HomeMy WebLinkAbout03226 - Technical Information Report " , 1.,. � -
f,.
'TEC�TICAL INFQl�:MATIUN REPORT J�N�3 ��
F .
�;�„�,�3Y
F��
MERRILL GARDENS AT RENT�N CENTRE �
� �
June 11, 2004 �'
PREPARED FOR:
Friedman Development,LLC
P.O. Box 1018
Mercer Island, WA 98040
PREPARED BY
_�---�
�s_.-_�_�_------t
, ��
� I�.� %
-�`� ��` _/ —�/
,�, lJ v � I
Penhaliegon Associaies Consulting Engineers,Inc
v
750 Sixth Street South Kirkland,WA 98033 �
Phone� 425-827-201� Fa�: 425-527-5043
+ .,
'�'ECHNICAL INFORMATION REPORT
FOR
M�RRILL GARDENS AT RENTON CENTRE
June 11, 2004
PREPARED FOR:
Friedman Development, LLC
P.O. Box 1018
Mercer Island, WA 98040
�
� ' � -W ��0� •
� ��
�
��, �'�
a�x � - O�
��G ���
��+� o �
PREPARED BY
�'
_ ��
Penhalle�on Associates Consulting Engineers, Inc
?50 Sixth Street South Kirkiand,WA 940�3
Phone: 425-82'-2014 Fax:425-827-5043
•1 II
Merrill Gard�s at Renton Centre �
June 11,2004
Table of �ontents
Section 1 Project Overview ............................................•---.......................................... 1
1.1 General Description.................................................................................... 1
12 Fxig inv Couditions-------------------------------------------------------------------------------------2
Figure 1 -Vicinity Map
Figure 2- Do«�nstream Drainagel Vicinity Map
Section 2 Conditions and Requirements Summary.........................................................3
2.1 Core Requirements......................................................................................3
2_1.1 Core Rec}uuement#L--------•--•._...--------------------.._._....._..._._......._..---3
2.1.2 Core Requirement#2...................................................................4
2.1.3 Core Requirement#3........................��---......................................4
2_1_4 Core Rec}uirement#4----------------------------------------------------------•---.___.4
2.1.5 Core Requirement#5......--•..........................................................4
2.1.6 Core Requircment#6...................................................................4
2.1.7 Core Requirement#7.......................................................�---------�-5
22 Sp�;cial Ri:quiremcnts............................................................................�---..5
Section3 Offsite Analysis......................�---.................---•------........................................ 7
3.i Offsite Analvsis .......................................................................................... 7
Section 4 RunoffControl.....-�-�--�--�.............................................................................. 12
4.1 Flow Control............................................................................................. 12
, 42 Water QualiLy .-•-�------•-•---------------------------------------------------------------------�------- 12
Section 5 Conveyance System Analysis and Design ................................................... 13
Section 6 Erosion and Sedime�t Contrd..................................................................... }�
6.1 Temporary Erosion and Sediment Control................................................. 1�3
6.1.1 Clearing Limits...........................................•------•------•-------•---.._.. 14
6.12 Cover IVfeasures.......................-------------� -�- .....--�-------�-�---�-- --. l4
6.1.3 Perimeter Protection.................................................................. 14
6.1.4 Traffic Area Stabilization.-•........................................................ 14
6.1.5 SedimentRetention..._---------------------------------------------------------------- 14
6.1.6 Surface Water Control............................................................... 14
6.2 Permanent Erosion and Sediment Control ................................................. 15
Section 7 Maintenance and Operations....................................................................... 16
7.1 Operation and Maintenance.......................................................... 16
Section 8 Bonds and Liability...........................................................�---._.................... 17
8.1 Bond Quantities........................................................................................ 17
82 Facilities Summars�.........................................................•-----------------------.. 17
8.3 Declaration of Covenant............................................................................ 17
Appendi� TIR V�'orksheet,Storm���ater Facility Summary Sheet,Ex. &Developed
Area Maps&Operations and Mairrtenance Manual
i Penhallegon Associates
Consulting Engineers
Tecluiical Infonualio�►Rcport
.� ��
Merrill Gardens at Renton Centre
JuQe 11, 2004 _g
�.
Section i Project Overview
1.1 General Description
The project is located at 104 Bumett Avenue South in Renton,Washington. The 1.88-acre site is
currently the location of McClendon's Hardware. See vicinity map below. The site and the
surrounding area is located in the Urban Center Design Overlay, District A, Downtown Conidor.
The taac parcel numbers associated with the project site are 0007200156, 0007200154,
0007200104, 7231502030 and 7231502120.
�MAi�41�EST`"� i � i L�
�£ - t p � p> 0�60a"�t
Q t F �c � n
� � _ .y y# � � � o � � � Td 4t4i St *,
� � ':?� Q; � � � � ¢
y, �� a; � y � g N hdar�Sf,f
� � �
� i` < o z � N 3rd 5t r
� ,
m � .
z z z � _
� z
, ;�w
� ° 4,�'` tn i 'F � 'm
p,�Q _..Airport Way � �.:r rs�� �o
��c1�.',. S Titicu m St a t g��
�.; , S Tobir� St � � �n � ��.�•�-"�"-- ,`
m f Renton 9 � �d�`, ,�*
� ' � �d �i�s�es Par�a�9.L'(nert;, r_
Z' � p S 2nd St � � � �� -
�2 ,_.—m.c.._ --- _..�_-.o..__...��_...�.�_ �= � ....
I .�p1 cn � � i ��ya`1;n-
`�� S 3rd st �..0. .�_.�_ � j,�,,n•s��'..
�. �'�.,�:"_sA..'"�"` `_'�n�^$r A
- � S 3sd� -. _ D �
�a
S4thSt D �U� ��
��-'`� c. �
� ,Q! N; �
, `S 5tn St �� °C
� F
,�� _1_.+�-' �
._..�- " �� [' �
02044 A4apQuesi.mm,Jnc.;G2004 NAVTEQ
Figure 1 -Vicinih�Map
1 Penhallegon Associates
Consulting Engincers
Technical Information Rcport
„ .�
Memll Gardens at Renton Centre /�������
June 1 I,2004 ( J' , �
�_��;�.,'
The project involves construction of an approximately 150-unit senior housing facility and
associated parking. For more project information, see Appendi�c A, Technical Information Report
Worksheet.
1.2 �xisti�g Conditiorzs
The site is rectangular in shape with a length of approaumately 550 feet and a width of
approximately 115 feet. The site slopes generally from south to north with appro�cimately 1-1/2
fi;c:t in fall. With the e�ception of a few planter beds and strips, the site is paved and has three
existing storage sheds. Approximately 1.77-acres of the 1.88-acre site is covered with impervious
surfaces(roofs, pavement).
Penhallegon Associates
Consulting Engineers 2
Tcchnical Infonnation Report
.� �
Merrill Gardens at Renton Centre �---�
lune 11, 2004 ,
. �
Section 2 Conditions and Requirements Summary
2.0 Drainage Review Types and Requirements
The City of Renton has adopted the 1990 King Cour►ty Surface Water Design Manual
(KCSWDM)for surfa�ce water management and design:
� The project is outside of any sensitive areas according to King County I-Map
� T'he site is located in an azea that makes it susceptible to groundwater conta�„in�t_,'on
(medium to high risk)in accordance «-ith King County I-Map.
• The proposed project does not add any impervious surfaces onsite. The area of
impervious surfaces is reduced by approximately 300-sf.
• The project adds approximately 3,800 of new contiguous PGIS to the project site.
• The site is not a high-use site.
Per Section 1.1.1. of the KCSWDM, the project requires Drainage Review since it collects and
concentrates surface and storm water runoff from a draina.ge area of more than 5,000-sf. Thus,
the applicant must demonstrat�; that the proposed project complies «ith the follo«�ing Core
Requirements:
• Core Requirement#1: Discharge at Natural Location
• Core Requirement#2: Offsite Analysis
• Core Requirement#2: Runoff Control
• Core Requirement#4: Conveyance System
• Core Requirement#5: Erosion and Sediment Control
• Core Requirement#6: Maintenance and Operations
� Core Requirement#7: Bonds and Liabiliri�
Further addressed will be Special Requirements.
2.1 Core Requirements
2.1.1 Core Requirement#1: Discharge at Natural Location
Requirement: 77ze discharge from a proposed project must occur at the natural IocaJion.
The proposed project will discharge stormwater runoff at the Natural I.ocation. The project is
furthermore not located within a Landslide Hazard Drainage Area, nor is it adjacent to or
containing Sensitive Areas such as Wetland, Landslide, Coal Mine. Seismic or Erosion hazard
Sensitive Area Ordinance (SAO)areas.
3 Penhallegon Associates
Consulting Engineers
Tecluiie;al Intoni►alioii Report
�� ,
Merrill Gardens at Renton Centre �'
June 11,2004 { � :
. i
2.1.2 Core Requirement#2: Offsite Analysis
Requirement: All proposed pt-ojects must identify the upstream tributary drait�a�;e area and a
downstream analysis. Levels ofanalysis required depend on the problems identified or predicted.
At a minimum, a Level l analysis must be submitted x�ith the initial permit application.
See Section 3 for an Offsite Analysis for the proposed project area.
2.1.3 Core Requirement#3: Runoff Control
! Requirement: Proposed projects must provide runoff eorrtrols to limit the developed conditions
peak rates of runof�to the pre-development peak rates for specific design storm events based on
the proposed pro�ject site existing runoffconditions, and install biofiltration measures.
Flow control will not be proposed for this project. The improvements do not add greater t�an
5,000-square feet of new impervious surfaces to the site (Negligible Peak Runoff Rate Increase
EYemption, 12.3-5). The impervious surfaces under progosed conditions ���ill be appro.Yimatel_y
300-sf less than under existing conditions. The total proposed impervious area is 1.50 acres. I
Biofiltration facilities are not proposed since the project adds less than 5,000-sf of ne�v pollution
generating impervious surface (PGIS) to the site. The dc�elopmcnt onl} adds approsima.tely
i 3,800 of new contiguous PGIS to the project site
2.1.4 Core Requirement#4: Conveyance System
Requirement: All conveyance systems for proposed projects must be crnalyzed, designed and
constructed for existing tributary off-site runof�and developed on-site runoff from the proposed
pro ject.
New pipe systems «�ill be analyzed and designed to have sufficient capacity to convey and
contain the 25-year peak flow, assuming developed conditions for onsite tributary areas. New
pipe systems «ill also be designed to accommodate runoff that will be contributed b} o�sitc
areas east off the site that will drain to���ards the new onsite drainage system.
2.1.5 Core Requirement#5: Erosion and Sediment Cantrol
Requirement: All engineering plans for proposed projects that propose to construct new, or
modify existing drainage facilities, must inelude a plan to install measures to eontrol erosion and
sedimentation during construction and to permanently stabilize soil exposed during cot�.structiotz_
Erosion and Sediment ControI measures will be implemented. See Section 5 for discussion
regarding Erosion and Sediment Control mcasures.
2.1.6 Core Requirement#6: Maintenance and Operations
Requirement: Maintenance and operation ofadl drainage_facilities constructed or modified by�u
proposed project is the responsibility of the property owners (see Maintenance Requirements for
Privately Maintained Drainage Facilities in Appendix A), except City of Renton may assume
maintenance of drainage facilities u�l�ere grantec� an eusetnent, tract. or right-of=�ti�av arrc.f
of�'icic�lly c�sszanzes maintennnee and opercatio�z
Penhallegon Associates
Consulting Engineers 4
Technical Information Rcport
., ,
Merrill Gardens at Renton Centre
)une 11, 2004 �
Ttie Property Owner/Developer will maintain the onsite drainage facilities. The stormwater
facilities loca.ted on the site will be incorporated in a maintenance easement (Declaration of
Covenant) that will be recorded upon final approval of the convevance facilities if required_ See
Appendix, Operation and Maintenance Manual, for more maintenance and operation
requirements. The City of Renton will assume maintenance responsibility for storm
unprovements constructed in public right-of-«7ays or easements.
2.1.7 Core Requirement#7: Bonds and Liability
Requirement: All drainage facilities for proposed projects (except drainage stub-out
connections, downspout roof drain infiltration systems and downspout dispersion systems for
single family residential lots) must be constructed in conformance with the bond and liabiliry
t•equirements of City of Renton.
The Developer will meet bonds and liability requirements. See also Section 7_
2.2 Special Requirements
2.2.1 Special Requirement#1: Critical Drainage Areas
Not applicable-project not kno�s�to be«�ithin Critical Drainage Area
2.2Z Special Requirement#2: Compliance with an E�sting Master Drainage Plan
Not applicable-project is not included in eYisting Master Drainage Plan
2.2.3 Special Requirement#3: Conditions Requiring a Master Drainage Plan
Not applicable - project dces not meet the minimum requirements to trigger Master Drainage
Plan
2.2.4 Special Requirement#4: Adopted Basin or Community Plans
Not applicable-Project is not lrnow to lie within an area with an adopted Basin or Community
Plan
2.2.5 Special Requirement#5: Special Water Quality Controls
Not applicable - project does not meet the minimum 1-acre threshold to require special water
quality controls per the 199U KCSWDM. Furthermore, the project does not meet the City of
Renton 5,000-sf threshold for mandating water quality treatment. The project adds only
approsimately 3;800 of ne«�contiguous PG�S to the project site.
2.2.6 Special Requirement#b: Coalescing Plate OiU Water Separators
Not applicable - the proposed project (1.61 acres) does not meet minimum 5-acre threshold for
triggering oil contrQl.
2.2.7 Special Requirement#7: Closed Depression
Not applicable-the proposed project does not discharge into any closed depression.
2.2.8 Special Requirement #8: Use of Lakes, Wetlands or closed Depressions for Peak
Rate Runoff Control
Not applicable - the project does not propose runoff control and furthermore does not discharge
runoff into a lake, wetland or closed depression.
� Penhallegon Associates
Consulting Engineers
Technical I�dormation Report
q ��
Memll Gardens at Reirton Centre �-�------
June 11, 2004 >> ' ' ;�
.��.
2.2.9 Special Requirement#9: Delineation of 100-Year Floodplain
Not applicable - the proposed project does not contain or abut a stream, lake, wetland or closed
depression and is not loca.ted�vithin the 100-Year Floodplain.
2.2.10 Special Requirement#1�: Flood Protection Facilities for Type 1 and 2 Streams
Not applicable-project docs not abut a Type i or Type 2 stream.
2Z.11 Special Requirement#11: Geotechnical Analysis and Report
Not applicable-the project does not propose to install a pond or infiitration facility and dces not
modify a flood protection facility.
2.2.12 Special Requirement#12: So�7s Analysis and Report
Not required since the soils in the area have been mapped. However, it is expected that the
Developer will provide a Geotechnical and Soils Analysis and Report as is customary for such
proiect
Penhallegon Associates
Consulting Engineers G
Tecluucal Infom�ation Repori
�� .
Memll Gardens at Renton Centre ��
Juc►e 11, 2004
�'
Section 3 Offsite Analysis
3.1 O.ffsite Analysis
Task 1. Study Area Defmition and Maps
For the purposes of task 2 belo��, the study area shall e�end 1 mile do��mstream of the proposed
project discharge location. There is no offsite drainage azea tributary to this project site, so the
upstream azea is excluded from this analysis. For purposes of tasks 3, 4, and 5, the study area
shall e�ctend downstream to a point on the drainage system where the proposed project site
constitutes a minimum of 15%of the total tributary drainage area, but not less than %4 mile. This
project will not produce backwater effects upstream of the site, and therefore the upstream area
was excluded from this analysis. Refer to Figure 2, Downstream DrainageNicinity Map.
Task 2. Resource Review
A resource review �vas conducted to determine potential problems downstream of the project site.
The follo«�ing is a list of references used in gathering information for the do«mstream anahrsis.
• King County IMAP Sensitive Areas Map
• USGS Map
• Topographic Survey by Penhallegon Associates Corrsulting Engineers, Inc. dated June
2004
7 Penhallegon Associates
Consulting Engineers
Technical Infom�alion Repari
_ �r �"�.�"x� P '�:✓' � i gp� � a I �
.w.. Y°�Iprr�r:.iM7� �;�pt�w+1,..x"p.°�j nt�l re � ���� 7�,x �� r `` j�� �:t.
�I y���"YC�iy.� `���''�.�. v���4i� '�,�,w,, aY° w. <a»x� � i..,� * .
:'' ��. b� �� , ,, � ,� �' r'-. .,�r• � �
�'�.bhe�ts�`Y"� ��, �ry '.` �,. r � . r _�.� i �wS w��r g�,
a �
o:' ...u, ���'��+�'` � ' �,I�. ���u „k �r i�?� ���..} � � � "�1'4q4 '
� � � , �,a> y,� »+y a r� ,��,���;,�� 1�,� �
�` r,;, , �'��'�,�'���� � y�� x , ti` � ` l x,i.. � ,, ' h�r��'� „i � �,�,..�� �. .
�� ,.,��yy ��^y
rrl ``�d�� ;� � � 'U O - .�.�� .� �+ �L�. y � 3U' �E
y ♦`W..�4 a� br �X '1' '^ e�a' �^'S4 rd�3 : :� �i
! � a yr+, .y"" �-1 "S'M a 4 �1�'��� � il ��}e{''�'f'pA ,ey��jI ,o
. t \ ,y����k �y7�y, .N � �fi.. � � F� �� �$ �� �� ^'"'�fi'M`. f].
���`'h,,. V�µs �,l:�d. - 4'{�� fi �{}�._: J� j ���� �"�1.'�P�� �" 1�...
'�'�'�'��'h� �1���'; f �"��, � .�� �' 9 W�"T' ��P Vw�� �@'�"���a
; '� "�'.��'+��' ' a µ ������.',�'s"-�,! �'1 , . �- . ��h��d�..k��.
�P
� 4 n 1..�t r 1�:�! �y,.��, �'r+� flC�'���*���ira"�r1'tWt���i �y�y�yy.,
M ���.�b �u.`. ^„� i�++f �' :� f �1���� �� I '.. �� . :J� ��u �p .
� f �A,�/ ) ..�.� p ' 1
�,n1� :. � �,1�'(�p���y��� #�y .""a '�+�� '��i1 �;� � ' �y���y'yP�..} .. �
;�1,r � ��'o"W �^t i ��pri�n � r� � � .� t�r-
� �, {
�y� ��dr� p � ��.daA�6.,: a :�m, �� arks�ptfi .��alYi �
!
�.�e; ��.�� p�'� �,� �', � ���. � � � � w �' � '�''�1' �il�������'�'"4r , �
t� �r� ���� +�"� u �� ay ������,� ���� •� ;� r� �� i�
� ��y ,�� ��� a� �q ��� � �u��� ,, � p
�.,,� �q �u_ �. v 4, �u�P�.: �a�.� w u'�' � " �' �ri �c�
� : �°e'"wwa wx�r �+'"b� daeen'�<tutsflM�Bffi y „r� �
�n�a� �7t0tt�ty "��i � 1� �
a �C�t�R� 'I,�k'�i�E��`�ik�L�a�'L+�tv3l�af*C'�.mP, � ����.����:��. ` �4�•
��f� ��Y�F ���� ���p �� � {p'^ � � ' .. � w� '3 i
���� r ;�� ' ' �� '��t�,
� 1� �� �p w'In W9 rn . ;'.�
,� ` d ��` ��w�t�+��,.i� �,�„�,���`, �� f'
r°�� ,�,F�.�� i � '�+ a � . , sd�Odtiifk'�8�.° ?"4�', p„ o0
�.��. ��"�dA�M 1� ,1. k;:.� w1 m��. me � "t�+:;j-.. '�{ �
�y �� ���Y ��!��Wap R ,�� '` J' MWii'Sca9'1�',�:: 'k..
y 1 j
1w��� �` C M �w��V � ;� *�� °'FyWn \ �' '. �'� i�7v�j� ���� �p+f
�, 'an�.� y ."4 y�n �., """ y.tw.,'_K+r tn, �� ,_�i'
"� y,� ,pp� '��r., wm y �pp .:.i
,$, .�dIF�'��l�h�� ..Aa4 -MPh�R "�i"1�'F l�R�� I N '�� �pi B i'.. �k �� c�41 y.�Fj
� � ���` {�
���y N V��_ { � ftl '. .p V
^ � ° ? #.� � ,�' �NM �„'N i �5" �.�" ��,rc. 1�i.�e� ��t cA.+ � 4S
�ry5�
�r . .... ����rl � i�� r � .., .,., � � � ,. ��,�-
4�. xr�N+wi�C'�II{�� ' � � ,, k A �.� ab�"" ��"��� '3��ri"� � .,� � . � -
"�' �� � � yt mx zr •t dx CQ
i.+ �L `R7IdW�Adai�y�„ [� �7�� k` � v t x, ��iM;i� �'M �" i.
r� � ' " ����lw y�';�`A�'7GS '�211{,�����,.:.. � ` $ -..�4t� � Y`�" � .�
�,a.,�� � r kn � � ti �
Q �i W�a�+ ;� 1� � �`wt � i ms �a , t "A' � q ���I. �t�`., � +• � �
q �u �i �I�����i ti� �r �i� ` � �� ��,�� ,o�w,,,����� � ""$R ` ��'; � � ��/
� � I �� `� �D3! � �'��. ll X.'��t � P � G�^ i P C" I-�
� .. .� �, �""�' r�a �;� 'Aepe"y,'1.��""'_"W.° d?Pu�it'�„ w�,.. . t,�r r�1�"' �'.'� �
a n � e`��y bNy„ O
� �. � �� .. .. . ; �a , � . . N �N
�'t 9+ r�
� iu� ia,- � � �. �y � � � �t iT ��,�y� r�•�' � Q .'��'
� � �i 'i� �'- �ry'� �`'� ;; }. � �,� ; I� � "�m i I�.�: ��� � o;o �
N �f , ��°"�,"�x� � �`� �,u �µrt. . t� Spn 'w+�^k '�i k �� �(� �l3-. � Q y0,�
S r A W G
� N � `"�wrry�{� � � � t!y �w716 r� r �p � � r'�wx���P7iMrw0..4':.+�v .4i;i,' ,��� � � ��..
(� � � ,.�� � �'� '�D ��s.>,y ' M 'w �� N a�i •� �
,� � � ; i `. , ' .
�" .., .r� r�x�r +� �`'s,` ,,,#�s �;,�n � . � w ~ ,� �
� �R. ���.,. (�" , v ��: v � ��>"� � i..; ,��,... , ..�� `4/' �� :. �� � c�
G N ° t �„ ` I�,, i m. ! +r r 1 '� � ,�, �: ' � O GJ
�I 'f�' r s . 1 4v � ��.. � i�, �����, ., �
�-+ F-f �, (�r�'d..... � �+� w�� �f+'�+k K��'���t.� y� .�� �t t�. � h� ��k�i� �y (3w V F"'
� ir ;�., � � � a �'� �a
�, u.��w .. n ..r.l . `1 . .5; '�,s. ...
. �
Merrill Gardens at Renton Centre �
June 11, 2004
Task 3. Fietd Inspection
A level 1 field inspection �i�as conducted on Tuesday, June 8, 2004 at appro�imately 1:00 pm.
The weather was sunny and appro�umately 65 degrees Fahrenheit. A minor amount of
precipitation had fallen within the previous 24 hours.
Task 4. Drainage System Description and Problem Descriptions
Dra'n�e from the site will be conveyed to the 8" public storm drain (PSD) located along the
centerline of Burnett Avenue South and the 8" public storm drain located along the east side of
��Villiams Avenue South.
The 8" PSD on Burnett Avenue South directs flow north from MH#1 (at the southwest comer of
site)approximately 660 feet to MH#2 (located about 110 feet north of South Tobin Street. From
MH #2, an 8" PSD directs flow east approximately 28U feet to MH #4 (located at Williams
Avenue South).
The 8"PSD on Williams Avenue South directs flow north from MH#3 (at the southeast corner of
site)appro�mately 710 feet to MH#4.
From MH #4, a 12" PSD directs flow north approximately 90 feet and discharges into the Cedar
River. The point of discharge is approximately 0.15 to 0.20 miles dowastream of the site. Refer
to included photographs of vicinity of MH#4 and the outfall.
No current or recent drainage complaints were found by researching the King County IMAP
Sensitive Areas Map wreb site.
Task 5. Mitigation of Ezisting or Potential Problems
No existing or potential problems were identified in thc resource revie�i� or field inspection. The
project is not expected to negatively affect the downstream system since peak runoff rates and �
durations are eYpected to remain essentially constant. The total area of impervious surfaces under
both caisting and proposcd conditions is appro�matel_y 1.50-acres.
I
9 Penhallegon Associates
Consulting Engineers
Technical Information Repori �
� !
Merrill Gardens at Renton Centre /`�
June 11, 2004 � , ` ,� �
J `7 . .�
{ ����� ��'•k- �... ����'fiP�Fr.�?w j � ��'�' �� .A,�.i 1 ,.,j� . .
�� �� �} �¢ t'�`�
' �{� }W_ S�',!. � �E.� ai�.
��
�_ �'.
� ' � ��
�� �� -:��-���iz�-i'.f;.
. 1�'� - �� �R. .
�
'f.
:;i' -'Ta�Y� x :.i,.'�y.
���� �„� ..�° � _, v i-;t'f
` ' �.
'�y, 1 � ' �.,:
�' � � �` _� �^ :�
- ' `�-::�a' ''a:. t�-.ss s:� - -
e y�
:"9 , -
r g
't �5 . _
x��s'_s. W �.,'•�.�."d' ��-0y.+� •:y a�.. - �,.� �. �..i; .�
.`,� W ' � ��� 4 � . �^ ��
� �A�. . x .�� ..::. ..��x F �". _ ;�` A .
� ��q..:����r.l�, �� � � "t.—.�:`" " �`�}frtt� . � '�- --- � �`Z
if — AC +� • ±�g
� s� _, 'a6- .r'�.r t,. . II j, .,." . .�. . �i.y.��. .�0 _ .._ _..__ ._.___.
� .. . � ' ,,,� . , '� -� ��r'�F, �.re�=.-
�}'
�k`���y ��i�'�_'�. "s8` . .... -a._W,...,��.. ...:.e;�r8.. ... ' .:.r+4� �. '
�'���� .irP4 - —
�"t""z"�,� ^�,���
� ��'.r'+�a.�,i- -,_-...��.�t,� - � ����41�� - '^� 1'�'�ra t,,,��
.. . ..G _•}�6F'h�yt�i`J�y-p�s��
n"�Hi+
T �. � �•�.'� �g p: .+.lSN.�'1_us.t.G t
p-x P � _ - . +�'i u�� '"PS .Y'h,F,
1 3 ,: � ^�.__ � � � c5�p�6(w Li
� �' . S - J._,� �'
R���A ���
'i�. �� " �^� �
�'
1 ` a . _
"'� i�trFj � ��� . .. . . �� �. .
1 �f� �.. �.. ' .. .�� � . ..
Photo# 1 - Vicinitv of MH#� looking north �
Penhallegon Associates
Consulting Engineers lU
Technical Information Report
�. �A' . �; � , `����`'�G„����:"y ' t, � ��ii ,�� ,� � � �
� ti t. ;��.. �-p ti � `r� ,� v
� ta�s�,,�, w �'��r . � ' � a �r� ��i� 1' c� ��
�� � . � 6 "�.dN a ��� ��3�4't �9 t� A;,. .e�M ����yY�Y'�'"�^` ����. y .ri .r�.
�� 'r-� �. ki� �s � '`a �t�'-�a.� a" �' ;:�` f � � W O
m "d �p �,�yP, .y_ �,�,y' '� =„r � t ':+
�±�.�� �iE�a'" r��k��:� �n v , ;'� � � °��
, ,� , ��
} ,j�� �. �� � �� � �
,�."i���� ��� �°"�'�,�.�'^a�. � � �.r ' '�g�;f�€r���'� �°� ��+w{ � O
r
u .r.�. �J i' � 4.
i i. ;.��� e�iA4 �h ��i�.� y � ��.*��x`�,y �r a��� � 0 r.�..i
- � �$$ .Y� ^Yl,y d 'p �` � lY� ..1 � V �
s F �'��i � � �`' �c. �
4 r'a
4��� l�" W � ' �'�st9( "�i �
�
� a���#�' ���,rt y< � �
x '
�` ` E—�
"r� �
q � �� ��t"+�'7 b�cY � k ���i
�L �� I
�� �.� � �...� f •. :4 y�' �d �
/ � �
§�rk ��r'`>. �w' '�i�r 1 d, '`� aY,,.t Y� � �
+ � . '��F� � �4
,qy-t� 4
t 1.��w .. d.i '. � ri� � � J d�r Y vt � �� '�
ti �a � �, �,�� � � ,�. � '.� �r �� t:.� " '�.�i,,-�,
� �� ] A �, i'�qp . Y� .
r
h
wty��yx ,Ye l y� { t� , �
C
1 � $� '� g � � l
�" ��ak V�T � �a %e Pr 5 . �[ '�`�� '� t i�J �:�
� ��..� � � �'�'ar � ��' �� �� 'I�b d �"� ���p��r ".�'
"a J},� �P�i� � "4. ��p ' �9.'� { + �
�. ..� �,I a Y t r�� F" d y b1) �
K I a � � � P a �°".�G�� ...i
P,C�.f:°.�. !r k'�qS ���a ;Y k f�`�yI S f x�ddd ti . �.l 4� � ��'Q++
"�"��"���.. * +��� .'� �S a CN�•y Y8 k�� � ���� +��'x i i� 1, O
�p „� '�f � 4��t�;
�� . � c:�*,R� i�� '"� l��P� �� � �, i��,��"�rid i j�i�'��,
�� � �� �.. ���_ I � � � rn
n��� �a�g�� �� � � �.�."' � � � w F;� � � �
..¢ .a��1 �.9� �� ' �
_ �y»�. S- o s�' {� �'�� x� -. �,,S�,�S�fr-g r�j . ol .p
- ��,,.'�:� ^^'F`t � • t a,"1t'�r• 3,yra,�.� „, , ,� ,�M ?,
�
t
� --" '���'�F��� ;� f y,t P i, ��V+��-y i ,n�:�.� ^"�� �.� u�rw � ' ;,o �
�r
w } k i ; 'r ��" � �4w^t i f'O
� y '�„�X, �tay."�`�3r � � vw `�!'��} `'� r�y,���. � �i+��°'�
ti��. �41 . .�+Q J ✓G k N"�7 F :,�
U 'iry jl, 'S k od � °�E '* r ��" �`l��q;� �'6 h� 3, a � ��
,fa-c' sW P � �» � f : '�VM � �' I t 1 Y� �
� i �1 W F ' b .�t'�'.l 6 '�� ,�, Ya ., I !I �.".-�
�
Gi a' a ��q x'� � �a '� '. '�.. 6 3 � . f �
� ;� ,� ? �rc '�,�4r :� Y � ��{ � ��,k� YR ^�'.r" , �y I 1� �p J, `�7
� ��.,���""�.. 7 w �� ��;4 �v,�rY,;�.: `a� �� � ,f��, i�6�� A e^s�y��`'`�{}� 1 �� , O
�/ ,jt, � s w � 1�
F�r �.�w.� �„�' ^�,q" ��,ay��`��� � 4 i "�t„� �.� (,� +�"�^ r V�`G I O
�y `a y, Yq I! ! qp 'y w y,M t"4 k {�;'Cd� I,
y.{ „��,.a° X�` .�}���, �r?Yli, Y �".c fF� �� ' 'i.�! Iti
CC `' `�� �f xrov,xik` r�.'+1 h e, �.., t ry id �I ytX �,''
� � �����r'�y' h° +.,� �" � " � ��p��,��rW� �p k �'
v� t...�{ i'� S �✓�4 �p �� � i� t �' � 7:���'r�yY r i ',�
� Q �.� ����`"�,j�!�b'A�*w}�,��dq -yfr��r°43"�,t � :i',�� X �'�'y°�w�'� '� ; �;�,�p'�' �� U
���
� �,�. �.{ �� '� t�R� ��r�'`�w �Y�4 '' s . r �`,f
��3 �i ' r � � x�
C,7 , ra,� � �4"��t�win�,,"t�a� u� �,; � �� ,j� � . • �r tr `�'�tt��`� I
"_,, �te'`�,� �y� �w"k' °(�i�, �W"'" qk�� ""`'� v � ;� � '��." iW�,� �"1��t��
�, r„ 7�ia'�,, •�-.� ��p�i,`;���a� �u� ��rTMV, w�"tr�' � �„ ��". � O
� � �r;:s
� 6� �. ��';��, �j�`�;a,� t fi� � ��e' �`�� � �� �''
y ' �m ,�w r }fi� �� ti y.. No '� m",- �. O
�^'� ,p,,� 3 4. :. � r +g �i. „' �'^ µL �r �
y •
'
�-'f ^7*•V ,,. ..�"t. . . . ,.. ...�nt�i. k�' .¢. �.��.�,:. �.
rCy '��v i . � .',�' :: `.. +��e . �'��kd�.
, �
Merrill Gardens at Renton Centre �—��
June 11,2004 r ' ,�
Section 4 Runoff Control
4.1 Flow Control
As has been determined in Part 2 of this report, the proposed project qualifies for the 5,000-sf
area exemption and is not subject to flow control analysis and design. The total area of
impervious surfaces onsiie remains fairly constant at 1.77-acres and actually decreases by roughlv
300-sf.
4.2 Biofilt.ration
The project is exempt from biofiltration/water quality requirements since it proposes to add less
than 5,000-sf of new PGIS as part of the development.
Penhallegon Associates
ConsWting Engineers 12
Tec}u�ical Inforn�ation Report
. �
Merrill Gardens at Renton Centre ��'"�—``���
Jane 11, 2004 J�� � ,�._ '
Section 5 Conveyance System
Analysis and Design
�.1 Conveyance Desi����
New pipe systems have been anaiyaed and designed to have sufticient capacit} to convey and
contain the 25-year peak flow, assuming developed conditions for onsite tributary areas. New
pipe systems w�ili also be designed to accommodate runoff that will be contributed by offsite
areas east offthe site that will drain towards the new onsite drainage system.
Conveyance capacit_y for the systems was sized using the conservative Rational Method to
calculate peak flo�i�s �vithin each catch basin sub-basin.
13 Penhallegon Associates
Consulting Engineers
Technical Iaformation Report
. �
Memll Ga.rdens at Renton Centre ���
June 11,2004 �'I
Section 6 Erosion and Sediment Controi
6.1 Tempora�}�Erosion and Sedim�nt Controt
A temporary erosion and sediment control (TESC) plan will be developed for the site in order to
uiinimize the suspension of sediment into surface water, and to prevent sediment-laden water
from leaving the site. The main aspects of this plan are outlined as follows:
6.1.1 Clearing Limits
Clearing limits shall be installed prior to the clearing and/or grading of the site. Clearing limits
shall be delineated using filter fabric fence (where indicated) in combination with survey
flagging. Clearing limits shall be maintained throughout the duration ofthe project.
6.1.2 Cover Measures
Cover measures shall be provided to protect areas cleared or graded for the project that are left
unworked for more than t�i-o days. Cover materials will be plastic sheeting or mulching. Any
area un«orked for more ti�130 da��s�i i11 be seeded_
6.1.3 Perimeter Protection
Filter fabric fence �vill be installed downslope of disturbed areas, and will be installed prior to
upslope grading.
6.1.4 Traffc Area Stabilizatio�
The existing asphalt entrances«ill be utilized as the construction entrance.
6.1.5 Sediment Retention
Perimeter protection with filter fabric fence �iill be provided do«vslope of all disturbed areas and
«ill be instailed pnor to upslope grading. In addition, storm drain inlet protection itiill be
provided for all storm drain inlets downslope of the disturbed areas.
Taking into account that the e�isting conveyance system flo«-s to a sedimentation pond, the
measures noted above are considered adequate to meet the required sediment retention standards.
6.1.6 Surface Water Control
Surface water controls have not been proposed for this project. The site is graded and paved to
provide adequate surface water controls for the project.
In addition to the above requirements, all construction debris will promptly be removed from the
site to minimize demolition and construction impacts on the site. The contractor sha11 implement
additianai Best Management Practices as required and/or recommended by the King CountS�
inspector and as approved and/or required by other agencies as required during construction to
prevent construction debris, waste, material, fuel, oil, lubricants, and other fluids from entering
the public right of way and existing storm conveyance systems.
Penhallegon Associates
Consulting Engineers 14
Technic�il Information Report
• � ��---
Merriil Gardens at Renton Centre �`' '
�une 11, 2004 ! -
�
6.2 Perf�7anent Erosion and.Sedin�e�rt Control
The new building or new pavement will permaneutly cover a11 areas disturbed during
constniction.
1� Penhallegon Associates
Consutting Engineers
Technical Inforn�ation Report
. �
Merrill Gardens at Renton Centre �-----
June 31,2f?04 � t
, r a � �� ,
Section 7 Maintenance and Operations
7.1 O�erations and Maintenance
Ap�endi�A"Maintenance Standards for Pri�=atelti�Maintained Draina.ge Facilities"from the 1998
KCSWDM has been included as the operations and maintenance manual for the drainage
facilities proposed for this site(see Appendix C).
Penhatlegon Associates
Consulting Engineers 16
Technical Inforn�ation Report
i �
► /—_
Merrill Gardens at Renton Centre �
June 11, 2004 i / , / ,
Section 7 Bonds and Liability
7.1 Bond Quantities
A completed Bond Quantity Worksheet (BQW) will be completed upon preliminary approval of
the site work design.
7_2 Facility Summaries
A Facility Summary Sheet is included in Appendix A_
7.3 Declaration of Covenant
Not applicable at this time. A completed Declaration of Covenant will be submitted upon
approval of the site�vork design.
17 Penhallegon Associates
Consulring Engineers
. Technical Information Report
APPENDIX
Technical Information Report (TIR) Worksheet
Stormwater Facility Summary Sheet
Existing & Developed Area Maps
Operations and Maintenance Manual
� �
Figure 1. TIR Worksheet
King County Department of Development and Environmental Services
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
Part 1 PROJECT OWNER AND Part 2 PROJECT LOCATION AND
PROJECT ENGINEER DESCRIPTION
Project Owner Project Name
Friedman Development Merrill Gardens at Renton Centre
Address
P.O. Box 1018 Location
Mercer Island, WA 98040 Township 23 N
Phone Range 5 E
206-232-8330 Section 18
Project Engineer
Jeff Brown. P.E. Project Size 1.88 acres
Company PACE Enqineers Upstream Drainage Basin Size N/A
Phone 425-827-2014
Part 3 TYPE OF PERMIT Part 4 OTHER REVIEWS AND PERMITS
APPLICATION :
DFW HPA Shoreline Management
Subdivision
COE 404 Rockery
Short Subdivision
DOE Dam Safety
X Grading
Commercial FEMA Floodplain X Other(see list in Section
COE Wetlands VII of Drainage Report)
X Other Drainaqe Review
Part 5 SITE COMMUNITY AND DRAINAGE BASIN
Community
Renton, Washington
Drainage Basin
Cedar River Drainage Basin
Part 6 SITE CHARACTERISTICS
River Floodplain N/A
N/A
Wetlands N/A
Stream N/A
Seeps/Springs
Critical Stream Reach N/A
— High Groundwater Table N/A
Depressions/Swales N/A
— Groundwater Recharge N/A
Lake N/A
i Other N/A
, , Figure 1 -cont.TIR Worksheet
Stesp Slopes
_ _ _ ___
Part? SOILS -
Soil Type Slopes Erosion Potential Erosive Velocities
Additional Sheets Attached
Part 8 DEVELQPMENT LIMITATIONS ' = - _ -
REFERENCE LIMITATIONlSITE CONSTRAINT
Additional Sheets Attached
_
Part 9 -ESC REQUIREMENTS -
MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS
DURING CONSTRUCTION AFTER CONSTRUCTION
� Perimeter Runoff Control � Stabilize Exposed SurFace
� Clearing and Grading Restrictions X Remove Temporary ESC Facilities
X Cover Practices X Clean and Remove All Silt and Debris
X Construction Sequence x Ensure Operation of Perma�ent Facilities
Other
Other
. ,
Figure 1 -conL TIlZ Worksheet
- _ , _ : -
Rart 10 SURFACE WATcR SYST�i1ll '- -= - ; -- -
Grass Lined Method of Analysis
Channel Energy Dissapator Depression �
v°� Pipe System Wetland Flow Dispersal Compensation/Mitigation
Open Channe! Stream Waiver of Eiiminated Site
Storage
Dry Pond Regional
Wet Pond Detention �
Brief Description of System Operation:
Facilify Related Site Limitations
Reference Faciiity Limitation
Core Req.#4 Convevance Desiqn for 25-vear peak flew
Part 11 STRUCTURAL ANALYSiS - i'Part 12 EASEMENT5ITRACTS
: __ � --_
Rocicery >4' High Access Easement
Structural on Steep Slope Native Growth Protection Easement
Other Tract
Other
Part 13 SIGNATURE OF PROFESSIONAL ENGINEEa = - = -
I or a civil engineer under my supervision has visited the site. Actuai site conditions as observed
' were incorporated into this worksheet and the attachments. To the best of my knowledge the
,
irtformation provided here is accurate.
I� �� ��+.�� � 2�1�9z � 6 s a4—
Si ned/Date
�,
_ _ __ ____ __- �
• • ��
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
STORMWATER FACILITY SUNIMARY SHEET i
Development Memll Gardens at Renton Centre Date 6/11/04
Location Renton, WA I
ENGINEER DEVELOPER �
Name Jeff Brown, P.E. Name Steve Friedman ,
Firm Penhallegon Associates Consulting Firm Friedman Development, LLC '
En �neers
Address 750 6`� Street South Address P.O. Box 1018
Kirkland, WA 98033 Mercer Island, WA 98040
Phone 425-827-2014 Phone 206-232-8330
Developed Site: Acres 1.88 Number of lots 5
Number of detention facilities on site: Number of infiltration facilities on site:
0 ponds 0_ponds
0 vaults 0 vaults
_0 tanks 0 tanks
Flow control provided in regional facility (give location)
N/A
No flow control required X Exemption number #1 _
Downstream Drainage Basins
Immediate Major Basin
Basin A Cedar River Cedar River
Basin B
Basin C
Basin D
Number& type of water quality facilities on site:
biofiltration swale(regular) sand filter(basic or large?))
sand filter, linear(basic or large?)
combined detention/WQ pond sand filter vault(basic or large?)
(WQ portion basic or large?)
combined detention/wetvault stormwater wetland
compost filter wetpond(basic or large?)
filter strip wetvault
flow dispersion
farm management plan
landscape management plan
oil/water separator(baffle or coalescing plate?)
catch basin inserts:
Manufacturer
pre-settling pond
pre-settling structure:
Nlanufacturer
flow-splitter catchbasin
199�3 Surrace 1�r'atcr Design Manual 9.;1i93
1
. � KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANU'AL
DESIGN INFORMATION iNDIVIDUAL BASIN
A B C D
Water Quali desi flow N/A
Water Quality treated volurne or N/A
wet nd Vr
DESIGN TOTAL INDIVIDUAL BASIN
INFORMATION,
cont'd
Drainage basin(s) A B C D
Onsite area
Offsite area
Type of Storage
Facility
Live Stora e Volume
Predeveloped Runoff
Rate ,
Developed runoff rate 10-year
(Basin A
25- ear
T e of restrictor
Size of
orifice/restriction
FLOW CONTROL & WATER QUALITY FACILITY SUMMARY SHEET SKETCH
All detention, infiltration and water quality facilities must include a sketch per the following
criteria:
1. Heading for the dra�vings should be located at the top of the sketch (top right-hand corner).
The heading should contain:
• North arrow (point up or to left) • D9#
• Plat name or short plat number • Address (nearest)
• Date drawn(or updated) • Thomas Brothers page, grid number
?. Label CBs and MHs with the plan and profile designation. Label the control structure in
writing or abbreviate with C.S. Indicate which structures provide spill control.
3. Pipes-- indicate:
Pipe size
Pipe length
Flow direction
yil;'98 1998 Surface Water Design�fanual
�
+ • KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANL'AL
Use s single heavyweight line
4. Tanks-- use a double, heavyweight line and indicate size (diameter)
5. Access roads
• Outline the limits of the road
• Fill the outline with dots if the road is gravel. Label in writing if another surface.
6. Other Standard Symbols: I
• Bollards: • • • • ■ ■ ■ ■
• Rip rap o00000
000000
Fences --x---x---x--x---x---x---
• Ditches �n----�D--��D--�CD
7. Label trash racks in writing.
8. Label all streets with the actual street sign designation. If you don't laiow the actual street
name, consult the plat map.
9. Include easements and lot lines or tract limits when possible.
10. Arrange all the labeling or writing to read from left to right or from bottom to top with
reference to a properly oriented heading.
11. Indicate driveways or features that may impact access,maintenance or replacement.
1998 Surf�ce Water Design vlanuai 9/1/98
�
. �
- - - _�� _ WILLIAM3 AVE. S. -
�,�- - - _ _ _
, _ __ _ . ,_ , _--- __ .. ._
- , , . _ _ r _ -
, �
�' I- --� ---T
� - _. .:, ' i
I �
� . � . � . . ! IMPERVIOUS (ROOFS,
�,
� _ , . ; ; , � -
I ��� '�,- - - �� WALKS, ETC. -TYP.)
-1 � �� _ �- � : _ _ _ � , �
'.`"` �PJf' 1� Y �
i j _ . _ � � �
� P.G.I.S. (11YP.) � TOTAL SITE 82.036 SF 1.8� AC I z=; � I
I �1 ' I � TOTAL IMPER�I IOUS = 1.77 A� I � �
� I TOTAL P.G.I.S. _ = 1.18 AC ; � I
i � _ -_ -- - ` j PERVIOUS ( NDSCAPING) = 0.11 AC J � � I
, �
� � � � i _ _ -- _ ° `
, -_._
„ I f j:_ _ __ ._ ____ __�___ `. ;� I
. ;
� � ; _; - f ` � �
_ � : , _
_, , .
,
_._ ;_.. ,.: -- - _. . . . ,;.._ .� �
, � ,�
I ��
� ' � ' _ I �\�`� �
--L ; ' � ����_��� �
� --L_ . I I i �
�� , — _ ` `
� , : � . , ---��_,_,..__ _ - �,� .�� ��
_.i_.�_ --- \`\ �
`� � � . �� ,\ � ' . —�— -�__�,�_�_
�, `�� �, ' � � .��, �,'�',\. .\ �..��-,��._��� t . `� � ,.\.
�� \ � �.���— � .\ \
- '�.- -� '� . �1 . \ -.
� ` � ,` I , \. \�
� \ i� �� � �_\
�y ♦ \_\ �� \ \ \ �
( \ \ \
- ��' � � ,\ ♦�\ `� � �
'� �\� .
\ �-\ ,
♦ �
- I � ��
.� `.
\�\
`� _
'� ,
\� � .
�/' .� \ -
� � � �:
♦ �\ `
_� t � .
`�
\
�
�� S�'
. � �
„ , -
. � , . � , �__ �,
� �
.�
.
.
. �'T
.: r , .
.. .� , r
.,
.
�� _
, _.. � ., _ . �
_ �'�.���.., \ +��:-� ... \\_,'�._ �� -.•��:-�:'` ��� _ ._y..__..i: J \ `�\�` \ �\ . . . -_ � � , . - . _ ��.. \y .�\ ���a . _..._. .
_ � � ..., ��\\ �� �.:.� �\ ., _ . . \� � �� \ \ \�� . � `\� . � f ` `� ���\ �\\
' ' '',`��.` 1 �'-.'. �\ \�� �-� ���\ \�:. � � \\ ,�, \`\�\
_ �. � ,
. ,
, _ ��
: � �. �,. ... ��. � . l . , . - ..
1
. `� . , ..., .. \ `�
��� :��'-
. . � . \•� �'�. `�. •�_-`�.� �� �a, \ �\\ t ��'�t M \\
\ ,\ �\ \
�. � \ . � ���. i PErRViOUS (ROOF'S \� \ ��� �
� � .���• � �._ I � �•. � \� • ' � � `� `� �'\ � �
- � � � � �,, ��� � ` `�\:;� �. � �\ ,� �,_ �`_\`�� \ �
� ,
, �
- `� � �
� I :,; , , -,,\ � , � � `:!\ .� ��� . .,\ \���� WAL�C ETC. -TYP.) :-� .� ,, �`
, . ; . , .
.
� , , � � . � � �� ` � , .•�
;
, � ., . ; . , ._ �. � _{_ ;\ � .,\, \. ��� � � �
� , t �
, � �
_ _ . ... �\ _ .:_. _ . � . . � ;.� ; . \ ' - • - � \ - `� \ � \
� � � � �
- � � \- � � \ � \ � . � �.� � , � � ,\, �� � � _ �` �,_ - _
� � _ .
� ;� �� _ :�\ ...� _ � . ``. \ � � �: � �. ♦_ `. "�.� \ \..\\ �,`
. \ `
�_ � � ., '!-.. � � : ."i `,_ �. ._ \ . ' _., ..: .\ '. _.- - ' ' \\ \ �`\ •.�, � \ �.. .,\ `� � �� _
\ � . �c• � \ � �� \\ \\\� `' �.\ �� .� \ \ � \ �\�� F,�``.,
�. � . � �� i.�: �� �; �;\ � � ���,` �� ��� ��,. � ; �-' F
' � � � �� , :� _ � " _ � •'� :.: ' _ '��` ` � \ ;\ �� \ � ���. � .\ ,.
.,
: ._ :- \.�� `. .� � �� . ._, � \. ;�>,..t . � '-- � ♦ �: r\ \ ��\ \� \\� \���� \� �\ \"\ � \\� � \ �1 �� �,��\��'�`\� �r�'�
' � � - -.\ ��� �\ � 1 \ � �\ ��`�\\ � <\ � \\`� � � ��` - ��\ \ `��"�� .
�� \ \ ' � �� .\ \. ..� \ >\\.\� \:\ �� :\��. \ \ \\ `� `!� � \ \ �_ � �� .� � }
�� -:'.�- '� � � � •_����.. \ �.__\�\ \ � `� � ��� �. � �\� � �--.._
i: :
„ - .
� .....
�� � \_: �'� � -t-- -�--. '� � ��\ ��_,\.� � ,� �\ ti. �\� _ '\ . .
L � : ���. � \ ,��.�� `'� � � _ ''� `'�� ;�
� _ `
� I . � ,� . . . � - � .� \ ,;
_
.
� , , � � �;� ;.�. �.� �,�
� � --�... . , �.1 - _ =. . . `� , ., . _ t _ , . ..,\�`� �. \ \' �. �� � �.� � '�� -•�
- \ � � � ;�.\_.� l .. �-� � \ � � \� \ � . � �`�\ \ '� � `��.�� �\' =F �r-.
� � � \` , � � `: � \
� �; . `��\ ��— - �,� � \.� ♦ .�'\.� s _ \ �\ ��\ \\��.\\\ -_ _ _ � .�:- i\ `�.�' �� ������- \ �\ `,�� �� �. -..},
� `
. ,
� �
..:� —�\ � � ' .� � � � �-. \�� � _ ' - \' � _ \ ` � \,
� � . - � - � ��- j E`� . .: � , � � , ; �' ,� ;� ,� ��i .,��; ,,�\� �
_ � � � � � � . ,�� , _
` w=\� �` � ` � `.\ � ,..., .� �-.\� `< l =� �-�:.. _ ,:\ �� \ � � '\\ \ ` -�l�
�'\ \ \ �\� +. �� \, �\��� �� �� \ \ � ��'1 '\ '1` - _ � � ��\� � �-.\- \ ��\�1 _
� , ..
_ , � � � � .
� .
\ - .\ -`c ��..
� .` / �
_ `
.. , .- -. ..� \ � •` ` \\ ', � �• � • -�� ; \ \ ��� ( \> �\ � � � � �` � � \' � � i
� � - � -� � ER�S GRAS$;, ��, �� � `\� �' �� � � � � \ ,`
' . \ _ �_ '� ♦ \.:, `\ \ \ - v y�'��.\�i � '\�_, \ '\� 3' ��r.- \ �`_' �."' ��� _
���` � \ \ _� \ ` \ \ �' ..��\ \ � .�. ..�\ � .� '�. `f ..
� - .
-Im ,�\��-- �� �\ �� � \� '-s`�\ -�: ��\ �Di7�Y./�N\G�� `��� �\\ �, � \ �\� �� \ �� \\� �r� � '�� \ � � `� \` `.'.
� c
.� \
� � � ` �� �� ...` -'�. �•- �� �� \ �� \ .i \ � �_ �� \ \ � "��(� - \ \
�� �
-., -, . . , , ,._� `. �
.
.
�'Q�•,q � �`�, �.., `'` �\ . \ �\� •, � -. '• i . _. . . '.,.. ` --. '� � "�-� �`\� �` � � 1 �\ � \`� �\ \� ��-\\�.�� .�� \ � � ��� � __ 'l .� •.�\��., .� __ .. .
_
. ,
�i,-:., . .. � , '�: -. . ., � � ..., _. �. .., . �.\ \ ..` \ \. ���� - - 1-�� - _.\ \-..1�.��..�_��_ ` �� - s:`
� � ��� . . . . �. . �-. �. -� � �. I - �� - - �'`\ i", �'-
\ `._ „\ ,_, \ . .., ., � -� ., �� �, .
I �� ,.� � _ �• � �� �\`'�` \. \ � :.�.
- \ � �`�'\� ♦ �t-- �
- • � \ .,� \\� '� 'ti � �. �\ �
_ . . , . . _
, . , �
� . � . . . _
. •
, ,
_ \
. . ., .� . . . . . „ , , . ,, ,
.
., . . - �
,
4=- � . �-�.\ � . . .l� . . , - �<.. , ,` •, .. � \� �, � � -� � � . � �� `'.,� �
_� . �. , , . , . . , , �; �, `�
� . , . . . � �
'o �..3 .. , �. � -. `,. � , � .,.- , ., r � �'.�� �\ .� �l ��_
. -
,, .
�, �� �„�� , . , _ � • .k ,. , �` ., , ., ` �-._._. .�\ .. �_. . �� ��` `. \\�j � �` � �'•
� \�
, _�� � L� ��� _�� � �~�� \`�� �, `� \ ! \� \ c
.
, ` \
_ .
j : �� �� � �`� � - - -� � - �� \ �� �`\��
_ __ _ .=- ._ , `
�
� � - _ ._...„ ..,, ... _ -- �: - -- -- - ._.__. -� ._ .. - ���-^..�� �.r��.�s-_iy _ �--�\�� ''� ... __. ,`\\ �. -. - ,.
_ ,
�v � \
_._.. —�_ �' . _ � - , . . _.�__ :.._. \ �
-- ..___...._ ... .,._. �
. .Va�� ��� ��� \~ �
. .
a �- .... r_'" ._..- ��... -.- _ _ _". J..r., _ ' _ _- ... . ,._._ __._.... .... . � ..�� -��� ,.... .� • _
, ._.. ._ _"" �.+.:..._"'__ ..:-.� - '_ " '"'_ . " "._ .__�.___... _ ��
a , .. .. . � -...'__._._."_ "'"'.' ` � 9kW-. , . .:,. . _�y� "
-. . . : .. �._: �- �,
\
��
,, �
.
.. ..._.,. ......_. ' ��
� ...._v_..._.._.�.-. .. __._ .r, ."__....:.- ..: .., ,..., - ��
� � - . _. •. . . _ - - . . . .._..-_.... .._�:. _ '_._ _._ , -._.... - . . .. . . . . ... . _ �-•+r�.:
.. .._._'"'. .- ..."" _ ." '_ '%;. _..
. � ��
. _�_. .....
� ., - � � ' � .. __._...-"_.'__. .__ . .__._ _'__... � .. . .._._.. _. _. ...,: . . �.�... _.__ "' .._._ ".'_ .__ . . . . .. . . - _ _..
. . ... . . "_" ' '___' "_�Z � ..._ �_ . ...-: . _.
_ �
_ ..: .._ "'" _.,
Im .. .. . � . .. . � . .-.. - . . . . . . _... - - .._._""'.... __..._._ .-.. _ _._... . � �� _. .
. .. � �' .":- . "
. . . _. ._ ,.� � ��.='` ..:< .
. _ .. _ ... _. . .7^ .., --_
�' . ._...._. . . . _ . . .._._...,_.. ..- ._.. . . � � ... .. .. _. _._. � . . . . _ ..... . . .. - - .
_.� � . �� .. .. . .. . . . ' , �-�� . _ - . . ... .. . . .
.. .�e ��� .. . . -----�- —
Fe Iti � . . . - � �.� . . _ . _ .. . . . .... ._._. . .. - - . . . . . ._ �. ... . . �_- _ . - �. .. .. . . . . ... ,�� ._. . . r � !� _
�. �._ ' _
. �
�
_ � � �I�M '
I'I� ._ . ��. — _-
�N��ER
'�� � ,� Engineering -- '— 'Planriing Surveying FRIEDIiAAN DEVELOPMENT �� MERRILL OARDENS
�_ � � PenhsUegon Associatea Consulfing Engineera, Inc. JUNE 12. 2004 04441.00
- , �����.�,� �,�, 98101 ...,�.„,,.�m P.o. sox �o�s ryc EXISTIN(i CONDITIONS o�„o.Po,,,,
�c�>�,_�� ,-�-�u-� ����>••e-�16J MERCER ISLAND. WA 98040 A R E A M A P s�F I Q. a�2
i Is. ClEO� �B rn I�N9d1 W1E BY Kru.�w . s..ra. . F.d..r w.r • c�� . A,n,,.,,e 1'—4 0'
___ _
• o
' I
I
_ - � � . . . . . _... . .... _-�._._-. ..�...::;; _...__ . . . ._ .
. �- �� . _ . . : _. _.,.. �`._ .. . .... . .. ,_._..._
. ..,. . _T.__.._..._--'.. �.-:�.. _-^>
.. . . . . . . '---_.._.._ y :. : . . �'_. .-'.._'z.._--.__"'--.
� :._ . _ - . . ... . . . . . .. � -..._ ,s..�._ . ,.;-:,.-.' `: . .. . _... — . _. . . . � .
. . �� T� _ - _. . . . ._ � ..�.- � -� .. .. --.� . , �:. . _.., . :,._. _ :�.. ..-�.. S •... � �.. . .. . � .
I T � � . � T- —i - --
�
. . .. . . -'-•- - - .-. . . �. � ' �� . � . -
, ��.�
. . . , c: . . . .
. .. . ... -.. . . . ...��-. . . . � . . . .
. . n
. . - .._. . . ... , . . . i. . .
. . ._.... .. .. 'x . . , . .
.. � . _ - ... .. . -.. x: . i
� �
.. � . * , - - t -:7F. - ` :����.�_:. .- �.:'^c�•-•-�- � � ... ., . . '=_C f" ��.� . . � . .
-'�r.,. f+ - - �� . . I . - .. � . ` \. . \ . .
�-,�� .. . . ..... . .. a _,.. ,;ti� _ - . � ; n � ... � . .+��` ����\ ��I,
� . ., � � � _ � 1 � ��y�' _ �
( + �: , } -"� P.G.I.S. (TYP.)
� � , �
t ' I i �:
� TOTAL SITE 82,036 SF = �1.88 AC k _
� ����
'-- - -- ;: ,,
.. _ , , .,. � �
� " - TOTAL IMPERYIOUS = 1. 7 AC � ;`� %'
_
-
, - __ _.
� : TOTAL P.i�.I.S. = 0.27 AC� _ '� ��� � �
, �� �,,��
�
_
.
,
I ( :, PERVIOUS,� (LANDSCAPING)! = 0.11 AC i �
- .. ,
.
: , .
�
I i _ �� �
y
� �
;
_� i_ I I I `1 •
r.. � _ � � I �, � . ; ._ , ;,,,� . �
�....._� .,.���� � ' -1- ; ; -
-. .��..�r� ��
. �-_ , � �� __�__,.._,_ ,...._-- �,,,,�_� , ;-�.
r � �,
� ; � �
_ I , '' ' ,' ; } C : ' �; { t, r-- u__
, � ; _, �� a „
= � ` (� ; I �' { 1, !� • r �, � rc t � �
� I !; � � !! i is � � j ,I ! `- ...
_ � �i��G� , �.' — � � ,.
_ / I I
- _ . . f - , � . / � . �a
; �.
' .. . . . ' '. _ I . :. -� � .�: .__.. �� � .
- � .. .. � . . � � ...:
„ � — — : .,_ "` �. ,� �` _
,. _ �
. . �.. . , . . I r
. � , . , �.��:� ,�� � _ - .
� �
�
_; � �� li - t s . st i. :1 ! x" �� _ W fYf� � d �s
� � � . , { _ :. `�- ' `i
; . .� , : ., � , . Y��
.,.... � .._
,
r , t .. e . . . �..� � ' � _ _
' ` I
�
�
i ; � t - � f.
J � + t�.
t r, ;�'
�; r �� FF�O.� - � �" ��
`:• r—� � I I ��` ~_ {.
: l ��,.
_R .. I . o.""r "�:, :.:,...�,....i.� '•�r'r;• ' "'• tv' .'. '•'+'•' ' ;: � �" �.'4 .:� .
+ ; � •i!�•.+V��M�ivi� +Tti•+';`�.�1.i1 �e����'��M��+r..�y,� �C.":c, -- � � ~_` .
' •• . . �„
� . . .. ,T
. ,. ,
. '� 4 " �:: .i. � , . � t.
. .
. .
.. �f .
• ..
.. .. . :.
. . ,
. . . ...• n. . . �I /
.
.
�.� . [
t �. ' .t , f ,. .., :. � ' . ` ,T . . ' ` `.\ \ '� ; !
I . r. .
� ♦ • �... � . �t� •�- A \ /• •f� (�
. .
� •
..
� � :
. . • %'
. . .
.
...
�_I� • � � �� • ..� . I '. �'.. ...... . . . � � �\ �'� .
_ • ` �� ~ ��
� . . •
.•
ai �._ �.� . . . .�..�.. .�� .-.:..�� , . ♦� � .; . .. �.. . .. . . ' - �•.Y.'� '% ,�� -
. �
. •.
.
.... . . . .�Y
��� �� I ..\ , •, ����.
' . . . �.. ..• ... • .i
. .♦ . : . � '
�I� ♦ . . • •' � w • J• .
. . . ..•� . . . � ..• � --�!
.• •
. . . . . :..
•
. . . . . .
o�l� ... ..-' . . . . ... _ Y ♦ . .w . .�. . � �J 1 .. \ • •� == � • ' '
.
' � ��� ... � •� •
�., . _ .
\ 'A.
• . . � � .l•
.
n ' _ _
. .
. �
.
i
��
. ..
.�
�.ti t• �1
\�
�irn � - � . � . _. . .. •• • y, � ��•�, ��
.
.
a .. _ _.. _ . . . '. - .
..,, . . . -._.. . .. 'S�
��� . .. ......_.. . _ ... . '. ... � � . , ���--', .-� . . _ .. ~. •'�• ._. : .w F .-.- _
�. '. .•. • ' ..
�..,r .�.,.j . .•�
. , .. .r. ..
.
. • �.....
.. .•..at .;. '. v. -.
..:. . .. � : . ..w . . .•s
�� __ �____ - ERVtOUS (GRASS,.,... - _ - :�.,.� � :_
_ : . ,__ : , , _ _ _ __ __.__ :
$ _ - -LANDSCAPING =_TYP.) : __-- _ _
—_-------- ° � __, ---
------.-� .,,. - � --- -
_ _ _ --------- —-----�---__ __ _.� . � e _ -�
_...
_ _ _ — — _ � _.
_ . __ _._�.� �„ _ ___ _
'Y __ . _;_ — ��. ,_ �_ _ —�� _ - _
_-- _ IMPERVIOUS {ROOFS� WALKS,
��� <�. . _ _
� _ __-- _
m - -r :. - -
y�,_ . __ _ ,. -:; .. -_- --�-^� -•--
- �
p � - . ETC. -TYP.)
> �
�a_ �_, _
� - : . _ . _ ,
T
vI � � � .. . . . . . . Engineering Pianning Surveying � �� �N��
� � � FRIEDMAN DEVELOPMENT MERRILL (3ARDEN3 04441.00
PerM�tlegon Associatea ConsulfJng Engfneera, lne. JUNE 12 2004
-': oruw iw P.O. BOX 1018 DEVLOPED CONDITIONS
'� ,eo�2.a,.•..u.9.b,000 S.otu...r, Ys,�i ....,ac..i,.<an 01`u�
�;�
rk txn�«,-sess ,-em-ws-ebe v�x:cza>�+6-�,fii MERCER ISLAND, WA 98040
°�tl�,s6 — sw �sa o�1E er ' ,ow.d . s..ee,. . i.s.r w.. • a.E..� . .a.r�e t'—ao' AREA MAP s[Et FIQ• c�3
E -
. �
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
A3 �11��11' A
MAINTENANCE S'I'ANDARDS FOR
PRIVATELY l�IAINTAINED DRAINAGE FACILITIES
N0. 1 -INFILTRATION
Maintenance Defect Conditions When Maintenance Results Expected When
Component Is Needed Maintenance Is Performed
General Trash&Debris Any trash and debris which exceed 1 cubic foot Trash and debris cleared from site.
per 1,000 square feet(this is about equal to the
amount of trash it would take to fil1 up one
standard size office garbage can). In general,
there should be no visual evidence of dumpi�g.
Storage Area Sediment A percolation test pit or test of facility indieates Sediment is removed and/or facility
facility is only working at 90%of its designed is cleaned so that infittration system
qpabilities. If iwo inches or more sediment is works according to design.
present,remove.
lVote: Sediment accumulation of more ri�an.25 inches per year may rndicafe excessive erosion is occuiring upstream of fhe facility or that
conveyance systems are not being properfy maintained. The contributing drainage area should be checked for e�osion problems or
inadequate mainfenance of conveyance sysiems if excessive sedimentaSon is noted in an infrltratron facility.
Check hvice a year during first 2 years of operation;once a year thereafter. Clean manholes/catch basins,repair damaged inlets/out/efs,
cJean trash racks.
NO. 2 -CONTROL STRUCTURE/FLOW RESTRICTOR
Maintenance Defect Condition When Maintenance is Needed Results Expected When
Component Maintenance is Performed
General Trash and Debris Distance beiween debris build-up and bottom of All trash and debris removed.
(Indudes Sediment) orifice plate is less than 1-1/2 feeL
Structural Damage Structure is not securely attached to manhole wall Structure securely attached to
and ouUet pipe structure should support at►east wall and outlet pipe.
1,000 Ibs of up or down pressure.
Structure is not in upright position(allow up to Structure in correct position.
10%from plumb). '
Connections to outlet pipe are not watertight and Connections to outlet pipe are
show signs of rust. wate�tight;structure repaired or
replaced and works as
designed.
Any holes—other than designed holes—in the Structure has no holes other
structu�e. than designed holes.
Cleanout Gate Damaged or Missing Cleanout gate is not watertight or is missing. Gate is watertight and works as
designed.
Gate cannot be moved up and down by one Gate moves up and down easily
maintenance person. and is watertight.
Chain leading to gate is missing or damaged. Chain is in place and works as
designed.
Gate is rusted over 50%of its surface area. Gate is repaired or replaced to
meet design standards..
Orifice P1ate Damaged or Missing Control device is not working properly due to Plate is in placs and works as
missing,out of place,or bent orifice plate. designed.
1998 Surface Water Design vtanual 91U98
A-1
� A�ENDIX A MAINTENANCE ST.�..�IDARDS FOR PRIVATELY�1AINTAINED DRAINAGE FACtI,ITIES
Obstructions Any trash,debris,sediment,or vegetation Plate is free of all obstructions
blocking the plate. and worics as designed.
Overflow Pipe Obstructions Any trash or debris biocking(or having the Pipe is free of all obstructions
potential of blocking)the overflow pipe. and works as designed.
NO. 3-CATCH BASINS
Maintenance Defect Condiiions When Maintenance is Needed Results Expected When
Component Maintenance is perfortned
General Trash&Debris Trash or debris of more than 1/2 cubic foot whicfi is No Trash or debris located
(Includes Sediment) located immediately in front of the catch basin immediately in front of catch
opening or is blocking capacity of the basin by basin opening.
more than 10%
Trash or debris(in the basin)that exceeds 1/3 the No trash or debris in the catch
depth from the bo8om of basin to inveit the bwest basin.
pipe into or out of the basin.
Trash or debris in any inlet or outlet pipe blodcing Inlet and ouUet pipes free of
more than 1/3 of its height. trash or debris.
Dead animals or vegetation that could generate No dead animals or vegetation
odors that could cause complaints or dangerous present within the catch basin.
gases(e.g.,methane).
Deposits of garbage exceeding 1 cubic foot in No condition present which
volume would attract or suQport the
breeding of insects or rodents.
Structure Damage to Comer of frame extends more than 3/4 inch past Frame is even with curb.
Frame and/or Top Slab curb face into the street(If applicable).
Top slab has holes larger than 2 square inches or Top slab is free of holes and
cracks wider than 1/4 inch (intent is to make sure cracks.
all material is running into basin).
Frame not sitting flush on top slab,i.e.,separation Frame is sitting flush on top
of more than 3/4 inch of the frame from the top slab.
slab.
Cracks in Basin Walls/ Cracks wider than 1/2 inch and longer than 3 feet, Basin replaced or repaired to
Bottom any evidence of soil partides entering qtch basin design standards.
through cracks,or maintenance person judges that
structure is unsound.
Cracks wider than 1!2 inch and longer than 1 foot No cracks more than 114 inch
at the joint of any inlet/outlet pipe or any evidence wide at the joint of inlet/outlet
of soil partides entering catch basin through pipe.
cracks.
SedimenU Basin has settled more than 1 inch or has rotated Basin replaced or repaired to
Misalignmeni more than 2 inches out of alignment. design standards.
9i 1;98 1998 Surface Wa[er Design Manual
�-Z
. ..
APPENDIX A IviAINT`ENANCE STANDARDS FOR PRIVATELY�AINTAINED DRAINAGE FACILITIES
N0. 3 -CATCH BASiNS {CONTINUED)
Maintenance Derect Conditions When Maintenance is Needed i�esults Expected When
Component Maintenance is performed
Fire Hazard Presence of chemicals such as naturai gas,oil and No flammable chemipls
gasoline. present.
Vegetation Vegetation growing across and blocking more than No vegetation blodcing opening
10%of the basin opening. to basin.
Vegetation growing in inlet/ouUet pipe joints that is No vegetation or root growth
more than six inches tall and less than six inches present.
apart.
Pollution Nonflammable cfiemicals of more than 1/2 cubic foot No pollution¢resent other than
per three feet of basin length. surface film.
Catch 8asin Cover Cover Not in Place Cover is missing or only partially in place.Any open Catch basin cover is dosed
catch basin requires maintenance.
Lodcing Mechanism Mechanism cannot be opened by on maintenance Mechanism opens with proper
Not Working person with proper tools.Bolts into frame have less tools.
than 1/2 inch of thread. '
Cover Difficult to One maintenance person cannot remove lid after Cover can be removed by one
Remove applying 80 Ibs.of lift;intent is keep cover from maintenance person.
sealing off access to maintenance.
Ladder Ladder Rungs Ladder is unsafe due to missing rungs,misalignment, Ladder meets design standards
Unsafe rust,cracks,or sharp edges. and allows maintenance person
safe access.
Metal Grates Grate with opening wider than 7/8 inch. Grate opening meets design
(If Applicable) standards.
Trash and Debris Trash and debris that is blocking more than 20%a of Grate free of trash and debris.
grate surface.
Damaged or Grate missing or broken member(s)of the grate. Grate is in place and meets
Missing. design standards.
1998 SurYace Water Design Manual 9/1i98
A-3
� �PENDIX A MAINTENANCE STAi�IDARDS FOR PRIVATELY MAINTAI�IED DRAINAGE FACILITIES
NO. 4-CONVEYANCE SYSTEtVIS (PiPES 8�DITCHES)
Maintenance Defect Conditions Whe�Nlaintenance is Needed Results Expected When
Component Maintenance is Performed
Pipes Sediment&Debris Accumulated sediment that exceeds 20%of the Pipe cleaned of all sediment
diameter of the pipe. and debris.
Vegetation Vegetation that reduces free movement of water All vegetation removed so water
through pipes. flows freely through pipes.
Damaged Protective coating is damaged;rust is causing Pipe repaired or replaced.
more than 50%deterioration to any part of pipe.
Any dent that decreases the cross section area of Pipe repaired or replaced.
pipe by more than 20%.
Open Ditcfies Trash&Debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debris cleared from
square feet of ditch and slopes. ditches.
Sediment Accumulated sediment that exceeds 20%of the Ditch cleaned/flushed of alf
design depth. sediment and debris so that it
matches design.
Vegetation VegetaGon that reduces free movement of water Water flows freely through
through ditches. ditches.
Erosion Damage to See"Ponds"Standard No. 1 See°Ponds"Standard No.1
Slopes
Rock Lining Out of Maintenance person can see native soil beneath Replace rocks to design
Place or Missing(If the rodc lining. standards.
Applicable).
Catch Basins See"Catch Basins:Standard No.5 See"Catch Basins°Standard
No.5
Debris Barriers See"Debris Barriers"Standard No.6 See"Deb�s Barriers"Standard
(e.g.,Trash Rack) No.6
NO. 5 -GROUNDS(LANDSCAPING)
Maintenance Defect Conditions When Maintenance is Needed Results Expected VYhen
Component Maintenance is Performed
General- Weeds Weeds growing in more than 20%of the landscaped Weeds present in less than 5°/a
(Nonpoisonous) area(trees and shrubs only). of the landscaped area.
Safety Hazard Any presence of poison ivy or other poisonous No poisonous vegetation
vegetatio�. present in landscaped area.
Trash or Litter Paper,cans,bottles,totaling more than 1 cubic foot Area clear of litter.
within a landscaped area(trees and shrubs only)of
1,000 square feet.
Trees and Shrubs Damaged Limbs or paRs of trees or shrubs that are split or Trees and shrubs with less than
broken which affect more than 25%of the total 5%of total foliage with sptit or
foliage of the tree or shrUb. broken limbs.
Trees or shrubs that have been blown down or Tree or shrub in place free of
knacked over. injury.
Trees or shrubs whicli are not adequately supported Tree or shrub in piace and
or are leaning over,causing exposure of the roots. adequately supported;remove
any dead or diseased trees.
9i1/98 � 1998 Surface Water Design Manual
A-4
. .
1
riPPENDIX A MAINTENANCE STANDARDS FOR PRNATELY:v1AINTAINED DRAINAGE FACILITTES
NO. 6 -YVENAULT
+-Aqaintenance Defect Conditio�When Maintenance is Needed Results Expected When
Component Maintenance is Performed
Wetvault Trash/Debns Trash and debris accumulated in vault,pipe or Trash and debris removed from
Accvmuiation inleU outlet,(indudes floatables and non- vault.
floatables).
Sediment Accumulation Sediment accumulation in vauit bottom that Removal of sediment from vault
in Vault exceeds the depth of the sediment zone plus 6-
inches.
Damaged Pipes Inlet!outlet piping damaged or broken and in Pipe repaired and/or replaced.
need of repair.
Access Cover Cover cannot be opened or removed,especially Pipe repaired or replaced to
Damaged/Not Working by one person. proper working specifications.
Vault Structure Vault Cradcs wider than 1/2-inch and any No cracks wider than 1/4-inch at
Damaged evidence of soil partides entering the structure the joint of the inleU ouUet pipe.
through the cracks,or maintenance/inspection Vault is determined to be
personnel detertnines that the vault is not structurally sound.
structurally sound.
Baffles Baffles corroding,cracking,warping and/or Repair or replace baffles to
showing signs of failure as determined by specifications.
maintenance/inspection staff:
Access Ladder Damage Ladder is corroded or deteriorated,not functioning Ladder replaced or repaired to
properly,missing rungs,has cracks and/or specificafions,and is safe to
misaligned. use as determined by inspection
personnel.
�
1998 Surface Water Design Manual 9,�1r98
A-5