NC0064050_Wasteload Allocation_19900904

D 61 AF R EO U ESTNPDES WASTE LOAD ALLOCATION
PERMIT NO.: NCO064050
of
PERNff= NAME: Town Apex / Middle Creek W WTP
Facility Status: Existing
Permit Status: Renewal
Major ✓ Minor Xq__
Pipe No.: 001 , r acne 8(1I4o
Design Capacity: ZAGD Qskvv, % � I Ow t .
Domestic (% of Flow): 81.7 %
Industrial (% of Flow): 18,3 %
Comments:
pretreatment information attached
RECEIVING STREAM: an unnamed tributary to Middle Creek
Class: C-NSW
Sub -Basin: 03-04-03
Reference USGS Quad: E 23 NE (please attach)
County: Wake
Regional Office: Raleigh Regional Office
Previous Exp. Date: 1/31/91 Treatment Plant Class: Class III
Classification changes within three miles:
none ETET
PLO
Requested by: Rosanne Barona Date: 6/18/90
Prepared by: Date: 2 q D
Reviewed by: Date: CI 0
� go�. w Aal q q �o
Modeler
Date Rec.
I #
.?CM
6 /9 yo
1 5-75-
Drainage Area (mil ) j . k O Avg. Streamilow (cfs): 1.3 Q
7Q10 (cfs)Winter 7Q10 (cfs)() 30Q2 (cfs)()
Toxicity Limits: IWC 61 Q % Ac e/Chmnic �eza"
Instream Monitoring:
Parameters Sae 0.k- C& 10 J Nl IQNAA
Upstream Location
Downstream Location
M
Effluent
Characteristics
Summer
Winter
BOD5 (m )
I
NH3-N (mg/1)
2
D.O. (mg/1)
6
TSS (mg/1)
F. Col. (/100 ml)
20 O
pH (SU)
G — Cl
C�('A9 (Q
Z
,�Y C
CAAJe
g$
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URM�,�5
NPDES WASTE
� � ��
LOAD ALLOCATION
fl
PERMIT NO.: NCO064050 �
-S
Facility Status. Existmg
Permit Status: Renewal
Major ✓ Minor
Pipe No.: 001
Design Capacity: 3.6 MGD
Domestic (% of Flow):
Industrial (% of Flow):
Comments:
81.7 %
18.3 %
pretreatment information attached
RECEIVING STREAM: an unnamed tributary to Middle Creek
Class: C-NSW
Sub -Basin: 03-04-03
Reference USGS Quad: E 23 NE (please attach)
County: Wake
Regional Office: Raleigh Regional Office
Previous Exp. Date: 1/31/91 Treatment Plant Class: Class III
Classification changes within three miles:
none
Requested by: Rosanne Barona
Prepared by:
Reviewed by:
Date: 6/18/90
Date: 9 / [I- [ 4D
Date:
<W;
cM
6llq 4D
s�S� B
7Q10 (cfs) Winter 7Q10 (cfs)
Toxicity Limits: IWC Q q %
Ci 30Q2 (cfs) p
Acut Chronic
Instream Monitoring:
Parameters sae a� tL.� � 5��.,.►ru r\n
Upstream y Location
t tDtown1stream � Location ^
C �`VOuY MGOU��N!'1Ww �V ��/1 .Fif. k/1V
E uent
Characteristics
Summer
Winter
BODS (m )
S
to
NH3-N (mg/1)
1
l g
D.O. (mg/1)
6
TSS (mg/1)
3 p
20
F. Col. (/100 nil)
LO O
Z O O
PH (SU)
6 — q
6 —q
P� � �-Q
5
( AItr'406�4
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2-

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v
n
o
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'P ' 0;1,�. ,/ ,\\off•, �� --t_�> _ ;� 1
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Sunset
ai0l,
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NPDF,S P �"I'RFATMF:NT r- -T`OkMATION R.�QUF.ST FORM 0 Z
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FACILITY NAAE: /d (AM 0 � P X 6i �
- /� � a �p'�c k NPDES NO. NCO 0
REQUESTER:
o a n F
RMION:
r
—6-Zf L �, r
PEWIT CONDITIONS OOVERING
r
PRF; rRFA'IT�3V'r
r
This facilityhas no ; IUs and should not have pretreatment language.
This facility should and/or is developing a
Please include the
pretreatment
following conditions: program.
'
Program Development
JUN 1990
Phase I due
U
Phase II due
Additional Conditions '
(attached)
facility is currently imple -enti a r
pretreatment program.
F?� 11V-4E lease include the following
t11V1�' r
conditions ;
r
'
,
Program Implementation
Additional Conditions '
r
(attached)
r
r
r
SIGNIFICANT INDUSMIAL USFMS' (SIUs) OONIRTAUTIONS
r •
S IU FLOW - TOTAL :
je rW4 ac ,
r
! y, D MAD ,
- COMPXITION:
r
T ITLE. '
MGD r
-*M.FTAL FINISHING: M® • l�S
M /� _ N'N'��j
1�
OTHER: ° w5 D, Dap O Mai
r
' Wac,a3 5
MCz
MGD r
r
,
,
.HEMa0FOCS REVIEW
,
r
,
AD IN LRS/DAY ` -- P",7
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DammnC PER4rjMM
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Sb
9Phenol
C3vaOd
3
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o
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RE(IVED : �0 / (� / REVI DIED BY: 6 �
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Request
-------- WASTELOAD ALLOCATION APPROVAL FORM
Facility Name: Town of Apex
NPDES No.: NC0064050
Type of Waste: 81.7% Dom/18.3% Ind
No.: 5757,
Status:
Existing/Renewal
Receiving Stream:
UT to Middle Creek
Classification:
C - NSW
'85 0208788525
Subbasin:
020403
Drainage
area:
1.10
Wasteflow (mgd)
BODS (mg/1)
NH3N (mg/1)
DO (mg/1)
TSS (mg/1)
Fecal coliform (#/100ml)
pH (su)
Cadmium (ug/1)
MENDED EFFLUENT LIMITS -----------
EXISTING PROPOSED PROPOSED
0
0
0
0
GAO � a
�9
sq 5i
cfs'
0 cfs
cfs
cfs
SUMMER
3.60
1.80
3.60
10
10
5
2
2
1
6
6
6
30
30
30
1000
200
200
6-9
6-9
6-9
n/a
2
2
PROPOSED
WINTER
3.60
10
1.8
6
30
200
6-9
2
Chromium
(ug/1):
n/a
50
50
50
Nickel
(ug/1):
n/a
88
88
88
Lead
(ug/1):
n/a
25
25
25
Cyanide
(ug/1):
n/a
5
5
5
Total Res. Chlor.
(ug/1):
n/a
n/a
17
17
Toxicity Testing Req.:
n/a
Chronic/Ceriod/Qrtrly
@
99 %
Total Phosphorus
(mg/1):
n/a
* 2
2
2
Effluent Monitoring:
n/a
Cu,Zn,Ag
& Ar (at 1.8 & 3.6
MGD)
----------------------------
MONITORING
----------------------------------
Upstream (Y/N):
Y
Location: At
dirt road
leading into WWTP
property
Downstream (Y/N):
Y
Location: Three
sites -see
attached-
-----------------------------
COMMENTS
-----------------------------------
SEE ATTACHED MEMO moptyt,� t(, be tj }etc L Bk.a
-------------------------S ri_ rus w C�Q H6D ----
Prepared by:
Juan C. Mangles
Reviewed by
Instream Assessment:
Regional Supervisor:
Permits & Engineering:
RETURN TO TECHNICAL SUPPORT BY: SEP 00 1990
LAA.4�- w Fc� Qxr� ?SB`x�i
Date: 8111gv
Date:
Date:
Date:
p,g9,b
AUG FUN
4 7&ju
P�RmlllS z ,r...
Tf�IGc9fnrn

DIVISION OF ENVIRONMENTAL MANAGEMENT
August 9, 1990
MEMORANDUM
TO: Tim Donnelly
FROM: Juan C. Mangles
THROUGH: Carla Sanderson
Trevor Clements
SUBJECT: Town of Apex WWTP
Permit Renewal
NPDES Permit No. NCO064050
Wake County
The Technical Support Branch has completed the wasteload allocation for the
subject permit renewal. Our review indicated that the Town of Apex WWTP discharges
into a 7Q10/30Q2 = 0 flow stream. Our files indicate that this facility was
permitted to discharge into a zero flow stream shortly before the Director issued a
mandate not allowing new discharges into zero flow streams and the eventual removal
of existing discharges to zero flow streams. Therefore, the following recommend-
ations are provided:
The Town of Apex has constructed wastewater treatment works with a design
capacity of 1.8 MGD. No ATC has been issued for expansion of the existing treat-
ment works to the currently permitted 3.6 MGD flow. Therefore, this office
recommends that the subject permit be reissued with the existing limits at 1.8 MGD
flow and that more stringent limits be applied upon expansion to 3.6 MGD design
capacity. Furthermore, the Town of Apex should provide an evaluation of disposal
alternatives prior to issuance of the ATC for the expanded treatment works. The
engineering evaluation of alternatives should be conducted in accordance to DEM
a" guidelines.
It is our understanding that the Town of Apex WWTP has capabilities to direct
flow to the City of Raleigh. Furthermore, it is understood that the pump station
and sewer lines connecting to the City of Raleigh sewer system were constructed
with funds obtained from Construction Grants.
It is recommended that the Town of Apex implement an extensive instream
monitoring program to assess the impact of the discharge into the receiving waters.
Please note that Sunset Lake is located downstream from the discharge. Therefore,
the instream monitoring program should include parameters associated with eutrophi-
cation of the water impoundment.
Finally, DEM is currently conducting a study to determine the impact of
effluent dominated headwaters to small impoundments. Therefore, the permit should
contain the following condition: "The Division of Environmental Management
reserves the right to reopen this permit upon completion of an ongoing study
designed to assess the impact of this discharge into Sunset Lake. Therefore,

-
nutrient limitations which may be more stringent than the current basinwide
nutrient limitations reflected in this permit may be required in the future."
It is recommended that the Raleigh Regional Office contact the permittee
about the changes contained in the renewed NPDES permit.
If you need further clarification on this matter, please contact me at (919)
733-5083.
Attachment
cc: Town of Apex WLA
Central Files
Dale Overcash
Zu��"-^�` �c cQ-s•�•---fir'^-`"`�`
.�%� Liz:--%�'� ��-�� ��'• � G,-�.c�
iL

10/89
Facility Name Permit # rV c-0 064 0 V%
CHRONIC TOXICITY TESTING REQUIREMENT (QR'rRLY)
The effluent discharge shall at no time exhibit chronic toxicity in any two consecutive toxicity tests,
using test procedures outlined in:
1.) The North Carolina Ceriodaphnia chronic effluent bioassay procedure (North Carolina Chronic
Bioassay Procedure - Revised *September 1989) or subsequent versions.
The effluent concentration at which there may be no observable inhibition of reproduction or
significant mortality is 9—CL9o' (defined as treatment two in the North Carolina procedure
document). The permit holder shall perform quarterjy monitoring using this procedure to establish
compliance with the permit condition. The first test ilI perfo ed a, ftjurty days from
issuance of this permit during the .months co0'j .Effluent
sampling for this testing shall be performed at the NP15E9 pMhiited in effluent discharge below
all treatment processes. .
All toxicity testing results required as part of this permitcondition will be entered on die Effluent
Discharge Monitoring Fora (MR 1) for the month in which it was performed, using the parameter
code TGP3B. Additionally, DEM Form AT 1(original) is to be sent to the following address:
Attention: Environmental Sciences Branch
North Carolina -Division of
Environmental. Management
P.O. Box 27687
Raleigh, N.C. 27611
Test data shall be complete and accurate and include all supporting chemical/physical measurements
performed in association with the toxicity tests, as well as all dose/response data. Total residual
chlorine of the effluent toxicity sample must be measured and reported if chlorine is employed for
disinfection of the waste stream
Should any single quarterly monitoring indicate a failure to meet specified limits, then monthly
monitoring will•begin immediately until such time that a single test is passed. Upon passing, this
monthly test requirement will revert to quarterly in the months specified above.
Should any test -data from this monitoring requirement or tests performed by the North Carolina
Division of Environmental Management indicate potential impacts to die receiving stream, this
permit may be re -opened and modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum
control organism survival and appropriate environmental controls, shall constitute an invalid test
and will require immediate retesting(within 30 days of initial monitoring event): Failure to submit
suitable test results will constitute noncompliance with monitoring requirements.
7Q10 cfs
Pem-ited Flow • 'g MGD Recommended by:
IWC% k 0 0_
Basin &Sub -basin 1
Receiving $,lre V t °mot
County VU Date I f I ff 10
**Chronic Toxicity (Ceriodaphnia) P/F att%,_epA_, See Part , Condition
pry 0) v

INSTREAM MONITORING UPSTREAM DOWNSTREAM DOWNSTREAM DOWNSTREAM
SITE 1
SITE 2
SITE 3.
DO
WEEKLY
WEEKLY
WEEKLY
WEEKLY
TEMPERATURE
WEEKLY
WEEKLY
WEEKLY
WEEKLY
CONDUCTIVITY.
WEEKLY
WEEKLY
WEEKLY
WEEKLY
pH
WEEKLY
WEEKLY
WEEKLY
WEEKLY
FECAL COLIFORM
WEEKLY
WEEKLY
WEEKLY
WEEKLY
TP
2/MO
2/MO
N/A
2/MO
PO4
2/MO
2/MO
N/A
2/MO
TKN, TN, NH3-N
2/MO
2/MO
N/A
2/MO
CHLOR A
2/MO
2/MO
N/A
2/MO
UPSTREAM SITE LOCATION: AT DIRT ROAD ACCESS TO THE WWTP
DOWNSTREAM LOCATIONS:
SITE 1: AT NCSR 1301
SITE 2: AT NCSR 1152
SITE 3: IN SUNSET LAKE (AT DAMS WALKWAY) -SUNSET LAKE LODGE-
INSTREAM MONITORING (EXCEPT TP,PO4, TKN, TN, NH3-N, & CHLOR A) IS TO BE
SAMPLED 3/WEEK DURING DUNE, JULY, AUGUST & SEPTEMBER
* PARAMETERS AT THIS STATION SHOULD BE SAMPLED BEFORE 8:00 AM
TP, PO4, TKN, TN, NH3-N & CHLOR A PARAMETERS ..RE TO BE SAMPLED ONLY
DURING JUNE, JULY, AUGUST & SEPTEMBER

ti♦
.r •_
LI
-
G

DIVISION OF ENVIRONMENTAL MANAGEMENT
RALEIGH REGIONAL OFFICE
August 27, 1990
M E M O R A N D U M
TO Steve Tedder
FROM Arthur Mouberr !
Y
SUBJECT Letter of August 21, 1990 -
Town of Apex
NPDES Permit NCO064050
Wake County
On Friday evening August 24, 1990 in the interoffice mail I
received a copy of a August 21, 1990 letter that was sent to Apex
regarding their permit renewal. It concerns me that this letter
was sent prior to any Regional office input, especially when the
Raleigh Regional office (RRO) had requested that no letter be
sent until we had a chance to comment. The letter as written
does not reflect the commitment the Division made to Apex when
the permit was originally issued. This letter will surely create
unnecessary concerns on Apex's part about the Division's
integrity on any future dealings that we may have with them. We
are trying hard at the Raleigh Regional Office (RRO) to develop a
good working relationship with all of our regulated public, the
message this letter sends is very detrimental to our effort along
this line. I expect the Division will receive a letter of
objection from the Town of Apex on this matter.
On August 13, 1990 the RRO received a copy of the draft WLA-
for Apex's permit renewal request. The RRO was to review and
comment on this draft WLA by September 8, 1990. That same week
we received a copy of the draft letter to comment on. As I was
out on annual leave that week the Central Office was notified
that the RRO comments would be provided when I returned. RRO
comments were made and the draft WLA was signed off on and mailed
on August 24, 1990. As I understand the process the RRO is to
have input into the final WLA. A letter such as the one sent to
Apex should not have been sent until the WLA was finalized.
Back in 1985-86 when the Town was working to get their
permit issued, the Division had already made the decision to not
issue any more permits to zero flow streams. A meeting between
the Town and the Division resulted in an agreement to allow the
Town to be issued a permit for a discharge up to 3.6 mgd.
Barring any documented instream water quality impacts the
Division should honor this original commitment and allow

Steve Tedder
August 27, 1990
Page 2
expansion to 3.6 mgd. If the Town is not impacting water quality
standards, they should not be required to expend the time and
money, which could be quite substantial, to evaluate other
disposed alternatives which would not be used at this time.
In order to meet the Divisions original commitment to Apex
it is requested that the draft permit be prepared with three sets
of effluent limits as follows:
1) 1.8 mgd with current limits and a revised fecal (200)
and requirements to do an extensive instream monitoring
program.
2) 1.8 mgd with current limit and a revised fecal and a 2
mg/l Total Phosphorus to be effective May 1993.
3) 3.6 mgd with 5 and 1 limits and 2 mg/1 Total
Phosphorus.
The draft WLA is proposing Toxicity Testing, metal limits,
residual chlorine, and metal monitoring which the RRO does not
object to. However, until it is determined that a town cannot
comply with toxicity testing we have concerns about assigning
metal limits that will be very expensive for the Town.
Your assistance in getting this matter resolved is
appreciated.
AM:sd
cc: Trevor Clement
Dale Overcash
Preston Howard

State of North Carolina
Department of Environment, Health, and Natural Resources
Division of Environmental Management
512 North Salisbury Street • Raleigh, North Carolina 27611
James G. Martin. Governor
William W. Cobey, Jr., Secretary
August 21, 1990
Mr. Steven E. Stewart
Town of Apex
P.O. Box 250
Apex, North Carolina 27502
George T. Everett, Ph.D.
Director
Subject: Town of Apex WWTP
Permit Renewal
NPDES Permit No. NCO064050
Wake County
Dear Mr. Stewart:
The Division of Environmental Management (DEM) has received the subject NPDES
permit renewal request. Please be advised that the Town's wastewater treatment
facility discharges into an unnamed tributary to Middle Creek which has no natural
flow on at least seven (7) consecutive days during a ten (10) year period and at
least thirty (30) consecutive days during a two (2) year period. This designates
the stream a zero 7Q10 and 30Q2 flow stream. Current regulations (15 NCAC 2B
.0206) do not allow new or expanded (additional) oxygen consuming discharges into
zero 7Q10/30Q2 flow streams.
Since the subject facility consists of treatment works with a design capacity
of 1.8 MGD, DEM intends to reissue the Town of Apex NPDES permit with a flow
limitation of 1.8 MGD with the existing BOD5. NH3-N and dissolved oxygen
limitations. Fecal coliform limitations, and toxics limitations and requirements
will be updated to reflect new standards and regulations which went into effect on
October 1, 1989.
Please note that DEM will require the Town to submit an engineering evalua-
tion of wastewater disposal alternatives in accordance with the enclosed DEM
guidelines before an Authorization to Construct for an expansion of your facility
is issued. The engineering evaluation should analyze the option of rehabilitating
the existing pump station and sewer lines that connect to the City of Raleigh
sewerage system. It is our understanding that this pump station and interceptor
were constructed with funds allocated through the Construction Grants Section of
this Division.
Should the Town continue to discharge wastewater into the zero flow stream
upon expansion to 3.6 MGD, summer (winter) limits of 5 (10) mg/1 BOD51 1 (1.8) mg/l
NH3-N and 6 mg/1 dissolved oxygen will apply until expiration of the permit per 15
NCAC 2B .0206 (d).
Polludon Pn radon Pays
P.O. Box 27687. Raleigh. North Carolina 27611-7687 Telephone [phone]
An Fry ul (lnnnm inin. AMvmamm Arnn F,Hl ,

Mr. Steven E. Stewart
Page Two
Finally, DEM is currently conducting a study to determine the impact of
effluent dominated headwaters to small impoundments. Therefore, the permit will
contain a condition to reopen the permit should the study conclude that more
stringent nutrient limitations are necessary to maintain the best usage of Sunset
Lake downstream from the discharge.
If you need further clarification on this matter, please contact Mr. Trevor
Clements or Mr. Donald Safrit of my staff at [phone].
Sincerely,
Steve W. Tedder
Water Quality Section Chief
Enclosure
cc: Donald Safrit
Tim Donnelly
Central Files
Town of Apex WLA

08/09/90
ver 3.1
T O X I C
S R E V
I E W
Facility:
Town of Apex
NPDES Permit No.:
NC0064050
Status (E, P,
or M) :
E
.
Permitted
Flow:
1.8
mgd
Actual Average
Flow:
0.9
mgd
Subbasin:
030403
Receiving Stream:
UT to MIddle Creek
I ------ PRETREATMENT DATA ---------- 1----EFLLUENT DATA---- I
Stream Classification:
C
I
ACTUAL
PERMITTEDI
I
7Q10:
0.0
cfs
I
Ind. +
Ind. + I
FREQUENCY I
IWC:
100.00
4
1
Domestic
PERMITTED
Domestic I
OBSERVED of Chronic)
Stn'd /
Bkg
I Removal
Domestic
Act.Ind.
Total
Industrial
Total I
Effluent Criteria I
Pollutant
AL
Cone.
I Eff.
Load
Load
Load
Load
Load I
Cone. Violations)
(ug/1)
(ug/1)
I t
(#/d)
(#/d)
(#/d)
(#/d)
(#/d) I
(ug/1) (#vio/#sam)I
Cadmium
S
2.0
1 92%
0.010
0.010
0.020
0.026
0.036 1
1
Chromium
S
50.0
1 76%
0.030
0.110
0.140
1.080
1.110 I
I I
Copper
AL
7.0
1 82%
0.150
0.220
0.370
1.450
1.600 1
1 N
Nickel
S
88.0
1 32%
0.060
0.080
0.140
0.220
0.280 I
I P
Lead
S
25.0
1 81$
0.010
0.010
0.020
0.309
0.319 I
1 U
Zinc
AL
50.0
1 77%
0.560
0.160
0.720
1.042
1.602 1
1 T
Cyanide
S
5.0
1 59%
0.020
0.030
0.050
0.049
0.069 I
I
Mercury
S
0.012
1 86%
0.000
0.000
0.000
0.000
0.000 I
I S
Silver
AL
0.06
I 94%
0.040
0.000
0.040
0.026
0.066 I
I E
Selenium
S
5.00
1 0%
I
I C
Arsenic
S
50.00
I 40%
0.030
0.000
0.030
0.014
0.044 I
I T
Phenols
S
NA
1 99%
0.000
0.000
0.000
0.000
0.000
NH3-N
C
1 0%
I
1 0
T.R.Chlor.AL
17.0
1 0%
I
I N
I
I {
1
I
I 4 P' 4♦♦``'„
I---------------
ALLOWABLE PRBCT D
PRDCT D
PRDCT D---------MONITOR/LIMIT---------
is
1--ADTN L RECMMDT i3.;,= I
I
Effluent
Effluent
Effluent
Instream
I Recomm'd
I
Cone.
using
using
Cone.
Based on
Based on
Based on I FREQUENCY INSTRE;;. I
I Allowable
CHRONIC
ACTUAL
PERMIT
using
ACTUAL
PERMITTED
OBSERVED I Eff. Mon. Monitot;:. I
Pollutant
I
Load
Criteria
Influent
Influent
OBSERVED
Influent
Influent
Effluent I based on Roe ? I
om� ,
I
(#/d)
(ug/1)
(ug/1)
(ug/1)
(ug/1)
Loading
--------
Loading
--------
Data I OBSERVED (YES/NO)' 1
---------I--------------=' I
---------
Cadmium,
--
S
I---------
1
0.19
--------
2•.000
---------
0.211
-------
0.378
--------
0.00
Limit
Limit
1 I A
Chromium
S
1
1.58
50.000
4.422
35.057
0.00
Monitor
Limit
( I N
Copper
AL
1
0.30
7.000
8.764
37.900
0.00
Monitor
Monitor
1 I A
Nicked'.:
S
1
0.98
88.000
12.528
25.056
0.00
Limit
Limit
I ( L
Lead ::• .�''t:
S
I
1.00
25.000
0.500
7.976
0.00
Monitor
Limit
I I Y
Zinc
AL
I
1.65
50.000
21.792
48.479
0.00
Monitor
Monitor
1 I S
Cyanide
S
I
0.09
5.000
2.698
3.723
0.00
Limit
Limit
I I I
Mercury
S
I
0.00
0.012
0.000
0.000
0.00
( I S
Silver
AL
1
0.01
0.060
0.316
0.518
0.00
Monitor
Monitor
I I
Selenium
S
1
0.04
5.000
0.000
0.000
0.00
I I R
Arsenic
S
1
0.63
50.000
2.369
3.458
0.00
Monitor
Monitor
I I E
Phenols
S
I
0.000
0.000
0.000
0.00
I I S
NH3-N
C
I
0.000
0.00
I l U
T.R.Chlor.AL
I
17.000
0.00
I I L
T
S

JCM
8-2-90
Town of Apex Notes
UT to Middle Creek
030403
- This facility was permitted to discharge into a zero flow stream shortly
before the Director issued a mandate, in February '86, which does not allow new
facilities to discharge into zero flow streams and calls for the eventual removal
of existing facilities discharging into zero flow streams.
- DEM informed the facility in May 1, 198.6 that 5/2 limitation would have
applied if the permit was to be reissued in May 1, 1986 or at time of renewal of
current permit. DEM should have said that the facility would not have: been per-
mitted to start with and failure to remove the discharge would cause 5/2 limits at
permit renewal.
- Construction Grants has informed us that a pump station and sewer connec-
tion to the City of Raleigh exist. These works were funded by Construction Grants.
- Facility has only treatment works to 1.8 MGD. No ATC has been issued for
expansion to 3.6 MGD which is the flow limitations contained in the current permit.
- Facility averages flow of less that 1 MGD currently.
- Biomonitoring studies conducted in May 1987 indicate that S' many of the
abundant taxa collected from Middle Creek, below the Apex WWTP, are tolerant to the
effects of low dissolved oxygen and indicated the effects of the Apex effluent at
this point."
- A review of the Toxicity database indicates that the facility passed a
chronic tox test in 1988.
- DO samples collected by me on 7-16-90 indicated DO stream standard is met
in the receiving waters (please note that facility is doing an excellent job in
treating the wastewater as documented in the DMR's):
Effluent DO = 7.8
No upstream flow
DO at NCSR 1301 = 7.0 Temp. = 23.5
DO at NCSR 1152 = 6.0 Temp. = 24.0
DO at bottom of lake (at dam) = 11.2 Temp. = 23
No adverse impact was visually observed in the lake during my visit.
- Attached memo which was sent to RRO documents our approach to this permit
reissuance (telephone conversation with Tim Donnelly indicated he opposes flow
reduction; however, he was going to let Arthur Mouberry to decide upon receipt of
WLA)

' `07/02/90
ver 3.1
T 0 X I C
S R E V
I E W
Facility:
Town of Apex
NPDES Permit No.:
NCO044050
Status (E, P, or M) :
E
Permitted Flow:
3.6
mgd
Actual Average Flow:
0.9
mgd
Subbasin:
030403
Receiving Stream:
UT to MIddle Creek
I--------- PRETREATMENT DATA--------------I----EFLLUENT DATA---- I
Stream Classification:
C
I
ACTUAL
PERMITTEDI
I
7Q10:
0.0
cfs
I
Ind. +
Ind. + I
FREQUENCY I
IWC:
100.00
#
I
Domestic
PERMITTED
Domestic I
OBSERVED of Chronicl
Stn'd / Bkg
l Removal
Domestic
Act.Ind.
Total
Industrial
Total I
Effluent Criteria I
Pollutant
AL Cone.
I Eff.
Load
Load
Load
Load
Load I
Cone. Violations)
---------
--
(ug/1) (ug/1)
----------------
I %
--------
(#/d)
--------
(#/d)
--------
(#/d)
--------
(#/d)
---------
(#/d) I
--------
(ug/1) (#vio/#sam)l
-----------------
Cadmium
S
2.0
I
l 92%
0.010
0.010
0.020
0.026
l
0.036 I
i
I
Chromium
S
50.0
1 766
0.030
0.110
0.140
1.080
1.110 I
I I
Copper
AL
7.0
( 82$
0.150
0.220
0.370
1.450
1.600 I
I N
Nickel
S
88.0
1 32%
0.060
0.080
0.140
0.220
0.280 I
I P
Lead
S
25.0
I 81$
0.010
0.010
0.020
0.309
0.319 l
l U
Zinc
AL
50.0
I 77$
0.560
0.160
0.720
1.042
1.602 (
I T
Cyanide
S
5.0
I 59%
0.020
0.030
0.050
0.049
0.069 I
I
Mercury
S
0.012
l 86%
0.000
0.000
0.000
0.000
0.000 J
I S
Silver
AL
0.06
I 90
0.040
0.000
0.040
0.026
0.066 J
I E
Selenium
S
5.00
I 0%
I
I C
Arsenic
S
50.00
( 40$
0.030
0.000
0.030
0.014
0.044 I
I T
Phenols
S
NA
( 99%
0.000
0.000
0.000
0.000
0.000 (
l I
NH3-N
C
I 0$
I
1 0
T.R.Chlor.AL
17.0
1 06
I
I
I
I N
I
I
I---------------
I
I
ALLOWABLE PRDCT'D
PRDCT'D
PRDCT'D
I
I I
--------- MONITOR/LIMIT --------- 1--ADTN'L RECM DTN'S-- l
I
Effluent
Effluent
Effluent
Instream
I Recomm'd I
I
Cone.
using
using
Cone.
Based on
Based on
Based on I FREQUENCY INSTREAM
l Allowable
CHRONIC
ACTUAL
PERMIT
using
ACTUAL
PERMITTED
OBSERVED I Eff. Mon. Monitor. I
Pollutant
I Load
Criteria
Influent
Influent
OBSERVED
Influent
Influent
Effluent I based on Recomm'd 2 l
1 (#/d)
(ug/1)
(ug/1)
---------
(ug/1)
--------
(ug/1)
--------
Loading
--------
Loading
--------
Data I OBSERVED (YES/NO) I
---------I----------------- I
---------
Cadmium
--
S
I---------
I 0.19
--------
2.000
0.211
0.378
0.00
Limit
Limit
i I A
Chromium
S
I 1.58
50.000
4.422
35.057
0.00
Monitor
Limit
J I N
Copper
AL
( 0.30
7.000
8.764
37.900
0.00
Monitor
Monitor
I I A
Nickel
S
1 0.98
88.000
12.528
25.056
0.00
Limit
Limit
l I L
Lead
S
I 1.00
25.000
0.500
7.976
0.00
Monitor
Limit
( I Y
Zinc
AL
1 1.65
50.000
21.792
48.479
0.00
Monitor
Monitor
( I S
Cyanide
S
I 0.09
5.000
2.698
3.723
0.00
Limit
Limit
I I I
Mercury
S
1 0.00
0.012
0.000
0.000
0.00
I I S
Silver
AL
I 0.01
0.060
0.316
0.518
0.00
Monitor
Monitor
I I
Selenium
S
I 0.04
5.000
0.000
0.000
0.00
I I R
Arsenic
S
( 0.63
50.000
2.369
3.458
0.00
Monitor
Monitor
I I E
Phenols
S
1
0.000
0.000
0.000
0.00
1 I S
NH3-N
C
1
0.000
0.00
I I U
T.R.Chlor.AL
l
17.000
0.00
I I L
I
I IT
I
I
I I S
I I

State of North Carolina
Department of Environment, Health, and Natural Resources
Division of Environmental Management
512 North Salisbury Street • Raleigh, North Carolina 27611
James G. Martin, Governor George T. Everett, Ph.D.
William W. Cobey, Jr., Secretary Director
Mr. Stephen E. Stewart
Town of Apex
P.O. Box 250
Apex, North Carolina 27502
Subject: Chlorine Toxicity
NDPES Permit No. NCO064050
Wake County
Dear Mr. Stewart:
Chlorine, a widely used wastewater disinfectant for the treatment of coliform organisms, often
remains instream in residual amounts that may prove to be toxic under critical low stream flow
conditions. In the last decade, EPA assessed the potential adverse effects of chlorine to the aquatic
environment and has taken steps to reduce the impacts through the development of federal criteria.
In 1986, EPA recommended that all states have a chlorine standard by their next.triennial review of
water quality standards.
In revising its water quality standards in 1989, North Carolina developed an action level for
chlorine of 17 ug/l (freshwater classes only). In addition, the fecal coliform limit was reduced from
1000 colonies/100 ml to 200 colonies/100 ml. Under a new DEM procedure, dechlorination and
chlorine limits are now recommended for all new or expanding dischargers proposing the use of
chlorine for effluent disinfection. The Division is reviewing chlorine levels from all existing
dischargers as part of their NPDES permit renewal process.
Our records indicate that chlorine from your facility's effluent discharge may be toxic to aquatic
life in the receiving stream under low flow conditions, i.e., the amount of chlorine discharged causes
an exceedance of the instream action level for chlorine (17 ug/1 for chronic effects aad 28 ug/1 for
acute effects) under 7Q10 conditions (the lowest average daily flow for seven (7) consecutive days
during a ten (10) year period). Action should be taken to reduce the effluent concentration of
chlorine to an acceptable level. Based on your instream waste concentration of 100%, an acceptable
level of chlorine in your effluent is 17 ug/1 or 0.017 mg/l. If this level is not feasible, you should
consider dechlorination or alternate methods of disinfection for your facility to ensure that both
chlorine and bacterial limits are met. In addition, if your facility plans to undertake any phase of
construction, dechlorination or alternate disinfection should be included. However, please note that
an authorization to construct must be obtained from this Division prior to any alteration to your
treatment plant.
Pollution Prevention Pays
P.O. Box 27687, Raleigh, North Carolina 27611-7687 Telephone [phone]
An Equal Opportunity Affirmative Action Employer

-2-
The Division is currently reviewing its water quality regulations pertaining to chlorine. In the
future, effluent limits and/or dechlorination may be required of existing facilities with chlorine
problems. If the chlorine levels in your facility's effluent remain unchanged, a chlorine limit or
whole effluent toxicity requirement may be added to your permit limitations.
Please feel free to call Mr. Timothy Donnelly of the Division's Regional Office at (919) 733-
2314, if you have any questions or comments regarding this issue.
Sincerely,
teve W. Tedder
Water Quality Section Chief
SWT/jcm
cc: Raleigh Regional Office
Central Files
Pollution Prevention Pays
P.O. Box 27687, Raleigh, North Carolina 27611-7687 Telephone [phone]
An Equal Opportunity Affirmative Action Employer