Date: 2025 08-August 26

Link:

• Public Hearing: TVA Allen Fossil Plant (TVA ALF) West Ash Disposal Area (WADA)
• tn.gov/content/dam/tn/environment/solid-waste/documents/public-notices/ppo_sw-ccr-allen-cara-plan.pdf

Key concerns are:

• Metals
  • molybdenum
  • lead

A citizen asked

• How will legislation be used to hold companies accountable retroactively

During environmental investigation

• TVA installed deep borings
• U of M CESAR performed drawdown / breach tests
• Hydraulic containment was identified as an issue, with downward migration
• U of M has research on breaches in the region (a la Sarah Houston)

Sarah Houston

• Have breaches been identified on the West Ash Disposal Area?
• TDEC: There is a thick clay layer (~100 ft) there, so TDEC gladly reports that there are no breaches in that area.

TVA Allen Fossil Plant - Ash Disposal Presentation

Focus:

• Ground water
• Determine if the clay layer is competent

History:

• All coal ash has already been removed
• The commissioners order: OGCIS-0117
• The EPA implemented the TDEC approved plan
• TDEC accepted the environmental assessment report, and the EPA then issued recommendations.

Abbreviations

EIP - Environmental Investigation Plan
ROD - Record of Decision
CBR - Closure by removal
IRA - Interim response action
WADA - West Ash Disposal Area
CARA - Corrective action / risk assessment

Findings

• There is a fluctuation of the ground water
• MCL's (standard exceedances)
  • Moly
  • Arsenic
  • Lithium
  • These exceedances are only among 6 wells, and are lower in the west than in the east
• Modeling by attenuation is feasible, but it will require more data than has been collected thus far
• Install recovery wells on the north side, over time.

The Care Plan

• All actions that TVA will take at the site
• They must list the methods of reaching the goal
• TVA must provide a schedule
• Ground water extraction with an eye on ground water protection standards
• The source material has been removed, there is no risk of further contamination.
• TVA will implement adaptive management.
  • Install treatment system
  • Monitor ground water, for concentrations changing over time - so that dynamic decisions can be made at a short time scale.
  • If concentrations naturally attenuate, we will be able to shorten the necessary life span of the system.
• Statistically improved performance must be demonstrated, to be below the ground water protection standard.
  • Quarterly ground water sampling
  • For several years, to have enough data to truly determine.

Citizen concern

• Pollution of the David Well Field
• Wastewater odor
• Seeps
  • Located on north side
  • Mitigated due to dewatering process
  • TVA must still do seep inspections for dam management
  • Will McKellar Lake be sampled for monitoring? No.
• Arsenic and pH data that is unique to the Allen site.
  • Where did it come from? No idea.