NC0024937_Speculative Limits_19970519

NPDES DOCUMENT SCANNING COVER SHEET
NC0024937
Sugar 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
201 Facilities Plan
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date: i
May 19, 1997
This documeat is printed cork reuse paper - igzzore a.ny
coateat cork the re'erse glide

State of North Carolina
Department of Environrnent,
Health and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
May 19, 1997
46:17:1•ICIVHA
EDEHNR
Mr. J. Reed Atkinson, Superintendent
Charlotte -Mecklenburg Utility Department
600 E. 4th St.
Charlotte, N.C. 28202-2870
Subject: Speculative Limits for City of Charlotte - Sugar Creek WWTP
NPDES Permit No. NC0024937
Mecklenburg County
Dear Mr. Atkinson:
This letter is in response to Mr. Ben Leatherland of HDR Engineering's request for
speculative effluent limits for Sugar Creek WWTP's proposed expansion from 20 MGD to
25 MGD. This request has been reviewed by the staff of the Instream Assessment Unit of
the Technical Support Branch.
Please be advised that response to this request does not guarantee that the Division
will issue an NPDES permit to discharge treated wastewater into these receiving waters. It
should be noted that new and expanding facilities, involving an expenditure of public funds
or use of public (state) lands, will be required to prepare an environmental assessment (EA)
when wasteflows: 1) exceed or equal 0.5 MGD, or 2) exceed one-third of the 7Q10 flow
of the receiving stream. DWQ will not accept a permit application for a project requiring an
EA until the document has been approved by the Department of Environment, Health and
Natural Resources and a Finding of No Significant Impact (FONSI) has been sent to the
state Clearinghouse for review and comment.
The EA should contain a clear justification for the proposed facility and an analysis
of potential alternatives which should include a thorough evaluation of non -discharge
alternatives. Nondischarge alternatives or alternatives to expansion, such as spray
irrigation, water conservation, inflow and infiltration reduction or connection to a regional
treatment and disposal system, are considered to be environmentally preferable to a surface
water discharge. In accordance with the North Carolina General Statutes, the practicable
waste treatment and disposal alternative with the least adverse impact on the environment is
required to be implemented. If the EA demonstrates that the project may result in a
significant adverse effect on the quality of the environment, an Environmental Impact
Statement would be required. Michelle Suverkrubbe of the Water Quality Planning Branch
can provide further information regarding the requirements of the N.C. Environmental
Policy Act.
Based on available information, the tentative limits for conventional constituents for -
the Sugar Creek WWTP at the expansion flow of 25 MGD are:
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

Letter to Mr. Atkinson
- page 2 -
Summer Winter
BOD5 (mg/1) 5 10
NH3-N (mg/1) 1 2
TS S (mg/1) 15 15
Dissolved Oxygen (mg/1) 6 6
Fecal Coliform (#/100m1) 200 200
pH (SU) 6-9 6-9
Chlorine (µg/1) 18 18
It should be noted that the summer and winter NH3-N limits recommended for all
these plants are based on protecting the receiving streams against instream toxicity. North
Carolina is evaluating all NPDES dischargers for ammonia toxicity following the
Environmental Protection Agency (EPA) guidance to protect the waters for an instream
criteria of 1 mg/1 in the summer and 1.8 mg/1 in the winter, under 7Q10 flow conditions.
The Division of Water Quality (DWQ) is requiring chlorine limits and
dechlorination for all new or expanding dischargers proposing the use of chlorine for
disinfection. The process of chlorination/dechlorination or an alternate form of
disinfection, such as ultraviolet radiation, should allow the facility to comply with the total
residual chlorine limits recommended in the above scenarios.
A Phase II chronic toxicity testing requirement at 90% with quarterly monitoring
will remain a condition of the NPDES permit. A complete evaluation of limits and
monitoring requirements for metals and other toxicants will be addressed at the time of
formal permit application. However, as a point of reference, tentative limits based on
existing metals are as follows:
Wkly Avg. Da. Max.
Cadmium 2.2 µg/1 5.4 µg/1
Lead 27 14/1 37 14/1
Cyanide 5.4 µg/l 17 14/1
Mercury 0.013 µg/1 0.052 14/1
Chromium 54 µg/1 218 µg/1
DWQ is currently on its second round of implementation of a basinwide water
quality management initiative for the Catawba River Basin. Our next installment of the
Catawba River Basin plan is scheduled for publication in the year 2000 . We will attempt
to further address all sources of point and nonpoint pollutants where deemed necessary to
protect or restore water quality standards. In addressing interaction of sources, wasteload
allocations may be affected. Those facilities that already have committed to high levels of
treatment technology are least likely to be affected.

Letter to Mr. Atkinson
- page 3 -
Final NPDES effluent limitations will be determined after a formal permit
application has been submitted to the Division. If there are any additional questions
concerning this matter, please feel free to contact Ruth Swanek (ext. 503) or Jackie Nowell
(ext. 512), of my staff at [phone].
cerely,
onald L. Safrit,
Assistant Chief foTc&VSupport
Water Quality Section
DLS/JMN
cc: Rex Gleason
Bobby Blowe
Ben Leatherland, HDR Engineering, Inc.
Michelle Suverkrubbe
Central Files
WLA File

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TOXICANT ANALYSIS
Facility Name
CMUD-Sugar Creek WWTP
NPDES#
NC0024937
Qw (MGD)
25
7010s (cfs)
_.._.._.._.._.._. 3.4
91.93
IWC (%)
Rec'ving Stream
Little Sugar Creek
Stream Class
C
FINAL RESULTS
Cd
Max. Pred Cw
48.3
ug/I
Allowable Cw
2.2
ug/I
Max. Value
21
Cr
Max. Pred Cw
57.6
ug/I
Allowable Cw
54.4
ug/I
Max. Value
36
Ni
Max. Pred Cw
75.4
ug/I
Allowable Cw
95.7
ug/I
Max. Value
58
Pb
Max. Pred Cw
104
ug/I
Allowable Cw
27.2
ug/l
Max. Value
40
Cn
Max. Pred Cw
21
ug/l
ug/I
Allowable Cw
5.4
Max. Value
14
Hg
Max. Pred Cw
12.74
ug/I
Allowable Cw
0.0
ug/I
Max. Value
4.9
Cu
Max. Pred Cw
127.5
ug/I
Allowable Cw
7.6
ug/I
Max. Value
75
Zn
Max. Pred Cw
2000
ug/I
Allowable Cw
54.4
ug/I
Max. Value
1000
Ag
Max. Pred Cw
68.8
ug/I
Allowable Cw
0.1
ug/I
Max. Value
43
5/5/97 PAGE

CMUD-SUGAR CREEK WWTP INSTREAM METALS DATA
Date
Ups Cn
Dwn Cn
Ups Ag
Dwn Ag
Ups Cu
Dwn Cu
Ups Zn
Dwn Zn
Dec-96
no data
no data
no data
no data
no data
no data
no data
no data
Nov-96
no data
no data
no data
no data
no data
no data
no data
no data
Oct-96
3
2
<30
<30
<30
<30
<50
<50
Sep-96
2
2
<30
<30
<30
<30
<50
<50
Aug-96
<2
<2
<30
<30
<30
<30
<50
<50
JuI-96
<2
<2
<30
<30
<30
<30
<50
<50
Jun-96
<2
2
<30
<30
<30
<30
<50
<50
May-96
3
<2
<30
<30
<30
<30
<50
<50
Apr-96
<30
<30
<30
<30
<50
<50
Mar-96
<2
<2
<30
<30
<30
<30
<50
<50
3
e. 2
`f

cmud-sugar creek
Residual Chlorine
7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
UPS BACKGROUND LEVEL (UG/L)
IWC (%)
Allowable Concentration (ug/I)
Fecal Limit
Ratio of 0.1 :1
Ammonia as NH3
(summer)
3.4 7Q10 (CFS)
25 DESIGN FLOW (MGD)
38.75 DESIGN FLOW (CFS)
17.0 STREAM STD (MG/L)
0 UPS BACKGROUND LEVEL (MG/L)
91.93 IWC (%)
18.49 Allowable Concentration (mg/I)
Ammonia as NH3
(winter)
7Q10 (CFS)
200/100m1 DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
UPS BACKGROUND LEVEL (MG/L)
IWC (%)
Allowable Concentration (mg/I)
3.4
25
38.75
1.0
0.22
91.93
1.07
5.5
25
38.75
1.8
0.22
87.57
2.02
NC0024937
5/9/97

UPSTREAM
DOWNSTREAM
MONTH Temp DO Saturation Fecal Conductivity Temp DO Saturation Fecal Conductivity
Oct-96
17
9.4
97%
681
228
18
7.5
79%
585
428
Sep-96
22
9.2
105%
3037
178
22
7
80%
1842
357
Aug-96
25
7.6
92%
1488
204
24
6.6
78%
468
382
Jul-96
27
7.6
95%
280
281
25
7
85%
1974
383
Jun-96
25
7.8
94%
824
224
25
7.4
90%
1574
414
May-96
20
8.3
91%
2515
226
20
7.3
80%
2226
366
Apr-96
15
10.2
101%
514
223
16
8.9
90%
838
358
Oct-96
0%
17
9.4
97%
681
228
Sep-96
0%
22
7.1
81%
1500
334
Aug-96 „
0%
25
6.6
80%
1232
343
JuI-96
0%
25
6.8
82%
311
354
Jun-96
0%
25
7.1
86%
1235
352
Notes Ups -Sugar Creek above outfall
Dwn1-Hwy 521 @ pineville
Dwn2-Hwy 51 @ Pineville
NC0020451 5/7/97

UPSTREAM
DOWNSTREAM
MONTH Temp DO Saturation Fecal Conductivity Temp DO Saturation Fecal Conductivity
Oct-95
17
9.1
94%
197
19
7.5
81 %
339
Sep-95
22
8.6
98%
1984
193
23
7.1
83%
5925
327
Aug-95
27
7.5
94%
776
201
26
6.1
75%
1300
355
Jul-95
27
7.5
94%
1095
195
27
7.1
89%
629
327
Jun-95
23
7.6
89%
3020
157
24
6.6
78%
7823
255
May-95
23
8.2
96%
1729
23
10.4
121%
2478
347
Apr-95
18
8.9
94%
441
222
18
6.5
69%
227
402
Oct-95
0%
20
8
88%
279
Sep-95
0%
23
7.4
86%
236
278
Aug-95
0%
28
6.8
87%
476
294
Jul-95
0%
28
6.6
84%
90
243
Jun-95
0%
24
6.9
82%
1207
264
Notes Ups -Sugar Creek above outfall
Dwn1-Hwy 521 @ pineville
Dwn2-Hwy 51 @ Pineville
NC0020451 5/7/97

March 14, 1997
Ms. Ruth Swanek
NC Division of Water Quality
Water Quality Section, Instream Assessment Unit
P.O. Box 29535
Raleigh, NC 27626-0535
Eaz
Re: Mecklenburg County Sugar Creek WWTP Modification and Expansion
Speculative Assessment
HDR Project No. 00121-200-018
Dear Ms. Swanek:
HDR Engineering is currently evaluating the environmental impacts associated with the
above project. This project will include various on -site modifications to the existing
treatment processes, but will not require the construction of new buildings or facilities.
Prior to performing this work, the Charlotte -Mecklenburg Utility Department (CMUD) is
requesting an increase in permitted maximum month discharge capacity for the facility, from
20.0 million gallons per day (MGD) to 25.0 MGD. The various on -site improvements will
be based on the discharge limits required by DWQ at the increased permitted discharge
capacity (i.e. 25 MGD). The enclosed maps provide the site location and layout.
We would like to request from your office a speculative assessment based on this proposed
increase in permitted discharge. The discharge location itself will remain the same. At this
point, potential improvements have been outlined, but the final decision regarding specific
modifications will be made based on input from your office and DWQ effluent limits for the
increased permitted discharge. This will allow for the optimal use of resources in meeting
water quality goals.
The following information is included in order to provide a more complete picture of the
project itself:
The existing facility is one of five wastewater treatment plants serving the water reclamation
needs of Charlotte -Mecklenburg. It discharges to the Little Sugar Creek basin and serves
the entire central section of Charlotte. The increased discharge is requested to address
future needs in the area, and to reduce stresses on the other treatment plants in the system.
The proposed modifications will serve to reduce pollutant levels in the facility's effluent,
and improve the overall quality of Little Sugar Creek. The previously mentioned on -site
HDR Engineering, Inc.
of North Carolina
Suite 1400 Telephone
128 S. Tryon Street 704 338-6700
Charlotte, North Carolina Fax
28202-5001 704 338-6760
Engineering
Construction Services

improvements will be based on the discharge limits required by DWQ at the increased
permitted discharge capacity (i.e. 25 MGD). These modifications will not require any new
property development, and will focus instead on improving system efficiencies and more
effectively using existing processes. The facility is sited within 75 acres of property owned
by Charlotte -Mecklenburg and is located near the intersection of Park Road and Tyvola
Road in south Charlotte. These two roads have average traffic volumes of 31,000 and 31-
36,000 vehicles per day, respectively. The land area surrounding the WWTP property is
characterized by highly -developed residential communities, in addition to significant office
and retail/commercial development near the SouthPark Mall area located approximately 1.5
miles to the east.
Soil types present on -site include Urban (Ur), Monacan (MO), and Monacan with Arents
(MS). These soils are typically associated with low-lying areas of the landscape, with the
Ur and MS classifications denoting a high degree of man-made alteration and impervious
surface cover. The dominant vegetational cover surrounding the project is comprised of
young -mature to mature hardwood forest, with open field areas near the physical structures
of the facility.
No wetland areas are currently known to exist on -site. The facility is located on the high
eastern bank of the creek and contains only those surface water features associated with
standard wastewater treatment processes. Additionally, no cultural resources are currently
known to be located within the property boundaries of the facility. It is anticipated that
comments regarding these and other issues will aid in the analysis of potential project
impacts.
Should you have any questions or specific comments concerning the project, or require
additional information, I can be reached at 800/727-3431. The project manager, Paul
Delphos, may also be contacted at this number to discuss any issues which may arise.
Thank you for your time and assistance in this effort.
Sincerely,
HDR Engineering, Inc. of North Carolina
e,,,, .Z.did-,/
Ben Leatherland
Environmental Scientist
cc: Arnold Jarrell, CMUD
Paul Delphos, HDR
Michael Wolfe, HDR

Sugar Creek WWTP
Mecklenburg County
ID7(

•of t� tx.
N
Location Map

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LEGEND
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FIGURE 2
SUGAR CREEK TREATMENT PLANT
SITE LAYOUT