HomeMy WebLinkAboutStormwater Pollution Plan - BLD Engineering / Geo-tech Reports - 10/10/2016 A'=`,A N.L.01son&Associatesinc,
Engineering, Planning and Land Surveying.
October 10, 2016 RECEIVED
Michael MacSems OCT 12 2016
Mason County Department of Community Services
615 W. Alder 615 W.Alder Stl W
Shelton, WA 98584
RE: 150 E. Stretch Island Rd N. -Boles Residence
Submittal#1
Dear Mr. MacSems:
Please find four copies of the revised Construction Stormwater Pollution Plan Checklist
and four copies of the revised Storm Drainage Analysis in response to the comments sent
by e-mail on 9/28/2016 regarding Submittal No. 1:
1. The Construction Stormwater Pollution Plan submittal checklist has been updated
with more detailed references to the storm report, including page, section, and
paragraph.
2. The Storm report has been updated, most notably with more detail on adjacent
residences (page 1,paragraph 2), and more detailed information on the soils(page
1,paragraph 3).
3. No phasing is proposed, and construction is expected to commence upon plan
approval.
4. Operation and Maintenance Covenant form is enclosed.
5. Revised checklist is stamped.
6. Although grading threshold for SEPA is reached,the project falls under the
Categorical Exemption for minor construction mentioned in WAC 197-11-
800(1)(b)(i)and Mason County Code 8.16.020 due to being a single family
residence. Although the plan allows for minor clearing and conversion to pasture
in the area of the reserve drainfield, no excavation or grading will be required
within 200 feet of the wetland. Thus, and SEPA should not be required for this
project.
7. Titles have been revised to emphasize the address (150 E Stretch Island Rd N.)in
the project title to ensure the plans are with the location, rather than the owner.
If you have any questions or need an additional copy of the above plans,please do not
hesitate to call mys r Ron Johnson at 360-867-2284. Thank you.
Sincerel
No an L. Olson II, P. E.
N.L. Olson& Associates, Inc.
encl
2453 BETHEL AVENUE, P.O. BOX 637, PORT ORCHARD, WASHINGTON 98366
(360) 876-2284 FAX (360) 876-1487
RECEIVED
OCT 12 2016
Mason County g15 W fVgrA Construction Stormwater Pollution Plan Submi a e
Project Name: 150 E. Stretch Island Road N - Boles Residence
Parcel#'s: 12108-75-00080
County Project No.:
Author of Report: NL Olson & Associates, Inc.
Minimum Reguirements of the DOE 2005 Stormwater Manual
The Stormwater checklist identifies the minimum requirements of the DOE 2005 Stormwater Manual.
The Checklist is intended to identify the locations within the plan that addresses the minimum
requirements. Mason County will not perform a technical evaluation of the submittal. Rather,the
checklist provides a guide to allow Mason County to review the submittal and determine if the applicant
has addressed the minimum features that make up a Stormwater plan.
It is incumbent upon the applicant and his/her engineer to fulfill all the applicable requirements of the
2005 Stormwater Plan as it relates to the proposed project. Review by Mason County is intended to
determine if the plan has addressed the minimum requirements.Applicant's engineer shall be responsible
for the technical accuracy of the submitted Stormwater plan.
During construction of the project,the stormwater plan engineer of record or his/her authorized
representative shall inspect the site to ensure the stormwater plan is being implemented as designed. Upon
completion of the project,the engineer or his authorized representative shall be required to certify that the
stormwater plan has been implemented as designed.
Failure to meet the minimum requirements could result in delay or rejection of the application until the
deficiencies are corrected.
Section I—Construction SWPPP Narrative
1. Construction Stormwater Pollution Prevention Elements
x a. Describe how each of the Construction Stormwater Pollution Prevention Element has been
addressed though the Construction SWPPP.
x b. Identify the type and location of BMPs used to satisfy the required element.
x c. Written justification identifying the reason an element is not applicable to the proposal.
12 Required Elements—Construction Stormwater Pollution Prevention Plan
x 1. Mark Clearing Limits, See page/paragraph Page 7, Section 1, Element 1 & Figure 3
x 2. Establish Construction Access, See page/paragraph Page 7, Section 1, Element 2, & Figure 4
x 3. Control Flow Rates, See page/paragraph Page 7, Section 1, Element 3& Figure 4
x 4. Install Sediment Controls, See page/paragraph Pg 2, Sect V& Pg7, Sect 1 Element 4& Figure 4
x 5. Stabilize Soils, See page/paragraph Pg 7, Sect 1, Element 4 &Sheets C3.0, C3.1-Civil Plan Set
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x 6. Protect Slopes, See page/paragraph "Page 1, Section 1, Element 6
x 7. Protect Drain Inlets, See page/paragraph **Page 7, Section 1, Element 7
x 8. Stabilize Channels and Outlets, See page/paragraph **Page 8, Section 1, Element 8
x 9. Control Pollutants, See page/paragraph **Pages 4-6, Section E, Paragraphs 1-4
x 10. Control De- Watering, See page/paragraph **Pages 6-7, Section F, Paragraph 3
x 1 l. Maintain BMPs, See page/paragraph **Page 8, Section 1, Element 11
x 12. Manage the Project, See page/paragraph **Page 8, Section 1, Element 12
2. Project Description
x a. Total project area. Acres 0.75 Sq. Ft. 33,000
x b. Total proposed impervious area. Acres 0.11 Sq. Ft. 4,700
x c. Total proposed are to be disturbed, included off-site borrow and fill areas.
Acres 0.75 Sq. Ft. 33,000
x d. Total volumes of proposed cut and fill. Cubic Yards —1,100cy cut/ 1,100 Cy fill
3. Existing Site Conditions
x a. Description of the existing topography. See page/paragraph** Page 1, Section I, Paragraph 4 & Figure 2
x b. Description of the existing vegetation. See page/paragraph ** Page 1, Section I, Paragrpah 4
x c. Description of the existing drainage. See page/paragraph** Page 1, Section I, Paragraphs 4 & 5
4. Adjacent Areas
x 1. Description of adjacent areas that may be affected by the site disturbance
x a. Streams, See page/paragraph ** Page 2, Section IV, Paragraph I
x b. Lakes, See page/paragraph ** Page 2, Section IV, Paragraph I
x c. Wetlands, See page/paragraph ** Page 1, Section I Paragraph 4
x d. Residential Areas, See page/paragraph ** Page 1, Section I, Paragraph 2
e. Roads, See page/paragraph**Appendix A, Figure 1 - Vicinity Map, Figure 2 - Topo Survey
N/A f. Other, See page/paragraph N/A
x I1. Description of the downstream drainage path leading from the site to the receiving body of water.
(Minimum distance of 400 yards), See page/paragraph **Page 2, Section IV, Paragraph I
5. Critical Areas
x a. Description of critical areas that are on or adjacent to the site.
See page/paragraph ** Page 1, Section I, Paragraph 4 & Section 2
x b. Description of special requirements for working in or near critical areas.
See page/paragraph No work in or within 200' of wetland
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** Storm Drainage Analysis
6. Soils
Description of on-site soils.
x a. Soil name(s), See page/paragraph ** Page 1, Section I, Paragraph 3
x b. Soil mapping unit, See page/paragraph **Appendix A, Figure 6
x c. Erodibility, See page/paragraph Page 1, Section I, Paragraph 3
x d. Settleability, See page/paragraph Page 1, Section I. Paragraph 3
x e. Permeability, See page/paragraph Page 1, Section I, Paragraph 3
x f. Depth, See page/paragraph Page 1, Section I, Paragraph 3
x g. Texture, See page/paragraph Page 1, Section I, Paragraph 3
x h. Soil Structure, See page/paragraph Page 1, Section I, Paragraph 3 and Slope Assessment
7. Erosion Problem Areas ** Page 2, Section V,
x Description of potential erosion problems on site. See page/paragraph Paragraph I Page 8, Section 7
8. Construction Phasing
** Pages 2 & 3, Section V, Subsection A, Page 6,
x a. Construction sequence, See page/paragraph Section F Paragraphs 1-3
x b. Construction phasing (if proposed) , See page/paragraph ** Page 8, Section 8
9. Construction Schedule
x 1. Provide a proposed construction schedule, See page/paragraph ** Pages 8 & 9. Section 9
x 11. Wet Season Construction Activities
x a. Proposed wet season construction activities, See page/paragraph Pages 8 & 9, Section 9
x b. Proposed wet season construction restraints for environmentally sensitive/critical areas. See
page/paragraph Pages 8 & 9, Section 9
10. Engineering Calculations
Provide Design Calculations.
N/Aa. Sediment Ponds/Traps, See page/paragraph No sediment ponds/traps required
N/A b. Diversions, See page/paragraph No diversion trenches required
N/A c. Waterways, See page/paragraph No waterways on site
x d. Runoff/Stormwater Detention Calculations, See page/paragraph Page 10, Section V.B. 2 & 3
11. Operations and Maintenance.
x An operation and maintenance schedule shall be provided for all proposed stormwater facilities and
BMPs, and the party (or parties) responsible for maintenance and operation shall be identified. An
operation and maintenance (O&M) Declaration of Covenant will be required to cover all privately
owned and maintained stormwater facilities. O&M Declaration of Covenant forms are available at
the Mason County Permit Assistance Center, 615 W. Alder Street, Shelton, WA 98584. The
proponent shall record a copy of the completed Declaration with the Mason County Auditors' office.
A copy of the recorded document must be submitted to the Permit Assistance Center together with
this completed Checklist. See page/paragraph Minimal Maintenance Required
O&M Covenant is included
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** Storm Drainage Analysis
Section II—Erosion and Sediment Control Plans
1. General
x a. Vicinity Map, See page/paragraph **Appendix A, Figure 1, Plan Set Drawing C1.0
X b. Clearing and Grading Approval Block, See page/paragraph Plan Set Drawings C3.0, C5.0
x c. Erosion and Sediment Control Notes, See page/paragraph Plan Set Drawing C3.1
2. Site Plan
x a. Legal description of subject property
x b. North Arrow
X c. Indicate boundaries of existing vegetations, e.g. tree lines, pasture areas, etc Storm Report
x d. Identify and label areas of potential erosion problems, See page/paragraph Page 8. Section 7
X e. Identify any on-site or adjacent surface waters, critical areas and associated buffers
N/A f. Identify FEMA base flood boundaries and Shoreline Management boundaries(if applicable), See
page/paragraph N/A
x g. Show existing and proposed contours
X h. Indicate drainage basins and direction of flow for individual drainage areas
x i. Label final grade contours and identify developed condition drainage basins
x j. Delineate areas that are to be cleared and graded
x k. Show all cut and fill slopes indicating top and bottom of slope catch lines
3. Conveyance Systems
•a. Designate locations for swales, interceptor trenches, or ditches
•b. Show all temporary and permanent drainage pipes, ditches, or cut-off trenches required for erosion
and sediment control
x c. Provide minimum slope and cover for all temporary pipes or call out pipe inverts
x d. Show grades, dimensions, and direction of flow in all ditches, swales, culverts, and pipes
x e. Provide details for bypassing off-site runoff around disturbed areas
X f. Indicate locations and outlets of any dewatering systems
4. Location of Detention BMPs (No detention proposed)
N/A a. Identify location of detention BMPs.
5. Erosion and Sediment Control Facilities (No facilities other than silt fence proposed)
N/A a. Show the locations of sediment trap(s), pond(s), and pipe structures.
N/A b. Dimension pond berm widths and inside and outside pond slopes.
N/A c. Indicate the trap/pond storage required and the depth, length, and width dimensions.
N/A d. Provide typical section views through pond and outlet structure.
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** Storm Drainage Analysis
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N/A e. Provide typical details of gravel cone and standpipe, and/or other filtering devices. N/A
N/A f. Detail stabilization techniques for outlet/inlet. No detail
N/A g. Detail control/restrictor device location and details. (No control)
h. Specify mulch and/or recommended cover of berms and slopes. Sheet C3.1
N/A i. Provide rock specifications and detail for rock check dams. (No check dams)
N/A j. Specify spacing for rock check dams as required. N/A
N/A k. Provide front and side sections of typical rock check dams. N/A
1. Indicate the locations and provide details and specifications for silt fabric. Sheets C3.0 & C3.1
m. Locate the construction entrance and provide a detail. Sheets C3.0 & C3.1
6. Detailed Drawings
x a. Any structural practices used that are not referenced in the Ecology Manual should be explained and
illustrated with detailed drawings. N/A
7. Other Pollutant BMPs
x a. Indicate on the site plan the location of BMPs to be used for the control of pollutants other than
sediment, e.g. concrete wash water. N/A
8. Monitoring Locations
x a. Indicate on the site plan the water quality sampling locations to be used for monitoring water quality
on the construction site, if applicable. N/A
11.1.1 ....... ...... ........ ......... ........ .........
I certify that the stormwater plan submitted for this project fulfills the applicable provisions of the 2005
DOE Stormwater Manual.
/g Its 1L �oN A/Y
E e Date ����w ��o Z
10 f 12 / 16 79
Applicant Date s 1
Place eng. stamp and sign/date above.
5 of 5 Updated May 20,2009
** Storm Drainage Analysis