BC_CoverLetterToSheliaHolman_20181115

f DUKE
*. ENERGY
November 15, 2018
Ms. Sheila Holman
Assistant Secretary for Environment
North Carolina Department of Environmental Quality
1611 Mail Service Center
Raleigh, North Carolina 27699-1611
Paul Braovitch
Senior We President
Environmental, Health & Safety
526 S. Church Sheet
Mail Code: EC3XF
Charlotte, NC 28202
[phone]
Subject: Belews Creek Steam Station ash basin closure options analysis, groundwater modeling
and community impact analysis
Dear Ms. Holman:
Duke Energy is providing information in response to the North Carolina Department of
Environmental Quality's requests on September 13 and October 8, 2018, to submit preliminary
updates to the closure options analysis, groundwater modeling and community impact analysis
for the Belews Creek Steam Station. These studies represent a key portion of the work the
company has performed to develop closure plans that balance a variety of considerations.
Duke Energy is committed to closing ash basins in ways that are safe, timely, environmentally
sound, and based on thorough science and engineering. In addition, effective closure plans are
site -specific and must ensure ash is managed in ways that continue to protect public health,
safety and the environment. Importantly, the planning process also considers how closure
choices may affect neighbors and communities.
After considering a number of potential closure options at Belews Creek, three options were
advanced for detailed analysis: closure -in -place, closure -by -removal to an on -site landfill and a
hybrid closure approach.
Based on a comprehensive assessment, Duke Energy recommends a hybrid closure plan to
safely close the Belews Creek ash basin. This approach continues to protect people and the
environment, while also minimizing disruption to communities and managing cost. Under this
plan, ash would be excavated from the northern end of the basin and consolidated to the
southern end and then capped with a final engineered cover system. This closure option
reduces the size of the ash footprint by about half.
North Carolina As a National Leader
To help ensure that the work done in North Carolina balances various considerations and
incorporates interdisciplinary perspectives, the company created the National Ash Management
Advisory Board (NAMAB) in 2014. This group of well -recognized experts in environmental
engineering, waste remediation, toxicology and other fields continues to provide ongoing
technical input and vet the various choices and tradeoffs inherent to any closure plan.
As previously stated, the enclosed documents represent key elements among the extensive
science and engineering being conducted by dedicated teams at Duke Energy and outside

experts, with ongoing input from NAMAB, to identRy safe and smart basin closure plans for
remaining sites in North Carolina.
Groundwater Modeling
As multiple sources have validated, the ash basin has not affected neighbors' drinking water
wells near the Belews Creek Plant. For communities concerned that nearby well water could be
affected in the future, state lawmakers in 2016 passed legislation requiring the company to
proactively provide permanent drinking water sources. The company has completed the
installation of advanced, whole -home filtration systems for neighbors within a half -mile of the
Belews Creek basin, even though evidence demonstrates the basin is not impacting them, and
most neighbors' well water already met the appropriate performance standards for the filter
systems.
In addition to advanced planning for safe drinking water, the N.C. Coal Ash Management Act
(CAMA) outlines an elaborate process to monitor and study groundwater near ash basins. This
involves thousands of monitoring wells across the state and using those real -world data points
to develop site -specific models that seek to predict how groundwater will respond to various
closure scenarios. This process also involves several iterations of extensive groundwater
studies and developing proposed corrective action steps that will work in tandem with basin
closure as necessary to address groundwater impacts.
Based on extensive study, the company has determined that coal ash impacts are very
localized at Belews Creek near the ash basin and generally on plant property. In any closure
scenario, the most effective step the company can take to improve groundwater is to safely
remove the free water from the ash basin. When predicting future groundwater response at
Belews Creek, the models demonstrate that:
• Groundwater responds similarly to the various closure options, and the time to achieve
compliance with the state's groundwater quality standards at the compliance boundary is
approximately 100 to 200 years.
• The simulations indicate there will continue to be no impact to drinking water wells.
Groundwater impacts will continue to be evaluated as the updated modeling expands to other
parameters.
The models do not include the effects of any additional groundwater remediation steps the
company may take in the future. As part of a separate state -directed process, the company will
submit corrective action plans that propose steps that can be taken where groundwater
necessitates additional or more timely improvement. In particular, the company will pursue
groundwater remedial actions where needed with a focus on any surface water or offsite
property impacts.
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Community Impact Analysis
In addition to relying on strong science and engineering, the company felt it was important to
consider various stakeholder interests and community impacts when developing its
recommended ash basin closure plans. In addition to its own research, which is included in the
comprehensive options analysis, the company relied on an outside consulting firm, Exponent, to
study the potential community impacts of various closure scenarios. Key take-aways include:
• All closure options evaluated would be protective of human and ecological health.
• Excavation causes greater disturbance to the local community, in comparison to the
other options.
• Hybrid closure better maximizes environmental benefits, compared to excavation and
capping, because it offers equivalent protection of human and ecological, health, has
relatively lower disturbances to the neighboring community, and produces a net gain in
habitat -derived environmental services.
The community impact analysis does not compare greenhouse gas emissions from onsite and
offsite trucking activity; therefore, a supplemental analysis will be provided comparing the
impact of various closure options on greenhouse gases and other air emissions.
The results of the community impact analysis vary by site, but in all cases cap -in -place closure
may be performed without adversely impacting the community. In some cases, reforestation of
land parcels may be advisable to offset any net habitat losses.
The conclusions in the community impact analysis are subject to revision if new landfill space
must be created to accommodate production ash. In such circumstances, excavation options
would score lower in the community impact analysis.
Options Analysis
The company's options analysis considers the many aspects and tradeoffs related to basin
closure including environmental protection, schedule and the company's own analysis of
community impacts. In addition, as a regulated utility, Duke Energy is obligated to evaluate the
cost-effectiveness of the closure options. The company developed a relative weighting and
scoring system with input from the NAMAB that was used to evaluate and score various closure
alternatives.
For Belews Creek, key take-aways from the options analysis include:
• The hybrid option has the lowest estimated capital construction cost, while excavation
would cost more than triple that amount. .
• Under the excavation scenario, trucks would cross Pine Hall Road to the new adjacent
landfill location more than 200 times per day, on average, for nearly 11 years. The
resulting landfill would grow to 200 feet in height by the time work was finished.
• Construction schedules for capping or the hybrid options are similar, and meeting the
CAMA deadline of 2029 would be a challenge for both options. Excavation would take
up to 16 years, extending well beyond the CAMA deadline of 2029 and likely the final
CCR deadline of 2034.
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The company's recommended closure approach across its North Carolina sites reflects a
science -based combination of excavating, capping in place and recycling ash for concrete and
other beneficial purposes. Duke Energy remains committed to safely closing ash basins and
welcomes input from DEQ and the public to best balance these various tradeoffs.
5incchely,
Paul Draov' h
Senior Vic., President
Environmental, Health & Safety
cc: Jim Wells, Duke Energy
Dave Renner, Duke Energy
Randy Hart, Duke Energy
Ed Mussler, DWM
Jon Risgaard, DWR
Andrew Brooks, DEMLR
Bill Lane, NCDEQ General Counsel
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