NC0088552_Engineering Alternatives Analysis_20070312

NPDES DOCUMENT !;CANNIN`i COVER :SHEET
NPDES Permit:
NC0088552
Colonial Woods — Wells 1 & 2 WTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
r
Engineering Alternatives (EAA
..
Report
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document
Date:
March 12, 2007
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content on the reirerse side

Existing Wastewater Discharge
Engineering Alternatives Analysis
Aqua North Carolina, Inc.
Colonial Woods Subdivision Well No. 2
Mt. Airy, N.C.
Surry County
Applicant : Aqua North Carolina, Inc.
4163 Sinclair Street
Denver, N.C. 28037
Ph: 704-489-9404
Contact: Gary Moseley
Facility
Prepared by:
Colonial Woods Subdivision Well # 2
Aqua North Carolina, Inc.
Atkins Lane
Mt. Airy, N.C. 27030
Ph: 704-489-9404
Contact: Gary Moseley
J. Thurman Horne, P.E.
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124
Ph: 704-788-4455
Date: March 12, 2007

2
foal
Section 1:
Section 2:
Section 3:
Section 4:
Section 5:
Section 6:
Appendix
Appendix
Appendix
Appendix
Appendix
mom Appendix
Appendix
Appendix
Appendix
Appendix
Appendix
Appendix
Appendix
Pwl
Table of Contents
Page
General 3
1.01 Introduction. 3
1.02 Scope. 3
,Background Information ..3
2.01 Project Area. 3
2.02 Site Characteristics. 4
2.03 Receiving Stream Characteristics 4
Existing Utilities ..4
3.01 Public Facilities'
3.02 Private Facilities.
Alternatives For Service
4
4
5
4.01: On site surface and/or subsurface disposal 5
4.02: Wastewater Reuse. 6
4.03: Surface Water Discharge 6
4.04: Combination of Alternatives 6
Summary and Conclusions* 7
Proposed Wastewater Treatment Facilities. 8
A
B
C
D
E
F
G
H
J
K
L
M
Cost Analysis of Alternatives
USGS Location Map and Aerial Photo
Possible Route for Connection to POTW
Possible Locations for Subsurface Land Disposal
Possible Locations for Surface Land Disposal
SCS Soil Maps and Soil Descriptions
Summary of Analysis of Well Water Constituents
Existing Process Flow Schematic
Residuals Management Plan
Local Government Review
Possible Location for *Combined Subsurface Land Disposal
Possible Location for *Combined Surface Land Disposal
Possible Route for *Combined Connection to POTW
(*Combined disposal of backwash from Well No. 1 and Well No.2)

Poi
Section 1: General
1.01 Introduction:
Aqua North Carolina, Inc. (Aqua NC) currently owns and operates an existing well
water system serving Colonial Woods Subdivision (Colonial Woods), located south
of Mt. Airy, N.C. in Surry County. Well #2 of the water system uses an assembly
of green sand filters in the treatment of groundwater prior to distribution to the
Colonial Woods community. These filters are backwashed, using potable water,
approximately once every two days. This backwash is a relatively small volume of
approximately 1,680 gallons. The discharge leaves the well house via a 2" PVC
pipe and is released into an intermittent stream that is an unnamed tributary to Bull
Creek in the Yadkin River basin.
The well has a good overall history of compliance with water supply regulations,
but is required to obtain an NPDES permit for the continued operation of the
existing backwash discharge.
The Colonial Woods water system currently has 80 customers. Well # 2 is
approved for 36 gpm. No expansion of this well is planned and the system is
sufficient to serve the subdivision. Whereas the subdivision is fully developed and
since no expansion of the subdivision or service area is planned, there is no
potential for any population increase to affect the existing rate of water use or
backwash discharge flow.
The review of this source and the consideration of alternatives is being made with
inclusion of consideration of the guidance contained in "Permitting Strategy For
Greensand Filtration Water Treatment Plants - January 2004")
Pol
1.02 Scope:
The scope of this project is limited to the investigation and evaluation of
alternatives for treating and/or disposing of the existing green sand filter backwash
from Well # 2 at Colonial Woods subdivision. This includes consideration of the
1114' feasibility of continuing the existing discharge and options for eliminating the
existing discharge.
Section 2:. Background Information
2.01 Project Area:
The existing service area is limited to the Colonial Woods Subdivision. All homes
are single family residences. There are no commercial or industrial customers. All
pal
wastewater is typical backwash from green sand filters.
The existing discharge coordinates are: Longitude: -80.6287161 W
Latitude: 36.4110797 N

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2.02 Site Characteristics:
The subdivision is located in a rural portion of Surry county, outside any municipal
limits and remote from public water and/or sewer. The nearest existing sewer is
approximately 5 miles away.
The general area has soil characteristics which are limited to the possibility of on
site treatment and disposal.
Terrain is generally rolling but has been graded level at the existing well site.
2.03 Receiving Stream Characteristics:
The receiving stream is intermittent in nature and is an unnamed tributary to Bull
Creek, which is C waters. The receiving stream is obviously a zero flow stream
(7Q10 and 30Q2 = 0) but since the wastewater discharge is not oxygen
consuming, discharge into the zero flow stream should be allowable under state
procedures.
This receiving stream has no known outstanding features or characteristics that
should preclude the continuation of the existing discharge. There are no known
endangered or threatened species and these are not threatened or impaired
waters.
Section 3: Existing Utilities
3.01 Public Facilities:
The nearest existing public sewer is located approximately 5 miles northwest of
the existing well near the junction of 1-74 and Rockford Street (at Mountain View
Lane.) The distance that would be required for sewer force mains to be installed
would be approximately 26,750 ft. This would be the route that appears to be the
most practical from an engineering perspective to take advantage of following
existing highway right of way and have minimal impact to adjacent property
owners.
The City of Mt. Airy, Public Works Department provides sewer services in this
area. Mr. Mitch Williams, P.E., City Engineer, was consulted and has advised that
there are no plans for extension of sewer service any closer to Colonial Woods
Subdivision within the next ten years or beyond.
3.02 Private Facilities:
There are no known existing private sewer utilities within any reasonable proximity
of Colonial Woods Subdivision that would be available for consideration as a
possible alternative. A review of available records did not reveal that there are any
private sewer facilities within a three and a half mile radius.

5
Section 4: Alternatives For Service
4.01: On site surface and/or subsurface disposal:
Subsurface Disposal:
Appendix E contains portions of soil survey reports that provide insight as to the
suitability of the soils for subsurface disposal. As described in the report, these
soils are mainly Woolwine Fairview -Westfield soils with characteristics that are
somewhat limited to very limiting with respect to the potential for subsurface
disposal. In addition to researching the information available from NRCS soils
maps, the engineer consulted with Mr. Johnny E. Easter, RS, Surry County
Environmental Health Director concerning the possibilities of subsurface disposal.
Mr. Easter suggested that, for purposes of evaluating this based on the limited
information available, an application rate of 0.25 gpd/SF would be a reasonable
assumption. Of course, before a final design and/or approval could be given, an
actual on site soils evaluation would be required. For the purposes of evaluating
this as a possible option, a design application rate of 0.25 gpd/SF will be used.
Subsurface disposal requires buffers and land for the drainfields as well as equal
areas of suitable soil, be available and maintained as potential repair/replacement
areas.
Aqua North Carolina owns a lot of approximately 1.15 acre. This lot is roughly 200
feet by 250 feet. Whereas the well must have a 100 foot buffer to any disposal
site, this would necessitate that Aqua North Carolina acquire additional property to
allow for the possible subsurface disposal site, repair/reserve area and buffers..
Given the limitations described in the attached soil survey and discussed above, it
is doubtful that this is a viable option. A full and extensive soils investigation of
potential sites would be necessary to confirm if useable areas are available. In
keeping with the state guidance for alternatives evaluation, the cost effectiveness
of this alternative is further evaluated to determine if a detailed soils analysis is
appropriate. The costs associated with this option are estimated in Appendix A.
This option would require that the existing discharge be conveyed to an acquired
site having sufficient area for subsurface disposal and a suitable reserve area of
equal size, and that these areas include adequate buffers from property lines,
homes, wells, etc.
Surface Irrigation:
Disposal by irrigation requires storage capacity for periods of inclement weather
when application is not allowable. Therefore consideration of this as a possible
alternative must also include the provision of storage of the backwash waters
during periods of inclement weather.

OMR
6
FOR
finf
ISM
As noted earlier, the soils surveys for this area have determined this to have
limited to severely limited potential for on site subsurface disposal. Consideration
of this alternative is based on an assumed allowable application rate of 0.20
inches per week which is based on a typical range of 0.15 to 0.25 inches per week
for this geographic area and the soil conditions generally described in the soils
survey. Storage requirements for this area are typically in the range of 45 to 90
days. For purposes of this assessment, a storage requirement of 60 days will be
assumed.
,Considering the relatively benign nature of the current discharge it is not expected
that any additional treatment would be required for surface application. Although
the additional cost of conveyance and the additional costs for on site disposal
should readily be recognized as a significant cost increase as compared to the
alternative of continued discharge, an estimate of the costs for this alternative is
included in Appendix A for comparison.
The evaluation is based on a very conservative assumption that the nearest
available lands that could be reasonably used would actually be available. A
comparison of the costs were made first, using the best (lowest cost) reasonable
assumptions. It would obviously be necessary to perform a more detailed site
investigation and ascertain if the property owner would consider allowing these
lands to be acquired for this purpose.
4.02: Wastewater Reuse
Options for reuse of wastewater for this area are essentially nil. Reuse is usually
associated with non -potable uses such as irrigation. This becomes potentially
more viable if there is a need or outlet for reuse such as irrigation of a golf course.
The volume of this discharge is very low and would have little attraction as a
source for recycle purposes. This area does not have a golf course, nor are there
any other viable options for reuse associated with the subdivision or in the
surrounding area.
4.03: Surface Water Discharge
This is the current method of wastewater disposal. There is no anticipated need to
add any new facilities for additional treatment.
Po` An estimate of the costs for the continuation of this alternative is included in
Appendix A for comparison.
4.04: Combination of Alternatives
WIMP

7
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Alternatives to discharge that may be technologically feasible, such as connection
to the nearest public sewer, subsurface disposal and/or surface irrigation, could
Inot be employed in conjunction with the current method of disposal (surface water
discharge) and yield any reduction in total capital or operating expenditures. The
evaluation of alternatives shows that these alternatives are clearly not viable due
to the overwhelming magnitude of associated cost.
Combining one of these alternatives while continuing the periodic discharge, yields
no reduction in the cost for non -discharge alternatives and merely increases the
overall costs. There would be no reduction in capital costs for any of these
alternatives and the operating costs for combining surface discharge with either of
the other alternatives would be greater than for any single alternative that might be
selected.
In short, whereas the conclusion that continued surface discharge is the only
viable option due to the overwhelming differential in capital and operating costs,
any addition of an additional alternative would merely make the cost differential
worse.
Whereas there is a second well (Well No. 1) in this development with a surface
water discharge, that is also undergoing an evaluation of alternatives (and
application for NPDES permit), an evaluation has been made of the potential
implications of eliminating these discharges by combining the two and eliminating
these as surface water discharges by conveying the combined backwash waters
to the nearest available POTW sewer. Similarly, evaluations have been made of
the potential for onsite disposal for a single site to serve the combined backwash
waters.
Section 5: Summary and Conclusions:
As can be seen from a comparison of the net present value of the various
alternatives, there is a wide difference between the cost estimate of the option of
,., continuing discharge and options to eliminate the discharge.
Compared to the cost of the next most cost effective and reliable alternative
(subsurface disposal) the estimated Net Present Value is approximately 1,047 %
greater. This represents a difference of $ 1,646 NPV per customer.
The accompanying engineering alternatives analysis for Well No. 1 reveals a cost
difference between the option of continued surface discharge and subsurface
disposal that constitutes a difference of $ 1,730 NPV per customer.
As can be seen from a review of the estimated costs for combining the backwash
discharges from Well No. 1 and Well No. 2, the estimated cost for subsurface
disposal for the combined wells is $ 268,241. When this is compared to the total
1111111

8
Fill
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Pin
Net Present Value for continuing the discharge of both wells, the cost of combining
these two wells to use a common subsurface disposal system become more
favorable (cost Tess than two stand alone subsurface disposal systems.) The NPV
for the cost of combining the two discharges, as compared to the cost of continued
surface water discharge represents a NPV cost of $ 3,005 per customer. Although
this is less than the NPV cost of eliminating the discharges with separate
subsurface disposal systems ( $ 1,730 + $ 1,646 = $ 3,376), the analysis shows
that the estimated cost of eliminating the two existing discharges either
independently or combined, represents an excessive cost differential that makes
this impractical.
In light of the financial impracticality, it is not necessary to further pursue whether
connection is politically acceptable to the POTW or whether land based disposal
options are workable.
By far, the most practical and cost effective and reasonably practical alternative is
r the continued discharge of the relatively benign filter backwash waters.
Section 6: Proposed Wastewater Treatment Facilities:
Based on the findings of this evaluation, it has been concluded that the most
economical and practical alternative is to continue discharge to surface waters.
FIM

9
Appendix A
Cost Analysis of Alternatives
Note: Cost estimates based on, National Construction Estimator, Means Building Construction
Cost Data, consultation with contractors and the engineers experience.

10
Min
1. Surface Water Discharge at 1,680 GPD Flow Rate:
Whereas this is the existing method of disposal and considering that no additional
treatment is expected as a consequence of any forthcoming permit, there are no
estimated additional capital costs.
The only anticipated increase in operation and maintenance costs are those associated
with the collection, analysis and reporting of effluent discharge samples as required by an
NPSES permit.
Capital Cost:
Total Capital Cost = $ 0.00
Operation & Maintenance Cost
(Present Value, 20 year life, 5.875% interest):
Annual Cost
Operation & Maintenance
($ 100/mo. X 12 mo/yr)
Total Annual Cost = $ 1,200
PV Annual Cost = $ 13,905
Total Net Present Value
$ 13,905
$ 1,200

11
PIM
Pon
2. Connection to POTW Sewer System near junction of 1-74 and Rockford Street:
Install new lift station to collect discharge and conveybyforce main alongexistinghigh
9 9
way right of way to junction with existing municipal sewer.
Distance = approx. 26,750 LF
Begin elev. = approx. 1310.0
Highest elev. = approx. 1460.0
Lift station Avg. flow = 1,680 gpd = 1.2 gpm
Peak flow = 2.5 x 1.2 gpm = 3 gpm
Pump Design
Use 1" Sch. 40 PVC, approx. 26,750 LF
FH @ 3 gpm = 0.68 ft/100 ft = 181.9 ft.
SH = 150 ft (approx.)
Use TDH = 335 ft.
Use dual effluent pumps (rated at 335 ft. TDH at 3 gpm) OSl P101012 or approved equal
Capital Cost:
Item: Quantity: Unit Cost: Cost:
1" force main sewer 26,750 LF $ 8 $ 214,000
Air release 9 Ea. $ 2,500 $ 22,500
Pump Station 1 Ea $ 45,000 $ 45,000
Manholes 1 Ea $ 1,800 $ 1,800
Tap Fee 1 Ea. $ 3,000 $ 3,000
Wastewater Capacity Use Fee 1 Ea. $ 3,000 $ 3,000
Road Crossings 7 Ea $ 5,000 $ 35,000
Creek Crossings 8 Ea $ 5,000 $ 40,000
Metering Station 1 Ea. $ 30,000 $ 30,000
Tie to exist. MH 1 Ea $ 1,000 $ 1,000
Erosion control LS $ 40,000 $ 40,000
Surveying 6 days $ 1,500 $ 9,000
Easement/Right of Way 500 LF $ 10 $ 5,000
Clearing (approx. 3.0 acre) 3.0 acre $ 6,500 $ 19,500
Electrical LS $ 7,500 $ 7,500
Legal LS $ 8,000 $ 8,000
Sub -total $ 484,300
Engineering 15 % 72,645

12
Total Capital Cost = $ 556,945
Operation & Maintenance Cost:
Local government sewer fee = $ 3.44/1000 Gallons
Annual sewer charges
foul
_ $ 3.44/1000 Gal x 1,680 gpd x 183 day/yr
= $ 1,058
m Annual electrical charges = $ 125/month X 12 mo/yr = $ 1,500
Annual sample analysis charges = $ 100/mo. X 12 mo/yr = $ 1,200
Annual repair and maintenance = $ 100/mo. X 12 mo/yr = $ 1,200
Total annual costs = $ 4,958
(Present Value, 20 year life, 5.875% interest)
Present Value Annual Cost
Total Net Present Value
$ 57,450
$ 614,395

13
3. Land Based Disposal:
3A. Subsurface Disposal:
Based on the soil survey information and the engineers field observations, the soils in this
area appear to be limited to severely limited as a medium for subsurface disposal. In the
event that it was found to be apparently a cost effective alternative, an in depth site
specific soil investigation would need to be done to confirm that the soils could in fact be
used. However, for the purpose of comparing the potential alternatives within the scope
of this evaluation, it will be assumed that a typical low design loading rate would be
workable. Therefore, it will be assumed that a loading rate of 0.25 gpd/sq. ft. is
acceptable.
Therefore, based on the design flow, the area required for subsurface disposal is:
1,680 gpd / 0.25 gpd/sq. ft. = 6,720 SF
Whereas it is required to maintain an equal size area as a reserve for future repair, the
required area is 13,440 SF. Appendix D contains a map, which delineates the area that
might be available for subsurface disposal.
Assuming a roughly rectangular field (116 ft x 116 ft. for the initial drain field plus repair
and In order to maintain the required 50 foot buffer to property lines), the minimum
estimated land required is 46,656 SF or 1.1 acres.
Capital Cost:
Item: Quantity: Unit Cost:
4" sewer drain in 3' trenches 2,240 LF
Site Clearing .6 acre
Land 1.1 acres
1" FM ' 250 LF
Pump Station 1 Ea
Surveying 2 days
Soils Investigation 1 day
Phase I Environmental Site Assessment LS
Erosion control LS
Electrical LS
Legal LS
Engineering 15
$ 12
$ 6,500
$ 15,000
$ 8
$ 20,000
$ 1,500
$ 1,500
$ 2,000
$ 5,000
$ 3,000
$ 2,500
Sub -total
Total Capital Cost
Cost:
$ 26,880
$ 3,900
$ 16,500
$ 2,000
$ 20,000
$ 3,000
$ 1,500
$ 2,000
$ 5,000
$ 3,000
$ 2,500
$ 86,280
12,942
$ 99,222

14
Operation & .Maintenance Cost (Present Value, 20 year life, 5.875 % interest):
Annual Cost
O & M of drain field,
Pump station and force main = $ 2,500/yr $ 2,500
Annual electrical charges = $ 125/month X 12 mo/yr = $ 1,500
,,,,, Total Annual Cost = $ 4,000
PV Annual Cost = $ 46,349
Total Net Present Value = $ 145,571

15
3B. Surface Irrigation:
Surface irrigation preliminary design is based on an assumed allowable application rate
of 0.20 gpd/sq. ft. and a required storage basin for 60 days design flow. Based on the
design flow of 1,680 gpd, this results in an estimated disposal area of 8,400 SF. Allowing
a recommended 50% repair area, the required total area is 12,600 SF. Assuming a
roughly rectangular field (415 ft x 415 ft. for the initial spray field plus repair and in order
to maintain the required 150 foot buffer to property lines), the minimum estimated land
required is 172,225 SF or approximately 4 acres.
Capital Cost:
Item: Quantity:
100,800 gal. storage basin
Surface irrigation system
Monitoring wells
Land
Fencing
Site Clearing
2" FM
Manholes
Pump Station
Surveying
Soils Investigation
(1)
8,400 SF
4 ea
4 acres
2,000 LF
.5 acre
200 LF
1 Ea
1 Ea
3 days
3 days
Phase I Environmental Site Assessment LS
Erosion control LS
Electrical LS
Legal LS
Sub -total
Engineering 15 %
Total Capital Cost =
(1) Storage:
Excavation 625 cu. Yds. @ $ 6.00/yd
Compaction and Lining 4,500 SF @ $ 3.50/SF
Sub -total
Unit Cost: Cost:
$ 19,500
$ 0.35 $ 2,940
$ 4,000 $ 16,000
$ 15,000 $ 60,000
$ 6.00 $ 12,000
$ 6,500 $ 3,250
$ 8.50 $ 1,700
$ 1,600 $ 1,600
$ 35,000 $ 35,000
$ 1,500 $ 4,500
$ 1,500 $ 4,500
$ 3,000 $ 3,000
$ 8,000 $ 8,000
$ 5,000 $ 5,000
$ 5,000 $ 5,000
$ 181,990
$ 209,289
= $ 3,750
= $ 15,750
= $ 19,500
27,299

16
Operation & Maintenance Cost
wit (Present Value, 20 year life, 8% interest):
f
Annual Cost
4 & M of spray field,
Pump station and force main = $ 3,500/yr $ 3,500
Annual electrical charges = $ 250/month X 12 mo/yr = $ 3,000
Annual sample analysis charges = $ 100/mo. X 12 mo/yr = $ 1,200
Total Annual Cost = $ 7,700
PV Annual Cost = $ 89,222
�-+ Total Net Present Value = $ 298,511

17
4. Combining Backwash from Well No. 1 and Well No. 2
Connection to POTW Sewer System near junction of 1-74 and Rockford Street:
Install new lift station to collect discharge and conveybyforce main alongexistinghigh
9 g
ca.way right of way to junction with existing municipal sewer.
Distance = approx. 26,750 LF
Begin elev. = approx. 1310.0
Highest elev. = approx. 1460.0
Lift station Avg. flow = 3,680 gpd = 2.6 gpm
Peak flow = 2.5 x 2.6 gpm = 6.5 gpm
Pump Design
Use 11/2" Sch. 40 PVC, approx. 26,750 LF
FH @ 6.5 gpm = 0.36 ft/100 ft = 96.3 ft.
SH = 150 ft (approx.)
Use TDH = 250 ft.
Use dual effluent pumps (rated at 250 ft. TDH at 6.5 gpm) OSI P201512 or approved
equal
Capital Cost:
Item: Quantity: Unit Cost: Cost:
11/2" force main sewer 26,750 LF $ 10 $ 267,500
"'p Air release 9 Ea. $ 2,500 $ 22,500
Pump Station 1 Ea $ 65,000 $ 65,000
Manholes 2 Ea $ 1,800 $ 3,600
I. Tap Fee 1 Ea. $ 3,000 $ 3,000
Wastewater Capacity Use Fee 1 Ea. $ 5,000 $ 5,000
mg
Road Crossings 7 Ea $ 5,000 $ 35,000
Creek Crossings 8 Ea $ 5,000 $ 40,000
Metering Station 1 Ea. $ 40,000 $ 40,000
,�, Tie to exist. MH 1 Ea $ 1,000 $ 1,000
Erosion control LS $ 40,000 $ 40,000
Surveying 7 days $ 1,500 $ 10,500
,e, Easement/Right of Way 500 LF $ 10 $ 5,000
Clearing (approx. 3.0 acre) 3.0 acre $ 6,500 $ 19,500
Electrical LS $ 10,000 $ 10,000
Legal LS $ 8,000 $ 8,000

18
lug
Sub -total $ 575,600
Engineering 15 % 86,340
Total Capital Cost = $ 661,940
Operation & Maintenance Cost:
Local government sewer fee = $ 3.44/1000 Gallons
Annual sewer, charges
_ $ 3.44/1000 Gal x 3,680 gpd x 183 day/yr
$ 2,317
Annual electrical charges = $ 200/month X 12 mo/yr = $ 2,400
Annual sample analysis charges = $ 100/mo. X 12 mo/yr = $ 1,200
Annual repair and maintenance = $ 150/mo. X 12 mo/yr = $ 1,800
M+ Total annual costs = $ 7,717
(Present Value, 20 year life, 5.875% interest)
Present Value Annual Cost = $ 89,419
P
Total Net Present Value = $ 751,359

19
Pat
PIA
AEI
lag
mi
5. Combining Backwash from Well No. 1 and Well No. 2
Land Based Disposal:
5A. Subsurface Disposal:
Based on the soil survey information and the engineer's field observations, the soils in
this area appear to be limited to severely limited as a medium for subsurface disposal. In
the event that it was found to be apparently a cost effective alternative, an in depth site
specific soil investigation would need to be done to confirm that the soils could in fact be
used. However, for the purpose of comparing the potential alternatives within the scope
of this evaluation, it will be assumed that a typical low design loading rate would be
workable. Therefore, it will be assumed that a loading rate of 0.25 gpd/sq. ft. is
acceptable.
Therefore, based on the design flow, the area required for subsurface disposal is:
3,680 gpd / 0.25 gpd/sq. ft.= 14,720 SF
Whereas it is required to maintain an equal size area as a reserve for future repair, the
required area is 29,440 SF. Appendix K contains a map, which delineates the area that
might be available for subsurface disposal.
Assuming a roughly rectangular field (175 ft x 175 ft. for the initial drain field plus repair
and In order to maintain the required 50 foot buffer to property lines), the minimum
estimated land required is 75,625 SF or 1.74 acres.
Capital Cost:
Item: Quantity: Unit Cost: Cost:
4" sewer drain in 3' trenches 4,907 LF $ 12 $ 58,884
Site Clearing .8 acre $ 6,500 $ 5,200
Land 1 1.74 acres $ 15,000 $ 26,100
1" FM 500 LF $ 8 $ 4,000
Pump Station 2 Ea $ 20,000 $ 40,000
Surveying 3 days $ 1,500 $ 4,500
Soils Investigation 1 day $ 1,500 $ 1,500
PhaseI Environmental Site Assessment LS $ 2,000 $ 2,000
Erosion control LS $ 6,000 $ 6,000
Electrical LS $ 6,000 $ 6,000
Legal LS $ 3,500 $ 3,500
Sub -total $ 157,684
Engineering 15 % 23,653

20
Total Capital Cost
$181,337
Operation & Maintenance Cost (Present Value, 20 year life, 5.875 % interest):
Pal
Annual Cost
O & M of drain field,
Pump ,stations and force main = $ 4,5001yr $ 4,500
Annual electrical charges = $ 250/month X 12 mo/yr = $ 3,000
fin Total Annual Cost = $ 7,500
PV Annual Cost = $ 86,904
Total Net Present Value = $ 268,241

21
5B. Surface Irrigation:
Surface irrigation preliminary design is based on an assumed allowable application rate
of 0.20 gpd/sq. ft. and a required storage basin for 60 days design flow. Based on the
design flow of 3,680 gpd, this results in an estimated disposal area of 18,400 SF.
Allowing a recommended 50% repair area, the required total area is 27,600 SF.
Assuming a roughly rectangular field (167 ft x 167 ft. for the initial spray field plus repair
and in order to maintain the required 150 foot buffer to property lines), the minimum
estimated land required is 218,089 SF or approximately 5.0 acres.
Capital Cost:
Item:
220,800 gal. storage basin
Surface irrigation system
Monitoring wells
Land
Fencing
Site Clearing
2" FM
Manholes
Pump Station
Surveying
Soils Investigation
Quantity:
(1)
18,400 SF
4 ea
5.0 acres
2,500 LF
.8 acre
600 LF
2 Ea
2 Ea
4 days
3 days
Phase 'I Environmental Site Assessment LS
Erosion control LS
Electrical LS
Legal LS
Sub -total
Engineering 15 %
Total Capital Cost =
(1) Storage:
Excavation 1,277 cu. Yds. @ $ 6.00/yd
Compaction and Lining 8,300 SF @ $ 3.50/SF
Sub -total
Unit Cost:
$ 0.35
$ 4,000
$ 15,000
$ 6.00
$ 6,500
$ 8.50
$ 1,600
$ 40,000
$ 1,500
$ 1,500
$ 3,000
$ 9,000
$ 10,000
$ 6,000
$ 311,825
$ 7,662
= $ 29,050
= $ 36,712
Cost:
$ 36,712
$ 6,440
$ 16,000
$ 65,000
$ 15,000
$ 5,200
$ 5,100
$ 3,200
$ 80,000
$ 6,000
$ 4,500
$ 3,000
$ 9,000
$ 10,000
$ 6,000
$ 271,152
40,673

22
Operation & Maintenance Cost
(Present Value, 20 year life, 8% interest):
Annual Cost
0 & MI of spray field,
Pump station and force main = $ 5,500/yr $ 5,500
Annual electrical charges = $ 500/month X 12 mo/yr = $ 6,000
Annual sample analysis charges = $ 100/mo. X 12 mo/yr = $ 1,200
Total Annual Cost = $12,700
,_, PV Annual Cost = $ 147,158
Total Net Present Value = $ 458,983

Appendix B
USGS Location Map and Aerial Photo

1:6,000
Dobson
7.5-minute Quadrangle
Exist Discharge
Longitude: -80.6287161 W
Latitude: 36.4110797 N
Index map
North
Colonial Woods Subdivision - Well # 2
USGS Map
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 3, 2007

I. 4.
, .4
�: �%lr.:atfiY44=dia4 JAliXti.. :..:... .._n..i _.�_`
firr`.�✓,.. iM
(
North
Colonial Woods Subdivision - Well J.' 2
Aerial Photo
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 3, 2007

24
Appendix C
Possible Route for Connection to POTW
7

9
Prop. Connection to POTW P
Prop. Force Main
Exist. Wel
Colonial Woods Subdivision - Well # 2
Possible Route for Connection to POTW
r
i
•
)\,k
North
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 3, 2007
Mt. Airy, N.C.
Scale: l" = 2,000'

25
Appendix D
Possible Location for Subsurface Land Disposal

Colonial Woods Subdivision - Well # 2
Possible Location for Subsurface Disposal
Dobson, N.C. Scale: 1" = 110'
North
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 3, 2007

26
Appendix E
Possible Locations for Surface Land Disposal
n
n

Prop. Surface Disposal
(Property must be acquired)
North
Colonial Woods Subdivision - Well # 2
Possible Location for Surface Disposal
Mt. Airy, N.C. Scale: 1" = 333'
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 3, 2007

27
Appendix F
SCS Soil Maps and Soil Descriptions

North
Colonial Woods Subdivison - Well if 2
NRCS Soils Map
Scale: I" = 342'
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 3, 2007

Web Soil Survey
Page 2 of 3
PEI
PEI
Poi
foll
flooded
CsA Colvard and 15.3 2.9
Suches soils, 0 to
3 percent slopes,
occasionally
flooded
FfD Fairview cobbly 32.4 6.2
fine sandy loam,
15 to 25 percent
slopes, stony
FnB2 Fairview cobbly 27.2 5.2
sandy clay loam,
2 to 8 percent
slopes,
moderately
eroded, stony
FnC2 Fairview cobbly 36.4 7.0
sandy clay loam,
8 to 15 percent
slopes,
moderately
eroded, stony
RsC Rhodhiss-Stott 7.9 1.5
Knob complex, 8
to 15 percent
slopes, stony
RsD Rhodhiss-Stott 9.7 1.9
Knob complex, 15
to 25 percent
slopes, stony
RsE Rhodhiss-Stott 17.5 3.3
Knob complex, 25
to 45 percent
slopes, stony
W Water 1.2 0.2
WfB2 Woolwine- 13.4 2.6
Fairview -Westfield
complex, 2 to 8
percent slopes,
moderately
eroded
WfC2 Woolwine- 166.3 31.8
Fairview -Westfield
complex, 8 to 15
percent slopes,
moderately
eroded
WoD Woolwine- 160.2 30.7
Fairview -Westfield
complex, 15 to 25
percent slopes,
stony
WoE Woolwine- 31.6 6.0
Fairview -Westfield
http://websoilsurvey.nres.usda.gov/app/WebSoilSurvey.aspx 03/04/2007

am Web Soil Survey Page 3 of 3
complex, 25 to 45
percent slopes,
stony
FOIA ( Accessibility Statement I Privacy Policy I Non -Discrimination Statement ( Information Quality I
USA.gov I White House
http://websoilsurvey.nres.usda.gov/app/WebSoilSurvey.aspx 03/04/2007

Sewage Disposal
Surry County, North Carolina
WfB2:
Woolwine, moderately eroded 48 Very limited
Depth to bedrock
Slow water
movement
Map symbol
and soil name
Pct.
of
map
unit
Septic tank absorption fields
Sewage lagoons
Rating class and
limiting features
Fairview, moderately eroded
34 Somewhat limited
Slow water
movement
Westfield, moderately eroded 17 Somewhat Limited
Depth to bedrock
Slow water
movement
WfC2:
Woolwine, moderately eroded 50 Very limited
Depth to bedrock
Slope
Slow water
movement
Fairview, moderately eroded
32 Somewhat limited
Slope
Slow water
movement
Westfield, moderately eroded 13 Somewhat limited
Depth to bedrock
Slope
Slow water
movement
WoD:
Woolwine, stony
Fairview, stony
53 Very limited
Slope
Depth to bedrock
Slow water
movement
26 Very limited
Slope
Slow water
movement
I Value
Rating class and
limiting features
Value
Very limited
1.00 Depth to soft bedrock
0.50 Slope
Seepage
1.00
0.68
0.50
Somewhat Limited
0.50 Seepage 0.98
Slope 0.68
Somewhat limited
0.86 Seepage
0.50 Slope
Depth to soft bedrock
Very limited
1.00 Depth to soft bedrock
0.63 Slope
0.50 Seepage
Very limited
0.63 Slope
0.50 Seepage
Very limited
0.86 Slope
0.63 Seepage
0.50 Depth to soft bedrock
Very limited
1.00 Depth to soft bedrock
1.00 Slope
0.50 Seepage
Very limited
1.00 Slope
0.50 Seepage
0.98
0.68
0.61
1.00
1.00
0.50
1.00
0.98
1.00
0.98
0.61
1.00
1.00
0.50
1.00
0.98
USDA Natural Resources
Conservation Service
Tabular Data Version: 8
Tabular Data Version Date: 01/19/2007
Page 4 of 6

Sewage Disposal
Surry County, North Carolina
Map symbol
and soil name
WoD:
Westfield, stony
Meadowfield, stony
WoE:
Wootwine, stony
Fairview, stony
Westfield, stony
Meadowfield, stony
Pct.
of
map
unit
Septic tank absorption fields
Sewage lagoons
Rating class and
limiting features
13 Very limited
Slope
Depth to bedrock
Slow water
movement
8 Very limited
Slope
Depth to bedrock
Slow water
movement
47 Very limited
Slope
Depth to bedrock
Slow water
movement
24 Very limited
Slope
Slow water
movement
10 Very limited
Slope
Depth to bedrock
Slow water
movement
6 Very limited
Slope
Depth to bedrock
Slow water
movement
I Value
Rating class and
limiting features
Very limited
1.00 Slope
0.86 Seepage
0.50 Depth to soft bedrock
1.00
1.00
0.02
Very limited
Depth to hard
bedrock
Slope
Seepage
Very limited
1.00 Depth to soft bedrock
1.00 Slope
0.50 Seepage
Very limited
1.00 Slope
0.50 Seepage
Very limited
1.00 Slope
0.86 Seepage
0.50 Depth to soft bedrock
1.00
1.00
0.02
Very limited
Depth to hard
bedrock
Slope
Seepage
Value
1.00
0.98
0.61
1.00
1.00
0.98
1.00
1.00
0.50
1.00
0.98
1.00
0.98
0.61
1.00
1.00
0.98
USDA Natural Resources
Conservation Service
Tabular Data Version: 8
Tabular Data Version Date: 01/19/2007
Page 5 of 6

Oil
Sewage Disposal
This table shows the degree and kind of soil limitations that affect septic tank absorption fields and sewage
lagoons. The ratings are both verbal and numerical. Rating class terms indicate the extent to which the soils are
limited by all of the soil features that affect these uses. "Not limited" indicates that the soil has features that are very
favorable for the specified use. Good performance and very low maintenance can be expected. "Somewhat limited"
indicates that the soil has features that are moderately favorable for the specified use. The limitations can be
overcome or minimized by special planning, design, or installation. Fair performance and moderate maintenance
fmi can be expected. "Very limited" indicates that the soil has one or more features that are unfavorable for the
specified use. The limitations generally cannot be overcome without major soil reclamation, special design, or
expensive installation procedures. Poor performance and high maintenance can be expected.
Numerical ratings in the table indicate the severity of individual limitations. The ratings are shown as decimal
fractions ranging from 0.01 to 1.00. They indicate gradations between the point at which a soil feature has the
greatest negative impact on the use (1.00) and the point at which the soil feature is not a limitation (0.00).
"Septic tank absorption fields" are areas in which effluent from a septic tank is distributed into the soil through
subsurface tiles or perforated pipe. Only that part of the soil between depths of 24 and 72 inches or between a
depth of 24 inches and a restrictive layer is evacuated. The ratings are based on the soil properties that affect
absorption of the effluent, construction and maintenance of the system, and public health. Saturated hydraulic
conductivity (Ksat), depth to a water table, ponding, depth to bedrock or a cemented pan, and flooding affect
absorption of the effluent. Stones and boulders, ice, and bedrock or a cemented pan interfere with installation.
r+� Subsidence interferes with installation and maintenance. Excessive slope may cause lateral seepage and surfacing
of the effluent in downslope areas.
Some soils are underlain by loose sand and gravel or fractured bedrock at a depth of less than 4 feet below the
distribution lines. In these soils the absorption field may not adequately filter the effluent, particularly when the
system is new. As a result, the ground water may become contaminated.
"Sewage lagoons" are shallow ponds constructed to hold sewage while aerobic bacteria decompose the solid
and liquid wastes. Lagoons should have a nearly level floor surrounded by cut slopes or embankments of
compacted soil. Nearly impervious soil material for the lagoon floor and sides is required to minimize seepage and
contamination of ground water. Considered in the ratings are slope, saturated hydraulic conductivity (Ksat), depth
to a water table, ponding, depth to bedrock or a cemented pan, flooding, large stones, and content of organic
matter.
fon
Poi
aq
Saturated hydraulic conductivity (Ksat) is a critical property affecting the suitability for sewage lagoons. Most
porous soils eventually become sealed when they are used as sites for sewage lagoons. Until sealing occurs,
however, the hazard of pollution is severe. Soils that have a Ksat rate of more than 14 micrometers per second are
too porous for the proper functioning of sewage lagoons. In these soils, seepage of the effluent can result in
contamination of the ground water. Ground -water contamination is also a hazard if fractured bedrock is within a
depth of 40 inches, if the water table is high enough to raise the level of sewage in the lagoon, or if floodwater
overtops the lagoon.
A high content of organic matter is detrimental to proper functioning of the lagoon because it inhibits aerobic
s■a activity. Slope, bedrock, and cemented pans can cause construction problems, and large stones can hinder
compaction of the lagoon floor. If the lagoon is to be uniformly deep throughout, the slope must be gentle enough
and the'I oil material must be thick enough over bedrock or a cemented pan to make land smoothing practical.
Information in this table is intended for land use planning, for evaluating land use alternatives, and for planning
fan site investigations prior to design and construction. The information, however, has limitations. For example,
estimates and other data generally apply only to that part of the soil between the surface and a depth of 5 to 7 feet.
Because of the map scale, small areas of different soils may be included within the mapped areas of a specific soil.
The information is not site specific and does not eliminate the need for onsite investigation of the soils or for
testing and analysis by personnel experienced in the design and construction of engineering works.
Government ordinances and regulations that restrict certain land uses or impose specific design criteria were
not considered in preparing the information in this table. Local ordinances and regulations should be considered in
;Ei planning, in site selection, and in design.
sem
USDA Natural Resources
Conservation Service
Tabular Data Version: 8
Tabular Data Version Date: 01/19/2007 Page 6 of 6

28
Appendix G
Summary of Analysis of Well Water Constituents
i�
CM W5

PEI
Pal
1,11,1
Pori
Oxford Laboratories
1316 South 5th Street
Wilmington, NC 28401
Phone: [phone]/ Fax: [phone]
NEW WELL INORGANIC CHEMICAL ANALYSIS
Note: a information roust be supplied for plan review audit.
WATER SYSTEM ID #: 02-86-103
Name of Water System: Colonial Woods
Sample Type: ® Source for Plan Review
Location Where Collected: Wellhead #2
Location Code: WE2
Collected By: Billy Young
(P1.v= Print)
Mail Results to (water- system representative):
Ms. Mary Armentrout
Heater Utilities
r� PO Box 859
Denver, NC 28037
County: Surry
Collection Date Collection Time
09/02/03 12:31 PM
(MM DD YY) (Sp-.u11- AM or PM)
Phone #: [phone]
Fax #: [phone]
*NOTE: Please complete portion above double line on Page 2.
rem
LABORATORY ID #:37721
❑ SAMPLE UNSATISFACTORY ❑ RESAMPLE REQUIRED
REQUIRED NOT DETECTED ALLOWABLE
CONTAM METHOD QUANTIFIED
PM CODECONTAMINANT CODE RESULTS I.1M1T . i e R R 1.1 R1:5lJl:CS LIMIT*
(RILL)
.. - ., .:;.•... ..:.,. .: •. ♦..K'Ts.� (X)?Y.^..•'I•:r44.............ra.R'K1r+Cl�3Ci0t=RZ.J'!•'Jrl?l�A:—.:L...:v'.G:.v-..+,.
0100 Turbidity 001 0.10 ntu 12.4 ntu N/A
1005 Arsenic 170 0.00E mg/L ® mg/L 0.010 mg/L
1010 Barium 170 0.4 mg/L ® mg/L 2.000 mg/L ,
1015 Cadmium 170 0.001 mg/L ® . mg/L 0.005 mg/L
1016 Calcium 101 1.0 mg/L ❑ 13.4 mg/L N/A
1017 Chloride 127 5.0 mg/L ® mg/L 250.0 mg/L
1020 Chromium 170 0.020 mg/L ® mg/L 0.100 mg/L ,
1022 Copper 170 0.050 mg/L ® mg/L 1.300 mg/L .
1024 Cyanide 150 0.040 mg/L ® mg/L 0.200 mg/L i.
1025 Fluoride 107 0.100 mg/L ❑ 0.17 mg/L 4.000 mg/L
1028 Iron 101 0.060 mg/L3.15 0 mg/L 0.300 mg/L ±s
pm
1030 Lead 170 0.003 mg/L ® mg/L 0.015 mg/L
1031 Magnesium 101 1.0 mg/L 0 1.56 mg/L N/A
rim 1032 Manganese 170 0.010 mg/L ❑ 0.222 mg/L 0.050 mg/L
1035 Mercury 103 0.0004 mg/L El mg/L 0.002 mg/L
* Note: Concentrations for Lead and Copper are action levels, not MCLs.

Oxford Laboratories
1316 South 51h Street
Wilmington, NC 28401
Phone: [phone]/ Fax: [phone]
114
NEW WELL INORGANIC CHEMICAL ANALYSIS
(continued)
Now: au iufonuation must be supplied for plan rovaow tzwtit.
�•r
WATER SYSTEM ID #: 02-86-103
Location Code: WE2
ht.„„.0),-4k
SS(.1"-' •
r.v4,4t) ) Collection Date
f 09/02/03
(MM DD YY)
Collection Time
12:31 PM
(Sp -.cif • AM or PM)
faif
LABORATORY ED #: 37721
fug CONTAM METHOD REQUIRED MI DETECTED QUANTIFIED
CONTAMINANT REPORTING LIMIT ABOVE R.R.L.
CODE CODE �R R L) i1� RESULTS
1036 Nickel 170 0.100 mg/L
• 1040 Nitrate 163 1.00 mg/L Ng
1041 Nitrite 163 0.10 mg/L
1045 Selenium 170 0.010 mg/L
11
rner 1050 Silver 170 0.05 mg/L El
1 052 Sodium 101 1.0 mg/L ❑
1055 Sulfate 137 5.0 mg/L ❑
A*► 1068 Acidity 157 1.0 mg/L 0
1074 Antimony 170 0.003 mg/L El
1075 Beryllium 170 0.002 mg/L
ma 1085 Thallium 170 0.001 mg/L 13
1095 Zinc 170 1.0 mg/L El
1905 Color 129 5 units ❑
W I
1915 Total Hardness 141 1.0 mg/L ❑
1925 pH 135 N/A N/A
1927 Alkalinity 142 1.0 mg/L 0
`INT 1930 Total Dissolved Solids 139 10.0 mg/L ❑
* Note: Concentrations for Lead and Copper are action levels, not MCLs.
DATE:
ANALYSES BEGUN: 09/03/03
wnwunnm
ANALYSES COMPLETED: ` 10/02/0 * 11:00 AM
03,•dt7 Aids Pas)
ALLOWABLE
LIMIT*
mg/L N/A
mg/L 10.00 mg/L
mg/L 1.00 mg/L
mg/L 0.050 mg/L
mg/L 0.100 mg/L
4.36 mg/L N/A
19 mg/L 250.0 mg/L
6 mg/L N/A
mg/L 0.006 tng/L
mg/L 0.004 mg/L
mg/L 0.002 mg/L
mg/L 5.0 mg/L
40 units 15 units
36 mg/L N/A
6.83 units 6.5 — 8.5 units
41 mg/L N/A
96 mg/L 500.0 mg/L
TIME:
Laboratory Log #: 301-6261 Certified By.
(Print and sign name)
12:00 PM
COMMENTS: UPS 1Z 27X 368 221000 023 7 Zinc detected at 0.347ppm. Selenium analyzed by Tritest, Inc.
4$psdly AM sr PM)
ti t

Foq
rmi
Poi
Date: 10/21/03
Sample ID: Colonial Woods Backwash Water
Sample
ID #:
Collection
Date:
Collection
Time:
Iron
mg/L
#1
10/16/2003
1121
3.84
Total
#1
10/16/2003
1121
0.906
Dissolved (2u)
#1
10/16/2003
1121
0.057
Dissolved (0.45u)
#2
10/16/2003
1231
2.58
Total
#2
10/16/2003
1231
1.49
Dissolved (2u)
#2
10/16/2003
1231
0.098
Dissolved (0.45u)
Note: Dissolved analysis performed using both 2.0u and 0.45u filtration; EPA Method 200.7.
'`' Analysis Date: 10/20/2003
By:-Yoyt7 671-<-1
Lab Certification: #37-7-11 Water
#NC050 Wastewater

29
Appendix H
Existing Process Flow Schematic

Four Existing
Potassium
Permanganate
Feed Tanks
(One each to each
green sand filter)
To Storage Tank and Colonial Woods Subdivision Water System
==>
Four Existing Green Sand
Filters
(In parallel)
fi
Chlorine & Caustic
Addition
ft
Well Water
=>
Backwash
Discharge to
unnamed tributary
to UT to Bull
Creek
Colonial Woods Subdivision — Well # 2
Existing well System - Process Flow Diagram
Mt. Airy, NC Scale: NTS
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 7, 2007
1

Appendix I
Residuals Management Plan

31
PIA
01111
furl
Residuals Management Plan
Prepared by: J. Thurman Horne, P.E.
Horizon Engineering & Consulting, Inc.
Residuals Management Plan:
l
The proposed continued surface water discharge will have no impact on existing residuals management.
There are no wastewater treatment facilities.
The nature of the operation (backwashing of green sand filters) is such that only minor amounts of solids
(less than 30 mg/I) are released with the discharge.
There is no generation of anygrits, sludges or residuals for removal or disposal.
g p
This project does not increase or alter the amounts of sludge produced or impact the current methods of
disposition.

32
Appendix J
Local Government Review

33
A copy of the permit application and the local government review form has been mailed by
certified mail to the County Manager. A copy of the response will be forwarded immediately
upon receipt.

34
PO
MI
Awl
INIT
PER
MR
INgl
fir
PNIP
mg
fail
Awl
faill
MI
PM
OW
Appendix K
Possible Location for *Combined
Subsurface Land Disposal
(*Combined disposal of backwash from Well No. 1 and Well No.2)

11
I
;11. •
110‘
• .4 •k• yW
j•Pl.,?
7,:•e"
---t --• • -
••,••:.-- I -----•,. 's
".,...,,_
II,, 1 i
J, [ i
. 11 ,:•,. , J ....._. . . ii yi i
..,„, i •,..1,;\
II' i'r.:Tholati 1, , , ._
‘-- '"•'-' -1.1.:.i--gNs L-Tv
•
- - •
_ 1
•
-L•q
. • i7
• -qe.,
•
Prop. Subsurface Disposal
Exist. Wei
1.,:_____1,5?..;71(Property must be acquired)'c''
l •
. • • • • "-- • r
• ,-, •
•
1
1
•••••••
• *
I., • ,•
, 1 . fr) • •
s^..„
• ••
C`..e-"" . • ,
-r
•
f..
• .
wriammis ..- • _ '
'L.- • • .1
11,
. . • .• 'J ' . • .1 • • . 1. hte•-•.' .
, r
.!•• 00; -
Exist. Well
7 .•
North
Colonial Woods Subdivision - Combined Well # 1 & Well II 2
Possible Location for Subsurface Disposal
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 3, 2007
Mt. Airy, N.C. Scale: 1" =333'

35
CIMPI
NMI
fog
1101
fir
Appendix L
Possible Location for *Combined
Surface Land Disposal
,,,, (*Combined disposal of backwash from Well No. 1 and Well No.2)

Exist. Well
Prop. Surface Disposal
(Property must be acquired)
North
Colonial Woods Subdivision - Combined Well # 1 & Well # 2
Possible Location for Surface Disposal
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 3, 2007
Mt. Airy, N.C. Scale: 1" = 333'

36
Appendix M
Possible Route for *Combined Connection to POTW
(*Combined disposal of backwash from Well No. 1 and Well No.2)

Colonial Woods Subdivision - Combined Well # 1 & Well # 2
Possible Route for Connection to POTW
Mt. Airy, N.C.
Scale: 1" = 333'
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124 March 3, 2007