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SPCC Requirements and Pollution Prevention Practices for Mines and Quarries
This guide will assist mines and quarries with
the prevention and control of oil spills. Other guides have been
developed to assist other industry sectors in the regulated community.
This guide discusses the equipment and operating practices needed
to meet the requirements of the Federal Oil Pollution Prevention
Regulation found in Title 40 Code of Federal Regulations (CFR) Part
112, which includes the Spill Prevention Control and Countermeasure
(SPCC) Plan requirements and the Facility Response Plan (FRP) requirements.
The SPCC requirements are the focus of this guide; other guides
are available for the facility response planning requirements (40
CFR 112.20 and 112.21) and general information on the Oil Pollution
Prevention Regulation.
Recommended practices for pollution prevention and avoiding discharges
of oil are also included in this guide. These practices may also
assist facilities in achieving compliance with the SPCC requirements
and reduce the possibility of product loss and a discharge.
* A discharge is essentially a spill that reaches
a navigable water or adjoining shoreline. The legal definition can
be found in 40 CFR 112.2(b).
The mining and quarrying sector consists of all facilities that
remove natural resources, other than oil and gas, from the earth's
crust. This includes underground and surface metal and nonmetal
mines, coal mines, rock quarries, and sand and gravel pits. Many
facilities in this sector consume large quantities of oil in their
operations, and use several types of diesel powered equipment. Therefore,
these facilities store a large quantity of oil.
The typical underground mine generally has the mine
opening, vertical or shaft openings and horizontal adits, a processing
plant which generally concentrates the ore, and the associated buildings,
including change house, offices, shops, and compressor building.
Shops on the surface at underground mines tend to be small because
of the inconvenience of bringing equipment out of the mine.
The typical surface mine generally has a mine or pit, a processing
plant for concentrating the ore, and the associated buildings, including
a change house, offices, shops, and compressor building. The shops
at surface mines tend to be larger than those at underground mines
because of the amount of mobile equipment that is used.
The typical quarry is similar to the surface mine except, in general,
the quarry does not concentrate the material, just sorts it. Some
quarries may have a plant located onsite or nearby; these would
include asphalt plants and concrete plants.
In addition to oils consumed at the mine or quarry, some facilities
use oils as part of the processing that is done on site. Such facilities
include asphalt plants located at a quarry or a copper solvent exchange/
electrowinning (SX/EW) plant that utilizes an oil as the solvent
to remove the copper from the leach solution.
Applicability
of the SPCC Requirements to Mines and Quarries
EPA's SPCC requirements (40 CFR 112.1 through 112.7) apply to nontransportation-related
facilities that could reasonably be expected to discharge oil into
or upon the navigable waters of the United States or adjoining shorelines,
and that have (1) a total underground buried storage capacity of
more than 42,000 gallons; or (2) a total aboveground
oil storage capacity of more than 1,320 gallons,
or (3) an aboveground oil storage capacity of more than 660
gallons in a single container.
Some facilities may not be regulated if, due to their location,
they could not reasonably be expected to discharge oil into navigable
waters of the U.S. or adjoining shorelines. SPCC-regulated facilities
must also comply with other federal, state, or local laws, some
of which may be more stringent.
Many mines and quarries, but not all, have the capacity to trigger
the SPCC regulations. To determine if a facility has the capacity
to trigger the requirements, all oil storage and use capacity must
be considered. This includes tanks, drums, equipment capacity, and
electrical transformers. For example, a surface mine or quarry that
has a 20,000-gallon underground tank, ten 55-gallon drums of various
oils, 15 trucks, loaders, and other equipment, each with an oil
capacity of 40 gallons, a service truck with a 150-gallon tank,
and five transformers with an 8-gallon capacity would trigger the
regulations because the facility would have an aboveground capacity
of 1,340 gallons (550 gallons in drums, 600 gallons in equipment,
150 gallons on the service truck, and 40 gallons in the transformers).
Oil capacity in underground mines would be considered
aboveground if any spill could reach the surface. For example, an
underground mine that has natural drainage (i.e., all flow from
the mine exits by gravity flow from a low opening adit) would be
considered to be aboveground. In a shaft mine, the capacity would
be considered underground oil capacity.
Although many mines and quarries are subject to the SPCC requirements,
they are usually not subject to the FRP requirements due to their
storage capacities. However, all facilities must document this determination
by completing the "Certification
of the Applicability of the Substantial Harm Criteria Checklist,"
provided as Attachment C-II in Appendix C of 40 CFR 112. This certification
should be kept with the facility's SPCC Plan.
SPCC and Specific
Spill Prevention Requirements for Mines and Quarries
The owner or operator of an SPCC-regulated facility
is required to have a written site-specific spill prevention plan,
which details how a facility's operations comply with the requirements
of 40 CFR 112.
Requirements for specific elements to be included in the SPCC Plan
are found in 40 CFR 112.7. The SPCC Plan must be reviewed and certified
by a Registered Professional Engineer who is familiar with SPCC
and has examined the facility. To be in compliance, the facility's
SPCC Plan must satisfy all of the applicable requirements for drainage,
bulk storage tanks, tank car and truck loading and unloading, transfer
operations (intrafacility piping), inspections and records, security,
and training. Most importantly, the facility must fully implement
the SPCC Plan. Newly constructed facilities and facilities that
make modifications must prepare or revise their SPCC Plan within
six months. Modifications may include, for example, changes in piping
arrangements or installation or removal of tanks.
SPCC requires containment of drainage from the operating areas of
a facility to prevent oil spills and contaminated runoff from reaching
storm drains, streams (perennial or intermittent), ditches, rivers,
bays, and other navigable waters.
Secondary containment and diversionary structures should be in place
to control oil-contaminated drainage (e.g., rainwater) or leaks
around tanks, truck loading and unloading areas, diesel-powered
equipment and associated pipelines, valves, and joints. For these
purposes, facilities should use dikes, berms, curbing, culverts,
gutters, trenches, absorbent material, retention ponds, weirs, booms,
and other barriers or equivalent preventive systems. For temporary
units, facilities may deploy temporary booms which encircle the
operations. High density polyethylene liners can be used on soil
surfaces to collect any spills within bermed areas. The secondary
containment structure must be impervious and must prevent water
and fuel from percolating through the soil, contaminating the soil
and groundwater and possibly surfacing aboveground into navigable
waters or adjoining shorelines. SPCC requirements are performance-based,
which permits facility owners and operators to substitute alternative
forms of spill containment if the substitute provides substantially
equivalent protection against discharges to navigable waters to
that provided by the systems listed in 40 CFR 112.7(c).
Substantially equivalent containment systems may be
possible for AST systems (e.g., small double-walled ASTs equipped
with spill prevention devices) that generally have capacities of
less than 12,000 gallons. Alternative containment systems may not
be appropriate for tank systems larger than 12,000 gallons or for
systems that consist of several tanks connected by manifolds or
other piping arrangements that would permit a volume of oil greater
than the capacity of one tank to be spilled as a result of a single
system failure.
Diked Areas
Facilities most often use poured concrete walls or earthen berms
to contain drainage and provide secondary containment for storage
tanks and curbing and catchment basins for truck loading/unloading
areas. These contained areas are considered diked areas. Concrete
and earthen dike containment structures around storage tanks may
accumulate significant amounts of water. Drain lines, which must
be watertight, are usually installed through the dike walls and
are used to drain accumulated stormwater from the diked area. These
lines should be fitted with valves or other positive means of closure
that are normally sealed closed and locked to prevent any oil discharges
from escaping the diked area. These valves must be open-close manual
valves; flapper valves are not acceptable.
These valves must be opened to drain rainwater and resealed following drainage by trained and authorized facility personnel only. Adequate records must be kept of such drainage events (i.e., date, time, personnel names) and made part of the SPCC Plan. The accumulated rainwater must be examined and determined to be free of oil contamination before diked areas are drained. If any oil sheen or accumulation of oil is observed, an alternate method of draining the diked area must be employed. The contaminated water may be diverted to an onsite treatment plant or oil-water separator; however, the adequacy of these systems is determined on a case-by-case basis for each one's adherence to good engineering practices and ability to retain a spill in the event of a system malfunction.
Mines and quarries may employ many different types
and designs of drainage control systems and oil-water separators.
Facilities must implement a system that is consistent with good
engineering practices, based on the size and complexity of their
operations.
One design may consist of a sump located inside a containment area, which may be a blind sump (no drains) or a sump restrained by a normally closed valve. Facilities may remove the floating oil product by manual skimming or using sorbent materials. These materials must be disposed of properly or recovered for reuse. Any oil removed from skimming or the sorbent material must be disposed of as a waste oil. The remaining water in the sump must be inspected before discharging it outside the containment areas. Once sufficiently inspected and found to be free of oil, the water may be discharged by authorized personnel as long as the discharge is supervised and documented.
Another alternative is to pump out diked areas with
a manual pump or vacuum truck. Any oil-contaminated water must be
transported to an appropriate waste-handling facility for disposal
or treated on site.
Other operating areas of a facility that do not have
secondary containment systems specifically designed for those areas
(otherwise referred to as "localized containment") are
considered undiked areas. Drainage must be controlled around truck-to-tank
and mobile equipment filling sites and (unloading), piping and manifold
areas. All undiked areas can be designed to control drainage through
a combination of curbing, trenches, catchment basins, and retention
ponds, as necessary to retain a spill. These structures must be
inspected and examined for integrity and their effectiveness. For
example, if a paved area is improperly graded or if a curb is deteriorating,
contaminated water may escape from the facility. For this reason,
a Professional Engineer must certify the SPCC Plan to ensure that
the drainage system is adequately designed and properly maintained
in accordance with good engineering practices.
Because of the potential of spills from mobile equipment
(e.g., a hydraulic hose breaking and spilling the oil in the system
or a fuel line breaking that empties the fuel tank) at many mines
and quarries, the facility should be designed to minimize the amount
of stormwater that flows through the site. Berms and trenches should
be used to prevent stormwater from entering the mine or quarry.
In addition, techniques that are used to prevent stormwater erosion
can be helpful by removing stormwater from travel ways. The stormwater
from the roads and other travel ways should be directed into a containment
area, such as a retention pond, to capture any spills from mobile
equipment.
Whatever techniques are used, the facility's drainage
systems should be adequately engineered to prevent oil from reaching
navigable waters in the event of equipment failure or human error
at the facility.
Oil Storage: Bulk Storage Tanks, Portable Tanks, Drums, and Oil-Containing Equipment [40 CFR 112.7(e)(2)]
Many types of units are used to store oil products.
Storage containers or tanks may be located aboveground, underground,
partially underground, and inside buildings.
Tank Material
No tank should be used for the storage of oil unless
its construction material is compatible with the material stored
and conditions of storage such as pressure, physical and chemical
properties, and temperatures.
It is recommended that the construction, materials,
installation, and use of tanks conform with relevant portions of
industry standards, such as American
Petroleum Institute (API), National
Fire Protection Association (NFPA), Underwriters
Laboratory (UL), or American
Society of Mechanical Engineers (ASME), which may be required
in the application of good engineering practices or by state or
local regulations.
All storage containers (e.g., tanks, oil-water separators)
must have secondary containment for the entire contents of the largest
single container within the containment area, plus sufficient freeboard
to allow for precipitation. An alternative system could consist
of a complete drainage trench enclosure arranged so that a spill
could terminate and be safely confined in a catchment basin. The
containment structure must be sufficiently impervious to the types
of oil products stored at a facility. Diked areas should be free
of pooled oil; spills should be removed promptly.
The volume of freeboard should be based on regional
rainfall patterns. Facilities in states with large amounts of rainfall
(e.g., Washington, Alaska, and Hawaii, and the Commonwealth of Puerto
Rico) will require secondary containment to accommodate greater
amounts of water.
Precipitation data is available from the National Oceanic and Atmospheric Administration's (NOAA) National Climatic Data Center (NCDC). The NCDC can be reached by telephone at (828) 271-4800 and at http://www.ncdc.noaa.gov/oa/climate/research/monitoring.html on the worldwide web.
The following table describes the most common secondary containment systems.
Secondary Containment Systems | |
Type of System | Description |
Poured Concrete Walls | Poured concrete walls are strong, fairly watertight, and
resistant to petroleum penetration if adequately designed
and maintained according to good engineering practices. Limitations:
|
Containment Curbs | Containment curbs are similar to speed bumps and are often
used where vehicles need to access the containment area. Limitations:
|
Containment Pits/Trenches | Pits or trenches are belowgrade containment structures,
which may be covered with metal grates and lined with concrete.
Limitations:
|
Earthen Berms | Earthen berms containing clay or bentonite mixtures are
commonly used at very large oil storage facilities. Limitations:
|
Concrete Block Walls | Concrete block walls are also commonly used for containment.
Limitations:
|
Tank Integrity - Inspections
and Testing
ASTs should be properly maintained to prevent oil
leaking from bolts, gaskets, rivets, seams, and any other part of
the tank. The older riveted or bolted steel tanks tend to "weep"
oil from rivets and bolts. Personnel should note visible oil leaks
on an inspection form and report them to the person in charge of
spill prevention. Leaks should be repaired immediately. In some
cases, the product in the tank will require removal.
Another area of concern for ASTs is tank bottom deterioration.
Tank bottoms may be subject to extensive corrosion, which may not
be evident during visual inspections. Measures must be taken to
prevent this corrosion based on the type of tank installation and
tank foundation. Corrosion protection can be provided by dielectric
coatings and carefully engineered cathodic protection. Some facilities
have installed double-bottom tanks to reduce the corrosion factor.
Corrosion of a tank's surface may also result in tank
failure. Corrosion that is concentrated in small areas of a tank's
surface or "pitting" creates a high potential for tank
failure. If tanks are rusty, holes may form causing the tank to
leak. Tank supports and foundations should also be inspected for
cracks, crumbling, deterioration, and seepage.
ASTs should be subjected to periodic integrity testing.
Some of the accepted methods for testing are the following:
- X-ray or radiographic analysis measures wall thickness and
detects cracks and crevices in metal.
- Ultrasonic analysis measures shell metal thickness.
- Hydrostatic testing shows leaks caused by pressure.
- Visual inspection detects some cracks, leaks, or holes.
- Magnetic flux eddy current test used in conjunction with
ultrasonic analysis detects pitting.
Internal steam-heating coils are sometimes used in
heavy oil tanks to maintain the oil in a fluid, less viscous state
in cold weather. The deterioration of the steam-heating coils from
internal corrosion can result in product leakage when oil drains
through a corroded coil to discharge into a nearby waterway. To
control leakage through defective internal heating coils, the following
factors should be applied:
- The steam return or exhaust lines from internal heating coils
that discharge into an open water course should be monitored
for contamination or routed to a settling tank, skimmer, or
other separation system to remove oil;
- Consider using external heating coils and insulating the
sides of the tank if necessary. Because of the problems encountered
with internal steam-heating coils, there has been a movement
away from their use to more modern external heat-exchanger systems.
When transferring diesel or other fuel to tanks and
other equipment, great care must be exercised to ensure that an
overfill does not occur. Facilities should ensure that the capacities
of the equipment are accurately accounted for and transfers should
be continuously monitored.
For ASTs, level gauging systems must be selected in accordance with good engineering practices based on the size and complexity of operations at a facility. It is not adequate to only "stick" a tank. A second overfill protection measure should be used as a backup. Some trucks have automatic shutoff systems, which shut off the pump once the meter reaches the volume of product that has been determined to be a safe fill level (e.g., 90% of capacity). The following table provides examples of some acceptable systems.
Level Gauging Systems and Alarms | |
Type of System | Description |
Direct Sight Level Gauges | In the simplest case, the gauge is a small-diameter glass
or plastic tube vertically attached to two openings in the
tank shell. Liquid level in the tank is shown by the level
in the tube. Another common sight level gauge is a float gauge. A float rides on top of the liquid in the tank and moves a marker attached to a cable or chain on the outside of the tank. The marker moves up or down with the product level in the tank. |
Digital Computers or Telepulse | Telepulse is a simple and accurate system for remote supervision of storage tank liquid levels and temperatures. The unit consists of a transmitter and receiver to relay and receive tank temperature and product level readings. Digital computers can be tied in to display data at more than one location. Portable fill alarm systems are also available that can be used while liquid cargoes are transferred from a storage container into a transportation vehicle. Many variations of these systems are in use. |
High Liquid Level Alarms | High liquid level alarms are usually tied into a float gauge or level gauging system. The alarms produce an audible or visual signal when the liquid level in the tank reaches a predetermined height. In older systems, a simple sound is produced by air motion; this is called an audible air vent. |
High Liquid Level Pump Cutoffs | This consists of a fill-level alarm connected to a pump control that automatically shuts down the pump when a preset liquid level is reached. This system eliminates the possibility of human failure and is effective at stopping overfilling of tanks. |
Direct Audible/Code Signal Communication | This system consists of communication between the tank gauger and pumping station and relies on human perception of liquid levels in the tanks and pumping rates to avoid overfilling tanks. Human error could cause a spill if the tank gauger or pumping station misreads an audible or code signal to start or stop pumping. Communication between the gauger and pump station is usually through two-way radio. |
Additional Safety Features | Relief valves and overflow lines are part of safety and level control systems on most petroleum storage tanks. Valves for pressure and vacuum relief will prevent tank damage but may result in a spill or discharge of liquid. Excess liquid may be allowed to flow into another tank through an overflow line. Vacuum vents prevent a tank from collapsing when liquid is pumped out of the tank. |
Underground Storage
Tanks
When compared to ASTs, USTs have some advantages for
storing petroleum products, such as reduced vapor loss, increased
safety, efficient land use and greater security. The obvious disadvantages
are undetected leaks and higher corrosion factors for metal tanks.
Fiberglass-reinforced plastic tanks are commonly used for storing
petroleum products underground. They have a distinct advantage over
metal tanks in being corrosion-free. Corrosion-resistant coatings
are also available.
Steel USTs should be protected from corrosion by coatings,
cathodic protection, or other effective methods compatible with
local soil conditions. Underground corrosion of metal surfaces is
a direct result of an electric current that is generated by the
reaction between the metal surfaces and chemicals present in the
soil and water. The flow of current from one portion of the tank
to another causes metal ions to leave the surface of the metal,
creating pits. The rate of destruction of the metal is directly
related to soil moisture and chemical makeup.
All USTs should also be subjected to regular pressure
testing and adequate records must be kept of such tests. These records
must be made part of the SPCC Plan and kept for at least three years.
The Federal UST regulations found in 40 CFR Part 280
have technical requirements consistent with the underlying regulatory
purposes of the SPCC program and are equally protective for purposes
of preventing discharges of oil into waters of the United States.
These regulations contain provisions for corrosion protection, leak
detection, tank overfill and spill prevention equipment, and tank
tightness testing. Facilities should refer to the full text of 40
CFR Part 280 when making determinations of compliance.
Partially Buried Storage
Tanks
Partially buried metallic storage tanks used for petroleum
storage should be avoided unless the buried section of the shell
is adequately coated. Partial burial in damp earth can cause rapid
corrosion of metallic surfaces due to water collecting at the soil
surface. Protective corrosion-resistant coatings and cathodic protection
should be used to prevent corrosion. Partially buried tanks are
considered to be aboveground tanks and are subject to the same requirements
as other aboveground tanks under the provisions of 40 CFR Part 112
due to their potential threat to surface waters.
Portable Oil Storage
Containers
Mobile
or portable oil storage tanks (including trucks containing product),
55-gallon drums, and other small containers should be positioned
or located so as to prevent spilled oil from reaching navigable
waters. A secondary means of containment, such as dikes, basins,
or spill pallets, must be provided. The containment area must hold
the contents of the largest container stored in the area. Many facilities
keep drums and portable oil tanks inside covered, contained warehouse
storage areas. It is best to have a covered area to reduce exposure
to the elements so that the containers remain in good condition
and runoff is eliminated. These storage areas must be located where
they will not be subject to periodic flooding or washout.
Containment for drums and other small containers does
not have to be expensive. If there are a small number of drums,
a facility may purchase spill pallets or portable containment devices
(e.g., overpack drums) designed for drum containment. Other inexpensive
alternatives, such as plastic troughs, are available at feed stores
for larger containers.
At mines and quarries, portable oil storage tanks
and drums are commonly used to transport oils to the job site, including
into an underground mine or the location of equipment at a surface
mine or quarry. This would include tanks that are designed to be
handled by forklift, fuel trucks, and the transport of drums. These
units should be designed to prevent spills by such means as protecting
valves and fittings from accidental damage or methods to prevent
the forks of a forklift from rupturing the tank or drum. For example,
a fuel truck should not have any fittings or valves located so that
they could be accidentally damaged if the side of the truck should
strike against something.
Transfer operations consist of piping, valves, gauges,
regulators, compressors, pumps and other mechanical devices used
to transfer oil from one area to another within a facility. Piping
which is used for the transport of oil exclusively within the confines
of a mine or quarry is regulated under the SPCC program. Some of
the more common mechanical transfer systems are the piping systems
required to bring a tank into service. Another common piping system
at mines and quarries transfers fuel, usually diesel fuel, to an
underground (in the mine) storage tank. Flexible hoses are commonly
used for transferring oil products from ASTs to equipment, such
as pumps, compressors and generators. Piping is also used at mines
and quarries to transfer heating oil.
SPCC requires that the terminal connection at the
transfer point be capped or blank-flanged and marked as to origin
for a pipeline that is not in service or in standby service for
an extended time. Aboveground pipe supports should be designed and
spaced in order to prevent sagging, minimize abrasion and corrosion,
and allow for expansion and contraction.
Buried piping must have a protective wrapping and
coating, and should be cathodically protected if used in corrosive
soil conditions. If any section of buried piping is exposed for
any reason, it must be examined for deterioration and corrosion
and repaired, if necessary. Obviously, buried piping cannot be visually
examined and must be subjected to periodic pressure testing, regardless
of materials of construction. Plastic or fiberglass-reinforced pipes
do not require protective coatings or cathodic protection.
All aboveground pipes and valves should be regularly
examined on a scheduled basis by operating personnel. Flange joints,
expansion joints, valve glands and bodies, and metal surfaces should
be evaluated. Piping in high spill probability areas should be periodically
subjected to pressure testing. Pipes, valves, and connecting joints
should be free of leaks, drips, and oil-saturated soil underneath.
Defective or leaking equipment should be replaced or repaired, and
adequate records should be made of such repairs. All records should
be made part of the SPCC Plan and kept for at least three years.
Pumps, valves, and gauges are covered under the same
regulations as piping. They must be regularly examined by facility
personnel. They should be free of leaks, drips, or any defects which
could lead to a spill. Soil underneath pumps, valves, and connections
should be free of oil stains or pooled oil. Flow valves must be
periodically packed with grease to prevent leakage, and gaskets
must be replaced periodically. Pumps require periodic rebuilding
and connecting lines need to be resealed to prevent leaks.
Drivers granted entry into a facility must be verbally
cautioned or warned by appropriate signs to assure that their vehicle,
because of its size, will not endanger aboveground piping or hosing.
Tank truck loading/ unloading areas should have appropriate protection
for aboveground pipes (e.g., bumper poles) and adequate signs posted
to warn drivers of the presence of aboveground pipes in traffic
areas.
Product loading and unloading operations include the receipt of product from tank trucks or smaller carriers and fueling activities for stationary and mobile field equipment.
Regardless of the types of trucks servicing a facility,
all drivers must follow loading/ unloading procedures established
by the Department of Transportation (DOT) in 49 CFR Parts 171, 173,
174, 177, and 179. Training programs should thoroughly address these
requirements and procedures should be incorporated into a Standard
Operating Procedures (SOP) manual for product transfer. Moreover,
facilities should consider ways to ensure that other commercial
drivers or contractors are competent in these procedures (e.g.,
issue driver certifications).
Secondary Containment
Due to their function, truck loading/ unloading areas
have a high probability for spills. Secondary containment systems
must be designed specifically for a facility's topography configuration,
and the size of the tank car/truck loading or unloading at the site.
Loading/unloading areas typically are designed to
permit vehicle access and incorporate a secondary containment system.
The most common loading area containment system is a covered, curbed,
and graded area that drains to a sump. Alternatively, loading/unloading
areas can drain to retention ponds or catchment basins designed
to retain oil or return it to the facility. A system that incorporates
good engineering practices minimizes the volume of water, ice and
snow that enters the containment area.
The containment system must be designed to hold the
maximum capacity of the largest compartment of a tank car or truck
loaded or unloaded at the facility. If there are separate areas
for different unloading or loading operations, each area should
be designed specifically to hold the capacity of the largest carrier
anticipated to conduct operations in that area. An engineer must
look at the entire facility as a unit to determine the adequacy
of the spill containment systems in place.
Warning or Barrier
System
An interlocked warning light or physical barrier system
(such as a brake-interlock system), or warning signs should be provided
in loading/unloading areas to prevent a bottom-loading vehicle from
leaving before being completely disconnected from the fuel transfer
lines.
Prior to filling and departure of a tank car or truck,
the lowermost drain and all outlets of such vehicles should be closely
examined for leakage. If necessary, valves should be tightened,
adjusted, or replaced to prevent leaking in transit.
Inspections help prevent spills due to equipment or
containment system failure. Adequate inspection and maintenance
programs are a critical component of a spill prevention program.
Inspection and maintenance records provide the only real evidence
of compliance testing of storage tanks, piping, level gauging systems,
alarms and related equipment.
Records of inspection procedures (including frequencies
of inspections), maintenance, and draining of diked areas should
be included in the facility's SPCC Plan.
Records of drainage of diked areas are important in
determining a facility's compliance, especially when drainage flows
directly into a navigable waterway and bypasses in-plant treatment
systems.
The following table includes the types of records that should be maintained at a facility. Such records must be kept for a minimum of three years.
Inspection and Maintenance Program Records | |
Aboveground Storage Tanks and Piping | Regular visual inspections and/or tank integrity
testing (e.g., shell thickness testing). Pipe supports, pipes, valves and pumps (regular visual inspections). Piping in high risk spill areas (periodic pressure testing). Storage tank flow valves, supports, foundations (regular visual inspections). Storage tank level gauges and alarms (regular mechanical function testing/visual inspections). |
Underground Storage Tanks and Piping | Pressure testing of tanks and piping.
Inventory monitoring for leaks. Testing of cathodic protection system. |
Dikes, Berms, Secondary Containment Systems | Containment dikes and berm integrity (regular visual inspections).
Records of drainage of rainwater from diked containment areas (must be recorded whenever areas are drained). Rainwater must be free of oil sheen. Date, time, and signature of employee who performed drainage and/or manager. |
Security is critical to preventing accidental releases or vandalism by the public. The security measures required under SPCC are simple precautions that greatly reduce the risks of vandalism and undetected spills.
The perimeter of a facility should be protected with
good lighting, fencing, and locked gates. Motion detectors and video
cameras may be used for added security. Access to the facility should
be restricted during nonbusiness hours. Starter controls for fuel
pumps should be locked. Any valves that will allow the direct outflow
of product are also required to be locked (e.g., water draw-off,
sampling, and sparge valves). It is recommended that tanks and pipelines
be labeled and kept out of public access areas. Loading/ unloading
connections and pipelines should be capped or blank-flanged when
they are not in service.
A large number of spills are caused by operator error;
therefore, training and briefings are important for the safe and
proper functioning of a facility. Training encourages up-to-date
planning for the control and response to a spill and an understanding
of the facility's spill prevention controls and SPCC Plan. Regular
safety and spill prevention briefings should be held to facilitate
discussions of spill events or failures, malfunctioning equipment,
and recently developed precautionary measures. Also, one person
must be designated accountable for spill prevention at the facility.
Owners and operators are responsible for properly instructing drivers, tank gaugers, pumpers, and any other operating personnel involved in oil operation systems in the operation and maintenance of equipment to prevent the discharge of oil and applicable pollution control laws, rules and regulations. All employees should be familiar with the SPCC Plan and where it is kept, or have a copy of the Plan available for their use.
Records of employee training and spill prevention
briefings for personnel should be included in the SPCC Plan and
kept for a minimum of three years.
Facilities should consider current operations and how they can be
improved to prevent spills and meet the regulatory requirements
by conforming with good engineering practices. This section discusses
problem areas and best management practices (BMPs). The BMPs may
be supplemental to the regulatory requirements. Others may be essential
to achieving compliance with the SPCC requirements or state regulations.
Facility Drainage Control
Mines and quarries often are large sites covering many acres and,
in some cases, many square miles. Drainage controls, such as berms
and ditches, are used to divert stormwater from entering the mine.
This is done for many reasons, including prevention of stormwater
from becoming contaminated from the site. One other reason is that
stormwater that reaches the mine or quarry then must be handled
(i.e., pumped and treated) increasing the cost of the operation
and possibly impacting production. As a result, mines and quarries
should have a good system of diversionary structures in place to
prevent stormwater from entering the mine site.
Some surface mines and quarries use the mine or quarry as a large
sink or pit for the containment of drainage including spills. This
practice requires a case-by-case analysis and may not be acceptable
for diverting spills. In any case, facilities would need to remove
any contamination or spills which enter the pit. Other methods of
diversion would probably be less costly.
Trenches and sumps at mines and quarries may become clogged with
debris. Facilities must conduct regular inspections of drainage
systems to ensure that they will function properly.
Fixed And Mobile Storage
Tanks and Drum Storage Areas
Fixed storage and drum storage areas generally have secondary containment
constructed of concrete, pavement, or compacted earth to contain
spills. In addition, these areas may be directed to a sump or containment
area. Drip pans are often used with drums to contain spills when
filling containers such as in a shop.
Mobile storage tanks should be designed to minimize spillage during
movement. This is done by protecting valves and fittings from accidental
breakage during movement, such as welding short pieces of pipe around
the fitting. In addition, to the extent possible, fuel trucks should
be equipped with safety devices to prevent accidental spillage.
For example, if the fuel truck uses an electric pump driven off
the engine, a safety switch should be in place to prevent pumping
when the truck is in gear.
Tanks in flood-prone areas should be designed so that the lowest
floor is elevated to or above the base flood level or be designed
so that the structure below the base level is watertight with walls
substantially impermeable to the passage of water, with structural
components having the capability to resist effects of buoyancy.
Piping and Hosing
In general, there are two types of piping and hoses
utilized at mines and quarries, those that transfer oils from one
place to another, such as from an AST (a tank located on the surface)
to an underground tank (a tank located in the underground mine)
and those pipes and hoses that supply oils from a tank to a point
of consumption, such as a line from a tank to a compressor. These
pipes and hoses should be installed in a manner to contain any leakage
including a rupture of the line. This can be accomplished through
the use of ditches and berms in the area of the pipelines and hose
to collect any spills or leakage. Another technique would be to
use double-lined piping.
Piping and hose installations should be designed to prevent the
damage caused by insufficient support for the weight of the piping
or hose and the fluid that they contain. This design should also
consider any vibrations, such as from air hammers, that may occur
during operations.
Loading/Unloading Rack(s)
and Fueling Islands
Truck loading and unloading areas and fueling areas must be protected
from accidental damage. This could include such items as barriers
to prevent equipment from damaging transfer and storage facilities.
However, at many mines and quarries, the equipment involved is large
and the normal barriers may not be effective. For example, in many
cases a four- to six-inch steel pipe is filled with concrete to
protect fueling areas, but this would not even hinder a 50-ton piece
of equipment. Because of this, the design of the truck loading/unloading
area and fueling areas must consider the equipment that will be
used at the mine or quarry.
It is frequently recommended that the truck loading/unloading and
fueling areas be paved to minimize the potential for spills to enter
soils; however, at some mine sites, this may not be practicable
because of the equipment that will be used at the site. Heavy equipment
will damage the pavement.
Inspections, Records
and Preventive Maintenance
Maintenance of oil storage and transfer facilities should be conducted
as part of the normal preventive maintenance of the mine or quarry.
This would include the operator of a piece of equipment conducting,
as part of the "walk around" inspection, a check of all
hoses, fittings and other possible sources of leaks. Other preventive
maintenance measures include regular visual inspections of all oil
storage and transfer areas as part of regular inspections.
Regular scheduled inspections must be conducted to meet the requirements.
This should include visual inspections and a product storage inventory
reconciliation to identify possible leaks.
Records of the these inspections can include other reports that
many mines and quarries currently perform to meet other regulatory
requirements, including the daily walk around inspection conducted
by the operator, shift reports, and maintenance records.
Site Security
Site security is important at mines and quarries. The security is
necessary for the protection of the public from the many hazards
that exist. These hazards vary by the type of mine but include for
underground mines the danger of someone falling down the shaft.
For surface mines and quarries the hazards include blasting, movement
of heavy equipment, and potential unstable rock walls. Fueling areas
at many facilities are often located near the guard station and
are therefore visible to that location.
As a means of security, the controls to pumps are often in locked
buildings. Another method of security is for the guard to control
the switches for the tanks.
Drum storage should be inside fenced areas to control the access
to the drums.
Spill Response Planning
At the majority of mines and quarries, leaks and spills occur in
areas that are unpaved; therefore spill response consists of utilizing
the mining equipment to respond to and control a spill. The equipment
that could be utilized at surface mines and quarries would include
loaders, dozers, trucks, and backhoes. In addition, most mines and
quarries, because of the activities that occur (i.e., handling flammables,
explosives, and chemicals), have fire extinguishers and other fire
control equipment strategically placed in operating areas.
There are a variety of ways for a facility to be designed
and constructed to achieve compliance with SPCC requirements. Mines
and quarries may differ greatly in the types of diversionary structures
and spill control equipment employed. Because many surface mines
and quarries are quite large and constantly changing, the diversionary
structures and spill control must be constantly updated as drainage
and other conditions change.
Facilities should also consult industry associations, which specifically
identify technical and engineering standards for the design and
construction of tanks and pipelines; cathodic protection of tanks
and pipelines; AST tank bottom liners; tank inspection, repair,
alteration, and reconstruction; tank cleaning; and tank overfill
protection. These standards may assist the facility in identifying
good engineering practices and achieving compliance with the SPCC
requirements.
Summary of Common Industry Standards | |
Underwriters
Laboratory (UL) Standard 142
Steel Aboveground Tanks for Flammable and Combustible Liquids |
This standard applies to steel atmospheric tanks intended for aboveground storage of noncorrosive, stable, flammable, and combustible liquids that have a specific gravity not exceeding that of water. The standard does not apply to API Standard 650, 12D, and 12F tanks. |
National
Fire Protection Association (NFPA) Code 30A
Automotive and Marine Service Station Code, Chapters 1 and 2 |
This standard applies to automotive and marine service stations and to service stations located inside buildings (special enclosures). The code does not apply to service stations that dispense liquefied petroleum gas, liquefied natural gas, or compressed natural gas as motor fuels. |
National Fire Protection Association (NFPA)
Code 30
Flammable and Combustible Liquids Code, Chapter Two |
This standard applies to all flammable and combustible liquids, including waste liquids (except those that are solid at 100 degrees Fahrenheit or above and those that are liquefied gases or cryogenic). Chapter Two, Tank Storage, applies to aboveground and indoor storage of liquids in fixed tanks and portable tanks with storage capacities of more than 660 gallons. |
American
Petroleum Institute (API) Standard 620
Design and Construction of Large, Welded, Low-Pressure Storage Tanks |
This standard addresses large field-assembled storage tanks that have a single vertical axis of revolution and contain petroleum intermediates and finished products, as well as other liquid products handled and stored by the petroleum industry. |
API Standard 650
Welded Steel Tanks for Oil Storage |
This standard provides material, design, fabrication, erection, and testing requirements for vertical, cylindrical, aboveground, closed- and open-top, welded steel storage tanks in various sizes and capacities. |
API Recommended Practice 651
Cathodic Protection of ASTs |
This recommended practice describes the corrosion problems characteristic in steel ASTs and associated piping systems and provides a general description of the two methods used to provide cathodic protection. |
API Recommended Practice 652
Lining AST Tank Bottoms |
This recommended practice describes the procedures for achieving effective corrosion control in ASTs by application of tank bottom linings to existing and new storage tanks. |
API Standard 653
Tank Inspection, Repair, Alteration, and Reconstruction |
This standard pertains to carbon and low alloy steel tanks built in conformance with API Standard 650 or 12C and provides criteria for the maintenance, inspection, repair, alteration, relocation and reconstruction of welded or riveted, nonrefrigerated, atmospheric pressure ASTs after they have been placed in service. |
API Recommended Practice 920
Prevention of Brittle Fracture |
This recommended practice addresses toughness levels for pressure vessels to prevent failure by brittle fracture. |
API Standard 2015
Safe Entry and Cleaning of Tank |
This standard provides guidelines for the development of safety practices for planning, managing, and conducting work in atmospheric and low pressure storage tanks. |
API Recommended Practice 2350
Overfill Protection for Petroleum Tanks |
This recommended practice provides guidelines for establishing operating procedures and for selecting equipment to assist in the reduction of overfills. |
API Standard 2610
Design, Construction, Operation and Maintenance and Inspection of Terminal and Tank Facilities |
This standard compiles various standards, specifications, and recommended practices developed by API and other entities for managing terminals and tanks. |
References
SME Mining Engineering Handbook, 1973. Arthur
B. Cummins and Ivan A. Given, Editors, Society of Mining Engineers,
New York.
Mining Engineering, Journals of SME (Society of Mining,
Metallurgy and Exploration), Littleton, CO.
Communication with Frank Malry, Nevada Department of Environmental
Protection (NDEP), Bureau of Mining Regulation and Reclamation.
August 1997.