Above-normal levels of arsenic and copper have been found in Lake Anne, according to a new study released last week, but the Reston Association is not worried.
"The study didn't surprise me," said Larry Butler, RA director of Parks and Recreation. "It was pretty straight forward and, essentially, it was follow up on their previous study looking at lead."
The study, conducted by the U.S. Geological Survey (USGS), and published in the "Environmental Science and Technology" journal, found amounts of the two elements that "exceeded what would be expected to occur naturally in this setting." Results of the four-year study were released last week.
As Karen Rice, the study's author and an environmental research hydrologist with the USGS, points out, there is not an United States federal health standard for either arsenic or copper in lake sediment as there is in drinking water. "But if a Canadian standard is applied to the Lake Anne sediment samples," Rice said, "there is enough arsenic in Lake Anne to probably cause harmful effects to aquatic life and enough copper to possibly cause harmful effects to aquatic life."
"I don't know how relevant it is to use Canadian standards," Butler said. "It is not as if we have found any evidence of biological toxins or fishkills in Lake Anne."
<b>KAREN MONAGHAN</b>, RA's director of communications, says there is no reason for Reston residents who live on or near Lake Anne to be alarmed. "I found it interesting, but that's about it," she said.
RA, according to Monaghan, currently has no plans to try to eliminate the arsenic and copper.
After building up for some 30 years, the arsenic is located deep down in the man-made lake. "At this point, it is bound to the sediments. It is stuck in the lake, until something is done about it," Butler said.
"Eventually, it should be phased out," Rice said, of the arsenic-laced sediment. "What's in there now is there to stay unless it is removed by dredging."
Butler went on to say that RA, even if it wanted to, doesn't have the financial ability or the equipment to dredge to the bottom of Lake Anne. In the past when RA has dredged, he said, the process typically only covered about two or three acres. Reston lakes, according to Butler, are dredged, on average, about once every 10 to 12 years.
RA will take up the issue of arsenic in Lake Anne during its monthly Board of Directors meeting, Thursday, Feb. 27 at 7 p.m. Rice, who lives in Charlottesville, Va. and Butler will both report on the study. "We knew this study was coming out and we invited her speak to the board about it," said Gerald Volloy, the RA executive vice president. "We want our board to be educated and we want our residents to be educated. We want people to understand what this study is not a threat; we want to be out front on this one."
<b>PRESSURE-TREATED WOOD</b> which is treated with chromated copper arsenate (CCA), and is used in many decks, docks, bulk heading and fences around Lake Anne, is to blame for nearly half of all the arsenic found in the suburban lake, according to the study. Much of the remaining arsenic likely came from feeder streams that carried arsenic from other sources of CCA-treated wood upstream, according to Rice.
Beginning next year, the Environmental Protection Agency will prohibit CCA treated wood for most residential settings. The move away from CCA comes after a voluntary step by the lumber industry in February 2002 to steer consumer use away from CCA pressure-treated wood, in favor of new alternative wood products, like TREX.
Much of the copper found in Lake Anne arrived from runoff caused by the dust from wear of an automobile's brake linings.
<b>RICE PRAISED</b> the Reston Association’s “proactive” effort to encourage the use of more environmentally friendly shoreline wood products. In the last five years, RA says it has dramatically reduced its use of pressure-treated wood bulkheads.
“In those cases where plantings and stone may not work, Reston Association is proactively encouraging those living on and near Lake Anne to use vinyl bulk heading and recycled plastic timbers, which, over time, will reduce the amount of arsenic being contributed to the lake," Rice said.
Volloy said he is "proud" of the work that RA is doing to "mitigate" the problems created by pressure-treated lumber. Volloy said RA has begun educating, with pamphlets and one-on-one discussions, lake front residents about the importance of decreasing the arsenic and copper levels. Volloy said it is very possible to moor boats and protect Reston's shorelines while preserving the beauty of RA's four lakes.
Rice noted in an interview that she suspected she would find similar results in any of a number of suburban man-made lakes. "Everybody today wants a boat," she said, "so these types of lakes are ubiquitous."
“Although this study was limited to one site, it was designed to answer scientific questions about the important pathways and processes controlling movement of copper and arsenic from CCA-treated wood to the aquatic environment in general,” said Rice.