A worker patches a leak at the Freedom Industries site where 10,000 gallons of MCHM leaked into the Elk River in January. Tom Hindman/Getty Images

Seven weeks after a tank holding a coal-cleaning chemical leaked into the Elk River in West Virginia, contaminating the water supply for 300,000, efforts to prevent similar events in the future may be stalling.

A West Virginia legislative committee changed a proposal meant to stiffen aboveground storage tank regulations and safeguard water systems against chemical spills to exempt tanks holding less than 1,310 gallons and facilities that mix or make chemicals.

The tank that spilled the coal cleaner MCHM into the Elk River on Jan. 9 held approximately 10,000 gallons.

The bill would also require public water systems that use water from lakes, rivers and streams to develop protection plans, potentially with money from state reserves.

But there is concern that legislators are running out of time. With a week remaining before the close of the current legislative session, the bill must pass two committees before coming to a House vote. The Senate would need to agree on any House changes. The bill has already been completely revamped by both the state’s House and Senate, and some lawmakers are urging more discussion.

Twenty-seven state delegates have asked Gov. Earl Ray Tomblin to convene a special session to allow for more debate on the bill, a move that angered some.

“I regret that these members want to give up on passing a bill during the regular session when we still have plenty of time to perfect it,” House speaker Tim Miley said in a press release.

Previous iterations of the bill were criticized for being filled with potential loopholes that would allow aboveground storage tanks like the one owned by Freedom Industries that leaked into the Elk River, to remain largely uninspected.

Meanwhile, some lawmakers are asking the Centers for Disease Control and Prevention to study MCHM and its effects on human health.

The CDC was criticized after the spill for deeming Elk River water drinkable without citing comprehensive studies on the toxicity of MCHM.

The state's five-member Congressional delegation sent a letter to the CDC Thursday backing Gov. Tomblin's request made last week for more toxicology studies and urged that the CDC analyze information from patients with symptoms that could have come from contact with the chemical.

It’s unclear what role Freedom Industries has played in the cleanup of the spill. This week, the company’s leaders defended themselves in court in front lawyers representing hundreds of creditors. The company has declared bankruptcy.

At a meeting on Tuesday, administered by a U.S. Department of Justice official, Freedom Industries President Gary Southern and Chief Financial Officer Terry Cline answered questions on company finances.

After the hearing, Southern told reporters he's "absolutely committed" to cleaning up environmental damage and finding jobs for 51 employees as the company winds down operations.

Al Jazeera and wire services