TERRE HAUTE, Ind. -- The Army has agreed to halt shipments of nerve agent waste from Indiana to Texas for incineration until a federal judge decides whether to block the transfers.

A federal judge on Tuesday scheduled a hearing for July 16 on a preliminary injunction sought by the Sierra Club and other environmental groups in the lawsuit they filed last month against the Army.

The lawsuit claims the 900-mile truck shipments of the VX nerve agent waste from the Newport Chemical Depot through eight states pose “an imminent and substantial endangerment” to public health and the environment and violate state and federal laws.

The agreement between the environmental groups and the Army calls for the shipments to Port Arthur, Texas, to be stopped until Judge Larry McKinney rules on the injunction request, according to court documents.

“We are very excited,” said Hilton Kelly, director of the Community In-Power Development Association in Port Arthur, one of the plaintiffs in the lawsuit. “This is a victory, and I believe we will prevail at the injunction hearing.”

Greg Mahall, a spokesman for the Army’s Chemical Materials Agency, said the agreement to suspend the shipments was a good-faith effort to cooperate with the court.

“It is voluntary, and we fully believe everything we have done is safe,” he said. “We do not expect the stay to impact our continuing neutralization efforts at Newport.”

In April, the Army signed a $49 million contract with Veolia Environmental Services to incinerate about 2 million gallons of the chemical waste, which is called VX hydrolysate and is stored at the Newport depot, about 30 miles north of Terre Haute.

Mahall said that about 25 percent of Newport’s total expected hydrolysate has been shipped to Texas in the past nine weeks without any troubles.

Two years ago, a contractor began destroying the nerve agent at Newport through chemical neutralization, and the Army contends the waste being shipped in truck convoys from Newport to Port Arthur contains only a minuscule amount of VX -- 20 parts per billion or less—and is no more dangerous than other hazardous wastes shipped each day across the nation.

The environmental groups, however, contend the waste contains higher levels of VX and hazardous chemicals than the Army claims.