Sandia LabNews

Sandia researchers study methods for removing arsenic from drinking water to help meet new EPA standards

Sandia researchers study methods for removing arsenic from drinking water to help meet new EPA standards

Over the next several months a team of Sandia researchers led by Malcolm Siegel (6118) will be studying different methods of arsenic removal at the Desert Sands Mutual Domestic Water Consumers Association (MDWCA) in Anthony in southern New Mexico.

A ceremony marking the start of the project was held Aug. 26 at the utility’s main well site. On hand were representatives from Sandia, Sen. Pete Domenici’s office, the New Mexico state legislature, and the water utility.

The arsenic research is sponsored by the Arsenic Water Technology Partnership. The partnership is a consortium of Sandia, the Awwa Research Foundation (AwwaRF), and WERC, a consortium for environmental education and technology development. Domenici secured the funding for the project through DOE as chairman of the Senate Energy and Water Development Appropriations Subcommittee.

MOU signing

At the Aug. 26 ceremony Sandia and the MDWCA signed a memorandum of understanding (MOU) to begin the research.
Signing for Sandia was John Merson, deputy director for Geoscience & Environment Center 6100. The utility representative was Rosaura Pargas, president.

“The Desert Sands project will supplement a full-scale demonstration by the US EPA [Environmental Protection Agency] for evaluation of a removal technology that uses granular iron oxide to filter arsenic from water,” Malcolm says. “As water is pumped through the system, arsenic sticks to the iron oxide. The Desert Sands MDWCA wants Sandia to compare the performance of the [iron oxide] material they are currently using to other adsorptive media. We should be able to give them some practical advice based on what we learn.”

Best absorptive material

The Sandia field team includes lead engineer Malynda Aragon and field technicians Randy Everett and William Holub (all 6118). Malynda anticipates they will test between eight and 12 different arsenic removal systems at the Anthony site. “We’ll be looking at which material best adsorbs arsenic to compare how often the adsorptive media needs to be changed,” she says.

The treatment system, including plastic columns filled with adsorptive material and monitoring equipment, was built at Sandia and was recently relocated to the Desert Sands utility.

Desert Sands serves a population of 1,535 from two wells in a rural community along the New Mexico-Texas state line, north of El Paso. It has a new water treatment plant built by Severn Trent Corp. that uses the iron oxide treatment method.
The Anthony research is a follow-up to work in Socorro, N.M., where the Sandia team tested five arsenic removal technologies at a geothermal spring. The pilot test in Socorro compared five innovative technologies. These treatment processes were chosen from more than 20 candidate technologies that were reviewed by teams of technical experts at Arsenic Treatment Technology Vendor Forums organized by Sandia and held at the 2003 and 2004 New Mexico Environmental Health Conferences.

Congressional support and design of the Arsenic Water Technology Partnership was developed under Domenici’s leadership to help small communities comply with the new EPA drinking water standard for arsenic. The new regulation, which goes into effect in January 2006, reduces the maximum contaminant level (MCL) from 50 micrograms per liter (µg/L) to 10 µg/L and is intended to reduce the incidence of bladder and lung cancers caused by exposure to arsenic.

Arsenic levels high in west

Levels of naturally occurring arsenic in the southwestern US often exceed the new MCL. The new compliance requirements will affect small communities that lack the appropriate treatment infrastructure and funding to reduce arsenic to newly required levels.

Malcolm says the goals of the program are to “develop, demonstrate, and disseminate information about cost-effective water treatment technologies in order to help Native Americans and small communities in the Southwest and other parts of the country comply with the new EPA standard.”

Besides the Socorro and Desert Sands experiments, additional demonstrations, based on technologies reviewed at vendor forums and developed by DOE labs or in laboratory studies managed by AwwaRF, are also being considered in consultation with the New Mexico Environment Department, the EPA, the Indian Health Service, the Navajo Nation EPA, and the Interstate Technology Regulatory Council.

WERC, a consortium of research institutions in New Mexico, will evaluate the economic feasibility of the technologies, work on technology transfer activities, and conduct educational outreach.

Whether a current proposal to phase in stricter arsenic requirements over years takes hold or not, there will still be a need to help communities modify systems to perform better, Malcolm says. Scientists are also beginning to look at other contaminants that may be regulated in the future.

“We need to stay ahead of the curve so communities can invest in proven systems that will address multiple contaminants,” he says.