B09_Amendment_3_Yellowstone_Canyon_Project_Report_0003.pdf

Chapter 3 Permit to Construct

Design Report

Yellowstone Modular Housing Project

Canyon Government Area

Park County

June 19, 2026

Prepared for:

National Park Service

Wyoming Department of Environmental Quality

Prepared by:

Stantec Consulting Services, Inc.

Sign-off Sheet

The conclusions in the Report titled Yellowstone Modular Housing Project, Canyon Government Area, Park County) are

Stantec’s professional opinion, as of the time of the Report, and concerning the scope described in the Report. The opinions in the document are based on conditions and information existing at the time the scope of work was conducted and do not take into account any subsequent changes. The Report relates solely to the specific project for which Stantec was retained and the stated purpose for which the Report was prepared. The Report is not to be used or relied on for any variation or extension of the project, or for any other project or purpose, and any unauthorized use or reliance is at the recipient’s own risk.

Stantec has assumed all information received from National Park Service (the “Client”) and third parties in the preparation of the Report to be correct. While Stantec has exercised a customary level of judgment or due diligence in the use of such information, Stantec assumes no responsibility for the consequences of any error or omission contained therein.

This Report is intended solely for use by the Client in accordance with Stantec’s contract with the Client. While the Report may be provided to applicable authorities having jurisdiction and others for whom the Client is responsible, Stantec does not warrant the services to any third party. The report may not be relied upon by any other party without the express written consent of Stantec, which may be withheld at Stantec’s discretion. Drafted by Ben Weaver and Alden Davis.

Project Manager

Signature

Jesse Carlson, PE

Printed Name 6/18/2026

DESIGN REPORT YELLOWSTONE MODULAR HOUSING PROJECT (CANYON)

Table of Contents

ABBREVIATIONS ..................................................................................................................... II

1.0 INTRODUCTION

2.0 PROJECT AREA DESCRIPTION

3.0 PROPOSED PROJECT SYSTEM IMPROVEMENTS

4.0 WATER SYSTEM DEMANDS

4.1 WATER DEMANDS

4.2 FIRE FLOW DEMANDS

5.0 WATER DISTRIBUTION LINE

5.1 WATER STORAGE

5.2 PUMPING SYSTEM

5.3 TREATMENT FACILITIES

6.0 EXISTING SANITARY SEWER SYSTEM

6.1 EXISTING SEWER MAIN SLOPE

7.0 PROPOSED SANITARY SYSTEM IMPROVEMENTS

7.1 SANITARY SEWER MAIN DESIGN

7.2 SANITARY SEWER SERVICES

7.3 SANITARY SEWER MANHOLES

LIST OF TABLES

Table 1: Project Area Pressures during Fire Flow Plus Peak Hour Demand Scenario

Table 2: Water Distribution Line Chapter 12 Requirements and Design Parameters

Table 3: Existing and Proposed Sewer Main Capacities

Table 4: Sewer Line Chapter 11 Requirements and Design Parameters

LIST OF APPENDICES

APPENDIX A - PERMIT DRAWINGS

APPENDIX B - SPECIFICATIONS

APPENDIX C - POTABLE WATER HYDRAULIC ANALYSIS

APPENDIX D - SEWER MAIN CAPACITY CALCULATIONS

APPENDIX E - TREATMENT PLANT BASIS OF DESIGN REPORT

ii

Abbreviations

ADD

CIP

DEQ

DIP

FT

GPM

NPS

PHD

PDD

PSI

PVC

VC

WWDC

WYDOT

Average Day Demand

Cast Iron Pipe

Wyoming Department of Environmental Quality

Ductile Iron Pipe

Feet

Gallons Per Minute

National Park Service

Peak Hour Demand

Peak Day Demand

Pounds per Square Inch

Polyvinyl Chloride

Vitrified Clay

Wyoming Water Development Commission

Wyoming Department of Transportation

INTRODUCTION

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1.0 INTRODUCTION

The National Park Service (NPS) is planning to construct modular housing developments for utilization by employees working in the Canyon, Mammoth and Northeast Entrance Government Areas. This report addresses the proposed work at the Canyon Government Area. Separate reports have been prepared for Mammoth and Northeast Entrance.

The intent of the proposed work at the Canyon Government Area is to construct 10 modular housing units. This report will address the utility design consisting of potable water service, fire suppression, and sanitary sewer mains and services (hereby referred to as the Project). No additional water treatment, wastewater treatment, pumping facilities or water storage are proposed with this project.

The proposed modular building design includes the installation of 10 modular prefabricated buildings. These buildings will be 2-bedroom modular units for all locations. An initial review of existing information and site reconnaissance was performed to determine the location and capacity of existing potable water and sanitary sewer infrastructure for the

Project. The NPS is proposing to install a new 8-inch PVC main (AWWA C900 DR18) and connect 10 water services to the proposed main. Approximately 1,460 LF of the 8” water main and approximately 50 to 80 LF of service line for each unit will be installed.

In addition to the waterline replacement, the NPS is proposing placement of approximately 1,030 LF of new 8-inch

SDR26 PVC sanitary sewer main. This will tie into the existing sewer. Additional improvements include ten (10), 4-inch SDR26 PVC sanitary sewer services.

The purpose of this design report is to provide DEQ, as required by Chapter 11 and Chapter 12 of the Wyoming

Water Quality Rules and Regulations information regarding the construction of the proposed water services and sanitary sewer main replacements. The Project is designed according to the requirements of Chapter 11, Chapter 12.

This report includes a brief description of the Project area, the Project, the proposed design, and appendices containing supporting information. Construction of the Project is anticipated to begin Fall of 2026.

2.0 PROJECT AREA DESCRIPTION

The Project is located in Canyon Government Area on portions of Badger Road and Wolf Road. The Project is in the

SE ¼ of Section 17 and SW ¼ of Section 16, Township 55 N, Range 113 W in Park County, WY.

3.0 PROPOSED PROJECT SYSTEM IMPROVEMENTS

The NPS is proposing to install a new 8-inch PVC main (AWWA C900 DR18) and connect ten (10) HDPE water services to the proposed main. Approximately 1,460 LF of the 8” water main will be installed. In addition to the waterline replacement, the NPS is proposing placement of approximately 1,030 linear feet of a new 8-inch SDR26

PVC sanitary sewer main. This will tie into the existing sewer. Additional improvements include ten (1)0, 4-inch

SDR26 PVC sanitary sewer services. The proposed water and sewer mains are shown in Appendix A – Permit

Drawings.

WATER SYSTEM DEMANDS

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The proposed water distribution line and sewer main will be constructed to meet the Wyoming Public Works Standard

Specifications (2023 edition), herein referred to as the State Specifications.

4.0 WATER SYSTEM DEMANDS

An initial review of existing information and site reconnaissance was performed to determine the location and capacity of existing potable water infrastructure for each area of the Project. Yellowstone National Park owns and maintains the Canyon water treatment and distribution system. The proposed modifications to the water distribution system will continue to be owned and maintained by Yellowstone National Park. The existing water treatment system has adequate capacity for the water demands described below.

4.1 WATER DEMANDS

The proposed water man and service lines are in an area that is not looped. EPANET® was used to model the water demands in the proposed water distribution line for peak hour and fire suppression scenarios.

Stantec utilized field hydrant testing for the analysis presented below. The following estimated maximum water demands were used to analyze the water system modifications:

• Average Daily Demand: 2,500 gallons per day (Wyoming DEQ Water Quality Rules and Regulations – Chapter 12, Section 8)

• Maximum Daily Demand: 6,800 gallons per day (Wyoming DEQ Water Quality Rules and Regulations – Chapter 12, Section 8)

• Peak Hour Demand: 18.9 gallons per minute (Wyoming DEQ Water Quality Rules and Regulations – Chapter 12, Section 8)

• Automatic Fire Suppression Demand: 55 gallons per minute (Modular Building Design Narrative)

Stantec believes the EPANET model provides an acceptable assessment for this Project. Analyses are included in

Appendix C – Potable Water Hydraulic Analysis.

The modified system provides dynamic pressures range from 55.38 psi minimum to 81.72 psi maximum during peak hour demand conditions. The system maintains a minimum of 55.14 psi of residual pressure at the location of fire suppression and a minimum of 58.05 psi of residual pressure in the rest of the system, during fire suppression demand conditions. However, this does not include additional 7.5 psi drop from the water meter and pit at 55 gpm per the manufacturer’s documents for the Sensus iPerl 1” water meter. The maximum pressure fluctuation at any location within the pressure zone between peak hour demand and minimum hour demand does not exceed 30 psi.

4.2 FIRE FLOW DEMANDS

The existing water distribution line includes the two existing hydrants where hydrant testing was completed. The

EPANET model was also used to show that the proposed system worked under fire flow conditions with a new

WATER DISTRIBUTION LINE

cj https://stantec-my.sharepoint.com/personal/jesse_carlson_stantec_com/documents/desktop/deq/20260618_yellowstone canyon project reportdocx.docx 3 hydrant flowing 1000 gallons per minute at the end of the water main. The following estimated maximum water demands were used to analyze the water system:

1-hour Site Fire Flow: 1,000 gallons per minute (2018 International Fire Code - Section B105.1, Table B105.1(1) for

Residential Group R-3 and R-4 (0-3, 600SF)

The existing system fire flow analysis is included in Appendix C – Potable Water Hydraulics Analysis. This analysis confirms that the proposed system meets the Chapter 12 requirement to maintain a minimum of 20-psi during all flow scenarios. Table 1 shows the modeled pressures in the Project area during the fire flow analysis.

Table 1: Project Area Pressures during Fire Flow Plus Peak Hour Demand Scenario

Hydrant Name

Fire Flow Required (gpm)

Calculated Residual

Pressure at Available Fire

Flow (psi)

Hydrant 1 1,000 32.36

5.0 WATER DISTRIBUTION LINE

The proposed water distribution system modifications to the Canyon Government Area consists of the installation of an 8” PVC main (AWWA C900 DR18) and individual 2-inch HDPE water and fire service connections to each of the

10 modular units. Approximately 1,460 LF of the 8” water main and new service lines for each unit will be installed.

Valves will be installed at the beginning of each new and intermediate location on the main lines as shown on the

Permit Drawings. The Canyon Government Area proposed potable water main extension will be a dead-end potable water main, with the end being past the last proposed residential service. This dead-end potable water main will have a fire hydrant and will require periodic flushing to maintain suitable water quality in the main line associated with this area. The proposed potable water system connection will be adjacent to the existing maintenance facilities located approximately 650 feet south of the proposed modular units. This distribution line has a single air release valve at the highest point and gate valve spacing is no greater than 500 feet. A summary of the Chapter 12 requirements and the design parameters are provided in Table 2.

Table 2: Water Distribution Line Chapter 12 Requirements and Design Parameters

Chapter

Section Requirement Design Parameter

16.b.i.

PVC pipe: Less than four inches diameter, ASTM D 2241; or four inches and larger diameter, AWWA C900

Buried water distribution pipeline will be PVC water pipe certified to meet AWWA C900 standards.

16.b.ii Ductile iron, AWWA C151 These materials are not proposed.

16.b.iii Fiberglass pressure pipe, AWWA C950 These materials are not proposed.

16.b.iv Polyethylene pipe: 3/4 inch through three inches diameter, AWWA C901; four inches through 65 inches diameter, AWWA C906

Service connections will be 2" HDPE water pipe certified to meet AWWA C901 standards.

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Chapter

Section Requirement Design Parameter

16.b.v Other material submitted with the permit application and approved by the Administrator

These materials are not proposed.

16.c Flanged piping shall not be allowed for buried pipe except for connection to valves.

These materials are not proposed.

16.d

New water mains shall be sized after the hydraulic analysis required by Section 9(l)(i) of this Chapter and the design shall demonstrate that: (i) At maximum day demand plus current State of Wyoming-required fire flow, or the fire flow of an authority having jurisdiction, the pressure in the municipal distribution system will not fall below 20 pounds per square inch (psi); and (ii) The normal system working pressure shall be greater than 35 psi.

Refer to the hydraulic calculations. The calculations show the fire flow scenario and associated pressures; residual pressures are maintained above 20-psi in all cases.

16.e When fire protection is provided, the water main system shall be designed to also serve fire flows.

Refer to the hydraulic calculations. The distribution line has been designed to carry fire flows.

16.f

Hydrants shall: (i) Have hydrant leads that are a minimum of six inches in diameter; (ii) Have valves installed; (iii) Be protected from freezing at hydrant leads and barrels; (iv) Where groundwater levels are above the gravel drain area, hydrants shall be pumped dry or otherwise dewatered and hydrant weep holes shall not be used; and (v) Have drains that are not connected to or located within 10 feet of a sanitary sewer or storm drain.

The proposed fire hydrant will meet these requirements and will be placed in accordance with State Specifications.

16.g Fire hydrants or active service taps may be substituted for air relief in 6- and 8-inch lines.

A fire hydrant will be placed.

16.h

Where excavation is performed for distribution systems: (i) The trench bottom shall be excavated for the bell of the pipe; (ii) All rock shall be removed within six inches of the pipe; and (iii) The trench shall be dewatered for all work.

The trench shall be over excavated to provide a minimum depth of cradle of 6 inches.

16.i

Distribution system bedding for rigid pipe shall be designed in accordance with ASTM C12 Classes A, B, or C. Flexible pipe bedding shall be designed in accordance with ASTM D2321 Class I, II, or III.

Bedding used will meet Type A or B in accordance with State Specifications.

16.j

Distribution system pipe shall be joined to ensure a watertight fitting and installed in accordance with the following standards, as applicable: (i) For ductile iron pipe, AWWA C600; (ii) For PVC pipe, AWWA M23; and (iii) For HDPE pipe, AWWA M55.

The water system will be installed to the manufacturer’s recommendations, and AWWA M23. Pressure and leakage testing will be performed on all installed pipe. All fittings will be watertight.

16.k.i

Backfill for distribution systems shall: (i) Be performed without disturbing pipe alignment; (ii) Not contain debris, frozen material, unstable material, or large clods; (iii) Not contain rocks or stones that are greater than three inches in diameter within two feet of pipe; and (iv) Be compacted to a density equal to or greater than the surrounding soil

Backfill will be performed to meet State Specifications.

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Section Requirement Design Parameter

16.l.i

Separation of water mains from sanitary and storm sewers: Where the minimum vertical or horizontal separation distances required by incorporation by reference of 2018 TSS parts 8.8.2 and 8.8.3 of paragraph (a) of this Section cannot be met, the sewer or water line shall be placed in a separate conduit pipe or meet the flow-fill requirements of paragraphs (ii) and (iii) of this Paragraph (l)

Separation from sewers will be maintained. If unanticipated conditions necessitate the use of flow fill, cement-treated backfill shall be installed in accordance with Chapter 12 requirements.

16.l.ii.A

Flow-fill for pipelines shall comply with the following:

Cement-treated fill, non-shrink backfill, low-density concrete backfill, or structural backfill may be used as flow-fill when the material has a 28-day compressive strength of 30-60 psi

These materials are not proposed.

16.l.ii.B

Flow-fill for pipelines shall comply with the following:

The pipe to be encased shall be laid on a four to six-inch bed of washed gravel that has been widened, with the walls of the trench benched away from the center-line of the trench, so the pipe is uniformly supported over the length or supported on blocks no further than 10 feet apart

These materials are not proposed.

16.l.ii.C Flow-fill for pipelines shall comply with the following:

The flow-fill and washed gravel or blocks shall rest on an undisturbed trench bottom

These materials are not proposed.

16.l.ii.D

Flow-fill for pipelines shall comply with the following: The pipe shall not move laterally or float during placement of the flow-fill and the line and grade of the pipe shall be maintained

These materials are not proposed.

16.l.ii.E

Flow-fill for pipelines shall comply with the following: The flow-fill shall extend from trench sidewall to trench sidewall and extend at least two inches above the top of the pipe

These materials are not proposed.

16.l.iii.A Flow-fill for pipe crossings shall comply with the following: To the extent possible, there shall be no joints or taps within nine feet of the crossing

These materials are not proposed.

16.l.iii.B

Flow-fill for pipe crossings shall comply with the following: The flow-fill shall extend from undisturbed earth at the bottom of the lower pipe to at least two inches above the top of the upper pipe

These materials are not proposed.

16.l.iii.C Flow-fill for pipe crossings shall comply with the following: The block of flow-fill shall be wide enough to ensure the structural integrity of the installation

These materials are not proposed.

16.l.iii.D

Flow-fill for pipe crossings shall comply with the following: Pipes that cross one another shall be separated by a minimum of two inches when encased in flow-fill

These materials are not proposed.

16.m.i.A.I

Require backflow prevention devices for each water service connection in accordance with Table 4 of this Section, with the exception of (B)(I) residential water service connections

All water connections are considered residential water service connections.

EXISTING SANITARY SEWER SYSTEM

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Section Requirement Design Parameter

16.m.i.B.I

Residential water service connections shall be considered to be low hazard back-siphonage connections unless determined otherwise by a Hazard Classification.

All connections will be considered low hazard back-siphonage.

16.m.i.E

All backflow prevention devices shall be in-line serviceable (repairable), in-line testable except for devices meeting ASSE 1024, and installed in accordance with manufacturer instructions and applicable plumbing codes.

Backflow prevention devices will be in-line serviceable (repairable), in-line testable except for devices meeting ASSE 1024, and installed in accordance with manufacturer instructions and applicable plumbing codes.

16.m.i.F

All backflow prevention devices must have a certification by an approved third-party certification agency. Approved certification agencies are: (I) American Society of Sanitary Engineers (ASSE); (II) International Association of Plumbing/Mechanical officials (IAPMO); and (III) Foundation for Cross- Connection Control and Hydraulic Research, University Of Southern California (USC-FCCCHR).

Backflow prevention devices will be certified by an approved third party.

16.m.i.G.I

Backflow prevention devices at water service connections shall be inspected and certified by a certified backflow assembly tester at the time of installation. Certification of the assembly tester shall be by one of the following: (I) The American Society of Sanitary Engineers (ASSE); or (II) American Backflow Prevention Association (ABPA)

Backflow prevention devices at water service connections will be inspected and certified by a certified backflow assembly tester at the time of installation.

5.1 WATER STORAGE

The proposed Project will include no additional storage capacity for the Town of Mammoth.

5.2 PUMPING SYSTEM

The proposed Project will include no pumping system.

5.3 TREATMENT FACILITIES

The proposed Project does not include any treatment facilities or revisions to the current Town water treatment plant.

6.0 EXISTING SANITARY SEWER SYSTEM

An initial review of existing information and site reconnaissance was performed to determine the location and capacity of existing sanitary sewer infrastructure for each area of the Project. Yellowstone National Park owns and maintains the sanitary sewer collection infrastructure serving the project areas. The proposed sewer collection modifications will also be maintained and owned by Yellowstone National Park. The existing wastewater treatment plant was designed to maximum month flows of 0.5 MGD and has adequate capacity to handle the flows described

PROPOSED SANITARY SYSTEM IMPROVEMENTS

cj https://stantec-my.sharepoint.com/personal/jesse_carlson_stantec_com/documents/desktop/deq/20260618_yellowstone canyon project reportdocx.docx 7 below (See Rehabilitate/Replace Canyon Village Wastewater Treatment Plant Schematic Design and Supplemental

Services YELL 310402 Basis of Design Report).

6.1 EXISTING SEWER MAIN SLOPE

Invert elevations measured at manhole locations, were used to establish the existing sewer main slopes and identify system components for design purposes within the Project area. Invert elevation measurements indicate that the existing 6-inch sewer main has slopes that range from 0.0103 to 0.0468 ft/ft.

7.0 PROPOSED SANITARY SYSTEM IMPROVEMENTS

7.1 SANITARY SEWER MAIN DESIGN

The Project will consist of placing the sanitary sewer main and manholes as shown in Appendix A – Permit Drawings.

The proposed 8-inch sewer consists of approximately 1030 feet of PVC and 6 new 48-inch manholes. The proposed slope of the sewer main is approximately 0.60 to 3.70 feet per 100 foot. The sanitary services shall have a minimum slope of 2.00 feet per 100 foot. The sanitary sewer pipe material will be 8-inch SDR 26 PVC pipe. The thicker SDR 26 pipe is preferred by the NPS and exceeds the minimum DEQ pipe material requirements.

The capacity of the existing 6-inch main being tied into has been evaluated and adequate capacity exists to allow for these new connections (See Appendix D – Sewer Main Capacity Calculations for the design calculations). A variance is requested by NPS to go from proposed 8-inch to tie into the existing 6-inch sewer line as existing capacity is adequate.

Design calculations comparing the capacities of the existing sewer main and proposed sewer main are summarized in Table 3 and provided in Appendix D – Sewer Main Capacity Calculations.

Table 3: Proposed Sewer Main Capacities

Sewer Main Material

Type Size (in)

Min.

Slope (ft/ft)

Full Flow Capacity

(gpm)

Full Flow Velocity (ft/sec)

Proposed Sewer Main Extension PVC 8 0.0060- 0.0370

322 2.057

Existing Sewer PVC 6 0.0103 332 2.224

A summary of the Chapter 11 requirements and DEQ policies and the design parameters are provided in Table 4.

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Table 4: Sewer Line Chapter 11 Requirements and Design Parameters

Chapter 11 Section

Requirement Design Parameter

9.a

Separate sewers. Separate sewers shall be provided for collection of stormwater and wastewater. Roof, areaway, drive or foundation drains shall not be connected to sanitary sewers.

Refer to the Permit Drawings. No storm collection systems are connected to the sanitary sewer system.

9.b.i

Wastewater characteristics. Pipe materials shall resist acid and alkaline solutions, organic solvents, and other wastewater constituents and environmental conditions encountered.

All sewer pipe will be manufactured of PVC plastic.

9.b.ii

Pipe loadings. Pipe materials shall be chosen and the pipeline shall be designed to withstand all trench and superimposed surface live loads with a minimum factor of safety. Rigid pipes shall have a minimum factor of safety of 1.5, and flexible pipes shall have a minimum factor of safety of 1.25.

Refer to the Permit Drawings for a typical sanitary sewer trench detail.

9.b.iii

Soil characteristics. Pipe materials shall be chosen to resist corrosion due to aggressive soil characteristics by the soil it contacts. Iron or steel pipe shall be protected from corrosion with polyethylene encasement or cathodic protection.

All sewer pipe will be manufactured of PVC plastic.

9.b.iv Joints. Pipe joints shall be flexible, durable and designed to minimize infiltration/exfiltration and exclude roots.

All sewer pipe will be bell and spigot type with rubber gasket type joints.

9.b.v Performance tests. Piping shall be subjected to leakage tests. Leakage tests shall be infiltration, exfiltration, or air tests.

All constructed sewer pipe will be subjected to an exfiltration test.

9.b.v.D

Deflection. Maximum five percent deflection after flexible pipe is backfilled for 30 days. A mandrel of 95 percent of pipe diameter shall be used. No mechanical pulling of mandrel is permitted.

Sewer line will be installed using a laser to ensure grade and a mandrel test will be conducted on the constructed sewer main.

9.b.vi

Approved pipe material specifications. Type of commercial pipe approved for gravity sanitary systems include: (B) PVC sewer pipe and fittings: ASTM D3034-80, SDR35, ASTM F679-81, or ASTM F794-83.

All sewer pipe will be SDR 26 PVC manufactured in accordance with ASTM D3034.

9.c.i.A Depth. Sewers shall be located to protect them from freezing and frost heave as prudently possible.

The proposed sanitary sewer lines will have depths of cover over 6 feet in all locations.

9.c.i.B

Size. Sewers to be aligned straight shall be 8-inch diameter or larger except 6-inch sewers may be used in cul-de-sacs, or other dead end locations where the sewer cannot be extended in the future. Eighteen-inch or larger sewers may be laid on curves. Lines shall be sized for 200 percent of maximum daily flow or more. In the absence of data deriving maximum daily flow, the chart on Figure 1-1 shall be used to determine maximum daily flow.

The proposed sewer mains are 8-inch. Refer to Section 7.1 of this report for an explanation of sewer main capacity. The existing line being tied into is 6-inch but has adequate capacity. Refer to Appendix E.

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Section

Requirement Design Parameter

9.c.i.C Slope. Sewers shall be laid with uniform slope between manholes. Minimum slopes shall be:

0.40' per 100' for 8" pipe

The proposed 8-inch sewer main has a slope of approximately 0.60 to 3.70 feet per 100 foot. An explanation of this slope is included in Section 7.1.

9.c.i.D Velocity. Minimum velocities shall be 2 fps when flowing full. Velocities greater than 10 fps require special design considerations.

The proposed 8-inch sewer main has a velocity of 2.06 fps when flowing full. Refer to Section 7.1 of this report for an explanation of sewer main velocities.

9.c.i.E

Increasing size. All sewer pipe size changes shall be at manholes. Pipe size shall not be decreased in the direction of flow. The energy gradient line should be maintained when a smaller sewer joins a larger one.

Refer to the Permit Drawings. Proposed sewer does not change size between manholes.

9.c.i.F.I

Excavation. Trench width from the trench bottom to a point one foot above the top of the pipe shall be no less than the outside diameter of the pipe plus 8 inches but not more than 24 inches plus the pipe O.D. The trench bottom shall be excavated for the pipe bell. All rock shall be removed within six inches of pipe. The trench shall be dewatered for all work.

Refer to the Permit Drawings. The trench width will be the pipe O.D. plus 24 inches.

9.c.i.F.II Bedding. Bedding shall be designed in accordance with: Flexible pipe. Types I, II, III, ASTM D2321-74.

Bedding used will meet Type I or II in accordance with ASTM D2321.

9.c.i.F.III

Backfill. Backfill shall be performed without disturbing pipe alignment. Backfill shall not contain debris, frozen material, unstable material, or large clods. Stones greater than three inches in diameter shall not be placed within two feet of pipe. Compaction shall be to a density equal to or greater than the surrounding soil.

Backfill will be performed to meet Wyoming Public Work Sections 02225.

9.c.ii Force mains and pressure sewers.

The Project does not contain force mains or pressure sewers.

9.c.iii.A Size: minimum size shall be four (4) inches (10.2 cm).

Services will be 4 inches.

9.c.iii.B Slope: minimum slope shall be 2 feet/100 feet (2 m/100 m).

The minimum slope for services will be 2 feet per 100 foot.

9.c.iii.C Flow: flow shall be determined from a fixture unit count and the sewage size based on flowing full.

Sewer size is based on sewage flowing full.

9.c.iii.D

Connections: all service connections to sewage collection lines shall be made with a wye or tee for new construction and a tapping saddle for connection to existing collection lines.

Service connections will be made with a wye.

9.d.i

Location. Manholes shall be located at all changes in pipe size, vertical or horizontal alignment, pipe intersections, and the end of lines. Maximum spacing for various line sizes are as follows: maximum M.H. spacing of 400 ft for line size 15 in or less

Spacing of the proposed manholes are less the maximum spacing requirement.

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Section

Requirement Design Parameter

9.d.ii Size. Minimum manhole interior size is four feet.

All proposed manholes are 4 feet in diameter.

9.d.iii

Drop manhole. Drop manholes must be constructed where the change in elevation between two lines is greater than 24 inches.

Concrete encasement shall be provided around the drop pipe.

The Project does not contain drop manholes.

9.d.iv

Invert. Manhole inverts shall be constructed to conform to the shape of the sewer. The bench shall drain to the invert. Connections to the manhole shall be watertight and allow differential settlement between the manhole and pipe. Minimum fillet height shall be one half of the pipe diameter.

Refer to the Permit Drawings. The manhole inverts will be grouted to allow smooth flow through the manhole and benches will drain to the invert. The flow-through channel will be 1/2 the pipe diameter and the manhole will have a watertight connection

9.d.v

Cover. The manhole cover shall be suitable to withstand all loads, including impact loading without deformation, slip or rattle. The manhole cover shall be watertight in areas subject to flooding and a bolt-down type in areas subject to unauthorized dumping or vandals.

Manhole covers will be rated for HS-20 loading. The manholes are not located within a floodplain and therefore are not prone to flooding.

9.d.vi Steps. Access to manholes shall be with portable ladders, or with cast iron manhole steps spaced at 16 inches maximum.

Access to the proposed manholes will be by cast steps at appropriate spacing.

9.d.vii

Materials. Manholes shall be constructed watertight and durable using cast-in-place concrete, or precast concrete with gasketed joints. Where precast concrete bases are used, the first 12 inches of wall will be monolithically cast with the base.

The manhole will be precast reinforced concrete with a monolithic base.

9.d.viii

Access. A 22 inch minimum diameter clear opening shall be provided on all manholes. All manholes shall be located to be accessible by motorized equipment for maintenance.

The covers will be 24-inch covers with 22-inch openings.

9.e Special structures.

No special structures are proposed on this Project.

9.f.i Cross connections. There shall be no cross connections between sewer lines and potable water lines.

No cross connections between sewer lines and water lines will occur.

9.f.ii

Horizontal and vertical separation from water mains. Minimum horizontal separation shall be ten feet where the water main is less than 1.5 feet above the elevation of the sewer.

Minimum vertical separation shall be 1.5 feet at crossing. Joints in sewers at crossing shall be located at least ten feet from water mains.

The upper line of a crossing shall be specially supported. Where vertical and/or horizontal clearances cannot be maintained, the sewer shall be placed in a separate conduit pipe.

Separation from water mains will be maintained.

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7.2 SANITARY SEWER SERVICES

All sanitary sewer service connections to the sewer main will be placed with new PVC SDR 26 pipe. The sizes of the sanitary sewer services will be 4” with a minimum slope of 2%. Each unit will require a service of approximately 35 feet in length. The following estimated maximum sanitary sewer generation was used to analyze the sewer system modifications for each of the new services (serving 10 units total) on the site:

• Maximum daily generation: 2,800 gallons per day for the site

• Peak hour generation: 7.8 gallons per minute for the site using a peak factor of 4

7.3 SANITARY SEWER MANHOLES

Manholes for the Project will be 4-foot diameter precast reinforced concrete manholes with barrel sections. A flexible watertight gasket will be used to connect the sewer pipe to the manhole. The exterior of each manhole will be coated with two coats of approved asphalt sealant. Details of a typical manhole installation are provided in Appendix A –

Permit Drawings.

APPENDIX/DIVIDER TITLE

APPENDIX A - PERMIT DRAWINGS

A

APPENDIX A - PERMIT DRAWINGS

jecarlson Text Box

SUBMITTED SEPARATELY

Appendix B - SPECIFICATIONS

B

APPENDIX B - SPECIFICATIONS

YELLOWSTONE NATIONAL PARK

MODULAR HOUSING UNITS

YELL 326141

PROJECT SPECIFICATIONS

NATIONAL PARK SERVICE (NPS)

DENVER SERVICE CENTER (DSC)

100% Final CDs

June, 2026

YELL 326141 33 14 00 - 1

WATER UTILITY TRANSMISSION AND DISTRIBUTION

Yellowstone National Park YELL 326141

SECTION 33 14 00 - WATER UTILITY TRANSMISSION AND DISTRIBUTION

PART 1 GENERAL

1.1 WORK SUMMARY

A. This section covers the requirements to perform work including but not limited to furnishing and installing waterlines, valves, meters, fire hydrants, other appurtenances, enclosures, and waterline drains for a complete water system as shown on the Drawings, and as otherwise directed by NPS.

B. Provide all labor, materials, tools, equipment, services, and incidentals as necessary to perform the work as described in this section and in accordance with the Contract Documents and

Drawings and to the satisfaction of NPS.

C. Contractor shall provide all cleaning, flushing, disinfection and testing services, unless noted otherwise.

D. This section does not apply to irrigation systems nor plumbing systems within buildings, unless noted otherwise.

1.2 RELATED WORK

A. Attention is directed to the General Requirements and related work specified in other sections includes, but is not limited to:

1. Section 03 30 50 - Minor Concrete

2. Section 31 23 00 - Excavation and Fill

3. Section 31 50 00 - Excavation Support and Protection

4. Section 32 16 00 - Concrete Curbs, Sidewalks, Aprons, and Pads

1.3 DEFINITIONS

A. Not used.

1.4 SUBMITTALS

A. Submittals shall be in conformance with Contracting Requirements, Specifications, and

Division 1 - General Requirements.

B. Submit supporting documentation, certificates of compliance, shop drawings, and supplier or manufacturer information prior to ordering materials or placement in the work for each proposed material and product, for review and acceptance of NPS for conformance to the material specifications.

YELL 326141 33 14 00 - 2

C. Submittals include but are not limited to construction methods, manufacturer�s descriptive literature, performance and test data, and manufacturer�s data for sizes, pressure rating, rated capacity, listing/approval stamps, labels and other marking on equipment made to the specified standards for materials and settings of selected models for the following:

1. Pipe and fittings

2. Gaskets, couplings, sleeves, casing spacers, and assembly bolts and nuts

3. Gate valves and ball valves

4. Air release and vacuum valves

5. Pressure reducing valves

6. Backflow preventers

7. Clean outs and drains

8. Valve boxes, frames, covers, and grates

9. Service saddles and corporation stops

10. Water meters and boxes. Water meter product data shall include information on the radio read system and confirmation that the meters will be compatible with the Park�s existing

FlexNet radio read system.

D. Provide the following test reports where applicable.

1. Water Pressure Report: Contractor shall perform or engage a qualified testing service to conduct or complete a flow test of the existing supply system. Provide date and location of test, type and method of test performed, static pressure and residual pressure in psig, observed flow in gpm, and orifice size.

2. Hydrostatic Pressure Testing: Provide copy of standard test procedures; and certified test results to NPS for compliance. Provide records of calibrated testing equipment and gauges. For failing tests, provide proposed corrective actions to NPS for review and approval.

3. Bacteriologic (Bac-T) Testing: Provide copies of the test results indicating water sample meets Wyoming Drinking Water Standards.

1.5 REFERENCES

A. The Standard Specifications for Construction of Roads and Bridges on Federal Highway

Projects (FP-24), dated 2024; and published revisions thereto.

https://flh.fhwa.dot.gov/resources/specs/

1. Payment descriptions in the FP-24 Standard Specifications shall not apply. Refer to

Section 01 27 00 � Definition of Contract Line Items.

2. In case of conflict with the FP-24 Standard Specifications, the most stringent specification shall apply.

B. Wyoming Public Works Standard Specifications (WPWSS), 2023 Edition.

C. Applicable ASTM, AASHTO, American Water Works Association (AWWA), American

National Standards Institute (ANSI), and Underwriters Laboratory (UL) standards.

D. Uniform Plumbing Code, 2024 Edition (International Association of Plumbing and Mechanical

Officials, IAPMO/ANSI UPC1-2024).

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E. A reference within parentheses to a law or regulation is included in the Contract for convenience only and is not a comprehensive listing of related laws and regulations. Lack of a reference does not indicate no related laws or regulations exist.

F. Where the version of a referenced document is not specified, use the most recent version in effect on the date of the Notice to Bidders.

G. A code not specified as a federal code is a Wyoming code.

H. An agency or a department not specified as a federal or local agency or department is a

Wyoming agency or department.

1.6 QUALITY ASSURANCE

A. Conform to the Contract Documents including but not limited to Permits, Technical Conditions, Drawings, and Standard Specifications.

B. The Contractor shall furnish manufacturer�s certificates of compliance. A certificate of

�Compliance with Specification� or suitable alternative shall be furnished for all materials to be supplied.

C. All Contractor required �Quality Control� materials testing shall be based upon applicable

ASTM and AWWA Test Methods referenced herein for the materials specified, including manufacture recommendations for testing procedures. All equipment, material, and labor necessary for Quality Control testing shall be supplied by and all costs borne by the Contractor.

1. Provide copies of all applicable testing procedures and standards (per ASTM, AWWA, and manufacture recommendations).

2. Provide certifications for calibration of all testing equipment.

3. A report of the test results shall be furnished.

4. All defects which become present from testing shall be rectified, and the piping system shall be retested, until passed.

D. All tests shall be performed in the presence of the Contracting Officer.

1.7 PROJECT CONDITIONS AND REQUIREMENTS

A. In confined linear areas where protection of existing infrastructure, vegetation, and/or soils is specified only equipment that can be safely operated in the confined construction corridor will be permitted.

B. Work performed under this Section shall meet the requirements of the Uniform Plumbing Code, and applicable Wyoming Building Standards Code(s), current editions. In cases where the

Drawings or National Codes conflict with local codes, the local codes shall apply.

C. The following codes and standards will apply to disinfecting water mains and components of the water system.

1. ANSI / AWWA Standard C651

2. AWWA Manual M20, �Water Chlorination/Chloramination Practices and Principles�.

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D. Deliver materials to site in unopened cartons or bundles as appropriate, clearly identified with manufacturer's name, standards label, grade or identifying number.

E. Store in a clean, dry space. Maintain factory wrapping or provide an additional heavy canvas or heavy plastic cover to protect equipment and material from dirt, water, construction debris, and traffic.

1.8 TOLERANCES

A. Horizontal locations, grades and elevations for water systems facilities are to be established from referenced benchmarks, as shown on the Drawings, and as otherwise directed by the

Contracting Officer.

PART 2 PRODUCTS

2.1 GENERAL

A. All materials shall conform to sizes, capacities, qualities and quantities as shown on the

Drawings and described in the specifications.

B. All water system components and materials must be NSF/ANSI 14 & 61 compliant, be wetted surface Lead Free, approved for potable water service, and acceptable to the Wyoming

Department of Environmental Quality.

C. All pipe and fittings of a similar material type shall be from a single manufacturer, who is fully experienced, reputable and qualified to provide continuous quality control through plant inspection and certification of materials.

1. The pipe manufacturer must certify compliance with the specified materials and standards.

2. All pipe shall be clearly marked with type, class and/or thickness as applicable. Lettering shall be legible and permanent under normal conditions of handling and storage.

D. Materials shall be from new stock, delivered in good condition, and no used or damaged stock is allowed.

E. Where no material certification or method of test materials is specified, the latest certification or test specified by ASTM or AWWA shall be enforced.

2.2 PIPE AND FITTINGS

A. Polyethylene Pipe, Tubing and Fittings:

1. Polyethylene pipe, tubing and fittings shall be made from resin meeting the requirements of the Plastic Pipe Institute as PE4710, cell class per ASTM D3350, with 2% minimum carbon black for UV stabilizer.

2. Polyethylene pressure pipe/tubing and fittings (nominal size 1/2-inch through 3-inch) designated for construction of water lines shall comply with AWWA C901.

a. Polyethylene pipe, tubing and accessories for 1/2-inch through 3-inch diameter

(IPS/SDR) shall be pressure class 250psi, SDR 9 rated pipe/tubing, manufactured and tested in accordance with applicable ASTM and AWWA standards.

YELL 326141 33 14 00 - 5

b. Dimensions and workmanship shall be as specified by ASTM D3035 (pipe), and

ASTM D2737 (tubing).

3. Polyethylene fittings, transitions, connections and accessories shall have a pressure rating equal to or greater than the associated pipe, manufactured and tested in accordance with applicable ASTM and AWWA standards.

4. Polyethylene fittings and transitions shall conform to the following:

a. Butt fusion and associated fittings shall conform to ASTM D3261

b. Electrofusion and associated fittings shall conform to ASTM F1055

c. Socket type fittings and accessories shall conform to ASTM D2683

5. Joints for service fittings and valve coupling to polyethylene pipe shall be bronze body meeting ASTM B584 for 3/4-inch pipe (IPS) or compression service fittings and adaptors for 2 inch and smaller pipe (IPS).

a. All service brass shall comply with AWWA C800 and be approved for potable water services.

6. Butt heat fusion for joining polyethylene pipe shall conform to ASTM F2620.

B. Galvanized Steel Pipe and Fittings:

1. Galvanized steel pipe shall conform to the requirements of ASTM Specification A-120 and approved for use with potable water. The pipe shall be standard weight Schedule 40, hot dipped zinc coated, and shall have ends prepared with male iron pipe threads.

2. Galvanized steel pipe fittings shall be 150 lb., malleable iron, banded fittings with the material conforming to ASTM Specifications A-47 and the dimensions and threads conforming to ASA Specifications B-16.3 and B-2.1. The fittings shall be hot dipped galvanized in accordance with ASTM Specification A-153 and approved for use with potable water. Ends shall be prepared with female iron pipe threads.

C. Polyvinyl Chloride (PVC) Pipe and Fittings:

1. Pipe and fittings shall be manufactured as a system and be the product of one manufacturer.

2. PVC pipe for water mains shall meet the requirements of AWWA C900 made to ductile iron O.D.�s for �push-on� joints. Pipe joints shall be with an elastomeric gasket or joint.

Pipe class shall be as shown on the Drawings.

3. PVC pipe with a nominal pipe size of 3 inches and smaller shall be solvent weld pressure pipe, Schedule 80 (IPS). Pipe shall be NSF approved, manufactured from virgin rigid

PVC and meet the requirements of ASTM D1785.

4. PVC fittings for nominal pipe size of 3 inches and smaller shall be of compatible size and same material as the pipe it serves, minimum Schedule 80 (IPS). Fittings shall be NSF approved and meet the requirements of ASTM D2467. PVC threaded fittings shall be

Schedule 80 and conform to ASTM D2464.

5. PVC solvent cements and primer for use with PVC pipe and fittings shall comply with the Uniform Plumbing Code Installation Standard IAPMO IS 8-92, 316.1.5 and a type recommended by pipe manufacturer. Conform to ASTM D2564.

6. Any connections to pipe 4-inches and larger installed below ground shall make changes in direction with Ductile Iron Flanged fittings of the same size and class as to the pipe it serves. All PVC and Ductile Iron fittings shall be joined together using a Mechanical

Joint (MJ).

D. Pipe Thread Sealing Paste:

YELL 326141 33 14 00 - 6

1. Pipe sealant compound shall be a non-hardening, non-seizing, and non-toxic sealing paste containing TFE-Fluorocarbon approved for use with potable water.

E. Casing Spacers:

1. Casing spacers shall be polyethylene, with configuration for centered restrained.

2. Casing spacers shall be compatible with carrier pipe, and sleeve/casing material.

3. Casing spacers may be required for single or multi-pipe clusters per Drawings.

4. Provide compatible end seals from same manufacture as casing spacers.

5. A minimum of two casing spacers per joint or every 5-feet of pipeline is required.

2.3 VALVES

A. Provide valves approved for water systems with ends as appropriate for the adjoining pipe, fitting or accessory.

B. Provide valves for service sizes as shown on the Drawings, conforming to applicable AWWA and ASTM standards.

C. Gate Valves

1. Gate valves shall be iron body, bronze mounted, double disc gate valves with non-rising stems with design, construction and pressure rating conforming to AWWA C515, with modifications specified herein.

2. Stem seals shall be double �O� ring seals designed so the seal above the stem collar can be replaced with the valve under pressure in full-open position.

3. Gate valves for underground installation shall have a two-inch square nut wrench nut for key operation. All valves shall open counterclockwise unless indicated otherwise.

D. Resilient Seated Gate Valves

1. Resilient seated gate valves shall be iron body, with non-rising stems with design, construction and pressure rating confirming to AWWA C515, standard for Reduced

Wall, Resilient Seated Gate Valves with modifications specified herein.

2. Waterway shall be smooth and have no depressions or cavities in the seat area where foreign material can lodge and prevent closure or sealing.

3. Stem seals shall be �O� ring seals designed so that the seal above the stem collar can be replaced with the valve under pressure in full-open position.

4. Resilient seated gate valves for underground installation shall have 2-inch square wrench nut for key operation. All valves shall open counterclockwise unless indicated otherwise on the Drawings.

5. The resilient seated gate valves� interior parts and surfaces shall be coated in accordance with AWWA C550.

E. Valve Boxes

1. Valve boxes shall be cast iron, 5-1/4-inch diameter adjustable valve boxes. Valve boxes shall be screw type and sufficient length for the bury depth specified. The cast iron cover of the valve box shall have an arrow indicating the direction of opening and the word

�Water� stamped thereon. Cast iron covers shall be traffic rated for H20 loading.

YELL 326141 33 14 00 - 7

2. Reinforced concrete collars shall be placed as shown on the Drawings.

3. Valve boxes shall be wrapped in polyethylene encasement.

F. Ball Curb Stop Valves (2-inch and smaller)

1. Conform to ANSI / AWWA C800.

2. Rated for 300-psi maximum working pressure.

3. Operating nut and handle.

G. Air Valves

1. Provide air release (ARV), air/vacuum (AVV), or combination air (CAV) valves for service size as shown on the Drawings, and where there are high points and changes in gradient of the water…