Local water alkalinity could impact river life

By: Erin Serpico
Publisher: The Diamondback
Published: September 23, 2013

Alkalinity in local rivers is on the rise, and human activity could be to blame.

A recent study conducted by a university-led team of researchers links human activity to shifts in the chemical makeup of rivers. The study, published in the Environmental Science & Technology journal in July, shows increasing alkalinity in rivers — a trend happening in this state and across the eastern part of the United States, said geology professor Sujay Kaushal, the leading author of the study.

The increase in alkalinity, water’s ability to neutralize an acid, is alarming to scientists because it could affect drinking water and harm aquatic life.

The team collected and analyzed water data from 97 sites along streams and rivers in the eastern U.S. and found an increase in alkalinity at 62 of them, including a site in Washington on the Potomac River and another in Bowie on the Patuxent River. Using additional records from the U.S. Geological Survey, the team was able to draw conclusions by comparing the newest data to information collected over the past 25 to 60 years.

Researchers attributed the increase in alkalinity to acid rain, which could cause rocks in watershed regions to weather, said Michael Pace, environmental sciences professor at the University of Virginia and co-author of the paper. When these rocks corrode, Pace said, alkaline particles wash into the streams and rivers.

As a result, the waters are becoming “harder,” Kaushal said, meaning they contain more minerals like calcium and magnesium. The added minerals make hard water difficult to clean and could complicate drinking-water safety, he said.

“One consequence of this process is that it increases the salinity of the water,” Kaushal said. “You’re dissolving all of these rocks with salt … so that water can affect drinking-water quality.”

This change in water chemistry could also have dangerous consequences for aquatic life, he added. Increased alkalinity could lead to accelerated algae growth, he said, harming living organisms and bodies of water.

Other reports suggest acid rain is less of an issue and the air is cleaner than in past years. But researchers believe their study’s results suggest acid rain has long-term effects on the chemistry of the studied bodies of water.

“People think that the problem went away,” Kaushal said. “But it didn’t.”

Former university research assistant Melissa Grese — who now works at AKRF, an environmental consulting firm — was one of the two research assistants who collaborated with Kaushal on this study. She worked on data collection and organization of the study.

It’s important for people to practice sustainable planning and consider the potentially harmful effects of their actions, Grese said.

By looking at possible issues such as acid rain, she said, people could gain more insight into the root of water problems.

“It’s undeniable that we, as humans, are often the root cause for many environmental problems,” said Aastha Kaul, a sophomore cell biology and genetics major. The issue is especially important now, she said, because of its potential effects on living organisms.

Among the paper’s other authors were ecologist Gene Likens from the Cary Institute of Ecosystem Studies and Ryan Utz from the National Ecological Observatory Network. Likens, part of the effort that originally discovered acid rain in North America, contributed greatly to the report.

“[The study findings] show how much humans are impacting what you would think is a relatively natural process,” Pace said. “We humans are causing that to change in substantial and significant ways.”

Reprinted from The Diamondback with permission. http://www.diamondbackonline.com/news/local/article_9722c04c-2408-11e3-8e1f-001a4bcf6878.html.