^ REGULATORY IMPACT ANALYSIS OF THE
EFFLUENT GUIDELINES REGULATION FOR THE
OFFSHORE SUBCATEGORY OF THE
OIL AND GAS EXTRACTION INDUSTRY
Office of Water Regulations and Standards
U.S. Environmental Protection Agency
Washington, DC 20460
Februaiy 28, 1991
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TABLE OF CONTENTS
EXECUTIVE SUMMARY i
1. INTRODUCTION 1
2. BACKGROUND 3
3. NEED FOR THE REGULATION 7
3.1 Marketplace Failures 7
3.2 Environmental Factors 7
3.3 Legal Requirements 8
4. EVALUATION OF ALTERNATIVES AND TECHNOLOGY OPTIONS 9
4.1 Alternatives to the Regulation 9
4.2 Industry Overview 9
4.2.1 Background 9
4.2.2 Existing Facilities 11
4.2.3 Facility Distribution for Shallow Water and Deep Water Platform Groups 13
4.2.4 New Sources 14
4.3 Discharge Characterization of Major Waste Streams 19
4.3.1 Drilling Fluids 19
4.3.2 Drill Cuttings 20
4.3.3 Produced Water 21
4.4 Drilling Fluids Treatment Options 21
4.5 Produced Water Treatment Options 25
5. EVALUATION OF COSTS AND ECONOMIC IMPACTS 29
5.1 Evaluation of Costs 29
5.2 Economic Impacts 30
5.3 Secondary Impacts of the Regulation 32
6. EVALUATION OF BENEFITS AND WATER QUALITY IMPACTS 35
6.1 Introduction 35
6.2 Overview of the Methodology and Its Limitations 36
6.2.1 Quantified and Monetized Benefits for Drilling Fluids, Cuttings,
and Produced Water 37
6.2.2 Quantified Benefits: Water Column and Pore Water Quality 39
6.2.3 Quantified Impacts (Case Studies) of Drilling Fluids, Cuttings,
and Produced Water 44
6.3 Results 47
6.3.1 Quantified and Monetized Benefits 47
6.3.2 Quantified, Non-Monetized Benefits and Impacts 64
6.3.3 Non-Quantified, Non-Monetized Benefits 78
7. REFERENCES 80
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TABLE OF CONTENTS (cont'd.)
APPENDICES
Appendix A Summaries of Proposed BAT, BCT, and NSPS Effluent Guidelines
Appendix B Schematic Diagrams of Drilling and Production Treatment Technologies and Waste
Generation Sources
Appendix C Supporting Tables for the Benefits Assessment Technical Support Document
Appendix D Results of the Supplemental Benefits Assessment to the Technical Support Document
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LIST OF TABLES
Table 1. Summary of Offshore Oil and Gas Subcategory Federal Register Notices 6
Table 2. Number of Existing Facilities by Geographic Region, Production Type,
and Water Depth That are Potentially Affected by Produced Water BAT Guidelines 12
Table 3. Existing Producing Platforms According to Distance from Shore 15
Table 4. Estimate of New Offshore Wells Drilled According to Distance from Shore 16
Table 5. Estimate of New Offshore Producing Platforms According to Distance from Shore 17
Table 6. 1991 Proposed Regulatory Options for Drilling Fluids and Drill Cuttings 22
Table 7. 1991 Proposed Regulatory Options for Produced Water 26
Table 8. Summary of Waste Stream Impacts on a Gulf-12 Oil and Gas Project 31
Table 9. Incremental Annualized Benefits and Costs of Offshore Oil and Gas
BAT/NSPS Options for Drilling Fluids and Cuttings 51
Table 10. Cancer Risk Reduction Benefits for Drilling Fluids and Cuttings - BAT/NSPS 52
Table 11. Lead-Related Monetized Health Benefits for Drilling Fluids and Cuttings
BAT/NSPS Options 54
Table 12. Incremental Annualized Benefits and Costs of Offshore Produced Water
BAT Options 57
Table 13. Incremental Annualized Benefits and Costs of Offshore Produced Water
NSPS Options 58
Table 14. Incremental Benefits from Reductions in Excess Cancer Lifetime
Risk for Produced Water (BAT) 59
Table 15. Incremental Benefits from Reductions in Excess Cancer Lifetime
Risk for Produced Water (NSPS) 60
Table 16. Number of Pollutants with Water Quality Criteria Exceedances Under
Evaluated BAT/NSPS Options - Drilling Fluids and Cuttings with Lubrication 66
Table 17. Number of Pollutants with Water'Quality Criteria Exceedances Under
Evaluated BAT/NSPS Options - Drilling Fluids and Cuttings without Lubrication 67
Table 18. Number of Pollutants with Water Quality Criteria Exceedances Under
Evaluated Produced Water BAT/NSPS Options 69
Table 19. Marine Studies of Drilling Fluids Impacts 71
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LIST OF TABLES (cont'd.)
Table 20. Coastal and Marine Studies of Produced Water Impacts 76
Table Al. 1985 Proposed BAT Effluent Limitations A-l
Table A2. 1985 Proposed BCT Effluent Limitations A-2
Table A3. 1985 Proposed NSPS Effluent Limitations (Shallow Water) A-3
Table A4. 1985 Proposed NSPS Effluent Limitations (Deep Water) A-4
Table CI. Average Industry-wide Pollutants Present in Discharges from OCS Platforms C-l
Table C2. Average Health Risks Under Each Regulatory Control Scenario,
Drilling Fluids and Cuttings, Finfish Consumption C-2
Table C3. Average Health Risks Under Each Regulatory Control Scenario,
Drilling Fluids and Cuttings, Shrimp Consumption C-3
Table C4. MEI Health Risks Under Each Regulatory Control Scenario,
Drilling Fluids and Cuttings, Finfish Consumption C-4
Table C5. MEI Health Risks Under Each Regulatory Control Scenario,
Drilling Fluids and Cuttings, Shrimp Consumption C-5
Table C6. Benefits of Reduced Infant Mortality as Associated with Maternal Blood Lead
Levels from Drilling Fluid Discharges C-6
Table C7. Annual Incremental Lead-Related Benefits: Adult Males C-7
Table C8. Annual IQ-Related Benefits to Children from Reduced Lead Exposure C-8
Table C9. Average Health Risks Under Each Regulatory Control Scenario,
Produced Waters (BAT), Finfish Consumption C-9
Table CIO. Average Health Risks Under Each Regulatory Control Scenario,
Produced Waters (BAT), Shrimp Consumption C-10
Table Cll. MEI Health Risks Under Each Regulatory Control Scenario,
Produced Waters (BAT), Finfish Consumption C-ll
Table C12. MEI Health Risks Under Each Regulatory Control Scenario,
Produced Waters (BAT), Shrimp Consumption C-12
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LIST OF TABLES (cont'd.)
Table C13. Average Health Risks Under Each Regulatory Control Scenario,
Produced Waters (NSPS), Finfish Consumption C-13
Table C14. Average Health Risks Under Each Regulatory Control Scenario,
Produced Waters (NSPS), Shrimp Consumption C-14
Table C15. MEI Health Risks Under Each Regulatory Control Scenario,
Produced Waters (NSPS), Finfish Consumption C-15
Table C16. MEI Health Risks Under Each Regulatory Control Scenario,
Produced Waters (NSPS), Shrimp Consumption C-16
Table D1 Human Health Risk Factors for Produced Waters: Additional
Contaminants Removed by Membrane Filtration D-l
Table D2 Noncarcinogenic Risks -- Membrane Filtration within 4 Miles,
BPT Beyond (Existing Sources) D-2
Table D3 Noncarcinogenic Risks BPT (Existing Sources) D-3
Table D4 Carcinogenic Risks Membrane Filtration within 4 Miles,
Versus BPT - All Baseline (Existing Sources) D-4
Table D5 MEI Carcinogenic Risks - Membrane Filtration within 4 Miles,
Versus BPT - All Baseline (Existing Sources) D-5
Table D6 Cancer Risk Reduction Benefits (Existing Sources) D-6
Table D7 Noncarcinogenic Risks -- Membrane Filtration within 4 Miles,
BPT Beyond (New Sources) D-7
Table D8 Carcinogenic Risks Membrane Filtration within 4 Miles,
Versus BPT - All Baseline (New Sources) D-8
Table D9 Cancer Risk Reduction Benefits (New Soruces) D-9
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LIST OF FIGURES
Figure Bl. Treatment Technology for Drilling Fluids and Cuttings B-l
Figure B2. Treatment Technology for Produced Water B-2
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LIST OF ABBREVIATIONS
AED
Assessment and Evaluation Division (EPA/OWRS)
AWPD
Assessment and Watershed Protection Division (EPA/OWRS)
BAT
Best Available Technology Economically Achievable
BCF
Bioconcentration Factor
BCT
Best Conventional Pollutant Control Technology
BOD
Biochemical Oxygen Demand
BOE
Barrels of Oil Equivalent
BPJ
Best Professional Judgement
BPT
Best Practicable Control Technology
CE
Cost Effectiveness
CFR
Code of Federal Regulations
COD
Chemical Oxygen Demand
DEHP
bis(2-ethylhexyl)phthalate
DOC
Department of Commerce
DOI
Department of the Interior
EPA
Environmental Protection Agency
FR
Federal Register
ITD
Industrial Technology Division (EPA/OWRS)
MEI
Most Exposed Individual
MMS
Minerals Management Service (DOI)
NOAA
National Oceanic and Atmospheric Administration (DOC)
NPDES
National Pollutant Discharge Elimination System
NSPS
New Source Performance Standards
OCS
Outer Continental Shelf
OOC
Offshore Operators Committee
OWRS
Office of Water Regulations and Standards (EPA)
PAH
Polyaromatic Hydrocarbons
PbB
Elevated Blood Lead
PE
Pounds Equivalent
RIA
Regulatory Impact Analysis
TSD
Technical Support Document
TSS
Total Suspended Solids
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EXECUTIVE SUMMARY
The combined monetized benefits of regulating drilling fluids, drill cuttings, and produced water
in offshore subcategory of the oil and gas extraction industry are found to be reasonably
commensurate with their costs. The total monetized benefits for the selected options (1986
dollars; Gulf of Mexico only) range from $13.4 to $65.2 million annually. The total annualized
BAT and NSPS costs (1986 dollars; Gulf of Mexico only) range from $47.4 million for drilling
fluids, drill cuttings, and produced water (membrane filters) to $67.6 million for drilling fluids,
drill cuttings, and produced water (granular filters). Monetized benefits are based solely on
health-related impacts; benefits associated with regulating drilling fluids and cuttings greatly
predominated over those associated with regulating produced water; for drilling fluids and
cuttings, lead-related health benefits greatly predominate over carcinogen-related health
benefits. Quantified, non-monetized water quality and sediment pore water quality benefits also
are projected for the selected options, including reduced exceedances in water quality criteria
for marine life and human health. The quantified, non-monetized benefits assessment includes
a review of case studies of environmental impacts of drilling fluids and cuttings and produced
water that document local, adverse chemical and biological impacts due to these discharges had
occurred; low-level regional chemical alterations have been shown for drilling fluids.
Background
For all major rulemaking actions, Executive Order 12291 requires a Regulatory Impact Analysis
(RIA), in which benefits of the regulation are compared to costs imposed by the regulation. This report
presents the Environmental Protection Agency's RIA of the proposed rule on the effluent limitation
guidelines for the Offshore Subcategory of the Oil and Gas Extraction Industry. This proposed regulation
has been deemed a major rule. Three types of benefits are analyzed in this RIA: quantified and monetized
benefits; quantified and non-monetized benefits; non-quantified and non-monetized benefits.
Overview of the Industry
The offshore subcategory (as defined at CFR 435.10) of the Oil and Gas Extraction Point Category
covers those structures involved in exploration, development, and production operations located seaward of
the inner boundary of the territorial seas. Section 502(8) of the Clean Water Act defines the inner boundary
of the territorial seas as the line of ordinary low water along that portion of the coast which is in direct
contact with the open sea and the line marking the seaward limit of inland waters.
For the oil and gas extraction industry, exploration operations include activities necessary to locate,
drill, and complete wells for the assessment of potential hydrocarbon reserve. Exploratory activities normally
involve a small number of wells and are generally conducted from mobile drilling units. Development
operations involve the drilling and completion of production wells, and commences once a commercially-
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recoverable hydrocarbon reserve has been identified. Development activities, in contrast to exploratory
activities, usually involve a large number of wells and are typically conducted from a fixed platform.
Production operations include all post-completion work necessary to recover hydrocarbon reserves from the
producing formation, and may begin as each well is completed during the development phase.
An estimated 2,260 existing structures produce oil and/or gas in the offshore waters of the United
States. This estimate includes all tracts leased offshore in the Gulf of Mexico, California, and Alaska. Of
these existing structures, 2,233 are estimated to be located in the Gulf of Mexico; 27 structures are located in
the Pacific; there are no structures currently located in the Atlantic Ocean. There are a few structures in
Alaskan waters that are not included in these estimates because this offshore area contains facilities located
on gravel islands that are considered to be in the onshore subcategory by the State of Alaska. In addition,
structures located in state waters in the Gulf of Mexico are not included in this summary, although the total
volume of produced water being discharged, based on industry estimates, used for costing the regulatory
options included state water activities.
With respect to new sources, activity varies from year to year: the number of wells drilled from 1972
to 1982 averaged 1,100 wells/year; in 1981 almost 1,500 offshore wells were drilled. However, drilling activity
has declined since 1982. The Agency estimates that between 1986 and the year 2000, there will be an
average of 980 offshore wells/year drilled (based on an average oil price for that time period of $21/barrel).
Of these 980 wells/year, 590 wells/year would become producing wells drilled on new structures and the
remaining 390 wells/year would be dry holes. At the present time, in addition to the Gulf of Mexico and
Pacific areas, there is exploration occurring that may ultimately lead to new source development and
production activities in the Chukchi and Beaufort Seas of Alaska and possibly in the Atlantic Ocean. The
Agency estimates that between 1986 and 2000, 851 new platforms will be producing in U.S. offshore waters,
of which 755 will be in the Gulf of Mexico.1
Overview of the Industry's Waste Streams
For this industrial subcategory, the RIA addresses the costs and benefits associated with regulating
of the three major types of discharges from offshore oil and gas extraction, development, and production
operations: drilling fluids, drill cuttings, and produced water. These waste streams are selected for two
reasons. First, they comprise the majority of the effluent discharge volumes from facilities in this industrial
subcategory. Second, among the twelve waste streams identified, they possess a relatively high potential for
toxic effects and for producing adverse environmental impacts, either due to their toxic components or to
their suspended solids content.
Projections assume development unrestricted by Pacific moratoria on drilling and leasing and reflects
projections of continued Atlantic development.
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Drilling fluids range from relatively simple to complex combinations of finely-ground solid
components and specialty chemical additives. These solids (up to 70% solids, by weight) are dispersed in
water or varying ratios of oil-in-water or water-in-oil. These solids can produce physical alterations and
impacts to the marine environment, but generally have a low chemical toxicity. Specialty chemicals, on the
other hand, are generally used in low concentrations but can be highly toxic to marine life.
Drill cuttings are the particles of the subsurface strata that are generated by the drill bit. Drill
cuttings range in size from coarse sand to fine silt. They are suspended and carried to the surface in drilling
fluids. Drill cuttings are most often referred to as a combined waste stream with drilling fluids, i.e., as
"drilling fluids and cuttings". This association occurs because drill cuttings normally are not discharged alone,
but rather as a slurry comprised of an approximate 1:1 ratio of drill cuttings and drilling fluids. The principal
environmental impact of drill cuttings derives from their physical alteration of the environment, unless they
are associated with an oil-based drilling fluid or contaminated with oil added to a water-based drilling fluid.
Produced water is the geologic water that has been trapped with the oil or oil/gas reserves for
thousands of years, and is co-produced with the oil from an oil or oil and gas well. Produced waters are
highly saline, ranging from about twice the salinity of seawater to as much as four or five times the salinity of
seawater. In the open marine waters of the Gulf of Mexico covered by this RLA, the principal environmental
impacts analyzed for produced waters are caused by toxic petroleum hydrocarbon components that are
dispersed in produced water and are derived from the crude oil/formation water association.
Overview of the Methodology and Its Limitations
Methodology
Four categories of benefits that could potentially be quantified and monetized are investigated:
human health benefits; commercial fisheries benefits; recreational fisheries benefits; and intrinsic or nonuse
benefits. Monetized benefits focused exclusively on the benefits associated with human health risk reduction
through reduced concentration of drilling/platform-related pollutants in selected recreational fish species and
commercial fish. Predictions could not be made to quantify and monetize impacts of current discharges and
proposed regulations on: composition and abundance of finfish and shellfish populations; recreational fishing
and other recreational activities; commercial fishing; or nonuse benefits because the myriad environmental,
commercial, and sociological data necessary for such projections are not sufficiently reliable for
quantification, are too difficult to obtain, or simply are not obtainable.
Both the RIA's quantified/monetized benefits and its quantified/non-monetized benefits are based
on impacts in the Gulf of Mexico because the overwhelming percentage of both existing and new structures
are or will be located in the Gulf of Mexico, it is a major fisheries region, and the Gulf of Mexico, in terms
of its data and its environmental character, is more compatible with the RIA's industry-wide (i.e., regional)
modeling and predictive approach. Projections of the impacts of the proposed regulatory actions on
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monetized human health-related benefits, on non-monetized water quality and environmental impact benefits,
and on other non-quantifiable benefits was accomplished using existing data and approaches.
The intent of the methodology of the RIA is to conceptually relate physical and chemical changes in
the marine environment to changes in marine water quality and human health values. The exposure
assessment/risk characterization was performed in several stages. First, average subcategory-wide pollutants
for this industrial subcategory were identified. Then, effluent concentrations of pollutants and dispersion
modeling were used to project the aqueous concentrations of these pollutants in the water column and in
sediment pore water. Projected water column and sediment pore water concentrations were used (1) to
predict the tissue levels of bioconcentrated pollutants in shrimp and fish routinely consumed by humans, and
(2) to compare these concentrations to water quality criteria for an assessment of water quality impacts on
marine life and human health (consumption of contaminated seafood only).
The latter information, when combined with the geographic distributions of oil and gas operations
and those of shrimp and selected fish species, is used to estimate the amount of contaminated seafood (i.e.,
kilograms of seafood affected) and the level of contamination (i.e., milligrams of pollutant per kilogram
edible fish tissue) resulting from "Current" discharges and each regulatory control option. Human health
impacts are predicted from the amount and level of seafood contamination. Health risks associated with
current operating conditions provide a baseline level of risk. Risks associated with regulatory control options
are assessed and compared to the baseline level of risk to obtain an assessment of the incremental risk
reductions associated with the projected health risks of each regulatory control option.
Of the three major types of health risk reductions relevant to these guidelines (carcinogenic risks,
systemic toxicant risks other than lead, and lead-related risks), only carcinogenic and lead-related impacts are
monetized in this RIA. Cancer risks are quantified using average individual exposure levels applied to the
exposed population and Agency-established unit risk factors; the linear dose-response relationship enables a
straight forward quantification of total excess cancer cases.
Monetized lead-related risk reductions are subdivided into: benefits to infants, benefits to adult
males, and benefits to children; these may represent only a limited portion of health benefits attributable to
reduced exposure to lead. These limited benefits are due to both limited data and the unsettled status as to
the appropriate means of quantifying and/or valuing several important health effects associated with lead
exposure. Lead benefits are based on a weighted-average consumption pattern, weighted for the number of
individuals consuming seafood at the various consumption levels of the U.S. population.
In the benefits analysis, mortalities for both cancer-related and lead-related benefits are valued at
$1.74 - $8.75 million, a widely accepted range of literature values per statistical fatality avoided. Lead-related
adverse health effects for adult males are valued on a per-case basis at $277 for hypertension, $72,254 for
cardiovascular heart disease, and $52,200 for stroke. IQ reductions are valued at $471 per IQ point
decrement in lost earnings and $2,043 for supplemental education per child with an IQ level below 70 points.
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These health benefit values are presented in 1988 dollars. The resulting projected monetized benefits are
converted to 1986 dollars using the GNP implicit deflator (0.939) to make the RIA's benefits estimates
comparable to its cost estimates.
Non-monetized assessments of water quality benefits are based on predictions of average case
effluent concentrations and plume dispersion to obtain the ambient concentrations of subcategory-wide
pollutants at the edge of a 100-meter mixing zone. These predicted ambient levels are then compared to
Federal marine water quality criteria and human health criteria for fish consumption. To assess sediment
pore water quality, the ambient sediment concentrations of subcategory-wide pollutants are calculated from
EPA's estimated waste stream loadings, assuming an even distribution throughout a platform impact area.
Pore water concentrations are based on known leachate characteristics or on sedimentrpore water
partitioning, based on organic carbon content and sediment:aqueous partition coefficients.
For the RIA's case study analysis, EPA conducted an extensive review of virtually all relevant
literature available to identify and review potentially applicable field impact studies assessing impacts of
drilling and production discharges. An initial bibliography of 483 potentially relevant studies was distributed
to Federal and state agencies for their review to identify additional studies. A second list of 405 citations of
potentially relevant reports resulted. A review of these lists identified 23 case studies of environmental
impacts that are appropriate to this effort and which are reviewed and summarized for the RIA.
Limitations
Quantified and Monetized Benefits
Monetized benefits cited in the RIA are based solely on health-related impacts.
Monetized benefits are based on highly averaged case scenarios (averaged subcategory
pollutant concentrations and loadings; average ambient exposure and bioconcentration
scenarios for the species selected for use in the human exposure assessment; average
consumption, for carcinogens, or average consumption weighted by the fraction of
individuals consuming at that level for lead-related analyses); results for Most Exposed
Individual (MEI) scenarios predict risks two to three orders of magnitude above those of
average cases, but MEI results are omitted in the monetization of benefits.
Monetized benefits pertain only to a very limited set of contaminants (one carcinogens plus
lead for drilling fluids and cuttings; two carcinogens for granular-filtered produced water;
three carcinogens for membrane-filtered produced water), relative to the large number of
pollutants that will be controlled by the regulation.
Health risks are, in part, determined only for four species of recreationally-caught finfish,
selected not because they are the most important species in assessing human exposure, but
because they are the only species for which sufficient, compatible distribution and landings
data existed for use in this assessment.
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Projected health effects are based solely on the environmental process of bioconcentration,
i.e., only on aqueous exposures of consumed seafood species to pollutants in seawater;
exposures to discharge-related pollutants via ingestion of contaminated food or sediment are
not used to derive tissue levels of pollutants in consumed seafood that are used in health
effects assessments, although data suggest these pathways may be important.
Monetized benefits for lead are based on a limited set of potential health impacts.
Monetized benefit estimates for lead are likely to be understated because of the limited
application of risks to small subsets of the population and the highly conservative aspect of
some of the valuation concepts that are applied.
Localized/platform-specific benefits are omitted because benefit projections are based on
only a limited subset of subcategory-wide pollutants; numerous pollutants occurring at less
than subcategory-wide frequencies could represent a substantial increase in projected
impacts and benefits if their individual contributions are integrated into the projected
benefits in the RIA.
For produced water, two potentially important classes of pollutants are not addressed in the
RIA -- biocides and radionuclides; scant data on the specific, often proprietary, chemical
nature and operational usage of biocides has precluded any meaningful assessment these
substances; the radioactivity of produced waters has only recently been recognized by the
Agency as a potential source of concern in this waste stream, and has neither been
controlled in the proposed regulation nor been included in the RIA's environmental and
health-related benefits analyses.
For membrane filtration treatment of produced water, analyses were conducted and results
reported only for the selected option (4 Mile Filter - BPT Beyond) and the BPT baseline.
Quantified and Non-monetized Benefits
Quantified benefits for water quality and sediment pore water quality also are based on
highly averaged scenarios (averaged subcategory pollutant concentrations and loadings;
average ambient exposure scenarios, i.e., estimates of dispersion based on average
environmental parameterizations in the modeling effort).
As was the case for health-related benefits, localized/platform-specific benefits are omitted
because projections are based on a limited subset of subcategory-wide pollutants; those
occurring at low frequencies are omitted from these analyses; such omissions ignore any
potential benefits associated with local impacts on water quality.
For membrane filtration treatment of produced water, analyses were conducted and results
reported only for the selected option (4 Mile Filter - BPT Beyond) and the BPT baseline.
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Summary of Results
Monetized Benefits
The combined monetized benefits of regulating drilling fluids, drill cuttings, and produced water in
offshore subcategory of the oil and gas extraction industry are found to be reasonably commensurate with the
costs. The total monetized benefits for the selected options range from $13.4 to $65.2 million annually. The
total annualized BAT and NSPS costs range from $47.4 million for drilling fluids, drill cuttings, and produced
water (membrane filters) to $67.6 million for drilling fluids, drill cuttings, and produced water (granular
filters).
Drilline Fluids and Cuttines
The monetized human health benefits that result from the proposed BAT/NSPS for drilling fluids
and drill cuttings range from $13.4 to $65.2 million annually, compared to the estimated total annualized
costs of $29.5 million. The projected benefits due to reductions in exposure to contaminants that enter the
environment through regulated waste waters include: reduced cancer risks (based on the U.S. national impact
of average case scenarios for selected seafood species that are exposed to discharge-related pollutants and
average patterns of human consumption of these seafood species) and lead-related, adverse health effects
(based on average case exposures of selected seafood species to discharge-related pollutants and weighted
average U.S. seafood consumption patterns). Of these two sources of benefits, lead-related benefits
predominate, accounting for more than 99% of the total quantified and monetized health-related benefits
due to the regulation.
Average case exposure scenarios for excess cancer risk yield projected risks that are below the
normal range of concern (> 10"6) for the Agency. Risks from seafood consumption, at the "Current " level
of treatment and for all options, range from zero to 4 x 10"9. Average case scenarios also provide minimal
potential risks from consumption of seafood for systemic toxicants other than lead, with all options exhibiting
oral intake values that are positive but could not be distinguished from 0%.
MEI scenarios for drilling fluids and cuttings suggest that for individuals who consume more than
the average amount of seafood, cadmium could present a health risk. MEI scenarios also indicate that
cancer risks due to arsenic ingestion attain levels of regulatory concern for MEI levels of shrimp
consumption (10"6) and approach levels of concern for finfish (10'7) for all discharge options. The analyses of
the RIA indicate cadmium could amount to as much as 10% of the oral RfD for these individuals in some of
the options evaluated by the Agency at the "Current" level of treatment and for all "5/3" options.
The selected drilling fluids and cuttings BAT/NSPS option is zero discharge for facilities located
within 4 miles of shore and a 1 mg/kg limitation on cadmium and mercury in the whole fluid. For the
selected option, the annual reduction in excess cancer cases for consumption of seafood is 0.0021 cases
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avoided per year, for an incremental monetized benefit range of $3,500 to $17,700. The benefits of reduced
mortality among infants due to lead range from $0.6 million to $2.7 million. The annual monetized lead-
related benefits for adult males range from $12.8 million to $62.3 million. The lead-related annual
monetized benefits for children are $70,000. Thus, the total lead-related benefits of the selected option range
from $13.4 - 65.2 million, compared to its projected cost of $29.5 million.
Produced Water
Monetized human health benefits resulting from the proposed BAT option for produced water are
comparatively small. Benefits of the 4 Mile Filter - BPT Beyond option range from $1,200 to $6,100 for
membrane filtration and from $2,000 to $9,000 for granular filtration. These BAT benefits figures compare
to total annualized BAT costs of $9 million (membrane filtration) and $24 million (granular filtration). The
same pattern occurred for the proposed NSPS option: monetized benefits range from $300 to $1,800 for
membrane filtration and from $200 to $1,000 for granular filtration. These NSPS benefits figures compare to
estimated total annualized NSPS costs of $9 million (membrane filter) and $14 million (granular filter). The
difference in monetization between BAT and NSPS options is due to different levels of activity under the
BAT and NSPS options, which when applied to the same unit risk factor, produces different benefit values.
The projected monetized benefits for produced water only include incremental reductions for
average case scenario cancer risks: respectively, membrane filtration and granular filtration technologies
demonstrate avoiding 0.0007 and 0.0011 cases for the proposed BAT option and 0.0002 and 0.0001 cases
avoided for the proposed NSPS option. Average case exposure scenarios for excess cancer risk yield
projected risks that are below the normal range of concern for the Agency (> 10 ฎ), ranging from 10"8 to
10"8 at the "Current" (BPT) level of treatment and 10"11 to 10"ฎ for evaluated BAT and NSPS options. Similar
to drilling fluids, MEI scenarios yield excess cancer risks that attain or approach levels of regulatory concern.
(MEI risks are quantified only for granular filtration technology, for both BAT and NSPS.) The MEI excess
cancer risks for BAT analyses range from 10"6 to 10 5 at the "Current" (BPT) level of treatment to lO'6 for
evaluated BAT options; MEI excess cancer risks for NSPS analyses range from 10"ฎ at the "Current" level of
treatment to 107 for evaluated NSPS options.
Comparing produced water incremental benefits and costs, for all BAT and NSPS options, including
membrane and granular filtration technologies, reveals that benefits are orders of magnitude lower than their
corresponding costs. BAT benefits range from $1,200 to $31,600 while costs range from $9 million
(membrane filters) to $777 million (granular filters). NSPS benefits range from $200 to $16,400 while costs
range from $9 million (membrane filters) to $187 million (granular filters).
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Quantified Non-Monetized Benefits and Impacts
Water Quality Improvement Benefits
The quantified, non-monetized benefits that are identified include: (1) for drilling fluids and drill
cuttings, elimination of the projected aquatic life and human health criteria exceedances from the more
sensitive shallow water areas (within a 4 mile distance from the shore) and reduction of projected impacts in
deeper water areas (beyond 4 miles from shore); and (2) reduction of the human health criteria exceedances
magnitude in the same more sensitive shallow water areas for produced water.
For all options that allow discharge of drilling fluids and cuttings, the water quality criterion for
human health is exceeded for arsenic in the water column by 25-fold to 392-fold for drilling fluids both with
and without lubricity2. For lead, drilling fluids of either type exceed the criterion for aquatic life for all
three options having a 5/3 limitation on cadmium and mercury in barite 2-fold to 5-fold. Mercury exceeds
the criterion for human health by 2-fold for the same three options having a 5/3 limitation, but only for
drilling fluids with lubricity.
Exceedances for mercury for the criterion for aquatic life also vary between drilling fluid types.
Drilling fluids with lubricity show exceedances (3-fold to 13-fold), for all discharge options; fluids without
lubricity show exceedances (5-fold) only for options having a 5/3 limitation. Projected sediment pore water
concentrations of pollutants in drilling fluids and cuttings discharges are also compared to Federal water
quality criteria. Arsenic fails to meet the criteria for human health by 5-fold to 22-fold for every option and
both drilling fluids with and without lubricity for the selected option.
The selected option eliminates aquatic life lead impacts (for drilling fluids with lubricity and without
lubricity), reduces the magnitude of the mercury aquatic impacts (to a 3-fold exceedance, for drilling fluids
with lubricity), and eliminates mercury aquatic impacts for drilling fluids without lubricity. The selected
option also eliminates human health impacts for mercury (for drilling fluids with lubricity) and reduces
human health impacts from arsenic for drilling fluids, both with and without lubricity.
For produced water, water column concentrations of pollutants in discharges from all platform types
(oil, oil and gas, gas only) do not exceed any of the water quality criteria using granular filtration technology.
In supplemental analyses conducted for membrane filtration technology, the water column criteria for human
health (fish consumption only) is exceeded 8-fold for BPT All (as the baseline and an evaluated option) and
5-fold for the selected option (4 Mile Filter - BPT Beyond). However, the criterion for human health for
bis(2-ethylhexyl)phthalate is exceeded in sediment pore water in waters less than 20 meters deep for both
2 Drilling operations often require the use of a lubricant, either diesel, mineral, or vegetable oil. In this
analysis, "lubricity" refers to the use of oils in the mud system to prevent stuck pipe; a "pill" refers to the
use of a small volume (100 bbl or so) of oil-based mud to free stuck pipe.
ix
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granular and membrane filtration technologies. Exceedances for granular filtration are 8-fold to 27-fold for
BPT and 3-fold for all options that included filtration as a treatment {Filter Shallow - BPT Deep; 4 Mile Filter
- BPT Beyond; Filter and Discharge All); for membrane filtration, exceedances for BPT discharges are 25-
fold. For the selected option (4-Mile Membrane Filter - BPT Beyond), exceedance of the criterion for human
health for bis(2-ethylhexyl)phthalate is reduced to a 1.3-fold exceedance.
Environmental Impact Improvement Benefits
The quantified non-monetized water quality impacts assessment includes summarized case studies of
localized impacts found near oil and gas drill sites and platforms located in the Gulf of Mexico, in Southern
California, and in Alaska. Discharged drilling fluids and drill cuttings are shown to cause contamination of
sediments with heavy metals and hydrocarbons. Documented biological effects include elimination and
inhibited growth of seagrasses, declined abundance in benthic species, altered benthic community structure,
decreased coral coverage, and bioaccumulation of heavy metals.
Biological impacts from single wells are observed to occur on a scale from several hundred meters
to several kilometers; chemical impacts have been noted from several to tens of kilometers. Produced water
discharges are shown to cause contamination of sediments with polynuclear aromatic hydrocarbons (PAH),
local elimination and depressed abundance of benthic species, and alteration of benthic communities.
Studies do not indicate larger-scale (more than several hundred to a thousand meters) impacts occur.
However, these studies are not adequate to conclude that regional-scale impacts do not occur.
Non-Quantified, Non-Monetized Benefits
The identified non-quantifiable, non-monetized benefits from the proposed regulation include:
(1) increased recreational fishing values due to the perception of decreased health risks from the regulation;
(2) improved aesthetic quality of the near-platform waters resulting in increased recreational fishing
participation; and (3) enhanced fisheries due to the reduced pollutant loadings. These potential benefit
predictions are highly speculative, but any positive impact of the regulation would be appreciable: a 0.1%
increase in recreational value would yield benefits on the order of $12 to $14 million per year.
The proposed regulation may also have a beneficial impact on two federally-designated endangered
species, the Kemp's Ridley Turtle and the Brown Pelican. No data indicate adverse effects on these species,
but given that the bioconcentration of offshore subcategory pollutants in fish tissue was sufficient enough to
pose human health impacts, it is possible that the proposed regulation will reduce stress on the endangered
species.
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1. INTRODUCTION
This report has been prepared to comply with Executive Order 12291 which requires the Agency to
complete a Regulatory Impact Analysis (R1A) for each major rule it proposes or promulgates. The
accompanying regulation, defining best available technology economically achievable (BAT), best
conventional pollutant control technology (BCT), and new source performance standards (NSPS), for the
offshore subcategory of the oil and gas extraction industry, meets the Order's definition of a major rule.
The principal requirement of the Executive Order is that the Agency perform an analysis comparing
the benefits of the regulation with the costs which the regulation imposes. Wherever possible, the costs and
benefits are to be expressed in monetary terms. To address this analytical requirement, this report is
organized into five major sections:
Background
Need for the Regulation
Evaluation of Alternatives and Technology Options
Evaluation of Costs and Economic Impacts
Evaluation of Benefits and Water Quality Impacts
In Section 2 ("Background"), the history of the regulation is discussed.
In Section 3 ("Need for the Regulation"), a brief explanation of marketplace failures that water
pollution control regulations are intended to correct is provided. Also, the Agency's legal mandate for
developing effluent limitation guidelines for the offshore subcategory of the oil and gas extraction industry is
summarized. In addition, this section discusses the environmental factors germane to the need for the
development of these regulations.
The section entitled "Evaluation of Alternatives and Technology Options" (Section 4) describes the
rationale for the technology-based effluent limitations proposed/reproposed for this industry.
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Section 5 of this document ("Evaluation of Costs and Economic Impacts") presents: (1) the costs of the
regulation; (2) the associated impacts on the industry in terms of closures, profitability, and cost as a percent
of sales; (3) the mitigation of impacts - small plant issues; and (4) the cost-effectiveness of the regulation.
In the "Evaluation of Benefits and Water Quality Impacts" of this document (Section 6), the benefits
and water quality improvements that the Agency expects will occur from the implementation of this
regulation are presented.
2
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2. BACKGROUND
The 1972 Federal Water Pollution Control Act, as amended by the 1977 Clean Water Act
Amendments and the Water Quality Acts of 1987 (Clean Water Act), requires EPA to develop technology-
based effluent limitation guidelines and standards for categories of industries, including the oil and gas
extraction category, of which offshore oil and gas activities are a subcategory. These effluent limitation
guidelines and standards are defined based upon the following levels of pollution control:
Best Conventional Pollutant Control Technology (BCT)
Best Available Technology Economically Achievable (BAT)
New Source Performance Standards (NSPS).
BCT limitations control of discharge of conventional pollutants: BOD, TSS, oil and grease, pH, and
COD. BAT limitations address listed toxic pollutants that are discharged from existing sources of pollution
based on the best available, economically achievable control technology developed for that particular
industry. NSPS limitations require new sources within a particular industry to meet the most stringent
limitations attainable, based on the best demonstrated available technology.
The Natural Resources Defense Council (NRDC) filed suit against EPA on December 29, 1979,
seeking an order to compel the Administrator to promulgate final NSPS for the offshore subcategory. In
settlement of the suit (NRDC vs. Costle. D.D.C. No. 79-3442 (JHP)), the Agency agreed to take steps to
issue such standards. However, because of the length of time that had passed since proposal, EPA believed
that examination of additional data and reproposal were necessary. Consequently, the Agency withdrew the
proposed NSPS on August 22, 1980 (45 FR 56115). The proposed BAT regulations were withdrawn on
March 19, 1981 (46 FR 17567).
The Settlement Agreement was revised in April 1990. Under the modified agreement, EPA was to
propose or repropose BAT and BCT effluent limitations guidelines and new source performance standards
for produced water, drilling fluids and drill cuttings, well treatment fluids, and produced sand, as described at
50 FR 34595 (August 26, 1985), by November 16, 1990. EPA is to promulgate final guidelines and standards
covering these waste streams by June 19, 1992.
3
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EPA also was to determine by November 16, 1990 whether to propose effluent limitations guidelines
and new source performance standards covering deck drainage and domestic and sanitary wastes and, if it
determined to do so, to promulgate final guidelines and standards covering those waste streams by June 30,
1993.
For the offshore subcategory, the current BPT regulations limit the discharge of oil and grease in
produced water to a daily maximum of 72 mg/1 and a thirty day average of 48 mg/1; prohibits the discharge
of free oil in deck drainage, drilling fluids, drill cuttings, and well treatment fluids; requires a minimum
residual chlorine content of 1 mg/1 in sanitary discharges for facilities continuously manned by 10 or more
persons; and prohibits the discharge of floating solids in sanitary and domestic wastes.
On August 26, 1985, EPA proposed effluent limitations guidelines for certain waste streams covering
BCT, BAT, NSPS (shallow water), and NSPS (deep water). A summary of the proposed options is
presented in Appendix A, Tables A-l through A-4. The BAT proposed effluent limitations guidelines would
prohibit the discharge of free oil in drilling fluids, deck drainage, drill cuttings, produced sand and well
treatment fluids; prohibit the discharge of drilling fluids that are oil-based or that contain diesel oils; prohibit
the discharge of drill cuttings that are contaminated with diesel oil or that are generated with the use of
drilling fluids that are oil-based; limit the acute toxicity to drilling fluid discharges to a minimum 96-hr LC50
(a concentration lethal to 50 percent of the test organisms) of 30,000 ppm (volume:volume) as measured in
the suspended particulate phase (SPP) of a l-to-9, effluent-to-seawater suspension; and limit the discharge of
cadmium and mercury in drilling fluids to a maximum of 1 mg/kg, each on a whole fluid, dry weight basis.
BAT effluent limitations guidelines for produced water, and for deck drainage, produced sand and well
treatment fluids for pollutants other than free oil were reserved for future rulemaking.
EPA proposed BCT equal to the previously promulgated BPT effluent limitation guideline, for oil and
grease in produced water discharges. BCT effluent limitations guidelines, however, were reserved for
additional conventional pollutant parameters in deck drainage, drilling fluids, drill cuttings, produced sand
and well treatment fluids for future rulemaking. New source performance standards were also proposed.
The proposed standards were the same as the Agency's proposed BAT/BCT effluent limitations guidelines
with one exception. EPA proposed a prohibition on the discharge of produced water from all offshore oil
production facilities that are located in or would discharge to shallow water areas, as defined in the proposed
regulation, (see Section 4.2.3 for details of the proposed, shallow water definitions). Produced water
discharges from all other new source offshore facilities engaged in exploration, development, and production
4
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activities would be limited to a maximum oil and grease concentration of 59 mg/1 (i.e., no single sample to
exceed).
The Agency received comments and collected additional data after the August 26, 1985 proposal. On
October 21, 1988, the Agency published a Notice of Data Availability for public review and comment on new
technical, economic, and environmental assessment information relating to the regulation of the waste
streams. The notice presented variations on the originally proposed BAT and NSPS limitations on the
mercury and cadmium content of discharged drilling fluids. The notice presented limitations of 5 mg/kg and
3 mg/kg, respectively, of cadmium and mercury in the stock barite based on the use of existing barite
supplies and limitations of 2.5 mg/kg and 1.5 mg/kg, respectively, of cadmium and mercury in the drilling
fluid (whole fluid basis). The notice also discussed EPA's initial investigation into the application of an oil
content limitation on drilling waste streams.
On November 26, 1990, EPA published an initial proposal and reproposal of the options presented in
this RIA (55 FR 49094). The Agency presented the major regulatory options for drilling fluids, drill cuttings,
produced water, deck drainage, produced sand, well treatment/workover fluids, and domestic and sanitary
waste. A summary of Federal Register notices is presented in Table 1.
5
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Table 1. Summary of Offshore Oil and Gas Subcategory Federal Register Notices
Level of Control
Action
Date
BPT
BAT/NSPS
BPT/BAT/NSPS
NSPS
BAT
BAT/BCT/NSPS
BAT/BCT/NSPS
BAT/BCT/NSPS
Interim Final
Proposal
Final (BPT)
Reserved (BAT/NSPS)
Withdraw Proposal
Withdraw Proposal
Proposal
Notice of Data Availability
(Drillings Fluids & Cuttings)
Initial Proposal and
Reproposal
September 15, 1975
(40 FR 42543)
September 15, 1975
(40 FR 42572)
April 13, 1979
(44 FR 22069)
August 22, 1980
(45 FR 56115)
March 19, 1981
(46 FR 17567)
August 26, 1985
(50 FR 34592)
October 21, 1988
(53 FR 34592)
November 26, 1990
(55 FR 49094)
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3. NEED FOR THE REGULATION
The Executive Order requires that the Agency identify the need for the regulation being
proposed/reproposed. This section will discuss: (1) the reasons why the marketplace is unable to provide
for adequate water pollution control; (2) the environmental factors that indicate why additional water
pollution controls are necessary for the offshore subcategory of the oil and gas extraction industry; and
(3) the legal requirements that dictate the timing of this regulation.
3.1 Marketplace Failures
In the absence of government intervention, operators will generally base their decisions about pollution
control primarily on the costs that they incur and the benefits that accrue directly to them. They will tend to
minimize all other costs and benefits related to pollution control.
This kind of neglect of social costs and benefits is inherent in a market system without government
intervention. Firms in competitive product markets cannot independently choose to reduce their discharges
without risking being placed at a competitive disadvantage compared to those that do not. Consumers
typically do not distinguish high prices that result from poor management from high prices that result from
good citizenship. But this market behavior, while predictable and understandable from the profit-marking
perspective, has unfortunate social consequences. Companies that use the environment to receive their waste
may ignore important health, recreational, ecological, and aesthetic damages that result from their
discharges. Therefore, they may not install controls that society finds worthwhile. Thus, the prices for the
products made by these dischargers fail to reflect all of the social costs of their production.
3.2 Environmental Factors
The end result of the market's failure to control pollution was the degraded condition of the Nation's
rivers, streams, and coastal areas. Federal, state, and local regulatory programs have since caused the
cleanup of the most visible problems; however, many waterbodies are still adversely affected by pollutant
discharges. Section 6 contains a discussion of the water quality impacts of the offshore subcategory, oil and
gas extraction discharges.
7
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Total pollutants and toxic pollutants that would be discharged by drilling fluids and drill cuttings waste
streams under current regulations, over the next 15 years, are estimated at 2,016,694,820 lbs/year (total
pollutants) and 963,141 lbs/year (toxic pollutants). After implementation of proposed BCT, BAT, and NSPS
regulations (Note: the great majority of drilling wastes will be subject to NSPS requirements), discharges of
total pollutants and toxic pollutants would be decreased to 1,689,892,180 lbs/year and 779,693 lbs/year,
respectively.
Total pollutants and toxic pollutants discharged in produced water from existing sources under current
regulations, over the next 15 years, are estimated at 59,371,561 lbs/year and 2,679,360 lbs/year, respectively.
After implementation of proposed BCT and BAT regulations, discharges of total pollutants and toxic
pollutants would be reduced respectively to 54,571,561 lbs/year and 2,205,293 lbs/year for membrane
filtration technology and to 55,923,900 lbs/year and 2,465,743 lbs/year for granular filtration technology.
Total pollutants and toxic pollutants discharged in produced water under current regulations from new
sources, over the next 15 years, are estimated at 47,022,222 lbs/year and 2,152,715 lbs/year, respectively.
After implementation of NSPS requirements, the discharges of total pollutants and toxic pollutants would be
reduced respectively to 37,522,222 lbs/year and 1,212,283 lbs/year for membrane filtration technology and to
40,226,629 lbs/year and 1,739,571 lbs/year for granular fdtration technology.
3.3 Legal Requirements
The Agency is proposing/reproposing effluent guidelines and standards for the Offshore Oil and Gas
Extraction Subcategory under the authority of Sections 301, 304, 306, 307, and 501 of the Clean Water Act
(the Federal Water Pollution Control Act Amendments of 1972, 33 U.S.C. 1251 et seq., as amended by the
Clean Water Act of 1977, Pub. L. 95-217 and the Water Quality Act of 1987, Pub. L. 100-4). also called the
"Act." These effluent guidelines and standards are also being proposed/reproposed in response to the
Settlement Agreement described above and in accordance with EPA's Effluent Guidelines Plan under
Section 304(m) of the Clean Water Act (55 FR 80; January 2, 1990).
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4. EVALUATION OF ALTERNATIVES AND TECHNOLOGY OPTIONS
This section presents the alternatives to the regulation and the options for the technology-based
effluent limitations for this industrial regulation.
4.1 Alternatives to the Regulation
Potential alternatives to the concept of uniform national effluent limits based on available technology
include allowing waivers from national standards for the non-toxic priority pollutants (nonconventionals)
based on economic or site-specific water quality considerations, or establishing a single effluent limitation
which would apply to a number of discharge pipes on one platform or even to a number of platforms (the
"bubble" concept). The RLA is limited to a description of the rationale for the technology-based effluent
limitations proposed/reproposed for the offshore subcategory of the oil and gas extraction industry, and will
not evaluate alternatives to the regulation.
4.2 Industry Overview
4.2.1 Background
The offshore subcategory (as defined at CFR 435.10) of the Oil and Gas Extraction Point Category
covers those structures involved in exploration, development, and production operations seaward of the inner
boundary of the territorial seas. The inner boundary of the territorial seas is defined in Section 502(8) of the
Clean Water Act as:
"the line of ordinary low water along that portion of the coast which is in direct contact with the
open sea and the line marking the seaward limit of inland waters."
In some areas the inner boundary of the territorial seas is clearly established and is shown on maps.
For example, the Texas General Land Office (Survey Division) has available 7.5 minute quadrangle maps for
the entire coastline of Texas which clearly show the inner boundary of the territorial seas. Additionally, the
Louisiana State Minerals Board (Civil and Engineering Division) has available maps for the Louisiana
9
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coastline showing the inner boundary of the territorial seas. In other areas, such as Alaska, the baseline is
not clearly established.
Ocean discharge criteria applicable to this industrial subcategory were promulgated on October 3, 1980
(45 FR 65942) under Section 403(c) of the Act. These guidelines are to be used in making site-specific
assessments of the impacts of discharges. Section 403 limitations are imposed through Section 402 National
Pollutant Discharge Elimination System (NPDES) permits. Section 403 is intended to prevent unreasonable
degradation of the marine environment and to authorize imposition of effluent limitations, including a
prohibition of discharge, if necessary, to ensure this goal. In 403(c) determinations where it is questionable
whether the discharge is beyond the baseline or not, the appropriate state agency is consulted to make site-
specific determinations. In relation to the implementation of the BPT limitations guidelines, no problems
have been associated with the definition of the inner boundary of the territorial seas.
Exploration and development activities for the extraction of oil and gas include work necessary to
locate, drill, and complete wells. Exploration activities involve the drilling of wells to determine the potential
hydrocarbon reserves. They are usually of short duration at a given site, involve a small number of wells,
and generally are conducted from mobile drilling units. The major waste streams from exploration activities
are drilling fluids and drill cuttings.
Development activities involve the drilling and completion of production wells once a commercial
hydrocarbon reserve has been identified. These operations, in contrast to exploration activities, usually
involve a large number of wells and are typically conducted from a fixed platform. The major waste streams
are drilling fluids and drill cuttings. Other associated waste streams include fracturing and well stimulation
fluids, well treatment, and well completion fluids.
Production operations include all post-completion work necessary to bring hydrocarbon reserves from
the producing formation. They begin as each well is completed during the development phase. The major
waste stream associated with production activities is produced water; however, produced sand is a minor
associated waste stream. Both of these waste streams originate with the gas and/or oil product stream, and
are separated from the oil product in the initial processing of the production stream. Generalized schematic
diagrams are provided in Appendix B, Figures B-l and B-2 for treatment technologies and waste generation
sources respectively, from drilling activities and production activities.
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4.2.2 Existing Facilities
An estimated 2,260 structures produce oil and/or gas in the offshore waters of the United States. This
estimation is based upon information from two sources: Minerals Management Service Platform Inspection,
Complex/Structure Data Base, March, 1988 and Oil and Gas Activities Affecting California's Coastal Zone: A
Summary Report, California Coastal Commission, December, 1988. This estimate includes all tracts leased
offshore in the Gulf of Mexico, California and Alaska. There are no development or production platforms in
the Atlantic Ocean.
Table 2 presents a summary of the production activity in offshore waters. There is production activity
not reflected in Table 2 for the Alaska offshore areas because these wells are on gravel islands and are
considered to be in the onshore subcategory by the State of Alaska. These wells collect all of their produced
water and reinject it at one location. In addition, structures located in state waters in the Gulf of Mexico are
not included in this summary. However, the total volume of produced water being discharged and used as
the basis for costing the regulatory options is based on industry estimates that include state water activities.
The state offshore records consulted have permitted structures under three subcategories instead of only
offshore: onshore (for those structures with the well head on land but the bottom hole is offshore); coastal;
and offshore. Also, state records are generally maintained on a well basis, not a structure basis. In the maps
available from the National Oceanic and Atmospheric Administration (NOAA) and other sources, there is
no indication of how many wells there are per structure, if any of the wells are producing, or what product
may be produced.
The Agency believes that the capital costs and the operating and maintenance costs for pollution
control of produced waters from existing platforms are valid even though the profiling effort does not include
those structures located in State waters. Peak water production volumes from offshore Federal waters only
were used by the Agency in the development of capital costs while average annual water production volumes
from offshore Federal waters only were used to calculate operating and maintenance costs. The Minerals
Management Service (MMS) reported the water production volumes for offshore Federal waters in the year
1987 and state waters records reported water production volumes for state offshore waters for the year of
1986. The Agency's estimate of average water production volumes in offshore Federal water areas only
exceeded the summation of the MMS and state records volumes reported by 60%. Since the Agency's water
production volume did exceed actual volumes, the capital costs and the operating and maintenance costs that
were developed accounted for those structures in state waters that the Agency was unable to profile.
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Table 2. Number of Existing Facilities by Geographic Region, Production Type, and Water Depth
That are Potentially Affected by Produced Water BAT Guidelines8
Shallow Water Deep Water
Region
Oil
Oil and
Gas
Total
Oil
Oil and
Gas
Total
Total
Only
Gas
Only
Shallow
Only
Gas
Only
Deep
All
Gulf
126
497
676
1,299
35
471
428
934
2,233
Pacific
0
10
0
10
0
16
1
17
27
Alaska
0
0
0
0
0
0
0
0
0
Atlantic
0
0
0
0
0
0
0
0
0
Totals
126
507
676
1,309
35
487
429
951
2,260
8 As defined in the 1985 proposal, "shallow" in the Gulf of Mexico is defined as 20 meters or less; in the
Atlantic it is defined as 20 meters or less; in the Pacific it is defined as 50 meters or less; in Alaska it is
defined as 10 meters or less in the Beaufort Sea, 20 meters or less in Norton Sound, and 50 meters or
less in Cook Inlet, the Gulf of Alaska, and the Bristol Bay/Aleutian Island Chain.
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4.2.3 Facility Distribution for Shallow Water and Deep Water Platform Groups
The 1985 proposed effluent guidelines considered a shallow/deep platform grouping under certain
options for the regulation of discharges for production activities. This grouping allowed for the option of
onshore reinjection of produced water from those structures located in shallow water due to their proximity
to shore. Through the compilation of data from industry, the following water depths were proposed to be
shallow water.
Gulf of Mexico: Industry data indicate that 52% of all the projected new sources in 15 meters or less
of offshore waters would pipe produced water to shore. The Agency believed the same percentage of
platforms in water depths of 20 meters of less could pipe to shore and reinject.
Atlantic: The water depth of 20 meters was selected for this region since there was no historic trend
for production.
California: It was determined that 60% of the active production platforms located in water depths of
50 meters or less pipe to shore for treatment, while only 8% of the structures in depths greater than 50
meters pipe to shore for treatment. Based on this data, a depth of 50 meters or less was selected as
shallow water in California.
Alaska: It was assumed that southern Alaska bathymetry (ocean depth) was similar to California's
bathymetry, so a water depth of 50 meters or less was proposed to be shallow. The southern Alaska
region includes the Bristol Bay/Aleutian Island Chain, Cook Inlet, and the Gulf of Alaska. For other
parts of Alaska the Agency proposed shallow water to be of a depth of 20 meters or less in the Norton
Basin and 10 meters or less in the Beaufort Sea. The water depths in these Northern areas were
proposed as less than the 50 meters selected for southern Alaska because the harsher climates in the
more northern region made the probability of piping to shore for treatment less probable.
For determination of water depth, the 1985 proposed guidelines referenced recent nautical charts of
bathymetric maps available from NOAA. The water depth of the structure was defined to be based on the
proposed location of the structure's well slot structure or produced water discharge point.
The shallow/deep water platform grouping was considered in 1985 only for the production phase of the
subcategory. This distinction was evaluated for certain zero discharge options based on reinjection of
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produced water. The 1990 proposal included the same shallow/deep grouping for produced waters but also
is applying it to drilling fluids and cuttings.
For this 1991 proposal/reproposal, EPA considered platform grouping schemes other than a
shallow/deep grouping in an effort to mitigate potential non-water-quality impacts associated with zero
discharge options for drilling wastes. These impacts were due to the fuel requirements and resulting air
emissions expended for the barging of solid wastes to shore for disposal. Also, EPA was concerned with the
long-term availability of onshore disposal capacity to support the zero discharge options.
EPA evaluated a platform grouping based on structure location in terms of distance from shore. The
distances evaluated were 4, 6, and 8 miles from shore. EPA has determined that the use of a 4 mile
boundary for analysis of the regulatory options is preferable to the other options (6- and 8-mile boundaries)
for two reasons. First, distances greater than 8 miles do not provide sufficient reductions in non-water-
quality impacts, and second, the differences between the pollutant removals at 6 miles from those at 4 miles
are not significantly greater.
Table 3 presents the number of existing producing facilities based on a 4-mile boundary.
Approximately 9% of the total are located within the 4-mile distance. Table 4 presents the estimated
number of new wells that will be drilled within 4 miles of shore and Table 5 presents the number of new
producing platforms that will be located within 4 miles of shore. Approximately 9% of existing Gulf of
Mexico platforms will be located within this platform group.
4.2.4 New Sources
The 1985 proposed guidelines include a definition for the term "new source." While the provisions in
the NPDES regulations that define new source (40 CFR 122.29(b)) were applicable to the offshore
subcategory, there were two terms defined in the proposed subcategory-specific new source definition: "water
area" and "significant site preparation work" due to certain unique aspects of the activities in this subcategory.
Section 306(a)(2) defines a new source to mean "any source, the construction of which is commenced"
after publication of the proposed NSPS. Drilling rigs are moved from site to site over a period of several
years while production platforms are built onshore and transported to an offshore site. The determination of
whether a drilling rig or production platform is a new source is not the date of the building of such
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Table 3. Existing Producing Platforms According to Distance from Shore
< 4 Miles > 4 Miles
Region
Oil Only
Oil & Gas
Gas
Sub
Total
Oil Only
Oil & Gas Gas
Sub
Total
Total
Gulf of Mexico
50
63
84
197
111
905
1,020
2,036
2,233
Pacific
0
11
0
11
0
15
1
16
27
Atlantic
0
0
0
0
0
0
0
0
0
Alaska
0
0
0
0
0
0
0
0
0
Total
50
74
84
208
111
920
1,021
2,052
2,260
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Table 4. Estimate of New Offshore Wells Drilled According to Distance from Shore8
% of New Wells
Region < 4 Miles > 4 Miles Total by Region
Gulf of Mexico 72 643 715 73.0
Pacific 71 166 237 24.2
Atlantic 0 16 16 1.6
Alaska 9 3 12 1.2
152 828 980 100.0
a Assumes S21/BOE average 1986-2000 and development unrestricted by Pacific moratoria on drilling and
leasing and reflects MMS projections of continued Atlantic development.
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Table 5. Estimate of New Offshore Producing Platforms According to Distance from Shoreฎ
< 4 Miles > 4 Miles
% of Wells
Region Oil Only Gas Subtotal Oil Only Gas Subtotal Total by Region
Gulf of Mexico
56
84
140
252
363
615
755 88.7
Pacific
20
0
20
47
17
68
84 9.9
Atlantic
0
0
0
3
5
8
8 0.9
Alaska
2
0
2
1
1
2
4 0.5
Total
78
84
162
303
386
689
851 100.0
a Assumes $21/BOE
leasing and reflects
average 1986-2000 and development unrestricted by Pacific moratoria
MMS projections of continued Atlantic development.
on drilling and
17
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structures, but instead when the rig or platform is placed at the offshore site where the drilling and
production activity and discharge would occur.
In the 1985 proposed guidelines, "water area" was defined to mean the specific geographical location
where the exploration, development, or production activity is conducted, including the water area and the
ocean floor beneath such activities. Therefore, if a new platform is built at or moved from a different
location, it would be considered a new source if placed at the new site where its oil and gas activities take
place even if the platform is placed next to an existing platform.
The second special term proposed in 1985, "significant site preparation work" was defined to mean "the
process of surveying, clearing, and preparing an area of the ocean floor for the purpose of constructing or
placing a development or production facility on or over the site." Exploration activities were not considered
to be "significant site preparation work" because such activities are not necessarily followed by development
or production activities at that site.
In terms of development operations, offshore drilling varies from year to year depending on such
factors as the hydrocarbon economic market conditions, State and Federal leasing programs and reservoir
discoveries. In 1981, there were almost 1,500 wells drilled offshore culminating the upward trend of the
1970s. The average number of wells drilled during the 1972-1982 time period was 1,100 wells/year. Drilling
activity has declined since 1982 and in a 1988 notice the Agency estimated that between 1986 and the year
2000, there would be an average of 980 wells/year drilled (based on an average oil price for the years 1986 -
2000 to be $21/barrel). Of these 980 wells/year, 590 wells/year would become producing wells drilled on
new structures and the remaining 390 wells/year would be dry holes. The projected distribution of wells
drilled 4 miles or less from shore is shown in Table 4. At the present time, in addition to the Gulf of
Mexico and Pacific areas, there are exploration activities occurring in areas within the Chukchi and Beaufort
Seas of Alaska as well as in the Atlantic Ocean which may ultimately lead to new source development and
production activities.
Between the years 1986 and 2000, an estimated 851 new platforms installed offshore will be producing
oil or gas. As shown in Table 5, an estimated 162 of these platforms will be within four miles of the shore
and subject to the proposed limits that can be achieved by filtration of produced water prior to discharge.
(Both the projections of new wells and new platforms estimated here assume that offshore development is
not restricted by any limitations on drilling and production in the Pacific and that, as projected by MMS in
1986, some Atlantic offshore drilling occurs prior to the year 2000. Scenarios that consider restricted
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offshore development are presented in the Economic Impact Analysis, but none of the restrictions affects the
Gulf of Mexico, the focus of this RIA.)
4.3 Discharge Characterization of Major Waste Streams Considered in the RIA
The focus of this regulatory effort is on the major waste streams from exploration, development, and
production operations based on their volumes and potential toxicity. This RIA for the proposal/reproposal
evaluated only three major waste streams; drilling fluids, drill cuttings, and produced water. The volumes
and potential toxicity of the other miscellaneous wastes are generally less than these discharges, and
therefore were not considered in this RIA.
4.3.1 Drilling Fluids
Drilling fluids, or muds, are suspensions of solids and dissolved materials in a base of water or oil that
are used in rotary drilling operations to lubricate and cool the drill bit, carry cuttings from the hole to the
surface, and maintain hydrostatic pressure downhole. Drilling fluids can be water-based or oil-based. Oil-
based drilling fluids are those in which oil serves as the continuous phase with water as the dispersed phase.
Such fluids contain blown asphalt and usually one to five percent water emulsified into the system with
caustic soda or quicklime and an organic acid. Silicate, salt, and phosphate may also be present. Oil-based
drilling fluids have been more costly and more toxic than water-based drilling fluids, and are used for
particularly demanding drilling conditions (deep or highly deviated wells), including offshore wells.
In water-based drilling fluids, water is the suspending medium for solids and is the continuous phase,
whether or not oil is present. Water-based drilling fluids are used for more routine drilling conditions
offshore and are comprised of anywhere from 30 percent to 90 percent water by weight, with a variety of
mud additives constituting the remainder.
Drilling fluids are specifically formulated to meet the physical and chemical requirements of a
particular well. Mud composition is affected by geographic location, well depth, rock type, and is altered as
well depth, geologic formations, and other conditions change. The number and nature of mud components
varies by well, and several products may be used at any given time to control the properties of a mud system.
The eight basic functions of a drilling fluid are as follows:
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1. Transport drill cuttings to the surface,
2. Suspend drill cuttings in the annulus when circulation is stopped,
3. Control subsurface pressure,
4. Cool and lubricate the bit and drill string,
5. Support the walls of the wellbore,
6. Help suspend the weight of the drill string and casing,
7. Deliver hydraulic energy upon the formation beneath the bit, and
8. Provide a suitable medium for running wireline logs.
Four basic components account of approximately 90 percent by weight of all materials contained in
drilling fluids, namely barite, clays, lignosulfonate, and lignites. Other components include lime, caustic soda,
soda ash, and a multitude of specialty additives. These additives are used to modify the characteristics of
drilling fluids as dictated by well requirements to control site-specific drilling conditions.
4.3.2 Drill Cuttings
Drilling fluids circulate in the bore hole and move up the annular space between the drill string and
the borehole to the surface, carrying drill cuttings with it. Cuttings are removed from the drilling fluid in a
step-wise process which removes particles of decreasing size.
Upon reaching the surface, fluids and cuttings pass to the shale shaker, which is a vibrating screen that
removes large particles from the fluid. Standard shaker screens generally remove particles larger than
440 mm, and fine screen shakers using cloth finer than 30 mm, remove particles down to approximately
120 mm. If shale shaker damage or shaker by-passing is a problem, the fluid is then passed to the sand trap,
a gravitational settling tank removing particles from approximately 64 to 120 mm. A desilter, a hydrocyclone
using centrifugal forces, can then be used to remove silt-size particles (approximately 5 to 75 mm). After
removal, the cuttings are usually discharged from the rig near the water surface or below the surface of the
sea. Processed drilling fluids return to the mud tanks for recirculation to the well.
Solids removal system discharges consist of: drill cuttings, wash solution, and drilling mud that still
adheres to the cuttings. At one well drilled on the Southern California outer continental shelf, normal
cuttings discharged from solids control equipment was comprised of 0-96% cutting solids and only 4%
adhered drilling fluids. However, data from one well drilled on the mid-Atlantic outer continental shelf and
one well drilled in Alaskan waters suggested cuttings discharges were approximately 40 percent drill cuttings
and 60 percent drilling fluids.
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4.3.3 Produced Water
Produced water (also known as production water or produced brine) is process water discharged
during oil and gas extraction. It is comprised of the formation water, which has been brought to the surface
with the oil and gas, injection water (if used for secondary oil recovery and has broken through into the oil
formation), and various chemicals added during the oil/water separation process. Produced water contains
dissolved, emulsified, and particulate crude oil constituents, natural and added salts, organic chemicals, solids,
and trace metals. Produced water constitutes the major waste stream from offshore oil and gas production
activities.
4.4 Drilling Fluids Treatment Options
Most offshore oil and gas facilities are operating under Best Professional Judgement (BPJ) permits
that are more stringent than BPT effluent guidelines. The BPJ permit issued for the Gulf of Mexico OCS is
used as the baseline for determining the costs and benefits for this RIA because this level of control most
accurately represents the technology-based pollutant control being used by most facilities at the present time.
However, currently, operations in the territorial seas of Texas and Louisiana are operating under an
administratively extended BPT general permit unless state BPJ permits have been issued, and facilities
located in Federal waters offshore of California also are operating under an administratively extended BPT
permit unless an individual permit has been issued by EPA.
Seven options are considered in this RIA for drilling fluids; these are presented in Table 6. The 5/3
All option proposes for all structures a prohibition on the discharge of diesel oil; a toxicity limitation of
30,000 ppm LC50; no discharge of free oil to be detected by the static sheen test method; and drilling fluids
and drill cuttings would be required to meet limitations of 5 mg/kg and 3 mg/kg, respectively, on cadmium
and mercury in the stock barite.
The 1/1 All option includes the same diesel oil, toxicity, and free oil limitations as the 5/3 All option,
however, the limitations on cadmium and mercury are proposed as 1 mg/kg of each in the drilling fluids and
drill cuttings, on a dry weight solids basis, at the point of discharge. Different sources of barite contain
varying amounts of cadmium and mercury. Bedded deposits contain low metal levels, while vein deposits
have higher concentrations. Use of bedded, or "clean", deposits would reduce toxic discharges of cadmium
and mercury.
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Table 6. 1991 Proposed Regulatory Options for Drilling Fluids and Drill Cuttings
Regulatory Option
Parameter
Limitation
5/3 All
All Structures
1/1 All
All Structures
Zero Discharge 4 Miles - 5/3 Beyond
Structures < 4 miles from shore
Structures > 4 miles from shore
Zero Discharge 4 Miles - 1/1 Beyondฎ
Structures < 4 miles from shore
Structures > 4 miles from shore
Diesel Oil
Toxicity
Cadmium
Mercury
Free Oil
Diesel Oil
Toxicity
Cadmium
Mercury
Free Oil
No Discharge
Minimum 96-hr LC50 of the SPP shall be
3 percent by volume
5 mg/kg dry weight maximum in barite
3 mg/kg dry weight maximum in barite
None by static sheen test method
No Discharge
Minimum 96-hr LC50 of the SPP shall be
3 percent by volume
1 mg/kg maximum at the point of
discharge in drilling fluids and drill
cuttings solids
1 mg/kg maximum at the point of
discharge in drilling fluids and drill
cuttings solids
None by static sheen test method
No Discharge
Same as 5/3 All option
No Discharge
Same as 1/1 All option
Selected option.
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Table 6. (continued)
Regulatory Option
Parameter
Limitation
Zero Discharge Shallow - 5/3 Deep
Shallow Water (1985 Proposal definition)
Deep Water
Shallow - 1/1 Deep
Shallow Water (1985 Proposal definition)
Deep Water
Zero Discharge All
All Structures
No Discharge
Same as 5/3 All optionZero Discharge
No Discharge
Same as 1/1 All option
No Discharge
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The Zero Discharge 4 Miles - 5/3 Beyond option requires no discharge in waters 4 miles or less from
shore. Discharges at distances beyond that boundary are subject to the same limitations as the 5/3 All
option.
The Zero Discharge 4 Miles - 1/1 Beyond option also prohibits discharge in waters 4 miles or less from
shore. However, discharges beyond that distance must meet the limitations of the 1/1 All option.
The Zero Discharge Shallow - 5/3 Deep option requires no discharge of drilling fluids or cuttings in
shallow waters. Shallow waters were defined as those specified in the 1985 proposal, and were presented in
Section 4.2.3 of this document. This zero discharge requirement could be met through recycling/reusing the
spent mud system or by transporting it to shore with the drill cuttings for treatment and/or land disposal.
Deep water discharges would need to meet the same requirements as the 5/3 All option.
The Zero Discharge Shallow - 1/1 Deep option has the same shallow water discharge prohibition, but
deep water discharges are subject to the limitations of the 1/1 All option (1 mg/kg cadmium and 1 mg/kg
mercury at the point of discharge). This option would offer more protection to the deeper waters from
metal pollutants than the similar, preceding option.
The most protective option considered, the Zero Discharge All option, requires no discharge from all
structures, shallow or deep. This would offer the most protection for all offshore areas, provide the highest
reduction in pollutant discharges, and results in the most benefits with the highest associated costs. This
option was proposed in 1985. Under the current proposal, the technology basis for this option is product
substitution and recycle/reuse, or transport to shore for treatment and disposal onshore.
The Agency has selected the Zero Discharge 4 Miles - 1/1 Beyond option as the proposed limitations
for drilling fluids and cuttings. This option prohibits discharge from facilities at a distance of 4 miles or less
from shore. Wells drilled at distances greater than 4 miles would be allowed to discharge after meeting the
toxicity limitation, mercury and cadmium concentrations of 1/1 mg/kg, no static sheen, and no discharge of
diesel oil. Alaska facilities would have to meet the requirements of the 1/1 All option because climate and
safety conditions can make barging difficult and hazardous.
The Zero Discharge 4 Miles - 1/1 Beyond option, when compared to the Zero Discharge All option,
reduces the amount of material that requires land disposal, and lowers the air emissions and fuel use from
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barging. The other shallow/deep options do not appreciably reduce the non-water-quality impacts compared
to the Zero Discharge 4 Mile - 1/1 Beyond option.
4.5 Produced Water Treatment Options
Seven options are considered in the initial RIA assessment. Four of these options include granular
fdtration treatment of produced water. Two options are considered in the supplemental assessment (BPT All
and 4 Mile Filter - BPT Beyond (with membrane fdtration treatment of produced water). All of the
regulatory options considered for produced water are presented in Table 7. In the development of the RLA's
analyses for produced water, cost data were available for both granular and membrane fdtration technologies.
However, the effluent pollutant characterization data, which are used to estimate benefits, were initially
available only for granular filtration effluent and only recently became available for membrane fdtration
effluent. Thus, membrane filtration-specific benefits are developed only for the BPT baseline and the 4 Mile
Filter - BPT Beyond option. The seven options considered in the RIA are each briefly discussed below.
The BPT All option requires current levels of treatment for produced water discharges, i.e., the same
as those required by the BPT guidelines: 48 and 72 mg/1 oil and grease, respectively, for monthly and daily
averages; the BPT All option proposed a continuance of the BPT level of treatment for all structures.
The 4 Mile Filter - BPT Beyond option requires filtration prior to discharge for structures located in
waters 4 miles or less from shore. For this option and all other options that include fdtration, two alternative
technologies were considered: granular media or membrane separation. Discharges at distances beyond 4
miles would be allowed if the current BPT conditions for oil and grease and free oil are met.
The Filter Shallow - BPT Deep option requires fdtration (granular media or membrane separation)
before discharge of produced water in shallow water (defined in the 1985 proposal) and the equivalent of
BPT in deep water. Filtration will offer reduction of toxic pollutant discharges with the removal of some of
the bulk phase oil.
The Filter and Discharge All option requires that all structures filter their effluent (using granular
media or membrane separation) before discharge. This option provides additional protection to the shallow
areas compared to BPT and provides more protection to the deep areas as well.
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Table 7. 1991 Proposed Regulatory Options for Produced Water
Regulatory Option
Parameter
Limitation
BPT All
All Structures
4 Mile Filter - BPT Beyond"
Structures < 4 miles from shore
Structures > 4 miles from shore
Filter Shallow - BPT Deep
Shallow Water (1985 Proposal definition)
Deep Water
Filter and Discharge All
All Structures
Reinject Shallow - BPT Deep
Shallow Water (1985 Proposal definition)
Deep Water
Reinject Shallow - Filter Deep
Shallow Water (1985 Proposal definition)
Deep Water
Reinject All
All Structures
Current BPT
Filterb
Current BPT
Filterb
Current BPT
Filterb
No Discharge
Current BPT
No Discharge
Filterb
No Discharge
a Selected option. Discharge limits for "filter and discharge" options are being proposed based on
membrane filtration. The discharge limits for oil and grease are 13 mg/1 daily maximum and 7 mg/1
monthly average.
b This option includes consideration of two alternative technologies: granular filtration and membrane
filtration; for all other options that contain a filtration component, only granular filtration technology is
considered.
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The Reinject Shallow - BPT Deep option proposes zero discharge in shallow water. The effluent would
be filtered and reinjected. In deep water the BPT limitations would apply. Reinjection in shallow water
eliminates the discharge of pollutants and offers more protection to these more environmentally-sensitive
areas.
For the Reinject Shallow - Filter Deep option, deep water platforms would also filter (granular media or
membrane separation) and discharge produced water, but shallow water platforms would filter and reinject.
This option provides maximum protection to the shallow areas.
The Reinject All option requires all facilities, regardless of location or water depth, to reinject all
produced waters.
The Agency has selected the 4 Mile Filter - BPT Beyond option for both BAT and NSPS, based on
membrane filtration technology, for proposal. This option requires all existing production structures located
at a distance of 4 miles or less from shore to meet discharge limitations based on membrane filtration; all
existing production structures located at a distance greater than 4 miles from shore must meet the current
BPT limitation. EPA has determined this option to be economically and technically feasible.
Membrane filtration is being used as the technology basis for the proposed limits on produced water
BAT because it is a demonstrated technology and EPA has acquired sufficient data to develop effluent limits
of 13 mg/1 for daily maximum with a composite sample and 7 mg/1 for the maximum monthly average.
Although not yet in widespread use in the oil and gas industry, membrane filtration is a commercially
demonstrated technology in several other industries and is considered to be applicable to oil and gas
effluents.
EPA did not select the most stringent option, Reinject All, for three reasons. First, there are questions
concerning the applicability of reinjection to all structures. Although reinjection may be technically feasible
in general, depending on geological conditions, specific structures would not be able to reinject. Second, the
air emissions and fuel use associated with the large pumps necessary to reinject fluids are unacceptably high.
Finally, reinjection for all production structures would result in a production loss. This loss of production is
not merely a cost concern. Loss of production has independent significance in light of the statutory directive
that EPA consider energy impacts in establishing effluent limitations and new source performance standards
under the Clean Water Act.
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EPA did not select the Filter and Discharge All option as the preferred option because of the potential
adverse effects on oil and gas production (approximately 3 million BOE per year, based on membrane
filtration). The other options considered would require filtration for near-shore wells, but BPT controls for
wells farther offshore. These options use water depth or distance from shore as alternative means of
reducing the loss of oil and gas production. EPA chose the 4-mile distance for its selected option (4 Mile
Filter - BPT Beyond) because it minimizes the loss of oil and gas production resulting from controls on
produced water and because it is consistent with the 4-mile distance used in the preferred options for control
of drilling fluids and drill cuttings. The selected option also has the lowest associated fuel requirements and
air emissions of any of the options considered.
Reinjection does eliminate potential discharge of radionuclides, particularly radium-226 and -228.
These radionuclides have been measured at elevated levels (as high as several thousand pCi per liter) in
produced water discharges in coastal and near-shore areas in the Gulf of Mexico. EPA is concerned about
the possible effects of radium in produced water discharges on human health and the environment. Options
involving zero discharge based on reinjection will receive further consideration as more data on radionuclides
are obtained.
The Filter and Discharge All option is also being given consideration as the basis for BAT for
promulgation, because the potential effect of this option on offshore production is a very small percentage
(1.1 percent, assuming membrane filtration is installed) of the total of present value of offshore production at
existing structures.
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5. EVALUATION OF COSTS AND ECONOMIC IMPACTS
This section presents the estimated costs for each of the regulatory options being considered for the
offshore subcategory of the oil and gas extraction industry in the Economic Impact Analysis of Proposed
Effluent Limitations Guidelines and Standards of Performance for the Offshore Oil and Gas Industry (ERG,
1991a) and evaluates those costs in terms of their associated economic impacts on the subcategory and their
cost-effectiveness for pollutant removal. The economic impact and cost effectiveness analyses do not
consider those shallow/deep options for either major waste streams, because, as explained above in Section
4.2, these options do not appreciably reduce non-water-quality impacts.
5.1 Evaluation of Costs
Capital costs and operating and maintenance costs for model platforms and for model wells were
developed by the Industrial Technology Division of EPA. Annualized costs for the offshore subcategory
were then developed by the Agency using estimates of existing and new sources, as explained in Sections
4.2.2 and 4.2.3 above. Estimates of costs and impacts, as well as the cost-effectiveness, presented in this
economic section are for all U.S. offshore wells and platforms. The RIA focuses on costs and benefits
affecting the offshore oil and gas subcategory in the Gulf of Mexico. The Gulf is a major site of U.S.
offshore energy drilling and production. As a portion of U.S. offshore activity, the Gulf represents:
99 percent of current production;
99 percent of existing producing platforms;
73 percent of new wells drilled, 1986-2000; and
89 percent of new producing platforms, 1986-2000.
Future (NSPS) drilling and development presented in the RIA assume $21 per barrel of oil (1986 dollars)
and assume unrestricted development (see Section 4.2). Annualized costs and benefits of the regulatory
options are incremental to pollution control practices required by current regional permits and state
regulations.
For purposes of costing and estimating impacts, options requiring zero discharge for drilling fluids and
cuttings are assumed to be achieved by product substitution and barging these wastes to shore for transport
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and land disposal. Options requiring zero discharge for produced water are assumed to be achieved by
reinjection.
All costs presented in this section are in 1986 dollars and are for the entire U.S. offshore oil and gas
subcategory assuming no restriction on offshore development. Costs for the Gulf of Mexico alone are
presented in Tables 9, 12, and 13 in Section 6 of this RIA. For produced waters, filtration options are costed
both using a granular filter and using a membrane filter and are presented below in the summary of
annualized incremental costs:
Total U.S. Offshore
Incremental Cost Summary, millions (1986) dollars
Range of Options Proposed Option
Granular Filtration Membrane Filtration
Drilling Fluids & Cuttings
$ 2 to $ 283
$ 50
$ 50
Produced Waters
BAT
$13 to $ 845
$ 41
$ 13
NSPS
$17 to $ 275
$ 27
$ 17
Combined Options
$32 to $1,403
$118
$ 80
5.2 Economic Impacts
In order to analyze impacts and costs of the options on the offshore oil and gas subcategory, 34 model
projects were defined to account for the diversity of platform sizes (i.e., the number of well slots per
platform), geographic location, and production type.
The economic impact analysis examines impacts on typical offshore facilities (the Gulf 12-well platform
producing oil and gas is presented here as an example), on typical companies, and on production. Selected
impacts of the options are summarized on Table 8.
All options, including the proposed option, are economically achievable. The selected option would
have only a minor impact on production. None of the options considered for drilling fluids and cuttings,
including the proposed option, would have any negative impact on production. Minor production losses are
projected for the proposed option for produced water. Some of the model platforms within 4 miles from
shore that would have to install filtration prior to discharging produced water are projected to shut down
early. However, none of the existing or new platforms projected to be installed by the year 2000 are
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Table 8. Summary of Economic Impacts of Proposed Regulation (Percent Change)
Drilling
Fluids
& Cuttings
Produced
Water
BAT
Produced
Wafer
NSPS
Corporate Cost of BOEa
Range
Proposed Option
Membrane Filtration
Granular Filtration
Impact on Gulf-12 Oil and Gas Project
0 to -1.3
-0.2
-0.2
-1.6 to -19.0
-1.6
-15.2
-0.6 to -2.1
-0.6
-1.2
Net Present Value
Range
Proposed Option
Membrane Filtration
Granular Filtration
0 to -6.7
-0.9
-0.9
-4.7 to -24.2
-4.7
-19.9
-2.2 to -5.6
-2.2
-3.6
Internal Rate of Return
Range
Proposed Option
Membrane Filtration
Granular Filtration
Years of Production
Range
Proposed Option
Membrane Filtration
Granular Filtration
0 to -5.9
-1.0
-1.0
0
0
N/A
N/A
N/A
0 to -11.1
-11.1
-11.1
-1.4 to -3.8
-1.4
-2.5
0
0
Impact on Typical Company's Working Capital
Major Company
Range
Proposed Option
Membrane Filtration
Granular Filtration
0 to -0.8
0.1
-0.1
0 to -2.9
0
-0.1
-0.1 to -0.7
N/A
-0.1
Independent Company
Range
Proposed Option
Membrane Filtration
Granular Filtration
0 to -8.2
-1.0
-1.0
-0.5 to -30.6
-0.5
-1.4
-0.6 to -7.5
N/A
-0.6
Source: Eastern Research Group, 1991a.
a BOE = Barrel of oil equivalent
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projected to close rather than install pollution control equipment. As a result of early shutdowns, the
proposed options are estimated to cause only a minor loss in production. This loss is estimated to be 4
million barrels of oil equivalent (BOE), or 0.03 percent for granular filtration, or 2 million BOE, or 0.015%
for membrane filtration, of a total present value of offshore production (1986 - 2000) from all model
platforms of 13.3 billion BOE.
The offshore oil and gas subcategory is comprised of a small number of very large and independent
companies. The proposed option has little or no impact on the financial ratios of the typical company
involved in offshore drilling and production. Table 8 shows the impact on working capital, the parameter
most sensitive to any increase in costs, assuming the costs of pollution control were funded out of working
capital. To the extent there are impacts, they are greater for the independent than for the major company.
However, the typical independent's working capital would probably not be reduced as much shown on Table
8 because a combination of working capital and debt would be used.
Because none of the companies involved in offshore development and production of oil and gas is a
small business by any standard, a Regulatory Flexibility Analysis (RFA) of this regulation was not required.
5.3 Secondary Impacts of the Regulation
The impact of the effluent guidelines regulations on Federal revenues, State revenues, and the balance
of payments has been analyzed. Federal revenues are impacted by the tax effects of effluent guidelines
expenditures and by potential reductions in taxes and lease/bonus bids. The potential impact of the pro-
posed regulations on Federal revenues is estimated to be $82 million for granular filtration and $50 million
for membrane filtration in the year 2000. The potential impact of the proposed options on state revenues
due to reductions in lease/bonus bids and is estimated to be $5 million for granular filtration and $3 milliion
for membrane filtration in the year 2000. For Texas, this impact represents less than 0.1 percent of that
state's total 1986 revenues. No significant impacts on the U.S. balance of trade or inflation are projected.
Cost Effectiveness
Cost effectiveness (CE) analyses offer a useful way of quantifying comparisons among pollution control
alternatives. Cost-effectiveness is defined as the incremental annualized cost associated with a pollution
control option in an industry or industry subcategory divided by the incremental "pounds-equivalent" of
pollutant removed. As calculated, CE is a relative, not absolute, measure.
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Central to the study of a regulatory cost-effectiveness analysis is the ability to provide a meaningful
comparison of costs and effects of various regulatory alternatives on both an intra- and inter-industry basis.
To do this, the Agency chose to use a weighting scheme which varies the relative importance of the
pollutants based on their toxicities. The development of this weighting scheme was based primarily on EPA
criteria for the protection of aquatic life and human health. The toxic weighting factor for each pollutant
was calculated by dividing the criterion for a particular pollutant being discharged into the criterion for a
selected standard pollutant. Copper was selected as the standard pollutant for developing these weighting
factors, although the selection of any pollutant as a standard will give the same relative results.
Once the weighting factors have been established, the "pounds-equivalent" (PE) removed under a
specified treatment option is calculated by multiplying the weighting factor for each pollutant by the number
of pounds removed for that pollutant, and then summing the results across all pollutants. The cost
effectiveness of an option is the incremental cost divided by the incremental pounds-equivalent removed. To
facilitate inter-industry comparison, cost-effectiveness is expressed in 1981 dollars.
The results of the cost-effectiveness analysis of the proposed options are as follows: for drilling fluids
and drill cuttings, $28/PE; for produced waters, BAT, $2,350/PE using granular filtration and $60/PE using
membrane filtration; and for produced waters, NSPS, $800/PE using granular filters and S40/PE using
membrane filters. These numbers reflect unconstrained development. The pollutants considered in the cost
effectiveness analysis for selected (as well as all evaluated) options for drilling fluids, drill cuttings, and
produced waters are listed in Cost Effectiveness Analysis of Proposed Effluent Limitations Guidelines and
Standards of Performance for the Offshore Oil and Gas Industry (ERG, 1991b).
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6. EVALUATION OF BENEFITS AND WATER QUALITY IMPACTS
6.1 Introduction
Estimating benefits of environmental improvements attributed to regulatory actions is a challenging
exercise. Beneficial outcomes must be identified, quantified, and converted to monetary values. Thus,
analysis of the economic benefits of the proposed effluent limitation guidelines requires that to the extent
feasible all favorable outcomes be: (1) identified; (2) quantified; and (3) valued in dollar terms. In order to
properly execute the procedure, an enormous amount of scientific and socioeconomic information is
required. Due to deficiencies in the relevant data and inherent difficulties in measuring nonmarket
commodities, this economic benefits analysis represents an effort to estimate only the general magnitude of
benefits.
The Agency has attempted to identify and, where possible, quantify in monetary terms, the
environmental benefits of the effluent limitation guidelines for the offshore subcategory of the oil and gas
extraction industry. This benefit assessment has pursued three principal lines of investigation. The first
approach was to address benefits that could be quantified and monetized, and included estimates of
commercial, recreational, and national health-related benefits that could result from controlling pollutants in
effluent discharges from drilling and production waste streams. The second approach was to conduct
analyses of water quality benefits attributable to the guidelines. The third approach was to compile case
studies of documented environmental impacts from these discharges that, similar to water quality benefits,
can be quantified but not easily monetized.
Of the twelve waste streams identified for this industrial subcategory, the RIA addresses the costs and
benefits of three major waste streams: drilling fluids, drill cuttings, and produced water. These waste
streams were selected because they comprise the majority of effluent discharge volumes from oil and gas
exploration, development, and production facilities and because of their potential for producing adverse
environment effects and their toxicity. This RIA assesses and evaluates seven options for drilling fluids and
cuttings (see Table 6 for a listing of drilling fluid and cuttings options and their limitations). This RIA also
assesses and evaluates seven options and two filtration technologies (granular media and membrane
separation) for produced water. Table 7 presents a listing of produced water options and their limitations.
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Also the RIA only addresses quantified benefits based on analyses that were restricted to the Gulf of
Mexico. This restriction is based on two considerations. First, the vast majority of platforms are located in
the Gulf of Mexico, which has 2,233 of 2,260 total U.S. offshore structures. This compares to 27 structures
offshore in Southern California and no structures on the Alaskan or Atlantic OCS. On an industry-wide
basis, therefore, the greatest portion of environmental benefits would reasonably be expected to occur in the
Gulf of Mexico. Also, regional environmental and landings data, which are important to the modeling and
predictive approach of the benefits assessment, were more appropriate to an analysis for the Gulf of Mexico.
This region is more appropriate because, as variable as the environments covered by these guidelines in the
Gulf of Mexico are, there is a far greater degree of regional similarity in the Gulf of Mexico than the much
more complex bathymetry and habitat considerations of the Southern California OCS. The complexity of this
latter area lends itself more to site-specific, or platform-specific modeling and predictive analyses that are
less easily developed into an industry-wide assessment.
6.2 Overview of the Methodology and Its Limitations
Estimating the benefits of the effluent guidelines for offshore oil and gas facilities requires knowledge
of many complex physical relationships and responses that require quantitative measurement and prediction.
Estimating the benefits of the proposed regulatory actions is accomplished through the application of existing
studies that credibly link physical changes in the marine environment to changes in human activities and
social values using "off the shelf' results from existing models. This is the same approach that was used to
evaluate effluent guidelines for the iron and steel industry and for the organic chemicals, plastics, and
synthetic fibers industry. This RIA focuses almost exclusively on the benefits associated with reduced risks to
human health, stemming from the lack of an appreciable predicted impact of the regulation on fisheries
population dynamics.
The exposure assessment/risk characterization analysis is performed for contaminants representing
average subcategory-wide discharges under each regulatory control option (see Appendix C, Table C-l).
Health risks represented by current operating conditions (i.e., for the same group of subcategory-wide
pollutants) provide a baseline level of risk. This baseline is then compared to results derived for each
control option, which indicates the degree to which the control option provides reductions in health risks as
compared to the baseline.
In the present study, health risks are determined for the consumption of both commercially-caught
shellfish (shrimp) and recreationally-caught finfish exposed to platform discharges within the Gulf of Mexico
area. The categories of fmfish considered are Atlantic croaker, red drum, seatrout and red snapper.
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Impacts on commercial finfish catch are very difficult to project, and are thought to be relatively smaller than
impacts on recreational finfish catch because commercial fishermen avoid the immediate areas around
platforms and because finfisheries are mobile.
Only those health risk reduction benefits that are readily quantified and monetized have been assessed.
In interpreting the results presented in this section, it is important to recognize that the analysis is extremely
limited in terms of the full range of risk reductions that the proposed regulations will obtain.
The first major limitation is that the quantified and monetized health benefits (Avanti Corporation and
TRI, 1991a; RCG/Hagler, Bailly, Inc., 1991a) pertain only to a very limited set of the contaminants
(carcinogens and lead) that will be controlled by the regulation.
A second limitation of this benefits assessment is that health-related impacts associated with
radioactive pollutants in produced water (primarily ^Ra and ^Ra), which have only recently received
recognition by the Agency as potential pollutants of concern and are not being controlled in this proposed
regulation, have not been included in this assessment.
A third significant limitation is that for lead, the Agency has only been able to address a limited set of
the adverse health impacts associated with the contaminant.
Lastly, even for those lead-related health risks that have been quantified and valued in this section, the
benefit estimates are likely to be understated. This underestimate results from the limited application of the
lead-related health risks to small subsets of the population. Additionally, some of the valuation concepts
applied are highly conservative (e.g., valuing reductions in adverse health impacts according to the medical
costs avoided rather than the willingness-to-pay to avoid the health effect).
6.2.1 Quantified and Monetized Benefits for Drilling Fluids, Cuttings, and Produced Water
Estimating the monetized benefits of an improvement in health and environmental quality requires that
a chain of events and physical relationships be specified and understood. Thus, to estimate the benefits of
water pollution controls directed at reducing pollutant loadings, links have to be made from the regulatory
action (change in effluent limits) all the way through to outcomes that are of direct value to society. Such
outcomes, for example, include increases in the value of recreational fishing and/or reductions in risks to
human health. Four broad categories of benefits that could potentially be quantified and monetized were
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investigated: human health benefits; commercial fisheries benefits; recreational benefits; and intrinsic or
nonuse benefits.
The extent of dilution afforded by the marine environment, in combination with the average
concentrations for the selected subcategory-wide pollutants, results in environmental levels too low to be
analytically tractable. That is, the low level contamination of larger (mesoscale) components of the
environment is much more difficult to assess reliably than spatially localized impacts that exceed threshold
levels of detectibility. Thus, under current regulatory controls, no direct quantifiable impacts on the Gulf of
Mexico fishery can be attributed to the platform-related impacts on the discharges.
Predictions could not be made to quantify direct impacts of current discharges and proposed
regulations on: composition and abundance of finfish and shellfish population; recreational fishing and other
recreational activities; commercial fishing; or nonuse benefits. Therefore, the RIA focuses almost exclusively
on the benefits associated with human health risk reduction through reduced concentration of platform-
related pollutants in selected recreational fish species and commercial shrimp. Both carcinogenic and
systemic human toxicants are considered. Results are presented in Section 6.3.1 of the RIA. These
quantified and monetized incremental benefits are compared to the annualized incremental cost in the Gulf
of Mexico for the BAT and NSPS control options under consideration for proposal.
6.2.1.1 Human Health Benefits
Human health benefits arise from reduction in the risk of adverse health effects due to reductions in
exposure to contaminants that enter the environment through regulated wastewaters. The extent of the
reduced fish tissue levels depends on the change in environmental concentrations that apply to the relevant
pollutants and fish species. Fish tissue levels are estimated, first, by combining effluent concentrations of
pollutants in each regulatory option with transport and fate modeling analyses to estimate the ambient
concentrations of these pollutants in seawater (for water column exposure scenarios) or in sediment pore
water (for benthic exposure scenarios). Then, using chemical-specific bioconcentration factors, and fish
species-specific lipid content factors for organic pollutants, fish tissue pollutant concentrations are predicted
based on ambient seawater or pore water concentrations. Health benefits for carcinogens and most systemic
toxicants are calculated based on scenarios that reflect Americans' fish consumption patterns, including both
average individual risks and most exposed individual (MEI) risks. For the systemic toxicant lead, health
benefits are calculated using a weighted average exposure scenario for fish consumption. This scenario is
based on the distribution of national fish consumption levels weighted by the proportion of the U.S.
population consuming fish at that level, all of which are normalized to the total amount of fish consumed.
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Standard dose-response data are used to translate reduced exposure levels into reduced levels of health risk.
The quantified risk reductions are valued according to literature-derived estimates, compatible with EPA's
RIA guidelines.
6.2.1.2 Commercial Fishing
Commercial fishing is a vital component of the Gulf of Mexico regional economy. Regulation-induced
improvements in the Gulfs commercial fishery are not discernable in the RIA's environmental assessment
and, therefore, are not pursued in this analysis. There are data that could be used to suggest correlations
between oil and gas extraction activities and fisheries catch statistics. However, because of the complex
interaction between fisheries and numerous natural and other anthropogenic factors, developing any causal
relationships is extremely difficult, if not impossible.
6.2.1.3 Recreational Fishing
Recreational fishing is generally the largest category of benefits in freshwater-related benefits analyses;
the same may hold for marine recreational fishing as well. To estimate recreational fishing benefits, the
change in participation in recreational fishing activities must be quantified. However, the RIA's analysis does
not indicate a discernable change in the marine recreational fishery that is related to regulation-induced
improvements. Therefore, no recreational benefits are assessed in this report.
6.2.1.4 Intrinsic Benefits
Intrinsic (nonuse) benefits can only be measured through carefully designed and field implemented
contingent valuation method surveys. Such surveys are beyond the scope of this analysis. There are no past
research efforts available that can be applied to the marine setting. Therefore, in this benefits analysis,
intrinsic benefits are described qualitatively.
6.2.2 Quantified Benefits: Water Column and Pore Water Quality
The potential effects on water quality of effluent discharges from this industrial subcategory have been
analyzed. Drilling fluids and cuttings, by virtue of their very high solids content (10-70% by weight) have a
demonstrated capability to produce adverse benthic impacts. Produced water, although relatively free of
solids, has a high enough dissolved solids content to produce negatively buoyant discharge plumes that have
demonstrated the ability to impact the benthos, especially in shallow water. Therefore, because waste
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streams for drilling fluids, cuttings, and produced water all have a high potential for adverse benthic effects,
these analyses include assessments of water quality, both in the water column and in sediment pore water.
Analyses of water quality impacts in the water column are primarily targeted at assessing potential impacts
on finfish resources. Analyses of pore water quality impacts are primarily targeted at assessing potential
impacts on benthic resources, which for the RIA have been taken to be represented by the shrimp fishery.
6.2.2.1 Drilling Fluids and Cuttings
Water column water quality benefits for drilling fluids and cuttings are based on predictions of the
ambient concentration of subcategory-wide pollutants at the edge of a 100-meter mixing zone and
comparison of these ambient levels to Federal marine water quality criteria. Predictions of ambient pollutant
concentrations are based on EPA's estimates of subcategory-wide pollutants in these waste streams and
estimates of drilling mud dilution and dispersion based on results of model runs of the Offshore Operators
Committee (OOC) Mud Discharge Model.
Two scenarios were developed: average case and reasonable worst case. Average case scenarios are
based on the average dilution or dispersion for all of the model runs. Reasonable worst case scenarios were
hot minimum dilution/dispersion values, but are based on the average dilution or dispersion for the model
runs producing the lower half of the dilution/dispersion values in the data sets. Also, depending on the type
of pollutant, either plume dilution or plume dispersion is used to assess water quality impacts.
The reader should note that, for drilling fluids, dilution in this document refers to the behavior of the
soluble and fine particulate components of drilling fluid. Dilution is expressed as the volume of mud relative
to the volume of ambient seawater in which it is diluted. Dispersion in this document refers to the behavior
of the heavier particulate component of drilling fluid. Dispersion is expressed as the weight of mud solids in
seawater relative to the initial weight of mud solids in the discharged mud. Dilution estimates are used for
assessing water quality impacts from organic pollutants because these pollutants are found with the finer
particulates in the soluble phase of discharged drilling fluids. Dispersion estimates are used for metal
pollutants because these are primarily found with mud solids in the particulate phase.
For assessing pore water quality benefits, the ambient sediment concentration of industry-wide
pollutants is calculated from EPA's estimated waste stream loadings, assuming an even distribution
throughout a platform impact area. This area was determined from an analysis of field studies of sediment
barium (Ba) alterations, and is established as a radial distance of 6,280 meters. For organics, ambient
sediment levels are converted to pore water concentrations based on organic carbon content (f^ and organic
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carbon partitioning (K^. For metals, estimates of pore water concentrations are based on leachability
factors derived from industry studies of the solubility of trace metals in barite. Pore water concentrations are
then compared to Federal marine water quality criteria. Section 6.3.2 presents the results of these analyses.
There are three considerations for these data and analyses. First, for water column benefits, there is
great difficulty in attempting to generalize about plume behavior of discharged drilling fluids "in the Gulf of
Mexico" because the average or typical scenario is so different from the more extreme cases. For example,
the average discharge scenario is very different from those in 2 meters of water or in 300 meters of water.
Thus, while some effort was made to be conservative with respect to protecting water quality, the results are
primarily based on average conditions, even with respect to reasonable worst case scenarios. Minimum
dilutions and dispersion in the modeling data sets, for example, are 3-fold to nearly 8-fold less than the
values used for reasonable worst case scenarios.
Furthermore, even the shallow water data set is not a worst case exercise, in as much as it is based on
a water depth of 5 meters and not a 1- or 2-meter water depth, which better represents the extreme case for
assessing dilution/dispersion predictions. Conceptual, empirical, and practical limitations are responsible for
the inability to model the fate of these discharges in very shallow (<5 m depth) water. These limitations
include those related to theoretical aspects and computational aspects of modeling and those related to the
lack of necessary ambient environmental data.
A second consideration, for both water column and benthic benefits, is the inclusion of only eight
subcategory-wide pollutants for drilling fluids and cuttings in this analysis. Other priority pollutants and
nonconventional pollutants are likely to be present on a case-by-case basis. These other pollutants are
excluded for consideration in this subcategory-wide analysis. However, the presence of such pollutants, other
than the eight subcategory-wide pollutants considered in this RIA, could produce local adverse water quality
and/or living resource impacts on a facility-specific basis. The exclusion of these potential local impacts thus
could result in the underestimation of potential environmental benefits in the RIA.
Also, average pollutant concentrations are used throughout, not more conservative estimates, such as
the upper 90th or 95th percentile concentrations. Using large-scale average concentrations can lead to
underestimating impacts particularly if threshold-type effects are involved, such as for systemic toxicants.
This underestimation occurs if, for example, the average is below a threshold value resulting in an entire
population exhibiting no effect, whereas a higher confidence limit would produce an effect in some
proportion of that same population. The third consideration, which applies only to sediment benefits, is that
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because of both the variation in organic carbon content, on a Gulf-wide basis, and the uncertainties
associated with Kk values, these calculations should be considered as first-order approximations at best.
6.2.2.2 Produced Water
In the development of the RIA, two somewhat different methodologies are used to assess the benefits
associated with the regulation of produced water using granular filtration and membrane filtration
technologies. The methodology described immediately below is that which was used initially for assessing the
benefits of evaluated seven regulatory options including BPT associated with granular filtration technology,
and is the methodology presented in the technical support documents for the environmental and benefits
assessments (Avanti Corporation and TRI, 1991a; RCG/Hagler, Bailly, Inc., 1991a). The differences
between the methodologies in these assessments and the supplemental assessments specific to membrane
filtration are presented briefly at the end of this section (Section 6.2.2.2) and described in detail in
supplemental reports (Avanti Corporation and TRI, 1991b; RCG/Hagler, Bailly, Inc., 1991b).
Water column water quality benefits for produced water are based on predictions of ambient
concentrations of industry-wide pollutants at the edge of a 100-meter mixing zone and comparison of these
ambient levels to Federal marine water quality criteria. Predictions of ambient pollutant concentrations are
based on EPA's estimates of the average concentrations of these pollutants in produced water and estimates
of produced water dilution based on the results of EPA's ocean outfall model, UDKHDEN, which was
modified to accommodate a negatively buoyant discharge plume.
Two water column scenarios were developed, average case and worst case. The average case dilution
estimate is based on the lowest average dilution for each of the platform types (i.e., oil only, gas only, or oil
and gas platforms) among all of the regulatory options and platform locations (i.e., shallow or deep). This
average dilution, which was available for each option, platform location, and platform type, is based on
EPA's estimate of the average discharge rate of produced water (bbl/day) among these platforms. The
worst case dilution scenario is based on the least dilution among regulatory options, locations, and platform
types. The modeling data are based on scenarios that include water depths of 5 to 20 meters, discharge rates
of 15 bbl/day to 5,650 bbl/day, and discharge port diameters of 1", 2", and 4".
For assessing pore water quality impacts, three studies of production facilities were analyzed. Based on
a characterization of effluent and sediment pollutant levels, effluent-to-sediment ratios were identified and
sediment levels of four organic pollutants predicted. Based on sediment concentrations, organic carbon
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content, and organic carbon partitioning, sediment pore water concentration of these pollutants are
estimated. Several considerations apply to these analyses.
First, the discharge modeling is subject to opposing uncertainties and assumptions. Using model runs
limited to 5- to 20-meter water depths may underestimate available dilution for waters deeper than 20 meters
and overestimate dilution for waters shallower than 5 meters. However, two other factors indicate that
estimated dilution is overestimated overall. One factor is that discharge rates were examined in a range (15
to 5,650 bbl/day) that includes most platforms, including average platforms. However, larger central
processing facilities are capable of discharging at rates more than an order of magnitude (50,000 to
150,000 bbl/day) higher than the maximum rate modeled (5,650 bbl/day).
A second factor is that getting the model to run at lower discharge rates required using very small port
diameters (l"-4"). These discharge port diameters, in all probability, are smaller (and perhaps much smaller)
than those actually used. A significant data gap is that of the industrial characteristics of the discharge
configuration for this waste stream (location; port diameter). At larger port diameters, less dilution would
be expected. Therefore, the dilution used here should be accepted as average estimates, even for the "worst
case" scenarios.
The second consideration is that using only subcategory-wide pollutants restricts the number of
potential pollutants. For example, 21 priority pollutants were measured in 79 samples of produced water
collected from 30 platforms. However, these 21 pollutants were detected at a frequency of 30% or less, and
were omitted from this industry-wide analysis. Their presence at individual platforms could produce impacts
on water quality and/or living resources at a local level or on a case-by-case basis. Also, average pollutant
concentrations, which can lead to an underestimate of potential benefits, are used throughout, not more
conservative estimates based on some upper confidence limit. Although more pollutants are identified for
the supplemental analyses of membrane filtration than granular filtration (23 versus 8 pollutants,
respectively), the lack of data necessary to quantify risks and monetize benefits reduced the number of
pollutants contributing to the benefits assessment to a few.
Third, modeling for the entire Gulf of Mexico, again, necessarily will involve some type of limitation on
potential ambient conditions, so discharges in very shallow water (1-2 meters) or under usually stagnant or
stratified conditions are not included. Lastly, biocides and radioactivity are not considered in the RLA. The
potential impacts of biocides could not be assessed because sufficiently reliable data on the materials used,
their chemical and toxicological properties, and their usage levels and frequencies could not be obtained in
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time to be included in this document. Likewise, the issue of radionuclides in produced water has only
recently evolved, and time constraints precluded inclusion of any analysis in the RIA.
As discussed previously, supplemental environmental and benefits assessments, which are specific to
produced water membrane filtration technology, were prepared once effluent pollutant data specific to this
technology became available. However, in the supplemental assessments, only the BPT baseline and the
selected option (4 Mile Filter - BPT Beyond) were evaluated. The methodologies used in these supplemental
assessments are identical to those used in initial assessments, with two exceptions.
The first difference is that the list of identified pollutants for the membrane filtration assessment is
expanded to 23 pollutants (from 8 pollutants in the initial assessments. Impacts to water quality are based
on all 23 pollutants; 6 pollutants are included in projections of quantified health risks; 3 pollutants are
included in projections of monetized health benefits. The second difference is the type of data provided for
pollutant concentrations in BPT and membrane filtration effluents which were provided on a subcategory-
wide basis, versus concentrations in the initial assessments that are specific to platform types (oil, oil and gas,
or gas platforms) and locations (shallow or deep).
The initial environmental and benefits assessments for the BPT baseline are based on disaggregated
effluent concentration data and disaggregated platform frequency/flow data; initial assessments for granular
filtration are based on aggregated concentration data but disaggregated platform frequency/flow data. In
contrast, the supplemental environmental and benefits assessments for membrane filtration technology
considered only aggregated concentration data and aggregated platform frequency/flow data for assessments
of both the BPT baseline and the membrane filtration option.
Therefore, membrane filtration BPT baseline impacts in the supplemental assessments do not exactly
match the initial (granular filtration) BPT baseline values; likewise, the BAT and NSPS benefits in the
supplemental benefits assessment do not exactly match the BAT and NSPS benefits for initial (granular
filtration technology) assessments. The results are comparable, however, even though they are not identical.
6.2.3 Quantified Impacts (Case Studies) of Drilling Fluids, Cuttings, and Produced Water
An extensive review of the literature to identify and review potentially applicable field impact studies
was undertaken by EPA to document impacts due to drilling and production discharges. In an effort to
capture as many reports of case studies as possible, a very broad interpretation of "potentially relevant" was
applied during the literature search process, producing an extensive bibliography of reports that included
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operational data, physical/chemical/biological characterization studies, laboratory studies, and regulatory
support documents in addition to field impact case studies. An initial review of 483 potentially relevant
studies or reports resulted. A list of these citations was distributed to 22 contacts at EPA, MMS, and coastal
state agencies to identify any additional sources of information potentially relevant to the case study analysis
portion of the RIA. As a result of this effort, an additional list of 405 citations of potentially relevant studies
and reports was compiled. A review of these two lists of citations for field impact case studies was
conducted for the RIA.
Results of this review of potentially applicable field impact studies are discussed in Section 6.3.3 of the
RIA. The findings of this review are that localized biological effects (<500 meters to several kilometers)
were observed for drilling and production wastes, and that regional-scale impacts could be inferred
chemically, but not biologically or ecologically. However, there are five principal sources of concern that
merit discussion with respect to the poor ability of these studies to demonstrate conclusive adverse
environmental impacts at anything other than local scales.
It must be noted that this criticism is not so much directed at the studies conducted, which were often
state of the art and/or resource limited. These criticisms do not invalidate these studies. Rather, these
criticisms are intended to give the findings of these studies some perspective, and consequently give greater
weight to their limited observations of impact because of the natural, anthropogenic, technical, and cost
factors that all act separately or in concert to reduce our ability to demonstrate the type and extent of
environmental changes from discharges of this industrial subcategory. Thus, these comments or concerns are
an indictment of the level of confidence we can have when we make or accept statements about the limited
nature of the effects of these discharges.
One source of concern in evaluating field studies of offshore oil and gas discharges is the type of study
design used to detect potential environmental alterations. In the Gulf of Mexico, where drilling has occurred
for decades, a host of rig monitoring studies have been conducted, i.e., studies of single exploratory well
operations. Several factors contribute to the reduced ability of such studies to detect changes. One factor is
the absence of necessary reference values. That is, studies often did not have comparative annual or
temporal reference data to evaluate drilling programs less than a year in duration. The lack of such
comparative data introduces uncertainty in any observed changes because of the potential contribution of
seasonal effects. Also, spatial reference stations were either not used or, as more often was the case, an
assumption was made that stations located at 1 kilometer or 2 kilometers from the drillsite could validly
serve as reference stations. However, often there was no analysis or consideration of these "reference"
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stations with respect to their comparability to the drillsite, their independence from drilling-related effects of
the drillsite, or their independence from the effects of other nearby drilling or production activities.
Also, related to this concern about study design is the historical insistence on the selection of
exploratory sites, at which only one well was drilled, for impact studies. This approach necessarily reduces
our ability to detect environmental changes when compared to multiple well, development facilities. For the
expedience of cost effectiveness, the effort to measure environmental changes should be pursued in cases
where the potential magnitude of change would be the greatest, and thus most easily detected. Specifically, if
changes due to drilling discharges were to be examined, a development drilling platform with 24+ wellslots
would afford a better study site than a single-well, exploratory site because of the greatly increased pollutant
loadings and concomitant potential for causing adverse environmental changes. Yet, although sediment
chemistry has been studied, primarily after the fact, no benthic biological studies of development drilling has
occurred in the Gulf of Mexico. One such study has been initiated offshore southern California. A hard
bottom study has begun, but a soft-bottom study has been suspended because the scheduled placement of the
platform has not occurred.
The second and third sources of concern in evaluating offshore oil and gas case studies are related-
natural, sampling, and analytical variability is one concern; statistical power is the other. Because of high
levels of natural, sampling, and analytical variability and high costs inherent to marine Held studies, the
statistical power of such studies is limited. Thus, many studies have shown "no effect" or have shown
statistically significant adverse effects to a limited spatial extent (several hundred meters). These statements,
however, also should be considered in light of the limiting question: "How large an effect could be
observed?" The answer for most studies is that the magnitude of change that would be required in order to
statistically observe such a change have ranged from "large" for chemistry data to "very large" for biological
data. For example, in one of the most sophisticated and well-funded studies conducted, sampling at 60
photoquadrats per station per cruise resulted in the ability to statistically resolve 70% reductions or greater
in coral coverage. This level of detectibility gives some measure of definition to and confidence in the
conclusion that "No statistically significant changes were noted."
The fourth source of concern in evaluating these case studies is the issue of "background" or the
reference value against which changes are measured. This consideration applies both to the spatial and
temporal changes. For example, drilling fluid components have been shown to be regionally dispersed:
studies have found large mass transport (up to 95% of discharged particulates) beyond 3 kilometers of the
drillsite and document the transport of solid components at least 35 miles from the discharge point. Thus,
defining sampling stations at 1 kilometer or 2 kilometers distant from a drillsite as reference stations may not
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be a very sound assumption. In studies thorough enough to address the issue of nearby drilling activity, the
study invariably identifies other previous or concurrent well-drilling operations, ranging from single wells
being located from 500 meters to a few kilometers from the discharge point to multiple (225) wells drilled
within a 10-mile radius of the study area. Both situations cast serious doubt on the establishment of a true
"background" level for comparative purposes.
The fifth and last source of concern in evaluating any field impact study is the issue of confounding
factors, which is an inherent problem of all field studies and has accounted for some uncertainty concerning
environmental changes related to oil and gas discharges. This factor was and is a significant one in the Gulf
of Mexico, where heavy ship traffic and fishing, and the large influence of the Mississippi River have
confounded study plans and the interpretation of their results.
Given the wide distribution of mud components, the situation is akin to that of acid precipitation
impacts assessment - there are great difficulties (technical and financial) in measuring low-level, regional-
scale effects at meaningful levels of statistical power and in our ability to ascribe cause-effect relationships.
Assessing large scale, low level impacts is very difficult in such cases. When even large effects (e.g., >50%)
may often go unnoticed or unprovable, assessing more subtle changes is nearly impossible in any way other
than extrapolation. Nonetheless, total impacts at the 1-10% effect level that occur over many square
kilometers, and which cannot be statistically resolved and thus documented, may easily exceed the total
impacts associated with changes at the 50-100% effect level that can be documented within a few hundred
meters of a discharge.
In view of the above discussion, it is perhaps surprising to find any evidence of documented adverse
impacts due to drilling and production wastes. Evidence is largely based on chemical alteration of sediments,
which although easier to demonstrate, is of uncertain ecological significance. However, localized adverse
biological effects have been noted, and these findings should be appropriately weighted because of the
considerations discussed above.
6.3 Results
6.3.1 Quantified and Monetized Benefits
In this section human health benefits of the regulations are quantified and assigned monetary values, to
the extent feasible. This is accomplished within limits of the data, the state of knowledge, and EPA-accepted
methodologies. There are three major types of health risk reductions relevant to the guidelines covering the
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three major waste streams of this industrial subcategory--carcinogenic risk reduction, systemic toxicant risks
(expressed as a fraction of the RfD values), and as a special case of systemic toxicants notable in its own
right, lead-related risk reductions. Although carcinogenic, general systemic, and lead-related impacts are
quantified, only carcinogenic and lead-related impacts are monetized.
Cancer risks are quantified and monetized using average individual exposure levels, which are applied
to the exposed population (shrimp consumers and recreational anglers), and Agency-established unit risk
factors. Average exposures are used to mass balance human uptake with pollutant levels, and the linear
dose-response relationship enables the straight-forward quantification of total excess cancer cases.
Regulatory actions resulting in reduced mortality are valued in the RIA's benefits analysis at $1.74 million to
$8.75 million, representing a widely accepted range of values in the literature per statistical fatality avoided
(see U.S. EPA, 1989a).
Risk reductions associated with lead intake from drilling fluids require more complex analyses, because
the dose-response functions are not linear. Therefore, different exposure scenarios are utilized and applied
to population subcategories so as to maintain a mass balance between fish tissue totals and human intake.
The analysis is further subdivided into three types: benefits to infants, benefits to adult males, and benefits
to children. The monetized lead benefits represent only a limited portion of the types of health benefits that
may be attributable to reduced exposure to this metal. These limited benefits are due to limited data and
the unsettled status as to the appropriate means of quantifying and/or valuing several of the important health
effects associated with lead exposure.
6.3.1.1 Summary
The combined monetized benefits of regulating drilling fluids, drill cuttings, and produced water in the
offshore subcategory of the oil and gas extraction industry were found to be reasonably commensurate with
the costs. The total monetized benefits for the selected options range from $13.4 to $65.2 million annually.
The total annualized BAT and NSPS costs for both major waste streams range from $47.4 million to $67.6
million (1986 dollars). (The primary difference in the cost range reflects membrane filtration at the low end
and granular filtration at the high end.)
Drilling Fluids and Cuttings
The monetized human health benefits that result from the proposed BAT/NSPS options for drilling
fluids and drill cuttings range from $13.4 to $65.2 million annually, compared to the estimated total
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annualized costs of $29.5 million. The projected benefits, due to reduction in exposure to contaminants that
enter the environment through regulated wastewaters, include reduced cancer risks and lead-related, systemic
effects from consumption of contaminated fish and shrimp.
For carcinogens and all evaluated systemic toxicants with the exception of lead, these projected benefits
are based on average/average case scenarios, that is, based on both average exposures of selected seafood
species to effluent-related pollutants and average exposures of human populations to such affected seafood
species (i.e., through consumption). For lead-related risk reduction benefits, average/weighted average
scenarios are used, which combine average exposures for the selected seafood species with human exposure
scenarios that are based on various levels of seafood consumption weighted by the fraction of individuals who
consume seafood at each level of consumption.
Of these two sources of benefits, lead-related benefits predominate: while cancer risk reduction
benefits are on the order of $3,500 to $17,700 per year (see Table 10), lead-related risk reduction benefits
are on the order of $13.4 million to $65.2 million per year (see Table 11).
Produced Water
For produced water, monetized incremental annual benefits for the selected BAT option are small,
ranging from $2,000 to $9,000 for granular filtration and $1,000 to $6,000 for membrane filtration. The
health-related risk reduction benefits due to the regulation for produced water, employing the same methods
as used for drilling fluids and cuttings, are based on average/average case scenarios for carcinogens. The
same pattern of small incremental benefits that is observed for BAT also occurred for the selected NSPS
option: benefits range from $200 to $1,000 for granular filtration and from $300 to $2,000 for membrane
filtration. For both BAT and NSPS incremental benefits, cancer risk reduction is the source of the benefit;
no monetized systemic benefits were predicted.
Comparing produced water incremental benefits and costs, for both BAT and NSPS, shows that
projected benefits are orders of magnitude lower than corresponding costs. The total annualized cost for the
selected BAT option ranges from $9 million (membrane filter) to $24 million (granular filter). NSPS costs
range from $9 million (membrane filter) to $14 million (granular filter).
49
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6.3.1.2 Drilling Fluids and Cuttings
For drilling fluids and cuttings, proposed guidelines covering both existing sources (the Best Available
Technology Economically Achievable, or "BAT" level of treatment) and new sources (the Ne.w Source
Performance Standard, or "NSPS" level of treatment) are considered equivalent. All benefits and costs
related to drilling fluids and cuttings, therefore, are presented in the following discussion without reference to
their derivation as either "BAT" or "NSPS".
Drilling Fluids and Cuttings Health Risk Reductions - Cancer Risk
For drilling fluids and cuttings, comparing the results for total benefits from all health risk reductions
(Table 9) to the average case scenario for cancer risks indicates relatively few health benefits accrue from
cancer risk reductions of the regulatory options (Table 10). Carcinogenic risks for the average scenario from
finfish and shrimp consumption combined are orders of magnitude below the 10"" to 10"ฎ range targeted for
most Agency programs. Compared to a baseline ("Current") excess risk level of 4 x 10'9, regulatory options
ranged from none for the Zero Discharge All option to 4 x 10"8 for the 5/3 All option. The annual reduction
in excess cancer cases ranges from a low of 0.0002 cases avoided per year for the Zero Discharge 4 Miles -
5/3 Beyond option to a high of 0.0026 for the Zero Discharge All option. (The 5/3 All option is analytically
considered equivalent to current treatment, thus yielding no cases avoided.) Incremental monetized benefits,
based on $1.74 million to $8.75 million representing the range of statistical values for a life (see U.S. EPA
1989a), range from $500 to $21,400 per year for all evaluated options. For the selected option, the annual
reduction in excess cancer cases for consumption of finfish and shrimp, in this average case scenario, is
0.0021 cases avoided per year; the incremental monetized benefit for the selected option ranges from $3,500
to $17,700 per year (see Table 10).
In contrast to the average case scenario results, the MEI cancer risk results for drilling fluids and
cuttings suggest there may be substantial health risks for individuals who consume more than the
"average"amount of fish. Cancer risk levels are at levels of concern (1 to 5 x 10"6) for shrimp consumption
(arsenic), and approach levels of concern (1 to 7 x 10'7) for recreational finfish consumption (Appendix C,
Tables C-4 and C-5). These MEI values are three to four orders of magnitude greater than the average case
excess risk values for shrimp consumption, which ranged from 10"9 to 10'10 and five to six orders of
magnitude greater than average case excess risk values for finfish consumption, which ranged from 10"12 to
10"13 (Appendix C, Table C-2 and C-3).
50
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Table 9. Incremental Annualized Benefits and Costs of Offshore
Oil and Gas BAT/NSPS Options for Drilling Fluids and Cuttings'
(thousands of 1986 dollars per year)
Regulatory Options
Incremental Benefits15
Incremental Costs
Current
5/3 All
1/1 All
Zero Discharge 4 Miles -
5/3 Beyond
Zero Discharge 4 Miles -
1/1 Beyondd
Zero Discharge Shallow -
5/3 Deep
Zero Discharge Shallow -
1/1 Deep
Zero Discharge All
13,431 - 65,184
12,396 - 60,381
13,431 - 65,184
12,584 - 60,856
13.431 - 65,185
13.432 - 65,188
All incremental values relative to current treatment.
Monetized benefits only.
Current treatment assumed to be equivalent to 5/3 All option for analytic purposes.
Selected option for proposal.
Incremental costs incurred are due to monitoring requirements.
0
787ฎ
8,466
22,493
29,500
81,119
86,279
211,859
51
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Table 10. Cancer Risk Reduction Benefits (Arsenic) for Drilling Fluids and Cuttings - BAT/NSPS
Annualized Incremental Benefits"
Lifetime Excess Lifetime Excess Reduced Benefits
Regulatory Option
Risk Level"
Cancer Cases
Cancers"
($ x 103)c
Current
3.8 x 109
0.19
0
0
5/3 All
3.8 x 109
0.19
nd
nd
1/1 All
8.2 x 1010
0.04
0.0020
3.4 - 17.2
Zero Discharge 4 Miles -
5/3 Beyond
3.4 x 10"B
0.17
0.0002
0.5 - 2.3
Zero Discharge 4 Miles -
1/1 Beyondฎ
7.3 x 10"10
0.04
0.0021
3.5 - 17.7
Zero Discharge Shallow -
5/3 Deep
2.4 x 10"9
0.12
0.0009
1.6 -8.1
Zero Discharge Shallow -
1/1 Deep
5.1 x 10"10
0.02
0.0023
3.8 - 19.0
Zero Discharge All
0
0
0.0026
4.2 - 21.4
8 Reflects combined average risk from shrimp and selected finfish consumption.
b All increments are relative to "Current" treatment practices.
c 1986 dollars.
d Current treatment assumed to be equivalent to 5/3 All option for analytic purposes.
e Selected option for proposal.
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Drilling Fluids and Cuttings Health Risk Reductions - Systemic Toxicant Risk (Non Lead-related)
Similar to cancer risks, for the average case scenario there appear to be few appreciable health benefits
for finfish consumers due to regulatory options for systemic toxicants. For all pollutants, intake rounded to
0% of their RfD values (Appendix C, Tables C-2 and C-3). However, also similar to cancer risk reductions,
the MEI results for drilling fluids and cuttings reveal that there are appreciable health risk reductions that
may be attributable to the regulations for those individuals who consume more than the "average" amounts of
fish (Appendix C, Tables C-4 and C-5). Cadmium can be a considerable share of its oral RfD: for either
finfish or shrimp consumers, cadmium levels approximate 10% of the RfD for any option with a 5 mg
limitation on cadmium; this percentage decreases to 0.01% to 0.5% of the RfD for cadmium options
imposing a 1 mg/kg limitation on cadmium or a zero discharge limitation for all structures.
Drilling Fluids and Cuttings Health Risk Reductions - Lead-related Risk
The lead-related monetized health benefits from the regulation are summarized in Table 11 and
comprise the predominating fraction of all health-related benefits derived from regulating drilling fluids and
cuttings (Table 9). The benefits due to the regulation appear to be appreciable, especially with respect to
benefits accrued by adult males. These analyses are discussed in more detail below. Reviewers should note
that for all the regulatory options at least a stringent as 1/1 All, lead-related health benefits are held
constant. This result occurs because at the level of the 1/1 All option, incremental blood lead distributions
become indistinguishable from those due to zero incremental fish-related lead ingestion (i.e., background
lead ingestion).
Benefits to Infants: Reduced Mortality Amons Infants
There are many likely benefits to infants that could be attributable to reduced lead exposure via
maternal blood. However, the only effect quantified and valued in EPA's sludge analysis, and therefore in
this instant analysis, is the reduced risk of mortality in the first year of life (Appendix C, Table C-6). Annual
monetized benefits of this reduction is summarized in Table 11. Reductions in infant mortalities are assigned
dollar values in accordance with the literature-established range for the value of a "statistical" life: $1.74 to
$8.75 million (see U.S. EPA 1989a). The resulting monetized lead-related health benefits to infants range
from a low of $500,000 (for both Zero Discharge - 5/3 options) to a maximum of $2.7 million per year (for
all "1/1" options and the Zero Discharge All option). For the selected option, monetized benefits of reduced
mortality among infants range from $0.6 to $2.7 million.
53
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Table 11. Lead-Related Monetized Health Benefits for Drilling Fluids and Cuttings
BAT/NSPS Options (millions of 1986 dollars per year)
Benefit Categoryฎ
Lead Exposure Lead Exposure Lead Exposure Total
Regulatory Increment Infants Adult Males Children Benefit
Current
0
0
0
0
5/3 All
nb
nb
nb
nb
1/1 All
0.6 - 2.7
12.8 - 62.3
0.07
13.4 - 65.2
Zero Discharge 4 Miles -
5/3 Beyond
0.5 - 2.3
11.9 - 58.0
0.04c
12.4 - 60.4
Zero Discharge 4 Miles -
1/1 Beyondc
0.6 - 2.7
12.8 - 62.3
0.07
13.4 - 65.2
Zero Discharge Shallow -
5/3 Deep
0.5 - 2.3
12.1 - 58.5
0.04c
12.6 - 60.8
Zero Discharge Shallow -
1/1 Deep
0.6 - 2.7
12.8 - 62.3
0.07
13.4 - 65.2
Zero Discharge All
0.6 - 2.7
12.8 - 62.3
0.07
13.4 - 65.2
a All incremental benefits are from "current" level of treatment.
b Current treatment level assumed to be equivalent to 5/3 All option.
c Selected option for proposal.
54
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Benefits to Adult Males: Reduced Circulatory Svstem-Related Effects
Elevated blood lead (PbB) levels in adult males have been linked statistically to several adverse health
risks associated with the circulatory system: increased incidence of hypertension, strokes, cardiovascular
heart disease events (CHDs, e.g., heart attacks), and death. Adverse health effects avoided are converted
into dollar values based on the "cost of illness" approach used in the EPA sludge benefits assessment. This
approach undoubtedly substantially undervalues the reduced cases because it omits the value of pain and
suffering and averting behavior (e.g., diet restrictions, etc.). Fatalities due to the relationship between PbB,
blood pressure, and deaths from all causes, are valued between $1.74 million and $8.75 million, representing
a widely accepted range of values per statistical fatality avoided (see U.S. EPA, 1989a). The resultant lead-
related monetized health benefit estimates for post-BPJ options range from $11.9 million to $62.3 million
(Table 11). The annual monetized lead-related benefits to adult males for the selected option (Zero
Discharge 4 Miles - 1/1 Beyond) range from $12.8 million to $62.3 million. More detailed analyses and
results are presented in Appendix C, Table C-7.
Benefits to Children: 10 Impacts, Future Earnings. and Special Education Costs
Children are considered especially vulnerable to lead exposure. Of the health effects related to lead in
children, the most analytically tractable is the relationship between PbB and intelligence, typically measured
in IQ points. Based on estimated PbB levels, the number of children with a specific adverse impact was
estimated, and was limited to (1) the present value of future earning losses due to the IQ decrements
associated with elevated PbB levels and (2) the expense of supplemental education for those additional
children with IQ levels below 70 points due to shrimp-related exposures. The present value of lost earnings
is valued at $471 per IQ point decrement, and the cost of supplemental education is estimated at $2,043 per
child (as per U.S. EPA, 1989a).
The lead-related monetized health benefit to children of moving from the current level of treatment to
more stringent BAT/NSPS options ranges between $0 and $70,000 per year (Table 11). The annual
monetized lead-related health benefits for children from the selected option (Zero Discharge 4 Miles - 1/1
Beyond) are $70,000. More detailed results are presented in Appendix C, Table C-8.
6.3.1.3 Produced Water
For produced water, the Agency is proposing guidelines both for existing sources (i.e., Best Available
Technology Economically Achievable, or "BAT" guidelines) and for new sources (i.e., New Source
55
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Performance Standards, or "NSPS" guidelines). In contradistinction to drilling fluids and drill cuttings waste
streams, the costs and benefits of BAT and NSPS guidelines are treated separately for produced water
because both existing sources and new sources present substantial but different benefit and cost
characteristics. The reviewer should note that the BPT (Best Practicable Treatment) level of treatment for
produced water represents not only the baseline condition for incremental benefit and cost comparison
calculations, but also was considered as an option for both proposed BAT and proposed NSPS guidelines.
In the following discussion on produced water, the reviewer will find many references similar to "BAT
excess lifetime risk" or "NSPS excess risk". This terminology is an abbreviated format for discussing the
incremental risk reductions due to the evaluated option, relative to the baseline, for existing sources ("BAT")
or new sources ("NSPS").
Lastly, the reviewer will notice references similar to "supplemental membrane filtration assessment" or
"supplemental report". This terminology uniformly refers to the data, analyses, and results of the
supplemental and membrane filtration-related assessments and reports (Avanti Corporation and TRI, 1991b);
(RCG/Hagler, Bailly, Inc., 1991b). These supplemental assessments evaluate the risks and benefits of
proposed BAT and NSPS options, (4 Mile Filter - BPT Beyond) based on membrane filtration technology,
using recently obtained BPT and membrane filtration effluent pollutant characterization data. No other
options were evaluated. References to the results of these evaluations are made below using the terminology
described above.
Produced Water Health Risk Reductions - Cancer Risk (Initial Granular Filtration-Related Benefits)
For produced waters, monetized cancer risk reduction benefits at average exposure levels are small for
both BAT and NSPS (Tables 12 through 15). BAT excess lifetime cancer risk from carcinogenic pollutants
in produced water (benzene and bis(2-ethylhexyl)phthalate), for BPT All (as the baseline and an evaluated
option) for combined finfish and shrimp average consumption is 8 x 10"9 for BAT and is 4 x 10"9 for NSPS.
For evaluated BAT options, lifetime excess risk for combined finfish and shrimp (average consumption)
ranges from none for the Reinject All option, to 9 x 10'11 for the lowest risk option allowing discharge, to a
maximum of 8 x 10 9; for selected option (4 Mile Filter - BPT Beyond) it is 5 x 10"9 (Table 14).
Lifetime NSPS excess risk for combined finfish and shrimp average consumption ranges from none for
the Reinject All option, to 5 x 10'11 for the lowest risk option allowing discharge, to a maximum of 4 x 10"9;
for the selected option (4 Mile Filter - BPT Beyond) it is 4 x 10"9 (Table 15). Risk reductions for these
56
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Table 12. Incremental Annualized Benefits and Costs of Offshore
Produced Water BAT Optionsฎ
(thousands of 1986 dollars per year)
Incremental Benefits6 Incremental Costs
_ Membrane Granular Membrane Granular
Regulatory Options Filter Filter Filter Filter
BPT All
0
0
0
0
4 Mile Filter - BPT Beyondc
1 - 6
2-9
8,787
24,287
Filter Shallow - BPT Deep
n/a
4 - 22
59,378
n/ad
Filter and Discharge All
n/a
6 - 31
139,609
438,067
Reinject Shallow - BPT Deep
n/a
5 - 23
247,059
n/a
Reinject Shallow - Filter Deep
n/a
6-31
327,326
n/a
Reinject All
n/a
6-32
458,736
776,772
" All incremental values relative to current (BPT) treatment level.
b Incremental benefits reflect monetized health benefits only. Membrane filter benefit projections derived
from industry-wide, flow-weighted averages for 3 carcinogens are not directly comparable to granular filter
projections based on individual production groups for 2 carcinogens.
0 Selected option for proposal.
" n/a = not available.
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Table 13. Incremental Annualized Benefits and Costs of Offshore
Produced Water NSPS Optionsฎ
(thousands of 1986 dollars per year)
Incremental Benefitsb Incremental Costs
Membrane Granular Membrane Granular
Regulatory Options Filter Filter Filter Filter
BPT All
0
0
0
0
4 Mile Filter - BPT Beyondc
0.3 - 2
0.2 - 1
9,079
13,842
Filter Shallow - BPT Deep
n/ad
3- 13
26,236
n/a
Filter and Discharge All
n/a
3 - 16
56,558
86,845
Reinject Shallow - BPT Deep
n/a
3- 14
81,398
n/a
Reinject Shallow - Filter Deep
n/a
3-17
111,629
n/a
Reinject All
n/a
3 - 17
145,572
186,608
a All incremental values relative to current (BPT) treatment level.
b Incremental benefits reflect monetized health benefits only. Membrane filter benefit projections derived
from industry-wide, flow-weighted averages for 3 carcinogens are not directly comparable to granular filter
projections based on individual production groups for 2 carcinogens.
c Selected option for proposal.
d n/a = not available.
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Table 14. Incremental Benefits from Reductions in Excess Cancer Lifetime Risk for
Produced Water (BAT)
Annualized Incremental
Benefits6
Lifetime Excess Lifetime Excess Reduced Benefits
Regulatory Option Risk Level8 Cancer Cases Cancers ($ x 103)c
Based on Benzene and bis(2-ethylhexyl)phthalate
BPT All
7.7E-9
0.27
0
0
4 Mile Filter (Granular) - BPT Beyondd
5.4E-9
0.19
0.0011
1.9 - 9.4
Filter Shallow (Granular) - BPT Deepd
2.3E-9
0.08
0.0027
4.4 - 22.2
Filter (Granular) and Discharge Alld
4.6E-10
0.01
0.0037
6.1 - 30.6
Reinject Shallow - BPT Deep
1.9E-9
0.08
0.0028
4.6 - 23.0
Reinject Shallow - Filter (Granular) Deepd
9.2E-11
0.003
0.0038
6.2 - 31.4
Reinject All
0
0
0.0039
6.3 - 31.6
Based on Arsenic, Benzene, and bis(2-ethylhexyl)phthalate
BPT All'
2.0E-8
0.141
0
0
4 Mile Filter (Membrane) - BPT Beyond6,'
1.3E-8
0.089
0.0007
1.2 - 6.1
a Reflects combined average risk from shrimp and selected finfish consumption.
b All increments are relative to BPT (current) treatment level.
c 1986 dollars.
d Estimates of risks and benefits based on granular filtration removal capabilities.
e Selected option for proposal.
' Estimates for incremental risks and benefits based on membrane filtration effluent pollutant data.
59
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Table 15. Incremental Benefits from Reductions in Excess Cancer Lifetime Risk for
Produced Water (NSPS) (Benzene and bis(2-ethylhexyl)phthalate)
Annualized Incremental
Benefits6
Lifetime Excess Lifetime Excess Reduced Benefits
Regulatory Option Risk Level" Cancer Cases Cancers ($ x 103)c
Based on Benzene and bis(2-ethylhexyl)phthalate
BPT All
4.1E-09
0.14
0
0
4 Mile Filter (Granular) - BPT Beyondd
3.7E-09
0.13
0.00001
0.2
- 1.1
Filter Shallow (Granular) - BPT Deepd
7.8E-10
0.027
0.0016
2.6 -
13.2
Filter (Granular) and Discharge All"
3.2E-10
0.007
0.0019
3.1 -
15.6
Reinject Shallow - BPT Deep
5.0E-10
0.021
0.0017
2.8 -
13.9
Reinject Shallow - Filter (Granular) Deep"
4.5E-11
0.001
0.0020
3.3 -
16.2
Reinject All
0
0
0.0020
3.3 -
16.4
Based on Arsenic,
Benzene, and bis(2-ethylhexyl)phthalate
BPT All'
6.3E-9
0.043
0
0
4 Mile Filter (Membrane) - BPT Beyond0''
3.9E-9
0.027
0.0002
0.3
- 1.8
a Reflects combined average risk from shrimp and selected finfish consumption.
b All increments are relative to BPT (current) treatment level.
c 1986 dollars.
" Estimates of risks and benefits based on granular filtration removal capabilities.
e Selected option for proposal.
' Estimates for incremental risks and benefits based on membrane filtration effluent pollutant data.
60
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options correlate to annualized incremental BAT benefits of $1,900 to $31,600 and NSPS benefits of $200 to
$16,400 (Tables 14 and 15). The selected option results in incremental annualized BAT benefits of $1,900 to
$9,400 and NSPS benefits ranging from $200 to $1,100.
When finfish and shrimp consumption are considered separately, BAT excess lifetime cancer risk from
carcinogenic pollutants in produced water for average finfish consumption ranges from none for the Reinject
All option, to 3 x 10"11 for the minimum risk option that allowed discharge; to a maximum of 4 x 10 s. For
the selected option (4 Mile Membrane Filter - BPT Beyond), excess lifetime cancer risk is 3 x 10'9 for average
finfish consumption (Appendix C, Table C-9). This value is well below regulatory levels of concern for
carcinogens.
Excess BAT lifetime cancer risks from carcinogenic pollutants in produced water, for average shrimp
consumption, ranges from none for the Reinject All option, to 6 x 1011 for the minimum risk discharge
option, to a maximum of 4 x 10'9 for the produced water options evaluated (Appendix C, Table C-10). For
the selected option (4 Mile Membrane Filter - BPT Beyond), BAT excess lifetime cancer risk is 2 x 10"9, well
below regulatory levels of concern for carcinogens.
Similarly, NSPS excess cancer risks from carcinogenic pollutants in produced water for average finfish
consumption (Appendix C, Table C-13), for BPT All (as the baseline and an evaluated option) and all other
evaluated options, range from none for the Reinject All option, to 3 x 10'11 for the lowest risk discharge
option, to a maximum of 3 x 10'9. For the selected option (4 Mile Membrane Filter - BPT Beyond) excess
cancer risks are 3 x 10"9 for average finfish consumption. For average shrimp consumption, NSPS excess
cancer risks range from none for the Reinject All option, to 1 x 10'11 for the lowest risk discharge option, to a
maximum of 8 x 10"10. Also similar to BAT, these NSPS risks are far below any level of regulatory concern.
For the selected option (4 Mile Membrane Filter - BPT Beyond) NSPS excess cancer risks are 7 x 10"10 for
average shrimp consumption (Appendix C, Table C-14).
Similar to the findings on MEI versus average case scenarios for drilling fluids, MEI scenarios for
produced water present excess cancer risks that are just within the realm of regulatory concern. The BAT
excess lifetime risk for MEI consumption of finfish and shrimp combined, for BPT All (as the baseline and
an evaluated option), is 2 x 10'5; the excess lifetime risk for regulatory options range from none for the
Reinject All option, to 2 x 10"6 for the lowest risk discharge option, to a maximum of 2 x 10"5, for combined
finfish and shrimp MEI risks (See Appendix C, Tables C-ll and C-12). For the selected option (4 Mile
Membrane Filter - BPT Beyond), the MEI BAT excess cancer risk from combined finfish and seafood
61
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consumption is 1 x 10"6. These levels of risk under MEI scenarios, therefore, are approximately three orders
of magnitude greater than the average scenario risks discussed above (Table 14).
NSPS excess lifetime risk, for MEI consumption of finfish and shrimp combined, for the baseline (BPT
All) is 2 x 10"6; excess lifetime risk for regulatory options ranges from none for the Reinject All option, to 9 x
10"6 for the lowest risk discharge option, to a maximum of 2 x 10"ฎ (See Appendix C, Tables C-15 and C-16
for finfish and shrimp MEI risks). For the selected option (4 Mile Membrane Filter - BPT Beyond), the
excess MEI cancer risk is 1 x 10"6. For MEI scenarios, the excess cancer risks are approximately three
orders of magnitude greater than the average case scenario risks discussed above (Table 15).
For MEI finfish consumption, BAT excess cancer risk for BPT and all regulatory options evaluated
(Appendix C, Table C-ll; Appendix D, Table D-5), for carcinogenic pollutants in produced water, range
from none for the Reinject All option, to 2 x 10"6 for the lowest risk option allowing discharge, to a maximum
of 2 x 10"5 (BPT All). For MEI shrimp consumption (Appendix C, Table C-12), BAT excess cancer risk
ranges from none for the Reinject All option, to 4 x 10"8 for the lowest discharge option, to a maximum of
1 x 10"6 {BPT All).
For MEI NSPS excess cancer risks (Appendix C, Tables C-15 and C-16) are somewhat less than BAT
risks. For MEI finfish consumption excess risks range from none for the Reinject All option, to 5 x 10"8 for
the lowest risk discharge option to 1 x 10"6 for the highest risk discharge option (BPTAll). For MEI shrimp
consumption, excess risk ranges from none for the Reinject All option, to 4 x 10"8 for the lowest risk
discharge option to a maximum of 1 x 10"6 (BPT All).
Produced water incremental BAT costs are generally several orders of magnitude higher than their
corresponding benefits (Table 12). While BAT benefits for average consumption of evaluated options are in
the $2,000 to $32,000 range, costs are in the $24 million to $777 million range. For the selected BAT option
(4 Mile Filter - BPT Beyond) with granular fdtration benefits based on average consumption, are estimated at
$2,000 to $9,000 while costs are estimated at $24 million. Incremental NSPS costs and benefits show a
similarly high ratio of costs to benefits (Table 13), with benefits in the $200 to $17,000 range and costs in the
$14 million to $187 million range for evaluated options. For the selected NSPS option (4 Mile Filter - BPT
Beyond) with granular filtration benefits based on average consumption, amount to $200 to $1,000 while costs
are estimated at $14 million.
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Produced Water Health Risk Reduction - Cancer Risk (Membrane Filtration-Related Benefits)
Results of the supplemental assessment indicate that excess BAT lifetime cancer risk from carcinogenic
pollutants in produced water (arsenic, benzene, and bis(2-ethylhexyl)phthalate) for baseline (BPT) conditions
and for combined average finfish and shrimp consumption is 2 x 10"8 for BAT. For the selected option (4
Mile Membrane Filter - BPT Beyond) is 1 x 10"6 for average finfish and shrimp consumption combined
(Table 14). The NSPS lifetime excess risk for BPT All (as the baseline and an evaluated option) is 6 x 10'9
for average finfish and shrimp combined (Table 15); for the selected option (4 Mile Membrane Filter - BPT
Beyond) it is 4 x 10'9.
The BAT lifetime cancer risk for average finfish consumption is 2 x 10"8 for the BPT All (as the
baseline and an evaluated option) and 1 x 10"8 for the selected option (4 Mile Filter - BPT Beyond). Excess
BAT lifetime cancer risk from carcinogenic pollutants in produced water for average shrimp consumption is
4 x 10'10 for BPT All (as the baseline and an evaluated option); for the selected option (4 Mile Filter - BPT
Beyond) it is 3 x 10"10 (Appendix D, Table D-4).
NSPS excess cancer risk from carcinogenic pollutants in produced water, for average finfish
consumption is 6 x 10"9 for BPT All (as the baseline and an evaluated option) and 4 x 10'8 for the selected
option (4 Mile Filter - BPT Beyond). For average shrimp consumption, NSPS excess cancer risk is 7 x 10'11
for BPT All and is 6 x 10"11 for the selected option (4 Mile Filter - BPT Beyond) (Appendix D, Table D-8).
For MEI finfish consumption, BAT excess cancer risk for BPT All (as the baseline and an evaluated
option) from carcinogenic pollutants in produced water was 3 x 10*, it was 2 x 10* for the selected option (4
Mile Filter - BPT Beyond). For MEI shrimp consumption, the BAT excess cancer risk was 5 x 10'1 for BPT
All (as the baseline and an evaluated option) and was 5 x 10"7 for the selected option (4 Mile Filter - BPT
Beyond). (Appendix D, Table D-5).
The projected monetized BAT benefits for the selected option (4 Mile Filter - BPT Beyond) using
membrane filtration are several orders of magnitude lower than the projected BAT costs. BAT benefits,
based on average case consumption projected at $1,200 to $6,100 while BAT costs are projected at $8.8
million (Table 12). The projected monetized NSPS benefits for the selected option (4 Mile Filter - BPT
Beyond) also are several orders of magnitude lower than projected NSPS costs. NSPS average case benefits
are projected at $300 to $2,000 while NSPS costs are projected at $9.1 million (Table 13).
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Produced Water Health Risk Reductions - Systemic Risk
The BAT and NSPS systemic health risk reductions for produced water options evaluated for this
regulation both appear to be insignificant for all options analyzed under average case scenarios (Appendix C,
Tables C-9, C-10, C-13, and C-14; Appendix D, Tables D-2, D-3, and D-7). For all pollutants assessed and
for both finfish and shrimp consumption, the percentage RfD values for average case scenarios rounded to
zero. Under the MEI scenarios, minimal risks were estimated (Appendix C, Tables C-ll, C-12, C-15, and
C-16; Appendix D, Tables D-2, D-3, and D-7). Two exceptions were bis(2-ethylhexyl)phthalate and
ethylbenzene, which indicated potential health benefits of reduced exposure under BAT, for finfish
consumption only. Pollutants assessed for BAT showed consumption of contaminated finfish resulted in
exposures of <0.5% of the respective RfD's, with the exception of bis(2-ethylhexyl)phthalate (0.26% to 2.5%
of the RfD) and ethylbenzene (0.15% to 1.3% of the RfD).
6.3.2 Quantified, Non-Monetized Benefits and Impacts
6.3.2.1 Summary
An assessment of quantified, non-monetized water quality benefits involved a comparison of projected
water column and sediment pore water pollutant concentrations, resulting from discharges at the current
level of treatment and for evaluated options, to acute and chronic marine criteria and human health criteria
for fish consumption. This benefits assessment projected exceedances of Federal marine life and human
health water quality criteria by drilling fluids, drill cuttings, and produced water discharges. The quantified,
non-monetized benefits identified for the selected options include: (1) for drilling fluids and drill cuttings,
elimination of the projected aquatic life and human health criteria exceedances from the more sensitive
shallow water areas (within a 4 mile distance from the shore) and reduction of projected impacts in deeper
water areas (beyond 4 miles from shore); and (2) reduction of the human health criteria exceedances
magnitude in the same more sensitive shallow water areas for produced water.
The assessment of quantified, non-monetized impacts also includes a review and summarization of case
studies of localized impacts found near oil and gas drill sites and platforms located in the Gulf of Mexico, in
Southern California, and in Alaska. Discharged drilling fluids and drill cuttings are shown to cause
contamination of sediments with heavy metals and hydrocarbons. Documented biological effects include
elimination and inhibited growth of seagrasses, declined abundance in benthic species, altered benthic
community structure, decreased coral coverage, and bioaccumulation of heavy metals. Biological impacts
from single wells are observed to occur on a scale from several hundred meters to several kilometers;
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chemical impacts have been noted from several to tens of kilometers. Produced water discharges are shown
to cause contamination of sediments with polynuclear aromatic hydrocarbons (PAH), local elimination and
depressed abundance of benthic species, and alteration of benthic communities. Studies do not indicate that
larger-scale (more than several hundred to a thousand meters) impacts occur. However, these studies are
not adequate to conclude that regional-scale impacts do not occur.
63.2.2 Quantified Benefits: Water Column and Pore Water Quality
Federal water quality criteria as determined from the 1989 Toxics Data Base (U.S. EPA, 1989b) are
compared to the projected average ambient concentration of pollutants at the edge of a 100-meter mixing
zone. The dilutions and dispersions used to determine the ambient concentrations are based on the average
of the number of dilutions or dispersions available at 100 meters. This provides an average over the entire
mixing zone that is divided into the effluent pollutant concentration. The resulting projected pollutant
concentration (after dilution) has been compared to the Federal water quality criteria for marine acute and
chronic effects. The human health criteria for fish consumption are also evaluated.
Drilling Fluids and Cuttings
Projected water column and sediment pore water concentrations of drilling fluid pollutants at current
level of treatment and for evaluated options are compared to marine acute, marine chronic, and human
health (fish consumption only) criteria. The ambient concentrations used for this comparison are for drilling
fluids with lubricity and drilling fluids without any lubricity to which a pill was added. The effluent pollutant
concentrations are weighted averages of the drilling fluids and oil used over the total well depth. Minimum
dispersions and dilutions are used to calculate the highest average ambient concentration over a 100-meter
mixing zone for each regulatory option.
Water quality criteria exceedances are presented both for drilling fluids with lubricity (Table 16) and
for drilling fluids without lubricity (Table 17). For all options that allow discharge the water column water
quality criterion for human health is exceeded by arsenic (range: 25-fold to 392-fold) for drilling fluids both
with and without lubricity. For lead, drilling fluids of either type exceed the criterion for aquatic life for all
three options having a 5/3 limitation on cadmium and mercury in barite (range: 2-fold to 5-fold). Mercury
exceeds the criterion for human health (2-fold) for the same three options having a 5/3 limitation, but only
for drilling fluids with lubricity. Exceedances for mercury for the criterion for aquatic life also varies
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Table 16. Number of Pollutants with Water Quality Criteria Exceedances
Under Evaluated BAT/NSPS Options
(Drilling Fluids and Cuttings with Lubrication)
Aquatic Life Human Health
Water Column Sediment Water Column Sediment
Current 2 Pb (5), Hg (13) - As (392), Hg (2) As (22)
5/3 All 2 Pb (5), Hg (13) - As (392), Hg (2) As (22)
1/1 All 1 Hg (3) - As (66) As (5)
Zero Discharge 4 Miles - 5/3 Beyond
shallow
deep 2 Pb (5), Hg (13) - As (392), Hg (2) As (22)
Zero Discharge 4 Miles- 1/1 Beyond8
shallow
deep 1 Hg (3) - As (66) As (22)
Zero Discharge Shallow - 5/3 Deep
shallow
deep 2 Pb (5), Hg (13) - As (392), Hg (2) As (22)
Zero Discharge Shallow - 1/1 Deep
shallow
deep 1 Hg (3) - As (66) As (22)
Zero Discharge All
a Selected option.
Notes:
1. Water quality analysis represents average subcategory discharge flows and pollutant loadings.
2. Total number of pollutants in database = 8 (As, Cd, Hg, Pb, fluorene, naphthalene, phenanthrene,
phenol).
3. Numbers preceeding pollutants listed under aquatic life criteria indicate the number of criteria exceeded
(i.e., acute and/or chronic marine criteria); Numbers in parentheses are factors by which ambient levels
are projected to exceed criteria.
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Table 17. Number of Pollutants with Water Quality Criteria Exceedances
Under Evaluated BAT/NSPS Options
(Drilling Fluids and Cuttings without Lubrication)
Aquatic Life Human Health
Water Column Sediment Water Column Sediment
Current 2 Pb (2), Hg (5) - As (141) As (22)
5/3 All 2 Pb (2), Hg (5) - As (141) As (22)
1/1 All - - As (25) As (22)
Zero Discharge 4 Miles - 5/3 Beyond
shallow
deep 2 Pb (2), Hg (5) - As (141) As (22)
Zero Discharge 4 Miles - 1/1 Beyondฎ
shallow
deep - - As (25) As (5)
Zero Discharge Shallow - 5/3 Deep
shallow
deep 2 Pb (2), Hg (5) - As (141) As (22)
Zero Discharge Shallow - 1/1 Deep
shallow
deep - - As (25) As (5)
Zero Discharge All -
a Selected option.
Notes:
1. Water quality analysis represents average subcategory discharge flows and pollutant loadings.
2. Total number of pollutants in database = 8 (As, Cd, Hg, Pb, fluorene, naphthalene, phenanthrene,
phenol).
3. Numbers preceeding pollutants listed under aquatic life criteria indicate the number of criteria exceeded
(i.e., acute and/or chronic marine criteria); Numbers in parentheses are factors by which ambient levels
are projected to exceed criteria.
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between drilling fluid types. Drilling fluids with lubricity show exceedances (3-fold to 13-fold), for all
discharge options; fluids without lubricity show exceedances (5-fold) only for options having a 5/3 limitation.
Projected pore water concentrations of pollutants in drilling fluids and cuttings discharges are also compared
to Federal water quality criteria. Arsenic fails to meet the criteria for human health (5-fold-to 22-fold) for
every option allowing discharge of drilling fluids, both with and without lubricity.
For the selected option (Zero Discharge 4 Miles - 1/1 Beyond) drilling fluids without lubricity,
discharged from structures greater than 4 miles from shore, are projected to exceed the criterion for human
health for arsenic (25-fold in the water column; 5-fold in pore water). Discharged drilling fluids with
lubricity also are projected to exceed the human health criterion for arsenic (66-fold in the water column and
22-fold in pore water) and exceed the aquatic life criterion for mercury in the water column by 3-fold.
Produced Water
Produced water pollutant concentrations at BPT and six evaluated treatment options (initial granular
filtration-related assessment) were divided by the lowest average dilution for each of the scenarios (e.g., oil
platform/deep water, gas platform/shallow water) for comparison to the Federal water quality criteria. The
water column concentrations resulting from discharges from all platform types (oil, oil and gas, gas, and
filtered effluent) did not exceed any of the water quality criteria (Table 18). However, the criterion for
human health for DEHP was exceeded in pore water (8- to 27-fold) for BPT and 3-fold for all options that
included filtration as a treatment (Filter Shallow - BPT Deep; 4 Mile Filter - BPT Beyond; Filter and
Discharge All), including selected option (4 Mile Filter - BPT Beyond).
For the selected option {4 Mile Filter - BPT Beyond) with membrane filtration technology, the criteria
for human health are exceeded by projected pore water concentrations of bis(2-ethylhexyl)phthalate (1.3-fold)
and by projected water column concentrations of arsenic (5-fold). An analytical artifact should be noted for
pore water bis(2-ethylhexyl)phthalate results. For any option with a distance from shore or water depth
distinction, discharges are assumed to produce benthic impacts in depths 20 meters or less and not to
produce such impacts in water deeper than 20 meters. This assumption is based on predicted plume
trajectories that indicate plume/sediment interaction is likely in water depths less than 20 meters. The actual
situation is not so neatly discreet.
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Table 18. Number of Pollutants with Water Quality Criteria Exceedances
Under Evaluated Produced Water BAT/NSPS Options
Aquatic Life Human Health
Water Column Sediment Water Column Sediment
BPT All - - - DEHP (8-27)a
4 Mile Filter (Granular) - BPT Beyond
4 miles or less - - - DEHP (3)
> 4 miles - - -
Filter Shallow - BPT Deep
shallow - - - DEHP (3)
deep - - -
Filter and Discharge All
shallow - - - DEHP (3)
deep - - -
Reinject Shallow - BPT Deep
shallow - - -
deep - - -
Reinject Shallow - Filter Deep
shallow - -
deep - - -
Reinject All
BPT Allb - - As (8) DEHP (25)
4 Mile Filter (Membrane) -
BPT Beyond" - - As (5) DEHP (1.3)
a Human health criteria for fish consumption is exceeded by a factor of 8 for oil facility discharges; 26 for
gas facility discharges; and 27 for oil and gas facility discharges.
b Estimates are based on membrane filtration effluent pollutant data; analyses are presented in the
supplemental environmental assessment.
Notes:
1. Water quality analysis represents average subcategory discharge flows and pollutant loadings.
2. Total number of pollutants in database = 8 for granular filtration assessments and = 23 for membrane
filtration assessments.
3. DEHP = bis(2-ethylhexyl)phthalate.
4. Numbers in parentheses are factors by which ambient levels are expected to exceed fish consumption
human health criterion.
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6.3.2.3 Quantified Impacts: Case Studies
Drilling Fluids and Cuttings
A review of the available literature identified 16 field impact studies that were analyzed for their
findings on the environmental effects of drilling fluids and cuttings discharges. A synthesis of this review is
provided below. This review suggests that these discharges are capable of producing localized impacts, but
do not document larger-scale impacts. However, these studies are not sufficient to conclude regional-scale
impacts are not occurring. A tabulated summary is provided in Table 19.
Modeling of drilling fluid plume dispersion and field studies of discharge plumes indicate that, as a
generalization, plume dispersion is sufficient to minimize, water quality impacts and water column toxicity
concerns in energetic, open waters of the OCS. This generalization does not extend to the benthos (see
below).
In shallow water areas (e.g., less than 5-10 meters), field data on plume dispersion are minimal, and
are insufficient to conclude that water column effects present only a minor potential concern. Some
modeling data suggest water quality and toxicity parameters could be adversely affected under shallow water
conditions. Also, in water depths of less than 5 meters, the reliability of most models that are suitable for
application to drilling fluid discharges becomes questionable. Thus, the potential water column impacts of
those discharges in shallow (< 5 meter) waters is not known with any degree of confidence.
The principal impacts of these discharges are benthic effects, due to the very high solids content of
drilling fluids (10% to 70% solids by weight). Benthic community changes have been hypothesized to largely
be due to physical effects. However, no studies have quantitatively discriminated between impacts from
physical effects (altered sediment texture) and chemical effects (sediment-associated toxics). It is reasonable
to assume both effects occur, and that either could predominate, depending on the characteristics of the
discharged mud.
The most clearly documented point source effect of these discharges has been alterations in sediment
barium (Ba), a tracer for drilling fluids solids. Observations on sediment alterations from field studies of
both single-well and multiple-well facilities include:
Increases in Ba levels of 2-fold to 100-fold above background at the drillsite, with typical values of
10-fold to 40-fold
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Table 19. Marine Studies of Drilling Fluids Impacts
Study Site
Site
Charact.
Water
Depth (m)
Sediment
Impacts
Biota
Northwestern
Gulf of Mexico
Region VI
South Texas
Region VI
Mid - Atlantic
Region II
OCS
OCS
OCS
36
120
Elevated:
Ba up to 3000 m, Pb
(3.8x) @ 500 m,
hydrocarbons (5x) @
250 m, also Cd, Cu, Zn
ND
NDa
ND
physical/chemical
changes @ 800 m
declined abund. up to
1000m (benthics)
Cr, Cu, Fe, Ni, V, uptake
(squid)
altered communities
@ 300m
Uptake of Ba, Hg, Pb, in
mollusk
Beaufort Sea
Region X
Prudhoe Bay
Region X
coastal
OCS
Elevated As, Cd, Cr,
Pb, Zn
ND
bioaccumulation of Hg
(tissue)
reduced benthic biomass
density
simulated above-ice
disposal site study;
reduced abundance: 99%
1st year, 95% 2nd, 64%
3rd
Alabama State Waters OCS
Block 132
40-60
Elevated Ba to 500 m;
2-5 fold increase at
1,000 m
Elevated Cd, Pb, Cr, Fe
behind barrier islands
Elevated As in oysters
behind barrier islands.
Elevated oil and grease
between pre-drilling and
post-drilling surveys
8 ND = no data
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Table 19. (continued)
Site Water Impacts
Study Site Charact. Depth (m) Sediment Biota
Pensacola Area OCS
Block 996
Gulf of Mexico
Alabama State Waters OCS
Block 132
Gainesville Area OCS
Block 707
Gulf of Mexico
50-60
40-60
20-25
Increased Ba deposition
to 2,000 m
Elevated Cd, Hg, Ba
during drilling
ND
Reduced bryozoan
coverage within 2,000 m
of discharge.
ND
Burial by cuttings at 25
m; 14% decrease in algal
coverage at 500 m algal;
coverage increased 14%
at reference point
Seagrass eliminated
within 300 m of drill site;
growth inhibited beyond
300 m to a distance of 3.7
km
East Breaks Area
Block 166
Gulf of Mexico
OCS
200-375 Elevated Ba at edge of
Bank (approx. 3,500 m)
ND
West Cameron Area
Block 663
Gulf of Mexico
OCS
130-160
Elevated Ba at 4,000 m ND
High Island Area
Block A-389
Gulf of Mexico
OCS
60-150
Ba, Cr increase to 2,000 ND
Total hydrocarbon
increase to 300 m after
use of lubricants
South Marsh Island
Area Block 161
Gulf of Mexico
OCS
80-88
Ba increase to 3,400 m
Ba increase at (approx.
3 mi.)
ND
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Table 19. (continued)
Study Site
Site
Charact.
Water
Depth (m)
Impacts
Sediment
Biota
Mustang Island
AreaTilock A-85
Gulf of Mexico
Georges Bank
Atlantic
Santa Maria
Basin, California
ocs
70-90
OCS
OCS
90-410 m
Ba increased during
drilling to 1,506 m;
cores showed Ba
enrichment due to
previous drilling
25% of barite deposited
within 6 km; Ba
transport to 35 km
ND
ND
Sediment flux related to
decreased soft coral
coverage; statistical power
of study limited to 70%
or greater
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Average measured background levels are reached, statistically, at 1,000-3,000 meters; single transect
values have been elevated at up to 8,000 meters
Increases in Ba fall off logarithmically with distance from the drillsite; regression analyses indicate
background levels are achieved at 2,000-20,000 meters.
Increases in a suite of other trace metals associated with drilling fluids (As, Cd, Cr, Cu, Hg, Pb, Zn)
have also been observed. These increases:
Are of a lower magnitude than seen for Ba (generally not more than 5- to 10-fold above
background)
Are more spatially limited, when compared to background levels, than seen for Ba (generally
within 250-500 meters of the drillsite, although increases at 1,000-2,000 meters have been noted)
Are noted consistently as a group, but are variable for any specific chemical among the various
studies.
Observations on the long-term, regional scale fate of drilling fluid solids indicate that the materials may
be very widely dispersed over large areas. Dispersion is related directly to bottom energies of the receiving
water (more shallow waters being more energetic than deeper waters).
In shallow water (13-34 meters) only about 6% of discharged Ba was accounted for within a 3
kilometer radius of three drillsites; in contrast, for three drillsites in deeper waters (76-102
meters), 47% to 84% of the discharged Ba was found within a 3 kilometer radius
At these same six sites, Ba concentrations 3 kilometers from the drillsites ranged from 1.2 to 2.9
times predicted background at the shallow water sites and at the deep water sites ranged from 2.0
to 4.3 times predicted background
Drilling fluid solids can be transported over long distances (35-65 kilometers) to regional areas of
deposition, albeit at low concentrations, based on a study of eight wells.
Biological effects have routinely been detected statistically at distances of 200 meters to 500 meters.
Less routinely, effects have been observed at greater distances (1-2 kilometers). These effects more typically
are found to fall into one of two categories: those that are statistically significant at the level of individual
stations but cannot be integrated into an easily defined pattern or those that are not statistically significant at
the level of individual stations but do form significant correlations at larger levels of integration. Specific
observations are as follows:
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The most affected community appears to be seagrass communities. Data on seagrasses are limited
to a single study, but it documented damage much more severe than in any other study to date.
Seagrasses were completely absent within 300 meters of the drillsite, and were only 25% recovered
at a distance of 3.7 kilometers from the drillsite.
Fauna also have been affected, including changes in abundance, species richness (number of
species), and diversity. Taxa include annelids, mollusks, echinoderms, and crustaceans.
Alterations to benthic community structure are virtually always observed within 300 meters of the
drillsite. However, changes have been noted in some cases at 500-1,000 meters, and a few reports
indicate alterations have occurred at 1-2 kilometers.
Changes have been ascribed to purely physical alterations in sediment texture and to platform-
associated structural effects (i.e., from the fouling community) more frequently than to toxic
effects. These causes are plausible, but there are no systematic studies of their relative
contribution to observed impacts. Also, alterations due to physical causes may not be any less
adverse than those due to toxic pollutants, and may be more persistent.
Bioaccummulation has been observed for a suite of metals (Ba, Cd, Cu, Hg, Ni, Pb, V), but the
magnitudes of this effect are usually low (i.e., less than a factor of 5).
Produced Water
When viewed as a whole, limited field studies of the impacts of produced water show that produced
water contaminants can accumulate in sediments, disturb benthic fauna, and have the potential for
bioaccummulation. Factors that influence the degree to which the affects will be observed include discharge
volume, effluent contaminant levels, water depth, and hydrologic mixing. However, these factors apparently
operated in a complex manner, and cannot easily be used to predict the potential extent of contaminant
changes.
A review has been conducted of seven study sites that have been reported in four studies. These
studies indicate that localized benthic impacts occur, and may extend up to several kilometers. A finding of
this review is that such impacts can be highly dependent on the specific characteristics of the site. These
studies found that open water Gulf of Mexico sites were less impacted than coastal or estuarine sites. A
tabular summary of the findings of these studies is presented in Table 20 and are discussed below.
A study of a produced water discharge into a shallow (2-3 m) Texas bay involved effluent chemical
analyses, sediment naphthalene analyses, and monthly benthic surveys of numbers of both species and
individuals over a 21-month period. Sediment naphthalene levels were elevated over the entire study area
(2.9-4.48 mg/kg sediment at 13,000-19,000 feet from the surface); the sediment naphthalene levels averaged
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Table 20. Coastal and Marine Studies of Produced Water Impacts
Study Site
Site
Charact.
Water
Depth
(m)
Effluent
Flow
(bbl/day)
Impacts
Sediment
Biota
Pass Fourchon
(LA)
Bayou Rigaud
(LA)
coastal;
low
energy
coastal;
well
flushed
45,000
4-5
150,000
PAH enrichment up
to 2800 m
PAH enrichment up
to 1300 m
Abundance:8
0 @ disch
0 @ 0.4 km
58 @ 1 km
437 @ 2.5 km
Abundance:
0 @ disch
20 @ 1 km
54 @ 2.8 km
East Timbalier Bay coastal
(LA) outside
Trinity Bay
(TX)
estuary;
low
energy
69,000
PAH enrichment up
to 50+ m
4,000 - 10,000 PAH enrichment up
to 1800 m
ND"
Abundance:
0 @ disch.
depressed
abundance up
to 5 km
Eugene Island OCS
(LA)
Lake Pelto OCS
(LA)
Buccaneer Field OCS
(TX)
2-3
20
1570
2750
120 - 2,000
PAH enrichment up
to 20-300 m
PAH enrichment up
to 300-1000 m
(phenanthrene)
PAH enrichment up
to 200 m
a Abundance = (number of individuals) was dominated by mostly opportunistic species
b ND = no data
ND
ND
depressed
abundance
within 100 m
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21.0 ppm 50 feet from the outfall, fell to about half that value at 250-500 feet, and then gradually decreased
to about 3.5 ppm at 13,000-19,000 feet.
Sediment within the immediate vicinity of the outfall was virtually devoid of benthic organisms.
Benthic abundance was depressed 90% at 50 feet, 70-80% at 250-500 feet, and 50% at 600-700 feet. A zone
of"stimulation (120-130%) apparently occurred at 2,000-5,000 feet, when compared to abundances at 13,000-
19,000 feet. Regression analyses of these data indicate benthic abundance achieving background levels at
5,800-16,000 feet, depending upon the selection of the "true" background levels of sediment naphthalene.
Three coastal sites in Louisiana, representing large volume discharges into differing hydrologic
conditions, have been studied as part of an assessment of OCS impacts in coastal waters. Dilution of the
produced water plume, as inferred from salinity profiles, showed rapid dilution beyond the immediate area of
the discharge in areas where swift bottom currents existed. However, only some 20-fold dilutions could be
deduced at 800 m from the discharge in a much less energetic, closed pass. Contamination of fine-grained
sediment with petroleum hydrocarbons was observed near the discharges at all three sites, extending from
several hundred meters to over one kilometer from the point of discbarge.
PAH levels in sediments near discharges exceeded apparent background levels by more than an order
of magnitude. Sediment contamination at these three coastal sites was higher than observed in a study of
two open Gulf sites but was comparable to that found at another coastal (Texas) site. These differences in
sediment petroleum hydrocarbon contamination were attributed to larger effluent volumes and less
dispersion at the three coastal Louisiana sites. Sediment metals were less affected at the three sites, with
only zinc emerging as a probable contaminant at two of the three sites.
Biologically the areas were observed to be of low diversity, populated by opportunistic species. Sites
were considered biologically disturbed areas due to dredging, vessel traffic, and fine-grained sediment
accumulations. Nonetheless, biological effects were observed even in these hardy species, in terms of
reduced densities and diversities of macrobenthic fauna. Also, results from limited hydrocarbon analyses of
oyster and mussel samples demonstrated a clear potential for uptake of produced water-associated
hydrocarbons by mollusks.
Two production platform sites located on the upper continental shelf were studied recently. One
facility discharged 2,750 bbl/day into 2-3 m of water, while the other facility discharged 1,570 bbl/day into
8 m of water. It was found that at the deeper water (8 m) site, background levels of petroleum hydrocarbons
were found at all but the 20 m sampling sites, although sediment hydrocarbon levels could also be
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interpreted as indicative of a patchy distribution of sediment contamination. At the shallow water (1-2 m)
site, elevated PAH concentrations occurred from 300-1,000 m from the outfall. Sediments were particularly
contaminated with phenanthrene, exhibiting average levels at 100 m sampling stations at least 85 times
background (i.e., 85 x the average level observed at the 1,000 m stations).
A study of a production platform located in 20 meters of water on the South Texas OCS was
conducted. The study site was located in a highly active oceanographic area. Current data and surficial
sediment data indicated that considerable movement of fine-grained material occurred at the site, serving as
a potential mechanism for transporting contaminated sediments from the site. Also, the discharge rate at the
platform was relatively low (600 bbl/day) compared to values observed in EPA's 30 platform study (a mean
of 4,011 bbl/day excluding central processing facilities; a mean of 9,577 bbl/day including such facilities).
Alterations in benthic fauna (depressed abundance) were observed at stations located within 100
meters of the platform. Also, petroleum hydrocarbon levels in fish tissues collected near the platform were
measured in two species that actively fed on the platform's fouling community, one species that fed much less
on the community, and one highly mobile species unlikely to feed on the fouling community. Tissue levels of
petroleum hydrocarbons corresponded to the utilization of the fouling community as a food source.
6.3.3 Non-Quantified, Non-Monetized Benefits
6.3.3.1 Summary
The non-quantified, non-monetized benefits assessed in this RIA are recreational fishing, commercial
fishing, aesthetic quality of the near-platform waters, and benefits to threatened or endangered species that
inhabit the Gulf of Mexico. These potential benefits predictions are highly speculative, but any positive
impact of the regulation will be appreciable. A 0.1% increase in recreational value would yield benefits on
the order of $12 to $14 million per year. There are no data that indicate adverse effects on the endangered
species found in the Gulf of Mexico (the Kemp's Ridley Turtle and the Brown Pelican), but it is possible that
the proposed regulation will reduce stress on the endangered species.
6.3.3.2 Non-Quantified Benefits
This RIA focusses on the quantification and monetization of health-related benefits of the proposed
effluent guidelines. This is due to the limits of the analytic techniques for predicting nonhealth impacts. For
example, there are no anticipated direct changes in the abundance or composition of the offshore
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recreational fishery. However, there are three indirect means by which recreational fishing benefits may
accrue to society due to the regulations:
There are no data to indicate the degree to which fishing levels or utility may be constrained by
the perception that the Gulfs fisheries, particularly those caught near rigs, pose a risk to health; to
the extent the regulation changes those perceptions, recreational fishing values may increase.
To the degree that the regulation improves the aesthetic quality of the near-platform waters
frequented by anglers, they may increase the average consumer surplus associated with a fishing
day, and/or might induce higher levels of participation.
While there are no analytically discernable direct improvements to the target fishery that are
attributable to the regulations, it is conceivable that more subtle ecosystem impacts may arise that
could enhance the fishery. (For example, the guidelines may reduce pollutant concentrations,
positively affect lower-level organisms in the food chain, and improve reproductive success,
increase the ability to avoid predation, improve growth, etc.)
Absent data to further evaluate these hypotheses, any prediction of potential recreational fishing
benefits is purely speculative. However, given the extremely high value of the activity, if the regulations do
have any positive impact on recreation, then the benefits will be appreciable. For example, even if the
impacts are limited to only a 0.1% increase in recreational value, the regulation's recreational fishing benefits
would still be on the order of $12 to $14 million per year.
Other potential benefits not related to health risk reductions, in addition to recreational fishing
benefits, are nonuse benefits associated with environmental improvements in water quality, which have been
shown to be highly significant potential benefits. A review of the literature by Fisher and Raucher (1984)
revealed that, in freshwater settings, such benefits were generally no less than 50% of the associated
recreational values. Also, the regulation may have a beneficial impact on two federally-designated
endangered species, the Kemp's Ridley Turtle and the Brown Pelican, Gulf of Mexico is part of their habitat.
Although there are no data to indicate adverse impacts on these species, given that the bioconcentration of
pollutants in fish tissue is sufficient enough to pose some risks to human health, it is possible that the
regulations will reduce stresses on these endangered populations.
Lastly, the Gulfs commercial fishery is extremely valuable. As described above for recreational fishing,
absent evidence of fishery mortality associated with offshore oil and gas effluent, there are no direct links
that can be established between the proposed regulations and commercial fishery benefits. However, indirect
impacts on the size or composition of the fishery, or on consumer demand for Gulf fishery products, may
generate commercial fishery benefits. There are no data with which to evaluate the likelihood or potential
magnitude of any such benefits.
79
-------
7. REFERENCES
Avanti Corporation and Technical Resources, Inc. 1991a. Technical Support Document for the
Development of the Regulatory Impact Analysis. Volume I - Modeled Impacts. Prepared for
Assessment and Watershed Protection Division, Office of Water Regulations and Standards, U.S. EPA.
Avanti Corporation and Technical Resources, Inc. 1991b. Technical Support Document for the
Development of the Regulatory Impact Analysis. Volume II - Supplemental Report, Assessment of
Membrane Filtration Technology for Produced Water Discharges. Prepared for Assessment and
Watershed Protection Division, Office of Water Regulations and Standards, U.S. EPA.
Avanti Corporation and Technical Resources, Inc. 1991c. Technical Support Document for the
Development of the Regulatory Impact Analysis. Volume III - Case Study Impacts. Prepared for
Assessment and Watershed Protection Division, Office of Water Regulations and Standards, U.S. EPA.
Avanti Corporation and Technical Resources, Inc. 1991d. Technical Support Document for the
Development of the Regulatory Impact Analysis. Volume IV - State Land Disposal Regulations and
Practices. Prepared for Assessment and Watershed Protection Division, Office of Water Regulations
and Standards, U.S. EPA.
California Coastal Commission. 1988. Oil and Gas Activities Affecting California's Coastal Zone: A
Summary Report, California Coastal Commission, December 1988, pages 31-33.
Eastern Research Group. 1991a. Economic Impact Analysis of Proposed Effluent Limitations Guidelines
and Standards of Performance for the Offshore Oil and Gas Industry. Prepared for Analysis and
Evaluation Division, Office of Water Regulations and Standards, U.S. EPA.
Eastern Research Group. 1991b. Cost Effectiveness Analysis of Proposed Effluent Limitations Guidelines
and Standards of Performance for the Offshore Oil and Gas Industry. Prepared for Analysis and
Evaluation Division, Office of Water Regulations and Standards, U.S. EPA.
Fisher, A. and R. Raucher. 1984. Intrinsic Benefits for Improved Water Quality: Conceptual and Empirical
Perspectives. Advances in Applied Microeconomics. Vol 3, eds. V.K. Smith and A.D. White,
Greenwich, CT. JAI Press.
Minerals Management Service. 1988. Mineral Management Service Platform Inspection, Complex/Structure
Data Base. Produced by MMS, March 1988, supplied by ERG.
RCG/Hagler, Bailly, Inc. 1991a. The Economic Benefits of Effluent Limitation Guidelines for Offshore Oil
and Gas Facilities. Final Report. Prepared for Economic Analysis Branch, Office of Water
Regulations and Standards, U.S. EPA.
RCG/Hagler, Bailly, Inc. 1991b. The Economic Benefits of Effluent Limitation Guidelines for Offshore Oil
and Gas Facilities. Supplemental Report, Membrane Filtration Technology for Produced Waters
Wastestream. Prepared for Economic Analysis Branch, Office of Water Regulations and Standards,
U.S. EPA.
81
-------
REFERENCES (cont'd.)
U.S. Environmental Protection Agency. 1989a. Health Effects Assessment Summary Tables, 2nd quarter,
FY1989, U.S. EPA, OSWER, OS-230.
U.S. Environmental Protection Agency. 1989b. Toxics Data Base. Office of Water Regulations and
Standards.
82
-------
APPENDIX A
-------
Table A-l. 1985 Proposed BAT Effluent Limitations
Waste Source
Pollutant Parameter
or Characteristic
BAT Effluent Limitations
Produced Water
Deck Drainage
Drilling Fluids
Drill Cuttings
Sanitary M10a
Sanitary M9IMb
Domestic Waste
Produced Sand
Well Treatment
Fluids
[Reserved]
Free Oil
All Other Pollutants
Free oil
Oil-Based Fluids
Diesel Oil
Toxicity
Cadmium
Mercury
Free Oil
Oil-Based Fluid
Diesel Oil
None
None
None
Free Oil
All Other Pollutants
Free Oil
All Other Pollutants
[Reserved]
No Discharge
[Reserved]
No Discharge
No Discharge
No discharge in Detectable Amounts
96-hr LC50 of the suspended particulate
phase (SPP) of the drilling fluid shall not
be less than 3.0 percent by volume
1 mg/kg dry weight maximum in the
whole drilling fluid
1 mg/kg dry weight maximum in the
whole drilling fluid
No Discharge
No Discharge
No Discharge in Detectable Amounts
No Discharge
[Reserved]
No Discharge
[Reserved]
a M10 defined as any facility manned continuously by 10 or more persons
b M9IM defined as any facility manned continuously by 9 or fewer persons or manned intermittently by any
number of persons.
A-l
-------
Table A-2. 1985 Proposed BCT Effluent Limitations
BCT Effluent Limitations
Average of Daily
values for 30
Pollutant Parameter Maximum for consecutive days
Waste Source or Characteristic any one day shall not exceed
Produced Water
Oil and Grease
72 mg/j2
48 mg/ฃ
Deck Drainage
Free Oil
No Discharge
All Other Pollutants
[Reserved]
[Reserved]
Drill Cuttings
Free Oil
No Discharge
All Other Pollutants
[Reserved]
[Reserved
Sanitary M10
Residual Chlorine*
Minimum of 1 mg/2
and maintained as
close to this
concentration as
possible
Sanitary M9IM
Floating Solids
No Discharge
Domestic Waste
Floating Solids
No Discharge
Produced Sand
Free Oil
No Discharge
All Other Pollutants
[Reserved]
[Reserved]
Well Treatment
Fluids
Free Oil
All Other Pollutants
No Discharge
[Reserved]
[Reserved]
* For the control of fecal coliform.
A-2
-------
Table A-3. 1985 Proposed NSPS Effluent Limitations (Shallow Water)
Waste Source
Pollutant Parameter
NSPS Effluent Limitations
Produced Water
Deck Drainage
Drilling Fluids
Drill Cuttings
Sanitary M10
Sanitary M9IM
Domestic Waste
Produced Sand
Well Treatment
Fluids
Free Oil
All Other Pollutants
Free Oil
Oil-Based Fluid
Diesel Oil
Toxicity
Cadmium
Mercury
Free Oil
Oil-Based Fluid
Diesel Oil
Residual Chlorine
Floating Solids
Floating Solids
Free Oil
All Other Pollutants
Free Oil
All Other Pollutants
No Discharge"
No Discharge
[Reserved]
No Discharge
No Discharge
No Discharge in Detectable Amounts
Minimum 96-hr LC50 of the SPP shall be
3 percent by volume
1 mg/kg dry weight maximum in the
whole drilling fluid
1 mg/kg dry weight maximum in the
whole drilling fluid
No Discharge
No Discharge
No Discharge in Detectable Amounts
Minimum of 1 mg/2. and maintained as
close to this concentration as possible
No Discharge
No Discharge
No Discharge
[Reserved]
No Discharge
[Reserved]
* Structures must be in compliance with the no discharge standard no later than 300 days after
commencement of development drilling operations. Prior to that date, discharges shall comply with the oil
and grease standard of 59 mg/ฃ maximum.
A-3
-------
Table A-4. 1985 Proposed NSPS Effluent Limitations (Deep Water)
Waste Source
Pollutant Parameter
NSPS Effluent Limitations
Produced Water
Deck Drainage
Drilling Fluids
Drill Cuttings
Sanitary M10
Sanitary M9IM
Domestic Waste
Produced Sand
Well Treatment
Fluids
Oil and Grease
Free Oil
All Other Pollutants
Free Oil
Oil-Based Fluid
Diesel Oil
Toxicity
Cadmium
Mercury
Free Oil
Oil-Based Fluid
Diesel Oil
Residual Chlorine
Floating Solids
Floating Solids
Free Oil
All Other Pollutants
Free Oil
All Other Pollutants
50 mg/ฃ Maximum
No Discharge
[Reserved]
No Discharge
No Discharge
No Discharge in Detectable Amounts
Minimum 96-hr LC50 of the SPP shall be
3 percent by volume
1 mg/kg dry weight maximum in the
whole drilling fluid
1 mg/kg dry weight maximum in the
whole drilling fluid
No Discharge
No Discharge
No Discharge in Detectable Amounts
Minimum of 1 mg/ฃ and maintained as
close to this concentration as possible
No Discharge
No Discharge
No Discharge
[Reserved]
No Discharge
[Reserved]
A-4
-------
APPENDIX B
-------
Recycle Muds
Discharge Muds
Figure B-1. Treatment Technology for Drilling Fluids and Drill Cuttings
-------
w
I
to
Production
Well
Gas to Sales
Backwash Water
Figure B-2. Treatment Technology for Produced Water
-------
APPENDIX C
-------
C-l. Average Industry-wide Pollutants Present in Discharges from OCS Platforms
Quantitative Source of
Constituent Type Mode of action Risk Value Risk Units Risk Value
Drilling Fluids and Cuttings
Arsenic
Metal
Carcinogen (A)1
1.8E+00
l/(mg/kg/dy)
IRIS
Cadmium
Metal
Systematic toxin
1.0E-03
(mg/kg/dy)
HEA
Fluorene
Organic
(undetermined)
(none)
Lead
Metal
Systemic toxin, possibly
also carcinogenic
Blood Lead
level2
(microg/dl)
OAQPS
Mercury
Metal
Systemic toxin
3.0E-04
(mg/kg/dy)
HEA
Naphthalene
Organic
Systemic toxin
4.0E-01
(mg/kg/dy)
HEA
Phenanthrene
Organic
(undetermined)
(none)
Phenol
Organic
Systemic toxin
6.0E-01
(mg/kg/dy)
IRIS
Produced Water
Benzene
Organic
Carcinogen (A)1
2.9E-02
1/(mg/kg/dy)
IRIS
Bis(2-ethylhexyl)
phthalate
Organic
Carcinogen (B2)1,
also systemic toxin
1.4E-02
2.0E-02
l/(mg/kg/dy)
(mg/kg/dy)
IRIS
IRIS
Ethylbenzene
Organic
Systemic toxin
1.0E-01
(mg/kg/dy)
IRIS
Naphthalene
Organic
Systemic toxin
4.0E-01
(mg/kg/dy)
HEA
Phenol
Organic
Systemic toxin
6.0E-01
(mg/kg/dy)
IRIS
Toluene
Organic
Systemic toxin
3.0E-01
(mg/kg/dy)
IRIS
Zinc
Metal
Systemic toxin
2.0E-01
(mg/kg/dy)
HEA
2,4 Dimethyl
phenol
Organic
(undetermined)
(none)
1 Classification of carcinogens is made based on weight of evidence:
A: Known human carcinogen
Bl: Probable carcinogen, limited evidence of human carcinogenicity
B2: Probable carcinogen, sufficient evidence of carcinogenicity in animals, inadequate evidence of human carcinogenicity
C: Possible human carcinogen
D: Not classifiable as to human carcinogenicity
E: Evidence of non-carcinogenicity in humans
2 Determination of lead risk is a special case, as described in the text
C-l
-------
Table C-2. Average Health Risks Under Each Control Scenario
Drilling Fluids and Cuttings
Finfish Consumption
Zero Disch.
Current; 4 Miles -
5/3 All" 1/1 All 5/3 Beyond
Zero Disch. Zero Disch.
4 Miles - Shallow -
1/1 Beyond 5/3 Deep
Zero Disch. Zero
Shallow - Discharge
1/1 Deep All
A. Systemic toxins
Fraction of
oral RfD
Naphthalene
2.4E-09
2.4E-09
1.3E-09
1.3E-09
1.7E-10
1.7E-10
zero
Phenol
zero
zero
zero
zero
zero
zero
zero
Mercury
7.6E-09
1.5E-09
4.0E-09
7.9E-10
1.3E-09
2.8E-10
zero
Cadmium
1.2E-07
6.0E-10
6.3E-08
3.1E-10
2.1E-08
1.1E-10
zero
%of
Naphthalene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
oral RfD
Phenol
zero
zero
zero
zero
zero
zero
zero
Mercury
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Cadmium
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
B. Carcinogenic toxins
Excess
Lifetime
Probability Arsenic 8.2E-12
C. Toxins lacking quantitative numbers
1.8E-12 4.3E-12
Intake in
Micrograms Fluorene zero zero zero
Phenanthrene zero zero zero
Lead 6.1E-05 8.8E-07 3.2E-05
D. Special Case: Mean blood lead level for avg. 5-yr. old
Micrograms/dl
Lead
5.0
5.0
5.0
1.3E-12
zero
zero
4.4E-07
5.0
4. IE-12
zero
zero
3.4E-05
5.0
6.3E-13
zero
zero
1.5E-07
5.0
zero
zero
zero
zero
zero
* "Current" level of treatment is assumed to be equivalent to 5/3 All option for analytic purposes.
C-2
-------
Table C-3. Average Health Risks Under Each Control Scenario
Drilling Fluids and Cuttings
Shrimp Consumption
ฆ^ - . ^^.. . i. M
Zero Disch. Zero Disch. Zero Disch. Zero disch. Zero
Current; 4 Miles - 4 Miles - Shallow - Shallow - Discharge
5/3 Allฎ 1/1 All 5/3 Beyond 1/1 Beyond 5/3 Deep 1/1 Deep All
A. Systemic toxins
oral RfD
Naphthalene
3.2E-09
3.2E-09
2.9E-09
2.9E-09
2.0E-09
2.0E-09
zero
Phenol
zero
zero
zero
zero
zero
zero
zero
Mercury
3.5E-06
6.9E-07
3.1E-06
6.2E-07
2.1E-06
4.3E-07
zero
Cadmium
7.1E-05
3.6E-07
6.4E-05
3.2E-07
4.4E-05
2.2E-07
zero
%of
Naphthalene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
oral RfD
Phenol
zero
zero
zero
zero
zero
zero
zero
Mercury
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Cadmium
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
B. Carcinogenic toxins
Excess
Lifetime
Probability
Arsenic
3.8E-09
8.2E-10
3.4E-09
7.3E-10
2.4E-09
5.1E-10
zero
C. Toxins lacking quantitative numbers
Intake in
Micrograms
Fluorene
zero
zero
zero
zero
zero
zero
zero
Phenanthrene
: zero
zero
zero
zero
zero
zero
zero
Lead
5.7E-02
8.2E-04
5.1E-02
7.4E-04
3.5E-02
5.1E-04
zero
D. Special Case: Mean blood lead level for avg. 5-yr. old
Micrograms/dl
Lead
5.0
5.0
5.0
5.0
5.0
5.0
zero
* "Current" level of treatment is assumed to be equivalent to 5/3 All option for analytic purposes.
C-3
-------
Table C-4. MEI Health Risks Under Each Control Scenario
Drilling Fluids and Cuttings
Finfish Consumption
Zero Disch. Zero Disch. Zero Disch.
Current; 4 Miles - 4 Miles - Shallow -
5/3 All" 1/1 All 5/3 Beyond 1/1 Beyond 5/3 Deep
Zero Disch. Zero
Shallow - Discharge
1/1 Deep All
A. Systemic toxins
Fraction of
oral RfD
Naphthalene
1.1E-03
1.1E-03
3.4E-04
3.4E-04
3.4E-04
3.4E-04
zero
Phenol
zero
zero
zero
zero
zero
zero
zero
Mercury
4.6E-04
9.2E-05
4.6E-04
9.2E-05
4.6E-04
9.2E-05
zero
Cadmium
8.9E-02
4.5E-04
8.9E-02
4.5E-04
8.9E-02
4.5E-04
zero
%of
Naphthalene
0.11%
0.11%
0.03%
0.03%
0.03%
0.03%
zero
oral RfD
Phenol
zero
zero
zero
zero
zero
zero
zero
Mercury
0.05%
0.01%
0.05%
0.01%
0.05%
0.01%
zero
Cadmium
8.90%
0.05%
8.90%
0.05%
8.90%
0.05%
zero
B. Carcinogenic toxins
Excess
Lifetime
Probability Arsenic 6.7E-07
C. Toxins lacking quantitative numbers
Intake in
Micrograms Fluorene zero
Phenanthrene zero
Lead 3.9E+00
1.4E-07 6.7E-07
1.4E-07
6.7E-07 1.4E-07
zero
zero
zero
zero
5.7E-02 3.9E+00
D. Special Case: Mean blood lead level for avg. 5-yr. old
zero
zero
5.7E-02
zero
zero
Micrograms/dl
Lead
n/ab
n/a
n/a
n/a
n/a
zero
zero
3.9E+00 5.7E-02
n/a
* "Current" level of treatment is assumed to be equivalent to 5/3 All option for analytic purposes.
b n/a = not available.
zero
zero
zero
zero
n/a
C-4
-------
Table C-5. MEI Health Risks Under Each Control Scenario
Drilling Fluids and Cuttings
Shrimp Consumption
Zero Disch. Zero Disch. Zero Disch. Zero Disch. Zero
Current; 4 Miles - 4 Miles - Shallow - Shallow - Discharge
5/3 Allฎ 1/1 All 5/3 Beyond 1/1 Beyond 5/3 Deep 1/1 Deep All
A. Systemic toxins
Fraction of
oral RfD
Naphthalene
4.4E-06
4.4E-06
4.4E-06
4.4E-06
4.4E-06
4.4E-06
zero
Phenol
zero
zero
zero
zero
zero
zero
zero
Mercury
4.8E-03
9.5E-04
4.8E-03
9.5E-04
4.8E-03
9.5E-04
zero
Cadmium
9.8E-02
4.9E-04
9.8E-02
4.9E-04
9.8E-02
4.9E-04
zero
%of
Naphthalene
<0.01%
<0.01%
<0.01%
<0.01%
<0.01%
<0.01%
zero
oral RfD
Phenol
zero
zero
zero
zero
zero
zero
zero
Mercury
0.5%
0.1%
0.5%
0.1%
0.5%
0.1%
zero
Cadmium
9.8%
0.05%
9.8%
0.05%
9.8%
0.05%
zero
B. Carcinogenic toxins
Excess
Lifetime
Probability Arsenic 5.2E-06
C. Toxins lacking quantitative numbers
1.1E-06 5.2E-06
1.1E-06
5.2E-06
Intake in
Micrograms Fluorene zero zero zero
Phenanthrene zero zero zero
Lead 7.8E+01 1.1E+ 00 7.8E+01
D. Special Case: Mean blood lead level for avg. 5-yr. old
zero
zero
LIE+ 00
zero
zero
7.8E + 01
Micrograms/dl
Lead
13.5
5.1
13.5
5.1
13.5
1.1E-06
zero
zero
1.1E+ 00
5.1
zero
zero
zero
zero
zero
"Current" level of treatment is assumed to be equivalent to 5/3 All option for analytic purposes.
C-5
-------
Table C-6. Benefits of Reduced Infant Mortality as Associated with
Maternal Blood Lead Levels from Drilling Fluid Discharges
Benefits Annual Monetized
Regulatory Increment Annual Mortalities Reduced (millions 1988 dollars)
Current
0
0
5/3 All
na
na
1/1 All
0.33
0.6 - 2.9
Zero Discharge 4 Miles - 5/3 Beyond
0.28
0.5 - 2.5
Zero Discharge 4 Miles - 1/1 Beyond
0.33
0.6 - 2.9
Zero Discharge Shallow - 5/3 Deep
0.29
0.5 - 2.5
Zero Discharge Shallow - 1/1 Deep
0.33
0.6 - 2.9
Zero Discharge All
0.33
0.6 - 2.9
* "Current" level of treatment served as analytical baseline and was considered equal to 5/3 All option.
C-6
-------
Table C-7. Annual Incremental Lead-Related Benefits: Adult Malesฎ
Total Incremental Benefits1*
Regulatory Increment Health Effect Cases Avoidedb ($ x 108)
Current; 5/3 All nc nc
1/1 All Stroke 1.1 0.06
CHDd 5.8 0.4
Hyper. 259 0.07
Death 7.5 13.1-65.9
TOTAL - 13.6-66.4
Zero Discharge 4 Miles - Stroke 1.0 0.05
5/3 Beyond CHD 5.4 0.4
Hyper. 229 0.06
Death 7.0 12.2-61.3
TOTAL - 12.7-61.8
Zero Discharge 4 Miles - Stroke 1.1 0.06
1/1 Beyond CHD 5.8 0.4
Hyper. 259 0.07
Death 7.5 13.1-65.9
TOTAL - 13.6-66.4
Zero Discharge Shallow - Stroke 1.05 0.06
5/3 Deep CHD 5.5 0.4
Hyper. 236 0.07
Death 7.1 12.4-61.8
TOTAL - 12.9-62.3
Zero Discharge Shallow - Stroke 1.1 0.06
1/1 Deep CHD 5.8 0.4
Hyper. 259 0.07
Death 7.5 13.1-65.9
TOTAL - 13.6-66.4
Zero Discharge All Stroke 1.1 0.06
CHD 5.8 0.4
Hyper. 259 0.07
Death 7.5 13.1-65.9
TOTAL 13.6-66.4
0 Applies only to white males aged 40-59 years, except for hypertension, which applies to all males 20-74
years of age.
b Total cases annually, and incremental benefits in millions of dollars (1988) per year.
c "Current" level of treatment served as baseline and was considered equal to 5/3 All option.
" CHD refers to Cardiovascular Heart Disease events, namely heart attacks.
C-7
-------
Table C-8. Annual IQ-Related Benefits to Children from Reduced Lead Exposureฎ
Regulatory Increment
Health Effect
Total Incremental Benefitsb
Cases Avoidedb (S x 108)
Current; 5/3 All
IQ <70ฐ
IQ dec."
nฎ
ne
1/1 All
IQ < 70
IQ dec.
0.7
151
0.00
0.07
0.07
Zero Discharge 4 Miles -
5/3 Beyond
IQ < 70
IQ dec.
0.4
88
0.00
0.04
0.04
Zero Discharge 4 Miles -
1/1 Beyond
IQ < 70
IQ dec.
0.7
151
0.00
0.07
0.07
Zero Discharge Shallow -
5/3 Deep
IQ < 70
IQ dec.
0.4
90.5
0.00
0.04
0.04
Zero Discharge Shallow -
1/1 Deep
IQ < 70
IQ dec.
0.7
151
0.00
0.07
0.07
Zero Discharge All
IQ < 70
IQ dec.
0.7
151
0.00
0.07
0.07
* Pertains to five-year old cohort group only (i.e., those children who are five years of
calendar year).
b Total cases annually, and incremental benefits in millions of dollars (1988) per year.
age in a given
e Number of children reduced to IQ under 70.
d IQ decrements are total lost IQ points, which equals the average IQ loss per child times number of
children in the exposure group.
"Current" level of treatment serves as baseline and is considered equal to 5/3 All option.
C-8
-------
Table C-9. Average Health Risks Under Each Control Scenario
Produced Waters (BAT)
Finfish Consumption
4 Mile
Filter
Filter &
Reinject
Reinject
Filter -
Shallow -
Discharge
Shallow -
Shallow -
Reinject
BPT Allฎ
BPT Beyond
BPT Deep
All
BPT Deep
Filter Deep
All
A. Systemic toxins
Fraction of
oral RfD
Zinc
9.8E-08
1.4E-07
3.4E-08
2.6E-09
3.2E-08
7.4E-10
zero
DEHP
3.1E-06
4.4E-06
6.8E-07
3.6E-07
3.6E-07
3.5E-08
zero
Ethylbenzene
1.7E-06
2.4E-06
3.0E-07
1.3E-07
1.9E-07
2.2E-08
zero
Naphthalene
2.0E-07
2.6E-07
8.7E-07
7.5E-08
1.9E-08
7.3E-09
zero
Phenol
3.7E-08
4.2E-08
4.1E-09
1.3E-09
2.9E-09
1.3E-10
zero
Toluene
9.9E-07
1.2E-06
1.7E-07
8.1E-08
9.4E-08
8.0E-09
zero
%of
Zinc
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
oral RfD
DEHP
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Ethylbenzene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Naphthalene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Phenol
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Toluene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
B. Carcinogenic toxins
Excess
Lifetime
Benzene
3.0E-09
2.3E-09
4.8E-10
2. IE-10
2.9E-10
2.0E-11
zero
Probability
DEHP
8.7E-10
7.0E-10
1.9E-10
1.0E-10
1.0E-10
9.9E-12
zero
C. Toxins lacking quantitative numbers
Intake in
Micrograms
2,4 Dimethyl
phenol
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
zero
8 BPT All is the current level of treatment, but also was being considered as an option for this proposal.
C-9
-------
Table C-10. Average Health Risks Under Each Control Scenario
Produced Waters (BAT)
Shrimp Consumption
4 Mile
Filter
Filter &
Reinject
Reinject
Filter -
Shallow -
Discharge
Shallow -
Shallow -
Reinject
BPT All" BPT Beyond
BPT Deep
All
BPT Deep
Filter Deep
All
A. Systemic toxins
Fraction of
oral RfD
Zinc
zero
zero
zero
zero
zero
zero
zero
DEHP
n/ab
n/a
n/a
n/a
n/a
n/a
zero
Ethylbenzene
4.3E-06
4.0E-06
2.0E-06
43E-07
1.8E-06
1.8E-07
zero
Naphthalene
1.2E-06
1.2E-06
6.6E-07
2.8E-07
5.0E-07
1.1E-07
zero
Phenol
3.8E-08
3.6E-08
1.8E-08
5.6E-09
1.5E-08
2.3E-09
zero
Toluene
2.8E-06
2.6E-06
1.2E-06
13E-07
1.1E-06
5.4E-08
zero
%of
Zinc
zero
zero
zero
zero
zero
zero
zero
oral RfD
DEHP
n/a
n/a
n/a
n/a
n/a
n/a
zero
Ethylbenzene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Naphthalene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Phenol
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Toluene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
B. Carcinogenic toxins
Excess
Lifetime
Benzene
3.8E-09
2.4E-09
1.6E-09
1.5E-10
1.5E-09
6.2E-11
zero
Probability
DEHP
n/a
n/a
n/a
n/a
n/a
n/a
zero
C. Toxins lacking quantitative
numbers
Intake in
Micrograms
2,4 Dimethyl
<0.001
<0.001
phenol
0.002
0.001
<0.001
<0.001
zero
" BPT All is the current level of treatment, but also was being considered as an option for this proposal.
b n/a = not available due to inability to calculate shrimp tissue concentration of DEHP.
C-10
-------
Table C-ll. MEI Health Risks Under Each Control Scenario
Produced Waters (BAT)
Finfish Consumption
4 Mile
Filter -
BPT All8 BPT Beyond
Filter
Shallow -
BPT Deep
Filter &
Discharge
All
Reinject
Shallow -
BPT Deep
Reinject
Shallow - Reinject
Filter Deep All
A. Systemic toxins
Fraction of
oral RfD
%of
oral RfD
Zinc
1.9E-03
1.9E-03
1.9E-03
3.8E-05
1.9E-03
3.8E-05
zero
DEHP
2.5E-02
9.7E-03
9.7E-03
2.6E-03
9.7E-03
2.6E-03
zero
Ethylbenzene
1.3E-02
1.5E-03
5.1E-03
1.5E-03
5.1E-03
1.5E-03
zero
Naphthalene
1.1E-03
4.3E-04
4.3E-04
5.4E-04
4.3E-04
5.4E-04
zero
Phenol
2.0E-04
4.5E-05
4.5E-05
9.5E-06
4.5E-05
9.5E-06
zero
Toluene
5.4E-03
5.9E-04
2.1E-03
5.9E-04
2.1E-03
5.9E-04
zero
Zinc
0.19%
0.19%
0.19%
0.00%
0.19%
0.00%
zero
DEHP
2.50%
0.97%
0.97%
0.26%
0.97%
0.26%
zero
Ethylbenzene
1.30%
0.51%
0.51%
0.15%
0.51%
0.15%
zero
Naphthalene
0.11%
0.04%
0.04%
0.05%
0.04%
0.05%
zero
Phenol
0.02%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Toluene
0.54%
0.21%
0.21%
0.06%
0.21%
0.06%
zero
B. Carcinogenic toxins
Excess
Lifetime
Probability
Benzene
DEHP
1.6E-05
6.9E-06
6.4E-06
2.7E-06
6.4E-06
2.7E-06
1.5E-06
7.3E-07
6.4E-06
2.7E-06
C. Toxins lacking quantitative numbers
Intake in
Micrograms
2,4 Dimethyl
phenol
0.6
0.5
<0.01
<0.01
<0.01
1.5E-06
7.3E-07
<0.01
zero
zero
zero
BPT All is the current level of treatment, but also was being considered as an option for this proposal.
C-ll
-------
Table C-12. MEI Health Risks Under Each Control Scenario
Produced Waters (BAT)
Shrimp Consumption
4 Mile
Filter
Filter &
Reinject
Reinject
Filter -
Shallow -
Discharge
Shallow -
Shallow -
Reinject
BPT All"
BPT Beyond
BPT Deep
All
BPT Deep
Filter Deep
All
A. Systemic toxins
Fraction of
oral RfD
Zinc
zero
zero
zero
zero
zero
zero
zero
DEHP
n/ab
n/a
n/a
n/a
n/a
n/a
zero
Ethylbenzene
1.5E-03
1.5E-03
1.5E-03
1.2E-04
1.5E-03
1.2E-04
zero
Naphthalene
5.4E-04
5.4E-04
5.4E-04
7.9E-05
5.4E-04
7.9E-05
zero
Phenol
2.0E-05
2.0E-05
2.0E-05
1.6E-06
2.0E-05
1.6E-06
zero
Toluene
1.2E-03
1.2E-03
1.2E-03
3.7E-05
1.2E-03
3.7E-05
zero
%of
Zinc
zero
zero
zero
zero
zero
zero
zero
oral RfD
DEHP
n/a
n/a
n/a
n/a
n/a
n/a
zero
Ethylbenzene
0.15%
0.15%
0.15%
0.01%
0.15%
0.01%
zero
Naphthalene
0.05%
0.05%
0.05%
0.01%
0.05%
0.01%
zero
Phenol
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Toluene
0.12%
0.12%
0.12%
0.00%
0.12%
0.00%
zero
B. Carcinogenic toxins
Excess
Lifetime
Benzene
1.1E-06
4.6E-07
4.6E-07
4.3E-08
4.6E-07
4.3E-08
zero
Probability
DEHP
n/a
n/a
n/a
n/a
n/a
n/a
zero
C. Toxins lacking quantitative numbers
Intake in
Micrograms
2,4 Dimethyl
phenol
0.6
0.5
0.2
<0.01
<0.01
<0.01
zero
* BPT All is the current level of treatment, but also was being considered as an option for this proposal.
b n/a = not available due to inability to calculate shrimp tissue concentration of DEHP.
C-12
-------
Table C-13. Average Health Risks Under Each Control Scenario
Produced Waters (NSPS)
Finfish Consumption
4 Mile
Filter
Filter &
Reinject
Reinject
Filter -
Shallow -
Discharge
Shallow -
Shallow -
Reinject
BPT All8
BPT Beyond
BPT Deep
All
BPT Deep
Filter Deep
All
A. Systemic toxins
Fraction of
oral RfD
Zinc
1.3E-07
1.4E-07
2.8E-08
2.8E-09
2.5E-08
8.4E-10
zero
DEHP
4.2E-06
4.3E-06
6.1E-07
3.6E-07
2.8E-07
3.9E-08
zero
Ethylbenzene
2.4E-06
2.4E-06
3.6E-07
2.3E-07
1.5E-07
2.5E-08
zero
Naphthalene
2.5E-07
2.6E-07
8.2E-08
7.5E-08
1.4E-08
8.2E-09
zero
Phenol
4.6E-08
4.2E-08
3.1E-09
1.3E-09
1.9E-09
1.4E-10
zero
Toluene
1.3E-06
1.2E-06
1.4E-07
8.2E-08
6.9E-08
8.9E-09
zero
% of
Zinc
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
oral RfD
DEHP
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Ethylbenzene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Naphthalene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Phenol
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Toluene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
B. Carcinogenic toxins
Excess
Lifetime
Benzene
2.5E-09
2.3E-09
3.9E-10
2.0E-10
2. IE-10
2.3E-11
zero
Probability
DEHP
8.0E-10
7.8E-10
1.7E-10
1.0E-10
7.7E-11
1.1E-11
zero
C. Toxins lacking quantitative numbers
Intake in
Micrograms
2,4 Dimethyl
phenol
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
zero
a BPT All is the current level of treatment, but also was being considered as an option for this proposal.
C-13
-------
Table C-14. Average Health Risks Under Each Control Scenario
Produced Waters (NSPS)
Shrimp Consumption
4 Mile
Filter -
BPT All" BPT Beyond
Filter
Shallow -
BPT Deep
Filter &
Discharge
All
Reinject
Shallow -
BPT Deep
Reinject
Shallow - Reinject
Filter Deep All
A. Systemic toxins
Fraction of
oral RfD
%of
oral RfD
Zinc
zero
zero
zero
zero
zero
zero
zero
DEHP
n/ab
n/a
n/a
n/a
n/a
n/a
zero
Ethylbenzene
8.2E-07
6.9E-07
3.3E-07
6.2E-08
3.0E-07
3.1E-08
zero
Naphthalene
2.5E-07
2.1E-07
8.8E-08
4.0E-08
6.8E-08
2.0E-08
zero
Phenol
8.1E-09
6.8E-09
2.0E-09
8.1E-10
1.6E-09
4.0E-10
zero
Toluene
5.7E-07
4.7E-07
1.6E-07
1.9E-08
1.5E-07
9.5E-09
zero
Zinc
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
DEHP
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Ethylbenzene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Naphthalene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Phenol
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Toluene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
B. Carcinogenic toxins
Excess
Lifetime
Probability
Benzene
DEHP
7.8E-10
n/a
6.5E-10
n/a
2.2E-10
n/a
2.2E-11
n/a
2.0E-10
n/a
1.1E-11
n/a
zero
zero
C. Toxins lacking quantitative numbers
Intake in
Micrograms 2,4 Dimethyl
phenol <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 zero
* BPT All is the current level of treatment, but also was being considered as an option for this proposal.
b n/a = not available due to inability to calculate shrimp tissue concentration of DEHP.
C-14
-------
Table C-15. MEI Health Risks Under Each Control Scenario
Produced Waters (NSPS)
Finfish Consumption
4 Mile
Filter
Filter &
Reinject
Reinject
Filter -
Shallow -
Discharge
Shallow -
Shallow -
Reinject
BPT All8
BPT Beyond
BPT Deep
All
BPT Deep
Filter Deep
All
A. Systemic toxins
Fraction of
oral RfD
Zinc
4.1E-05
4.1E-05
4.1E-05
1.1E-06
4.1E-05
1.1E-06
zero
DEHP
1.1E-03
4.4E-04
4.4E-04
2.0E-04
4.4E-04
5.8E-05
zero
Ethylbenzene
6.0E-04
2.3E-04
2.3E-04
1.3E-04
2.3E-04
3.6E-05
zero
Naphthalene
5.0E-05
2.0E-05
2.0E-05
4.2E-05
2.0E-05
1.2E-05
zero
Phenol
9.3E-06
2.1E-06
2.1E-06
7.4E-07
2.1E-06
2.1E-07
zero
Toluene
2.5E-04
9.7E-05
9.7E-05
4.6E-05
9.7E-05
1.3E-05
zero
%of
Zinc
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
oral RfD
DEHP
0.10%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Ethylbenzene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Naphthalene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Phenol
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Toluene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
B. Carcinogenic toxins
Excess
Lifetime
Benzene
7.4E-07
2.9E-07
2.9E-07
1.7E-07
2.9E-07
3.4E-08
zero
Probability
DEHP
3.2E-07
1.2E-07
1.2E-07
5.7E-08
1.2E-07
1.6E-08
zero
C. Toxins lacking quantitative numbers
Intake in
Micrograms
2,4 Dimethyl
phenol
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
zero
" BPT All is the current level of treatment, but also was being considered as an option for this proposal.
C-15
-------
Table C-16. MEI Health Risks Under Each Control Scenario
Produced Waters (NSPS)
Shrimp Consumption
4 Mile Filter Filter & Reinject Reinject
Filter - Shallow - Discharge Shallow - Shallow - Reinject
BPT All" BPT Beyond BPT Deep All BPT Deep Filter Deep All
A. Systemic toxins
Fraction of
Zinc
zero
zero
zero
zero
zero
zero
zero
DEHP
n/ab
n/a
n/a
n/a
n/a
n/a
zero
Ethylbenzene
1.3E-03
1.1E-03
6.5E-04
1.2E-04
6.5E-04
1.2E-04
zero
Naphthalene
4.0E-04
3.5E-04
1.7E-04
7.9E-05
1.7E-04
7.9E-05
zero
Phenol
1.3E-05
1.1E-05
4.0E-06
1.6E-06
4.0E-06
1.6E-06
zero
Toluene
9.2E-04
7.6E-04
3.2E-04
3.7E-05
3.2E-04
3.7E-05
zero
%of
Zinc
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
oral RfD
DEHP
zero
zero
zero
zero
zero
zero
zero
Ethylbenzene
0.10%
0.10%
0.00%
0.00%
0.00%
0.00%
zero
Naphthalene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Phenol
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
Toluene
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
zero
B. Carcinogenic toxins
Excess
Lifetime Benzene 1.3E-06 1.0E-06 4.2E-07 4.3E-08 4.2E-07 4.3E-08 zero
Probability DEHP n/a n/a n/a n/a n/a n/a zero
C. Toxins lacking quantitative numbers
Intake in
Micrograms 2,4 Dimethyl
phenol 0.7 0.6 0.3 <0.1 0.3 <0.1 zero
* BPT All is the current level of treatment, but also was being considered as an option for this proposal.
b n/a = not available due to inability to calculate shrimp tissue concentration of DEHP.
C-16
-------
APPENDIX D
-------
TABLE D-l
Human Health Risk Factors for Produced Waters:
Additional Contaminants Removed by Membrane Filtration8
Compound
Oral RfD
(mgAg/day)
Carcinogenicity Oral Slope
Factor (mg/kg/day)"1
Radium
no data (IRIS)
no data (IRIS)
DEHP
2 E-2
1.4 E-2
m-xylene
2 EO
N/A (Class D)
p-Cresol
5 E-2
N/A (Class C)
2-Butanone
5 E-2
N/A (Class D)
Boron
9 E-2
no data (IRIS)
Arsenic
pending (IRIS)
1.8 EO
Barium
7 E-2
no data (IRIS)
Benzene
pending (IRIS)
2.9 E-2
a Extracted from the Integrated Risk Information System (IRIS), current as of
February 4, 1991.
D-l
-------
NONCARCINOGEN1C RISKS -
TABLE D-2
- MEMBRANE FILTRATION WITHIN 4 MILES, BPT BEYOND
(Existing Sources)
Average Exposure
MEI Exposure
Contaminant
Oral
RFD*
Intake**
% RFD
Intake**
% RFD
Finfish:
DEHP
2.00E-02
3.61E-04
0.000%
9.90E-02
0.007%
m-Xylene
2.00E+00
3.65E-04
0.000%
9.97E-02
0.000%
p-Cresol
5.00E-02
9.13E-05
0.000%
2.48E-02
0.001 %
2-Butanone
5.00E-02
2.50E-05
0.000%
6.84E-03
0.000%
Shrimp:
m-Xylene
2.00E+00
1.33E-03
0.000%
2.75E+00
0.000%
p-Cresol
5.00E-02
1.33E-04
0.000%
2.75E-01
0.000%
2-Butanone
5.00E-02
1.51E-07
0.000%
3.I3E-04
0.000%
* mg/kg/day
** ug/day
D-2
-------
TABLE D-3
NONCARCINOGEN1C RISKS -
(Existing Sources)
- BPT
Average Exposure
MEI Exposure
Contaminant
Oral
RFD*
Intake**
% RFD
Intake**
% RFD
Finfish:
DEHP
2.00E-02
5.56E-03
0.000%
1.42E+00
0.101%
m-Xylene
2.00E+00
5.66E-03
0.000%
1.44E+00
0.001%
p-Cresol
5.00E-02
1.44E-03
0.000%
3.67E-01
0.011%
2-Butanone
5.00E-02
3.87E-04
0.000%
9.88E-02
0.003%
Shrimo:
m-Xylene
2.00E+00
2.14E-03
0.000%
2.75E+00
0.000%
p-Cresol
5.00E-02
2.14E-04
0.000%
2.75E-01
0.000%
2-Butanone
5.00E-02
2.44E-07
0.000%
3.13E-04
0.000%
* mg/kg/day
** ug/day
D-3
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TABLE EM
CARCINOGENIC RISKS MEMBRANE FILTRATION WITHIN 4 MILES
VERSUS BPT-ALL BASELINE
(Existing Sources)
Oral
Slope
Carcinogen Factor*
Filtration within 4 miles
BPT
Lifetime
Exposure Excess
(ug/day) Risk Level
Lifetime
Exposure Excess
(ug/day) Risk Level
Finfish:
Arsenic 1.80E+00
Benzene 2.90E-02
DEHP 1.40E-02
4.65E-04 1.20E-08
4.29E-04 1.78E-10
3.61E-04 7.22E-11
5.99E-04 1.54E-08
6.75E-03 2.80E-09
5.57E-03 1.11E-09
TOTAL (Finfish)
1.22E-08
1.93E-08
Shrimp:
Benzene 2.90E-02
6.04E-04 2.50E-10
9.74E-04 4.03E-10
TOTAL (Shrimp)
2.50E-10
4.03E-10
* From IRIS, in [l/(mg/kg/day)]
D-4
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TABLE D-5
MEI CARCINOGENIC RISKS MEMBRANE FILTRATION WITHIN 4 MILES
VERSUS BPT-ALL BASELINE
(Existing Sources)
Oral
Slope
Carcinogen Factor*
Filtration within 4 miles
BPT
MEI Lifetime
Exposure Excess
(ug/day) Risk Level
MEI Lifetime
Exposure Excess
(ug/day) Risk Level
Finfish:
Arsenic 1.80E+00
Benzene 2.90E-02
DEHP 1.40E-02
6.84E-02 1.76E-06
1.18E-01 4.87E-08
9.90E-02 1.98E-08
8.30E-02 2.13E-06
1.72E+00 7.14E-07
1.42E+00 2.84E-07
TOTAL (Finfish)
1.83E-06
3.13E-06
Shrimp:
Benzene 2.90E-02
1.25E+00 5.18E-07
1.25E+00 5.18E-07
TOTAL (Shrimp)
5.18E-07
5.18E-07
* From IRIS, in [l/(mg/kg/day)]
D-5
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TABLE D-6
CANCER RISK REDUCTION BENEFITS
(Existing Sources)
Regulatory
Level
Lifetime
Excess
Risk
Excess Cases
Per
Lifetime
Reduction
in
Annual Cases
Annual
Value of Risk
Reduction
($000, 1986)
Finfish:
BPT-A11
1.93E-08
0.121
Membrane filtration
within 4 miles,
BPT Beyond
1.22E-08
0.076
0.0006
$1.0- $5.2
Shrimp:
BPT-A11
4.03E-10
0.020
Membrane filtration
within 4 miles,
BPT Beyond
2.50E-10
0.013
0.0001
$0.2 - $0.9
TOTAL BENEFITS
$1.2-$6.1
D-6
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NONCARCINOGENIC RISKS
TABLE D-7
MEMBRANE FILTRATION WITHIN 4 MILES, BPT BEYOND
(New Sources)
Average Exposure
MEI Exposure
Contaminant
Oral
RFD*
Intake**
% RFD
Intake**
% RFD
Finfish:
DEHP
2.00E-02
1.15E-04
0.000%
9.90E-02
0.007%
m-Xylene
2.00E+00
1.16E-04
0.000%
9.97E-02
0.000%
p-Cresol
5.00E-02
2.91E-05
0.000%
2.48E-02
0.001%
2-Butanone
5.00E-02
7.94E-06
0.000%
6.84E-03
0.000%
ShrimD:
m-Xylene
2.00E+00
3.15E-04
0.000%
2.75E+00
0.000%
p-Cresol
5.00E-02
3.15E-05
0.000%
2.75E-01
0.000%
2-Butanone
5.00E-02
3.59E-08
0.000%
3.13E-04
0.000%
* mg/kg/day
** ug/day
D-7
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TABLE D-8
CARCINOGENIC RISKS MEMBRANE FILTRATION WITHIN 4 MILES
VERSUS BPT-ALL BASELINE
(New Sources)
]
Oral
Slope
Carcinogen Factor*
'iltration within 4 miles
BPT
Lifetime
Exposure Excess
(og/day) Risk Level
Lifetime
Exposure Excess
(ug/day) Risk Level
Finfish:
Arsenic 1.80E+00
Benzene 2.90E-02
DEHP 1.40E-02
1.48E-04 3.81E-09
1.36E-04 5.65E-11
1.15E-04 2.30E-11
1.92E-04 4.93E-09
2.16E-03 8.95E-10
1.78E-03 3.56E-10
TOTAL (Finfish)
3.88E-09
6.18E-09
Shrimp:
Benzene 2.90E-02
1.42E-04 5.88E-11
1.71E-04 7.09E-11
TOTAL (Shrimp)
5.88E-11
7.09E-11
* From IRIS, in [l/(mg/kg/day)]
D-8
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