U.S. EPA reports on contaminated water

By Alastair Lee Bitsoi
Navajo Times

PINEDALE, N.M., May 15, 2014

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(Times photo — Donovan Quintero)

Larry King from Springstead, which is north of Church Rock, N.M., says his drinking water comes from the Mariano Lake area, as poses near his faucet at his home on Tuesday night. The 1979 uranium tailings spill contaminated the wash that runs near his home.

The ground water located beneath the United Nuclear Corporation Superfund Site is mostly contaminated by what U.S. EPA officials say are secondary drinking water contaminants. In other words, these contaminants are aluminum, chloride, manganese, sulfate, and dissolved solids, which are solids that can filter through two-micrometer pores.

They exceed the maximum contaminant level, meaning that if humans and animals drank from this groundwater their health would be negatively affected. This is according to Janet Brooks, U.S. EPA Region 6's remedial project manager of the UNC Superfund Site. EPA Region 6 and the U.S. Nuclear Regulatory Commission are the regulatory agencies that have jurisdiction over the former mill site, which processed uranium ore from 1977 to 1982.

The disposal site covers about 25 and 100 acres, with its processing mill facilities and byproduct material disposal cells. In her second discussion with local residents Tuesday, Brooks updated them on the ongoing groundwater cleanup of the Superfund site. Specifically, she mentioned how the groundwater beneath the mill site also contains radionuclides, such as radium 226 and 228 and uranium, as well as metals like selenium and vanadium.

These contaminants are located within the Pipeline Canyon Arroyo at three different plume locations known as the Southwest Alluvium, Zone I and Zone III Contaminants. A plume refers to pollutants that get swept into the flows of groundwater, thereby contaminating it. "Zone III is most contaminated," Brooks said, before adding, "We're still having problems out there." Out of the 23 monitoring wells EPA Region 6 installed to examine for contaminants, some of them exceeded site regulatory standards.

For example, radium 226 and 228, which are radioactive metals, were found in 18 of the 23 wells. Cobalt and nickel, both metals found in 16 of the 23 wells, also exceed site regulatory standards. Brooks added that Zone III is a plume of contaminants moving toward reservation land, which is located north of where the mill site is.

"How far is the plume from the Navajo Nation boundary?" asked a local woman, who refused to have her named printed in the paper.

"Roughly 300 feet," Brooks said. "Not all of it is hazardous, portions of it are."

At Zone I, where there are 10 monitoring wells, nickel was the most pronounced element that exceeded site regulatory standards. It was found in half of the 10 wells there. Radium 226 and 228 were also found in four of the 10 wells.

The Southwest Alluvium, which consists of a 7,000-feet long by 800-feet wide plume, contains nickel as the only element that exceeds site regulatory standards. When a question about drinking water for animals was asked, Brooks said that a well being installed where the plumes are moving would result in "a problem."

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