New Waves October 2011

Breaking news about water resources research and education in Texas

BST researchers "genetically fingerprinting" E. coli from Lampasas and Leon watersheds

BST researchers genetically fingerprinting E. coli from Lampasas and Leon watersheds When working to improve water quality, detecting bacteria in a stream is only half the battle—figuring out the source of the bacteria can be very complicated. Researchers for the Lampasas and Leon Bacterial Source Tracking (BST) Assessment project are working to do just that.

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 there 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 predominately rural and agricultural area, there has been some conjecture that the sources of E. coli are livestock related, said Dr. June Wolfe, an 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.

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, Wolfe said. As the fecal samples are collected, and the DNA fingerprinting completed, the results are included in the Texas E. coli bacterial source tracking library. The DNA fingerprinting is done by Dr. George Di Giovanni at the Texas AgriLife Research laboratory in El Paso.

The BST project, administered by the Texas Water Resource Institute, 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.

“This approach will utilize proven scientific methods that will distinguish the various sources of bacteria,” Wolfe said.

Identifying the exact sources of contamination will allow the formation of a watershed protection plan that is fair, balanced and effective, Wolfe said.

Read the full AgriLife TODAY article.

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