20080915 Ver 1_Lookout Shoals 4-24-16 minflow dev notice_dwr.pdf_20160510

W a ter Resources
ENVIRONMENTAL QUALITY
PAT MCCRORY
Govei no,
DONALD R. VAN DER VAART
SeO etcay
S. JAY ZIMMERMAN
Director
May 10, 2016
Mr. Mark Oakley
Water Strategy, Hydro Licensing and Lake Services
Duke Energy Carolinas LLC
526 South Church Street
Mail Code EC12Y
Charlotte, NC 28202
RE: Lookout Shoals Development, Catawba - Wateree Hydro (FERC Project No. P-2232)
Minimum flow deviation
Dear NU. Oakle :
This letter is in response to the document filed with the Federal Energy Regulatory Commission
(FERC) on April 29, 2016, entitled Notification of Deviation fi^om Minimum Continuous Flow
("notice"), for the Lookout Shoals Development --a component of Duke Energy's Catawba--
Wateree Hydro Project ("Project") (FERC Project No. P -2232) --reporting a flow deviation on
April 24 between 1:15 a.m. and 5:45 a.m. As reported, the minimum flow of 80 cubic feet per
second was not verifiably available to the Catawba River between these two time stamps
(Enclosure 1). The loss of flow was reportedly due to a combination of mechanical and operator
error. Under the Project's Comprehensive Relicensing Agreement Maintenance and Emergency
Protocol (MEP), Duke categorizes this deviation as a `B.2" [Maintenance of the Normal Means
of Providing Minimum Flows (Unscheduled)].
To document this drop in flow, the notice includes a screenshot (Enclosure 2) of the stage height
at the downstream, U.S. Geological Survey (USGS)-installed gage, which has been functional
since March, 2016. Enclosure 1 of the notice indicates that 100 percent exceedance of the
minimum flow was not achieved while Enclosure 2 may suggest that impacts were mitigated to
some extent by leakage. Although the notice states that the USGS also installed an oxygen
monitoring device in the tailrace, no dissolved oxygen readings were provided. Also, the notice
states:
"By copy of this letter, the North Carolina Wildlife Resources Commission, the
North Carolina Department of Environmental Quality, and the United States Fish
and Wildlife Service are notified and asked to advise Duke Energy immediately if
further consultation is needed."
State of North Carolina I Environmental Quality I Water Resources
1611 Mail service Center I Raleigh, North Carolina 27699-1611
919 707 9000

Mark Oakley, Duke Energy Carolinas LLC May 10, 2016
RE: Lookout Shoals Hydro Facility (FERC Project No. 2232)
In this regard, the Division of Water Resources offers the following comments.
1. The notice does provide strategies to address apparent staffing and notification deficiencies
that will hopefully reduce the likelihood of such future occurrences at Lookout Shoals as well
as the Project's other generation facilities.
2. The notice states the following:
"No adverse environmental impacts were observed or reported as a result of this
short -duration incident...."
Given that (1) the operator was unaware of the alternate minimum flow unit's failure to activate
and (2) the outage occurred during the pre -dawn hours, it is unclear what actions were
undertaken in the Catawba River downstream of Lookout Shoals to assess the environmental
impacts. To address the monitoring requirements of the MEP's B.2(2), for this incident and for
future outages under the MEP, if Duke Energy would please provide additional details, e.g., field
notes, photographs, readings, etc., to better understand and evaluate the impacts associated with
such outages. In addition, the training described as a component of the "corrective actions"
should include steps to document an environmental assessment and when to request additional,
qualified personnel.
Although there is a reasonable expectation that there was no significant environmental impact
associated with this episode, without additional details it is not possible to make an informed
conclusion.
If you have questions or wish to discuss further, please feel free to contact me by phone at 919-
707-9029, or by email at [e-mail].
Sincerely,
Fred R Tarver III
Attachment
ec: Chris Goudreau, NCWRC
Bryan Tompkins, USFWS
Karen Higgins, NCDWR-401 Unit

Mark Oakley, Dul<e Energy Carolinas LLC
RE: Lool<out Shoals Hydro Facility (FERC Project No. 2232)
Catawba-Wateree Project (FERC No. 2232)
Comprehensive Relicensing Agreement
Lookout Shoals
Device Location Rationale
The minimum continuous flaw will be provided by either one of the small auxiliary hydro
units (Location 2) during periods when the larger hydro units are not operating. The
configuration of the Lookout Shoals tailrace (large pool upstream of first downstream
hydraulic control) exhibits very little stage change with or without the auxiliary hydro unit
generation. In addition, the elevation of the tailrace is also a function of Lake Norman's
C -W CRA Sig Copy (Rev 1) 10-2046 F - 11
May 10, 2016
Approximate
Map
Data
Recommended
Distance
Comments
Data Collection
Location
Location
Downstream
(miles)
Temperature
East W ngwail -
In Situ - Pope ,
Wired to Station
I
Dissolved
Tailrace
0-01
Monitor Location
Computer
Oxygen
Unchanged
Minimum
Continuous
Turbine
2
Flows
Turbine Records
nla
n!a
Generation
Project Hourly
Records
Flows
Current Device on
Wired to Station
3
Reservoir Levels
Lookout Forebay
n!a
the Intake
Computer
Structure
Device Location Rationale
The minimum continuous flaw will be provided by either one of the small auxiliary hydro
units (Location 2) during periods when the larger hydro units are not operating. The
configuration of the Lookout Shoals tailrace (large pool upstream of first downstream
hydraulic control) exhibits very little stage change with or without the auxiliary hydro unit
generation. In addition, the elevation of the tailrace is also a function of Lake Norman's
C -W CRA Sig Copy (Rev 1) 10-2046 F - 11
May 10, 2016

Mark Oakley, Duke Energy Carolinas LLC
RE: Lookout Shoals Hydro Facility (FERC Project No. 2232)
Catawba-Wateree Project (FERC No. 2232)
Comprehensive Relicensing Agreement
reservoir level (at full pond, the reservoir level extends upstream of the hydraulic
control). Therefore, the minimum continuous flow and hourly flow rates would be best
monitored by the individual generation records of each hydro unit at Lookout Shoals
Hydro.
The previous water quality monitoring site was located on the east wingwall downstream
of Unit 1. That site adequately represented the water quality of the turbine flow when all
the hydro units were identical. The nearest downstream structure to place a monitor in
the center of the channel is the 1-40 Bridge which is 1.3 miles downstream. The 1-40
Bridge site is strongly influenced by Lake Norman's reservoir level, and the long travel
time of the minimum flow would influence the water quality at minimum flow. Therefore,
the 1-40 Bridge location is not preferred for water quality monitoring. Since no other
downstream structure exists to place a monitor in the center of the river, the wingwall
site (Location 1) represents the best logistical option available for water quality
monitoring. This wingwall site will be accessible under all Project flows, and will provide
a rapid response of the station to water quality conditions. The monitor will be secure
since it is located inside the security fence.
C -W CRA Sig Copy (Rev 1) 10-20-06 F - 12
May 10, 2016
M