Sludge Watch ==> Study Finds Contaminated Water Reaching Florida Keys

[Maureen Reilly]

Study Finds Contaminated Water Reaching Florida’s Offshore Keys
7/30/2007

Athens, GA — A new University of Georgia study finds that 
sewage-contaminated groundwater is reaching the offshore reefs of the Upper 
Florida Keys, possibly threatening corals and human health.

“The widespread use of in-ground waste disposal through septic tanks and 
injection wells appears to be leading to the contamination of submarine 
groundwater even up to six miles offshore,” said study author Erin Lipp, 
associate professor at the UGA College of Public Health. “When the 
contaminated groundwater mixes with surface water and reaches the reef, the 
corals as well as human health might be harmed.”

The findings were presented Tuesday at a meeting of the Florida Keys 
National Marine Sanctuary Water Quality Protection Program Steering 
Committee in Marathon, Fla.

Lipp and doctoral student Carrie Futch, along with Dale Griffin of the U.S. 
Geological Survey in Tallahassee, sampled surface water, groundwater and 
corals from five sites from nearshore to offshore beginning outside of Port 
Largo Canal and ending near Molasses Reef. Their three-year study revealed 
common fecal indicator bacteria and human viruses.

The fecal indicator bacteria, which are not pathogens themselves but rather 
serve as surrogates for other disease-causing microbes found in sewage, 
declined with distance from shore but tended to be elevated in the surface 
layers of coral mucus relative to the surrounding water. High levels of 
fecal indicator bacteria from canals were also shown to move into the 
nearshore environment on outgoing tides. Lipp said the detection of these 
bacteria in predominantly nearshore stations suggests that land-based 
sources of sewage pollution such as cesspits and septic systems may be a 
significant contributor.

Genetic material from enteric viruses, which cause disease in humans but are 
only found in infected human feces and urine, also were commonly found 
throughout the sampled area, including ground water more than six miles 
offshore. The frequency of detecting viruses increased with rainfall in the 
summer months, when the viruses were most likely to be found in groundwater. 
Lipp cautioned, however, that the test used to identify the enteric viruses 
was not designed to determine whether the viruses were alive or dead.

“Until we actually know the level of risk, our findings are just an 
indication that there could be some level of sewage contamination offshore,” 
she said. “It doesn’t indicate that people need to change their behavior, 
but does show that the appropriate treatment of water through centralized 
sewage is needed.”

Bill Kruczynski, Florida Keys Program Scientist for the U.S. Environmental 
Protection Agency, said the installation of new wastewater management 
systems such as centralized collection and advanced wastewater treatment 
facilities, as recommended by the Water Quality Protection Program (WQPP) 
for the Florida Keys National Marine Sanctuary and required by Florida State 
Law 99-395, is essential to restore and maintain water quality in the 
Florida Keys. In addition, the WQPP recommended improved storm water 
treatment practices to further reduce pollutant loading to nearshore waters.

“The Sanctuary and Monroe County are taking the right steps to improve water 
quality by enacting no dumping ordinances and implementing centralized 
sewage,” Lipp said. “The next step is to ensure that it’s working and 
hopefully document an improvement in water quality.”

The study was funded by the U.S. Environmental Protection Agency.

SOURCE: University of Georgia


www.wateronline.com/content/news/article.asp?docid=69753619-4675-459c-b761-09e72a5ba4cb