NC0024945_Authorization to Construct_19980729

NPDES DOCUMENT SCANNING COVER SHEET
NC0024945
Irwin Creek WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC) .
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Draft Permit
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
July 29, 1998
This document is printed on reuse paper -ignore arty
content on the reverse wide

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
June 29, 1998
Ms. Kathy Freeze
Charlotte Mecklenburg Utilities Department
5100 Brookshire Blvd.
Charlotte, North Carolina 28216
A7A
DENR
Subject: Permit No. NC0024945
Authorization to Construct
Sludge Storage Facility
Irwin Creek WWTP
Mecklenburg County
Dear Ms. Freeze:
The Division received a letter of request for an Authorization to Construct on April 27, 1998 and
final plans and specifications for the subject project have been reviewed and found to be satisfactory.
Authorization is hereby granted for the construction and installation of a sludge storage facility
(including drainage system with pumping station) that discharges to Irwin Creek in the Catawba River
basin.
Kevin Mosteller (HDR) indicated to Paul Clark of our staff that the valve vault will not be
constructed. This change has been identified on the approved plans.
This Authorization to Construct is issued in accordance with Part III, Paragraph A of NPDES
Permit No. NC0024945 issued October 4, 1996 and modified November 4, 1996 and June 15, 1998 and
- shall be subject to revocation unless the wastewater treatment facilities are constructed in accordance
with the conditions and limitations specified in Permit No. NC0024945.
Any sludge generated from this treatment facility must be disposed of in accordance with G.S.
143-215.1 and in a manner approved by the North Carolina Division of Water Quality.
In the event that the facility fails to perform satisfactorily, including the creation of nuisance
conditions, the Permittee 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 Mooresville 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

Ms. Freeze
June 29, 1998
NC0024945/ACCO24945
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 NPDES Unit, P.O. Box 29535, Raleigh, NC 27626-0535.
The Permittee, for the life of the facility, shall maintain a copy of the approved plans and
specifications on file. -
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 Paul Clark, telephone number [phone]
extension 580.
Sincerely,
. Preston Howard, `5r., P.E.
cc: Central Files
Mooresville Regional Office, Water Quality
Technical Assistance and Certification Unit
Point Source Compliance/Enforcement Unit
L. Kevin Mosteller, HDR Engineering, Inc.
Suite 1400
128 South Tryon Street
Charlotte, NC 28202-5001

AC0067342 Summary
1 ay2S,1998
P5
On April27, 1998, CMUD submitted an ATC request to modify the existing sludge
drying beds at the Irwin Creek WWTP to improve residuals storage. The modifications
consist of demolishing the existing sludge drying beds and constructing a covered
residuals storage building.
The existing WWTP consists of a screening, Pista grit removal system, influent flow
measurement, three primary clarifiers, four high rate trickling filters, pH adjustment,
aeration basin (diffused), three final clarifiers, tertiary filters, polishing lagoon (currently
not in use), dual chlorine contact chambers, bisulfite addition, (dechlorination), six
anaerobic sludge digesters, sludge storage tanks, a belt filter press, and cascade aeration.
The system discharges to Irwin Creek, a Class C stream in Catawba River Basin.
Review of plans and specifications indicate they are very thorough.
980625 (correction): Kevin Mosteller (HDR) indicated to Paul Clark that the valve vault
would not be constructed. The correction has been indicated on the plans.
Page 1 of 1

SOC PRIORITY PROJECT: No
To: Permits and Engineering Unit
Water Quality Section
Attention: Phyllis Cameron
Date: May 15, 1998
AUTHORIZATION TO CONSTRUCT
NPDES PERMIT
REPORT AND RECOMMENDATIONS
County: Mecklenburg
MRO No.: 98-29
Permit No. ACCO24945
PART I - GENERAL INFORMATION
1. Facility and Address:
Irwin Creek WWTP
c/o CMUD
5100 Brookshire Blvd.
Charlotte, N.C. 28216
2. Date of On -Site Investigation (if conducted): N/A
3. Report Prepared By: Michael L. Parker, Environ. Engr. II
4. Persons Contacted and Telephone Number: N/A
5. Verified Discharge Point(s), List for All Discharge Points:
Latitude: 35° 11' 44" Longitude: 80° 54' 27"
USGS Quad No.: G 15 NW
yVIEE 11))
1,i4Y r
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PO!NT SOURCE- BRANCH
6. Site size and expansion area consistent with application? Yes. Ample area exists for the
construction of the proposed facilities.
7. Topography (relationship to flood plain included): Generally flat to moderate slopes.
Portions of the WWTP site appear to be located in the 100 year flood plain, however, a
berm has been constructed for protection from flooding. The sludge storage area does not
appear to be in the flood plain.
8. Location of Nearest Dwelling: None within 500 feet of the site.

Page Two
PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
1. Existing Treatment Facility
a. Current permitted capacity: 15.0 MGD.
b. Date(s) and construction activities allowed by previous ATCs issued in the
previous two (2) years: N/A.
c. Actual treatment capacity of the current facility (design volume): 15.0 MGD.
d. Description of existing or substantially constructed WWT facilities: screening, a
Pista grit removal system, influent flow measurement, three (3) primary clarifiers,
four (4) high rate trickling filters, pH adjustment, aeration basins (diffused), three
(3) final clarifiers, tertiary filters, polishing lagoon (currently not in use), dual
chlorine contact chambers, bisulfite addition (dechlorination), six (6) anaerobic
sludge digesters, sludge storage tanks, a belt filter press, and cascade aeration.
2. Type of Proposed Treatment Facility: The applicant proposes to construct covered sludge
storage facilities, which will involve modifications to the currently unused sludge drying
beds.
3. Residuals Handling and Utilization/Disposal Scheme: Land Applied.
a. DWQ Permit No. WQ0000057
Residuals Contractor: AMSCO, Inc.
Telephone No. [phone]
b. Residuals Stabilization: Class B
4. Treatment Plant Classification (attached completed rating sheet): Class IV (The proposed
modifications/additions will not change the present WWTP classification)
5. SIC Code(s): 4952
6. Wastewater Code(s): 01
Main Treatment Unit Code: 04603
6. Important SOC/JOC or Compliance Schedule Dates: N/A

Page Three
PART III - EVALUATIONS AND RECOMMENDATIONS
CMUD proposes to modify the existing sludge drying beds at the Irwin Creek WWTP to
improve residuals storage. The modifications consist of demolishing the existing sludge drying
beds and constructing a covered residuals storage building.
This Office has reviewed CMUD's request and, pending a technical review by P&E, it is
recommended that an ATC be issued.
-/e_41 � /S9f
Signature of Report Preparer Date
Water Quality Regional Supe
h:\atc\atc98\irwincrk.atc

LJn 1° T
Non -Discharge
-
December 17, 1997
NCDENR
Water Quality Division
512 North Salisbury Street
Raleigh, NC 27611-7887
Attention: Mr. Steve Pellei
Re: Irwin Creek WWTP (4C d 4c\4S
Accelerated Biosolids Improvements
Equipment Installation
HDR Project No. 00121-240-018 (INS-11)
Dear Mr. Pellei:
The purpose of this letter is to confirm our telephone conversation of December 17, 1997. As we
discussed, the referenced project consists mainly of rehabilitation of existing structures. Based
on our conversation; my understanding is that an Authorization to Construct will not be required.
Please feel free to call if you have any questions.
Sincerely,
HDR Engineering, In. of North Carolina
William C. Eller
Project Engineer
WCE/wce
HDR Engineering, Inc.
of North Carolina
Employee -owned
Suite 1400 Telephone
128 S. Tryon Street 704 338-6700
Charlotte, North Carolina Fax
28202-5001 704 338-6760