NCG510399_staff report_19980528

cc: Permits and Engineering
Technical Support Branch
County Health Dept.
Central Files
WSRO
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SOC PRIORITY PROJECT: Yes _ No3X J�)
To: Permits and Engineering Unit
Water Quality Section
Attention: Jeff Myhra
Date: May 28, 1998
NPDES STAFF REPORT AND RECOMMENDATION FOR PERMIT MODIFICATION
Issac's Tire and Service Center Site
US Highway 421 North
County Watauga
General Permit No. NCG510000
Certificate of Coverage NCG510399
PART I - GENERAL INFORMATION
1. Facility and Address: Isaac's Tire and Service Center Site
9838 U.S. Highway 421
Zionville, NC
2. Date of Investigation: May 28, 1998
3.. Report Prepared by: Beth Morton
4. Persons Contacted and Telephone Number: David Cox, Geophex [phone],
Groundwater Section Sherri Knight [phone]
5. Directions to Site: From Boone, take 421 N towards Tennessee. Isaac's Tire Service
Station is on the right side of 421. The site is on the left side below the trailer park.
6. Discharge Points(s), List for all discharge points:
Latitude: 36°17'21" Longitude: 81' 44' 50"
U.S.G.S. Quad No. B12 SW U.S.G.S. Quad Name Zionville
7. Site size and expansion area consistent with application? Yes X No If No, explain:

NPDES PERMIT STAFF REPORT
May 28, 1998
Page 2
8. Topography (relationship to flood plain included): The area is mountainous. The facility is
not located in a flood plain.
9. Location of nearest dwelling: 50 feet to trailer park.
10. Receiving stream or affected surface waters: UT to Sharp Creek
a. Classification C
b. River Basin and Subbasin No.: WAT 04 02 01
C. Describe receiving stream features and pertinent downstream uses: The receiving
stream is a rocky mountain stream with fish and wildlife present.
Part H - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
1. a. Volume of Wastewater to be permitted: 2400 gallons per day (Ultimate Design
Capacity)
b. What is the current permitted capacity of the Waste Water Treatment facility? So
far the system has treated a total of 157,020 gallons of wastewater according to
the flow meter on site.
C. Actual treatment capacity of the current facility (current design capacity)? less
than 2400 gallons per day
d. Date(s) and construction activities allowed by previous Authorizations to
Construct issued in the previous two years. A/C issued for the current system on
the site described in the current general permit.
e. Please provide a description of existing or substantially constructed wastewater
treatment facilities;
The portable groundwater plant consists of recovery wells, free product storage
tank, oil/water separator, air stripper, two sediment filters, transfer pumps and
carbon filtration for petroleum contaminated groundwater.
f. Please provide a description of proposed wastewater treatment facilities. An
oil/water separator, 3 wetland cells, a carbon filter unit, and recirculation pumps.
g. Possible toxic impacts to surface waters: No information given on level of
treatment for domestic waste is provided. The applicant proposes to use domestic
waste to treat the groundwater. No disinfection of the waste is proposed.

NPDES PERMIT STAFF REPORT
May 28, 1998
Page 3
h. Pretreatment Program (POTWs only): not needed X
2. Residuals handling and utilization/disposal scheme: Disposal of free product at an
appropriate certified waste handler.
a. If residuals are being land applied, please specify DEM Permit No. NA.
b. Residuals stabilization: ETA
C. Landfill: NA
d. Other disposal/utilization scheme (Specify): NA
3. Treatment plant classification (attach completed rating sheet). Class I
4. SIC Code(s): 4941
Primary Secondary
37 NA
Main Treatment Unit Code: 53 0 X 0 (No codes exist for wetlands treatment)
PART III - OTHER PERTINENT INFORMATION
1. Is this facility being constructed with Construction Grant Funds or are any public monies
involved. Yes. State trust fund money is involved.
2. Special monitoring or limitations (including toxicity) requests: No disinfection of the
wastewater is proposed.
3. Important SOC, JOC or Compliance Schedule dates: (Please indicate). None.
4. Alternative Analysis Evaluation: Has the facility evaluated all of the non -discharge
options available. Please provide regional perspective for each option evaluated. NA
because discharge is to a positive flow stream.
Health Dept was contacted.
5. Other Special Items: NONE

NPDES PERMIT STAFF REPORT
May 28, 1998
Page 4
PART IV - EVALUATION AND RECOMMENDATIONS
The current system appears to be working well. David Cox mentioned that the property owner
who planned to allow the wetlands to be built on his property has now reconsidered and plans to
develop the property for homes/trailers. If this happens there may not be enough land available
for constructing a wetlands system. It would be difficult to meet buffer requirements between a
wetlands area and the trailers because the site is so small.
It is the opinion of this office that the current system is reliable, adequate and a proven method for
treatment. The proposed method has not been demonstrated to be equivalent treatment to the
current method in use. There are concerns about the proposed method discharging domestic
effluent that has not been disinfected into the receiving stream.
Recommendation is made to further evaluate the treatment process before issuing the permit.
Given the information provided about the proposed system, this office would not concur with
issuance of the permit.
�Y► mil' U �'`-�
Signature of report preparer
Water QualityRegion upervisor
5 -Z g-95
Date

N
direction of
0 1000 2000 feet
•
streamflow N
Graphic Scale f
Figure 2. Location of temporary water treatment site as shown
Geophex on the USGS 7.5 minute quadrangle maps of Zionville,
NC -TN (1976) and Sherwood, NC -TN (1969).

RATING SCALE FOR CLASSIFICATION OF WATER POLLUTION CONTROL SYSTEMS
Name of Facility: fiGQ a, CIS Ye' & SE
Owner or Contact Person: _ A1(1 G_kK -
Mailing AdclrFess: ✓d a (mil G 0�—
County: a(AG— Telephone: 9/ 733 L3l
Present Classifica'l on: New Facility Existing Facility
NPDES Per. No. N 510000 Nondisc. Per. No.WO Health Dept.Per No.
Rated by: iPW Telephone: 033677/¢/dIO Date: 5 7 476
Reviewed by: Health Dept. Telephone:
Regional Office Telephone:?Gw00
Central Office Telephone:
ORC: �lM�(t11X Grade: = Telephone:
Check Classification(s): _ SubsuSpray Irrigation Land Application
Wastewater Classification: (Circle One) I 11 III IV Total Points:_
SUBSURFACE CLASSIFICATION
(check all units that apply)
f-septic tanks
2. pump tanks
3. siphon or pump -dosing systems
4. sand filters
5. grease trapinterceptor
6. oil/water separators
7. gravity subsurface treatment and disposal:
8. pressure subsurface treatment and disposal:
SPRAY IRRIGATION CLASSIFICATION
(check all units that apply)
1. preliminary treatment (definition no. 32 )
2. lagoons
3. septic tanks
4. pump tanks
5. pumps
6. sand filters
7_ grease traptinterceptor
8. oil/water separators
9 disinfection
10. chemical addition for nutrient/algae control
II. -spray irrigation of wastewater
In addition to the above classifications, pretreatment of wastewater In excess of these components shell
be rated using the point rating system and will require an operator with an appropriate dual certification.
LAND APPLICATION/RESIDUALS CLASSIFICATION (Applies only to permit holder)
1. Land application of biosolids, residuals or contaminated soils on a designated site.
-------------------------
WASTEWATER TREATMENT FACILITY CLASSIFICATION
The following systems shall be assigned a Class I classification, unless the flow is of a significant quantity or the technology is unusually
complex, to require consideration by the Commission on a case-byrase basis: (Check it Appropriate)
1. Oil/water Separator Systems consisting only of physical separation, pumps and disposal;
2. Septic Tank/Sand Fitter Systems consisting only of septic tanks, dosing apparatus, pumps,sand filters, disinfection
and direct discharge;
3. Lagoon Systems consisting only of preliminary treatment, lagoons, pumps, disinfection, necessary chemical treatment for
algae or nutrient control, and direct discharge;
4. Closed -loop Recycle Systems;
5.T-Groundwater Remediation Systems consisting only of oilfwaler separators, pumps, air -stripping, carbon adsorption, disinfection
and disposJ;
6. Aquacuiture operations with discharge to surface waters;
7. Water Plant sludge handling and back -wash water treatment;
6. Seafood processing consisting of screening and disposal.
9. Single.family discharging systems, with the exception of Aerobic Treatment Units, will be classified it permitted after July 1,
1993 or it upon Inspection by the Division, it is found that the system is not being adequately operated or maintained. Such
systems will be notified of the classification or reclassification by the Commission, in writing.

The following scale is used for rating wastewater treatment facilities: (circle appropriate points)
ITEM POINTS r
(1) Industrial
Pretreatment Units or Industrial Pretreatment Program (see defintion No. 33)...................................................4
(2) DESIGN FLOW OF PLANT IN gpd [not applicable to ran -contaminated cooling waters, sludge handling facilities for
water purification
plants. totally closed cycle systems(see definition No. 11), and facilities consisting only of hem
(4)(d) or Items (4)(d) and (11)(d))
0 - 20,000................................................................................................................................................1
20.001 - 50,000......................................................................................................................................2
50,001 - 100.000....................................................................................................................................3
100.001 - 250.000.................................................................................................................................. A
250.001 - 500.000.................................................
....................................................................... .........5
500.001 - 1,000,000................................................................................................................................a
1.000.001 - 2,000.000.................. .. ...... ..................................................... ...............10
. ... ...... .. ....... ... . .....
2.000.001 (and up) rate 1 point additional for each 200.000 gpd capacity up to a maximum of .................30
Design Flow (gpd)
(3) PRELIMINARY UNITSIPROCESSES (see definition No.32)
(a)
Bar Screens...............................................................................................................................................1
or
(b)
Mechanical Screens, Static Screens or Comminuting Devices..........................................................................2
(c)
Grit Removal..............................................................................................................................................1
or
(d)
Mechanical or Aerated Grit Removal...................................................................................................... .. .2
(e)
Flow Measuring Device................................................................................................................................I
or
(f)
Instrumented Flow Measurement................................................................................................................2
(g)
Preaeratlon............................................................................................................................................2
(h)
Influent Flow Equalization .........................................................................................................................2
(i)
Grease or Oil Separators - Gravity.................................................................................................................2
Mechanical................................................................................................................................................3
DissolvedAir Flotation................................................................................................................................a
III
Prechlorination................................................................5
........ . ............................................ ...................
(4) PRIMARY TREATMENT UNITS/PROCESSES
(a)
Septic Tank (see definition No. 43)...........................................................................................................2
(b)
Imhoff Tank............................................................................................................................................5
(c)
Primary Clarfflers..........................................................................................................................................6
(d)
Settling Ponds or Settling Tanks for Inorganic Non -toxic Materials (sludge handling facilities for water
purffication plar4s, sand. gravel. stone, and other mining operations except recreational activities such as gem
orgold mining)........................................................................................................................................2
(5) SECONDARY TREATMENT 1,10 (PROCESSES
(a)
Carbonaceous Stage
(1) Aeration -High Purity Oxygen System...............................................................................20
DiffusedAir System...............................................................................................10
......
MechanicalAir System (fixed. floating or rotor).................................................................8
SeparateSludge Reaeration............................................................................................3
(11) Tridding Filter
HighRate....................................................................................................................7
StandardRate...............................................................................................................5
Packed Tower .................
. .... .....................................................................................5 .....
(ill) Biological Aerated Filter or Aerated Biological Filter.....„.................................................. „.10
(iv) Aerated Lagoons......................................................................................................10
(v) Rotating Biological Contactors......................................................................................10
(VI) Sand Filters -intermittent biological..................................................................................2
Recirculatingbiological....................................................................................................3
(vil) Stabilization Lagoons....................................................................................................5
(vili) Clarifier..........................................................................................................................5
(Ix) Single stage system for combined carbonaceous removal of BOD and nitrogenous removal by
nitrification (see definhion No. 12)(Points for this hem have to be In addition to items
(5)(a)(1) through (5)(a)(viff),
utilizing the extended aeration process (see definition No.3a)...........................................2
utilizing other than the extended aeration process............................................................a
(x) Nutrient additions to enhance BOO removal......................................................................5
(XI) Biological Culture ('Super Bugs•)addhion........................................................................5
(b)
Nitrogenous Stage
(i) Aeration - High Purity Oxygen System ....................................................... ..................... 20
DiffusedAir System............. ......................... . . ..........................................................10
.....
Mechanical Air System (fixed. floating or rotor)..........„........„............................................a
SeparateSludge Reaeratlon............................................................................................3
(11) Trickling Filter -High Rate...................................................................................................7
StandardRate................................................................................................................6
PackedTower.................................................................................................................6
(ill) Biological Aerated Filter or Aerated Biological Filter .............................................................10
(Iv) Rotating Biological Contactors......................................................................................10
(v) Sand Filter - Intermittent biological...................................................................................2
Recirculatingbiological....................................................................................................3
(VI) CLtAbr...........................................................................................................................
(6) TERTIARY OR ADVANCED TREATMENT UNITS/PROCESSES
(a)
Activated Carbon Beds -
withoutcarbon regeneration...................................................................................................5
withcarbon regeneration.......................................................................................................15
(b)
Powdered or Granular Activated Carbon Feed -
withoutcarbon regeneration.................................................................................................5
withcarbon regeneration.....................................................................................................15
(c)
Air stripping.............................................................................................................................................5
(d)
Denitrification Process..............................................................................................................................10
(0)
Electrodlalysis............................................................................................................................................5
(f)
Foam Separation........................................................................................................................................5
(g)
Ion Exchange............................................................................................................................................5
(h)
Land Application of Treated Effluent (see definition No. 22b) (not applicable for sand. gravel. stone
and other similar mining operations) by high rate Infiltration......„...„....„...„.......................„....„...„...„.........4
(i)
Microscreens........ ............ .. .......................................................... .5
.. ........................... ..... .................. ..... ..
(1)
Phosphorous Removal by Biological Processes (See definition No. 26).........................................................20
(k)
Polishing Ponds - without aeration............................................................................................................2
withaeration....„...........................................................................................................5