A Native American nation intends to sue the US Environmental Protection Agency over an accidental wastewater spill they claim affected more than 100,000 people.

Russell Begaye, president of the Navajo Nation, told TIME that more than two-thirds of the population - spanning territory in parts of Utah, Arizona and New Mexico - had been affected.

Almost three million gallons of wastewater, reportedly laden with lead, arsenic and other metals, was released into the Animas and San Juan rivers on 5 August.

The accident occurred during an investigation by EPA crews into the potential contaminated Gold King Mine, southwest Colorado.

“The spill has impacted us religiously, emotionally, financially,” Mr Begaye said.

The lawsuit asks the government to cover the livelihoods of farmers affected by the spill, who have been forced to move their cattle from the riverbeds and relocate to inland areas.

According to Mr Begaye, the accident has also forced the government to turn off irrigation water from the San Juan River as well as drinking water.

Bottled water is reportedly becoming scarce within the semi-autonomous nation.

"This is a huge issue," Mr Begaye told the Associated Press.

"This river, the San Juan, is our lifeline, not only in a spiritual sense but also it's an economic base that sustains the people that live along the river.

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Although hastily assembled clean-up crews have built a series of four pools to attempt to prevent the contaminated yellow water from seeping into the main river, authorities admit the pools are not preventing water joining the main rivers.

Frustration has mounted within the territory, as many feel authorities have been too slow to act and the Native American group has borne the brunt of the accident.

Environmental Protection Agency Administrator Gina McCarthy said on Wednesday she intended to tour the affected region.

"I am absolutely, deeply sorry that this ever happened," she told reporters in Washington.

Although the Agency did not return The Independent’s requests for comment, a statement posted three days ago on its official website said the “plume” had dissipated downstream but that the organisation’s “primary objectives” remained ensuring people had safe access to drinking water and evaluating the possible effects on the “aquatic and fish” populations.