By ROBERT HANLEY

RIVER VALE, N.J., March 11 — Gov. James E. McGreevey expanded his campaign to clean up New Jersey's drinking water supplies today by proposing that the state's highest purity standards for untreated water be applied to two Bergen County reservoirs.

"We need to take the most stringent measures to protect our drinking water supplies," Mr. McGreevey said during a news conference on the banks of one of the reservoirs, Lake Tappan. "This fundamentally must be our commitment to families across New Jersey."

He said protection of drinking water is among the state's most important quality-of-life issues, along with preserving open space and curbing sprawl.

He also said that he was the first New Jersey governor to protect reservoirs with the water-purity standards known as Category 1, which have traditionally been used for pristine trout streams.

Mr. McGreevey proposed Category 1 status today for Lake Tappan, a 3.5-billion-gallon reservoir created in 1967; for Woodcliff Lake, a 100-year-old, one-billion-gallon reservoir about 10 miles west of here; and for about 30 streams that flow into the two reservoirs. About 750,000 people in Bergen and Hudson Counties get water from them. The reservoirs are owned by a private utility, United Water New Jersey, which said it supported the governor's proposal.

The governor's announcement opened a process of hearings, public comment and analysis that the state's environmental commissioner, Bradley M. Campbell, estimated would take about a year to complete.

Legally, Category 1 protection, which applies to water before it reaches purification plants, bars a measurable degradation of the water quality in a stream, river or other body of water. The regulations intended to achieve this goal include creating 300-foot buffer zones along designated streams, rivers, lakes and reservoirs; tightening treatment levels in sewage plants discharging wastewater into them; and increasing the amount of runoff water that must be transferred into the ground instead of into streams.

Governor McGreevey started his water-quality campaign last April when he proposed nine reservoirs in the state for Category 1 designation. Mr. Campbell, who accompanied the governor here, said today that he expected the regulations for those reservoirs to be approved by his department next month.

Developers have fought the proposals, and Mr. Campbell's aides said today that state officials had proceeded cautiously in writing the regulations in hopes the rules would be solid enough to withstand expected court challenges.

Mr. Campbell said it was unlikely that the regulations for today's nominations would be prepared more quickly than last April's; he noted that the mayors of the 22 towns in the watershed of the two reservoirs would help him choose which portions of the 30 feeder streams would be classified as Category 1.

Last April, Mr. McGreevey nominated the Oradell Reservoir, a sister reservoir south of Lake Tappan and Woodcliff Lake, for Category 1. Since then, environmentalists have urged him to add Lake Tappan and Woodcliff Lake, as well as their feeder streams, to his list because all the water in them eventually flows into Oradell Reservoir.

Environmentalists in River Vale said the governor's choice of Lake Tappan had a certain urgency because a developer has proposed about 100 town houses on 26 acres on the reservoir's western shore.

Burton Hall, chairman of the town's open space advisory committee, said he was thinking about asking Mr. McGreevey for a building moratorium if the developer's plans were approved before Lake Tappan got tighter protection.

Aides to the governor and Mr. Campbell said they doubted either official had the legal authority to order such a moratorium.