Hydrogen sulfide possible at Piedmont Dam

July 22, 2010

HUNTINGTON, WV - The Huntington (WV) District of the U.S. Army Corps of Engineers (USACE) has determined that conditions exist in the outlet works area at the dam at Piedmont Reservoir in Belmont County, Ohio, that could result in the presence and possible release of hydrogen sulfide (H2S) gases.


Hydrogen sulfide is a colorless gas that can be easily recognized by its "rotten egg" odor. Symptoms of exposure to high levels of H2S include fatigue, dizziness, nausea and headaches. Young children are at particular risk.


This problem is confined to the area adjacent to the outlet works only (downstream area past the dam) and the condition does not pose a problem to recreational users of the lake. There are no restrictions for boating and other activities at the lake. There is no indication that fish taken from these lakes pose a health risk if consumed.


The USACE has developed a plan of action to monitor H2S levels. Project employees will take readings to detect any presence of H2S gases around the outlet works and surrounding areas.


In the event that H2S gases at any public access site reaches levels that could pose a health risk to the public, those areas will be closed. Due to public safety, the area immediately adjacent to the discharges at Piedmont Lake have been closed and will remain closed until the problem naturally corrects itself in the fall.


Hydrogen sulfide forms when the concentrations of sulfates in the watershed immediately behind these dams are higher than normal. During the summer months, the sulfates are converted to hydrogen sulfide gas through microbial activity occurring in the bottom layers of the lake. As the water leaves the lake, the hydrogen sulfide gas is released into the air, creating an unhealthy situation in the tailwater areas.


USACE personnel will continue to monitor the situation for the presence of H2S and will notify appropriate agencies as well as the public if H2S concentration levels are determined to pose a threat to public safety.


For more information, please contact the Piedmont Lake Office at (740) 968-4440, the Muskingum Area Office at (330) 343-3613, or the Public Affairs Office at (304) 399-5353.




« Back to News