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.

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:

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:

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.

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.

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.

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.