Drip Pads

At wood preserving plants, chemicals are used to treat wood so that it will not deteriorate in the outdoor environment. Chemical preservative solutions are applied to the wood using a pressure treating process. The preservative solution is then allowed to drip from the wood. Special engineered structures, called "drip pads," are required to gather the drippage from the treatment process. The drippage (along with rainwater) is collected in a tank or other container and treated as hazardous waste until it is recycled, treated, or disposed of.

Drip pads must meet several requirements, including the following:

• Be constructed of non-earthen material.
• Be sloped to drain chemical drippage and precipitation run-off to a collection system.
• Have a curb or berm around its perimeter.
• Meet specific criteria relating to the flow of liquids.
• Be strong and thick enough to prevent failure under climate and operating conditions.
• Be designed to control the tracking of hazardous materials by human and equipment traffic.

It must also be possible to clean the drip pad, so that it can be closely inspected on a weekly basis. Each cleaning and the procedure used must be recorded in the facility's operating record. When the facility is permanently closed, the owner or operator is responsible for removing or decontaminating all waste residues, contaminated system components, and any soil, structures, or equipment that have been contaminated. All of these must be managed as hazardous wastes.

To learn more about RCRA visit our RCRA Hazardous Waste Safety Online Training web page.