Rejecting efforts by its own Republican leaders to relax environmental regulations, the House of Representatives abandoned a controversial plan Thursday to sharply restrict the power of the U.S. Environmental Protection Agency.

Three times in barely three months, the House has tackled a series of 17 legislative proposals, or “riders,” authored by conservative Republicans to restrict the environmental agency’s authority to enforce some of its most stringent limits on air and water pollution. The House voted in August to kill the riders, reversed itself on a second vote four days later and then, on Thursday, reversed itself yet again.

The latest tally was 227-194 and reflected the sharp divisions within Congress when environmental regulations come up against the anti-regulatory fervor at the heart of this year’s Republican legislative agenda.

The turnabout means that for at least another year, the EPA, despite sharp cuts in its funding, will be allowed to carry out regulations limiting hazardous emissions from sewage plants, oil refineries and other industrial sites.

“This is the most important and closely watched environmental vote of the year,” said Rep. Bill Richardson, D-N.M., moments before the vote.

Thursday’s vote instructs those House members who negotiate with Senate counterparts over differences in EPA funding legislation to ignore the 17 environmental riders contained in the House bill. Although the instructions are non-binding, the conferees are expected to take them into account.

The Senate version of next year’s EPA funding bill lacks most of the restrictions included in the House version. But even if the final funding measure contains none of the riders, its future is problematic. The Clinton administration objects to proposed cuts in the environmental agency’s budget - a 34 percent reduction ordered by the House and a 23 percent reduction in the Senate measure.

President Clinton, while praising Thursday’s vote, said in a written statement that it represents “a step in the right direction, but we still have a long way to go if we are to stop Congress’ assault on public health and the environment.”

Opponents of the 17 riders put together a winning coalition made up of minority Democrats and crossover Republicans, largely a moderate bloc from the Northeast and Midwest, to overcome nearly uniform voting among conservative Republicans in support of the restrictions.

Among the 227 members voting to instruct the conferees to ignore the riders were 63 Republicans. A total of 165 Republicans and 29 Democrats voted to retain the riders.

xxxx? FAILED RESTRICTIONS The 17 restrictions to which the House objected were attached to the fiscal 1995 appropriation bill for the EPA. Among other steps, the provisions would have: Limited the wetlands protection program; Banned new limits on discharges of pollutants into waterways; Halted the implementation of uniform water quality standards for the Great Lakes; Prohibited the implementation of controls on sewage overflows; Exempted oil refineries from standards regulating emission of toxic gases into the atmosphere; Exempted kilns used in making cement from toxic air standards; and Prohibited the issuance of standards on the amount of arsenic and radon in tap water.