HomeMy WebLinkAbout03487 - Technical Information Report - Drainage �
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� Drainage Report
FOR
Van's Auto Repair Shop
at
4405 NE 4th Street
Renton, WA 98059
Building permit#B-080342
June, 2008
Revised January, 2009
Prepared for: (' O�
Van Nguyen 8� Minh-Du Huynh �� ���
2012 Duvall Avenue NE ,
Renton, WA 98059 � 4• ���0'
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Prepared By: Jerry O'Connell, P.E. `"Y : :_� _�
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-- _ _ `
Lovell-Sauerland & Associates, Inc.
19400 33rd Avenue W. Suite 200
Lynnwood, Washington 98036
LSA FILE No: 5102
,
3 �'8�
Van's Auto Repair Shop Drainage Review#3 Page 1 of 1
Van's Auto Repair Shop Drainage Review #3
Allen Quynn
Sent: Monday,January 26, 2009 2:19 PM
To: Arneta]. Henninger
Cc: Ronald Straka;Allen Quynn
Arnie,
I have the following review comments regarding Van's Auto Repair Shop drainage report and plans dated
January 2009:
� 1. In sizing the media filter vault, the engineer is using a cartridge design flow rate of 15 gal/min. Based on the
� design requirements in the Department of Ecology's Evaluation of Emerging Stormwater Treatment Technologies
website, Contech Stormwater Solutions, Inc. Media Filtration System is to be sized assuming a design flow rate
of 9 GPM per cartridge (18-in diameter, 22-in tall cartridge) using WWHM or other approved continuous runoff
model. Engineer will need to confirm cartridge sizing criteria and revise drainage report accordingly.
� 2. The Surface Water Utility's previous review comments requested the engineer determine if the project was I
classified as a high use site and triggered enhanced water quality treatment. The be considered a high use site, �
the project has to meet the following criteria: ',
A commercial or industrial site that(1) has an expected average daily traffic (ADT) count equal to or greater ��
than 100 vehicles per 1000 SF of gross building area; (2) is subject to petroleum storage of transfer in excess of
1500 gallons per year or(3); is subject to use, storage or maintenance of a fleet of 25 or more diesel
vehicles that are over 10 tons net weight.
The full definition can be found on Page 10 of the Definitions chapter in the 2005 King County Surface Water
Design Manual. Number 2 above would most likely apply to this project since it is an auto repair facility
that probably conducts engine oil changes. The drainage report will need to include an analysis that
quantifies the amount of stored and transferred petroleum on the site in one year. If the thresholds above are
exceeded, the engineer with need to provide enhanced water quality treatment per Section 6.1.5 of the manual.
3. Drawings need to clearly show the drainage pipe in the wall that is intercepting offsite drainage and
bypassing around the project site. The plans must include a detail of the wall with the drain pipe.
4. Site plan shows approximately 1200 sf of driveway entrance is sloped towards NE 4th St. which means that
any runoff from the area will drain to the street and bypass water quality treatment. Engineer will need to
capture this area and direct it to the media filter. If grade precludes this, then the engineer will need to
investigate other BMP options such as bioswale or filter strip in the planter strip along NE 4th St.
Please call me if you have any questions (ext. 7247).
Thanks, —
� �-G � _,., --- -
� _ _� _ .__ __--_.
Allen — � �
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tile:;,`C:�`,Documents and Settings'�,aquynn`,Local Settin�s'��Temporary Internet Files`�,Conten... 10;�27�?009
1 '
Allen Quynn
From: Jerry O'Connell [JerryO@Isaengineering.com]
Sent: Wednesday, January 28, 2009 9:13 AM
To: Allen Quynn
Subject: RE: van's auto repair-site modelling
I will include a trench detail.
Contech said the 9 gpm is for another product the CDS media filter system not the stormfilter system we are using. '
Jerry O'Conneil
LSA Engineering
Alderwood Business Campus
19217 36rd Ave. W., #106 '
Lynnwood, WA 98036
phone: (425) 775-1591
email: jerry�lsaengineering.com I
From: Allen Quynn [mailto:aquynn@Rentonwa.gov]
Sent: Wednesday, January 28, 2009 8:19 AM
To: Jerry 0'Connell
Subject: RE: van's auto repair- site modelling
Jerry,
The cartridge sizing is fine. Did you ever check with Contech to clarify why Ecology uses a cartridge design flow rate of 9
GPM? Also, I don't see where you have identified the trench drain. I think I see it on the plans but it's not very clear.
Make sure you include a detail of the drain.
Allen
From: Jerry O'Connell [JerryO@Isaengineering.com]
Sent: Wednesday, ]anuary 28, 2009 7:29 AM
To: Allen Quynn
Subject: RE: van's auto repair - site modelling
Allen for your review...
Based on your review comments&Contech sizing (using 7.5 gpm)we propose a 4-cartridge design.
I've also added a intercept�r trench with pipe at the back of sidewalk & a slotted drain in the dwy to send the area north
of the parking to the 4vq cb. '
Jerry O'Connell
LSA Engineering
Alderwood Business Campus
19217 36rd Ave. W., #106
Lynnwood, WA 98036
phone: (425) 775-1591
email jerryo(a�lsaenqineerin .c�com
1
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.
From: Allen Quynn [mailto:aquynn@Rentonwa.gov]
Sent: Tuesday, January 27, 2009 3:06 PM
To: Jerry O'Connell
Subject: RE: van's auto repair- site modelling
Yes, if it can be designed in accordance with the 2005 manual which means you need to have sufficient water quality
storage and minimum surface area at the design depth in the tank. Basically, you need to meet the requirements in
Chapter 5, Section 6.4.2, (see Pg. 6-85, Requirement No. 10).
Allen
From: Jerry O'Connell [JerryO@Isaengineering.comJ
Sent: Tuesday, January 27, 2009 Z:51 PM
To: Allen Quynn
Subject: RE: van's auto repair -site modelling
lust as a thought, is dead storage in a tank acceptable in the city for basic wq treatment? (instead of using the wq cb?)
Jerry O'Connell
LSA Engineering
Alderwood Business Campus
19217 36rd Ave. W., #106
Lynnwood, WA 98036
phone: {425) 775-1591
email: ierryo(c�lsaenqineerinq.com
From: Allen Quynn [mailto:aquynn@Rentonwa.gov]
Sent: Tuesday, January 27, 2009 8:12 AM
To: Jerry O'Connell
Subject: RE: van's auto repair - site modelling
I would have to agree.
Thanks,
Allen Quynn, P.E.
Project Manager
City of Renton
Surface Water Utility Engineer
425-430-7247
From: Jerry 0'Connell [JerryO@Isaengineering.com]
Sent: Tuesday, January 27, 2009 8:12 AM
To: Allen Quynn
Subject: van's auto repair - site modelling
Definition of project site.
My read is that you model only the area of your property that you are developing,
Jerry O'Connell
LSA Engineering �
Alderwood Business Campus
19217 36rd Ave. W., #106
Lynnwood, WA 98036
2
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� phone: (425) 775-1591
email: jerryo(c�isaenqineering.com
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Drainage Report
FOR
Van's Auto Repair Shop
at
4405 N E 4th Street
Renton, WA 98059
Building permit#B-080342
June, 2008
Revised January, 2009
Prepared for: �
Van Nguyen 8� Minh-Du Huynh
2012 Duvall Avenue NE
Renton, WA 98059
Prepared By: Jerry O'Connell, P.E.
� � AU
E N A 1 X E E R S I 9 U R V E Y O R 9 �
-- _ _ �
Lovell-Sauerland & Associates, Inc.
19400 33rd Avenue W. Suite 200
Lynnwood, Washington 98036
LSA FILE No: 5102
January Revision—Executive Summary
This revision was prepared to acidress.the City's second review comments:
The following revisions were made:
1. The disturbed area of the e.xisting site was modeled as Till Forest
2. A larger tank (200 LF of 6'diameter) was required(70 LF of 4'tank previously)for
flow contro� Water qualiry treatment will be provided by media filter catch basin.
3. Using the updated KCRTS Version 6 computer model, which allows for orifice sizes
less than 0.5'; a tank was able to be sized that would meet the design requirements.
The previously submitted tank could not pass even using the minimum orifice size
allowed by the KCRTS Version S model,primarily due to the small site and low target
values. In conversations with King County, the new 2009 version of KCSWDM will
allow orifice sizes less than 0.5'; which more readily allows for compliance.
4. A bypass system has been arided convey runoff from the undisturbed portion of the
e.zisting site and offsite land Future development of the southern site would require
flow control& water quality, but was not proposed under this permi�
Sr VJJ^� !'l:�.9j ,,���i. fj., /
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Lovell-Sauerland and Associates Van's Auto Repair
Drainage Report January,2009
LSA n5102 Bldg Permit kB-080342
Project Overview
Project Name: Van's Auto Repair
Project Site Address: 24405 NE 4'h Street
Renton, WA 98059
Assessor Parcel Number: �182-1000-3902
Project Engineer: Lovell-Sauerland&Associates, Inc.
19400 33'd Avenue W., Suite 200
Lynnwood, Washington 98036
Phone: (425) 77�-1951
Project Applicant/Owner: Van Nguyen &Minh-du Huynh
2012 Duvald Ave NE
Renton, WA 98059
Project Total Area: 0..535 Acres (23,301s�
Disturbed site area: 0.2.5 Acres
Soils Data: Alderwood(AgC) - Type C soil
Modeled as Till in KCRTS
I.ovell-Sauerland and Associates Van's Auto Repair
' Drainage Report January,2009
LSA#�102 Bldg Permit#B-080342
Level 1 Downstream Analysis:
On June 16, 2008 a Level 1 analysis was performed on the downstream system. There are no
apparent onsite storm drain facilities. The site generally sheetflows westerly and drains into NE
4`h St., where it is collected in the public catch basin near the northeast corner of the Post Office
site; it then travels westerly about 500' across the Post Office Site (City project#2823) and the
newly constructed Ribera-Backo Plat (City project#3111); and is discharged into a desiltation
pond via a public 60"type-2 catch basin and 36" storm dra.in. It then discharges into a drainage
course that is the headwaters of Maplewood Creek at a point about 600' downstream from the
site. This drainage course then runs southeasterly along the perimeter of the Ribera-Backo Plat
continues for about 2900' until it enters Maplewood Creek, at a point about 0.7-miles
downstream from the site. There were no apparent signs of flooding, overtopping, or erosion
along the existing downstream system.
Flow Control & Water Quality Facility Analysis & Design
Existing site hydrology:
An existing conditions exhibit has been included to show the drainage patterns. The site
generally drains uniformly to the northwest at a general slope of 7%toward NE 4`" Street. The
site has been previously developed with a now vacant single-family house and related residential
landscaping. Access was from a driveway to NE 4`�near the northwest lot corner. Due to the
location of the existing water meter box, it appears the site was served by water from the main in ',
NE 4th, and had a septic system in the southern portion of the lot. Adjacent land uses are as
, follows: to the north-NE 4`" St. and a Safeway in a retail shopping area; to the east-a vacant
wooded lot; to the south-the Ridgeview Court residential Plat; to the west-a main Post Office.
Developed site hydrology:
The site will be developed with a 3,OOOsf auto repair building, 10 paved parking spaces and a 26'
wide access lane. The water quality runoff from these pollution generating impervious surfaces
will be collected and treated in the proposed media filter catch basin near the northwest of the
parking lot. A flow restrictor w�ill control the developed release rate to the required target levels
and release into a new catch basin placed within the existing NE 4�'public storm drain. The
developed site map has been included in this report.
Flow control svstem:
KCRTS design calculations have been included to show the facility required to match the level2
criteria, which requires developed runoff to be released not to exceed the existing 2-yr and 10-yr
levels, as well as sizing the facility to have developed release match flow durations between 50%
of the existing 2-year and the 50-year values. The 0.25-acres of disturbed site area was modeled
as till forest. The runoff from the remaining undisturbed portion of the site will be collected in a
grass-lined swale & underground conveyance system, and then discharged into the NE 4�' storm
system. This bypass system will reduce the amount of runoff currently going onto offsite
properties. Flow control &water quality systems will be designed under a separate permit at the
time of any future development for the remaining undisturbed site.
Lovell-Sauerland and Associates Van's Auto Repair
' Drainage Report January,2009
LSA#5102 Bldg Permit#B-080342
Water quality system:
A perlite media filter catch basin was proposed to provide runoff treatment. Please refer to the
attached drainage calculations.
ESC Analysis and design
A temporary erosion control plan has been prepared as part of the Civil Engineering plans. It
shows the BMPs that are proposed in order to prevent silty water from leaving the site. BMPs
such as a temporary construction entrance, silt fencing, and rock check dams will be constructed,
monitored, and revised as needed to prevent disturbance of the adjacent properties.
__ _ __ __
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Lovell-Sauertand and Associates Van's Auto Repair
, Drainage Report Januarv,2009
LSA#5102 Bldg Permit#B-080342
Appendix �
_ __ �
LOVELL-SAUERLAIVD&ASSOCIATES,L'V"C.
19400 33'd W.,Suite 200
Lynnwood, WA 98036
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KING ,COUNTY SOIL SURVEY
SOIL LEGEND
1973
1952 MAP �
SYMBOIS SYMBOLS MAP UNIT NAME
� Aa,Ac,Ee AqB Alderwood gravelly sandy loam, 0-6o slopes
�' Ab,Ae AgC Alderwood gravelly sandy loam, 6 15o slopes �
Ad AqD Alderwood gravelly sandy loam, 15 30o slopes
� Rh AkF Alderwood and Kitsap soils, very steep
Aa,Ac AmB Arents, Alderwood material, 0-6% slopes
Ab,Ae AmC Arents, Alderwood material, 6-15o slopes
Eh,Ek An Arents, Everett material
Cc,Cf BeC Beausite gravelly sandy loam, 6 15$ slopes
Cd,Ce BeD Beausite gravelly sandy loam, 15-30% slopes
Cd,Rk BeF Beausite gravelly sandy loam 40-75� slopes
'� Nc,Bf Bh Bellingham silt loam �
Pk Br Brisco� silt loam
Bg,Bh Bu Buckley silt loam
Cg Cb Coastal beaches
i Pd Ea Earlmont silt loam I
Ea Ed Edgewick fine sandy loam
Ba,Eh,Se,Sg EvB Everett gravelly sandy loam,0-5a slopes
Ek,Ba,Sh EvC Everett gravelly sandy loam, 5-15� slopes
Eg,Bd,Bd EvD Everett gravelly sandy loam, 15 30o slopes
EwC Everett-Aldenaood gravelly sandy loam, 6 15� slones
Gravel Pit G.P. Gravel Pit
La InA Indianola loam fine sandy, 0 4$ slopes
Ic TnC Indianola loamy fine sand, 4-15o slopes
' � Ib InD Indianola loamy fine sand, 15-30o slopes
Kb KpB Kitsap silt loam, 2-8$ slopes
Kb KpC Kitsap silt loam, 8-15� slopes
� Ka KpD Kitsap silt loam, 15-30$ slopes
i
Kc,Kd KsC Klaus gravelly loamy sand, 6-15� slopes
! Af Ma Mixed alluvial land
I� Ef,Be,Sf NeC Dieilton very gravelly loamy sand, 2-15o slopes
I ;--�
Pk Ng Newberg silt loam
Na Nk Nooksack silt loam
Nb No Norma+ sandy loam
'
3.2.2 KCRTS/RUNOFF FILES 1�4ETHOD—GENERATING TI.�1E SERIES
���� �TABLE 3.2.2.B EQC�IVALENC� 6ET1�'EE?\SCS SOIL TYPES t�ND KCRT�S��SOIL T�'PES � ��
� SCS Soil Type SCS KCRTS Soil Notes
Hydrologic Group
' Soil Group
� Alderwood (AgB gC AgD) C Tiil �
, Arents, Alderwoo aterial (AmB, AmC) C Till
- Arents, Everett Material (An) B Outwash 1
Beausite (BeC, BeD, BeF) C Till 2
, Bellingham (Bh) D Till 3
Briscot(Br) D Till 3
Buckley(Bu) D Till 4
Earlmont(Ea) D Till 3
' Edgewick(Ed) C Till 3
Everett(EvB, EvC, EvD, EwC) A/B Outwash 1
Indianola (InC, InA, InD) A Outwash 1
Kitsap (KpB, KpC, KpD) C Till
Klaus (KsC) C Outwash 1
Neilton (NeC) A Outwash 1
Newberg (Ng) B Till 3
Nooksack(Nk) C Till 3
Norma (No) D Till 3
- Orcas (Or) . . D Wetland
Oridia (Os) ' D Till 3
� Ovall (OvC, OvD, OvF) C Till 2
Pilchuck(Pc) C Till 3
Puget(Pu) D Till 3
Puyallup(Py) B Till 3
Ragnar(RaC, RaD, RaC, RaE) B Outwash 1
Renton (Re) D Till 3
Salal (Sa) C Till 3
Sammamish (Sh) D Till 3
Seattle (Sk) D Wetland
Shalcar(Sm) D Till 3
Si (Sn) C Till 3
Snohomish (So, Sr) D Till 3
Sultan (Su) C Till 3
Tukwila (Tu) D Till 3
Woodinville (Wo) D Till 3
Notes:
1. Where outwash soils are saturated or underlain at shallow depth (<5 feet)by glacial till,they should
be treated as till soils.
2. These are bedrock soils, but calibration of HSPF by King County DNRP shows bedrock soils to
have similar hydrologic response to till soils.
3. These are alluvial soils, some of which are underlain by glacial till or have a seasonally high water
table. In the absence of detailed study,these soils should be treated as till soils.
4. Buckley soils are formed on the low-permeability Osceola mudflow. Hydrologic response is
�. assumed to be similar to that of till soils.
� 2�05 Surface Water Design Manual 1/24;2005
3-25
SECTION 3.2 RIJNOFF CONiPUT.ATION AND ANALYSIS 1�4ETHODS
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' 1/24/2005 2005 Surface Water Design Manual
3-22
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Drainage Calculations
NE 4t" Auto Repair
Flow Control— Detention Sizing
Flow Control Standard: Flow Conservation
Land Use: Historic Site Conditions (forested)
Redevelopment Project? NO - (ez. impervious area=24.5%<35% threshald)
Predeveloped Condition
Land Use—Forested Condition
� .
--Ar�a____._ _ � �,
T�11 �ares# 0,25 acres'�'
Tiil P�stureli O.UO acres''
Ti#I �Eass 0.0�1 acres'
�uiwash Forest fl.Dtl acr��
O�twash Pastu�e' D,U� acr�s
Outavash Gr�ss; �1.�� a�xes:
We#tand': Q.�O ��res'
Impervious Q,�O at�es';
�Tatal-�_� __�
�.25 ��es'
Scale F��t�r: �.t10 Nourt�t_ Re�uced ����
Time Series: predev�s� 33
Com�ute Ti€ne Serias
Modi#y User lnput
__�._._�� ..� _» Fle fior�computed'Rme �eries [.TS�] ��__.___ _�. �,._�_.���
Flow Frequency Analysis
Time Series File:predev-st.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob �
(CFS) (CFS) Period
0.016 2 2/09/01 18:00 0.020 1 100.00 0. 990 I
0.004 7 1/06/02 3:00 0. 016 2 25.00 0. 960
0.012 4 2/28/03 3:00 0. 012 3 10.00 0. 900 '
0.001 8 3/24/04 21:00 0. 012 4 5.00 0. 800 I
0.007 6 1/05/05 9:00 0. 010 5 3.00 0. 667 ,
0.012 3 1/18/06 20:00 0.007 6 2.00 0.500 ��
0.010 5 11/24/06 4:00 0.004 7 1.30 0.231
0.020 1 1/09/08 9:00 0.001 8 1.10 0.091 ,
Comouted Peaks 0.019 50.00 0. 980 �i
5102-calcs-tank.doc II
'
.
Developed Condition
� « �
, 11res._..._._.__.._. ._ �
Till �'orest; Q.OQ acres;
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� Till Pasture� Q.O� acres;
__ TI{ Grass 0.06 �ares';:
Uutwash �arest 0.0� acres;
Oula�rash Pasture O.O�I acres!
flutwash �rass: D.00 acres
�letland 4.00 a�es
Impervious: 0.1 J acres'
�-Tatal�-���.� � � �
; 0.25 acres''
___.._ .. .--_---�.._,
Scsle �actvr : 1.�I� Hourty Redt�c�d
Time Ser�es: dev�st »
Compute Tim� Se�es
M�ndi#y User Input
______�__._ _._.�.__ __�_r_��_.__. �___._�__._.._..__---___ .___..�.._ � � ,, __ �____
F!e for cort�puted Tirr�e Se�ies t.TSFj
Flow Frequency Analysis
Time Series File:dev-st.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) {CFS) Period
0.052 6 2/09/O1 2:00 0. 102 1 100.00 0.990 '
0.044 8 1/05/02 16:00 0.071 2 25.00 0.960
0.061 3 2/27/03 7:00 0. 061 3 10.00 0.900
0.049 7 8/26/04 2:00 0. 058 4 5.00 0.800 '
0.058 4 10/28/04 16:00 0.055 5 3.00 0. 667 �
0.055 5 1/18/06 16:00 0.052 6 2.00 0.500 'i
0.071 2 10/26/06 0: 00 0.049 7 1. 30 0.231 '�
0.102 1 1/09/08 6: 00 0.044 8 1. 10 0.091 �I
Computed Peaks 0.092 50.00 0. 980 �i
' 5102-calcs-tank.doc
Target duration curve
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' S102-calcs-tank.doc
Duration Comparison
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Protfabifity�ceederie
Duration Comparison Anaylsis
Base File: predev-st.tsf
New File: rdout-st.tsf
Cutoff Units: Discharge in CFS
-----Fraction of Time----- ---------Check of Tolerance-------
Cutoff Base New �Change Probability Base New %Change
0.003 I 0. 10E-01 0.78E-02 -22.7 � O. 10E-01 0.003 0.003 -13.1
0.004 � 0.73E-02 0.75E-02 2.9 I 0.73E-02 0.004 0.004 2 . 6
a.004 I 0. 65E-02 0. 62E-03 -90.5 � 0.65E-02 0.004 0.004 -7 .0
0.005 I 0.59E-02 0.59E-03 -90.1 ( 0.59E-02 0.005 0.004 -14.9
0.005 I 0.54E-02 0.57E-03 -89.5 � 0.54E-02 0.005 0.004 -21.6
0.005 ( 0.45E-02 0.55E-03 -87.8 I 0.45E-02 0.005 0.004 -27.3
0.006 I 0. 41E-02 0.54E-03 -87.0 � 0.41E-02 0.006 0.004 -32 .3
0.006 I 0.38E-02 0 .52E-03 -86. 1 � 0.38E-02 0.006 0.004 -36. 6
0.007 � 0.34E-02 0.52E-03 -84.5 I 0.34E-02 0.007 0.004 -40.4
0.007 I 0.29E-02 0.52E-03 -81.8 � 0.29E-02 0.007 0.004 -43.7
0.008 I 0.27E-02 0.49E-03 -81. 6 � 0.27E-02 0.008 0.004 -46.7
0.008 I 0.24E-02 0.47E-03 -80.4 I 0.24E-02 0.008 0.004 -49. 4
0.008 I 0.22E-02 0.42E-03 -81.0 � 0.22E-02 0.008 0.004 -51. 9
0.009 I 0. 17E-02 0.39E-03 -77 . 4 � 0.17E-02 0.009 0.004 -54.1
0.009 � 0. 15E-02 0.33E-03 -78 .0 � 0.15E-02 0.009 0.004 -56. 1
0.010 � 0. 14E-02 0.29E-03 -78.3 I 0.14E-02 0.010 0.004 -58 .0
0.010 I 0. 99E-03 0.24E-03 -75 .4 � 0.99E-03 0.010 0.004 -59.7
0.010 I 0.83E-03 0.21E-03 -74 .5 � 0.83E-03 0.010 0.004 -61.2
0.011 � 0.72E-03 0. 18E-03 -75.0 I 0.72E-03 0.011 0.004 -62.7
0.011 � 0. 64E-03 0. 18E-03 -71.8 I 0.64E-03 0.011 0.004 -62.7
0.012 � 0. 38E-03 0. 13E-03 -65.2 I 0.38E-03 0.012 0.009 -23.4
0.012 I 0.33E-03 0 . 98E-04 -70.0 I 0.33E-03 0. 012 0.009 -21 . 9
' S102-calcs-tank.doc
0.012 � 0.29E-03 0.82E-04 -72.2 I 0.29E-03 0. 012 0.010 -22.7
; -
0.013 I 0.28E-03 0.82E-04 -70.6 � 0.28E-03 0. 013 0.010 -24.5
0.013 � 0.21E-03 0.82E-04 -61.5 I 0.21E-03 0.013 0.010 -21.5
' 0.014 � 0.18E-03 0.65E-04 -63. 6 � 0.18E-03 0.014 0.011 -17 . 8
0.014 � 0. 15E-03 0.65E-04 -55. 6 � 0.15E-03 0.014 0.011 -19.3
, 0.014 I 0. 15E-03 0.33E-04 -77.8 � 0. 15E-03 0.014 0.011 -21. 6
0.015 ( 0. 82E-04 0.33E-04 -60.0 I 0. 82E-04 0.015 0.013 -10.1
0.015 � 0. 65E-04 O.00E+00 -100.0 � 0. 65E-04 0.015 0.014 -6.1
0.016 I 0. 16E-04 O.00E+00 -100.0 I 0. 16E-04 0. 016 0.015 -3.7
0.016 I 0. 16E-04 O.00E+00 -100.0 � 0. 16E-04 0.016 0.015 -6.2
Maximum positive excursion = 0.000 cfs ( 3.3%)
occurring at 0.004 cfs on the Base Data:predev-st.tsf
and at 0.004 cfs on the New Data:rdout-st.tsf
Maximum negative excursion = 0.007 cfs (-63.1�)
occurring at 0.011 cfs on the Base Data:predev-st.tsf
and at 0.004 cfs on the New Data:rdout-st.tsf
Retention/Detention Facility
Type of Facility: Detention Tank
Tank Diameter: 6. 00 ft
Tank Length: 200.00 ft
Effective Storage Depth: 4.22 ft
Stage 0 Elevation: 0.00 ft
' Storage Volume: 4250, cu. ft
Riser Head: 4.22 ft
Riser Diameter: 12.00 inches
Number of orifices: 2
Full Head Pipe
Orifice # Height Diameter Discharge Diameter
(ft) (in) (CFS) (in)
1 0.00 0.28 0.004
2 3.70 0.75 0.011 4.0
Top Notch Weir: None
Outflow Rating Curve: None
, Stage Elevation Storage Discharge Percolation
' {ft) (ft) (cu. ft) (ac-ft) {cfs) (cfs) I
0.00 0.00 0. 0.000 0.000 0.00 ���
_ , 0.01 0.01 11. 0.000 0.000 0.00 I
0.02 0.02 22. 0.001 0.000 0.00
0. 12 0.12 133. 0.003 0.001 0.00
0.22 0.22 245. 0.006 0.001 0. 00
0.32 0.32 359. 0.008 0.001 0.00
0. 42 0.42 474. 0. 011 0.001 0.00
0.52 0.52 590. 0. 014 0.002 0.00
0. 62 0.62 707. 0. 016 0.002 0.00
0.72 0.72 825. 0. 019 0.002 0.00
0.82 0.82 944. 0. 022 0.002 0.00
0. 92 0. 92 1063. 0.024 0.002 0.00
1.02 1 . 02 1183 . O. G27 0.002 �. 00
' 5102-calcs-tank.doc
1. 12 1.12 1303. 0.030 0.002 0. 00
1.22 1.22 1423. 0.033 0.002 0. 00
1.32 1.32 1543. 0. 035 0.002 0.00
1. 42 1.42 1662. 0.038 0.003 0.00
1. 52 1.52 1782. 0.041 0.003 0.00
1. 62 1.62 1901. 0. 044 0.003 0.00
1.72 1.72 2020. 0. 046 0.003 0.00
1.82 1.82 2138. 0.049 0.003 0. 00
1. 92 1.92 2255. 0.052 0.003 0. 00
2. 02 2.02 2371. 0.054 0.003 0.00
2. 12 2.12 2486. 0.�57 0.003 0.00
2.22 2.22 2600. 0.060 0.003 0.00
2. 32 2.32 2712. 0.062 0.003 0.00
2.42 2.42 2823. 0.065 0.003 0.00
2.52 2.52 2932. 0.067 0.003 0.00
2. 62 2.62 3039. 0.070 0.003 0.00
2.72 2.72 3145. 0.072 0.004 0.00
2.82 2.82 3247. 0.075 0.004 0.00
2. 92 2. 92 3347. 0.077 0.004 0. 00
3.02 3.02 3445. 0.079 0.004 0. 00
3. 12 3.12 3539. 0.081 0.004 0.00
3.22 3.22 3631. 0.083 0.004 0.00
3. 32 3.32 3718. 0. 085 0.004 0.00
3. 42 3.42 3802. 0. 087 0.004 0.00
3. 52 3.52 3881. 0. 089 0.004 0.00
3. 62 3. 62 3956. 0.091 0.004 0. 00
3.70 3.70 4012. 0.092 0.004 0. 00
3.71 3.71 4018. 0.092 0.004 0.00 I
3.72 3.72 4025. 0.092 0.005 0.00 i,
3.73 3.73 4032. 0.093 0.006 0.00 I
3.74 3.74 4038. 0.093 0.007 0.00 '�
3. 75 3.75 4045. 0.093 0.008 0.00
3.76 3.76 4051. 0.093 0.008 0.00
3. 86 3.86 4112. 0.094 0.010 0.00
3. 96 3.96 4165. 0.096 0.012 0.00
4. 06 4.06 4209. 0.097 0.014 0.00
4. 16 4.16 4240. 0.097 0.015 0. 00
4.22 4.22 4250. 0.098 0.015 0.00
4. 32 4.32 4250. 0. 098 0.324 0.00
4. 42 4.42 4250. 0. 098 0.889 0.00
4. 52 4.52 4250. 0 . 098 1. 620 0.00
4. 62 4.62 4250. 0. 098 2.410 0.00
4.72 4.72 4250. 0.098 2.690 0. 00
4.82 4.$2 4250. 0.098 2. 950 0.00
4. 92 4. 92 4250. 0.098 3.190 0.00
5.02 5.02 4250. 0.098 3.410 0.00
5. 12 5.12 4250. 0.098 3.610 0.00
5.22 5.22 4250. 0.098 3.810 0.00
5.32 5.32 4250. 0.098 3.990 0.00
5.42 5.42 4250. 0.098 4.170 0.00
5.52 5.52 4250. �.098 4.340 0.00
5. 62 5.62 4250. 0.098 4.500 0. 00
5.72 5.72 4250. 0.098 4. 660 0. 00
5. 82 5.82 4250. 0. 098 4 . 810 0.00
' 5102-calcs-tank.doc
5. 92 5.92 4250. 0. 098 4. 960 0.00 i
6.02 6.02 4250. 0. 098 5.100 0.00
6. 12 6.12 4250. 0. 098 5.240 0.00
6.22 6.22 4250. 0.098 5.380 0.00
Hyd Inflow Outflow Peak Storage
Target Calc Stage Elev (Cu-Ft) (Ac-Ft)
1 0.05 0.02 O.Q1 3. 94 3. 94 4151. 0.095
2 0.10 ******* 0.01 3. 94 3. 94 4153. 0.095
3 0.06 ******* 0.00 3.59 3.59 3930. 0.090
4 0.05 ******* 0.00 2.96 2. 96 3391. 0.078
5 0.06 ******* 0.00 2.24 2.24 2621. 0.060
6 0.04 ******* 0.00 2.08 2.08 2439. 0.056
7 0.03 ******* 0.00 1. 97 1. 97 2313. 0.053
8 0.05 ******* 0.00 1.34 1.34 1561. 0.036
----------------------------------
Route Time Series through Facility
Inflow Time Series File:dev-st.tsf
Outflow Time Series File:rdout-st
Inflow/Outflow Analysis
Peak Inflow Discharge: 0.102 CFS at 6:00 on Jan 9 in Year 8
Peak Outflow Discharge: 0.015 CFS at 20:00 on Feb 9 in Year 1
Peak Reservoir Stage: 4.18 Ft
Peak Reservoir Elev: 4.18 Ft
Peak Reservoir Storage: 4244. Cu-Ft
. 0.097 Ac-Ft
Flow Frequency Analysis
Time Series File:rdout-st.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) (CFS) (ft) Period
0.015 1 2/09/Ol 20:00 0.015 4. 18 1 100.00 0.990
0.003 6 1/07/02 4:00 0.012 3. 94 2 25.00 0. 960
0.010 3 3/06/03 22:00 0.010 3.86 3 10.00 0. 900
0.003 8 8/26/04 8:00 0.004 2. 97 4 5.00 0.800
0.003 7 1/08/05 6:00 0.003 2.28 5 3.00 0. 667
0.003 5 1/19/06 7:00 0. 003 2.09 6 2.00 0.500
0.004 4 11/24{06 12:00 0.003 2.04 7 1.30 0.231
0.012 2 1/09/08 16:00 0.003 1.37 8 1. 10 0.091
Computed Peaks 0.014 4.05 50.00 0. 980
F1ow Duration from Time Series File:rdout-st.tsf
Cutoff Count Frequency CDF Exceedence Probability
C FS °s a o
0.000 78 0.127 0.127 99.873 0. 999E+00
0.001 30993 50.543 50.670 49.330 0. 493E+00
0.001 2574 4.198 54.868 45.132 0.451E+00
0.001 13366 21.797 76.665 23.335 0.233E+00
0.002 1082 1 .70'S 78 .430 21 . 570 C.216E+00
' 5102-caics-tank.doc
Water Quality Calculation
Design Flow Method with 15-minute developed peak flow
� �
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Compute Timc Se�ies 7 ' .;�.� _ �~-
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File fnr compui�d Time Series [.T�F]
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Flow Fre uenc Anal sis y\,,,, ��Js ��� U� �,
q Y Y � � �,J'��
Time Series File:dev-st-l5.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) (CFS) Period '
0.090 6 8/27/Ol 18:00 0.255 1 100.00 0. 990 '
0. 063 8 9/17/02 17:45 0. 184 2 25.00 0. 960
'�, 0. 184 2 12/08/02 17: 15 0. 124 3 10.00 0. 900 '�
0.073 7 8/23/04 14:30 0. 105 4 5.00 0.800 I,
0.099 5 10/28/04 16:00 0.099 5 3.00 0. 667 ��I
i 0.105 4 10/27/05 10:45 0.090 6 2.00 0.500 i
'�, 0. 124 3 10/25/06 22: 45 0.073 7 1.30 0.231
0.255 1 1/09/08 6: 30 0.063 8 1.10 0. 091
Computed Peaks 0.231 50.00 0. 980
- Treatment flow = 60� of developed 2-yr = 0.6 x 0.090 = 0.054cfs
No. of cartridges at 0.0334cfs/ea= 0.540/0.0334=1.62 (use 2 cartridges)
' S102-calcs-tank.doc
�
5.3.4 CONTROL STRUCTURES—DESIGN CRITERIA
FIGURE 5.3.4.A FLOW RESTRICTOR(TEE)
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5 Surface Water Design i�lanual 11/O1/2006
5-39
1 � �� ��
l
V
July 25, 2008 Earth Solutions NW LLC
ES-1311
•Geotechnical Engineering
•Construction Monitoring
• Environmental Sciences
Mr. Robert Champion, AIA
3802 - Cofby Avenue
Everett, Washington 98201
Subject: Geotechnical Recommendations
Proposed Auto Re�air Building
4405 - Northeast 4 Street
Renton, Washington
Reference: Structural Engineering Plans
Prepared by Swenson Say Faget
Dated May 14, 2008
Dear Mr. Champion:
In accordance with your request, Earth Solutions NW, LLC (ESNV1� has prepared this letter
providing geotechnical recommendations for the subject site. We reviewed the following
documents andlor resources:
• King County iMAP online GIS resource;
• Composite Geologic Map of King County, Booth et al, 2006, and;
• King County Soil Conservation Survey (SCS).
Proiect Description
The subject site consists of a single, rectangular tax parcel with an area of approximately 0.5
acres, which is located near the southwestern corner between Northeast 4th Street and 136rn
Avenue Southeast in Renton, Washington. The site is bordered to the north by Northeast 4tn
Street, to the south by a residential development, to the east by a vacant parcel and to the west
by a retail development. The property is currently developed with a vacant single-family
residential structure and associated improvements and is otherwise forested. Site topography
is relatively level, with elevations ranging from between appraximately 405 to 410 feet.
We understand the site will be redeveloped with an automobile service facility and associated
improvements. The service bay portion of the structure will be one-story in height and will
utilize conventional foundations and either concrete masonry unit (CMU) or wood framing. A
second story space will be constructed in the northern portion of the building. Slab-on-grade
floors will be utilized across the structure. We anticipate minimal grading will be required to
achieve design elevations, generally less than five feet.
, 2881 1�2nd.A�-enue NF• Redmond,bVA 98052 • �-125i 28-3-3300• FAX(425) 284-2855 •Toll Free i8661 336-8710
('� S��2�)
Mr. Robert Champion, AIA ES-1311
� July 25, 2008 Page 2
If the above design estimates are incorrect or change, ESNW should be contacted to review the
recommendations in this report. ESNW should review the final design to confirm that our
geotechnical recommendations have been incorporated into the final design.
Subsurface Conditions
Three hand-auger test pits were excavated across accessible portions of the site to
characterize the subsurface conditions which may impact site designs. Please see the soil logs
attached to this letter for a more detailed description of the site soil and groundwater conditions
observed at our boring locations.
In general, underlying a thin topsoil and fill layer, firm native soils were encountered. The native
soils consisted primarily of inedium dense to dense silty sand with gravel extending to the
maximum exploration depth of three and one-half feet below existing grades where refusal was
encountered.
Geologic Setting
Based on our review of the referenced geologic map, the site is underlain by glacial till deposits
(Qvt). The referenced SCS resource indicates the site is underlain by Alderwood series (AgB)
glacial till soils.
The soil conditions encountered at our test sites generally correlate with the published geologic
map resources. The native soils encountered at the test sites were consistent with glacial till
deposits.
Groundwater
Groundwater was not observed at our test pit locations during our fieldwork (July 2008). It
should be noted that groundwater seepage rates and elevations fluctuate depending on many
factors, including precipitation duration and intensity, the time of year, and soil conditions. In
general, groundwater seepage rates and levels are generally higher during the wetter, winter
months.
Site Preparation and Earthwork
The primary geotechnical considerations during the proposed site preparation and earthwork
activities will involve structural fill placement and compaction, site drainage and erosion control.
In-situ Soils
From a geotechnical standpoint, the native soils encountered at our test sites are generally
suitable for use as structural fill. The moisture sensitivity of the native soils can be generally
characterized as moderate to high. Because the native soils are moderately to highly sensitive
to moisture, successful use of the on-site soils will largely be dictated by the moisture content of
the soils at the time of placement and compaction. Soils encountered during site excavations
that are excessively over the optimum moisture content may require moisture conditioning prior
to placement and compaction. Conversely, if the native soils are found to be dry at the time of
placement, moisture conditioning through the application of water may be necessary prior to
compacting the soil.
, Earth Solutions NW,LLC
1
Mr. Robert Champion, AIA ES-1311
� July 25, 2008 Page 3
If the on-site soils cannot be successfully compacted, the use of an imported soil may be
necessary. Imported soil intended for use as structural fill should consist of a well graded
granular soil with a maximum aggregate grain size of six inches, and a moisture content that is
at or near the optimum level. During wet weather conditions, imported soil intended for use as
structural fill should consist of a well graded granular soil with a fines content of five percent or
less defined as the percent passing the #200 sieve, based on the minus three-quarter inch
fraction.
Structural Fill Placement
In general, areas to receive structural fill should be sufficiently stripped of organic matter and
other deleterious material. The project geotechnical engineer should observe cleared and
stripped areas of the site prior to structural fill placement.
Structural fill is defined as compacted soil placed in foundation, slab-on-grade, and roadway
areas. Fills placed to construct permanent slopes and throughout retaining wall and utility
trench backfill areas are also considered structural fill. Soils placed in structural areas should
be compacted to a relative compaction of 90 percent, in general accordance with the maximum
dry density as determined by the Modified Proctor Method (ASTM D-1557) and placed in
maximum 12 inch lifts. In pavement areas, the upper 12 inches of the structural fill should be
compacted to a relative compaction of at least 95 percent and be in stable, non-yielding
condition.
Excavations and Slopes
The Federal Occupation Safety and Health Administration (OSHA) and the Washington
Industrial Safety and Health Ace (WISHA) provide soil classification in terms of minimum
temporary slope inclinations. Based on the soil conditions observed at our test sites, the
weathered native soils and fill encountered in the upper approximately one to two feet would be
classified as Type C soils by OSHA. Type C soils should be sloped no steeper than 1.5H:1V
(Horizontal:Vertical). The dense glacial soils encountered below about two feet would be �
characterized as Types A and B by OSHA, and should be sloped no steeper than 0.75H:1 V and
1 H:1 V, respectively. ESNW should observe temporary slopes to provide supplemental ,
recommendations, as necessary.
Permanent slopes should be sloped no steeper than 2H:1V. Permanent slopes should be
mulched or vegetated with appropriate species of plants to reduce the potential for surface ,
erosion. The project geotechnical engineer should observe temporary and permanent slopes to '
verify that the inclination is appropriate, and to provide additional grading recommendations, as
necessary.
' Earth Solutions NW,LLC I
I
, Mr. Robert Champion, AIA ES-1311
July 25, 2008 Page 4
Utilitv Trench Backfill
In our opinion, the soils observed at the test sites are generally suitable for support of utilities.
Organic or highly compressible soils encountered in the trench excavations should not be used
for supporting utilities. In general, the native soils anticipated to be exposed during grading
should be suitable for use as structural backfill in the utility trench excavations, provided the soil
is at or near the optimum moisture content at the time of placement and compaction and fines
contents are within acceptable limits to maintain stability. Moisture conditioning of the soils may
be necessary at some locations prior to use as structural fill. Utility trench backfill should be
placed and compacted to the specifications of structural fill provided in this report, or to the
appticable specifications of the City of Renton, as appropriate.
Foundations
In our opinion, the proposed building can be supported on conventional spread and continuous
footings bearing on competent, undisturbed native soils or structural fill. Assuming the building
will be supported as described above, the following parameters should be used for design of
the new foundations:
■ Allowable Soil Bearing Capacity 2,000 psf
■ Passive Resistance 300 pcf (equivalent fluid)
■ Coefficient of Friction 0.30
■ IBC Site Class Site Class C (Table 1613.5.2, 2006 IBC)
■ Liquefaction Susceptibility Low
A one-third increase in the allowable soil bearing capacity can be assumed for short-term wind
and seismic loading conditions.
Competent soils suitable for support of foundations are anticipated to be encountered at depths
of approximately one to finro feet below existing grades. Where loose or unsuitable soils are
encountered at the foundation subgrade elevation, the soil should be recompacted or replaced
with a suitable structural fill soil, as appropriate.
Slab-On-Grade Floors
Slab-on-grade floors for the proposed building should be supported on a firm and unyielding
subgrade consisting of competent native soil or structural fill. Unstable or yielding areas of the
subgrade should be recompacted or overexcavated and replaced with suitable structural fill
prior to construction of the slab. A capillary break consisting of a minimum of four inches of free
draining crushed rock or gravel should be placed below the slab. The free draining material
should have a fines content of five percent or less (percent passing the #200 sieve, based on
the minus three-quarter inch fraction). In areas where slab moisture is undesirable, installation
of a vapor barrier below the slab should be considered. If a vapor barrier is used it should
consist of a material specifically designed for that use and should be installed in accordance
with the manufacturers specifications.
' Earth Solutions NW,LLC
. ,
Mr. Robert Champion, AIA ES-1311
July 25, 2008 Page 5
Retaininp Walls
If retaining wall will be utilized at this site, they should be designed to resist earth pressures and
any applicable surcharge loads. For design, the following parameters can be assumed for
retaining wall design:
• Active Earth Pressure (Yielding Wall) 35 pcf(equivalent fluid)
• At-Rest Earth Pressure (Restrained Wall) 55 pcf
• Traffic Surcharge (Passenger Vehicles) 70 psf(rectangular distribution)
• Passive Resistance 300 pcf(equivalent fluid)
• Coefficient of Friction 0.30
Additional surcharge loading from foundations, sloped backfill, or other loading should be
included in the retaining wall design. Drainage should be provided behind retaining walls such
that hydrostatic pressures do not develop. If drainage is not provided, hydrostatic pressures
should be included in the wall design. ESNW should review retaining wall designs to verify the
recommendations earth pressure values and drainage have been incorporated into design, and
to provide additional recommendations, as necessary.
Retaining walls should be backfilled with free draining material that extends along the height of
the wall, and a distance of at least eighteen inches behind the wall. The upper one foot of the
wall backfill can consist of a less permeable (surFace seal) soil, if desired. A rigid, perforated '
drain pipe should be placed along the base of the wall, and connected to an approved
discharge location.
Drainaqe ;
, No groundwater seepage or indications of the seasonal groundwater table were observed at j
the time of our �eldwork (July 2008). However, perched groundwater commonly travels along '
the shallow contact befinreen the weathered and unweathered soil horizon within glacial till
deposits. As such, groundwater seepage could be encountered in deeper site excavations,
i particularly during the wetter winter months. Temporary measures to control groundwater
seepage and surface water runoff during construction would likely involve interceptor trenches
I and sumps, as necessary.
In our opinion, perimeter drains should be installed at or below the invert of the building
i _
footings.
�
, Earth Solutions NW,LLC
Mr. Robert Champion, AIA ES-1311
July 25, 2008 Page 6
Seismic Considerations
The 2006 International Building Code specifies several soil profiles that are used as a basis for
seismic design of structures. As previously mentioned, based on the soil conditions observed
at the test sites, Site Class C, from table 1613.5.2, should be used for design.
In our opinion, liquefaction susceptibility at this site is low. The relative density of the site soils
and the absence of a relatively shallow groundwater table is the primary basis for this
designation.
LIMITATIONS
The recommendations and conclusions provided in this letter are professional opinions !
consistent with the level of care and skill that is typical of other members in the profession
currently practicing under similar conditions in this area. A warranty is not expressed or
implied. Variations in the soil and groundwater conditions encountered at the test sites may
exist, and may not become evident until construction. ESNW should reevaluate the
conclusions in this geotechnical engineering study if variations are encountered.
We trust this letter meets your current needs. If you have any questions, or require additional
information, pleas call.
Sincerely, ��' �Ati��e
�� ��WAS�,�lN �C
EARTH SOLUTIONS NW, LLC �y�� 4� `'� �
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tt S. ' , L. . Kyle R. Campbell, P.E.
�J�S nior o�ect gist Principal
�,/
Attachments:Site Plan
Soil Logs
, Earth Solutions NW,LLC
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JOB NO. )311 CLIENT �o�r�- Ch�.-� �d� TEST PIT NO.
DATE `?� I'1 IO$ BY S(S ELEVATION fi W� C�� (-�f�1— �,
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0
Test Pit terminated at Z`S feet below existing grade. (� Groundwater(table/seepage)encountered
at feetduring excava6on.
Earth Solutions NW��c
'
i
JOB NO. /3� � CLIENT ���� e.�a,�.��Rp� TEST PiT NO.
DATE -]� ��l D g BY �4� ELEVATION �' t-{f O� N� - �
CONTRACTOR SHEET � of I
�, � u� � �� � SURFACE CONDITIONS
E E E n N nY V -°�a ��SS � �S'a�►'t�j��5 �1
v�i c uWi -a � v•� � c°�
NOTE: DEPTH OF TOPSOIL& SOD�
S(1� 'row� s;?-�_��N��v_�-fL��f`ay c\�_�e ��.�1'L Q���,J�o1 Si
O 1 -- -
--------- ---------------------------------
2 c 5 P�
-------------------------------------------
3,c� 3
! -2--�\_ o�__��se _ ��\-S��-�---------------
_ ' 4
-------------------------------------------
5
'� -------------------------------------------
6
_ -------------------------------------------
" ------------------------------------------- �
-------------------------------------------
, p i
-------------------------------------------
- 3
-------------------------------------------
-------------------------------------------
5
6 ,
-------------------------------------------
7
--------------------------------------------
8
-------------------------------------------
9
-------------------------------------------
0
Test Pit terminated at 3 feet below existing grade. ( I�O Groundwater(table 1 seepage)encountered
at feet during excavation.
Earth Solutions NWuc
'
. �
, - JOB NO. J3� 1 CLIENT ����-�- C�a �a� TEST PIT NO.
DATE � J'� {� $ BY ��� ELEVATION 'f' �-/'C`? S � }�/�- �j
CONTRACTOR SHEET � of �
�, �, u� � � � SURFACE CONDITIONS
�E E n. o �� � o �CZt�'2� Su��e. ,r
v�0i c vf°i v � �°' � � NOTE: DEPTH OF TOPSOIL& SOD�
� sM 3rou9v� s_,l _���_UL+ ���1� ��+,�'''-�'�'_ '�11 ----
C�,5 � S,� 8 w � S ;�-h c e � vr�D t �
� ------- --------------------------------
,� c���5 2
-------------------------------------------
3
� ---- ------ ----- ----� ---------------
3 , � 4 �,,�. � ;c` S�,C-
-------------------------------------------
5
-------------------------------------------
6
-------------------------------------------
7
-------------------------------------------
8
-------------------------------------------
-------------------------------------------
0
------------------------------------------
-------------------------------------------
-------------------------------------------
-------------------------------------------
5
! -------------------------------------------
-------------------------------------------
7
--------------------------------------------
' 8
-------------------------------------------
0
Test Pit terminated at 3 `� feet below existing g�ade. (�j Groundwater(table/seepage) encountered
�, at feet during excavation.
Earth Solutions NW��c
'