Idaho Arsenic Standards for Human Health

Arsenic pollution

In water, arsenic is both naturally occurring and caused by human activities. Arsenic is well known for causing cancer—including bladder, skin, liver, kidney, and prostate cancers—as well as other chronic diseases. Arsenic can damage almost every human function, including the nervous, cardiovascular, renal, and respiratory systems.

Idaho Arsenic Standards

In 2010, Idaho updated its water quality standards under the Clean Water Act (CWA), standards that apply to the levels of pollution in streams and rivers. But instead of using the relatively low levels that EPA recommended, it used EPA-recommended levels under the Safe Drinking Water Act (SDWA). The difference was stark: a maximum of 0.14 µg/L under the CWA versus 10 µg/L under the SDWA. The reason is two-fold. First, the SDWA takes water treatment into account because it applies at the end of a tap. And, second, the SDWA level was a highly political choice by the President George Bush Administration. Contrary to its own policies, EPA then approved Idaho’s choice of a dangerous level of arsenic.

NWEA Challenges EPA

 In 2015, NWEA challenged EPA’s approval of the Idaho arsenic standard for human health. And, in 2016, EPA agreed in a court order to reverse its approval and establish new arsenic standards for Idaho by mid-2019. In a separate out-of-court agreement, EPA committed to issue CWA discharge permits using more protective levels during the interim period before the new standards are in place. And, EPA agreed to increase monitoring of pollution discharges to detect arsenic. In September 2016, EPA disapproved Idaho’s arsenic criteria.