HomeMy WebLinkAboutBLD-2025-0358 - RESIDENTIAL SINGLE FAMILY BUILDING (3) Storm Water Drainage Report
Minimum Requirements 1 through 5
lo
f ENGINEERING DEPARTMENT
4v 904 6t"Street Anacortes, WA 98221
www.anacorteswa.gov
Official Use Only: (Information to Inspectors)
Required Storm Water Facility and other related requirements:
Project Address: 3913 ROCK RTDGE PKWY � ` 125
Parcel Number: P127674 evi
Permit Number: BLD-2025-0358 Reviq `. _,aurn
Accept `i ce b t "(C0A):
FRONT OF REPORT: Stormwater Review
Submittal Checklist: (All items listed below are required for a complete submittal)
o Cover Sheet (Preparer to Provide): Project title, Location, Revision dates, Engineer's Stamp
o TAB 1: Minimum Requirement#1 — Preparation of Stormwater Site Plans
o TAB 2: Minimum Requirement#2 — Construction Stormwater Pollution Prevention (SWPP)
o TAB 3: Minimum Requirement#3 — Source Control of Pollution
o TAB 4: Minimum Requirement#4 — Preservation of Natural Drainage Systems and Outfalls
o TAB 5: Minimum Requirement#5 — On-site Stormwater Managements
o APPENDIX 1 - Survey performed by a Professional Land Surveyor
o APPENDIX 2 - Soils Analysis (Volume 1, Chapter 3.1.1)
o APPENDIX 3 - Model Soil Management Plan for BMP T5.13
o APPENDIX 4 - Determining Construction Site Sediment Damage Potential (Appendix 7)
o APPENDIX 5 - Site Plan with all applicable information (Minimum Size 11x17 —30 scale)
o APPENDIX 6 - Documented Site Photos (North, South, East and West)
o APPENDIX 7 - Drainage BMP Facility Maintenance Covenant, if applicable. To be recorded prior to the
Temporary Certificate of Occupancy, Certificate of Occupancy or Final Acceptance.
o APPENDIX 8— Maintenance and Operations Manual
o APPENDIX 9— Geotech Report
Stormwater Management Requirements:
o Refer to the 2019 Department of Ecology Manual - 2024 manual will be adopted soon
o See also, City of Anacortes Municipal Code 19.76 for additional information
o See also, current Engineering Development Standards, Chapter 2- Storm Drainage for additional
information.
Version date:07/26/24 Page 1
Lot size listed on site
Project Description and Summary plan is 7,765.65 SF
Summary Table
Existing Proposed
Development Type Residential SFR
Number of Lots
Lot Acreage in SF 7,525.11 SQ.FT. 7,525.11 SQ.FT.
Soil Type(s) ed e.
Site Sediment Transport Score (High\Low) >100
Depth to Ground Water Table (Feet and Inches)
(See completed Soils Analysis (Volume 1, Chapter 3.1.1)
Infiltration Rate during Rainy Season (Inch\Per Hour)
Impervious Surface (on-site) 0 (NOT COUNTING THAT 4,200.66 SQ. FT.
THE LOT IS MOSTLY ROCK
Impervious Surface (off-site) 90 SQ. FT.
New and Replaced Hard Surface Total (SF) Lot coverage listed on site FT.
Lot Coverage (Percentage) plan is 2 705.85 SF (34.84%) 2,8.5%). SQ.FT.
' 28.5% . . J
BMP (Required Minimum Requirement 5) BMP T5.13 o n Soils
Water Quality Method (Minimum Requirement 6) N/
Water Quantity Method (Minimum Requirement 7) N/
Existing Site Conditions Summary:
(Additionally, provide information on previous permits, if any, like Grade and Fill, Clear and Grade, topography,
vegetation, drainage, Critical Areas adjacent to the site and how it may affect this project if soils are disturbed,
Soils Type (Included in Soils Analysis Report), Erosion Problem Areas, Construction PhasinglSequence)
• The site was developed under the Rock Ridge South, Phase 3, which has all the appropriate permits and has been
accepted by the City of Anacortes Council and has been recorded.
• The site is sloping mostly from the SW to WNW.
• The site is part of a common plan development. The development has the detention pond upsized for flow control
for Rock Ridge Phase 3. The report is part of the recorded subdivision and covered in Minimum Requirements
1,3,4,5,67,8, and 9 for each lot. This project is submitting Minimum Requirement 1-5.
• A soils analysis was not done for this site as it is solid rock and is identified as impervious surface. We do have a
soil analysis for the entire development that was done and that is attached. As the development is rock though, the
report has minimal information. See Appendix 6 for photos demonstrating rocky conditions.
• There are no known critical areas on this site and no known erosion issues that might impact construction.
• Construction Plan: Install erosion and sediment BMP's, Minor rock excavation, Install ftg's/foundation, Construct
home, Connect utilities, install MR##5 BMP, Backfill of site BMP T5.15 post construct., soils, landscaping, driveway
etc. see appendix— Model Soil Management Plan for BMP T5.13
Developed Conditions Summary:
(Additionally, to be shown on the site plan. Identify cut and fill areas, proposed slopes of all hard
surfaces , proposed contours)
See site plan for contours
Drainage Basin (2007 Storm Comp Plan — City website\publicworks\engineering\comprehensive plans): What
Drainage Basin are you in? G8 Identify any downstream drainage issues Yes, Identified (Storm Comp Plan), If so,
describe:
Problem Area #l13— Oaks Avenue and Georgia Avenue
Problem: A natural depression exists on a parcel that will soon be developed. A pipe drains the depression to the
North side of Oakes Ave.
Version date:07/26/24 Page 2
Solution: Install a trash rack like that described for Area #5 to keep pipe inlet clear of debris.
Eg§ponse. The natural depression was filled in revising the natural drainage path for this parcel insofar as raising
the elevation. The natural discharge is still at the same location. This issue has bee resolved with development and
does not affect this project.
Problem Area #28— Kansas Ave. and West 6111 Street
Problem: A shallow manhole is located at the intersection.
Solution: The City has preliminary plans for the new storm system in this area. The new system will divert existing
flows to Illinos Ave. The downstream system should be analyzed for capacity
Complete the Applicability Requirements — Flow Chart (See next page(s)
- Highlight the path and attach
- Add a map of where your stormwater goes from your project to the discharge site
Version date:07/26/24 Page 3
City of Anacortes Engineering
PO Box 547, Anacortes,WA 98221
Telephone:360.293.1920
`?60)
Construction Completion Report
In accordance with City of Anacortes (COA) procedures, a Construction Completion Report is required for all
approved construction projects. Engineers of Record must submit a Construction Completion Report to the City of
Anacortes within twenty(20)days of completion and before use of any third party constructed facilities including;
but not limited to grading, streets, sidewalks, water lines, sanitary and storm sewers and related items.
Please type or print legibly in ink:
Name of Project or Development
Owner or Project Contact Name COA Project No.
Mailing Address Date Construction Documents Approved by COA
City State Zip
Phone Number E-Mail Address
PROJECT NAME AND DESCRIPTIVE TITLE
Check one:
❑ Entire Project Completed. ❑ Description of Portions Completed
Complete(Attach additional sheets as needed)
PROFESSIONAL ENGINEER'S ACKNOWLEDGEMENT
The undersigned professional engineer(PE), or their authorized agent has inspected the above-described project
in its entirety and the project has been constructed and is substantially completed in accordance with the
construction plans and specifications approved by the COA. In the opinion of the undersigned engineer, the
installation, and physical testing procedures were carried out in accordance with COA construction standards and
principles of standard engineering practice. I have reviewed the following:
❑ disinfection procedures sewer air pressure test pressure test results
❑ ❑
❑ alignment videos sewer/storm paving/asphalt structures sewer/storm
❑ results of the bacteriological test(s) ❑ permanent stormwater facilities
for this project and certify that they comply with the requirements of the construction standards/specifications
approved by the COA. (Check all boxes that apply that are consistent with the nature of this project.)
Date Signed
P.E.
SEAL Engineer's Signature
9
State/Federal Funding Type (if any)
Version date:07/26/24 Page 4
Figure 1-3.1: Flow Chart for Determining Requirements for New
Development
$tart Does all stormwater runoff Yes The UIC Rule (Chaptei" 173-218 WAC)
Here frorn the Project Site discharge applies. Refer to 1-4 UIC Program
to a Class V UIC Well? Guidelines for UIC Program Requirements.
t fr
Do
to
e
the
e
a
all
P Class s
0's
j or
Pro
ject't S
s V L
No
s S I e �i See Redevelopment Project
a r I
e ,Does the Site have 35% Yes Thresholds and the Figure "Flow
or more
f x I st I g existing
xi
or more of e isting hard
surface
ov 9 9 Chart for Determining
ov
Urface coverage? Requirements for Redevelopment".
No
Does the Project result in 2,000 square feet or more of new plus replaced hard Surface area?
OR
Does the land disturbing activity total 7,000 square feet or greater?
� Yes No
Minimum Requirements#1 IF
through#5 apply to the new
and replaced hard surfaces Minimum Requirement#2 applies.
and the land disturbed.
Next Question
Does the Project add 5,000 square feet or more of new plus replaced hard Surfaces?
OR
Convert X acres or more of vegetation to lawn or landscaped areas?
OR
Convert 2.5 acres or more of native vegetation to pasture?
Yes No
All Minimum Requirements IF
apply to the new and replaced No additional requirements
hard Surfaces and converted
vegetation areas.
Flow Chart for Determining Requirements for
DEPARTMENT OF New Development
ECOLOGY
State of Washington Revised September 2022
2024 Stormwater Management Manual for Western Washington
Version date:07/26/24 Volume /-Chapter 3-Page 109 Page 4
Figure 1-3.2: Flow Chart for Determining Requirements for
Redevelopment
Start Does all stormwater runoff from the Project Site Yes The UIC Rule(Chapter 173-218 WAC)applies.
......................... discharge to a Class V UIC Well? Refer to 1-4 UIC Program Guide'linos for UIC
Here Program Requirements.
No
Does the Site have less than 35% Yes See New Development Project Thresholds and
of existing hard surface coverage? 10 the Figure"Flow Chart for Determining
I Requirements for Now Dovolopmeol".
No
Does the Project result in 2,000 square feet or more of new plus replaced hard surface area?
OR
Does the land disturbing activity total 7,000 square feet or greater? I
Yes No
Minimum Requirements#1 through#5 apply to the new
I
and replaced hard surfaces and the land disturbed.
Mnm-u--I Requirement#2 applies.
Next Question
Does the Project add 5,000 SCIIJare feet or more of new hard SLJrfaCeS? All Minimum
OR Yes Requirements apply to
ConvertY,acres or more of vegetation to lawn or landscaped areas? the new hard surfaces
OR and the converted
Convert 2.5 acres or more of native vegetation to pasture? vegetation areas.
No Next Question
Is this a road related project? —J
Does the Project add 5,000 square feet or morp Of new PILIS
replaced hard surfaces?
Yes AND
No Does the VaILIP of the proposed improvements-including
interior improvements-exceed 50%Of the assessed value
(or replacement value)of the:
* existing Project Site improvements?(for
Does the Project add 5,000 sqUare feet or more of new commercial or industrial projects)OR
PIUS replaced hard surfaces? * existing Site improvements?(for all other projects)
AND
DO the new Plus replaced Ihard surfaces total 50%or No
more of the existing hard surfaces within the Site'?
No Is the project on a commercial or industrial Site?
AND
No Does the Project add 5,000 square feet or more of new
No additional PIUS replaced hard surfaces?
Yes requirements. AND
Do the new plus replaced hard surfaces total 50%or more E�D- Yes
of the existing hard surfaces within the Site?
L————
�Yes
All Minimum Requirements apply to the new and replaced hard surfaces and converted vegetation areas.
Flow Chart for Determining Requirements for
DEPARTMENT OF Redevelopment
ECOLOGY
State of Washington Revised April 2024
2024 Stormwater Management Manual for Western Washington
Version date:07/26/24 Volume /-Chapter 3-Page 110 Page 5
TAB 1 (MINIMUM REQUIREMENT#11)
The site iS part Cf a common plan development. The development has the detention pond Upsized for flow control
for Rock Ridge Phase 3. The report is part of the recorded subdivision and covers Minimum Requirements
1,3,4,5'67A and 9 for each |Q1.
° 1-3.4.1 Minimum Requiremnent#1 — PmmpammaStormnwaterSitmP|an
Note: The level of detail needed for each step depends upon the project size. Provide a narrative
description of each step.
Step I —Analyze Existing Stie Conditions to Determine LID Feasibility
The existing site analysis is intended to determine the pre-development conditions on the site in
addition to determining the appropriateness for use of Low Impact Development (LID) techniques.
Site conditions as identified in this step will determine the feasibility of the overall atormvvater
design including use of LID techniques. The development context shall be established by an
existing site analysis consistent with the requirements detailed in this Step.
The initial inventory and analysis process will provide baseline information necessary to design
strategies that utilize areas most appropriate to evaporate, tranopire, and infi|trateetormvvater.
and achieve the goal of mimicking the pre-development natural hydrologic conditions on the site.
The existing site analysis shall inn|ude, at nnininnurn, the following information:
1. A survey prepared by a registered land surveyor, civil engineer, or other qualified
professional showing: (See this section for additional items toinclude)
2. A soils report prepared by a professional soil scientist certified by the Soil Science Society of
America (or an equivalent national program), or by other suitably trained persons working
under the supervision of professional engineer, geo|ogiet, hydrogeo|ogiot, or engineering
geologist registered in the State ofWashington.
The site iBpart of a common plan development. The development has the detention pond upsized
for flow control for Rock Ridge Phase 3. A survey has been prepared byB registered land
surveyor and provided in the permit package. Also, drainage reports for common plan of
development have been provided.
Per the provided Geotech report and site inspection, the site iSprimarily bedrock and has no real
collection of soil. See pictures under Appendix 6 and Geotech report under Appendix 9. There is
little to no infiltration on site. Concentrated Flow Dispersion measures are infeasible. Project will
be tying the st0rrnVVBter1ight|ine for the house into the city provided storrnYVa1ersys1ern stub-out.
The Site is flow-control exempt and should provide no difficulties in tying into Btorrnvva1ersys1ern.
Based upon the existing site analysis results, locate the hui|dings, roads, parking lots, landscaping
features, LID BMPs, and preliminary location of Runoff Treatment and Flow Control BIVIPs for the
proposed development. Consider the following points when laying out the site:
° Fit development to the terrain to minimize land disturbance; confine construction activities to
the least area necessary, and away from critical areas.
° Preserve areas with natural vegetation (especially forested areas) as much as possible.
~ On sites with a mix of soil types, locate impervious areas over less permeable soil (e.g., till),
try to restrict development over more porous soils or take advantage of them by locating
hioratandon. rain gardens and/or permeable pavement over them.
Version date:o7/zo/z4 Page
• Cluster buildings together.
• Minimize impervious areas.
• Maintain and utilize the natural drainage patterns.
The site plan has been designed to be as efficient as possible and provided under Appendix 5.
Roads, buildings, driveways, etc. have been laid out in the most economical way possible due to
the site being entirely bedrock and sloped significantly for the most part.
Step 3 - Perform Off-site Analysis
City of Anacortes requires an off-site analysis for projects that add 5,000 SF or more of new
hard surfaces, or convert 3/4 acres of vegetation to lawn or landscape areas, or convert 2.5
acres of forested area to pasture.
Off-site analysis extends to '/4 mile downstream of the project site.
The site is part of a common plan development. The development has the detention pond upsized
for flow control for Rock Ridge Phase 3. The report is part of the recorded subdivision and covered
Minimum Requirements 1,3,4,5,6,7,3, and 9 for each lot. Original drainage reports have been
submitted again for review.
Site does not add more than add 5,000 SF or more of new hard surfaces, or convert 3/ acres of
vegetation to lawn or landscape areas, or convert 2.5 acres of forested area to pasture.
Step 4 — Determine and Read the Applicable Minimum Requirements (Place at the front end of
the document before MR#1)
1-3.3 Applicability of the Minimum Requirements establishes project thresholds for the
application of Minimum Requirements to new development and redevelopment projects. Figure
1-3.1: Flow Chart for Determining Requirements for New Development (Included in the report)
and Figure 1-3.2: Flow Chart for Determining Requirements for Redevelopment (Included in
the report) provide the same thresholds in a flow chart format. Based on the preliminary
layout, determine whether Minimum Requirements #1 and #2 only apply to the project, or#1
through #5 only apply to the project, or#1 through #9 apply.
Minimum requirement#1-#5 are needed for this project.
Step 5 - Prepare a Permanent Stormwater Control Plan (Place in Appendix 5 of this report)
(Due to the extent of required information for this section, refer to this section of the Ecology
Manual for requirements.)
The site has been assessed, and a permanent stormwater control plan has been developed. The
developed site plan has been submitted with the permit package and is included in this document.
Step 6 - Prepare a Construction Stormwater Pollution Prevention Plan (Place in MR#2 — 13
Elements)
The Construction SWPPP for projects adding or replacing 2,000 square feet of hard surface or
more, or clearing 7,000 square feet or more, must contain sufficient information to satisfy the
local government Plan Approval Authority that the potential pollution problems have been
adequately addressed for the proposed project. Local governments may adopt a standard
SWPPP format for use by projects less than 1 acre. An adequate Construction SWPPP
includes a narrative and drawings. The narrative is a written statement to explain and justify the
pollution prevention decisions made for a particular project. The narrative contains concise
information concerning existing site conditions, construction schedules, and other pertinent
Version date:07/26/24 Page
items that are not contained on the drawings. The drawings and notes describe where and
when the various BMPs should be installed, the performance the BMPs are expected to
achieve, and actions to be taken if the performance goals are not achieved.
See 1-2.4 Preparing Construction SWPPPs for details about what to include in the project's
Construction SWPPP.
A detailed SWPPP has been put together and is included in this document as well as aspects
being shown on the site plan.
Step 7 - Complete the stormwater site plan
The Stormwater Site Plan encompasses the entire submittal to the Local Agency with drainage
review authority. Refer to this section of the Manual for further clarification of each item
and what is required. See below:
A. Project Overview (Front End)
B. Existing Conditions Summary (Front End)
C. Off-site Analysis Report (Minimum Requirement 1, Step 3)
D. Permanent Stormwater Control Plan (Appendix 5)
E. Construction Stormwater Pollution Prevention Plan (Minimum Requirement 2)
F. Special Reports and Studies (Survey—Appendix 1, Geotechnical —Appendix 2, all
others placed after Appendix 8)
G. Other Permits, if applicable
H. Operation and Maintenance Manual (Appendix 8)
1. Declaration of Covenant for Privately Maintained Flow Control and Treatment Facilities.
(See attached Drainage BMP Maintenance Covenant BMP Agreement) (Appendix 7)
J. Declaration of Covenant for Privately Maintained On-site Stormwater BMP's (See
attached Drainage BMP Maintenance Covenant BMP Agreement) (Appendix 7)
K. Bond Quantities Worksheet, if applicable
Stormwater site plan is complete.
Step 8 - Check Compliance with all Applicable Minimum Requirements
Before Submitting this report, a Stormwater Site Plan as designed and implemented should
specifically fulfill all Minimum Requirements applicable to the project. The Stormwater Site Plan
should be reviewed to check that these requirements are satisfied.
Note: The report will be returned if determined incomplete.
Everything has been reviewed and to the best our ability and knowledge is complete and all
requirements are satisfied.
Version date:07/26/24 Page
W—WF
PLANNING, COMMUNITY,& ECONOMIC DEVELOPMENT DEPARTMENT
Moiling Address:P.O. Box 547,Anocortes, WA 98221
Office Location:904 6ah Street, Anocortes WA 98821
Phone: (360)293-1901
Weekly Erosion Control Self-Inspection Reports
All sites that have a Stormwater Pollution
acorn Prevention Plan #2, 1-5 or 1-9 are required to
submit a weekly erosion control/BMP monitoring
I inspection report through the citizen portal.
These reports can be found on the city website
and through the link on the submittals tab in the
permitting customer portal.
Il o N IN
PwrvOt Subrnfttals HMOhMpR60'VuiuM'f'*u 4'mir7(e6Nu*m;6M�M iMAIW�Ie_wu;*1'eff LNoTComplete�e Turning in the
weekly report
u""erU r i9N4 v r5D imd 4oPr.;,s fY� �yr�e'drr mf'o rva dd:J a 0$4
uRi°Vw,sl 1sir.r�r,�,�;r ry..i(" M sA" NWY. Ve r n V .,.A. N1 ! 6r') 56"0 11,9ux a,r v tN consistently will
help keep your
project on
schedule and
avoid unnecessary
r� xt�� NAw:o � to� GUU Mdot..wrr�Nml�rm rgvrt ��ti.�:q�� iu .t delays due to
mrea ear Nl rwu 1Nu ,�w„aa�rt: r lk r,m,p� ul �rNi; cancelled
w' inspections.
�'-�'i,uNx.ams i�isV.�`��ae i6UdV'¢�r�a ufi�.rn�v,UQril Nri�lf�swrr.,Piir�r rV��g p, Vu,arva rrr'�v�:'�H°arAirO`� i>wt��s � C�N'fns�Nirr.�i?� +,�luloiur��
���rc�,,,i YrViJr.�r,�a4vnri�,a�w'u��w�ill,�uw�r��,�bur�,rhr� ��I�rcRsa�oeu�.o�wll^��lu>t��r
i"0r4ffnk"i1110Jrirr. t,nuaiV lie aitadd�,"'v ,rPus.ry tin FV (wrflexuler^i6Ok",�,
Olin Mwt
Eiresiien-Contiroll Ilins ectiiein-IFoirirrr�...._ iites II...ess Than Cane- care fiillllable IPI�I� anaceir eswa. �v
................................................................................................................... ..................................................................................................................................................................................................................................................................................................................................................................................................... ...............�.
St®.irmw :�.e.t:... o.:�e....�..irk.sp..tgjtioir�....F.o.t. .....�. .0. . o s ..g y.�. (For larger sites)
We appreciate your assistance in keeping our documentation up to date.
Version date:07/26/24 Page
TAB 2 (MINIMUM I E T )
• 1-3.4.2 Minimum Requirement#2 — Construction Stormwater Pollution Prevention Plan(SWPP)
All new development and redevelopment projects are responsible for preventing erosion and
discharge of sediment and other pollutants into receiving waters.
Projects which result in 2,000 square feet or more of new plus replaced hard surface area, or which
disturb 7,000 square feet or more of land must prepare a Construction Stormwater Pollution
Prevention Plan (SWPPP) as part of the Stormwater Site Plan (see MR1: Preparation of Stormwater
Site Plans).
Projects below those thresholds (listed above) are not required to prepare a Construction SWPPP,
but must consider all of the Construction SWPPP Elements (listed below) and develop controls for all
Construction SWPPP Elements that pertain to the project site.
General Requirements:
The Construction SWPPP shall include a narrative and drawings. All BMPs shall be clearly
referenced in the narrative and marked on the drawings. The Construction SWPPP narrative shall
include documentation to explain and justify the pollution prevention decisions made for the project.
Each of the 13 Construction SWPPP Elements (listed below) must be considered and included in the
Construction SWPPP unless site conditions render the Element unnecessary and the exemption from
that Element is clearly justified in the narrative of the SWPPP.
Clearing and grading activities for developments shall be permitted only if conducted pursuant to an
approved site development plan (e.g., subdivision approval) that establishes permitted areas of
clearing, grading, cutting, and filling. These permitted clearing and grading areas and any other areas
required to preserve critical or sensitive areas, buffers, native growth protection easements, or tree
retention areas, shall be delineated on the site plans and the development site.
The Construction SWPPP shall be implemented beginning with initial land disturbance and until final
stabilization. Sediment and Erosion control BMPs shall be consistent with the BMPs contained in II-3
Construction Stormwater BMPs.
Seasonal Work Limitations: From October 1 through April 30, clearing, grading, and other soil
disturbing activities shall only be permitted if shown to the satisfaction of the local permitting authority
that silt-laden runoff will be prevented from leaving the site through a combination of the following:
1. Site conditions including existing vegetative coverage, slope, soil type and proximity to
receiving waters; and
2. Limitations on activities and the extent of disturbed areas; and
3. Proposed erosion and sediment control measures.
The following activities are exempt from the seasonal clearing and grading limitations:
1. Routine maintenance and necessary repair of erosion and sediment control BMPs,
2. Routine maintenance of public facilities or existing utility structures that do not expose the soil
or result in the removal of the vegetative cover to soil, and
3. Activities where there is one hundred percent infiltration of surface water runoff within the site
in approved and installed erosion and sediment control facilities.
Version date:07/26/24 Page
Construction Stormwater Pollution Prevention Plan Checklist
Project Mune-
City ReferenceNo.
Constniction Pennit N .
Review Date:
On-site Inspection Re-,iew Date:
C'on,.;;tnxtionS'�X?PP Reviewer.'
S# ton I—Constimcdon SNP? Naive i, tiv
Consti-mn'on Stormwater Pollution Pr#v anon Elements
Dmribe how each of the, Constnidion, St rm w itff Pollution Pieventim Elements
has weed thougli the e"" nstn t S ".
Identify the type mid location of BNIPsused tatf�the, reqWred element.
.. PIMide, INTittell j t flat li identifying, the reason aelementis not applicable to the
proposal-
TIdrte#n Requiled Elements_ Consftmcfion StormAvater Poflution Prev#ntion Plan.
Establish Constnirtion access
3. Cot&ol Flow,Kates
hist.-dI Sedinrut Controls
5 Stabihze Sol,
.. Protect Slopes
7. Protect Drams Inlets
. Stabilize Chmmcls and t" tet
Control Pollutants
Control, De-Watering
w Maintain BNPs
11 Protect Low Iinpact Development BN2s
Project Dextiption
. Total project area
Total use . pen o ae
3. Total r , zu ato be,distitbedd. including site borrow and,fill mrezas
4. Total voltunes of proposedcut - fill
Reiised Felmary01
Version date:07/26/24 Page
Eusdug site("Olubtious
L Description of the i tnn topography
I Description of the existing,vegetation
Description the existing,drzumige
.. Description of adjacent areas wbich may be affectedsite distiubance, or dn mi to
Inn ° t Site..
gin. Streams,
tn. Ls
. to
. Roads
f. Other
2. Description of the downstream drainage t o leading from the Site to the receiving
body of water. (Mininumi distance of 400 ynds.)
I. Description of chfical meal that me on or acent to tine site.
. Dewription of special n n, m nnts' for worIcing,inn Dr war critical zueas,
Soils
I Description of cc-site, Soils.
gin.. Soil
. " t mapping nut
.. Erodibility
Settleability
_ . , wabi t
If t
9. ' "ex nn
n. Soil Structure
Revised Febnixy 2016
Version date:07/26/24 Page
Erosion Problem Areas
Description polential ffosicni problems on site.
Constnxtion seqmice
areasConstruction Schedule
a, Proposed ivet season constnicticniactivities,
.
Finnn FO m i-ship Responsibilities
1 Identify the prop mresponsible for the auttation of bonds" amd/or othef
fu ciao.securities..
2_ Describe or other eMence of fimilicial responsibilityfor liability
associated with crosionand sedimentation iti4xIct .
. Sedinwnt aps
. Ehvmions
C. watemays
d.. Rim fSt , mat x Detention Cak-Wations
Reused Febmmy 2016
Version date:07/26/24 Page
Section 11-Erosion and Sediment Control Plans
General
al
l,. Vicinity t
2, City/Cotinty of Clearmg=1 Gra(,hng Approval Block
3 Erosion and S cli s rrrt Control Notes
Site Plan
1.. Note legptl desciiption ofstibject pr jvrl�r-
mNrth - s .
. Indicate Marc&ra s of existing vegetation, e,g, try lures, pastirezueas, etc.
Identify label re��s f potential erosion ro lerars.
Identify ar-site or adjacentnittace waters. critical ue s and associated buffers.
Identify FEMA base flood boa caries and Shoreline Maingenient loraard ies
(if Wline .
. Sliow existing and proposed contoirs.
. ira is ate drainage basins zuid direction w for individual draimage areas..
9. Libel el anal grade contours xid i t , tier eloped ccxaltion draiinge b asi s.
It .. Delineate, areas that are to be cleared and graded,
i . Show ss°all cut and fill slopes indicating top and bottcnn of slope catch lames.,.
Conveyance Svstelns
I Desigmte locations for sw°ales, interceptor trenches, or ditches.
. Sloan all tern Para y and pennmew drainage,e, pipes. ditches„ or cut-off trenches
r '�re,d for erosion and sedunent control.
. Provide nii=nun slope and cover for all tempo..7 pipes or call out pipe inverts.
Show grades, dimensiom, md direction f floss in all clitclresm s°as°ales,culverts wid
ils.,
. Provide details for bypassing off site nuloff aroiuid distuxt)ed areas.
.. Indicate locations grid outlets of my flew atering s sternsLocation of Detention B]NIPs
1 klentify location of detention BNVs.
`sed el ran illti
Version date:07/26/24 Page
Erosion and , inn t nntrol Facilities
Show the locafions of'sedinlent t n , p ), pipes mid tn Lures.
. Dfinension pcmd bemi widths mkiaiside and cnitsidepond slopes.
. hidicate the trap/pond-simige rftjnitredEnid the nth. length. and width dimemions.
Provide t*cAsection nnr through pond and outlet stnicture.
.. Provide,typical nails of gravelmid stun n , aud/or other filtering � , ices.
Detail stabilization techniques for outlet/inlet.
Detail t l/ est i tor device location aid details,,
.. S i t mulch an&or reconinmided come ofl and sl es..
9m Ptovide rock specificationsand detail for rock check&m'*,$), if alTlicable.
M S e n s a nnng foT rock nos as required,
. Provide front anntl sidesections of typical rock check
11 Indicate the locations annul provide details and specifications forsift fabric.
11 Locate the c nnmst nnct% nn entmiceand provide a detail..
Detailed Dira nn nn s
1, _. nor st ,nctn A practices used tivit any not referenced in the Ec l y m it,s td
be explained illustrated itln detailed drawitigs..
Others, Pollutant BUN
l. Indicate on the site plan the location ofBMPs to be used for the mitrol of pollutants
nnit n , g Loci-nti nn.s
l.. Indicate on the site plan the wraterqtWity s .0 l nng,locatims to be n,n;sed for
momtorbig water quAiq,on the constniction site. if applicable.
Reiised,February 16
Version date:07/26/24 Page
13 Elements of SWPPP
(Construction Stormwater Pollution Prevention Plan)
Please check off boxes to show that each element has been read and understood. Provide details where
applicable and if certain aspects are unnecessary or exempt, clearly justify. Details of the 13 Elements and
the correlating BMPs are listed Above from the 2019 Stormwater Management Manual for Western
Washington (SWMMWW). A link is provided on the City of Anacortes website, under Planning, Community, &
Economic Development Department, as well as under Stormwater on the Engineering Division of Public
Work's page.
Owner Name: Owen Moon
Site Address: 3913 Rock Ridge Parkway,Anacortes,WA 98221
Prepared By: Jason Sterling
The Stormwater checklist or building permit determined that:
E The 13 elements must be addressed for These elements must be addressed
construction activity adding under for construction activity adding 2,000
2,000 sq. ft. of hard surface area. sq. ft. or more of hard surface area.
This means that an attached narrative
and site plan are required with this
document.
Under each element, provide the BMP's that will be applicable to Your protect. Use the attached Tables
provided.
ELEMENT 1: Preserve Vegetation/Mark Clearing Limits
Before beginning land disturbing activities, including clearing and grading, clearly mark all clearing
limits, sensitive areas and their buffers, and trees that are to be preserved within the construction area.
I Retain the duff layer, native top soil, and natural vegetation in an undisturbed state to the maximum
degree practical.
Suggested BMPs for Element 1:
• BMP C101: Preserving Natural Vegetation
• BMP C102: Buffer Zones
• BMP C103: High-Visibility Fence
• BMP C233: Silt Fence
How did you comply with this section?
A hi h visibilitga construction fence will be installed at the North, West, East and South lot boundary. This will be
installed rior to be innin construction. BMP to be monitored dail and re aired as needed.
Version date:07/26/24 Page
ELEMENT 2: Establish Construction Access
Limit construction vehicle access and exit to one route, if possible.
Stabilize access points with a pad of quarry spalls, crushed rock, or other equivalent BMPs, to minimize
tracking onto roads.
Locate wheel wash or tire baths on site, if the stabilized construction entrance is not effective in
preventing tracking sediment onto roads.
If sediment is tracked off site, clean the affected roadway thoroughly at the end of each day, or more
frequently as necessary (ex: wet weather). Remove sediment from roads by shoveling, sweeping, or
pick up and transport the sediment to a controlled sediment disposal area.
Conduct street washing only after sediment is removed in accordance with the above bullet.
Control street wash wastewater by pumping back on site or otherwise preventing it from discharging
into systems tributary to waters of the State.
Additional Guidance for Element 2
Minimize construction site access points along linear projects, such as roadways. Street washing may
require local jurisdiction approval.
Suggested BMPs for Element 2:
• BMP C105: Stabilized Construction Access
• BMP C106: Wheel Wash
• BMP C107: Construction Road / Parking Area Stabilization
How did you comply with this section?
Per BMP C105 a Stabilized Construction Entrance will be installed. Vehicle traffic to the construction site will
be limited to one route° Any dirt or mud that is tracked onto the roadway will be clean immediately. Will use the
lower driveway as entrance. To be installed prior to construction. BMP to be monitored daily and repaired as
needed.
ELEMENT 3: Control Flow Rates
Protect properties and waterways downstream of development sites from erosion and the associated
discharge of turbid waters due to increases in the velocity and peak volumetric flow rate of stormwater
runoff from the project site.
Where necessary to comply with the bullet above, construct stormwater retention or detention facilities
as one of the first steps in grading. Assure that detention facilities function properly before constructing
site improvement (e.g. impervious surfaces).
If permanent infiltration ponds are used for flow control during construction, protect these facilities from
siltation during the construction phase.
Version date:07/26/24 Page
Additional Guidance for Element 3
• Conduct a downstream analysis if changes in flows could impair or alter conveyance systems,
streambanks, bed sediment, or aquatic habitat. See III-3.2 Preparing a Stormwater Site Plan for off-site
analysis guidelines.
• Even gently sloped areas need flow controls such as BMP C235: Wattles or other energy dissipation /
filtration structures. Place dissipation facilities closer together on steeper slopes. These methods
prevent water from building higher velocities as it flows downstream within the construction site.
• Control structures designed for permanent detention BMPs are not appropriate for use during
construction without modification. If used during construction, modify the control structure to allow for
long-term storage of runoff and enable sediment to settle. Verify that the BMP is sized appropriately for
this purpose. Restore BMPs to their original design dimensions, remove sediment, and install a final
control structure at completion of the project.
• Erosion has the potential to occur because of increases in the volume, velocity, and peak flow rate of
stormwater runoff from the project site. The local permitting agency may require infiltration or detention
BMP designs that provide additional or different stormwater flow control than the designs detailed in
this manual. These requirements may be necessary to address local conditions or to protect properties
and waterways downstream.
• Velocity of water leaving the site should not exceed 3 feet/second, if the discharge is to a stream or
ditch. Install velocity dissipation, such as BMP C207: Check Dams or BMP C202: Riprap Channel
Lining to ensure reduction of the flow velocity to a non-erosive level.
• If the discharge from a project site is to a municipal storm drainage system, the allowable discharge
rate may be limited by the capacity of the public system. It may be necessary to clean the municipal
storm drainage system prior to the start of the discharge to prevent scouring solids from the drainage
system. Obtain permission from the owner of the collection system before discharging to it. Ensure that
no downstream pipes are surcharged as a result of increased flows from the project site.
• If the discharge from a project site is directly to a flow control exempt receiving water listed in Appendix
I-A: Flow Control Exempt Receiving Waters or to an infiltration system, there is no discharge flowlimit.
Suggested BMPs for Element 3
• BMP C203: Water Bars
• BMP C207: Check Dams
• BMP C209: Outlet Protection
• BMP C235: Wattles
• BMP C240: Sediment Trap
• BMP C241: Sediment Pond (Temporary)
• See also V-12 Detention BMPs
How did you comply with this section?
Flow rates to be controlled by development design and BMPs. Applicable BMPs will be used to protect and
properties from erosion such as BMP C235 if necessary. There are no storm-water swales or retention facilities
to control.
Version date:07/26/24 Page
ELEMENT 4: Install Sediment Controls
Design, install, and maintain effective erosion controls and sediment controls to minimize the discharge
of pollutants.
Construct sediment control BMPs (sediment ponds, traps, filters, etc.) as one of the first steps in
grading. These BMPs shall be functional before other land disturbing activities take place.
Minimize sediment discharges from the site. The design, installation and maintenance of erosion and
sediment controls must address factors such as the amount, frequency, intensity and duration of
precipitation, the nature of resulting stormwater runoff, and soil characteristics, including the range of
soil particle sizes expected to be present on the site.
Direct stormwater runoff from disturbed areas through a sediment pond or other appropriate sediment
removal BMP, before the runoff leaves a construction site or before discharge to an infiltration facility.
Runoff from fully stabilized areas may be discharged without a sediment removal BMP, but must meet
the flow control performance standard in Element#3, bullet#1.
Locate BMPs intended to trap sediment on-site in a manner to avoid interference with the movement of
juvenile salmonids attempting to enter off-channel areas or drainages.
Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to
increase sediment removal, and maximize stormwater infiltration.
Where feasible, design outlet structures that withdraw impounded stormwater from the surface to avoid
discharging sediment that is still suspended lower in the water column.
Additional Guidance for Element 4
• Outlet structures that withdraw impounded stormwater from the surface to avoid discharging sediment
that is still suspended lower in the water column are for the construction period only. If installing a
floating pump structure, include a stopper to prevent the pump basket from hitting the bottom of the
pond.
• If a sediment trapping BMP utilizes a control structure that will also be used in a permanent detention
BMP application, the control structure construction must be finalized for the permanent BMP application
upon project completion.
• Install sediment controls in a manner that protects the sensitive areas and their buffers marked in
accordance with Element 1: Preserve Vegetation / Mark Clearing Limits.
• Where feasible, direct stormwater to vegetated areas to increase sediment removal and maximize
stormwater infiltration.
• Seed and mulch earthen structures such as dams, dikes, and diversions according to the timing
indicated in Element 5: Stabilize Soils.
• Full stabilization includes concrete or asphalt paving; quarry spalls used as ditch lining; or the use of
rolled erosion products, a bonded fiber matrix product, or vegetative cover in a manner that will fully
prevent soil erosion.
• The Local Permitting Authority may inspect and approve areas fully stabilized by means other than
pavement or quarry spalls.
Version date:07/26/24 Page
Suggested BMPs for Element 4:
• BMP C231: Brush Barrier
• BMP C232: Gravel Filter Berm
• BMP C233: Silt Fence
• BMP C234: Vegetated Strip
• BMP C235: Wattles
• BMP C240: Sediment Trap
• BMP C241: Sediment Pond (Temporary)
• BMP C250: Construction Stormwater Chemical Treatment
• BMP C251: Construction Stormwater Filtration
How did you comply with this section?
Per BMP C233 a silt fence will be installed on the lower section of the lot boundaries er the site plan. BMP
C220 I-40.20-00} and BMP C123 are also bein implemented as well as BMPs C105/107. To be installed prior
to the start of construction. BMP to be monitored dail and repaired as needed.
ELEMENT 5: Stabilize Soils
Stabilize exposed and unworked soils by application of effective BMPs that prevent erosion. Applicable
BMPs include, but are not limited to: temporary and permanent seeding, sodding, mulching, plastic
covering, erosion control fabrics and matting, soil application of polyacrylamide (PAM), the early
application of gravel base early on areas to be paved, and dust control.
Control stormwater volume and velocity within the site to minimize soil erosion.
Control stormwater discharges, including both peak flow rates and total stormwater volume, to minimize
erosion at outlets and to minimize downstream channel and stream bank erosion.
Soils must not remain exposed and unworked for more than the time periods set forth below to prevent
erosion.
o During the dry season (May 1 — Sept 30): 7 days
o During the wet season (Oct 1 —Apr 30): 2 days
Stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather
forecast.
Stabilize soil stockpiles from erosion, protect with sediment trapping measures, and where possible, be
located away from storm drain inlets, waterways, and drainage channels.
Minimize the amount of soil exposed during construction activity.
Minimize the disturbance of steep slopes.
Minimize soil compaction and, unless infeasible, preserve topsoil.
Version date:07/26/24 Page
Additional Guidance for Element 5
• Soil stabilization BMPs should be appropriate for the time of year, site conditions, estimated duration of
use, and potential water quality impacts that stabilization agents may have on downstream waters or
ground water.
• Ensure that gravel base used for stabilization is clean and does not contain fines orsediment.
Suggested BMPs for Element 5:
• BMP C120: Temporary and Permanent Seeding
• BMP C121: Mulching
• BMP C122: Nets and Blankets
• BMP C123: Plastic Covering
• BMP C124: Sodding
• BMP C125: Topsoiling /Composting
• BMP C126: Polvacrylamide (PAM) for Soil Erosion Protection
• BMP C130: Surface Roughening
• BMP C131: Gradient Terraces
• BMP C140: Dust Control
How did you comply with this section?
Stabilize exposed and unworked soils by application of effective BMPs that prevent erosion. Applicable BMPs
may include but are not limited to: BMP C120 tempora and ermanent seedin BMP C124 sodding, BMP
C121 mulchin , BMP C123 lactic coverin , erosion control fabrics and mattin , BMP C126 soil a lication of
polyacrylamide ( � ), the earl application of gravel base early on areas to be paved, and BMP C140 dust
control. Install plastic covering per BMP C123 on Soils Stockpiles° Installed BMPs to be monitored daily and
repaired as needed°
ELEMENT 6: Protect Slopes
Design and construct cut-and-fill slopes in a manner to minimize erosion. Applicable practices include,
but are not limited to, reducing continuous length of slope with terracing and diversions, reducing slope
steepness, and roughening slope surfaces (Ex: track walking).
Divert off-site stormwater (run-on) or ground water away from slopes and disturbed areas with
interceptor dikes, pipes, and/or swales. Off-site stormwater should be managed separately from
stormwater generated on the site.
At the top of slopes, collect drainage in pipe slope drains or protected channels to preventerosion.
Temporary pipe slope drains must be sized to convey the flow rate calculated by the one fo the
following methods:
• Single Event Hydrograph Method: The peak volumetric flow rate calculated using a 10-minute
time step from a Type 1A, 10-year, 24-hour frequency storm, or;
• Continuous Simulation Method: The 10-year peak flow rate, as determined by an approved
continuous runoff model with a 15-minute time step.
The hydrologic analysis must use the existing land cover condition for predicting flow rates from
tributary areas outside the project limits. For tributary areas on the project site, the analysis must use
the temporary or permanent project land cover condition, whichever will produce the highest flow rates.
Version date:07/26/24 Page
If using the Western Washington Hydrology Model (WWHM) to predict flows, bare soil areas should be
modeled as 'landscaped" area.
Place excavated material on the uphill side of trenches, consistent with safetyand space
considerations.
Place check dams at regular intervals within constructed channels that are cut down a slope.
Additional Guidance for Element 6
• Consider soil type and its potential for erosion.
• Stabilize soils on slopes, as specified in Element 5: Stabilize Soils.
• BMP combinations are the most effective method of protecting slopes with disturbed soils. For
example, use both BMP C121: Mulching and BMP C122: Nets and Blankets in combination.
Suggested BMPs for Element 6:
• BMP C120: Temporary and Permanent Seeding
• BMP C121: Mulching
• BMP C122: Nets and Blankets
• BMP C123: Plastic Covering
• BMP C124: Sodding
• BMP C130: Surface Roughening
• BMP C131: Gradient Terraces
• BMP C200: Interceptor Dike and Swale
• BMP C201: Grass-Lined Channels
• BMP C203: Water Bars
• BMP C204: Pipe Slope Drains
• BMP C205: Subsurface Drains
• BMP C206: Level Spreader
• BMP C207: Check Dams
• BMP C208: Triangular Silt Dike (TSD)
How did you comply with this section?
Design and construct cut-and-fill slopes in a manner to minimize erosiono Applicable practices may include, but
are not limited to reducin continuous len th of slo e with BMP C131 terracing and diversions and BMP C130
rou henin slo e surfaces for exam le brakin u rock with excavator and BMP C121 Mulchin once rock
has been broken up. To be installed as soon as radin for home site is established and slopes are present at
the site. Installed BMPs to be monitored daily and repaired as needed.
Version date:07/26/24 Page
ELEMENT 7: Protect Drain Inlets
Protect all storm drain inlets made operable during construction so that stormwater runoff does not
enter the conveyance system without first being filtered or treated to remove sediment.
Clean or remove and replace inlet protection devices when sediment has filled one-third of the available
storage (unless a different standard is specified by the product manufacturer).
Additional Guidance for Element 7
• Protect all existing storm drain inlets so that stormwater runoff does not enter the conveyance system
without first being filtered or treated to remove sediment.
• Keep all approach roads clean. Do not allow sediment and street wash water to enter storm drains
without prior and adequate treatment (as defined above) unless treatment is provided before the storm
drain discharges to waters of the State.
• Inlets should be inspected weekly at a minimum and daily during storm events.
Suggested BMPs for Element 7
• BMP C220: Inlet Protection
How did you comply with this section?
Per detail 1-40.20-00 Storm Drain Inlet protection devices will be installed at existing catch basins in the
immediate vicinit of the roject. To be installed prior to the start of and construction. BMP to be monitored dail_
and repaired as needed.
ELEMENT 8: Stabilize Channels and Outlets
Design, construct, and stabilize all on-site conveyance channels to prevent erosion from the flow rate
calcultated by one the following methods:
o Single Event Hydrograph Method: The peak volumetric flow rate calculated using a 10-minute
time step from a Type 1A, 10-year, 24-hour frequency storm, or;
o Continuous Simulation Method: The 10-year peak flow rate, as determined by an approved
continuous runoff model with a 15-minute time step.
The hydrologic analysis must use the existing land cover condition for predicting flow rates from
tributary areas outside the project limits. For tributary areas on the project site, the analysis must use
the temporary or permanent project land cover condition, whichever will produce the highest flow rates.
If using the Western Washington Hydrology Model (WWHM) to predict flows, bare soil areas should be
modeled as 'landscaped" area.
Provide stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent
streambanks, slopes, and downstream reaches at the outlets of all conveyance systems.
Additional Guidance for Element 8
The best method for stabilizing channels is to completely line the channel with BMP C122: Nets and
Blankets first, then add BMP C207: Check Dams as necessary to function as an anchor and to slow the
flow of water.
Version date:07/26/24 Page
Suggested BMPs for Element 8
• BMP C122: Nets and Blankets
• BMP C202: Riprap Channel Lining
• BMP C207: Check Dams
• BMP C209: Outlet Protection
How did you comply with this section?
No stormwater runoff will be conve�red off site via channels, swales, or streams.
ELEMENT 9: Control Pollutants
Design, install, implement and maintain effective pollution prevention measures to minimize the discharge of
pollutants. The project proponent must:
Handle and dispose of all pollutants, including waste materials and demolition debris that occur on site
in a manner that does not cause contamination of stormwater.
Provide cover, containment, and protection from vandalism for all chemicals, liquid products, petroleum
products, and other materials that have the potential to pose a threat to human health or the
environment. On-site fueling tanks must include secondary containment. Secondary containment
means placing tanks or containers within an impervious structure capable of containing 110% of the
volume contained in the largest tank within the containment structure. Double-walled tanks do not
require additional secondary containment.
Conduct maintenance, fueling, and repair of heavy equipment and vehicles using spill prevention and
control measures. Clean contaminated surfaces immediately following any spill incident.
Discharge wheel wash or tire bath wastewater to a separate on-site treatment system that prevents
discharge to surface water, or to the sanitary sewer, with local sewer district approval.
Apply fertilizers and pesticides in a manner and at application rates that will not result in loss of
chemical to stormwater runoff. Follow manufacturers' label requirements for application rates and
procedures.
Use BMPs to prevent contamination of stormwater runoff by pH-modifying sources. The sources for this
contamination include, but are not limited to: recycled concrete stockpiles, bulk cement, cement kiln
dust, fly ash, new concrete washing and curing waters, waste streams generated from concrete
grinding and sawing, exposed aggregate processes, dewatering concrete vaults, concrete pumping and
mixer washout waters.
Adjust the pH of stormwater if necessary to prevent violations of water quality standards.
Assure that washout of concrete trucks is performed off site or in designated concrete washout areas
only. Do not wash out concrete truck drums or concrete handling equipment onto the ground, or into
storm drains, open ditches, streets, or streams. Washout of small concrete handling equipment may be
Version date:07/26/24 Page
disposed of in a formed area awaiting concrete where it will not contaminate surface or ground water.
Do not dump excess concrete on site, except in designated concrete washout areas. Concrete spillage
or concrete discharge directly to ground water or surface waters of the State is prohibited. Do not wash
out to formed areas awaiting infiltration BMPs.
Obtain written approval from Ecology before using chemical treatment other than CO2, dry ice, or food
grade vinegar to adjust pH.
Uncontaminated water from water-only based shaft drilling for construction of building, road, and bridge
foundations may be infiltrated provided the wastewater is managed in a way that prohibits discharge to
surface waters. Prior to infiltration, water from water-only based shaft drilling that comes into contact
with curing concrete must be neutralized until pH is in the range of 6.5 to 8.5(su).
Additional Guidance for Element 9
• Wheel wash and/or tire bath wastewater can be combined with wastewater from concrete washout
areas if the wastewaters will be properly disposed of at an offsite location or treatmentfacility.
• Do not use upland land applications for discharging wastewater from concrete washout areas.
• Woody debris may be chopped and spread on site.
• Conduct oil changes, hydraulic system drain down, solvent and degreasing cleaning operations, fuel
tank drain down and removal, and other activities which may result in discharge or spillage of pollutants
to the ground or into stormwater runoff using spill prevention measures, such as drip pans.
• Clean contaminated surfaces immediately following any discharge or spill incident. Emergency repairs
may be performed on-site using temporary plastic placed beneath and, if raining, over thevehicle.
Suggested BMPs for Element 9
• BMP C151: Concrete Handling
• BMP C152: Sawcutting and Surfacing Pollution Prevention
• BMP C153: Material Delivery, Storage, and Containment
• BMP C154: Concrete Washout Area
• BMP C250: Construction Stormwater Chemical Treatment
• BMP C251: Construction Stormwater Filtration
• BMP C252: Treating and Disposing of High pH Water
• Also see the Source Control BMPs detailed in Volume IV
How did you comply with this section?
Per BMP C154 a Concrete Washout Area is to be installed onsite to capture contaminated water from concrete
washouts. To be installed prior to foundation / concrete installation. If r7eeded, a concrete washout area to be
installed near the construction entrance. BMP to be monitored dail and re aired as needed.
Version date:07/26/24 Page
ELEMENT 10: Control De-Watering
Discharge foundation, vault, and trench dewatering water, which have characteristics similar to
stormwater runoff at the site, into a controlled conveyance system before discharge to BMPC240:
Sediment Trap or BMP C241: Sediment Pond (Temporary).
Discharge foundation, vault, and trench dewatering water, which have similar characteristics to
stormwater runoff at the site, into a controlled conveyance system before discharge to Discharge clean,
non-turbid dewatering water, such as well-point ground water, to systems tributary to, or directly into
surface waters of the State, as specified in Element 8: Stabilize Channels and Outlets, provided the
dewatering flow does not cause erosion or flooding of receiving waters. Do not route clean dewatering
water through stormwater sediment BMPs. Note that "surface waters of the State" may exist on a
construction site as well as off site; for example, a creek running through a site.Handle highly turbid or
contaminated dewatering water separately from stormwater.
Handle highly turbid or otherwise contaminated dewatering separately from stormwater.
Other dewatering treatment or disposal options may include:
1. Infiltration
2. Transport off-site in a vehicle, such as a vacuum flush truck, for legal disposal in a manner that
does not pollute state waters.
3. Ecology-approved on-site chemical treatment or other suitable treatment technologies.
4. Sanitary or combined sewer discharge with local sewer district approval, if there is no other
option.
5. Use of a sedimentation bag with outfall to a ditch or swale for small volumes of localized
dewatering.
Additional Guidance for Element 10
• Channels must be stabilized, as specified in Element 8: Stabilize Channels and Outlets.
• Construction equipment operation, clamshell digging, concrete tremie pour, or work inside a cofferdam
can create highly turbid or contaminated dewatering water.
• Discharging sediment-laden (muddy)water into waters of the State likely constitutes violation of water
quality standards for turbidity. The easiest way to avoid discharging muddy water is through infiltration
and preserving vegetation.
• Dewatering water from contaminated sites must be handled separately from stormwater. Direct
contaminated stormwater to a sanitary sewer where allowed by the local sewer authority, or to other
approved treatment.
Suggested BMPs for Element 10
• BMP C203: Water Bars
• BMP C236: Vegetative Filtration
How did you comply with this section?
No dewaterinq will occur durinct the construction of this site.
Version date:07/26/24 Page
ELEMENT 11: Maintain BMPs
Maintain and repair all temporary and permanent erosion and sediment control BMPs as needed to
assure continued performance of their intended function in accordance with BMP specifications.
Remove all temporary erosion and sediment control BMPs within 30 days after achieving final site
stabilization or after the temporary BMPs are no longer needed.
Additional Guidance for Element 11
• Some temporary erosion and sediment control BMPs are biodegradable and designed to remain in
place following construction. BMP C122: Nets and Blankets is an example of a BMP with biodegradable
options.
• Provide protection to all BMPs installed for the permanent control of stormwater from sediment and
compaction. All BMPs that are to remain in place following completion of construction shall be
examined and placed in full operating conditions. If sediment enters the BMPs during construction, it
shall be removed and the facility shall be returned to the conditions specified in the construction
documents.
• Remove or stabilize trapped sediment on site. Permanently stabilize disturbed soil resulting from
removal of BMPs or vegetation.
Suggested BMPs for Element 11
• BMP C150: Materials on Hand
• BMP C160: Certified Erosion and Sediment Control Lead
How did you comply with this section?
Will have a CESCL to monitor site er BMP C160. Installed BMPs to be monitored dail and re aired as
needed.
ELEMENT 12: Manage the Project
Phase development projects to the maximum degree practicable and take into account seasonal work
limitations.
Inspect, maintain and repair all BMPs as needed to assure continued performance of their intended
function. Projects regulated under the Construction Stormwater General Permit (CSWGP) must
conduct site inspections and monitoring in accordance with Special Condition S4 of the CSWGP.
Maintain, update, and implement the Construction SWPPP.
Projects that disturb one or more acres must have site inspections conducted by a Certified Erosion
and Sediment Control Lead (CESCL). Project sites disturbing less than one acre may have a CESCL or
a person without CESCL certification conduct inspections. By the initiation of construction, the
Construction SWPPP must identify the CESCL or inspector, who must be present on site or on-call at
all times.
Version date:07/26/24 Page
Additional Guidance for Element 12
The project manager must ensure that the project is built in such a way to comply with all Construction SWPPP
Elements, as detailed in this section. Considerations for the project manager include, but are not limited to:
• construction phasing
• seasonal work limitations
• coordination with utilities and other contractors
• inspection
• monitoring
• maintaining an updated construction SWPPP
Phas
ing of Construction
Phase development projects where feasible in order to prevent soil erosion and transporting of sediment
from the site during construction. Revegetate exposed areas and maintain that vegetation as an integral part
of the clearing activities for any phase.
Clearing and grading activities for developments shall be permitted only if conducted using an approved site
development plan (e.g., subdivision approval) that establishes permitted areas of clearing, grading, cutting,
and filling. Minimize removing trees and disturbing or compacting native soils when establishing permitted
clearing and grading areas. Show on the site plans and the development site permitted clearing and grading
areas and any other areas required to preserve critical or sensitive areas, buffers, native growth protection
easements, or tree retention areas as may be required by local jurisdictions.
Inspection
All BMPs must be inspected, maintained, and repaired as needed to assure continued performance of their
intended function. Site inspections must be conducted by a person knowledgeable in the principles and
practices of erosion and sediment control. The person must have the skills to 1) assess the site conditions
and construction activities that could impact the quality of stormwater, and 2) assess the effectiveness of
erosion and sediment control measures used to control the quality of stormwater discharges.
For construction sites one acre or larger that discharge stormwater to surface waters of the state, a CESCL
must be identified in the construction SWPPP; this person must be on-site or on-call at all times.
Certification must be obtained through an approved training program that meets the erosion and sediment
control training standards established by Ecology. See BMP C160: Certified Erosion and Sediment Control
Lead.
Appropriate BMPs or design changes shall be implemented as soon as possible whenever inspection and/or
monitoring reveals that the BMPs identified in the Construction SWPPP are inadequate, due to the actual
discharge of/or potential to discharge a significant amount of any pollutant.
The CESCL or inspector must examine stormwater visually for the presence of suspended sediment,
turbidity, discoloration, and oil sheen. They must evaluate the effectiveness of BMPs and determine if it is
necessary to install, maintain, or repair BMPs to improve the quality of stormwater discharges.
Based on the results of the inspection, construction site operators must correct the problems identified by:
• Reviewing the Construction SWPPP for compliance with the 13elements and making appropriate
revisions within 7 days of the inspection.
• Immediately beginning the process of fully implementing and maintaining appropriate source control
and/or treatment BMPs as soon as possible, addressing the problems no later than within 10 days of
the inspection. If installation of necessary treatment BMPs is not feasible within 10 days, the
construction site operator may request an extension within the initial 10-day response period.
• Documenting BMP implementation and maintenance in the site log book(applies only to sites that have
coverage under the Construction Stormwater General Permit).
Version date:07/26/24 Page
The CESCL or inspector must inspect all areas disturbed by construction activities, all BMPs, and all
stormwater discharge points at least once every calendar week and within 24 hours of any discharge from
the site. (For purposes of this condition, individual discharge events that last more than one day do not
require daily inspections. For example, if a stormwater pond discharges continuously over the course of a
week, only one inspection is required that week.) The CESCL or inspector may reduce the inspection
frequency for temporary stabilized, inactive sites to once every calendar month
Maintaining an Undated Construction SWPPP
Retain the Construction SWPPP on-site or within reasonable access to the site.
Modify the Construction SWPPP whenever there is a change in the design, construction, operation, or
maintenance at the construction site that has, or could have, a significant effect on the discharge of
pollutants to waters of the state.
The Construction SWPPP must be modified if, during inspections or investigations conducted by the
owner/operator, or the applicable local or state regulatory authority, it is determined that the Construction
SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the
site. Modify the Construction SWPPP as necessary to include additional or modified BMPs designed to
correct problems identified. Complete revisions to the Construction SWPPP within seven (7) days following
the inspection.
Suggested BMPs for Element 12
• BMP C150: Materials on Hand
• BMP C160: Certified Erosion and Sediment Control Lead
• BMP C162: Scheduling
How did you comply with this section?
Will have a CESCL to monitor site er BMP C160. Installed BMPs to be monitored dail and re aired as
needed. Weekly erosion and sedimentation reports to the buildin department to be submitted.
ELEMENT 13: Protect Low Impact Development BMPS
The primary purpose of On-Site Stormwater Management is to reduce the disruption of the natural site
hydrology through infiltration. BMPs used to meet 1-3.4.5 MR5: On-Site Stormwater Management (often called
LID BMPs) are permanent facilities.
Protect all LID BMPs (including, but not limited to BMP T7.30: Bioretention, BMP T5.14: Rain Gardens,
and BMP T5.15: Permeable Pavements) from sedimentation through installation and maintenance of
erosion and sediment control BMPs on portions of the site that drain into the LID BMPs. Restore the
BMPs to their fully functioning condition if they accumulate sediment during construction. Restoring the
BMP must include removal of sediment and any sediment-laden Bioretention/Rain Garden soils, and
replacing the removed soils with soils meeting the design specification.
Maintain the infiltration capabilities of LID BMPs by protecting against compaction by construction
equipment and foot traffic. Protect completed lawn and landscaped areas from compaction due to
construction equipment.
Control erosion and avoid introducing sediment from surrounding land uses onto BMP T5.15:
Permeable Pavements. Do not allow muddy construction equipment on the base material or pavement.
Do not allow sediment-laden runoff onto permeable pavements or base materials.
Version date:07/26/24 Page
Permeable pavement fouled with sediments or no longer passing an initial infiltration test must be
cleaned using procedures in accordance with this manual or the manufacturer's procedures.
J Keep all heavy equipment off existing soils under LID BMPs that have been excavated to final grade to
retain the infiltration rate of the soils.
Additional Guidance for Element 13
See Chapter 5: Precision Site Preparation, Construction & Inspection of LID Facilities in the LID Technical
Guidance Manual for Puget Sound (Hinman and Wulkan, 2012) for more detail on protecting LID integrated
management practices.
Note that the LID Technical Guidance Manual for Puget Sound (Hinman and Wulkan, 2012) is for additional
informational purposes only. You must follow the guidance within this manual if there are any discrepancies
between this manual and the LID Technical Guidance Manual for Puget Sound (Hinman and Wulkan, 2012).
Suggested BMPs for Element 13
• BM C102: Buffer Zones
• BMP C103: High-Visibility Fence
• BMP C200: Interceptor Dike and Swale
• BMP C201: Grass-Lined Channels
• BMP C207: Check Dams
• BMP C208: Triangular Silt Dike (TSD)
• BMP C231: Brush Barrier
• BMP C233: Silt Fence
• BMP C234: Vegetated Strip
How did you comply with this section?
There are no LID BMP's proposed on this ro ect.
Jason Sterling 7/24/2025
Applicant Signature Date
Version date:07/26/24 Page
T (MINIMUM REQUI E T 3)
• 1-3.4.3 Minimum Requirement#3 — Source Control of Pollution
All known, available and reasonable source control BMP's must be applied to all projects. Source
control BMP's must be selected, designed, and maintained according to the reference Ecology Manual.
The intent of source control BMP's is to prevent stormwater from coming in contact with pollutants.
They are a cost-effective means of reducing pollutants in stormwater and should be considered in all
projects.
Supplemental Guidelines
Source Control BMPs include Operational BMPs and Structural Source Control BMPs. See Volume IV
for design details of these BMPs. For construction sites, see II-3.2 Construction Source Control BMPs.
Structural Source Control BMPs should be identified in the stormwater site plan and should be shown
on all applicable plans submitted for local government review and approval.
An adopted and implemented Basin Plan (see Appendix I-B: Basin Plans) or Total Maximum Daily Load
(see E2.13 Total Maximum Daily Loads (TMDLs)) may be used to develop more stringent source
control requirements that are tailored to a specific basin.
Identifying Source Control Strategies in a Basin Plan
Basin Plans can identify potential sources of pollution within the basin and develop strategies to
eliminate or control these sources to protect beneficial uses.
A Basin Plan can include the following Source Control strategies:
1. Detection and correction of illicit discharges to storm sewer systems, including the use of dry
weather sampling and dye-tracing techniques;
2. Identification of existing businesses, industries, utilities, and other activities that may store
materials susceptible to spillage or leakage of pollutants into the storm sewer system or tothe
ground via wells, drains, or sumps;
3. Elimination or control of pollutant sources identified in (2);
4. Identification and control of future businesses, industries, utilities, and other activities which may
store materials susceptible to spillage or leakage of pollutants into the storm sewer system; and
5. Training and public education
A Basin Plan that incorporates the standard requirements from this section as well as more stringent
requirements does not require Ecology approval.
What Source Control BMP's are applicable to your project?
O SOURCE CONTROL BMP'S ARE APPLICABLE TO THIS PROJECT.
Version date:07/26/24 Page
TA (MINIMUM REQUI P T )
• 1-3.4.4 Minimum Requirement#4— Preservation of Natural Drainage Systems and Outfalls
Natural drainage patterns shall be maintained and discharges from the project shall occur at the natural
location, to maximum extent practicable. The manner by which runoff is discharged from the project site
must not cause a significant adverse impact to downstream receiving waters and down gradient
properties. All outfalls require energy dissipation.
The objective is to preserve and utilize drainage systems to the fullest extent because of the multiple
stormwater benefits these systems provide; and to prevent erosion at the downstream of the discharge
location.
Refer to the referenced section of the manual for supplemental guidelines and additional information
under this section.
Will this project disturb the Natural Drainage System or Outfall of the project Site? Yes\ o. If
yes, refer to section 1-3.4.4 for Supplemental Guidelines for additional information.
SITE IS PRIMARILY ROCK AND IS MOSTLY IMPERVIOUS. FLOW WILL NOT DISTURBTHE
NATURAL DRAINAGE SYSTEM R OUTFALL.
Version date:07/26/24 Page
Does the entire project qualify as Flow Control exempt(per MR#7)?
Yes No
Did the project developer choose to meet Does the project trigger NO
the LID Performance Standard? only MRs#1 -#5? (Per (the project triggers Is the project outside
the Project Thresholds in MRs#1 -#9) the UGA on a parcel
No Applicability of the that is 5 acres or larger?
Minimum Requirements
Yes Section).
REQUIRED: For each
surface, consider the BMPs Yes No
in the order listed in List#3
for that type of surface. Use
the first BMP that is Did the project
considered feasible. developer chooseto
meet the LID Yes
NOT REQUIRED: Performance Did the project
Achievement of the LID Standard? developer chooseto
Performance Standard. No meet the LID
Performance
Standard?
Yes Yes
REQUIRED: For each
surface, consider the a,7 No
BMPs in the order
listed in List#1 for that
type of surface. Use
the first BMP that is
considered feasible.
NOT REQUIRED:
Achievement of the LID
Performance Standard.
► ► '►
REQUIRED: Meet the LID
REQUIRED: Meet the LID Performance REQUIRED: For each Performance Standard through
Standard through the use of any Flow Control surface, consider the BMPs the use of any Flow Control
BMP(s) in this manual. in the order listed in List#2 BMP(s) in this manual.
for that type of surface. Use
REQUIRED: Apply BMP T5.13 Post the first BMP that is REQUIRED: Apply BMP T5.13
Construction Soil Quality and Depth. considered feasible. Post-Construction Soil Quality
and Depth.
NOT REQUIRED: Applying the BMPs in Lists NOT REQUIRED:
#1, #2, or#3. Achievement of the LID NOT REQUIRED: Applying the
Performance Standard. , or 92
81r
Flow Chart for Determining MR #5
DEPARTMENT0 Requirements
ECO1OG
,sion ate: 0 /26/24 Revi Pg194� rCh 2019
T (MINIMUM REQUI E T )
• 1-3.4.5 Minimum Requirement#5— On-site Stormwater Management
Projects shall employ Stormwater Management BMPs in accordance with the following thresholds,
standards, and lists to infiltrate, disperse, and retain stormwater runoff on site to the extent feasible
without causing flooding or erosion impacts.
Project thresholds that trigger Minimum Requirements #1 through #5, shall utilize the On-site
Stormwater Management BMP's from List#1 for all surfaces within each type of surface in List#1; or,
Demonstrate compliance with the LID Performance Standard. Projects selecting this option cannot use
Rain Gardens. They may choose to use Bioretention BMP's as described in Chapter V-7— Infiltration
and Bioretention Treatment Facilities to achieve the LID Performance Standard.
Refer to this section of the reference Manual for all Feasibility or Infeasibility Criteria for List#1
and List#2.
Is this project Flow Control Exempt? NO (Yes\No) (See Appendix I-E: Flow Control-Exempt
Surface Water). If yes, provide reasoning from the applicability section of 1-2.5.7 Minimum
Requirement#7: Flow Control). If No, then the project triggers Minimum Requirement#7 (1-2.5.7)and
possibly Minimum Requirement#8 (1-2.5.8).
• The project is under the square footage thresholds required to address Minimum Requirement
7, so#7 is not required. The project will address the feasibility of the items in List#1.
• Per the provided Geotech report and site inspection, the site is primarily bedrock and has no
real collection of soil. There is no infiltration on site. All Infiltration and Dispersion measures are
infeasible. There is insufficient space to disperse as well as improper vegetation. This property
is also uphill of neighboring properties which could cause issues as natural slope would convey
stormwater into other properties and houses. Project will be tying the stormwater tig tline for the
Ouse into the city provided stormwater system stub-out, but infeasibility for List#1 items have
been provided.
• Stormwater receiving detention pond has been upsized to handle increased stormwater from
the rock ridge developments.
If the project is Flow Control Exempt, select from the List 3 below: (Skip List 1 and List 2)
o BMP T5.13 Post Construction Soils Quality and Depth
Roofs:
o BMP T5.10A: Downspout Full Infiltration, or;
o BMP T5.10B Downspout Dispersion Systems, or;
o BMP T5.10C: Performated Stub-out Connections, or;
Other Hard Surfaces:
o BMP T5.12: Sheet Flow Dispersion, or;
o BMB T5.11: Concentrated Flow Dispersion
LID Performance Standard
The LID Performance Standard compliance method for Minimum Requirement#5 requires modeling the
proposed Flow Control BMPs to demonstrate the flow reduction as described below. Note that in order
to meet the LID Performance Standard, the chosen Flow Control BMPs will most likely need to include
infiltration.
Stormwater discharges shall match developed discharge durations to pre-developed durations for the
range of pre-developed discharge rates from 8% of the 2-year peak flow to 50% of the 2-year peak flow.
Refer to the Flow Control Performance Standard section in 13.4.7 MR7: Flow Control for information
about the assignment of the pre-developed condition. Project sites that must also meet 1-3.4.7 MR7:
Flow Control must match flow durations between 8% of the 2-year flow through the full 50-year flow.
Designers selecting this option cannot use BMP T5.14: Rain Gardens to achieve the LID Performance
Standard. They may choose to use BMP T7.30: Bioretention to achieve the LID Performance Standard.
The List Approach
The List Approach compliance method for Minimum Requirement#5 requires evaluating the BMPs in
Table 1-3.2: The List Approach for MR5 Compliance.
For each surface, evaluate the feasibility of the BMPs in the order listed, and use the first BMP that is
considered feasible. The designer must document the site conditions and infeasibility criteria used to
deem BMPs infeasible. Once a BMP is deemed feasible and used for a surface, no other BMP from the
list is necessary for that surface.
If all BMPs in the list are infeasible, then the designer must document the site conditions and infeasibility
criteria used to deem each BMP infeasible. This documentation will demonstrate compliance with
Minimum Requirement#5.
Feasibility shall be determined by evaluation against:
• Design criteria, limitations, and infeasibility criteria identified for each BMP in this manual;and
• Competing Needs Criteria as listed below.
All sites are required to utilize BMP T5.13 — Post Construction Soil Quality and Depth.
For each surface, consider the BMP's in the order listed for that type of surface. Use the first BMP that
is considered feasible. No other on-site Stormwater Management BMP is necessary for that surface.
Feasiblity shall be determined by evaluation against:
1. Design criteria, limitations and infeasiblity criteria identified for each BMP in this manual,and;
2. Competing needs criteria listed in Chapter V-5— On-site Stormwater Management.
Lawn and Landscaped Area:
• BMP T5.13: Post-Construction Soil Quality and Depth. (Attach Detail in Report)
Refer to this site for requirements and specifications. All projects are required to utilize this BMP.
See Appendix 3 for the "Model Soil Management Plan for BMP T5.13" to be submitted with
Drainage Report and Application Material.
An alternate document acceptable to the City of Anacortes is a Test Report provided by the Soils
Supplier that identifies the soils to be used meet the specifications outlined under Minimum
Requirement 5. The specifications are in both WSDOT and CSI Formats. For specifications, refer to
the above referenced PDF.
This submittal can be a deferred submittal since most projects are not sure who the supplier will be
at the time of building permit application. For projects that trigger Minimum Requirements 1 through
5, the Test Report will be provided to the Building Department. Projects triggering Minimum
Requirements 1
List #1 — Project Triggering Minimum Requirement 1 through 5
For each surface, consider the BMPs in the order listed for that type of surface. Use the first BMP that
is considered feasible. No ther On-site Stormwater Management BMP is necessary for that surface.
Provide feasible detail under each BMP with maintenance and operations specifications in Minimum
Requirement 5.
Roofs: List#1
1. BMP T5.30: Full Dispersion (Feasible)
If infeasible, provide the criteria:
Clue to slope of grade and available area of lot,there is not adequate room for full dispersion. Also, lot is mostly rock,see
Geotech report,and will not infiltrate properly.As this lot is uphill,there is also concern of runoff affecting lower homes and lots.
Or, T5.10A: Downspout Full Infiltration (Feasible)
If infeasible, provide the criteria:
Per the provided Geotech report and site inspection, the site is primarily bedrock and has no real collection of soil.
There is no infiltration on site.All Infiltration and Dispersion measures are infeasible.
2. BMP T5.14: Rain Gardens (Feasible)
If infeasible, provide the criteria:
Due to space constraints on lot, and poor infiltration, see geotechnical report, Rain gardens are not feasible.
Or, BMP T7.30: Bioretention Cells, Swales, and Planter Boxes (Feasible
If infeasible, provide the criteria:
Again,there is insufficient space and depth to bedrock to be able to implement Bioretention cells.
3. BMP T5.10113: Downspout Dispersion Systems (FeasibleMEW
If infeasible, provide the criteria:
Per the provided Geotech report and site inspection, the site is primarily bedrock and has no real collection of soil.
There is no infiltration on site.All Infiltration and Dispersion measures are infeasible. Also, due to slope of site, erosion
or flooding of downstream properties is a concern.
4. BMP T5.10C: Perforated Stub-out Connections (Feasible
If infeasible, provide the criteria:
Per the provided Geotech report and site inspection, the site is primarily bedrock and has no real collection of soil.
There is no infiltration on site.All Infiltration and Dispersion measures are infeasible. Also, due to slope of site, erosion
or flooding of downstream properties is a concern.
Other Hard Surfaces: List#1
1' BKNPT.5.30 Full Dispersion
If infeaoib|e, provide the criteria:
Due to slope ofgrade and available area of lot,there ienot adequate room for full dispersion. Also, lot ia mostly rock,see
Geotech report,and will not infiltrate properly.As this lot is uphill,there is also concern of runoff affecting lower homes and lots.
2' BKNPT5.15: Permeable Pavements (Feasible
If infeasible, provide the criteria:
Per the provided Geotech report and site inspection, the site is primarily bedrock and has no real collection of soil.
There is no infiltration on site.
Or, BMPT.14: Rain Gardens /Feas/b/e
If infeasible, provide the criteria:
Due to space constraints on |ot, and poor infi|tration, see gmotmchnice| report. Rain gardens are not feasible.
Or, BMPT7.3O: Biomentiom Cells, SxvaUemamd Planter Boxes /FmaadbAa
If infeasible, provide the criteria:
Again,there is insufficient space and depth to bedrock to be able to implement Biormteniion nyUa.
3' BNUPT5.12: Sheet Flow Dispersion (Feasible
If infeasible, provide the criteria:
Per the provided Geotech report and site inspection, the site is primarily bedrock and has no real collection of soil.
There iano infiltration onsite.All Infiltration and Dispersion measures are infeasible. Also, due 0o slope of site, erosion
or flooding of downstream properties iaaconcern.
Or. BMP T5.11: Concentrated Flow Dispersion (Feasible
If infeasible, provide the criteria:
Per the provided Geotech report and site inspection, the site is primarily bedrock and has no real collection of soil.
There is no infiltration on site.All Infiltration and Dispersion measures are infeasible. Also, due to slope of site, erosion
or flooding of downstream properties iaaconcern.
Jason Sterling 8/22/2025
Applicant Signature Date
Version date:o7/zo/z4 Page
Figure Runoff Treatment BMP Selection Flow Chart
Step 1: Determine the
receiving waters and
pollutants of concern
based on off-site
analysis
Step 2:Determine if Ves
an Oil Control BMP is Select an Oil Control BMP
Select a Pretreatment BMP required (see the text in this section for
(see the section"Pretreatment Oil Control BMP options)
BMPs"for details) N®
—Note that some BMPs have Step 3: Determine if it is
pretreaternent provided as part of Yes practicable to provide Runoff 6,
the BMP(e.g.settling in Treatment by infiltrating into
bioretention,and the wearing coarse the native soil
in permeable pavement) No
Step 4: Determine if a, Ves. select a Phosphorus Treatment BMP
Phosphorus Treatment (see the text in this section for
Select an Infiltration BMP, BMP is required Phosphorus Treatment BMP options)
utilizing the native soils for Runoff
Treatment,per the"Site Suitability No
Criteria"section.
I is�l 5: Determine if a Determine il�i Metals
"Is
**Runoff Treatment BMP 0 -nent BMP Treatment BMP is required
Selection Complete— Step
T D, .It,, 's required
Iis required
No
Yes **Runoff Treatment BMP
Step 6:Select a Basic Treatment BMP Selection Complete**
(see the text in this section for Basic Ves y
Treatment BMP options) Is the selected Phosphorus Treatment BMP
also listed as a Metals Treatment BMP?
**Runoff Treatment BMP Selection
Complete— �No �Yes
**Runoff
Select a Metals Treatment BMP Treatment BMP
(see the text in this section for Metals Selection
Treatment BMP options) Complete**
**Runoff Treatment BMP Selection
Complete**
Runoff Treatment BMP Selection Flow Chart
DEPARTMENT OF
ECOLOGY
I State of Washington, Revised March 2024
2024 Stormwater Management Manual for Western Washington
Version date:07/26/24 Volume 111-Chapter 1 -Page 463 Page
APPENDIX Survey performed by a Professional Land Surveyor
The object of this appendix is to ensure that the property has a minimum of 3 out of 5 property corners
visible to ensure that the structures are placed within the required setbacks.
- SURVEY SUBMITTED WITH PERMIT PACKAGE FILES AND ATTACHED.
Version date:07/26/24 Page
APPENDIX 2 —Soils Analysis (Volume 3, Chapter a e )
Provide the soils report in this appendix
- FINAL SOILS REPORT TO BE DEFERRED SUBMITTAL TO BE PROVIDED FROM SOIL COMPANY NEAR
FINAL GRADING. SITE IS MOSTLY ROCK AND HAS LITTLE SO
1L BUT SOIL SAMPLE FROM UFVFLC)F'MFNT
HAS SEEN ATTACHE®.
Version date:07/26/24 Page
APPENDIX 3 — Model Soil Management Plan for BMP T5.1
An alternate document acceptable to the City of Anacortes is a Test Report provided by the Soils Supplier that
identifies the soils to be used meet the specifications outlined under Minimum Requirement 5. The
specifications are in both WSDOT and CSI Formats. For specifications, refer to the above referenced PDF.
This submittal can be a deferred submittal since most projects are not sure who the supplier will be at the time
of building permit application. The form needs to be uploaded to your SmartGov account.
- SMP T5.13 to be a deferred submittal, to be completed at final grading
Version date:07/26/24 Page
DEFERRED SUBMITTAL: PROVIDE A TEST REPORT FROM SOILS SUPPLIER TO THE BUILDING DEPT.
PROJECT INFORMATION "Model Soil Management Plan for BMP T5.13" age# of pages
Com lete all information on page 1;only site address and permit number on additional pages.
Site Address/Lot No.:
Permit Type: Permit Number:
Permit Holder: Phone:
Mailing Address:
Contact Person: Phone:
Plan Prepared By:
ATTACHMENTS REQUIRED (Check off'reguired items that are attached to this plan)
Site Plan showing,to scale: _Areas of undisturbed native vegetation(no amendment required)
New planting beds and turf areas(amendment required)
Type of soil improvement proposed for each area
Soil test results(required if proposing custom amendment rates)
Product test results for proposed amendments
AREA# (should match Area#on Site Plan)
PLANTING TYPE _Turf Undisturbed native vegetation
Planting Beds Other:
SQUARE FOOTAGE OF THIS AREA: square feet
SCARIFICATION inches(depth)of scarification needed to achieve finished total 12"loosened depth.
Subsoil will be scarified
PRE-APPROVED inches of compost or imported topsoil applied
AMENDMENT METHOD: X 3.1 (conversion factor, inches to cubic yards) PRODUCT:
Topsoil import =cu.yards per 1,000 sq.ft.
Amend with compost X 000s sq.ft. in this area
Stockpile and amend =cubic yards of amendment QUANTTTY: CU.YDS.
(_cu.yds. stockpiled) (needed to cover this area to designated depth)
CUSTOM AMENDMENT Attach test results and calculations.
Topsoil import inches organic matter or topsoil import PRODUCT:
Topsoil&compost lift X 31
Amend =cu.yards/ 1,000 sq.ft.
Stockpile and amend X 000s sq.ft. in this area
(-cu.yds. stockpiled) =cubic yards of amendment QUANTTTY: CU.YDS.
MULCH ,000 sq.ft. PRODUCT:
X 62(conversion, to give 2 inch mulch depth)
=cubic yards of mulch-->--).-->-->-->--). QUANTTTY: CU.YDS.
TOTAL AMENDMENT/TOPSOIL/MULCH FOR ALL AREAS complete on page 1 only, totaling all areas/pages in this Plan)
❑ Product#1: ❑ Quantity: cu.yds.
❑ Test Results: %organic matter C:N ratio<25:1 (except mulch,or<35:1 for native plants) "stable"(yes/no)
❑ Product#2: ❑ Quantity: cu.yds.
❑ Test Results: %organic matter C:N ratio<25:1 (except mulch,or<315:1 for native plants) "stable"(yes/no)
❑ Product#3: ❑ Quantity: cu.yds.
❑ Test Results: %organic matter C:N ratio<25:1 (except mulch,or<315:1 for native plants) "stable"(yes/no)
Date: Inspector: Approved: Revisions Required:
Date: Inspector: Approved: Revisions Required:
Version date:07/26/24 Page
APPENDIX 4— Determining Construction Site Sediment Damage Potential (Appendix 7— NPDES Phase
11 Permit)
Note: See attached. All projects within the City of Anacortes are required to complete that document under
Appendix 4.
Version date:07/26/24 Page
Western Washington Phase II Stormwater Permit
i. APPENDIX 7 - Determining Construction Site
Sediment Damage Potential
The following rating system allows objective evaluation of a particular development site's potential to
discharge sediment. Permittees may use the rating system below or develop alternative process
designed to identify site-specific features which indicate that the site must be inspected prior to clearing
and construction. Any alternative evaluation process must be documented and provide for equivalent
environmental review.
Step one is to determine if there is a sediment/erosion sensitive feature downstream of the development
site. If there is such a site downstream complete step two, assessment of hydraulic nearness. If there is
a sediment/erosion sensitive feature and it is hydraulically near the site then go to step three to
determine the construction site sediment transport potential.
ii. STEP 1 — Sediment/Erosion Sensitive Feature Identification
Sediment/erosion sensitive features are areas subject to significant degradation due to the effect of
sediment deposition or erosion. Special protection must be provided to protect them.
Sediment/erosion sensitive features include but are not limited to:
i. Salmonid bearing fresh water streams and their tributaries or freshwater streams that
would be Salmonid bearing if not for anthropogenic barriers;
ii. Lakes;
tit. Category I, II, and III wetlands;
iv. Marine near-shore habitat;
V. Sites containing contaminated soils where erosion could cause dispersal of
contaminants; and
vi. Steep slopes (25% or greater) associated with one of the abovefeatures.
Identify any sediment/erosion sensitive features, and proceed to step two. If there are none the assessment
is complete.
iii. STEP 2 — Hydraulic Nearness Assessment
Sites are hydraulically near a feature if the pollutant load and peak quantity of runoff from the site will not
be naturally attenuated before entering the feature. The conditions that render a site hydraulically near
to a feature include, but are not limited to, the following:
i. The feature or a buffer to protect the feature is within 200 feet downstream of the site.
ii. Runoff from the site is tight-lined to the feature or flows to the feature through channel
or ditch.
�EFwrE.F�� Ir Il iGAIA�,e, ti���� �iE.Frar lta, „'r' 7 P� e'kllm,��p°���ii��.iir �f I e ,
Version date:07/26/24 Page
A site is not hydraulically near a feature if one of the following takes place to provide attenuation
before runoff from the site enters the feature:
iv. Sheet flow through a vegetated area with dense ground cover
V. Flow through a wetland not included as a sensitive feature
vi. Flow through a significant shallow or adverse slope, not in a conveyance
channel, between the site and the sensitive feature.
Identify any of the sediment/erosion sensitive features from step one that are hydraulically near
the site, and proceed to step three. If none of the sediment/erosion sensitive features are
hydraulically near the site, the assessment is complete.
vii. STEP 3— Construction Site Sediment Transport Potential
Using the worksheet below, determine the total points for each development site. Assign points
based on the most critical condition that affects 10% or more of the site.
If soil testing has been performed on site, the results should be used to determine the
predominant soil type on the site. Otherwise, soil information should be obtained from the
county soil survey to determine Hydrologic Soil Group (Table of Engineering Index Properties
for step 1.D) and Erosion Potential (Table of Water Features for step 1.E)
When using the county soil survey, the dominant soil type may be in question, particularly when
the site falls on a boundary between two soil types or when one of two soil types may be present
on a site. In this case, the soil type resulting in the most points on the rating system will be
assumed unless site soil tests indicate that another soil type dominates the site.
Use the point score from Step 3 to determine whether the development site has a high potential
for sediment transport off of the site.
Total Score Transport Rating
<100 Low
:1 100 High
A high transport rating indicates a higher risk that the site will generate sediment contaminated
runoff.
Version date:07/26/24 Page
Construction Site Sediment Transport Potential Worksheet
A. Existing slope of site (average, weighted by aerial extents Points
2% or less ...0
>2-5% ..............................................................................................5
>5-10% ..........................................................................................15
>10-15% ........................................................................................ 30
>15% .............................................................................................50
B. Site Area to be cleared and/or graded:
<5,000 sq. ft ...................................................................................0
5,000 sq. ft. — 1 acre.....................................................................30
>1 acres.......................................................................................50
C. Quantity of cut and/or fill on site:
<500 cubic yards............................................................................0
500 — 5,000 cubic yards.................................................................... 5
>5,000 — 10,000 cubic yards.........................................................10
>10,000 — 20,000 cubic yards.......................................................25
>20,000 cubic yards .....................................................................40
D. Runoff potential of predominant soils (Natural Resources Conservation Service): Hydrologic
soilgroup A....................................................................................0
Hydrologic soil group B.................................................................10
Hydrologic soil group C.................................................................20
Hydrologic soil group D.................................................................40
E. Erosion Potential of predominant soils (Unified Classification System): GW, GP, SW,
SPsoils..........................................................................................0
Dual classifications (GW-GM, GP-GM, GW-GC,
GP-GC, SW-SM, SW-SC, SP-SM, SP-SC)..........................10
GM, GC, SM, SC soils..................................................................20
ML, CL, MH, CH soils ...................................................................40
F. Surface or Groundwater entering site identified and intercepted 1:
Yes.................................................................................................0
No ................................................................................................25
G. Dpth of cut or height of fill >10 feet:
Yes...............................................................................................25
No ..................................................................................................0
H. Gearing and grading will occur in the wet season (October 1 — May 1):
Yes.................................................................................................50
No ..................................................................................................0
TOTALPOINTS............................................................................................. >100
1 If no surface or groundwater enters site, give 0 points.
Version date:07/26/24 Page
APPENDIX 5—Site Plan with all applicable information (Minimum Size 11x17 at a legible scale)
- SIT PLAN SUBMITTED WITH PERMIT PACKAGE FILES AND ATTACHED.
Version date:07/26/24 Page
APPENDIX — Documented Site Photos (Show all directions of the site, including frontage)
I;
°a1T
t<o.
�r C.
,2s✓
Location: Aerial Shot
Description of the photo: Looking down on lot
Photo taken by: Skagit iMap
01
1 ri
Location: Aerial Shot
Description of the photo: Looking down on lot
Photo taken by: Skagit iMap
Version date:07/26/24 Page
d
r
,
r�
i
Location: North-West end of Lot
Description of the photo: Looking from NW. end to SE. end of lot.
Photo taken by: Jason Sterling.
carp�� i w rid r i
Yf ,
Location: North end of lot.
Description of the photo: Looking N. end to SW. end of lot.
Photo taken by: Jason Sterling.
Version date:07/26/24 Page
V
it ayt, t � a
i'sCl
j
Location: North middle end of Lot
Description of the photo: Looking from N. end to S. end of lot.
Photo taken by: Jason Sterling.
av
f
t
i k
I
r
Location: Middle of lot.
Description of the photo: Looking middle of lot to W. end of lot.
Photo taken by: Jason Sterling.
Version date:07/26/24 Page
APPENDIX — Drainage BMP Facility Maintenance Covenant
Deferred Submittal
Note: To be recorded prior to: 1) Temporary Certificate of Occupancy; 2) Final Certificate of Occupancy, and
or; 3) Final Acceptance of the project.
This is Covenant is required for any Permanent Stormwater Facility constructed on a project site. The applicant
should work with the the City of Anacortes Engineering Department on formalizing the document for recording.
Version date:07/26/24 Page
APPENDIX 8 — Maintenance and Operations Manual
- Deferred Submittal
Maintenance and Operations Manual is required by DOE:
www.anacorteswa.gov/DocumentCenterNiew/26423/Stormwater-BMP-Maintenance-
Standards?bid ld=
Version date:07/26/24 Page
APPENDIXoch Report
- (.AFC TECH REPORT SUBMITTED WITH PERMIT PACKAGE FILES AND ATTACHED.
- ALSO SEE SUBMITTED DEVELOPMENT DRAINAGE ANYALYSIS.
Version date:07/26/24 Page
� V y,
STRATUM GRouP
P.O.Box 2546,Bellingham,Washington 98227
July 21, 2025
Owen and Maria Moon
3043 Treeline View
Colorado Springs, CO 80904
Re: Geologic Hazard Assessment
3913 Rock Ridge Parkway
Anacortes, WA
This geologic hazard evaluation was conducted to assess the slope stability of the site. it is my
understanding that you are planning on building a home on the site. Home plans were provided
to me as part of this assessment.
Based on my geologic hazard assessment, it is my opinion that there are no landslide hazards on
the property. Building a home on the site as proposed will not increase the risk of landslides or
erosion on or off the site.
The bedrock at the site is very hard metamorphosed igneous rock. Additional grading for the
s i t . t a t f o r tured
rock from past gra ing and existing bedroc outcrops and poten tal for rock shifting, we
recommend that final grades for the foundation be inspected by an engineering geologist or
geotechnical engineer to ensure foundation support will not be impacted by rock shifting or
possible settlement. Previous rading has taken lace on and adjacent to the site such as the c t
a e r g a e o a o on
of the northeast side of the site.
This geologic hazard assessment included a field inspection of the subject property and vicinity
and review of proposed site plans and foundation plans. My evaluation also included review of
historic aerial photographs, available geologic mapping, lidar (light detecting and ranging)
imagery, and our own notes and observations we have made in the vicinity of the site and at
locations with similar-geologic conditions.
GENERAL GEOLOGY
The subject property is on the southern edge of the Bedrock Geologic_ Map of the Port Townsend
30- by 60-Minute Quadrangle, get Sound Region, Washington (Whetten and others, 1988)
indicates that the subject property and vicinity is underlain by intrusive igneous rocks of the
Fidalgo Ophiolite.
Stratum Group File: 6.1.25
1
July 21,2025
3913 Rock Ridge Parkway,Anacortes,WA
Geologic Hazard Assessment
ite
E 1 516 0 R 1
f
.:
r�
� � I
I
/�f
h.
M'• �frt'�IYxU. k ..
Figure 1.Jfi intrusive rocks of the Fidalgo Ophiolite,Jfl—layered gabro of the Fidalgo Ophiolite,Jfb—breccia of
the Fidalgo Ophiolite,Jfs—sandstone of the Fidalgo Ophiolite,Jfsp—serpentine of the Fidalgo Ophiolite,Jfa—
argillite of the Fidalgo Ophiolite,Quk=thicker unconsolidated deposits,Qun=thinner unconsolidated deposits,
The metamorphosed intrusive rocks are the root of a former ocean island are that was accreted to
the North American margin along with ocean floor rocks that make up the Fidalgo Ophiolite (a
section of deep to ocean crust with a volcanic arc). My observations are consistent with the
geology map.
SITE SPECIFIC OBSERVATIONS
The property is bounded on the northwest by Rock Ridge Parkway. A home is located on the
adjoining property to the southwest. There is a thin intervening strip of land that belongs to the
City of Anacortes. A home is located on the adjoining property to the northeast. A vacant rocky
graded lot bounds the site to the southeast.
Overall the property slopes moderately to the northeast. There is a steep slope on the northwest
side of the property down to Rock Ridge Parkway (Figure 2). This slope is at least in part a cut
slope associated with Rock Ridge Parkway. The southwestern part of this slope is intact bedrock.
The southeastern portion of the slope is covered with angular rocks that were from past grading
on and in the vicinity of the property. The bedrock is massive metamorphosed diorite. There are
joints and cracks in the bedrock such that there are some potential detachment areas on the
existing bedrock outcrops of the steep slope (Figure 3).
Intact bedrock is present on the surface on southeastern portion of the site (Figure 4). Other areas
are covered with angular rock(Figure 5 and Figure 2) with a limited area where a few older trees
are present where no past grading has taken place.
Stratum Group File: 6.1.25
2
July 21,2025
3913 Rock Ridge Parkway,Anacortes,WA
Geologic Hazard Assessment
v F^
ei'irtir,IL�ry �,
»ir � ' �nrrr )p/rrr�rirrrilyl/�/ �(yG,,fJililr?!f� rr.��;r�'
ill ���r,',Ir �1��,��'l'���'�a�;✓�%;�r�r'u A�'.i�.?r14���ill' ��, G;�� �J,. Y J1 � u, ti' '' ��tij' � '�
IrNs'� ��,7 �r�1� ✓��1?r��i�, )l �' rv„�i t ��.-!" �� � r �`, l I �"r==� � �7 � ,r
Figure 2.View of cut slope on property above Rock Ridge Parkway with intact rock on the right and angular broken
rock on the left.
r
/ �irl i y r a
�r
� 9
r
k NJ/aml ��
Figure 3. Closer view of bedrock cut.Joints and fractures in the intact bedrock that are potential rock detachment
surfaces. Site grading is anticipated in this area.
Stratum Group File: 6.1.25
3
July 21,2025
3913 Rock Ridge Parkway,Anacortes,WA
Geologic Hazard Assessment
/10
r r
p
6r
d
i
Figure 4.Bedrock on southeast area of the property looking towards the southeast side of the property.
f��� �� w"ui I�1 ����J1�CiV�N'�1n1U�1/pi�(,'V°✓' i�lll�if�00��lll�X�� �4G�i�H1� o, r,
Figure 5.Loose angular broken rock from past grading on site viewed from the southwest looking northeast down
the overall slope on the site.Bedrock outcrop is in the foreground.
Stratum Group File: 6.1.25
4
July 21,2025
3913 Rock Ridge Parkway,Anacortes,WA
Geologic Hazard Assessment
CONCLUSIONS
Based on my geologic assessment, it is my opinion that the site will not be at risk of landslide or
erosion hazards. Building on site as proposed will not increase the risk of landslides or erosion
on or off the site.
Development of the site will require excavation and grading of areas underlain by bedrock and
0 0 -e o t t 1 i
additional bedrock may take extra time and of ort. e recommend that the ma foundation
excavation should be inspected by an engineering geologist or geotechnical engineer prior to
foundation lacement. A bearin value of 2,500 psf may be used for foundation design. High
s a e e t u u s e a o i p t n g r
values are used. We can provide rock/soil parameters for retaining wall design if requested.
Stratum Group appreciates the opportunity to be of service to you. Should you have any
questions regarding this assessment please contact me at(360) 510-5406 (cell) or(360) 714-
9409 (office).
Sincerely yours, ,+
ok Was
Stratum Group
1376
Dan McShane, L.E.G., M.Sc.
Licensed Engineering Geologist DA IEL IIMc HANE
Stratum Group File: 6.1.25
5