INDUSTRIAL STORMWATER
FACT SHEET SERIES
Sector I; Oil and Gas Extraction Facilities
U.S. EPA Office of Water
EPA-833-F-06-024
December 2006
What is the NPDES stormwater permitting program for industrial
activity?
Activities, such as material handling and storage, equipment maintenance and cleaning, industrial
processing or other operations that occur at industrial facilities are often exposed to stormwater. The
runoff from these areas may discharge pollutants directly into nearby waterbodies or indirectly via
storm sewer systems, thereby degrading water quality.
In 1990, the U.S. Environmental Protection Agency (EPA) developed permitting regulations under the
National Pollutant Discharge Elimination System (NPDES) to control stormwater discharges associated
with eleven categories of industrial activity. As a result, NPDES permitting authorities, which may be
either EPA or a state environmental agency, issue stormwater permits to control runoff from these
industrial facilities.
What types of industrial facilities are required to obtain permit
coverage?
This fact sheet specifically discusses stormwater discharges from oil and gas extraction facilities as de-
fined by Standard Industrial Classification (SIC) Major Group 13. This includes oil and gas exploration,
production, processing or treatment operations, or transmission facilities that discharge stormwater
that has been contaminated by contact with raw material, intermediate products, finished products,
by-products, or waste products. Facilities and products in this group fall under the following catego-
ries, which require coverage under an industrial stormwater permit with some exceptions:
4 Crude petroleum and natural gas (SIC 1311)
4 Natural gas liquids (SIC 1321)
4- Drilling oil and gas wells (SIC 1381)
4 Oil and gas field exploration services (SIC 1382)
4 Oil and gas field services, not elsewhere classified (SIC 1389)
EPA defines contaminated stormwater discharges from these oil and gas field activities or operations
generally to include discharges (1) resulting in the discharge of a reportable quantity for which notifi-
cation is or was required or (2) that contributes to a violation of a water quality standard. Field activi-
ties or operations that can contribute to contamination of stormwater include, but are not limited to:
4 Drilling and production equipment and other machinery
4 Raw materials
4 Waste products and by-products
4 Oil and gas treatment units
4 Finished products
4 Storage areas
4 Fuels and lubricants
4 Waste treatment areas
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This also includes stormwater discharges from access roads and rail lines used or traveled by carriers of
raw materials, manufactured products, waste materials, or by-products created by the facility.
What does an industrial stormwater permit require?
Common requirements for coverage under an industrial stormwater permit include development of
a written stormwater pollution prevention plan (SWPPP), implementation of control measures, and
submittal of a request for permit coverage, usually referred to as the Notice of Intent or NOI. The
SWPPP is a written assessment of potential sources of pollutants in stormwater runoff and measures
that will be implemented at your facility to minimize the discharge of these pollutants in runoff from
the site. These measures include site-specific best management practices (BMPs), maintenance plans,
inspections, employee training, and reporting. The procedures detailed in the SWPPP must be imple-
mented by the facility and updated as necessary, with a copy of the SWPPP kept on-site. The industrial
stormwater permit also requires collection of visual, analytical, and/or compliance monitoring data to
determine the effectiveness of implemented BMPs. For more information on EPA's industrial stormwa-
ter permit and links to State stormwater permits, go to www.epa.gov/npdes/stormwater and click on
"Industrial Activity."
What pollutants are associated with activities at my facility?
Pollutants conveyed in stormwater discharges from facilities involved with the exploration and
production techniques will vary depending on the type and characteristics of formations, pollutants
present, and waste management controls. Therefore, impacts associated with stormwater discharges
from oil and gas extraction facilities will vary from site to site. There are a number of factors that
influence to what extent industrial activities and significant materials can affect water quality.
4 Geographic location
4 Hydrogeology
4 Topography
4 Type of ground cover (e.g., vegetation, caliche, crushed stone, or dirt)
4 Outdoor activities (e.g., material storage, loading/unloading, vehicle maintenance)
4 Size of the operation
4 Type, duration, and intensity of precipitation events
4 Historical activities (e.g., past oil and gas operations).
The activities, pollutant sources, and pollutants detailed in Table 1 are commonly found at oil and gas
extraction facilities.
Table 1. Common Activities, Pollutant Sources, and Associated Pollutants at Oil and Gas Extraction
Facilities
Activity
Construction of:
Access roads
Drill pads
Mud/Reserve pits
Personnel quarters
Surface
impoundments
Storage tanks
Pipelines
Well drilling
Well completion/
stimulation
Pollutant Source
Soil/dirt, leaking equipment, and vehicles
Drilling fluid*, lubricants, mud, cuttings,
and produced water
Fluids (used to control pressure in well),
cement, residual oil, acids, surfactants,
solvents, produced water, and sand
Pollutant
Total suspended solids (TSS), Total dissolved
solids (TDS), oil and grease
TSS, TDS, oil and grease, chemical oxygen
demand (COD), chlorides, barium, naphthalene,
benzene, lead, arsenic, fluoride
TSS, TDS, oil and grease, COD, acid, acetone,
toluene, ethanol, xylenes
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INDUSTRIAL STORMWATER FACT SHEET SERIES
Sector /: Oil and Gas Extraction Facilities
Table 1. Common Activities, Pollutant Sources, and Associated Pollutants at Oil and Gas Extraction
Facilities (continued)
Activity
Production
Vehicle and equipment
cleaning and repairing
Site closures
Vehicle fueling
Pollutant Source
Produced water, oil, waste sludge, tank
bottoms, acids, oily debris, and emulsions
Cleaning solvents, lubricants, and chemical
additives
Residual muds and oily debris
Diesel fuel
Pollutant
Chlorides, IDS, oil and grease, TSS, pH,
benzene, phenanthrene, barium, arsenic, lead,
antimony
TSS, IDS, oil and grease, pH
TSS, IDS, oil and grease, pH
TSS, TDS, oil and grease
* The potential contaminants to be found in drilling fluid varies from site to site, depending on the components of the fluid and
any pollutants added due to use of the fluid. Stormwater discharges that come into contact with used drilling fluids may include the
following pollutants, among others: toluene, ethyl benzene, xylene, phenol, benzene, and phenanthrene. Used drilling fluids may also
contain inorganic pollutants from additives or downhole exposure, such as arsenic, chromium, lead, aluminum, sulfur, and sulfate salts.
What BMPs can be used to minimize contact between stormwater
and potential pollutants at my facility?
A variety of BMP options may be applicable to eliminate or minimize the presence of pollutants
in stormwater discharges from oil and gas extraction facilities. You will likely need to implement a
combination or suite of BMPs to address stormwater runoff at your facility. Your first consideration
should be for pollution prevention BMPs, which are designed to prevent or minimize pollutants
from entering stormwater runoff and/or reduce the volume of stormwater requiring management.
Prevention BMPs can include regular cleanup, collection and containment of debris in storage areas,
and other housekeeping practices, spill control, and employee training. It may also be necessary to
implement treatment BMPs, which are engineered structures intended to treat stormwater runoff
and/or mitigate the effects of increased stormwater runoff peak rate, volume, and velocity. Treatment
BMPs are generally more expensive to install and maintain and include oil-water separators, wet
ponds, and proprietary filter devices.
The types of BMPs used may depend upon the methods of waste management utilized at a facility.
Waste management and disposal practices at oil and gas extraction facilities may vary significantly.
For example, techniques for disposal of produced water and associated wastes include the following:
4 Landfarming/spreading (spreading wastes on land surfaces to stimulate biological degradation)
4 Backfilling (storing wastes in a pit and then covering with dirt or other materials)
4 Evaporation (in more arid parts of the country, liquid wastes are left exposed and eventually
evaporate or percolate into the ground)
4 Discharging wastes (sometimes treated) to waters of the United States (NPDES permits are
required for such discharges)
4 Injection (injecting wastes back into the ground for disposal)
4 Offsite disposal (wastes are taken offsite to a commercial facility for disposal)
The pollutants of concern and the BMPs employed at an oil and gas extraction facility depend upon
which, if any, of the disposal techniques listed above are utilized. Where wastes are land applied,
for example, all pollutant constituents of that waste need to be considered a potential contributor
to contaminated stormwater discharges. In addition, BMPs must be implemented in the areas at the
facility where road application occurs.
BMPs must be selected and implemented to address the following:
Good Housekeeping Practices
Good housekeeping is a practical, cost-effective way to maintain a clean and orderly facility to
prevent potential pollution sources from coming into contact with stormwater. It includes establishing
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INDUSTRIAL STORMWATER FACT SHEET SERIES
Sector /: Oil and Gas Extraction Facilities
protocols to reduce the possibility of mishandling materials or equipment and training employees
in good housekeeping techniques. Common areas where good housekeeping practices should be
followed include trash containers and adjacent areas, material storage areas, vehicle and equipment
maintenance areas, and material loading/unloading areas. Good housekeeping practices must
include a schedule for regular pickup and disposal of garbage and waste materials and routine
inspections of drums, tanks, and containers for leaks and structural conditions. Practices also include
containing and covering garbage, waste materials, and debris. Involving employees in routine
monitoring of housekeeping practices has proven to be an effective means of ensuring the continued
implementation of these measures.
Specific good housekeeping practices that should be implemented include:
4 Confining vehicles and equipment awaiting or having undergone maintenance to designated
areas.
4 Implementing measures to minimize contaminants from these maintenance areas (such as drip
pans, indoor storage, etc.).
4 Maintaining material and chemical storage areas in good condition.
4 Labeling all hazardous materials clearly.
4 Implementing measures that prevent or minimize contamination of stormwater runoff from
chemical mixing areas.
Minimizing Exposure
Where feasible, minimizing exposure of potential pollutant sources to precipitation is an important
control option. Minimizing exposure prevents pollutants, including debris, from coming into contact
with precipitation and can reduce the need for BMPs to treat contaminated stormwater runoff. It can
also prevent debris from being picked up by stormwater and carried into drains and surface waters.
Examples of BMPs for exposure minimization include covering materials or activities with temporary
structures (e.g., tarps) when wet weather is expected or moving materials or activities to existing
or new permanent structures (e.g., buildings, silos, sheds). Even the simple practice of keeping a
dumpster lid closed can be a very effective pollution prevention measure.
Erosion and Sediment Control
BMPs must be selected and implemented to limit erosion on areas of your site that, due to
topography, activities, soils, cover, materials, or other factors are likely to experience erosion. Erosion
control BMPs such as seeding, mulching, and sodding prevent soil from becoming dislodged and
should be considered first. Sediment control BMPs such as silt fences, sediment ponds, and stabilized
entrances trap sediment after it has eroded. Sediment control BMPs should be used to back-up
erosion control BMPs.
Unless covered under a stormwater permit for construction activity, specific sediment and erosion
control practices that should be implemented include:
4 Implementing vegetative practices designed to preserve existing vegetation where attainable
4 Re-vegetating open areas as soon as practicable after grade-drilling
4 Maintaining a vegetated buffer around well pads, roads, and other industrial areas
4 Beginning the implementation of appropriate vegetative practices on all disturbed areas
within 14 days following the last activity in that area
4 Inspecting all sediment and erosion control measures once every seven days
Management of Runoff
Your SWPPP must contain a narrative evaluation of the appropriateness of stormwater management
practices that divert, infiltrate, reuse, or otherwise manage stormwater runoff so as to reduce the
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INDUSTRIAL STORMWATER FACT SHEET SERIES
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discharge of pollutants. Appropriate measures are highly site-specific, but may include, among others,
vegetative swales, collection and reuse of stormwater, inlet controls, snow management, infiltration
devices, and wet retention measures.
A combination of preventive and treatment BMPs will yield the most effective stormwater
management for minimizing the offsite discharge of pollutants via stormwater runoff. Though not
specifically outlined in this fact sheet, BMPs must also address preventive maintenance records or
logbooks, regular facility inspections, spill prevention and response, and employee training.
All BMPs require regular maintenance to function as intended. Some management measures have
simple maintenance requirements, others are quite involved. You must regularly inspect all BMPs to
ensure they are operating properly, including during runoff events. As soon as a problem is found,
action to resolve it should be initiated immediately.
Implement BMPs, such as those listed below in Table 2 for the control of pollutants at oil and gas
extraction facilities, to minimize and prevent the discharge of pollutants in stormwater. Identifying
weaknesses in current facility practices will aid the permittee in determining appropriate BMPs that
will achieve a reduction in pollutant loadings. BMPs listed in Table 2 are broadly applicable to oil and
gas extraction facilities; however, this is not a complete list and you are recommended to consult with
regulatory agencies or a stormwater engineer/consultant to identify appropriate BMPs for your facility.
Table 2. BMPS for Potential Pollutant Sources at Oil and Gas Extraction Facilities
Pollutant Source
BMPs
Construction
FJ Limit the amount of land disturbed during construction of access roads and facilities and
preserve existing vegetation.
FJ Implement erosion and sediment controls such as vegetated swales, diversion berms, or
dikes to limit or isolate land disturbance and process areas to retain/detain flows and limit
stormwater run-on in these areas.
Q Divert stormwater away from contaminated areas.
Q Inspect the area regularly to ensure BMPs are implemented and maintained.
Well drilling
Q Use diking and other forms of containment and diversion around storage tanks, oil drums,
acid, production chemicals and liquids, reserve pits, and impoundments.
Q Use diking and other forms of containment and diversion around material handling and
processing areas.
Q Use porous pads under drum and tank storage areas.
FJ Use covers and/or lining for waste reserve and sludge pits to avoid overflows and leaks.
FJ Use drip pans, catch basins, or liners during handling of materials such as tank bottoms.
FJ Re-use collected stormwater for industrial process or as an irrigation source.
FJ Develop and implement spill plans for pipelines, tanks, drums, etc.
FJ Recycle oily wastes, drilling fluids and other materials on-site, or dispose offsite.
FJ Use oil - water separators.
FJ Inspect the area regularly to ensure BMPs are implemented and maintained.
Well completion
Utilize diking and other forms of containment and diversion around storage tanks, oil drums,
acid, production chemicals and liquids, reserve pits, and impoundments.
Use diking and other forms of containment and diversion around material handling and
processing areas.
Use porous pads under drum and tank storage areas.
Use covers and/or lining for waste reserve and sludge pits to avoid overflows and leaks.
Use drip pans, catch basins, or liners during handling of materials such as tank bottoms.
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INDUSTRIAL STORMWATER FACT SHEET SERIES
Sector /: Oil and Gas Extraction Facilities
Table 2. BMPS for Potential Pollutant Sources at Oil and Gas Extraction Facilities (continued)
Pollutant Source
BMPs
Well completion
(continued)
FJ Reinject or treat produced water instead of discharging it.
FJ Re-use collected stormwater for industrial process or as an irrigation source.
FJ Develop and implement spill plans for pipelines, tanks, drums, etc.
Q Recycle oily wastes, drilling fluids and other materials on-site, or dispose of offsite.
Q Use oil water separators.
Q Inspect the area regularly to ensure BMPs are implemented and maintained.
Vehicle and
equipment cleaning
and maintenance
Good Housekeeping
FJ Eliminate floor drains that are connected to the storm or sanitary sewer; if necessary, install a
sump that is pumped regularly. Collected wastes should be properly treated or disposed of by a
licensed waste disposal company.
Q Prevent and contain spills and drips.
Q Do all cleaning at a centralized station so the solvents stay in one area.
Q If parts are dipped in liquid, remove them slowly to avoid spills.
FJ Use drip pans, drain boards, and drying racks to direct drips back into a fluid holding tank for
reuse.
FJ Drain all parts of fluids prior to disposal. Oil filters can be crushed and recycled.
Q Promptly transfer used fluids to the proper container; do not leave full drip pans or other open
containers around the shop. Empty and clean drip pans and containers.
Q Clean up leaks, drips, and other spills without using large amounts of water. Use absorbents
for dry cleanup whenever possible.
FJ Prohibit the practice of hosing down an area where the practice would result in the discharge
of pollutants to a stormwater system.
Q Do not pour liquid waste into floor drains, sinks, outdoor storm drain inlets, or other storm
drains or sewer connections.
Q Maintain an organized inventory of materials.
FJ Eliminate or reduce the number and amount of hazardous materials and waste by substituting
nonhazardous or less hazardous materials.
FJ Label and track the recycling of waste material (e.g., used oil, spent solvents, batteries).
Q Store batteries and other significant materials inside.
Q Dispose of greasy rags, oil filters, air filters, batteries, spent coolant, and degreasers in
compliance with RCRA regulations.
Minimizing Exposure
FJ Perform all cleaning operations indoors or under covering when possible. Conduct the cleaning
operations in an area with a concrete floor with no floor drainage other than to sanitary sewers
or treatment facilities.
Q If operations are uncovered, perform them on a concrete pad that is impervious and contained.
Q Park vehicles and equipment indoors or under a roof whenever possible and maintain proper
control of oil leaks/spills.
FJ Check vehicles closely for leaks and use pans to collect fluid when leaks occur.
Management of Runoff
Q Use berms, curbs, or grassed swales other diversion measures to ensure that stormwater runoff
from other parts of the facility does not flow over the maintenance area.
Q Collect the stormwater runoff from the cleaning area and provide treatment or recycling.
FJ Discharge vehicle wash or rinse water to the sanitary sewer (if allowed by sewer authority),
wastewater treatment, a land application site, or recycle on-site. DO NOT discharge washwater
to a storm drain or to surface water.
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INDUSTRIAL STORMWATER FACT SHEET SERIES
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Table 2. BMPS for Potential Pollutant Sources at Oil and Gas Extraction Facilities (continued)
Pollutant Source
BMPs
Vehicle and
equipment cleaning
and maintenance
(continued)
Inspections and Training
FJ Inspect the maintenance area regularly to ensure BMPs are implemented.
FJ Train employees on waste control and disposal procedures.
Vehicle fueling
Stationary fueling areas
Q Conduct fueling operations (including the transfer of fuel from tank trucks) on an impervious
or contained pad and under a roof or canopy where possible. Covering should extend beyond
spill containment pad to prevent rain from entering.
Q When fueling in uncovered area, use concrete pad (asphalt is not chemically resistant to the
fuels being handled).
FJ Use drip pans where leaks or spills of fuel can occur and where making and breaking hose
connections.
FJ Use fueling hoses with check valves to prevent hose drainage after filling.
FJ Keep spill cleanup materials readily available.
FJ Clean up spills and leaks immediately.
FJ Use dry cleanup methods for fuel area rather than hosing down the fuel area. Sweep up
absorbents as soon as spilled substances have been absorbed.
Q Do not "top-off" fuel tanks.
Q Use spill and overflow protection devices.
Q Minimize/eliminate run-on into fueling areas with diversion dikes, berms, curbing, surface
grading or other equivalent measures.
Q Collect stormwater runoff and provide treatment or recycling.
Q Provide curbing or posts around fuel pumps to prevent collisions from vehicles.
Q Regularly inspect and perform preventive maintenance on fuel storage tanks to detect potential
leaks before they occur.
FJ Inspect the fueling area for leaks and spills.
FJ Train personnel on vehicle fueling BMPs.
Mobile fueling areas
FJ Use drip pan under the transfer hose.
FJ Use fueling hoses with check valves to prevent hose drainage after filling.
FJ Ensure the fueling vehicle is equipped with a manual shutoff valve.
FJ Do not allow topping off of the fuel in the receiving equipment.
FJ Train personnel on vehicle fueling BMPs.
What if activities and materials at my facility are not exposed to
precipitation?
The industrial stormwater program requires permit coverage for a number of specified types of
industrial activities. However, when a facility is able to prevent the exposure of ALL relevant activities
and materials to precipitation, it may be eligible to claim no exposure and qualify for a waiver from
permit coverage.
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If you are regulated under the industrial permitting program, you must either obtain permit coverage
or submit a no exposure certification form, if available. Check with your permitting authority for
additional information as not every permitting authority program provides no exposure exemptions.
Where do I get more information?
For additional information on the industrial stormwater program see
www.epa.gov/npdes/stormwater/msgp.
A list of names and telephone numbers for each EPA Region or state NPDES permitting authority can
be found at www.epa.gov/npdes/stormwatercontacts.
References
Information contained in this Fact Sheet was compiled from EPA's past and current Multi-Sector
General Permits and from the following sources:
4 Horizon Environmental Services, Inc. April 2004. Guidance Document: Reasonable and Prudent
Practices for Stabilization (RAPPS) of Oil and Gas Construction Sites.
4 U.S. EPA Office of Science and Technology. 1999. Preliminary Data Summary of Urban
Stormwater Best Management Practices. EPA-821-R-99-012.
www.epa.gov/OST/stormwater/
4 U.S. Department of the Interior Bureau of Land Management and U.S. Department of
Agriculture Forest Service. 2005. Fourth Edition. Surface Operating Standards for Oil and Gas
Exploration and Development "Gold Book."
4 U.S. EPA, Office of Wastewater Management. NPDES Stormwater Multi-Sector General Permit
for Industrial Activities (MSGP).
www.epa.gov/npdes/stormwater/msgp
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