By Diamond Hillyer
Dr. Joel Moore of Towson University said that the 10 to 17 million tons of salt used on U.S. roads and highways is contaminating local streams, causing toxicity in plants, organisms, and even drinking water.
Speaking to a group of about 20 people Friday at Towson, Moore said 65 percent of the water Americans drink comes from these contaminated streams, and the levels of sodium chloride is only rising as more ice and snow storms hit.
The large amounts of salt are also stunting plant growth and killing off trees in forests, Moore said. Maryland currently uses between 300 and 500 pounds of salt per snow storm, with that amount doubling when storm lasts more than one night.
“These high levels of sodium eventually gets into streams and has toxic effects on aquatic organisms,” Moore said. “Eventually, that toxicity will affect the quality of the water we drink.”
Moore is conducting a study in collaboration with six graduate students and professors of the university’s geology department to determine the impact of the state’s salt policy on the Owings Mills and Gwynns Falls watersheds.
The study seeks to discover what pathways the salt is following into streams and how the salt affects the concentration and fluxes of other important ingredients in the environment.
The contamination trend is not exclusive to Maryland or the winter months, Moore said.
According to his pre-study, the northeastern United States has shown the most increased levels of chloride through streams. Though the levels are higher in the winter due to road safety from ice and snow, the effects will last year round, he said.
Moore said the cause of these elevated levels is due to a number of factors, including the population growth of 72 percent within the last 70 years, urbanization, and the use of more vehicles.
“Sodium chloride levels in streams rise as the population does,” Moore said. “And in the last 50 years, urban areas have seen more damage to land plants and trees because of the transfer of salt from impervious surfaces to streams.”
Moore’s focus for his research is also on the installment of storm water management basins (SMBs) and the regulation that attempts to redirect the salt’s runoff to groundwater.
The simple solution to the issue would be to ask state highway administrations to reduce the amount of salt being spread on the road, Moore said.
Moore said he and his research team tried this approach in Maryland. But when the state budget cuts went into effect in 2014, the attempt to change salt policy failed, Moore said.
Moore said there are alternatives to salt on snow-covered roads.
“Beetle juice and whey can be put down,” Moore said. He acknowledged that these ingredients were not perfect, but he said “it would have less of a negative effect than sodium chloride.”
Moore’s research project is being funded by Towson University, the National Institute for Water Resources (NIWR), the Urban Environmental Biogeochemistry Laboratory of Towson and the Maryland Resources Research Center.