Wake County has closed two recreational swimming areas at Falls Lake indefinitely due to high levels of disease-causing bacteria. The beaches, Beaverdam and Sandling, are each located on the northern shore of Falls Lake, next to Highway 50, which cuts across Raleigh's drinking-water source to the east. This is the fourth time this summer that Wake County has shut down beaches (xls, 32 KB) at Falls Lake due to high levels of bacteria, according to records provided to the Indy.
In its most recent finding, Wake County detected levels of the bacteria, enterococci, that were more than twice the EPA-recommended limit at Beaverdam Beach, and more than 1.5 times the limit at Sandling Beach. Enterococci indicate the presence of fecal matter and directly correlate with gastro-intestenal complications such as vomiting and diarrhea. According to the Environmental Protection Agency, sources of the bacteria (PDF, 168 KB) can include agriculture-related runoff such as animal manure, as well as "improperly functioning wastewater treatment plants, leaking septic systems, and storm water runoff."
Since the late 1990s, portions of Falls Lake have been classified as impaired by the EPA due to runoff from development. In its draft 2008 Impaired Waters report, EPA listed the entire lake as being impaired, meaning it is in violation of the federal Clean Water Act.
A stakeholder process to develop a clean-up plan for Falls Lake--similar to that for Jordan Lake--has been underway for several years. The N.C. Department of Environment and Natural Resources (DENR) has requested that the deadline to develop clean-up rules be delayed until 2011, though activists say the protections must begin no later than 2010.
"There's an effort in the Legislature to try and do everything possible to speed up the Falls Lake rules process," Elizabeth Ouzts, state director for Environment North Carolina, told the Indy. "One [idea] is to get temporary rules in place by early January  that would at least provide some protections to the lake while the rules are finalized, and then hopefully the final rules would be done by Fall of next year."
Like Jordan Lake, Falls Lake is in violation of EPA standards due to the presence of algal blooms, caused by runoff from development. Roads and roofs and other impervious surfaces are the largest sources of pollution; they prevent water from being naturally cleansed of pollutants, which then drain into the lake and kill or damage aquatic life. Discharges from wastewater treatment plants, and other sources of pollution, further contribute to algal blooms.
In addition, portions of the lake have violations due to high turbidity, or excess sediment, also caused by runoff from development and wastewater discharge. According to the EPA, high turbidity increases water temperature, thus reducing the amount of oxygen in water and harming aquatic life. It also reduces the amount of natural sunlight that penetrates water, further decreasing oxygen production and photosynthesis. In addition, high levels of turbidity can kill fish by clogging their gills, lowering their resistance to disease, and smothering their eggs.
Read the Indy's account of a turbidity-filled day at Falls Lake.