07-102761CITY OF
ti Federal Way
January 14, 2009
Ms. Suzanne Anderson
Otak, Inc.
10230 NE Points Drive, Suite 400
Kirkland, WA 98033
CITY HALLFiLE
33325 8th Avenue South
Mailing Address: PO Box 9718
Federal Way, WA 98063-9718
(253) 835-7000
www.cityoffederalway.com
RE: FILE #07-102761-00-EN; MIRROR ESTATES ENGINEERING PLAN REVIEW
Dear Ms. Anderson:
The purpose of this letter is to forward revisions to the Mirror Estates engineering plans for your review
and comment. The revisions were submitted to the City on January 8, 2009, and hopefully address your
March 2008 comments.
Please find the following:
o Revised wetland mitigation plan prepared by Altmann Oliver, LLC, dated January 6, 2009,
including W1.1, W2.1, W3.1, and W4.1;
o Landscape plans prepared by GHA Landscape Architects, dated December 30, 2008, sheets L1
and L2;
o Mirror Estates Civil Plans prepared by J3ME, print date November 19, 2008, sheets 1 through 15;
o TIR dated November 24, 2008, prepared by J3ME;
o Cover letter to Ann Dower dated January 8, 2009; and
o Cover letter to Deb Barker dated January 8, 2009.
Please review these revised plans and provide comments as appropriate. We'd appreciate your comments
as close to February 16, 2009, as possible.
Please contact me at 253-835-2642 if you have any questions about this request.
Sincere
Deb Barker
Senior Planner
c: Ann Dower, Senior Engineering Plans Reviewer
Enclosures as listed
Doc I.D. 48495
Technical Memorandum
To:
From:
10230 NE Points Drive
Copies:
Suite400
Kirkland, WA 98033
Phone (425) 8224446
Date:
Fax (425) 827-9577
Subject:
Project No.:
Deb Barker, Senior Planner, City of Federal Way
Suzanne Anderson, Senior Wetland Biologist
February 10, 2009
Mirror Estates: Review of January 8, 2009
Re -submittals
30879E1
As requested by the City of Federal Way, Otak conducted a review of the revised Mirror Estates
wetland mitigation plan and associated documents that were submitted to the City of Federal Way
on January 8, 2009. The purpose of this review was to verify compliance with specifications in the
March 17, 2008 Otak Technical Memorandum.
Otak reviewed the following document for this memorandum:
• Wetland Mitigation Plan Mirror Estates, Sheets W1.1, W2.1, W3.1, and W4.1 by Altman Oliver
Associates, LLC, revision date 01 /06/09 (referred to in this memorandum as the 01106109 mitigation
plan);
• Mirror Estates Civil Plans: Sheets 1 through 15, by J3ME; including: Cover Sheet, Survey Sheet,
T.E.S.C. Plan and notes, Road and Storm Drainage Plan and Details, Road and Storm Drainage
Plans and Profiles, Pond Sections and Details, Horizontal Control Plan, Curb Alignment Plan,
and General Details, revision date 11/19/08 (referred to in this memorandum as the 11 / 19/08 civil
plans);
• Letter to Deb Barker of Federal Way from Jerrit Jolma, PE of J3ME dated January 8, 2009,
subject: Mirror Estates Permit No. 07-102791 EN; and
• Letter to Ann Dower of Federal Way from Jerrit Jolma, PE of J3ME dated January 8, 2009,
subject: Mirror Estates Permit No. 07-102791 EN.
Previously reviewed documents referred to in this memorandum include:
• Wetland Mitigation Plan Mirror Estates, Sheets W1.1, W2.1, W3.1, and W4.1 by Altman Oliver
Associates, LLC, revision date 01 /21 /08 (referred to in this memorandum as the 01121108 mitigation
plan);
• Mirror Estates Civil Plans: Sheets 1 through 15, by J3ME, including: Cover Sheet, Survey Sheet,
T.E.S.C. Plan, Road and Storm Drainage Plan and Details, Road and Storm Drainage Plans and
K:\project\30800\30879E\Reports\09_0210 memo.doc
Deb Barker, Planner, City ofTederal Way
Mirror Estates. Review of January 8, 2009 Re -submittals
Page 2
February 10, 2009
Profiles, Pond Sections and Details, Horizontal Control Plan, Curb Alignment Plan, and General
Details, revision date 12/19/07 (referred to in this memorandum as the 12/ 19/07 civil Ians); and
Technical Memorandum to Deb Barker, City of Federal Way from Suzanne Anderson of Otak,
Inc., dated March 17, 2008, subject: Mirror Estates: Review of January 28, 2008 Re -submittals
(referred to in this memorandum as the Otak 3117108 memo).
Introduction and Conclusions
The Mirror Estates project included a Process IV application for proposed wetland elimination and
buffer intrusions and for the proposed compensatory mitigation. The Hearing for approval of the
Process IV application was held on January 30, 2007, and the Hearing Examiner's Decision was
handed down on February 9, 2007. Since that decision, project plans have been revised and re-
submitted in response to reviews by the City three times: on May 21, 2007, January 28, 2008, and
most recently on January 8, 2009.
The Otak 3/17/08 memo provided review comments for the January 28, 2008 submittals (01/21/08
mitigation plan and 12/19/07 civil plans). In response to the Otak review and other reviews from
the City, the applicant revised the documents and submitted the 01/06/09 mitigation plan and
11/19/08 civil plans on January 8, 2009. Review comments on those recently submitted documents
are included below.
The conclusion is that because the 01/06/09 mitigation plan and 11/19/08 civil plans adequately
address the outstanding issues from the Otak 3/17/08 memo, I recommend approval of the plans.
1/06/09 Mitigation Plan
The 01 /06/09 mitigation plan sheets adequately address all of the outstanding issues from the Otak
3/17/08 memo. As a result, I recommend approval.
I 1 / 19/08 Civil Plans
The 12/19/07 civil plans adequately address all of the outstanding issues from the Otak 3/17/08
memo. Although there are a couple of small errors (listed below), it is my opinion that these errors
are so minor that plan revisions are unnecessary. As a result, I recommend approval.
• Sheet 6 Correction: the Flow Dispersal Trench detail is located on Sheet 15, not Sheet 13.
• Sheet 7 Corrections: the Sensitive Area Sign detail is located on Sheet 10, not Sheet 9; and the
Flow Dispersal Trench detail is located on Sheet 15, not Sheet 13.
If you have any questions regarding this memorandum, please contact me at 425-822-4446 or
suzanne.anderson otak.com
K:\project\30800\30879E\Reports\09_0210 memo.doc
Deb Barker
From: Tom Barghausen [tbarghausen@barghausen.com]
Sent: Saturday, March 17, 2012 2:37 PM
To: Ann Dower
Cc: Ken Miller; Deb Barker; Mark Sumrok; Bryan Schwartz; Trevor Lanktree; Wayne Potter; Doug
Jones; Linda Reid
Subject: Mirror Estates
Attachments: 15419-D-CIVL-J3M E-2009-04-07-11 x17. pdf
Importance: High
Hi Ann,
We recently received our formal contract authorization on behalf of West Coast Bank to work with the City of Federal
Way to obtain final construction -plan approval for Mirror Estates so that this project can potentially commence with
construction this summer. At a minimum, we want to be able to clear and grade the property per the approved plans in
order to complete the filling of the unregulated wetlands during the dry season.
As you know, the J3ME (Jerrit Jolma) is no longer in business and the CAD files for the road/drainage plans are nowhere
to be found. I've spoken with Jerrit who says that he gave the CAD files to Multi -Tech out of Oregon that was first
engaged by West Coast Bank in 2009. He says that he does not have them and that he is not allowed by his current
employer to do any consulting work of any kind —so he cannot be of assistance.
I've been in contact with both West Coast Bank and Multi -Tech concerning the location of these CAD files.
Unfortunately no one has any clue as to where these are —or if they were even sent by J3ME. I don't know what
happened and it doesn't matter how this happened, but I have given up trying to find where the files are. We have to
proceed on the basis that they won't be found. However, we also don't want to start over and reinvent the entire
project design from scratch.
From my review of the documents and the files in the City, as well as our meeting a couple of months ago (you and me
and Deb), I believe the attached set of plans with comments provided on the drawings by the City represent the last
version and that the plans can be approved for construction once these changes are made.
Is this your understandin ?
If so, I would like to proceed under the following basis:
• We are completing a new Boundary survey so we can certify the final plat ma . This work is underway. We are
also going to update the as -built survey of the offsite road stubs and frontage that are being improved or
. affected by the proposed construction to be sure that nothing has changed since 2005 when the plans were first
prepared.
We assume that the TIR and the supporting drainage calculations and other information that J3ME provided to
the City as part of the review process will remain valid and won't have to be revised.
49 Assuming our boundary survey is virtually identical to the prior surveyor (and I would assume that will be the
case), we will then re-create the drawings on a new set of plans with our title block and professional
certification. Unfortunately, without the CAD files there is no easy way to do this other than to redraw the plans
using CAD.
The new drawings should essentially be identical to the J3ME drawings unless we find in our reviewlpreparation
that there are issues that we think need to be addressed. I understand that Jerrit did a good job and that the
City was confident in his ability. Therefore I am assuming that we won't find anything of significance. If we do,
we'll point these out to at the time of submittal.
We will incorporate the last comments from the City that are shown on the attached plaps.
• We will work with Altman Oliver Associates to update their wetland mitigation/open space plans as needed for
final approval. The last set that I have indicates they revised the plans in January of 2009 and I recently had Gary
Schultz review the plans and the last "Technical Memorandum" from the city to confirm if all comments have
been addressed and he believes they have been —unless there are comments we don't know about.
7 1,46� Ajg�(
o We will also work with Tim Miller of Transpo ation Consulting Northwest to update his electrical street li htin
plans if they are not yet ready to be approved. W�k 1� t9q
The water and sewer plans have already been approved by LUD and we don't want to have to draw those plans �(
again either. I'm going to talk with LUD to see if we can't just re -activate the permits and not have to do any (�(/
other work on the plans.
• We are going to acquire an NPDE5 permit so that if the project goes into construction this summer we will havei
that permit in place from DOE. (V�,
Eventually we may seek a separate clearing/grading permit if the bank or a buyer wants to only complete the clearing
and grading of the property this summer and can't get the rest of the plat built before the rainy season starts.
Please review the above and let me know if you think f have outlined the steps properl .
If u think we need to meet in advance please let me know. I'll be available at your convenience.
I will lik have Bryan Schwartz in my office be the design engineer on this going forward, since he is also doing the
work on t Campus re p oject for Quadrant. This way you won't have to coordinate with different engineers —other
than me!
Thanks Ann. I look forward to working with you on this project.
Tom
1IhomasA. Barghausen T.E.
President
Barghausen Consufting Engineers, Inc. (1
18215 - 72ndAvenue South �J
xent, 'Washington, 98032
1-425-251-6222 (Office)
1-206-954-7947 (Cefo
BACKUP FOR ASSIGNMENT OF FUNDS
MIRROR ESTATES WETLAND MITIGATION
Pacific Green Landscape Co
Amount
Notes
Plant material
$13,407
Based on approved plans
dated
Soil compost 15 cu yards
bark mulch 15 cu yards
$1,452
Temporary irrigation
$3,225
H droseed wetland mix only
$3,220
Subtotal
$21,304
9.5% tax
$2,023.85
Total
$23 327.85
All Around Fence Company
270 feet split rail fence, post
and pole
$4,430
+$420.56 (9.5% tax)
Total
$4,850.85
Pacific Green Landscape Co
$23,327.85
All Around Fence Company
$4,850.85
Subtotal
$28,178.70
Plus 20% contingency
$5,635
Assignment of funds total
$33,814.44
Doc. I. D. 60731
FILE
CITY OF
� Federal
March 24, 2008
J3 Civil Engineers
Mr. Jerrit Jolma
1375 Mall Street, Suite 3
Issaquah, WA 98027
CITY HALL
33325 8th Avenue South
y Mailing Address: PO Box 9718
Federal Way, WA 98063-9718
(253) 835-7000
www. cityoffederal way. com
RE: PERNUT #07-102761-00-EN; MIRROR ESTATES 2"° REVIEW BY WETLAND CONSULTANT
Dear Mr. Jolma:
This letter forwards comments from the City's wetland consultant of plans submitted to the City on
January 28, 2008. While the wetland plans generally look favorable, the consultant Otak notes that
revisions are necessary to the TESC plans, clearing limits and construction scheduled so that the civil
plans are consistent with the wetland mitigation plans.
Enclosed please find comments dated March 17, 2007 from Suzanne Anderson with Otak, Inc.
I can be reached at 253-835-2642 should you have any questions about this letter or the enclosed
technical comments.
Sincerely,
/Q,tl- &Jq4�1 ---
Deb Barker
Senior Planner
Enclosure as noted
cc: Ann Dower
Doc. I.D. 44745
Technical Memorandum
To: Deb Barker, Planner, City of Federal Way
From: Suzanne Anderson, Senior Wetland Biologist
102-0NE'Polwlr Dwe
.fyCopies:
1?e -/00
, hI ram,' IV4 AfOiJ
Phame /Z2>"Ja 72 f 6 Date: March 17, 2008
fa-k-(-12-9?2, 7-9j7i
Subject: Mirror Estates: Review of January 28, 2008
Re -submittals
Project No.: 30879E
As requested by the City of Federal Way, Otak conducted a review of the revised Mirror Estates
wetland mitigation plan and associated documents submitted on January 28, 2008. The purpose of
this review was to verify compliance with specifications in the August 31, 2007 Otak Technical
Memorandum.
Otak reviewed the following document for this memorandum:
Wetland Mitigation Plan Mirror Estates, Sheets W1.1, W2.1, W3.1, and W4.1 by Altman Oliver
Associates, LLC, revision date 01/21/08 (mlelmllainlhir,movrimd-vxrar16e01/2110XA5�14w&on
Mirror Estates Civil Plans: Sheets 1 through G, by J3ME, including: Cover Sheet, Survey Sheet,
T.E.S.C. Plan, Road and Storm Drainage Plan and Details, Road and Storm Drainage Plans and
Profiles, Pond Sections and Details, Horizontal Control Plan, Curb Alignment Plan, and General
Details, revision date 12/19/07 (refi^willainaslhe 12/19/07ai,il�Iv»r�; and
Letter to Suzanne Bagshaw of Otak from Jerrit Jolma, PE of J3ME dated January 23, 2008,
subject: Mirror Estates, City of Federal Way #07-102791 EN, Otak Project #30879E.
Previously reviewed documents referred to in this memorandum include:
Wetland Mitigation Plan Mirror Estates, Sheets W1.1, W2.1, W3.1, and W4.1 by Altman Oliver
Associates, LLC dated May 18, 2007 (re�er»dlo an thisi��er�rora��n'aiii aslhe S/1�/07rr�t�%a;
Mirror Estates Civil Plans: Sheets 1 through 13, by J3ME, including: Preliminary Plat Map,
T.E.S-C. Plan, Road and Storm Drainage Plan, Pond Sections and Details, Curb Alignment Plan,
and General Details, dated 5/15/07 (refinVIa nlhisi�re�irorrui�l�r�ff ax113e and
Technical Memorandum to Deb Barker, City of Federal Way from Suzanne Bagshaw of Otak,
Inc., dated August 31, 2007, subject: Review of Re -submittals for Mirror Estates Plat (refeiredla irr
this 111e1"rrrnllrw1 as the Olah X/j1/07mem� .
\\Kirae0l\prof\project\30800\30879E\Reports\08_0317 memo.doc
Deb Barker, Planner, City o£Federal Way Page 2
11/lirrnr rrerl�c Rcrrievr fJrrrm4g, 2S, 200T Re ferdiiil!!rr/ Afar-h 17, 2008
Introduction
The Nlirror Estates project included a Process IV application for proposed wetland elimination and
compensatory mitigation, as well as for proposed buffer intrusions. The Hearing for approval of the
Process IV application was held on January 30, 2007, and the Hearing Examiner's Decision was
handed down on February 9, 2007. The Hearing Examiner's Decision approved the Mirror Estates
project Process IV application with the condition that"...lhedrArrlrlea.Ilrrror�orrrrall
rrra ri»enflrrlrorrrfi�N tfieJarrrrary 19 20070T,4KT&h&lcaljWeworarrr i loo lrr�6lecvrrclrrrcliaH re/rrded
darra�veirlirrrfrevfraraprtrer�l� Ciy_olaf.." In response to the Hearing Examiner's Decision, the
applicant submitted a set of revised documents on May 21, 2007. Those documents were reviewed
by Otak (Otak 8/31/07 memo). In response to that review, the applicant revised the documents and
submitted the 1/21/08 mitigation plan and 12/19/07 civil plans on January 28, 2008_ Review
comments on those documents are included below_
The 1/21/08 mitigation plan and 12/19/07 civil plans adequately address most of the .outstanding
issues from the Otak 8/31/07 memo. However, some corrections and additions are required for
final approval - those items are listed below. To avoid confusion, the numbering system used below
is a continuation of the system used in the Otak 8/31/07 memo. Section 3 is referenced to the
1/21/08 mitigation plan, and Section 4 is referenced to the 12/19/07 civil plans. The numbers in
parentheses after the items listed below refer to specific comments from the Otak 8/31/07 memo_
The items listed below must be addressed in revised documents which must be submitted to the City
for approval.
3. 1/2 1 /08 Mitigation Plan
The 1/21/08 mitigation plan sheets adequately address all of the outstanding issues from the Otak
1 / 19 /07 memo (Ola,6 1. a ,1Ar&&,ah IA.
3.a. There are still differences between the 1/21/08 mitigation plan and the 12/19/07 civil plans
for the T.E.S.C. plan and proposed clearing limits for the wetland mitigation area (Olak 1a).
However those differences should be addressed in revisions to the 12/19/07 civil plans (see
comment 4.b below).
3.b. Due to changes in the expected construction schedule, there is one minor error on Sheet
W4.1, Section 13 — As -Built Plan: "flrrs�»rirr�l�trlrr!!allorr oeearrrarjllarrrre� eJrrrleo�r lFrrrce
rreonilarrirg everelr�rrld�crerlate in 2006arearlie2007ovorr�
However, because the paragraph immediately preceding those dates specifies that the As -Built
report and plan will be submitted to the City of Federal Way".►wz*v�Odayrafler�i/alrlirA it
ca11101Wrd", no correction of the 1/21/08 mitigation plan sheets is necessary.
\\Kirae0l \proi\project\30800\30879E\Reports\08_0317 memo.doc
1
Deb Barker, Planner, City of Federal Way Page 3
lylirrorEr�a�er I�rtiir, f��r�rary 28 200,f1?-r#ha1i,�&h Mamh 17, 200X
4. 12/19/07 Civil Plans
The 12/19/07 civil plans adequately address Otak 1/19/07 memo items 2.a through 2.e. However,
revisions to both the civil plans and the mitigation plan since the Otak 8/31 /07 memo result in the
following issues that must be addressed:
4.a. Legend for buffer perimeter fence. Sheer 1: Include a symbol (the line with X's) and text for
the buffer perimeter Open -Rail Fence. The comment on Sheet 6 "I��iRrriiFrr�rralon�yTrack fl'
fiorrh%efg, trD4&11 Ae 10' is somewhat confusing, since at the southwest corner by Lot 17, the
buffer perimeter fence will be located between the trail and buffer edge (as shown by the fence
symbol), not along the perimeter of Lot 17 which is the boundary of Track `A'.
4.b. Wetland Mitigation Area Clearing Limits and T.E.S.C. Plan Slieets 3 and 4: The clearing
limits for the wetland mitigation area in the 12/19/07 civil plans differ significantly from those
shown in the 1/21/08 mitigation plan Sheet W2.1. Revise the wetland mitigation clearing limits
on appropriate civil plan Sheets to those specified on Sheet W2.1 of the 1/21/08 mitigation
plan. The extent of buffer clearing shown in the 12/19/07 civil plans results in additional buffer
impacts and tree loss. Construction and silt fences marking wedand mitigation clearing limits
shall be installed according to specifications on 1/21/08 mitigation plan Sheet W4.1, Section
1.3 - Existing Vegetation to Remain. This includes installing orange construction fencing
around the entire perimeter of the wetland mitigation clearing limits, and around trees to
remain, as specified on 1/21/08 mitigation plan Sheet W2.1.
The 1/21/08 mitigation plan specifies installing orange silt fence only along the downslope side
of the grading area for the created/enhanced wedand. To ensure protection of Wedand B, the
silt fence must extend all along the boundary of wetland creation/enhancement grading area
that is adjacent to or in the wetland. This silt fence must extend uphill (westward) to the
western edge of the grading area.
Silt fences should not be installed along the entire east and west edges of Wedand B as shown
on Sheets 3 and 4. The chances for potential damage to buffer areas by installing and removing
silt fences far outweigh any potential benefit in areas where no earthwork will be done. Silt
fence as specified in the detail on Sheet 5 must be installed around the perimeter of outside
edge of the buffer as is shown on Sheets 3 and 4, while allowing construction access to the
created/enhanced wetland grading area.
To minimize soil compaction and avoid damage to existing vegetation to remain, heavy
equipment is only allowed in Wetland B and its buffer within the clearing limits for the
created/enhanced wetland area. The only exception may be in the northeast corner of Wetland
B buffer, in the vicinity of the existing shed that will be removed (see comment 4.c below).
4.c. Removal of Existing Sized Sheet 4 and other applicable Sheets: provide specifications for
removal of the wood shed located adjacent to the northeast corner of Wetland B. If possible,
access to remove the shed should be via the property to the north (who constructed the shed)
where the buffer is already degraded. Whether access is from the north or from the site,
\\Kirae0l\proj\project\30800\30879E\Reports\08_0317 memo.doc
1
Deb Barker, Planner, City ofFederal flay Page 4
1111rrorErtrrlri Review ffnn�r�riy 2S 200,f Re-rah1&-t11alr Mar-h 17, 200E
intrusions into the buffer must be minimized, and no trees may be removed for the work. To
avoid damage to desirable native vegetation and compaction of soils in the buffer, heavy
machinery is only allowed within the grading area for the wetland creation/enhancement area.
However, if heavy machinery use is absolutely necessary to remove the shed, a silt fence must
be installed around the perimeter of the work area before the start of demolition. After
completion of shed removal, the soil must be decompacted, then the silt fence must be
removed and the affected area replanted as specified in the 1/21/08 mitigation plan.
4.d. Construction Schedule Sheet 5: Water levels in Wetland B are regulated by the culvert
located at the wetland's south end, which is the only outlet. Consequently, replacement of that
culvert must be completed before the start of the rainy season, otherwise the hydroperiod of
Wedand B will be altered. In addition, the schedule must include timing specifications from the
1/21/08 mitigation plan. Provide the following additions to the Construction Schedule:
• Replacement of the culvert at the south end of Wetland B (27" Wedand Overflow) shall be
completed before October 1.
• All earthwork in the created/enhanced wedand area shall be completed by August 31 (as
specified in the 1/21/08 mitigation plan Sheet w4.1, section 1.1 - Grading Schedule).
4.e. Non -motorized Path Detail, Sheet 6: Provide text to the detail for the Non -motorized Path to
specify that the segment of the trail adjacent to Wetland B buffer (from the east end of the road
north of Lot 17 eastward to the stormpond access road) is only 8-feet wide. The specification for
4-foot clearings with planters on either side of the path does not apply to this section of trail.
41. Sheet 6 Correction: Sensitive Area Sign detail is located on Sheet 10, not Sheet 9.
If you have any questions regarding this memorandum, please contact me at 425-822-4446 or
suzsane.andersr�ii a �tak.coln
\\Kirae0l \prof\project\30800\30879E\Reports\08_0317 memo.doc
F1
Technical Memorandum
i r To: Deb Barker, Planner, City of Federal Way
From: Suzanne Bagshaw, Wetland Biologist
10230NEP91n1rDim
Jsrsfe 400
Kirkland, /ffl 98033
Phone (5t2SJ 8224446
Fax /429 821-19S7i
Copies:
Date:
Subject:
Project No.:
August 31, 2007
Review of Re -submittals for Mirror Estate Plat
30879E
As requested by the City of Federal Way, Otak conducted a review of the revised Mirror Estates
wetland mitigation plan and associated documents submitted on May 21, 2007. The purpose of this
review was to verify compliance with the project condition specifying that submittals must comply
with recommendations in the January 19, 2007 Otak Technical Memorandum.
Otak reviewed the following document for this memorandum:
• Wetland Mitigation Plan Mirror Estates, Sheets W1.1, W2.1, W3.1, and W4.1 by Altman Oliver
Associates, LLC dated May 18, 2007 (referredia /n t13iraieisrora1iAw ariieS/18/07nrir &'1lioW Ala*
• Mirror Estates Civil Plans: Sheets 1 through 13, by J3ME, including: Preliminary Plat Map,
T.E.S.C. Plan, Road and Storm Drainage Plan, Pond Sections and Details, Curb Alignment Plan,
and General Details, dated 5/15/07(referredio/rtt1i/rwdrar�dawartl�eS/1S/07civ/l�lanrj;
• Letter to Deb Barker of Federal Way from Simone Oliver, L.A. of Altmann Oliver Associates,
LLC dated May 18, 2007, subject: Wetland Mitigation Revisions per Otak's 1/19/07 Letter
(referredio in thirwe��rora�drir,� arthe OlmerS/1�/07leiie�j;
• Technical Information Report - Mirror Estates, by Jerrit Jolma, P.E. of J3 ME, dated March
30,2007 (referredla /n A&-&en,v,rdV lrrryr ar the T17�;
• Hearing Examiner's Decisions: from Stephen K. Causseaux, Jr., Hearing Examiner, to Jerrit
Jolma P.E., J3 Civil PLLC, dated February 9, 2007,1) regarding: Preliminary Plat of Mirror
Estates FWHE#06-12, FW#05-100590-00-SU; and 2) regarding: Wetland Elimination and
Wetland Mitigation for Mirror Estates Preliminary Plat, Process IV, FWHE#06-12, FW#07-
100304-00-UP (referredla is7 artheFlearingExaw/nerfl7ec/r/an�;
Previously reviewed documents referred to in this memorandum include:
• Wetland Mitigation Plan, Sheets W1.1, W2.1, W3.1, and W4.1 by Altman Oliver Associates, LLC
dated March 16, 2006 (referredio in th/r�ewnrnrfdiiw ar the 3/16/OGwlt/grr�io»lar�);
K:\project\30800\30879E\Rcports\07-0831memo.doc
Deb Barker, Planner, City ofFederal Way Page 2
Xev/ear R�rvdirisftalrfrAflimrE.rvlePlat Allgmrl31 2007
• Technical Memorandum to Deb Barker, City of Federal Way from Suzanne Bagshaw of Otak,
Inc., dated January 19, 2007, subject: Mirror Estates: Review of Revised Mitigation Plan (rgkrred
to /n t13/sr��ealmazidlIm ar Ahe Otak ///9/07mem�;
Introduction
The Mirror Estates project included a Process IV application for proposed wetland elimination and
compensatory mitigation, as well as for proposed buffer intrusions. The Hearing for approval of the
Process IV application was held on January 30, 2007, and the Hearing Examiner's Decision was
handed down on February 9, 2007. The Hearing Examiner's Decision approved the Mirror Estates
project Process IV application with the condition thatall
recwr��rehrda�a�ffrnrrr�,be_%arr�rar� �J�, 2007 0T�4KTec/i�%I�Yler�ora�drrni /�sta a�plr�a�le to�.r,�e�fl r�Iar�d
dowIlle,71i r/=a .,wa&da,0Amual y ch' ri .." In response to the Hearing Examiner's Decision, the
applicant submitted a set of revised documents on May 21, 2007.
The revised project documents adequately address most of the outstanding issues from the Otak
1/19/07 memo. However, some corrections and additions are required for final approval. Those
items are listed below in Section 1 which is referenced to the 5/18/07 mitigation plan, and Section 2
which is referenced to the 5/15/07 civil plans. The numbers in parentheses after the items listed
below refer to specific comments from the Otak 1/19/07 memo. The items listed below must be
addressed in revised documents which must be submitted to the City for approval.
1. 5/ 18/07 Mitigation Plan
.a. Sheet W2.1, Detail #2: Detail specifications for the silt fence differ from those in the civil
plans (Sheet 4, Filter Fence Detail). Since the mitigation plan specifies that erosion control
details are located in the civil plans (Note 2 on Sheets W1.1, W2.1, and W3.1), either remove
this detail or correct it (OiakS.�.
.b. Sheet W2.1, Detail #4: Open -Rail Fence: Design specifications for the buffer perimeter
fence are different than those in the 5/15/07 civil plans (Sheet 9, Split Rail Fence Detail).
Coordinate with the project engineer to choose one design or the other, and include the same
specification on both plan sets (0iak3l4).
.e. Sheets W2.1 and W3.1, Legends: Include a symbol and text for the Open -Rail Fence (Oiak
3.a.�j.
A Sheets W3.1: Otak 1/19/07 memo comments 3.c.2 and 3.c.3 specify 6 inches of arborist
mulch, which is the mulch that is generated when shrubbery and tree limbs are chipped. The
Otak comments specified arborist mulch because it is readily available, and arborists can
usually supply it at little or no cost. Because of its composition, arborist mulch is so "fluffy"
that within a very few weeks of application, it settles and compacts down to approximately
half to a third of its original depth. So in order to end up with at least 3 inches of mulch (as
specified in the planting details in the 3/16/06 mitigation plan), applying 6 inches of arborist
K:\project\30800\30879E\Reports\07_0831merno.doc
l
Deb Barker, Planner, City ofFederal [may Page 3
RerrieryPlat _41& cr1J?1 2007
mulch is necessary. On Sheet W3.1, correct notes 2 and 3 in both planting details #1 and #2
to apply 6 inches of arborist mulch
.e. Sheets W3.1 and W4.1: The 5/18/07 mitigation plan incorrectly deleted all mention of the
wetland seed mix that must be planted in the created wetland (plant schedule, specifications,
application instructions, maintenance, etc.). Seeding the created wetland was approved by the
Hearing Examiner as part of the 3/16/06 mitigation plan. Establishing thin -stemmed
emergent species in the created wetland is a vital part of the approved compensatory wetland
mitigation plan. Mitigation goal number 2 is to &TWrirare
atr�rerrgtr�rra�icirevereGrrriera�da»r��Grda,�' and Performance Standard number 7 requires cover
by native emergent species in the created wetland. On Sheet W3.1, replace the wetland seed
mix specifications from the 3/16/06 mitigation plan into the Plant Schedule. On Sheet W4.1,
replace text from the 3/16/06 mitigation plan that is applicable to seeding the created wetland
area into Sections: 3.3 Hydroseed; 9.6 Reseed Disturbed Areas; and Part 12-One Year
Maintenance — restore the provision to reseed bare areas greater than 36" by 36" in the
created wetland (Otak3d.10, jd.11, 3d.21 3.d.2,).
.f. Sheet W4.1, Section 1.7 - Excavate Mitigation Area. Second paragraph: Correct the depth of
over -excavation from 6 inches to 12 inches to be consistent with Note 4 on Sheets W1.1 and
W2.1 (Otak3dsj.
2. 5/ 15/07 Civil Plans
2.a. Sheet 4: Include design details and installation specifications for the straw roll (T.E.S.C.
measure around the created wetland) that is cross-referenced on Sheet 2 (OtakS�.
2.b. Sheets 5 and 6: Correct the location of the buffer perimeter fence adjacent to the pedestrian
trail at the south end of the wetland. The fence is currently shown on the south side of the
trail. The fence must be located along the north side of the trail - between the trail and the
buffer edge. See mitigation plan Sheets W2.1 and W3.1 for correct fence locations (Otak Vic,
2.e. Sheet 6: Show the roof -drain outlet to the wetland buffer from Lot 8 (Otak 'b, 3b_�.
2.d. Sheet 9, Split Rail Fence Detail: Design specifications for the buffer perimeter fence differ
from those in the 5/18/07 mitigation plan (Sheet W2.1, #4: Open -Rail Fence Detail).
Coordinate with the project landscape architect to choose one design or the other, and include
the same specification on both plan sets (01ak3l4).
2.e. Sheet 13: Include design details for the outlet structure from Wetland B as cross-referenced
on Sheet 5 (Otak fa).
K:\project\30800\30879E\Reports\07_0831 memo.doc
r�
4. Clearing limit issue — Submitted plans depict clearing limits beyond the areas approved for
infrastructure develonment.
Lot 4
Why to be cleared
Significant
Significant
% Sig.
Comments on proposed
trees on lot
trees
removed
clearing/grading action
moved
27
Sump installation at
9
Not Supported. Why can't this
rear of lot
U
sump be located on lot that is
proposed for filling (25 or 26)?
Clearing limits do not look
alistic.ft
Filling wetland that is
1
26
0
0
This clearing is permitted with
on this lot as well in the
the infrastructure installation
ROW
25
Filling wetland that is
0
0
0
This clearing is permitted with
on this lot as well in the
the infrastructure installation
ROW
20
Filling wetland that is
1
1
100%
Only western portion of this
on this lot as well in
clearing is supported. See Blue
ROW
►
line markup.
19
Filling wetland that is
1
1
100%
Only western portion of this
on this lot as well in
clearing is supported. See Blue
ROW
line markup.
18
Grade and fill for lot
0
0
0
Not supported
establishment
21
Grade and fill for lot
0
0
0
Not supported
establishment
16
Stockpile area, storm
1
100%
Not supported. Why can't lots
easement
25 and 26 be used for a
stockpile area?
7
Regrading for roof
4
4
100%
Only western portion of this
drain runoff
clearing is supported. See Blue
line markup
Supported.
8
Regrading for roof
1
1
100%
drain runoff, and
retaining wall for pond
6
Grading for roof drain
1
0
0
Only northern portion of this
runoff
clearing is supported. Are
clearing limits realistic? See
Blue line markup
5
Grading for roof drain
2
1
50%
Only northern portion of this
runoff
clearing is supported. See Blue
line marku
9 Stockpile area, and
5
5
100%
Supported.
1 clearing for pond wall
construction
10
Stocklpile area and
5
5
100°l
_
Not supported
Grade and fill for lot
establishment
11
Regrading for lot
3
2
(P (� �Uc
Not Supported
establishment
Z
r
Filling of wetland A
2
2
100%
This clearing is permitted with
the infrastructure installation
2
Filling of wetland A
0
0
0
This clearing is permitted with
the infrastructure installation
1
Regrading for lot
2
0
C)
Only southern portion of
development
clearing is supported. see blue
lines on sheet 2&3.
18 out of 27
Total
Total
79% of
Remaining significant trees on
lots proposed
significant
significant
significant
remaining lots?
to be
trees on
trees on
trees
cleared/graded.
these lots:
lots
removed.
39
removed:
31
Cm�
9
A�kCITY OF
Federal Way
July 23, 2007
Ms. Suzanne Bagshaw
Otak, Inc.
10230 NE Points Drive, Suite 400
Kirkland, WA 98033
RE: File #07-102761-00-EN; AUTHORIZATION TO PROCEED
Mirror Estates Preliminary Plat
Dear Ms. Bagshaw:
CITY HALL FILE
33325 8th Avenue South
Mailing Address: PO Box 9718
Federal Way, WA 98063-9718
(253) 835-7000
www. cityoffederal way. com
The purpose of this letter is to authorize the services of Otak, Inc. in a review of the Wetland Mitigation
Plan prepared by Altmann Oliver, Associates, LLC, dated May 18, 2007, for construction of the above -
referenced subdivision application.
Authorization to Proceed
In a July 3, 2007 task authorization request, the City requested an estimate from Otak, Inc. for review of
the proposed construction level documents and wetland mitigation plan for conformance with the
February 9, 2007, Hearing Examiner Conditions of Process IV approval. Your scope of work, dated July
12, 2007 and received via e-mail on July 18, 2007, indicated that a budget of $4,123.00 would be
appropriate for the identified tasks.
As discussed with the applicant, there is a balance of $1,619.55 in the pass -through account established to
fund peer review of the initial wetland proposal for the subdivision site. While the outstanding balance
does not account for the entire scope of work funding as identified above, the applicant has provided
written authorization for this surplus to be used to fund initial review of the application, and also
ascertained that full funding ($2,503.45) will be provided by the end of this week. The applicant
understands that your review will not conclude until fully funded. A copy of the applicant e-mail is
enclosed.
Therefore, please consider this letter as an authorization to proceed with the review as detailed in the
City's July 3, 2007 task authorization, your July 12, 2007 scope of work, and as discussed above.
I can be reached at 253-835-2642 if you have any questions about this letter.
Sincerely,
Deb Barker
Senior Planner
enc.: E-mail from Jerrit Jolma dated July 20, 2007
c: Ann Dower, Public Works Engineering Plans Reviekver
Jerrit Jolma, J31V1E, via e-mail Jerrit@j3me.net
Doc I D 41705
CITY OF
4k
Federal Way
July 20, 2007
�1FILE
CITY HALL
33325 8th Avenue South
Mailing Address: PO Box 9718
Federal Way, WA 98063-9718
(253) 835-7000
www. cityo ffederal way. com
J3 Civil Engineers Via e-mail.jerrit@j3nze.net
Jerrit Jolma
1375 Mall Street, Suite 3
Issaquah, WA 98027
RE: File #07-102761-00-EN; FORWARD WETLAND CONSULTANT ESTIMATE
Mirror Estates Engineering Review
Dear Mr. Jolma:
Enclosed please find an estimate for review of the Mirror Estates wetland mitigation plans as prepared by
Altmann Oliver Associates, LLC, dated May 18, 2007, for the above -referenced project. Otak, the City's
wetland consultant, was asked to provide an estimate for their review of the plans in order to confirm that
the proposal meets the Hearing Examiner conditions of approval for wetland elimination and wetland
mitigation. The Otak estimate, dated July 12, 2007, is enclosed.
The normal course of action is for the City to set up an account to be funded by the applicant and drawn
down by the work performed by Otak. If the money is not used, it will be returned to the applicant. In this
case, there is a surplus of funds remaining from Otak's previous review of the preliminary plat and
Process IV applications, in the amount of $1,619.55.' The July 12, 2007 Otak memo, calls for an estimate
of $4,123.00. If this estimate is offset with the remaining $1,619.55, a balance of $2,503.45 would be
required.
At this point, please review the proposed Otak cost estimate. If you agree with the cost estimate and agree
to use the existing surplus of funds towards this new review, a check in the amount of $2,503.45, payable
to the City of Federal, Way must be submitted_ With your written confirmation, I will authorize Otak to
begin their review of the plans based on use of the fund surplus. An e-mail response will be acceptable.
I can be reached at 253-835-2642 if you have any questions about this letter or the estimate.
Sincerely,
Deb Barker
Senior Planner
enc: Otak July 12, 2007 Scope of work memo, Invoice for remittance
c: Ann Dower, Public Works Engineering Plans Reviewer
' File 05-100590-SU
Doc I D 41677
CITY OF ' '
Federal Way
CITY OF FEDERAL WAY
WETLAND CONSULTANT AUTHORIZATION FORM
Date: July 3, 2007
City: City of Federal Way
Department of Community Development Services
PO Box 9718
Federal Way, WA 98063-9718
Consultant: Otak, Inc.
Attn: Dyanne Sheldon & Suzanne Bagshaw
10230 NE Points Drive, Suite 400
Kirkland, WA 98033
Project: Mirror Estates Preliminary Plat Engineering Review
File No: Permit #07-102761-00-EN; Mirror Estates
Project Proponent: J3 Civil Engineers
Jerrit Jolma
1375 Mall Street, Suite 3
Issaquah, WA 98027
Project Planner: Deb Barker, Senior Planner (253-835-2642)
Documents Provided:
o Wetland Mitigation Revisions Per Otak 1119107 letter as prepared by
Altmann Oliver Associates, LLC dated May 18, 2007
o Technical Information Report (TIR) prepared by Jerrit Jolma, PE dated
March 30, 2007
o Description of Stormwater Modification request dated May 16, 2007
o Geotechnical Engineering Study prepared by Geotech Consultants, Inc.
dated April 19, 2007;
o Wetland Mitigation Plan sheets W 1.1, W2.1, W3.1 and W4.1 prepared by
Altmann Oliver Associates, LLC dated May 18, 2007
o Civil Plans (sheets 1-13) prepared by J3ME, print date May 15, 2007
Task Scope: The Federal Way City Council granted preliminary plat approval for the 28 lot
subdivision. The Federal Way Hearing Examiner granted conditional approval
to proposed wetland elimination, wetland creation and wetland buffer
restoration associated with plat construction. At this time, the applicant has
submitted engineering plans for plat construction including wetland mitigation.
Doc.I.D_ 41447
K
Please complete the following tasks:
1) Review provided documents and information for conformance with the
Hearing Examiner conditions of approval_
2) Provide memorandum(s) identifying any additional information necessary.
3) Possible meetings on site and with applicant.
4) Final memorandum of conformance.
Task Schedule: Provide task cost estimate by July 16, 2007.
Task Cost: Not to exceed $ without a prior written amendment to this Task
Authorization. (The total task amount to be filled in by planner after the
consultant returns this form with all items filled out including the total work
estimate and said estimate has been approved by the Project Planner.)
Acceptance:
City of Federal Way (Planner) Date
(Consultant) Date
(Project Proponent) Date
Doc. I.D. 41447
Description of Stormwater
Modification Request
Mirror Estates
File #05-100590-00-SU
May 16, 2007
Description of Adjustment Re nest:
We are requesting approval of a modification to the stormwater design requirements
(KCSWDM 5.2.2) to allow area routed to the wetland area to be modeled as grass and
therefore not be subject to bypass design requirements.
ARRlicable Section of Standards:
KCSWDM 5.2.2
The King County Stormwater Design Manual, as adopted by the City, allows stormwater
runoff from impervious surfaces to be modeled as grass provided that a 50-foot
vegetated flow path is provided, and the lot size is greater than 22,000 sf.
Justification:
The site contains a large central wetland that will be enhanced as part of the proposed
development. Additionally, wetland creation is proposed to mitigate for the removal of
two onsite regulated wetlands. In order to maintain hydrology to the existing wetland
and provided adequate hydrology for the proposed wetland creation area, roof runoff
from 11 homes will be routed directly to this area. The City's Wetland Biologist,
Suzanne Bagshaw has specifically asked us to route the runoff from 11 homes to the
wetland areas. Combined, the 11 lots account for approximately 56,000 sf.
Conclusion:
The intent of this stormwater requirement is to limit the effects of runoff to neighboring
properties. In this case the water is going to be directly discharged to the
wetland/wetland buffer, which will affectively provide the same protection.
The design of the proposed stormwater system meets safety objectives, maintainability,
and most importantly, sound engineering judgment. Therefore, we respectfully request
this modification to allow for the narrower path.
RECEIVED
MAY 2 1 2007
CITY OF FED 6RAL WAY
BUILDING KEPT,
Altmann Oliver Associates, LLC AOA
PO Box 578 Carnation, WA 9.8014
May 15, 2007
Deb Barker, Planner
City of Federal Way
Office (425) 333-4535 Fax (425) 333-4509
Reference: Mirror Estates - 30879E
Subject: Wetland Mitigation Revisions per Otak's 1/19/07 Letter
Dear Deb,
Environmental
Planning &
Landscape
Architecture
AOA-3215
Attached, please find the revised wetland mitigation plans for Mirror Estates. The plane
have been revised to include the changes noted below. Pelow are our responses to Otak's
comments — from 1/19/07 letter by Suzanne Bagshaw —,are noted in green.
3. Review of the Mitigation Plan Sheets
Provide the following corrections and additions listed below. Text that should be added is
indicated by midoylrnxne and atadrer.
3.a. Sheet W 1.1
3.a.1 Pedestrian Path: correct the layout and width of the pedestrian path so that it is
consistent among all of the site plan sets (e.g. mitigation plans, civil site plans, etc.).
Done
3.a.2 Buffers of Wetlands A and C/D: include only the onsite portions of the buffers of
Wetlands A and C/D. Provide square footages for the existing onsite buffers for each
of Wetlands A and C/D. Correct the designated locations and square footages of
these buffer impacts on Sheet W1.1 and all other applicable drawings and site plans,
including the civil plan set.
As depicted on Drawing W1.1, buffer impacts associated with on -site filling of Wetland A
result in 6995 sf of buffer impact. Wetland C/D buffer impact is 12,142 sf. The trail, REejEIVE0
located in the SE portion of the Wedand B buffer encompasses 3229 sf of additional buffer
impact for a total onsite buffer impact of 22,366 sf. MAY 2 1 2007
3.a.3 Wetland B Buffer: provide the square footage of the existing onsite buffer for
Wetland B. Correct the designated locations and square footages of impacts to CfrY OF FEDERAL, WAY
Wetland B Buffer —both the pedestrian path and any existing buffer square footage BUILDING DEPT.
M
Deb Barker
May 18, 2007
Page 2 of 14
located outside of the path (area between the outer edge of the path and the outside
edge of the buffer) are buffer impacts and must be designated and counted as such.
The existing onsite Wetland B buffer is 43,727 sf in total. Buffer replacement along the west
side of Wetland B accounts for an additional 7514 sf of buffer area. Impacts associated with
the trail and the area between the trail and the south property line, that we believe will still
function as buffer is 3229 sf for a total Wetland B buffer of 48,012 sf of enhanced buffer.
3.a.4 Created Wetland: correct the square footage of created wetland.
The total square footage of created wetland is 11,255 sf.
3.a.5 Buffer Enhancement: correct the designated location and square footage of buffer
enhancement. Neither the created wetland nor any of existing buffer square footage
located outside of the path (area between the outer edge of the path and the outside
edge of the buffer) count as buffer enhancement.
The total area of buffer enhancement include the 50' enhanced buffer in addition to the
7514 sf of buffer area for a total of 48,012 sf of enhanced buffer.
3.a.6 Buffer Addition areas: using a different fill pattern, designate and label the
proposed buffer addition areas, and provide square footages.
See W1.1.
3.a.7 Buffer Perimeter Fence: show the location of the buffer perimeter fence. Where
the buffer is adjacent to lots (Lots 7, 8, 17, 18, 21, and 22), the buffer perimeter fence
shall be located along the edge of the buffer. Where the path intrudes into the buffer
and buffer addition areas, the buffer perimeter fence shall be located along the
wetland side of the path. Show the location of the buffer perimeter fence on all
applicable drawings and site plans, including the civil plan set. Provide design details
for the buffer perimeter fence on Sheet W2.1. The buffer perimeter fence (split -rail
fence or similar) shall allow for the passage of small animals.
The location of the buffer fence has been added to Drawing W1.1 and Detail 4 on Drawing
W2.1 depicts the fence detail.
3.a.8 Signs: designate locations for critical area signs along the buffer perimeter fence.
Signs shall say that human and pet access into the buffer and wetland is prohibited.
There shall be a minimum of one permanent sign per lot. Designate locations along
the pedestrian trail for installation of educational signs which explain the important
functions that wetlands and buffers perform. There shall be a minimum of two
permanent educational signs. Show the locations of the signs on all other applicable
drawings and site plans, including the civil plan set. Provide design details for the
critical areas signs and the educational signs on Sheet W2.1.
6 critical area signs and 2 educational signs shall be installed — see locations depicted on
Drawing W 1.1. The City shall approve of design and language prior to installation as
discussed with Suzanne.
3.b. Sheet W2.1
3.b.1 The grading plan proposes a limited section of 1:1 slope along the western side of
the created wetland. This is too steep. Wherever possible, and without damaging
existing tree roots, relax the slope to a maximum of 3:1 (run:rise). In areas where the
Deb Barker
May 16, 2007
Page 3 of 14
slope needs to be 1:1 to preserve tree roots, place large two- or three man rocks, or
large woody debris (as shown in the drawing) along the slope to stabilize it. Provide
specifications to decompact the construction access route to the created wetland.
The grading plan has been revise to show placement of large woody material where slopes
exceed 3:1. The specifications have also been revised to reflect this. Section 2.2 and
Section 4.1 of the specifications on Drawing W4.1 have been modified to provide detail
related to placement of large woody material on slopes greater the 3:1 and for decompaction
of construction access points.
3.b.2 Detail 1 Snag w/Nest Box Detail. Provide corrections to the text and title to
include:
• There is no nest box: delete from the title.
The snag should be cedar if possible, with 20-inch minimum dbh (as specified).
However, the City may be willing to approve a smaller dbh (minimum of 12
inches) if the snag is cedar rather than Douglas fir. Because this snag will be
installed in a wetland with expected inundation of two feet or more, a minimum
of 30 percent of the total length of the snag should be buried. Extra diligence
must be taken to firmly compact the soil around the buried snag since the area of
created wetland where it will be installed is expected to have saturated or
inundated soils year-round.
See revised Detail 1 on Drawing W2.1.
3.b.3 Add roof drain outlets into Wedand B buffer from Lots 18 and 21 to provide
additional hydrology to the created wetland area. Show the location of the roof drain
outlets from Lots 18 and 21, as well as those from Lots 4 through 8 and Lot 22, on all
other applicable drawings and site plans, including the civil plan set. All roof drain
outlet structures should be placed at the outer edges of the buffer.
See revised Drawing W1.1 and revised civil plan set. Here is the information related to
wetland hydrologic support we received from the engineer, Jerrit Jolma.
Wetland -A Historic Discharge Volume Analysis
Total Existing Area Tributary to Wetland A = 2.38 ac
Please see Figure 2: Existing Conditions Map
Till Forest = 2.23 acres
Wetland = 0.13 acres
Impervious = 0.02 acres
Historic Discharge Volume between 10/01/48 — 9/30/98 = 73.55 ac-ft (please see KCRTS output
in Appendix A.
Area required to match volume flows during the same time period.
Assume: 4,000 sf of impervious surface per lot
6 lots x 4,000 sf = 24,000 sf or 0.55 ac
Deb Barker
May 1b, 2007
Fage4of14
Historic Discharge Volume between 10/01/48 — 9/30/98 = 73.10 ac-ft (please see KCRTS output
in Appendix A.
By routing downspouts from 6 lots directly to Wetland B, the historic discharge volume from
Wetland A will be replaced to within 0.6%.
In addition, per the City's Wetland Biologists request, roof downspout drains from 5 additional
homes will be routed to the Wetland B creation area.
Existing onsite Wetlands A, C/D, and E are proposed to be filled and mitigated for by expanding
Wetland A. The volume lost from these wetlands is approximately 7,948 cf. This storage volume
will be replaced as part of the proposed wetland creation, which will add approximately 24,624 cf.
3.b.4 As specified in 3.a.7 and 3.a.8, provide design details for the buffer perimeter fence,
the permanent critical areas signs, and the permanent educational signs.
6 critical area signs and 2 educational signs shall be installed — see locations depicted on
Drawing W 1.1. The City shall approve of design and language prior to installation as
discussed with Suzanne.
3.b.5 Provide a detailed grading plan as specified in comment 4.e.
The existing contours for this project are at 2-foot contour intervals. We interpolated
contour 287 on Drawing W2.1 to provide more detail to the grading within the creation area
only.
3.b.6 Correct Note 5: "All wetland and bu er mitigation planting..."
Done
3.c. Sheet W3.1 Done
3.c.1 Planting Plan: provide corrections:
• Do not install trees, shrubs, or cuttings in the channel to the wetland outlet
structure at the south end of the wetland.
• Scouler willow (Salix scouleriana) prefers drier conditions than other common
native willow species. Add Sitka willow (Salix sitchensis) and Hooker willow (Salix
hookeriana) to install next to or in wetland areas.
• Clustered rose (Rosapisocwpa) prefers wet conditions. Add Nootka rose (Rosa
nutkana) for the drier locations in the buffer.
• High -bush cranberry (Viburnum edule) prefers somewhat damp conditions.
• Consider adding ocean -spray (Holodiscus discolor) and mock orange (Philadephus
lewisii) for drier upland conditions. We added mock orange by no ocean spray.
• Areas where the buffer is less than 50 feet wide (e.g. along the pedestrian path)
should be especially densely planted. In these areas two -gallon trees should be
spaced at eight feet on center.
3.c.2 Detail 1 Container Shrub Detail. Provide corrections to the text and tide to include:
• The majority of the trees will be planted as two -gallon containers. Add "tree" to
the tide.
• The soil moisture retention agent shall not be used in any wetland areas.
M7
Deb Barker
May 18, 2007
Page 5 of 14
• Mulch shall not be used in any wetland areas. In the buffer on the west side of
the wetland, apply 6 inches of arborist mulch to the entire area of dense
plantings. On the east side of the wetland where plantings are scattered, apply 6
inches of arborist mulch to a minimum width of 36 inches around installed
plants. Mulch should be pulled back approximately 4 inches from all stems.
Mulch shall not touch stems or trunks of installed plants. We apply 2" of mulch
to plantings as 6" we feel is too deep and may be detrimental to the plant
material. 2" is the industry standard.
• Add the note from Detail 2 for planting on slopes.
3.c.3 Detail 2 Bare -Root Planting Detail. Provide corrections to the text to include:
• Mulch shall not be used in any wetland areas. In the buffer on the west side of
the wetland, apply 6 inches of arborist mulch to the entire area of dense
plantings. On the east side of the wetland where plantings are scattered, apply 6
inches of arborist mulch to a minimum width of 36 inches around installed
plants. Mulch should be pulled back approximately 4 inches from all stems.
Mulch shall not touch stems or trunks of installed plants. We apply 2" of mulch
to plantings as 6" we feel is too deep and may be detrimental to the plant
material. 2" is the industry standard.
3.c.4 General Planting Installation Notes. Done
• Note 3 correct: "...or in exposed areas." delete "year"
• Note 4 correct "...remove after oneyear."
• Note 6 correct: fertilizer shall not be used in any wetland areas. Add text to
conform with Section 9.3 on Sheet W4.1
• Note 7 correct: soil moisture retention agent shall not be used in any wetland
areas. Add text to conform with Section 9.2 on Sheet W4.1
• Add: Dote 8. All installed plants shall ke ffa woon
,ro that tba can be id nfi ed thr ou hout the ue e r wonitarin eriod.
3.e.5 Plant Schedule. A vigorous root system is the most important factor for successful
establishment of restoration/enhancement plantings. The height of the plant above
ground is much less important. Twelve inch height for the one- or two- gallon
container -grown shrubs and 18 inches for the two -gallon container -grown trees is
adequate. Generally speaking, container -grown plants have a significantly higher
survival and establishment rate than bare -root or balled and burlapped plants. Except
for willow stakes, install one- or two -gallon container -grown shrubs, and two- or five -
gallon container -grown trees. OK and Done.
3.c.6 Plant Schedule. Trees: Provide corrections to the text to include: Done
• Indicate that Pacific willows will be installed as dormant cuttings December 1
through March 1, and as one -gallon container -grown plants during the rest of the
year.
• Most trees should be installed as two -gallon container -grown plants, except for
the larger cedars and hemlocks which will be installed on the east side of the
wetland. These should be five -gallon container -grown plants.
3.c.7 Plant Schedule. Shrubs: Provide corrections to the text to include: Done
Deb Parker
May 18, 2007
f aoe 6 of 14
Indicate that willows will be installed as dormant cuttings December 1 through
March 1, and as one -gallon container -grown plants during the rest of the year.
Scouler willow (Salix scouleriana) prefers drier conditions than other common
native willow species. Add Sitka willow (Salix sitchensis) and Hooker willow (Salix
hookeriana) to install in or adjacent to wetland areas.
Clustered rose (Rosapisocarpa) prefers wet conditions. Add Nootka rose (Rosa
nutkana) for the drier locations in the buffer.
• Consider adding ocean -spray (Holodiscus discolor) and mock orange (Philadephus
leavisia) for drier upland conditions.
3.c.8 Plant Schedule. Buffer Seed Mix: Provide corrections to the title and text to
indicate that grass seed shall not be planted in the buffer areas. Research has shown
that seeding grass in enhancement areas significantly reduces the growth and vigor of
installed trees and shrubs. Done nor are we seeding in the wetland.
3.e.9 Detail 3 Cutting Planting Detail. Provide corrections to the text to include: Done
• "Use at least a 36 inch steel bar.... when planting all cuttings. Insert spike to a
minimum o4 inc es or to at least one hal o tbe Len tit the coffin �vhic suer is dee et:
Insert cutting and..."
• "Insert cuttings manually ... to a depth of at least 24 inches, onto at least one halg
the len th of the cuttin tvhichever i er. Leave a minimum of 16 inches of cutting
above ground..."
• Note 1. "Dormant cuttings shall be avillow species as noted in Section 17.4 on Sheet
W14. >. Cuffi'ngs w1l oni be drsed �lantingoccurs behmen December 1' and Mach K For
Plantingbetween March I"and December 1" one- allow container- ro2vn lants s all be
installer. Native millow coffins shall he eLown agel collecte in the Lower P et .V ound area
from dormant trees and shrubs.
• Note 2. "Cuttings shall beat least 318 in diameter and..."
• Notes 3, 4, and 5. Provide corrections to these notes to be consistent with
paragraph 7 of corrected Section 8.1 on Sheet W4.1 (comment 3.d.14).
3.c.10 Notes. Correct Note 5 to: "All wetland and bu ermitigation planting areas shall be
irrigated...." Done
3.d. Sheet W4.1 Done
3.d.1 Section 1.1 - Grading Schedule. Provide corrections to the text to include:
• First paragraph: earthwork in the created wetland area must be completed by
August 31 to ensure adequate establishment of the seeds of the emergent species
prior to the rainy season. Exposed areas of the buffer shall be stabilized with
arborist mulch, not by seeding grass.
Add the following text to the second paragraph "Pre erentiall , planting should
occur anytime between December 1 and March 31, exceit durine periods of free in
tear errrtures or snow, to to ua toe a natora moist
3.d.2 Section 1.2 - General Site conditions. Add the following text to the end of the
second paragraph: Clea7ine limits shall be dqgge and TE S'C m sures shall 1ae installed be ore
I-)
al
Deb Barker
May 18, 2007
Page 7 of 14
he comyenc gent a an clearan or radin activities.
3.d.3 Section 1.3 - Existing Vegetation to Remain.
• First paragraph, correct the first sentence to: "Prior to grading... at the chi line or
the Llearind gra in Z limits rvhid) ewr distance.is reater, r all iree.r .
• Correct the second paragraph, last sentence to: "Plant species and quantities to
be approved by PEaad the CiU o Fed ral prior to installation."
3.d.4 Section 1.5 - Clear and Grub.
• First paragraph, after the sentence "Landscape Contractor shall remove
blackberry... by hand, with minimal disturbance to the existing vegetation." add:
It is simn I recozymended that a lifted WrenA TM h : rvww n eedrrrrench.com be gFed to
remove black, bet 7 y crowns and mots when the sail as moist. Mn-naiive invasive ecies shall be
r ewovedfrom the anaire G letland B bu�"er area and the created lvetland area.
• First paragraph, after the last sentence add: Reed canaiygrass caat be left inblace ithe
PE determines that 1-ermval actions M ht damage existin v etation t remain - articular/
orr the east side of the ry tland and ace acent to the xistin wetland.
• Second paragraph add: "PE and the City of Federal Vla to designate any additional
plant species..."
3.d.5 Section 1.7 - Excavate Mitigation Area. Second paragraph, correct depth of
excavation and topsoil replacement from 6 inches to 12 inches to be consistent with
Note 4 on Sheets W1.1 and W2.1.
3.d.6 Section 1.9 - Bentonite Contingency. First paragraph, after the first sentence add:
The CL4 of Federal W ryxrfst rr the d sin arid use a enton' e cl lies r.
3.d.7 Section 2.1 - Install Snag. First paragraph, after the first sentence add: The snag will
he inva fled acco rdin to DcWl I Sna ry Ili st ox Detail on Sl ea W2.1. Correct this
paragraph to concur with corrections for that detail in comment 3.b.2 above,
specifically, there is only one snag to be installed; the snag should be cedar if possible
with 20-inch minimum dbh, although the City may be willing to approve a smaller
dbh (minimum of 12 inches) if the snag is cedar; and a minimum of 30 percent of the
total length of the snag should be buried.
3.d.8 Section 3.1- Place Stockpiled Topsoil. Second paragraph, the correct depth of
topsoil replacement from 6 inches to 12 inches to be consistent with Note 4 on
Sheets W1.1 and W2.1.
3.d.9 Section 3.2 - Irrigation. Add the following text to the end of the fourth paragraph:
FQ�n thX conditions or tvarrn ft erahtres W necessitate be irrnilr ir7i n sooner in the
season, andl or 117&aLn4 MOre fi_-eOentl rlu awing the season.
3.d.10 Section 3.3 - Hydroseed. Provide corrections to the text to include: only the
created and disturbed wetland areas should be seeded (with the wetland mix). Bare
soils in the buffer areas shall not be seeded with grass. Instead stabilize bare soils in
the buffer with arborist mulch.
3.d.11 Section 5.1 - Soil Stabilization. Provide corrections to the text to include: as in
comment 3.d.10 above, only the created and disturbed wetland areas should be seeded
(with the wetland mix). Bare soils in the buffer areas shall be stabilized with arborist
mulch.
Deb Barker
May 18, 2007
Image 8 of 14
3.d.12 Part 6 - Damage and Road Maintenance. At the end of the third paragraph add:
"Any changes or modifications to this plan must receive prior approval from AOA
and the lag a F deral IYWa
3.d.13 Section 7.2 - General Conditions.
• First paragraph, provide corrections to the text to include: except for areas that
will be graded, use only manual means to remove non-native invasive plant
species from the entire Wetland B buffer. Use of a Weed Wrench TM
(http://www.weedwrench.com/) to remove blackberry crowns and roots from
moist soil is recommended.
• Add the following text to the end of the first paragraph: Herbicide rrse shall not be
tallarved in rvetlancl areas. Limit 1 erbidde use ma I be alloured in ub land brr er areas onl >
with a meal fim tl Cit o ederal W ter manual control e orts have wile l.. On
Rodeos a PIvbh osate b er laicide or- otJser he)- irides tba t are gpproved Lor use in wetland crud
s am has err shallbe -used Herhicide shall not be ra ed in htr er crrecrs j e or aint
0?roved herGacide on leartes or cart stems as_a m mate -late sumrner is assa{al the most
effective season for hervicide rise. To control blackberries in the late sanm rer crrt - roams to
within G" qf the gLwend and irnarnediate uint rvi cut ends with ca centrated Radea9. hLML
nraiive invasive genes shall l)e rem med from the entire Ketland B bar er aria and the created
wetland area Reed canary ►a s can lie 1 in Iac a the PE determines that re- val actives
mi ht darrla a ex' tin rre tation to rerrrain - mtr.'cular! on the ea t side o the wetland and
ad acent to the eacistin rvetlancl
3.d.14 Section 8.1 - Plant Materials.
• First paragraph, last sentence add: "PE and the Cif o,fFederal Gly± shall pre -
approve...
• Second paragraph, provide corrections to the text to include: no horticultural
varieties of native species shall be used.
• Third paragraph, add the following text to the end of the last sentence: Plant
eci s sarh tltution ► 'res rvv al ro the Ci o Federal ll/a .
• Fourth paragraph: balled and burlapped plants should not be installed (see
comment 3.c.5 above). Delete those specifications.
• Seventh paragraph, provide corrections to the first sentence: "Native willow
cuttings shall be grown and collected in the LAiverRqpet.sound area. Curtin s 2vi116e
harvested one, from dorrrrani rvillorvs " Third sentence: "Dormant cuttings shall be a
minimum..." Second to the last sentence and last sentence: "Cuttings shall only
be used if planting occurs between December 1 and March 1. For-plandng behveen
Ma rch 1 arld Decerrrber 1 one- allon container- raaarn Nants s all be installed."
3.d.15 Part 9 - Plant Installation. Add the following text: All installed !ants shall be flagged or
oth ravine marked at or be ore installation so that th ran be identi red thr u boat theue ear
monitoting petiod.
3.d.16 Section 9.1 - Soil Preparation/Amendments. Provide corrections to the text to
include: the soil moisture retention agent shall not be used in any wetland areas.
3.d.17 Section 9.2 - Soil Moisture Retention Agent. Provide corrections to the text to
include: the soil moisture retention agent shall not be used in any wetland areas.
W
Deb Barker
May 18, 2007
f age9of14
3.d.18 Section 9.3 - Fertilizer. Provide corrections to the text to include: fertilizer shall
not be used in any wetland areas.
3.d.19 Section 9.4 - Mulch. Provide corrections to the text to include: Mulch shall not be
used in any wetland areas. In the buffer on the west side of the wetland, apply 6
inches of arborist mulch to the entire area of dense plantings. On the east side of the
wetland where plantings are scattered, apply 6 inches of arborist mulch to a minimum
width of 36 inches around installed plants. Mulch should be pulled back
approximately 4 inches from all stems. Mulch shall not touch stems or trunks of
installed plants.
3.d.20 Section 9.5 - Staking. Provide corrections to the text to include: only large trees (5
gallon) require staking.
3.d.21 Section 9.6 — Re -seed Disturbed Areas. Provide corrections to the text to include:
only the created and disturbed wetland areas should be seeded (with the wetland mix).
Bare soils in the buffer areas shall not be seeded with grass. Instead stabilize bare soils
in the buffer with arborist mulch.
3.d.22 Part 12 - One -Year Maintenance. Provide corrections to the text to include: only
the created and disturbed wetland areas should be re -seeded (with the wetland mix).
Replace mulch in bare areas in the buffers.
3.d.23 Part 13 -As-Built Plan. Add the following text to the end of the first paragraph:
The As-Bailt Ke ort will list xrantrties ecdes and s of glAnts installed in t miti anon a —,-
It ail/ include a site ao ivith th locations of- all installed tees and shrubs in the her er and treat .
ivetland • all perniarx stt a•1ronitorin lots all emianent j5halt oints the tavo ie- ozwters • the sna all
installed Gat faxes and downed to s or !a e woad dehras the hu er poixeter once information
ins, and the pedesh an nail.
3.d.24 Part 15 - Long -Term Monitoring Program. Provide the following corrections and
additions to the "Monitoring will include data collection of the following items:"
• "Count all installed trees and shrubs in the mitigation areas for
mortality/survival" - on the west side of the wetland where the plants are densely
planted, it is recommended that a sufficient number of representative permanent
monitoring plots be established to count a minimum of ten percent of the
installed trees and shrubs, rather than counting all of them. Count all of the
installed trees and shrubs on the east side of the wetland where they will be more
scattered. Also establish at least 4 one -meter square permanent monitoring plots
in the created wetland to monitor percent cover by emergent species. Done,
although all plants will be counted and assessed.
• "Assess the health of all installed plants... for any disease, infestation, or dame by
rvildli a e.. ra n lin tc. .
• "Estimate percent cover by son -native inversive e 'es, and specify locations extent and
maintenance/removal techniques in order to semisfy the Pe orrtrance .standard o ffess
than 10% cover area to promote the growth and survival of all installed plants.
• "Photograph the created wetland and enhanced buffer areas from at least 5
m&an gn Q 1 oto P 0 ints Which are deli nat&I by a metal -fen ce p ost r othea• mark er. The
location and ...."
Deb Barker
May 18, 2007
Page 10 of 14
• Assess tlae conditions and rvildli a uLrqez of the sna at axes air installed lu e woody dehrxs.
Also note uyildli a h resence and use o tland and Lu& areas. The iolo aai will record
observations a ecies rr rvildli e Indic t rs such as scat nts nests boles Gmrvsin marks
etc.
• ,Establish at least 2 ie onpet rs in the created wetland ai ca to m onitor h dM G . fnstarll orre
i ometer in a location rvh re ear=round saturated soils are eoLcled and the second in a
location avhere seasonal saturation is n ected. Measure )voter d th in the e ureters Of de t$
ofstcandin� rvater�durang each motworzng asit. Also note the species, candition. a►rd
ea njKz:mate cover by ohkeate plants in the created zvetlapid area.
• Observe and note gen era l site conditions and urainterranee actions that mmst b a to en in ludin
brit not limited to): bat box mLagr re lacerrxeni race re air trash removal a mulch
re lacement.
• "Submit the results of the annual monitoring... following field monitoring." Each
arronitoring 130 arts rill include: a hoto-docunfentation &2 rn a1l p erarranent pbolo- oints' G
percent surryival of installed !cants - based on tl e results of both the urortitorrrr p lots an the west
side a f the :vs tlrarrd rand the total count on the east side Qf the wetland • c enerrtl health and vi or
of installed trees and shrubs • c ercent cover by erne ent s ecies in the cleated rvedmi
anarsitors�nX platss rl) results of h4droloa monit srLxrrg.• water dertl} an tlre�ire arrreterr. arrd
resence and extent o abli ate lasts in the created wetland area a condition and yvildli e use o
the sna !rat boxes, arrd d Tuned to s LaPiZe wood-1 debri eesent aerial cover h + non-native
invasive OLecies in the entire lair r rind created wedarsd area as reel! as in the rraonitoreel lots'
condi 'ons of the Liar pefimeter ence and in ormatianal si ns
whether trash is present in the bu er and wetland' i ernes al site conditions• an assessrrrerrt
whether Per formance .Standards are bgng met• reegYmeyrded zved ten race activities to
ensure that Pe oivaance Standards are metand w e her corstin err m as ns are necessar .
3.d.25 Section 15.1 Mitigation Goals. Provide the following corrections and additions:
• "1. Improve existing wetland buffer habitat and function...."
• "2. Create new wetland ... and amphibians. Provide h Gitat eatxres includin a sna bat
boxes and lame avaody rlebrar
3.d.26 Section 15.2 Performance Standards. Provide the following corrections and
additions:
• "4. Provide a minimum of 80 percent survival of all installed trees and shrubs
throughout the five years of monitoring."
• "5. Maintain less than ten percent non-native, invasive plant cover in the created
-wegland and all Welland B bu er areas throe bout the five years of monitoring."
• G. Esta lislr Eetland h dr olo Mroulaoart the created rrletland area.
• 7. Ay the end of the 5_+ear monitoring liersod there shall he 60% cover by native emergent
ecies in the sections o the created wetland where seasonal inundation does not prevent the
e orvth of emergent species.
• S. There shall be visyral u deuce that thg installed trees and shrubs are ari araaus e.. n Try roruth
and nw visible si ns stress .
•9, The sna bat boxes and installed la e mood debris shall he resent and in ood condition
thou hoist the rrre ears o monitorin .
Deb Barker
May 18, 2007
Page 11 of 14
3.d.27 Part 17 - Long -Term Maintenance Specifications. Add the following text to the
end of the first paragraph: Maintenance activities inclsrde mrt are not limtmited to : ar ' atian
weed cantrot mulch re .item ist MLJaLlzng as recess re aarin aplgLnZ and rrmaintainin . the
snu at boxes the bu er err eter ence and in ormational sa ns trash remnaval from the lmrm er and
wetland areas, • reg val o silt Lomas and other TE.S'C devices when approved by PE removal qftree
brotcctim eating when ai mad y PE: and removal etree stakes when g, ooved b� PE.
3.d.28 Section 17.1 Weed Control.
• At the end of the first sentence add: Use o a Deed lllrench TM
Owlrvwrv. rveecdaa wench. corn to remrzove weed crowns and roots m m ist soil is
recommended. Herbicide use shall not be allowed in rvetlarzd areas. Limited herbicide use ma
be allowed in 41and bu er areas aril with a royal m the i o Federal lea ter
mmmanuaI control e oris have aided n ly Rodeo 8 a 1 hosate 1 rhici e Or otber herlmici es
that are aMroved for use in wetland and stream lm ers shall be used Herbicide shall riot be
rdr r d in brow er areas. 6i�a e or paint a roved herbicide on leaves or cut stems as a ro riate -
late sKrmmnmer is usually the most ective season for ber bicide use. To control blac berries in the
late summrmer out a-s
prouts to adhin G inches oL the wosrnd crud 4 rmnredaatel r azrrt Z rvi a eut
ends tvath co centrated Rodw&
• Delete the sentence "Chemical means...";
• Provide corrections to the text to include: "Undesirable and weedy exotic plant
species listed above shall be maintained at levels below terr errant total cover in the
entire Wetland B Lu er area anti the created wetland area at all times during the five-year
monitoring period. All remmmoUed weed,rat Taal shall he renmovedfiam the site arid di�o d a
ro erl
3.d.29 Section 17.2 Reed Canary Grass Control.
• At the beginning of the first paragraph add: Reed canarerass can be l ft hiPkace i t e
PE detemines that removal acwu ma ht darrma e existan ve etation tither installed or
remaining earastinQ vegetation) - tmarxicularI& on the east side of the wetland and gdjacent to the
exisfin wetlar d
• At the end of the first paragraph add: jil removed weed atraterial s all be rein ved roam
the rite and &osed of Lnoerly,
• Provide corrections to the text of subsection 1 to include: Deed ry ckers shall ,rot
be used in areas where trees and shiwbs were install d Herbicide use shall not be allowed in
wetland areas. Lairmited b erbici e mse a v be allowed in yp land bu er- are s on with royal
m the i o Fe er 1 W u ter manual control e arts have ailed. On& RodeoO a
ghbhosate- lze&i-c-ida or other herbicides that are raved or use in wetland and str earrm bu rjhff_s
11 be used Lgle surnmmmer ir usual the mnost effective season for herbicide us .
• Provide corrections to the text of subsection 2 to include: "Areas shall be staked
with dorrrmant willowy cuttings... During March 1 through November 30... in place
of cuttings. Nlairstcain and rrmonitor these re- !anted removal areas."
3.d.30 Section 17.3 Himalayan and Evergreen Blackberry Control. Delete this section
and substitute the following text: Hamd an and .Evergreen blackberries shall be removed ram
the entire lletland bu r area and the rreated ra etland area. i.Yjlien the soil i s moist cant nd
re ove longcanes leavin a roxirrmale one oat o the canes above rosin Us a/ lY/renc
Deb Barker
May 1b, 2007
f aeo12of14
TM to extract crmvns rind mots rn m ist so 1 Ill rrmove
black beM nraterxals shall be removed frgg the sate crud di used o n4 er_ . Herbicide use shall not
be allowed hi wetland areas. 1-mited herbicide arse my be allowed in Oland bw er acas onl rvitl3
approval frow the Ci o Fed ral V , a er r�ranuul c ntml e arts r Iackberries have ailed Oral
Rodeos a hosa e Lmrkd e or other herbicides that are i4troved or use an wetland and strram
bu ers .rall be used Herkdde shall not he sprayed in hrr er areas. To corrtrol blackberries in the
late srsnlrxrer cut g- marts to ivithin 6" o t e cround and im ,,e iatelX _Lainll rani e cwt wdr with
oncentrcrted Rodeo. Re:plant all areas in the bu er and civated wetland area e rral to or neater
thorn 16 saage feet where black bem s are removed Stake wetland areas mith native willow cuttin s
see .Saking List and Staking S eci cations below . Dunn March 1 thmu lr Nov rn r 30one-
alloy lants shall be used in lace of m6j s For the bw er arias ar r a iro hate V-disLro—mithe
gifig anon blan p latrt schedule and irrsta111 anon shru, s at 3 -feet ov c nter and 2 anon trees at 8
-feet OC, lvlaintain and monitor these re- lasted removal areas.
3.d.31 Section 17.4 - Staking List (from Wet to Dry). Substitute the following text for the
staking list: Para i willow Salix lrrada Hoo er willow .Salix hoa rsana Sitka rr illou� Salax
sitcherasis and Scowler• villa w Salix scouki Lana .
3.d.32 Section 17.4 - Staking Specifications. Provide corrections to the text to include:
Willow cuttings shall be dormant when they are harvested and installed. Cuttings shall
conform to specifications in corrected Section 8.1 (3.d.14). Specifications for
installing cuttings are listed in Detail 3 - Cutting Planting Detail on Sheet W3.1.
Willow cuttings or container -grown plants will also will also be installed in areas of
blackberry infestations listed above in corrected Section 17.3 (3.d.30). Dormant
cuttings will be installed in pilot holes to a minimum of two feet, or to at least one
half of the length of the cutting whichever is deeper.
3.d.33 Section 17.7 - Maintenance of Trees. Provide corrections to the text to include: no
weed -whacking shall be done in planted areas.
3.d.34 Part 18 - Contingency Plan. Correct the first sentence to: "All dead plants ... or a
sarbstitute &ties a aced by the 0 that meets the goals of the mitigation
plan.
4. Additional Information Required
4.a. Provide design details for the outlet structure from Wetland B in the civil plans as well
as in the mitigation plan sheets. The outlet elevation shall be the same as the current
outlet elevation (288 feet) to avoid altering existing wetland hydroperiod. The details
are on the civil plan set and are not on the mitigation set, as we do not feel
comfortable providing details on our drawings that were not prepared by our firm —
per discussions with Suzanne.
4.b. In the civil plans as well as in the mitigation plan sheets, provide design details and
locations for the outlet structures into Wetland B buffer from the roof drains from
Lots 4 through 8 and Lot 22. Add roof drain outlets into Wetland B buffer from Lots
18 and 21 to provide additional hydrology to the created wetland area. All roof drain
outlet structures should be placed at the outer edges of the buffer. The details are on
Deb Barker
May 18, 2007
page 13 of 14
the civil plan set and are not on the mitigation set, as we do not feel comfortable
providing details on our drawings that were not prepared by our firm — per
discussions with Suzanne.
4.c. Pedestrian Path: correct the layout and width of the pedestrian path so that it is
consistent among all of the site plan sets (e.g. mitigation plans, civil site plans, etc.)
(comment 3.a.1). Done
4.d. Provide specifications in the Mitigation Plan Sheets to decompact the construction
access route to the created wetland. See Drawing W1.1 and Section 4.1 on Drawing
W4.1
4.e. Provide a detailed grading plan for the created wetland areas with existing and
proposed one -foot contours. Include a minimum of three cross -sections. One cross-
section should include the deepest part of the created wetland, and a second should
show the widest location of the created wetland with a proposed hummock. Include
corrections for the section of 1:1 slope (comment 3.b.1).
The existing contours for this project are at 2-foot contour intervals. We interpolated
contour 287 on Drawing W2.1 to provide more detail to the grading within the creation area
only. The 1:1 slope issue has been corrected, see Section 2.2 on Drawing W4.1. Preparation
of 3 cross sections is cost-prohibative, as discussed with Suzanne. The landscape contractor
will be able to interpret this small grading plan with no difficulty. In addition, the project
biologist will be reviewing the grading implementation at multiple times per the
specifications.
41. Show the Buffer Perimeter Fence (comment 3.a.7) and locations of permanent signs
(comment 3.a.8) on all appropriate sheets including the civil plans as well as in the
mitigation plan.
See response to 3.a.7 above.
5. Recommended Conditions
5.a. Address all issues and provide corrections and additions specified in this
memorandum.
5.b. Submit a revised mitigation plan sheet set (Sheets W1.1, W2.1, W3.1, and W4.1) for
review and approval and conditioning by the City of Federal Way.
5.e. The City's wetland biologist shall review the Temporary Erosion and Sediment
Control Plans.
5.d. The City's wetland biologist shall review the final Technical Information Report
(TIR).
The items have been addressed as noted in blue above. We. recommend having the City
adopt Standardized mitigation specifications since it is evident from the details of these
conditions, that they would be warranted. Many of the detailed conditions within this
letter are not Standardized in the industry and vary from consultant to consultant. If
the City adopts standardized Specifications, then a great deal of time associated with
(I )
w
Deb Barker
May 15, 2007
Page 14 of 14
peer review and revisions would be Saved which could be utilized in restoration of degraded
wetland and streams throughout the City.
If you have any queotions, please call me at (425) 333-4535.
Sincerely,
ALTMANN OLIVER A550CIATES, LLC
Simone Oliver
Landscape Architect
Attachments
1. revised mitigation drawings W1.1-W4.1
cc:
Gary Schulz & Jerrit Jolma
GEOTECH
CONSULTANTS, INC_
Celebrating 20 Years 1986-2006
New Concept Homes, Inc.
P.O. Box 1229
Issaquah, Washington' 98027
Attention: Christine Balyeat
Subject: Transmittal Letter — Geotechnical Engineering Study
Proposed Residential Plat
Mirror Estates near Southwest 316th Place
Federal Way, Washington
Dear Ms. Balyeat:
13256 Northeast 20th Street, Suite 16
Bellevue, Washington 98005
(425) 747-5618 FAX (425) 747-8561
April 19, 2007
JN 07117
We are pleased to present this geotechnical engineering report for the proposed residential plat to
be constructed in Federal Way. The scope of our services consisted of exploring site surface and
subsurface conditions, and then developing this report to provide recommendations for general
earthwork placement and compaction and design criteria for foundations, retaining walls, and
pavements. This work was authorized by your acceptance of our proposal, P-7304, dated March
12, 2007.
The attached report contains a discussion of the study and our recommendations. Please contact
us if there are any questions regarding this report, or for further assistance during the design and
construction phases of this project.
cc: J3ME — Jerrit Jolma
via email
ZJM/MRM: jyb
Respectfully submitted,
GEOTECH CONSULTANTS, INC.
/-r. M5 ,
Marc R. McGinnis, P.E.
Principal
RECEIVED -
MAY 2 1 Z007
GEOTECH CONSULTANTS, INC.
CITY OF FEDERAL WAY
BUILDING DEPT.
GEOTECHNICAL ENGINEERING STUDY
Proposed Residential Plat
Mirror Estates near Southwest 316th Place
Federal Way, Washington
This report presents the findings and recommendations of our geotechnical engineering study for
the site of the proposed residential plat to be located in Federal Way.
We were provided with site plans and a topographic map. J3ME developed these plans, which are
dated January 22, 2007. Based on these plans, we understand that the development will consist of
dividing the 9.37 acre site into approximately 27 lots for single-family residences, extending several
of the existing roads onto and through the site to provide access, creating a large improved wetland
near the center of the property and building a detention pond near the south central portion of the
site.
We anticipate that this site will require some fairly heavy grading to accommodate for the new
homes, roads and utilities that will be required for the new development. Several small wetlands
will be filled in as a part of the site grading. Design of the houses themselves will be completed
later.
If the scope of the project changes from what we have described above, we should be provided
with revised plans in order to determine if modifications to the recommendations and conclusions of
this report are warranted.
SITE CONDITIONS
SURFACE
The Vicinity Map, Plate 1, illustrates the general location of the site. The property is located in a
currently undeveloped tract of land in the Mirror Lake Subdivision of Federal Way. The site is
approximately 9.4 acres, and except for a square parcel not included in the property in the
northeast corner, is rectangular in shape. The surface topography of the site is gently undulating
with a general trend down to the center of the site, which the City of Federal Way has declared a
wetland. There are no steep slopes on, or near, the site. Several other smaller wetlands dot the
property and have been marked by surveyors. The site is surrounded by single-family homes and
several roads dead-end near the property line.
Both 8th Place Southwest and 11 th Place Southwest dead end at the north and south boundaries
of the site.
SUBSURFACE
The subsurface conditions were explored by excavating test pits at the approximate locations
shown on the Site Exploration Plan, Plate 2. Our exploration program was based on the proposed
construction, anticipated subsurface conditions and those encountered during exploration, and the
scope of work outlined in our proposal.
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The test pits were excavated on March 22, 2007 with a rubber -tired backhoe, which you provided.
A geotechnical engineer from our staff observed the excavation process, logged the test pits, and
obtained representative samples of the soil encountered. "Grab" samples of selected subsurface
soil were collected from the backhoe bucket. The Test Pit Logs are attached to this report as
Plates 3 through 10.
Soil Conditions
We excavated sixteen test pits, which encountered approximately 6 to 12 inches of topsoil
overlying loose to medium -dense, brown silty sand and gravel (weathered glacial till), which
became gray and dense to very dense at approximately 2.5 to 3 feet below the existing
grade. This non -weathered dense to very -dense, glacially consolidated mixture of sand, silt
and gravel is commonly referred to as glacial till. Glacial till was encountered to the
maximum of 7 feet below the existing grade. Cobbles and boulders were common in our
test pits.
Groundwater Conditions
Slight groundwater seepage was observed at a depth of 2.5 to 3.5 feet in several test pits in
the lower elevations on the site. This seepage represents subsurface water that is perched
on the relatively impervious glacial till. This is what causes the wetlands. The test pits were
left open for only a short time period. Therefore, the seepage levels on the logs represent
the location of transient water seepage and may not indicate the static groundwater level.
It should be noted that groundwater levels vary seasonally with rainfall and other factors.
We anticipate that groundwater could be found in more permeable soil layers pockets within
the till and between the near -surface weathered soil and the underlying denser soil.
The stratification lines on the logs represent the approximate boundaries between soil types at the
exploration locations. The actual transition between soil types may be gradual, and subsurface
conditions can vary between exploration locations. The logs provide specific subsurface
information only at the locations tested. The relative densities and moisture descriptions indicated
on the test pit logs are interpretive descriptions based on the conditions observed during
excavation.
The compaction of backfill was not in the scope of our services. Loose soil will therefore be found
in the area of the test pits. If this presents a problem, the backfill will need to be removed and
replaced with structural fill during construction.
CONCLUSIONS AND RECOMMENDATIONS
GENERAL
THIS SECTION CONTAINS A SUMMARY OF OUR STUDY AND FINDINGS FOR THE PURPOSES OF A
GENERAL OVERVIEW ONLY. MORE SPECIFIC RECOMMENDATIONS AND CONCLUSIONS ARE
CONTAINED IN THE REMAINDER OF THIS REPORT. ANY PARTY RELYING ON THIS REPORT SHOULD
READ THE ENTIRE DOCUMENT.
The test pits conducted for this study encountered loose to medium -dense weathered till soils,
which became dense near 2.5 feet below the surface. Based on our findings, it is our opinion that
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the proposed houses can be supported on conventional continuous and spread foundations
bearing on the medium -dense to dense, native silty sands or on structural fill properly placed and
compacted above these competent native soils. The silty sands are moisture sensitive and it may
be prudent to cover the bearing surfaces with a 3- to 4-inch thick protective rock layer to prevent
disturbance from foot traffic during formwork. The rock should consist of 2- to 4-inch, clean
crushed rock or clean, recycled concrete. However, this rock will likely not be necessary during
relatively dry weather.
A significant geotechnical consideration for development of this site is grading of the overly moist to
wet, condition of the silty soils. Based on our observations, the moisture contents of the on -site
soils are significantly above the optimum moisture content necessary for the required structural fill
compaction. These fine-grained, silty soils are sensitive to moisture, which makes them impossible
to adequately compact when they have moisture contents even 2 to 3 percent above their optimum
moisture content. The reuse of non -organic soils as structural fill to level the site will only be
successful during hot, dry weather as aeration of each loose lift of soil will be required to dry it
before the lift is compacted. Alternatively, the soil could be chemically dried by adding lime, kiln
dust, or cement, provided this is allowed by responsible building department. Regardless of the
method of drying, the earthwork process will be slowed dramatically. Wet weather earthwork will
be more difficult and expensive as adequate compaction of even the dried or treated soils will not
be possible in rainy weather or wet conditions. The earthwork contractor must be prepared to
rework areas that don't achieve proper compaction due to high moisture content. Utility trench
backfill in structural areas, such as pavements, must also be dried before it can be adequately
compacted. Improper compaction of backfill in utility trenches and around control structures is a
common reason for pavement distress and failures. Imported granular fill will be needed wherever
it is not possible to dry the on -site soils sufficiently before compaction.
The erosion control measures needed during the site development will depend heavily on the
weather conditions that are encountered. We anticipate that a silt fence will be needed around the
downslope sides of any cleared areas. Rocked construction access roads should be extended into
the site to reduce the amount of soil or mud carried off the property by trucks and equipment.
Wherever possible, these roads should follow the alignment of planned pavements, and trucks
should not be allowed to drive off of the rock -covered areas. Existing catch basins in, and
immediately downslope of, the planned work areas should be protected with pre -manufactured silt
socks. Cut slopes and soil stockpiles should be covered with plastic during wet weather. Following
rough grading, it may be necessary to mulch or hydroseed bare areas that will not be immediately
covered with landscaping or an impervious surface.
Crawl spaces or slabs extending close to, or into, the dense soils, or below visible seepage, should
be provided with an underdrainage system. This is intended to collect subsurface water that may
bypass the perimeter footing drains. Typically, a minimum 8 to 9-inch gravel layer containing
perforated pipes on approximate 20 to 25-foot centers provides adequate drainage for a depressed
crawl space or slab. As with most residential plats, additional drainage measures can be required
on a lot -by -lot basis and may not be evident until rough grading is complete.
The drainage and/or waterproofing recommendations presented in this report are intended only to
prevent active seepage from flowing through concrete walls or slabs. Even in the absence of active
seepage into and beneath structures, water vapor can migrate through walls, slabs, and floors from
the surrounding soil, and can even be transmitted from slabs and foundation walls due to the
concrete curing process. Water vapor also results from occupant uses, such as cooking and
bathing. Excessive water vapor trapped within structures can result in a variety of undesirable
conditions, including, but not limited to, moisture problems with flooring systems, excessively moist
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air within occupied areas, and the growth of molds, fungi, and other biological organisms that may
be harmful to the health of the occupants. The designer or architect must consider the potential
vapor sources and likely occupant uses, and provide sufficient ventilation, either passive or
mechanical, to prevent a build up of excessive water vapor within the planned structure.
Geotech Consultants, Inc. should be allowed to review the final development plans to verify that the
recommendations presented in this report are adequately addressed in the design. Such a plan
review would be additional work beyond the current scope of work for this study, and it may include
revisions to our recommendations to accommodate site, development, and geotechnical
constraints that become more evident during the review process.
We recommend including this report, in its entirety, in the project contract documents. This report
should also be provided to any future property owners so they will be aware of our findings and
recommendations.
SEISMIC CONSIDERATIONS
In accordance with Table 1615.1.1 of the 2003 International Building Code (IBC), the site soil pro-
file within 100 feet of the ground surface is best represented by Soil Profile Type C (Very Dense
Soil). The soils that will support the structures are not susceptible to seismic liquefaction.
CONVENTIONAL FOUNDATIONS
The proposed structure can be supported on conventional continuous and spread footings bearing
on undisturbed, dense, native soil, or on adequately compacted structural fill placed above this
competent native soil. See the section entitled General Earthwork and Structural Fill for
recommendations regarding the placement and compaction of structural fill beneath structures.
Adequate compaction of structural fill should be verified with frequent density testing during fill
placement. This is especially important if on -site or silty soils are used as structural fill. Prior to
placing structural fill beneath foundations, the excavation should be observed by the geotechnical
engineer to document that adequate bearing soils have been exposed. We recommend that
continuous and individual spread footings have minimum widths of 16 and 24 inches, respectively.
Exterior footings should also be bottomed at least 18 inches below the lowest adjacent finish
ground surface for protection against frost and erosion. The local building codes should be
reviewed to determine if different footing widths or embedment depths are required. Footing
subgrades must be cleaned of loose or disturbed soil prior to pouring concrete. Depending upon
site and equipment constraints, this may require removing the disturbed soil by hand.
Depending on the final site grades, overexcavation may be required below the footings to expose
competent native soil. Unless lean concrete is used to fill an overexcavated hole, the
overexcavation must be at least as wide at the bottom as the sum of the depth of the
overexcavation and the footing width. For example, an overexcavation extending 2 feet below the
bottom of a 2-foot-wide footing must be at least 4 feet wide at the base of the excavation. If lean
concrete is used, the overexcavation need only extend 6 inches beyond the edges of the footing.
An allowable bearing pressure of 2,500 pounds per square foot (psf) is appropriate for footings
supported on competent native soil. A higher bearing capacity of 4,000 psf could be used for deep
structures, such as vaults, that bear directly on dense, native soils. A one-third increase in this
design bearing pressure may be used when considering short-term wind or seismic loads. For the
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above design criteria, it is anticipated that the total post -construction settlement of footings founded
on competent native soil, or on structural fill up to 5 feet in thickness, will be less than one inch,
with differential settlements on the order of half an inch in a distance of 50 feet along a continuous
footing with a uniform load.
Lateral loads due to wind or seismic forces may be resisted by friction between the foundation and
the bearing soil, or by passive earth pressure acting on the vertical, embedded portions of the
foundation. For the latter condition, the foundation must be either poured directly against relatively
level, undisturbed soil or be surrounded by level structural fill.
We recommend using the following ultimate values for the foundation's resistance to lateral
loading:
PARAMETER
Coefficient of Friction
VALUE
0.50
Passive Earth Pressure
350 pcf
Where: (1) pcf is pounds per cubic foot, and (ii) passive earth
pressure is computed using the equivalent fluid density.
If the ground in front of a foundation is loose or sloping, the passive earth pressure given above will
not be appropriate. We recommend maintaining a safety factor of at least 1.5 for the foundation's
resistance to lateral loading, when using the above ultimate values.
PERMANENT FOUNDATION AND RETAINING WALLS
Retaining walls backfilled on only one side should be designed to resist the lateral earth pressures
imposed by the soil they retain. The following recommended parameters are for walls that restrain
level backfill:
PARAMETER
Active Earth Pressure *
VALUE
35 pcf
Passive Earth Pressure
350 pcf
Coefficient of Friction
0.50
Soil Unit Weight
135 pcf
Where: (i) pcf is pounds per cubic foot, and (ii) active and
passive earth pressures are computed using the equivalent fluid
pressures.
* For a restrained wall that cannot deflect at least 0.002 times its
height, a uniform lateral pressure equal to 10 psf times the height
of the wall should be added to the above active equivalent fluid
pressure.
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The values given above are to be used to design permanent foundation and retaining walls only.
The passive pressure given is appropriate for the depth of level structural fill placed in front of a
retaining or foundation wall only. The values for friction and passive resistance are ultimate values
and do not include a safety factor. We recommend a safety factor of at least 1.5 for overturning
and sliding, when using the above values to design the walls. Restrained wall soil parameters
should be utilized for a distance of 1.5 times the wall height from corners or bends in the walls.
This is intended to reduce the amount of cracking that can occur where a wall is restrained by a
corner.
The design values given above do not include the effects of any hydrostatic pressures behind the
walls and assume that no surcharges, such as those caused by slopes, vehicles, or adjacent
foundations will be exerted on the walls. If these conditions exist, those pressures should be added
to the above lateral soil pressures. Where sloping backfill is desired behind the walls, we will need
to be given the wall dimensions and the slope of the backfill in order to provide the appropriate
design earth pressures. The surcharge due to traffic loads behind a wall can typically be
accounted for by adding a uniform pressure equal to 2 feet multiplied by the above active fluid
density.
Heavy construction equipment should not be operated behind retaining and foundation walls within
a distance equal to the height of a wall, unless the walls are designed for the additional lateral
pressures resulting from the equipment. The wall design criteria assume that the backfill will be
well -compacted in lifts no thicker than 12 inches. The compaction of backfill near the walls should
be accomplished with hand -operated equipment to prevent the walls from being overloaded by the
higher soil forces that occur during compaction.
Retaining Wall Backfill and Waterproofing
Backfill placed behind retaining or foundation walls should be coarse, free -draining
structural fill containing no organics. This backfill should contain no more than 5 percent silt
or clay particles and have no gravel greater than 4 inches in diameter. The percentage of
particles passing the No. 4 sieve should be between 25 and 70 percent. A minimum 12-
inch width of free -draining gravel should be placed against the backfilled retaining walls.
The drainage composites should be hydraulically connected to the foundation drain system.
Free -draining backfill or gravel should be used for the entire width of the backfill where
seepage is encountered. For increased protection, drainage composites should be placed
along cut slope faces, and the walls should be backfilled entirely with free -draining soil. The
later section entitled Drainage Considerations should also be reviewed for
recommendations related to subsurface drainage behind foundation and retaining walls.
The purpose of these backfill requirements is to ensure that the design criteria for a
retaining wall are not exceeded because of a build-up of hydrostatic pressure behind the
wall. The top 12 to 18 inches of the backfill should consist of a compacted, relatively
impermeable soil or topsoil, or the surface should be paved. The ground surface must also
slope away from backfilled walls to reduce the potential for surface water to percolate into
the backfill. The section entitled General Earthwork and Structural Fill contains
recommendations regarding the placement and compaction of structural fill behind retaining
and foundation walls.
The above recommendations are not intended to waterproof below -grade walls, or to
prevent the formation of mold, mildew or fungi in interior spaces. Over time, the
performance of subsurface drainage systems can degrade, subsurface groundwater flow
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patterns can change, and utilities can break or develop leaks. Therefore, waterproofing
should be provided where future seepage through the walls is not acceptable. This typically
includes limiting cold -joints and wall penetrations, and using bentonite panels or
membranes on the outside of the walls. There are a variety of different waterproofing
materials and systems, which should be installed by an experienced contractor familiar with
the anticipated construction and subsurface conditions. Applying a thin coat of asphalt
emulsion to the outside face of a wall is not considered waterproofing, and will only help to
reduce moisture generated from water vapor or capillary action from seeping through the
concrete. As with any project, adequate ventilation of basement and crawl space areas is
important to prevent a build up of water vapor that is commonly transmitted through
concrete walls from the surrounding soil, even when seepage is not present. This is
appropriate even when waterproofing is applied to the outside of foundation and retaining
walls. We recommend that you contact a specialty consultant if detailed recommendations
or specifications related to waterproofing design, or minimizing the potential for infestations
of mold and mildew are desired.
The General, Slabs -On -Grade, and Drainage Considerations sections should be
reviewed for additional recommendations related to the control of groundwater and excess
water vapor for the anticipated construction.
SLABS -ON -GRADE
Floors can be constructed as slabs -on -grade atop competent, non -organic native soil, or on
structural fill. The subgrade soil must be in a firm, non -yielding condition at the time of slab
construction or underslab fill placement. Any soft areas encountered should be excavated and
replaced with select, imported structural fill.
Even where the exposed soils appear dry, water vapor will tend to naturally migrate upward through
the soil to the new constructed space above it. All interior slabs -on -grade, including garage slabs,
must be underlain by a capillary break or drainage layer consisting of a minimum 4-inch thickness
of gravel or crushed rock that has a fines content (percent passing the No. 200 sieve) of less than
3 percent and a sand content (percent passing the No. 4 sieve) of no more than 10 percent. As
noted by the American Concrete Institute (ACI) in the Guides for Concrete Floor and Slab
Structures, proper moisture protection is desirable immediately below any interior on -grade slab or
ones that will be covered by tile, wood, carpet, impermeable floor coverings, or any moisture -
sensitive equipment or products. ACI also notes that vapor retarders, such as 6-mil plastic
sheeting, are typically used. A vapor retarder is defined as a material with a permeance of less
than 0.3 US perms per square foot (psf) per hour, as determined by ASTM E 96. It is possible that
concrete admixtures may meet this specification, although the manufacturers of the admixtures
should be consulted. Where plastic sheeting is used under slabs, joints should overlap by at least
6 inches and be sealed with adhesive tape. The sheeting should extend to the foundation walls for
maximum vapor protection. If no potential for vapor passage through the slab is desired, a vapor
barrier should be used. A vapor barrier, as defined by ACI, is a product with a water transmission
rate of 0.00 perms per square foot per hour when tested in accordance with ASTM E 96.
Reinforced membranes having sealed overlaps can meet this requirement.
We recommend that the contractor, the project materials engineer, and the owner discuss these
issues and review recent ACI literature and ASTM E-1643 for installation guidelines and guidance
on the use of the protection/blotter material. Our opinion is that with impervious surfaces that all
means should be undertaken to reduce water vapor transmission.
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The General, Permanent Foundation and Retaining Walls, and Drainage Considerations
sections should be reviewed for additional recommendations related to the control of groundwater
and excess water vapor for the anticipated construction.
EXCAVATIONS AND SLOPES
Excavation slopes should not exceed the limits specified in local, state, and national government
safety regulations. Temporary cuts to a depth of about 4 feet may be attempted vertically in
unsaturated soil, if there are no indications of slope instability. However, vertical cuts should not be
made near property boundaries, or existing utilities and structures. Based upon Washington
Administrative Code (WAC) 296, Part N, the soil at the subject site would generally be classified as
Type A. Temporary cut slopes greater than 4 feet in height should not be excavated at an
inclination steeper than 0.75:1 (Horizontal:Vertical), extending continuously between the top and
the bottom of a cut. Flatter cuts or other protective measures would be necessary where caving
soils or heavy seepage are observed.
The above -recommended temporary slope inclination is based on the conditions exposed in our
explorations, and on what has been successful at other sites with similar soil conditions. It is
possible that variations in soil and groundwater conditions will require modifications to the
inclination at which temporary slopes can stand. Temporary cuts are those that will remain
unsupported for a relatively short duration to allow for the construction of foundations, retaining
walls, or utilities. Temporary cut slopes should be protected with plastic sheeting during wet
weather. It is also important that surface water be directed away from temporary slope cuts. The
cut slopes should also be backfilled or retained as soon as possible to reduce the potential for
instability. Please note that loose soil can cave suddenly and without warning. Excavation,
foundation, and utility contractors should be made especially aware of this potential danger. These
recommendations may need to be modified if the area near the potential cuts has been disturbed in
the past by utility installation, or if settlement -sensitive utilities are located nearby.
All permanent cuts into native soil should be inclined no steeper than 2.5:1 (H:V). Fill slopes
should not be constructed with an inclination greater than 2.5:1 (H:V). To reduce the potential for
shallow sloughing, fill must be compacted to the face of these slopes. This can be accomplished
by overbuilding the compacted fill and then trimming it back to its final inclination. Adequate
compaction of the slope face is important for long-term stability and is necessary to prevent
excessive settlement of patios, slabs, foundations, or other improvements that may be placed near
the edge of the slope.
Water should not be allowed to flow uncontrolled over the top of any temporary or permanent
slope. All permanently exposed slopes should be seeded with an appropriate species of vegetation
to reduce erosion and improve the stability of the surficial layer of soil. Topsoil is often placed on
regraded slopes to promote growth of vegetation. Proper preparation of the regraded surface, and
use of appropriate topsoil is necessary to prevent the topsoil from sliding off the slope. This is
most likely to occur following extended wet weather if a silty topsoil is used. On steeper slopes, it
may be necessary to "track walk" the slope or cut small grooves across the slope prior to placing
the topsoil.
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DRAINAGE CONSIDERATIONS
Foundation drains should be used where (1) crawl spaces or basements will be below a structure,
(2) a slab is below the outside grade, or (3) the outside grade does not slope downward from a
building. Drains should also be placed at the base of all earth -retaining walls. These drains should
be surrounded by at least 6 inches of 1-inch-minus, washed rock and then wrapped in non -woven,
geotextile filter fabric (Mirafi 140N, Supac 4NP, or similar material). At its highest point, a
perforated pipe invert should be at least 6 inches below the bottom of a slab floor or the level of a
crawl space, and it should be sloped for drainage. All roof and surface water drains must be kept
separate from the foundation drain system. A typical drain detail is attached to this report as Plate
11. For the best long-term performance, perforated PVC pipe is recommended for all subsurface
drains.
As discussed in the General Section, rainage inside the building's footprint should- also be
provided where (1) a crawl space will slope or be lower than the surrounding ground surface, (2) an
excavation encounters significant seepage, or (3) an excavation for a building will be close to the
expected high groundwater elevations.
As a minimum, a vapor retarder, as defined in the Slabs -On -Grade section, should be provided in
any crawl space area to limit the transmission of water vapor from the underlying soils. Also, an
outlet drain is recommended for all crawl spaces to prevent a build up of any water that may
bypass the footing drains.
Groundwater was observed during our field work. If seepage is encountered in an excavation, it
should be drained from the site by directing it through drainage ditches, perforated pipe, or French
drains, or by pumping it from sumps interconnected by shallow connector trenches at the bottom of
the excavation.
The excavation and site should be graded so that surface water is directed off the site and away
from the tops of slopes. Water should not be allowed to stand in any area where foundations,
slabs, or pavements are to be constructed. Final site grading in areas adjacent to a building should
slope away at least 2 percent, except where the area is paved. Surface drains should be provided
where necessary to prevent ponding of water behind foundation or retaining walls.
PAVEMENT AREAS
The pavement section may be supported on competent, native soil or on structural fill compacted to
a 95 percent density. Because the site soils are silty and moisture sensitive, we recommend that
the pavement subgrade must be in a stable, non -yielding condition at the time of paving. Granular
structural fill or geotextile fabric may be needed to stabilize soft, wet, or unstable areas. This is
most likely where the pavement subgrade exposes the looser, near -surface soils, which are easily
softened under vehicle loads. To evaluate pavement subgrade strength, we recommend that a
proof roll be completed with a loaded dump truck immediately before paving. In most instances
where unstable subgrade conditions are encountered, an additional 12 inches of granular structural
fill will stabilize the subgrade, except for very soft areas where additional fill could be required. The
subgrade should be evaluated by Geotech Consultants, Inc., after the site is stripped and cut to
grade. Recommendations for the compaction of structural fill beneath pavements are given in the
section entitled General Earthwork and Structural Fill. The performance of site pavements is
directly related to the strength and stability of the underlying subgrade.
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The pavement for lightly loaded traffic and parking areas should consist of 2 inches of asphalt
concrete (AC) over 4 inches of crushed rock base (CRB) or 3 inches of asphalt -treated base (ATB).
We recommend providing heavily loaded areas with 3 inches of AC over 6 inches of CRIB or 4
inches of ATB. Heavily loaded areas are typically main driveways, dumpster sites, or areas with
truck traffic. Increased maintenance and more frequent repairs should be expected if thinner
pavement sections are used.
The pavement section recommendations and guidelines presented in this report are based on our
experience in the area and on what has been successful in similar situations. As with any
pavements, some maintenance and repair of limited areas can be expected as the pavement ages.
Cracks in the pavement should be sealed as soon as possible after they become evident, in order
to reduce the potential for degradation of the subgrade from infiltration of surface water. For the
same reason, it is also prudent to seal the surface of the pavement after it has been in use for
several years. To provide for a design without the need for any maintenance or repair would be
uneconomical.
GENERAL EARTHWORK AND STRUCTURAL FILL
All building and pavement areas should be stripped of surface vegetation, topsoil, organic soil, and
other deleterious material. The stripped or removed materials should not be mixed with any
materials to be used as structural fill, but they could be used in non-structural areas, such as
landscape beds.
Structural fill is defined as any fill, including utility backfill, placed under, or close to, a building,
behind permanent retaining or foundation walls, or in other areas where the underlying soil needs
to support loads. All structural fill should be placed in horizontal lifts with a moisture content at, or
near, the optimum moisture content. The optimum moisture content is that moisture content that
results in the greatest compacted dry density. The moisture content of fill is very important and
must be closely controlled during the filling and compaction process.
Fills placed on sloping ground should be keyed into the dense, native soils. This is typically
accomplished by placing and compacting the structural fill on level benches that are cut into the
competent soils. The allowable thickness of the fill lift will depend on the material type selected, the
compaction equipment used, and the number of passes made to compact the lift. The loose lift
thickness should not exceed 12 inches. We recommend testing the fill as it is placed. If the fill is
not sufficiently compacted, it can be recompacted before another lift is placed. This eliminates the
need to remove the fill to achieve the required compaction. The following table presents
recommended relative compactions for structural fill:
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Beneath footings, slabs 95%
or walkways
Filled slopes and behind 90%
retaininq walls
95% for upper 12 inches of
Beneath pavements subgrade; 90% below that
level
Where: Minimum Relative Compaction is the ratio, expressed in
percentages, of the compacted dry density to the maximum dry
density, as determined in accordance with ASTM Test
Designation D 1557-91 (Modified Proctor).
The General section should be reviewed for considerations related to the reuse of on -site soils.
Structural fill that will be placed in wet weather should consist of a coarse, granular soil with a silt or
clay content of no more than 5 percent. The percentage of particles passing the No. 200 sieve
should be measured from that portion of soil passing the three -quarter -inch sieve.
LIMITATION
The conclusions and recommendations contained in this report are based on site conditions as
they existed at the time of our exploration and assume that the soil and groundwater conditions
encountered in the test pits are representative of subsurface conditions on the site. If the
subsurface conditions encountered during construction are significantly different from those
observed in our explorations, we should be advised at once so that we can review these conditions
and reconsider our recommendations where necessary. Unanticipated soil conditions are
commonly encountered on construction sites and cannot be fully anticipated by merely taking soil
samples in test pits. Subsurface conditions can also vary between exploration locations. Such
unexpected conditions frequently require making additional expenditures to attain a properly
constructed project. It is recommended that the owner consider providing a contingency fund to
accommodate such potential extra costs and risks. This is a standard recommendation for all
projects.
This report has been prepared for the exclusive use of New Concept Homes, and its
representatives, for specific application to this project and site. Our conclusions and
recommendations are professional opinions derived in accordance with current standards of
practice within the scope of our services and within budget and time constraints. No warranty is
expressed or implied. The scope of our services does not include services related to construction
safety precautions, and our recommendations are not intended to direct the contractor's methods,
techniques, sequences, or procedures, except as specifically described in our report for
consideration in design. Our services also do not include assessing or minimizing the potential for
biological hazards, such as mold, bacteria, mildew and fungi in either the existing or proposed site
development.
GEOTECH CONSULTANTS, INC.
New Concept Homes
April 19, 2007
JN 07117
Page 12
ADDITIONAL SERVICES
In addition to reviewing the final plans, Geotech Consultants, Inc. should be retained to provide
geotechnical consultation, testing, and observation services during construction. This is to confirm
that subsurface conditions are consistent with those indicated by our exploration, to evaluate
whether earthwork and foundation construction activities comply with the general intent of the
recommendations presented in this report, and to provide suggestions for design changes in the
event subsurface conditions differ from those anticipated prior to the start of construction.
However, our work would not include the supervision or direction of the actual work of the
contractor and its employees or agents. Also, job and site safety, and dimensional measurements,
will be the responsibility of the contractor.
During the construction phase, we will provide geotechnical observation and testing services when
requested by you or your representatives. Please be aware that we can only document -site work
we actually observe. It is still the responsibility of your contractor or on -site construction team to
verify that our recommendations are being followed, whether we are present at the site or not.
The following plates are attached to complete this report:
Plate 1 Vicinity Map
Plate 2 Site Exploration Plan
Plates 3 - 10 Test Pit Logs
Plate 11 Typical Footing Drain Detail
GEOTECH CONSULTANTS, INC.
New Concept Homes
April 19, 2007
JN 07117
Page 13
We appreciate the opportunity to be of service on this project. If you have any questions, or if we
may be of further service, please do not hesitate to contact us.
ZJM/MRM: jyb
Respectfully submitted,
GEOTECH CONSULTANTS, INC.
Zack J. Munstermann
Geotechnical Engineer
,;?,• AIC0
( VA
'f92745�
Marc R. McGinnis, P.E.
Principal
GEOTECH CONSULTANTS, INC.
-P 7
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OLYWIC
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GEOTECH
CONSULTANT'S, INC.
s s,
vi 4;-----'"l�-
304TH K •S 30411i ST
(Source: Thomas Brothers King County Street Guide and Directory, 2007)
VICINITY MAP
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job Date: ca e: Plate:
07117 April 2007 1 Not to Scale 1
1 � 1
co
...........
`L ' 8th PI. SW
rL
1
8th PI. SW �—
'
i F-
i
i
H i
i c0
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CL
.......... ..............
i�
i
i c
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Wetland i
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O
(Approximate) ;
' ; a
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i a ! E
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71 co
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i I-1 I— CL 1 Q
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11 th PI. SW i 11 th PI. SW
GEOTECH
CONSULTANTS, INC.
SITE PLAN
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job Date: scale: Plate:
07117 April 2007 Not to Scale I 2
TEST PIT 1
o 1141, ti �
CP �v ��G Description
Brown, silty SAND with gravel and organics, medium- to fine-grained, moist, loose
- becomes gray, no organics, dense
- becomes very dense
5 * Test Pit was terminated at 4 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
5
10
15
o���a�� �aG�
TEST PIT 2
Description
Brown, silty SAND with gravel and organics, medium- to fine-grained,
moist, loose
SM - becomes medium -dense, no organics
becomes dense
honrimpQ rsrav vary rinnea
* Test Pit was terminated at 4 feet on March 22, 2007.
* Groundwater seepage was observed at 3.5 feet during excavation.
* No caving was observed during excavation.
GEOTECH
CONSULTANT'S, INC.
TEST PIT LOG
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job Date: ILoggedby. JPlate:
07117 nar.2007 ZJM 3
,��� TEST PIT "
,0
Description
Brown, silty SAND with gravel and organics, medium- to fine-grained,
moist, loose
- becomes gray, with cobbles, no organics, dense
l;::i:J�i... I - becomes very dense
5 * Test Pit was terminated at 4.5 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
TEST PIT 4
9�1 G Description
Brown, silty SAND with gravel and organics, medium- to fine-grained,
moist, loose
- becomes gray, no organics, dense
- becomes very dense
5 Test Pit was terminated at 4.5 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
Y ' GEOTECH
CONSULTANT'S, INC.
4
TEST PIT LOG
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job Date: Logged by: Plate: 4
07117 Apr. 2007 1 zim
TEST PIT 5
�e CP Description
Brown, silty SAND with gravel and organics, medium- to fine-grained,
moist, loose
- becomes dense with no organics
- becomes aray. very dense
5 * Test Pit was terminated at 4 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
TEST PIT 6
°fi�°p t75 Description
Brown, silty SAND with gravel and organics, medium- to fine-grained,
moist, loose
SM - becomes medium -dense, no organics
II, , - becomes gray, dense
- becomes very dense
5 * Test Pit was terminated at 4.5 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
GEOTECH
CONSULTANTS, INC.
TEST PIT LOG
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job Date: Logged by. Plate:
07117 Apr. 2007 ZJM 1 5
tes `O
TEST PIT 7 `)
Description
Brown, silty SAND with gravel and organics, medium- to fine-grained,
moist, loose
- becomes gray, no organics, dense
5 * Test Pit was terminated at 4 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
TEST PIT 8
XP `�� Description
5
Brown, silty SAND with gravel and organics, medium- to fine-grained, moist, very
- becomes gray, dense, no organics
- becomes very dense
* Test Pit was terminated at 7 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
10 * No caving was observed during excavation.
15
GEOTECH
CONSULTANTS, INC.
TEST PIT LOG
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job IDAapter:2007
Logged by. Plate:
07117 I ZJM 1 6
�e�\tilt TEST PIT 9
CP �}`�� Description
Brown, silty SAND with gravel and organics, medium- to fine-grained,
moist, loose
- becomes gray, no organics, dense
5 Test Pit was terminated at 4 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
5
10
15
TEST PIT 10
CP Description
Brown, silty SAND with gravel and organics, medium- to fine-grained, moist, loose
* Test Pit was terminated at 5 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
GEOTECH
CONSULTANTS, INC.
TEST PIT LOG
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job Date: I Logged by. Plate:
07117 1 Apr- 2007 ZJM 7
TEST PIT 11
CP 0 'j Description
Brown, silty SAND with gravel and organics, medium- to fine-grained, moist, loose
- becomes medium -dense, no organics
- becomes gray, dense
5 * Test Pit was terminated at 4 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
TEST PIT 12
1 pp G° e �`� Description
Brown, silty SAND with gravel and organics, medium- to fine-grained, moist, loose
- becomes gray, with cobbles, no organics, dense
- becomes very dense
5 * Test Pit was terminated at 4.5 feet on March 22, 2007.
* Slight groundwater seepage was observed at 2.5 feet during excavation.
* No caving was observed during excavation.
10
15
GEOTECH
CONSULTANTS, INC.
TEST PIT LOG
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job Date: Logged by: Plate: $
07117 Apr. ZJM
5
10
15
TEST PIT 13
o tie, 0- 1 p C�
C,°��Description
Brown, silty SAND with gravel and organics, medium- to fine-grained, moist, loose
- becomes medium -dense
- becomes gray, dense, no organics
* Test Pit was terminated at 4 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
TEST PIT 14
9 41G � �] Description
Brown, silty SAND with gravel and organics, medium- to fine-grained, moist, loose
SM - becomes gray, dense, no organics
- becomes very dense
5 * Test Pit was terminated at 4 feet on March 22, 2007.
* Slight groundwater seepage was observed at 2.5 feet during excavation.
* No caving was observed during excavation.
10
15
GEOTECH
CONSULTANTS, INC.
4
TEST PIT LOG
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job Date: Logged by: Plate:
07117 Apr. 2007 1 ZJM 1 9
C'�010� TEST PIT 15
aY' �
G Description
Brown, silty SAND with gravel and organics, medium- to fine-grained, moist, loose
SM - becomes gray, dense, no organics
5 * Test Pit was terminated at 4 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
TEST PIT 16
4 CP Description
� Brown, silty SAND with gravel and organics, medium- to fine-grained, moist, loose
7 SM I - becomes gray, dense, no organics
I - i.i.P - uc.wuca rcY ascuac_
5 * Test Pit was terminated at 4 feet on March 22, 2007.
* No groundwater seepage was observed during excavation.
* No caving was observed during excavation.
10
15
GEOTECH
CONSULTANTS, INC.
4
TEST PIT LOG
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Fob— Date: ILoggedby: JPlate:
07117 Apr. 2007 ZJM 10
Slope backfill away from
foundation. Provide surface
drains where necessary.
Washed Rocl
(7/8" min. size)
4" min.
Backfill
(See text for
requirements)
Nonwoven Geotextile
Filter Fabric _
O
C
a
LL
Tightline Roof Drain
(Do not connect to footing drain)
Possible Slab
❑'.s7:'.p.0:,•p,.Cl:�-.D.•C3:b".p•,•Q.:�'.p
.f3.•p•.p..C7.;0.p'.¢
uv°D •�rco
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ao'dvo�d �v
va
D60 ��o°••D07V
�to
oD aaaD0aoc•'va•opco�
Q �
Lag
•O
d
- .•o'.'�v ..•t P
a0
0o
.•'o'�.o
n
4" Perforated Hard PVC Pipe
(Invert at least 6 inches below
slab or crawl space. Slope to
drain to appropriate outFall.
Place holes downward.)
Vapor Retarder/Barrier and
Capillary Break/Drainage Layer
(Refer to Report text)
NOTES:
(1) In crawl spaces, provide an outlet drain to prevent buildup of water that
bypasses the perimeter footing drains.
(2) Refer to report text for additional drainage, waterproofing, and slab considerations.
GEOTECH
CONSULTANT'S, INC.
FOOTING DRAIN DETAIL
Mirror Lake Estates near SW 316th PI
Federal Way, Washington
Job Date: Scale: Plate: 11
07117 April 2007 Not to Scale
Scope of Work
City of Federal Way
Mirror Estates Preliminary Plat Engineering Review
Amendment to Otak Project No. 30879E
Proposal for Professional Services
July 12, 2007
Scope of Work
The following scope of work and cost estimate was developed by Otak, Inc. (Otak) to review revised
documents (submitted on May 21, 2007) for the Mirror Estates Preliminary Plat Engineering Review
(Permit # 07-102761-00-EN; Mirror Estates). This scope of work includes: reviewing the
documents listed below for conformance with project conditions; preparing a memorandum of
findings and request for additional information; attending a meeting; reviewing final documents;
preparing a final memorandum of conformance; and project management.
This is a not -to -exceed cost estimate and the client will be billed as hours are accrued. All in-house
reimbursable costs (such as copies, reproductions, facsimiles, etc.), and any out -of -house direct costs
(such as mileage), will be in addition to the labor fee and will be invoiced at cost plus ten (10)
Percent.
Because this scope of work is an amendment to the previous Otak scope for reviewing the Mirror
Estates Process IV application, the task numbers below are a continuation from that previous scope.
Task 5—Review Re -submittals
Otak will review the documents provided by the City for conformance with the Hearing Examiner's
Conditions of Approval. Those documents include:
• Letter from Simone Oliver, LA, of Altman Oliver Associates, Inc., to Deb Barker, City of
Federal Way, Re: Mirror Estates — 30879E Wetland Mitigation Revisions per Otak's 1/19/07
Letter, dated May 18, 2007;
• Technical Information Report (TIR) Mirror Estates, by Jerrit Jolma, P.E. of J3ME, dated March
30, 2007;
• Description of Stormwater Modification Request dated May 16, 2007;
• Geotechnical Engineering Study prepared by Zach J. Munstermann and Marc McGinnis, P.E. of
Geotech Consultants, Inc., dated April 19, 2007;
• Wedand Mitigation Plan, Sheets W1.1, W2.1, W3.1, and W4.1 prepared by Altman Oliver
Associates, LLC dated May 18, 2007;
Mirror Estates: Preliminary Plat Engineering Review
otak
\\Kirae0l \prof\projcct\30800\30879E\Contract\30879E 07_0711 amendment SOW.doc
Scope of Work
Continued
Mirror Estates Civil Engineering Plans, Sheets 1 through 13, prepared by Jerrit Jolma, P.E. of
J3ME, dated March 30, 2007;
Technical Memorandum from Suzanne Bagshaw of Otak to Deb Barker, City of Federal Way,
regarding Mirror Estates: Review of Revised Mitigation Plan, dated January 19, 2007; and
Hearing Examiner's Decision for the Mirror Estates project.
Task 6—Prepare Memorandum of Findings
Otak will prepare a memorandum of findings summarizing our review of the re -submittals for
conformance with the Hearing Examiner's Conditions of Approval. The memorandum will identify
any necessary additional information.
Task 7— Meeting (optional)
At the request of the City and the applicant, Otak staff will attend a meeting to discuss the review
(Task 5) and memorandum of findings (Task 6).
Assumptions:
• The meeting will last for two hours. If the meeting lasts longer than two hours,
additional time will be approved by the City of Federal Way and the applicant at the time
of the meeting, and will be billed by Otak on a time and materials basis.
• The meeting will be held either onsite or at Federal Way City Hall.
• This task includes travel time for Otak staff.
• This task does not include preparation of a meeting memorandum.
Task 8—Review Final Documents
Otak will review documents submitted by the applicant in response to the memorandum of findings
prepared under Task 6 and the meeting under Task 7.
Assumptions:
• This review will cover only one set of revised documents.
• This set of revised documents will have addressed all issues raised in the memorandum
of findings prepared under Task 6.
Task 9—Prepare Final Memorandum of Conformance
Otak will prepare a final memorandum of conformance confirming that the documents reviewed
under Task 8 conform to conditions in the Hearing Examiner's report.
Task I O—Project Management and Coordination
This task will include general project management, team coordination, and coordination with City
staff.
Mirror Estates: Preliminary Plat Engineering Review
otak
\\Kirae01\proj\project\30800\30879E\Contract\30879E 07_0711 amendment SOW.doc
Scope of Work
Continued
Fees
Our proposed fee summary is as follows:
Task 5—Review Re -submittals
$840.00
Task 6—Prepare Memorandum of Findings
$1,1 13.00
Task 7—Meeting (optional)
$ 420.00
Task 8—Review Final Documents
$ 630.00
Task 9—Prepare Final Memorandum of Conformance
$ 625.00
Task I0—Project Management and Coordination
$ 420.00
Estimated Project Reimbursables
$ 75.00
Proposed Fee Total $4,123.00
Budget
We estimate that we can complete the above scope of work on a time and materials basis for a
budget not to exceed $4,123.00. The project team will not exceed this budget without prior approval
from the City of Federal Way. If conditions are found that are different from those described to us
or from those specified in the assumptions above, Otak will notify the City of Federal Way
immediately and discuss any impacts to the scope of work and budget.
Mirror Estates: Preliminary Plat Engineering Review
3
otak
\\KiraeO] \proj\project\30800\30879E\Contract\30879E 07_0711 amendment SOW.doc