The Senate and the House are at odds over a chemical spill in West Virginia that left 300,000 people without tap water for five days, as the Democrat-led upper chamber is planning hearings on chemical safety while House Speaker John Boehner, R-Ohio, said Tuesday that current regulations are sufficient.

Boehner said the spill of thousands of gallons of 4-methylcyclohexane methanol, which is used to treat coal, from a storage facility into the Elk River near Charleston would not affect the House GOP's efforts to remove environmental regulations. Instead, he pinned the blame on lax oversight, as he noted the facility hadn't been inspected by state or federal regulators since 1991.

"The issue is this: We have enough regulations on the books," Boehner said at a news conference in the Capitol. "What the administration ought to be doing is actually doing their jobs."

Environmental Protection Agency oversight of chemicals has long been an issue, U.S. Chemical Safety Board Chairman Rafael Moure-Eraso noted in a June Senate Environment and Public Works Committee hearing. The agency, which investigates chemical accidents, had asked the EPA and the Occupational Safety and Health Administration in 2002 to strengthen oversight of chemicals.

Moure-Eraso said the agencies have not acted on those recommendations, but he also noted that a probe of an April explosion at a fertilizer plant in West, Texas, that killed 15 people revealed regulatory gaps.

Sen. Barbara Boxer, D-Calif., chairwoman of the Senate Environment and Public Works Committee, said the West Virginia incident raised concerns about regulatory oversight.

"The Chemical Safety Board is a very key player in that," Boxer told reporters in the Capitol, who said the first of two hearings would be held in February. "It's really important to ask the questions that if you have storage of dangerous chemicals right near drinking water supplies, there needs to be some rules governing that. And there just were not."

Democrats are pushing for hearings on the House side as well, as Rep. Henry Waxman, D-Calif., the top Democrat on the Energy and Commerce Committee, and Rep. Paul Tonko, D-N.Y., the ranking member on the panel's Energy and Environment Subcommittee, called for more oversight Monday.

In a letter to House Energy and Environment Subcommittee Chairman Rep. John Shimkus, R-Ill., the Democrats argued the committee should enhance its understanding of the risks posed by such spills if the House takes up a bipartisan Senate bill that would revise the federal toxic chemical law, the Toxic Substances and Control Act.

Critics of the law argue that it makes it too difficult for the EPA to protect the public against harmful chemicals, which has led to a patchwork of state rules governing them.

"[I]t is critically important that we understand how the law allowed a potentially harmful chemical to remain virtually untested for nearly 40 years," Waxman and Tonko wrote.

The Energy and Commerce Committee is waiting on more information before it decides it course of action, said Charlotte Baker, a majority spokeswoman for the panel.

"The committee is currently monitoring the federal investigation and working to fully obtain the facts surrounding situation," she said.

A pair of West Virginia Democrats also sounded a cautious tone while emphasizing the failure to inspect the facility.

"The question, of course, is, 'Were they required to do those inspections?' But requirements or not, it should be incumbent upon — whether it's local, state or federal officials — to constantly monitor discharges into the water," Rep. Nick Rahall said Tuesday on C-SPAN's "Washington Journal."

"I'm attacking basically how we could have, for two decades, nobody going to inspect it, or even look at it," Sen. Joe Manchin told reporters Tuesday in the Capitol.

Sean Lengell contributed to this report.