20120658 Ver 1_More Info Received_20120814

Strickland, Bev
From: Mcmillan, Ian
Sent: Tuesday, August 14, 2012 10:26 AM
To: Dennison, Laurie; Strickland, Bev
Subject: FW: Duke Pond Minimum Release Structure
Attachments: Minimum Release Siphon - DWQ Exhibit.pdf
E -mail correspondence to and from this address may be subject to the
North Carolina Public Records Lai and may he disclosed to third parties.
From: Yates, Kevin [mai Ito: yates johnrmcadams.com]
Sent: Thursday, August 02, 2012 11:36 AM
To: Kulz, Eric; Mcmillan, Ian; Alsmeyer, Eric C SAW
Cc: Caldwell, James
Subject: FW: Duke Pond Minimum Release Structure
All,
James Caldwell in our office has re- designed the riser structure of the proposed water re -use pond at Duke so that the
minimum release water is pulled from 4 -ft to 6 -ft below normal pool dependent upon the pond fluxuation. While we can't
give an exact water temperature, we know that the water will be noticeably cooler at 4 -ft to 6 -ft below the surface than if
the minimum release were to be pulled from the surface. Below is more detail on the design and attached is a schematic
with the re- designed riser structure.
Call or email with any questions.
Thanks,
Kevin
From: Caldwell, James
Sent: Thursday, August 02, 2012 10:30 AM
To: Yates, Kevin
Subject: Duke Pond Minimum Release Structure
Kevi n,
For the Duke Pond, the attached sketch /exhibit shows the spillway riser structure and the minimum release and valve
layout. The bottom of the pond is at 301 and the minimum release is set at 308.80' This minimum release is a 6" pipe
and is sized for the 0.15 cfs minimum release to hold the pool at 309.0. The pipe turns down into the lake down to 307,
so when the pool is at 309, the water is drawn from 2' below the surface.
The flux of the pond is from 309 to 313, with it likely operating around 311 most days. So at 311, the minimum release
water will be pulled from 4' below the surface and when the pond is full to 313, it will be 6' below the surface.

The minimum release will be operated by an automated valve system. There are also valves at 309 and 311 to allow
Duke to control the 4' flux better. So obviously when either the 309 or 311 valves are open, the release will be much
greater than the 0.15 cfs.
-James
James W. Caldwell, PE
Project Manager
Office: 919- 287 -0891
Cell: 919- 475 -4092

EL. = 31 7.50
EL. = 313.00
EL. = 31 1.00
L. = 309.
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WATER A division of The John R. McAdams Company, Inc.
SCALE: YV A'TER RECLAMATION POND ENGINEERS • PLANNERS • SURVEYORS • ENVIRONMENTAL
N. T. S. RESEARCH TRIANGLE PARK • CHARLOTTE
DURHAM, NORTH CAROLINA 2905 Meridian Parkin Durham NC 27713
C/] DATE: 08 -02 -2012 800 -733 - 5646.— johmmeadams.com. License No.: C -0293