HomeMy WebLinkAboutStormwater Report - PLN General - 6/30/2016 North Mason School District
Stadium Project
Stormwater Report
Prepared for:
North Mason School District No. 403
71 East Campus Drive
Belfair, Washington 98528
Contact: Eric Nelson
Phone: (253) 380-3947
Cq-
Liz_
Prepared by:
Sitts & Hill Engineers, Inc.
4815 Center Street
Tacoma, Washington 98409
Contact: Marty Merriott
Phone: (253) 474-9449
June 2016 S&H Job Number 16,331
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
• STORMWATER REPORT Job Number 16,331
I hereby state that this Stormwater Report for the North Mason School District—Stadium Project has
been prepared by me or under my supervision and meets the standard of care and expertise which is
usual and customary in this community for professional engineers. I understand that Mason County
does not and will not assume liability for the sufficiency, suitability, or performance of drainage facilities
prepared by me.
HA��
"oV T4Sj�
30794
�•SIpIt'AL E�
v
SITTS & HILL ENGINEERS, INC.
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
TABLE OF CONTENTS
1.0 Project Overview ...............................................................................................................................................2
1.1 Scope 2
1.2 Existing Conditions.....................................................................................................................................................2
1.3 Proposed Conditions .................................................................................................................................................3
2.0 Discussion of Minimum Requirements................................................................................................................4
2.1 Minimum Requirement#1: Preparation of Stormwater Site Plans ..........................................................................8
2.2 Minimum Requirement#2: Construction Stormwater Pollution Prevention Plan (CSWPPP)...................................8
2.3 Minimum Requirement#3: Source Control of Pollution...........................................................................................8
2.4 Minimum Requirement#4: Preservation of Natural Drainage Systems and Outfalls...............................................8
2.5 Minimum Requirement#S: On-site Stormwater Management................................................................................8
2.6 Minimum Requirement#6: Runoff Treatment .........................................................................................................8
2.7 Minimum Requirement#7: Flow Control..................................................................................................................8
2.8 Minimum Requirement#8: Wetlands Protection.....................................................................................................8
2.9 Minimum Requirement#9: Basin/Watershed Planning...........................................................................................9
2.10 Minimum Requirement#10: Operations and Maintenance...................................................................................9
2.11 Optional Guidance#1: Financial Liability................................................................................................................9
2.12 Optional Guidance#2: Off-site Analysis..................................................................................................................9
3.0 Permanent Stormwater Control Plan................................................................................................................12
APPENDIX A—EXISTING PROJECT SITE CONDITIONS EXHIBIT.................................................................................A-1
APPENDIX B—PROPOSED PROJECT SITE CONDITIONS EXHIBITS............................................................................. B-1
APPENDIX C—STORMWATER CALCULATIONS....................................................................................................... C-1
CAConveyance Analysis ..............................................................................................................................................C-2
APPENDIX D Infiltration Calculations....................................................................................................................D-1
DAInfiltration Trench ................................................................................................................................................. D-1
D.1.1 Predeveloped Input.................................................................................................................................... D-1
D.1.2 Developed Input......................................................................................................................................... D-1
D.1.3 WWHM Results—Infiltration Trench......................................................................................................... D-2
APPENDIX E—OPERATIONS& MAINTENANCE MANUAL.........................................................................................E-1
E.1 Purpose...................................................................................................................................................................E-2
E.2 Permanent Facilities Description............................................................................................................................E-2
E.3 Discussion of Maintenance.....................................................................................................................................E-2
EAMaintenance Frequency.........................................................................................................................................E-3
E.5 Annual Cost Estimate..............................................................................................................................................E-3
APPENDIXF—Soils Report....................................................................................................................................F-1
SITTS & HILL ENGINEERS, INC.
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
1.0 PROJECT OVERVIEW
1.1 Scope
This report addresses the proposed new stadium and associated stormwater facility improvements. The
site address is 300 East Campus Drive, Belfair, WA 98528. The improvements are proposed on parcel
number 122082260000. This report has been prepared in accordance with Mason County Standards and
the 2005 and 2012 Washington State Department of Ecology's Stormwater Management Manual for
Western Washington (DOE Manual).
The proposed porous and non-porous asphalt pavement, track, field, covered home and visitor
grandstands, concessions building, and landscaping will replace the existing grass field as well as other
nearby areas that are currently comprised of gravel, asphalt pavement, concrete walkway, and a few small
buildings.
The project also includes demolition of old kitchen buildings (3 total), two portables, and one Boys & Girls
Club building.
1.2 Existing Conditions
The project site is located on the east side of SR 3 between East Alta Drive and SR 302. Please see Figure
1 (Vicinity Map). The existing project site' is 9.31 acres. Historically, runon has been documented from
adjacent areas within the district's campus, but due to recent and proposed replacement of the North
Mason High School, Middle School (Hawkins), and PACE Academy, little to no runoff is tributary to the
project site. The site is bounded on the north and west by wooded areas and East North Mason School
Road. It is bordered to the east by water towers, wooded areas, and parking and landscaped areas as part
of the PACE Academy site, per Phase 2 (submitted separately). It is bordered to the south by the existing
administration building and gym/music building.
Per the 2005 DOE Manual, "Site" is defined as area within a parcel subject to new development or
redevelopment.
SITTS & HILL ENGINEERS, INC. 2
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Fi ure 1 —Vicinity Ma
New Stadium
Project Site Location
New High School Site
r
PACE Academy
Existing High School / New Existing Hawkins Middle
Hawkins Middle School School To Be Demolished
ti
vv L
S
1.3 Proposed Conditions
The North Mason School District proposes to construct a new track&field, concessions building, covered
home and visitor grandstands, and associated improvements. The proposed project site will contain
concrete walkways, porous and non-porous asphalt pavement, gravel surfacing, roof area, and landscaped
areas. See the table included in this section for a breakdown of project areas. The project site has been
graded to primarily drain to proposed on-site conveyance systems comprised of Type 1 and 2 catch basins,
trench drains, French drains, and storm drainage piping that discharge to a proposed on-site infiltration
trench. Stormwater runoff generated by the proposed roofs will be conveyed through 6 diameter storm
drainage piping. The north perimeter of the project site will continue to drain to the existing roadside
ditch, south of East North Mason School Road. The west portion will continue to drain to East Campus
Drive.
SITTS & HILL ENGINEERS, INC. 3
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Existing Proposed
(Acres) (Acres)
Pervious Surface 7.40 3.77
Pervious Pavement 0.00 3.41
Impervious Pavement 1.55 1.82
Roof 0.36 0.31
Total 9.31 9.31
The geotechnical investigation, performed by Migizi, indicates the site soils infiltrative capacity is
approximately 10" per hour. The geotechnical report has been included with this report as Appendix F.
Stormwater discharge will generally be mitigated (by way of full infiltration) in accordance with the 2012
DOE Manual. The aforementioned infiltration facilities will be outfitted with an emergency overflow
system, comprised of two catch basins at the northwest and southwest corners of the track that will
release runoff during events larger than the 100-year 24-hour storm event (as calculated in WWHM).
The proposed cut/fill for the project site is shown in the following table. Of the cut volume, 12,000 CY will
be organic enriched fill found beneath the west edge of the site while performing test pits. This material
will be overexcavated and hauled off-site to an approved off-site facility. Of the fill volume, 9,700 CY will
be imported from the existing stockpile located on the new high school site.
Cubic Yards
(CY)
Cut 23,700
Fill 21,400
Net(Cut) 2,300
2.0 DISCUSSION OF MINIMUM REQUIREMENTS
Although the 2005 DOE manual minimum requirements are to be applied to this project, per a
telephone conversation with Loretta Swanson on November 12, 2013, the minimum requirements
thresholds are those found in the 1992 DOE manual. A discussion of the flow charts in Volume 1 of the
1992 DOE Manual follows.
Per Figure 1-2.1 and Figure 1-3.3 of the 1992 DOE Manual, this is a REDEVELOPMENT project because it is
not an individual detached SFR or duplex AND there is existing development on site. Per Figure 1-3.5,
Minimum requirements 1-11 apply to the entire site because this project is a REDEVELOPMENT project
and the existing site is > 1 acre with >50% impervious area.
SITTS & HILL ENGINEERS, INC. 4
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT lob Number 16,331
Figure 2—1992 DOE Minimum Requirement Thresholds
STORK"TER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN
Figure I-3.3 Flowchart Showing Various Development Types
START HEM
Is this
no Individual GO TO FLOW CHART A
detached SFR
or duplex?
IID
Is there
existing YES GO TO FLOW DIM 0
development an �♦
site?
NO
Is the
prepsed NO 00 TO FLOW CHART A
development
>So" ft=?
YES
Is there
Vt scro of YES GO TO FLOW CHART C
land disturbing
activity?
no
00 TO FLOW
CHART 0
I-3-6 FEBRUARY, 1992
SITTS & HILL ENGINEERS, INC. 5
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Figure 2 - 1992 DOE Minimum Requirement Thresholds contin'd
STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN
Figure I-3.5 Flowchart Showing Steps for Redevelopment
This 1. REDEVELOPMENT.
Thera are TNR15MMOS
. to apply Yi■I YUY
REOUIREIE NTS 1 - It to
all or part of the Sit._
At ■ Mlnlmma. NIIIIYUY
11
r111 apply to the
portion of the alta
being developed.
Also. SOURCE CONTROL
(YININIM REOUIRENENT Ill
will apply to the
ENTIRE SITE.
Is the
•sl.ting site
>1 acre with >sox
iapervloYs
area
NO
<*>�
YIN. REQUIRElEl1TS I-11
o apply to the ENTIRE SITE
r TESatMtty practlubl• or tchoilule:
[e• Section I-2.4.25
NO
Ar•
.ddiMnal Begin d—iop.wnt of
s t or.s.•te r
controls reeuir.d the STORVNATER SITE PLAN
Uy a baf n a
ra urshed plan. (SS?) for the ENTIRE
or the
GMAT SITE: [.a Saetlon 1-3.e
MO
c ont o coatl"o to
a.l P•M nos WM
I-s-S FEBRUARY, 1992
SITTS & HILL ENGINEERS, INC. 6
TACOMA, WASHINGTON
III
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
r STORMWATER REPORT Job Number 16,331
Figure 2—1992 DOE Minimum Requirement Thresholds contin'd
STOR10ATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN
NtUtY REOMIN iffS 2-11
As part of the SS►.
apply to the
deterflno appropriate
PORTIOII of the site
SOURCE CONTROL NarS to
helop developed.
apply (See Chapter 1-e)
See Section 1-2.4.29
NoNI■ developments Dewlep a UML FARM
of the SIONM TER SITE Is the site EROSI011 NEXT
YES
PLAN (SSP)fer the Iola than I acre CONTROL PLAN (WESC) for
PORTION of ton site aolop In al seT all or a partials of the
dewlaped: Section 1-I-4 sits. as appropriate.
Iq
Develop a LARGE PARCEL
EROSION AIM►SEDIMENT
CONTROL PLAN (LPISC) for
all or a portion of the
site. as appropriate.
A PERMANENT STOINNOITEN
WJ41TT CONTROL PLAN
should be dowlapod for
of l or a Portion of the
a1L. a• approprlate.
Select NWa
for the PSOC Pleal
Chapter I-e
Apply any other
STORYMTO SITE
PLAIT roaelronollte as
necessary. Sec. I-3.4
Your STORMIER
SITE PLAN
.% n— —let*.
I-3-9 FEBRUARY, 1992
r SITTS & HILL ENGINEERS INC.
7
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWA TER REPORT Job Number 16,331
Since the minimum requirements found in the 1992 and 2005 editions of the DOE manual differ, and since
the thresholds found in the 1992 DOE manual require all minimum requirements, it is the understanding
of Sitts and Hill Engineers, Inc. that all of the 2005 DOE Manual minimum requirements are applicable to
the portions of the site that are being developed by this project. See Figure 2 at the end of this section for
a flowchart of the 2005 DOE requirements.
2.1 Minimum Requirement#1: Preparation of Stormwater Site Plans
This report and the accompanying plans satisfy this requirement. Both the plans and report have been
prepared in accordance with the 2005 DOE Manual by a licensed Civil Engineer.
2.2 Minimum Requirement#2: Construction Stormwater Pollution Prevention Plan (CSWPPP)
A Construction Stormwater Pollution Prevention Plan (CSWPPP) has been included with this submittal as
a separate document.
2.3 Minimum Requirement#3: Source Control of Pollution
Operational and Structural Source Control BMPs will include the maintenance of stormwater drainage
systems as described in the Operations and Maintenance Manual, included within this report. Please see
Appendix D.
2.4 Minimum Requirement#4: Preservation of Natural Drainage Systems and Outfalls
The project does not propose to alter the downstream flow path from the project site. Stormwater
generated by the existing project site infiltrates through existing grass or sheetflows to the ditch along
East North Mason School Road. Upon completion of the proposed project, stormwater will continue to
infiltrate through the native soils via a new infiltration trench with emergency overflow conveyed to the
roadside ditch as it is in the existing condition.
2.5 Minimum Requirement#5: On-site Stormwater Management
This project proposes to employ stormwater management BMPs to convey and fully infiltrate stormwater
on-site. The proposed infiltration trench will prevent disruption of the natural hydrologic characteristics
of the project site.
2.6 Minimum Requirement#6: Runoff Treatment
Runoff generated by the proposed project site does not require treatment since the proposed
improvements do not propose to create 5,000 sf or more of pollution-generating impervious surface.
2.7 Minimum Requirement#7: Flow Control
This project proposes to satisfy this requirement through full infiltration in the proposed infiltration
trench. Therefore, by inspection the project will not cause a 0.1 cubic feet per second increase in the 100-
year flow frequency from a threshold discharge area.
2.8 Minimum Requirement#8: Wetlands Protection
Not applicable. There are no wetlands on the project site.
SITTS & HILL ENGINEERS, INC. 8
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
2.9 Minimum Requirement#9: Basin/Watershed Planning
No basin plans have been found for the project site location. The site is in the Devereaux Lake sub-basin
of the Hood Canal Basin.
2.10 Minimum Requirement#10: Operations and Maintenance
Stormwater conveyance and infiltration facilities located on the property will be privately owned and
maintained. An Operations and Maintenance Manual is included in Appendix D of this report.
2.11 Optional Guidance #1: Financial Liability
Since the North Mason School District is a public entity, performance bonding is not required.
2.12 Optional Guidance #2: Off-site Analysis
We are not proposing to convey any runoff off-site, therefore, no off-site analysis has been performed.
SITTS & HILL ENGINEERS, INC. 9
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Figure 2—Flow chart for Determining Requirements for New Development per the 2005 DOE Manual
Start Here
Does the site have Yes See Redevelopment
35%or more of Minimum
existing impervious Requirements and
coverage? Flow Chart
Does the project convert (Figure 2.3)
No '/, acres or more of native
IF vegetation to lawn or
Does the project add No landscaped areas, or
5,000 square feet or convert 2.5 acres or more
more of new of native vegetation to
impervious surfaces`' pasture'
Yes Yes No
Does the project have
All Minimum 2,000 square feet or
more of new, replaced,
Requirements apply to or new plus replaced
the new impervious impervious surfaces?
surfaces and converted
pervious surfaces. Yes No
IF
Minimum Does the project have
Requirements#1 land-disturbing
through #5 apply to activities of 7,000
the new and replaced Yes square feet or more:'
impervious surfaces
and the land disturbed. No
IF
See Minimum
Requirement#2,
Construction
Stormwater Pollution
Prevention
Figure 2.2—Flow Chart for Determining Requirements for New Development
SITTS & HILL ENGINEERS, INC. 10
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Do the new,replaced,or new plus replaced impervious surfaces total 2,000
square feet or more?
OR
Does the land disturbing activity total 7,000 square feet or more?
Yes No
Minimum Requirements#I through#5 Apply Minimum Requirement#2,
apply to the new and replaced impervious Construction Stormwatcr Pollution
surfaces and the land disturbed. Prevention
Next Qnesdon
Does the project add 5,000 square feet or more of new impervious surfaces?
OR
Convert 1/4 acres or more of native vegetation to lawn or landscaped areas?
OR
Convert 2.5 acres or more of native vegetation to pasture'?
Yes No
xeatt
Minimum Requirements#1 through#10 Question Is this a road-
apply to the new impervious surfaces and related project'?
the converted pervious surfaces_ Yp
xo
Docs the project add 5,000 square feet or more of new impervious surfaces?
Yes No
Do new impervious surfaces add 501116 or Is the total of the new plus replaced
more to the existing impervious surfaces impervious surfaces 5,000 square feet or
within the project limits? more,AND does the value of the
proposed improvements—including
No Yes interior improvements—exceed 50%of
the assessed value(or replacement value)
No additional of the existing site impro ments?
Frequirements
Ya No
No additional
Minimum Requirements#I through#10 requirements
apply to the new and replaced impervious
surfaces.
Figure 2.3—Flow Chart for Determining Requirements for Redevelopment
2-10 Volume I—Minimum Technical Requirements February 2005
SITTS & HILL ENGINEERS, INC. 11
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
3.0 PERMANENT STORMWATER CONTROL PLAN
The proposed improvements are part of a multiphase project.
The proposed project site improvements will consist of new / replaced asphalt and gravel surfaces,
concrete walkways, track & field, and landscaped areas. The proposed improvements have been graded
so they drain to a proposed infiltration trench. Emergency overflow from the infiltration trench will convey
stormwater to the roadside ditch along East North Mason School Road.
As documented by the attached geotechnical report, the soils beneath the existing forested areas, porous
asphalt track, gravel shotput area, and proposed turf field will infiltrate runoff immediately (> 1in/hr) to
the highly permeable native soils. Therefore, these areas have been excluded from the infiltration trench
size calculations.
Please see Appendix A & B of this report, which provides a breakdown of the existing project site surface
areas, proposed project site surface areas, and proposed areas tributary to the proposed infiltration
facility.
The calculations included in Appendix C indicate that the proposed 6" storm drain piping will adequately
convey the 100-year, 24-hour event for any of the proposed roof areas. Appendix D demonstrates that
the proposed 3 foot by 5 foot infiltration trench with perforated pipe will have adequate capacity to
infiltrate runoff for up to the 100-year, 24-hour event. Appendix C also shows that the two 12" proposed
emergency overflow pipes from the infiltration trench will have adequate capacity to convey runoff to the
roadside ditch adjacent to East North Mason School Road in the event of a system failure.
SITTS & HILL ENGINEERS, INC. 12
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
APPENDIX A - EXISTING PROJECT SITE CONDITIONS EXHIBIT
SITTS & HILL ENGINEERS, INC. A-1
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT
Sifts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Fi ure 7 — Existing Conditions
1 2 3 4
I.EGM
WERYOUS 9MACE n_55 kCKS;
L_J PER'AOUS WACE,(7.40 ACRES)
Water Towers RonP(o36A )
A PRNECT UY(S(031 ACRES)
A
Pumphouse I Existing Proposed Tributary to Infiltration
j (Acres) (Acres) Trench (Acres)
Portables I Pervious Surface 7.40 3.77 1.01
I
Pervious Pavement 0.00 3.41 0.00
I I Impervious Pavement 1.55 1.82 1.18
I
Shed j Roof 0.36 0.31 0.26
Total 9.31 9.31 2.45
e i -
- W <
Jz
i
0a uJ
w-
1 1 H z x'a.
1 (n z
a LL,
1
I 1
t 1
1 I ozo� o
I "s
1 • Administration
Building s
{ (to remain)
I ———— m Uj
Uj
1 - i ~�
IL
FIL
1 I QQ
-------------------------- -----------------
--� ------------ ------ �=>ca
Teen Center LL x
Building
Kitchen Building
'
EX-1
EXj M COND7M E O-W 0 —-
Aa 4 T� NORTH 16331
SITTS & HILL ENGINEERS, INC. A-2
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
APPENDIX B - PROPOSED PROJECT SITE CONDITIONS EXHIBITS
SITTS & HILL ENGINEERS, INC. B-1
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Figure 8—Proposed Conditions
1 2 3 4
LEGEND
- U-MOOS WAa(1.87 kOCS)
L_J PROM WACE(377 AMS)
L_J ROUF(031 AMS)
a
- H0U5 A OOT(341 ACRES)
A Water Towers PERPR0.EC1 LF.(8.31 ACRES)
————————————— —————
PumphOuse j ———————if
Existing Proposed Tributary to Infiltration
I (Acres) (Acres) Trench (Acres)
Pervious Surface 7.40 3.77 1.01
Concessions Building Pervious Pavement 0.00 3.41 0.00
Impervious Pavement 1.55 1.82 1.18
Home Grandstand 1 Roof 0.36 0.31 0.26
—— Total 9.31 9.31 2.45
� I
Visitor Grandstand '
r C> ; a s
J ?. JZ
otf
W
t
Ile ^\ 0Lu
sm
n-
1 1 ° Z
LU
1 1
t 1
1 1
1 _ �
1 1 �
1 1
0
C 1 )0000.111
13
1 u
n
1 I
1 I Administration 3
Building a
1
(to remain)
1 --_--------, W
a
1�-----------------------------------------------\_ --------- m------ 0—
EX-2y``)....o
W N '
_
PR01060 COPDMCN3 Br —M0
SCAlf R rs — NOMH 16331
SITTS & HILL ENGINEERS, INC. B-2
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Figure 9 Area Tributary to Infiltration Trench
+ 2 a 4
LEGM
WERUM$WALE(118 ACKS)
L_J PJYMUS WACE(1.01 ACRES)
L_J ROOT(026 A01n) .M
TOTAL TRSUTART 10 RfXTRATI",M 6OCH 12.+5 ACKF,: a
A
Existing Proposed Tributary to Infiltration
1—
———————————————— I (Acres) (Acres) Trench(Acres)
I
I I Pervious Surface 7.40 3.77 1.01
Concessions Building I I a
I Pervious Pavement 0.00 3.41 0.00 # a
Home Grandstand I Impervious Pavement 1.55 1.82 1.18
I Roof 0.36 0.31 0.26
Visitor Grandstand ; i Total 9.31 9.31 2.45
J Z
ad
NZ `"
I 1
1 1
1 1 �
I 1 0
C I I ? 3
I n
1 1 < m
1 ¢
�... �-------------I
I I
1 I Administration 3
Building a
1 I (to remain) CO
1 I
1 -----------
-I � o
1 I o
1 ^
1 <
11-----------------------------------------------\,a -------------------�
01, EX-3
AWA TFAWAW TO N:L7MTM TRENW -IT
WORTH 16
SITTS & HILL ENGINEERS, INC. B-3
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
APPENDIX C - STORMWATER CALCULATIONS
SITTS & HILL ENGINEERS, INC. C-1
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
C.1 Conveyance Analysis
The SBUH method has been used to determine peak flows for the conveyance calculations in this
section. Table C1 from the 2005 DOE manual contains curve numbers used in the SBUH method.
Table C1 — Runoff Curve Numbers for SBUH method
Table 2.2
Runoff Curve Numbers for Selected Agricultural,Suburban and Urban Areas
(Sources:TR 55.1986.and Stormw•ater Management Manual, 1992.See Section 2.1.1 for explanation)
CNs for h drolo is soil group
Cover type and hydrologic condition. A B C D
Curve Numbers for Pre-Development Conditions
Pasture,grassland,or range-continuous forage for grazing:
Fair condition(ground cover 50%to 75%and not heavily grazed). 49 69 79 84
Good condition ground cover>75%and lightly or onlv occasional) grazed) 39 61 74 80
Woods:
Fair(Woods are grazed but not bume(,and some forest litter covers the soil). 36 60 73 79
Good(Woods are protected from grazing,and litter and brush adequately cover the soil). 30 55 70 77
Curve Numbers for Post-Develo meot Conditions
Open space(lawns,parks,golf courses,cemeteries,landscaping,etc.)
Fair condition(grass cover on 50%-75%of the area). 77 90 92
Good condition(grass cover on>75%of the area) 68 80 86 90
Impervious areas:
Open water bodies:lakes,wetlands,ponds etc. 1 o0 I 1 u0 100
Paved parkinglots,roofs',driveways,eta (excluding right-of-wa ) 98 98 98 98
Permeable Pavement(See Appendix C to decide which condition below to use)
Landscaped area 77 85 90 92
50%landscaped area+'50%impervious 8? 91 Q4 96
1001%impervious area 98 A 98 98
Paved 98 98 98 98
Gravel(includin right-of-way) 76 89 91
Dirt(including ri ht-of-wav) 72 82 87 89
Pasture.grassland,or range-continuous forage for grazing:
Poor condition(ground cover<50%or heavily grazed with no mulch). 68 79 86 89
Fair condition(ground cover 50%to 75%and not heavily grazed). 49 69 79 84
Good condition(ground cover>75%and lightly or only occasionally grazed) 39 61 74 80
Woods:
Poor(Forest litter,small trees,and brush are destroyed by heavy grazing or regular burning). 45 66 77 83
Fair(Woods are grazed but not burned,and some forest litter covers the soil). 36 60 73 79
Good(Woods are rotected from grazing,and litter and brush adequately cover the soil). 30 55 70 77
Single family residential': Should only be used for Average Percent
Dwelling Uniu'Gross Acre subdivisions>50 acres impervious area
1.0 DU:GA 15 Separate curve number
1 5 DU GA 20 shall be selected for
2.0 DU'6A 25 pervious&impervious
2.5 DUiGA 30 portions of the site or
3.0 DUGA 34 basin
35 DU GA 38
4.0 DU:GA 4'
4.5 DU GA 46
5.0 DU:GA 48
5.5 DU:GA 50
6.0 DU:GA 52
6.5 DU GA 54
70 DU GA 5o
7.5 DU UA 58
PUD's,condos,apartments,commercial %impervious Separate curve numbers shall
businesses,industrial areas& must be be selected for pervious and
&subdivisions<50 acres computed impenious portions of the site
For a more detailed and complete description of land use curve numbers refer to chapter two(2)of the Soil Conservation Service's Technical
Release No.55,(210-VI-TR-55,Second Ed.,.tune 1986).
'Composite CN's may be computed for other combinations of open space cover type.
'Where roof runoff and driveway runoff are infiltrated or dispersed according to the requirements in Chapter 3,the average percent impervious
area may be adjusted in accordance with the procedure described under-Flow Credit for Roof Downspout Infiltration"(Section 3.1.1),and"Flow
Credit for Roof Downspout Dispersion'(Section 3.1.2).
`Assumes roof and driveway runoff is directed into street/storm system.
'All the remaining pervious area(lawn)are considered to be in good condition for these curve numbers.
February 2005 Volume 1!I—Hydrologic Analysis and Flow Control BMPs 2-15
SITTS & HILL ENGINEERS, INC. C-2
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Isopluvial map for 100-year, 24-hr storm event from the 2005 DOE Stormwater Management Manual
Western Washington lsopluvial 100-year, 24 hour
124 123 122 121
49 _ S
4
f
FRIDAY HAR R PORT STAN —'— ✓
t� VE
T. —
Qts �
N �
1 T F +_
48 )TO.�'', E
s t a
r= fi 40 �
'� � e
— 5 f TAWKA r l
47 ~
E T = s'
85�
� 9 I
46
Q r
100-YEAR 24. OUR PRECIPITATION
—3d —ISOPLUYIA S OF 100-YEAR 24-!FOUR a `
PRECIPITATION IN TENTHS OF AN INCH 5 ��
NUAL 4 5 60 5 X
124 123 122 121
SITTS & HILL ENGINEERS, INC. C-3
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Roof Conveyance Calculation
The following information shows that a 6" pipe will be adequate to convey runoff for any of the
proposed roof areas on the project site. The largest roof area (home grandstand roof) was used for this
calculation and by inspection, the other roof areas will also be adequately served by a 6" pipe. An
isopluvial map from the 2005 DOE Stormwater Management Manual for the 100-year, 24-hr storm
event is included in this section (pg. C-3) and shows that 7 inches should be selected for this calculation.
Runoff curve numbers from the DOE manual are also included in this section.
SBUH Hydrograph Synthesis
Pervious Area 0.000 (acres) CN 86.0 S 1.63
Impervious Area 0.120 (acres) CN 98.0 S 0.20
Time of Concentration 6 (min.) P 7.00 (inches) d, 10 (min.)
Total Area: 0.12 (acres) w 0.4545 (min.)
Results:
Peak Flow 0.21 cfs Peak Time 7.67 hours Voiume 2945 cubic feet
Mannings Equation- Circular Pipe
Pipe Diameter D 6.0- (inches)
Manning's "n" n 0.013
Slope S 0.50 (%) Formulas:
Flow Depth d 310 (inches)
Flow Depth Ratio d/D 0.52 (%) d/D = (d/D)
Flow Point Angle 0 183.7 (deg) 0 = 2*COS-'((1-(2*d/D))
Flow Area A 0.102 (ft2) A = 1/8*(RADIANS(OrYSIN(Or))*(D/12)2
Wetted Perimeter WP 0.802 (ft) WP = n*(D/12)*Or/(2*n)
Hydraulic Radius R 0.128 (ft) R= A/WP
Flow Q 0.210 (cis) Q = (1.49/n)*A*R2i3*SO.5
Velocity V 2.054 (fps) V = Q/A
SITTS & HILL ENGINEERS, INC. C-4
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT lob Number 16,331
Emergency Overflow Conveyance Calculation
The following information shows that two 12" pipes will be adequate to convey runoff from the
proposed infiltration trench in the event that it fails to infiltrate. As shown below, WWHM indicates that
overflow pipes must convey 1.97 cfs for the 100-year 24-hr storm event. The associated Mannings
equation shows that a single 12" pipe can adequately convey 1.97 cfs, therefore, by inspection, two 12"
pipes can convey the emergency overflow.
"Sz hematic i3,Basin 1 Mitigated
SCENARIOS t Subbasin Name:Basin 1 r Designate as Bypass forPOC:
Red-eloped
Interfluw Groundwater
'` ❑
i® ed Flows To:
Mitigated Area in Basin r Sho.OrJy Selected
® Available Pervious Acres Available Impervious Acres
rr A/B,Forest,Mod —j® ROOFTOPSIFLAT 26
Flow Frequency r✓A/B,Lawn,Flat SIDEWALKS/FL4T 1.18
'Plow(cfs) Predeveloped Mitigated
2 Year = 0.0346 0.9180 r A/B,Lawn,Mod
�5 Year = 0.0977 1.2104
110 Year = 0.1565 1.3986
25 Year = 0.2454 1.6316
50 Year = 0.3194 1.8024
100 Year = 0.3978 1 1.9713
Mannings Equation- Circular Pipe
Pipe Diameter D 12.0 (inches)
Manning's "n" n 0.013
Slope S 0.50 (%) Formulas:
Flow Depth d 7.97 (inches)
Flow Depth Ratio d/D 0.66 N d/D = (d/D)
Flow Point Angle 0 218.4 (deg) 0 = 2*COS-1((1-(2*d/D))
Flow Area A 0.554 (ft2) A = 1/8*(RADIANS(0r)-SIN(0r))*(D/12)2
Wetted Perimeter WP 1.906 (ft) WP = n*(D/12)*0,/(2*n)
Hydraulic Radius R 0.291 (ft) R = A/WP
Flow Q 1.970 (cfs) Q = (1.49/n)*A*R2i1*So.5
Velocity V 3.557 (fps) V = Q/A
SITTS & HILL ENGINEERS, INC. C-5
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
APPENDIX D Infiltration Calculations
D.1 Infiltration Trench
D.1.1 Predeveloped Input
n-Basin 1 Predeveloped E3
"Elaim
Subbnsin Name:Bash 1
Surface Intmfbw Groudwatm
1 Flows To:
Area in Basin r Show Only Selected
Available Pervious Acres Available Impervious Acres
A/B,Forest,Flat 156
- - (r A/B,Forest,Mod OBS
D.1.2 Developed Input
Schematic E, ci::37 n,Basin 1 Mitigated £3_
SCENARIOS Subbasin Name:8asb 1 r Designate as Bypass forPOC:
Surface Intwilow Groundwater
❑Predeveloped Flows To: GravelTremhBedl Gravel TrenchBedl
❑v Mitigated — Area in Basin r Show O*Selected
Scen Available Pervious Acres Available Impervious Acres
A/B,Forest,Mod O35 r ROOFTOPS/RAT O26
BesicEbments --- -- r A/B,Lawn,Flat Q12 (J SIDEWALKS/FLAT 1.18
®PIN®® A 1 r,A/B,Laorn,Mod ft54
SITTS & HILL ENGINEERS, INC. D-1
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
D.1.3 WWHM Results — Infiltration Trench
Schematic -s7= H-Gravel Trench Bed 1 Mitigated
SCENARIOS o J Facility Name Gra Trench Bed 1
�./ Outlet 1 Outlet 2 Outlet 3
IlMll❑Predeveloped Downstream Connection 0�
__. Facility Type .Gravel Trench/Bed
❑Mitigated Facility
Applied to Facility Quick Trench
Run Scenario Evaporation Applied to Facility Facility Dimension Facility Dimension Diagram
Basic Elements - ----
®®® Facility Dimensions Outlet Structure Data
A Trench Length(ft) 711
®®■® Trench Bottom Width(ftl Riser Height(ft) �J-J
Effective Total Depth[ft)
Riser Diameter(n) 10 J
H®®® Bottom slope(ft/ft) 00001 Riser Type Rat J
Left Side Slope(HN) 0 0001 Notch Type
09 Right Side Slope(HN) p.00p1
Pro Elements
Material Layers for Trench/Bed
Layer 1 Thickness(ft) Orifice Diameter Height
Layer l porosity(0-1) 0.4 Number (in) (ft)
Layer 2 Thickness(ft) 1 F-—1 F0—J i
— Layer 2 porosity(0-1) 0.44 2 fF—J�Fo---
Layer 3 Thickness(ft) 3 lu> lu
Layer 3 porosity(0-1) Q4
Trench Volume at Riser H ead(ac-R) 104
Infiltration YES
Commercial Toobox Measured Infiltration Rate[in/hr) l0 J
Reduction Factor(nfik`factor) Show Trench Open Table J
-- - Use Wetted Surface Area(sidewals) NO J Initial Stage(ft) 0
i Move Ebmxrts—1
To alVdumeIn*ated(acft) 345.634 Total Volume ThroughFac y ac t 345.651
A\I Total Voume Through Riser(acft) 0.017 Percent Infiltrated 100
SITTS & HILL ENGINEERS, INC. D-2
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
APPENDIX E - OPERATIONS & MAINTENANCE MANUAL
SITTS & HILL ENGINEERS, INC. E-1
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
E.1 Purpose
The purpose of this Manual is to provide guidelines for maintaining the permanent on-site storm drainage
system constructed as a part of the new/replaced driving surfaces,concrete walkways, porous pavement,
track&field, and landscaping improvements.These improvements are located on the North Mason School
District New Stadium site. The site address is 300 East Campus Drive, Belfair, WA 98528.
Storm utility improvements have been proposed as a part of the new/replaced driving surfaces, concrete
walkways, and landscaping. Storm utility improvements include:
o Type 1 and 2 Catch Basins
0 12" Storm Drain Piping
0 6" Roof Drain Piping
o Infiltration Trench
Each portion of the system has to be maintained in good working condition for the system to function
properly.
Operations and Maintenance will be the responsibility of the Owner, North Mason School District.
E.2 Permanent Facilities Description
The proposed drainage system has been des igne-&V51— filtrate all collected stormwater on-site. Collected
stormwater from impervious surfaces will discharge to a proposed infiltration trench. Type 1 and 2 catch
basins and storm drainage piping (6" and 12") are used to collect and convey stormwater. An emergency
overflow will convey runoff to the roadside ditch along East North Mason School Road. Collected roof
runoff will be collected in gutters and downspouts and conveyed to the proposed infiltration trench by 6"
roof drain piping.
E.3 Discussion of Maintenance
Any buildup of sediment, debris, vegetation, or trash that impedes the designed conveyance system may
cause problems. As a result, care must be taken to keep drainage structures clean. A "vactor" truck, or
other approved means, should be used to clean the on-site catch basins. Deposits on the paved surface
should be swept or mechanically removed in order to prevent sediment or debris from entering the
drainage system. Sediment removed must be disposed of at an approved site.
Per the 2012 DOE Manual BMP T5.15 Permeable Pavements, porous asphalt surfaces should be cleaned
using suction, swept with suction or high-pressure wash and suction (sweeping alone is minimally
effective). Hand held pressure washers are effective for cleaning void spaces and appropriate for smaller
areas such as sidewalks. Small utility cuts can be repaired with conventional asphalt or concrete if small
batches of permeable material are not available or are too expensive.
DOE Structural Source Control BMPs applicable to the project include the following:
Applicable BMPs: BMP S412 Loading and Unloading Areas for Solid Material
SITTS & HILL ENGINEERS, INC. E_2
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
• BMP S424: Roof/Building Drains at Commercial Buildings
B M P T5.15: Permeable Pavements
The applicable maintenance checklists and excerpts from the 2012 DOE Manual have been included with
the Operations and Maintenance Manual for review during routine maintenance inspections.
E.4 Maintenance Frequency
Following construction of the project, all facilities shall be inspected and maintained according to their
respective maintenance checklists included at the end of this manual. One form should be filled out for
each facility on-site. It is recommended that the maintenance checklists be kept in a log book or binder
on-site for documentation and review purposes.
Facilities will be inspected monthly, annually, or after every significant storm event where the
precipitation is greater than or equal to one inch in 24 hours.
When deficiencies are noted, the problems are to be corrected as soon as possible. Any spill of hazardous
material (e.g. fuel, lubricant, herbicide, etc.) will be cleaned up immediately and will be reported to the
Division of Emergency Management (1-800-258-5990). Contaminated material will be disposed of
properly. A sample Spill Record Form is included at the end of this manual and may be copied for further
use.
Any questions about the existence of a problem should be directed to a Professional Engineer.
E.5 Annual Cost Estimate
Annual maintenance costs for the storm system will include cleaning of the catch basins, French drain,
trench drain, porous pavement, and conveyance elements. Approximate annual costs for these tasks are
tabulated in the table included in this section. All maintenance activities will be the responsibility of North
Mason School District No. 403 upon occupation of the facility.
System to Maintain No.of New Facilities/Structures Approximate Annual Cost
Catch Basins 12 $2,100
Infiltration trench 1 $1,000
Trench Drain 1 $250
Porous Pavement 1 $1,000
French Drain 1 $250
Total $4,600
See the following pages for plan sheets showing facilities to be maintained.
SITTS & HILL ENGINEERS, INC. E-3
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
UJI
0
c
7 1 1— — — — — — — — — — — — — -- - 0
------------- ------------ U
4U ♦ Yj
'Z z
wo, 0
ok� V)
U1j
711
7*
4 ME
r
--- --------------------
(_7
tip 0
< Ci
U z
z
<
1E------------—----------------------- L
7 0
z 0 o 0
< .0 0 U
v)
< C
< M
>
0 z z 6 0
ALT 0-1 1 ji
aiFF
---------
L
-T
— — — — — — — — — —
— — — — — — — — — - --
r�,_ jmw
v,
Call 2 Working Dap Before You Dig prp.mf W21116
GRADINGAND DRAINAGE PLAN GRADING GRADING AND DRAINAGE PLAN Utilities Underground Location Center
SEE SHEET C21 SEE SHEET C2.2
SITTS & HILL
ENGINEERS, INC.
CIVIL -SMCTVRAL-WF.vE)v4G
IMF A—.k_."" C2.0
NO
"
HUR17ONTAL 5CAU I'_40e
OMM41 GROM AND DR"GE RANa 40 Be Fvooet Na: K3311 P.,a W: KLK
M F 1'=4d
SITTS & HILL ENGINEERS, INC. E-4
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT-STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
I , b� - • LEGEND
A \-,j, +�\ \\,'�\\ \ \\1 \\ ��� I RID■f� Qi
sraw GRAN Plot DrmaN ar r►Esx wxc 2af ,L
-c��-]Ywf�-_ _- -.D- ROOF pMN IF Ds DOWNSPOUT > S E
-'------ �- '1 \ -ID- FOOTING DRAM/EIR1910H DRAIN GS GRADE ELEVATION /Ord S 9
TRENCH DRAW rc TOP Or GRAVEL 11 e
GRACE INL11, rP Fro O PAD U s
UYrts CE A/Jh, BR BACK O COMA 2
I f `I} - \I •\ \ ` i .r I. �f//r ~•~ \`t` V Krt7ATEO/Iroo:LIVED SAAIE/ IN, TaP OF Otx
E su JE
\\ d Y' \\\ \ - SURFACEMAY tc TOP of cmO
RNNGM1O11 BOTIOW Wt%M OF ONTO _
E '. ■ TYPE 1 CATCH BAsxh7Rm DRAM
TA
TOP DE ASPkKT
\ El \ 1 ItFOP OF 16U U
I E 91�\ e M 2 CA10R BA
f I I i ff I Gi a h iF l E# } _ Y�jrl /- 1't•'R:; R 1 ROOF DRAIN CEEFMOUT(00)
- l '1' �. tNWLL
WE W104 EX5-IK EA EXISTING
IT I I I 66r 't 2O- E B �1: A FIRE HYDRANT L1J
VALVE
I ✓ / Tp 210BB r �1 A (aB6iAL NOITES _
ti
t R E ` yV'`� / !1 (A•/ I .v`��i� ; 1. 11[BRAISE UMli6 M i1K M"Cr ARE"Do N THEIR
MP""'WAT LOCATION"i"*W 0*0 Etl5TM0"A"
`I ^`�/�R�p�p�����I (SEE SIEE75 C7-St27 u1UTE5 MAY NW�$IFDRIF ON TI'M PLANS.THE CONTRACTOR 9ULL CONTACT ML UTILITY CpiAlrts Mm HAVE TEEN
\ 1111 i ` E i , WIP VPl DAM 0.f1DFNILE FOR STMOM DETAES) LOCATION YARNED ON TK QRaRm PAIDR 70 O]ISDEICTION THE 00IIIRACRN ILL PROTECT,OR IMMEDIATELY IEPAF AIY
b 1
TF�s0 D '�'� \ �^ sJ r I sTINcrLRE� 9PEIr E1Ev wlEs o.YAaD unuTr'0500'QED-ON nas wm.Ecr.THNfuT ADDITIONAL cOstt
�L j i' I ac `•l- / c_ �• . I 2 MAINTAIN 6 YNFW 1(RTKAL AND 3'L HOWOMIAL QEAtANCE(OUTSIDE SURFACES)�IiEN STONY THAN PF{s
/F ?1 I / IE.7Eq(TT TE51
rr�V. E _ A p - �G- 1 0 pl INL9y SOLO LOG1m IEf FRAE GFAX AND O1MER UlEltt PIPES AD OJIOA7S IReF.SS OMERIRSE NOTED,
t r'1(�� 1t11 b I / \ - LD If 6" EB IF P' _ E.17E]I(f 0) ME GET&B2
IUA
d8-- /i PVC 0� i IN HEIGHTPVT 0 09 3, THE I CATTM MASKS HEIGHT(FIRM M NAfRT)TO HAVE STANDARD D LADOER5 2 CATCH RASNS PER O.ba
a N k Ii A 92 If 6"PLC•OL r.le F-277.a by KS) TV[2-W u/Mo
t E - - Ch p2 28M E-27T.F7(B'E] F/TEE(2)10 MIS LOWK FORD
YF LAIDY_l8F - T;.tex»=1�LF 6"PIK _ C.
�I1l� Sa11 COMB,SEE DETAL M/E'L7 a ALL CATCH BASIN GRATES TD BE Ti0.r 000 GRATES SEE ASSOCIATE DETAILS ON SEER C25-Lz6
h� , 1. _ _lU-^I_-- l --_-__-T_TFw:aa.n • , PVC _ 5, AL CATCH BASIN MISTS N OR ADY4NT TO FAMED AREAS SHALL BE YAFM WITH A 779N SiFNG:. SEE DETAIL At/C3S
M U 6"PNO.2.OF._- 83'T70 B.iO�- .� -
! E.22E10 SC S) TAPE 1-M/tDOONG SOD RECT.
p. IE.27E0i l�E) COMIH.SEE DETAIL B2/C26 E. CONTRACTOR AND/OR SIIPTHEOt 9MLL OALCLLAIE PIPE SLOPES EA BASED T/FE N1QT yDMCELEVATIONS SNORES SIN TIE PEARS
cp I E) fRMOt TO a CONSCMk THE C8N1RLCrOt 9AHL IROIFY THE A16]RiFLr/U101E1A 6 A1r OSCIFPAICZS PROP TO nF1D
,1 131f T PK :vA' -t, 13 l STNOIG AD CONS1RlIC1RIN.
1 lx -'r" II I M41-SC
[(( p ON / y,I I ( L E-2t7Es(IT I/la(1)TD a B/Lww 1. AL ROOF DRAW(RD)LHS TO IE:5'PK SDR-B AT A MINMM SLOPE OF 1s(WYIN).UNLESS OT EAIH NOTE)
-- I �� E^S� RORD�D NEIC SEE MAIL
Pit U \ '_. •., YR ICI E - '�� L_- -�-----"-- -- J BI/427 t COMRACIIP TO FIELD MERIT NORO TAL LOCATION Of CATCH BASIN SDDICIIRES MIH FtSPEET TO OMNG/CWEM 0
Y I f0 B,Bi - - PADS PRIOR TO CATCP fYSN DL%M NT STMNC Or PARTIAL Cuf05/PADS AT TALK O CATCH BASIN STAANC CORD BE Q
CD>a COd 210.95 E-277.t5 IT FIFE 2-Af HE(ESSAPr
N�. 1 wAOC/NG ROM SOD COVER t i Q� iCRA_1D0.90 Lal F ( R�S) 9. (TRADING LIMITS ARE AS SH ONIN.0 Dk C)
E 'I't 9 I 1 LM2B0.70 �~ 1F! TYPE I
TO THE CONTRACTOR SNM4 SET FRACES AS NECESSARY TO MATCH GLOSS Sam OF THE FINI41 GRADE J
E E ' f I II 110 T P10F �l0.10 E-27EN(if(6'Slll) OEfµ B2/CT 11. SEE ARORIEC.1RU PLANS FOR LOCATU6 OF DOWSPOU6 AND COODNAIF FED PPNG d DOMLSPOUT ASSES CC Z O
m �t I7BBa Ob p6 2W15 N/SOD LOOPING RELY.tbMR SFE O ("')
1'�, O9.0.L �. ACCODRAlT Q C
TC/TA-7EB90i1w2MA2- - 1F2E0.10 SB.SBD. I Tom' 12 iR LANDSCAPE 91E P.AM FOR ACOOIONAL SIC ELFRENIS p, = O
- \\. a p7 2d56 E-DIAL'IT NQ r/SOLID L0001IG 1M1 .COVER SEE?tie/ ,%1F2N97 ' EkTIIN(r 58) DETAIL 02/Q.6 13 THE CONTRACTOR SIMIL TEIPORAFILY REPO[Tiff PROTECTION TO Pf16AN GRADING, ` N z
1 ) y U
K 80111DAR MID IOPOOtARRC NFOHIAIEN SNCrI ON 71E 91F ME AS 9ATRAI OI A iffOOtAA1C SURREY(XMW:TED BY
CLEAN
ryr p�y.py. ism gem C2`r-G2.7 SIFTS AYIL ONOf]LS(.ION NO IS,773}SEE THE ASSSOO.VTID TCAOGRAPN[PLANS ON CG.I-00.2(PREPARED BY SITS AND Z -
'Tt Mi�OUT�L�ME FOR STADAD DETAILS) ,EL EMfiF➢6J ETR IIDIIUTAL 9NMr IFOEIATILN.APPIf1" TOPOGRAPHIC NFOONTTON ALONG THE NORTHEAST V
CODE a TINE SF 6 FEW THE PHASE 2 PAGE AGWM PROECT MAD SOUTHEAST EDGE or THE SITE 6 FROM PHASE 3 Q ❑
E 1� 1�I 'Px /J'f A i . .•'a I 00 pI 291.50 E-28DA0(6') �C� MAMO S ALUMS SCHOOLPROJECT(PREPARED BY SITTS A FILL0021C t5 I11C)/OE51G N PLANS(Iqr AS BJET). Q = O
CO fI OMpETE COLA. 15 AL STORM ORAN PPE TO BE OE➢.UNLESS OROFW NOTED INSTALL REAL DETAIL 02/tI3 A DI/:'15.
-I /// �• 002 251.50 E-2L10(E') ❑ Z O
III COKKIE W1At, 16 COORDINATE TRIM SIMATIIG RAINS SEE UTILITY PI/MS FOR ALL S7WI/UWTl CROSSINGS. Z O U
0o N szm E-200 R7 SEE DETFa A2A23 Q vl In
_ CO NAA 2" [.LE76(R') SEE OCTAI A2/43 CT 17, ALL F➢ NM GRAMS MUST HE TICKTI FD ALTO A CATCH BASIN.DO NOT,COI ECF TO ROOF DRAIN LINES Q
! \ z 5 N
1fl ALL FOORAG GRAN(TO)IlES TO IF i PERFORATED PVC SOR-S AROUND BUYDIID PFkdfflEll.fO17NG DRAIN IUNTIRIES Z `
p4 I I TR-X.9c� �I L` ' 1 W201.40 �N(, / CD 05 21M E•210.7E(E') SEE:WDL AM= 'RCM A CATCH BASIN TO THE NRAG SHALL BE SOLD WALL PVC S R-35 ALL FRENCH DBMS(M$'rFD)LINES TO A 6
__.-__ k__ HE SOLD WALL PK SOR-n
___________RIOT _-------,---_ __I CO P E TEAL E' 8 PYRE A2/C1,5 19 n�E WIIRACTID SWIl FULLY IESRN' c�n(N.iRC11C1 OtM1 7M]InNQ F7Nd A CATCH BASIN 70 THE
FitO/ChDRAU ❑
PK SOR-R RUM FFUOI GRAIN 9'L
CD P6 SEE MIAL Q
1 ! FI- -- L
k (.) ALNIN"AIHNG+AIL STONY SYS1aR5(EXISTING AND PROP95U)THROD71 O
ng ALL PHASES OF CO69FNCION AND THROUGH RD.ECT COMPLETION TI(CONTRACTOR SHALL SUBMIT A 5� AND POROUS � o
l A T +I 1 PAYDIEN'RAN FOR 7IMPORAR1 MEASURES BETIM PHASE PR SrFONNG FOR ENGINEER FEYFP Z Z
/
I�27s.6P t 2 ;,-V�\\ �11 I - - I MY NDM y P HA
DNA W ' O RNIERM DRAIN,, DESK 05/M5
`
A7 OVERFLOW OUM PPE MsrAu OE■16 LAWf L'
.{ 281 PER LIAAAL G RP RIP RA RMAID AID RAP PAD.SEE PLAN y(" >�
Tf-2B090 - FOR LE D PAD YREWI OR[1G9GN5
E } �'� � 1r �A.2BO70- r..,crr. L_•,�i S-15
orawNc IAAw
SC 03m/id
Call 2 Working Days Before You DID D312P/16
2 C6171!16
- �- -_ - - - �' _ - 1-800-424-5555
-zir - _ ' - _= Utilities Underground Location Center
1T= =T= SIT
ENGINEERS,INC.
----� ? -
z _ TN i \ +
Y,-A __-_ #A•/r¢ --s++F-7/
r -�\•: - J ` GALL •STFNCTURAL.SUR4£1TNG
G t �//ry7H1 �EA,h �[ A.�/ / RyYpnA .n!rEFIRR stRtET TMriAw,.A mwR
- ..___ \ • b.N1�I(y4 IB 6�_ / `4 a '! I A�yt / / \A\It lE_ / \•.\I'rri�' sl rPLR M hHONE(2SI)al.-PUP i
/�p��yE/�++d�/���p��Ry/S\�pI�� \ ?S7" E 3` drt -e A ,.>LOEJC• t�.n _ k NOI3MTA SCALE:1'z30'
Vl1'LARRA!tiO D WMtIG ELM 70 G 30 60 Prow MF: 163N pO1Mt Yp.: Y.LKIN '
SCALE f.]U P*End- NX Pn/Palls LMY
SITTS & HILL ENGINEERS, INC. E-5
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT-STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT
Job Number 16,331
- � Z
, --
ae-N^. ah Yxb 3�` ` -ID- SIGN awl PIPE <
13DTST ra>Q.a 5C � s 94 t DEFCIION a FINISH alcE SLOPE > €3
11"W710 - l ` -RO- ROO WAIN A4 S
� as DOWSPDur 8€
4 TAF pII.20 .I -� ♦41 E I \X I rD rooRms aHM/TIEIACH«RAM GS (MADE ELEVATION O c E
rr.r�u.
e t,� � Y ra+OF mAvrE.
Y! ` � 1 h ------ JM A TOP Of
U
a GRACE ORE ,j
pp B W75 OF ROPY BR BACc OF PALM
)// 4 •
$ Li N ae�m KAFEDR RDa LKL SNYL, TN P Or o N Z
SURF11 ' V j�+ --• --- � -' -- ---� --- /-'�•r. ---� /-- ---' -- yTFT .i®,. TC ,OPV NRB O
I 1 F
R/IKXR71 BDTiUY Do BDR011 Or fiRB N _
`;\\ m.n No, �� I --» � , o` I� 719E I GiiN 9A91/rAio DRAIN TA TOP OF ASPWII INC
\'''�j, �j'y,�(/ I _a. \ • TYRE uIa M9N U
/ M,^ \ \`.� O / ,MIL LOP OF.41
A�k�1 4 1�]aSOa Oa/ �(./ \, Y� R °RAIN aFNlart(m) WE MICH CASTING E1 EKING w
3f"` - A• iF306.N r p `s' \ r• FIRE NMRW7
�pN��� vulc
k k` IF70SM -- ' /Q `✓G' flY ` �S} ' \\\�\'d/' i/ I GENERAL NOTES
S. -f ,` f✓`i es xk k^ �I EAR• �i `\ / / e ' I. THE BARED UTILITIES ON IMrs PR6ECT I%SHOWN N THER APPRa91A&LOCATION THERE MOON.OTHER OEM eDl�
\�[ .< I � 3 yf` tg �t Cr R� YYYY 6( 1 \\\/// i E UT1uTES NAY NOT CE SNONM ON YK%PLANS TIE CONTRACTOR 4MLL COATKI kL uIU,Y COMPANIES No M1f IIER
�Y`ax= pa YYY % / Y DM4EC DI 'DWO*PEC'oN PROLOCATION WAND 04 THE GHA.NC PRIER 10 JECT TIMW o0`ITRA-TOR TIRE PROTECT OR IROATav gDAR ANY
Pe� / \B\ v EF3aau IE .M +yy.i to aYPtsB E
COSTS
!Il I IL 1E1TFFS2NfL ' aiE Esk�q- •. IR 2 MAIWAINNNWN`S i AND S wul 10WIS Q F(OUTSIDE SURFACES)BE1EfM SRN DRAIN PIPES15 AND OTHER U Ltt PIPES OOGR i UNIM OTHERWISE NOTED.H
/��(n\\ allll 1 TYPE 1 CATCH BASINS>:M HEIGHT(RN TO PnOn TO HA%E STANTUM LAMM TYPE 2 CAT«SASKS PEP MAIL
31a F= ee (jI ' \ _ u/1:2.6
55 LF lay a 6'TD a a! 'yf� �i\\�' .;; - k iZ a YA \•v 1� 1. ALL CA"M9.GRATES TC BE B47 DOM GRATES YE ASSOCIATED DETAILS GH ARTS CZ5-U6
E am a"^Px ,. 2p �\ [ 1 � VIA $° k ! A j■ Lc S ALL CATCH BASIN NUYS N OR ADMIErt TO PALED YEAS 90LL aE YARNED WITH A T9 SMXCF' SEE DETAE N/C 5
r]2 �P a tFAI.W `• ` �s 6. COIIRE w atR,e gw
ACWw Modal SVR.EYJR SMALL CMDLAM PPE SLOES III ON THE INVENT MIDATKNS 910N1 a THE PLANS
CONCESSION=IDT2N T'fi�[ y[T� i� � '' tawi.SD - S /' PR eTar l M°Irr AN THE AxoETT:er,Exrome°r .DISCREPANCIES PRIOR rEID
.22
_ �1a TY��DT42\ c o
'E ZOH 17 2EI.17 •TMS5 T• - \ `6 y R f' 7. ALL ROOF OHM(RD)LEES TO HE C PVC SM-35 AT A IMOM YSR O 1,S (WE",UNLESS OMPIIH MOTO �
7p2a1.06 IIr7RF 6 \. kfl y' A �A1 B CONTRACTOR TO FIELD VRFY HORIZONTAL LOCATION OF CATCH BASIN STRICTURES 67H REJECT M aXIM/CMOFr, Q 16 if 6'm �I S. A�N��yNL�p�� r�. (RE SPEE-R C2_5C3 7 FOR
TZbC ..• 1W-299.02 Fe y b ' A-NPSIR.11E vPJFE 'E�JAILE STAIOMO DETAILS) PADS PRIOR ro GTbI BASH RKEIDIT STARNC OF PAR11A fDRL5,9ADi AT FADE OF GT[N BASH SIANIG Co"CE
150 J _�0. I,wyLl♦. hV e 1 . 4/ B •b k. NEOSSAIn Q
T 29B(R \.. g i > I �� RN INERT Ed,, NOTE H
o EIEV 9 GRADING LIMITS ARE AS SNOW HERON Cn
as ke /
1Y L5j
A
. �y-�--x/r 2m.90 �. t \ f �'!/,}� Wg Ep.B E-277.63 E-?7791({B-E) 10 THE CONTRACTOR 9MLL SET FRMES AS NECESSARY TO MATCH CROSS SLOW Of THE FRBI CLAM O
�� •" n-nss \ /,bV/Q H. SEEw1rJ6TEcnxlK RAMS FOR LOCATIONS OF DOWNSPOUTS AMcoamwATE AT r�Rlc 6 DOWNSPOUT
en
h1 ACCOEMQY Q Q
T■.aa ISO 10/EM1af0 Is. T\ ,\•`\31-'. _ - _ GO ON
,z WE lMD9VVC SITERN1 PR'ADDITIONAL 9rE ELEIaN1S a U Z
E.z77.a7(T Iq 11 M COYMACICR SHALL TEW-DRNEY RENOVE TREE PROTECTION To PERFORM GRADING U
r Itl� +2Rw N' 1A. BOROMIT AND TOPOGPopRC TA'OIWTHN SHOW OI 11E Sr ARE AS 9VAN W A TOVp1AFHC SAWY QOIOUCIED RY T.3
Q n0 f SETS L ILL ONbEERS(DB NO 5,7731_SEE THE As:OCIAIEO TWOGMPNC P-N6 CN GET-f12(PREPARED By SOTS AND Z N LLLLJJ I O\ \` .� MM Y4 E-m as TY ELf NL vNOEas)FOR xGTIOMu SRSHEr RwwLA1pL 9.wEElENrAI raO9tAREC RsaBlAxa ALONG nE NarnICAsr
a u \ :;,_ , COB PI [=GORE��5) EDGE OF THE 5TE R FROM THE PHASE 2 PACE ACAMO PROECT AMID SOUTHEAST EDGE OF IHE SE IS FRd1 PNSF 5 Q
lob Eye J I_ \�'� _ MAWNS IEi11E SOYJLL PROJECT(PPFPMFD er 9TI5 R nu EMiEIItS.MC.)/bE"RM6 OHOr AS ELLT). EY = Q
CIO \T '\\\ ` _ -ALL _ e_ E-rnN 1s ALL STIMII GRAN PPE ro BE CEP.UNLESS UTERNH NOTED INSTALL PER METAL 02/M3 a D1�2.5 C Z C7
_ C r
(4"L
LyzJ � 1 � 1��6. � � - �1 �•c`�� � § a nx I.13 Eti76.N(1'EM 16 GWOMTE NiN sGPAOIF PVMS.sfE uITLm PlAlls FDit ALL SWON/UTU71'ONSSHLS. Q O IU
� 110.0 �.. `` _ 17. ILL FOOTINGS MANS NUSf IF R(INiLPED INTO A U701 BASH.g}..BOj OaREC'W 70 Roar DRAIN LNG Q C
YT~cl I PY-a1.13 1 E�E77.63(IY Nj,N (' S
Ob 10E-2ea6e �'■\\ ��\ _ � - CI n3 16 A,,FOOTIIC GRAIN(TO)DIES TO BE:PERFORATED PVC Sal-35 AROUND BU M PERIMETER.FDOTNG TWO MAIT.RES Z ` O
` Y _- i -_ - FROM A CATCH BASM TO ft MUL NG SMALL BE SPED MIA MI PVC WR-35 ALL FRENCH DRYS(ALSO-M)LINES ro BE 6• o
O ��.a�.IAN } r 1F2RN -�rt \_ PERFORATED Py SON-35 RN/1 FRENCH atlM SECTION FRENCH GRAIN,IGHRINES FROM A CATCH BASIN TO THE TREND, C
��RLyB�� $D 1 •^-N. I Do _ _ _ OIAN 70 BE$0.1D M41 P'FC 2R-35
----Jam
-- -""-'-'-"- ----- T' TC/WMZBafF r iMLtl3 r 11Ai.T�---Or�f t 1y0- -- -1 �''�-tir 1-- (SEE S TC15-AILS) 7 FIR
Tl71L6B _ _ -NH- �-µ 19, ALLTHE PHASES F 9NLL H FN AN RESPGI�If FORD THRUJIGH PROJECT
MMWNNG ALL STORM WACTOR HALL SUMMIT MID PSFCRW )7 PROD
SOWLE SiAMDA1O OETALS7
N. P VERENT PLAN Fw TEMPORARY IEASRIES LLIIEEEM PMASE 1RNIS'VIN FG OR DNOPMR RET�W A SIGN NO POH11R O Z
C0�0B [=zA.01 11�
Ba SOB
I a � g� lllllll I : „RI,..� �:• ___`� I e J�--- l�'
p AEON Na21177- - -
I Eby MM/�R�p
TF21IP 15 PAG1 NOTES y A
N // I ITT
I - ^k.a6.07 O 71EMO1 WHIN,PER OCTAL 0.5/C25
. IN �/. L5 LF i 1`•LLL 2B6SO _- - O OVRRLOM CURET PPE NSLu Dom I~
BELIN I 11b207 W ■g ? PER OETAE IT/C2.5 AND RP RAP PAD,SEE PLAN
��Ieh R11b2B1.13 _ 11/TM7N.E i t 9'• FOR LE No RP RIP PAD M/Yll DREIAOK 1
-} /DOT-2111OE3 I. ITNLL-7Y.50 - '4e
TER-2E1.M ITkDTI.w OS PATCH GSCOM1ECim PPE cGNEEnaMs PER CETALro�`°
rE-2sf 1 TR.20o96 ' SEE 9EF I a1/C25
1 Fw ALTo-t
f.�
TR-2IRA0 �; .l A ooMT E
1R2y0
t 9N 1C/,A2B090 E O __ j�a F r.71r•.rl 201515
5a _-- ®^3� iM2I0. I J 5L, JMW
1 SC 03/03/16
,n ur CPEP•D67H u.2m. 1_ _my p Call 2 Working Days Before You Dig ro 01n9/16
TL-21L50 06n T/16
a TA nLO2- �;- - & - ti 1-800-424-5555
/«- / 1PI7LT 17YLL-2W0 ,��--�
_ ? wa2.sB .c TA-sLP6 __TCW w � `- RP_ _ IT RA /,' Utilities Underground�ocaTf on Center
F�o. 1s� Fo-2n.a sc-2ma _nu-2sti9-Eo-ssn fEFui6o___ y±/`�
_ - FC•m3..1W5 1C 77f3A -' - �T- = =�-' •.f.
�- J _ SITTS & HILL
-- --- :�
ENGINEERS INC. SN•et
6 - lNc C2.2
Yr7IlE cL .sr�cTUP>L.sueeEr
/M ` [// n� ',.ems 1 i uls-TER I T T- r RRN6R
NOM
��������T��//5��p��P IIa�.TAL SCAIE:I,
NiIPY/FR1 P+rV DRAIU GE 1 WTI 30 0 b 60 R.Od No 153M P.0d 0'. Stu
• $CAE:H--SD RN,E.9w-. ILL N'6j w Jrfl
SITTS & HILL ENGINEERS, INC. E-6
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
• Catch Basins
Catch basins are underground concrete structures typically provided with a slotted grate to collect
stormwater runoff and route it through underground pipes. Catch basins can also be used as a junction in
a pipe system and may have a solid lid. There are two catch basin types.
A Type 1 catch basin is a rectangular box with approximate dimensions of 3'x2'x5'.Type 1 catch basins are
utilized when the connected conveyance pipes are less than 18 inches in diameter and the depth from the
grate to the bottom of the pipe invert is less than 5 feet.
Type 2 catch basins, also commonly referred to as storm manholes, are round concrete structures ranging
in diameter of 4 feet to 8 feet. Type 2 catch basins are used when the connecting conveyance pipe is 18
inches or greater or the depth from grate to pipe bottom exceeds 5 feet.Type 2 catch basins typically have
manhole steps mounted on the side of the structure to allow for access.
Both catch basin types typically provide a storage volume (sump) below the outlet pipe to allow sediments
and debris to settle out of the stormwater runoff. Some catch basins are also provided with a spill control
device (inverted elbow on outlet pipe) intended to contain large quantities of grease or oils.
The most common cleaning method for catch basins is to utilize a truck with a tank and vacuum hose
(vactor truck) to remove sediment and debris from the sump. Catch basins may be an enclosed space
where harmful chemicals and vapors can accumulate. Therefore, if the inspection and maintenance
requires entering a catch basin, it should be conducted by an individual with training and certification in
working in hazardous confined spaces.
grace
/ BIRD'S-EYEVIEW
i
base section
i e
o lei PVc ® MP.
Type (I SIDE PROFILE
Type 2
SITTS & HILL ENGINEERS, INC. E-7
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Catch Basins Checklist
Date
Frequency Drainage '� `� `� `� Problem Conditions to Check For Conditions That
System Should Exist
Feature
ANNUAL General "Dump no Stencil or stamp should be Warning signs
pollutants" visible and easily read (e.g.,"Dump No
Stencil or stamp Waste-Drains to
not visible Stream")shall be
painted or
embossed on or
adjacent to all
storm drain inlets.
MONTHLY,STORM General Trash&Debris Trash or debris which is No trash or debris
located immediately in front located
of the catch basin opening or immediately in
is blocking inletting capacity of front of catch
the basin by more than 10%. basin or on grate
opening.
MONTHLY General Trash&Debris Trash or debris(in the basin) No trash or debris
that exceeds 60 percent of the in the catch basin.
sump depth as measured from
the bottom of basin to invert
of the lowest pipe into or out
of the basin,but in no case
less than a minimum of six
inches clearance from the
debris surface to the invert of
the lowest pipe.
MONTHLY General Trash&Debris Trash or debris in any inlet or Inlet and outlet
outlet pipe blocking more pipes free of trash
than 1/3 of its height. or debris.
MONTHLY General Trash&Debris Dead animals or vegetation No dead animals
that could generate odors that or vegetation
could cause complaints or present within the
dangerous gases(e.g., catch basin.
methane).
MONTHLY General Sediment Sediment(in the basin)that No sediment in the
exceeds 60 percent of the catch basin
sump depth as measured from
the bottom of basin to invert
of the lowest pipe into or out
of the basin,but in no case
less than a minimum of
6inches clearance from the
sediment surface to the invert
of the lowest pipe.
SITTS & HILL ENGINEERS, INC. E-8
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
• Catch Basins Checklist (continued)
Frequency System ✓ ✓ ✓ ✓ Problem Conditions to Check For Conditions That
Feature Should Exist
ANNUAL General Structure Damage to Top slab has holes larger than Top slab is free of
Frame and/or Top Slab 2 square inches or cracks holes and cracks.
wider than 1/4 inch(Intent is
to make sure no material is
running into basin).
ANNUAL General Structure Damage to Frame not sitting flush on top Frame is sitting
Frame and/or Top Slab slab,i.e.,separation of more flush on the riser
than 3/4 inch of the frame rings or top slab
from the top slab. Frame not and firmly
securely attached. attached.
ANNUAL General Fractures or Cracks in Maintenance person judges Basin replaced or
Basin Walls/Bottom that structure is unsound. repaired to
design standards.
ANNUAL General Fractures or Cracks in Grout fillet has separated or Pipe is re-grouted
Basin Walls/Bottom cracked wider than 1/2 inch and secure at
and longer than 1 foot at the basin wall.
joint of any inlet/outlet pipe
or any evidence of soil
particles entering catch basin
through cracks.
ANNUAL General Settlement/Misalignment If failure of basin has created Basin replaced or
a safety,function,or design repaired to
problem. design standards.
MONTHLY General Vegetation Vegetation growing across No vegetation
and blocking more than 10% blocking opening
of the basin opening. to basin.
MONTHLY General Vegetation Vegetation growing in No vegetation or
inlet/outlet pipe joints that is root growth
more than six inches tall and present.
less than six inches apart.
MONTHLY General Contamination and Any evidence of oil, No contaminants
Pollution gasoline,contaminants,or or pollutants
other pollutants(Coordinate present.
removal/cleanup with local
water quality response
agency).
ANNUAL Catch Cover Not in Place Cover is missing or only Any open catch
Basin partially in place. basin requires
Cover maintenance.
Catch basin cover
is closed
SITTS & HILL ENGINEERS, INC. E-9
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWA TER REPORT Job Number 16,331
Catch Basins Checklist (continued)
Date
Frequency Drainage `� `� `� Problem Conditions to Check For Conditions That
System Should Exist
Feature
ANNUAL Catch Basin Locking Mechanism cannot be opened by Mechanism opens with
Cover Mechanism one maintenance person with proper tools.
Not Working proper tools.Bolts into frame have
less than 1/2 inch of thread.
ANNUAL Catch Basin Cover Difficult One maintenance person cannot Cover can be removed
Cover to Remove remove lid after applying normal by one maintenance
lifting pressure.(Intent is to keep person.
cover from sealing off access to
maintenance.)
ANNUAL Ladder Ladder Rungs Ladder is unsafe due to missing Ladder meets design
Unsafe rungs,not securely attached to standards and allows
basin wall,misalignment,rust, maintenance person
cracks,or sharp edges. safe access.
ANNUAL Grates Grate opening Grate with opening wider than 7/8 Grate opening meets
Unsafe inch. design standards.
MONTHLY,STORM Grates Trash and Trash and debris that is blocking Grate free of trash and
Debris more than 20%of grate surface debris.
inletting capacity.
ANNUAL Grates Damaged or Grate missing or broken member(s) Grate is in place and
Missing. of the grate. meets design
standards.
If you are unsure whether a problem exists, please contact a Professional Engineer.
Key:
(MONTHLY) Monthly from November through April
(ANNUAL) Once in late summer (preferable September)
(STORM) After any major storm (use 1-inch in 24 hours as a guideline).
Comments:
SITTS & HILL ENGINEERS, INC. E-10
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Debris Barriers (e.g. Trash Racks)
Debris barriers consist of bar grates over the open end of a culvert or conveyance pipe.The intent of a debris barrier
is to prevent large materials from entering a closed pipe system. Debris barriers are typically located on the outlet
pipe from a detention pond to the control structure. If a debris barrier is not located on the outlet pipe, one should
be provided to prevent plugging of the control structure and possible flooding.
Access barriers are similar to debris barriers but are included on all pipe ends that exceed 18 inches in diameter.
Their function is to prevent debris and unauthorized access into the storm conveyance pipe. Removing debris and
maintenance to the debris barrier when there is flow through the conveyance pipe should be performed by qualified
personnel only.
bar frame
Flow
i
anchor strips
SITTS & HILL ENGINEERS, INC. E-11
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
• Debris Barrier Checklist
Date
Frequency Drainage Problem Conditions to Check For Conditions That Should
System Exist
Feature
MONTHLY,STORM General Trash and Debris Trash or debris that is plugging Barrier cleared to
more than 20%of the openings in design flow capacity.
the barrier.
ANNUAL General Damaged/Missing Bars are bent out of shape more Bars in place with no
Bars. than 3 inches. bends more than 3/4
inch.
ANNUAL General Damaged/Missing Bars are missing or entire barrier Bars in place according
Bars. missing. to design.
ANNUAL General Damaged/Missing Bars are loose and rust is causing Barrier replaced or
Bars. 50%deterioration to any part of repaired to design
barrier. standards.
ANNUAL General Inlet/Outlet Pipe Debris barrier missing or not Barrier firmly attached
attached to pipe. to pipe.
If you are unsure whether a problem exists, please contact a Professional Engineer.
Key:
(MONTHLY) Monthly from November through April.
(ANNUAL) Once in late summer (preferable September)
(STORM) After any major storm (use 1-inch in 24 hours as a guideline).
Comments:
SITTS & HILL ENGINEERS, INC. E-12
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
• Energy Dissipaters
Energy dissipaters are provided on the inlet and outlet to a closed pipe system to prevent erosion at these
locations. Design of an energy dissipater can vary significantly from highly engineered systems (concrete
or rock gabion structures) to the more commonly used rock pad. The rock pad is typically constructed of
4- to 12-inch diameter rocks a minimum of 12 inches thick and is often lined with filter fabric. The rock
pad should extend above the top of the pipe a minimum of 1 foot.
discharge pipe
filter fabric liner
under rock
SITTS & HILL ENGINEERS, INC. E-13
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Energy Dissipaters Checklist
Date
Frequency Drainage System Problem Conditions to Check For Conditions That
Feature Should Exist
External:
MONTHLY Rock Pad Missing or Moved Only one layer of rock exists above Rock pad
Rock native soil in area five square feet replaced to
or larger,or any exposure of native design standards.
soil.
MONTHLY Rock Pad Erosion Soil erosion in or adjacent to rock Rock pad
pad. replaced to
design standards.
MONTHLY Rock Pad Pipe Plugged with Accumulated sediment that Pipe
Sediment exceeds20%of the design depth. cleaned/flushed
so that it
matches design.
MONTHLY Rock Pad Not Discharging Water Visual evidence of water Infiltration
Properly discharging at concentrated points gallery
along trench(normal condition is a redesigned or
"sheet flow"of water along rebuilt to
trench).Intent is to prevent standards.
erosion damage.
MONTHLY Rock Pad Perforations Plugged. Over 1/2 of perforations in pipe Perforated pipe
are plugged with debris and cleaned or
sediment. replaced.
MONTHLY Rock Pad Water Flows Out Top Maintenance person observes or Facility rebuilt or
of"Distributor"Catch receives credible report of water redesigned to
Basin. flowing out during any storm less standards.
than the design storm or its
causing or appears likely to cause
damage.
MONTHLY Rock Pad Receiving Area Over- Water in receiving area is causing No danger of
Saturated or has potential of causing landslides.
landslide problems.
Internal:
MONTHLY Manhole/Chamber Worn or Damaged Structure dissipating flow Structure
Post,Baffles,Side of deteriorates tol/2 of original size replaced to
Chamber or any concentrated worn spot design standards.
exceeding one square foot which
would make structure unsound.
MONTHLY Manhole/Chamber Trash Debris Trash or debris(in the basin)that No trash or
exceeds 60 percent of the sump debris in the
depth as measured from the catch basin.
bottom of basin to invert of the
lowest pipe into or out of the
basin,but in no case less than a
minimum of six inches clearance
from the debris surface to the
invert of the lowest pipe.
SITTS & HILL ENGINEERS, INC. E-14
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Energy Dissipaters Checklist (Continued)
Frequency Drainage System `� `� Problem Conditions to Check For Conditions That
Feature Should Exist
Internal(Continued):
MONTHLY Manhole/Chamber Trash Debris Trash or debris in any inlet or outlet pipe Inlet and outlet
blocking more than 1/3 of its height. pipes free of trash
or debris.
MONTHLY Manhole/Chamber Trash Debris Dead animals or vegetation that could No dead animals
generate odors that could cause or vegetation
complaints or dangerous gases(e.g., present within the
methane). catch basin.
MONTHLY Manhole/ Sediment Sediment(in the basin)that exceeds 60 No sediment in
Chamber percent of the sump depth as measured the catch basin
from the bottom of basin to invert of the
lowest pipe.There shall be a minimum
of6 inches clearance from the sediment
surface to the invert of the lowest pipe.
ANNUAL Manhole/ Structure Damage to Frame Top slab has holes larger than 2 square Top slab is free of
Chamber and/or Top Slab inches or cracks wider than 1/4 inch holes and cracks.
(Intent is to make sure no material is
running into basin).
ANNUAL Manhole/ Structure Damage to Frame Frame not sitting flush on top slab,i.e., Frame is sitting
Chamber and/or Top Slab separation of more than 3/4 inch of the flush on the riser
frame from the top slab.Frame not rings or top slab
securely attached and firmly
attached.
ANNUAL Manhole/ Fractures or Cracks in Basin Maintenance person judges that structure Basin replaced or
Chamber Walls/Bottom is unsound. repaired to design
standards.
ANNUAL Manhole/ Fractures or Cracks in Basin Grout fillet has separated or cracked Pipe is re-grouted
Chamber Walls/Bottom wider than 1/2 inch and longer than 1 and secure at
foot at the joint of any inlet/outlet pipe or basin wall.
any evidence of soil particles entering
catch basin through cracks.
ANNUAL Manhole/ Settlement/Misalignment If failure of basin has created a safety, Basin replaced or
Chamber function,or design problem. repaired to design
standards.
SITTS & HILL ENGINEERS, INC. E-15
TACOMA, WASHINGTON
' NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
' STORMWATER REPORT Job Number 16,331
' Energy Dissipaters Checklist (Continued)
Drainage Problem Conditions to Check For Conditions That Should
' System Exist
Frequency Feature
Internal(Continued):
' MONTHLY Manhole/ Contamination Any evidence of oil,gasoline,contaminants, No contaminants or
Chamber and Pollution or other pollutants(Coordinate pollutants present.
removal/cleanup with local water quality
response agency).
ANNUAL Catch Basin Cover Not in Place Cover is missing or only partially in place. Any open catch basin
Cover requires maintenance.
Catch basin cover is
closed
ANNUAL Catch Basin Locking Mechanism cannot be opened by one Mechanism opens with
Cover Mechanism Not maintenance person with proper tools.Bolts proper tools.
Working into frame have less than 1/2 inch of thread.
ANNUAL Catch Basin Cover Difficult to One maintenance person cannot remove lid Cover can be removed by
Cover Remove after applying normal lifting pressure.(Intent one maintenance person.
is to keep cover from sealing off access to
maintenance.)
If you are unsure whether a problem exists, please contact a Professional Engineer.
Key:
(MONTHLY) Monthly from November through April.
(ANNUAL) Once in late summer (preferable September)
(STORM) After any major storm (use 1-inch in 24 hours as a guideline).
Comments:
SITTS & HILL ENGINEERS, INC. E-16
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Fencing/Shrubbery Screen/Other landscaping
Fencing and shrubbery screen are provided around open stormwater management facilities to limit
unauthorized access for safety purposes and to minimize the visual impact of the facility.
Fencing/Shrubbery Screen/Other Landscaping Checklist
Date
Frequency Drainage Problem Conditions to Check For Conditions That Should Exist
System
Feature
MONTHLY General Missing or broken Any defect in the fence or Fence is mended or shrubs
parts/dead screen that permits easy entry replaced to form a solid barrier to
shrubbery to a facility. entry.
MONTHLY,STORM General Erosion Erosion has resulted in an Replace soil under fence so that no
opening under a fence that opening exceeds 4 inches in height.
allows entry by people or pets.
MONTHLY General Unruly vegetation Shrubbery is growing out of Shrubbery is trimmed and weeded
control or is infested with to provide appealing aesthetics.Do
weeds. not use chemicals to control
weeds.
ANNUAL Fences Damaged parts Posts out of plumb more than 6 Posts plumb to within 1-1/2 inches
inches. of plumb.
ANNUAL Fences Damaged parts Top rails bent more than Top rail free of bends greater than
6inches. 1 inch.
ANNUAL Fences Damaged parts Any part of fence(including Fence is aligned and meets design
posts,top rails,and fabric)more standards.
than 1 foot out of design
alignment.
ANNUAL Fences Damaged parts Missing or loose tension wire. Tension wire in place and holding
fabric.
ANNUAL Fences Damaged parts Missing or loose barbed wire Barbed wire in place with less than
that is sagging more than 2-1/2 3/4-inch sag between posts.
inches between posts.
ANNUAL Fences Damaged parts Extension arm missing,broken, Extension arm in place with no
or bent out of shape more than bends larger than 3/4 inch.
1-1/2 inches.
ANNUAL Fences Deteriorated paint Part or parts that have a rusting Structurally adequate posts or
or protective or scaling condition that has parts with a uniform protective
coating affected structural adequacy. coating.
MONTHLY Fences Openings in fabric Openings in fabric are such that No openings in fabric.
an 8-inch diameter ball could fit
through.
Key:
(MONTHLY) Monthly from November through April.
(ANNUAL)Once in late summer(preferable September)
(STORM)After any major storm (use 1-inch in 24 hours as a guideline).
SITTS & HILL ENGINEERS, INC. E-17
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
• #2—Maintenance Checklist for Infiltration Facilities
Date
Drainage
System Maintenance Activities and Conditions
Frequency Feature ✓ ✓ ✓ ✓ Problem Conditions to Check For That Should Exist
M,S General Trash and Debris Any trash and debris which exceed 5 cubic feet Trash and debris cleared from site.
per 1,000 square feet(this is about equal to the
amount of trash it would take to fill up one 32
gallon garbage can).In general,there should
be no visual evidence of dumping.If less than
threshold all trash and debris will be removed
as part of next scheduled maintenance.
A General Any poisonous or nuisance vegetation which No danger of poisonous vegetation where
Poisonous may constitute a hazard to maintenance maintenance personnel or the public might
Vegetation and personnel or the public.Any evidence of normally be.(Coordinate with Tacoma-Pierce
noxious weeds noxious weeds as defined in the Pierce County County Health Department)Complete
Noxious Weeds List(Apply requirements of eradication of noxious weeds may not be
adopted integrated pest management policies possible.Compliance with state or local
for the use of herbicides.) eradication policies required
M,S General Contaminants and Any evidence of oil,gasoline,contaminants or No contaminants or pollutants present
Pollution other pollutants (Coordinate removalldeanup with Pierce
County Surface Water Management 253-
798-2725 and/or DOE Spit Response 8006
424-8802.)
M General Rodent Holes If the facility is constructed with a dam or berm. Rodents removed and dam or berm repaired.
look for rodent holes or any evidence of water (Coordinate with Tacoma-Pierce County
piping through the dam or berm. Health Department;coordinate with Ecology
Dam Safety Office if pond exceeds 10 acre-
feet.)
M General Beaver Dams Beaver dam results in an adverse change in the Facility is returned to design function.
functioning of the facility. (Contact WDFW Region 6 to identify the
appropriate Nuisance Wildlife Control
Operator)
A General Insects When insects such as wasps and hornets Insects destroyed or removed from site.
interfere with maintenance activities. Apply insecticides in compliance with
adopted integrated pest management
policies.
SITTS & HILL ENGINEERS, INC. E-18
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Date
Drainage
System Maintenance Activities and Conditions
Frequency Feature ✓ ✓ ✓ ✓ Problem Conditions to Check For That Should Exist
S General Performance Check crest gauge against design expectations Record reading. Notify county if not meeting
(see maintenance plan) design performance.
M,S Crest Gage Crest Gage Crest gage is not functioning property.has Repair/replace
Missing/Broken been vandalized,or is missing.
M Storage Water Not Infiltrating Water ponding in infiltration pond after rainfall Sediment is removed and/or facility is
Area ceases and appropriate time allowed for cleaned so that infiltration system works
infiltration(24 hours or design infiltration time). according to design,
(A percolation test pit or test of facility indicates
facility is only working at 90 percent of its
designed capabilities.If 2 inches or more
sediment is present,remove).
M Filter Bags Filed with Sediment Sediment and debris fig bag more than one-half Filter bag is replaced or system is
(if and Debris fug. redesigned.
applicable)
M,S Rock Filters Sediment and By visual inspection,little or no water flows Gravel in rock filter is replaced.
Debris through filter during heavy rain storms.
A.S Trenches Observation Well Water ponds at surface during storm events. Remove and Replace/Clean rock and
(Use surface of Less than 90 percent of design infiltration rate. geomembrane.
trench if well is not
present)
M Ponds Vegetation Exceeds 18 inches, Mow
M Ponds Vegetation Bare spots, Revegetate and stabilize immediately.
M Side Slopes Erosion Erosion damage over 2 inches deep where Slopes should be stabilized using appropriate
of Pond cause of damage is still present or where there erosion control measure(s):a g.,rock
is potential for continued erosion, reinforcement planting of grass,compaction.
A Pond Settlements Any part of berm which has settled 4 inches Dike is built back to the design elevation.
Berms lower than the design elevation.If settlement is
(Dikes) apparent,measure berm to determine amount
of settlement.Settling can be an indication of
more severe problems with the berm or outlet
works.A licensed civil engineer should be
consulted to determine the source of the
settlement.
SITTS & HILL ENGINEERS, INC. E-19
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT lob Number 16,331
Date
Drainage
System Maintenance Activides and Conditions
Frequency Feature ./ ./ V d Problem Conditions to Check For That Should Exist
A Pond Piping Discemable water flow through pond berm. Piping eliminated.Erosion potential
Berms Ongoing erosion with potential for erosion to eliminated.
(Dikes) continue,(Recommend a Geotechnical
engineer be called in to inspect and evaluate
condition and recommend repair of condition.
A General Hazard Trees If dead,diseased,or dying trees are identified Remove hazard trees
(Use a certified Arborist to determine health of
tree or removal requirements)
A General Tree Growth and Tree growth and dense vegetation which Trees and vegetation that does not hinder
Dense Vegetation impedes inspection,maintenance access or inspection or maintenance activities.
interferes with maintenance activity(i.e.,slope Harvested trees should be recycled into
mowing,silt removal,vectoring,or equipment mulch or other beneficial uses(e.g.,alders
movements). for firewood
A Pond Tree Growth Tree growth on berms over 4 feet in height may Trees should be removed. If root system is
Berms lead to piping through the bens which could small(base less than 4 inches)the root
(Dikes) lead to failure of the berm. system may be left in place. Otherwise the
roots should be removed and the berm
restored. A licensed civil engineer should be
consulted for proper bern/spilway
restoration.
A Emergency Tree Growth Tree growth on emergency spillways creates Trees should be removed.If root system is
Overflow/ blockage problems and may cause failure of small(base less than 4 inches)the root
Spillway the berm due to uncontrolled overtopping. system may be left in place.Otherwise the
roots should be removed and the berm
restored.A licensed civil engineer should be
consulted for proper berm/spilway
restoration.
A Emergency Rock Missing Only one layer of rock exists above native soil Rocks and pad depth are restored to design
Overflow/ in area 5 square feet or larger,or any exposure standards.
Spilway of native soil at the top of out flow path of
spillway.
(Riprap on inside slopes need not be replaced.)
SITTS & HILL ENGINEERS, INC. E-20
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Date
Drainage
System Maintenance Activities and Conditions
Frequency Feature ✓ ✓ ✓ ✓ Problem Conditions to Check For That Should Exist
A Emergency Erosion Erosion damage over 2 inches deep where Slopes should be stabilized using appropriate
Overflow/ cause of damage is still present or where there erosion control measure(s);e.g.,rock
Spillway is potential for continued erosion. reinforcement,planting of grass,compaction.
Any erosion observed on a compacted bens If erosion is occurring on compacted berms a
embankment. licensed civil engineer should be consulted to
resolve source of erosion,
M Presettling Facility or sump 6 inches or designed sediment trap depth of Sediment is removed.
Ponds and filed with Sediment sediment.
Vaults and/or debris
If you are unsure whether a problem exists,please contact a professional engineer.
Key:
(M) Monthly from October through April.
(A) Once in late summer(preferably September)
(S) After any major storm(use 1 inch in 24 hours as a guideline).
SITTS & HILL ENGINEERS, INC. E-21
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Grounds (Landscaping)
Landscaping is an essential component of stormwater management. Bare soil areas generate higher levels
of stormwater runoff and sedimentation in stormwater facilities. The following check list gives some
general guidance for landscape management.
Grounds (Landscaping) Checklist
Date
Frequency Drainage Problem Conditions to Check For Conditions That Should Exist
System
Feature
MONTHLY General Weeds Weeds growing in more than 20% Weeds present in less than 5%of the
(nonpoisonous) of the landscaped area(trees and landscaped area.
shrubs only).
MONTHLY General Insect hazard Any presence of poison ivy or No poisonous vegetation or insect
other poisonous vegetation or nests present in landscaped area.
insect nests.
MONTHLY,STORM General Trash or litter See Ponds Checklist. See Ponds Checklist.
MONTHLY,STORM General Erosion of Noticeable rills are seen in Causes of erosion are identified and
Ground Surface landscaped areas. steps taken to slow down/spread
out the water.Eroded areas are
filled,contoured,and seeded.
ANNUAL Trees and Damage Limbs or parts of trees or shrubs Trim trees/shrubs to restore shape.
shrubs that are split or broken which Replace trees/shrubs with severe
affect more than 25%of the total damage.
foliage of the tree or shrub.
MONTHLY Trees and Damage Trees or shrubs that have been Replant tree,inspecting for injury to
shrubs blown down or knocked over. stem or roots.Replace if severely
damaged.
ANNUAL Trees and Damage Trees or shrubs which are not Place stakes and rubber-coated ties
shrubs adequately supported or are around young trees/shrubs for
leaning over,causing exposure of support.
the roots.
If you are unsure whether a problem exists,please contact a Professional Engineer.
Key:
(MONTHLY) Monthly from November through April.
(ANNUAL)Once in late summer(preferable September)
(STORM)After any major storm (use 1-inch in 24 hours as a guideline).
Comments:
SITTS & HILL ENGINEERS, INC. E-22
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Inlet/Outlet Storm Pipe
The inlet and outlet stormwater pipes convey stormwater in, through, and out of stormwater facilities.
Storm sewer pipes convey stormwater. Pipes are built from many materials and are sometimes perforated
to allow stormwater to infiltrate into the ground. Stormwater pipes are cleaned to remove sediment or
blockages when problems are identified. Stormwater pipes must be clear of obstructions and breaks g p ppto
prevent localized flooding.All stormwater pipes should be in proper working order and free of the possible
defects listed below.
In addition, outlet stormwater pipes should be inspected to make sure stormwater exits the facility
without causing any negative impacts to the drainage area, if applicable.
SITTS & HILL ENGINEERS, INC. E-23
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Inlet/Outlet Storm Pipe Checklist
Date
Frequency Drainage Problem Conditions to Check For Conditions That Should Exist
System
Feature
MONTHLY General Obstructions Storm pipe-root enters or Use mechanical methods to remove root.
including roots deforms pipe,reducing flow. Do not put root-dissolving chemicals in storm
sewer pipes.If necessary,remove the
vegetation over the line.
MONTHLY General Pipe dented or Inlet/outlet piping damaged or Pipe repaired and/or replaced.
broken broken and in need of repair.
MONTHLY General Pipe rusted or Any part of the piping that is Pipe repaired and/or replaced.
deteriorated crushed or deformed more than
20%or any other failure to the
piping.
MONTHLY Erosion Erosion Eroded or scoured areas due to For ruts or bare areas less than 12 inches wide,
flowchannelization,high flows, repair the damaged area by filling with crushed
or vehicular damage. gravel.If bare areas are large,generally greater
than 12 inches wide,the damaged area should
be re-graded and re-seeded.For smaller bare
areas,overseed.
MONTHLY Pipe outfall Missing or Only one layer of rock exists Rock pad replaced to design standards.
removed rock above native soil in area five
square feet or larger,or any
exposure of native soil.
MONTHLY Pipe outfall Erosion Soil erosion in or adjacent to Rock pad replaced to design standards.
rock pad.
SITTS & HILL ENGINEERS, INC. E-24
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Inlet/Outlet Storm Pipe Checklist (Continued)
Frequency Drainage `� Problem Conditions to Check For Conditions That Should Exist
System
Feature
MONTHLY Pipe Erosion/Scouring Eroded or scoured ditch or For ruts or bare areas less than 12
outfall stream banks due to flow inches wide,repair the damaged area
channelization,or higher by filling with crushed gravel.If bare
flows. areas are large,generally greater than
12 inches wide,damaged area should
be re-graded and re-seeded.For smaller
bare areas,overseed.
MONTHLY Pipe Missing or Only one layer of rock Rock pad replaced to design standards.
Outfall Moved Rock exists above native soil
area in area five square
feet or larger,or any
exposure of native soil.
MONTHLY Pipe Erosion Soil erosion in or adjacent Rock pad replaced to design standards.
Outfall to rock pad.
If you are unsure whether a problem exists, please contact a Professional Engineer.
Key:
(MONTHLY) Monthly from November through April.
(ANNUAL)Once in late summer(preferable September)
(STORM)After any major storm(use 1-inch in 24 hours as a guideline).
Comments:
SITTS & HILL ENGINEERS, INC. E-25
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
S412 BMPs for Loading and Unloading Areas for Liquid or Solid Material
Description of Pollutant Sources:Operators typically conduct
loading/unloading of liquid and solid materials at industrial and
commercial facilities at shipping and receiving,outside storage,fueling
areas,etc.Materials transferred can include products,raw materials,
intermediate products,waste materials,fuels,scrap metals,etc.Leaks and
spills of fuels,oils,powders,organics,heavy metals,salts,acids,alkalis,
etc.during transfer may cause stormwater contamination.Spills from
hydraulic line breaks are a common problem at loading docks.
Pollutant Control Approach:Cover and contain the loading/unloading
area where necessary to prevent run-on of stormwater and runoff of
contaminated stormwater.
Applicable Operational BMPs:
At All Loading/Unloading Areas:
• A significant amount of debris can accumulate at outside,uncovered
loadinglunloading areas.Sweep these surfaces frequently to remove
loose material that could contaminate stormwater.Sweep areas
temporarily covered after removal of the containers,logs,or other
material covering the ground.
• Place drip pans,or other appropriate temporary containment device,at
locations where leaks or spills may occur such as hose connections,
hose reels and filler nozzles.Always use drip pans when making and
breaking connections(see Figure 2.2.2).Check loading/unloading
equipment such as valves,pumps,flanges,and connections regularly
for leaks and repair as needed.
Volume 1V-Source Control BMPs-August 2012
2-27
SITTS & HILL ENGINEERS, INC. E-26
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Drip pan
Figure 2.2.2—Drip Pan
At Tanker Truck and Rail Transfer Areas to Above/Below-ground
Storage Tanks.
• To minimize the risk of accidental spillage,prepare an"Operations
Plan"that describes procedures for loading/unloading.Train the
employees,especially fork lift operators,in its execution and post it or
otherwise have it readily available to all employees.
• Report spills of reportable quantities to Ecology.
• Prepare and implement an Emergency Spill Cleanup Plan for the
facility(Sec S406 BMPs for Spills of Oil and I lazardous Substances)
which includes the following BMPs:
Ensure the cleanup of liquid/solid spills in the loading/unloading
area immediately,if a significant spill occurs,and,upon
completion of the loading/unloading activity,or,at the end of the
working day.
Retain and maintain an appropriate oil spill cleanup kit on-site for
rapid cleanup of material spills.(See S406 BMPs for Spills of Oil
and Hazardous Substances).
Ensure that an employee trained in spill containment and cleanup
is present during I oading/un loading.
At Rail Transfer Areas to Above/below-ground Storage Tanks:Install a
drip pan system as illustrated(see Figure 2.2.31 within the rails to collect
spills/leaks from tank cars and hose connections,hose reels,and tiller
nozzles.
Volume 1V-Source Control BMPs—August 2012
2-28
SITTS & HILL ENGINEERS, INC. E-27
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Drip pop within rats
Figure 2.2.3—Drip Pan Within Rails
Loading/Unloading fromlle jUarine Vessels:Facilities and procedures for
the loading or unloading of petroleum products must comply with Coast
Guard requirements specified in Appendix IV-D 11.5.
Transfer of Small Quantities from Tanks and Containers:Refer to
BMPs Storage of Liquids in Permanent Above-Ground Tanks,and Storage
of Liquid.Food Waste,or Dangerous Waste Containers,for requirements
on the transfer of small quantities from tanks and containers,respectively.
Applicable Structural Source Control BMPs:
At All Loading/Unloading Areas:
• Consistent with Uniform Fire Code requirements(Appendix IV-D
and to the extent practicable,conduct unloading or loading of
solids and liquids in a manufacturing building,under a roof,or lean-to,
or other appropriate cover.
• Berm,dike,and/or slope the loading/unloading area to prevent run-on
of stormwater and to prevent the runoff or loss of any spilled material
from the area.
• Place curbs along the edge of the shoreline,or slope the edge such that
the stormwater can flow to an internal storm sewer system that leads to
an approved treatment BMP.Avoid draining directly to the surface
water from loading areas.
• Pave and slope loading/unloading areas to prevent the pooling of
water.Minimize the use of catch basins and drain lines within the
interior of the paved area or place catch basins in designated
"alleyways"that are not covered by material,containers,or equipment.
• Retain on-site the necessary materials for rapid cleanup of spills.
Volume IV-Source Control BAIPs—August 2012
2-29
SITTS & HILL ENGINEERS, INC. E-28
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT lob Number 16,331
Recommended Structural Source Control BAM For the transfer of
pollutant liquids in areas that cannot contain a catastrophic spill,install an
automatic shutoff system in case of unanticipated off-loading interruption
(e.g.coupling break,hose rupture,overfill,etc.).
At Loading and Unloading Docks:
• InstalI/maintain overhangs,or door skirts that enclose the trailer end
(see Figures 2.2A and 2.2.5)to prevent contact with rainwater.
• Design the loadinglunloading area with berms,sloping,etc.to prevent
the run-on of stormwater.
Figure 2.2.4-Loading Dock with Door Skirt
i
Figure 2.2.5-Loading Dock with Overhang
At Tanker Truck Transfer Areas to Above/Below-Ground Storage
Tanks:
• Pave the area on which the transfer takes place. If any transferred
liquid,such as gasoline,is reactive with asphalt,pave the area with
Portland cement concrete.
Volume IV-Source Control BMPs-August 2012
2-30
SITTS & HILL ENGINEERS, INC. E-29
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
• Slope,berm,or dike the transfer area to a dead-end sump,spill
containment sump,a spill control oil/water separator,or other spill
control device.The minimum spill retention time should be 15 minutes
at the greater flow rate of the highest fuel dispenser nozzle through-put
rate,or the peak flow rate of the 6-month,24-hour storm event over
the surface of the containment pad,whichever is greater.The capacity
of the spill containment sump should be a minimum of 50 gallons with
adequate additional volume provided for grit sedimentation.
S424 BMPs for Roof/ Building Drains at Manufacturing and Commercial Buildings
Description of Pollutant Sources:Stormwater runoff from roofs and
sides of manufacturing and commercial buildings can be sources of
pollutants caused by leaching of roofing materials,building vents,and
other air emission sources.Research has identified vapors and entrained
liquid and solid droplets/particles as potential pollutants in roof/building
runoff.Metals,solvents,acidic/alkaline pH,BOD,and organics,are some
of the pollutant constituents identified.
Ecology has performed a study on zinc in industrial stormwater.The study
is presented in Ecology Publication 08-10-025 Suggested Practices to
reduce Zinc Concentrations in Industrial Stormwater Discharges,website:
http://www_ecy.wa.gov/biblio/0810025_html.The user should refer to this
document for more details on addressing zinc in stormwater.
Pollutant Control Approacb:Evaluate the potential sources of
stormwater pollutants and apply source control BMPs where feasible.
Applicable Operational Source Control BMPs:
• If leachates and/or emissions from buildings are suspected sources of
stormwater pollutants,then sample and analyze the stormwater
draining from the building.
• Sweep the area routinely to remove any zinc residuals.
• If a roof/building stormwater pollutant source is identified,implement
appropriate source control measures such as air pollution control
equipment,selection of materials,operational changes,material
recycle,process changes,etc.
Applicable Structural Source Control BMPs:
• Paint/coat the galvanized surfaces as described in Ecology Publication
#08-10-025.
Applicable Treatment BMPs:
Treat runoff from roofs to the appropriate level.The facility may use
enhanced treatment BMPs as described in Volume V of the SWMMWW.
Some facilities regulated by the Industrial Stormwater General Permit,or
local jurisdiction,may have requirements than cannot be achieved with
enhanced treatment BMPs.In these cases,additional treatment measures
may be required.A treatment method for meeting stringent requirements
such as Chitosan-Enhanced Sand Filtration may be appropriate.
Volume IY-Source Control BMPs—August 2012
2-46
SITTS & HILL ENGINEERS, INC. E-30
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Cover Sheet for Inspection Forms
Name of Inspector:
Date of Inspection:
Number of Sheets Attached:
Inspector's Signature:
SITTS & HILL ENGINEERS, INC. E-31
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Maintenance Log
Action Name Date How Procedure Problems Additional Actions
Taken Was Performed Encountered Recommended
i
L
SITTS & HILL ENGINEERS, INC. E-32
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
APPENDIX F - Soils Report
SITTS & HILL ENGINEERS, INC. F-1
TACOMA, WASHINGTON
` NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Soils Report
North Mason High School Stadium Project
74 East Campus Drive
Belf air, Washington
April 20, 2016
re cared or:
p P �
Erickson McGovern Architects
Attention: Ray Mow, Principal Architect
101 E 261h St, Suite 300
Tacoma, Washington 98421
prepared by:
Migizi Group, Inc.
PO Box 44840
Tacoma, Washington 98448
(253)537-9400
MGI Project P578-T16
i
SITTS & HILL ENGINEERS, INC. F-2
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
TABLE OF CONTENTS
Page No.
1.0 SITE AND PROJECT DESCRIPTION...............................................................................................2
2.0 EXPLORATORY METHODS.............................................................................................................2
2.1 Test Pit Procedures................................................................................................................3
2.2 Infiltration Test Procedures..................................................................................................4
3.0 SITE CONDITIONS............................................................................................................................4
3.1a Soil Conditions-Northeastern Half of Proposed NMHS Stadium/Athletic Field......4
3.1b Soil Conditions-West Side of Proposed NMHS Stadium/Athletic Field....................4
3.1c Soil Conditions-South End of Proposed NMHS Stadium/Athletic Field ...................5
3.1d Soil Conditions-Proposed NMHS Stadium Septic Area...............................................6
3.2 Groundwater Conditions......................................................................................................6
3.3 Infiltration Conditions and Infiltration Rate......................................................................7
4.0 CONCLUSIONS AND RECOMMENDATIONS............................................................................8
4.1 Pervious Pavement................................................................................................................9
5.0 RECOMMENDED ADDITIONAL SERVICES..............................................................................10
6.0 CLOSURE...........................................................................................................................................10
List of Tables
Table 1. Approximate Locations and Depths of Explorations.............................................................................3
Table 2. Laboratory Test Results for Non-Organic Onsite Soils..........................................................................7
Table 3. Field Infiltration Test Results....................................................................................................................8
List of Figures
Figure 1. Topographic and Location Map
Figure 2. Site and Exploration Plan
APPENDIX A
Soil Classification Chart and Key to Test Data..................................................................................................A-1
Log of Test Pits TP-1 through TP-6 and S-1 through S-6......................................................................A-2...A-13
APPENDIX B
Log of E3RA,Inc.Test Pits TPI-22 through TPI-24
APPENDIX C
LaboratoryTesting Results..........................................................................................................................C-1...C-8
i
SITTS & HILL ENGINEERS, INC. F-3
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
MIGIZI GROUP, INC.
PO Box 44840 PHONE (253)537-9400
Tacoma,Washington 98448 FAX (253)537-9401
April 20,2016
Erickson McGovern Architects
101 E 26th St,Suite 300
Tacoma,WA 98421
Attention: Ray Mow,Principal Architect
Subject: Soils Report
North Mason High School Stadium Project
74 East Campus Drive
Belfair,Washington
MGI Project P578-T16
Dear Mr.Mow:
Migizi Group,Inc.(MGI)is pleased to submit this supplemental report describing soil conditions
within the proposed North Mason High School stadium and field location in Belfair,Washington.
This new development is being performed in conjunction with a series of developments within the
North Mason School District facilities. Amongst these are the construction of the new North Mason
High School and adjacent PACE Building. Construction of these new facilities has largely been
completed. Geotechnical evaluations for these previous improvements had been performed by the
undersigned during previous employment with E3RA,Inc.(E3RA). E3RA previously prepared a
Design Level Geotechnical Report for the new North Mason High School dated October 25,2013,
Supplemental Soils Reports for infiltration and septic systems on January 29,2014,April 21,2014
and February 9,2015,and a Supplemental Soils Report for the new PACE Building on June 10,2015.
Copies of these geotechnical evaluations and corresponding explorations were made available to us
for review with our current study.
This report has been prepared for the exclusive use of Erickson McGovern Architects, and their
consultants, for specific application to this project, in accordance with generally accepted
geotechnical engineering practice.
Page 1 of 10
SITTS & HILL ENGINEERS, INC. F-4
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Erickson McGovern Architects—North Mason High School Stadium,Belfair,WA April 20,2016
Soils Report P578-T16
1.0 SITE AND PROJECT DESCRIPTION
The project site is an irregularly shaped area located towards the northwest comer of the North
Mason School District property,found along the east side of Washington State Route 3,south of
East North Mason School Road, as shown on the enclosed Topographic and Location Map
(Figure 1).
The project area is delineated by the extent of the proposed high school stadium, field and
associated facilities. The proposed location is currently occupied by the recreational/soccer field for
Hawkins Middle School, a Boys &Girls Club, two portable buildings, asphalt pavements, and
associated outbuildings. The north side of the project area is in close proximity to E North Mason
School Rd,and the west side of the project area is directly adjacent to a densely vegetated sloped
region,which descends to the west down to E North Mason School Rd. The east side of the project
area is marked by a small sloped area which ascends to the east towards Hawkins Middle School
and the PACE building. The southern boundary of the proposed development extends nearly to the
North Mason Administrative Building, in an area currently occupied by driving surfaces and
parking facilities.
Improvement plans involve the construction of the new North Mason High School stadium,athletic
field, and associated facilities. Existing structures located in the proposed footprint will be
demolished as part of the development. Stormwater produced by the proposed improvements will
be retained on site,with pervious pavements being proposed beneath the track alignment. An
additional septic site will also be evaluated in the densely wooded region immediately west of the
project area.
2.0 EXPLORATORY METHODS
Explorations for our supplemental soils report were conducted on March 151h and March 171h of
2016. Our exploration and evaluation program for our soils report was comprised of the following
elements:
• Surface reconnaissance of the site;
• Twelve test pits(designated TP-1 through TP-6 and S-1 through S-6);
• A review of the three test pit explorations (designated TPI-22 through TPI-24)
conducted by E3RA within the project area on January 2,2015;and
• Four sieve analyses performed on soil samples collected from test pit explorations.
Table 1 summarizes the approximate functional locations and temlination depths of our subsurface
explorations,and Figure 2 depicts their approximate relative locations.
Migizi Group,Inc. Page 2 of 10
SITTS & HILL ENGINEERS, INC. F-5
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Erickson McGovern Architects-North Mason High School Stadium,Belfair,WA April 20,2016
Soils Report P578-T16
TABLE 1
APPROXIMATE LOCATIONS AND DEPTHS OF EXPLORATIONS
Exploration Functional Location Termination
Depth(feet)
TP-1 Northeast comer of proposed track alignment 13.5
TP-2 Centrally,north end of proposed stadium field 15
TP-3 Northwest corner of proposed track alignment 15
TP-4 North half,west side of proposed track alignment 15
TP-5 Centrally,southern half of proposed stadium field 15
TP-6 East of the southeast corner of the proposed track alignment 15
S-1 North end of sloped area west of proposed stadium field location 4.8
S-2 Center of sloped area west of the proposed stadium field location 5.1
S-3 Southern half of sloped area west of the proposed stadium field location 4.8
S-4 West of test pit exploration S-3 4.8
S-5 South of test pit exploration S4 4.5
S-6 South of test pit exploration S-3 4.8
The specific number and locations of our explorations were selected in relation to the existing site
features, under the constraints of surface access, underground utility conflicts, and budget
considerations.
It should be realized that the explorations performed and utilized for this evaluation reveal
subsurface conditions only at discrete locations across the project site and that actual conditions in
other areas could vary. Furthermore, the nature and extent of any such variations would not
become evident until additional explorations are performed or until construction activities have
begun. If significant variations are observed at that time,we may need to modify our conclusions
and recommendations contained in this report to reflect the actual site conditions. The following
sections describe the procedures used for excavation of test pits.
Ll Test Pit Procedures
Our exploratory test pits were excavated with a steel-tracked excavator operated by an excavation
contractor under subcontract to MGI. An engineering geologist from our firm observed the test pit
excavations,collected soil samples,and logged the subsurface conditions.
The enclosed test pit logs indicate the vertical sequence of soils and materials encountered in each
test pit,based on our field classifications. Where a soil contact was observed to be gradational or
undulating,our logs indicate the average contact depth. We estimated the relative density and
consistency of the in-situ soils by means of the excavation characteristics and the stability of the test
pit sidewalls. Our logs also indicate the approximate depths of any sidewall caving or groundwater
seepage observed in the test pits. The soils were classified visually in general accordance with the
system described in Figure A-1,which includes a key to the exploration logs. Summary logs of the
explorations are included as Figures A-2 through A-13.
- Migizi Group,Inc. Page 3 of 10
SITTS & HILL ENGINEERS, INC. F-6
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Erickson McGovern Architects—North Mason High School Stadium,Belfair,WA April 20,2016
Soils Report P578-T16
JZ Infiltration Test Procedures
In-situ field infiltration tests were performed for determination of a Design Infiltration Rate in
general accordance with the 1980 EPA Falling Head Percolation Test Method.
A 6-inch-diameter PVC pipe was tamped into the soil of the upper part of the infiltration layer,or as
near to the upper level of the infiltration layer as safety permitted, then rock was placed at the
bottom of the pipe to prevent scouring. Soil was placed and tamped outside the pipe for
stabilization and to prevent upwelling of test water around the pipe. The pipe was then filled with
the equivalent of at least 12 inches of water to pre-saturate the tested soils. Because,in all cases,the
pre-saturation water infiltrated the test soil in less than 10 minutes,and we performed our field
testing shortly after a substantial rain event,further saturation was deemed unnecessary and the
infiltration test proceeded.
The pipe was then filled with the equivalent of 6 inches of water and,because site soils were found
to be rapidly permeable,the time required for infiltration of the entire 6 inch column of water was
recorded.
3.0 SITE CONDITIONS
The following sections present our observations, measurements, findings, and interpretations
regarding soil and groundwater conditions.
3,U Soil Conditions-Northeastern Half of Proposed NMHS Stadium/Athletic Field
Subsurface explorations TP-1 and TP-2 advanced by MGI, and explorations TPI-22 and TPI-23
performed by E3RA were conducted within the north half of the project area,and in our opinion,
represent soil conditions which can be expected within the northeastern half of the proposed
stadium and field footprint,if the project area were to be arbitrarily bisected from the northwest to
southeast. Subsurface conditions were fairly consistent within this portion of the site;consisting
primarily of a surface mantling of 5 to 8 inches of sod and topsoil underlain by recessional outwash
containing an upper, weathered horizon, and deeper, unweathered deposits. This upper,
weathered horizon varied in composition from fine silty sand to a fine to medium sand with silt,
whereas the unweathered deposits consist of fine to medium sand with varying amounts of gravel,
and some to trace silt. The depth of contact between the weathered and unweathered deposits
varied from 0 to 2 feet below existing grade; with unweathered deposits being encountered at
grade,beneath the thin surface mantle of topsoil in the vicinity of test pit exploration TP-1. This
portion of the project area represents the most favorable geologic conditions in respect to the
proposed development and stormwater retention. This is due in part, in our opinion, to the
likelihood that grading cuts,rather than fill,were utilized in this portion of the project area during
the initial development of the site.
= Soil Conditions-West Side of Proposed NMHS Stadium/Athletic Field
Subsurface explorations TP-3 and TP-4 advanced by MGI,and exploration TPI-24 performed by
E3RA were conducted along the west side of the project area. The MG] explorations were
performed along the western margin of the site,a short distance inside(to the east)of the fence line
Migizi Group,Inc. Page 4of 10
SITTS & HILL ENGINEERS, INC. F-7
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT-STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Erickson McGovern Architects-North Mason High School Stadium,Belfair,WA April 20,2016
Soils Report P578-T16
which marks the west side of the existing athletic field, whereas the E3RA exploration was
performed just north of the north side of the Boys and Girls Club.
Looking at the gradients of slope proponents marking the western and eastern margins of the
project area,it was anticipated that a fill proponent would be present along the west side of the
existing athletic field. This was confirmed in test pit explorations TP-3 and TP4. In the vicinity of
these explorations, 3 to 7 feet of fill material was observed,with the overall thickness generally
increasing towards the south. Approximately 2 feet of fill material was also observed in the vicinity
of test pit exploration TPI-24,but in our opinion,is associated with the construction of the Boys and
Girls Club rather than the leveling of the project area as with the other explorations.
Fill materials contained a conglomerate of materials,generally comprised of silty,gravelly sand,
with extensive pockets of organics in the vicinity of test pit explorations TP-3 and TP4.Underlying
the fill material,we encountered recessional outwash containing an upper,weathered horizon,and
deeper,unweathered deposits. This upper,weathered horizon was comprised of fine silty sand,
whereas the unweathered deposits consist of fine to medium sand with varying amounts of gravel,
and some to trace silt. The depth of contact between the weathered and unweathered deposits
varied from 2 to 11 feet below existing grade;with the deeper contact being observed along the
western margin of the site.
The fill proponent observed along the western margin of the site represents a"wedge"of material
utilized to level out the project area during the original grading of the site. We anticipate that this
fill material will taper out towards the south of areas explored as gradients to west become gentler.
Given the high organics content of this material, it will likely have to be over-excavated for
foundation elements of the proposed stadium,and underlying pervious pavements in an attempt to
facilitate retention.
= Soil Conditions-South End of Proposed NMHS Stadium/Athletic Field
Subsurface explorations TP-5 and TP-6 were advanced in what can be considered the south end of
the project area. TP-6 was performed just outside of the project area to the east,along a small knoll
due to utility conflicts within the southeast corner of the project area. TP-5 was performed adjacent
to the southeast comer of the Boys and Girls Club. It was initially proposed further to the south,
adjacent to existing asphalt pavements,but we encountered evidence of an existing septic drain
field in that portion of the site. We encountered 3 to 5 feet of fill material in the vicinity of these
explorations.
Fill material was generally comprised of fine silty sand containing pockets of organic materials.
Underlying the fill material,we encountered recessional outwash. In the vicinity of TP-5,the upper
21A of the recessional outwash deposits was moderately weathered, and comprised of fine to
medium sand with silt and gravel. No weathered stratum was observed in the vicinity of test pit
explorations TP-6. The unweathered recessional outwash deposits consist of fine to medium sand
with varying amounts of gravel, and some to trace silt. With depth in both explorations, we
observed intermittent lenses of silt and silty fine sands within the more massive sand deposits. The
fill material in the vicinity of 1P-6 is likely resultant from grading activities upslope to the east,with
Migizi Group,Inc. Page 5 of 10
SITTS & HILL ENGINEERS, INC. F-8
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Erickson McGovern Architects-North Mason High School Stadium,Belfair,WA April 20,2016
Soils Report P578-T16
cuttings being pushed down the slope. Native soils in this area were encountered in close
proximity to existing grades of the adjacent athletic field. We anticipate that native soils will be
encountered within close proximity to existing grade towards the southeast corner of the project
area.
Fill soils observed in the vicinity of test pit exploration TP-5 are likely associated with the
development of the Boys and Girls Club. Given this fact,and the presence of an existing drain field
south of this location,extensive over-excavations will likely be necessary for structural elements and
infiltration facilities proposed within the south-central portions of the project area.
Md Soil Conditions—E=osed NMHS Stadium St9tic Area
Subsurface explorations S-1 through S-6 were performed at locations provided by Erickson
McGovern Architects, and are in the vicinity of the proposed septic area to accompany the
construction of the proposed stadium and associated facilities. These explorations were performed
in the heavily wooded,sloped area,located immediately west of the primary project area. They
were performed on either side of a paved access road which travels through this portion of the
North Mason School District property.
Subsurface conditions were fairly consistent between these explorations;consisting primarily of a
surface mantling of 5 to 7 inches of forest duff underlain by recessional outwash containing an
upper,weathered horizon, and deeper, unweathered deposits. This upper, weathered horizon
consists of fine silty sand,whereas the unweathered deposits consists of relatively clean,fine to
medium sand. The depth of contact between the weathered and unweathered deposits varied from
2 to 4 feet below existing grade;being shallowest in the vicinity of test pit exploration S-1 and
deepest in the vicinity of explorations S-2 and S-4. No fill soils were observed within this portion of
the site.
The enclosed exploration logs (Appendix A) provide a detailed description of the soil strata
encountered in our subsurface explorations. E3RA test pit logs are attached as Appendix B.
Groundwater Conditions
At the time of the subsurface explorations for this report,March 151h and 171h of 2016,we observed
slow groundwater seepage at a depth of 11 ti4 feet in test pit exploration TP-5. Groundwater seepage
was not observed in any of our other test pit explorations. This seepage was observed at the contact
between relatively clean sandy soils and underlying,more restrictive,silt soils. It is our opinion that
this is representative of seasonally perched groundwater,and not indicative of actual groundwater
levels. Based on our knowledge of the region gained through the review of extensive subsurface
explorations performed within the subject property since the onset of recent improvements,it is our
opinion that groundwater is at a sufficient depth so as not to adversely impact the performance of
the infiltration and septic systems at their proposed locations.
Migizi Group,Inc. Page 6of 10
SITTS & HILL ENGINEERS, INC. F-9
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Erickson McGovern Architects-North Mason High School Stadium,Belfair,WA April 20,2016
Soils Report P578-T16
31 Infiltration Conditions and Infiltration Kate
As discussed in Sections 3.1a through 3.1c, subsurface conditions vary considerably across the
proposed footprint of the stadium and athletic field. Towards the northeastern half of the
alignment,native recessional outwash deposits are encountered are relatively shallow depths,and
massive,relatively clean,sandy deposits extend to depths of up to at least 15 feet below existing
grade. Along the western margin of the project area, a substantial "wedge" of fill material is
present above native deposits,extending to depths of up to 7 feet below grade. Towards the south-
central portion of the project area,an additional fill element is present,being associated with the
building pad of the Boys&Girls Club and associated septic drain field. At both of these locations,
however,native recessional outwash deposits were encountered with depth.
Our test pit explorations revealed that the outwash deposits contain an upper,weathered horizon,
overlying cleaner, more rapidly permeable deposits. Sieve analyses were performed on soil
samples of the above described weathered and unweathered recessional outwash layers obtained
from test pit explorations TP-1,TP-2,TP-5 and TP-6. Field observations and grain size analyses
indicate that weathered horizon contains a fines(percent silt and clay)content in excess of 6 percent,
whereas unweathered deposits typically contain a fines content of less than 3 percent. For design
purposes,we recommend that the bottom of the gravel reservoir,underlying proposed pervious
pavement sections,extend into the unweathered glacial outwash deposits described above. This
will likely require over-excavations along the western and south-central portions of the site.
The results of our soil grain size analyses are presented below, and the attached Soil Gradation
Graphs(Appendix C)display the grain-size distribution of the samples tested.
TABLE 2
LABORATORY TEST RESULTS FOR NON-ORGANIC ONSITE SOILS
%Coarse %Fine Coarse Fine
Soil Sample,Depth Gravel Gravel Sand Medium Sand %Fines Dia
Sand
TP-I,S-1,1 foot 9.1 24.9 11.3 25.t 27.9 1.2 0.22
TP-2,S-2,4 feet 0.0 27.1 16.4 29.9 0.8 0.21
TP-5,S-1,5 feet 0.0 12.3 8.5 50.8 6.5 0.10
TP-6,S-1,6 feet 0.0 1 0.0 0.3 1.0 1 o.7 1A 0.31
Design Infiltration Rate
In conjunction with test pit explorations TP-1, TP-2, TP-5 and TP-6, we also performed field
infiltration testing at the contact with unweathered recessional outwash deposits. The in-situ field
test employed was the 1980 EPA Falling Head Percolation Test Method. After excavating,setting
up the test apparatus, and employing an appropriate saturation period, the time required to
infiltrate 6 inches of standing water was recorded for each trial. The results of our in-situ field
testing are described below.
Migizi Group,Inc. Page 7 of 10
SITTS & HILL ENGINEERS, INC. F-10
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
- April20 2016
Erickson McGovern Architects North Mason High School Stadium,Belfair,WA
Soils Report P578-T16
TABLE3
FIELD INFILTRATION TEST RESULTS
Field Infiltration Rate for 6
Test Pit Location Depth of Test inch Column(min)
Number (feet)
Trial Trial
TP-1 Northeast comer of proposed track alignment 4 8.50 8.66
TP-2 Centrally,north end of proposed stadium field 4 1.85 1.95
TP-5 Centrally,southern half of proposed stadium field 51/1 2.50 2.82
TP-6 East of the SE corner of the proposed track alignment 6 1.17 1.48
As indicated in the measurements recorded above, field infiltration rates were quite rapid.
Averaging the measurements,and converting from minutes per 6-inches of water,to in/hr,we get a
preliminary infiltration rate of 100.2 in/hr. As described in Table 3.9,in Volume III,of the 2005 DOE
Stormwater Management Manual for Western Washington,appropriate safety factors need to be
applied to in-situ infiltration measurements to obtain a long-term design infiltration rate. The total
correction factor(CF)should be a product of partial correction factors CFv,CFm, and CR CFv
accounts for site variability and number of locations tested,with a recommended range of 1.5 to 6.
CFm accounts for the degree of long-term maintenance to prevent siltation and bio-buildup,with a
recommended range of 2 to 6. CFi accounts for the degree of influent control to prevent siltation
and bio-buildup, with a recommended range of 2 to 6. We recommend employing a partial
correction factor of 4 for CFv,4 for CFm,and 2 for CFi;resulting in a CF of 10. Applying this safety
factor to our in-situ infiltration rate, we recommend utilizing a design infiltration rate of
10 inches/hour for the design of pervious pavements with this project. This infiltration rate applies
to relatively clean,unweathered glacial outwash deposits underlying the project area.
4.0 CONCLUSIONS AND RECOMMENDATIONS
Improvement plans involve the construction of the new North Mason High School stadium,athletic
field, and associated facilities. Existing structures located in the proposed footprint will be
demolished as part of the development. Stormwater produced by the proposed improvements will
be retained on site,with pervious pavements being proposed beneath the track alignment. An
additional septic site will also be evaluated in the densely wooded region immediately west of the
project area. We offer these recommendations:
• Proposed NMHS Stadium Septic Area: Subsurface conditions were fairly consistent
within the proposed septic area;consisting primarily of a surface mantling of 5 to
7 inches of forest duff underlain by recessional outwash containing an upper,
weathered horizon, and deeper, unweathered deposits. This upper, weathered
horizon consists of fine silty sand, whereas the unweathered deposits consist of
relatively clean,fine to medium sand. We recommend that the civil engineer in
charge of septic design for the project determine the suitability of this area for septic
system construction.
• Infiltration Conditions: Subsurface conditions varied considerably over the
proposed footprint of the new stadium and athletic field,with extensive fill soils
being observed along the western and south-central portions of the project area. In
all areas,however,recessional outwash was encountered with depth,containing an
Migizi Group,Inc. Page 8 of 10
SITTS & HILL ENGINEERS, INC. F-11
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Erickson McGovern Architects—North Mason High School Stadium,Belfair,WA April 20,2016
Soils Report P578-T16
upper,weathered horizon,and deeper,unweathered deposits. For design purposes,
we recommend that the bottom of the gravel reservoir, underlying proposed
pervious pavement sections extend into the unweathered glacial outwash deposits.
We recommend utilizing a long-term design infiltration rate of 10 inches/hr for this
soil stratum.
The following section of this report presents our specific geotechnical conclusions and
recommendations concerning the construction of pervious pavement. The Washington State
Department of Transportation(WSDOT)Standard Specifications and Standard Plans cited herein
refer to WSDOT publications M41-10, Standard Specifications for Road, Bridge, and Municipal
Construction,and M21-01,Standard Plans for Road,Bridge,and Municipal Construction,respectively.
11 Pervious Pavement
We understand that pervious pavement will be installed under the track alignment of the new
stadium and athletic field. Site grading will consist of removal of sufficient sod and underlying soil
to install a thick coarse gravel reservoir along with a slightly finer gravel pavement base course
under the area to receive porous paving. The actual thickness of these elements will be determined
by the design engineer;however, a minimum of one foot of separation needs to be maintained
between from the bottom of the gravel reservoir and seasonally high groundwater levels. We offer
the following comments and recommendations for pavement construction.
Subgrade Preparation: The existing subgrade under all pervious pavements must remain in an
uncompacted condition to facilitate water infiltration. Traffic from construction equipment and
vehicles should be limited to the extent practical prior to placement of the pavement section.
Control erosion and avoid introducing sediment from surrounding land uses onto permeable
pavements. Do not allow muddy construction equipment on the base material or pavement. Any
concentrated areas of fines accumulation due to ponding may be removed to a maximum depth of
6 inches. If desired, these areas may be re-leveled using clean sand. Materials meeting the
requirements for "Sand Drainage Blanket" in Section 9-03.13(1) of the WSDOT Standard
Specifications may be used for this purpose.
We recommend placement of a nonwoven filter fabric such as Mirafi 16ON or equal over the
prepared subgrade prior to construction of the pervious pavement section.
Maintenance Considerations: Do not allow sediment laden runoff onto permeable pavements.
Pavements fouled with sediments or no longer passing an initial infiltration test must be cleaned
using procedures from the local stonnwater manual or the manufacturer's procedures.
Construction Observation: We recommend that an MGI representative be retained to observe and
document the placement of each course before any overlying layer is placed.
Migizi Group,Inc. Page 9 of 10
SITTS & HILL ENGINEERS, INC. F-12
TACOMA, WASHINGTON
1
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Erickson McGovern Architects—North Mason High School Stadium,Belfair,WA April 20,2016
Soils Report P578-T16
5.0 RECOMMENDED ADDITIONAL SERVICES
Because the future performance and integrity of the structural elements will depend largely on
proper site preparation, drainage, fill placement, and construction procedures, monitoring and
testing by experienced geotechnical personnel should be considered an integral part of the
construction process. Subsequently,we recommend that MGI be retained to provide the following
post-report services:
• Review all construction plans and specifications to verify that our design criteria
presented in this report have been properly integrated into the design;
• Prepare a letter summarizing all review comments(if required);
• Check all completed subgrades for footings and slab-on-grade floors before concrete
is poured,in order to verify their bearing capacity;and
• Prepare a post-construction letter summarizing all field observations,inspections,
and test results(if required).
6.0 CLOSURE
The conclusions and recommendations presented in this report are based, in part, on the
explorations that we observed for this study;therefore,if variations in the subgrade conditions are
observed at a later time,we may need to modify this report to reflect those changes. Also,because
the future performance and integrity of the project elements depend largely on proper initial site
preparation, drainage, and construction procedures, monitoring and testing by experienced
geotechnical personnel should be considered an integral part of the construction process. MGI is
available to provide geotechnical monitoring of soils throughout construction.
We appreciate the opportunity to be of service on this project. If you have any questions regarding
this report or any aspects of the project,please feel free to contact our office.
Respectfully submitted,
MIGIZI GROUP,INC. �5 E' Bh'l
Zach L.Logan James E.Brigham,P.E.
Staff Geologist Principal Engineer
Migizi Group,Inc. Page 10 of 10
SITTS & HILL ENGINEERS, INC. F-13
TACOMA, WASHINGTON
1`I JI I ii 1 I r uw u�
I 't LII 111 III I III 'I II 'II
I7IN1lllp AIII//1
i 011
ky
MA All
' 1I1f� itl�� 1'l1I11�
I �
,r� f
I11 III I I 1 I 11 ''111 ;III
North • SchoolStadium •
♦ East Campus
Belfair, WashingtonTopographic and Location Map
•
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
22
• -4 I -_ - - - 100 O 100 200
SCALE IN FEET
♦ \
s Y..•r�. �.$ - —r-Z - TEST PIT LOCATION
TP-1
NOTE:
80UNDARY AND TOPOGRAPHY ARE BASED ON MAPPING
PROVIDED TO MIGIZI OBSERVATIONS MADE IN THE FIELD.
THE INFORMATION SHOWN DOES NOT CONSTITUTE A
FIELD SURVEY BY MIGIZI.
PROJECT: 74 E Campus Dr.
Migizi Group,Inc. BeHair.Washington
PO BOX 44840 SHEET TITLE:Site and Exploration Plan
Tacoma,WA 98448
253-537-9400 DESIGNER: CRL JOB NO.P578-T16
253-537-9401 fax DRAWN BY: CRL SCALE: 1'=100'
www.mig¢gmup.mm CHECKED BY:JEB FIGURE-2
DATE:Mar.29.2016 FILE: Fig2.dwg
SITTS & HILL ENGINEERS, INC. F-15
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
APPENDIX A
SOIL CLASSIFICATION CHART AND
KEY TO TEST DATA
LOG OF TEST PIT
SITTS & HILL ENGINEERS, INC. F-16
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
MAJOR DIVISIONS TYPICAL NAMES
CLEAN GRAVELS GW WELL GRADED GRAVELS.GRAVEL-SAND MIXTURES
GRAVELS WITH LITTLE OR
MORE THAN HALF NO FINES GP o1 POORLY GRADED GRAVELS,GRAVEL-SAND MIXTURES
COARSE FRACTION
n IDo
GM SILTY GRAVELS,POORLY GRADED GRAVEL-SAND-SILT
-' d IS LARGER THAN
O N GRAVELS WITH MIXTURES
Q N NO.4 SIEVE OVER 15%FINES
CLAYEY GRAVELS,POORLY GRADED GRAVEL-SAND-CLAY
z ;` GC MIXTURES
<
rY
Uj CLEAN SANDS SW WELL GRADED SANDS.GRAVELLY SANDS
w �
SANDS WITH LITTLE
O OR NO FINES SP t r' POORLY GRADED SANDS,GRAVELLY SANDS
MORE THAN HALF
COARSE FRACTION
IS SMALLER THAN SM r; SILTY SANDS,POOORLY GRADED SAND-SILT MIXTURES
NO.4 SIEVE SANDS WITH
OVER 15%FINES
SC ; CLAYEY SANDS,POORLY GRADED SAND-CLAY MIXTURES
INORGANIC SILTS AND VERY FINE SANDS,ROCK FLOUR,
ML SILTY OR CLAYEY FINE SANDS,OR CLAYEY SILTS WITH
SILTS AND CLAYS SLIGHT PLASTICITY
a+ INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY,
LIQUID LIMIT LESS THAN 50 CL GRAVELLY CLAYS,SANDY CLAYS,SILTY CLAYS,
o
LEAN CLAYS
O
o
o 4CH
ORGANIC CLAYS AND ORGANIC SILTY CLAYS OF LOW
w v PLASTICITY I
z = INORGANIC SILTS,MCACEOUS OR DIATOMACIOUS FINE
SANDY OR SILTY SOLS.ELASTIC SILTS
z d SILTS AND CLAYS
ILLoINORGANIC CLAYS OF HIGH PLASTICITY,FAT CLAYS
LIQUID LIMIT GREATER THAN 50
OH{ ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY,
ORGANIC SILTS
HIGHLY ORGANIC SOILS Pt PEAT AND OTHER HIGHLY ORGANIC SOILS
8 Modified California RV R-Value
® Split Spoon SA Sieve Analysis
Pushed Shelby Tube SW Swell Test
m Auger Cuttings TC Cyclic Triaxial
® Grab Sample TX Unconsolidated Undrained Tnaxial
Sample Attempt with No Recovery TV Torvane Shear
CA Chemical Analysis UC Unconfined Compression
CN Consolidation (1.2) (Shear Strength,ksf)
CP Compaction WA Wash Analysis
DS Direct Shear (20) (with%Passing No 200 Sieve)
PM Permeability Water Level at Time of Drilling
PP Pocket Penetrometer Water Level after Dnlling(with date measured)
a'
c�
m
SOIL CLASSIFICATION CHART AND KEY TO TEST DATA
I
z
z Figure A-1
z
z
o
SITTS & HILL ENGINEERS, INC. F-17
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migizi Group,Inc. TEST PIT NUMBER TP-1
PO Box PAGE 1 OF 1
Tacoma,
WA WA 98448 Figure A-2
Telephone: 253-537.9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Proiect
PROJECT NUMBER P578-T116 PROJECT LOCATION 74 East Campus Drive,BeHair,Washington
DATE STARTED 3/15116 COMPLETED 3115/16 GROUND ELEVATION TEST PIT SI2E
EXCAVATION CONTRACTOR DSE GROUND WATER LEVELS:
EXCAVATION METHOD Steel Tracked Excavator AT TIME OF EXCAVATION —
LOGGED BY ZLL CHECKED BY JEB AT END OF EXCAVATION —
NOTES AFTER EXCAVATION --
Q.
2 �-W VI U
S
w � a p MATERIAL DESCRIPTION
o gZ
a �
0.0
Sod and sandy topsoil
4 ,40.7
GB (SP)Graylbrown fine to medium sand with some gravel(medium dense,moist)(Recessional Outwash)
S-1
SP
a'
2.5 2.5
a (SP)Gray fine to medium sand with some gravel(medium dense,moist)(Recessional Outwash)
m
w
t SP
a Falling Head Test at 4'
5.0 1 15.0
SM 5 5 (SM)Gray/brown fine sitty,sand(medium dense,moist)(Recessional Outwash)
_ (SP)Gray fine to medium sand with some gravel(medium dense,moist)(Recessional Outwash)
s
0
m
za SIP
m
r I
a �
N 7.5 GB 7.5
aS-2 SP 8,0 (SP)Gray fine to medium sand with gravel(medium dense,moist)(Recessional Outwash)
(SP)Gray fine to medium sand with some gravel(medium dense,moist)(Recessional Outwash)
h
w
c
a
U
h
N
W
10.0
N
J
SP
0 12.6
°
w
m
° G8 13.5
LL
y S-3 Severe caving observed from 2 to 13.5 feet
o No groundwater seepage observed
The depths on the test pit logs are based on an average of measurements across the test pit and should be
= considered accurate to 0.5 foot.
m
. � Bottom of test pit at 13.5 feet.
w
. z
w
C7
0
O
Y
V
SITTS & HILL ENGINEERS, INC. F-18
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT lob Number 16,331
Migizi Group,Inc. TEST PIT NUMBER TP-2
PO Box PAGE 1 OF 1
Tacoma,
WA WA 98448 Figure A-3
Telephone: 253-537-9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Proiect
PROJECT NUMBER P578-T16 PROJECT LOCATION 74 East Campus Drive.Belfair,Washington
DATE STARTED 3/15/16 COMPLETED 3/15116 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR DSE GROUND WATER LEVELS:
EXCAVATION METHOD Steel Tracked Excavator AT TIME OF EXCAVATION —
LOGGED BY ZLL CHECKED BY JEB AT END OF EXCAVATION —
NOTES AFTER EXCAVATION —
w
_ oc v) U
��
U 5-w J MATERIAL DESCRIPTION
p 0-
z p C9
U)
0.0
0 4 Sod and sandy topsoil
(SP-SM)Light brown fine sand with silt(medium dense,moist)(Weathered Recessional Outwash)
GB
S-1 SP-
SM
2.0
0 2 5 (SP)Gray fine to medium sand with gravel(medium dense,moist)(Recessional Outwash)
a
o
GB
a S-2 Falling Head Test at 4'
5.0
S
z
SP
0
m
0
m
r
a
N 7.5
w
ti
O
w
9.0
(SP)Gray fine to medium sand(medium dense,moist)(Recessional Outwash)
w
10.0 GB
LU S-3
U
SP
3
0 12.5
23
w
K
'o Grades to wet at 1 T
LL
14.0
SP SM (SP-SM)Gray fine sand with silt(medium dense,wet)(Recessional Outwash)
� .
m 15.0 GB 15.0
S d No caving observed
W No groundwater seepage observed
w
The depths on the test pit logs are based on an average of measurements across the test pit and should be
considered accurate to 0.5 foot.
Bottom of test pit at 15.0 feet.
U
SITTS & HILL ENGINEERS, INC. F-19
TACOMA, WASHINGTON
i
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migizi Group,Inc. TEST PIT NUMBER TP-3
PO Box 44840 PAGE 1 OF 1
�umm Tacoma,WA 98448 Figure A-4
Telephone: 253-537-9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Project
PROJECT NUMBER P578-T16 PROJECT LOCATION 74 East Campus Dnve Belfair,Washington
DATE STARTED 3/15/16 COMPLETED 3/15/16 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR DSE GROUND WATER LEVELS:
EXCAVATION METHOD Steel Tracked Excavator AT TIME OF EXCAVATION 3 00 It Slow seepage__
LOGGED BY ZLL CHECKED BY JEB AT END OF EXCAVATION --
NOTES AFTER EXCAVATION --
w
s a: C6 U
S
w W to y K MATERIAL DESCRIPTION
O CL
QZ KV,
rn
0.0
Sod and topsoil
0.7
(SM)Graylbrown fine to medium sand with silt,some gravel and intermittent lenses of brown silty sand(medium
GB dense,moist)(Fill)
3-1 SM
a
y 2.5 2.5
F SM 3.0 (SM)Dark brown silty sand with organic woody debris(loose,moist)(Old Forest Duff Horizon)
GB (SM)Redlbrown fine silty sand(medium dense,moist)(Weathered Recessional Outwash)
S-2
a
50 SM
N
C
C
m
0 6.5
N GB (SP)Gray fine to medium sand(medium dense,moist)(Recessional Outwash)
a S-3
N 7.5
W
r
a`
0
W
s
U
N
y
W
10.0
W
U
J
SP
0 12.5
it
n
y
U
0
fL
m 15.0 1 1150
No caving observed
W Slow groundwater seepage observed at 3 feet
W
The depths on the lest pit logs are based on an average of measurements across the test pit and should be
o considered accurate to 0.5 foot.
Bottom of test pit at 15.0 feet.
U
SITTS & HILL ENGINEERS, INC. F-20
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migizi Group,Inc. TEST PIT NUMBER TP-4
PO Box 44840 PAGE 1 OF 1
Irmina Tacoma,WA 98448 Figure A-5
Telephone: 253-537.9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason Hiah School Stadium Project
PROJECT NUMBER P578-T16 PROJECT LOCATION 74 East Campus Drive,Belfair,Washington
DATE STARTED 3/15/16 COMPLETED 3115116 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR DSE GROUND WATER LEVELS:
EXCAVATION METHOD Steel Tracked Excavator AT TIME OF EXCAVATION —
LOGGED BY ZLL CHECKED BY JEB AT END OF EXCAVATION —
NOTES AFTER EXCAVATION --
w
_ �ui W v;
wuj uj CL j MATERIAL DESCRIPTION
0
Q Z (0
0.0
— Sod and topsoil
o.e
GB (SM)Graybrown fine to medium sand with silt,some gravel and intermittent lenses of brown silty sand(medium
S-1 dense,moist)(Fill)
SM
y 2.5
° 13.0
w (SM)Dark brown silty sand with organic woody debris(loose,moist)(Old Forest Duff Horizon)
,o
17
a
5.0 SM
�i
z
it
0
m
w 7.0
a (SM)Light brown fine silty sand(medium dense,moist)(Weathered Recessional Outwash)
N 7.5
0.
0.
O
w
0
SM
N
fn
W
10.0
W
N
1:1
U
11.0
(SP)Gray fine to medium sand(medium dense,moist)(Recessional Outwash)
e
`7
0 12.5
O
w
SP
0
lL
h
m 15.0 15.0
No caving observed
No groundwater seepage observed
w
The depths on the test pit logs are based on an average of measurements across the test pit and should be
considered accurate to 0.5 foot.
Bottom of test pit at 15.0 feet.
� U
SITTS & HILL ENGINEERS, INC. F-21
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migizi Group,Inc. TEST PIT NUMBER TP-5
PO Box 44840 PAGE 1 OF 1
Tacoma,WA 98448 Figure A-6
Telephone: 253-537-9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Project
PROJECT NUMBER P578-T16 PROJECT LOCATION 74 East Campus Drive,Belfair,Washington
DATE STARTED 3/17/16 COMPLETED 3117/16 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR DSE GROUND WATER LEVELS:
EXCAVATION METHOD Steel Tracked Excavator Q AT TIME OF EXCAVATION 11.50 ft Slow seepage
LOGGED BY ZLL CHECKED BY JEB AT END OF EXCAVATION —
NOTES AFTER EXCAVATION —
yW
a. Wm (0
W �g MATERIAL DESCRIPTION
o 2z
a r.9
0.0
Sod and topsoil
(SM)Graylbrown silty sand with gravel(medium dense,moist)(FRI)
SM
20
2 5 (SM)Dark brown silty sand with gravel and pockets of burned organics(medium dense,moist)(Fill)
SM
a 13.0
F (SP-SM)Redibrown fine to medium sand with sill and some gravel(medium dense,moist)(Weathered Recessional
Outwash)
17
i SP-
SM .:
5.0 GB
N S-1
Z (SP)Gray fine to medium sand with some gravel(medium dense,moist)(Recessional Outwash)
E
0
o Falling Head Test at 5.5'
SIP
a
N 7.5
w
CL
0
0
8.5
'a
GB (SP)Gray fine to medium sand(medium dense,moist)(Recessional Outwash)
N S-2
W
10.0
Uj
SP
U
Grades to wet at 11'
12.0
0
12.5 GB (ML)Gray/brown well-stratified silt(medium stiff,wet)(Recessional Outwash)
w S-3 ML
13.5
(SP)Gray fine to medium sand(medium dense,wet)(Recessional Outwash)
o SP
� ta.s
m 15.0 ML 15 (ML)Graylbrown well-stratified silt(medium stiff,wet)(Recessional Outwash)
a No caving observed
i Slow groundwater seepage observed at 11.5 feet
w
LL The depths on the test pit logs are based on an average of measurements across the test pit and should be
considered accurate to 0.5 foot
• � Bottom of test pit at 15.0 feet
� U
SITTS & HILL ENGINEERS, INC. F-22
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migizi Group,Inc. TEST PIT NUMBER TP-6
PO Box PAGE 1 OF 1
Tacoma,
WA WA 98448 Figure A-7
Telephone: 253-537-9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Project
PROJECT NUMBER P578-T16 PROJECT LOCATION 74 East Campus Drive,Belfair,Washington
DATE STARTED 3117116 COMPLETED 3/17/16 GROUND ELEVATION TEST PIT SIZE
EXCAVATION CONTRACTOR DSE GROUND WATER LEVELS:
EXCAVATION METHOD Steel Tracked Excavator AT TIME OF EXCAVATION —
LOGGED BY ZLL CHECKED BY JEB AT END OF EXCAVATION —
NOTES AFTER EXCAVATION --
w
S �W uj V) V
JCo
U 0
w
o J MATERIAL DESCRIPTION
2z
0.0
Sod and sandy topsoil
t.0
(SP-SM)Gray/brown fine to medium sand with silt and gravel(medium dense,moist)(Fill)
15.0
2.525
a (SP-SM)Dark brown fine to medium sand with silt,gravel and pockets of organic woody debris(medium dense,
y moist)(Fill)
N
a
6
5.0
yGP ° ° 5.5 (GP)Gray gravel with fine to medium sand(medium dense,moist)(Recessional Outwash)
sGB (SP)Gray fine to medium sand(medium dense,moist)(Recessional Outwash)
S-1 Falling Head Test at 6'
0
a
SP
N 7.5
w
a'
0
S.5
9 (SM)Gray fine silty sand(medium dense,moist)(Recessional Outwash)
a
Q
W SM
10.0 GB
S-2
10.5
i5 GB °Q (GP)Gray gravel with fine to coarse sand(medium dense,moist)(Recessional Outwash)
S-3 GP o 0
O
o ° 12.0
12.5 (SP)Gray fine to medium sand(medium dense,moist)(Recessional Outwash)
cUJ
w
SP :.
0
0
m 15.0 1 1. .115.0
No caving observed
iNo groundwater seepage observed
w
LL
The depths on the test pit logs are based on an average of measurements across the test pit and should be
o considered accurate to 0.5 foot
Bottom of test pit at 15.0 feet.
U
SITTS & HILL ENGINEERS, INC. F-23
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migizi Group,Inc. TEST PIT NUMBER S-1
PO Box 44840 PAGE 1 OF 1
Tacoma,WA 98448 Figure A-8
Telephone: 253-537-9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Project
PROJECT NUMBER P578-T16 PROJECT LOCATION 74 East Campus Drive,Belfair,Washington
DATE STARTED 3/17/16 COMPLETED 3/17/16 GROUND ELEVATION HOLE SIZE
DRILLING CONTRACTOR DSE GROUND WATER LEVELS:
DRILLING METHOD Steel Tracked Excavator AT TIME OF DRILLING --
LOGGED BY ZLL CHECKED BY JEB AT END OF DRILLING --
NOTES AFTER DRILLING —
W
}W U
Fuj S
w CL
¢O MATERIAL DESCRIPTION
Ov �Z KJ
Q � �
0.0
0.4 Forest Duff
Light brown loamy sand(medium dense,moist)
2.0
m 2.5 Gray fine to medium sand with silt and gravel(medium dense,moist)
a
H
W
H
H
aD
N
r 14.8
N No caving observed
No groundwater seepage observed
0
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
$ accurate to 0.5 foot.
Bottom of borehole at 4.8 feet.
o�
r
a
N
w
r
E
O
w
C
U
y
fn
W
7
N
w1'
N
7
U
v
O
W
K
7
O
LL
tll
U
ao
F
2
am
C
• W
Z
• w
O
7a
O
U
SITTS & HILL ENGINEERS, INC. F-24
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migia Group,Inc. TEST PIT NUMBER S-2
PO Box PAGE 1 OF 1
Tacoma,
WA WA 98448 Figure A-9
Telephone: 253-537.9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Project
PROJECT NUMBER P578-T16 PROJECT LOCATION 74 East Campus Drive,Belfair,Washington
DATE STARTED 3/17/16 COMPLETED 3117/16 GROUND ELEVATION HOLE SIZE
DRILLING CONTRACTOR DSE GROUND WATER LEVELS:
DRILLING METHOD Steel Tracked Excavator AT TIME OF DRILLING --
L000ED BY ZLL CHECKED BY JEB AT END OF DRILLING --
NOTES AFTER DRILLING —
w
_ }u U
F-W =
w e uj Co <O MATERIAL DESCRIPTION
o Qz �
0.0
Forest Duff
0.6
Light brown loamy sand(medium dense,moist)
'a
2.5
a
w
co
4.2
Gray fine to medium sand(medium dense,moist)
°° 5.0 5.1
4 No caving observed
ZNo groundwater seepage observed
e
$ The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
o accurate to 0.5 foot.
Bottom of borehole at 5.1 feet.
r
a
y
w
g�
b
N
W
O
G
yV_
N
W
3
N
1'
W
4!
7
v
a
0
w
s
0
LL
y
y�
F
m
• a
c
• i
c�
� V
SITTS & HILL ENGINEERS, INC. F-25
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migia Group,Inc. TEST PIT NUMBER S-3
PO Box 44840 PAGE 1 OF 1
Tacoma,WA 98448 Figure A-10
Telephone: 253-537-9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Project
PROJECT NUMBER P578•T16 PROJECT LOCATION 74 East Campus Drive,Belfair,Washington
DATE STARTED 3/17116 COMPLETED 3/17/16 GROUND ELEVATION HOLE SIZE
DRILLING CONTRACTOR DSE GROUND WATER LEVELS:
DRILLING METHOD Steel Tracked Excavator AT TIME OF DRILLING --
LOGGED BY ZLL CHECKED BY JEB AT END OF DRILLING --
NOTES AFTER DRILLING —
CL
>w
S ~W V
W cUJQ p MATERIAL DESCRIPTION
o aZ �
0.0
CD
Forest Duff
0.5
Light brown loamy sand(medium dense,moist)
Large roots down to 28"
'a
fn 2.5
a 2.8
w Gray fine to medium sand(medium dense,moist)
e
a
6
� 4.8
No caving observed
No groundwater seepage observed
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
°m accurate to 0.5 foot.
Bottom of borehole at 4.8 feet.
r
a
w
0
O
W
C
Q
�Ns
N
W
7
y
K
W
N
J
U
'a
H
O
V
ui
K
O
LL
f/1
aO
F
i
m
� Z
W
(7
• V
SITTS & HILL ENGINEERS, INC. F-26
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migizi Group,Inc. TEST PIT NUMBER S-4
PO Box 44840 PAGE 1 OF 1
Tacoma,WA 98448 Figure A-11
Telephone: 253-537-9400
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Project
PROJECT NUMBER P578-T16 PROJECT LOCATION 74 East Campus Drive,Belfair,Washington
DATE STARTED 3/17/16 COMPLETED 3117/16 GROUND ELEVATION HOLE SIZE
DRILLING CONTRACTOR DSE GROUND WATER LEVELS:
DRILLING METHOD Steel Tracked Excavator AT TIME OF DRILLING
LOGGED BY ZLL CHECKED BY JEB AT END OF DRILLING --
NOTES AFTER DRILLING —
w
w =
a a O MATERIAL DESCRIPTION
0 0-
Q �
to
0.0
Forest Duff
0.6
Light brown loamy sand(medium dense,moist)
Small roots down to 17-
°d 25
ii:
in
w
r
ti
co 4.0
a Gray fine to medium sand(medium dense,moist)
4-6
No caving observed
yNo groundwater seepage observed
z The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
$ accurate to 0.5 foot.
z Bottom of borehole at 4.8 feet.
a
y
a
N
W
H
O
N
W
0
'a
yU_
W
W
7
W
WC'
N
iJ
4
O
ui
O
y
O
O
S
m
Z
w
O
• U
SITTS & HILL ENGINEERS, INC. F-27
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migizi Group,Inc. TEST PIT NUMBER S-5
PO Box 44840 PAGE 1 OF 1
ra®�! Tacoma,WA 98448 Figure A-12
Telephone: 253-537-9400
Fax: 253-537-9401
CLIENT EdCkson MCGovem Architects PROJECT NAME North Mason High School Stadium Project
PROJECT NUMBER P578-T16 PROJECT LOCATION 74 East Campus Drive,Belfair,Washington
DATE STARTED 3117116 COMPLETED 3/17116 GROUND ELEVATION HOLE SIZE
DRILLING CONTRACTOR DSE GROUND WATER LEVELS:
DRILLING METHOD Steel Tracked Excavator AT TIME OF DRILLING --
LOGGED BY ZLL CHECKED BY JEB AT END OF DRILLING —
NOTES AFTER DRILLING —
w
>X U
a r m a.C7
w` Lu a.O MATERIAL DESCRIPTION
0 2
a z cD
0.0
Forest Duff
0.6
Light brown loamy sand(medium dense.moist)
2.5
a
w 3.3
Gray fine to medium sand(medium dense,moist)
r
m
N
1 4.5
No caving observed
N No groundwater seepage observed
3
iThe depths on the test pit logs are based on an average of measurements across the test pit and should be considered
E accurate to 0.6 foot.
$ Bottom of borehole at 4.5 feet.
0
m
r
a
r
w
r
a
0
w
U
y
N
W
a
N
C'
W
H
_7
3
ui
c9
LL
N
a�
F
S
f0
C
W
Z
- w
C7
0
U
SITTS & HILL ENGINEERS, INC. F-28
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Migizi Group,Inc. TEST PIT NUMBER S-6
>®� PO Box 44840
Tacoma.WA 98448 PAGE 1 OF 1
Telephone: 253-537.9400 Figure A-13
Fax: 253-537-9401
CLIENT Erickson McGovern Architects PROJECT NAME North Mason High School Stadium Project
PROJECT NUMBER P578-T116 PROJECT LOCATION 74 East Campus Drive.BeHair.Washington
DATE STARTED 3/17116 COMPLETED 3117116 GROUND ELEVATION HOLE SIZE
DRILLING CONTRACTOR DSE GROUND WATER LEVELS:
DRILLING METHOD Steel Tracked Excavator AT TIME OF DRILLING -
LOGGED BY ZLL CHECKED BY JEB AT END OF DRILLING --
NOTES AFTER DRILLING —
}}ui
= F W U
2
w c Q O MATERIAL DESCRIPTION
o a_
a
0.0
— 0A Forest Duff
Light brown loamy sand(medium dense,moist)
a'
r2.5 2.7
NGray fine to medium sand(medium dense,moist)
rW-
e
a
G
4.8
No caving observed
yNo groundwater seepage observed
c�
oThe depths on the test pit logs are based on an average of measurements across the test pit and should be considered
m accurate to 0.5 foot.
Bottom of borehole at 4.8 feet.
m
C.
co
co
W
H
6
W
O
G
U
H
N
W
N�
WK
N
3
U
m
m
H
O
w
K
7
O
LL
pJ
F
m
W
Z
4U
O
� U
SITTS & HILL ENGINEERS, INC. F-29
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
APPENDIX B
LOG OF E3RA, INC. TEST PITS TPI-22
THROUGH TPI-24
SITTS & HILL ENGINEERS, INC. F-30
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
E3RA Inc. TEST PIT NUMBER TPI-22
P.O.Box 44840
E3RA Inc. Tsowm4 WA qua PAGE I OF 1
TaWwra- ZM37-9400 Figure A-4
Fax 253-537-9401
CLIENT Erldcaw MoGovem Archfteds PROJECT NAME H&Mdns Middle School
PROJECT NUMBER T13096d PROJECT LOCATION Weir,Washington
DATE STARTED 1015 COMPLETED.1/2/15 GROUND ELEVATION_ TEST prT sw-c
EXCAVATION CONTRACTOR DSE GROUND WATER LEVELS:
EXCAVATION METHOD Rubber-tacked Excavator AT TIME OF EXCAVATION
-
LOGGED BY ZLL CHECKED BY JEB AT END OF EXCAVATION
NOTES AFTER EXCAVATION
w
x
0: 'i
ui
I.- M (j
(L C! MATERIAL DESCRIPTION
Lu
z
0.0
IL . 0.4 Sod and Topsoil
9L (SM)Light brown firm silty sand(medium dense,moist)
2.0
2.6 (-SP)Gray fine to medium sand with gravel and tracesllt(medium dense,Moist)
SP
5.01 w 15.0
No wwAng observed
No groundwater seepage observed
The depths on the test of lop we based on an average of ffmwmTwft across the test;*and should be considered
0 a=x*a to 0.5 fool.
Bottom of test pit at 5.0 feet.
0
SITTS & HILL ENGINEERS, INC. F-31
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWA TER REPORT Job Number 16,331
E3lA Inc. TEST PIT NUMBER TPI-23
P.O.Box 44840
Tacoma,WA 98448 PAGE 1 OF 1
Telephone: 253-537-9400
Figure A-5
Feu 253-537-9401
CLEW Erickson McGovern Architects PROJECT NAME Haw ldns Middle School
PROJECT NUMBER T13096d _ PROJECT LOCATION Belfair,Washington
DATE STARTED 1/2115 COMPLETED 1/2/15 GROUND ELEVATION TEST PIT sm
EXCAVATION CONTRACTOR DSE GROUND WATER LEVELS:
EXCAVATION METHOD Rubber-tracked E xavator AT TIME OF EXCAVATION _
LOGGED BY ZLL CHECKED BY JEB AT END OF EXCAVATION _
NOTES AFTER EXCAVATION —
w
a
ofLu
_U
�m n-0
o �g MATERIAL DESCRIPTION
a Z k7
rn
0.0
m
— \ o.a Sod and Topsoil
a (SM)Orangelbram fine silty sand(medium dense,moist)
GS
sM
r=
x2 5 (SP-SM)Gray/brown fine sand with sift(medium dense,moist)
w
s GB
0 S-2 SP-
s SM
s
0
z
z 5.0
s
> I L
No caving observed
3 No groundwater seepage observed
z
0
The depths on the test pit logs are based on an average of measurements across the test pit and should be considered
accurate to 0.5 foot.
o Bottom of test pit at 5.5 feet.
i=
w
J
LL
m
I �
S
N
a I
a
0
k7
m
z
0
N
C'1
O
J
a
x
I a4
• i
0
a
0
♦ U
SITTS & HILL ENGINEERS, INC. F-32
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
E3RA,try— TEST PIT NUMBER TPI-24
P.O.8=44840
E'RA Inc. Taoane,WA 9644E PAGE 1 OF 1
TdspIxM 253537-9400 Figure A-E
Faoc 263-537-9401
CLIENT Erickson McGovern Artidecs PROJECT NAME H&Mdns Middle Sdwc
PROJECT NUMBER T13095d PROJECT LOCATION BeMair.WasMnoOon
DATE STARTED 1015 COMPLETED 1/2115 GROUND ELEVATION TEST PR SUE
EXCAVATION CONTRACTOR DSE GROUD WATER LEVELS:
EXCAVATION METHOD Rubber-tracked Excaralor AT TIME OF EXCAVATION —
LOGGED BY ZLL CHECKED BY JEB AT END OF EXCAVATION —
NOTES AFTER EXCAVATION —
w
w
W to 96
x MATERIAL DESCRIPTION
Z
$ 0.3 Sod and Topsoil
(SM)Brown silly sand with grovel and pockets of pulverized brick(medum dense,moist)(Fil)
SM
0
2.5 (SM)Orargalbrown fine silty sand(medum dense,moist)
SM
35
GB (SP)Gray floe to madamuedca send with gravel and trace sit(rtn derma,moot)
5-1 �
5.0 GS 5A
S-2 (SP-SM)Graylbrown fine send wtrh dR(medkun dense,motet)
SM
No uarirg observed
No groundwater eeepgg1 observed
The depEm an the Last pit logs are based on an average of measurements across the tent pit and should be kcrmidered
accurate to 0.5 fooL
Bottom of test pit at 6.5 feet
e
e
r
S
x
m
O
0
r pY0
• 8
SITTS & HILL ENGINEERS, INC. F-33
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWA TER REPORT Job Number 16,331
APPENDIX C
LABORATORY TESTING RESULTS
SITTS & HILL ENGINEERS, INC. F-34
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT-STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Particle Size Analysis Summary Data
Job Name: NMHS Stadium Project
Job Number: P578-T16
Tested By: ZLL
Date: 3/21116
Boring#: TP-1
Sample#: 1
Depth: 12 inches
Moisture Content % 1 4.4%
Sieve Size Percent Size Fraction Percent By
Passing(%) Weight
3.0 in. 75.0 100.0 Coarse Gravel 9.1
1.5 in. 37.5 100.0 Fine Gravel 24.9
3/4 in. 19.0 90.9
3/8 in. 9.5-mm 78.1 Coarse Sand 11.3
No.4 4.75-mm 66.0 Medium Sand 25.6
No. 10 2.00-mm 54.7 Fine Sand 27.9
No.20 .850-mm 45.2
No.40(.425-mm) 29.0 Fines 1.2
No.60 .250-mm 12.3 Total 100.0
No. 100 .150-mm 3.7
No.200 .075-mm 1.2
LL
PI
D10 0.22
D30 0.44
D60 3.01
Cc 0.30
Cu 13.81
ASTM Classification
Group Name Gray poorly graded sand with gravel
Symbol (SP)(med.dense,moist)
F � Figure C-1
IWO
Soil Classification Data Sheet
SITTS & HILL ENGINEERS, INC. F-35
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
t
Sample Distribution
U.S.Standard Sieve Sizes
-•—Samcle oliwrtuaal
3' 1.5' 314' y8• 4 10 20 40 to 100 ZaD
100
90
80
70
c 60
r
Y
d 50
c
0
40
d
30
20
10
0
1000 100 10 1 0.1 0.01 0.001
Particle Size(mm)
Sample Distribution Job Name: NMHS Stadium Project ample#: 1
Job Number: P578-T16 Date
: : 3121/16
Figure: C-2 Tested B ZLL De the 12inches
Exploration#: TP-1
•
SITTS & HILL ENGINEERS, INC. F-36
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT-STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Particle Size Analysis Summary Data
Job Name: NMHS Stadium Project
Job Number: P578-T16
Tested By: ZLL
Date: 3/21116
Bonng#: TP-2
Sample#: 2
Depth: 4 feet
Moisture Content 1 4.5%
Sieve Size Percent Size Fraction Percent By
Passing(%) Weight
3.0 in. 75.0 100.0 Coarse Gravel
1.5 in. 37.5 100.0 Fine Gravel 27.1
3/4 in. 19.0 100.0
3/8 in. 9.5-mm 90.3 Coarse Sand 16.4
No.4 4.75-mm 72.9 Medium Sand 25.8
No. 10 2.00-mm 56.5 Fine Sand 29.9
No.20 .850-mm 44.7
No.40(.425-mm) 30.8 Fines 0.8
No.60 .250-mm 13.2 Total 777 100.0
No. 100 .150-mm 3.4
No.200 .075-mm 0.8
LL
PI
D10 0.21
D30 0.42
D60 2.40
Cc 0.34
Cu 11.38
ASTM Classification
Group Name Gray poorly graded sand with gravel
Symbol (SP)(med.dense. moist)
F = Figure C-3
Soil Classification Data Sheet
SITTS & HILL ENGINEERS, INC. F-37
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
Sample Distribution
U.S.Standard Sieve Sizes
-�-Swoo Distribution
7' 1.5' 3/4' yg• 1 10 70 �0 80 100 TOa
100 I
90
ao
70
60
p
4
d 50
`o
40
a
30
20
10
0
1000 100 10 1 0.1 0.01 0.001
Particle Size(mm)
Sample Distribution Job Name: NMHS Stadium Pro'ect Sam le#: 2
Job Number: P576-T16 Date: 3121/16
Figure: C-4 Tested By: ZLL De the 4 feet
Exploration#: TP-2
•
SITTS 8 HILL ENGINEERS, INC. F-38
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT-STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
1
Particle Size Analysis Summary Data
Job Name: NMHS Stadium Project
Job Number: P578-T16
Tested By: ZLL
Date: 3121/16
Boring#: TP-5
Sample#: 1
Depth: 1 feet
Moisture Content % 9.2%
Sieve Size Percent Size Fraction Percent By
Passing(%) Weight
3.0 in. 75.0 100.0 Coarse Gravel
1.5 in. 37.5 100.0 Fine Gravel 12.3
3/4 in. 19.0 100.0
318 in. 9.5-mm 96.8 Coarse Sand 8.5
No.4 4.75-mm 87.7 Medium Sand 21.8
No. 10 2.00-mm 79.2 Fine Sand 50.8
No.20 .850-mm 71.3
No.40(.425-mm) 57.4 Fines 6.5
No.60 .250-mm 33.8 Total 100.0
No. 100 .150-mm 15.5
No.200 .075-mm 6.5
ILL
PI
D10 0.10
D30 0.22
D60 0.48
Cc 1.06
Cu 4.94
ASTM Classification
Group Name Red-brown poorly graded sand with silt
Symbol (SP-SM)(med.dense,moist)
f = Figure C-5
Soil Classification Data Sheet
SITTS & HILL ENGINEERS, INC. F-39
TACOMA, WASHINGTON
I
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts& Hill Engineers, Inc.
STORMWATER REPORT Job Number 16,331
r
Sample Distribution
U.S.Standard Sieve Sizes
—�—Semple Distribution
3' 1.5' 3r4' 318' a 10 20 40 so 100 Zao
100
90
80
70
c 60
a
a
m
a 50
c
d
d
40
a
30
20
10
0
1000 100 10 1 0.1 0.01 0.001
Particle Size(mm)
Sample Distribution Job Name: NMHS Stadium Project
Number Sam le#: 1
Job Numb P578-T16 Date: 3121/16
Figure: C-6 Tested By: ZLL IDepthe 1 feet
Exploration#: TP-5
SITTS & HILL ENGINEERS, INC. F-40
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT-STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWA TER REPORT Job Number 16,331
f
Particle Size Analysis Summary Data
Job Name: NMHS Stadium Project
Job Number: P578-T16
Tested By: ZLL
Date: 3/21/16
Boring#: TP-6
Sample#: 1
Depth: 6 feet
Moisture Content I 7.1%
Sieve Size Percent Size Fraction Percent By
Passing(%) Weight
3.0 in. 75.0 100.0 Coarse Gravel
1.5 in. 37.5 100.0 Fine Gravel
3/4 in. 19.0 100.0
3/8 in. 9.5-mm 100.0 Coarse Sand 0.3
No.4 4.75-mm 100.0 Medium Sand 81.6
No. 10 2.00-mm 99.7 Fine Sand 16.7
No.20 .850-mm 59.0
No.40(.425-mm) 18.1 Fines 1.4
No.60 .250-mm 4.4 Total 100.0
No. 100 .150-mm 2.4
No.200 .075-mm 1.4
LL
PI
13110 0.31
D30 0.52
D60 0.87
Cc 1.00
Cu 2.79
ASTM Classification
Group Name Gray poorly graded sand
Symbol (SP)(med.dense,moist)
F = Figure C-7
Soil Classification Data Sheet
SITTS & HILL ENGINEERS, INC. F-41
TACOMA, WASHINGTON
NORTH MASON SCHOOL DISTRICT—STADIUM PROJECT Sitts & Hill Engineers, Inc.
STORMWA TER REPORT Job Number 16,331
t
Sample Distribution
U.S.Standard Sieve Sizes
3' IF ya• Ye' 4 io 70 Q eo 100 mo '�—S°mpb DlmbWon
100 I
90
80
70
ac 60
e
m
A. 50
c
e
0 40
`o
a
30
20
10
0 lit
1000 100 10 1 0.1 0.01 0.001
Particle Size(mm)
Sample Distribution Job Name: NMHS Stadium Project Sam le#: 1
Job Number: P578-T16 Date: 3/21/16
Figure: C-8 Tested B ZLL De the 6 feet
Ex lorat on#: TP-6
1
f
SITTS & HILL ENGINEERS, INC. F-42
TACOMA, WASHINGTON