NC0024333_Permit (Modification)_19960318

NPDES DOCUMENT !CANNINO COVER SHEET
NC0024333
Monroe WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
.Permit
Modificati.
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Report
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
March 18, 1996
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State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Environmental Management
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
�EHNR
March 18, 1996
Mr. Tom L. Frederick, Director of Water Resources
City of Monroe
P.O. Box 69
Monroe, North Carolina 28111 - 0069
Subject: Permit Modification
NPDES No. NC0024333
Monroe WWTP
Union County
Dear Mr. Frederick:
By letter dated December 11, 1995 and subsequent correspondence January 23, 1996, you
requested on behalf of the City of Monroe that the BOD5 limit in the current permit be modified.
Specifically, you requested that the BOD5 limit be raised to 7.25 mg/1 in exchange for the NH3-N
limit being lowered to 1.0 mg/1 during the summer months. Also, you requested that the BOD5
limit be raised to 14.5 mg/l in exchange for the NH3-N limit being lowered to 2.0 mg/1 during the
winter months. This request has been granted based on the fact that the BOD ultimate (the addition
of the calculated CBOD and NBOD) has remained the same. Enclosed please find the modified
effluent limits pages. These pages should be inserted into your permit and the old ones discarded.
Please note that since the facility has expanded to 9.0 MGD, no effluent limits pages for 7.0 MGD
have been included. This permit is 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 changed by this permit
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 27447, Raleigh, North Carolina
27611-7447. Unless such demand is made, this decision shall be final and binding.
Please take notice that this permit is not transferable. Part II, E.4. addresses the
requirements to be followed in case of change in ownership or control of this discharge. This
permit does not affect the legal requirement to obtain other permits which may be required by the
Division of Environmental Management or permits required by the Division of Land Resources,
Coastal Area Management Act or any other Federal or Local governmental permit that may be
required.
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX [phone]
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Page 2
City of Monroe
Permit Modification
NC0024333
If you have any questions concerning this permit, please contact Susan Wilson at telephone
number [phone], ext. 555.
S'ncerely,
off% -''A. Preston Howard, r., P.E.
cc: Central Files (PERMIT FILE)
Mooresville Regional Office, Water Quality Section
Permits and Engineering Unit
Facility Assessment Unit
Instrearn Assessment Unit

A. (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS SUMMER (April 1 - October 31)
Permit No. NC0024333
During the period beginning upon expansion above 7.0 MGD and lasting until expansion above 9.0 MGD or expiration, the Permittee is
authorized to discharge from outfall(s) serial number 001. Such discharges shall be limited and monitored by the permittee as specified below:
Effluent Characteristics
Discharge Limitations Monitoring Requirements
Monthly. Avg.
Flow 9.0 MGD
BOD, 5-Day, 20°C** 7.3 m g / I
Total Suspended Residue** 30.0 mg/I
NH3 as N 1.0 mg/I
Dissolved Oxygen***
Fecal Coliform (geometric mean) 200.0 /100 ml
Total Residual Chlorine
Temperature
Conductivity
Total Phosphorus
Total Nitrogen (NO2 + NO3 + TKN)
Cadmium
Cyanide
Nickel
Lead
Copper
Zinc
Chronic Toxicity****
Weekly Avg.
11.0 mg/l
45.0 mg/I
400.0 /100 ml
2.0 pg/I
5.0 µg/I
88.0 µg/I
25.0 µg/I
Measurement
Daily Max. Frequency
Continuous
Daily
Daily
Daily
Daily
Daily
17.0 µ g/I Daily
Daily
Daily
Monthly
Monthly
5.0 µ g / I Weekly
20.0 µg/I Weekly
352.0 µg/l Weekly
34.0 µg/I Weekly
2/Month
2/Month
Quarterly
Sample *Sample
Type
Recording
Composite
Composite
Composite
Grab
Grab
Grab
Grab
Grab
Composite
Composite
Composite
Grab
Composite
Composite
Composite
Composite
Composite
Location
I or E
I,E,U,D
I,E
E,U,D
E,U,D
E,U,D
E
E,U,D
E,U,D
E
E
E
E
E
E
E
E
E
* Sample locations: E - Effluent, I - Influent, U - Upstream at Walkup Avenue, D - Downstream (1) Below discharge at NCSR 1006, (2) below
Stewarts Creek at NCSR 1630.
Upstream and downstream samples shall be grab samples.lnstrcam samples shall be grab samples and shall be conducted 3 times per week during
the months of June, July, August, and September and once per week during the remainder of the year.
** The monthly average effluent BOD5 and Total Suspended Residue concentrations shall not exceed 15% of the respective influent value (85 %
removal).
*** The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/l.
**** Chronic Toxicity (Ceriodaphnia) P/F at 90%; March, June, September, and December; See Part III, Condition G.
The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall be monitored daily at the effluent by grab sample.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

A. (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS WINTER (November 1 - March 31)
Permit No. NC0024333
During the period beginning upon expansion above 7.0 MGD and lasting until expansion above 9.0 MGD or expiration, the Permittee is
authorized to discharge from outfall(s) serial number 001. Such discharges shall be litnited and monitored by the permittee as specified below:
Effluent Characteristics
Discharge Limitations
Monthly. Avg.
Flow 9.0 MGD
BOD, 5-Day, 20°C** 14.5 mg/I
Total Suspended Residue** 30.0 mg/I
NH3asN 2.0 mg/I
Dissolved Oxygen***
Fecal Coliform (geometric mean) 200.0 /100 ml
Total Residual Chlorine
Temperature
Conductivity
Total Phosphorus
Total Nitrogen (NO2 + NO3 + TKN)
Cadmium
Cyanide
Nickel
Lead
Copper
Zinc
Chronic Toxicity****
Monitoring Requirements
Measurement
Weekly Avg. Daily Max. Frequency
Continuous
22.0 mg/I Daily
45.0 mg/I Daily
Daily
Daily
400.0 /100 ml Daily
17.0 µg/I Daily
Daily
Daily
Monthly
Monthly
2.0 µg/I 5.0 µg/I Weekly
5.0 µg/I 20.0 µg/l Weekly
88.0 pg/I 352.0 µg/I Weekly
25.0 µg/I 34.0 WI Weekly
2/Month
2/Month
Quarterly
Sample
Type
Recording
Composite
Composite
Composite
Grab
Grab
Grab
Grab
Grab
Composite
Composite
Composite
Grab
Composite
Composite
Composite
Composite
Composite
*Sample
Location
I or E
I,E,U,D
I,E
E,U,D
E,U,D
E,U,D
E
E,U,D
E,U,D
E
E
E
E
E
E
E
E
E
* Sample locations: E - Effluent, I - Influent, U - Upstream at Walkup Avenue, D - Downstream (1) below discharge point at NCSR 1006, (2)
below Stewarts Creek at NCSR 1630.
Instream samples shall be grab samples and shall be conducted 3 times per week during the months of June, July, August, and September and
once per week during the remainder of the year.
** The monthly average effluent BOD5 and Total Suspended Residue concentrations shall not exceed 15% of the respective influent value (85 %
removal).
*** The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/1.
**** Chronic Toxicity (Ceriodaphnia) P/F at 90%; March, June, September, and December; See Part III, Condition G.
The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall be monitored daily at the effluent by grab sample.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

A. (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS SUMMER (April 1- October 31)
Permit No. NC0024333
During the period beginning upon expansion above 9.0 MGD and lasting until expiration, the Permittee is authorized to discharge from
outfall(s) serial number 001. Such discharges shall be limited and monitored by the permittee as specified below:
Effluent Characteristics
Discharge Limitations
Monthly. Avg.
Flow 11.0 MGD
BOD, 5-Day, 20°C** 7.3 mg/I
Total Suspended Residue** 30.0 mg/I
NH3 as N 1.0 mg/I
Dissolved Oxygen***
Fecal Coliform (geometric mean) 200.0 /100 ml
Total Residual Chlorine
Temperature
Conductivity
Total Phosphorus
Total Nitrogen (NO2 + NO3 + TKN)
Cadmium
Cyanide
Nickel
Lead
Copper
Zinc
Chronic Toxicity****
Weekly Avg.
11.0 mg/I
45.0 mg/I
400.0 /100 ml
2.0 µg/I
5.0 pg/I
88.0 p g/I
25.0 µg/I
Measurement
Daily Max. Frequency
Continuous
Daily
Daily
Daily
Daily
Daily
17.0 µg/I Daily
Daily
Daily
Monthly
Monthly
5.0 µg/I Weekly
20.0 pg/I Weekly
352.0 µ g / I Weekly
34.0 µg/I Weekly
2/Month
2/Month
Quarterly
Monitoring Requirements
Sample *Sample
Type Location
Recording I or E
Composite I,E,U,D
Composite I,E
Composite E,U,D
Grab E,U,D
Grab E,U,D
Grab E
Grab E,U,D
Grab E,U,D
Composite E
Composite E
Composite E
Grab E
Composite E
Composite E
Composite E
Composite E
Composite E
* Sample locations: E - Effluent, I - Influent, U - Upstream at Walkup Avenue, D - Downstream (I) below discharge at NCSR 1006, (2) below
Stewarts Creek.at NCSR 1630.
Upstream and downstream samples shall be grab samples.Instream samples shall be grab samples and shall be conducted 3 times per week during
the months of June, July, August, and September and once per week during the remainder of the year.
** The monthly average effluent BOD5 and Total Suspended Residue concentrations shall not exceed 15% of the respective influent value (85 %
removal).
*** The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/1.
**** Chronic Toxicity (Ceriodaphnia) P/F at 90%; March, June, September, and December; See Part III, Condition G.
The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall be monitored daily at the effluent by grab sample.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

A. (1). EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS WINTER (November 1 - March 31) Permit No. NC0024333
During the period beginning upon expansion above 9.0 MGD and lasting until expiration, the Permittee is authorized to discharge from
outfall(s) serial number 001. Such discharges shall be limited and monitored by the permittee as specified below:
Effluent Characteristics Discharge Limitations Monitoring Requirements
Measurement Sample *Sample
Monthly. Avg. Weekly Avg. Daily Max. Frequency Type Location
Flow 11.0 MGD Continuous Recording I or E
BOD, 5-Day, 20°C** 14.5 mg/I 22.0 mg/I Daily Composite I,E,U,D
Total Suspended Residue** 30.0 mg/I 45.0 mg/1 Daily Composite I,E
NH3 as N 2.0 m g / I Daily Composite E,U,D
Dissolved Oxygen*** Daily Grab E,U,D
Fecal Coliform (geometric mean) 200.0 /100 ml 400.0 /100 ml Daily Grab E,U,D
Total Residual Chlorine 17.0 µg/I Daily Grab E
Temperature Daily Grab E,U,D
Conductivity Daily Grab E,U,D
Total Phosphorus Monthly Composite E
Total Nitrogen (NO2 + NO3 + TKN) Monthly Composite E
Cadmium 2.0 µ g/ I 5.0 µ g/ I Weekly Composite E
Cyanide 5.0 µ g / I 20.0 µgII Weekly Grab E
Nickel 88.0 µg/I 352.0 µgII Weekly Composite E
Lead 25.0 µ g/ l 34.0 µ g/ l Weekly Composite E
Copper 2/Month Composite E
Zinc 2/Month Composite E
Chronic Toxicity**** Quarterly Composite E
* Sample locations: E - Effluent, I - Influent, U - Upstream at Walkup Avenue, D - Downstream (1) below discharge point at NCSR 1006, (2)
below Stewarts Creek at NCSR 1630.
Instream samples shall be grab samples and shall be conducted 3 times per week during the months of June, July, August, and September and
once per week during the remainder of the year.
** The monthly average effluent BOD5 and Total Suspended Residue concentrations shall not exceed 15% of the respective influent value (85 %
removal).
*** The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/I.
**** Chronic Toxicity (Ceriodaphnia) P/F at 90%; March, June, September, and December; See Part III, Condition G.
The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall be monitored daily at the effluent by grab sample.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

NOTES TO FILE
MONROE/ MINOR MODIFICATION REQUEST
NC0024333 / 0 3 G 71 h giso a Ce K,
3/13196
Monroe requested some leniency on the monthly average limit for BOD5 with a concurrent
decrease in NH3-N. The facility can achieve nitrification, but due to some higher influent
BOD5 contributors, the facility has some difficulty in meeting the 5 mg/1 BOD5 limit.
The facility must maintain the BODult in the current permit.
BODult (sum) =19 mg/1
BODult (win) = 38 mg/1
1/23/96 - Monroe requested BOD5, 7.25 mg/1 (sum) and NH3-N 1.0 mg/1 (win).
Using a multiplier of 2 (as was used in prior models) for BOD5 and stoich. ratio of 4.5 for
NH3-N:
BODult = 7.25 * 2 + 1 * 4.5 = 19 mg/1 (same as current permit)
(summer)
BODult = 14.5 * 2 + 2 * 4.5 = 38 mg/1 (same as current permit)
(winter)
The permit will be modified to reflect the requested changes.
3/12/96 - spoke with Tom Frederick (PW Dir., City of Monroe) and told him that we
would go through with this request, but these limits could change upon renewal of basin in
1999. This would be dependent on DO values instream and Monroe's effect on stream, as
well as any future changes.
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CITY OF MONROE
P.O. BOX 69 • MONROE. NORTH CAROUNA 28111-0069
FAX [phone]
January 23,1996
Mr. Dave Goodrich
NCDEHNR-DEM
NPDES Permits Group
Post Office Box 29535
Raleigh, North Carolina 27626-0535
CERTIFIED MAIL
RETURN RECEIPT REQUESTED
RE: Requested Amendment to Effluent Limits Based on Total Receiving
Stream Oxygen Demand
NPDES Permit NC0024333
Monroe Wastewater Treatment Plant
City of Monroe, Union County, North Carolina
Dear Mr. Goodrich:
flei'
;44
Based on a telephone call from Ms. Susan Wilson, Environmental Engineer, from your
office, we learned that the NCDEM formulas for converting ammonia -nitrogen and BOD-5
day to ultimate biochemical oxygen demand are as follows:
BODuit = (2.0)(BOD-5) +(4.5)(NH3-N)
BODuit = 19 mg/I (for Richardson Creek at Discharge Point for NPDES
NC0024333)
We have reconsidered our request for permit amendment dated December 11,1995 based
upon the understanding of these formulas and revise our request as follows:
Current Limits Requested Modified
Limits
Summer Effluent Limits
BOD-5 5 mg/1 7.25 mg/I
NH3-N 2 mg/I 1.0 mg/1 V
obi
--s

Mr. David Goodrich
January 23,1996
Page 2
Winter Effluent Limits
BOD-5 10 mg/1 14.5 mg/1 '''-
NH3-N 4 mg/1 2 mg/1 r/
130Po6r = H. S • Z -r 2 •1 ; - 3,�
cmo)
The $100.00 application fee has been previously submeitted with our initial December 11,
1995 request.
We request favorable review of our request. Please call me at [phone] if you have
any further questions.
ctfully,
To L. Fr derick
Director o Water Resources
c: Mr. Jerry Cox
Mr. Kim Hinson
tom 019b1d a v g0123. d o c

CITY OF MONROE
P.O. BOX 69 • MONROE, NORTH CAROL[NA 28111-0069
FAX [phone]
December 11,1995
Mr. Dave Goodrich
NCDEHNR-DEM
NPDES Permits Group
Post Office Box 29535
Raleigh, North Carolina 27626-0535
CERTIFIED MAIL
RETURN RECEIPT REQUESTED
RE: Requested Amendment to Effluent Limits Based on Total Receiving
Stream Oxygen Demand
NPDES Permit NC0024333
Monroe Wastewater Treatment Plant
City of Monroe, Union County, North Carolina
Dear Mr. Goodrich:
Please find enclosed a check for $100.00 payable to NCDEHNR for a permit modification
fee to process a request by the City of Monroe for an Amendment to the effluent discharge
limits for GODS and NH3-N in the City's existing NPDES permit. The request for
amendment is fully described in this letter.
Based upon total in -stream ultimate oxygen uptake ratio of 4.6:1 by ammonia -nitrogen as a
pollutant compared to biochemical oxygen demand, we are requesting the following
modifications:
Current Limits Requested Modified
Limits
Summer Effluent Limits
BOD-5 5 mg/1 7.3 mg/1
NH3-N 2 mg/1 1.5 mg/1
Winter Effluent Limits
BOD-5 10 mg/1 14.6 mg/I
NH3-N 4 mg/1 3 mg/1
Lc:

Mr. David Goodrich
December 11,1995
Page 2
This amendment is based upon an objective of maintaining an appropriate discharge with
positive effects on Richardson Creek as is designed in the current permit while also
considering the influent characteristics and performance of our Wastewater Treatment
Plant. A review of our data over the seven summer months of 1995 (see attached table)
show a total average BOD-5 effluent of 4.57 mg/1 (compared to a limit of 5.0 mg/1) and a
total average NH3-N effluent of 0.13 mg/1 (compared to a limit of 2.0 mg/1).
We request favorable review of our request. Please call me at [phone] if you have
any questions.
s ectfull
T m L. F ederick
Director of Water Resources
c: Mr. Jerry Cox
Mr. Kim Hinson
tom1295 davg1211.doc

Monroe Wastewater Treatment Plant Performance
Summer 1995
NPDES Permit NC0024333
Note: All Data Represent Monthly Averages Except "Total Summer Averages"
Month
Influent
BOD-5
(mg/1)
Influent
NH3-N
(mg/1)
Effluent
BOD-5
(mg/1)
Effluent
NH3-N
(mg/1)
Apr-95
332.00
28.60
5.00
0.36
May-95
308.00
25.70
3.37
0.06
Jun-95
298.00
21.60
4.72
0.13
Jul-95
282.00
26.10
4.52
0.05
Aug-95
Sep-95
230.04
329.25
24.93
23.65
5.18
4.47
0.06
0.08
Oct-95
276.22
19.97
3.45
0.13
Total Summer
Average
305.55
25.35
4.57
0.13