Dangerous nitrate levels in drinking water could persist for decades, increasing the risk for blue baby syndrome and other serious health concerns, according to a new study published by researchers at the University of Waterloo.
Nitrogen fertilizer applied to farmers’ fields has been contaminating rivers and lakes and leaching into drinking water wells for more than 80 years. The study, published this week in a special issue of the journal Environmental Research Letters, reveals that elevated nitrate concentrations in rivers and lakes will remain high for decades, even if farmers stop applying nitrogen fertilizers today.
The researchers have discovered that nitrogen is building up in soils, creating a long-term source of nitrate pollution in ground and surface waters.
“A large portion of the nitrogen applied as fertilizer has remained unaccounted for over the last decades,” said Nandita Basu, a professor in the Department of Earth and Environmental Sciences and Civil and Environmental Engineering. “The fact that nitrogen is being stored in the soil means it can still be a source of elevated nitrate levels long after fertilizers are no longer being applied.”