LAWRENCEVILLE - Georgia is taking steps to put Lake Lanier and other impoundments across the state on a federal list of polluted waterways.
The lakes have too much chlorophyll a, which signals the presence of algae.
Algae is an important source of food for aquatic life, but it can cause environmental damage such as fish kills if it becomes too abundant.
Excessive amounts can also make it more expensive for counties and cities to convert lake water into drinking water.
The amount of chlorophyll in the four lakes does not pose a health threat, environmental officials said.
"Chlorophyll a is not harmful to human health at these levels," said Linda McGregor, chief of EPD's Watershed Protection Branch. "It's just a nuisance."
If left unchecked, though, it could lead to toxic algae blooms and even kill large amounts of fish by sucking oxygen out of the water. It could also curtail fishing and other recreational activities.
Fertilizer, fecal matter and other pollutants that wash into the lakes when it rains has contributed greatly to the problem, McGregor said. Wastewater discharged by counties and cities accounts for about 10 percent of the problem, she said.
Besides Lanier, the state wants to have Carter's Lake, Lake Walter F. George and additional parts of Lake Allatoona put on what is known as the 303(d) list.
The final decision will be made by the federal Environmental Protection Agency. If it concurs, the state will have to devise a plan for reducing chlorophyll in the lakes.
That could make it more expensive for counties and cities around the waterways to put treated wastewater in them.
Gwinnett County, which is in the process of getting a discharge permit from the state, should not be affected, officials said. But others like Gainesville in neighboring Hall County may have use more expensive sewer equipment than it initially expected.
Two weeks ago Georgia EPD said it had not made a final decision on whether to have Lake Lanier put on the list of troubled waters.
But on Wednesday it announced it would take public comments before sending a proposal to the federal Environmental Protection Agency seeking the lakes' inclusion on the list.
Lanier, located at the northern tip of Gwinnett, is a major source of drinking water and recreation in metro Atlanta.
Those wanting to send comments to EPD can mail them to the EPD Watershed Protection Branch Chief at 4220 International Parkway, Suite 101, Atlanta, Ga., 30354. They can be faxed to 404-675-6244, or e-mailed to email@example.com.
Comments will be taken through May 15.