by:  Eric Reutebuch, Director, Lake Watch
 Appeared in October 2022 issue of Lake Magazine

Lake Watch of Lake Martin partnered with Auburn University last year to conduct a scientific study of surface water draining from Lake Martin’s watershed into the lake (see Lake Watch goes hi-tech with AU microbiologist, Lake Magazine – July 2021). The study was funded by a grant from the Alabama Water Resources Research Institute and matching contributions from Lake Watch and Lake Martin HOBO. The study focused on four streams that drain landscapes with mixed land uses and flow into the Tallapoosa River, which then flows into the upper lake.

We observed a proliferation of new chicken houses popping up above the lake and were concerned about what impacts the chicken waste (litter) would have on the waters flowing into Lake Martin. Lake Watch had been testing these streams for a couple of years and had found high levels of E. coli in the streams following significant rain events.

E. coli is a bacterium that inhabits the gut of warm-blooded animals (livestock, wildlife) and humans. Its presence in water indicates fecal contamination – a health risk to those that recreate in the water.

Once Lake Watch discovered the presence of high E. coli in streams above the lake, the next questions were: Where’s the poop coming from, and is it impacting the lake? The AU researchers, Dr. Feng and her graduate student Wenjing Ren, used microbial source tracking to analyze water samples from the four streams and the Tallapoosa River at Jaybird Landing, where Lake Martin begins.

MST employs genetic marker analysis to identify the critters from which the fecal contamination or animal tissue originated – like the testing used on NCIS to identify criminals. The researchers analyzed water for the presence of four different genetic markers: a human bacterial marker; a cattle bacterial marker, a chicken bacterial marker and a chicken tissue marker. E. coli concentrations were also measured.

Water samples were taken on 11 dates from September 2021 through May 2022. Half of the sampling targeted rain events when the streams had elevated flow, and the other half targeted dry periods when the streams were at normal level.

AU results verified Lake Watch monitor test results showing high concentrations of E. coli in the streams mentioned above in the Lake Martin watershed after significant rain events.

To our surprise, humans and cattle were the main sources of fecal contamination in the streams and the river at Jaybird Landing regardless of rainfall/streamflow levels. Both sources were found in all four streams and at Jaybird Landing and were highest after significant rain events. Crooked and Timbergut creeks usually had the highest concentrations of human and cattle genetic markers, as well as the highest concentrations of fecal contamination.

Timbergut Creek had the highest levels of fecal contamination, with six of the 11 sample dates having E. coli levels above EPA standards, mostly after rain events.

Chicken bacterial genetic markers were detected much less frequently, only on three sample dates in only three streams, Timbergut, Emuckfaw and Hillabee and at Jaybird Landing, after rain events.

Chicken tissue genetic markers were detected most frequently (on every sample date, 11 of 11 dates) in one stream, Crooked Creek, and also downstream in the Tallapoosa River at Jaybird Landing, on six of 10 sample dates, after rain events.

So what does this mean for the lake? For the time being, the proliferation of chicken houses above the lake appears to not be a threat to Lake Martin, according to the study. A major consideration is that the litter in chicken houses is only cleaned out once every two to three years. It is conceivable that the study may not have captured the impacts of chicken litter since the study was done over a limited time period (nine months) and could have missed impacts from chicken litter spread on local fields. Another possibility could be that chicken farmers are using appropriate best management practices that retain chicken waste on their fields so very little runs off into streams. And yet another confounding factor – when petroleum prices are high, manufactured fertilizer prices go up, and chicken litter becomes more valuable. Under these circumstances, poultry farmers sell their litter for use by farmers as fertilizer, and it is trucked out of the watershed and has no impact on local water quality. We don’t know the amount of litter spread during the study. Whatever the case may be, we need to keep an eye on the expanding poultry production in our watershed.

Based on the results of the AU study, it appears that we do have an issue with human and cattle waste in streams emptying into the river and ultimately into the upper lake. We need to work on tracking down these sources of contamination and get them resolved.

The detection of chicken tissue markers coming down Crooked Creek on every sampling date and detection at the beginning of the lake at Jaybird Landing was also a surprise. More testing is needed to determine the source of chicken tissue in Crooked Creek. We don’t yet know the implications of this finding and will need assistance to determine whether this poses any threat to lake users. We’ll keep you posted.

Be sure to check the Lake Watch Swim Alert at lakewatch.org/swim-guide to get the latest E. coli test results throughout the lake and at Hillabee and Emuckfaw creeks. Be safe and enjoy the water. And consider helping us out in our mission to protect our treasured lake, go to lakewatch.org/our-programs to learn more. 

Learn more about Lake Watch at lakewatch.org.