TRENTON - New Jersey lawmakers Monday passed what they and environmentalists described as the nation's toughest restrictions on fertilizer as part of a plan to reverse the declining health of Barnegat Bay.

The law could affect everyone who has a lawn in New Jersey, because it changes the type of fertilizer allowed to be sold in the Garden State and imposes restrictions on how and where it can be applied. The governor was expected to sign it.

The key provision requires that at least 20 percent of nitrogen in fertilizer be the slow-release type, to prevent it from easily washing into waterways.

Nitrogen is a major component of water pollution. It leads to algae blooms that deprive water of oxygen and kill fish and other marine life.

It also encourages the growth of stinging jellyfish, which have overrun the bay and rivers near it, including the Manasquan and Metedeconk, making them virtually unswimmable at times and clogging the engines of some boats.

"This is a monumental day for the environment," said Assemblyman John McKeon (D., Essex). "This will mark the beginning of the turnaround of Barnegat Bay. Shame on us for allowing it to get to where it is today."

The bay is suffering from lowered oxygen levels and declines in the population of some marine life and sea grasses.

Jeff Tittel, executive director of the New Jersey Sierra Club, said the bill was the toughest in the nation when it comes to nitrogen limits in fertilizer.

"It was designed for Barnegat Bay," he said, "but it will protect all of New Jersey's waterways, streams, lakes, and rivers."

The bill now goes to the desk of Republican Gov. Christie, who has indicated he would sign it as part of a comprehensive plan to save Barnegat Bay. In addition to the nitrogen limits, the heart of the larger plan is the early closure of the Oyster Creek Nuclear Generating Station in Lacey Township.

The plant sucks 1.4 billion gallons a day from the bay into its pipes and discharges warmer water back into the bay, which hurts water quality. The plant agreed to shut down in 2019 - 10 years earlier than planned - in return for New Jersey's backing off its demand that it build costly cooling towers to replace the massive water intake to cool the plant.

Other bills aimed at improving Barnegat Bay's water quality also passed the Assembly on Monday, including one that requires construction crews to restore soil to its original condition after work is done. That is to allow water to soak into the loose ground rather than running off hard, packed-down ground into sewers.

The Assembly also passed a bill to require the state Department of Environmental Protection to set a daily maximum amount of nutrients such as nitrogen and similar substances that can be allowed to make their way into Barnegat Bay and nearby waterways.

The package contained bills asking the federal Environmental Protection Agency to provide technical assistance on the daily nutrient limit.