Navy: Groundwater study on Tinian done

Additional study part of ‘revised’ EIS

The Department of Navy has completed its study on the groundwater aquifer on Tinian, according to the Marine Corps Forces Pacific, as Capitol Hill officials eagerly await a second wave of military studies on the impact of live-fire on the highly permeable limestone of Tinian.

“The administration is hopeful the Department of Navy will heed the concerns that were addressed—our comments, the EPA’s (U.S. Environmental Protection Agency), and local agencies,” said the administration of Gov. Ralph DLG Torres in a statement to Saipan Tribune last night.

The highly permeable Marianas limestone—which underlies most of the military project area on Tinian and “creates high susceptibility to contamination”—was not fully considered in the Navy’s earlier studies, the U.S. Environmental Protection Agency said in October. The Navy noted then that the limestone was porous—allowing water to readily flow through it—and that rainfall percolates rapidly downward into such rock—however—no discussion of the solubility of munitions constituents were included, nor were “any protections identified to prevent pollutants from infiltrating the soil and entering the aquifer,” the EPA said then.

“The Tinian Aquifer Study is complete and will be part of the Revised Draft [environmental impact statement],” Craig Whelden, executive director of Marine Corps Forces Pacific, told Saipan Tribune in an email.

Whelden also said his MARFORPAC team was in the CNMI all last week conducting meetings on various topics with CNMI officials. One of the meetings was on Tinian potable water.

The military plans on drilling five new vertical wells on the land under military lease, from which to draw potable water.

“With regards to water usage on Tinian, DOD is working with [the] CNMI to develop an alternative that is consistent with the lease,” Whelden said.

The forthcoming impact documents come after the military identified a need last October to undergo additional analysis of potential impacts to the ground water aquifer on Tinian; and coral on Tinian and Pagan, including related mitigation plans, among others.

“It was because it wasn’t in the EIS to begin with,” Sen. Arnold Palacios (R-Saipan) said yesterday, referring to the EPA and CNMI Division of Environmental Quality-requested studies on impacts to Tinian groundwater.

Palacios, a former Department of Lands and Natural Resources secretary, said there have been a lot of anecdotal evidence, or people telling of the “hundreds and hundreds of airplanes and military activities on Tinian” and what these left on the island.

“Some of the chemicals are still there, are still found on the island of Tinian. Palacios said. “Drums of chemicals are still found on pastures. It’ll be very interesting for EPA to take a closer look at the water lens in the aquifer and project forward and what other impacts this activity will have.”

The military has laid out plans for four range complexes on Tinian inclusive of grenade, tank, pistol, and mortar activity, and have stated plans to drill five new vertical wells on Tinian from which to draw potable water.

Palacios said the live-fire training could have potential long lasting impacts on a “very fundamental, almost basic resource”—water.

“That is the most basic question that DEQ and EPA found lacking in the previous EIS study,” he said. “You are talking about a substantial amount of live-fire and a substantial, protracted period of time—we don’t know. They can exercise it for however long, or…stop” while “holding on to the lease,” Palacios said.

Dennis B. Chan | Reporter
Dennis Chan covers education, environment, utilities, and air and seaport issues in the CNMI. He graduated with a degree in English Literature from the University of Guam. Contact him at

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