Project_15_-_Harlan_St_-_SWMP.pdf

STORMWATER

MANAGEMENT PLAN

(SWMP)

Prepared for:

City of Wheat Ridge, CO

Wheat Ridge, CO

Prepared by:

Olsson

1525 Raleigh Street, Suite 400

Denver, CO 80204

Project Address / Location:

City of Wheat Ridge

Project 15 – Harlan St, 32nd Ave to 35th Ave

Sidewalk Gap Program

August 2026

Olsson Project No. B25-03001

Project 15 – Harlan St, 32nd Ave to 35th Ave Sidewalk Gap Program

City of Wheat Ridge Project No. 025-029B August 2026

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TABLE OF CONTENTS

1. Introduction

2. Site Description

3. Site Map

4. SWMP Administrator

5. Potential Pollutant Sources and Stormwater Management Controls

6. During Construction

7. Materials Handling and Spill Prevention

8. Dewatering Operations

9. Final Stabilization

10. Inactivation Notice

11. Details for BMPs

12. SWMP Implementation

13. SWMP Retention

14. SWMP Review/Changes

15. Site Inspection

16. BMP Maintenance

17. Notification of Project Start

18. Snow and Ice Management

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1. INTRODUCTION

The Contractor shall comply with all contractual requirements, and all requirements associated with the CDPS-SCP on this project. The SWMP Administrator for Construction shall update the

SWMP to reflect current project site conditions.

Name of Project: Wheat Ridge Sidewalk Gap Program, Project 15

Street: Harlan Street, 32nd Avenue to 35th Avenue Wheat Ridge, CO

Township: 3 South, Range: 69 West, Section: 25

Latitude (+/- 15") 39°45’50” N, Longitude (+/- 15") 105°03’46” W

Metropolitan District: City of Wheat Ridge, Colorado

2. SITE DESCRIPTION

2.1 Nature of Construction Activities

The purpose of the project is to construct sidewalk along the east and west side of Harlan Street between 32nd and 35th Avenue. Improvements include construction and reconstruction of curb and gutter, sidewalks, driveways, and associated asphalt patching, as well as localized full-depth pavement reconstruction. Existing storm sewer facilities and other utilities that conflict with the proposed improvements will be relocated as necessary. Minor grading will be performed to tie proposed improvements into existing conditions. Upon completion of construction, all disturbed areas will be restored through landscape restoration and revegetation.

2.2 Proposed Sequence for Major Activities

Best Management Practices (BMPs) shall be implemented as follows:

• Prior to the commencement of construction activities, staging areas shall be established, as deemed necessary, and initial BMPs shall be installed as shown on the Plans or deemed necessary to control offsite run on and onsite runoff. All initial BMPs shall be installed prior to ground disturbance.

• As construction progresses through each phase of the project, BMPs shall be installed and maintained as appropriate by the Contractor and Engineer. BMPs that continue to serve their intended function shall be properly maintained, while BMPs that are no longer needed or functioning effectively shall be removed or replaced.

• Final stabilization measures shall be implemented as soon as practicable following grading operations. All disturbed areas shall be paved or covered through landscape restoration as shown on the Plans.

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2.3 Acres of Disturbance

• Total area of construction site (LOC (PERMITTED AREA): 2.01 acres

• Total area of proposed disturbance (LDA): 1.29 acres

• Total area of pervious surface: 0.19 acres

2.4 Existing Soil Data

• Urban land-Ciancio-Englewood complex o Hydrologic Soil Group: B (Ciancio) / C (Englewood) o Soil texture: Loam, sandy loam, clay loam, clay o K factor: 0.20-0.28

• Urban land-Elyria-Ascalon complex o Hydrologic Soil Group: C o Soil texture: loam, clay loam, o K factor: 0.20-0.43

Data Source(s): Natural Resources Conservation Services – Web Soil Survey

2.5 Existing Vegetation

Existing ground cover within the project area consists primarily of private landscaping, including grass, rock, gravel, mulch, shrubs, and trees. Small isolated areas of exposed soil are also present. See Section 2.4 for existing soil data and Section 2.8 for summary of existing topography and drainage patterns.

2.6 Potential Pollutant Sources

The following is a list of potential pollutant sources. Refer to Potential Pollutant Sources in

Section 5 for more information.

• Disturbed and stored soils

• Vehicle tracking of sediments

• Loading and unloading operations

• Stored materials including concrete, fertilizers, chemicals, etc.

• Vehicle and equipment fueling and maintenance

• Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, etc.

• On-site waste management practices (waste piles, liquid wastes, dumpsters, etc.)

• Concrete truck and equipment washing, including the concrete truck chute and all associated fixtures and equipment

• Non-industrial waste such as worker trash and portable toilets

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2.7 Allowable Non-stormwater Discharge

The following is a list of potential non-stormwater discharge sources. Other potential sources may occur and the SWMP Administrator for Construction shall update the SWMP accordingly.

• Concrete and masonry washout water

• Landscape irrigation return flows

Concrete and masonry washout water associated with the washing of concrete and masonry tools and concrete mixer chutes can be discharged to the ground if site is managed accordingly to prevent the water from leaving the site as surface runoff or reaching receiving waters. Soaps and solvents shall not be added to concrete and masonry washout water. Concrete waste is not allowed to leave the site and proper BMPs are required.

Construction dewatering is not allowed without a State dewatering permit and with the approval of the City’s Stormwater Coordinator.

2.8 Drainage Patterns

• Description of drainage patterns from the Site:

Existing drainage within the project area is divided by a roadway high point located approximately 175 feet south of 33rd Avenue. Along the east side of Harlan Street, drainage south of the high point is conveyed by curb and gutter to an existing slotted drain near 32nd Avenue, while drainage north of the high point is conveyed to an existing inlet at 35th Avenue.

Along the west side of Harlan Street, runoff is conveyed by a combination of curb and gutter and roadside swales. Runoff south of the high point generally drains to an existing inlet near 32nd Avenue, while runoff north of the high point flows north before outfalling west along 33rd Avenue or 35th Avenue. However, in several locations the roadside swale is discontinuous, causing runoff to sheet flow onto adjacent properties.

Proposed drainage patterns generally match existing conditions. However, proposed curb and gutter on the west side will replace the roadside swale to fully convey roadway runoff. Existing storm sewer infrastructure impacted by the improvements will be replaced with new inlets and pipe connected to the existing storm drainage system.

Additionally, a new inlet is proposed at the southwest corner of 35th Avenue and Harlan

Street to capture runoff that currently drains west along 35th Avenue, reducing surface flow along the roadway.

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• Names of immediate and ultimate receiving water(s) on site:

Stormwater originating south of the drainage high point is within the Sloan Lake Reach J

North Tributary watershed and is presumed to ultimately discharge to Sloan's Lake.

Stormwater originating north of the high point is presumed to flow northward and ultimately discharge to Clear Creek. Both Sloan's Lake and Clear Creek are designated as 303(d) impaired waters.

• Description of all stream crossings located within the Limits of Construction:

There are no stream crossings within the project limits.

3. SITE MAP

See Construction Plans for site map.

4. SWMP ADMINISTRATOR

The Contractor shall designate a SWMP Administrator for Construction upon accepting co-permittee of the permit. The SWMP Administrator for Construction shall become the operator for the SWMP and assume responsibility for all design changes to the SWMP implementation and maintenance. The SWMP Administrator for Construction shall be responsible for implementing, maintaining, and revising SWMP, including the title and contact information. The activities and responsibilities of the SWMP Administrator for Construction shall address all aspects of the project’s SWMP.

Prior to the commencement of work a qualified Stormwater Manager (SWMP Administrator for

Construction) will be selected and their contact information will be added below, and the City of

Wheat Ridge will be contacted with this information, preferable via Email. Add the minimum contact information: Name, Company, Title with Company, Cell # and Email address. Include the individual’s supporting documentation i.e. certifications and/or work experience related to the position of a Stormwater Manager.

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SWMP Administrator for Construction

Name: ________________

Company Name: ________________

Mailing Address: ________________

City, State, and Zip Code: ________________

Phone Number: ________________

Email: ________________

City’s Stormwater Coordinator

Name: Bill LaRow

Mailing Address: 7500 W. 29th Avenue

City, State, and Zip Code: Wheat Ridge, Colorado 80033

Phone Number: (303) 235-2871

Email: blarow@wheatridge.gov

SWMP Administrator for Design

Name: Nathan Stock

Company Name: Olsson

Mailing Address: 1525 N Raleigh St, Suite 400

City, State, and Zip Code: Denver, CO 80204

Phone Number: (303) 374-3113

Email: nstock@olsson.com

5. POTENTIAL POLLUTANT SOURCES AND STORMWATER

MANAGEMENT CONTROLS

The Contractor shall evaluate, identify, locate, and describe all potential sources of pollutants at the site in accordance with CDOT Standard Specifications subsection 107.25, CDPS-SCP and place in the SWMP notebook. All BMPs/Control Measures related to potential pollutants shall be shown on the SWMP site map by the Contractor’s SWMP Administrator for Construction.

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5.1 Disturbed and Stored Soils

Stockpile Management – Stockpile management will be used when soils or other erodible materials are stored at the construction site. Special attention should be given to stockpiles in close proximity to natural or manmade storm systems and close to the limits of construction.

Stockpile management shall be done in accordance with CDOT Standard Specifications subsections 107.25 and 208.07. Stockpiling of materials on sidewalks and streets shall not be permitted without prior approval from the City's Stormwater Coordinator. Approved stockpile areas shall be protected with appropriate BMPs to prevent the discharge of sediment, debris, or other pollutants. Upon completion of the work, the Contractor shall remove all stockpiled materials and fully clean and restore the stockpile area to the satisfaction of the City. Any sediment, debris, or staining resulting from stockpiling operations shall be promptly removed.

Temporary Stabilization/Seeding – Temporary soil stabilization is required for areas considered to be completed and substantially complete or will be dormant for more than 14 days receive temporary stabilization within 7 days. Temporary soil stabilization is not anticipated to be required. If required, temporary soil stabilization shall be incidental to the work.

Perimeter Sediment Controls – The Contractor shall describe and record BMPs/Control

Measures on the SWMP site map that have been implemented to address offsite run on water in accordance with CDOT Standard Specifications subsection 208.03.

Temporary control measures shall be installed prior to commencing construction activities associated with water quality in accordance with CDOT Standard Specifications subsection

208.04.

All sediment sources need to be accounted for no matter how small. Therefore, sediment from any offsite work (utility, potholing, surface disturbance, etc.) needs to be taken into consideration when determining placement and type of BMP.

All disturbed areas with concentrated flows require erosion controls (i.e. riprap, erosion control mat, etc.).

The Contractor shall install sediment control logs along the perimeter of the project to control run on and runoff from disturbed areas. Sediment control logs shall be installed prior to earth-disturbing activities and maintained throughout construction.

Perimeter control may consist of berms, silt fence, erosion logs (sediment control logs), existing landforms, or other BMPs/Control Measures as approved.

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The Contractor shall install curb socks along the flowline of curb and gutter as shown in the

Plans to capture sediment and prevent sediment-laden runoff from entering storm drain inlets or leaving the project site.

The Contractor shall install inlet protection at all storm drain inlets within the limits of construction as shown in the Plans. Inlet protection shall be installed, maintained, and replaced as necessary in accordance with MHFD criteria.

Unforeseen and Interim Site Conditions – All interim and permanent slopes that are steeper than 3:1 require erosion control best management practices (i.e. erosion control blankets, check dams, etc.). All existing, interim, and proposed disturbed areas with concentrated flows require erosion control at a minimum (i.e. swales, slopes, street cuts, etc.).

5.2 Vehicle Tracking of Sediments

Vehicle Tracking Control (VTC)

BMPs/Control Measures shall be implemented in accordance with CDOT Standard

Specifications subsection 208.04.

The proposed VTC will be evaluated on its effectiveness when dealing with the specific site conditions and nature of this project. If the proposed VTC is not adequate for the specific site conditions and/or activity (i.e. high frequency of traffic) changes will be made to the VTC, such as, but not limited to, addition of a wheel wash, cattle guard, increase the length of the VTC, increase the inspection frequency and/or maintenance of the VTC, and the use of an inspection/maintenance log (form) to keep for record keeping.

If a stabilized staging area (SSA) is required, the Contractor shall determine the location and size of the staging area and coordinate its use with the City prior to construction. The Contractor shall stabilize and protect the staging area to minimize erosion, sediment transport, and tracking onto public roadways. Upon completion of the work, the Contractor shall remove all stored materials and temporary stabilization measures and restore the staging area to pre-construction conditions or as directed by the City. All costs associated with furnishing, installing, maintaining, removing, and restoring the SSA shall be considered incidental to the project and shall not be paid for separately.

Vehicles and equipment are not allowed to go beyond the designated area of disturbance and

SSA; site layout may require onsite access controls. Site access will be limited to only entrances with VTC. This will be accomplished by using either Silt Fencing, Construction Fencing, or other approved control measures, if other give details.

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Street Sweeping – Street sweeping will be done when directed by the City of Wheat Ridge and immediately whenever excessive tracking occurs offsite. Street sweeping shall be done in accordance with CDOT Standard Specifications subsection 208.04.

When site conditions are wet and/or muddy all non-essential vehicles and equipment will be limited to only areas that are impervious; deliveries will be dropped off at the SSA, if applicable.

The City has a zero tolerance of tracking off-site and will be expected to make maximum extent practicable (MEP) to prevent tracking. Offsite means any City Street, both inside the project site and outside.

No washing of hard surfaces with water is allowed, unless full containment of the wash water can be captured and disposed of properly, no wash water will leave the site.

5.3 Management of Contaminated Soils

Contaminated soils are not anticipated to be encountered on site. If encountered, the Contractor shall handle contaminated soils in accordance with CDOT Standard Specifications section 250.

5.4 Loading and Unloading Operations

Materials Handling and Spill Prevention – Majority of deliverables are anticipated to be delivered to the SSA, if applicable, or other secure area. Handling Areas that generate waste or residual pollutants require either pollutants fully cleaned up immediately or covered. Spill kits are to be located in proximity of areas of loading and unloading operations with potential pollutants.

5.5 Outdoor Storage Activities

Materials Handling and Spill Prevention – All chemicals will be stored in the SSA if applicable, or other secure area as determined by the Contractor and approved by the City. All chemicals shall be appropriately protected from the elements with a secure and lockable chemical storage box designed to store and contain chemicals. A Spill kit(s) will be in proximity to all areas storing chemicals.

5.6 Vehicle and Equipment Maintenance and Fueling

Materials Handling and Spill Prevention – All vehicles and equipment will be inspected during the SWMP inspections; any leaking vehicles will be documented with an explanation of cleanup action and what measures were taken to prevent future discharges from leaking vehicles and equipment.

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5.7 Fugitive Dust and Wind Erosion Controls

Fugitive Dust and Wind Erosion Controls – Will be used to mitigate erosion caused by wind.

Inactive areas will be surfaced roughened to reduce wind erosion. During dry and windy conditions watering trucks will be used to water exposed, un-vegetated areas with potable water to control fugitive dust and wind erosion. An effort shall be made to use only the amount of potable water required for these operations so as not to create muddy conditions, runoff, and/or noticeable erosion.

If excessive dust and wind erosion occurs the application of bonded fiber matrix to disturbed areas will be applied as needed.

Sawcutting shall be done in accordance with CDOT Standard Specifications subsections

107.25, 208.02, 208.04, 208.05. All sawcutting waste generated from sawcutting, including liquids or dusts, will need to be either cleaned up while the cutting is taking place or contained in place and immediately cleaned up after cutting operation terminate.

5.8 Routine Maintenance Activities

Materials Handling and Spill Prevention – Routine activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, ect. are not expected to be needed on this site. If this condition is encountered, the SWMP shall be updated to include the necessary BMPs.

5.9 On-site Waste Management Practices

The following are good housekeeping practices:

• Provide approved waste management containers

• Establish proper building material staging areas

• Designate paint and concrete washout areas

5.10 Concrete Truck/Equipment Washing

Concrete washout areas (CWA) – shall be placed at least 100 feet from drainage conveyances. If a dug concrete washout area is not feasible a mobile type i.e. “eco pan” unit may be used instead with prior approval by the City’s Stormwater Coordinator. All cleaning operations involving concrete waste including, but not limited to, concrete truck/equipment washing, including chutes, fixtures and equipment will be done in an approved CWA.

Concrete and masonry washout water or waste from field laboratories and paving equipment shall be contained in accordance with CDOT Standard Specifications subsection 208.05.

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5.11 Dedicated Asphalt and Concrete Batch Plants

Dedicated asphalt and concrete batch plants are not expected to be needed for this project. If this condition is encountered, the necessary details of proposed BMPs are required to be added to the SWMP. BMP designs need to be based on the MHFD’s design and installation notes.

The City considers small masonry mixing operations as a temporary batch plant.

5.12 Non-industrial Waste Sources

Trash Management – All trash needs to be disposed of in an approved trash container.

Non-Industrial Water Management – All portable toilets will be secured down and placed on a flat surface area. They will be at a minimum of 50 feet away from drainage ways and surface waters.

5.13 Other Areas Where Potential Spills Can Occur

The SWMP Administrator for Construction is responsible for identifying any other areas or procedures where potential spills can occur and update the SWMP accordingly.

6. DURING CONSTRUCTION

The SWMP shall be implemented prior to commencement of construction activities. The plan shall be updated as appropriate. SWMP provisions shall be implemented until expiration or inactivation of permit coverage.

Responsibilities of the SWMP Administrator for Construction: A copy of the SWMP must be retained on site unless another location, specified by the permittee, is approved by the City. The

SWMP is considered a living or dynamic document. The SWMP needs to be updated whenever site conditions or BMPs change. When site changes are observed the SWMP needs to be changed within 72 hours. When BMPS are no longer needed or are removed the SWMP changes will be done prior to changes in the site conditions. During construction, the SWMP

Administrator for Construction shall have full responsibility to maintain and update the SWMP in accordance with CDOT Standard Specifications subsection 208.03(c).

During construction, the Contractor shall indicate how items that were not addressed during design are being handled in construction. If items are covered in other sections of the SWMP, indicate below what section the discussion takes place.

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The following is a summary of the construction phase and implementation of anticipated BMPs.

Initial activities

• Stockpile Management

• Perimeter Sediment Controls* o Curb Socks o Sediment Control Logs o Inlet Protection

• VTC*

• Street Sweeping

• Materials Handling and Spill Prevention

• Fugitive Dust and Wind Erosion Controls

• CWA

• Trash Management

• Non-Industrial Water Management

*Indicates control measure that shall be installed before construction activities associated with water quality commence.

Interim Activities

• Stockpile Management

• Perimeter Sediment Controls o Curb Socks o Sediment Control Logs o Inlet Protection

• VTC

• Street Sweeping

• Materials Handling and Spill Prevention

• Fugitive Dust and Wind Erosion Controls

• CWA

• Trash Management

• Non-Industrial Water Management

Permanent Stabilization

• Final Stabilization

• Trash Management

• Non-Industrial Water Management

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7. MATERIALS HANDLING AND SPILL PREVENTION

Prior to commencing Construction Activities Associated with Water Quality, the Contractor shall submit a Spill Response Plan. Materials handling and Spill Response Plan shall be in accordance with CDOT Standard Specifications subsection 208.06.

All chemicals will be stored in the SSA, if applicable, or other secure area as determined by the

Contractor and approved by the city. All chemicals shall be appropriately protected from the elements. A spill kit(s) will be in proximity to all areas storing chemicals, including fuel. A spill kit includes: rock socks, absorbent material, disposal container, shovel, etc.

Spill reporting shall be in accordance with 40 CFR 110, 40 CFR 117, and/or 40 CFR 302 as well as CDOT specifications.

Spill Related Contact Information:

CO Environmental Release and Incident Reporting Line: 1(877) 518-5608

National Reporting Center: 1(800) 424-8802

City of Wheat Ridge: 911

If fuel is stored on site, it will be stored in small quantities in designated areas out of the way of construction traffic and construction activities. Construction materials will be stored for short periods of time in relatively flat areas and covered when appropriate. Any liquids or fine grained soluble substances capable of polluting stormwater discharge will be stored in the original containers in sheltered and secure locations until time of use. Material wastes will be properly disposed of at approved off-site landfills. Concrete chute wash-out sump areas will be provided on site for concrete truck washout waters. The sump will be dewatered by evaporation and percolation

8. DEWATERING OPERATIONS

Dewatering operations are not expected for this project. If this condition is encountered the

SWMP administrator shall update the SWMP.

The city considers pumping of surface water that infiltrates areas of excavation as dewatering and requires all BMPs in place prior to discharging offsite. Furthermore the City requires to be notified before any water is discharged into the City’s municipal separate stormwater sewer system (MS4).

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9. FINAL STABILIZATION

Final site stabilization will be achieved through completion of the sidewalk, asphalt pavement, concrete pavement, and landscaping restoration. Landscape restoration shall be in accordance with Revision to Section 212 and may include seeding, sod, rock mulch, wood mulch, etc.

Achieving stabilization by vegetation requires uniform coverage of 70%. The permit is active and all SWMP requirements, which include inspections, are still required until stabilization is achieved.

10. INACTIVATION NOTICE

Coverage under the Stormwater Construction Permit may be inactivated by the permittee when the site has attained final stabilization, all temporary erosion and sediment control measures have been removed, and all components of the SWMP are complete.

11. DETAILS FOR BMPS

The City of Wheat Ridge has adopted all MHFD BMP details and standard operation procedure

(SOP) narratives. These details can be found on their website (www.mhfd.org). If a proposed

BMP is not covered by an MHFD detail or SOP, the Contractor may procure and install the BMP in accordance with the manufacturer's recommendations, subject to approval by the City's

Stormwater Coordinator.

12. SWMP IMPLEMENTATION

The SWMP shall be implemented prior to commencement of construction activities. The plan shall be updated as appropriate. SWMP provisions shall be implemented until expiration or inactivation of permit coverage.

13. SWMP RETENTION

A copy of the SWMP must be retained on site unless another location, specified by the permittee, is approved by the Division.

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14. SWMP REVIEW/CHANGES

The SWMP is considered a living or dynamic document. The SWMP needs to be updated whenever site conditions or BMPs change. When site changes are observed the SWMP needs to be changed within 72 hours. When BMPS are no longer needed or are removed the SWMP changes will be done prior to changes in the site conditions.

15. SITE INSPECTION

The permittee shall keep a record of inspections. Inspection reports shall be in accordance with the City’s and CDPHE requirements and must identify any incidents of non-compliance with the terms and conditions of this permit. Inspection records must be retained for three years from expiration or inactivation of permit coverage.

At least one inspection every 14 calendar days, plus post-storm event inspections conducted within 24 hours after the end of any precipitation or snowmelt event that causes surface erosion.

Inspection Reports must be kept with the SWMP and made available when the City requests a copy.

The required minimum inspection schedules do not reduce or eliminate the permittee’s responsibility to implement and maintain BMPs in good and effective operational condition, and in accordance with the SWMP, which could require more frequent inspections.

16. BMP MAINTENANCE

The Contractor shall reference the MHFD details and SOPs to determine maintenance guidelines for each BMP installed.

The State CDPHE permit does not a have a specific timeline for implementing maintenance procedures and is not included in this permit because BMP maintenance is expected to be proactive, not responsive. Observations resulting in BMP maintenance activities can be made during a site inspection, or during general observations of site conditions.

The City requires action to be taken immediately when notified by the City of non-compliance.

The City requires that any BMP that is ripped, torn, or showing obvious wear to be replaced immediately in most cases.

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17. NOTIFICATION OF PROJECT START

Prior to work commencing, the City of Wheat Ridge Public Works Department will be notified of the date of work commencing. At the discretion of the City’s Stormwater Coordinator, a preconstruction meeting may be required.

18. SNOW AND ICE MANAGEMENT

Snow and ice management operations will be done in a manner to prevent damage to temporary BMPs. Locations of snow stockpiles will be located as to limited excessive erosion caused by snow melt.