Water Treatment Plants

By: Marie McCarthy

We trust water treatment plants to filter out germs and pollutants and create safe, drinkable water. But even after the final step in the process, disinfection, contaminants can still thrive.

Water treatment does a great job of getting rid of bacteria like E. coli but the process doesn’t necessarily prevent microorganism growth.  Microorganisms can withstand disinfection at water treatment facilities and can infect humans when water is used in irrigation.

A researcher from New Mexico State University is evaluating how effective water treatment processes are in keeping the supply free of pathogens. Yanyan Zhang is looking at water samples before and after they go through the disinfection processes. She wants to find out how the microbes survive under those conditions.

Zhang says many times, the microbes can be transmitted to humans through potable water use, irrigation, and groundwater recharge.

She says the organisms can also thrive in pipes which can ironically be exacerbated by disinfection processes in some conditions. Sometimes, small amounts of disinfection cause the microbes to develop enough resistance that they can withstand water treatment processes.

It’s a scary possibility, which is why Zhang wants to expand her team at New Mexico State University. Groundwater is vital to the American population, with more than 43 million Americans obtaining their drinking water from these sources. 99 percent of rural Americans drink groundwater, too. A majority of the world’s drinkable water is found in the ground. Zhang’s research will help her understand how the microbes affect these sources. When microbe-infected water is used to irrigate fields, it can seep into the water table.

Zhang has a three-year research grant from the National Institutes of Health.