B09_Amendment_3_Yellowstone_Mammoth_Project_Report_0003.pdf

Chapter 3 Permit to Construct

Design Report

Yellowstone Modular Housing Project

Mammoth Government Area

Park County

July 21, 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, Mammoth 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 Parks 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.

Project Manager

Signature

Jesse Carlson, PE

Printed Name

6/18/2026

DESIGN REPORT YELLOWSTONE MODULAR HOUSING PROJECT (MAMMOTH)

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: 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 - PUMP CURVE CALCULATIONS

APPENDIX F - TREATMENT PLANT BASIS OF DESIGN REPORT

DESIGN REPORT YELLOWSTONE MODULAR HOUSING PROJECT

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 Mammoth, Canyon and Northeast Entrance Government Areas. This report addresses the proposed work at the Mammoth Government Area. Separate reports have been prepared for the Northeast and Canyon

Government Areas. Four new prefabricated modular housing units are proposed at Mammoth Government Area. 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.

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 connect four new water services to the existing 6-inch mains that run along Powerhouse Rd and Boneyard Service Rd.

In addition to the waterline replacement, the NPS is proposing replacement of approximately 430 linear feet of 8-inch vitrified clay (VC) with 8-inch PVC. The new PVC will be connected to an existing manhole to the east at Pinyon

Terrace St. and Highland Terrace Ave. New sanitary services will be installed at each unit.

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, sanitary sewer main replacement and proposed sanitary services. The Project is designed according to the requirements of

Chapters 11 and 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 Mammoth Government Area in the SE ¼ of Section 30 and NE ¼ of Section 31, Township

58 N, Range 114 W in Park County, WY. A project location map is included in the Permit Drawings presented in

Appendix A.

3.0 PROPOSED PROJECT SYSTEM IMPROVEMENTS

The NPS proposes to add 2-inch HDPE water and fire water service lines at each unit. The NPS also proposes to replace an existing 8-inch VC sanitary sewer main with 8-inch SDR 26 PVC.

This work will replace one section of existing sewer main that runs from Powerhouse Rd to Highland Terrace Ave.

Two manholes will be added and a connection to an existing manhole will be completed as a part of the Project. New

4-inch sanitary services will be installed at three of the units and 2-inch force service will be installed at one of the units. 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. The proposed improvements are shown in Appendix A.

WATER SYSTEM DEMANDS

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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 Mammoth 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 service lines are in an area that is looped, allowing flow in either direction to meet water demands occurring in any area of the associated pressure zone. 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: 1,500 gallons per day (Wyoming DEQ Water Quality Rules and Regulations – Chapter 12, Section 8)

• Maximum Daily Demand: 4,080 gallons per day (Wyoming DEQ Water Quality Rules and Regulations – Chapter 12, Section 8)

• Peak Hour Demand: 11.3 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 85.99 psi minimum to 100.3 psi maximum during peak hour demand conditions. The system maintains a minimum of 87.03 psi of residual pressure, 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 that hydrant testing was completed with. The

EPANET model was also used to show that the existing system worked under fire flow conditions with both hydrants flowing 1000 gallons per minute. The following estimated maximum water demands were used to analyze the water system:

WATER DISTRIBUTION LINE

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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 are 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 M1 1,000 33.90

Hydrant M3 1,000 23.26

5.0 WATER DISTRIBUTION LINE

The proposed water distribution system modifications to the Mammoth Hot Springs Government Area consist of the installation of 2” HDPE service connections to each of the 4 modular units. Each unit will require approximately 35 LF of service line from the existing potable water mains. The proposed services to the units along Lower Mammoth

Service Road will need to tie to a potable water main extension running along the Lower Mammoth Service Road. As only water services are being constructed, no gate valves or air release valves are being placed in this project. Refer to Appendix D – Product Data Sheets for material data. 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

These materials are not proposed.

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.

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.

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Chapter

Section Requirement Design Parameter

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.

These materials are not proposed.

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

These materials are not proposed.

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 I or II in accordance with ASTM D2321.

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 services will be installed to the manufacture's recommendations, and AWWA M55. 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 Mammoth Government Area.

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 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 sanitary sewer main to be replaced on this project includes the 8-inch main that runs along Powerhouse Rd to Highland Terrace Ave. The

PROPOSED SANITARY SYSTEM IMPROVEMENTS

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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 8-inch sewer main has a slope of 0.0193 ft/ft.

7.0 PROPOSED SANITARY SYSTEM IMPROVEMENTS

7.1 SANITARY SEWER MAIN DESIGN

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

Drawings. The proposed 8-inch replacement sewer consists of approximately 400 feet of PVC and two new 48-inch manholes along Powerhouse Rd. The proposed 8-inch sewer main on Main St. will be constructed at a different slope as the existing sewer main to tie in at a different location within the system. The proposed slopes of the new sewer main ranges from 2.0 and 3.5 feet per 100 foot.

The capacity of the 8-inch main has been evaluated, and adequate capacity exists to allow for these new connections

(See Appendix E – Sewer Main Capacity Calculations for the design calculations.).

The existing 8-inch VC pipe will be replaced with bell and spigot, 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 existing sewer main will be abandoned during construction of the replacement sewer main and the sewer entering the next downstream manhole at on the project site will be plugged and abandoned.

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

Table 3: Proposed Sewer Main Capacities

Sewer Main Material

Type Size (in)

Slope (ft/ft)

Full Flow Capacity

(gpm)

Full Flow Velocity (ft/sec)

Proposed Sewer Main PVC 8 0.0200 589 3.755

Proposed Sewer Main PVC 8 0.0346 775 4.939

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.

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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 slopes of 2.00 feet to 3.46 feet per 100 foot. An explanation of this slope is contained 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 3.8 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.A Depth. Force mains shall be located to protect them from freezing and frost heave.

The pressurized sewer service will be a minimum of 6 feet in depth.

9.c.ii.B Pressure sewer collection system piping shall be one (1) inch (2.5 cm) minimum.

The pressurized sewer service will be 2-inch

PVC

9.c.ii.C Velocity. Minimum velocity shall be 2.5 fps (0.76 mps).

Velocity is 2.84 fps

9.c.ii.D

Air release. Air release facilities shall be provided at the high point in the piping whenever the pipe crown elevation falls below the pipe invert elevation. Access to air release manholes shall not be in traffic-ways.

No air release facilities will be necessary.

9.c.ii.E Cleanouts. Cleanouts shall be provided at 400-foot (122 m) maximum spacing in pressure piping four-inch diameter or less.

The pressurized service line is less than 400 feet.

9.c.ii.F Pressure sewer systems. Pressure sewer collection systems shall be preceded by grinder pumps or septic tanks.

The grinder pump will be Zoeller 922 Simplex 48”x120“ Grinder Package with M803 Pump or approved equal.

9.c.ii.G

Pressure sewer collection system pumps.

Pumps shall be provided with isolation and check valves. If a septic tank is not provided before the pump, a grinder pump shall be

The grinder pump will be Zoeller 922 Simplex 48″ x 120″ Grinder Package with M803 or approved equal. The sump is ~200 gallons.

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Requirement Design Parameter required. Pump holding sumps shall not be steel, iron, or coated metal. The sump chamber shall be fifty (50) gallon (189 liters) volume, minimum.

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.

Flow is based on sewer size 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.

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.

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Requirement Design Parameter

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.

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 4 units total) on the site:

• Maximum daily generation: 1,560 gallons per day for the site

• Peak hour generation: 4.3 gallons per minute for the site using a peak factor of 4

There will be a pressurized sewer service for one of the houses. The sump will be located in the garage. Zoeller 922

Simplex 48”x120” Grinder Package with M803 system or engineer approved equal will be specified (Appendix E –

Pump Curve Calculations). The service line will run to a proposed manhole approximately 82 feet away. Inside the manhole, the service line will transition to a gravity service that connects to the existing 8-inch gravity main that is an additional 13 feet further away. Cleanouts for both the force and gravity service portions will be accessible inside of the manhole. This force service line portion will be 2-inch SDR26 PVC and the gravity service line portion will be 4-inch SDR26 PVC. Both portions will be buried a minimum of 6 feet below final grade.

7.3 SANITARY SEWER MANHOLES

Manholes for the Project will be 4-foot diameter precast reinforced concrete flattop 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

APPENDIX A - PERMIT DRAWINGS

Appendix B - SPECIFICATIONS

APPENDIX B - SPECIFICATIONS

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SANITARY SEWERAGE

Yellowstone National Park YELL 326141

SECTION 33 30 00 - SANITARY SEWERAGE

PART 1 GENERAL

1.1 WORK SUMMARY

A. This section covers the requirements to perform work including but not limited to furnishing and installing gravity and force sewer system piping, sanitary sewer manholes, and all associated connections and appurtenances 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. All sewage system materials and construction work shall conform to local, state and federal health standards for sewage disposal systems.

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 at least fourteen days (14) 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.

1. For precast structures, submit design drawings, details, and supporting calculations for review and approval prior to casting. Design drawings, shop drawings and calculations

YELL 326141 33 30 00 - 2

must be sealed and signed by an engineer who is registered as a civil engineer in the State of Wyoming.

2. Contractor must account for lead times on manufacture and delivery and allow for review of submittals by NPS. Design drawings, shop drawings and calculations shall include the following:

a. Design parameters, loadings, earth cover, buoyancy, and design standards (i.e.

ASTM, AASHTO, ACI) used for anticipated field conditions

b. Dimensions, location of openings, and invert elevations

c. Reinforcement, splice type and location, joint details, and gaskets

d. Frames, covers, risers, fittings, seals, hardware and other accessories

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. Cleanouts, caps, covers, and utility boxes

3. Gaskets, couplings, sleeves, and assembly hardware

4. Dye for sanitary sewer tracing

5. Force sanitary main components

6. Grinder pump

D. Provide the following test reports where applicable.

1. Leakage Testing (structures/vaults): Provide copy of standard test procedures; and certified test results to NPS for compliance. For failing tests, provide proposed corrective actions to NPS for review/approval.

2. Low-air Pressure Testing (sewer pipelines, exceeding 50-ft): Provide copy of standard test procedures; and certified test results to NPS for compliance. For failing tests, provide proposed corrective actions to NPS for review/approval.

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 Concrete Institute (ACI), 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 ‘Quality Control’ materials testing shall be based upon applicable ASTM and/or Plumbing

Code 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, Plumbing

Code, 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 system shall be retested, until passed.

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

D. For precast concrete structures, units may be rejected at the site upon visual inspection and where exhibiting any of the following:

1. Cracks passing through walls more than 1/16 inch wide

2. Nonrepairable honeycombed or spalled areas of more than 6 square inches

3. Noncompliance with reinforcement tolerances or cross sectional area shown

4. Wall, floor or lid less than minimum thickness

5. Internal dimensions less than plan dimensions by 1 percent or 1/2 inch, whichever is greater

6. Defects affecting performance or structural integrity

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.

YELL 326141 33 30 00 - 4

B. Work performed under this Section shall meet the requirements of the Uniform Plumbing Code, 2024 Edition.

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

D. 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 sanitary sewer system facilities are to be established from referenced benchmarks, as shown on the Drawings, and as otherwise directed by NPS.

PART 2 PRODUCTS

2.1 GENERAL

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

Drawings or described in the specifications.

B. 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.

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

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

2.2 PIPE AND FITTINGS

A. All new force sewer lines should be SDR 26 PVC of the size shown on the Drawings.

B. Gravity sewer pipe/conduit shall be of the size shown on the Drawings. The pipe shall be PVC, have a minimum pipe wall thickness equivalent to SDR 26, and conform to the requirements of

ASTM D3034. Joints with bell and spigot ends, and reinforced gasket joints. The rubber gasket shall be of composition rubber suitable for sewer service.

C. All fittings and accessories shall be from the same manufacturer of the pipe and have bell and/or spigot configurations compatible with that of the pipe.

D. Connections shall consist of PVC fittings, gaskets, couplings, adapters and other accessories for a watertight connection. Connections to structures shall consist of couplings precast into structure wall, or mechanical fittings for a watertight connection.

YELL 326141 33 30 00 - 5

2.3 BEDDING, FOUNDATION AND BACKFILL

A. Sanitary sewer (solid) pipe ‘bedding material’ shall be as shown on the Drawings, and conforming to Section 704.01 of FP-24 Standard Specifications and Section 31 23 00 -

Excavation and Fill.

B. Sanitary sewer structure foundation material shall be a coarse aggregate granular backfill as shown on the Drawings, and conforming to AASHTO M43, and Section 703, Aggregate of the

FP-24 Standard Specifications.

C. Sanitary sewer structure and plastic pipe ‘backfill material(s)’ shall be as shown on the

Drawings, and conforming to Section 704.01 of FP-24 Standard Specifications and Section 31

23 00 - Excavation and Fill.

2.4 CLEANOUTS

A. Cleanouts shall be installed at the locations shown on the Drawings or marked in the field by the Contracting Officer. Cleanouts shall be of the same size and material as the sewer line it serves.

2.5 UTILITY BOXES

A. Contractor shall verify utility box sizes required for sewer system facilities as shown on the

Drawings, and actual sizes and dimensions of materials placed in the work.

B. Provide precast concrete boxes with steel or cast iron covers marked “SEWER” and traffic rated for H20 loading. Provide risers and extensions as required.

C. Concrete collars around utility boxes shall conform to Section 03 30 50 - Minor Concrete.

2.6 MARKING TAPE AND TRACING WIRE

A. Marking tape shall be minimum 3 inches wide, colored in APWA approved green color, and imprinted with “Caution Buried Sewer Line Below” in black uniformly located along its entire length. Tape shall be minimum 5-mil tape with aluminum backing for locate using a non-ferrous locator. Where more than one utility is located in a common trench, marking tape shall be 6 inches wide with the imprint “Caution – Buried Utility Lines Below”.

B. Locating wire shall be minimum No. 14 gauge solid, coated, soft drawn copper wire (#14-

AWG). Locating wire shall be strapped to any run of sewer pipeline (over 5-ft in length) to facilitate pipe location, stubbed inside valve/utility boxes, and marked with an irremovable aluminum tag with the corresponding utility. Connection of any bare wire ends shall be approved splice kit for underground use to secure electrical joint.

2.7 GRINDER PUMP

A. The grinder pump shall be installed as shown on the Drawings. The pump shall be provided with isolation and check valves. The sump shall be over 50 gallons.

B. The pump shall be a Zoeller 922 Simplex 48″ x 120″ Grinder Package with M803 pump or approved equal in terms of size, performance and functionality.

YELL 326141 33 30 00 - 6

C. The operating point for the pump is 27.8 gpm @ 13.7 ft of total dynamic head.

D. The control panel for the pump shall include hand / off / auto switches, an elapsed time meter, and a pump cycle counter.

E. As shown on the Drawings, the wet well shall include a bolted solid fiberglass cover.

2.8 SEWER SYSTEM PRECAST MANHOLES

A. Manholes for sewer systems shall be precast concrete, conforming to the applicable requirements of ASTM C478 (manhole sections).

B. Structural design loads for precast concrete structures shall meet anticipated field conditions (as shown on Drawings), and conform to minimum design loading under ASTM C890 and ACI 318 and 350 codes, whichever is more stringent.

C. All underground sewer structures, and inlet/outlets and access openings shall be constructed to withstand corrosion and/or decay and shall be watertight. All joint seals, gaskets, connectors and fittings shall be watertight conforming to applicable ASTM and AASHTO standards for anticipated hydrostatic pressures and field conditions.

D. Manholes shall be of the general size and dimensions as shown on the Drawings, including:

1. Manholes shall be designed to withstand AASHTO HS20 (MS10) loading.

2. Manholes shall be constructed of precast concrete rings with frames and covers and steps in accordance with AASHTO M199 and as shown in the Drawings.

3. Adjusting rings may be used for adjusting the manhole top elevation to coincide with existing ground elevations, except the total height of adjusting rings used per manhole shall not exceed 12 inches. Adjusting rings shall be reinforced with the same percentage of steel as the riser and top.

4. Precast concrete rings shall conform to ASTM C478.

5. When required, noncorrosive steps of rubber encased steel, aluminum, or nylon shall be used. Steps shall withstand vertical loads of 400 pounds and pull out resistance of 1,000 pounds.

PART 3 EXECUTION

3.1 GENERAL

A. Conform to Section 612, Sanitary Sewer Systems or the FP-24 Standard Specifications and

WPWSS 2023. In case of conflict, the most stringent specification shall apply.

B. Applicable construction operations for excavation, bedding and backfill shall conform to

Section 31 23 00 - Excavation and Fill.

C. Conform to state and federal guidance criteria for the separation of potable water and sanitary sewer pipelines/facilities. Refer to Drawings and provide additional materials for proper construction as required.

D. Care shall be taken in loading, transporting and unloading to prevent damage to materials. Store and protect materials according to manufacture recommendations.

YELL 326141 33 30 00 - 7

E. All structures, pipe, fittings, accessories and materials…