Low water levels at Folsom Lake are causing an increase in air pollution from the $900 million Folsom Dam auxiliary spillway project.
The lake is filled to just 40 percent of capacity, which has allowed construction to proceed without the use of marine excavation equipment this year. The land equipment used instead has emitted more nitrogen oxide, said Katie Huff, spokesman for the U.S. Army Corps of Engineers. The corps is working with the U.S. Department of the Interior and the Bureau of Reclamation on the project.
Nitrogen oxide is formed by fuel combustion of automobiles, trucks and non-road vehicles like construction equipment.
Studies have linked short-term nitrogen oxide exposure, ranging from 30 minutes to 24 hours, with adverse respiratory effects, including airway inflammation in healthy people and increased respiratory symptoms in people with asthma.
Increased construction this year will cause the project to exceed federal threshold guidelines for nitrogen oxide emissions.
The annual federal threshold for such emissions is 25 tons per year. In 2014, the Folsom Dam Project is expected to emit 31.2 tons.
Although more nitrogen oxide is being emitted this year, ongoing dry conditions may allow the project to lower its total nitrogen oxide emissions, by project’s end, said Huff,
“We will have a 30 percent reduction, overall, between 2015 and 2017 from our original projections,” she said.
There are now over 100 pieces of construction equipment operating daily on the construction site. As many as 24 trucks make trips daily to and from the site, said Lori Kobza, spokeswoman for the Sacramento Air Quality Management District. The emissions are seen as too small to cause any health concern, said Kobza.
In Sacramento County roughly 50 tons of nitrogen oxide is emitted into the atmosphere every day.
Emissions from the Folsom Dam modification project is adding the equivalent of 0.08 tons daily to Sacramento County’s inventory for nitrogen oxide, said Kobza.