Welsh Plant

September 2019

Southwestern Electric Power Company continues groundwater monitoring activities around Welsh Plant’s coal ash storage sites. We analyze this data relative to EPA groundwater protection standards.

Analysis of this data by an independent third party indicates that these coal ash storage sites are not impacting groundwater quality.

We will continue groundwater monitoring at the Welsh Plant and will provide an update if we detect any samples above the EPA standards.

March 2018

Southwestern Electric Power Company (SWEPCO) completed the first steps in the new groundwater monitoring program under this rule.

SWEPCO took a series of groundwater samples at the boundaries of the three ash storage sites. We took some samples before the groundwater passed beneath the ash storage sites. (The reports refer to this as up-gradient.) We took other samples after it passed beneath the sites (down-gradient). We used the data to establish baseline levels for 21 different substances in the groundwater. Moving forward, we will use these baselines to help determine if our ash storage sites are impacting the groundwater.

It is important to remember that variations in the level of these substances in groundwater are natural and occur for many reasons.

The initial data at Welsh Plant showed potential groundwater impacts very close to our storage sites. Additional groundwater monitoring did not indicate impacts from these sites.

We proactively reached out and met with plant neighbors and community leaders to answer questions about the data collected so far and to discuss next steps.

An independent third party successfully completed Alternate Source Demonstrations for the primary bottom ash pond and bottom ash storage pond sites at Welsh Plant. The successful demonstrations identify other factors that could impact sampling results as the groundwater passes the CCR storage sites.

The plant will continue sampling groundwater at the primary bottom ash pond and bottom ash storage pond to determine any future need for additional monitoring.

November 2018

The CCR rule established location restrictions for coal ash storage sites. It requires that storage site locations be evaluated regarding proximity to groundwater aquifers, wetlands, fault areas, seismic zones and unstable areas (example: presence of quicksand).

AEP and SWEPCO recently completed the required review of location restrictions for Welsh Plant’s CCR storage sites. This review found:

• The Welsh primary bottom ash pond is separated from the uppermost aquifer by less than the five feet specified by the rule. It does meet the other four restrictions.

• The Welsh bottom ash storage pond and landfill meet all location restrictions.

• SWEPCO will continue to test water from all of these wells twice each year.

• If, at any time in the future, SWEPCO determines that an ash storage site is impacting the groundwater, we will seek public input as we develop a mitigation plan to address these impacts.

• We will stop placing CCRs in the primary bottom ash pond as soon as alternate storage can be made available. We then will begin closure activities.