Environmental Protection Agency Administrator Gina McCarthy speaks at the National Congress of American Indians executive council winter session in Washington, D.C., on February 22, 2016. Photo by Indianz.Com

The Senate Committee on Indian Affairs is holding a field hearing in Arizona next week.

The hearing will focus on the Environmental Protection Agency and its dealings with tribes. It has been controversial because the Obama administration didn't want to send an official to testify in person.

The impasse led the committee to issue its first subpoena in more than a decade. It was delivered to Administrator Gina McCarthy and Mathy Stanislaus, an assistant administrator, on Wednesday.

"It troubles me that this committee had to take the extraordinary step of issuing a subpoena to a confirmed federal official," said Sen. John Barrasso (R-Wyoming), the chairman of the panel.

Indianz.Com SoundCloud: Senate Committee on Indian Affairs Discusses EPA Subpoena

Still, McCarthy won't be at the hearing. But committee members expects Stanislaus and another senior official to appear.

The hearing takes place on April 22 at city council chambers in Phoenix. The witness list follows:

By Subpoena: The Honorable Gina McCarthy
Administrator, U.S. Environmental Protection Agency, Washington, DC

OR

By Subpoena: The Honorable Mathy Stanislaus
Assistant Administrator, Office of Land and Emergency Management, U.S. Environmental Protection Agency, Washington, DC

The Honorable Russell Begaye
President, Navajo Nation, Window Rock, AZ

The Honorable Herman G. Honanie
Chairman, The Hopi Tribe, Kykotsmovi, AZ

The Honorable Lorenzo Bates
Speaker, Navajo Nation Council, Window Rock, AZ

Clark Lantz, Ph.D.
Professor and Associate Head, Cellular and Molecular Medicine, The University of Arizona, Tucson, AZ

Committee Notice:
Field Oversight Hearing on “Examining EPA’s Unacceptable Response to Indian Tribes" (April 22, 2016)

Related Stories:
Senate Indian Affairs Committee sends subpoena to leader of EPA (4/13)
Sen. Barrasso calls on EPA leader to attend hearing on mine spill (4/12)
Senate Indian Affairs Committee weighs subpoena of EPA leader (4/11)
President of Navajo Nation calls on EPA to testify at field hearing (4/7)
Tribes and states work together to monitor water after mine spill (3/25)
Gina McCarthy: Flint water crisis puts attention on justice issues (03/15)
EPA encourages more tribes to develop water quality standards (03/02)
House committee issues subpoenas in Gold King Mine disaster (02/19)
Senate Indian Affairs Committee postpones field hearing into EPA (02/08)
EPA asserts a greater role as water crisis in Michigan continues (01/22)
Little River Band contributes $10K to assist city during water crisis (1/19)
House committee set for another hearing on Gold King Mine spill (12/07)
Saginaw Chippewa Tribe donates bottled water for city residents (10/7)
Bill aims to address claims arising from spill at Gold King Mine (09/23)
EPA chief faces fire for dealings with tribes after mine disaster (9/17)
House committees hold long hearing into Gold King Mine spill (9/18)
EPA Administrator to appear at three Gold King Mine hearings (09/11)
Navajo Nation hosts Erin Brockovich after spill at Gold King Mine (9/9)
House committee to hold first hearing into Gold King Mine spill (9/8)
Navajo Nation welcomes Erin Brockovich in aftermath of disaster (9/7)
Navajo Nation hires firm to pursue Gold King Mine spill lawsuit (9/1)
Multiple Capitol Hill hearings set into disaster at Gold King Mine (8/31)
Navajo Nation to reopen irrigation canal after Gold King mine spill (8/28)
EPA releases internal report into Gold King Mine spill disaster (8/27)
Senate Indian Affairs Committee to hold hearing on EPA mine spill (8/26)
Native Sun News: Tribes respond to toxic spill at abandoned mine (8/25)
Navajo Nation remains cautious after spill impacts water system (8/21)
Navajo Nation farmers losing crops amid mine spill concerns (8/18)
Leader of EPA visits Navajo Nation after mine spill in Colorado (8/13)
President of Navajo Nation upset with EPA's response to spill (8/12)
Navajo Leader: 'This is an assault on who we are as Dine people' (8/11)
Navajo Nation to sue EPA over release of mine waste into waters (8/10)