NC0076775_technical correction_20100521

AIM
NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
Governor Director Secretary
Mr. Mark Gross
Alcoa Power Generating, Inc.
P.O. Box 576
Badin, North Carolina 28009
Dear Mr. Gross:
May 21, 2010
Subject: Error Correction
NPDES Permit NC00076775
Falls Powerhouse
Stanly County
On August 20, 2009, the Division of Water Quality issued NPDES Permit No. NC0076775 to Alcoa Power
Generating, Inc. It has been brought to our attention that pH limit for Outfall 007 has been added due to an error. Please
insert the enclosed corrected effluent sheet and discard the old sheet. This permit modification becomes effective on the
effective date of the permit.
All other terms and conditions in the original permit remain unchanged and in full effect. These modifications are
issued pursuant to the requirements of North Carolina General Statute 143-215.1 and the Memorandum of Agreement
between North Carolina and the U.S. Environmental Protection Agency dated December 6, 1983.
If any parts, measurement frequencies or sampling requirements contained in this modification are unacceptable to
you, you have the right to an adjudicatory hearing upon written request within thirty (30) days following receipt of this letter.
This request must be in the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes,
and filed with the Office of Administrative Hearings, Post Office Drawer 11666, Raleigh, North Carolina 27604. Unless such
demand is made, this decision shall be final and binding. If you have any questions concerning this permit, please contact
Sergei Chernikov at telephone number (919) 807--6393.
cc: MRO-Surface Water Protection
NPDES File
Central Files
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone] Customer Service: 1-877-623-6748
Internet: www.ncwaterquality.org
An Equal Opportunity \ Affirmative Actidn Employer
NonrthCarolina
Naturally

Permit NC0076775
A. (2) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS [007]
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee is
authorized to discharge stormwater from outfall 007 [Sump Drain]. Such discharges shall be limited and
monitored by the Permittee as specified below:
PARAMETER
DISCHARGE LIMITATIONS
Monitoring Requirements
Monthly
Average
Daily
, Maximum.
Measurement
Frequency
Sample
Type
Sample
Location
Flow
Annual
Estimate
Effluent
Oil and Grease1
15.0 mg/L
20.0 mg/L
Annual
Grab
Effluent
pH2
Annual
Grab
Effluent
NOTES:
* Effluent or at the point closest to discharge where a representative sample of the discharge can
feasibly be obtained.
1 The tailrace shall be visually inspected for oil sheen attributed to facility operations on a weekly
basis in conjunction with inspections of the floor sump and rope skimmer. Confirmation that a
visual inspection was conducted shall be recorded in the operating log for the facility and provided
to the Division upon request.
2. There is no limit for effluent pH, however annual monitoring shall be required.
Best Management Practices (BMPs) must be employed to ensure that excessive pollutants are not discharged
to the surface water of the state. These practices should include as a minimum, routine maintenance of the
rope skimmer type oil/water separator and cleaning accumulated sediment in the bottom of the sump
annually.
Chemical wheel pit cleaning is permitted on a monthly basis. When wheel pit cleaning occurs, the
tailrace shall be inspected visually for foam and oil. Cleaning shall be conducted only with pre -
approved solvents. Should the Permittee wish to change solvents, a written request should be made to
the Division including the MSDS for the proposed solvent.
Mechanical cleaning operations, which do not contribute any wastewater to the discharge are not
limited by this permit. Non -discharging cleaning operations may be conducted as often as necessary to
ensure safety and proper facility operation.
Monitoring results obtained during the calendar year shall be recorded and reported on a Discharge
Monitoring Report (DMR) form and postmarked no later than January 30th following the completed
reporting period. Samples obtained for monitoring purposes may be collected anytime during the
calendar year.
There shall be no discharge of floating solids or visible foam (other than trace amounts} in the effluent,
unless ambient river conditions prevent compliance.