A state environmental board finally devised an Everglades cleanup rule Tuesday, which environmentalists promptly denounced as an "illusion" of protection for the ecosystem.

Though weary of the messy, amendment-riddled process that crafted the rule, the Florida Department of Environmental Protection hailed the outcome as progress toward reducing phosphorus pollution pouring into and harming the Everglades.

Critics found little to celebrate in the complex calculus and highly technical details of the proposal from the state's seven-member Environmental Regulation Commission, a body appointed by the governor. Its vote was unanimous.

There was consensus on this after 21/2 years of debate, testimony and intense lobbying that went into producing the rule: It is bound to face state administrative and other legal challenges.

"It's a very complex rule. Unfortunately, it's not designed for swift and sure enforcement" of water quality, said Audubon of Florida lobbyist Charles Lee. "It is designed to continue the process of [cleanup] obfuscation."

The rule, detailing how much phosphorus the marsh can absorb and where and how to measure levels of the pollutant, drew objections from the U.S. Environmental Protection Agency, which must review and approve it.

Environmental groups said the rule likely would run afoul of a 1992 federal court agreement supervised by U.S. District Judge William Hoeveler, a decree that guides the cleanup along with a related state law.

The DEP, which recently threatened to reject the rule if some proposals were adopted, accepted the result. DEP officials said the rule creates a four-part test for phosphorus from fertilizer washing into the Everglades from farms and suburbs. That test equates to the stringent limit environmentalists had sought: 10 parts per billion, they said.

Citing other strengths, DEP Secretary David Struhs said the rule is "intellectually honest" and applicable across the Everglades.

Beyond the intense rule wrangling, Struhs said, a milestone was passed with the setting of one of the nation's first numerical pollution limits for a body of water.

But Audubon's Lee said: "We have a rule that only presents an illusion of 10 [parts per billion] and at the same time creates a myriad of ways that 10 will never be enforced anywhere."

The Sierra Club said the rule relies on "ambiguous time and location variables" and averages results over too long a period of time: five years.

"Which means we really won't know for several years what the hell is going on" with the cleanup, said Sierra senior Florida representative Frank Jackalone. "Gov. Jeb Bush must ultimately accept the blame for the irresponsible action today by his environmental regulators."

The rule was partly shaped by amendments and last-minute lobbying by the sugar industry, a major phosphorus contributor to the Everglades. But U.S. Sugar Vice President Robert Coker expressed dissatisfaction, too. "It's very disappointing. We don't know what it does," Coker said. "It's just a mess."

The DEP will publish the last wave of rule amendments and wait to see whether there are challenges. The final version will be filed with the secretary of state. The rule must be in place by the end of this year.

Information from The Associated Press supplemented this report.