The Environmental Regulation Commission, whose members are appointed by Gov. Rick Scott, voted 3-2 to support changes that increase the number of regulated chemicals allowed in waterways.
The plan also imposes tougher limits on some chemicals, such as cyanide and beryllium, while reducing the levels on others, including benzene, a byproduct of the controversial drilling process known as fracking.
In supporting the changes, commission Chairwoman Cari Roth said it would be worse to delay the vote or implementation and that the state Department of Environmental Protection will have to defend the rules in future administrative hearings.
"We have not updated these parameters since 1992. There is more good than harm," said Roth, a Tallahassee attorney. "The practical effect is, it is not going to increase the amount of toxins going into our waters."
In voting against the changes, Commissioner Adam Gelber, a senior scientist at a Miami consulting firm, said the numbers don't appear "local enough to Florida."
"It would appear there are tweaks in the system that could be made across the board," Gelber said.
U.S. Sen. Bill Nelson, D-Fla., and eight Democratic members of the U.S. House quickly sent a letter Tuesday to federal Environmental Protection Agency Administrator Gina McCarthy, saying they have "serious concerns" about the changes, which will be sent to the federal agency for review and approval.
"We urge you to provide a more appropriate public comment period for the proposal and to carefully evaluate each proposed human health criteria to ensure the utmost protection for our population, environment, and economy," the letter said.
The state Department of Environmental Protection contends the "Florida specific" changes will ensure that people will be able to continue eating fish and drinking water and says there is no tie between the rule changes and fracking.
Tom Frick, director of the department's Division of Developmental Assessment, said the reclassifications have been under review for four years and are based on federal Environmental Protection Agency guidelines.
"The department has left no stone unturned in developing science-based, legally defensible criteria," Frick told the panel.
But critics during the daylong hearing expressed concern that the new standards will continue to degrade water quality in a state that is already facing major problems with toxic algae blooms on both coasts.
Anne Harvey Holbrook, staff attorney for the Save the Manatee Club, argued that more study is needed on the health impacts of the changes and that the final decision should be delayed until Scott fills two vacant slots on the panel.
"The technical supporting document acknowledges that the rule fails to address long-term health threats to children," Holbrook said. "And we argue that the rule accepts a too high risk for fishermen."
The vacant commission seats are slotted to representatives of the environment community and local governments.
Curtis Osceola, representing the Miccosukee Tribe of Indians of Florida, also called for a delay in the vote until the tribe could further review the proposal. Osceola said the tribe's water-quality standards were not taken into account when the changes were drafted.
"The tribe maintains its own water quality standards, and all waters on Miccosukee land must maintain the standards for the protection of the Miccosukee, their culture and tribal lands and the Everglades," Osceola said.
The federal EPA approved the tribe's water standards in 1999, Osceola said.
On Monday, Department of Environmental Protection Secretary Jon Steverson sent out a statement defending the state changes.
"Moving forward with the proposed criteria will nearly double the number of chemicals that the department will be able to regulate using stringent and protective criteria so we can continue to provide better public health protection for our state," Steverson said in a release.
Steverson's statement followed a request to the panel from Florida's congressional Democrats to reject the changes. Democrats said Tuesday the changes will lower standards and allow higher levels of some toxic substances in surface waters.
Former U.S. Rep. Joe Garcia, who is seeking to return to Congress in a South Florida district, said the vote gives "polluters the green light to contaminate our lakes, rivers and coasts," while U.S. Rep. Gwen Graham, called the vote "insulting."
"Allowing more cancer causing chemicals after the disaster in Flint is unconscionable," Graham, a Tallahassee Democrat, said, referring to highly publicized problems with lead in drinking water in Flint, Mich.
A state regulatory panel Tuesday narrowly approved the first changes to Florida's surface-water quality standards in nearly a quarter-century, despite objections from environmentalists who argued the new criteria potentially create more health hazards.