HomeMy WebLinkAboutConstruction Stormwater Pollution Prevention Plan - PLN General - 5/16/2012 Construction Stormwater Pollution Prevention Plan
for
Shearer Brothers Chipping, LLC.
Industrial Property
100 NE Katchemak Lane, Belfair
Parcel No. 12321-13-90051
Mason County, Washington
May 16, 2012
Project#1251
Prepared For:
Shearer Brothers Chipping, LLC
PO Box 2638
Belfair, Washington 98528 p�ti CLYDE s
wAsfjl�Ty7tt'
Prepared By:
Envirotech Engineering
PO Box 984 43045
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Belfair, Washington 98528 �s�R�
�SS�oNALtiN�' '
Phone: 360-275-9374
Fax: 360-275-4789
. I
Envirotech Engineering (Envirotech) has completed this construction stormwater pollution
prevention plan (SWPPP) in conjunction with the stormwater management plan for an industrial
property located at 100 NE Katchemak Lane, parcel number 12321-13-90051 in Mason County,
Washington(Project).
The following sections in this SWPPP includes Project Description, Existing Site Conditions,
Adjacent Areas, Critical Areas, Soils, Erosion Problem Areas, Construction Phasing/ Schedule,
Engineering Calculations, and the twelve (12) required SWPPP elements per the 2005
Department of Ecology Stormwater Management Manual
Project Description
Information pertaining to the Project was provided by the proponent of the property, and
observations from a field visit by Envirotech. The property is currently developed with a
mechanic/ work shop, onsite septic, liquid storage tanks, swales, retention pond, fencing, and
natural surfaced parking lot. The proposed development is expected to consist of a 120 x 60
building to be used as a dry storage facility.
It is anticipated that the new building will cover approximately 7200 square feet(sf). Including
adjacent storage and roof overhang, the roof area will be about 9260 sf. The existing ingress/
egress and parking area encompasses about 63,815 sf.The total proposed impervious surface area
is the new building (9260 sf). Considering both proposed and existing impervious surfaces, the
area is approximately 82,950 sf. The total land area that is anticipated to be disturbed as a result
of development is 0.28 acres.Cut and fill quantities were approximated to be 130 cubic yards(cy)
and 40 cy, respectively. See the accompanying stormwater management plans for an illustration
of current and proposed site features.
Existing Site Conditions
The Project is currently developed as previously mentioned, and surrounded by rural residential
and commercial development. Katchemak Lane extends just beyond the south side of the
property, and a US Naval railroad is located to the west of the property. Vegetation on and near
the property consists primarily of 2°d growth firs, and other trees and shrubbery common to this
area of the Pacific Northwest. The property is mostly cleared in conjunction with the existing
development. An aerial photo of the Project and immediate vicinity is provided on the following
page.
The topographic information provided in this section was extrapolated from a public lidar source,
and incorporated observations and field measurements. Where necessary, slope verification
included measuring slope lengths and inclinations with a cloth tape and inclinometer. Except for
the railroad embankment,descending slopes exceeding 15%were not observed within 300 feet of
the property.Natural slopes with grades averaging 10%were observed approximately 150 feet to
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the west of the property.
Ascending grades are generally located to the east and southeast of the planned development.The
immediate slope has been cut to approximately 2:1 with a vertical relief of up to 15 feet.Natural
ascending slopes with grades exceeding 15% were not observed within 300 feet of the Project.
The upland area of the property is situated on a gentle sloping hillside near a crest. Landforms are
primarily of glacial origin.
The majority of the stormwater runoff originating upslope from the anticipated development is
expected to be minimal. The upland watershed is very small. Significant scour, erosion and
sediment transport was not apparent on the Project. There are no apparent water bodies or
wetlands located upslope from the planned development that would significantly influence the
Project.
Adjacent Areas
Adjacent areas include vacant land, railroad, rural residential and industrial development. Site
disturbance is not expected to disturb adjacent areas if all provisions in the stormwater
management plan are followed. Currently, these areas and roads are near the project that has the
potential to be affected by the site disturbance. Streams, lakes,wetlands,or other significant areas
are not adjacent to the property.
Downstream drainage appears to naturally flow in a northwesterly direction. However, the
railroad embankment prevents surface water flow. This project is within the Hood Canal
watershed.
Critical Areas
Critical areas were not observed within the vicinity of the project. This project is not anticipated
to disturb any critical area, and special requirements (other than following the stormwater
management plan)are not required.
Soils
Information on infiltration rates and soil conditions pertaining to the Project was accomplished by
Envirotech. For complete details, see the Geological Assessment prepared for the Shearer
Brothers Chipping, LLC. Industrial Property, dated April 30, 2012. Selected information
pertaining to the drainage aspect of the project is provided below.
The following subsurface conditions are estimated descriptions of the Project subgrade utilizing
information from the depth of penetration at all testing, sampling, observed and investigated
locations. Specifically, soils for this project were described utilizing the Unified Soil
Classification System (USCS), Soil Conservation Service (SCS), and the U.S. Department of
Agriculture(USDA)Textural Classification System.
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The Project is composed of native soils with no indications of significant borrowed fill. For
engineering purposes,these native soils consist of distinguishable layers,as presented below.
Soils within the upper 10 feet of natural ground were primarily observed to be moist, brown
poorly graded sand with some gravel(SP).
According to the "Soil Survey of Mason County," by the United States Department of
Agriculture, Soil Conservation Service, the upland site soils are described as Indianola Loamy
Sand, Ib with 5%to 15% slopes. The soil designation is depicted in the aerial photograph below,
and complete descriptions are provided in Appendix B of this report.
According to the USDA Textural Classification System, the site soils are primarily classified as
medium sand. Soil structure may be described as granular.
From the water well report(s) and knowledge of the general area, permanent groundwater is
approximately 100 feet directly below the property at the lowest building pad location. Perched
groundwater at shallow depths was not observed on-site,nor indicated on the well reports.
The soil samples obtained at the Project site during the field investigation were preserved and
transported for possible laboratory testing. Visual classification of soils was performed in the
field at all observed soil profiles. Visual classifications were performed in accordance with the
American Standards for Testing and Materials(ASTM D2488).
The general results from the visual classification are presented above in the Subsurface
Conditions Section. Specifically,soils within the upper 10 feet in one testing location consisted of
approximately 5% gravel, 95%medium sand-sized soils, and nearly 0% fines with no plasticity.
Minor variations observed during the visual classification of particle size content (i.e. gravel,
sand, fines), or isolated pockets within the soil stratification were insignificant in relation to the
overall engineering properties of the soil. The soil gradation meets the requirements for pollution
liners per the 2005 Department of Ecology Stormwater Manual.
Based on the fines content,erodibility of the site soils is considered to be low. Based on the fines
content and fraction of clay within the fines content, settleability of the site soils is expected to be
moderate to fast. Permeability is expected to be high for this site due significance of moderate
density,poorly graded granular soils.
According to the 2005 Stormwater Management Manual for Western Washington prepared by the
Washington State Department of Ecology Water Quality Program, infiltration rates are
determined per the USDA Textural Classification of the soils,and an appropriate factor of safety.
Based on the soils consisting predominantly sand, and utilizing a factor of safety of 2, site
infiltration for stormwater facilities should be 2 inches/hour.
Erosion Problem Areas
There are no identified or mapped erosion hazard areas for this property. While the soil
characteristics provide a low erodibility factor,the steeper slopes could exacerbate erosion.
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Construction Phasing
Construction phasing for this project is not anticipated. The following includes the recommended
construction sequence and procedure for project development:
1. Delineate clearing and easement limits.
2. Construct all required temporary erosion control features.
3. Clear vegetation required for site development.
4. Perform initial earthwork and rough grading for constructing the building pad,
stormwater management facilities, etc. If necessary, exposed soils in stock piles must be
protected with plastic covering or County approved method.
5. Complete final grading of the subgrade, and materials placement per the plans and
specifications. This includes dredging sediments from temporary sediment facilities, if
necessary.
6. Maintain all temporary erosion and sediment control facilities, as needed, in order to
provide the required protection of downstream water quality. Additional temporary
erosion control shall be rendered throughout the duration of the project,if necessary.
7. Provide permanent erosion control in order to stabilize the project.
8. Remove temporary erosion sedimentation control facilities after construction is complete,
and the site is sufficiently stabilized.
Construction Schedule
The project is already cleared and graded in conjunction with the existing development.
Construction of this project is expected to take place in the latter half of 2012. Wet season erosion
control may be required for this project,but unlikely. Wet season construction constraints are not
necessary for critical areas.
Engineering Calculations g gC c s
Standard sediment ponds and traps were not utilized for this project.However, sedimentation due
to construction runoff is anticipated to be retained on site. Significant diversions and waterways
were not utilized for this project.
The drainage report consists of calculations for 100yr-24hr and 6mo-24hr storm events. Runoff
was shown to be contained on-site due to a 100yr-24hr event. Consequently, stormwater
accumulated from a 2yr-24hr temporary erosion storm event will be easily accommodated.
Operation and Maintenance
An operation and maintenance schedule for construction activities are provided below within the
Specific Construction SWPPP Items. An operation and maintenance schedule for all proposed
stormwater facilities and BMP's are provided under a separate cover titled "Operation and
Maintenance Manual for Shearer Brothers Chipping, LLC. Industrial Property"An operation and
Envirotech Engineering -- - ----- --- — Shearer Brothers Chipping,LLC
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maintenance Declaration of Covenant will be required to cover all privately owned and
maintained stormwater facilities.
Specific Construction SWPPP Items
The following 12 items are addressed herein per the 2005 Department of Ecology Stormwater
Manual
1.0 Mark Clearing Limits
Clearing limits shall be delineated on-site by the owner/contractor. Activities are not permitted
beyond the designated clearing limits without prior approval and/or permits. Currently, clearing
limits are designated as the existing fence line.
2.0 Establish Construction Access
Construction access shall be limited to a single entrance to access the project during construction.
If needed, a stabilized construction access adjacent to Katchemak Lane shall be built per the
erosion control plans.
3.0 Control Flow Rates
Properties and waterways located downstream from the construction site is protected from
erosion by adhering to the stormwater management manual by containing all construction runoff
on-site due to the 2yr 24hr storm event. Due to this, a downstream analysis is not necessary for
this project during construction.Temporary retention/detention stormwater facilities, if any, shall
be functional prior to the construction of site improvements. Additional or different stormwater
flow control may be necessary if current designed facilities are not functioning as intended. If
permanent infiltration ponds are used for flow control during construction, these facilities should
be protected from siltation during the construction phase.
4.0 Install Sediment Controls
Sediment controls deemed adequate for this project are vegetated facilities,designed interceptors,
or other controls as necessary. See the stormwater management plan for locations and details.
5.0 Stabilize Soils
Soil stabilization is necessary for this project.Temporary seeding and permanent soil stabilization
requirements are provided in the stormwater management plans. This also includes stabilizing all
exposed and unworked soils from runoff and wind erosion.
6.0 Protect Slopes
Both natural and fill slopes shall be protected per the stormwater management plans. This
includes stabilizing with vegetation,and maintaining natural vegetation.
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7.0 Protect Drain Inlets
There is one existing drain inlet on the property utilized for the existing development portion of
the project.The proposed construction is not expected to influence the drain inlet.
8.0 Stabilize Channels and Outlets
All designed channels and outlets, if any, shall be stabilized with vegetation, riprap, or other
appropriate means.Currently,two rock energy dissipaters are on-site at the junction of the swales
and the infiltration pond. See the stormwater management plans for locations and details.
9.0 Control Pollutants
Pollution generated from construction must be controlled at all times. Control of pollutants other
than sediments includes the following:
I. All pollutants other than sediments, including waste materials and demolition debris,that
occur on-site shall be handled and disposed of in a manner that does not cause
contamination of stormwater. Woody debris may be chopped and spread on site.
2. Cover, containment and protection from vandalism shall be provided for all chemicals,
liquid products,petroleum products,and non-inert wastes present on the project site.
3. Maintenance and repair of heavy equipment and vehicles involving oil changes,hydraulic
system drain down, solvent and de-greasing 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 must be conducted using spill prevention
measures, such as drip pans. Contaminated surfaces shall be cleaned immediately
following any discharge or spill incident. Emergency repairs may be performed on-site
using temporary plastic placed beneath and, if raining,over the vehicle.
4. Wheel wash or fire bath wastewater shall be discharged to a separate on-site treatment
system or to the sanitary sewer, if available.
5. Application of agricultural chemicals including fertilizers and pesticides shall be
conducted in a manner, and at application rates that will not result in loss of chemical to
stormwater runoff.Manufacturers' recommendations for application rates and procedures
shall be followed.
6. BMP's shall be used to prevent or treat contamination of stormwater runoff by pH
modifying sources. These sources include, but are not limited to, bulk cement, cement
kiln dust,fly ash,new concrete washing and curing waters,waste streams generated from
concrete grinding and sawing, exposed aggregate processes, and concrete pumping and
mixer washout waters. Stormwater discharges shall not cause or contribute to a violation
of the water quality standard for pH in the receiving waters.
7. Construction sites with significant concrete work shall adjust the pH of stormwater if
necessary to prevent violations of water quality standards.
10.0 Control Dewatering
Although dewatering will not be likely for this project, special provisions are required to be
followed when dewatering. The outlet for dewatering shall be located in a position as to prevent
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sediments and pollution from leaving the site.This may be accomplished by pumping water into a
sedimentation pond,or other standard control.
11.0 Maintain BMP's
All temporary BMP's must be inspected and maintained accordingly.This includes the following:
Stabilized Construction Entrance
The stabilized construction entrance shall be inspected at reasonable increments. Increased usage
of the construction entrance wan-ants more frequent inspections. Rock shall be added
periodically, if necessary.
Temporary Sediment Traps/Permanent Infiltration Ponds
Temporary sediment traps are to be inspected after each rainfall event, and daily during
prolonged rainfall.The accumulation of sediments that reaches no more than 1-foot in depth shall
be removed and used as appropriate on-site fill or disposed in an approved off-site dump. Side
slopes, weir and other sediment trap features shall be immediately repaired, if necessary.
Permanent infiltration ponds shall be inspected periodically, and maintained as necessary, for a
build-up of sedimentation,debris from trees or other vegetation,or any other foreign debris.
Permanent Vegetation
Permanent vegetation shall initially be inspected regularly to insure establishment and healthy
growth. Once established, vegetation may need to be periodically fertilized for continuous
growth.Vegetation shall be re-established in areas,if necessary.
While active construction is in process,all temporary erosion and sediment control facilities shall
be inspected and immediately maintained if necessary per the requirements provided above. In
the event that construction activities are discontinued for at least 4 consecutive days, the owner
shall be responsible for the inspection, and immediate maintenance if necessary,of all temporary
erosion and sediment control facilities immediately after storm events, and at least once every 7
days.
In addition to the aforementioned inspection and maintenance schedule, the owner shall install
additional erosion and sediment control facilities if proposed erosion and sediment control
measures prove to be inadequate.
Dust Control
RESPRAY AREA AS NECESSARY TO KEEP DUST TO A MINIMUM.
Concrete Handling
CONTAINERS SHALL BE CHECKED FOR HOLES IN THE LINER DAILY DURING
CONCRETE POURS AND REPAIRED THE SAME DAY.
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Maintenance Responsibility
Inspection, maintenance, and financial liability of all temporary/ permanent erosion and
sedimentation control facilities shall ultimately be the responsibility of the owner's utilizing the
facilities.Currently,the following proponent is in charge of this responsibility:
Shearer Brothers Chipping,LLC.
PO Box 2638
Belfair,Washington 98528
360-426-5546
Furthermore, the owner shall establish a Certified Erosion and Sediment Control Lead (CESCL)
for construction observation and oversight of the project to ensure compliance with the ESC
components of the approved Drainage and Erosion/ Sediment Control Plans. This designation
currently belongs to:
Shearer Brothers Chipping,LLC.
PO Box 2638
Belfair,Washington 98528
360-426-5546
12.0 Manage the Project
The designated manager for this project is:
Shearer Brothers Chipping,LLC.
PO Box 2638
Belfair,Washington 98528
360-426-5546
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May 16,2012
Mason County
Construction Stormwater Pollution Plan Submittal Checklist
Project Name: YFir f A- n LLC riu
Parcel#'s: M321-/3-9GCO
County Project No.:
Author of Report:
Minimum Requirements of the DOE 2005 Stor►nwater 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
_a. Describe how each of the Construction Stormwater Pollution Prevention Element has been
addressed though the Construction SWPPP.
b. Identify the type and location of BMPs used to satisfy the required element.
c. Written justification identifying the reason an element is not applicable to the proposal.
12 Required Elements-Construction Stormwater Pollution Prevention Plan
_ 1. Mark Clearing Limits, See page/paragraph
2. Establish Construction Access, See page/paragraph .5�4
3. Control Flow Rates, See page/paragraph sl�
4. Install Sediment Controls, See page/paragraph ,416
5. Stabilize Soils, See page/paragraph SZ7
IACommunity DevelopmenAPAC\STORMWATER 1 of 5 Updated May 20,2009
_6. Protect Slopes, See page/paragraph .r/B
7. Protect Drain Inlets, See page/paragraph Z
8. Stabilize Channels and Outlets, See page/paragraph 6�2
9. Control Pollutants, See page/paragraph
10. Control De-Watering, See page/paragraph 9'IS ,t 71/
l 1. Maintain BMPs, See page/paragraph 7/2- $ $/1 —¢
12. Manage the Project, See page/paragraph 15A
2. Project Description
a. Total project area. Acres Sq. Ft. �`Z 950
b. Total proposed impervious area. Acres Sq. Ft. 9?6_0
c. Total proposed are to be disturbed, included off-site borrow and fill areas.
Acres 0•% Sq. Ft.
_d. Total volumes of proposed cut and fill. Cubic Yards /70
3. Existing Site Conditions
a. Description of the existing topography. See page/paragraph
b. Description of the existing vegetation. See page/paragraph /fr-
c. Description of the existing drainage. See page/paragraph 2/3
4. Adjacent Areas
I. Description of adjacent areas that may be affected by the site disturbance
a. Streams, See page/paragraph
b. Lakes, See page/paragraph !!�
c. Wetlands, See page/paragraph /✓
d. Residential Areas, See page/paragraph
e. Roads, See page/paragraph
f. Other, See page/paragraph
II. Description of the downstream drainage path leading from the site to the receiving body of water.
(Minimum distance of 400 yards), See page/paragraph 2�s
5. Critical Areas
_a. Description of critical areas that are on or adjacent to the site.
See page/paragraph 2�1
b. Description of special requirements for working in or near critical areas.
See page/paragraph
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6. Soils
Description of on-site soils.
_a. Soil name(s), See page/paragraph NZ
b. Soil mapping unit, See page/paragraph /.�
c. Erodibility, See page/paragraph 3/
d. Settleability, See page/paragraph
e. Permeability, See page/paragraph
f. Depth, See page/paragraph 31'2-
g. Texture, See page/paragraph
h. Soil Structure, See page/paragraph /1-
7. Erosion Problem Areas
Description of potential erosion problems on site. See page/paragraph 3�/O
8. Construction Phasing
a. Construction sequence, See page/paragraph
b. Construction phasing(if proposed) , See page/paragraph �ffj
9. Construction Schedule
I. Provide a proposed construction schedule, See page/paragraph
_II. Wet Season Construction Activities
a. Proposed wet season construction activities, See page/paragraph
_b. Proposed wet season construction restraints for environmentally sensitive/critical areas. See
page/paragraph ff3
10.Engineering Calculations
Provide Design Calculations.
a. Sediment Ponds/Traps, See page/paragraph
b. Diversions, See page/paragraph
c. Waterways, See page/paragraph
d. Runoff/Stormwater Detention Calculations, See page/paragraph ¢�S
11. Operations and Maintenance.
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,426 W. Cedar 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 6 �- /
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Section II—Erosion and Sediment Control Plans
1. General
a. Vicinity Map, See page/paragraph
b. Clearing and Grading Approval Block, See page/paragraph /f/�
c. Erosion and Sediment Control Notes, See page/paragraph 5� Z
2. Site Plan
_a. Legal description of subject property
b.North Arrow
c. Indicate boundaries of existing vegetations, e.g. tree lines,pasture areas, etc.
d. Identify and label areas of potential erosion problems, See page/paragraph
e. Identify any on-site or adjacent surface waters, critical areas and associated buffers
f. Identify FEMA base flgoA boundaries and Shoreline Management boundaries(if applicable), See
page/paragraph
g. Show existing and proposed contours
h. Indicate drainage basins and direction of flow for individual drainage areas
i. Label final grade contours and identify developed condition drainage basins
j. Delineate areas that are to be cleared and graded
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
c. Provide minimum slope and cover for all temporary pipes or call out pipe inverts
d. Show grades, dimensions, and direction of flow in all ditches, swales, culverts, and pipes
_e. Provide details for bypassing off-site runoff around disturbed areas
f. Indicate locations and outlets of any dewatering systems
4. Location of Detention BMPs
a. Identify location of detention BMPs.
5. Erosion and Sediment Control Facilities
a. Show the locations of sediment trap(s),pond(s), and pipe structures.
b. Dimension pond berm widths and inside and outside pond slopes.
c. Indicate the trap/pond storage required and the depth, length, and width dimensions.
d. Provide typical section views through pond and outlet structure.
L•\Community Development\PAC\STORMWATER 4of5 Updated May 20,2009
i
e. Provide typical details of gravel cone and standpipe, and/or other filtering devices.
f. Detail stabilization techniques for outlet/inlet.
g. Detail control/restrictor device location and details.
_h. Specify mulch and/or recommended cover of berms and slopes.
i. Provide rock specifications and detail for rock check dams.
_j. Specify spacing for rock check dams as required.
k. Provide front and side sections of typical rock check dams.
_1. Indicate the locations and provide details and specifications for silt fabric.
in. Locate the construction entrance and provide a detail.
6.Detailed Drawings
_a. Any structural practices used that are not referenced in the Ecology Manual should be explained and
illustrated with detailed drawings.
7.Other Pollutant BMPs
_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.
8.Monitoring Locations
a. Indicate on the site plan the water quality sampling locations to be used for monitoring water quality
on the construction site, if applicable.
I certify that the stormwater plan submitted for this project fulfills the applicable provisions of the 2005
DOE Stormwater Manual.
CLYI,L�S
Engineer Date
r
N
1�
43045 1W�
Applican Date S�NALRG
Place eng. stamp and sign/date above.
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w
Mason County Review Checklist
For a Stormwater Plan
Instructions:
This checklist is intended to assist Staff in the review of a Stormwater Plan. The Stormwater Plan is
reviewed for completeness with respect to the 2005 Department of Ecology Stormwater Manual. If an
item is found to be not applicable, the Plan should explain the basis for the conclusion. The Plan is also
reviewed for clarity and consistency. If the drawings, discussion, or recommendations are not
understandable, they should be clarified. If they do not appear internally consistent or consistent with the
application or observations on site, this needs to be corrected or explained. If resolution is not achieved
with the author, staff should refer the case to the Planning Manager or Director.
Applicant's Name: &53i�
Permit# C —lV�-- vV �i,0001 `1 Parcel#
Date(s)of the Document(s) reviewed:
SECTION I—Construction SWPPP Narrative
(1) Construction Stormwater Pollution Prevention Elements:
(a) Describe how each of the Construction Stormwater Pollution Prevention Element has been
addressed through the Construction SWPPP.
OK? Comment:
(b) Identify the type and location of BMP's used to satisfy the required element.
OK? Comment:
(c) Written justification identifying the reason an element is not applicable to the proposal.
OK? Comment:
(d) 12 Required Elements—Construction Stormwater Pollution Prevention Plan
(1) Mark Clearing Limits.
OK? Comment:
(2) Establish Construction Access.
OK? Comment:
(3) Control Flow Rates.
OK? Comment:
(4) Install Sediment Controls.
OK? Comment:
(5) Stabilize Soils.
OK? Comment:
(6) Protect Slopes.
OK? Comment:
(7) Protect Drain Inlets.
OK? Comment:
(8) Stabilize Channels and Outlets.
OK? Comment:
(9) Control Pollutants.
OK? Comment:
(10)Control De-Watering.
OK? Comment:
(11)Maintain BMP's.
OK? Comment:
(12)Manage the Project.
OK? Comment:
Page 1 Form Effective May 2009
V
(2) Project Description.
(a)Total project area (acres/square feet).
OK? Comment:
(b)Total Proposed impervious area (acres/square feet).
OK? Comment:
(c)Total proposed area to be disturbed, included off-site borrow and fill areas (acres/square feet).
OK? Comment:
(d)Total volumes of proposed cut and fill (cubic yards).
OK? Comment:
(3) Existing Site Conditions.
(a) Description of the existing topography.
OK? Comment:
(b) Description of the existing vegetation.
OK? Comment:
(c) Description of the existing drainage.
OK? Comment:
(4)Adjacent Areas.
(1) Description of adjacent areas which may be affected by the site disturbance
(a) Streams
OK? Comment:
(b) Lakes
OK? Comment.-
(c)Wetlands
OK? Comment:
(d) Residential Areas
OK? Comment:
(e) Roads
OK? Comment:
(f) Other
OK? Comment:
(11) Description of the downstream drainage path leading from the site to the receiving body of water
(minimum distance of 400 yards).
OK? Comment:
(5) Critical Areas.-
(a) Description of critical areas that are on or adjacent to the site.
OK? Comment:
(b) Description of special requirements for working in or near critical areas.
OK? Comment:
(6) Soils: Description of on-site soils.
(a) Soil name
OK? Comment:
(b) Soil mapping unit
OK? Comment.
(c) Erodibility
OK? Comment:
(d) Settleability
OK? Comment:
(e) Permeability
OK? Comment:
(f) Depth
OK? Comment:
(g) Texture
OK? Comment:
Page 2 Form Effective May 2009
(h) Soil Structure
OK? Comment:
(7) Erosion Problem Areas.
(a) Description of potential erosion problems on site
OK? Comment:
(8) Construction Phasing.
(a) Construction sequence.
OK? Comment:
(b) Construction phasing (if proposed).
OK? Comment:
(9) Construction Schedule.
I. Provide a proposed construction schedule
OK? Comment:
II. Wet Season Construction Activities
(a) Proposed wet season construction activities.
OK? Comment:
(b) Proposed wet season construction restraints for environmentally sensitive/critical areas.
OK? Comment:
(10)Engineering Calculations. Provide design calculations.
(a) Sediment Ponds/Traps.
OK? Comment:
(b) Diversions.
OK? Comment:
(a) Waterways.
OK? Comment:
(b) Runoff/Stormwater Detention Calculations.
OK? Comment:
(11)Operations and Maintenance
(a). 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, 426 W. Cedar 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.
OK? Comment:
SECTION IIQ—Erosion and Sediment Control Plans
(1) General. (J ✓W �1 ��
(a) Vicinity Map.
OK? Comment:
(b) Clearing and Grading Approval Block.
OK? Comment:
(c) Erosion and Sediment Control Notes.
OK? Comment:
(2) Site Plan.
(a) Legal description of subject property.
OK? Comment:
(b) North Arrow.
OK? Comment:
Page 3 Form Effective May 2009
(c) Indicate boundaries of existing vegetation, e.g. tree lines, pasture areas, etc.
OK? Comment:
(d) Identify and label areas of potential erosion problems.
OK? Comment:
(e) Identify any on-site or adjacent surface waters, critical areas and associated buffers.
OK? Comment:
(f) Identify FEMA base flood boundaries and Shoreline Management boundaries (if applicable).
OK? Comment:
(g) Show existing and proposed contours.
OK? Comment:
(h) Indicate drainage basins and direction of flow for individual drainage areas.
OK? Comment:
(i) Label final grade contours and identify developed condition drainage basins.
OK? Comment:
(j) Delineate areas that are to be cleared and graded.
OK? Comment:
(k) Show all cut and fill slopes indicating top and bottom of slope catch lines.
OK? Comment:
(3) Conveyance Systems.
(a) Designate locations for swales, interceptor trenches, or ditches.
OK? Comment:
(b) Show all temporary and permanent drainage pipes, ditches, or cut-off trenches.
OK? Comment:
(c) Provide minimum slope and cover for all temporary pipes or call out pipe inverts.
OK? Comment:
(d) Show grades, dimensions, and direction of flow in all ditches, swales, culverts, and pipes.
OK? Comment:
(e) Provide details for bypassing off-site runoff around disturbed areas.
OK? Comment:
(f) Indicate locations and outlets of any dewatering systems.
OK? Comment:
(4) Location of Detention BMP's.
(a) Identify location of detention BMP's.
OK? Comment:
(5) Erosion and Sediment Control Facilities.
(a) Show the locations of sediment trap(s), pond(s), and pipe structures.
OK? Comment:
(b) Dimension pond berm widths and inside and outside pond slopes.
OK? Comment:
(c) Indicate the trap/pond storage required and the depth, length, and width dimensions.
OK? Comment.-
(d) Provide typical section views through pond and outlet structure.
OK? Comment:
(e) Provide typical details of gravel cone and standpipe, and/or other filtering devices.
OK? Comment:
(f) Detail stabilization techniques for outlet/inlet.
OK? Comment:
(g) Detail control/restrictor device location and details.
OK? Comment:
(h) Specify mulch and/or recommended cover of berms and slopes.
OK? Comment:
(i) Provide rock specifications and detail for rock check dams.
OK? Comment:
Q) Specify spacing for rock check dams as required.
OK? Comment:
Page 4 Form Effective May 2009
(k) Provide front and side sections of typical rock check dams.
OK? Comment:
(1) Indicate the locations and provide details and specifications for silt fabric.
OK? Comment:
(m) Locate the construction entrance and provide detail.
OK? Comment:
(6) Detailed Drawings.
(a) Any structural practices used that are not referenced in the Ecology Manual should be explained
and illustrated with detailed drawings.
OK? Comment:
(7) Other Pollutant BMP's.
(a) Indicated on the site plan the location of BMP's to be used for the control of pollutants other than
sediment, e.g. concrete wash water.
OK? Comment:
(8) Monitoring Locations.
(a) Indicate on the site plan the water quality sampling locations to be used for monitoring water
quality on the construction site, if applicable.
OK? Comment:
Are the Documents signed and stamped? "Ve-4,
Type and#of License:
If not approved, what is the next action/recommendation for further action?
Reviewed by on
Time spent in review:
SECOND REVIEW/ UPDATE:
Reviewed by on
Time spent in second review:
THIRD REVIEW/ UPDATE:
Reviewed by on
Time spent in third review:
Disclaimer: Mason County does not certify the quality of the work done in this Stormwater Plan.
Page 5 Form Effective May 2009