UA researcher examines the prevalence of untreated sewage in rural Alabama
After a rain this year, two University of Alabama students would load up a car and drive to the countryside to look for poop.
Of course, they use a more scientific name – fecal contamination – but remnants of human poop is what they set out to collect.
And they found it lurking in a stream in the Black Belt, a rural and poorer section of Alabama named after its topsoil. The way the stream water is collected shows the contamination comes from homes where, lacking better options, some dump wastewater onto the land where it remains until rainwaters drive it to the local streams.
“We’re looking to prove that’s actually happening, and it’s getting into the surface water,” said Parnab Das, a graduate student studying environmental engineering.
The scope of the problem is largely unknown, but Dr. Mark Elliott, who teaches and researches civil and environmental engineering at the University, is leading a project to get a grasp on how much raw wastewater, and the diseases it can spawn, flow into the region’s water.
“If I can provide some insight into the impacts of the problem and the scope of the problem, then I can try to work to getting the deep pockets, whether it’s state and federal money or foundations, into the area to try to make a difference,” Elliott said.
City folks and those in most other areas of the country can dispose of household wastewater safely, either into a sewer system that leads to a treatment plant or in a septic system that uses engineering and natural geology to filter out contaminants before reaching the groundwater.
The Black Belt, an area of 17 counties across lower central Alabama, is often different. Underneath the topsoil is clay and chalk, which holds water rather than letting it drain. Standard septic systems, which treat wastewater on the home’s property, use a designed system to settle out solids before filters, trenches and porous soil clean the water.
More than half the region is estimated to have soil where traditional septic systems do not work as intended. In one survey of Bibb County, 35 percent of homes without sewer had failing septic systems and another 15 percent of homes used a straight pipe for wastewater, meaning a pipe runs from the home to some other part of the property to drain untreated wastewater.
In a survey of homes without sewer connections Elliott conducted in Wilcox County, further south and poorer than Bibb, it was conservatively estimated that 60 percent of homes drain wastewater without treatment from a septic system, Elliott said.
Elliott said it is possible more than 500,000 gallons of raw sewage enter the rivers and streams in Wilcox County each day.
Added to the poor soil, the Black Belt is a poverty-stricken area of the country, especially outside its small towns. Many find it difficult to afford a regular septic system that costs a few thousand dollars, let alone the more complex systems needed for the soil costing in the neighborhood of $12,000.
“When you have this type of soil that intersects with rural poverty, a lot of people just have no option,” Elliott said.
Before coming to UA in 2013, Elliott worked a lot in developing countries such as Cambodia, where raw sewage run off is more common than in the developed world. When he arrived in Alabama, he learned of similar issues in the rural areas of the South, so he turned his attention to home.
“Instead of focusing on these issues in developing countries, I really feel an obligation to work on this in the state of Alabama,” Elliott said. “We’ve basically taken methods used in developing countries and brought them to the United States to try and quantify how big this problem is.”
Testing in Big Prairie Creek just outside the small town of Newbern in Hale County, less than an hour south of the University, Elliott’s team found after the 2016 drought there was a 1,000-fold increase in the E. coli bacteria in the stream, indicating rain run-off carried the untreated sewage into the creek.
Measurements taken in the creek before and after rains since have also shown an increase in sewage from one side of the town to the other, he said.
“What we are finding is the downstream sites have much higher concentrations of fecal bacteria than the upstream sites,” Elliott said.
The consequences of untreated wastewater for the health of Alabamians is coming into focus as researchers find diseases and parasites common in tropical areas and once thought contained in the United States showing back up in the Black Belt, Elliott said.
That is why it is important to understand the prevalence and effects of straight pipe systems on water quality, he said.
“The extent to which all these straight pipes are leading to disease has yet to be determined, but the preliminary evidence is very concerning,” Elliott said.
He hopes research that quantifies the prevalence of straight pipe systems in homes will lead to changes such as the extension of town sewage systems to nearby homes and putting in shared systems for clusters of homes in more rural areas.
Dr. Mark Elliott is an assistant professor in civil, environmental and construction engineering. This work is supported by the Environmental Protection Agency and the US Geological Survey through the Alabama Water Resources Research Institute.
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