Specifications (P/2022.-Coco 3 1 I .... .)
RECE: 4:'!-- 1
va3e0 baez mr /2-64 JAN 2 0 7r2
OFFICE COP
CiT 01 Ttlikft0
. CUP.22!NG DM.S.CN
I afghan associates,inc.
ENGINEERING
11300 SW Bull Mountain Road
STORMWATER REPORT & CALCULATION‘
11300 SW Bull Mountain Rd
Tigard,Oregon
• ess- 1 ,4'
• ' ii17 4 sr 'i
ior
0 "V 7 c1- .
i•\,41,..0,,,,,,*,,j‘›r
C7,..kWRES:e.4517--"
November 30, 2021
PROJECT NUMBER: A21061.10
AAI Engineering
4875 S.W. Griffith Drive
Suite 100
Beaverton,Oregon
PH 503.620.3030
FX 503.620.5539
EMAIL: Craigh@aaieng.com
11300 SW Bull Mountain Rd
Table of Contents
Project Summary 1
II. Stormwater Design 1
III. Conveyance Calculations 2
IV. Operations and Maintenance 2
V. Engineering Conclusion 2
Appendices
Appendix A
Existing Conditions
Appendix B
Site Plan
Appendix C
Storm Plan and Details
Appendix D
Stormwater Calculations and Design Guidelines
Appendix E
Geotechnical Report
Appendix F
Operations and Maintenance Plan (to be provided in final storm report)
11300 SW Bull Mountain Rd
ProjectSummary
This report has been prepared to outline the existing and proposed on-site stormwater conditions for the
11300 Bull Mountain Road project. The report is based off of field observations, existing survey, and
geotechnical information.
The project is located at the address of 11300 SW Bull Mountain Rd. The site is located on the south side of
the road, near the intersection of SW Bull Mountain Rd and Pacific Highway W. To the north is an existing
gas station, to the east is Pacific Highway W (99-W), and to the West is an apartment complex. The existing
site is comprised of a steep sloping parking lot and an existing building.
See Appendix A— Existing Conditions
The project improvements propose the reuse and renovation of the existing building onsite, with the
addition of ADA parking stalls and accessible walkways. Along with these changes, the exiting drive aisle to
the east of the building will be widened to allow for two lanes of traffic. The site also proposes the use of
a flow-through planter to treat the site and meet water quality requirements, which is designed with an
overflow which outlets to the existing stormwater conveyance system.
See Appendix B—Site Plan and Appendix C—Storm Plan and Details.
The following storm system has been designed per the CWS Stormwater R&O 19-5 as Amended by R&O
19-22, referencing guidelines outlined in the LIDA handbook.
II. Stormwater Design
Stormwater for the site is managed by sheet flowing and channelizing stormwater which arrives at catch
basins, area drains, and curb spillways onsite. It is not yet known where the area drains and catch basins
convey water to, and as such we have sized the stormwater treatment system to be able to treat the
entirety of the site's impervious area (modified, new, and existing), totaling 21,983 sf. Overflow from
the planter will discharge into the existing catch basin at the southern end of the site. Though the
planter is sized to treat the entire site, it is expected to receive only 14,891 sf of impervious area.
Pretreatment is not required as the flow-through planter will receive less than 15,000 sf of impervious area.
The flow-through planter is designed to per LIDA handbook guidelines and CWS requirements. The planter
area is to be 1,320 sf(6%of impervious area).
A flow-through planter was selected due to the low-infiltration soils on-site, and the system's ability to
collect surface flow.
See Appendix D - Stormwater Calculations and Design Guidelines for the LIDA Handbook Reference for
additional information on the proposed Stormwater system sizing and see Appendix E for Geotechnical
Report for additional information on the onsite soil properties. See Appendix C—Storm Plan and Details.
1
11300 SW Bull Mountain Rd
III. ConveyanceCalculations
As the water flows to the planter via surface sheet flow, conveyance calculations were only completed for
the outlet pipe from the overflow structure. See Appendix D—Stormwater Calculations and Design
Guidelines for conveyance calculations.
IV. Operations and Maintenance
See Appendix F—Operations and Maintenance Plan for O&M requirements.
V. Downstream Analysis
No negative impacts are anticipated downstream as the site will reduce in total impervious area, and
treatment will be included in site improvements. Treatment will utilize the existing outfall from the site,
and thus the changes to the downstream hydraulics are minimal.
VI. Engineering Conclusion
Based on the requirements of the CWS Stormwater Manual,the proposed site facilities will be adequately
designed to manage the proposed development conditions and should be approved as designed.
2
11300 SW Bull Mountain Rd
Appendix A
Existing Conditions
A
ADDRESS:
11290 SW BULL
// .
MOUNTAIN ROAD /
PACWEST ENERGY LLC
TAX LOT 1101 /
(MAP 2S110AC)
DE .
2008-019238OCUMNTNO
/
\_______________
:'
Ed
/o'
III
BUILDING 7)//
CARWASH
/
411 /z,
i o'r
-304 p /..
CO / " '
.._____
_______
/
--------- •. i/I
302 2 /
1 1111111111%N
3' CHAINLINK . : ,k/ �/
FENCE . GJ / //ty.
g ,
�� J� 3 / /
3 Soil Map—Washington County,Oregon 3
M
a 4
5161W 516160 516170 516180 516190 515200 516210 516220 516230
45°24'52'N ,.;z,,,.:- 45°24'52'N
o
Bull Mountain o
#.
1 •
4r I
ii
j .t r i �i
15 +R' .,-+r .. • t jam + SS
j waw ' _.A i, Irk,-:,;'
7.
i
I
I
I
A',--i 4s:Zi:ttl: 1
- .r, ! �'` I.4*
.�..... }rr,�
ti
o o
rii
45°24 48"N Off
45°24 48 N
5161W 516160 516170 516180 516190 516200 516210 516220 516230
3 3
M
4 Map Scale:1:599 fi printed on A portrait(8.5'x 11")sheet 4
N Meters
n 0 5 10 20 30
Feet
/V
0 25 50 m 100 150
Map projection:Web Mercator Corner coordinates:WGS84 Edge tics:IJTM Zone lON WGS84
USDA Natural Resources Web Soil Survey 9/24/2021
i
Conservation Service National Cooperative Soil Survey Page 1 of 3
Soil Map—Washington County,Oregon
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) TA Spoil Area The soil surveys that comprise your AOI were mapped at
Area of Interest(AOI) 1:20,000.
Stony Spot
Soils 1 Very Stony Spot Warning:Soil Map may not be valid at this scale.
Soil Map Unit Polygons
Wet Spot Enlargement of maps beyond the scale of mapping can cause
aE r Soil Map Unit Lines misunderstanding of the detail of mapping and accuracy of soil
Other line placement.The maps do not show the small areas of
® Soil Map Unit Points contrasting soils that could have been shown at a more detailed
Special Line Features
Special Point Features scale.
Blowout Water Features
Streams and Canals Please rely on the bar scale on each map sheet for map
Borrow Pit measurements.
Transportation
X Clay Spot Source of Map: Natural Resources Conservation Service
4-H Rails
Web Soil Survey URL:
Closed Depression Interstate Highways Coordinate System: Web Mercator(EPSG:3857)
• Gravel Pit US Routes Maps from the Web Soil Survey are based on the Web Mercator
Gravelly Spot Major Roads projection,which preserves direction and shape but distorts
distance and area.A projection that preserves area,such as the
0 Landfill Local Roads Albers equal-area conic projection,should be used if more
A. Lava Flow accurate calculations of distance or area are required.
Background
,, Marsh or swamp Aerial Photography This product is generated from the USDA-NRCS certified data as
of the version date(s)listed below.
Mine or Quarry
Soil Survey Area: Washington County,Oregon
O Miscellaneous Water Survey Area Data: Version 18,Jun 11,2020
Perennial Water Soil map units are labeled(as space allows)for map scales
^z Rock Outcrop 1:50,000 or larger.
Saline Spot Date(s)aerial images were photographed: Aug 1,2019—Sep
12,2019
Sandy Spot
The orthophoto or other base map on which the soil lines were
Severely Eroded Spot compiled and digitized probably differs from the background
imagery displayed on these maps.As a result,some minor
z Sinkhole shifting of map unit boundaries may be evident.
Slide or Slip
• Sodic Spot
USDA Natural Resources Web Soil Survey 9/24/2021
+00 Conservation Service National Cooperative Soil Survey Page 2 of 3
Soil Map—Washington County,Oregon
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AO1
7B Cascade silt loam,3 to 7 1.6! 93.8%
percent slopes
7C Cascade silt loam,7 to 12 0.1 6.2%
percent slopes
Totals for Area of Interest 1.7 100.0%
USDA Natural Resources Web Soil Survey 9/24/2021
a Conservation Service National Cooperative Soil Survey Page 3 of 3
Map Unit Description:Cascade silt loam,3 to 7 percent slopes---Washington County,Oregon
Washington County, Oregon
7B—Cascade silt loam, 3 to 7 percent slopes
Map Unit Setting
National map unit symbol: 220n
Elevation: 250 to 1,400 feet
Mean annual precipitation: 50 to 60 inches
Mean annual air temperature: 50 to 54 degrees F
Frost-free period: 165 to 210 days
Farmland classification: Prime farmland if drained
Map Unit Composition
Cascade and similar soils: 85 percent
Minor components: 5 percent
Estimates are based on observations, descriptions, and transects of
the mapunit.
Description of Cascade
Setting
Landform: Hills
Landform position (two-dimensional): Toeslope, summit
Landform position (three-dimensional): Base slope, interfluve
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Silty loess and old alluvium
Typical profile
H1 - 0 to 11 inches: silt loam
H2- 11 to 27 inches: silt loam
H3-27 to 60 inches: silt loam
Properties and qualities
Slope: 3 to 7 percent
Depth to restrictive feature: 20 to 30 inches to fragipan
Drainage class: Somewhat poorly drained
Capacity of the most limiting layer to transmit water
(Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr)
Depth to water table: About 18 to 30 inches
Frequency of flooding: None
Frequency of ponding: None
Available water supply, 0 to 60 inches: Low(about 5.1 inches)
Interpretive groups
Land capability classification (irrigated): 3w
Land capability classification (nonirrigated): 3w
Hydrologic Soil Group: C
Forage suitability group: Somewhat Poorly Drained
(G002XY005OR)
Other vegetative classification: Somewhat Poorly Drained
(G002XY005OR)
USDA Natural Resources Web Soil Survey 9/24/2021
41.1111 Conservation Service National Cooperative Soil Survey Page 1 of 2
Map Unit Description:Cascade silt loam,3 to 7 percent slopes---Washington County,Oregon
Hydric soil rating: No
Minor Components
Delena
Percent of map unit: 5 percent
Landform: Swales
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Other vegetative classification: Poorly Drained (G002XY006OR)
Hydric soil rating: Yes
Data Source Information
Soil Survey Area: Washington County, Oregon
Survey Area Data: Version 18, Jun 11, 2020
USDA Natural Resources Web Soil Survey 9/24/2021
Conservation Service National Cooperative Soil Survey Page 2 of 2
,. ,
Map Unit Description:Cascade silt loam,7 to 12 percent slopes---Washington County,Oregon
Washington County, Oregon
7C—Cascade silt loam, 7 to 12 percent slopes
Map Unit Setting
National map unit symbol: 220p
Elevation: 250 to 1,400 feet
Mean annual precipitation: 50 to 60 inches
Mean annual air temperature: 50 to 54 degrees F
Frost-free period: 165 to 210 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Cascade and similar soils: 85 percent
Minor components: 5 percent
Estimates are based on observations, descriptions, and transects of
the mapunit.
Description of Cascade
Setting
Landform: Hills
Landform position (two-dimensional): Shoulder, toeslope
Landform position (three-dimensional): Interfluve, base slope
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Silty loess and old alluvium
Typical profile
H1 -0 to 11 inches: silt loam
H2- 11 to 27 inches: silt loam
H3-27 to 60 inches: silt loam
Properties and qualities
Slope: 7 to 12 percent
Depth to restrictive feature: 20 to 30 inches to fragipan
Drainage class: Somewhat poorly drained
Capacity of the most limiting layer to transmit water
(Ksat): Moderately low to moderately high (0.06 to 0.20 in/hr)
Depth to water table:About 18 to 30 inches
Frequency of flooding: None
Frequency of ponding: None
Available water supply, 0 to 60 inches: Low (about 5.1 inches)
Interpretive groups
Land capability classification (irrigated): 3e
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Forage suitability group: Somewhat Poorly Drained
(G002XY005OR)
Other vegetative classification: Somewhat Poorly Drained
(G002XY005OR)
USDA Natural Resources Web Soil Survey 9/24/2021
-01111111 Conservation Service National Cooperative Soil Survey Page 1 of 2
Map Unit Description:Cascade silt loam,7 to 12 percent slopes---Washington County,Oregon
Hydric soil rating: No
Minor Components
Delena
Percent of map unit: 5 percent
Landform: Swales
Landform position (three-dimensional): Tread
Down-slope shape: Linear
Across-slope shape: Linear
Other vegetative classification: Poorly Drained (G002XY006OR)
Hydric soil rating: Yes
Data Source Information
Soil Survey Area: Washington County, Oregon
Survey Area Data: Version 18, Jun 11, 2020
USDA Natural Resources Web Soil Survey 9/24/2021
."� Conservation Service National Cooperative Soil Survey Page 2 of 2
11300 SW Bull Mountain Rd
Appendix B
Site Plan
B
.. ., . • ..
\ .....--"' -
, . . •
• • .4,' ' • •, ,. ..
...
,..- • • %. : ''.
\ ..,...--"'" ......-...."" ....--0---
ir
•
a a . • ! . - •:*: t , .•
• f i . f,. .tt:‘''':. i ••• 1,"
....
*• .*.*. • a . IC . .. •• : •
• • . ...
---*.
w ' ' * ' ••• % A \
•.4\•. .
• • .• •
•
' ' ' 4' 4 ' ' ; •*.:: C•
• .k...
• {
a Alt
. \.-
,
,I A
a a. • 4 ... ..11 :A., ,, .'
.
. . .
. .*\.:• Ir' :- %
.. . #
G BUILDING , . .• .
•
507.20 ..-• \-.
4• :. . A' 0
.. • :.
a •. 0
\------„.
........,_____
.........._____
40
//
. . 4 .4 • : 4. •-.. % -...,,,,,,,.......
. .
. . .: 4 ".. \'-..
fp
FiV5
r - • .:
'''4111111i• tillAtit. 4. ., . ,...I I,,: eh
/ • •,..,. re* . . 'a •
/14.
Alha..,
\
. . •• . .
44 , ., .
.
I. . • 1*-.*. . •: •:.:....:..... .
16
/
. :,:.-.:,"':.41.1 : ' • A 0,
..0 i i A cl.!ii:---,,:.„::,,,,• - \ ,
.
(..,-
.••••• 0
• . . .• :, :- :-...10: • ••- /
. .. • . . .,........ ::.....
. • . • .. .. • . •••
/. . . . • .
. . .. • 1 .... .,
••.• }
. ........ . . •.
...... .•...... • ••
\A,
• ••••'•••••••••'• 0 \
1/1j7/
................................... I I
•. ..•••. ....•••••
%
•::•: 1................. .......... .... .................. .2.
° %
. e
......... .... . .. . *''
\
.... ........... ..... ... .
..... .. ........ ... . .. . .
•••••••••....•••...... . .
................ ..........
. . ..............
. .............. .... 1
• ••••••••••••••••••• ,
................ ........ ,
. .. .. .... .. ,
•• c/-',,,,,.......„....s..._ss,....._..
...-...,-=• ,
1 \\IN
,
i
11300 SW Bull Mountain Rd
Appendix C
Storm Plan and Details
C
• , _ •
...
.- ..:' '....• • •" •- :'-'' .7. •• :.• 7•: *: 1 \--- .............. ......--* _
•••••••
, r
..........".-'• , ,
/ ' • = " *,"1 .. ,. -. , ,'..
.•/ • •, ...-----
. . . . " Flo!.,,t, 'it:"-:k- -: •.• i,•••• •
.wro 307'0. ..,. • .''..., ‘,. 1 '• , . a.'',$.%
. . • . ....
4 . •
. - A \
‘.
• • , • 0 .4 A' . , !,, ,
...r... 4'1.2' • \0„,:4 . . Ii•- 0 -1
' In '•4••\\' A b . ' 1
• • ..
• •
• '..
.., • ...\ ,.. , . ,;j'"
•
.14
0 .,44. •"
.
3 BUILDING •.
41‹ • .- -, -
307.20 ......„.
o\.*\ - - • . • ",.• '4. - ' s,„..,.......„,....
te) •\ . • el . •
\ .. 0b: 11*- 0
'
I ••••...„,„............
........,..,,,,,...... i d
.. * •4' !...\... •" ,* *.t.- --------...„.
. '' .40 .. A. %.:. $',..., -.................„.
• • •44% -• \v. ...I, -„! ,. . ...
...\. '
• • . .4 .4i I-.•''•*;.-
•
440U2 E. 0.,. ,ki.. ..: • t
,,ir6, .i'....ir ;i a. EFF11 1' I
/
... ...;•,--4,r.. \ • 4. .v
..„.......... ..... ,....:'...;,..a 4.-•....... . .. •.is,.• .• .' ,
,- .307 _,. .,.. ., ......: . . .
... 0 _,
- ..50E)...... .....: ,..,, .„, .
• 3... ..„ • .........• -501, \
'. •.•..,.0. ,.., 305
110.....-.., .
VW:- ti . . ........
. . . . • • ir
, F
411111 111!
/
. .. .. .... . r
C..)
. .... .... .. .... .
• •• •••••• • •• • • •.
.... . . .
1
.. ... ...... . ...........4) ••••
.. ..... .......... .........
••••••4 ‘.......4......4"... ///' ----- C
. .. .... . .. .... .... 02-- \\\ \\\\
......... ....... . .............
--- ----304,
..... ..:... .... ...... ....
........ .........
.•....
--4.-.1/ ------ -303
7
.................... ..Y
.•" . " • .•••••• ••.• . /
•••-_____ -.....,...
301
\ \ ...........
---„,..... •, •• 302, /
. .. .. ...
.....-=-• -302
.. . -,..........,
-).TC '3o'7--".....
_
BALL BE EXTENDED TO BACK OF SIDEWALK WITH 1. OVERFLOW INLET WITH ATRIUM GRATE. ATRIUM GRATE SHALL BE 6" DIAMI
CONTRACTION JOINT TO BE PLACED OVER €BRASS/GREEN PLASTICI FROM NDS OR APPROVED EQUAL.
:WALK OVERFLOW INLET
(8) SCALE: NTS
6„
R=%
BACKFILL TO
I: TOP OF CURB 36'-10"
E a ' •'a q • a 4
•
,�
Q d q t41. ! ° A,
CURB SPILLWAY PER ,
44, W 4, DETAIL 7 THIS SHEET L_
°, 9�, 4' OF SUBBASE a . •
4. 4, 4,
COURSE " y
W 4, 3'x3' RIP—RAP AREA
17'-3" q y � y '
4' 4, W W 4, W •L' * 1 W >
VARY AS SHOWN ON PLANS OR AS DIRECTED. a : x° 4, 4, W 4, w 4, w 4, w
3 AT 15' MAX. SPACING AND AT RAMPS. '6' 4,
4' ''' '4' '`' '6' '4' ``"
kT 200' MAX SPACING AT POINTS OF TANGENCY 4' '`' 4, 4, 4, 4, 4' 4
N a 4 4, w * w w w w
* W W W •Y 'Y V+ 4Y A
PE TOWARD THE ROADWAY AT 2% UNLESS _
. .
TED.
q 4 . 4 •
vIAY VARY TO CONFORM WITH CURB MACHINE AS a a - _ -el'
B - STANDARD
FREEBOARD VARIES (SEE PLAN) MAX WE
^ . TOPrOF T ,^
FMA Tu
11300 SW Bull Mountain Rd
Appendix D
Stormwater Calculations and Design Guidelines
I
D
,k ,.
•
•
Flow-Through Planter Page 1 of
'tO
x m,t w�1r r+'aa t: a4s x �`- :1.' .':4-«-dt` +,,, ac7't cst :;
j f 4 t tat., X+
,:,,,. .,......„.,,,. .„ ,.„., . ....„,,,,....„,,,,,.„,..„...).,,,,„„,:,,,,,:;:,., .
t 'nR` ',aAi �.Ts
%
s.�
_
Iff
' �n , ,,4 { „fi: ' v" '! ; a
re. '+: • ' * ii.
Si
parking areas
5 f & impermeable
' `K• landscape
, �JPI'iTiakr.<.
P
,f. ' --......_....._... sods
— ___ il
' . `..- Choker Course
rt£r§'s {y,.,++',; , rs , .a F z_. {, r?+,,t,'i}� 3 i lie t #6 Mitt , ( },(�b1 tr r1-kit r •f,.ar:
y a t Jf .a' £ tr1 a r an r:,Orr* , t#4
t �'�+ Y'�S!"R�•�.,u+tt .;+ zs ts}t��t ,� 1!y ¢ f� d vt+e'}$�#
{ ,tt r 'a f " 6 '. is a, r ) _t , a :r Ir a °xr!t' i�.
'i{ 3_: s r,... t• : I t;g ;t"rf:{rta .3{ t r i $ ,t� tr+:. i •i r t t -ry
:t P..s..?. ?+ ,a„e.:a, t.. .:.:.?`. . ,!�t.¢iP$:�.....� .,,.,.I #i ... �, t�.,h,.+Y'�°r�tz,�t;a �?`t3ts�x.to,S.daP' .3'r, : ,. .. .. ,..>, r. ....:.,r
Description Application & Limitations
Flow-through planters are structural landscaped reservoirs that Flow-through planters may help fulfill a site's land-scaping area
collect stormwater and filter out pollutants as the water percolates requirement and can be used to manage stormwater runoff from
through the vegetation,growing medium,and gravel.These all types of impervious surfaces on private property and within the
are appropriate where soils do not drain well or there are site public right-of-way.Check with the local jurisdiction if proposing
constraints. A liner may be required when located adjacent to to use a flow-through planter in the public right-of-way.Flow-through
buildings,over contaminated soils,and on unstable slopes.Excess planters can be placed next to buildings and are ideal for sites
stormwater collects in a perforated pipe at the bottom of the flow- with poorly draining soils,steep slopes or other constraints.Design
through planter and drains to an approved discharge point. variations of shape,wall treatment,and planting scheme will fit
the character of any site.
Tree box filters are flow-through planters with a concrete"box"that
contains filtering growing media and a tree or large shrub.Tree
box filters are used singly or in multiples,often adjacent to streets * =`
where runoff is directed to them to treat stormwater runoff before it AI,4 �' ,-'41
enters a catch basin. .,,,
r,
Headwaters at Tryon Creek, Portland
34 Low Impact Development Approaches Handbook C1eanWater Services
e2of4Flow-Through Planter Pag
,1 fa 7, , , :
{y
/
Structural wall
(with waterproofing) '*'k a C . 4 h� " s i'"e#
Downspout i,, ,ve, 1 I '� ! .4x5
Hooded overflow E , '•:T. ?., eboard
Gravel or splash block Ponding Depth
r
18"Growing Medium .
Perforated pipe
(to run length of planter)
Foundation drain fi� . ?,I.yy s _ 3"Choker Course
�f kz xa �
Structural footing �" 4 ,.
____._..__ ___. _ �..i,,. ,,,. : ;.>�. "1a,_ 9" Dran Roc___ -___....
..may;,.�.�.,"a��.. '�` '►
r o
. 1 ..
t ri;
Design Factors
Sizing
To calculate the planter size,multiply the impervious surface or adjacent parking lot areas via curb openings. The overflow
(rooftops,driveways,parking lots,etc.)area by 6%.The square drain allows not more than 6 inches of water to pond in the planter
footage is the peak water surface prior to overflow.For example,a prior to overflow.A perforated pipe system under the planter drains
1,200 sf rooftop and 300 sf driveway(1,500 sf total impervious area) water that has filtered through the topsoil to prevent long-term
requires a 90 sf stormwater planter(1,500 x 0.06).This could be ponding.On private property,the overflow drain and piping must
accomplished with one 9-foot by 10-foot flow-through planter. meet Plumbing Code requirements and direct excess and filtered
stormwater to an approved disposal point. Check with the local
Geometry/Slopes planters may be any shape,and can be jurisdiction or use Clean Water Services Design and Construction
• Stormwater square,rectangular,belar,circular,sh oblong,ore Standards for additional information on piping material for use in
designedegular. the public right-of-way.
irr• Regardless of the shape,a minimum planter width of
30 inches is needed to achieve sufficient time for =} , w43 ` ''
treatment and to avoid short-circuiting. C `'.
• The minimum treatment depth of 18 inches is achieved =;
in the growing medium.
• Planters are designed to evenly distribute and filter flows.
Surface longitudinal slopes should be less than 0.5%.
Piping for Flow Through Planters ,-,
Follow Plumbing Code requirements for piping that directs
stormwater from impervious surfaces to flow-through planters.
Stormwater may flow directly from the public street right-of-way Portland Rebuilding Center
Cteanwater Services Low Impact Development Approaches Handbook 3E
e3of Flow-Through Planter Pa 4
g
,la
4
` f
f e,F
f
a Igo
, , ,:f1 / ill
P Via+
ran„ - ti•r, m
OW
, .
Gr 1p s } ' sr; . r: l , .
l is t ai ' l 4
'te'1av, •
wt�
«fir. .; -— _._.-----..
r '}3o4f t,t f ni
,:7,',.'gytt -.""' " ..
I PN x ..§y, i .
,wir„, .
rt F� p rrsEf 2.`�3�' s• + t -'.:'� rx" , 'r q0.. - -"'
r
y „a.p;Felt • ," /- 7F°// .,F €,• , ; ,'
!/'!el€r l RiverEast Center,SE Portland
t } pv t 1 E. h�` .P,° l +P Ps xP
ett { r (; i, akd �FlPP1 r, s P l�-r i 1 t
fit ,� P 1 P � '�,�� , � .� F � ` ��;r,�,�, reduces erosion,and limits the spread of weeds.Appropriate,
'4-'-� .a., '_' ' t';''''' F.° r r 4:1 carefully selected plantings enhance the aesthetic and habitat
PSU Stephen Epler Hall,Portland value.For a complete list of allowable plants refer to page 76.
Design Factors (continued) The entire water quality treatment area should be planted
appropriately for the soil conditions.Walled infiltration run-on
Setbacks planters will be inundated periodically.Therefore the entire
Check with the local building department to confirm site-specific planter should be planted with herbaceous rushes,sedges,
requirements. perennials,ferns and shrubs that are well-suited to wet-to-moist
• For planters without an impermeable liner,generally the soil conditions.
minimum setback from building structures is 10 feet. Because the entire facility will be inundated periodically,plant
• Typically,no building setback is required for planters lined with the water quality treatment area with herbaceous species such
waterproofed concrete or 60 mil.PVC liner to prevent infiltration. as rushes,sedges,perennials,ferns and shrubs appropriate for
Amendment/Mulch wet-to-moist soil conditions. Most moisture-tolerant plants can
Soil Amendment/Mulch
appropriate compost and sand provide withstand seasonal droughts during the dry summer months and
Amendedn
numerous benefits: infiltration;detention;retention;better do not need irrigation after they become established.
plant establishment and growth;reduced summer irrigation Native plants are encouraged,but non-invasive ornamentals that
needs; reduced fertilizer need;increased physical/chemical/ add aesthetic and functional value are acceptable.All vegetation
microbial pollution reduction;and,reduced erosion potential. should be planted densely and evenly to ensure proper hydrological
Primary treatment will occur in the top 18 inch flow-through function of the flow through planter.
planter.Amended soil in the treatment area is composed of
organic compost,gravelly sand and topsoil. Compost is weed- Quantities per 100 square feet:
free,decomposed,non-woody plant material;animal waste is not •115 herbaceous plants,l'on center spacing,'/2-gal container
allowed.Check with the local jurisdiction or Clean Water Services size;or
for Seal of Testing Approval Program(STA)Compost provider. •100 herbaceous plants,l'on center,and 4 shrubs,1 gal
To avoid erosion,use approved erosion control BMPs for flow- container size 2'on center.
through planters.
Vegetation
Planted vegetation helps to attenuate stormwater flows and break
down pollutants by interactions with bacteria,fungi,and other
organisms in the planter soil.Vegetation also traps sediments,
36 Low Impact Development Approaches Handbook cteanwater Services
Flow-Throughe4of4 Planter Pag
'
iA y d i a • (iL z •tf 4-«^ } :,,,�Wt i -
.M} ' E '
• t $4.42 ,,it y tp
,, 0
.:444
iiiik' A 4 , i ;-, tipt,',I.- '., -:•:.. .,4414,,,VoRipkr=
• f �t' f4 }} i.ylik{F3 A
{IjE !NJ., t! ."IJ ,
,`tr,r # # 4 '7""•ti„F #:. t t ° ''rr, .t,{.,'h'—r !rtir,
Rose Quarter parking structure, NE Portland Washougal Town Square
, 41 Y
f. 4 t 't #^ Y
F d.'fix 't
!� - Aa, , a ,,•:
{ ; / r
,'J }
Aloha Dog and Cat Clinic, Washington County .' `"' i ' '1-. r ''* ,
k x fr, jy
Buckman Terrace Apartments, Portland
Required Maintenance Period References
Clean Water Services Design and Construction Standards
• Water-efficient irrigation should be applied for the first two years
after construction of the facility,particularly during the dry
summer months,while plantings become established.Irrigation
after these two years is at the discretion of the owner.
• If public,the permittee is responsible for the maintenance of
the flow-through planter for a minimum of two years following
construction and acceptance of the facility.
Long Term Maintenance
If private,the property owner will be responsible for ongoing
maintenance per a recorded maintenance agreement(see page 88
for example maintenance agreement).
•
For detailed Operation and Maintenance Plans that describe
proper maintenance activities please refer to page 91.
All publicly maintained facilities not located in the public
right-of-way must have a public easement to ensure access for
maintenance.
CleanWater r Services Low Impact Development Approaches Handbook 37
11300 SW Bull Mountain Rd
Appendix E
Geotechnical Report
E
REPORT OF GEOTECHNICAL ENGINEERING SERVICES
11300 SW Bull Mountain Road - Site Improvements
Tigard, Oregon
6ejltecJ)
Solutions Incl
May 6, 2021
GSI Project: bama-2 1-1-gi
G Teelons I ncl
May 6,2021 bama-21-1-gi
BAMA; auryn(c�bamadesign.com
REPORT OF GEOTECHNICAL ENGINEERING SERVICES
Infiltration and Pavement Improvements
11300 SW Bull Mountain Road, Tigard, Oregon
As authorized, we appreciate the opportunity to present this report of geotechnical engineering services
for the proposed grade and pavement improvements for the commercial facility at 11300 SW Bull
Mountain Road, Tigard, Oregon. Improvements are to pavements and infiltration. The purpose of our
work was to provide geotechnical recommendations for design. Our specific scope of work included
the following:
• Provide principal level project management including management of field and subcontracted
services, report writing, analyses, and invoicing.
• Review previous reports, geologic maps, and vicinity geotechnical information in our files as
indicators of subsurface conditions.
Complete a site reconnaissance to observe surface features relevant to geotechnical issues, such as
topography, vegetation, presence and condition of springs, exposed soils and rock, and evidence of
previous grading.
• Explore subsurface conditions by drilling in 2 locations, one to a depth of up to 20 feet and one to a
depth of up to 5 feet or refusal with a solid stem auger. Remove cuttings and patch the holes.
• Classify and sample materials encountered and maintain a detailed log of the explorations.
• Complete infiltration testing in the deeper hole using open hole falling head methods.
• Provide recommendations for pavement earthwork including site stripping and preparation, seasonal
material usage, use of granular working pads, fill preparation and compaction, and trench backfill
preparation and compaction.
Provide recommendations for pavement subgrade preparation and asphalt concrete, portland
cement concrete, and base rock thickness and materials.
• Provide an infiltration rate to the civil engineer, along with backfill material recommendations and
infiltrate strata and depth.
y Provide a written letter report summarizing the results of our geotechnical evaluation.
SITE OBSERVATIONS AND CONDITIONS
Surface Conditions
The site at I 1300 SW Bull Mountain Road in Tigard, Oregon as shown on the attached Site Plan. The
site is bordered by light commercial properties. The site is on the eastern lower flank of Bull Mountain
on a gently sloping site that was likely cut flatter for development. The southern portion of the site is
paved with asphalt concrete, and the northern includes the one-story building and abutting concrete
parking and landscaping. Aerial photos show the site as undeveloped in 1999, and with a structure after
about 2001, with no significant changes since.
1/6
20978 S Springwater Road, Estacada, OR 97023 503.869.8679;don@geotechsolutionsinc.com
May 6,202I bama-21-I-gi
Subsurface Conditions
General—The site was explored on May 5, 2021 by completing two borings to refusal in hard basalt at
depths of 5 to 8 feet at the approximate exploration locations shown on the attached Site Plan. In
general, the site consisted of Rooty silt to a depth of about 6 inches in landscape/grass areas, and several
feet of medium stiff to stiff silt, quickly transitioning to very stiff silt that represents residual soils of
severely weathered basalt. The silt became increasingly stiff with higher gravel and intact rock content
with depth, until refusal was met at depths of 8 and 5.5 feet in hard basalt. Moisture contents ranged
from 15%to 31%, and terminal blow counts (No) were over 50.
Detailed descriptions of the subsurface conditions encountered in our explorations are provided in the
attached Boring Logs, and results of moisture content testing are also attached.
Groundwater— Ground water seepage was not observed. It is possible that perched ground water is
present at shallow depths above the rock in the wet season. Seasonal high ground water is mapped at
depths of 120-140 feet (USGS 2007).
Infiltration Testing—We completed open hole infiltration testing in B-2 at a depth of 5.5 feet. Testing
was conducted after an initial wetting period and measurements were taken over time. Geotechnical
recommendations for infiltration rate are provided in the Infiltration section of this report.
Exploration Soil Tested Unfactored rate (in3/hr/in2) *
B-2@ 5.5 ft weathered basalt and silt <0.01*
* this value is unfactored and not to be used for design.
CONCLUSIONS AND RECOMMENDATIONS
General
Based on the results of our explorations and analyses, the proposed improvements are feasible following
the recommendations herein. The near surface soils at the site consist of silt which is moisture sensitive
and require protection in the wet season. Infiltration of storm water is not feasible due to very low
rates and potential for seasonal shallow perched ground water.
Stabilization and Soft Areas-After stripping, we must be contacted to evaluate the exposed
subgrade. This evaluation can be done by proof rolling in dry conditions or probing during wet
conditions. Soft areas will require over-excavation and backfilling with well graded, angular crushed
rock compacted as structural fill, overlying a separation geosynthetic such as a Propex Geotex 801 or
equivalent. If particularly soft areas are observed a geogrid may also be required, such as a Tensar
BXSQ2020 or equivalent punched and drawn biaxial or multiaxial geogrid.
Working Blankets- Construction equipment must not operate directly on the subgrade, as it is
susceptible to disturbance and softening. Rock working blankets placed over a geosynthetic in a
thickened advancing pad can be used to protect subgrades in wet conditions. We recommend that
sound, angular, pit run or crushed basalt with no more than 6 percent passing a#200 sieve be used to
construct haul roads and working blankets, overlying the preceding separation geosynthetic. Working
blankets must be at least 6 inches thick.
2/6
20978 S Springwater Road, Estacada, OR 97023 503.869.8679;don@geotechsolutionsinc.com
May 6,2021 bama-21-I-gi
The preceding rock and amendment thicknesses are the minimum recommended. Subgrade protection
is the responsibility of the contractor and thicker sections may be required based on subgrade
conditions during construction and type and frequency of construction equipment.
Earthwork
Preparation - Prior to earthwork construction, the site should be prepared by removing existing
structures, foundation elements, utilities, topsoil, and any encountered undocumented fill. Any
excavation resulting from the aforementioned preparation should be brought back to grade with
structural fill.
Slopes- Permanent slopes should be inclined no steeper than 2H:IV for slopes up to 8 feet high. The
face of fill slopes should be cut back into compacted materials with a smooth bucket excavator. Erosion
control is critical to maintaining fill slopes and should be as described for cut slopes. Drainage must be
routed away from slope faces.
Fill-The on-site fine-grained soils, or site gravel fill or crushed pavement (less than 2 inches in size) can
be used for structural fill if properly moisture conditioned. This will not be feasible during wet
conditions for the silt. In dry summer conditions the soils will require drying by scarification and
frequent mixing in thin lifts. Once moisture contents are within 3 percent of optimum, the material
should be compacted to at least 92 percent relative to ASTM D-I557 (modified proctor) using a
tamping foot or sheeps-foot type compactor. Fill should be placed in lifts no greater than 10 inches in
loose thickness. In addition to meeting density specifications, fill will also need to pass a proof roll using
a loaded dump truck, water truck, or similar size equipment.
In wet conditions, fill should be imported granular soil with less than 6 percent fines, such as clean
crushed or pit run rock. This material should also be compacted to 95 percent relative to ASTM D-
I557. Demolition materials such as concrete and masonry building rubble, demolished pavements, and
excavated base rock that are free of organic and other deleterious materials and crushed to no greater
than 2 inches in any dimension and are well graded may be suitable for fill. Such material must be
compacted in a manner to prevent voids and provide a dense, incompressible material. Recycled fill
materials should be placed in lifts no greater than 12 inches in loose thickness. In addition to meeting
density specifications, fill will also need to pass a wheel roll using a loaded dump truck.
Trenches - Utility trenches may encounter groundwater seepage and caving should be expected where
seepage is present. Shoring of utility trenches will be required for depths greater than 4 feet and where
groundwater seepage is present. We recommend that the type and design of the shoring system be the
responsibility of the contractor,who is in the best position to choose a system that fits the overall plan of
operation.
Depending on the excavation depth and amount of groundwater seepage, dewatering may be necessary
for construction of underground utilities. Flow rates for dewatering are likely to vary depending on
location, soil type,and the season during which the excavation occurs. The dewatering systems, if necessary,
should be capable of adapting to variable flows. Flowing conditions in soils with appreciable sand content may
occur and dewatering and shoring in these soils, if encountered, is critical, particularly to protect adjacent
infrastructure.
3/6
20978 S Springwater Road, Estacada, OR 97023 503.869.8679;don@geotechsolutionsinc.com
May 6,2021 bama-21-1-gi
Pipe bedding should be installed in accordance with the pipe manufacturers' recommendations. If
groundwater is present in the base of the utility trench excavation,we recommend over-excavating the trench
by 12 inches and placing trench stabilization material in the base. Trench stabilization material should consist
of well-graded,crushed rock or crushed gravel with a maximum particle size of 4 inches and free of
deleterious materials. The percent passing the U.S.Standard No.200 Sieve shall be less than 5 percent by
weight when tested in accordance with ASTM C 117.
Trench backfill above the pipe zone should consist of well graded, angular crushed rock or sand fill with
no more than 7 percent passing a#200 sieve. Trench backfill should be compacted to 92 percent
relative to ASTM D-1557, and construction of hard surfaces, such as sidewalks or pavement, should not
occur within one week of backfilling.
Infiltration
Based on the results of our testing and analyses, infiltration rates in the silt unit are very low, and with
potential for perched shallow seasonal groundwater, infiltration is not feasible.
Concrete Walkways, Hardscaping, Trash Enclosure
Concrete walkways and hardscaping and the trash enclosure slab and walls can be supported on 4
inches of compacted crushed rock over undisturbed medium stiff or better native soils.
Retaining Walls
General-The following recommendations are based on the assumptions that (I) Walls are
conventional concrete cantilever walls (2) Wall backfill consists of level, well-drained, angular, granular
material, (3) Walls are less than 6 feet in height, and (4) No surcharges such as stockpiled soil or
equipment are placed within 6 feet of the wall.
Walls restrained against rotation (braced prior to backfilling) should be designed using an equivalent fluid
pressure of 48 pcf. Walls not restrained against rotation should be designed using an equivalent fluid
pressure of 29 pcf. These forces can be resisted by passive pressure at the toe of the wall using an
equivalent fluid pressure of 450 pcf(this should exclude the top 12 inches of embedment) and friction
along the base using a friction coefficient of 0.45. Wall foundations can use a bearing pressure of 3,000
psf on the native medium stiff or better silt.
Backfill- Retaining walls should be backfilled with clean, imported, granular soil with less than 6 percent
fines, such as clean sand or rock. This material should also be compacted to a minimum of 92 percent
relative to ASTM D-1557 (modified proctor). Within 3 feet of the wall, backfill should be compacted to
not more than 90 percent relative to ASTM D-1557 using hand-operated equipment.
Retaining structures typically rotate and displace up to I percent of the wall height during development
of active pressures behind the wall. We therefore recommend that construction of improvements
adjacent to the top of walls be delayed until approximately two weeks after wall construction and
backfill.
Wall Drainage
All retaining walls must include a drain constructed as described in the following section. Foundation
and retaining wall drains should consist of a composite drain board such as an Amerdrain 500/520 or
4/6
20978 S Springwater Road, Estacada, OR 97023 503.869.8679;don@geotechsolutionsinc.com
May 6,2021 bama-21-1-gi
equivalent that extends full height to within one foot of the ground surface. The drain board can either
contact weep holes constructed through the lower external face of the wall at 8-foot centers, or be
integrated to a drain pipe routed to suitable down gradient discharge as determined by the civil
engineer. In either case one foot of low permeability soil (such as the on-site silt) should be placed over
the fabric protected top of the drain board to isolate the drain from surface runoff.
Pavement
Asphalt Concrete—At the time of this report we did not have specific information regarding the type
and frequency of expected traffic. We therefore developed new asphalt concrete pavement thicknesses
for areas exposed to passenger vehicles only and areas exposed to up to 3 trucks per day, such as a 3-
axle garbage or delivery truck, based on a 20-year design life. The sections herein can also support a
75,000 GVW fire truck. Traffic volumes can be revised if specific data is available.
Our pavement analyses are based on AASHTO methods and subgrade of structural fill or undisturbed
medium stiff or better native silt having a resilient modulus of 6,000 psi and prepared as recommended
herein. We have also assumed that roadway construction will be completed during an extended period
of dry weather. The results of our analyses based on these parameters are provided in the table below.
Each of these sections can support a 75,000 GVW fire truck.
Traffic 18k ESAL's AC (inches) CR (inches)
Passenger Vehicle Only - 2.5 6
Up to 3 Trucks Per Day I7,000 3 8
The thicknesses listed in the above table are the minimum acceptable for construction during an
extended period of dry weather where the roadway is not used as a haul road or working blanket.
Increased rock thicknesses and stabilization will be required for such uses and for construction during
wet conditions per the Stabilization section in this report. Crushed rock must conform to ODOT
base rock standards and have less than 6 percent passing the#200 sieve. Asphalt concrete must be
compacted to a minimum of 91 percent of a Rice Density.
Portland Cement Concrete -We developed PCC pavement thicknesses at the site for the assumed
one-way traffic levels as shown in the table below. Each of these sections is based on AASHTO
methods with no reduction for wander and a composite modulus of subgrade reaction of 350 pci
(AASHTO Figure 3.3 with Mr = 6,000 psi and 6 inches crushed rock base). Other parameters include
4,000 psi compressive strength portland cement concrete (PCC), and plain jointed concrete without
load transfer devices or tied concrete shoulders. PCC pavements over trench backfill should not be
placed within one week of fill installation unless survey data indicates that settlement of the backfill is
complete.
Traffic 18k ESALS PCC (inches) CRB (inches)
Up to 3 Trucks Per Day 17,000 5 6
Subgrade Preparation -The pavement subgrade must be prepared in accordance with the Earthwork
and Site Preparation recommendations presented in this report. All pavement subgrades must pass a
proof roll prior or probing by the geotechnical engineer prior to paving. Soft areas must be repaired
per the preceding Stabilization section.
S/6
20978 S Springwater Road, Estacada, OR 97023 503.869.8679;don@geotechsolutionsinc.com
May 6,2021 bama-21-1-gi
LIMITATIONS AND OBSERVATION DURING CONSTRUCTION
We have prepared this report for use by BAMA and the design and construction teams for this project
only. The information herein could be used for bidding or estimating purposes but must not be
construed as a warranty of subsurface conditions. We have made observations only at the
aforementioned locations and only to the stated depths. These observations do not reflect soil types,
strata thicknesses, water levels or seepage that may exist between observations. We must be consulted
g to observe all foundation bearing surfaces, subgrade stabilization, proof rolling of slab and pavement
subgrades, installation of structural fill, subsurface drainage, and cut and fill slopes. We must be
consulted to review final design and specifications in order to see that our recommendations are
suitably followed. If any changes are made to the anticipated locations, loads, configurations, or
construction timing, our recommendations may not be applicable, and we must be consulted. The
preceding recommendations must be considered preliminary, as actual soil conditions may vary. In
order for our recommendations to be final, we must be retained to observe actual subsurface
conditions encountered. Our observations will allow us to interpret actual conditions and adapt our
recommendations if needed.
Within the limitations of scope, schedule and budget, our services have been executed in accordance
with the generally accepted practices in this area at the time this report was prepared. No warranty,
expressed or implied, is given.
We appreciate the opportunity to work with you on this project and look forward to our continued
involvement. Please call if you have any questions.
Sincerely, �}�"`
lA
—4"i ,c
L
Don Rondema, MS, PE, GE
Principal MOON i
Attachments— Site Plan, Guidelines for Classification of Soil, Boring Logs, Moisture Contents.
6/6
20978 S Springwater Road, Estacada, OR 97023 503.869.8679;don@geotechsolutionsinc.com
b
To
mountain
R°ad� gUil
SVtiI
000roiomeooeo.owgiw :41".. .10
Al It
B_ i
4
: �}}fig, Buy
p •
,,:', a .,3 0 .Spy t�� uy ~f' 4i• . , '" - _.
-,'
B-2 gg ` ,.
'ib ::
3ma2 ' 1 r
. P x
...� . sat
.ram
fi
.
BASE PHOTO FROM GOOGLE EARTH 2020 AERIAL
Gutech SITE PLAN
Solutions I ncl bama-21-1-gi
GUIDELINES FOR CLASSIFICATION OF SOIL
Description of Relative Density for Granular Soil
Standard Penetration Resistance
Relative Density
(N-values) blows per foot
very loose 0-4
loose 4- 10
medium dense 10- 30
dense 30- 50
very dense over 50
Description of Consistency for Fine-Grained (Cohesive)Soils
Standard Penetration Torvane
Consistency Resistance(N-values) Undrained Shear
blows per foot Strength,tsf
very soft 0- 2 less than 0.125
soft 2-4 0.125 -0.25
medium stiff 4-8 0.25 -0.50
stiff 8- 15 0.50- 1.0
very stiff 15 - 30 1.0- 2.0
hard over 30 over 2.0
Grain-Size Classification
Description Size
Boulders 12- 36 in.
Cobbles 3 - 12 in.
Gravel '/,- 3/4 in. (fine)
3/4- 3 in. (coarse)
Sand No. 200- No.40 Sieve (fine)
No.40- No. 10 sieve (medium)
No. 10- No.4 sieve (coarse)
Silt/Clay Pass No. 200 sieve
Modifier for Subclassification
Percentage of Other
Adjective
Material In Total Sample
Clean/Occasional 0- 2
Trace 2- 10
Some 10- 30
Sandy, Silty, Clayey, etc. 30-50
,
Soil and Rock Description Samples and Data
Oft-
Medium stiff to stiff, brown SILT; moist. (root depth 6"). ri w=20%
Stiff, sandy SILT, with some weathered basaltic gravel; moist.
w= 15%
Stiff to very stiff, brown and black severely WEATHERED BASALT; moist. m
w=31%
Becomes hard to very hard BASALT- refusal at 8'.
io—
Boring completed on 5/5/21 and backfilled with bentonite.
20-
30-
N60=SPT blowcount
w= moisture content
40- f= percent fines
yd= dry unit weight
G otechh BORING B-I
solutions I ncl Bana-2l-I-gi
Soil and Rock Description Samples and Data
Oft-
Medium stiff to stiff, brown SILT; moist. (root depth 6").
w=24%
Stiff, sandy SILT,with some weathered basaltic gravel; moist.
Very hard BASALT or boulder- refusal at 5.5' S0/ w=22%
10-
Boring completed on 5/5/21 and backfilled with bentonite.
20-
30-
N60= SPT blowcount
w= moisture content
40- f= percent fines
yd=dry unit weight
e‘sG otech� BORING B-2
Solutions I ncl Bama-2l-I-gi
Exploration Depth,ft Moisture Content
B-1 1.0 20%
B-1 2.5 15%
B-1 5.0 31
B-2 2.5 24%
B-2 5.0 22%
e&O u
6MOISTURE CONTENTS
O lIc I O n S I n c l bama-21-1-gi
11300SW Bull Mountain Rd
Appendix F
Operations and Maintenance Plan
To be provided in final storm report.
F