USGS
Groundwater discharge from an aquifer test at the Tennessee Valley Authority Allen Combined Cycle Plant in October.
The Shelby County Health Department placed rules on how the Tennessee Valley Authority (TVA) uses five wells at its Allen natural gas plant this week.
The health department prohibited TVA from using the wells, which the utility previously committed to not using, except in three circumstances:
• Sampling for contaminants or studying the connection of the shallow and deep aquifers. Approval for the studies must be granted by the Tennessee Department of Conservation.
• Using the plant for water in an emergency when Memphis Light, Gas & Water cannot provide it. This is to be done only to avoid “serious damage or disruption to the regional power grid.”
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Limited Maintenance of up to 30 minutes each quarter.
These modified permits are in response to a December request to limit or prohibit TVA’s use of the wells by the Southern Environmental Law Center (SELC) on behalf of Protect Our Aquifer and the Sierra Club in order to avoid contamination of Memphis’ drinking water source.
The health department previously gave TVA permits to drill five wells into the Memphis Sand Aquifer in order to pump about 3.5 million gallons of water to cool its energy plant here.
After tests found high levels of arsenic and lead at the site, TVA said it would not use the wells until after a state investigation into groundwater contamination is completed.
A coal ash pond at TVA’s Allen Fossil Plant.
The five wells in question are housed in the Allen Combined Cycle Plant, which sits within a half-mile of a leaking coal ash pond operated by TVA. The ash pond is the center of ongoing state and federal investigations into groundwater contaminants, including arsenic and lead. Studies have suggested that use of the wells could put the Memphis Sand Aquifer at greater risk of contamination from the coal ash pond.
Research done by the University of Memphis and the U.S. Geological Survey last year showed that the coal ash pond is connected to the Memphis Sand Aquifer through gaps in the aquifer’s protective clay layers. The study also found that this connection could cause the contaminated groundwater to be pulled into the drinking water source when water is pumped from the wells.
Amanda Garcia, the senior attorney for SELC, said TVA should have never asked for the permits to use the wells, and that “we’re pleased to see that the county acknowledged, in a letter, that TVA would be denied permits to drill the wells if they had applied today.”
She added that the rules placed on utility’s usage demonstrates “how serious the pollution risk is to the county’s drinking water source.”
Ward Archer, president of Protect Our Aquifer, agreed, saying the county made the right decision in placing restrictions on TVA’s well use.
“Last year, the Shelby County Groundwater Control Board made the first step to better protect the Memphis Sand Aquifer by adopting stronger rules for obtaining permits and operating wells that pull from the Memphis Sand.
“However, we still need better local groundwater protections across the area and we hope Shelby County continues to work to conserve our most precious natural resource.”