A06_312237-MuWo_SHE-Prjct_Manual-App_F-Dft_SWPP-2022-10-27_1.pdf

Appendix F, Draft SWPP

PROJECT MANUAL

FOR

CONSTRUCTION

FOR THE

NATIONAL PARK SERVICE

SALMON HABITAT ENHANCEMENT

AT MUIR WOODS, PHASE 2

100% Construction Documents

PMIS-GOGA 312237

October 2022

Civil Engineers and Geomorphologists:

Northern Hydrology and Engineering

PO Box 2515

McKinleyville, CA 95519

PH/FAX: (707) 839-2195

STORMWATER POLLUTION PREVENTION

PLAN

for

MUIR WOODS SALMON HABITAT ENHANCEMENT, PHASE 2

RISK LEVEL 2

WASTE DISCHARGE IDENTIFICATION NUMBER (WDID):

Legally Responsible Person (LRP):

US National Park Service

Building 201, Fort Mason, San Francisco CA 94123 Laura Joss

415-561-4720

Prepared for:

Carolyn Shoulders

US National Park Service Building 201, Fort Mason, San Francisco CA 94123

Project Address:

1 Muir Woods Road, Mill Valley, CA 94941

SWPPP Prepared by:

Keish Environmental

6768 Crosby Ct, San Jose, CA 95129 Hayden Kessenich, QSD

SWPPP Preparation Date October 20, 2022

Estimated Project Dates:

Start of Construction:

July 3, 2023

Completion of Construction:

October 31, 2023

Muir Woods Salmon Habitat i October 2022 Enhancement, Phase 2

Table of Contents Table of Contents .................................................................................................... i

Qualified SWPPP Developer

Legally Responsible Person

Amendment Log

Section 1 SWPPP Requirements

1.1 Introduction

1.2 Permit Registration Documents

1.3 SWPPP Availability and Implementation

1.4 SWPPP Amendments

1.5 Retention of Records

1.6 Required Non-Compliance Reporting

1.7 Annual Report

1.8 Changes to Permit Coverage

1.9 Notice of Termination

Section 2 Project Information

2.1 Project and Site Description

2.1.1 Site Description

2.1.2 Existing Conditions

2.1.3 Existing Drainage

2.1.4 Geology and Groundwater

2.1.5 Project Description

2.1.6 Developed Condition

2.2 Permits and Governing Documents

2.3 Stormwater Run-On from Offsite Areas

2.4 Findings of the Construction Site Sediment and Receiving Water Risk Determination

2.5 Construction Schedule

2.6 Potential Construction Activity and Pollutant Sources

2.7 Identification of Non-Stormwater Discharges

2.8 Required Site Map Information

Section 3 Best Management Practices

3.1 Schedule for BMP Implementation

3.2 Erosion and Sediment Control

3.2.1 Erosion Control

Muir Woods Salmon Habitat ii October 2022

Construction and BMP material stockpiles will be covered to prevent wind erosion

3.2.2 Sediment Controls

3.3 Non-Stormwater Controls and Waste and Materials Management

3.3.1 Non-Stormwater Controls

3.3.2 Materials Management and Waste Management

3.4 Post construction Stormwater Management Measures

Section 4 BMP Inspection, Maintenance, and Rain Event Action Plans

4.1 BMP Inspection and Maintenance

4.2 Rain Event Action Plans

Section 5 Training

Section 6 Responsible Parties and Operators

6.1 Responsible Parties

6.2 Contractor List

Section 7 Construction Site Monitoring Program

7.1 Purpose

7.2 Applicability of Permit Requirements

7.3. Weather and Rain Event Tracking

7.3.1 Weather Tracking

7.3.2 Rain Gauges

7.4 Monitoring Locations

7.5 Safety and Monitoring Exemptions

7.6 Visual Monitoring

7.6.1 Routine Observations and Inspections

7.6.1.1 Routine BMP Inspections

7.6.1.2 Non-Stormwater Discharge Observations

7.6.2 Rain-Event Triggered Observations and Inspections

7.6.2.1 Visual Observations Prior to a Forecasted Qualifying Rain Event

7.6.2.2 BMP Inspections During an Extended Storm Event

7.6.2.3 Visual Observations Following a Qualifying Rain Event

7.6.3 Visual Monitoring Procedures

7.6.4 Visual Monitoring Follow-Up and Reporting

7.6.5 Visual Monitoring Locations

7.7 Water Quality Sampling and Analysis

7.7.1 Sampling and Analysis Plan for Non-Visible Pollutants in Stormwater Runoff Discharges

Muir Woods Salmon Habitat iii October 2022

7.7.1.1 Sampling Schedule

7.7.1.2 Sampling Locations

7.7.1.3 Monitoring Preparation

7.7.1.4 Analytical Constituents

7.7.1.5 Sample Collection

7.7.1.6 Sample Analysis

7.7.1.7 Data Evaluation and Reporting

7.7.2 Sampling and Analysis Plan for pH and Turbidity in Stormwater Runoff Discharges

7.7.2.1 Sampling Schedule

7.7.2.2 Sampling Locations

7.7.2.3 Monitoring Preparation

7.7.2.4 Field Parameters

7.7.2.5 Sample Collection

7.7.2.6 Field Measurements

7.7.2.7 Data Evaluation and Reporting

7.7.3 Sampling and Analysis Plan for pH, Turbidity, and SSC in Receiving Water

7.7.4 Sampling and Analysis Plan for Non-Stormwater Discharges

7.7.4.1 Sampling Schedule

7.7.4.2 Sampling Locations

7.7.4.3 Monitoring Preparation

7.7.4.4 Analytical Constituents

7.7.4.5 Sample Collection

7.7.4.6 Sample Analysis

7.7.4.7 Data Evaluation and Reporting

7.7.5 Sampling and Analysis Plan for Other Pollutants Required by the Regional Water Board 58

7.7.6 Training of Sampling Personnel

7.7.7 Sample Collection and Handling

7.7.7.1 Sample Collection

7.7.7.2 Sample Handling

7.7.7.3 Sample Documentation Procedures

7.8 Active Treatment System Monitoring

7.9 Bioassessment Monitoring

7.10 Watershed Monitoring Option

7.11 Quality Assurance and Quality Control

Muir Woods Salmon Habitat iv October 2022

7.11.1 Field Logs

7.11.2 Clean Sampling Techniques

7.11.3 Chain of Custody

7.11.4 QA/QC Samples

7.11.4.1 Field Duplicates

7.11.4.2 Equipment Blanks

7.11.4.3 Field Blanks

7.11.4.4 Travel Blanks

7.11.5 Data Verification

7.12 Records Retention

Section 8 References

Appendix A: Construction General Permit

Appendix B: Site Maps

Appendix C: Permit Registration Documents

Appendix D: SWPPP Amendment Certifications

Appendix E: Submitted Changes to PRDs

Appendix F: Construction Schedule

Appendix G: Construction Activities, Materials Used, and Associated Pollutants

Appendix H: CASQA Stormwater BMP Handbook Portal: Construction Fact Sheets

Appendix I: BMP Inspection Form

Appendix J: Project Specific Rain Event Action Plan Template

Appendix K: Training Reporting Form

Appendix L: Responsible Parties

Appendix M: Contractors and Subcontractors

Appendix N: Calculations

Appendix O: Weather Reports

Appendix P: Monitoring Records

Appendix Q: Example Storm Event Monitoring Forms

Appendix R: Field Meter Instructions

Appendix S: Supplemental Information

Muir Woods Salmon Habitat 1 October 2022

Qualified SWPPP Developer Approval and Certification of the Stormwater Pollution Prevention Plan

Project Name: MUWO SALMON HABITAT ENHANCEMENT, PHASE 2

Project Number/ID

“This Stormwater Pollution Prevention Plan and its appendices were prepared under my direction to meet the requirements of the California Construction General Permit (SWRCB Orders No. 2009- 009-DWQ as amended by Order 2010-0014-DWQ and Order 2012-0006-DWQ). I certify that I am a Qualified SWPPP Developer in good standing as of the date signed below.”

QSD Signature

Hayden Kessenich

Date

27913

QSD Name

QSD, Keish Environmental

QSD Certificate Number

(310) 924-4958

Title and Affiliation hayden@keishenv.com

Telephone Number

Email

Muir Woods Salmon Habitat 2 October 2022

Legally Responsible Person Approval and Certification of the Stormwater Pollution Prevention Plan

Project Name: MUWO SALMON HABITAT ENHANCEMENT, PH 2

Either the Legally Responsible Person (LRP) or Approved Signatory must electronically sign, certify, and submit via SMARTS to the SWRCB for Notice of Intent, Changes of Information, Annual Reports, and Notices of Termination. In doing so, the LRP or Approved Signatory is certifying:

“I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering the information, to the best of my knowledge and belief, the information submitted is, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.”

The LRP (and Approved Signatory, if applicable) for this project are:

Laura Joss

Legally Responsible Person

Kara Mirmelstein

Approved Signatory

Muir Woods Salmon Habitat 3 October 2022

Amendment Log

Project Name: MUWO SALMON HABITAT ENHANCEMENT, PH 2

Amendment No. Date Brief Description of Amendment, include section and page number Prepared and Approved By

Name:

QSD#

Muir Woods Salmon Habitat 4 October 2022

Section 1 SWPPP Requirements

1.1 INTRODUCTION

This Stormwater Pollution Prevention Plan (SWPPP) is designed to comply with California’s General Permit for Stormwater Discharges Associated with Construction and Land Disturbance Activities (General Permit) Order No. 2009-0009-DWQ (as amended by 2010- 0014-DWQ and 2012-006-DWQ) (NPDES No. CAS000002) issued by the State Water Resources Control Board (State Water Board) Appendix A. This SWPPP has been prepared following the SWPPP Template provided on the California Stormwater Quality Association Stormwater Best Management Practice Handbook: Construction (CASQA 2019). In accordance with the General Permit, Section XIV, this SWPPP is designed to address the following:

Pollutants and their sources, including sources of sediment associated with construction, construction site erosion, and other activities associated with construction activity are controlled;

Where not otherwise required to be under a Regional Water Quality Control Board (Regional Water Board) permit, all non-stormwater discharges are identified and either eliminated, controlled, or treated;

Site BMPs are effective and result in the reduction or elimination of pollutants in stormwater discharges and authorized non-stormwater discharges from construction activity to the Best Available Technology/Best Control Technology (BAT/BCT) standard;

Calculations and design details, as well as BMP controls, are complete and correct.

Stabilization BMPs are installed to reduce or eliminate pollutants after construction is completed are effective and maintained.

The Muir Woods Salmon Habitat Enhancement, Phase 2 Project site comprises approximately

1.08 acres. The Project is located at 1 Muir Woods Road in Mill Valley, California. The project’s location is shown on the Site Map in Appendix B.

1.2 PERMIT REGISTRATION DOCUMENTS

Required Permit Registration Documents (PRDs) shall be submitted to the State Water Board via the Stormwater Multi Application and Report Tracking System (SMARTS) by the Legally Responsible Person (LRP) or authorized personnel (i.e., Approved Signatory) under the direction of the LRP. The project-specific PRDs include:

1. Notice of Intent (NOI);

2. Risk Assessment (Construction Site Sediment and Receiving Water Risk Determination);

3. Site Map;

4. Annual Fee;

5. Signed Certification Statement (LRP Certification is provided electronically with SMARTS PRD submittal); and

6. SWPPP.

Site Maps can be found in Appendix B. A copy of the submitted PRDs shall also be kept in Appendix C along with the Waste Discharge Identification (WDID) confirmation.

Muir Woods Salmon Habitat 5 October 2022

1.3 SWPPP AVAILABILITY AND IMPLEMENTATION

The discharger shall make the SWPPP available at the construction site during working hours (see Section 7.5 of CSMP for working hours) while construction is occurring and shall be made available upon request by a State or Municipal inspector. When the original SWPPP is retained by a crewmember in a construction vehicle and is not currently at the construction site, current copies of the BMPs and map/drawing will be left with the field crew and the original SWPPP shall be made available via request by radio/telephone. (CGP Section XIV.C)

The SWPPP shall be implemented concurrently with the start of ground disturbing activities.

1.4 SWPPP AMENDMENTS

The SWPPP should be revised when:

If there is a General Permit violation.

There is a reduction or increase in total disturbed acreage (General Permit Section II Part C).

BMPs do not meet the objectives of reducing or eliminating pollutants in stormwater discharges.

Additionally, the SWPPP shall be amended when:

There is a change in construction or operations which may affect the discharge of pollutants to surface waters, groundwater(s), or a municipal separate storm sewer system (MS4);

There is a change in the project duration that changes the project’s risk level; or

When deemed necessary by the QSD. The QSD has determined that the changes listed in Table 1.1 can be field determined by the QSP. All other changes shall be made by the QSD as formal amendments to the SWPPP.

The following items shall be included in each amendment:

Who requested the amendment;

The location of proposed change;

The reason for change;

The original BMP proposed, if any; and

The new BMP proposed.

Amendment shall be logged at the front of the SWPPP and certification kept in Appendix D. The SWPPP text shall be revised replaced and/or hand annotated as necessary to properly convey the amendment. SWPPP amendments must be made by a QSD. The following changes have been designated by the QSD as “to be field determined” and constitute minor changes that the QSP may implement based on field conditions.

Muir Woods Salmon Habitat 6 October 2022

Table 1.1 List of Changes to be Field Determined

Candidate changes for field location or determination by QSP (1)

Check changes that can be field located or field determined by

QSP

Increase quantity of an Erosion or Sediment Control Measure X

Relocate/add stockpiles or stored materials X

Relocate or add toilets X

Relocate vehicle storage and/or fueling locations X

Relocate areas for waste storage X

Relocate water storage and/or water transfer location X

Changes to access points (entrance/exits) X

Change type of Erosion or Sediment Control Measure

X

Changes to location of erosion or sediment control X

Minor changes to schedule or phases X

Changes in construction materials X

(1) Any field changes not identified for field location or field determination by QSP must be approved by QSD

1.5 RETENTION OF RECORDS

Paper or electronic records of documents required by this SWPPP shall be retained for a minimum of three years from the date generated or date submitted, whichever is later, for the following items:

The date, place, and time of facility inspections, sampling, visual observations (inspections), and/or measurements, including precipitation;

The individual(s) who performed the facility inspections, sampling, visual observations (inspections), and /or measurements;

The date and approximate time of analyses;

The individual(s) who performed the analyses;

A summary of analytical results from the last three years, the method detection limits and reporting limits, and the analytical techniques or methods used;

Rain gauge readings from site inspections;

QA/QC records and results;

Non-storm water discharge inspections and visual observations (inspections) and storm water discharge visual observation records;

Visual observation and sample collection exemptions records;

NAL Exceedance Reports.

Muir Woods Salmon Habitat 7 October 2022

The records of any corrective actions and follow-up activities that resulted from analytical results, visual observations (inspections), or inspections; and

Results of field measurements and laboratory analyses must be kept in the SWPPP.

These records shall be available at the Site until construction is complete. Records assisting in the determination of compliance with the General Permit shall be made available within a reasonable time to the Regional Water Board, State Water Board, or U.S. Environmental Protection Agency (EPA) upon request. Requests by the Regional Water Board for retention of records for a period longer than three years shall be adhered to.

1.6 REQUIRED NON-COMPLIANCE REPORTING

If a General Permit discharge violation occurs, the QSP shall immediately notify the LRP. The LRP shall include information on the violation with the Annual Report. Corrective measures will be implemented immediately following identification of the discharge or written notice of non-compliance from the Regional Water Board. Discharges and corrective actions must be documented and include the following items:

The date, time, location, nature of operation and type of unauthorized discharge.

The cause or nature of the notice or order.

The BMPs deployed before the discharge event, or prior to receiving notice or order.

The date of deployment and type of BMPs deployed after the discharge event, or after receiving the notice or order, including additional measures installed or planned to reduce or prevent re-occurrence.

Reporting requirements for NALs exceedances are discussed in Section 7.7.2.7.

1.7 ANNUAL REPORT

The General Permit requires that permittees prepare, certify, and electronically submit an Annual Report no later than September 1 of each year. Reporting requirements are identified in Section XVI of the General Permit. Annual reports will be filed in SMARTS and in accordance with information required by the online forms.

1.8 CHANGES TO PERMIT COVERAGE

The General Permit allows for the reduction or increase of the total acreage covered under the General Permit when: a portion of the project is complete and/or conditions for termination of coverage have been met (see Section 1.9); when ownership of a portion of the project is purchased by a different entity; or when new acreage is added to the project.

Modified PRDs shall be filed electronically within 30 days of a reduction or increase in total disturbed area if a change in permit-covered acreage is to be sought. The SWPPP shall be modified appropriately and shall be logged at the front of the SWPPP and certification of SWPPP amendments are to be kept in Appendix D. Updated PRDs submitted electronically via SMARTS can be found in Appendix E.

1.9 NOTICE OF TERMINATION

A Notice of Termination (NOT) must be submitted electronically by the LRP via SMARTS to terminate coverage under the General Permit. According to the requirements of Section II.D.1 of the General Permit, the following method will be used to satisfy final cover requirements:

70 percent final cover method (no computational proof required)

Muir Woods Salmon Habitat 8 October 2022

RUSLE/RUSLE2 method (computational proof required) Custom method (discharger demonstrates that site complies with final stabilization)

The NOT must include a final Site Map and representative photographs of the project site that demonstrate final stabilization has been achieved. The NOT shall be submitted within 90 days of construction completion. The Regional Water Board will consider a construction site complete when the conditions of the General Permit, Section II.D, have been met.

Muir Woods Salmon Habitat 9 October 2022

Section 2 Project Information

2.1 PROJECT AND SITE DESCRIPTION

2.1.1 Site Description

The Muir Woods Salmon Habitat Enhancement, Phase 2 Project site comprises approximately

1.08 acres and is located at 1 Muir Woods Road in Mill Valley, California. The project site is located approximately 15 miles north of San Francisco in Marin County’s Redwood Creek watershed. The project is located at 37.89289/122.57250 and is identified on the Site Map in Appendix B.

2.1.2 Existing Conditions

As of the initial date of this SWPPP, the project site is primarily trail areas, access roads, or thickly vegetated adjacent areas. Trails run along both sides of Redwood Creek in or near the work area. The Main Trail (Redwood Creek Trail) is paved and has wooden boardwalks, and it runs along the northeast side of the creek and along the southwest side of the creek between Bridge 1 and Bridge 3.

2.1.3 Existing Drainage

The project site is in a valley along Redwood Creek. Surface drainage flows into the creek from both sides along heavily vegetated slopes. The creek drains to the south toward the Pacific Ocean at Muir Beach. The elevation within the disturbance area ranges from approximately 140 to 200 feet above mean sea level (msl).

Stormwater is conveyed through surface runoff. Stormwater discharges from the site are considered direct discharges, as defined by the State Water Board, into Redwood Creek because it lies directly downgradient of the work areas. Redwood Creek is not 303(d)-listed and does not have a sediment-related Total Maximum Daily Load, but has the beneficial uses of COLD, MIGRATORY, and SPAWN, which classifies it as sediment-sensitive.

2.1.4 Geology and Groundwater

The site is underlain primarily by bedrock of the Franciscan accretionary assemblage, which is a mixture of deformed metamorphic, igneous, and sedimentary rock at high elevations. At lower elevations, i.e., where the Kent Creek tributary flows into Redwood Creek, the site is underlain by alluvial sediments and clay. Groundwater elevation is variable as it is hydraulically connected to Redwood Creek but is typically 8-9 feet on the National Geodetic Vertical Datum (NGVD) during the rainy season as measured at Green Gulch Pasture, which is located approximately 1.2 miles southeast of the site at a similar elevation (National Park Service and Marin County, 2007). No known cases of groundwater or soil contamination were identified on the State Water Board website, Geotracker (http://geotracker.waterboards.ca.gov/). No groundwater elevation data within the vicinity of the project were available.

2.1.5 Project Description

The project’s approximate improvement areas extend from the visitor center to Bridge 3, upstream of the West Main Trail junction. Improvement work in the stream bed and up to the top of bank, including some work beginning in the stream bed but extending beyond the top of bank, will be covered under a 401 Water Quality Certification. The project area covered under the CGP will consist of staging and stockpile areas, access routes, and boardwalk and asphalt removal areas outside the stream channel. Project activities will include removal of a portion of

Muir Woods Salmon Habitat 10 October 2022 existing sewer line, moving large and small woody debris over the ground surface for placement in the creek channel, replanting, placement of duff material, installation of posts, staging and stockpiling of materials, and transport of materials from staging/stockpile areas to work areas.

2.1.6 Developed Condition

In the developed condition the project site will be returned to its pre-construction state. All grades, topographic features, and trails and slopes will be restored to their original condition.

All clearing and grubbing materials will be collected and stockpiled and reused as permanent stabilization on the work areas.

2.2 PERMITS AND GOVERNING DOCUMENTS

In addition to the General Permit, the following documents have been taken into account while preparing this SWPPP:

Golden Gate National Recreation Area BMP Handbook

Regional Water Board requirements

Basin Plan requirements

Contract Documents

Water Resource Control Board 401 Certification

National Marine Fisheries Service Biological Opinion dated September 20, 2017

2.3 STORMWATER RUN-ON FROM OFFSITE AREAS

Run-on to the site is generated by sheet flow dispersed through mature vegetation.

The stormwater runoff drainage area contributing to offsite run-on is estimated to be approximately 38.73 acres. The anticipated runoff coefficient is 0.25. The anticipated off-site run-on to the project site is estimated to be 2.27 ft3/second. Calculations are included in Appendix N.

Project Area Run‐off

Coefficient

Rainfall Intensity

(inches/hour) Drainage

Area

Run‐on Discharge

(ft3/second)

Staging Area 7

C x i x A = Q

0.25 x 0.232 x 38.73 = 2.27

The General Permit requires that temporary BMPs be implemented to direct offsite run-on away from disturbed areas using runoff controls. The following BMPs will be implemented:

if Rock/sand bags may be used to direct run-on away from staging areas if concentrated flows are observed within the parking lot Stream diversion dams will be installed around the perimeter of the work areas to prevent erosion and sediment from run-on in all work areas.

Muir Woods Salmon Habitat 11 October 2022

2.4 FINDINGS OF THE CONSTRUCTION SITE SEDIMENT AND

RECEIVING WATER RISK DETERMINATION

A construction site risk assessment has been performed for the project and the resultant risk level is Risk Level 2.

The risk level was determined using SMARTS. Soil erodibility factor (K) and LS values are automatically generated by project location and duration. The R value was calculated using the EPA Erosivity calculator. The risk level is based on project duration, location, proximity to impaired receiving waters and soil conditions. A copy of the Risk Level determination submitted on SMARTS with the PRDs is included in Appendix C.

Table 2.2 and Table 2.3 summarize the sediment and receiving water risk factors and document the sources of information used to derive the factors.

Table 2.2 Summary of Sediment Risk

RUSLE

Factor Value Method for establishing value

R 5.73 EPA Erosivity Calculator (https://lew.epa.gov/)

K 0.1 SMARTS Generated

LS 9.89 SMARTS Generated

Total Predicted Sediment Loss (tons/acre) 5.67

Overall Sediment Risk Low Sediment Risk < 15 tons/ acre Medium Sediment Risk >= 15 and < 75 tons/acre High Sediment Risk >= 75 tons/acre

Low Medium High

Runoff from the project site discharges into poorly to moderately defined channels that eventually flow into Redwood Creek, or directly into Redwood Creek, and then the Pacific Ocean.

Table 2.3 Summary of Receiving Water Risk

Receiving Water Name

303(d) Listed for Sediment Related Pollutant (1)

TMDL for Sediment Related Pollutant (1)

Beneficial Uses of

COLD, SPAWN,

and MIGRATORY

(1)

Redwood Creek Yes No Yes No Yes No

Overall Receiving Water Risk Low High

(1) If yes is selected for any option the Receiving Water Risk is High

Risk Level 2 sites are subject to both the narrative effluent limitations and numeric effluent standards. The narrative effluent limitations require stormwater discharges associated with construction activity to minimize or prevent pollutants in stormwater and authorized non-stormwater through the use of controls, structures and best management practices. Discharges

Muir Woods Salmon Habitat 12 October 2022 from Risk Level 2 site are subject to NALs for pH and turbidity shown in Table 2-4. This SWPPP has been prepared to address Risk Level 2 requirements (General Permit Attachment D).

Table 2.4 Numeric Action Levels

Parameter Unit Numeric Action Level Daily Average pH pH units Lower NAL = 6.5 Upper NAL = 8.5

Turbidity NTU 250 NTU

2.5 CONSTRUCTION SCHEDULE

The site sediment risk was determined based on construction taking place between 06/01/2023 and 11/30/2023. Modification or extension of the schedule (start and end dates) may affect risk determination and permit requirements. The LRP shall contact the QSD if the schedule changes during construction to address potential impact to the SWPPP. The estimated schedule for planned work can be found in Appendix F.

2.6 POTENTIAL CONSTRUCTION ACTIVITY AND POLLUTANT

SOURCES

Appendix G includes a list of construction activities and associated materials that are anticipated to be used onsite. These activities and associated materials will or could potentially contribute pollutants, other than sediment, to stormwater runoff.

The anticipated activities and associated pollutants were used in Section 3 to select the Best Management Practices for the project. Locations of anticipated pollutants and associated BMPs are shown on the Site Map in Appendix B.

For sampling requirements for non-visible pollutants associated with construction activity, please refer to Section 7.7.1. For a full and complete list of onsite pollutants, refer to the Safety Data Sheets (SDS), which are retained onsite at the construction trailer.

2.7 IDENTIFICATION OF NON-STORMWATER DISCHARGES

Non-stormwater discharges consist of discharges which do not originate from precipitation events. The General Permit provides allowances for specified non-stormwater discharges that do not cause erosion or carry other pollutants.

Non-stormwater discharges into storm drainage systems or waterways, which are not authorized under the General Permit and listed in the SWPPP, or authorized under a separate NPDES permit, are prohibited.

Non-stormwater discharges that are authorized from this project site include the following:

NONE

Steps will be taken, including the implementation of appropriate BMPs, to ensure that unauthorized discharges are eliminated, controlled, disposed, or treated on-site.

Muir Woods Salmon Habitat 13 October 2022

Discharges of construction materials and wastes, such as fuel or paint, resulting from dumping, spills, or direct contact with rainwater or stormwater runoff, are also prohibited.

2.8 REQUIRED SITE MAP INFORMATION

The construction project’s Site Map(s) showing the project location, surface water boundaries, geographic features, construction site perimeter and general topography and other requirements identified in Attachment B of the General Permit is located in Appendix B. Table

2.5 identifies Map or Sheet Nos. where required elements are illustrated.

Table 2.5 Required Map Information

Included on Map/Plan

Sheet No. (1) Required Element

SW-01 The project’s surrounding area (vicinity)

SW-01, SW-02 Site layout

SW-04 - SW-09 Construction site boundaries

SW-04 - SW-09 Discharge locations

SW-04, SW-06 &

SW-09 Sampling locations

SW-04 - SW-09 Areas of soil disturbance (temporary or permanent)

SW-04 - SW-09 Active areas of soil disturbance (cut or fill)

SW-04 - SW-09 Locations of runoff BMPs

SW-04 - SW-09 Locations of erosion control BMPs

SW-04 - SW-09 Locations of sediment control BMPs

SW-04 - SW-09 Locations of sensitive habitats, watercourses, or other features which are not to be disturbed

SW-04 - SW-09 Locations of all post-construction BMPs

SW-02 Waste storage areas

SW-02 Vehicle storage areas

SW-02 Material storage areas

SW-04 Entrance and Exits

N/A Fueling Locations Notes: (1) Indicate maps or drawings that information is included on (e.g., Vicinity Map, Site Map, Drainage Plans, Grading Plans, Progress Maps, etc.)

Muir Woods Salmon Habitat 14 October 2022

Section 3 Best Management Practices

3.1 SCHEDULE FOR BMP IMPLEMENTATION

BMPs will be implemented as per the schedule indicated in Table 3.1.

Table 3.1 BMP Implementation Schedule

BMP Implementation Duration

E ro si o n

C n tr o l

EC-1, Scheduling Prior to Construction Entirety of Project

EC-2, Preservation of Existing Vegetation Start of Construction Entirety of

Project

EC-7, Geotextiles and Mats As needed As needed

EC-15, Soil Preparation-Roughening Start of construction Entirety of project

EC-16, Non-Vegetative Stabilization As specified herein As needed

WE-1, Wind Erosion Control Start of construction Entirety of project

S e d im e n t C o n tr o l

SE-1, Silt fence Start of construction Entirety of project

SE-5, Fiber Rolls Start of construction Will remain, post-construction

SE-6, Gravel Bag Berms As needed As needed

SE-7, Street Sweeping As needed As needed

SE-10, Storm Drain Inlet Protection Start of construction Entirety of project

TC-1, Stabilized Construction Entrance and Exit

As needed As needed

TC-2, Stabilized Construction Roadway

As needed As needed

N o n -S to rm w a te r

NS-1, Water Conservation Practices Start of construction Entirety of project

NS-2, Dewatering Operations As needed As needed

NS-3, Paving and Grinding Operations

As needed As needed

NS-4, Temporary Stream Crossing As needed As needed

NS-5, Clear Water Diversion As needed As needed

Muir Woods Salmon Habitat 15 October 2022

Table 3.1 BMP Implementation Schedule

BMP Implementation Duration

NS-6, Illicit Connection/Discharge Start of construction Entirety of project

NS-8, Vehicle and Equipment Cleaning

Offsite only, no cleaning on-site

N/A

NS-9, Vehicle and Equipment Fueling

Start of construction Entirety of project

NS-10, Vehicle and Equipment Maintenance

As needed

NS-14, Material Over Water

NS-15, Demolition Adjacent to Water

W a st e

M a n a g e m e n t a n d M a te ri a ls P o ll u ti n

C n tr o l

WM-1, Material Delivery and Storage

Start of construction Entirety of project

WM-2, Material Use As needed As needed

WM-3, Stockpile Management Start of construction Entirety of project

WM-4, Spill Prevention and Control Start of construction Entirety of project

WM-5, Solid Waste Management Start of construction Entirety of project

WM-6, Hazardous Waste Management

As needed As needed

WM-7, Contaminated Soil Management

As needed As needed

WM-8, Concrete Waste Management

As needed As needed

WM-9, Sanitary-Septic Waste Management

Start of construction Entirety of project

WM-10, Liquid Waste Management As needed As needed

Muir Woods Salmon Habitat 16 October 2022

3.2 EROSION AND SEDIMENT CONTROL

Erosion and sediment controls are required by the General Permit to provide effective reduction or elimination of sediment related pollutants in stormwater discharges and authorized non-stormwater discharges from the Site. Applicable BMPs are identified in this section for erosion control, sediment control, tracking control, and wind erosion control.

3.2.1 Erosion Control

Erosion control, also referred to as soil stabilization, consists of source control measures that are designed to prevent soil particles from detaching and becoming transported in stormwater runoff. Erosion control BMPs protect the soil surface by covering and/or binding soil particles.

This construction project will implement the following practices to provide effective temporary and final erosion control during construction:

1. Preserve existing vegetation where required and whenever feasible.

2. The area of soil disturbing operations shall be controlled such that the Contractor is able to implement erosion control BMPs quickly and effectively.

3. Stabilize non-active areas within 14 days of cessation of construction activities or sooner if stipulated by local requirements.

4. Control erosion in concentrated flow paths by applying erosion control blankets, check dams, erosion control seeding, or alternate methods.

5. Prior to the completion of construction, apply permanent erosion control to remaining disturbed soil areas.

Sufficient erosion control materials shall be maintained onsite to allow implementation in conformance with this SWPPP.

The following erosion control BMP selection table, Table 3.2 indicates the BMPs that shall be implemented to control erosion on the construction site. Fact Sheets for temporary erosion control BMPs are provided in Appendix H.

Muir Woods Salmon Habitat 17 October 2022

Table 3.2 Erosion Control BMPs

CAS

QA

Fact Shee t

BMP Name Considere d for the Project (1)

BMP Used If not used, state reason and alternate BMP, if applicable YES NO

EC-1 Scheduling X

EC-2 Preservation of Existing Vegetation

X

EC-3 Hydraulic Mulch (2) X EC-2, EC-16 - Disturbed areas to be revegetated and stabilized with duff material.

EC-4 Hydroseed (2) X EC-2, EC-16 - Disturbed areas to be revegetated and stabilized with duff material.

EC-5 Soil Binders (2) X EC-2, EC-16 - Disturbed areas to be revegetated and stabilized with duff material.

EC-6 Straw Mulch (2) X EC-2, EC-16 - Disturbed areas to be revegetated and stabilized with duff material.

EC-7 Geotextiles and Mats (2) X

EC-8 Wood Mulching (2) X EC-2, EC-16 - Disturbed areas to be revegetated and stabilized with duff material.

EC-9

Earth Dike and Drainage Swales

(3) X Concentrated flows are neither anticipated nor desired.

EC-

Velocity Dissipation Devices

(3) X Concentrated flows are neither anticipated nor desired.

EC-11 Slope Drains (3) X Work will not be performed on large, steep slopes.

EC-12 Stream Bank Stabilization

X

Banks will be stabilized as needed through a combination of habitat-appropriate CMPs, and the work on stream banks will be covered under 401 Certification.

EC-14 Compost Blankets (2) X EC-2, EC-16 - Disturbed areas to be revegetated and stabilized with duff material.

EC-15 Soil Preparation- Roughening

X EC-2, EC-16 - Disturbed areas to be revegetated and stabilized with duff material.

EC-16

Non-Vegetated Stabilization (2) X

WE-1 Wind Erosion Control X

(1) The General Permit’s Fact Sheet Section II.J.1.c through II.J.1.g describes various BMPs that should be considered for use on the construction site.

(2) The QSD shall ensure implementation of one of the minimum measures listed or a combination thereof to achieve and maintain the Risk Level requirements.

(3) All run-on and runoff from the construction site shall be managed for LUP Types 2 and 3 and LUP Type 1 if the evaluation of quantity and quality of run-on and runoff deems them necessary or visual inspections show that the

Muir Woods Salmon Habitat 18 October 2022

Table 3.2 Erosion Control BMPs

CAS

QA

Fact Shee t

BMP Name Considere d for the Project (1)

BMP Used If not used, state reason and alternate BMP, if applicable YES NO site requires these controls. Run-on from offsite shall be directed away from all disturbed areas, diversion of offsite flows may require design/analysis by a licensed civil engineer and/or additional environmental permitting.

Muir Woods Salmon Habitat 19 October 2022

These temporary erosion control BMPs shall be implemented in conformance with the following guidelines and as outlined in the BMP Factsheets provided in Appendix H. If there is a conflict between documents, the Site Map will prevail over narrative in the body of the SWPPP or guidance in the BMP Fact Sheets. Site specific details in the Site Map prevail over standard details included in the Site Map. The narrative in the body of the SWPPP prevails over guidance in the BMP Fact Sheets.

Scheduling

Construction activities shall be scheduled to avoid anticipated rain events whenever feasible.

Preservation of Existing Vegetation

Preserve existing vegetation in areas not subject to project-related disturbances. Vehicle access will be limited to existing roads/trails as much as possible. Additionally, wherever possible vegetation will be cleared (cut at the surface) and not grubbed where equipment access paths leave existing trails to minimize soil and vegetation disturbance and protect against root damage. In areas outside of existing roads/trails where vegetation must be disturbed, plants and duff material will be salvaged and replanted/replaced.

Geotextiles and Mats

Erosion control blankets may be placed on disturbed areas or stockpiles as temporary erosion control.

Streambank Stabilization

Erosion control will be placed in combination with other habitat-appropriate BMPs to compliment the stream restoration and ensure appropriate stabilization of disturbed areas at the conclusion of work.

Non-Vegetated Stabilization

Non-vegetated stabilization will consist of duff found within the work area. Duff consists of leaves, branches, bark, stems, and other plant matter that typically covers the forest floor. This material generally serves a similar function to straw or wood mulch, protecting bare soil from rainfall impact, increasing infiltration, and reducing runoff. Duff from surrounding areas will be spread over disturbed soils in area of sewer line removal following mowing/scarification. Duff will also be used to cover any other disturbed soil including, equipment access paths that depart from existing roads/trails to the creek channel and tributary, and any soil disturbed by the movement of large and small wood debris.

Wind Erosion Control

Construction and BMP material stockpiles will be covered to prevent wind erosion.

3.2.2 Sediment Controls

Sediment controls are temporary or permanent structural measures that are intended to complement the selected erosion control measures and reduce sediment discharges from active construction areas. Sediment controls are designed to intercept and settle out soil particles that have been detached and transported by the force of water.

The following sediment control BMP selection table indicates the BMPs that shall be implemented to control sediment on the construction site. Fact Sheets for temporary sediment control BMPs are provided in Appendix H.

Muir Woods Salmon Habitat 20 October 2022

Table 3.3 Temporary Sediment Control BMPs

CASQ

A Fact Sheet

BMP Name Considered for the Project (1)

BMP used If not used, state reason and alternate

BMP, if applicable

YES NO

SE-1 Silt Fence (2) (3) X

SE-2 Sediment Basin X Project geometry and disturbance are such that this BMP is not practical or necessary.

SE-3 Sediment Trap X Project geometry and disturbance are such that this BMP is not practical or necessary.

SE-4 Check Dams X

Concentrated flows are neither anticipated nor desired in CGP-covered areas. Check dams in the stream channel will be covered by the 401 Certification.

SE-5 Fiber Rolls (2)(3) X

SE-6 Gravel Bag Berm (3) X

SE-7 Street Sweeping X

SE-8 Sandbag Barrier X This BMP is not anticipated to be necessary.

SE-9 Straw Bale Barrier X

Project geometry and slopes are not appropriate for this BMP and fiber rolls serve the same purpose with less mess given the shallow runoff flows expected.

SE-10 Storm Drain Inlet Protection RL2&3 X

SE-11 ATS X Project geometry and disturbance are such that this BMP is not practical or necessary.

SE-12 Manufactured Linear Sediment Controls

X SE-1, SE-5, and other BMPs will be used.

SE-13 Compost Sock and Berm (3) X SE-1, SE-5, and other BMPs will be used.

SE-14 Biofilter Bags (3) X SE-10 will be used for storm drain inlet.

TC-1 Stabilized Construction Entrance and Exit

X Most work areas are stabilized, so a full TC-1 is not required but rumble strips will be used.

TC-2 Stabilized Construction Roadway X

Muir Woods Salmon Habitat 21 October 2022

Table 3.3 Temporary Sediment Control BMPs

CASQ

A Fact Sheet

BMP Name Considered for the Project (1)

BMP used If not used, state reason and alternate

BMP, if applicable

YES NO

TC-3 Entrance Outlet Tire Wash X TC-1 and SE-7 should be sufficient for project scope.

(1) The General Permit’s Fact Sheet Section II.J.1.c through II.J.1.g describes various BMPs that should be considered for use on the construction site.

(2) The QSD shall ensure implementation of one of the minimum measures listed or a combination thereof to achieve and maintain the Risk Level requirements.

(3) All run-on and runoff from the construction site shall be managed. Risk Level 2 &3 shall provide linear sediment control along toe of slope, face of slope, and at the grade breaks of exposed slope.

Muir Woods Salmon Habitat 22 October 2022

These temporary sediment control BMPs shall be implemented in conformance with the following guidelines and in accordance with the BMP Fact Sheets provided in Appendix H. If there is a conflict between documents, the Site Map will prevail over narrative in the body of the SWPPP or guidance in the BMP Fact Sheets. Site specific details in the Site Map prevail over standard details included in the Site Map. The narrative in the body of the SWPPP prevails over guidance in the BMP Fact Sheets.

Silt Fence

Install silt fence at the perimeter, around staging areas or stockpiles, and along streams if needed or as directed by the QSD or QSP.

Fiber Rolls

Install fiber rolls as shown on the figures or directed by the QSD or QSP. Perimeter fiber roll will be installed on downgradient edge of road at gullies or tight turns. Fiber rolls along contour are not anticipated to be needed in any of the soil disturbance areas for this project.

Fiber rolls shall be clean, weed- and seed-free, biodegradable material (no plastic or “photodegradable” material allowed), filled with rice straw (no other type of straw is permitted), and be keyed into ground (but not more than 2” deep). Fiber rolls along perimeters shall be installed prior to soil-disturbing work.

Gravel Bag Berms

Gravel bags will be used to control sediment buildup and slow water during grading and construction operations. They will be used for anchoring stockpile covers. Gravel bags may also be used to divert run-on if deemed necessary.

Street Sweeping

Street sweeping or vacuuming shall be implemented as needed based on daily inspections.

Drain Inlet Protection

Gravel bags will be placed around drain inlets to create a barrier, where the gravel bags will overlap with adjacent gravel bags and be packed tightly together.

Stabilized Construction Entrance and Exit

Rumble racks may be used to limit tracking from the staging/work areas as needed and if street sweeping is not sufficient (to be assessed during daily inspections).

Stabilized Construction Roadway

The existing paved construction access path serves as a stabilized BMP, reducing erosion and improving mobility when working in sensitive areas.

Muir Woods Salmon Habitat 23 October 2022

3.3 NON-STORMWATER CONTROLS AND WASTE AND MATERIALS

MANAGEMENT

3.3.1 Non-Stormwater Controls

Non-stormwater discharges into storm drainage systems or waterways which are not authorized under the General Permit are prohibited. Non-stormwater discharges for which a separate NPDES permit is required by the local Regional Water Board are prohibited unless coverage under the separate NPDES permit has been obtained for the discharge. The selection of non-stormwater BMPs is based on the list of construction activities with a potential for non-stormwater discharges identified in Section 2.7 of this SWPPP.

The following non-stormwater control BMP selection table indicates the BMPs that shall be implemented to control sediment on the construction site. Fact Sheets for temporary non-stormwater control BMPs are provided in Appendix H.

Table 3.4 Temporary Non-Stormwater BMPs

CASQA

Fact Sheet

BMP Name Consider ed for the Project (1)

BMP used If not used, state reason and alternate BMP, if applicable YES NO

NS-1 Water Conservation Practices

X

NS-2 Dewatering Operation X

NS-3 Paving and Grinding Operation

X

NS-4 Temporary Stream Crossing

NS-5 Clear Water Diversion X

NS-6

Illicit Connection/Discharge

X

NS-7 Potable Water/Irrigation X Project scope does not include irrigation.

NS-8

Vehicle and Equipment Cleaning

X

NS-9 Vehicle and Equipment Fueling

X

NS-10 Vehicle and Equipment Maintenance

X

NS-11 Pile Driving Operation X Project scope does not include pile driving.

NS-12 Concrete Curing X Project scope does not include concrete curing.

NS-13 Concrete Finishing X Project scope does not include concrete finishing.

Muir Woods Salmon Habitat 24 October 2022

Table 3.4 Temporary Non-Stormwater BMPs

CASQA

Fact Sheet

BMP Name Consider ed for the Project (1)

BMP used If not used, state reason and alternate BMP, if applicable YES NO

NS-14

Material and Equipment Use Over Water

NS-15 Demolition Removal Adjacent to Water

X

NS-16 Temporary Batch Plants X Temporary batch plants will not be used.

(1) The General Permit’s Fact Sheet Section II.J.1.c through II.J.1.g describes various BMPs that should be considered for use on the construction site.

Muir Woods Salmon Habitat 25 October 2022

Non-stormwater BMPs shall be implemented in conformance with the following guidelines and in accordance with the BMP Fact Sheets provided in Appendix H. If there is a conflict between documents, the Site Map will prevail over narrative in the body of the SWPPP or guidance in the BMP Fact Sheets. Site specific details in the Site Map prevail over standard details included in the Site Map. The narrative in the body of the SWPPP prevails over guidance in the BMP Fact Sheets.

Water Conservation Practices

Dust controls, street sweeping, equipment cleaning, or other water-using practices shall only be performed as necessary to limit water use and potential discharges.

Dewatering Operations

Dewatering activities are anticipated for water that infiltrates the work area in the subsurface of the stream channel. If work-area dewatering becomes necessary, water must be drained such that:

Water released must not leave the site or enter waterways or storm drains.

Water released must not cause erosion.

To accomplish the above, it is recommended that the water be released to existing, onsite, pervious ground surfaces near Redwood Creek. Releases should be made through non-woven geotextile dewatering/filter bags or a similar method so as to reduce the potential for erosion at the point of release. Water release must be conducted at a rate that does not cause flow to waterways or drains but allows for infiltration into the surrounding ground surface, to be visually assessed at the time of release and on an ongoing basis during operations. Conditions of the 401 Certification will apply.

Paving and Grinding

Paving and grinding/AC removal activities shall be scheduled to avoid anticipated rain events whenever feasible.

Temporary Stream Crossing

Temporary stream crossings provide access while eliminating erosion and downstream sedimentation caused by vehicles or equipment. Precautions should be taken to avoid damage to vegetation by people or equipment. Remove a temporary crossing shortly after it is no longer needed. Temporary stream crossings are not anticipated but this BMP may be referred to if needed. Conditions of the 401 Certification will apply.

Clear Water Diversion

Clear water diversion consists of a system of structures and measures that intercept clear surface water runoff upstream of a project, transport it around the work area, and discharge it downstream with minimal water quality degradation from either the project construction operations or the construction of diversion. Clear water diversions are appropriate for isolating construction activities occurring within or near a water body Conditions of the 401 Certification will apply.

Illicit Connection- Illegal Discharge Connection

Inspect site and site perimeter for evidence of illicit connections, illegal dumping, or discharges.

Vehicle and Equipment Cleaning

Cleaning or maintenance of vehicles or equipment during construction shall not take place within any areas where an accidental discharge to waters of the State may occur. All vehicle and equipment cleaning shall take place offsite when possible.

Muir Woods Salmon Habitat 26 October 2022

Vehicle and Equipment Fueling

Vehicles shall be fueled offsite if possible. Small equipment such as chainsaws and larger immobile equipment such as excavators will be fueled onsite. Equipment shall be fueled using drip pans, absorbent pads, or other secondary containment. Portable fuel containers shall be certified in accordance with the California Code of Regulations and stored within locked secondary containment when not in use.

Fueling areas will be protected from stormwater run-on and run-off and will be located at least 50 ft away from drainage facilities and Redwood Creek. Fueling must be performed on level ground. Spill kits must be stored near fueling areas.

Vehicle and Equipment Staging

Vehicles and equipment kept in the staging area overnight will be parked over a non-permeable surface, such as a paved…