The Iowa Department of Natural Resources has passed new water quality standards that may force the Ames Water and Pollution Control plant to monitor coliform bacteria levels and disinfect wastewater more thoroughly.

The new provisions, passed by the DNR in April and currently waiting for approval from the Environmental Protection Agency, would classify every river and stream in Iowa by usage as well as set maximum allowable coliform bacteria levels in waters classified for recreation and wildlife use.

“The provisions involve a change in the philosophy of how we classify our streams,” said James Stricker, regional director of the Iowa DNR.

Stricker said that coliform bacteria is monitored as an “indicator organism” and that the presence of bacteria such as E. coli in water could mean that other pathogenic, or disease-causing, organisms are there.

“There’s a host of diseases historically transmitted by water: cholera, typhoid fever, dysentery and others we mostly think of as Third World problems,” Stricker said.

Stricker also said the provisions would go into effect following EPA approval, which could take anywhere from six to 18 months. Once ratified, the new standards may force facilities like the Ames Water and Pollution Control plant to implement new disinfection protocol and install new equipment.

“There’s basically two types of disinfection options: chlorine and ultraviolet light,” Stricker said.

Tom Neumann, Ames Water and Pollution Control director, said while the plant has no specific coliform bacteria removal technologies, 98 to 99 percent of the bacteria is removed from the water. However, he said this level of incidental removal does not meet the anticipated new DNR standard. No firm decision has been made on which disinfection method the plant will adopt, although Neumann said strong consideration will be given to ultraviolet light methods.

Neumann said the plant currently monitors and removes many pollutants ranging from heavy metals and industrial pollution to organic matter, ammonia-nitrogen and oxygen-consuming materials. He said 95 percent or more of the pollutants the plant is designed to remove are eliminated.

“We’re doing much better than the design standards set when the plant was placed online in 1989,” Neumann said.

The level of coliform bacteria would be assessed in terms of colony-forming units, or CFUs, per 100 milliliters of water examined. Water taken from a river or stream can be spread onto growth media, and any bacteria within the water can develop colonies and be counted; water that humans directly contact during recreation would have the lowest maximum allowable CFU limit.

James Colbert, associate professor of ecology, evolution and organismal biology, said that E. coli in Iowa lakes is measured in order to assess health risks to swimmers, but no such system is widely implemented for rivers and streams.

“There is routinely E. coli in our rivers, and it routinely exceeds swimming beach standards,” Colbert said.

Colbert said the major sources of E. coli include animal and human waste, faulty septic systems and outflow from sewage treatment plants. He said not all strains of E. coli are dangerous, but echoed that its presence can warn of other less easily identified pathogens.

“E. coli is not the only issue; E. coli is the indicator,” Colbert said.