Special Spill Containment Requirements Dry Cleaning Facilities For New Facilities Starting Operations After November 2004
Special Considerations For Drycleaning Plants Using Petroleum-Based Solvents
Spill Prevention Plans
If you have any solvent tanks that are larger than 660 gallons, or ever have more than 1320 gallons of petroleum-based solvent on the premises, your plant is subject to the Federal Spills Prevention, Control and Countermeasures (SPCC) requirements. The SPCC requirements also apply if your plant has the capacity to ever have more than 1320 gallons of solvent and any other petroleum compound, including any waste that is contaminated with any petroleum compound. There may be severe penalties for not complying with the SPCC program.
The SPCC requirements are considerably more complex in their containment requirements and call for the submittal of an approved plan by a certified engineer.
Containment for Petroleum Solvent Filter Wastes Petroleum drycleaners may air-dry their spent drycleaning filters. Once the filters are completely dry, they may be disposed of as regular trash disposal. While they are drying, the spent filters must be placed inside a pan or bucket. In turn, these containers will need to be placed inside of a containment area in case the pan or bucket is turned over before all of the solvent has evaporated.
Containment around machines and auxiliary equipment for new facilities.
The law requires that new facilities must use a metal pan or other rigid vessel around the drycleaning machine and auxiliary equipment. This vessel must be constructed of a nonreactive, impermeable material. Retrofitting with berms or dikes is not allowed around the drycleaning machines and auxiliary equipment.
(Note: Berms and dikes are permissible for the storage areas around extra solvents and wastes at new facilities.)
The containment vessel must hold at least one-third of the Total Tank Capacity of the machine or piece of equipment (Example A). In addition, the vessel must be able to hold all of the volume of the largest single tank in the machine or piece of equipment, if this volume is larger than one-third of the Total Tank Capacity (Example B).
Depending on the solvent pipe connections in the facility, the containment vessel may need to be much larger. If there are no safeguards to prevent a solvent storage tank from emptying into the machine, the vessel must also be able to hold all of the volume of the tank (Example C).
New Facilities must also meet all containment requirements for storage areas
Examples of Containment at New Facilities:
Example A: A new facility has one drycleaning machine with a Total Tank Capacity of 120 gallons of solvent, including all of the solvent in the various interconnected apparatus. A schematic drawing of the machine shows it is composed of various filters, stills and small solvent tanks, none of which contain more than 30 gallons of solvent. The containment vessel must be capable of containing one-third of the Total Tank Capacity (i.e. 40 gallons).
Example B: A new facility has one drycleaning machine that holds 75 gallons of solvent. Most of the solvent, 60 gallons, is retained in one large tank at the bottom of the machine while the rest is distributed throughout various pipes, filters and separators built into the machine. Since the largest tank (60 gallons) is larger than one-third of the Total Tank Capacity (25 gallons), the containment vessel must be designed to hold at least 60 gallons of solvent.
Example C: A drycleaning machine at a new facility holds 50 gallons of solvent inside of its various filters, piping and internal storage tanks. The machine is connected via pipes to a 300-gallon above ground storage tank located outside the plant. Solvent in the storage tank flows by gravity into the machine when a manual shut-off valve is turned on. Since there is nothing to prevent the valve from remaining open, the Total Tank Capacity of the machine is 350 gallons, including the capacity of the storage tank (50 gallons of the machine plus the 300 gallons of the storage tank). The containment vessel around the machine would have to have the capacity to hold 100% of the largest tank connected to the machine, i.e., 300 gallons.
Calculating Volumes
Determining Containment Vessel Capacities.
Containment Structures are required by law to hold specific volumes of spilled solvent or waste. In order to determine whether the structure complies with the requirements, the capacity of the structure must be determined. The required capacity of the containment structure depends on where the structure is used. These requirements are summarized below.
Summary of Required Containment Capacities |
Containment Area | Required Containment Structure Capacity | Refer to: |
Machine/ Auxiliary Equip. Existing Facilities | 1/3 of Total Tank Capacity* = | Total Tank Capacity |
Machine/ Auxiliary Equip. New Facilities | 1/3 of Total Tank Capacity* OR 100% of largest tank. | New Facilities |
Solvent or Waste Storage areas | 100% of largest container ever stored | Storage Containers |
*The Total Tank Capacity includes all solvent in any other piece of equipment or storage tank that can flow into the machine in the event of a leak |
The capacity of most structures can be estimated from measurements of the dimensions of the containment structure. Because some of the available space inside the structure may be occupied by pieces of equipment or containers, the calculations should take into account how much capacity is lost to the equipment and containers stored within the structure. These calculations are generally easier for rectangular or other regularly shaped containment structures.
For odd-shaped structures, the easiest way to estimate the capacity may be to fill the structure with a measured quantity of water. Care should be exercised to ensure that the water does not become contaminated with solvent or it may require handling as a hazardous waste.
Basic Volume Calculations
The exact containment capacity does not have to be accurately determined as long as the capacity is greater than what is required by the law. Considerably more effort is required to determine the volume for containment structures that are “just barely big enough". For these structures, it may be necessary to calculate the volume of solvent that would be retained in the piece of equipment in the event of a spill. The volume of most containment structures can be calculated using a few basic geometric formulas.
For rectangular structures and pieces of equipment, the basic formula for determining the volume is:
VOLUME* = LENGTH x WIDTH x DEPTH x 7.5 gallons/ cubic foot
(in gallons) (all dimensions measured in feet).
For drums, or other cylindrical containers, the basic formula uses the RADIUS of the cylinder. (The radius is half of the distance across the top of the drum). The Formula for converting the measurements of cylinders (in inches) to gallons is:
VOLUME* = RADIUS x RADIUS x HEIGHT x 0.014
(in gallons) (all measurements in inches)
*VOLUME refers to either the Overall Capacity of the containment pan or the Volume displaced by the piece of equipment or container.
Calculating Volume - General Rules:
• | All measurements should be made on the inside of the containment structure. |
• | The “Depth" of the structure is measured to the lowest point along the structure's wall where spilled solvent could overflow or pass through the wall (if not sealed). |
• | The overall capacity of the containment structure is reduced by the volume of the equipment or containers stored inside the structure. |
• | Only the portion of the equipment or container that is inside the containment structure actually displaces any of the volume (i.e., the “depth" of the containment structure is also the “depth" of the equipment). |
Example 1: The base of a drycleaning machine is 8 feet by 6 feet. The machine has a Total Tank Capacity of 75 gallons of solvent, so the containment structure must be capable of holding at least 25 gallons (i.e., 1/3 of 75). The machine is inside a metal containment pan that is 10½ feet long, 8 feet wide and 4 inches deep (i.e., 0.33 feet deep).
The overall capacity of the pan is: 10.5' x 8' x 0.33' x 7.5 = 208 gallons
The volume of the machine inside the pan is: 8' x 6' x 0.33' x 7.5 = 119 gallons.
The capacity of the pan, after accounting for the volume lost to the machine, is 208 gallons — 119 gallons = 89 gallons (exceeding the requirements for this machine.)
Adjusting For Solvent Retained in the Equipment
In Example 1, the capacity of the pan is much larger than the volume that is required for the machine. However, in many drycleaning plants, there is insufficient space to install such large containment structures. Occasionally, pans are constructed to be just slightly larger than the machine, and it may be necessary to consider whether some of the solvent would be retained in the equipment in the event of a spill. If this is the case, the calculated capacity of the containment structure can be adjusted to include the volume that would be retained in the equipment.
Example 2: The base of a drycleaning machine is 8 feet by 6 feet. The machine has a Total Tank Capacity of 75 gallons of solvent. The containment structure must be capable of holding at least 25 gallons (i.e., 1/3 of 75). The machine is inside a metal containment pan that is 8½ feet long, 7 feet wide and 3 inches deep (i.e., 0.25 feet).
The overall capacity of the pan is: 8.5' x 7' x 0.25' x 7.5 = 112 gallons.
The volume of the machine inside the pan is: 8' x 6' x 0.25' x 7.5 = 90 gallons
The capacity of the pan, after accounting for the volume lost to the machine, is: 112 gallons — 90 gallons = 22 gallons (Less than required)
Examination of the machine shows that the solvent is stored in a built-in tank at the bottom of the machine, which occupies approximately half of the machine's base (i.e., approximately 8 feet by 3 feet). If a hole were to develop in the solvent tank, any solvent below the level of the containment structure's wall would remain in the bottom of the tank. The volume of the bottom tank in the containment structure can be added back to the overall capacity as this is solvent that would not leak out of the structure.
The volume of solvent that would remain in the bottom tank in the event of a spill is: 8' x 3' x 0.25' = 4 ½ gallons.
Therefore, the actual capacity of the pan is: 22 gallons + 4 ½ gallons = 26 ½ gallons. (Barely meeting the requirement for this machine.)