NC0024911_Wasteload Allocation_19920826

NPDES DOCUHENT SCANNING COVER SHEET
NPDES Permit:
NC0024911
MSD Buncombe County WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Report
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
August 26, 1992
Thi'a document i'a printed on reu'ae paper - izore any
content on the reirerse'aide

NPDES WAS 1 i LOAD ALLOCATION
PERMIT NO.: JNCOO .z9
FACILITY NAME: b1/%r5y./. f7+*+ f1414.1 ag-triy Awci.u.ec G.
Facility Status: rjli
Permit Status: " 4 4
Major
Pipe No.:
Minor
00
Design Capacity: 10. 0
Domestic (% of Flow): 79
Industrial (% of Flow): -2/
Comments:
RECEIVING STREAM: v4 t•12
Class: C'
Sub -Basin: 09034
Reference USGS Quad: ri/t/V (please attach)
County: fl✓#'mob,-
Regional Office: 4,446.
Requested by:
Prepared by.
Reviewe
icc, = t 135-17\a j
Lv a
Date: 6�//l
Date: 8/27/3 L
Date: g aqqa--'
Modeler
Date Rec.
#
.U1AN
Wit I9i
'7 6 341
Drainage Area (mi2 ) 96 4.
Avg. Streamflow (cfs): .2/ "o
7Q10 (cfs) V.C,6 Winter 7Q10 (cfs) -�9S 30Q2 (cfs) yr /
Toxicity Limits: IWC ) �- % "� elirom-i
� C'hvcn.c c. Acut: ' onic
Instream Monitoring: `p0 %��
Parameters I'd /-.►..
Upstream Y Location
Downstream Y Locationtra.''�
Effluent
Characteristics
Summer
Winter
itift4/1(' Ait(
)247-
dv. (fir
;
ISI (45/A,
79
P-it,i, Co( mixt)
2470
, \.,
/
,.....„. ,.
PLO
ED
Comments:

RECEIVED
Water Quality Stcticxl
Facility Name:
NPDES No.:
Type of Waste:
Facility Status:
Permit Status:
Receiving Stream:
Stream Classification:
Subbasin:
County:
Regional Office:
Requestor:
Date of Request:
Topo Quad:
FACT SHEET FOR WASTELOAD ALLOCATION
Request # 1 0 3
Metropolitan Sewerage District of Buncombe County
NC0024911
79% Domestic / 21% Industrial
Existing
Renewal- 4e,,,47 04
French Broad River
C
040302
Buncombe
Asheville
Max Haner
6/1/92
ERNE
AUG 4 - 1992
��heville Regional Otter„
Asheville, North Caroline
Stream Characteristic:
USGS #
Date:
Drainage Area (mi2):
Summer 7Q10 (cfs):
Winter 7Q10 (cfs):
Average Flow (cfs):
30Q2 (cfs):
IWC (%):
966
466
595
2140
884
11.7
c;
co
Wasteload Allocation Summary
(approach taken, correspondence with region, EPA, etc.)
Effluent limit for BOD5 =30 mg/1 will be revised to CBOD5=25 mg/1 at the request of the Asheville
Regional Office.
Special Schedule Requirements and additional comments from Reviewers:
lieu) :140i.l Ce3aJ U.�
c4741(c n, -CO .1/°T c- eku. _
71e6Ayr-rick /tie-e7-tmlfze
L
Recommended by:
Reviewed by
Instream Assessment:
3 1244
Date: 6/17/92
7// /f
Date: j
Regional Supery s• �►r._ _� �__ �1•_. Date:
Permits & Engineering: �l �-- % ' Date: fkl n
RETURN TO TECHNICAL SERVICES BY: AUG 2 3 1992

2
Existing Limits:
CONVENTIONAL PARAMETERS
Monthly Average
Summer Winter
Wasteflow (MGD): 40.0
BOD5 (mg/1): 30
NH3N (mg/1): nr
DO (mg/1): monitor
TSS (mg/1): 30
Fecal Col. (/100 ml): 1000
pH (SU): 6-9
Recommended Limits:
Monthly Average
Summer Winter WQ or EL
Wasteflow (MGD): 40.0
CBOD5 (mg/1): 25
NH3N (mg/1): nr
DO (mg/1): monitor
TSS (mg/1): 30
Fecal Col. (/100 ml): 200
pH (SU): 6-9
Limits Changes Due To: Parameter(s) Affected
Change in 7Q10 data
Change in stream classification
Relocation of discharge
Change in wasteflow
Other (onsite toxicity study, interaction, etc.)
Instream data
New regulations/standards/procedures Fecal Coliform
New facility information BOD5
(explanation of any modifications to past modeling analysis including new flows, rates, field data,
interacting discharges)
(See page 4 for miscellaneous and special conditions, if applicable)

3
Type of Toxicity Test:
Existing Limit
Recommended Limit:
Monitoring Schedule:
Existing Limits
Chromium (µg/1)•
Copper WA):
Nickel (µg/1):
Lead (µgm):
Zinc (µg/1):
Cyanide (µg/1):
Silver (µg/1):
Recommended Limits
Chromium (µg/1):
Copper (µg/1):
Nickel (µg/1):
Lead (µgm):
Zinc (µg/1):
Cyanide (nil):
Silver (µg/1):
Limits Changes Due To:
Change in 7Q10 data
Change in stream classification
Relocation of discharge
Change in wasteflow
New pretreatment information
Failing toxicity test
Other (onsite toxicity study, interaction, etc.)
TOXICS/METALS
Phase 1 }Chronic Ceriodaphnia Qrtrly
Phase 2) Acute Fathead Minnow 24hr - No significant
mortality * for discharge into a flume
Phase 1) Chronic @ 11.7%
Phase 2) Acute Fathead Minnow @ 90%
Phase 1) Chronic @ 11.7%
Phase 2) Acute Fathead Minnow @ 90%
Feb May Aug Nov
Daily Max.
monitor
monitor
monitor
monitor
monitor
monitor
monitor
Daily Max.
monitor
monitor
monitor
monitor
monitor
monitor
monitor
WQorEL
WQ
WQ
WQ
WQ
WQ
WQ
WQ
Parameter(s) Affected
X_ Parameter(s) are water quality limited. For some parameters, the available load capacity of
the immediate receiving water will be consumed. This may affect future water quality based
effluent limitations for additional dischargers within this portion of the watershed.
OR
No parameters are water quality limited, but this discharge may affect future allocations.

4
INSTREAM MONITORING REQUIREMENTS
Upstream Location: above outfall in flume
Downstream Location: below outfall in flume
Parameters: Dissolved Oxygen, Temperature, Conductivity
Special instream monitoring locations or monitoring frequencies:
Recommend 3/week in the summer and 2/month in the winter
MISCELLANEOUS INFORMATION & SPECIAL CONDITIONS
Adequacy of Existing Treatment
Has the facility demonstrated the ability to meet the proposed new limits with existing treatment
facilities? Yes i No
If no, which parameters cannot be met?
Would a "phasing in" of the new limits be appropriate? Yes No
If yes, please provide a schedule (and basis for that schedule) with the regional
office recommendations:
If no, why not?
Special Instructions or Conditions
Wasteload sent to EPA? (Major) _Nit (Y or N)
(If yes, then attach schematic, toxics spreadsheet, copy of model, or, if not modeled, then old
assumptions that were made, and description of how it fits into basinwide plan)
Additional Information attached? (Y or N) If yes, explain with attachments.

Facility Name 474/6/06/4"/ S"",,'/L/44- "" - 5 L Permit # °.2f 9// Pipe # oo /
CHRONIC TOXICITY PASS/FAIL PERMIT LIMIT (QRTRLY)
(**Chronic Toxicity (Ceriodaphnia) P/F at J %,fEB /14Y4UG /1,b✓, See Part _, Condition .)
The effluent discharge shall at no time exhibit chronic toxicity 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 /2 % (defined as treatment two in the North Carolina procedure document). The permit holder shall perform
quarterly monitoring using this procedure to establish compliance with the permit condition. The first test will be
performed after thirty days from the effective date of this permit during the months of
,E6 RAY MI6- AV . Effluent sampling for this testing shall be performed at the NPDES
permitted final effluent discharge below all treatment processes.
All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge
Monitoring Form (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
4401 Reedy Creek Road
Raleigh, N.C. 27607-6445
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 the 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 464 cfs
Permitted Flow 1°• ° MGD
IWC% // 7
Basin & Sub -basin Fei °2-
ReceivingStream av
County
mended by:
7//�/9
QCLR Version 9/91

w i '7�JAt
Facility Name /ld'ye6f, a/ dFclr,. ,�d �vvv►4. p t # / �� �9i/
`/ Pipe #
ACUTE TOXICITY PASS/FAIL PERMIT LIMIT (QRTRLY)
The permittee shall conduct acute toxicity tests on a quarterly basis using protocols defined in the North Carolina
Procedure Document entitled "Pass/Fail Methodology For Determining Acute Toxicity In A Single Effluent
Concentration." The monitoring shall be performed as a Fathead Minnow (Pimephales promelas) 24 hour static
test, using effluent collected as a 24 hour composite. The effluent concentration at which there may be at no time
significant acute mortality is 90% (defined as treatment two in the North Carolina procedure document). Effluent
samples for self -monitoring purposes must be obtained during representative effluent discharge below all waste
treatment. The first test will be performed after thirty days from the effective date of this permit during the
months of 165 MAY MI F 4Ia✓
All toxicity testing results required as part. of this permit condition will be entered on the Effluent Discharge
Monitoring Form (MR-1) for the month in which it was performed, using the parameter code TGE6C.
Additionally, DEM Form AT-2 (original) is to be sent to the following address:
Attention: Environmental Sciences Branch
North Carolina Division of
Environmental Management
4401 Reedy Creek Road
Raleigh, N.C. 27607
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 either these monitoring requirements or tests performed by the North Carolina Division
of Environmental Management indicate potential impacts to the 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
Permitted Flow 90 MGD
IWC
Basin & Sub -basin F0-23 aL
Receiving Stream 1-f-C•4 5444 Mutes
County f30"4.4,4 c
mmended by:
Date t /3 of
! f 04.0 ./i itch 4 14'ML !l • MI4lmu/I
*. MJ 7/
jf
VL /VI.
lila kin d'SCJucc�, "14 Gel Is A.
IJ 71L 1 L . AL 7v/0 1 i ti r/�"K Affm-4 0,., , D¢%L C
QAL PIF Fathead 24 Version 9/91

State of North Carolina
Department of Environment, Health, and Natural Resources
Asheville Regional Office
James G. Martin, Governor
William W. Cobey, Jr., Secretary
DIVISION OF ENVIRONMENTAL MANAGEMENT
WATER QUALITY SECTIQN
June 1, 1992 .a
MEMORANDUM
To: Steve Tedder, Chief
Water Quality Section
Through:
From:
Subject:
Forrest R. Westall
Regional Water Quality
Max L. Haner
Environmental Chemist / ARO
Ann B. Orr
Regional Manager
REGERI ED
J O N 0 3 1992
TECHNICAL SUPPORT BRANCH
asor
Requested Policy Determination
Carbonaceous BOD5 vs Total BOD5
for NPDES Permit Compliance
MSD of Buncombe County (NC0024911)
Information obtained by MSD of Buncombe County (NC0024911) during
a March, 1992, performance test for its new RBC-Microscreen
facility shows specific interference in the actual BOD5
test from
nitrifying bacteria to the extent to cause concern forpossible
violation of effluent BOD5 limits. As result of the test
findings and since Standard Methods specifically provides for use
of nitrifying inhibitors in the BOD5 test procedure, MSD has been
reporting carbonaceous BOD5 data onitsDMRs. ARO has no
objection to use of these carbonaceous ROD5 test results and has
advised MSD accordingly by letter dated. June 1, 1992 (attached).
It appears appropriate for DEM to review use of these
carbonaceous BOD test results with respect to compliance with
terms and conditions contained in MSD's standard NPDES permit.
Absent any significant water quality concerns and since no
specific reference appears in the NPDES permit relating to use of
carbonaceous BOD5' it is recommended that wording in the MSD
NPDES permit recognize reporting of BOD data in accordance with
standard test procedures to demonstrates permit compliance. DEM
should consider modifying the standard wording in all NPDES
permits accordingly.
Interchange Building, 59 Woodfin Place, Asheville, N.C. 28801 • Telephone [phone]
t
An Equal Opportunity Affirmative Action Employer

Page 2
June 1, 1992
Thanks for your attention to this matter. A copy of MSD's-April
24, 1992, letter outlining the performance test findings as
related to use of carbonaceous BOD data is also attached. Should
you have questions or wish a more detailed discussion, please
advise.
Attachments
xc: Trevor Clements
Don Safrit

SDMetropolitan Sewerage District of
Buncombe County North Carolina
W. H. Mull, P.E., Engineer -Manager
P.O. Box 8969, Asheville, N.C. 28814
Telephone: Area Code 704-254-9646
Telecopler [phone]
John 8. Stevens, General Counsel
Mr. Max Haner
Environmental Chemistry Consultan
N.C. Dept.' of Environment, Health
& Natural Resources
59 Woodfin Place
Asheville, N.C. 28801
Subject: CBOD Reporting
Dear Mr. Haver:
RECEIVE°
Water Qul"rty. Section
APR 2 !9 1992
Seville Regional 01fi
Asheville, North Caroline
FrankS. $mithJil, Chairman
George.E. IveYL Ylcd-Chairman
.Striven T. Aceto
•Jackle.W. Bryson
M. Wayne Odwards
Richard P..Mass
Diane K.'McDonald
Charles W. Penny
Marvin E Waddey
Carolyn R. Wallace
April 24, 1992
The standard of performance requirements of Envirex's B - ...
Screen process
warranty specify that a 30 day- to
performance test be completed in order to ascertain the
ability of the "Bio-Screen" process to meet our 30 mg/I BOD - 30 m /I TSS
The test protocol requires that the treatment plant be placed into permit limital
configuration that simulates the 40 MGD design flow hydraulic and organic loading.
configuration is to be maintained for the entire 30 day testing period. Thissir This
design flow configuration consists of operating with only seven RBC trains simulated
intermediate clarifiers with the number of Primary and secondarysins and two
manipulated to match predetermined unit flows. The performance test was scheduled microscreens on line,
mutual agreement between Envirex and MSD to begin March 1, 1992. eduled by
In order to allow the RBC Biomass to reach equilibrium for the simulated
hydraulic/organic loading rates, we began test
beginning on February 3rd. By February 17th, theuRg removing RBC's from service
obtained. On March 1st, C testing configuration had been
the intermediate clarifiers and the primary/secondary
microscreens were placed into the test configuration.
During the month of February, we experienced higher than expected BOD
in our plant effluent. Our monthly average BOD was 34.2 mg/I. Even th values
e
modifying our plant configuration, the high plant effluent BOD was difficult
to e were
because our RBC effluent soluble BOD remained low (10.5 mg/I).
It explain

The low RBC effluent soluble BOD indicated that we were obtaining adequate
biological treatment. Good soluble BOD removal coupled with low effluent TSS (17.6
mg/I) led us to conclude that the increase in plant effluent BOD was due to an increase
in the soluble fraction of the total BOD. Additional BOD analysis of the clarifier effluent
and the secondary microscreen influent and effluent channels confirmed that the increase
in soluble BOD. occurs downstream of the RBC process, however the total BOD didn't
exhibit this same tendency.
Our initial investigation into ,the problem consisted of a search for plant variables
that we had not accounted for... We unsuccessfully searched for any plant side streams
or additions. Piggy backing an ISCO sampler on our effluent sampling point seemed to
eliminate our plant sampler as a problem source. Chlorination of the effluent sampler line
produced no positive results:: (Since our sample line is so long about 300 feet we are
proceeding with the installation: of a tap that will allow us to regularly chlorinate the sample
line as a quality control measure):
After numerous consultations with Envirex and the discovery of a timely article in
"Operators Forum" we began to look into the possibility of Nitrification occurring in our
BOD bottles. This possibility made sense because while operating all of the RBC shafts,
with actual plant flows at half the design flow, we probably maintained a population of
Nitriflers in the downstream reaches of our RBC basins. When we moved to simulation
of design flow, apparently the carbonaceous loading was moved farther downstream in
the RBC basins. The nitrifiers, no larger competitive, would have been pushed out of the
RBC basins. This possibility is supported by an increase in our effluent ammonia nitrogen
levels. Another bit of corroborating evidence is that we began to see some elevated
BOD's back in December that correlate with some in -plant changes. Beginning in early
December, we began to divert a portion of the primary microscreen's flow from RBC basin
#1 to RBC basin #2. This was in an effort to reduce the weight on the RBC basin #1's
shafts. This diversion of flow would have also resulted in allowing the carbonaceous
loading farther downstream in the RBC process, again moving the nitrifiers out. We
began running carbonaceous BOD's on the plant effluent starting March 12th. We found
that we were experiencing an effect from nitrification in the BOD bottles. There has been
since March 12th a 25% effect from nitrogenous BOD.
Standard Methods, 17th Edition, page 5-2 and 5-3 indicates that nitrogenous
demand is considered an interference in the determination of BOD and is not useful for
assessing the oxygen demand associated with organic material. Standard Methods goes
on to state "Many biological treatment plant effluents contain significant numbers of
nitrifying organisms. Because oxidation of nitrogenous compounds can occur in such
samples, inhibition of nitrification as directed in Paragraph B.4e6 is recommended for
samples of secondary effluent...".
Currently, the interference of nitrogenous BOD in our effluent is significant enough
to lead to non-compliance with our NPDES Permit. Envirex has indicated that a number
of RBC plants have experienced a similar problem. We believe that the current problem
at MSD is related to the simulation of design flow, and will probably subside once all of
the RBC shafts are back in service. We believe however that nitrogenous BOD will
remain a potential interference to our BOD analyses and will therefore be reporting CBOD
on our monthly monitoring reports.

After determining the impact that nitrogenous BOD was having on our ability to
meet our permit limits during February, we used the information we had gathered on
nitrogenous BOD effect to recalculate the BOD's on our. February report. We noted these
recalculations on the report. Our early testing showed a 24% effect from nitrification. Due
to the limited number of data points; however we decided to assume a conservative 20%
effect. Since then this effect has been shown to be 25% of the total BOD. You will fin d
the analyses. results we used to determine this effect attached to this letter..:
The March report will include CBOD's beginning on the 12th. The BOD's from the
2nd of March until the 11 th are total BOD's recalculated to reflect the conservative 20%
effect of nitrogenous BOD. All of our future monitoring reports will have BOD reported as
CBOD and will be noted as such.
hope I have provided an adequate explanation of our decision to report CBOD.
Please let me know if you need further explanation or`additionat. supporting data:
Sincerely,_.
E. Marc Fender
Assistant Superintendent
of Operations
MF:sc

MSD EFFLUENT TBOD/CBOD - MG/L
DATE
TBOD
CBOD
3/12/92
30
20
3/13/92
32
27
3/16/92
29
23
3/17/92
28
22
3/18/92
46
27
3/19/92
43
36
3/20/92
36
30
3/23/92
19
15
3/24/92
25
23
3/25/92
28
19
3/26/92
33
25
3/27/92
30
30
3/30/92
21
18
3/31/92
36
27
4/1/92
39
21
4/2/92
38
21
4/ //92
33
24
4/6/92
29
18
4/7/92
36
26
4/8/92
38
47
4/9/92
38
27
4/10/92
44
28
4/13/92
27
19
4/14/92
30
24
4/15/92
40
24
4/16/92
31
23
AVERAGE
33.0
24.7

State of North Carolina
Department of Environment, Health, and Natural Resources
Asheville Regional Office
James G. Martin, Governor
William W. Cobey, Jr., Secretary
DIVISION OF ENVIRONMENTAL MANAGEMENT
WATER QUALITY SECTION
June 1, 1992
Mr. E. Marc Fender, Assistant Superintendent
Metropolitan Sewerage District
of Buncombe County
Post Office Box 8969
Asheville, North Carolina 28807
Dear Mr. Fender:
Ann B. Orr
Regional Manager
Subject: Required Submittal of Amended
Discharge Monitoring Report (DMR)
For February, 1992
MSD of Buncombe County (NC0024911)
Following review of your letter of April 24, 1992, in which
you relate those findings of the 30-day performance test of MSD's
recently completed RBC-Microscreen type wastewater treatment
facility which support use of carbonaceous BOD5 test data on the
monthly discharge monitoring report (DMRs) andinaccordance with
our recent telephone discussion, this letter is to request that
MSD submit an amended DMR for February, 1992, to show actual BOD5
test data. As Standard Methods allows use of nitrifying
inhibitors as part of the BOD5 test, MSD may include actual
carbonaceous BODS test data on its DMRs until notified otherwise.
Resubmittal of the March, 1992, DMR will. not be required at this
time. I will request that this matter he reviewed by our
administrative staff in Raleigh to determine whether modification
to NPDES Permit Number NC0024911 will be necessary and will
advise you accordingly.
While findings during this performance test period (March,
1992) appear to conclusively show that nitrifying bacteria
provided interference in the BODS test, the absence of actual
carbonaceous BOD5 data during February, 1992, prevents use of
this information for that DMR period. This determination is with
full understanding that the facility was being readied for the
performance test during February, 1992, and many of the operating
conditions were comparable to the March, 1992 setup.
Interchange Building, 59 Woodfin Place, Asheville, N.C. 28801 • Telephone [phone]
An Equal Opportunity Affirmative Action Employer

Page 2
June 1, 1992
Mr. Fender
Thank you for your attention to this matter. I will advise
you of Raleigh's findings relative to possible permit amendment.
Your truly,
Max" L. Haner
Environmental Chemist
xc: W.H. Mull
Forrest R. Westall