EPA Asked To Revise Arid Western States' Groundwater Monitoring Criteria In

When the Environmental Protection Agency passed the final criteria for municipal solid waste landfill groundwater monitoring (40 CFR), it included an exemption for owners and operators of certain small, remote, arid landfills from the design and groundwater monitoring requirements. This exemption, however, soon was soon challenged and struck down by the U.S. Court of Appeals.

The court held that under RCRA 4020, the only factor that EPA could consider in determining whether facilities must monitor their groundwater was whether such monitoring was "necessary to detect contamination," not whether it is "practicable." The court noted that while EPA could consider the practicable capabilities of facilities in determining the necessary groundwater monitoring, EPA could not justify complete exemption.

In response to this ruling, 14 rural communities in Utah and Arizona represented by Tahoma Companies Inc. WDBE, Cedar City, Utah, petitioned EPA for revised design criteria. They argued that groundwater monitoring and impermeable liners at arid landfill sites yield little benefit compared to the high costs and that the likelihood of encountering shallow groundwater in many areas of the West is significantly less than in areas with precipitation equal to or greater than evaporation rates.

EPA held a meeting this summer in Salt Lake City, as well as in Washington, D.C., Texas and Alaska, to discuss alternatives for groundwater monitoring at dry, remote MSW landfills that accept less than 20 ton per year. Representatives from Colorado, eastern Oregon, Idaho, Nevada and Texas voiced concerns over the financial burden and impracticality of performing groundwater monitoring at these landfills. Their arguments included:

* Small, remote communities cannot afford groundwater monitoring and have few alternatives for waste disposal;

* Site-specific geology often provides natural barriers to groundwater and prevents contamination. Gary Player, principal geologist for Tahoma Co., presented three case studies that illustrated how permeable soils, such as shale or clay, not only provide barriers to groundwater but result in groundwater that lies hundreds of feet below ground level; and

* Leachate production is extremely limited under arid conditions. Many parts of the western United States receive less than 25 inches of precipitation per year. Unless waste comes in direct contact with the surface or groundwater, little or no leachate is produced.