February 2009, Vol. 21, No.2

Research Notes

Nitrogen and Phosphorus Pollution Costs a Bundle

Freshwater pollution by phosphorus and nitrogen has been found by Kansas State University (Manhattan) researchers to cost government agencies, drinking water facilities, and American citizens more than $2.2 billion annually.

Pollution causes private citizens to pay more for bottled water; water utilities to increase their spending to treat water, which results in increased water bills; waterfront property values to drop; and local economies to lose revenue from a decline in freshwater recreation, explained Walter Dodds, professor of biology at Kansas State University.

According to an article written by Dodds and several colleagues, “Eutrophication of U.S. Freshwaters: Analysis of Potential Economic Damages,” published Nov. 12 in the online version of the journal Environmental Science and Technology, the economic losses that can be attributed to a decrease in lakefront property values range between $3 million and $2.8 billion per year; to a decline in recreational use, between $3.7 million and $1.16 billion per year; to recovering threatened and endangered species, approximately $44 million; and to cleaning drinking water, approximately $813 million. The estimated $2.2 billion in costs is a conservative estimate, Dodds explained.

“We are providing underestimates,” Dodds said. “Although our accounting of the degree of nutrient pollution in the nation is fairly accurate, the true costs of pollution are probably much greater than $4.3 billion.”

Dodds worked with other researchers at the university to look at U.S. Environment Protection Agency (EPA) data on nitrogen and phosphorus levels throughout U.S. waters, according to a university press release. In 12 of 14 EPA ecoregions, more than 90% of rivers contained excessive nitrogen and phosphorus, and most of this pollution comes from nonpoint sources, Dodds explained.

According to the study, trajectories of reactive nitrogen loadings worldwide show increases in freshwater transport from the preindustrial level of 19 million Mg/yr (21 million ton/yr) to the current level of 36 million Mg/yr (40 million ton/yr). In addition, riverine transport of dissolved inorganic nitrogen has increased from the preindustrial level of about 1.8 million to 2.7 million Mg/yr (2 million to 3 million ton/yr) to the current level of about 14 million Mg/yr (15 million ton/yr). Dodds said he hopes the research can help quantify the costs associated with increased nutrients in freshwater ecosystems and highlight the value of clean water to society.