From: The Otter - Winter 2021

Historic Study Underway

A significant and historic research effort studying the relationship between the Big Sioux River and the aquifer that underlies its channel and those lands adjacent to the river is now being conducted by South Dakota’s Geological Survey, an agency of the state’s Department of Environment and Natural Resources. This multi-year project is especially interested in determining how river flows migrate into its aquifer, the speed of that movement, the association of aquifer volume and river flows, and how water quality in the Big Sioux River impacts the quality of water in the aquifer. Approximately 300,000 people consume water from wellfields tapping this aquifer.

River Wildlife Numbers Dwindle

River-based biodiversity is dramatically shrinking because of human activities. A study by University of Wisconsin researchers states, “Multiple environmental stressors, such as agricultural runoff, pollution and invasive species, threaten rivers that serve 80 percent of the world’s population. These same stressors endanger the biodiversity on 65 percent of the world’s river habitats, putting thousands of aquatic wildlife species at risk.” Though the researchers didn’t mention climate change, this factor certainly adds problems to water quality and flow patterns. The researchers declared that it is smarter and more cost-efficient to prevent river degradation rather than respond to degradation.

River Flows Are Changing Color

Shifting weather patterns and more powerful precipitation events triggered by climate change cause soils, agricultural chemicals and other pollutants to wash into rivers and change water chemistry and color. Analyzing nearly 16 million satellite images taken over three decades allowed researchers to discover that about 33% of America’s rivers have changed color since 1984, leaving only about 5% retaining their natural color. They also determined that 56% of America’s largest rivers (rivers at least 197 feet wide) were predominately yellow, because they carried excessive amounts of soil and sediment, and 38% appeared predominately green because of algae buildup due to fertilizer runoff. The same factors influencing the nation’s largest rivers also impact smaller rivers, such as the Big Sioux.

Pharmaceutical Waste

Often overlooked as a threat to clean water are the impacts associated with medicines and pharmaceuticals. Scientists with the United States Geological Survey were able to detect and identify chemicals used in pharmaceutical production as far as 18 miles downstream from where they were discharged into a waterway after so-called treatment. Not only does the manufacturing process for pharmaceuticals pollute waterways, so does the disposal of such chemicals by homeowners, landowners and businesses. This can happen by tossing them into the garbage or flushing them down the toilet. Many of the more than 4,000 prescription medications used for humans and animals ultimately find their way into the environment. To dispose of unused medicine and pills, deliver them to a local take-back facility. In Sioux Falls, old or unused prescriptions can be deposited in the lobby of the downtown police department. Your neighborhood Lewis Drug store also accepts such medications. Otherwise, mix them with dirt or coffee grounds and place the mixture in a sealed bag. Place the bag in your household trash. Recycle or trash empty bottles of drug packaging after removing labels.