Sunday, November 6, 2016

Groundwater along the river

Have you ever wondered about how the Ohio River affects groundwater near its banks? Whether water from the Ohio seeps into the water table and affects the quality of wells nearby? No? Well, I have.

Here is a description of how the Ohio River interacts with groundwater near its banks as described the publication "Assessment of Hydrogeologic Terrains, Well-Construction Characteristics, Groundwater Hydraulics, and WaterQuality and Microbial Data for Determination of SurfaceWater-Influenced Groundwater Supplies in West Virginia" by Mark D. Kozar and Katherine S. Paybins, published by the U.S. Geological Survey.

"Alluvial aquifers bordering the Ohio River in western West Virginia are also potentially highly susceptible to contamination because these alluvial aquifers can receive significant recharge from the adjacent Ohio River. Any potential contaminants that may be present in the river have the potential to enter the aquifer and contaminate wells completed within the sand and gravel alluvial sediments within which the wells are completed. These same alluvial sediments, however, help to retard the movement of bacteria and other potentially pathogenic organisms, such as Cryptosporidia and Giardia lamblia, into the aquifer. As a result, samples from alluvial aquifers bordering the Ohio River and elsewhere within the State do not commonly test positive for indicator bacteria, such as total coliform, fecal coliform, or Escherichia coli (E. coli). The alluvial sediments do not, however, provide assimilative capacity with respect to water soluble compounds such as nitrate and certain volatile and semi-volatile organic compounds. Therefore, the Ohio River alluvial aquifers are highly susceptible to organic compounds present in the river or on the land surface near a well. These aquifers are also susceptible to nitrate contamination from fertilizers, pesticides, and manure, which are commonly used on the fertile agricultural soils present on terraces along the Ohio River."
The entire document is nearly 70 pages, and if you have any curiosity about how the river affects the source of drinking water for a number of people along its banks whose water systems rely on groundwater, it's worth a read.

Diverging from this, reading the report and coming across the definition of a Ranney well took me back to 1978. In January of that year, a Chessie System train derailed in Point Pleasant, WV, and spilled about 20,000 gallons of a material called epichlorohydrin near the city's water intake well. The city had to close that wellfield and find a new source of water. I remember covering several city council meetings after the spill and listening to the mayor talk about the Ranney well field north of town. If memory serves, it had been developed to supply DNT (dinitrotoluene, used in the production on trinitrotoluene, or TNT) during World War II. The DNT production area was one of the places where the infamous Mothman was first seen, I think.

Back in the late 1960s and early 1970s, if you drove up Route 7 on the Ohio side you could see some concrete or stone block structures that were part of the DNT plant's Ranney well system. I don't recall having seen them in recent years, so I don't know if they're still standing.