Alamosa Drainage Project - Advertisement - Appendix M - Stormwater Management Plan.pdf

Template Revised: 6.20.2024

STORMWATER MANAGEMENT PLAN (SWMP) TEMPLATE 1 ACRE OR MORE ACRES OF DISTURBANCE (6/20/2024)

1. Site Description

The Contractor shall comply with all CDOT 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.

A. Project Site Location:

Location or address of construction office:

The site is located at the intersection of US 285 (West Ave) and 13th Street in Alamosa, CO. More particularly 1205 West Avenue, Alamosa CO.

B. Project Site Description:

The project will include demolition and replacement of concrete curb and gutter and concrete valley gutters and asphalt patching throughout the site. The south side of the site including the storm drain outlet box will be replaced to provide detention on-site. A drainage channel will be constructed on the adjacent site to the south along with an underground storm drain across Coop Road to provide a route to discharge site drainage into an existing drainage ditch to the south of Coop Road. The site drains away from the buildings to the north and south property lines at 2-4% and the gutters drain the majority of the site to a low point and inlet that functions as the outlet for the site. The southern curb on the site will be rebuilt to provide water quality and detention for the site with an Extended Detention Basin (EDB). The EDB will provide water quality capture volume (WQCV), and detention for the 10-year minor storm and 100-year major storm. The EDB will release to a constructed earthen swale and culvert that will release to the Alamosa Ditch south of Coop Road.

C. Proposed Schedule for Sequence for Major Construction Activities:

Stabilize all areas that are not paved or landscaped through establishment of vegetation cover. Initial erosion control BMPs will be installed, followed by demolition, overlot grading, utility construction, site paving, and finally site stabilization and construction activities BMP removal when vegetation is re-established.

D. Acres of Disturbance:

1. Total area of construction site (LOC (PERMITTED AREA)): 1.8 acres

2. Total area of proposed disturbance (LDA): 1.8 acres

3. Total area of seeding: 0.3 acres

4. Total area of pre-project impervious surface: 34,413 sq. ft.

5. Total area of final impervious surface: 34,413 sq. ft.

E. Existing Soil Data:

Man-made fill (AASHTO Classification A-2-4).

Data Source(s): CDOT Alamosa Facility Geotechnical Engineering Study (Kumar & Associates, 10/8/2019)

F. Existing Vegetation, Including Percent of Vegetative Cover:

During design, the SWMP Administrator for Design in consultation with the Engineer will determine if the SWMP Administrator for Design or the SWMP Administrator for Construction will conduct the Vegetation Transects. If the site is disturbed, an Adequate Reference Site(s) may be utilized, refer to the CDPS-SCP.

Pre-Construction Date of survey: Percent Existing Vegetative Cover:

Description of existing vegetation:

Method for determining percent vegetative cover:

Include a map or table showing transect locations, photos documenting pre-Construction vegetative cover, and methodology used to determine existing vegetative cover to SWMP Tab 17:

Post-Construction Date of survey: ______________ Percent Vegetative Cover: ______________ Description of vegetation:

The method used to determine pre-construction percent cover shall be used to determine post construction percent cover.

Include map or table showing transect locations, photos documenting post-Construction vegetative cover, and methodology used to determine existing vegetative cover to SWMP Tab 17:

G. Potential Pollutants Sources:

Refer to Potential Pollutant Sources in SWMP Section 4A. The SWMP Administrator for Construction shall prepare a list of all potential pollutants and their locations in accordance with subsection 107.25.

H. Drainage Patterns and Receiving Water(s):

1. Description of drainage patterns from the Site:

The site outfalls south to Alamosa Ditch, which flows east on the south side of Coop Road.

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

Alamosa Ditch (immediate); Rio Grande River (ultimate)

3. Description of all stream crossings located within the Limits of Construction:

No known stream crossings are located within the Limits of Construction.

I. Allowable Non-Stormwater Discharges:

Discharge Description Site Map # Method Statement (Location) Uncontaminated Springs Concrete and Masonry Washout Water (in-ground washout structure)#

Landscape Irrigation Return Flows Discharges from Diversions of State Waters Emergency Fire Fighting Discharges to the ground of water used to wash vehicles, equipment, and external buildings

#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.

J. Diversion Criteria:

1. Is a diversion planned for the Site? Yes ______ No __X__.

2. If yes, complete information below:

a. What is the 2-year peak flow for the waterway being diverted (cubic feet per second)?

b. What are the monthly averages if available? (provide averages for Jan-Dec if available)

c. What is the upstream contributing drainage area and imperviousness?

d. A method statement must be prepared by the Contractor and approved by CDOT for each diversion.

Diversion structures must minimize soil transport and erosion within the entire diversion, minimize erosion during discharge, and minimize run-on into the diversion and meet the conditions in the SCP.

e. If the conditions in the SCP cannot be met and an alternative is required, CDOT must approve the alternative and then it must be submitted and approved by CDPHE’s Water Quality Control Division prior to implementation.

2. Site Map Components:

Pre-construction

A. Project Construction Potential Site Boundaries:

Project Boundaries are shown on sheets C3.1, C3.2, and C3.3 and are delineated by limits of disturbance (LDA).

B. Flow Arrows that Depict Stormwater Flow Directions On-Site, Run-On and Runoff Direction:

See SWMP Site Maps.

C. All Areas of Ground Surface Disturbance:

D. Areas of Cut and Fill:

E. Areas Used for Storing and Stockpiling of Materials, Staging Areas (field trailer, fueling, etc.) and Locations of All Waste Storage and Batch Plants Including Masonry Mixing Stations:

F. Location of All Structural Control Measures Identified in the SWMP:

G. Location of Non-Structural Control Measures as Applicable in the SWMP:

H. Springs, Streams, Wetlands, Diversions, And Other State Waters Within or Bordering The Site, Including Areas That Require Pre-Existing Vegetation Be Maintained Within 50 Feet Of A Receiving Water:

No known springs, streams, or wetlands on the site.

I. Locations of All Stream Crossing Located Within the Limits of Construction:

No known stream crossings are located with the Limits of Construction.

J. Protection of Trees, Shrubs, Sensitive Habitat, and Cultural Resources:

No known trees, shrubs, or cultural resources are located within the LOC.

K. Locations of Pumped Stormwater Including Intake and Discharge Points and Locations of

Dewatering Activities If applicable, see SWMP Site Maps.

3. Qualified Stormwater Managers:

A. SWMP Administrator for Design:

CDOT Certified Individual responsible for developing SWMP Plan Sheets and SWMP Site Maps during the design phase.

Name/Title Contact Information [phone & email] Certification #

Bryan Camphouse, PE, Principal, Anderson & Hastings Consultants, Inc.

bcamphouse@ahceinc.com; 720-452- 0523 A5C42B28

David Mendel, Environmental and Hazardous Materials Unit Supervisor, CDOT

David.mendel@state.co.us; 720-642-0537 7915455A

B. SWMP Administrator for Construction: (As defined in Section 208) 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 in accordance to 208.03, the SWMP shall remain the property of CDOT. 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. (Update the information below for each new SWMP Administrator for Construction) (A copy of current TECS Certification must be included in the SWMP.)

Name/Title Contact Information (phone & email) Certification # Certification

Expiration Date Start Date

C. Erosion Control Inspector: (As defined in Section 208) The Contractor shall designate an Erosion Control

Inspector. The Erosion Control Inspector shall complete duties in accordance with subsection 208.03(c) (Copy of current TECS Certification must also be included in the SWMP.)

Name/Title Contact Information (phone & email)

TECS

Certification #

Certification Expiration Date Start Date

D. Permanent Stabilization Subject Matter Expert: This qualified individual will be either a Regional

Environmental Staff member, or an Independent Contractor Controller (Independent Assurance Program). This expert is a project team leader responsible for ensuring project adherence to requirements of the 207 and 212

Project Special Provisions as follows and will be available for questions regarding permanent stabilization requirements.

1. Review the Topsoil Management Plan and the Permanent Stabilization Site Maps.

2. Attend the Environmental Pre-Construction Conference.

3. Coordinate the Site Pre-Vegetation Conference.

4. Review and recommend approval of products.

5. Attend the Partial Landscape Completion Walkthrough.

6. Attend the Final Landscape Completion Walkthrough.

Name/Title Contact Information [phone & email]

Danielle Wilkinson, Water Quality Specialist 970-903-0752; Danielle.wilkinson@state.co.us

4. Stormwater Management Controls for Initial Construction Activities Associated with Water Quality

The Contractor Shall Perform the Following:

A. Potential Pollutant Sources:

Evaluate, identify, locate, and describe all potential sources of pollutants at the site in accordance with subsection 107.25, CDPS-SCP, and place in the SWMP. All control measures related to potential pollutants shall be shown on the SWMP Site Map by the Contractor’s SWMP Administrator for Construction.

B. Offsite Drainage (Run on Water):

Describe and record control measures on the SWMP Site Map that have been implemented to address off site run-on water in accordance with subsection 208.03.

C. Vehicle Tracking Control:

Control measures shall be implemented in accordance with subsection 208.04.

D. Perimeter Control:

1. Temporary control measures shall be installed prior to commencing construction activities associated with water quality in accordance with subsection 208.04.

2. Perimeter control may consist of berms, silt fence, erosion logs (sediment control logs), existing landforms, or other control measures as approved.

5. During Construction Responsibilities of the SWMP Administrator for Construction: Considered a “living document”, the SWMP is continuously reviewed and modified throughout the construction phases. During construction, the SWMP Administrator for Construction shall have full responsibility to maintain and update the SWMP in accordance with subsection 208.03(c).

During construction, 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.

A. Materials Handling and Spill Prevention and Response Plan: 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 subsection 208.06.

B. Other CDPS Permits or Guidance Documents: List applicable CDPS permits or guidance documents associated with the permitted site and activities.

C. Stockpile Management: Shall be done in accordance with subsections 107.25 and 208.07.

D. Concrete Washout: Concrete and masonry washout water or waste from field laboratories and paving equipment shall be contained in accordance with subsection 208.05.

E. Saw Cutting: Shall be done in accordance with subsections 107.25, 208.02, 208.04, 208.05.

F. Street Sweeping: Shall be done in accordance with subsection 208.04.

6. Inspections

A. Form 1176 Inspections shall be in accordance with subsection 208.03(c).

B. Permanent Stabilization Inspections shall be in accordance with subsections 208.04(e)4 and 208.10.

7. Control Measure Maintenance

At any time, regardless of the inspection schedule, CDOT or the Contractor shall identify control measures requiring corrective action. Identified noncompliance shall be corrected immediately, but no later than 2 calendar days from the time of observation. Corrective actions shall be in accordance with subsection 208.04(f).

8. Record Keeping

Records shall be kept in accordance with subsection 208.03(d).

9. Temporary, Permanent Stabilization and Long-Term Stormwater Management The Contractor shall comply with all temporary stabilization and permanent stabilization requirements in accordance with subsection 208.04(e).

A. Seeding Plan:

The following seed mix(es) and rates are for drill seeding method as shown on the Permanent Stabilization Site Maps shall be used:

COMMON NAME BOTANICAL NAME LBS. PLS PER

ACRE

Bluejoint reedgrass Calamagrostis canadensis 0.075 (wet areas)

Slender wheatgrass Elymus trachycaulus ssp. Trachycaulus “San Luis” 3 Blue grama Bouteloua gracilis “Hachita” or “Alma” 0.75 Needle and thread Hesperostipa comata 2.625 Western wheatgrass Pascopyrum smithii “Arriba” 1.875 Mountain brome Bromus marginatus “Garnet” or “Bromar” 3.75 Rocky Mountain fescue Festuca saximontana 0.375

Total 12.3 (12.375 with wet)

B. Seeding Application Method:

The following seeding methods shall be used for all areas shown on the Permanent Stabilization Site Maps. Soil compaction shall be minimized for areas where permanent stabilization will be achieved through vegetative cover.

Pay Item Seeding Method (subsection 212.05) Acre 212-00707 Seeding (Native) Hydraulic 0.3

Total 0.3

C. Soil Stabilization Methods:

Minimum soil stabilization methods (attached mulch) for all disturbances to receive seeding.

1. Apply a minimum of 2 tons/ac certified weed free hay or 2 ½ tons/ac of certified weed free straw and mechanically crimp into the soil in combination with natural mulch tackifier in accordance with Section 213.

2. Prior to winter shutdown or the summer seeding window closure: Uncompleted slopes shall be mulched with 2 tons of mulching (weed free) per acre, mechanically crimped into the topsoil in combination with an organic mulch tackifier in accordance with Sections 208 and 213.

D. Special Requirements:

1. Soil amendments, seedbed preparation, and permanent stabilization mulching shall be accomplished within four working days of placing the topsoil on the de-compacted civil subgrades. If placed topsoil is not mulched with permanent stabilization mulch within four working days, the Contractor shall complete temporary stabilization methods in accordance with subsection 208.04(e) at no additional cost to the Department.

2. Complete permanent stabilization mulching within 24 hours of hydraulic application of native seed.

3. The Contractor shall submit a proposed Permanent Stabilization Phasing Plan to the Engineer for approval showing how implementation of SWMP Permanent Stabilization Plans will minimize damage to seeded areas.

4. Due to high failure rates, hydroseeding will not be allowed for permanent stabilization.

E. Soil Amendment Requirements: Minimum amendment material requirements for all disturbances to receive seeding.

0.3 Total Acres of Seeding (Native) Hydraulic (Pay Item 212-00708)

Pay Item Description Amount/ Acre Units Total For This

Method 212-00700 Organic Fertilizer 300 Pounds 90

212-00702 Biotic Soil Amendments (Hydraulically Applied) 3500 Pounds 1,050

212-00703 Humate 200 Pounds 60

212-00704 Mycorrhizae 20 Pounds 6

F. Permanent Stabilization Application Under Structures:

Under structures, shade patterns should be considered and the use of Median Cover Material (Stone) or other stabilized options with an approved Project Special Provision should be used. See SWMP Site Map for locations.

G. Reseeding Operations/Corrective Stabilization:

Prior to stormwater construction work partial acceptance.

1. All seeded areas shall be reviewed by the SWMP Administrator for Construction and or Erosion Control

Inspector for bare soils caused by surface or wind erosion. Bare areas caused by surface or gully erosion, blown away mulch, etc. shall be re-graded, seeded, and have the designated mulching applied as necessary, at no additional cost to the project.

2. The Contractor shall maintain seeding/mulch/tackifier/blanket/TRM, mow to control weeds or apply herbicide to control weeds in the seeded areas, at no additional cost to the project.

H. Location and Description of Planned Permanent Control Measures:

Is Permanent Water Quality Required. Yes ______ No ___X__.

10. Prior to Project Final Acceptance A. When directed by the Engineer, removal and disposal of temporary control measures shall be included in the cost of work.

B. At the end of the project, all ditch checks shall consist of either temporary erosion logs (sediment control logs) (or equivalent) or permanent riprap.

C. All storm drains shall be cleaned prior to the Final Acceptance of the project. If required, include work in 202-

04002 Clean Culvert. [**Check with Region Water Quality staff to see if Clean Culvert PSP is needed and what Pay Item to use.**]

D. Refer to subsection 208.10 for Items to be completed prior to requesting partial acceptance of water quality work.

11. Narratives

Control Measure Matrixes During Construction:

1. Control measure narratives have been included for the CDOT Standard Specifications and Standard Plan M-208 and M-216 along with any non-standard control measures approved during the design process. If a Non-Standard

Control Measure not included in the SWMP is proposed and approved by the Engineer, the SWMP Administrator for Construction shall: Place an “X” in the column “M-208 Standard or ‘X’ for Non-Standard” and complete a Non- Standard Control Measure Specification and Narrative. The Narrative shall include drawings, dimensions, installation information, materials, implementation processes, control measure-specific inspection expectations, and maintenance requirements of the control measure. The appropriate “X” shall also be added to the implementation phase(s).

2. The SWMP Administrator for Construction shall place an “X” in the column “In Use On Site” when the control measure has been installed.

3. A “B” in the “Initial Activities” column indicates that the control measure shall be installed before construction activities associated with water quality commence. Locations and quantities will be discussed during the Environmental

Pre-Construction Conference with the Regional Water Pollution Control Manager.

Structural Control Measures that may be potentially used on the project for erosion and sediment control; practices may include, but are not limited to the following:

Application, Control measure Narrative

M- 208 Standard or “X” For Non-

Standard

In Use on Site

Initial Activities

Interim Activities

Permanent Stabilization

Storm Drain Inlet Protection in Paved Roadways (Type 1, 2 and 3 as shown on M-208-1, sheet 5 of 11)

Manufactured storm drain inlet protection placed prior to construction activities associated with water quality as detailed in M-208-1, to protect existing inlets or immediately upon completion of new inlets to prevent sediment from entering the inlet throughout construction.

M-208 X X X

Storm Drain Inlet Protection in Native Seed Areas (M-604 Standard Inlets Type C and D)

Erosion logs (sediment control logs) or aggregate bags placed around inlet grate to prevent sediment from entering inlet. Place prior to construction activities associated with water quality to protect existing inlets or immediately upon completion of new inlets.

M-208 X

Culvert Inlet/Outlet Protection Erosion logs (sediment control logs), aggregate bags

Placed at mouth of culvert inlets and over top of culvert at inlet and outlet where disturbance may be occurring adjacent to pipe to prevent sediment laden water from entering pipe or drainage. Place prior to the start of construction activities associated with water quality.

M-208 X X X

Type C, Type D And Type 13 Protection Erosion logs (sediment control logs), aggregate bags, erosion bales

Placed around inlet grate or slope and ditch paving to prevent sediment from entering inlet. Place prior to the start of construction activities associated with water quality. M-208 X X X

Stockpile Protection Temporary berm, erosion logs (sediment control logs), aggregate bags*

Placed within specified distance, in accordance with subsection 208.06, from toe to contain sediment around stockpile. *Aggregate bags are easily moved and replaced for access during the workday.

Place prior to start of stockpiling, increase control as the stockpile increases size.

M-208 X

Perimeter Control Erosion logs (sediment control logs), silt fence, temporary berms

Placed prior to construction activities associated with water quality commencing to address potential run-on water from off site, and to divert around disturbed area. M-208 X X

Outlet Protection Riprap, or approved other Material placed as an energy dissipater to prevent erosion at outlet structure. M-601-12 X X

Concrete Washout In-ground or fabricated

Construction control, used for waste management of concrete/masonry and concrete/masonry equipment cleaning. Place prior to the start of concrete and masonry activities. M-208 X X

Vehicle Tracking Pad Vehicle tracking pads shall be used at all vehicle and equipment exit points from the site to prevent sediment exiting the LOC. Place prior to the start of construction activities associated with water quality.

M-208 X X

Other

Non-Structural Control Measures that may be potentially used on the project for erosion and sediment control; practices may include, but are not limited to:

Erosion control devices are used to limit the amount of soil loss on site. Sediment control devices are designed to capture sediment on the project site. Construction controls are control measures related to construction access and staging. Control Measure locations are indicated on the SWMP Site Map.

Application, Control measure Narrative

M- 208 Standard Or “X” for Non- Standard

In Use on Site

Initial Activities

Interim Activities Permanent Stabilization

Vegetative Buffer Strip

Finishing component for filtering sediment-laden runoff from disturbance area. Area within CDOT ROW or temporary easement to be identified on SWMP prior to construction activities associated with water quality starting. Upgradient control measures must be installed immediately adjacent to vegetative buffers.

X X X

Grading Applications (Landform)

Existing or created landforms may be used as a control measure if they prevent sediment from entering or leaving the disturbance area. If a landform directs flow of water to a concentrated outfall point, the outfall point shall be protected to prevent erosion. Area to be identified on SWMP prior to construction activities associated with water quality starting.

M-208 X X

Topsoil Management Stockpile/Salvage Stockpile

Prior to any site disturbance work commencing, existing topsoil shall be scraped to a depth six inches or as specified, and placed in stockpiles or windrows. Upon completion of final grading, topsoil shall be evenly distributed over embankment to a depth of six inches or as specified.

M-208 X X X

Seeding (Temporary) Temporary stabilization used for over wintering of disturbance or used to control erosion for areas scheduled for future construction.

X

Bonded Fiber Matrix or Mulching (Hydraulic)

Not to be used in areas of concentrated flows, i.e.

ditch lines. To be for either Temporary or Permanent Stabilization placed as a surface cover for erosion control. May be used as surface cover when work is temporarily halted and as approved by the Engineer for stockpiles.

X

Straw or Hay Mulch/Mulch Tackifier

Temporary or Permanent Stabilization placed as a surface cover for erosion control and or seeding establishment. To be installed as Temporary Stabilization as a surface cover when work is temporarily halted and as approved by the Engineer

X X

Spray-On Mulch Blanket (Not to be used in areas of concentrated flows, i.e. ditch lines.)

Temporary or Permanent Stabilization placed as a surface cover for erosion control and or seeding establishment. To be installed as temporary surface cover when work is temporarily halted and as approved by the Engineer

X X

Seeding Permanent (Native Perennial)

Permanent Stabilization of disturbance and to reduce runoff and control erosion on disturbed areas.

X

Sweeping

Source control, used to remove sediment tracked onto paved surfaces and to prevent sediment from leaving the LOC. Sweep daily and at the end of the construction shift as needed. Kick brooms shall not be permitted.

X X X

Other

12. Tabulation of Stormwater Quantities A. Control Measure sediment removal and disposal shall be paid for as: 208 Removal and Disposal of

Sediment (Equipment) and 208 Removal and Disposal of Sediment (Labor). All other control measure maintenance shall be included in the cost of the control measure.

B. It is estimated that 10 hours of blading (140-250 horsepower), dozing (130-250 horsepower) and/or combination loader (80-125 horsepower) may be required for miscellaneous erosion control work as directed by the Engineer. Work shall be paid for as: 203 Blading, 203 Dozing and/or 203 Combination Loader.

C. Establishment of seeded areas from Substantial Landscape Completion shall be paid for as part of the bid. This shall include mowing, weed control, and reseeding/mulch/tackifier.

PSP

Spec.

Pay Item Description Pay Unit Initial Const

Interim Const.

Permanent Stabilization

*Total Quantity

X 202-04002 Clean Culvert Each 1 1

X 203-01594 Combination Loader Hour 5 5 10

207-00700 Topsoil (Onsite) CY 20 20

207-00704 Subgrade Soil Preparation SY 8500 8500

208-00012 Erosion Log Type 1 (9 inch) LF 1420 1420

208-00035 Aggregate Bag LF 760 760

208-00045 Concrete Washout Structure Each 1 1

208-00056 Storm Drain Inlet Protection (Type III) Each 1 1 2

208-00075 Pre-fabricated Vehicle Tracking Pad Each 1 1

208-00103 Removal and Disposal of Sediment (Labor) Hour 10 20 10 40

208-00106 Sweeping (Sediment Removal) Hour 5 10 5 20

208-00107 Removal of Trash Hour 5 5

208-00207 Erosion Control Management (ECM) Day 28 28

208-00300 Temporary Berm LF 200 200

212-00700 Organic Fertilizer Pounds 90 90

212-00702 Biotic Soil Amendments (Hydraulic Applied) Pounds 1,050 1,050

212-00703 Humate Pounds 60 60

212-00704 Mycorrhizae Pounds 6 6

212-00707 Seeding (Native) Hydraulic Acre 0.31 0.31

213-00003 Mulching (Weed Free) Acre 0.31 0.31

213-00061 Mulch Tackifier LB 60 60

*It is anticipated that additional control measures and control measure quantities not shown on the SWMP Site Maps shall be required on the project for unforeseen conditions and replacement of items that are beyond their useful service life, see subsections 208.03 and 208.04. Quantities for all control measures shown above are estimated and have been increased for unforeseen conditions and normal control measure life expectancy.

Quantities shall be adjusted according to the conditions encountered in the field as directed and approved by the Engineer. Payment shall be for the actual work completed and material used.

**Pay Item 208-00071 is included for anticipated maintenance of vehicle tracking pads based on the service life of the control measure in the field. The use of the material shall be directed and approved by the Engineer.

13. Biological Impacts and Dewatering

A. Environmental Impacts:

1. Wetland Impacts: NO

2. Stream Impacts: NO

3. Threatened and Endangered Species:

No species are anticipated to be impacted by the project.

B. Dewatering:

(Not covered under the CDPHE guidance document Low Risk Discharge Guidance Discharges of Uncontaminated Groundwater to Land):

https://drive.google.com/open?id=17ck1ZJojHSacJ_wxp2FfUr4rAxNgVWZv

1. Dewatering: Refer to other environmental permits in accordance with subsection 107.02 and the permits contained in Tab 16 of the SWMP.

2. If groundwater does not meet water quality standards for receiving water a separate CDPS Dewatering

Permit shall be obtained by the Contractor from CDPHE in accordance with subsections 107.02 and 107.25.

14. Notes

See Environmental Section of the Plan Sheet – CDPHE Permit required.