20100684 Ver 1_More Info Received_20110714

McGM
A S S O C I A T E S
July 11, 2011
Ms. Annette Lucas
North Carolina Department of
Environment and Natural Resources
Division of Water Quality
401 Oversight/Express Review Program
1650 Mail Service Center
Raleigh, North Carolina 27699-1650
JUL 1 4 2011
DENR - WA R 0
etlsnric t e._--
RE: Stormwater Management Plan Revision
Foothills Commerce Center - Phase One
DWQ No. 10-0684
Cleveland County, North Carolina
Dear Ms. Lucas:
Please accept this letter as a follow up to our telephone conversation on June 6, 2011 in
which we discussed revising the stormwater management plan for the Foothills Commerce
Center in the City of Shelby. We discussed revising the plan in several ways, including using
on-site soil for the wet detention basin liner and eliminating the liner at the wet detention basins
where appropriate.
We propose to use on-site soil for the liner in Wet Detention Basin Number 2 and to
eliminate the liner in Wet Detention Basin Numbers 1 and 3. Geotechnical investigations have
indicated that the on-site soil has an infiltration rate that will meet the 0.01 inches per hour
minimum rate. Enclosed with this letter, please find the geotechnical report that indicates the
groundwater elevation is within 6 inches of the seasonally high water table at Wet Detention
Basin Numbers 1 and 3. Also enclosed are revised sheets C-508 and C-509 of the approved plan
set. The sheets have been revised to include the seasonally high water table on the pond cross
sections.
E n g i n e e r i n g • P l a n n i n • F i n a n c e
McGill Associates, P.A. - P.O. Box 2259, Asheville, NC 28802 - 55 Broad Street, Asheville, NC 28801
828-252-0575 - Fax: [phone]
Ms. Annette Lucas
January 14, 2011
Page 2 of 2
Please contact Becky Johnson, PE, Dale Pennell, PE, or me if you have any questions or
concerns.
Sincerely,
McGILL ASSOCIATES, P.A.
s?
6i G H FMAN, PE
Project Engineer
cc: Mr. Rick Howell, City of Shelby (w/ enclosures)
Mr. Brad Cornwell, City of Shelby (w/ enclosures)
File (w/ enclosures)
P:\2009\09.00116\Letters\a122jun I l .docx

11LENC.
November 16, 2010 BUNNELL•LAMMONS ENGINEERING, INC.
GEOTEcHwAL, ENVIRONMENTAL AND CONSTRUMON MATERIALS CONSULTANTS
McGill Associates, P.A.
55 Broad Street
Asheville, North Carolina 28801
Attention: Mr. Dale Pennell, P.E., P.L.S.
Senior Project Manager
Subject: Report of Geotechnical Exploration and
Soil Infiltration Testing
Foothills Commerce Center
Phase I Wet Detention Basins
Shelby, North Carolina
BLE Project No: JIO-6667-02
Dear Mr. Pennell:
Bunnell-Lammons Engineering, Incorporated (BLE) is pleased to present the geotechnical exploration
and infiltration test results for the proposed Phase I Wet Detention Basins for the Foothills Commerce
Center project. The geotechnical exploration and infiltration testing was performed generally as
described in BLE Proposal No. P10-0672 dated October 21, 2010. The exploration was authorized by
your signing our Proposal Acceptance Sheet on November 5, 2010.
SITE AND PROJECT DESCRIPTION
We previously prepared a Report of Preliminary Geotechnical Exploration (BLE Project No. J09-
6667-01) dated September 24, 2009. The preliminary report should be read in conjunction with this
report. We have been provided with a drawing titled "Overall Plan" by McGill Associates, P.A. dated
July, 2010 showing the planned development, location of wet detention basins and the existing
topographic contours. The site consists of a 145-acre tract of land generally located within the
southeast quadrant of the intersection of Artee and Plato Lee Roads on the west side of Shelby, North
Carolina (reference Figure 1). We understand that the property is planned to be an industrial business
park. The geotechnical exploration and infiltration testing for this report are specific to the Phase I
Wet Detention Basins, which consists of three basin locations. The basins range in plan size from
11,926 to 35,628 square feet with maximum depths of 8 to I 1 feet.
A north-south trending creek divides the property with approximately 3/4 of the property located east of
the creek. The property east of the creek is used as farmland. The remaining '/4 of the site located
west of the creek was formerly a pine forest that was cleared some time ago and has since become
overgrown with brush. The site topography slopes down from the north/northeast to the
south/southwest to Little Beaver Dam Creek and then slopes up to the west to Plato Lee Road. The
ground surface elevations range from about 800 to 880 feet.
105 FAIRvnv ROAD, SUITEA
ASHEVILLE, NORTH CAROLINA 28803
PHONE [phone]
FAx [phone]

Report of Geotechnical Exploration and Soil Infiltration Testing November 16, 2010
Foothills Commerce Center - Phase 1 Wet Detention Basins BLE Project No. JI0-6667-02
Shelby, North Carolina
SUBSURFACE EXPLORATION
Ten soil test borings (B-1 to B-10) were previously performed as part of the Report of Preliminary
Geotechnical Exploration dated September 24, 2009 (reference Figure 1). Three soil test borings (B-
11 to B-13) were performed specific to the Phase I Wet Detention Basins (reference Figure 2) with a
Soil Sentry truck-mounted drill rig with 2 1/4-inch inside diameter hollow stem augers for the proposed
project. One test boring was drilled near the center of each proposed wet detention basin to depths of
17 to 20 feet. The test boring depth was extended to a minimum of four feet below the proposed
bottom at each wet detention basin. In addition, fourteen infiltration test borings (reference Figure 2)
were drilled within the footprint of the wet detention basins. Three infiltration test borings (I-1 to 1-3)
were performed in Basin No. 1, three infiltration test borings (I-4 to 1-6) were performed in Basin No.
2 and eight infiltration test borings (I-7 to 1-14) were performed in Basin No. 3.
Wet Detention Basin No. 1
Soil Conditions (B-11) - The surface consisted of approximately 5 inches of silty fine sand topsoil.
The subsurface soils generally consisted of loose to firm, moist to wet, slightly micaceous silty fine to
medium sand to a depth of about 4 feet. The loose to firm sand appeared to be alluvial (water
deposited) soils. A chemical odor was noted in the soil sample obtained from 4 '/z to 6 feet. Beneath
the alluvial sand, boring B-11 encountered residual soils that consisted of firm to dense, moist, slightly
micaceous silty fine to medium sand to auger refusal at 18 feet. Residual soils are soils weathered in-
place from the parent rock. Auger refusal likely occurred on partially weathered rock (MR).
Groundwater Conditions - Groundwater was not encountered
Groundwater was encountered at a depth of about 5 feet after 4 days.
moisture content and observed water levels, the hydrostatic water tal
Wet Detention Basin No. 2
during the drilling operations.
Based on sample coloration, soil
Soil Conditions (B-12) - The surface consisted of approximately 5 inches of slightly clayey, silty
sandy topsoil. The subsurface soils generally consisted of loose to firm, moist, slightly clayey sandy
silt to moist, silty fine to medium sand to the boring termination depth of 20 feet. This silty fine to
medium sand is residual soil. Residual soils are soils weathered in-place from the parent rock.
Groundwater Conditions - Groundwater was not encountered during the drilling operations or 4
days after the drilling operations. Based on sample coloration, soil moisture content and lack of water,
the hydrostatic water table was estimated to be below the test boring depth of 20 feet.
`Vet Detention Basin No. 3
Soil Conditions (B-13) - The surface consisted of approximately 5 inches of slightly clayey, silty
sand topsoil. The subsurface soils generally consisted of loose to firm, moist, slightly micaceous,
slightly clayey, silty fine sand to a depth of about 14 feet. These soils are residual soils which are
weathered in-place from the parent rock. Partially weathered rock or boulders were encountered from
14 to 17 feet. Auger refusal material was encountered at 17 feet.
2

Report of Geotechnical Exploration and Soil Infiltration Testing November 16, 2010
Foothills Commerce Center - Phase 1 Wet Detention Basins BLE Project No. JI0-6667-02
Shelby, North Carolina
Groundwater Conditions - Groundwater was encountered at a depth of 8 feet during the drilling
operations and at a depth of 6 '/2 feet after 4 days. Based on sample coloration, soil moisture content
and observed water levels, the hydrostatic water table was estimated to be at a depth of 6'/s feet during
the observation period.
Groundater Considerations
Groundwater levels may fluctuate several feet with seasonal and rainfall variations and changes in the
water level in adjacent drainage features. Normally, the highest ground-water levels occur in late winter
and spring and the lowest levels occur in late summer and fall. The seasonal high water table (SHWT) is
estimated to exist at a depth of 5 feet in the vicinity of Wet Detention Basins No. 1 and 3 and below a
depth of 20 feet in Wet Detention Basin No. 2.
LABORATORY TESTING
Natural Moisture Content
The natural moisture content of select soil samples was determined in accordance with ASTM D2216.
The moisture content of the soil is the ratio, expressed as a percentage, of the weight of water in a
given mass of soil to the weight of the soil particles. The results are shown on the table below.
Percent Finer than No. 200 Sieve
A percent finer than a No. 200 Sieve test was performed on three soil samples to determine the fines
content of these materials. After initial drying, the sample was washed over a U.S. Standard No. 200
sieve to remove the fines (particles finer than a No. 200 mesh sieve). This test was performed in a
manner similar to that described by ASTM D1140. The results are shown on table 1 below.
TABLE 1 - LABORATORY TEST RESULTS
Test
Boring No. Depth
(feet) Natural Moisture
Content (%) Percent Finer than No. 200
Sieve (%) USCS Soil
Classification
B-11 13.5-15.0 12.5 24 SM
B-12 13.5-15.0 26.7 37 SM
B-13 8.5-10.0 38.7 24 SM
INFILTRATION TEST PROCEDURE AND RESULTS
A borehole was drilled and converted to a monitoring well utilizing solid 2-inch diameter PVC casing
to a depth of 2 feet below the proposed pond bottom. The infiltration testing was performed in
general accordance with Appendix C - Testing Requirements for Subsoils for Infiltration, which is a
part of the Stormwater Best Management Practice Design Guide, Volume 2, Vegetative Biofilters
dated September 2004 prepared by the U.S. Environmental Protection Agency.
Upon completion of the infiltration (monitoring) well, and in accordance with the above referenced
testing requirements, the well was then filled with clean water to a depth of 24 inches and allowed to pre-
soak for 24 hours.
IBM-.
Report of Geotechnical Exploration and Soil Infiltration Testing November 16, 2010
Foothills Commerce Center - Phase 1 Wet Detention Basins BLE Project No. J10-6667-02
Shelby, North Carolina
Upon 24 hours later, the casing was refilled with clean water to the top of the casing and the water level
was monitored (measured) from the top of the casing for 1 hour. This test procedure was repeated 3
additional times for a total of four times. The PVC pipe was left in place for additional testing if
required. BLE can remove the PVC pipe and backfill the borehole with soil if no additional testing is
required. The average infiltration rate for each wet detention basin is presented in the following tables.
TABLE 2 - WET DETENTION BASIN NO.1 INFILTRATION TEST RESULTS
Infiltration No. Avera e Infiltration Rate (inches per hour)
I-1 0.31
I-2 1.20
I-3 0.15
Average of I-1 to I-3 0.55
TABLE 3 - WET DETENTION BASIN NO.2 INFILTRATION TEST RESULTS
Infiltration No. Average Infiltration Rate (inches per hour.
-- I-4 61.73
I-5 86.56
I-6 30.34
Average. of I-4 to I-6 59.54
TABLE 4 - WET DETENTION BASIN NO.3 INFILTRATION TEST RESULTS
Infiltration No. Average Infiltration Rate (inches per hour
I-7 0.33
I-8 17.72
I-9 1.92
I-10 0.88
I-11 0.79
1-12 0.79
I-13 1.06
I-14 0.12
Average of I-7 to I-14 3.32
Average w/o high & low Values (I-8 and I-14)
?2 t2 0.96
CONCLUSIONS AND ALTERNATE LINER RECOMAHNDATIONS
The average infiltration test results of 0.55 and 0.96 inch per hour for proposed Basins No. I and 3,
respectively are in the range of expected values for firm silty sand residual soil encountered by the test
borings. The infiltration test result of nearly 60 inches per hour for Basin No. 2 is typical for loose sands.
If these infiltration rates are higher than allowable for the basins, a low permeability liner would be
required. Based on the sandy soils encountered by the test borings, a bentonite clay amended liner is
recommended.
4
MILE.
Report of Geotechnical Exploration and Soil Infiltration Testing November 16, 2010
Foothills Commerce Center - Phase I Wet Detention Basins BLE Project No. JI0-6667-02
Shelby, North Carolina
The bentonite for a low permeability liner should be free-flowing, powdered, high-swelling, sodium
montmorillonite clay that is free of additives. The bentonite amendment should likely be in the range of
3 to 6 percent by dry weight. The soil used with the bentonite should be a silty sand with 100 percent
passing the No. 4 sieve and a maximum of 35 percent (preferably 25 percent) passing the No. 200 sieve.
The bentonite should be thoroughly mixed with the native soil using a tiller before adding sufficient
water to promote compaction. All fill used for replacement of material that is undercut or liner should be
uniformly compacted in 6-inch lifts to at least 95 percent of the standard Proctor maximum dry density
(ASTM D 698) at 2 to 5 percent above the optimum moisture content of the bentonite soil mixture. We
recommend laboratory tests be performed with samples of the bentonite/soil mixture to confirm the
required bentonite to achieve the required permeability. At the start of construction, a test pad should be
performed at the proposed finished grade within the basin. The test pad should be performed using the
same equipment and construction methods as the actual liner. We recommend that the lift thickness be 8
to 10 inches, loose measure before compaction. Infiltration tests should be performed on the test pad to
verify acceptable permeability rates.
All existing topsoil, vegetation, disturbed soils, and soils containing organic matter or other deleterious
materials should be stripped from within the proposed basins. After stripping and rough excavation
grading, we recommend that areas to provide support for the liner be carefully inspected for soft surficial
soils and proofrolled with a 25-ton, four-wheeled, rubber-tired roller or similar approved equipment. We
recommend a visual inspection rather than proofrolling basin areas that are within 2 feet of the
groundwater level. The proofroller should make at least four passes over each location, with the last two
passes perpendicular to the first two. Any areas which wave, rut, or deflect excessively and continue to
do so after several passes of the proofroller should be excavated to firmer soils. The excavated areas
should be backfilled in thin lifts with suitable compacted fill materials. The proofrolling and excavating
operations should be carefully monitored by an experienced engineering technician working under the
direct supervision of the geotechnical engineer.
We appreciate the opportunity to provide our professional services on this project. If you have any
questions regarding this report, please contact us at [phone].
Sincerely,
BUNNELL-LAMMONs ENGINEERING, IN
CARO?
S Al ??"••
William T. Gentry IIl, P.E. 033927
Senior Engineer 14- 16-q-?
NC Registration No. 33927 -5-(
?I/1111d11?`??\
GU04 ytt
Gary L. Weekley, P.E.
Senior Geotechnical Engineer
NC Registration No. 8251
Attachments: Figure 1 - Boring Location Plan for Preliminary Geotechnical Exploration
Figure 2 - Boring and Infiltration Location Plan for Phase I Wet Detention Basins
Field Exploration Procedures
Soil Test Boring Logs (3)
Key to Soil Classifications and Consistency Descriptions
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Field Exploration Procedures
Soil Test Borings
The borings were made by mechanically twisting a continuous flight steel auger into the soil. Soil
sampling and penetration testing were performed in general accordance with ASTM D 1586. At
assigned intervals, soil samples were obtained with a standard 1.4-inch I. D., 2-inch O. D., split-tube
sampler. The sampler was first seated 6 inches to penetrate any loose cuttings, and then driven an
additional 12 inches with blows of a 140-pound hammer falling 30 inches. The number of hammer
blows required to drive the sampler the final 12 inches was recorded and is designated the "standard
penetration resistance. The penetration resistance, when properly evaluated, is an index to the
strength of the soil and foundation supporting capability.
Representative portions of the soil samples, thus obtained, were placed in glass jars and transported
to the laboratory. In the laboratory, the samples were examined by a geotechnical engineer to verify
the field classifications of the driller. Test Boring Records are attached, showing the soil
descriptions and penetration resistance.
?LIBINC SOIL TEST BORING NO. B-11
. PROJECT: Foothills Commerce Center Phase 1 Wet Detention Basins PROJECT NO.: J10-6667-02
CLIENT: McGill Associates DATE START: 10-22-10 END: 10-22-10
BUNNELL-CANNONS LOCATION: Shelby North Carolina ELEVATION: 812.5
ENGINEEMO, INC. DRILLER: Metro Drill Inc R. Frye LOGGED BY: W. Gentry
GEOTEgYpCALAtO6MtQN11ENTAL
DRILLING METHOD: Soil Sentry Truck mount; 2-1/4 inch ID hollow stem auger
CONSULTANTS DEPTH TO - WA R> INITIAL: d AFTER 4 DAYS: 1 5 CAVING>
U

SOIL i )
W
i

STANDARD PENETRATION RESULTS
ELEVATION/
DEPTH (FT) SOIL DESCRIPTION TYPE Q BLOWSIFOOT
N 2 5 10 20 30 40 50 70 90

5-inches of tan and gray, silty SAND -(topsoil) '" .. :.
fine to medium SAND - (alluvium)
silty
moist
Loose 4
,
,
, s
..
810-

i......
........... ...... .
Firm, brown, tan, gray and white, wet, slightly micaceous, 2
silty, fine to medium SAND - (alluvium) s
5 Chemical odor noted in sample 7
7 7
brown, tan and white, moist, slightly micaceous, silty,
Firm s
,
fine to medium SAND - (residuum) 9
805 ?•` ? ? `?
Firm to dense, black, brown and tan, moist, slightly
' 6
micaceous, silty, fine to medium SAND - (residuum) :, _` ;'• s
a
?10
:
•`.
..•" -
800 _ .:. _..:.:.:

16
32
15
795
Boring terminated at 18 feet due to auger refusal. No - -
groundwater encountered at time of drilling, but was
2o encountered at 5 feet after 4 days. _

790 's L'
_ :.
7 p
25
785 _:. _ .:. .:. :_ :..:.: ..
p q
30 7 7
ti
780
N
35
N
? 775 { _.
3
L -
° SOIL TEST BORING NO. B-11
o Sheet 1 of 1

19LIBINC. TEST BORING NO. B-12
PROJECT: Foothills Commerce Center Phase I Wet Detention Basins PROJECT NO.: J10-6667-02
B KNELL-LAMMCM CLIENT: McGill Associates DATE START: 10-22-10 END: 10-22-10
E WMEERNG, INC. LOCATION: Shelby North Carolina ELEVATION: 866.0
GEOTEMSCAL.ANDEMPONIENTAL DRILLER: Metro Drill Inc. R. Frye LOGGED BY: W. Gentry
CONaULTANTS DRILLING METHOD: Soil Sentry Truck mount; 2-114 inch ID hollow stem auger
DEPTH TO - WATER> INITIAL: 7 dry AFTER 4 DAYS: T dry CAVING> 337
ELEVATIOW
DEPTH (FT) SOIL DESCRIPTION SOIL i
TYPE i
f STANDARD PENETRATION RESULTS
BLOWSIFOOT
2 5 10 20 30 40 50 70 90
5-inches of reddish-brown, slightly clayey, silty SAND -
865 (topsoil)
Firm, reddish-brown, moist, slightly clayey, fine to medium $ - f -
sandy SILT - (residuum) f :: :.: : _....:.. _...... __ _ .
s
...........
7
10

...........
'
5 7
7
_.. ..... _...._. _ ..:...
sso Firm to loose, reddish-brown and tan, moist, slightly clayey, i
fine to medium sandy SILT - (residuum) : ; ` .. a
. .. 2

ass Loose to firm, tan and white, moist, silty, fine to medium
SAND - (residuum) : .:: .. a

L 4
s
15
-
850 i L

4 7 7
5
7
20
845 Boring terminated at 20 feet. No groundwater encountered - -
at time of drilling.
25
840 _:.. :_ i...:.. _ :....: :. .:..: .:..:..

J
L
? 35
? 830 :__ :.:.:...:...._:. _.:.:.:..
j
D
' SOIL TEST BORING NO. B-12
Sheet 1 of 1

13LIBINC SOIL TEST BORING NO. B-13
PROJECT: Foothills Commerce Center Phase I Wet Detention Basins PROJECT NO.: J10-6667-02
StINNELL-LAMMONS CLIENT: McGill Associates DATE START: 10-22.10 END: 10-22-10
ENMEERNG, INC. LOCATION: Shelby North Carolina ELEVATION: 607.0
E
A DRILLER: Metro Drill Inc. R. Frye LOGGED BY: W. Gentry
NV AL
NO
GE0TEa* C L DRILLING METHOD: Soil Sentry Truck mount; 2-114 inch ID hollow stem auger
CONX)LTANT8 DEPTH TO - WATER> INITIAL: 8 AFTER 4 DAYS: 1 6.5 CAVING>M

ELEVATION]

SOIL DESCRIPTION

SOIL
TYPE N
W
a

STANDARD PENETRATION RESULTS
BLOWWOOT
DEPTH (FT)
C'3 2 5 10 20 30 40 50 70 90
5-inches of reddish-brown, slightly clayey, silty SAND - ' '
soil)
(to 3
p
605 Loose to firm, reddish-brown, moist, slightly clayey, silty, s a : - - -
fine to medium SAND
s

::.
.:;
;. 4
:_ __.:
.
:
5 . . ......
.._ .......
_.

Loose to firm, reddish-brown and black, moist, micaceous,
2
2
800 silty, fine SAND s ® .
s

7 .
?10 Trace rock fragments at 10 feet
795- -
..:

22
22
50 5^
PARTIALLY WEATHERED ROCK which sampled as wet rock 5015"
1s fragments with silty sand

790
Boring terminated at 17 feet due to auger refusal.
Groundwater encountered at 8 feet at time of drilling and at
6.5 feet after 4 days.

785
25
780

30
775- -
-35
i 770
i
i .... :.. :.. .:.._ ..... _..._.. _..:. -:..:..
?J SOIL TEST BORING NO. B-13
Sheet 1 of 1

11 L E.-
KEY TO SOIL CLASSIFICATIONS AND CONSISTENCY DESCRIPTIONS
BUNNELL-LAMMONS ENGINEERING, INC.
ASHEVILLE, NORTH CAROLINA
Penetration Resistance* Relative Particle Size Identification
Blows per Foot Density Boulder. Greater than 300 mm
SANDS Cobble: 75 to 300 mm
0 io 4 Very Loose Gravel:
Coarse -19 to 75 mm
5 to 10 Loose
Firm Fine - 4.75 to 19 mm
11 to 20
21 to 30 Very Firm Sand:
75 mm
coarse - 2 to 4
31 to 50
r 5o Dense
Very Dense .
Medium - 0.425 to 2 mm
ove Fine - 0.075 to 0.425 mm
Silt & Clay: Less than 0 075 mm
Penetration Resistance* Consistency
Blows per Foot
SILTS and C LAYS
0 to 2 Very Soft
Soft
12 Number of blows in first 64nches
3 to 4 Firm 15 Number of blows in second 6-inches
5 to B Stiff 16 Number of blows in third 6-inches
9 to 15
1S to 30 Very Stiff
31 to 50 Hard
over 50 Very Hard
'ASTM 0 1586
® Grab Sample
® Split spoon Sample
® Undistrurbed Sample
KEY TO SOIL CLASSIFICATIONS
Well-graded Gravel
4GJJ
0
l
?? Poorly-graded Gravel
GP
0
KEY TO DRILLING SYMBOLS
Groundwater Table at Time of Drilling
® Groundwater Table 24 Hours after Completion of Ddlling
Low Plasticity Clay
CL
Sandy Clay
CLS
Partially Weathered Rock Silty Clay
BLDRCBBL CL-ML
IN High Plasticity Clay Silt
CH ML
M Clayey Silt Silty Sand
MH SM
`, ,
Sandy Silt Topsoil
MLS O V" TOPSOIL
Sand Bedrock
J SW ffil BEDROCK
<v.
? 1` L-
Clayey Sand r <J Concrete
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i 1 ~ ~
I J ' , J 1 ' /
i~ , , , ` J 505 ~ 506 a / ~ ~ $2p' ee,itNlllllrrr~e'
~ ! 4/,~0 SF t (10' WIDE / r / l o X05 ~ ` , ~~P°°°®°®®,,°°)j'~,,~~
! , PERMANENT POOL. , , , ® 1 . ~ J ~ ~ J ~ ' ® /VEGETATED SHELF) ~ r / ~ ~ / ~ o ~ ~ ~ °~P~' °o~'l,~
. 1 ELEV, 807,5 , ~ o i to` `n e
® 1 TEMPORARY i ® ® 1 i / / / oaf W ~ °
~ 1 J SILT FENCE J 806
506 1 1 1~~ J
' J ' J ' 1 ` J ~
a> J , ' , / , ? , / ! 1II ,
J ` , J ` ~ '
1 1 1 J 804 / ~ i
504 ? ~ 1 - - J ' J i' ~ i~O~1 _
INV,= 06,0 J 1 J s, 1 J 1 / / ~ ~ -y/(~ / ~ ~~J 4~
1 ~ ~n J / / /a7~.~~' p
ji. , 6 J ~ ~ 1
1 J ~ J 802 / / / ? r / ~ ~ ~ s ~
o ~ 1 52 ~ ~ / / / / 0~ / / / ~ +_1,
J ' i ~ 24 ALUMINIZED J ' J Q / ~i'` / ? REINFORCED D1.UkRS(ONI~
CMP T J ` ~ / o~~~? ~ DITCy.-MATTED WITH N.A.G, ~ / ? / ~oa-~ ..-P~550 OR APPROVED EQUAL ~
~y . A IG T _ _a_L. D YL e J ~ PROPOSED' ~ QO ? / /,,,ir~..~--~~ ~-~`MON.,~
~ J , 1 i 8 10 DENT KITE ~ 800 ~ _RIPRAP'F`OREEAY / / ? ? ? -
800 , 1 CL Y LINER ? ~ ,1 WEIR ® rr --fi ~ i~ ~ : ~ ~ ~
1 , ~ y 4 ~J / Roy
® ~ , - / r
~ ' .

_ , '
10+4 10+60 1120 11+6A 12104 12+40 12+130 ~ 9+5A 1°FQO DRAINA~ EASEMENT ~ .~•--°'_^`~~G MAINTENANC~ACC,E/SS / ~ ~ T-. _ROw, ~ RIGHT-OF~WAY/r r ~ \ `
~ , - - / / _ ;
~ i
~o. i _ ~~a-- _ ~c~ ,
i -spa / 1 ~ , ~ i"..'MOa----_.../ Boa-_._..... /
HORI ONTA~, SCA~,~:1"=~0'-Q" ~ RIPRAP ~`OREB~ WEIR i~ ~ / Boa _ _ ~ Boa I r :TRAP/~`OREBAY -7-MOa__--_.... r Boa------_..,r'' ~ / / ~'----roloa--__ 1
i~ 874 i 574 _ ~ .
EXIS NG GRDUND ~ I ~ / / REINFORCED DIVE~SION ~
~ ~ ! ~ ~ ~ DI'~CH MATTED ~dITH N,A;G. ~ ~ ~ , ; _ ~ Q P550 OR AP~~20VED EQUAL ~ o
_ / A / , e ~ i ~ -
~ I ~ 59,10 865 , ~
672 ~ I ~ 572 ® ~ ' xA.
~ i i i / / ~ ~ m ~ ~ TEMPORARY
I v i s~4,50' / 860 SILT FENCE
x ~r, ~ i X / 860
A UMINIZED CMP I i ? I
870 i 1370 ~rv _ ~ I / r ~ _ / /
I / i -°~65 ? MAINTENANCE ~C~ES5 a
it a" P C i a ° ~ RIGHT-OF ;WAY ~ ~ I ( m r o ~
~ I i _ I a ~ ~ ~ 865 / m. ' / ~ $e°v~:~ww
~ A / ~ / 4
8613 / / 565
/ / / a ~ s , • ' 1 3830 SF ~ (10 WIDE ~ i~ ~ ~ o ~
i / I VEGETATED SHELF) ~I p~ w Q w o J o°,~ c
, / i / ~ ~I , ' ( 860 ~ ° ~ 17 ®v o ~ u`. o a
~
z 866 i ~ ~ Q
566 _ i ~ PERMANENT PO~fl1. / 865 ~6' ~ ~ s
T~ PORA~Y,.QOL ca ELEV, 8fi3,5 i I 1308 r 2.0 ORIFICE a / (SEE DETAIL, SHEET C-50) ~
EL V, 865.5 ~ / ~ ~
1 REINFORCED DIVERSION ~ /
~ 1 / ® 1 P ~ DITCH MATTED WITH N,A,G, a ! 564 ~ , ? ~ ~ o
4. _ P55O OR APPROVED EQUAL i i ~ ~p• - ~ s ~ ~ \ /
~ PE MANENT, OOL;,®. ® J ~ ( ~ ~ s ~ / ~ ~ ~ / ' % ~ e
® EL V. 863,5 _ /
' ! I / / _ Y 860 i
~ , 862 ~ ~ / L
1362 , i o / / ~ , ?
2 ~ ~ ~ ~ ~ /
w ~ 2.0 ORIFICE 862,75 J 9 J ® ! ~ , 1 , , Q , i~
~ ' J ,J ~ 865 0 $ 8 '
® ' , a 1 _ I J ~ , 866'/ I /
e INV.-8 2,0 s 1 660 ~ I , ~ 660 J ~ I , ~ ~ 865 '
/ ~ X65 60' o o
~ i ~ , \ ~ i ~ _ ~65r--R0~-- _ _ j _ ROW-- _ ~ i
, --ROW- / ROW-
1 ~ 856 ~ / ~ w _ f / ""-ROW--....~ --ROW
c _ ro rr / ~ I 8 -10 D NTONITE / !8 / / ROYd~--~ - - -ROW
24 ALUMINIZED ~ I CLAY LINE ~ DRAINAGE'EASEMENT I ® I
C P TO .~q ~ ~ RIPRAP EMERGENC~jOVERFLOW I EMERGENCY OVERFLOW {SEE DETAIL, SHEET C-509) I
c / ~ ~ , w DAYLIGHT ~ ~ , ~ s
s 856 ~ 656 g 7111/2011 GRH STORMWATER RESU6MITTAL FOR NCDENRIDQ (GROUNDWATER ELEVATION) -
0
0 o~ A4 2/25111 CRM STORMWATER RESUBMITTAL FOR NCDENRIDWQ (FEB. 9, 2011 COMMENTS)
3 w 0 1111111 RHH STORMWATER RESUBMITTAL FOR NCDENRID
2 11/16110 RHH STORMWATER SUBMITTAL FOR NCDENRIDWQ
c~ 1 1118110 RHH REVISED ROAD WIDTH AND SEDIMENT BASIN GRADING
11+20 11+60 12+00 12+40 12+80 +60 10+00 10+4 10+80 NO. DATE BY REVISION DESCRIPTION

\ I \ LENGTH, L W
I DRAINAGE EASEMENI~ 1 i REINFORCED D{VERSION \ ~ I I \ --~0~ \ DITCH MATTED WITH N,A.G, 1 ~ \ Y• ~ U
I TEMPORARY °w-- \ i P550 OR APPROVED EQUAL \ \ ~ \ VERTICALS ALE.1 -2-0
1 SILT F NCE'"~~ , i 1 ' \ RIZ NTAL ALE.1-20~G E 1 1 \ A V ~ A D
1 •-RQ~r \ \ \ \ 614 e
L-`" I ~ \ ~ PRO OSED GRO ND ~+'1 v v 614 I 1 l \ MAiN POND , ~ ~ ~ ~ ~ ~y
1 I \ ~
I t 1 a \ \ I 1 \I\ i \ \ , t~
1 1 \ \ EMERGENCY i I OVERFLOW ' ~
1 ~ 1 \ \ ~ 612 ~D' ~ (HARaENED) , ~ 4
t \ \ ~ 1312 \ \ i \ ii Y^~N
\ \ \ \ l \
\ \ \ \ ~ B
~ \ \ 6" PVC \ ~ \ \ ~ PVC WIDTH° w ~ ~ ~
1 \ 1 1 ~ \ \ t\ 1 \ , 610 1310 ~`i a , ~ o
\ ~ 1 \ N
v ~ v 36 ALU 36" ALU {N{ZED CM FoREaAY FLOW PATH ~ U
1 ~ \ ~ \ \ 1 ~ 1 \ \ ~ ~
\ 1 ~ i (3.1+ RECtDMMENDED) f
1 \ . \ v v A ~ v v 6013 SOS s ~
1 \ \ \I ~ 1 ~ ~ v v FOREBAY GERM ~ j aa~ ~snmw.
1 1 ~ ~ 10' VEGETATEp SHELF
1 1 1 \ \ \ OUTLET ~ ~ ~
1 1 ~ v v A(\ VEGETATED SIDE ~ 'STRUCTURE I~ ~ `7~~
i 1 1 \ \ \ \ \ 1 v ~ X06 ~ \ PERMANENT ~ i ~ ~ I + ~ 606 POOL LEVEL ~ ,
t \ \ 3 1 \
1 1 \ \ \ TEMPORA Y PO©L , , ~ . , . 79~,10~ , ra
1 I 1 \ \ \ ~ . ELEV. 80 ,5 NOT TO SCALE ~ W ~
1 ~ \ ~ 1 ~ \ \ \ i 1 ~ \ \ f
~ \ \ \ , ~ 0 604 ~\~~,,~u ~
\ \ v v A
\ \ \ \ 1 \ \ ERMANEN POOL B ` I\ ~ ,p. ,e~, ~ 00 v 00
~ \ 1 \ A PROXIMATE SH LEV. 803, f 1 , ( \ DXZ B DXZ ;tk' ~ ~a ~°gt~c~
\ \ \ 1 V A ~ \ \ ~ 1 \ \ 1 1 , G QTECHNICAL R PORT v Q ~8 a'
\ 1 + 1 f 602 EXISTING GROUNp = ~ ~ N ~ = ~
\ \ \ 1 ~ \ 1302 f ~ \ \ 1 1 ~ 0,9 Qv~
\ \ \ \ 1 I f \ \ t ~ 1 ~ ~ ~ ELEV, 802.75 f _
\ \ \ 1 1 i
~ ~ ~ ~ ~ ~ i 1 A 1 . ,INV.= 02.5 f
' 11=III=° ~ t s>' a 1 I 1=1I i~ I1=I I
v ~ 1 ~ ~ \ \ \ ~ goo \ \ I ' ~ -111.=~I.1 _ o o -~.1=111-11=~
1 1 ~ 1 ~ \ \ ~ ~ ~ (~=1 I I. 00 0 ~Oo -III=I i I=I I I-' I -ll-III-_ ° _ ~ ~ I 1- - - ~ 0 11-1T_l~ I1=1I I-I I - ~
\ ` i \ 1 1 ~ , I=~=C 11= ° I I 1=1 11=1L=1ll='' uNDISTURaED oR auRY ENps ~ ~ -1 L~ ~=~1__ _ _ _ 11- I I-~, ; ,I i I- ' coMaACT~a ~A~TH ' ~
\ 1 1 1 \ 1 1 1 I 1~ 1 l 92 MIN. I I ' ~~I I I I it ~ I ~11,11~ I I~I~~~ ~ ~~Ti~iTi ~ I I- ~
1 1 ~ 1 1 1 ~ i "-CLASS B RIPRAP LINING
1 t 79~ 1 1 1 1 I I I PERMA~JENT POO g 79S "I (UNLESS OTHERWISE NOTED) ~
\ 1 1 I I EL6..Ve 11.~ 3 ' d FILTER FABRIC (MIRIFI 140 N pR EQUAL) ~ ~ ,
I i i 1 ~ l 1 OVERLAP EDGES 12" MIN, WITH ANCHOR
~ 1 t i I i PROPOSEd I ~ ~ 1 1 7 I ® ~ -~rwv~ PINS EVERY 3' ALONG OVERLAP WET aETENTION 8A51N No. D Z LINING i 1 a
RIPRAP FdREBAY 1 I I I l ~I ~d
WEIR 1 i i i p $'-10" BEN ON{TE I ~ 796 i ~i ON{TE 796 ~ 40' .5' 3' CLASS B RIPRAP ~ 2 90' .5' 3° CLASS B RIPRAP
i I ~i C AY LINER 3
\ 1 I 1 I (I 1 a~ I i 3 52' 1' 3° CLASS a RIPRAP
l
I 1 1 I a 9+~0 1p+00 10+40 10+60 11+2® 11+60 r ~ i ~0 12+OQ ! 31 _
w I I e, 1 0 l s r I ~t, REVISION DATE • NOVEMBER 3, 200$ [
~ l 3fi5 I I i I ~ 4 ~
I i~ , 1 ~ I I~
7 I , rvv E.-~~, ~`:j
a I~ „ 1 3 I I I i 6 SCREW TYPE PLUG MOUNTED DN TEE i ~ 42"
1 I a l I e 3 PLANT LIST TABLE n
I I I I ~ 1 I I i $ TEt~PUr2ARY POOL t I I ~ I~ BrOTANI L COMMON CONTAINER PLANTING ~ KEY UATIT~(Isj lO TIO
1 1 I I i i I~ NAME NAME TYPE SEASON
I i I l i TRASH RACK n I ~ 6 TEE STUBBED INTO RISER NTIO BASIN c--
I I I 1 1 (SEE DETAIL SHEET C-503) 36" DIA, CMR N0.1 N0.2 N0.3 r -~1
p .O ® 1 ~0 ® I i ~I ~ i l) P RMA NT P00 3 Eremochloa Centipede TOP of berm ~ ~T^ _ ~ -
~ I ~ I I _ E NEB, L I I I ~ „ . I I I I I ( 36 ALUMINIZED CMP ophiuroides Grass 1/l0~sf 1/1000sf 1/L~Osf NA April-July and EXTERIOR
i i ~ 12" _ slo a of basin ~
I I ( ~ u I I I I ~ \ 36 ALUMINIZED CMP i i i Z Alisma Water 161 366 p6Multipot Aprill-July Shallow Water
I I I I I I I ~ ~ RISER PIPE OUTLET - subcordatum Plantain i5
I I 1 I ALUMINIZED CMP WITH 42"x42" BOTTOI V I ~ i ~ I OUTLET PIPE \ BOTTOM PLATE WELDE) BOTTOM PLATE April ~-July WELDED TO CMP 3 Irisvirginica Blue Flag iris 185 161 360 #6Multipot ~ Shallow Water
I i I I i I I ~ BOTTOM PLATE i ( I I I i POND 1:24" ~
1 ~ i PANG 2 ; 24" 6" ~ 6N I i i I I I 4 Pontederia Pickerelweed 185 161 360 #6Multipot Aprill-July Shallow Water
I I I I ~ ~ 6u CAP WITH HOLE I ( „ ~ DRILLED FOR ORIFICE cordate 15 ~ c
8630 SF~ (10 W DE ~ i I I I 12 \ Asclepias Swamp PlugTrayCells Spring- I ( a rn
S E I I f 1 i ~I VE ETATED H L~ i I I , i i ~I ~ 5 185 161 360 (2" die x 4°° Shallow Land - = m ~ incarnate Milkweed dee cells summer ~ o ~
1 i I r ~ \ a r / 4 1 1 ~I 12 ~
I I / I I Q I i ~ I 24 Plug Tray Cells °o ~ j: a ~ ~ Lobelia Great Blue Spring- of ~ m m > ® ~
I / / / l 1 a..a ,:.4 \ I / Q Q a 6 185 161 360 (Z" die x 4'° Shallow land o ~ p w w ti.i cn Q siphilitica Lobelia dee cells summer ~ W ~ ~ ~ ~ ~ ,
I I I 1 I 12^ a :4 . \ ® z m z ~ eara
I I / 1 Ii I I / / I 1 PROP05ED 4000 PSI CONCRETE l / / / 1 i Plug Tray Cells p g m ~ ~ ~ N ~ W °o Hibiscus Scarlet rose S rin -
i 4 I I 1 ( BOTTOM PLATE WELDED TO CMP I _POND BOTTOM _ _ _ i I ( / 1 3 7 185 161 360 (2 dsa x 4 Shallow Land O ~ uJ w O r o; c coccineus Mallow deep cells) summer ~ ®C1 U ®U u. o ¢
I ! l ,l I !
i i 1 / / i I ~ 3 / / _ 3
f I I ~ ~ ~ i I I ! ~ ;Note _
~ <1 I i J c~ I I I / / ~
I i ~ / / i I t ~ O T i ~ l ~ I / / / :Plant Supplier is Stoney Point Nurser/and Farms, NCDA lic. #5891 _ 8 g.__ _ E _ p _ P
•i I i ~ I 1 °Control of Invasive weeds, animal and vandal dame e, mulchin , waterln ,and mesh or tube rotectlon re lacement
~ i I s S 1 / ! I 6" SCREW TYPE PLUG MOUNTED ON TEE t 42°° shall beamplemented to the„extent needed to ensure..plantsun~ival . ,.....~.............,.......,.........,,.,......,.......,.....,.rv,...............,..,...:.......,' All plantings shall be warranted for two years At the end of the ferst year and again at tfve end of the two-year
r I i I / ~ ` ~ ;warranty period, aU.plants that do not survive mush be replaced uvith the same plantings.,
I 3 ( ~ \
I 3.5" OR11=1CE I / I i ' \ - . , - w TEMPORARY POOL I 1 I
I SEE DE~'AIL I 1 1 ' I ( ~ I I a i i I ( TRASH RACK NOTE;
I SHEET -509 I ~ i 6" TEE STUBBED INTO RISER •I :B 1 l ~ \ (SEE OETAIL SHEET C-503) 1. KEY NUMBERS SHOW LOCATION OF VEGETATIVE COVER. FOR SPACING OF PLANTS, SEE CHART ABOVE.
I I i 1 I 42" 36" ~ 36'° pIA< CMP
I I i ~ I ~ y \ PERMANENT POOL I I i I t - pp , I
a i I ~ \ 36 ALUMINIZED CPAP ~ I ! \ l \ ~
Q ~ t I 1 I \ 12 I ~ I \ ~ RISER PIPE OUTLET
\ „ a ~ ~ 1 I \ A WITH 42x42 a 1 \ p
a \ ~ \ BOTTOM PLATE ~ \ ~ \ BoTTo BOTTOM PLATE
\ ALUMINIZED CMP \ ydELDEI WELDED TO CMP 1, INSTALL EROSION AND SEDIMENT CONTROL MEASURES AS INDICATED ON PLANS.
OUTLET PIPE \ BOTTOM PLATE \ ~ 1 , ~ , o \ POND 3 ; 18" n \ u
m $05.0 9 \ I \ ~ 6\ s u \ /C , 1 6 CAP WITH HOLE ~ \ I \ 2, PROCEED VdITH GRADING, CLEARING AND GRUBBING. SEED AND PLACE EROSION CONTROL MATTING ON ALL CUT
--C - - \ \ I \ DRILLED FOR ORIFICE o \ AND FILL SLQPES THAT ARE NOT ROCK IMMEDIATELY UPON COMPLETION OF SLOPE STABILIZATION,
l \ , i I \ o ~ \ ` 8 \
w 1 ~ l \ \ c ~ o \ 1 1 I \ ~ ® 0 ~
~ \ V ~ V A 4. INSTALL OUTLET DEVICES AND LANDSCAPING PER THE PLANS.
o f , \ 11 \o a \ 1 ~ ~ \ \ ~ \ 4 24
c i / l 1 \ \ ;Q AINAGE AREA IS STABILIZED.
m \ ~ d .12,; \ a.
~ \ ~ I R~6.5O'~ 1 \ \ ~ ~ PROPOSED 4000 PSI CONCRETE ~ \ PROPOSED 4000 PSI CONCRETE 711119®11 r;~~a STORMWATER RESLIRMITTAI Fnla ~Ir°nFNi~fn?nrr~ rr:Rni inonw®rc~ ci ~verinnn
lux I
o i BOTTOM PLATE MELDED TO CMP / I_ _ _ _ _ _ POND BOTTOM o AINTEN NCE ACCLE S DITCH MATTED WITH 4 2/25111 CRM STORMWATER RESUBMITTAL FOR NCDENR/DWQ (FEB. 9, 2011 COMMENTS)
L REINFORCED DIVERSION 4 g RIPRAP MERGENCY OVERFLOW RIGHT-OF WAY N.A.G. P550 OR 3 1111/11 RHH STORMWATER RESUBMITTAL FOR NCDENR/DWQ ,
g (SEE DETAIL, SHEET o 509) t t I APPROVED EQUAL
~ 1 t ~ ~ I1 ~ v EA.- SUBMERGED ORIFICE OUTLET CONFIGURATION - BASIN 3 43 11/16/10 RHH STORMWATER SUBMITTAL FOR NCDENRIDWQ
1 11/$110 RHH REVISED ROAD WIDTH AND SEDIMENT BASIN GRADING ~ + NO. DATE BY REVISION DESCRIPTION
0 SCALE, - U- I NOT TO SCALE 1 1 \ \ 1
~ 1 t L7