Gallatin Fossil Plant discharges wastewater and industrial stormwater in accordance with National Pollutant Discharge Elimination System (NPDES) permits issued by the Tennessee Department of Environment and Conservation (TDEC) with oversight by the U.S. Environmental Protection Agency.
Wastewater discharges are covered by an individual NPDES Permit (No. TN0005428) and include the ash pond discharges (Outfall 001), condenser and equipment cooling water (Outfall 002) and other minor wastewater sources.
The NPDES permit monitoring requirements for the ash pond include:
The permit sets numeric limits for pH, total suspended solids, oil and grease and toxicity. All other parameters must be monitored and reported to TDEC in a monthly report. The permit also requires TVA to use best management practices to address controls on metals and ash pond discharges.
Outfall 002 is monitored for flow and temperature. The daily average discharge temperature is limited to 32.8 ° C, which is closely monitored—especially during the summer months. No biocides or other chemicals are added to the cooling water.
There are no limitations or monitoring requirements for IMPs 006 and 009 under the current permit. The plant intake water is monitored annually for the same metals monitored at the ash pond discharge plus total hardness (as CaCO3).
Stormwater discharged from the site is covered by the Tennessee Multi-Sector Permit for Storm Water Discharges Associated with Industrial Activity (TNR053186). As required by this permit, Gallatin has implemented a Storm Water Pollution Prevention Plan and performs visual monitoring of stormwater discharges on a quarterly basis and analytical monitoring annually.