NC0024406_Destratification Approval_19970721

State of North Carolina
Department of Environment, N:.
Health and Natural Resources `
Division of Water Quality
James B. Hunt, Jr., Governor Ilk
Jonathan B. Howes, Secretary [D E'---' N
A. Preston Howard, Jr., P.E., Director
July 21, 1997
Mr. Ron Lewis
Duke Power Company
Mail Code - MG03A5
13339 Hagers Ferry Road
Huntersville, North Carolina 28078-7929
Subject: Destratification Approval
Permit No. NCO024406
Belews Creek Steam Station
Stokes County
Dear Mr. Lewis:
Per the conference call with David Goodrich and Mary Cabe of my staff on June 25, the
Division hereby grants approval for Duke Power Company to initiate the new destratification
system (fine bubble diffuser) at Belews Creek Steam Station. It is the Division's understanding
that the old system will stay in place until environmental and process efficiency monitoring is
completed. Please submit to the Division your interpretation of the new systems effectiveness,
including the results of monitoring conducted during performance testing. _.
As always, I appreciate working with you and the staff at Duke Power Company. If this
system performs as envisioned, more efficient mixing could result in a lower volume of intake
water being used and fewer occurrences of high temperature discharges. This change should
benefit the station operation and the environment. If you have any questions or comments, please
contact Mary Cabe at [phone], extension 518.
Sincerely,
Steve Tedder, Chief
Water Quality Section
cc: Winston-Salem Regional Office/Water Quality Section
Permits & Engineering Unit
Mr.. Maurice D: 'Mclntosh, VY.
Duke Power Company
Fos sil/Hydrogeneration Dept.
NCSR 1908
Walnut Cove, North Carolina 27052
Mr. Scott Van Horn/Wildlife Resources Commission
Mr. Jay Sauber
Mr. Jimmie Overton
P.O. Box 29535, Raleigh; North Carolina 27626-0535 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post -consumer paper

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416/25/97 16:57 FAX [phone] DPCO GEN SVC 0 002
JUNE 25,1997
Conference Call with NCDEHNR - RELF.RI18 CREEK STEAM STATION
INTRODUCTION
Thanks for opportunity to review and dirnuss modification to
* Belews Creek Destratif cation System
* Renewal of NPDES permit
Modification of 17estratification System
Based on opezation of existing 5yatem, moving the air diffuser approximately 13
feet deeper will not create low levels of dissolved oxygen throughout the water
column when hypolimnetic water is lifted with rising air bubbles.
No additional cross-sectional area will be impacted. Fish will continue to have
"escape?' corridors or be able to move to areas of preferred habitat within Belews
Lake.
* Operation of the present desertification system has not resulted an super
saturation of oxygen. in, Belews Lake and "gas -bubble' disease in fish has not
been observed. The ocamence of "gas bubble" disease is unUoly due to
operation of the modified system.
The existing environmental monitoring program on Belews Lake, as described in
the report on assessment of balanced indigenous populations in Belews Lake that
was submitted to NCDEHNR for review in August 1996 along with the NPDES
renewal application, will be used to evaluate long term operation of the modified
system. Testing will include one additional long-term waiver quality monitoring
sample will be collected prior to operation of the modified system and water
temperature profile monitoring conducted as ,needed to evaluate operation of the
system.
The air diffuser in the modified system will have smaller air bubbles than the
present system. This will increase air to water surface area and provide more
efficient Lifting than, the present system and improve operation capability to more
,judiciously use the cool water resource- Optimizing, use of coal water to improve
station operation is also expected to minimize occurrence of high discharge water
temperatures. This is viewed as a win-win situation.
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,%46/25/97 16:57 FAX [phone] DPCO GEN SFC
R.eaewal of NPDES Permit Comments
Vice President and Department change from Maurice D. McIntosli Vice President
of Fossi VHydro Dopwtmcat to T.C. McMoekin 'Vies President of Power
Generation
Change Mass Limits back to concentration limits at Outfall 003 per
exception listed. in 40 CFR 122.45 (fl(1)(iii), since limitations or standards are
infeasible because the mass of the pollutant disebarged =mot he totally related to
a measure of operation of Bcicwa Creek Steam Station (i.e. raiuM events), Also
"actual production'' per 40 CFR 122.45(b) does not pertain to electric utility waste
stream flows and thus its mass discharges.
Eliminate or modify monitoring requirements on the internal waste stream at
Outfall 006 as monitoring; of these some parameters at OUtWI 003 is also
required. The language in 40 CFR 122.45 (h) (1) states that limitations or
stndwds may be imposed at the point of an internal discharge when imposing
permit effluent limitations or standards at the point of discharge are unpractical or
infeasible_
No discharge from the chemical metals cleaning holding pond has occurred since
the last boiler cleaning in 1993, This is the result of the change to an oxygen
addition corrosion/erosion treatment process. The need to do a chemical metals
cleaning is being determined via yearly inspection of boiler tube samples. No
chemical cleanings are planned for this year and are not expected to be required in
1998.
If limits are to be imposed, then change to concentration limits for chemical
MOWS cleaning wastes per 40 CFR 423.13 (e). Duly chemical metOls cleaning
wastes aze discharged to this pond. Mass limits should not he imposed per
exception listed In 40 CFR 122.45 (t)(1)(W) since Ihnitatiow arc infeasible
because the mass of the pollutant discharged cannot be totally related to a measure
of operation of Belews Creek Steam Station (i.e. rairffall events).
U 003

Page 1
Note for Mary Cabe
From: Don Safrit
Date:
Mon, Jun 16, 1997 8:54 AM
Subject:
RE: Duke Belews destratification
To:
Dave Goodrich
Cc:
Coleen Sullins; Mary Cabe
I agree - proceed to contact Duke and schedule a meeting - Thanks, Don
From: Dave Goodrich on Sun, Jun 15, 1997 12:49 PM
Subject: RE: Duke Belews destratification
To: Coleen Sullins; Don Safrit
Cc: Mary Cabe
Don and Coleen - I think we should sit down with Duke, Jay, Scott, and whoever else is
interested to discuss this proposal. Mary is working on finalizing their permit and we will be
receiving a call from Ron Lewis (Duke) soon to set up a conference call regarding a change in
their permit as a result of an EPA comment. (I saw Ron on Friday, Mary. He's checking
out compliance issues surrounding the new mass limit and will give you a call.)
The work surrounding the destratification plan should not hold up the NPDES permit, but I'd
ask that Mary and I be included in these discussions in the future. (Mary - Please print this
out for the files. We should share Jay's request for additional information with Duke.)
Thank you,
Dave
From: Coleen Sullins on Sat, Jun 14, 1997 12:37 PM
Subject: FW: Duke Belews destratification
To: Dave Goodrich
Sorry, forgot to cc you on this message. I am still waiting on the regional office.
Obviously, Jay has problems with this. Coleen
From: Don Safrit on Thu, Jun 12, 1997 7:46 AM
Subject: RE: Duke Belews destratification
To: Coleen Sullins
Thanks, Don
From: Coleen Sullins on Wed, Jun 11, 1997 6:13 PM
Subject: FW: Duke Belews destratification
To: Don Safrit
Here it is. Coleen
From: Jay Sauber on Tue, Jun 3, 1997 8:52 AM
Subject: Duke Belews destratification
To: Coleen Sullins
Cc: Jimmie Overton; Larry Ansley
Page 2
On May 27th I reveived a request from you for review of a memo from Duke Power( Ron
Lewis) addressed to SWT concerning a modification of the Intake Destratification System.
The memo provided little detail with which to make an environmental review. Since the
scheduled instalation and testing of this system is scheduled for June 1997 and you requested
comments to be returned to you by June 30, I am not sure of the permitting questions that
you may have.
Appropriate questions seem to be:
1. Will the destratification system create low levels of D.O. throughout the water column by
lifting hypolymnetic waters?
2. How much the available cross sectional area will be impacted either by lower temperatures
or lower D.O. ? Will fish have "escape" corridors?
3—What is the potential of rapid changes in the D.O. saturation levels affecting fish species
during transitional time periods? Likelyhood of "gas bubble" Disease in fish?
4. What are the details of the monitoring plans to be conducted during performance testing
time periods? Will monitoring be in place during the critical summer months of r�A�6gust and
ept,.her? '
5. If fine bubble difusers are to be used it can be expected to get some oxygen�dissolved into
the system. If "lifting" size bubbles ie big boys perhaps no additional DO will be a"vailable.
Finally I would suggest that any review include Mr. Scott Van Horne of the WRC, he is very
knowlegable of Belews issues and will provide comments in a timely manner.
I I
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- State of North Carolina
Department of Environment, .
Health and Natural Resources
Division of Water Quality .
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
July 7, 1997
Mr. David F. Mitchell, Technical System Manager
Duke Power Company
Electric System Support
Water Protection
13339 Hagers Ferry Road
Huntersville, North Carolina 28078-7929
Dear Mr. Mitchell:
�EHNR
Subject: Flow Measuring Changes
Duke Power NPDES Permits
The Division acknowledges receipt of your correspondance dated June 12, 1997 regarding flow
measurement at Plant Allen, Belews Creek, Buck, Cliffside, Dan River, Marshall and Riverbend steam
stations. With this letter, the Division approves the proposed changes to the flow measurement equipment
at the above referenced facilities. It is the Division's understanding that the proposed changes are being
made in order to improve flow measuring accuracy and to implement a consistent approach system -wide.
Should you have any questions concerning this matter, please do not hesitate to contact Mark
McIntire at [phone], extension 553.
Sincerely,
David A. Goodrich
NPDES Group Supervisor
cc: Central Files
Asheville Regional Office / Water Quality
Mooresville Regional Office / Water Quality
Winston-Salem Regional Office / Water Quality
Permits and Engineering Unit / NPDES Permit Files
NC0004979, NC0004774, NC0005088, NC0003468,
NC0004987, NC0004961, NCO024406
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post -consumer paper

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