Bacterial persistence in streams

Aug 05, 2008

A research team from the University of Tennessee (UT) has completed a study on an East Tennessee river to determine the connection between watershed hydrology and fecal bacteria statistical time series analysis. Shesh Koirala and colleagues report their findings in the July-August issue of the Journal of Environmental Quality.

The article presents a study of the temporal patterns and statistical persistence of total coliform based on data gathered from the Little River near an intake at a public water supply plant. The research was funded by UT's Center for Environmental Biotechnology.

The presence of bacteria from fecal pollution continues to be a problem in both rural and urban streams in the United States. Since 1990, when the U.S. EPA adopted the Coliform Rule, the presence of total coliform in water distribution systems has been closely monitored as an indicator of fecal pollution and possible bacterial or viral enteric pathogens. Many public water supply operations have monitored total coliform presence in streams near water intakes to assess the quality of the water prior to treatment.

Coliform bacteria are often present in nature, however bacteria in certain streams, particularly total coliform, may indicate on-going and ever-present issues related to fecal pollution and bacterial transport within watersheds. The UT research team investigated the temporal relationship between watershed processes and the presence of bacteria to better determine management needs related to potential pollution sources.

For the UT study, daily samples were collected from the Little River by water plant personnel, and the time series was analyzed to determine the persistence of total coliform in the stream. The analysis included both time-domain and frequency-domain approaches for comparison purposes. Koirala's team discovered that total coliform bacteria exhibit both short-term and long-term persistence at four-week and one-year intervals. Comparison of the total coliform time series with hydrologic data indicated that short-term persistence is dominated by runoff events, whereas longer-term persistence is likely related to baseflow, or groundwater, supply.

The UT research team's study will help scientists develop better conceptual models and provide direct benefit to local communities contending with fecal pollution. The UT team has been working closely with regional watershed groups to facilitate technology transfer and guide use of these data in managing watersheds. The researchers continue to build upon this study, as well as previous efforts, to devise better tools for quantifying fecal bacteria loads and defining temporal behavior in hydrologic watershed processes. These outcomes will assist local communities in improving management of their water supplies.

Source: American Society of Agronomy

Explore further: Switzerland 1st country to submit pledge for UN climate pact

add to favorites email to friend print save as pdf

Related Stories

Refined method to convert lignin to nylon precursor

18 minutes ago

A new study from the Energy Department's National Renewable Energy Laboratory (NREL) demonstrates the conversion of lignin-derived compounds to adipic acid, an important industrial dicarboxylic acid produced for its use as ...

SMAP satellite extends 5-meter reflector boom

18 minutes ago

Like a cowboy at a rodeo, NASA's newest Earth-observing satellite, the Soil Moisture Active Passive (SMAP), has triumphantly raised its "arm" and unfurled a huge golden "lasso" (antenna) that it will soon ...

Precision gas sensor could fit on a chip

35 minutes ago

Using their expertise in silicon optics, Cornell engineers have miniaturized a light source in the elusive mid-infrared (mid-IR) spectrum, effectively squeezing the capabilities of a large, tabletop laser onto a 1-millimeter ...

Recommended for you

Did climate change help spark the Syrian war?

1 hour ago

A new study says a record drought that ravaged Syria in 2006-2010 was likely stoked by ongoing manmade climate change, and that the drought may have helped propel the 2011 Syrian uprising. Researchers say ...

Pollution documentary attracts huge interest in China

6 hours ago

A slick new documentary on China's environmental woes has racked up more than 175 million online views in two days, underscoring growing concern in the country over the impact of air, water and soil pollution.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.