Installing Secondary Containment

Description

All containers used to store waste oils and other such potentially harmful liquids should have a form of secondary containment. The primary purpose being to provide additional storage capacity for any materials which may leak due to the failure, overfilling or improper draining of the primary storage container. Generally speaking, secondary containment should equal 110 percent of the capacity of the primary container and is usually provided by placing a non-leaching berm with an impervious bottom under or around the primary container. For more information, please visit The Environmental Guide for Marinas.

Implementation

In providing secondary containment to the liquid storage facilities at the participating marinas the decision was made to purchase commercially available products rather then constructing such facilities in-house. In all instances the product purchased was the Oil Dri Corporation of America's two drum spill pallet (product # 90525). Constructed to provide secondary containment for any two standard 55 gallon drums, these units can be easily transported in case of emergency and have been outfitted with spickets so that they may be drained of their contents when necessary. For your local Oil Dri Distributor call 1-800 Oil Drip.

Implementation of the secondary containment units was accomplished by first placing them in their designated storage locations. The primary containers (55 gallon drums) were then placed on top of the pallets and opened for use. No specific educational activities were undertaken. This BMP was evaluated by checking the amount of liquids that had collected in the bottom of the secondary containment units at the end of the boating season.

Evaluation

Cost: $241.00 each with minimal time for installation.

Pollutants Collected: One quart of liquid wastes was collected by one of the units. In this instance the leak was due to an improper filling of the primary storage container. If not for the presence of secondary containment this leaked material would have been released directly into the ground.

Cost Effectiveness: These two drum spill pallets represent a very cost effective means for providing secondary containment. In terms of pollutants collected, although only one quart of liquid wastes were captured this season, we are confident that these units would be capable of containing a complete failure of the primary storage containers placed upon them. In terms of economics, it is felt that the initial purchase cost for these high quality units is either equal too or less than the cost to produce a similar product in house. It is also important to recognize several benefits inherent in the spill pallets design. These being that they are very durable, easily transported and equipped for draining.

Lessons Learned/Recommendations

• Proper secondary containment facilities are effective in controlling both small leaks or spills and larger failures of primary storage containers.
• Secondary containment facilities should be regularly drained of any collected material so that their capacity at any point in time is equal to 110 percent of the primary storage containers.
• When standard 55 gallon drums are used as the primary storage containers, it may be cheaper to purchase commercially available containment units rather than trying to construct such facilities in-house.
• If larger storage containers (such as home heating fuel tanks) are used to store liquid wastes it may become more difficult to provide secondary containment. In these instances consider removing the larger tanks and replacing them with a series of standard 55 gallon drums and spill pallets.
• As another alternative to replacing large tanks, consider the construction of a central collection site. A particular method worth noting is the use of septic tanks cut in half and enclosed. This approach can provide secondary containment for large quantities of liquid wastes. Remember that in many states any storage facility which has the capacity to hold more than 500 gallons of petroleum products must be permitted (check with your department of environmental management).
• When constructing such facilities in house be sure to consider such design elements as overall capacity in comparison to the capacity of the primary containers, their permeability and their ability to be transported and drained.
• Spill pallets capable of holding four 55 drums are commercially available. With the capacity for four drums, these pallets can either be used for different types of liquid wastes (i.e. one drum for oil, one for antifreeze, one for solvents etc.) or to replace a larger container used for a single waste product.

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