Tucker, GA — A lake in Tucker drew attention this summer when it turned cloudy amid increased rainfall and hot temperatures. Residents who frequent Kelley Cofer Park reported the lake becoming “slick” and the color of “pea soup,” and began complaining to City Council members and the Tucker Parks and Recreation department.
The question: Who should clean up the mess?
Cofer Lake is an artificial lake on the north side of Tucker, about the size of an acre. In a residential area, the lake attracts people who like to casually fish by the dam. Just up the hill from the lake is a public pool and two baseball fields.
Government agencies stepped in quickly to evaluate the water quality after receiving reports about the lake’s appearance. DeKalb County Department of Watershed Management declared the water healthy, but experts want more testing.
Everyone agrees sediment build up is causing the lake to become shallow, and therefore hospitable to an algae bloom.
They disagree on what is causing the algae, how to resolve the problem and whether or not the algae are bad for the lake’s ecosystem.
But the county and city can’t agree on who is responsible for cleaning the lake up.
The city of Tucker took over parks and recreation facilities in 2018, but DeKalb County remains responsible for stormwater structures, which includes dams and lakes in the parks, according to an Intergovernmental Agreement (IGA).
“[Stormwater] does not fall into our responsibility,” said Rip Robertson, director of Tucker Parks and Recreation department. “But that being said, it doesn’t mean we are just going to put our hands in our pockets.”
However, DeKalb County also denies responsibility for addressing the lake.
“The lake at Kelly Cofer Park is a private pond and is not part of DeKalb County’s water and sewer systems,” said a spokesperson for DeKalb County. “The homeowners in the Cofer Park community are responsible for maintaining the pond’s water quality in compliance with the Georgia Department of Natural Resources standards and procedures.”
In a letter dated Aug. 18, DeKalb Watershed said the county’s inspection was the first-ever sample from Cofer Lake, and therefore had no baseline data. The data was measured against a wastewater treatment plant instead of comparing it to a similar body of water.
“However, I can tell you that these results fall well below the discharge limits set by EPD for the wastewater treatment plants to discharge to South River. Ponds that are not treated have higher limits, so that gives you an idea that the pond is very ‘healthy,’” wrote Jody Shoemaker, laboratory manager at DeKalb Watershed.
The comparison was inappropriate, said environmental consultant Marjorie Hall.
“DeKalb Watershed compared results to the wrong criteria. This is ambient water, not discharge pipe from a sewage treatment facility,” Hall said. “They probably used those standards because they were readily available, not because it was an appropriate comparison.”
It’s apples to oranges, Hall said.
DeKalb Watershed tested levels of phosphorus, ammonia, pH, dissolved oxygen, fecal coliform, conductivity and temperature. Phosphorus and dissolved oxygen were both elevated.
“A much more thorough assessment of water quality is needed,” said Hall citing new guidance published by the EPA in August on how to evaluate nutrients in lakes.
An overabundance of nitrogen and phosphorus can cause adverse health and ecological effects, according to the U.S. Geological Survey.
Elevated phosphorus is commonly found in suburban lakes, normally coming from fertilized lawns. The phosphorus result indicates a nutrient problem. It would be wise to also sample for chlorophyll and nitrogen, said Hall.
Residents fear fertilizer from the baseball fields is running down to the lake. Grass on the fields appears healthy and thick, and “the fields never looked better” say neighbors. During late summer, the smell of fertilizer was thick in the humid air.
But Robertson said he believes the water testing confirmed “there is no impact” from the baseball fields on the lake.
“We run a very controlled fertilization program out there. There is a lot of area between the fields and the lake. There’s just no evidence whatsoever that any fertilizer or any chemical that we use on the fields have impacted the lake at all,” said Robertson.
Robertson said Tucker Parks and Recreation spends a lot of time maintaining the fields for regular play. Residents have come to expect a high level of attention since Tucker took over parks in 2018.
“When the parks look good, then the bad parts really stick out,” said Robertson.
Jacqueline Echols, PhD., president of South River Watershed Alliance, confirmed
fertilizers negatively impact bodies of water. She suggested Tucker investigate what kind of fertilizers they are using, as some are safer for urban streams than others.
It’s plain and simple, echoed Hall. “If there’s a nutrient problem in the lake, and there is, fertilizer is bad for surface water. Fertilizers cause algae blooms. It’s worth evaluating how Tucker’s fertilization practices may be affecting the lake.”
Jason Ulseth, an expert in stormwater at Chattahoochee Riverkeeper, also reviewed the data. He said pH levels, water temperature and conductivity look “normal” for a water body of this type but agreed with other experts on additional testing.
“There is nothing unusual that we wouldn’t see in similar bodies of water,” said Ulseth. “When late summer-like humidity and air temps fall, the algae will die off.”
Additional tests at Cofer Lake would deduce if anything harmful is being produced by the present algae. Ulseth said cyanobacteria has been reported in Atlanta on the main stem of the Chattahoochee, on sloughs that receive low flows of water. Cyanobacteria is harmful to animals and humans.
Tucker is awaiting a sediment survey from United Consulting, which will reveal the depth of the sediment in and around the lake.
On Aug. 25, National Resources Conservation Service (NRCS, a division of the USDA) visited Cofer Lake. Their report supported dredging the lake.
“The sediment is taking up water storage space within the lake like ice in a glass of water. Removing the sediment would allow for the lake to function properly in the since [sic] of maximum water storage capacity. Also, the sediment is providing a shallow substrate for sunlight to penetrate to allow plant life (aquatic plants, algae, etc.) to grow,” wrote Ryan D.
Burgess, district conservationist for Gwinnett, DeKalb and Rockdale counties.
The report says the Cofer Lake’s dam is the most important component of the lake. Proper maintenance of the dam is critical.
NRCS said “adding fish to eat the aquatic plants, algae and/or chemicals to control these, would be efforts not well spent at this time if the root cause of sediment deposition is not addressed.”
Yet, Parks and Recreation said Tucker added 100 “grass-eating carp” into the lake in September to mitigate an algae bloom.
“Tucker is choosing to deal with a water quality problem by changing the ecosystem,” said Hall. “The easiest thing they can do is get an idea of the depth, then take a look at different kinds of environmentally friendly fertilizer.”
Tucker spokesperson Matt Holmes said there is a list of issues that need to be addressed at Cofer Park including dredging the lake, undergrowth at the playground, trail maintenance, playground maintenance and pool projects that are out to bid.
At Tucker City Council meeting on Oct. 12, Robertson announced the city will apply for a $3 million grant from Georgia Outdoor Stewardship Program to repair Twin Brothers Lake dam, located in Johns Homestead Park.
“Although this is a storm water issue and ultimately the responsibility of DeKalb County, the city works closely with the county on many projects. This project is costly and requires both of us to partner and try to get the positive results needed for this invaluable park,” said Holmes. “The matching funds will be negotiated by the city with the county once funding is secured. The other dams (Cofer and Henderson) are in need of repairs and are being discussed, as well. The Johns Homestead dam is most critical at this point and therefore getting immediate attention.”
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