Laboratory officials decided to install an ion-exchange unit at the treatment facility after an effluent sample taken late last month indicated elevated concentrations of perchlorate in effluent being discharged from the plant. The HEWTF has not discharged any effluent since the discovery, and the plant will not discharge any effluent until perchlorate has been removed.
Perchlorate is a non-radioactive chemical that has been linked to thyroid dysfunction. Perchlorate moves easily with water, and the U.S. Environmental Protection Agency added the chemical to its Safe Drinking Water Act Contaminant Candidate list in 1998 - although EPA has not issued a drinking water standard for the chemical. The Laboratory began monitoring groundwater and drinking water for the chemical in 1999.
Currently there is no federal or state discharge limit for perchlorate.
"Nevertheless, we are acutely aware of our responsibility to be good stewards of the environment, so we are taking initiative on our own to reduce perchlorate contamination in the environment," said Jim Holt, the Laboratory's associate director for Operations. "Adding ion-exchange treatment to the High Explosives Wastewater Treatment Facility will help protect the environment and promote our stewardship goals."
The HEWTF is located at Technical Area 16, near the Laboratory's southwest boundary. The treatment facility handles effluent from high explosives processing operations and from laboratories that conduct explosives research. The HEWTF is designed to remove high explosives contamination from wastewater, but was not designed to rid effluent of perchlorate.
On March 20, Laboratory hydrologists took an effluent sample from the HEWTF. The sample was split with personnel from the New Mexico Environment Department. Analyses of the sample were confirmed late last week and indicated elevated perchlorate concentrations in the effluent. Laboratory officials identified two sources: residual perchlorate from the HEWTF's carbon filters that had come from previous treatment of wastewater from propellant-research; and from wastewater collected from a different facility that had rinsed perchlorate-contaminated equipment.
As a result of the discovery, Laboratory officials decided to add an ion-exchange treatment unit to the HEWTF to ensure that perchlorate is eliminated from all wastewater handled by the HEWTF.
Last year, the Laboratory installed an ion-exchange treatment unit to the Laboratory's Radioactive Wastewater Treatment Facility at Technical Area-50. Since installation, tests of effluent from the RLWTF have not detected the presence of perchlorate using EPA's approved testing method.
"The ion exchange system at the TA-50 treatment facility has proven to be effective and cost efficient," Holt said. "I am confident that we will see similar success at our TA-16 treatment facility."
Note to news media/editors: Photo of Robert Garcia is available on-line at: http://www.lanl.gov/worldview/news/photos/HEWTF.jpg
Los Alamos enhances global security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health and national security concerns.
Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, The Babcock & Wilcox Company, and Washington Group International for the Department of Energy's National Nuclear Security Administration.
Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.