped in the sediments

TPH vs TOC

The correlation for TPH vs TOC was 0.98 for marinas when Elk Point TPH and

TOC was plotted When, Elk point was taken out of the calculation, the correlation

dropped to 0.69 for TPH and TOC in the marinas (Figure 1.5) Road runoff locations had

a correlation of 0.75 (Figure 1.6) Although, TPH related to TOC are slightly higher in

marinas (nearly 35%) TPH related to TOC is only 10.1 % for road runoff locations (Table

1.5) Other type of organic carbons such as organic debris and wood chips might add to

the high TOC content in the road dust Road runoff sites in Kings Beach area had high

TPH associated with TOC (10-28%) and conversely Zephyr Cove location had the lowest

content (0.9%)

PAH vs TOC

The correlation was highly positive in the road runoff locations for TPH vs TOC

(0.75), and PAH vs TPH (0.85), the PAH vs TOC correlation was poor (0.05) The

marina sediments had a positive 0.81 for PAH vs TOC probably the PAH from engine

emissions sorb and persist in the anaerobic sediments (Figure 1.7) Table 1.6 shows the

PAH concentration and TOC content of the marina and road runoff sites The low road

runoff correlation for PAH vs TOC, might be because certain sites although high in TOC

(6.7-10%) were low in PAH (Timber Cove, Kings beach tunnel area, Cave Rock parking

lot) resulting in very small positive correlation (Figure 1.8) This low correlation may be

in part be related to photooxidation of the roadway particle surfaces

Table 1.4: PAH concentration (ng/g) dry wt basis and TPH concentration (mg/kg) dry

wt basis in road runoff and marina locations in Lake Tahoe sediments

PAH concentration (ng/g) TPH concentrationdry wt basis (mg/Kg) dry wt

Kings beach dump facility 8460 7030

Kings beach tunnel area 5710 11400

Speckled Ave 559 731

Steel Head Ave 3090 1650

Golden Ave H20 collector 14500 7410

Salmon H;O collector 2560 550

Table 1.5: Percent total organic carbon as a result of total petroleum hydrocarbon in road

runoff and marina locations

PercentTPH TPH TOC TOC from(mg/kg) (%) (%) TPHRoad Run

Kings Beach dump facility 7030 0.70 2.49 28.1

Kings Beach Tunnel Area 11400 1.14 10.01 11.4

Kahle Drive 2920 0.29 2.37 12

Cave Rock parking lot 2540 0.25 7.07 3.54

Brockway Lake soil 50 0.05 0.30 3.33

Table 1.6: Road runoff and Marina TOC (%) and PAH (ng/g) dry wt basis

concentrations

Road runoff TOC (%) PAH (ng/g) dry wt basis

Brockway Lake soil 0.3 518

Cave Rock parking lot 7.07 1760

Kings Beach Tunnel Area 10.01 5710

Total PAH (ng/g) dry wt basis vs TPH (mg/kg) dry wt basis

from road runoff sites (n=17)

PAH (ng/g) dry wt basis

Figure 1.3: Polycyclic aromatic hydrocarbon (ng/g) dry wt basis vs total petroleum

hydrocarbon (mg/kg) dry wt basis in road runoff locations

Total PAH (ng/g) dry wt basis vs TPH (mg/kg) dry wt basis

from marina locations (n=9)

-PAH (ng/g) dry wt basis

Figure 1.4: Polycyclic aromatic hydrocarbon (ng/g) dry wt basis vs total petroleum

hydrocarbon (mg/kg) dry wt basis in marina locations