In early June, the U.S. Environmental Protection Agency (EPA) ordered landfill operator Republic Services of Southern Nevada to begin remediation work immediately at the Sunrise Mountain Landfill in Clark County, Nev. Cover on the Sunrise Landfill, a 440-acre closed municipal solid waste landfill, failed during a series of storms in September 1998, sending waste into the Las Vegas Wash., which discharges directly into Lake Mead.

The landfill is located three miles outside Las Vegas city limits and two miles above the Las Vegas Wash. Lake Mead is a primary drinking water resource for southern Nevada, including the Las Vegas metro area, as well as the Phoenix metro area and southern California.

"This order directs Republic to initiate stabilization work at the landfill to protect public health while steps are taken to finalize a comprehensive agreement to implement the entire remedy," said Jeff Scott, Waste Division director in the EPA’s Pacific Southwest region.

The order requires Republic to begin work immediately and submit plans to the EPA, including a final cover plan, a stormwater control plan, a groundwater monitoring plan, and other additional reporting and implementation tasks. The total cost of the work required is approximately $7 million.

"The EPA has identified a comprehensive engineering remedy with long-term integrity," said Steve Wall, an environmental engineer in the EPA’s Pollution Prevention and Solid Waste Office. "This durable and cost-effective landfill cover and stormwater system will meet the specific geographic and climatic needs of Nevada’s arid desert landscape."

Sunrise Mountain Landfill is unlined and contains more than 18-million tons of waste, including municipal solid waste, medical waste, sewage sludge, hydrocarbon-contaminated soils, asbestos, and construction waste. The landfill was operated on behalf of the county by entities related to Republic Services of Southern Nevada from the 1950s through 1993.

Following the landfill cover failure in 1998, the EPA cited Republic Dumpco and the Clark County Public Works Department for violations of the Clean Water Act and the Resource Conservation and Recovery Act. At that time, the EPA ordered the company to implement a stormwater control plan, repair the existing drainage system, upgrade the landfill cap to federal standards, control and monitor methane and groundwater, and submit a plan to maintain and monitor the site.

EPA said that although Republic has completed interim work, it has failed to implement surface drainage controls that would minimize erosion during major storm events, improve the cover to address threats of erosion and infiltration, or install an adequate groundwater monitoring system.

More information on EPA’s order—including scope of work, schedule, a site map, and other plans—is available online at www.epa.gov/region09/waste/sunrise.