Oil-filled operational equipment is covered by the SPCC rule. Oil-filled operational equipment includes equipment with an oil storage container (or multiple containers) in which the oil is present solely to support the function of the apparatus or the device. Examples of oil-filled operational equipment include, but are not limited to, hydraulic systems, lubricating systems (e.g., those for pumps, compressors and other rotating equipment, including pumpjack lubrication systems), gear boxes, machining coolant systems, heat transfer systems, transformers, circuit breakers, electrical switches, wind turbines, and other systems containing oil solely to enable the operation of the device.

The SPCC rule applies only to facilities that, due to their location, can reasonably be expected to discharge oil as described in §112.1(b). The rule does not define the term “reasonably be expected.” The owner or operator of each facility must determine the potential for a discharge from his/her facility. According to §112.1(d)(1)(i), this determination must be based solely upon consideration of the geographical and locational aspects of the facility. An owner or operator should consider the location of the facility in relation to a stream, ditch, gully, or storm sewer; the volume of material likely to be spilled; drainage patterns; and soil conditions.

COMPLIANCE

Properly designed, maintained, and operated oil water separators (OWS) may be used as part of a facility drainage system to meet the secondary containment requirements of the rule in §§112.7(c), 112.7(h)(1), 112.8(c)(2), 112.8(c)(11), 112.12(c)(2), and/or 112.12(c)(11). Additionally, §§112.8(b), 112.9(b), and 112.12(b) set forth design specifications for drainage associated with secondary containment provisions at a facility. Standard gravity and enhanced gravity separators, or other types of OWS, may be used to meet secondary containment requirements. In this application, the separators are expected to have oil and water present in the system when there is an oil discharge or oil-contaminated precipitation runoff within the drainage area.

When OWS is used to meet SPCC requirements, it must be properly operated and maintained to ensure it will perform correctly and as intended under the potential discharge scenarios it is aimed to address. The separator must be constructed to contain oil and prevent an escape of oil from the system prior to cleanup to comply with the secondary containment provision for which it is intended (§112.7(c)).

OWS SIZING

To comply with the general secondary containment requirements of §112.7(c) OWS sizing must address the most likely discharge from any part of the facility and should consider:

• The drainage area that flows to the separator;
• The corresponding anticipated flow rate of the drainage system to the separator; and
• The appropriate capacity of the OWS for oil and for wastewater.

Example: Substation A has one transformer with 187 gallons of mineral oil capacity, one transformer with 420 gallons of mineral oil capacity, and four transformers with 53 gallons of mineral oil capacity each. The area is not diked, as standing water at a facility where high voltage is present is a potential safety hazard. The peak rainfall intensity of 0.6 inch per hour (i) has been determined reasonable design criterion for the area. The drainage area is 8,000 sq. ft.(A) with 100% imperviousness with a run off coefficient of 0.88 (C).