NC0004626_AUTHORIZATION To Construct_19970404

State of North Carolina
Department of Environment,
Health and Natural Resources 4 •
Division of Water Quality
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary p E H N F 1
A. Preston Howard, Jr., P.E., Director
April 4, 1997
Mr. J.W. Buchanan
Senior Engineering Associate
PPG Industries, Inc.
Post Office Box 949
Lexington, North Carolina 27293
Subject: Permit No. NCO004626
Authorization to Construct
PPG Industries, Inc.
Davidson County
Dear Mr. Buchanan:
A letter of request for an Authorization to Construct was received December 3, 1996 by the
Division and final plans and specifications for the proposed project have been reviewed and found to be
satisfactory. Authorization is hereby granted for the construction of the following units with final
discharge of treated wastewater into North Potts Creek which is classified Class C waters in the Yadkin -
Pee Dee River Basin:
• Twin granular activated carbon adsorption units;
• pH adjustment units at the inlet and the outlet;
• Conversion of two existing effluent pumps to accommodate variable speed drives;
• Use of an existing effluent pump to force backwash water into the GAC vessels;
• Conversion of an existing 62,000 gallon clarifier to an equalization basin;
• Sump pump to control the flow rate of the backwash into the aeration basin;
• 600,000 gallon sludge holding tank.
This Authorization to Construct is issued in accordance with Part III, Paragraph A of NPDES
Permit No. NCO004626 issued August 1, 1995, and shall be subject to revocation unless the wastewater
treatment facilities are constructed in accordance with the conditions and limitations specified in Permit No.
NC0004626.
In the event that the facilities fail to perform satisfactorily, including the creation of nuisance
conditions, the Pernuttee shall take immediate corrective action, including those as may be required by this
Division, such as the construction of additional or replacement wastewater treatment or disposal facilities.
The Winston-Salem Regional Office, telephone number [phone], shall be notified at least
forty-eight (48) hours in advance of operation of the installed facilities so that an in-place inspection can be
made. Such notification to the regional supervisor shall be made during the normal office hours from 8:00
a.m. until 5:00 p.m. on Monday through Friday, excluding State Holidays.
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

Permit No. NC0004626
Authorization to Construct ,
PPG Industries, Inc.
April 4, 1997 '
Page 2
Upon completion of construction and prior to operation of this permitted facility, a certification
must be received from a professional engineer certifying that the permitted facility has been installed in
accordance with the NPDES Permit, this Authorization to Construct and the approved plans and
specifications. Mail the Certification to the Permits and Engineering Unit, P.O. Box 29535, Raleigh, NC
27626-0535.
A copy of the approved plans and specifications shall be maintained on file by the Permittee for the
life of the facility.
The Operational Agreement between the Permittee and the Environmental Management-
Commission is incorporated herein by reference and is a condition of this Permit. Noncompliance with the
terms.of the Operational Agreement shall subject the Permittee to all sanctions provided by G. S. 143-
215.6 for violation of or failure to act in accordance with the terms and conditions of this Permit.
Failure to abide by the requirements contained in this Authorization to Construct may subject the
Permittee to an enforcement action by the Division of Water Quality in accordance with North Carolina
General Statute 143-215.6A to 143-215.6C.
The issuance of this Authorization to Construct does not preclude the Permittee from complying
with any and all statutes, rules, regulations, or ordinances which may be imposed by other government
agencies (local, state, and federal) which have jurisdiction.
One (1) set of approved plans and specifications is being forwarded to you. If you have any
questions or need additional information, please contact Mr. Jeff Myhra, telephone number (919) 733-
5083, extension 597.
Sincerely,
A. Preston Howard, r., P.E.
cc: Central Files
Permits:&-Engineering_(,ATC-files),
Winston-Salem Regional Office,Water Quality
Training and Certification Unit

cc: Permits and Engineering
`Te�linical'Support Branch
County Health Department
Central Files
WSRO
SOC PRIORITY PROJECT: YES X NO R
IF Yes, SOC No. EMC WQ 95-18
To: Permits and Engineering Unit
Water Quality Section
Attention: (Jeff Myrha)
AUTHORIZATION TO CONSTRUCT
NPDES PERMIT REPORT AND RECOMMENDATIONS
Date: January 29, 1997
County: Davidson
Permit No. NCO004626
PART I GENERAL INFORMATION
1. Facility Name and Current Address: P.P.G. Industries, inc.
P. O. Box 949
Lexington, N.C. 27293
2. Date of most recent NPDES Staff Report: (attach copy)
February 7, 1994 (attached)
3. Changes since previous action on NPDES Permit: None
4. Verify Discharge Point(s) on plans with current NPDES Permit. List for all discharge
points.
Latitude: 35° 44' 18" Longitude: 80' 19' 32"
Attach a USGS map extract and indicate treatment facility site and discharge point on
map.
U.S.G.S. Quad No. U.S.G.S. Name T
Dischage Point: E17NE Southmont
Plant Site: D17SE Lexington West

5. Treatment plant classification: (attach completed rating sheet)
4
PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
(PROVIDE THE FOLLOWING INFORMATION IF IT IS NOT ON THE PREVIOUS NPDES
STAFF REPORT)
1. Existing treatment facility:
a. What is the current permitted capacity of the facility?
b. Date(s) and construction activities allowed by previous Authorizations to
Construct issued in the previous two (2) years:
c: What is the actual treatment capacity of the current facility (design volume)?
d. Please provide a description of existing or substantially constructed wastewater
treatment facilities.
2. Please provide a description of proposed wastewater treatment facilities: Installation of
vendor-supplied twin granular activated carbon adsorption units, operated in series, which
will replace the existing mixed media filters; pH adjustment units at the inlet (acid) and
outlet (caustic) of the unit; modification of two existing effluent pumps to accommodate
variable speed drives; use of an existing spare effluent pump to force backwash water
into the GAC vessels; conversion of an existing 62,000 gallon clarifier (not currently in
use) to an equalization basin for receipt of the backwash water, with a sump pump to
control flow rate of the backwash into the aeration basin; installation of a new 600,000
gallon sludge holding tank adjacent to the existing concrete sludge storage basin.
3. Residuals handling and utilization/disposal scheme:
a. If residuals are being land applied, please specify DEM permit no.
Residual Contractor:
Telephone No.
b. Residuals stabilization: PSRP PFRP Other
C. Landfill:
d. Other disposal/utilization scheme (Specify):

4. Important SCC, JGC or Compliance Schedule dates, if applicable: (Please indicate)
Submission of Plans and Specifications December 1, 1996
Begin Construction March 1 1997
Complete Construction June 1, 1997
PART III - EVALUATION AND RECOMMENDATIONS
P.P.G. intends to install the granular activated carbon unit to remove one or more
toxicants believed to be contributing to the facility's periodic failures of the chronic toxicity test.
The Company has run bench-scale tests which indicate the technology should work.
The new. sludge storage tank, while not a part of the toxicity issue, will give the
Company more flexibility with respect to sludge management issues.
The Region recommends the A. to C. be issued.
Signature of report prelzarer /
Water Quality Section Su ervisor
Date