As Houston’s population continues to grow, so does the city’s need for clean water.
White Oak and Buffalo bayous are listed under the Clean Water Act with high bacteria levels.
These bayous lay within the most densely populated region of Harris County. With funding from the Texas Commission of Environmental Equality, a team at Texas A&M University at Galveston led by Dr. Brinkmeyer and Dr. Amon tested them for the presence of the bacteria E. coli and for the concentration of organic matter and nutrients.
These bayous were sampled during a multiyear study starting in 2008. The purpose of the study is to find out what type of bacteria is present and how it is growing in the wild.
Samples of sediments and water were taken from the two bayous, two waste water treatment plants, as well as two natural control sites.
The control sites act as an example of what should be happening in nature without influence from urbanization. Molecular methods were used to determine the genes of the bacteria which were used to identify the type of bacteria present.
Chemical analysis was performed on the water to discover the chemical composition of organics and nutrients in the bayous. This information is important because E. coli should not be able to live outside of the human or animal intestine and scientists want to learn how they are surviving and reproducing in this environment.
Results showed that the E. coli concentrations exceeded the Texas water quality standard by tenfold. So what do we do? These bacteria have adapted to be able to grow and reproduce in sediments outside of a human host where it is normally found.
One explanation is that they do this by utilizing phytoplankton, which thrive on nitrates and phosphates. Eliminating these nutrients could help remove the E. coli from our waters.
To effectively remove nitrates and phosphates, a wastewater treatment plant must have three clean up steps for the water to go through. Houston treatment plants currently only implement two.
Other states have started adopting the three-step waste water treatment plants including the Chesapeake Bay area. While costly, the addition of a tertiary step to clean waste water would aid in the cleanup of our bayous and improve water quality.
As for Galveston Bay, the water from these polluted bayous flows into our Gulf, which means that whatever has been picked up in Houston is likely to end up in the bay.
This could have detrimental effects on our consumption of oysters which are filter feeders. As oysters take in the Gulf water, they retain what’s in the water including bacteria.
Houston is expected to grow to 9 million people by 2040 which means that a lot more water will be needed to support the city. Plans to divert the Trinity River toward Houston are in the works to provide for this demand.
However, more water into the city means more water out of it and into Galveston Bay. As more potentially contaminated water flows through Houston, the chances of impacting Galveston Bay increase.
Alyssa Adams is a senior ocean and coastal resources major and is scheduled to graduate in May. She hopes to attend graduate school and work toward a career in natural resource management.