TEMPLE The Lampasas and Leon Rivers watersheds have been listed as impaired by the state due to high counts of E. coli and other bacteria taken in the late 1990s, but from whom, what and where the contamination originates is unclear, say Texas AgriLife Research experts. Because the watersheds are located in a landscape that is predominately rural and agricultural, there has been some conjecture that the sources of E. coli are livestock related, said Dr. June Wolfe, a AgriLife Research scientist.
"However, the origin of the sources is unclear," said Wolfe, who is based at the Texas AgriLife Blackland Research and Extension Center at Temple.
And although routine sampling sometimes shows elevated bacteria levels in the watersheds, exactly how high are the levels throughout the year?
To identify the sources objectively, Wolfe and his research associate, Tony Owen, have been collecting water samples at 30 river sites 15 in the Lampasas River watershed and 15 in the Leon River watershed monthly since February. They've also been taking fecal samples from all over the watersheds of known possible sources: home septic systems, wildlife, livestock, pets and water-treatment plants.
The samples are then "genetically fingerprinted" to determine exactly what the source of E. coli is or otherwise, Wolfe said.
It's all part of the "Bacterial Source Tracking" project, which was funded by a Section 319(h) Clean Water Act nonpoint source grant from the Texas State Soil and Water Conservation Board and U.S. Environmental Protection Agency. The grant was administered by the Texas Water Resource Institute in College Station.
"This approach will utilize proven scientific methods that will distinguish the various sources of bacteria," Wolfe said. The DNA fingerprinting is done by Dr. George Di Giovanni at the Texas AgriLife Research laboratory in El Paso.
|Contact: Dr. June Wolfe|
Texas A&M AgriLife Communications