vvEPA
United States
Environmental Protection
Agency
INFORMATION SHEET
Final -January 2011
Regulating Petroleum Industry Wastewater Discharges in the United States and Norway
In the U.S. and Norway, government policies encourage the responsible development of domestic energy sources.
Petroleum exploration and development is closely regulated in each nation to protect public health and the
environment. U.S. and Norway regulations strictly limit offshore petroleum industry discharges including drilling
fluids or muds, drill cuttings, and produced water. This information sheet compares how the U.S. and Norway
manage wastewater discharges from petroleum exploration, development and production in coastal and offshore
waters. Comparisons here are generally focused on each nation's current wastewater discharge regulations.
U.S. Regulations
In the U.S., the Clean Water Act was enacted "to
restore and maintain the chemical, physical, and
biological integrity of the Nation's waters." The
Clean Water Act prohibits the discharge of any
pollutant into U.S. waters from petroleum activities
or other sources, unless the discharge complies with
specific requirements.
Section 402 of the Clean Water Act authorizes the
U.S. Environmental Protection Agency (EPA) to
regulate industry discharges through National
Pollutant Discharge Elimination System (NPDES)
permits.
NPDES permits must contain: numeric limits based
on the technology available to control pollutants,
without reference to the effect on the receiving
water; and if needed, more stringent limits to
control pollutants to meet the water quality
standards of the receiving waters.
EPA's NPDES regulations for the petroleum industry
limit discharges into marine waters, with different
restrictions for "coastal" and "offshore" waters.
Coastal waters are landward of the inner boundary
of the U.S. territorial seas. Offshore waters are
seaward of the inner boundary of the U.S. territorial
seas. Coastal discharge requirements are generally
more stringent than offshore requirements.
Section 403 of the Clean Water Act requires that
NPDES permits in offshore waters comply with EPA's
Ocean Discharge Criteria guidelines. EPA will issue an
NPDES permit only if the Ocean Discharge Criteria
Evaluation finds that the discharge will not cause
unreasonable degradation of the marine
environment.
Norway Regulations
In Norway, the Pollution Control Act regulations
require petroleum activities to be carried out with
the least possible risk of pollution. The Norway
Climate and Pollution Agency regulates petroleum
industry use of drilling fluids and muds, produced
water, and chemicals, with water discharge permits.
To further protect marine waters, Norway first
introduced a "zero discharge" goal for petroleum
activities (White Paper 58, 1996-1997). This goal was
later refined to mean zero discharge of
environmentally hazardous substances, using Best
Available Techniques, and following the
precautionary principle (White Paper 25,
2002/2003).
An advisory cooperative group composed of
government and industry representatives developed
a common definition that identified relevant
technologies to achieve zero discharge, and created
a standard manner to report discharges. This
advisory group found that a literal interpretation of
the zero discharge goal was not economically
feasible or environmentally beneficial.
Norway defines zero environmentally harmful
discharges as:
• Zero discharge of all added environmentally
hazardous chemicals classified as "red" or "black"
in the national classification system1;
• Zero harmful discharges from natural compounds
and chemicals classified as "yellow" or "green".
Norway established stricter requirements for drilling
operations and produced water in areas north of the
68th parallel in the Barents Sea and Lofoten area
(White Paper 38, 2003-2004).
This document is for informational purposes only. For U.S. oil and gas regulations see 40 CFR Part 435.
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Discharge Restrictions - More Information
U.S. Toxicity Testing Requirements
Coastal
Drilling fluids, drill cuttings, and dewatering
effluent are prohibited from discharge in all
coastal areas, except Cook Inlet. In Cook Inlet,
discharges of water-based drilling fluids, drill
cuttings, and dewatering effluent are limited to
concentrations that pass a toxicity test2 on
aquatic organisms.
No discharge is allowed for non-aqueous (oil-
based) drilling fluids, dewatering effluent, and
drill cuttings associated with non-aqueous
drilling fluids.
Offshore
For facilities located within 3 miles from shore,
except Alaskan facilities, the discharge of
drilling fluids and drill cuttings are prohibited by
the Best Available Technology economically
achievable and New Source Performance
Standards.
For facilities located beyond 3 miles from shore,
and all Alaskan facilities, water-based drilling
fluids and drill cuttings, as well as drill cuttings
associated with non-aqueous drilling fluids, are
limited to concentrations that pass an acute
toxicity test2 on aquatic organisms. The
discharge of non-aqueous (oil based) drilling
fluids is prohibited.
Norway Chemical Testing Requirements
Norway chemical approval regulations1 focus on
long-term effects of specific components, while
U.S. requirements focus on the acute toxicity of
drilling fluids.
U.S. Ocean Discharge Criteria Evaluation
Section 403 of the Clean Water Act requires an
Ocean Discharge Criteria Evaluation on NPDES
permits for discharges into the territorial sea,
contiguous zone, and oceans to prevent
unreasonable degradation of ocean waters.
In EPA's Ocean Discharge Criteria Evaluation,
unreasonable degradation is defined as:
• Significant adverse changes in ecosystem
diversity, productivity, and stability of the
biological community within the area of
discharge and surrounding biological
communities; or
• Threat to human health through direct
exposure to pollutants or consumption of
exposed aquatic organisms; or
• Loss of aesthetic, recreational, scientific, or
economic values, which are unreasonable
in relation to the benefit derived from the
discharge.
EPA will issue an NPDES permit only if the
Ocean Discharge Criteria Evaluation finds that
the discharge will not cause unreasonable
degradation of the marine environment (40 CFR
Part 125 subpart M).
U.S. and Norway Comparison Summary
Direct comparisons of the U.S. and Norway
offshore discharge regulations are difficult and
complex. Both nations have robust and
thorough regulatory regimes that aim to
balance environmental protection with
economic considerations in developing
domestic energy. U.S. and Norway regulations
continue to be refined based on environmental
concerns, economics, and innovations in
science and technology.
Norway's "zero discharge" goal is not a numeric
standard or a discharge level, but is instead a
goal based on the precautionary principle and
available technology. This is comparable to the
U.S. goal to prevent unreasonable degradation
of ocean waters.
In the U.S., oil and gas NPDES permits limit
discharges using both technology and water
quality-based controls. NPDES permits must
meet the requirements in the code of federal
regulations (40 CFR Part 435). In addition, all
permits for discharges in the territorial sea,
contiguous zone, and oceans must comply with
the Ocean Discharge Criteria.
This document is for informational purposes only. For U.S. oil and gas regulations see 40 CFR Part 435.
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Comparison of U.S. and Norway Regulations for Petroleum Industry Wastewater Discharges
Discharge Type
U.S.
Norway
Water-based drilling fluids and
associated drill cuttings
Drilling fluids are used in the rotary
drilling of wells to clean and condition
the hole, to counter balance formation
pressure, and transport drill cuttings to
the surface.
Drilling muds are a type of drilling fluid
made of bentonite and other clays or
polymers, and barite, mixed with oil or
water. Muds help carry the other
components in drillingfluids down the
drill pipe and bring cuttings back up the
well.
Discharge of muds and cuttings allowed from
entire well, subject to requirements below.
Toxicity test requirements: Acute Suspended
Particulate Phase toxicity tests2.
Coastal - No discharge allowed, except Cook
Inlet. In Cook Inlet, discharges require
offshore effluent limits and acute toxicity
tests2.
Offshore - No discharge within 3 miles from
shore, except in Alaska.
Discharges beyond 3 miles from shore and
Alaskan facilities within 3 miles from shore
require numeric effluent limits, toxicity
tests2. No free oil or diesel oil discharge,
determined by Static Sheen Test.
Mercury Img/kg, cadmium 3mg/kg dry
weight maximum in stock barite.
Alaska Water Quality Standards5 - Mercury
1.8ng/L acute, 0.94ng/L chronic, 0.051ng/L
human health; cadmium 40ng/L acute,
8.8ng/L chronic; total aromatic hydrocarbons
10ng/L, total aqueous hydrocarbons 15|ag/L
Toxicity, biodegradation, bioaccumulation
test requirements: For all components in
chemicals used offshore except "green"
chemicals list .
South of the 68th Parallel - Discharge of
muds and cuttings allowed from the entire
well. Some limitations, e.g., no discharge of
solids containing >1% oil, by weight.
Discharge permit for the chemicals in the
drilling fluid is required. Only "green" and
"yellow" chemicals allowed.
No toxicity testing of used drilling fluids.
Heavy metals in barite as low as possible.
North of the 68th Parallel - Same
requirements as south of 68th parallel.
In addition, discharge of muds and cuttings
allowed from only the "top hole"4 section
of the well, if the discharge would not
cause significant environmental impacts.
All other cuttings or fluids must be re-
injected or barged to shore.
Non-aqueous (oil-based) drilling
fluids
Discharge not allowed.
Discharge not allowed. Permit required for
use of the chemicals in the drilling fluid.
Drill cuttings associated with
non-aqueous (oil-based) drilling
fluids
Drill cuttings are the particles generated
by drilling into subsurface geologic
formations and carried to the surface
with the drilling fluids and muds.
Coastal - No discharge allowed, except Cook
Inlet. In Cook Inlet, if operators cannot
comply due to technical limitations,
discharges must meet offshore requirements
and limits (see below).
Offshore-Cuttings discharge must meet
water-based drilling fluids and cuttings limits.
Specific stock limitations and base fluid
requirements apply .
Toxicity, biodegradation, bioaccumulation
test requirements: For all components in
chemicals used offshore except "green"
chemicals list3.
South of the 68th Parallel - Oil-based and
synthetic-based cuttings restriction: no
discharge if base oil content is >1%.
North of the 68th Parallel - No discharge
allowed.
Produced Water
(Development & Production Only)
Beneath oil and gas reservoirs is a
natural water layer called formation
water. During production operations, sea
water is injected into the reservoirs to
help force the oil to the surface.
Produced water contains formation and
injected water, oil, gas, and any
chemicals added during the oil/water
separation process. At the surface,
produced water is treated to remove as
much oil as possible, and then
Coastal - No discharge allowed, except Cook
Inlet. In Cook Inlet, discharges require oil and
grease limits: 42mg/L maximum daily;
29mg/L monthly average.
Offshore - Discharge allowed if oil and grease
limits are achieved: 42mg/L maximum daily;
29mg/L monthly average.
Re-injection not required.
Toxicity, biodegradation, bioaccumulation
test requirements: For all components in
chemicals used offshore except "green"
chemicals list3.
South of the 68th Parallel - Discharge of
"green" and "yellow" chemicals allowed.
Oil in water < 30mg/L monthly average.
Document zero harm (e.g., discharges of oil
in water are well below 30mg/L)
North of the 68th Parallel - Produced water
This document is for informational purposes only. For U.S. oil and gas regulations see 40 CFR Part 435.
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Discharge Type
U.S.
Norway
discharged into the sea or injected back
into the wells.
discharges not allowed, except during
operational deviations (maximum 5%
produced water can be discharged).
Sanitary and Domestic Wastes
(including Food Waste)
Coastal and Offshore - For facilities
continuously manned by 10 people or more
(M10): minimum Img/L residual chlorine. For
facilities continuously manned by 9 people or
less or intermittently manned (M9IM): no
discharge of floating solids.
Alaska Water Quality Standard5 - Total
residual chlorine 13u.g/L acute, 7.5ug/L
chronic; fecal coliform bacteria 14 FC/lOOmL
acute, 43 FC/lOOmL chronic.
South and North of the 68th Parallel -
Discharge allowed.
Discharge of food waste allowed after
grinding.
Cooling Water
No federal standard for temperature.
Alaska Water Quality Standard5 - Not to
exceed 15°C or cause the weekly average to
increase by more than 1°C.
South and North of the 68 Parallel -
Discharge allowed for exploration.
Temperature increase assessment required
for development and production (must
achieve ambient temperature 100m from
platform).
Deck Drainage
(including Detergents)
Coastal and Offshore - No discharge of free
oil, determined by presence of film, sheen or
discoloration on surface of receiving water
(visual sheen). Deck drainage contaminated
with oil and grease must be processed
through oil/water separator prior to
discharge.
Alaska Water Quality Standards5 - total
aromatic hydrocarbons 10u.g/L, total
aqueous hydrocarbons 15u.g/L
Toxicity, biodegradation, bioaccumulation
testing requirements: For all components in
chemicals used offshore except "green"
chemicals list3.
South and North of the 68th Parallel -
Discharge of "green" and "yellow" products
allowed. Deck drainage contaminated with
oil and grease must be processed through
oil/water separator prior to discharge. Oil
in water < 30mg/L monthly average.
Bilge Water
Coastal and Offshore - No discharge of free
oil, determined by presence of film, sheen or
discoloration on surface of receiving water
(visual sheen).
Bilge water must be processed with oil/water
separator prior to discharge.
South and North of the 68 Parallel - Bilge
water must be processed with oil/water
separator prior to discharge. Oil in water <
30mg/L monthly average.
Blowout Preventer Fluids
Hydraulic Fluids
Well Treatment, Completion,
and Workover Fluids
Coastal - No discharge allowed, except Cook
Inlet. In Cook Inlet, discharges require oil and
grease limits: 42mg/L maximum daily;
29mg/L monthly average.
Offshore - Discharge allowed. Oil and grease
limits: 42mg/L maximum daily; 29mg/L
monthly average.
Alaska Water Quality Standards5 - total
aromatic hydrocarbons 10u.g/L, total
aqueous hydrocarbons 15u.g/L
Toxicity, biodegradation, bioaccumulation
test requirements: For all components in
chemicals used offshore except "green"
chemicals list3.
,th
South and North of the 68 Parallel -
Discharge of limited volumes of "green"
and "yellow" products allowed.
This document is for informational purposes only. For U.S. oil and gas regulations see 40 CFR Part 435.
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References
1 Norway follows the Oslo-Paris Convention of
the Marine Environment of the North-East
Atlantic (OSPAR) offshore screening chemical
guidelines. This means that the components in
the chemicals are tested for toxicity (on algae,
shrimp, and juvenile fish), biodegradation and
bioaccumulation.
Based on this testing, Norway requires
operators on the Norwegian Continental Shelf
to classify chemicals used offshore as "green",
"yellow", "red", or "black."
Norway requires zero discharge of all added
environmentally hazardous chemicals classified
as "red" or "black". However, "red" chemicals
may be discharged if an operator demonstrates
no other options are available and an active
search is underway for a replacement or
substitution.
This classification system is a risk assessment
approach to help operators determine the
chemicals and additives they are allowed to use
offshore, based on ecotoxicological data in the
OSPAR Harmonised Offshore Chemical
Notification Format and hazardous chemicals
on the priority list as outlined in White Papers
58 and 25.
2 Suspended Particulate Phase (SPP) toxicity test
is an acute toxicity measurement used to
determine levels of pollutant concentrations
which can kill a certain percentage of organisms
exposed to the suspended particulate phase of
the drilling fluids and cuttings.
The toxicity limit is expressed as a
concentration of the SPP from a sample of
drilling fluid that would kill 50% of marine
organisms exposed to that concentration of the
SPP, i.e., the lethal concentration, or LC50, of
the discharge.
Discharges of water-based drilling fluids and
cuttings in offshore waters and Alaskan
facilities, or cuttings associated with non-
aqueous drilling fluids, must meet a minimum
toxicity requirement: 96-hour LC50 of the SPP
toxicity test must be 3% by volume (>30,000
parts per million).
E.g., a discharge at a concentration of 3% or
more should kill no more than half a test
population of marine organisms continuously
exposed 96 hours.
3 Chemicals on Norway's "green" list are those
that Pose Little or No Risk ("PLONOR") to the
marine environment, based on the Convention
for the Protection of the Marine Environment of
the North-East Atlantic.
4 "Top Hole" is typically defined as the well
sections drilled before a conductor and riser are
installed. The depth of the top hole varies with
the total depth of the well and the integrity of
the formations. In Norway, most top holes
range from 100-700m deep.
5 Alaska Water Quality Standards (18 Alaska
Administrative Code 70) apply to discharges
within State waters.
6 Stock limitations (C16-C18 internal olefin, C12-
C14 ester or C8 ester): Mercury Img/kg and
cadmium 3mg/kg dry weight maximum in stock
barite; Polycyclic Aromatic Hydrocarbons (PAH)
< IxlO"5; Base fluid sediment toxicity ratio < 1.0;
Biodegradation rate ratio < 1.0; acute toxicity
tests; drilling fluid sediment toxicity ratio < 1.0;
no discharge of diesel or formation oil.
Base fluid retained on cuttings (C16-C18
internal olefin): 6.9g base fluid/lOOg wet drill
cuttings. Base fluid (C12-C14 ester or C8 ester
stock): 9.4g base fluid/lOOg wet drill cuttings.
For More Information
U.S. oil and gas extraction discharge limits are
found in the Code of Federal Regulations, Title
40, Part 435 at:
http://www.gpoaccess.gov/cfr/index.html
EPA permits for oil and gas wastewater
discharges in Alaska are found at:
http://yosemite.epa.gov/rlO/water.nsf/NPDES+Per
mits/CurrentAK822
Norway petroleum regulations are found at:
http://www.ptil.no/regulations/category87.html
This document is for informational purposes only. For U.S. oil and gas regulations see 40 CFR Part 435.
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