Stormwater managers can demonstrate compliance with their National Pollutant Discharge Elimination System (NPDES) permits using microbial source tracking (MST) results. This was one of the highlights of the presentation made by Source Molecular Corporation’s Daron Stein at a North Dakota conference.
Mr. Stein was one of the speakers at the North Dakota Water Quality Monitoring Council Conference held March 6-8, 2018, at the Bismarck State College National Energy Center of Excellence. The event was well attended by regulators, environmental consultants and watershed managers throughout North Dakota and nearby areas.
Traditional water quality monitoring methods relating to bacteria involved testing water samples for the presence of fecal indicator bacteria (FIB) such as E. coli and Enterococcus. However, FIB results will not be able to tell water managers if humans or animals are responsible for the fecal contamination. Modern MST methods, Mr. Stein said, involve filtration of water samples, DNA isolation and quantitative polymerase chain reaction (qPCR) to determine if the bacteria came from humans, pets, wildlife or farm animals.
“There are special microbes that are only associated with a given source and that’s what we analyze. So MST is a more superior tool for water quality monitoring than FIB and other legacy technologies,” Mr. Stein said. [The EPA has also recommended MST.]
Mr. Stein noted that MST has many applications including demonstrating permit compliance.
MST results is basically DNA evidence. For permittees to clear themselves of any wrongdoing, they just need to prove that the fecal bacteria in the receiving waters did not come from their pipes.
In the same Urban and Stormwater session of the conference, Galen Hoogestraat of the U.S. Geological Survey, Dakota Water Science Center discussed a project that Source Molecular was also involved in. Mr. Hoogestraat gave a presentation entitled, “Investigating Sources of Fecal Indicator Bacteria in Stormwater and Streams in Rapid City, South Dakota.”
The study focused on Rapid Creek which is viewed as a vital natural resource for wild brown trout, tourism and recreation. Its water quality has been affected by expanding urban development. Regular water testing has shown that it is impaired by fecal coliform bacteria. The West Dakota Water Development District sought to identify sources of fecal coliform bacteria.
The District sent water samples to Source Molecular for MST analysis and they found out that certain areas near the wastewater treatment plant with a large concentration in human DNA markers. MST results also showed that birds and dogs are major contributors to the fecal pollution in Rapid Creek.
To get an idea of how much it would cost to conduct an MST project, visit Source Molecular’s Live Pricing Calculator. Discuss more options with Source Molecular’s representatives simply by scheduling a call at a convenient time.