Georgia is raising the amount of allowable chlorophyll-a on Lake Lanier, a move that hasn’t stirred much dissent among lake and environmental groups.
The Department of Natural Resources board voted Tuesday to agree with the Environmental Protection Division’s proposal to raise the amount of allowable chlorophyll-a in testing samples to 6 parts per billion from 5 parts per billion at its Flowery Branch testing site and 7 parts per billion from 5 parts per billion at its Browns Bridge Road site.
“These are some of the most stringent and lowest levels of any lake in the state ... so it’s already at an extremely healthy level,” said Philip A. Wilheit Jr., Gainesville resident and an at-large member on the DNR board.
Chlorophyll-a concentrations indicate the amount of algae in water.
“Algae are an important food source for aquatic life, but excessive phosphorus entering a lake can cause algae growth and lead to environmental problems such as fish kills, lowered water clarity and the potential for toxic algae blooms,” the EPD has stated.
The standards change “is based on some updated modeling results that indicated the original standards that were adopted cannot be met,” said Elizabeth Booth, manager of EPD’s Watershed Planning and Monitoring Program. “They were too tight when they (were) established in 2000. We cannot obtain them.”
The EPD proposed the change to “remain in compliance” with the latest U.S. Environmental Protection Agency “methodology and guidance as it pertains to Georgia’s water quality control program.”
The Federal Clean Water Act requires states to review water quality standards periodically to make sure they are scientifically appropriate, and revise them as needed.
Under federal law, states are required to develop lists of impaired waters. As part of that effort, they must develop “total maximum daily loads,” a calculation of the maximum amount of a pollutant a body of water can receive and still safely meet water quality standards, according to the EPA.
The status of Lake Lanier at Flowery Branch and Browns Bridge Road has been labeled as “not assessed.” Other Hall County waters leading to Lanier, such as Flat and Mud creeks, are deemed “impaired.”
The lower numbers of allowable chlorophyll-a were set several years ago and, “based on new data, (available) because of better technology that we have now, (they) are not attainable,” said William Bagwell Jr., also of Gainesville and the DNR board’s 9th District representative. “It’s nonattainable even if there was no development and no human existence at all (surrounding the lake).
“I personally believe it’s prudent to combine new technologies, hindsight and common sense to identify a reasonable path for our future.”
Joanna Cloud, executive director of the Gainesville-based Lake Lanier Association, said last week the group’s board had discussed the issue and “the general consensus is that this (chlorophyll change) does not have much impact on Lanier.”
Juliet Cohen, general counsel for Chattahoochee Riverkeeper, has said, “While we’re not supportive, necessarily, of weakening the standards, our biggest concern is how EPD is going to work with the local governments and how they all are going to contribute to having a long-term plan for reducing the nutrient load into the lake system.”
The EPA has stated “excess nitrogen and phosphorus, or nutrient pollution, is the primary cause of water quality impairment ... and causes algae blooms.”
Jason Ulseth, technical programs manager for Chattahoochee Riverkeeper, said Georgia’s rainy weather season has had an environmental impact.
“What we have seen is a 30 to 60 percent increase in chlorophyll-a ... so far through the summer,” he said. “More rain equals more nutrients.”