An environmental watchdog today criticized U.S. EPA's decision to scale back its domestic radiation monitoring efforts nearly two months after a massive earthquake near Japan set off the world's worst nuclear disaster in 25 years.

Three weeks after a nuclear reactor at Japan's Fukushima Daiichi began spewing radioactive particles into the atmosphere, EPA and the Food and Drug Administration announced they had taken steps to increase the level of nationwide monitoring of milk, precipitation and drinking water through the government's RadNet radiation monitoring program. But EPA announced last week that it was returning to routine monitoring efforts that analyze milk and drinking water samples on a quarterly basis and rainwater monthly.

In addition, because of "consistently decreasing radiation levels," EPA said in a news release that it was evaluating the need to keep operating the additional air monitors it deployed in response to the crisis.

As Japanese authorities continue to work to contain the situation and shut down the plant -- a process that officials said last month could take half a year or more -- EPA's actions are not sitting well with Jeff Ruch, executive director of Public Employees for Environmental Responsibility.

"With the Japanese nuclear situation still out of control and expected to continue that way for months, and with elevated radioactivity continuing to show up in the U.S., it is inexplicable that EPA would shut down its Fukushima radiation monitoring effort," Ruch said in a statement today.

In its statement, PEER charged that the real reason EPA had to deploy additional monitors in response to the crisis in Japan was that the five-decade-old national radiation and ambient monitoring system is unreliable and has geographical gaps in its coverage area.

A spokesman for EPA Inspector General Arthur Elkins said this morning that the office is currently conducting a review of the RadNet system. An EPA IG report from January 2009 found that the full implementation of the RadNet system was behind schedule and that further delays were possible because of time needed to modify some monitors (Greenwire, March 23, 2011).

"As a result, the agency may have less information about the levels of radiation should a national radiological or nuclear emergency occur," the 2009 report states.

IG spokesman John Manibusan said in an email today that the objective of the current review is to determine whether EPA effectively implemented corrective actions from the 2009 report and to determine "whether quality control procedures are being followed to ensure data submitted from the RadNet monitors nationwide is reliable and accurate."

EPA spokesman Brendan Gilfillan today challenged PEER's assessment of RadNet's reliability.

"We have over 100 monitors up and running, more than enough to detect even the slightest fluctuations in background radiation levels," Gilfillan said. "The network was built specifically to ensure that if one monitor is down for maintenance, we still have overlapping regional coverage. ... Also, while RadNet as a network has been around for 50 years, these near-real-time air monitors were built and installed in the past five years."

Gilfillan noted that while EPA did decide to send deployable monitors to locations closer to Japan like Hawaii, Alaska, Guam and Saipan, an island in the U.S. Commonwealth of the Northern Mariana Islands, no decision has been made about whether or not to stand those monitors down.

He added that radiation levels detected in milk and rainwater, which PEER expressed the most concern about, have been consistently declining in recent weeks.

"The near-real-time air monitoring will continue to give EPA scientists data 24/7, and the agency stands ready to accelerate [milk, precipitation and drinking water] sampling if necessary, just as we did when this situation began," he said.