GEOTECHNICAL ENGINEERING STUDY - Rockville, Maryland

GEOTECHNICAL ENGINEERING

STUDY

Horizon Hill

Stormwater Management Facilities

City of Rockville, Maryland

PREPARED FOR:

CITY OF ROCKVILLE

PREPARED BY:

CENTURY ENGINEERING, INC.

10710 GILROY ROAD

HUNT VALLEY, MARYLAND 21031

December, 2012

CEI No. 028093.06

December 11, 2012 City of Rockville Department of Public Works 111 Maryland Avenue Rockville, Maryland 20850-2364 Attn: Mr. John Scabis, P.E. Re: Horizon Hill Stormwater Management Facilities City of Rockville, Maryland CEI Project No. 028093.06 Dear Mr. Scabis: Century Engineering, Inc. has completed the geotechnical investigation for the proposed stormwater

management facility retrofits at the above-referenced project. The scope of the investigation

included drilling standard penetration test borings, evaluating the subsurface conditions, soils

laboratory testing, and preparing a report. This report includes a summary of our findings and

recommendations for the design of the stormwater management (SWM) facility retrofits.

PROJECT DESCRIPTION: The project site is located at the Horizon Hill subdivision in the City of

Rockville, as indicated on Figure No. 1 “Vicinity Map,” in the Appendix. The site consists of three

SWM facilities that were constructed in the 1970’s in the Horizon Hill Park Stream Valley. The

existing SWM facilities are dry, extended detention ponds, with some base flow from the original

stream. The SWM facilities receive storm drainage runoff from the surrounding Horizon Hill

development, and the stormwater is released to Watts Branch downstream.

The project consists of environmental improvements to these SWM facilities with the objectives of

restoration and protection of the stream valley, improvements in water quality and stormwater

management to current design standards, repair and prevention of erosion, and protection of park

improvements, natural areas, and private property. The project includes “retrofitting” or conversion

of the lower and upper SWM ponds to wet ponds with permanent water surface elevations.

We understand that several alternatives for SWM pond retrofitting were considered and that the

option selected for meeting the objectives of the project is conversion of the lower pond (Sunrise

Horizon Hills December 11, 2012 Stormwater Management Facilities Page 2 of 8 CEI No. 028093.06

Pond) and the upper pond (Longhill Pond) to provide the maximum stormwater storage capacity

without the use of retaining walls. The Sunrise and Longhill Ponds will be converted from dry

extended detention facilities to wet extended detention facilities.

The Sunrise Pond will be lowered to establish a bottom of pond at El. 301.0, with a normal pool

water surface at El. 309.0. The wet pond conversion includes construction of a forebay with a

bottom at El. 303.0 The Longhill Pond will be lowered to establish a bottom of pond at El. 359.0,

with a normal pool water surface at El. 367.0. The wet pond conversion includes construction of a

forebay with a bottom at El. 363.0. The facility conversions will be constructed primarily by

excavation and will require placement of some embankment fill.

AREA GEOLOGY: The site is located in the Eastern Piedmont physiographic province where

bedrock generally consists of schist, gneiss, gabbro, and other highly metamorphosed sedimentary

and igneous rocks. The Geologic Map of Maryland (1968) shows that bedrock in the area of the

project site is characterized as Upper Pelitic Schist of Upper Cambrian to Lower Ordovician age.

The rock generally consists of coarse to medium grained albite-chlorite-muscovite-quartz schist with

sporadic thin beds of laminated micaceous quartzite. The natural soils are residual soils that have

been derived from the weathering and decomposition of the bedrock and typically consist of

micaceous silts.

The USDA-NRCS National Cooperative Soil Survey (http://websoilsurvey.nrcs.usda.gov) of

Montgomery County, Maryland (Version 7, February 2, 2007) shows that the project site is located in

an area inclusive of the following soils: Baile silt loam, Wheaton-Urban Land Complex, and

Brinklow-Blocktown channery silt loam. The predominant Baile silt loam is characterized as a poorly

drained soil, with the groundwater table at very shallow depths, and meeting hydrologic soil group D.

These soils meet USCS classifications of MH, ML, CL, SC, and SM. The Wheaton-Urban Land

Complex soils generally consist of well drained silt loam soils meeting USCS classifications of CL,

CL-ML, GC, and GC-GM, and hydrologic soil group B. The Brinklow-Blocktown channery silt loam

soils generally consist of well-drained silt loam soils, with shallow depth to bedrock, and meeting the

USCS classifications of ML, CL, CL-ML, GM, GC, and GC-GM, and hydrologic soil group B.

SOIL BORINGS: To determine the general subsurface conditions, Connelly & Associates, Inc.

drilled eight (8) test borings to depths ranging from 10.0-ft. to 21.5-ft. below the existing ground

surface, with a track-mounted Acker Soil Scout drilling rig. One of the test borings was drilled at the

http://websoilsurvey.nrcs.usda.gov/


Sunrise Pond embankment, and one of the test borings was drilled at the Longhill Pond

embankment. The remainder of the test borings were drilled at areas of proposed SWM pond

excavation. Century marked the boring locations in the field, and we estimated the ground surface

elevations at the boring locations. We were prepared to perform borehole infiltration tests at both of

the pond locations, but the tests could not be conducted due to shallow groundwater levels.

The test borings locations are shown on Figures No. 2a and 2b, “Boring Location Plan,” in the

Appendix. The borings were advanced with hollow-stem augers, and soil samples were obtained at

various intervals by driving a split-spoon sampler in accordance with the Standard Penetration Test

(SPT) ASTM D-1586. The soil samples were visually inspected and classified in the field, and

representative samples were selected for laboratory testing. Auger refusal materials (rock) were

encountered in two of the test borings, and very dense weathered rock materials were encountered

within the depths of most of the test borings.

The borings were left open for groundwater level readings and were backfilled after completion of

24-hr. water level readings. As requested, the SWM pond embankment borings were sealed

immediately using bentonite upon completion of the borings. We estimated the ground surface

elevations at the boring locations from the existing topography shown on the plan. The test boring

logs are included in the Appendix. Also included is a reference sheet which defines the terms and

symbols used on the test boring logs and explains the Standard Penetration Test procedure.

LABORATORY TESTING: In the soils testing laboratory, selected soil samples were tested for

moisture content (ASTM D 2216), and particle size distribution (ASTM D 422). The USCS soil

classification was determined for representative soil samples. Any field classifications recorded on

the test boring logs were revised as necessary. The natural moisture content was determined to

range from approximately 4.4 percent to 35.4 percent for selected soil samples. The laboratory test

results are included in the Appendix.

SUBSURFACE CONDITIONS: At the ground surface, all of the test borings encountered topsoil

ranging from 1-in. to 8-in. in thickness. The subsurface materials encountered in the test borings

can be classified using five general descriptions: recent sediments, embankment fill, residual soils,

weathered rock and rock. The subsurface conditions encountered at the test borings are indicated

on Figures No. 3a and 3b, “Generalized Subsurface Profile,” along with an approximation of the

existing and proposed finished grades, included in the Appendix.


Residual soils were encountered at all of the test boring locations, and have been derived in place

from the weathering of parent rock materials. Residual soil is typically defined as soil material

exhibiting a SPT N-value up to 60 blows/foot.

Weathered rock consists of rock that has been significantly weathered, but has not decomposed into

a material that behaves like a soil. Most of the test borings encountered weathered rock. For

purposes of evaluation for this project, weathered rock is defined as material containing a relic rock

structure and exhibiting a SPT N-value between 60 blows per foot and 50 blows per 1-inch of

penetration.

The upper surface of rock, or bedrock, is defined as material with a SPT N-value greater than 50

blows per 1-inch of penetration (or less penetration). Rock is also defined as material that

conventional augers cannot cut through, and is typically noted as “auger refusal” on the test boring

logs. Auger refusal materials typically consist of bedrock, large cobbles, or boulders that cannot be

penetrated with soil drilling equipment. Auger refusal materials were encountered within the depths

of one test boring at each pond location.

At the Sunrise SWM facility the test borings in the pond area encountered recent sediments

consisting of soft to stiff, Silty CLAY (CL) and Sandy SILT (ML), and very loose to loose, Silty SAND

(SM), to depths ranging from 3 ft. to 5 ft. below the existing ground surface. The test boring in the

Sunrise SWM pond embankment encountered fill materials consisting of stiff SILT and Sandy SILT

(ML) (FILL), with pockets of Silty CLAY (CL) to a depth of 13.5 ft. below the top of the embankment.

These embankment fill materials have SPT N-values ranging from 6 bpf to 14 bpf and appear to

meet SWM pond embankment requirements.

At the Sunrise Pond test borings the materials underlying the recent sediments and embankment fill

materials are natural residual soils generally consisting of medium dense, Sandy micaceous SILT

(ML). The residual soils encountered in the test borings extended to depths of about 7 ft. to 15 ft. or

more, below the existing ground surface. Underlying the residual soils, most of the test borings

encountered very dense weathered ROCK that extended to the termination depth of the boring. Test

boring B-4 encountered auger refusal at a depth of 10 ft.


At the Longhill SWM facility the test borings in the pond area encountered residual soils consisting of

stiff to hard, fine Sandy SILT (ML), with trace rock fragments, to depths of 2.5 ft. to 4.5 ft. below the

existing ground surface. Underlying the residual soils, the test borings encountered very dense

weathered ROCK that extended to the termination depths of the borings. Test boring B-7

encountered auger refusal on very dense ROCK at a depth of 10 ft.

The test boring in the Longhill SWM pond embankment encountered fill materials consisting of

medium stiff SILT (ML) (FILL), with pockets of Silty CLAY (CL) to a depth of 14.5 ft. below the top of

the embankment. These embankment fill materials have SPT N-values ranging from 8 bpf to 13 bpf

and appear to meet SWM pond embankment requirements. The materials underlying the

embankment fill materials are natural residual soils consisting of stiff, Sandy micaceous SILT (ML),

to a depth of 17 ft. below the top of embankment, and very dense weathered ROCK that extended to

the termination depth of the boring at 18.9 ft.

Groundwater was encountered in the SWM pond area test borings, and was subsequently noted at

depths ranging from 1.6-ft. to 5.9-ft. below the existing ground surface. Groundwater was not

encountered in the SWM embankment borings. The borings were monitored for groundwater levels

at completion, and at a 24-hr. interval prior to backfilling. If present, static groundwater levels were

noted on the test boring logs at completion and before backfilling. Otherwise, the depth of

groundwater on the test boring log is noted as “dry”.

Due to the shallow groundwater levels it was not feasible to perform the proposed borehole

infiltration testing at test borings B-3 and B-7. Additional groundwater level measurements were

recovered at the Sunrise and Longhill pond area borings. Temporary piezometer tubes were

installed and 48-hr. groundwater levels were recorded as indicated in the following table:

Table 1 – Additional Groundwater Readings (12-04-2012)

The actual level of the hydrostatic water table and the amount and level of perched water should be

Test Boring

Groundwater Depth (ft.)

Groundwater Elevation (ft.)

Sunrise Pond B-3 2.8 307.2 B-4 3.3 310.5

Longhill Pond B-7 1.7 362.8 B-8 1.5 364.7


anticipated to fluctuate throughout the year, depending upon variations in precipitation, stream flow,

surface run-off, infiltration, site topography, and drainage.

SWM FACILITY RECOMMENDATIONS:

The following recommendations have been developed on the basis of the previously described

project characteristics and subsurface conditions. We understand that the SWM retrofit design is at

60 percent completion. If there are any significant changes to the project characteristics or if

significantly different subsurface conditions are encountered during construction, Century should be

consulted so that the recommendations of this report can be reviewed, and revised as necessary.

It is important to note that the groundwater levels observed in most of the SWM pond area test

borings are above the proposed bottom elevation of the SWM facilities. It is likely that shallow

groundwater conditions will present issues for SWM facility construction as planned. Stream flow

diversion, proper groundwater control, and dewatering will be required for construction of the

proposed SWM pond conversions. It is anticipated that groundwater encountered during excavation

for SWM construction can be controlled by ditching and pumping from sumps. If excessive

groundwater flows are encountered during excavation, it may be necessary to provide wellpoints for

dewatering and to maintain dry excavations. The construction documents should include provisions

for stream flow diversion, dewatering of excavations, and groundwater control.

Existing utilities in the area of the proposed construction include buried sanitary and storm drain

systems. It is possible that other underground utilities are located in the vicinity of proposed

construction. It is important that the type and location of all utilities in the areas of proposed

construction be determined early in the project design phase and prior to construction.

Stormwater management embankments that impound water should be designed and constructed in

accordance with the USDA NRCS Maryland Standard Pond Code 378, with the exception that the

embankment material shall consist of Unified Soil Classification soil types GC, SC, ML, MH, CL, or

CH, or a combination of these groups free of rock or gravel larger than 4 inches in any dimension. It

appears that most of the excavated materials from the proposed pond grading will meet the

requirements for embankment fill materials. Moisture conditioning (drying) will be required for proper

compaction of the embankment fill.


The proposed SWM facility construction will require excavations to depths approaching 11-ft. at

Sunrise Pond and 6-ft. at Longhill Pond, and embankment fill heights up to about 4-ft. Dewatering of

excavations will be required at most locations. The SWM facility side slopes and embankments

should be constructed with slope ratios of 3(H):1(V), or flatter, interior and exterior.

The proposed pond excavations will require removal of very dense weathered rock materials. It

appears that the most of the weathered rock can be removed using heavy excavation equipment

with rock ripping attachments. Refusal materials described as rock were encountered in some of the

test borings. Rock may possibly be encountered within the anticipated depths of excavation for the

proposed SWM construction. If rock is encountered during construction, the material should be

removed using large excavators with reinforced buckets, hydraulic hoe ram equipment, or

jackhammers. The use of explosives for rock blasting should not be permitted. We recommend that

the project specifications include provisions for rock excavation, and that the contract include a

contingency for rock excavation. Otherwise, the contract may define excavation as “unclassified”

and require that the proposed excavations be completed to design grade regardless of the type of

materials encountered.

The proposed SWM ponds will be converted from dry ponds to wet ponds. This may present

potential seepage issues for the existing SWM pond embankments. It is our professional opinion

that the proposed SWM facilities should be lined with a natural clay liner along the upstream portion

of the existing SWM pond embankment. The liner should extend for the full width of the

embankment along the 10-year water surface elevation down to the bottom of pond elevation. At the

bottom of pond, a clay liner cutoff trench should be constructed along the toe of slope for the full

width of the pond bottom. The natural clay liner should be a minimum thickness of 2 ft. and should

terminate in the cutoff trench. The cutoff trench should extend to a depth of 4 ft. minimum below the

bottom of pond. The cutoff trench should have a minimum bottom width of 4 ft., and should have

side slopes no steeper than 1(H):1(V). The material for the liner and cutoff trench should consist of

Unified Soil Classification soil type CL. Offsite borrow material will be required.

An alternative method of seepage control is a flexible synthetic liner such as PVC or LDPE, placed in

accordance with MDE requirements. Typically, SWM facilities are limited to 4(H):1(V) interior slopes

(or flatter) where synthetic liners will be used. The proposed materials and sources of material for all

SWM pond construction should be submitted to the design engineer for review and approval.


All fill materials to be utilized as stormwater management facility embankment and liner should be

placed in 8-inch thick layers and should be compacted to at least 95 percent of Standard Proctor

(AASHTO T-99) maximum dry density at ± 2% optimum moisture content. A sufficient number of in-

place density tests should be performed by an Engineering Technician on a full-time basis to verify

that the proper degree of compaction is being obtained for all embankment fill, backfill, and natural

clay liner. Where fill materials are placed upon existing slopes or embankments, the slope shall be

continuously benched as the fill material is placed and compacted in horizontal layers. The bench

shall consist of a horizontal cut with a minimum bench width of 5 ft. Where a natural clay liner is to

be installed, the slope shall be benched as needed to ensure a minimum clay liner thickness of 2 ft.

As-built certification of the proposed stormwater management facilities is required. This requires

construction inspection and surveys under the direction of a registered professional engineer. The

engineer will certify that the facilities are constructed in accordance with the as-built plans and that

the facilities meet the design specifications. An Engineering Technician should be on-site during

construction to provide the required as-built inspection and testing services. Century Engineering,

Inc. should be retained to perform the construction inspection and surveys required for as-built

certification of the stormwater management facility.

Century Engineering appreciates having had the opportunity to provide geotechnical consultation for

this project. We will remain available to answer any questions related to this study, and to provide

the additional services recommended in this report. If you have any questions or should you require

additional consultation, please contact me at 443-589-2400 (ext. 1154).

Very truly yours, CENTURY ENGINEERING, INC.

James Jay Burtis III, P.E. Sr. Geotechnical Engineer Geotechnical Division

Appendix

DRAWN BY: APPROVED BY: SCALE: DATE:

VICINITY MAP

NTS

10710 Gilroy RoadHunt Valley, Maryland 21031

1

Horizon Hill SWM Facilities

City of Rockville

VICINITY MAP

NTSphone: 443-589-2400 fax: 443-589-2401

FIGURE No.:

12/7/2012PROJECT No.

028093.06JJB

NORTH

Project Site

18"

RC

P

18"

RCP

12"

PVC

310

315

310

315

308

305

315

TO

P

OF

EM

BA

NK

ME

NT= 317.6

305

308

305

305

301

301

305

310

311

301

3053

09310

315

317

317

310

315

317

315

320

305.04

305.00

S

S

INV 18" RCP=307.43

INV 18" RCP=314.34

INV.=305.04

48" CMPINV.=305.00

306.89

306.42

309.01

309.61

314.20

316.36

311.14

309.57

319.67

310.15308.7

1

318.46

RIP

RA

P

TOP RISER=314.25

TOP RISER=314.13

INV 18"CMP=304.92

THALWEG

THALWEG WOODEN SIDEWALK

WOODEN SIDEWALK

WOODSLINE

MAC SIDEWALK

WOOD FENCE

WOOD FENCE

X-SECTION REBAR

X-SECTION REBAR

TOP RIM=317.01

INV A OUT =302.46

INV B IN=302.48

INV C IN=302.48

A

C

B

E 1,2

60,1

00

N 511,500

305.8

0305.7

7

306.1

0

306.6

8

306.9

0

307.6

8

308.2

5

TOP BANK

TOP BANK

TOE

TOP BANK

TOE

TOP BANK

TOE

TOE

TOE

ELEV=305.94

ELEV=305.54

314.79

316.54315.39313.67

313.01

S

MAC.SIDEWALK

TOP OF WEIR=312.69

TOP OF WEIR=312.53

314.95316.22

316.41317.47

S

314.60

315.32

317.80

321.0

321.1

S

MAC. SIDEWALK

INV=317.10

27"RCP

A

BC

TOP RIM=330.83

INV A=318.99

INV B=319.15

INV C=319.03

8"

6"

6"

6"

8"

8"

6"

TOP RIM=319.49

INV A=311.27

INV B=311.39

INV C=311.45

AC

B

TOP RIM=314.17

INV A=304.14

INV B=304.52

INV C=304.25

AC

B

324

315

320

325

332

320

315

323

320

315

315

320

325

320

315

322

320

315310

315

310

310

315

302

307

324

325

320

313

312

311

311

312

313

314

314

310

315

320

THALWEG

THALWEG

X-SECTION REBARELEV=311.42

X-SECTION REBARELEV=310.58

TOP BANK

TOE

TOP BANK

TOE

TOP BANK

TOE

54" CMP

325.4

326.7

320.8

320.3

321.7

WOODS

LIMIT OF STONE

327.2

D

D

D

D

327.0

326.0

325.63

24.8

4' SPLIT-

RAIL FENCE

INV. 27"RCP=321.96

SDMH

TOP=330.54

REBAR & CAP

HFSO PLS 30

INV. 18"RCP=318.43

SDMH

TOP RIM=323.65

TOP RIM=316.95

INV 18"RCP A=309.57

INV 18"RCP B=309.82

A

B

SDMH

18"R

CP

TOP RIM=330.27

INV 18"RCP=321.40

SDMH

S

B

A

B

A TOP RIM=323.38

INV A IN =313.88

INV B OUT=313.78

TOP RIM=317.39

INV A IN =306.24

INV B OUT=306.14

15"R

CP

18"R

CP

RIPRAP

319.9

MAC

SD

WK

316.8

316.6

317.0

317.2

14"

14"18"

6"12"

60"

10"6"

12"

12"12"

14"

8"

8"

10"

14"

24"

18"

6"

24"

24"

16"

24"

15"

12"

12"

8" 15"

14"

12"

8"

8"15"

14"

24"

18"

26"6"

8"

6"

6"

30"

6"

12"

10"30"

30" 30"

20"

24"

24"30"

28"

310

315

320

320

315

310

305

305

TB

TOE

TOE

TB

10

13

15 8

6

18 17

1014

12

1811

8

8

6

8

19

8

9

1020

16

12

9

6

10

8

7

6

18

10

410

62

34 5 4

3 2

11 2

812

15

33

33

3

3

24

3

10

3

5

2 16 614

3

16513

18

1820

18

14

27

1420

1012

32

30

32

32

36

6

7

34

29

19

18

7

11

101812

0

14

15

122123

9

11108

10

19

20

23

1415

813

6

12

28

11

20

811

28

4

9

15

14

5

15

14613

12 12 12 12

18

10

11

6

24

30

22

23

22

16

18

11

18

24

40

35

10

61412

15

13

2

2

2

12

2

12

12

12

22

18

5

22

18

18

14

6

136

18

6

10

13

24

20

8

6

18

8

10

14

88

8

206

12

6

1216

18

712

14

188

11

2020

20

85

14

2024

2213

12

12

8

23

11

8

3

14005 N COMMONS WAY

Name: VAEZ-GHAEMI, REZA & S

POOL

S&W

SWM

NO.JOB NO.

DATE

CHIEF INSPECTOR

DATE

AS BUILT COMPLETED

DEPT.. W/R 9 FORM

DATE TRANS. TO FINANCE

DATE ACCEPTED BY CITY

DATE PROJECT COMPLETED

DATE PROJECT STARTED

OTHER

SD

PAV.

GRAD.

DIRECTOR OF PUBLIC WORKS

DATE

APPROVED

CHECKED

DRAFTED

DESIGNED SCALE DRAWING FILE

OF

REVISIONSNO. APP'D DATE

LEGEND

30' 30'0 60'

SCALE: 1"=30'

N

BORING REQUEST

AND STREAM RESTORATION

HORIZON HILL SWM RETROFITS

14002 N COMMONS WAY

Name: GAYNOR, MITCHELL M & R S

14004 N COMMONS WAY

Name: GOETZ, LAURA D & CHARLES J 3RD

1901 SUNRISE DR

Name: ZAPPALA, FRANCESCO M & J G

1903 SUNRISE DR

Name: SHEINTAL, AMI & N A

1905 SUNRISE DR

Name: COHEN, ROBERT P & L R

1907 SUNRISE DR

Name: FREDD, STEPHEN B & G E

1909 SUNRISE DR

Name: SIEGEL, JAMES R & L S

1911 SUNRISE DR

Name: ASLAN, IRENE

1913 SUNRISE DR

Name: SEGOVIA, MIGUEL A & E

1918 S FALLSMEAD WAY

Name: LACY, ANGELA Y


Name: BISBEY, SAMUEL & JYOTI


Name: CHAO, WILLIAM & HIEU

18 STARLIGHT CT

Name: TATE, HOWARD E & A

17 STARLIGHT CT

Name: SOW, CHEIKH TIDIANE &

16 STARLIGHT CT

Name: HERTZ, MICHAEL &

15 STARLIGHT CT

Name: GUTMAN, GEORGE G & G E S

EXISTING MINOR CONTOUR

EXISTING MAJOR CONTOUR

PROPOSED MINOR CONTOUR

PROPOSED MAJOR CONTOUR

EXISTING SANITARY LINE

3:1

X 314.0

BORING NO. DEPTH (FT.) NORTHING EASTING

BORING REQUEST

B-1 511421.381259884.8010.0'

B-2 511275.821259875.2622.0'

B-3 511304.421260034.2215.0'

B-4 511340.191260188.7716.0'

B-5 511394.781260435.3010.0'

B-1

B-2

B-3

B-4

B-5

PROPOSED BORING LOCATION

EXISTING EL.

319.2

316.4

310.0

313.8

316.3

1911 SUNRISE DR

Name: ASLAN, IRENE

1913 SUNRISE DR

Name: SEGOVIA, MIGUEL A & E

1909 SUNRISE DR

Name: SIEGEL, JAMES R & L S 1907 SUNRISE DR

Name: FREDD, STEPHEN B & G E

1905 SUNRISE DR

Name: COHEN, ROBERT P & L R

1903 SUNRISE DR

Name: SHEINTAL, AMI & N A

1901 SUNRISE DR

Name: ZAPPALA, FRANCESCO M & J G

14002 N COMMONS WAY

Name: GAYNOR, MITCHELL M & R S

14004 N COMMONS WAY

Name: GOETZ, LAURA D & CHARLES J 3RD


Name: LACY, ANGELA Y


Name: BISBEY, SAMUEL & JYOTI


Name: CHAO, WILLIAM & HIEU

18 STARLIGHT CT

Name: TATE, HOWARD E & A

17 STARLIGHT CT

Name: SOW, CHEIKH TIDIANE &

16 STARLIGHT CT

Name: HERTZ, MICHAEL &

15 STARLIGHT CT

Name: GUTMAN, GEORGE G & G E S

SITE HERE

ACCESS PROJECT

*AN INFILTRATION TEST WILL BE CONDUCTED NEAR BORING B-3.

*

SUNRISE DRIVE

WAY

COMMONS

NORTH

ACCESS PATH

FOR CITY UTILITY MARKINGS.

240-314-8567 A MINIMUM OF 48 HOURS PRIOR TO PERFORMING THE BORINGS

CENTURY ENGINEERING INC. MUST CONTACT THE CITY OF ROCKVILLE AT

IMPACTS TO PARK AND FORESTED AREAS SHALL BE MINIMIZED.

ALL TERRAIN VEHICLE. IMPACTS TO THE EXISTING PATH WILL BE AVOIDED.

PROPOSED BORING LOCATIONS SHALL BE ACCESSED WITH LOW IMPACT,

NOTES:

314.0

313.5

310.5

314.5

312.5

313.0

315.0

315.0

312.0

0+00

1+00

2+00

MARYLAND AT VINSON ROCKVILLE, MARYLAND

DEPARTMENT OF PUBLIC WORKS

CITY OF

ROCKVILLE

jburtis

Text Box

Figure No. 2a Boring Location Plan

359360

365

368

369

359

365

368

369

363

365

368

369

B

RIPRAP

CONC SIDEWALK

INV 15"R

CP=363.9

5

INV=365.4

6

MA

C

PA

TH

54"CMP

54"CMP

54"CMP

T/PIPE=366.65

X

XX

X

WO

OD FE

NCE

TOP RIM

=375.4

6

INV B

OU

T=366.14

INV

A IN

=368.5

0

INV=364.8

4

MA

CA

DA

M P

ATH

GRASS

GA

BIO

N

GRASSPLANTER

DIR

ON

LY

36"

X

X

6'

PRIV

AC

Y

INV.

15"=380.6

6

SD

MH

TOP=384.0

6

C

WEIR ELE

V.=

383.18

4'

SPLIT R

AIL

FE

NCE

FE

NCE

4'

PIC

KET

FE

NCE

6'

PRIV

AC

Y

FE

NCE

6'

PRIV

AC

Y

FE

NCE

PLA

NTER

META

LS

WIN

GSET

MAC.P

ATH

PO

OL

FIL

TER

PO

OL

WIT

H

CO

NC.

PA

TIO

381.3

8

A

B

36"

GR

ASS

TOP RIM

=373.5

8

INV

A IN

=362.3

9

INV B

OU

T=362.13

B

DIR

ON

LY

BC

@TH

RO

AT=374.4

8

X

XBIR

DH

OUSE

30" R

CP

INV=74.6

7

HE

AD

WA

LL

MAC

PATH

PR

OPERTY

OW

NER

REFUSE

D

AC

CESS

10/12/09

BR

US

H

CO

NC.

24"

RC

P

RIM

=378.3

7

15"

GUTTER

HILLDRIVE

BC

@TH

RO

AT=374.6

0

TOP RIM

=372.5

3

AB

BC

@TH

RO

AT=371.5

9

BC

@TH

RO

AT=371.7

3

INV 15"R

CP

A=367.0

9

INV 15"R

CP B=365.2

7

373

373

370

385

385

381

385

380.2

383

390

385

380380

375

375375

380

380

375

380

365

365

375

370

365

365

365

RIPRAP

L

X

STONE LINEDDITCH

STO

NE LIN

ED

DIT

CH

375

INV 15"R

CP

A=371.3

2

INV 15"R

CP B=370.3

1

AB

DIR

ON

LY

24"

14

18

16

6

8

10

6

8

78

8

20 10

612

18

14

12

8

6

16

18

18

24

20

24

8

8

30

14

16

16

919

719

4

12

36

6

8 5

12

2

10

10

7

8

11

10

66

14

97

10

5

9

12

25

8

8

6

17

18

10

24

30

28

10

7

712

10

8

12

8

8

12

12

16

9

8

6

8

11

10 8

89

9 11

7

76

8

38

8

8124

13

7

32

8

6

3

8

912

9

8

8

20

10

1212

8

5 6 6 8 8 8 5

8

1210

8

12

61112

8 636

8

11

1505 W K

ERSE

Y L

ANE

Name: NIK

AK

HTAR, N

ASER &

PO

OL

#2 IN

V=361.4

4

#1 IN

V=361.5

3

#3 IN

V=361.3

9

TO

E

TO

E

TO

E

TO

E

TOP B

AN

K

TOP B

AN

K

TOP B

AN

K

TOP RIS

ER

A=370.8

3

TOP RIS

ER B=370.8

1

TOP RIS

ER C=370.7

5TOP

OF

WEIR

A=368.8

8

TOP

OF

WEIR B=368.7

4

TOP

OF

WEIR C=368.6

0

T/PIPE=366.72

362.54

T/PIPE=366.64

CA

366.6

8

366.7

0

368.8

9

368.9

0370.5

0

370.6

7

370.9

1

370.9

9371.0

5

D

A

S

WO

OD RETAININ

G

WA

LL

374.3

5

D

D

378.9

0379.5

5

379.8

1

381.0

5381.8

4381.9

1

382.7

5

383.4

0

D

S&W

SWM

NO.JOB NO.

DATE

CHIEF INSPECTOR

DATE

AS BUILT COMPLETED

DEPT.. W/R 9 FORM

DATE TRANS. TO FINANCE

DATE ACCEPTED BY CITY

DATE PROJECT COMPLETED

DATE PROJECT STARTED

OTHER

SD

PAV.

GRAD.

DIRECTOR OF PUBLIC WORKS

DATE

APPROVED

CHECKED

DRAFTED

DESIGNED SCALE DRAWING FILE

OF

REVISIONSNO. APP'D DATE

19.0'

12.0'

11.0'

BORING NO. DEPTH (FT.) NORTHING EASTING

BORING REQUEST

B-6 510891.261262495.35

B-7 510768.991262562.40

B-8 510669.201262635.85

EXISTING EL.

373.0

364.5

366.2

N

1721 GLA

STO

NBERR

Y R

OAD

Nam

e: DJA

VANSHIR, G

HOLA

M &

1719 GLA

STO

NBERR

Y R

OAD

Nam

e: HSIA

O, H

UM

G-Y

U &

1717 GLA

STO

NBERR

Y R

OAD

Nam

e: AH

ADPO

UR, B

EH

DO

KHT F

1715 GLA

STO

NBERR

Y R

OAD

Nam

e: RH

ODES, D

AVID M & A

MY G

1713 GLA

STO

NBERR

Y R

OAD

Nam

e: LOR

D, B

YR

ON N & R K

1711 GLA

STO

NBERR

Y R

OAD

Nam

e: HO

NG, H

AE Y & W

1707 GLA

STO

NBERR

Y R

OAD

Nam

e: RO

NTA

L, HO

WAR

D & M

ARCELLE J E

T AL

5 RIC

HVIE

W C

T

Nam

e: SULLIV

AN, C

ATH

ERIN

E M

6 RIC

HVIE

W C

T

Nam

e: LAPKOFF, C

LIFFOR

D H

4 RIC

HVIE

W C

T

Nam

e: LEWIS, P

EER

Y B JR & C

ECILIA R

3 RIC

HVIE

W C

T

Nam

e: MUZZY, R

OBERT L &

M M

2 RIC

HVIE

W C

T

Nam

e: KIM, P

AUL S

UN

GH

WAN

1 RIC

HVIE

W C

T

Nam

e: DIN

MAN, JO

NATH

AN D &

BORING REQUEST

AND STREAM RESTORATION

HORIZON HILL SWM RETROFITS

EXISTING MINOR CONTOUR

EXISTING MAJOR CONTOUR

PROPOSED MINOR CONTOUR

PROPOSED MAJOR CONTOUR

EXISTING SANITARY LINE

LEGEND

PROPOSED BORING LOCATION

B-7B-8

*INFILTRATION TEST TO BE CONDUCTED NEAR BORING B-7.

*

SITE HERE

ACCESS PROJECT

LONGHILL DRIVE

ACCESS PATH

GLASTONBERRY ROAD

FOR CITY UTILITY MARKINGS.

240-314-8567 A MINIMUM OF 48 HOURS PRIOR TO PERFORMING THE BORINGS

CENTURY ENGINEERING INC. MUST CONTACT THE CITY OF ROCKVILLE AT

IMPACTS TO PARK AND FORESTED AREAS SHALL BE MINIMIZED.

ALL TERRAIN VEHICLE. IMPACTS TO THE EXISTING PATH WILL BE AVOIDED.

PROPOSED BORING LOCATIONS SHALL BE ACCESSED WITH LOW IMPACT,

NOTES:

30'

SCALE: 1"=30'

0 30' 60'

B-6

MARYLAND AT VINSON ROCKVILLE, MARYLAND

DEPARTMENT OF PUBLIC WORKS

CITY OF

ROCKVILLE

jburtis

Text Box

Figure No. 2b Boring Location Plan

319.10.1

316.23.0

311.28.0

309.210.0

0.01.5

2.54.0

5.06.5

8.510.0

S-1

S-2

S-3

S-4

14"

14"

18"

12"

13-4

57-7

68-5

1217-13

1" Topsoil

Reddish-Brown, moist, medium stiff to stiff, Silty CLAY, tr. f-mRock Fragments (Residual) (CL)

Reddish-Brown to Orange-Brown, moist, stiff, fine Sandy,micaceous SILT (w/pockets of Silty Clay) (Residual) (ML)

Olive-Brown, moist, medium dense, micaceous SILT, little f-mSand (Residual) (ML)

Bottom of Test Boring at 10.0 Ft.

Note: Boring backfilled after 24 hr. groundwater levelmeasurement.

Hammer Fall:

Size I.D.:

Hammer Wt.:

028093.06

DATE STARTENDDRILLER

S NORTHINGEASTING

None

Dry

Dry

-----

-----

-----

Time Water Casing Hole Type: :::::::

ELEVATION2.25"

10-22-12----

10-22-12

10-22-12

10-23-12

Date

CONTRACT NO.SHEET NO.

INSPECTOR

-----

5.0

5.0 ----

Enc.

Compl.

24 hr.

-----

10-22-12

T. Redman

:1 of 1:

1-3/8"

-----

-----

140 lb.

30 in.

-----

GROUNDWATER DEPTH (ft) OF: EQUIPMENT CASING SAMPLER CORE

319.2

HSA

C. Jacobs

Per 6"(RQD%)

SampleNumberType

SampleDepthRange(ft)

SampleRecov-ery

Elev-ation/Depth(ft)

FIELD CLASSIFICATION AND REMARKSDepthin

Feet

StrataChange

CaseBPF(Drill)(min/ft)

SamplerBlows

(in)

5

10

15

20

City of Rockville:CONTRACTOR

::

Hard

6-10

BORING

LooseVery Loose

DENSITYBLOWS/FT.

Nov 6, 12BORING

CLIENTPROJECT

4-5

CONSISTENCYBLOWS/FT.

Very Dense B-1

SAMPLE IDENTIFICATION

Very Stiff- See Remarks- W - Wash Sample

Dense

0-3

Horizon Hill SWM

- C - Diamond Core- U - Undisturbed Piston- T - Thin Wall Tube- S - Split Spoon

31+16-3011-15

Very Soft

51+31-5011-30 Medium Dense

Connelly & Associates, Inc.

StiffMedium Stiff

Soft

TEST BORING LOG

6-100-5

Samples:Rock:Overburden:

SUMMARY

B-1

316.10.3

310.46.0

306.99.5

302.913.5

301.914.5

300.915.5

294.921.5

0.01.5

2.54.0

5.06.5

8.510.0

11.012.5

13.515.0

16.016.3

18.518.9

20.021.5

S-1

S-2

S-3

S-4TS-4B

S-5

S-6TS-6B

S-7

S-8

S-9

18"

18"

18"

18"

18"

12"2 jars

NR

2"

18"

12-4

56-6

54-5

65-7

24-10

1713-7

50/3"

50/5"

2733-34

4" Topsoil

Reddish-Brown, moist, stiff SILT, little Sand, tr. fine RockFragments (FILL) (ML)

S-2: 81.7% finer than No. 200 Sieve

Lt. Brown / Orange-Brown, moist, stiff, fine Sandy micaceousSILT (w/pockets of Silty Clay) (FILL) (ML w/CL)

S-4: 81.3% finer than No. 200 Sieve.

Olive, moist, stiff SILT, little Sand, tr. f-m Gravel & Clay (FILL)(ML)

Brown/Gray, moist, dense, f-c Sandy Rock Fragments (Residual)(GM)

Reddish-Brown, moist, stiff, Clayey SILT (Residual) (ML)

Olive-Brown, fine Grained WEATHERED ROCK


Note: Boring sealed with 3/8" bentonite chips upon completion.

Hammer Fall:

Size I.D.:

Hammer Wt.:

028093.06


S NORTHINGEASTING

None

Dry

-----

-----

-----


ELEVATION3.25"

10-22-12----

10-22-12

10-22-12

Date


INSPECTOR

-----

Grouted

----

Enc.

Compl.

-----

10-22-12

T. Redman

:1 of 1:

1-3/8"

-----

-----

140 lb.

30 in.

-----


316.4

HSA

C. Jacobs

Per 6"(RQD%)

SampleNumberType


SampleRecov-ery



Feet

StrataChange


SamplerBlows

(in)

5

10

15

20


::

Hard

6-10

BORING

LooseVery Loose

DENSITYBLOWS/FT.

Nov 6, 12BORING

CLIENTPROJECT

4-5


Very Dense B-2



Dense

0-3

Horizon Hill SWM


31+16-3011-15

Very Soft



StiffMedium Stiff

Soft

TEST BORING LOG

6-100-5


SUMMARY

B-2

309.40.6

306.53.5

302.08.0

295.015.0

1.02.5

2.54.0

5.06.5

8.510.0

13.515.0

S-1

S-2

S-3

S-4

S-5

8"

18"

NR

18"

18"

12-3

32-1

11-2

76-14

914-16

7" Topsoil

Lt. Brown, very moist, medium stiff, Silty CLAY, tr. Roots andOrganics (CL)

Olive-Brown, moist to wet, soft to very soft, fine Sandy SILT, tr.Mica & Clay (Residual) (ML)

Olive Green & Brown, moist, medium dense, micaceous SILT,little f-m Sand (Residual) (ML)

S-4: 88.7% finer than No. 200 sieve.



Hammer Fall:

Size I.D.:

Hammer Wt.:

028093.06


S NORTHINGEASTING

7.5

5.0

3.3

-----

-----

-----


ELEVATION2.25"

10-22-12----

10-22-12

10-22-12

10-23-12

Date


INSPECTOR

-----

6.0

6.0 ----

Enc.

Compl.

24 hr.

-----

10-22-12

T. Redman

:1 of 1:

1-3/8"

-----

-----

140 lb.

30 in.

-----


310.0

HSA

C. Jacobs

Per 6"(RQD%)

SampleNumberType


SampleRecov-ery



Feet

StrataChange


SamplerBlows

(in)

5

10

15

20


::

Hard

6-10

BORING

LooseVery Loose

DENSITYBLOWS/FT.

Nov 6, 12BORING

CLIENTPROJECT

4-5


Very Dense B-3



Dense

0-3

Horizon Hill SWM


31+16-3011-15

Very Soft



StiffMedium Stiff

Soft

TEST BORING LOG

6-100-5


SUMMARY

B-3

313.20.6

310.33.5

308.85.0

306.37.5

303.810.0

0.01.5

2.54.0

5.06.5

8.58.7

S-1

S-2

S-3

S-4

18"

14"

8"

2"

22-2

22-1

510-16

50/2"

7" Topsoil

Lt. Brown / Reddish-Brown, very moist, soft, fine Sandy SILT(ML)

Med. Brown, very moist to wet, very loose, Silty Fine SAND(SM)

Orange-Brown, moist, medium dense, fine sandy micaceous SILT,tr. Decomposed Rock Fragments, Occasional QuartzFragments (Residual) (ML)

Olive-Brown/Green, fine grained micaceous WEATHEREDROCK

Bottom of Test Boring at 10.0 ft. Auger Refusal at 10.0 ft.


Hammer Fall:

Size I.D.:

Hammer Wt.:

028093.06


S NORTHINGEASTING

5.0

6.0

3.2

-----

-----

-----


ELEVATION2.25"

10-22-12----

10-22-12

10-22-12

10-23-12

Date


INSPECTOR

-----

7.0

5.0 ----

Enc.

Compl.

24 hr.

-----

10-22-12

T. Redman

:1 of 1:

1-3/8"

-----

-----

140 lb.

30 in.

-----


313.8

HSA

C. Jacobs

Per 6"(RQD%)

SampleNumberType


SampleRecov-ery



Feet

StrataChange


SamplerBlows

(in)

5

10

15

20


::

Hard

6-10

BORING

LooseVery Loose

DENSITYBLOWS/FT.

Nov 6, 12BORING

CLIENTPROJECT

4-5


Very Dense B-4



Dense

0-3

Horizon Hill SWM


31+16-3011-15

Very Soft



StiffMedium Stiff

Soft

TEST BORING LOG

6-100-5


SUMMARY

B-4

315.80.5

313.33.0

312.83.5

309.37.0

306.89.5

0.01.5

2.54.0

5.06.5

8.59.5

S-1

S-2TS-2B

S-3

S-4

14"

18"2 Jars

14"

12"

23-6

64-5

610-13

3650/6"

6" Topsoil

Reddish-Brown, moist, stiff, f-m Sandy Micaceous SILT, tr. f-mRock Fragments (ML)

Medium Brown, moist, loose, Silty Fine SAND (SM)

Olive-Brown & Green, moist, medium dense, f-m SandyMicaceous SILT (Residual) (ML)

Olive Green, f-m grained, Micaceous WEATHERED ROCK


Note: Hard augering from 7 ft. to 8.5 ft. Boring backfilled after24 hr. groundwater level measurement.

Hammer Fall:

Size I.D.:

Hammer Wt.:

028093.06


S NORTHINGEASTING

None

Dry

5.9

-----

-----

-----


ELEVATION2.25"

10-22-12----

10-22-12

10-22-12

10-23-12

Date


INSPECTOR

-----

6.0

5.9 ----

Enc.

Compl.

24 hr.

-----

10-22-12

T. Redman

:1 of 1:

1-3/8"

-----

-----

140 lb.

30 in.

-----


316.3

HSA

C. Jacobs

Per 6"(RQD%)

SampleNumberType


SampleRecov-ery



Feet

StrataChange


SamplerBlows

(in)

5

10

15

20


::

Hard

6-10

BORING

LooseVery Loose

DENSITYBLOWS/FT.

Nov 6, 12BORING

CLIENTPROJECT

4-5


Very Dense B-5



Dense

0-3

Horizon Hill SWM


31+16-3011-15

Very Soft



StiffMedium Stiff

Soft

TEST BORING LOG

6-100-5


SUMMARY

B-5

372.70.3

358.514.5

356.017.0

354.118.9

0.01.5

2.54.0

5.06.5

8.510.0

13.515.0

18.518.8

S-1

S-2

S-3

S-4

S-5

S-6

18"

18"

18"

16"

14"

4"

24-4

36-7

45-5

23-5

88-5

50/4"

3" Topsoil

Reddish-Brown / Med. Brown, moist, medium stiff SILT, somef-m Sand, tr. Clay & f-m Decomposed Rock Fragments(w/pockets of Silty Clay) (FILL) (ML)

S-4: 62.8% finer than No. 200 sieve.

Lt. Brown / Orange-Brown, moist, stiff, fine Sandy MicaceousSILT, tr. Decomposed Rock Fragments (Residual) (ML)

Lt. Brown, fine grained WEATHERED ROCK


Note: Boring sealed with 3/8" bentonite chips upon completion.

Hammer Fall:

Size I.D.:

Hammer Wt.:

028093.06


S NORTHINGEASTING

None

Dry

-----

-----

-----


ELEVATION3.25"

10-22-12----

10-22-12

10-22-12

Date


INSPECTOR

-----

17.0

----

Enc.

Compl.

-----

10-22-12

T. Redman

:1 of 1:

1-3/8"

-----

-----

140 lb.

30 in.

-----


373.0

HSA

C. Jacobs

Per 6"(RQD%)

SampleNumberType


SampleRecov-ery



Feet

StrataChange


SamplerBlows

(in)

5

10

15

20


::

Hard

6-10

BORING

LooseVery Loose

DENSITYBLOWS/FT.

Nov 6, 12BORING

CLIENTPROJECT

4-5


Very Dense B-6



Dense

0-3

Horizon Hill SWM


31+16-3011-15

Very Soft



StiffMedium Stiff

Soft

TEST BORING LOG

6-100-5


SUMMARY

B-6

364.00.5

363.51.0

360.04.5

355.59.0

354.510.0

0.01.5

2.54.0

5.05.8

8.58.8

10.010.0

S-1

S-2

S-3

S-4

S-5

18"

2"

8"

3"

0"

23-3

715-20

1650/4"

50/3"

50/0"

6" Topsoil

Lt. Brown, very moist, f-m Sandy SILT, tr. Decomposed RockFragments & Clay (Residual) (ML)

Olive to Light Brown, moist, hard, fine Sandy SILT, tr. f-c RockFragments (Residual) (ML)

Olive-Brown / Lt. Brown, fine grained WEATHERED ROCK

Lt. Gray, fine grained WEATHERED ROCK

Bottom of Test Boring at 10.0 ft. Auger Refusal at 10.0 ft.

Note: Hard augering from 5.5 ft. to 10.0 ft. Boring backfilledafter 24 hr. groundwater level measurement.

Hammer Fall:

Size I.D.:

Hammer Wt.:

028093.06


S NORTHINGEASTING

None

Dry

2.0

-----

-----

-----


ELEVATION2.25"

10-22-12----

10-22-12

10-22-12

10-23-12

Date


INSPECTOR

-----

8.0

8.0 ----

Enc.

Compl.

24 hr.

-----

10-22-12

T. Redman

:1 of 1:

1-3/8"

-----

-----

140 lb.

30 in.

-----


364.5

HSA

C. Jacobs

Per 6"(RQD%)

SampleNumberType


SampleRecov-ery



Feet

StrataChange


SamplerBlows

(in)

5

10

15

20


::

Hard

6-10

BORING

LooseVery Loose

DENSITYBLOWS/FT.

Nov 6, 12BORING

CLIENTPROJECT

4-5


Very Dense B-7



Dense

0-3

Horizon Hill SWM


31+16-3011-15

Very Soft



StiffMedium Stiff

Soft

TEST BORING LOG

6-100-5


SUMMARY

B-7

365.50.8

363.72.5

355.410.8

0.01.5

2.53.4

5.05.9

8.58.7

10.510.8

S-1

S-2

S-3

S-4

S-5

18"

11"

11"

NR

1"

35-7

2650/5"

2050/5"

50/2"

50/3"

8" Topsoil

Med. Brown, moist, stiff, fine Sandy SILT, tr. Clay and f-c RockFragments (Residual) (ML)

Lt. Brown, fine grained WEATHERED ROCK

S-2: Silty SAND (SM), 46.6% finer than No. 200 sieve.


Note: Hard drilling from 7 ft. to 10.5 ft. Boring backfilled after24 hr. groundwater level measurement.

Hammer Fall:

Size I.D.:

Hammer Wt.:

028093.06


S NORTHINGEASTING

6.0

5.0

1.6

-----

-----

-----


ELEVATION2.25"

10-22-12----

10-22-12

10-22-12

10-23-12

Date


INSPECTOR

-----

9.0

7.0 ----

Enc.

Compl.

24 hr.

-----

10-22-12

T. Redman

:1 of 1:

1-3/8"

-----

-----

140 lb.

30 in.

-----


366.2

HSA

C. Jacobs

Per 6"(RQD%)

SampleNumberType


SampleRecov-ery



Feet

StrataChange


SamplerBlows

(in)

5

10

15

20


::

Hard

6-10

BORING

LooseVery Loose

DENSITYBLOWS/FT.

Nov 6, 12BORING

CLIENTPROJECT

4-5


Very Dense B-8



Dense

0-3

Horizon Hill SWM


31+16-3011-15

Very Soft



StiffMedium Stiff

Soft

TEST BORING LOG

6-100-5


SUMMARY

B-8

Jay Kay Testing (AASHTO Accredited) *** see attached.

MC %

23.7

25.0

20.0

8.1

20.4

31.0

-

ML

-

-

-

-

-

-

-

-

-

-

81.7

-

81.3

-

-

-

-

88.7

-

B-5

B-5

B-6

19.2

15.0

26.2

18.3

21.5

-

-

-

-

-

-

-

-

-

22.1

16.4

7.8

17.2

-

B-4

10.9

34.3

14.0

18.0

11.0

14.4

18.2

20.3

11.9

28.1

25.2

35.4

30.9

2.5-4.0

5.0-6.5

0.0-1.5

2.5-4.0

2.5-4.0

5.0-6.5

8.5-9.5

0.0-1.5

2.5-4.0

5.0-6.5

B-4

B-4

B-5

B-5

B-5

-

-

-

-

-

-

-

***

-

-

-

***

-

-

***

SUMMARY OF LABORATORY TESTING

HORIZON HILL SWM (REPORT 1/2)

GRAIN SIZE

-

-

% FINES

-

-

-

ML

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

USCS

-

-

-

-

ML

-

ML

-

--

-

-

-

-

-

PROJECT # 028093.06

-

-

62.8

-

-

***

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

OM %pH

-

-

-

-

-

-

-

-

-

-

BORING

S-1

S-2

S-3

S-4

S-1

S-2

S-3

S-4 (BOT)

S-5

S-1

S-2

S-3

S-4

S-5

S-1

S-2

B-1

B-1

B-1

B-1

B-2

B-2

SAMPLE

B-2

B-2

B-2

B-3

B-3

B-3

B-3

0.0-1.5

DEPTH (ft.)

2.5-4.0

5.0-6.5

8.5-10.0

0.0-1.5

2.5-4.0

5.0-6.5

8.5-10.0

11.0-12.5

0.0-1.5

2.5-4.0

5.0-6.5

8.5-10.0

13.5-15.0

0.0-1.5

8.5-10.0

S-3

S-1

S-2 (TOP)

S-2 (BOT)

S-3

S-4

S-1

S-2

-

-

-

-

-

-

-

37

-

-

B-3

B-6

B-6

B-6

B-6

B-6

-

-

--

13.5-15.0

18.5-18.9

-

-

-

-

LL

-

-

-

-

-

46

-

39

-

-

-

-

NP

-

-

-

-

-

-

-

S-3

S-4

S-5

S-6

-

-

-

-

-

14

-

4

-

-

-

-

NP

-

-

-

-

-

-

NP

-

-

-

-

-

PL

-

-

-

-

-

32

-

35

-

-

-

-

-

-

-

-

31

-

-

PI

ATTERBERG LIMITS

-

-

-

-

-

-

6

-

-

Jay Kay Testing (AASHTO Accredited) *** see attached.

MC %

14.4

4.4

15.2

9.4

6.3

-

-

-

46.6

-

-

SM

-

***

-

SUMMARY OF LABORATORY TESTING

HORIZON HILL SWM (REPORT 2/2)

GRAIN SIZE

-

-

% FINES USCS

-

-

-

PROJECT # 028093.06

-

-

-

-

-

OM %pH

-

-

-

-

-

BORING

S-1

S-3

S-1

S-2

S-3

B-7

B-7

B-8

B-8

B-8

SAMPLE

0.0-1.5

DEPTH (ft.)

5.0-5.9

0.0-1.5

2.5-4.0

5.0-6.5

LL

-

-

-

NP

-

-

-

-

NP

-

PL

-

-

-

NP

-

PI

ATTERBERG LIMITS

pH

-

SHEET 1 OF 4

SOIL DESCRIPTION

Brown SILT with sand

TESTED BY: JMK REVIEWED BY: JB11/01/2012

46 32 14 A-7-5 ML

19.2 -

ATTERBERG LIMITS CLASSIFICATION

LL PL PI AASHTO USCS

Medium 2.9

Fine 7.8

MOISTURE CONTENT ORGANIC CONTENT

5.2 Fine 5.2 13.1

86.1 81.7

GRAVEL Coarse 0.0 CC CU SAND Coarse 2.4

#N/A 100.0 94.8 92.4 89.5 87.8% PASSING #N/A #N/A #N/A #N/A #N/A

#4 #10 #40 #60 #100 #200

0.147 0.074

Sieve Size 3" 2" 1.5" 1" 3/4" 1/2" 3/8"

12.7 9.51 4.76 2 0.42 0.25Diameter (mm) 75 50.8 37.5 25.4 19

S-2 2.5-4.0'

GRADATION ANALYSIS

HORIZON HILL SWM (REPORT 1/2)JAY KAY TESTING Project Number

5233 Lehman Road, Suite 110

Spring Grove, PA 17362

Phone: (410) 259-5101

028093.06

BORING SAMPLE DEPTH

B-2

0

10

20

30

40

50

60

70

80

90

100 0

10

20

30

40

50

60

70

80

90

100

0.001 0.01 0.1 1 10 100

PE

RC

EN

T C

OA

RS

ER

BY

WE

IGH

T

PE

RC

EN

T F

INE

R B

Y W

EIG

HT

GRAIN SIZE (mm)

SILT OR CLAY SAND GRAVEL

3/4

#4 #200

3 3/8 10 20 40 60 100

U.S. STANDARD SIEVE DIAMETER (mm) HYDROMETER

AASHTO T-88

0

10

20

30

40

50

60

0 20 40 60 80 100

Plasticity Index

Liquid Limit

AASHTO T-89 & T-90

pH

-

SHEET 2 OF 4

SOIL DESCRIPTION

Brown SILT with sand


39 35 4 A-4 ML

26.2 -



Medium 4.3

Fine 10.5


1.9 Fine 1.9 16.8

87.3 81.3


#N/A 100.0 98.1 96.1 91.8 89.6% PASSING #N/A #N/A #N/A #N/A #N/A

#4 #10 #40 #60 #100 #200

0.147 0.074

Sieve Size 3" 2" 1.5" 1" 3/4" 1/2" 3/8"

12.7 9.51 4.76 2 0.42 0.25Diameter (mm) 75 50.8 37.5 25.4 19

GRADATION ANALYSIS




Phone: (410) 259-5101

028093.06

BORING SAMPLE DEPTH

B-2 S-4 (BOT) 8.5-10.0'

0

10

20

30

40

50

60

70

80

90

100 0

10

20

30

40

50

60

70

80

90

100

0.001 0.01 0.1 1 10 100

PE

RC

EN

T C

OA

RS

ER

BY

WE

IGH

T

PE

RC

EN

T F

INE

R B

Y W

EIG

HT

GRAIN SIZE (mm)


3/4

#4 #200

3 3/8 10 20 40 60 100


AASHTO T-88

0

10

20

30

40

50

60

0 20 40 60 80 100

Plasticity Index

Liquid Limit

AASHTO T-89 & T-90

SHEET 3 OF 4

SOIL DESCRIPTION

Brown SILT


NP NP NP A-4 ML

20.3 -



Medium 4.1

Fine 6.8


0.0 Fine 0.0 11.3

pH

-

91.8 88.7


#N/A #N/A 100.0 99.6 95.5 93.3% PASSING #N/A #N/A #N/A #N/A #N/A

#4 #10 #40 #60 #100 #200

0.147 0.074

Sieve Size 3" 2" 1.5" 1" 3/4" 1/2" 3/8"

12.7 9.51 4.76 2 0.42 0.25Diameter (mm) 75 50.8 37.5 25.4 19

S-4 8.5-10.0'

GRADATION ANALYSIS




Phone: (410) 259-5101

028093.06

BORING SAMPLE DEPTH

B-3

0

10

20

30

40

50

60

70

80

90

100 0

10

20

30

40

50

60

70

80

90

100

0.001 0.01 0.1 1 10 100

PE

RC

EN

T C

OA

RS

ER

BY

WE

IGH

T

PE

RC

EN

T F

INE

R B

Y W

EIG

HT

GRAIN SIZE (mm)


3/4

#4 #200

3 3/8 10 20 40 60 100


AASHTO T-88

0

10

20

30

40

50

60

0 20 40 60 80 100

Plasticity Index

Liquid Limit

AASHTO T-89 & T-90

SHEET 4 OF 4

SOIL DESCRIPTION

Brown sandy SILT


37 31 6 A-4 ML

22.1 -



Medium 5.4

Fine 18.8


11.4 Fine 11.4 25.8

pH

-

71.5 62.8


90.8 89.4 88.6 87.0 81.6 76.9% PASSING #N/A #N/A #N/A #N/A 100.0

#4 #10 #40 #60 #100 #200

0.147 0.074

Sieve Size 3" 2" 1.5" 1" 3/4" 1/2" 3/8"

12.7 9.51 4.76 2 0.42 0.25Diameter (mm) 75 50.8 37.5 25.4 19

GRADATION ANALYSIS




Phone: (410) 259-5101

028093.06

BORING SAMPLE DEPTH

B-6 S-4 8.5-10.0'

0

10

20

30

40

50

60

70

80

90

100 0

10

20

30

40

50

60

70

80

90

100

0.001 0.01 0.1 1 10 100

PE

RC

EN

T C

OA

RS

ER

BY

WE

IGH

T

PE

RC

EN

T F

INE

R B

Y W

EIG

HT

GRAIN SIZE (mm)


3/4

#4 #200

3 3/8 10 20 40 60 100


AASHTO T-88

0

10

20

30

40

50

60

0 20 40 60 80 100

Plasticity Index

Liquid Limit

AASHTO T-89 & T-90

B-8 S-2 (2.5-4.0)

SOIL DESCRIPTION

Brown silty SAND

NP NP NP A-4 SM

pH

-

SHEET 1 OF 1TESTED BY: JMK REVIEWED BY: JB11/01/2012


Medium 12.5

Fine 28.1


10.1 Fine 5.6 43.3

9.4 -


60.0 46.6


95.5 92.1 89.9 87.2 74.7 68.3% PASSING #N/A #N/A #N/A 100.0 95.5

#4 #10 #40 #60 #100 #200

0.147 0.074

Sieve Size 3" 2" 1.5" 1" 3/4" 1/2" 3/8"

12.7 9.51 4.76 2 0.42 0.25Diameter (mm) 75 50.8 37.5 25.4 19

S-2 2.5-4.0'

GRADATION ANALYSIS




Phone: (410) 259-5101

028093.06

BORING SAMPLE DEPTH

B-8

0

10

20

30

40

50

60

70

80

90

100 0

10

20

30

40

50

60

70

80

90

100

0.001 0.01 0.1 1 10 100

PE

RC

EN

T C

OA

RS

ER

BY

WE

IGH

T

PE

RC

EN

T F

INE

R B

Y W

EIG

HT

GRAIN SIZE (mm)


3/4

#4 #200

3 3/8 10 20 40 60 100


AASHTO T-88

0

10

20

30

40

50

60

0 20 40 60 80 100

Plasticity Index

Liquid Limit

AASHTO T-89 & T-90

294

296

298

300

302

304

306

308

310

312

314

316

318

320

0 100 200 300 400 500 600 700 800

294

296

298

300

302

304

306

308

310

312

314

316

318

320

0 100 200 300 400 500 600 700 800

JJB 028093.06DATE :

FIGURE NO.

11/26/12

PROJECT :

DRAWN BY : APPROVED BY : CONTRACT NO.

10710 Gilroy RoadHunt Valley, MD 21031(443) 589-2400FAX: (443) 589-2401

CE

I 11

X 1

7 H

OR

IZO

N H

ILL

SW

M.G

PJ

SLH

TES

T2.G

DT

11/

26/1

2

Weathered RockResidual Soil

Existing Grade

?

????

Residual Soil

PondEmbankment

Fill

Residual Soil

Recent Sediments

Recent Sediments

Proposed Grade

Weathered Rock

Residual Soil

Weathered Rock

3a

Residual Soil

Residual Soil

Proposed Grade

Residual Soil

Generalized Subsurface Profile

SWM Pond Embankment

ProposedEmergencySpillway

??

Recent Sediments

?8"S

Key24-hr. groundwater depthSPT N-value

Pond Water SurfaceEl. 309.0

Horizon Hill SWM - Sunrise Pond

7

14

13

30

EL. 319.2

B-1

EL. 316.4

B-2

6

12

9

12

14

20

50/3"

50/5"

67

5

3

3

20

30

EL. 310.0

B-3

26

4

3

50/2"

EL. 313.8

B-49

9

23

50/6"

EL. 316.3

B-5

50/6"

350

352

354

356

358

360

362

364

366

368

370

372

374

0 50 100 150 200 250 300

JJB 028093.06DATE :

FIGURE NO.

11/27/12

PROJECT :

DRAWN BY : APPROVED BY : CONTRACT NO.

10710 Gilroy RoadHunt Valley, MD 21031(443) 589-2400FAX: (443) 589-2401

3b

CE

I 11

X 1

7 H

OR

IZO

N H

ILL

SW

M.G

PJ

SLH

TES

T2.G

DT

11/

27/1

2

Weathered Rock

??

Existing Grade

??

Residual Soil

PondEmbankment

Fill

Residual Soil

Proposed Grade

Residual Soil

Weathered Rock

Weathered Rock

Weathered Rock

Weathered Rock

Residual Soil

SWM Pond Embankment

350

352

354

356

358

360

362

364

366

368

370

372

374

Generalized Subsurface Profile0 50 100 150 200 250 300

50/6"

Key24-hr. groundwater depthSPT N-value

Proposed Grade

Pond Water SurfaceEl. 367.0

Horizon Hill SWM - Longhill Pond

8

13

10

8

13

50/4"

EL. 373.0

B-6

6

35

50/4"

50/3"

50/0"

EL. 364.5

B-7 12

50/5"

50/5"

50/2"

50/3"

EL. 366.2

B-8

INTERPRETATION OF BORING LOGS

*Note: The notations "WOR" (weight-of-rods) and "WOH" (weight-of-hammer) mean that the sampler penetrated the soil under the weight of the rods or hammer. This penetrationresistance corresponds to a SPT blow count of 0 blows per foot.

INTERPRETATION OF BORING LOGS PLATE NO. 1

The borings were drilled using the method(s) indicated on the boring logs. The various methods include hollow stem augers, solid flight augers, driven casing, rotary drilling, and rock coring using a diamond bit core barrel.

Penetration testing and split barrel sampling of the soils were conducted in the borings at regular intervals in accordance with ASTM Specification D-1586. The Standard Penetration Test (SPT) is conducted by driving a split-barrel sampler into the soil using a 140 lbs. hammer falling 30 inches. The sampler is attached to drilling rods and lowered to the bottom of the borehole. The sampler is first seated 6 inches into the soil to penetrate any loose material and then driven an additional 12 inches to obtain the SPT blow count. The number of blows is recorded for each 6 inch interval. For example, a blow count of 4-6-8 indicates that 4 blows were needed to drive the sampler the first 6 inches, 6 blows the next 6 inches and 8 blows the final 6 inches. The SPT blow count (blows/foot) is obtained by adding the blow counts for the second and third 6 inch interval (i.e. 6+8 = 14 blows/foot).

A representative portion of the soil obtained from each split-barrel sample is placed in a sealed glass jar and transported to our office. Descriptions of the soil samples and penetration resistance (SPT blow count) are shown on the boring logs. The soils are described by color, moisture, major component and minor components based on the following relationships:

The MAJOR component represents more than 50 percent of the soil sample. The components are described based on the following particle size designations:

Component Particle Size Boulders >12" Cobbles 3" to 12" Gravel - coarse 3/4" to 3" - fine #4 sieve (4.76 mm) to 3/4" Sand - coarse #10 sieve (2.0 mm) to #4 sieve - medium #40 sieve (0.42 mm) to #10 sieve - fine #200 sieve (0.074 mm) to #40 sieve Silt & Clay < #200 sieve (0.074 mm)

The following terms are used to describe the percentage of Minor components:

Adjective Percent "and" 35 to 50 "some" 20 to 35 "little" 10 to 20 "trace" 0 to 10

Moisture Description "Dry" Dusty, Dry to touch "Moist" Damp "wet" Visible free water

The SPT blow counts are used to describe the RELATIVE DENSITY of coarse-grained soils and the CONSISTENCY of fine-grained soils according to the following relationships:

Relative Density

SPT (Blows/Foot)* Relative Density 0 to 4 Very Loose 5 to 10 Loose 11 to 30 Medium Dense 31 to 50 Dense 51+ Very Dense

Consistency

SPT (Blows/Foot)* Relative Density 0 to 2 Very Soft 3 to 4 Soft 5 to 8 Medium Stiff 9 to 15 Stiff 16 to 30 Very Stiff 31+ Hard

GC

GM

GP

GW

DESCRIPTIONSTYPICAL

LETTERGRAPHSYMBOLSMAJOR DIVISIONS

SOIL CLASSIFICATION CHART

NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS

LIQUID LIMITGREATER THAN 50

LIQUID LIMITLESS THAN 50

(APPRECIABLE AMOUNTOF FINES)

SANDS WITHFINES

US

CS

_LE

GE

ND

12/

11/1

2

PT

OH

CH

MH

OL

CL

ML

SC

SM

SP

WELL-GRADED GRAVELS, GRAVEL -SAND MIXTURES, LITTLE OR NOFINES

PEAT, HUMUS, SWAMP SOILS WITHHIGH ORGANIC CONTENTS

ORGANIC CLAYS OF MEDIUM TOHIGH PLASTICITY, ORGANIC SILTS

INORGANIC CLAYS OF HIGHPLASTICITY

INORGANIC SILTS, MICACEOUS ORDIATOMACEOUS FINE SAND ORSILTY SOILS

ORGANIC SILTS AND ORGANICSILTY CLAYS OF LOW PLASTICITY

INORGANIC CLAYS OF LOW TOMEDIUM PLASTICITY, GRAVELLYCLAYS, SANDY CLAYS, SILTY CLAYS,LEAN CLAYS

INORGANIC SILTS AND VERY FINESANDS, ROCK FLOUR, SILTY ORCLAYEY FINE SANDS OR CLAYEYSILTS WITH SLIGHT PLASTICITY

CLAYEY SANDS, SAND - CLAYMIXTURES

SILTY SANDS, SAND - SILTMIXTURES

POORLY-GRADED SANDS,GRAVELLY SAND, LITTLE OR NOFINES

WELL-GRADED SANDS, GRAVELLYSANDS, LITTLE OR NO FINES

CLAYEY GRAVELS, GRAVEL - SAND -CLAY MIXTURES

SILTY GRAVELS, GRAVEL - SAND -SILT MIXTURES

POORLY-GRADED GRAVELS,GRAVEL - SAND MIXTURES, LITTLEOR NO FINES

(LITTLE OR NO FINES)

CLEAN SANDS

(APPRECIABLE AMOUNTOF FINES)

GRAVELS WITHFINES

(LITTLE OR NO FINES)

CLEANGRAVELS

HIGHLY ORGANIC SOILS

SILTSAND

CLAYS

SILTSAND

CLAYS

MORE THAN 50%OF COARSEFRACTIONPASSING ON NO. 4SIEVE

SANDAND

SANDYSOILS

MORE THAN 50%OF COARSEFRACTIONRETAINED ON NO.4 SIEVE

GRAVELAND

GRAVELLYSOILS

MORE THAN 50%OF MATERIAL ISSMALLER THANNO. 200 SIEVE SIZE

FINEGRAINED

SOILS

MORE THAN 50%OF MATERIAL ISLARGER THAN NO.200 SIEVE SIZE

COARSEGRAINED

SOILS

SW

GEOTECHNICAL ENGINEERING STUDY - Rockville, Maryland

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