Oil in the Sea Inputs, Fates, and Effects (1985) / Chapter Skim
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2. INPUTS
2. INPUTS
Pages 43-88
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From page 43... ...
This increase is shown in Table 2-1. Sources of PHC into the marine environment considered in this report include natural sources; offshore oil production; marine transportion (operational discharges, drydocking, marine terminals, bunker operations, bilge and fuel oil transfer, and accidental spillages)
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From page 44... ...
Ad\ - ( arm.
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From page 45... ...
, enter the marine environment naturally by means of two main processes -- submar ine seepage and erosion of sedimentary rocks. Estimating the contribution of each of these is a formidable problem for the following reasons: (hydrocarbons and other organic compounds with five 1.
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From page 46... ...
4. Most mar ine seeps are clustered within the continental margins where the thickness of sedimentary rocks, which provides the needed source rocks for the seepage, exceeds a certain minimum.
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From page 47... ...
9~-~\ Sod\. i .~: bait ~ If.
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From page 48... ...
Table 2-3 shows that to maintain petroleum seepage for a span of geologic time of at least 50 million years (most of the Tertiary period) requires that seepage rates be equal to or less than 2 mta, and
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From page 49... ...
They suggested this area for the study of natural seeps and erosional processes affecting the distribution of petroleum in the marine environment. Because no direct information is available on erosional inputs of petroleum into the oceans, an indirect approach must be taken.
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From page 50... ...
This ancient organic carbon is f inely dispersed in Plastic and carbonate rock particles, eroded from sedimentary rock formations on the continents (Ronov, 19761. In ancient sedimentary rocks the amount of extractable organic matter constitutes, on the average, about 6% of the total organic matter tHunt, 19791.
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From page 51... ...
environmental impact statements for outer continental shelf (OCS) lease sales assume a 0.6 water-to-crude-oil production ratio.
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From page 52... ...
Included are data on all crude oil spills . The USGS classif ies spills as minor (<7 metric tons or 50 barrels)
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From page 53... ...
With these data a range of 0.0027-0.0038 mta has been calculated as the estimate of petroleum entering the marine environment from minor spillage from offshore drilling and production activities worldwide. The best estimate is 0.003 mta, which is lower than the earlier NRC (1975)
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From page 55... ...
Major Spills As was mentioned previously, the USGS has maintained a computerized OCS events file for Gulf of Mexico oil and gas operations (Danenberger, 1976~. The history of major oil spills (<7 metric tons or 50 barrels)
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From page 56... ...
, bilges and fuel oil from all ships (0.3 mta) , and accidental spillages from tankers and other ships (0.4 mta)
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From page 57... ...
(1975 ~ estimated range for total mar ine transportation losses was 1. 5-2 .8 mta with a best estimate of 2 .1 mta.
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From page 58... ...
OPERATIONAL DISCHARGES Crude Oil Dur ing normal operations, oil tankers discharge into the sea a certain amount of oil contained in the ballast and tank washing water. OILPOL 1954/1969 stipulates that instantaneous rates of discharge from cargo tank areas of oil tanker s must not exceed 60 L/mi, and the total quantity of oil discharged dur ing any one ballast voyage must not exceed 1/15,000 of the total cargo carrying capacity (Tc)
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From page 59... ...
Because of the dearth of data for oil tankers engaged on trades in which major oil companies are not involved, particularly oil trades on spot market, the assumption is made that half the long-haul-voyage crude oil tanker fleet meet the 1/15,000 TO standard. AS long haul tankers carry 85% of the 1,319.3 mta total, discharges from this source would be 0.037 mta (1,319.3 x 0.85 x 0.5 x 0.0000671.
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From page 60... ...
These tankers would contribute negligible pollution. Other short haul tankers are engaged in dedicated trades that include arrangements to transfer contaminated ballast to shore reception facilities or to long haul, very large crude carriers (VLCC)
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From page 61... ...
There are no measured data on the quantities of oil residues for persistent oil trades. The operation of tankers carrying persistent product oil is assumed to be similar to that of crude oil tankers on short voyages; namely, 50% are engaged in dedicated trades that include arrangements to transfer contaminated ballast to shore reception facilities or are provided with arrangements to avoid contaminated ballast.
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From page 62... ...
The sum of crude oil plus product oil discharges is thus estimated at O .71 mta (crude oil 0 .67 , product oil 0.041.
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From page 63... ...
The majority of the 7,100 world tankers retain such bilge oil in slop tanks for cargo oil or discharge it to shore reception facilities. Assuming that 10% of the total bilge oil generated in machinery spaces of tankers may be discharged into the sea, the annual discharge of bilge oil from tankers is estimated to be 10.2 tons x 7,100 x 0.1 = 7,242 tons, or 0.007 mta.
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From page 64... ...
. Fuel Oil Sludge Worldwide annual use of heavy residual bunker fuel for mar ine application is 108 mt.
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From page 65... ...
Therefore, the total quantity of oil discharges due to mar itime accidents is estimated to be 0 .41 mta (tanker 0.39, nontanker 0.02~. The estimated range for quantity of oil discharged annually into the sea from transportation activities is 1.0-2.6 mta.
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From page 66... ...
04 0 . 02 TOTAL 1.00 - 2.60 1.45 ATMOSPHERE The estimated range of atmospheric input of PHC into the marine environment is 0.05-0.5 mta.
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From page 67... ...
Hahn (1980) found PAH to be 80% of the n-alkane concentration for aerosol samples from the southern North Atlantic.
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From page 68... ...
Data from over the open North Atlantic Ocean, from the Irish coast, and from Cape Grim, Tasmania, in the Indian Ocean are from the Ketseridis-EichmannHahn group {Ketseridis and Eichmann, 1978; Eichmann et al., 1979, 1980; Hahn, 19811. Data from Enewetak Atoll, Marshall Islands, in the tropical North Pacific, have been obtained by the Gagos ian-DuceZafiriou and Atlas-Giam groups (Gagosian et al., 1981, 1982; Zafiriou et al., 1982; Atlas and Giam, 19811.
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From page 69... ...
Table 2-14 lists the particulate n-alkane data from C15-C30, and Table 2-15 presents the vapor phase n-alkane data for C10-C30. Particulate n-alkane data for C1O-Cl4 were not presented, since these compounds cannot be quantitatively recovered during the extraction of the filter with organic solvent, the solvent evaporation, and the liquid chromatography steps in the analytical scheme (Mackay and Wolkoff, 19731.
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From page 70... ...
Particulate n-alkane concentrations from Enewetak Atoll are considerably lower than those over the North Atlantic or at Cape Grim. These data are probably more nearly representative of mid-North Pacific .
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From page 71... ...
Again, the Ireland' JASIN, and Cape Grim data appear to be most representative of concentrations over the North Atlantic Ocean and in coastal regions, while the Enewetak data may be more representative of concentrations over the Indian, South Atlantic, South Pacific, and mid-North Pacific Oceans. As can be seen from the data presented in Tables 2-14 and 2-15, the geographical coverage for atmospheric n-alkanes is very sparse.
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From page 72... ...
More precise estimates of the atmospheric input of petroleum to the ocean will have to await information on the inputs of the various components of petroleum into the sea surface and further understanding of the reaction products, pathways, and rates of transformation of these compounds in the atmosphere. COASTAL, MUNICIPAL, AND INDUSTRIAL WASTES AND RUNOFF The estimated range of the input of PHC into the mar ine environment from municipal and industrial wastewaters, urban and river runoff, and ocean dumping is from 0.6 to 3 .1 mta, with a best estimate of 1.2 mta (Table 2-17~ .
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From page 73... ...
Most Probable Likely Range Municipal wastewater 0.3 0.75 0.4-1~5 Industrial Nonrefinery 0.3 0.2 0.1-0.3 Refinery 0.2 0.1 0.06-0.6 Urban runoff 0.3 0.12 0.1-0.2 River discharges 1.6 0.04 0.01-0.45 Ocean dumping ~0.014 0.005-0.02 TOTAL 2.7 1.2 0.6-3.1 Knot estimated. The wastewater samples were analyzed for total extractable organics and for total hydrocarbons (THC)
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From page 74... ...
However, there is a quantity of PHC that goes more or less directly into the marine environment through coastal nonrefinery effluent discharges. Extremely limited quantitation of this source has been made, and even less information is published for reasons of confidentiality.
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From page 75... ...
Other refineries that do not have their own facilities are assumed to discharge their wastewater into municipal wastewater facilities. Recently, estimates were made of the amount of PHC discharged with refinery industry effluents (National Petroleum Council, 1981)
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From page 76... ...
Urban Runoff The global input of petroleum hydrocarbons to coastal waters from urban runoff was estimated by NRC (1975)
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From page 77... ...
Employing the unit per capita contribution of 1.0 g/cap/d per day and a coastal population of about 120 million, one can estimate the urban r unof f contr ibution of the United States to be about 0.04 mta. Assuming the United States uses about 0.3 of the world' s hydrocarbons, one can estimate the world urban runoff PHC contribution to the world ocean to be about O .12 mta, which is about one-third of the contr ibution e stimated by NRC ( 1975 ~ .
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From page 78... ...
and world coastal regions in association with municipal wastewater treatment plant sludge/underflow. The sludge is generally discharged from dumping by barge or by discharges through pipelines.
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From page 79... ...
The hydrocarbons that accompany these spoils are accounted for in other sections of this report and are not included in the ocean dumping category. GEOGRAPHICAL DISTRIBUI ION OF INPUTS The input of petroleum hydrocarbons into the ocean is certainly not distr ibuted evenly.
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From page 80... ...
would probably have typically large atmospheric inputs of PHC. Data are not available to estimate total PHC input by region except in an extremely qualitative manner.
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From page 81... ...
Certainly, significant improvements have been made in recent years in obtaining better analytical data on concentrations of PHC entering the marine environment from varied sources. However, additional work is still needed, particularly in the acquisition of improved data on PHC inputs from the atmosphere, from municipal and industrial waste sources, and from natural sources such as marine seeps and erosion of terrestrial sediments.
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From page 82... ...
4-1 .5 0 .7 Refineries 0.06-0.6 0.1 Nonr ef ining industr ial wastes 0 .1-0 .3 0 .2 Urban runoff 0.01-0.2 0.12 - River runoff 0.01-0.5 0.04 Ocean dumping 0 .
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From page 83... ...
6. Better solubility data are needed for n-alkanes and polynuclear aromatic hydrocarbons to better ascertain the importance of rain scavenging of gases and air-sea gas exchange processes to the contribution of the flux of atmospheric petroleum hydrocarbons to the ocean.
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From page 84... ...
1978. Speculations on the budget of particulate and vapor phase non-methane organic carbon in the global troposphere .
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From page 85... ...
1981. n-Alkane atmospheric input into the open North Atlantic Ocean, near the Irish coast, and Indian Ocean.
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From page 86... ...
1971. Natural oil seeps in or near the marine environment: a literature survey.
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From page 87... ...
1980. Report on work performed to control the Ixtoc I well, to combat the oil spill, and to determine its effects on the marine environment.
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From page 88... ...
1979. Petroleum hydrocarbons in urban runoff.
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