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Hazardous Materials Traps Transport Spill Containment for Stormwater Pollution Prevention along Texas Highwaysby John A. Marler, P.E., Dr. Michael E. Barrett, P.E., and Dr. Joseph Malina, P.E., D.E.E ABSTRACT Every day thousands of shipments of hazardous materials cross the State of Texas. When an accidental release of hazardous materials occurs, the goal of all agencies involved is a rapid response to contain the release in order to protect the health, safety and welfare of the public and to protect the environment. Hazardous materials traps are one tool that may be utilized to control these releases. No regulatory requirement for the installation of these devices along roadways exists. However, the use of hazardous materials traps makes sense in certain areas where an accidental release could be deemed catastrophic. The location of hazardous materials traps along Texas highways will be determined by the sensitivity of the watershed and the probability of an accidental release of hazardous materials. Certain areas in the State, like the Edwards Aquifer contributing zone, that represent delicate ecosystems or that are sources of drinking water are logical locations for the added protection of hazardous materials traps on stormwater collection systems. The prescribed routes listed in the National Hazardous Material Route Registry provide another guide to locating hazardous material traps. Statistical data on reported accidental releases from around the country indicate that the types of materials that are most commonly spilled fall into two main categories: corrosive materials and flammable liquids. Traditional oil/water separators that have been used for years in collection systems to separate spilled materials from stormwater are not effective in containing the corrosive materials. The effectiveness of such devices for removing petroleum products from stormwater collection systems also is limited. Oil/water separators and other proprietary stormwater treatment devices often lack the capacity to contain a spill of the size that might occur along highway routes designated for transport of hazardous materials. A capture volume of at least the maximum expected volume of 10,000 gallons is necessary, in order to capture the contents of a tanker truck hauling hazardous materials. Any type of compacted clay soil, flexible membrane or concrete lined capture basin can be used for this purpose. A lined capture basin will be able to contain most types of spilled hazardous materials, not just those that have a specific gravity which is significantly different from water. It is important to be able to drain the basin after rain events to maintain adequate capture volume. It is also important to be able to access the basin for maintenance and removal of captured hazardous materials. The proper placement and design of hazardous materials traps will be dictated by the location and site restrictions. Further study is required to develop design standards, which may be implemented at any location, providing a hazardous materials trap for spilled materials that enter a highway stormwater collection system. The economics and technical feasibility of the various technologies listed in this report should be compared to develop an optimal design for TxDOT installations. The highlighted links that follow are connected to Adobe pdf files of the corresponding material. To view them you must have the Adobe Acrobat Reader 3.0. View the Report...(409 KB)
These materials may be used for study, research, and education, but please credit the authors and the Center for Research in Water Resources, The University of Texas at Austin. All commercial rights reserved. Copyright 2002 Center for Research in Water Resources. |
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