Attachment_4_SOW_ONPVC_Sewer.pdf

SECTION 01 10 00

DIVISION 1 – GENERAL REQUIREMENTS

PART 1 – GENERAL

ITEM 1 – DESCRIPTION OF WORK

1.1 Background

The Olympic National Park Visitor Center comfort station sanitary sewer system was constructed in 2017 under Contract No. P17PC00299 and connects to Sanitary Sewer Manhole SS MH-01 prior to discharge toward SS MH-02. Record Drawings (Sheets C4.3 – Sanitary Sewer Plan and Profile, and C6.1 – Typical Pipe Bedding and Backfill) establish the original design intent for slope, bedding, and invert construction.

The 4-inch sanitary sewer service lateral from the stand-alone comfort station to SS MH-01 was installed using PVC SDR-35 pipe with elastomeric gasketed joints, a minimum 36-inch cover, and detectable warning tape above the pipe. Based on field measurement at the manhole rim, the estimated invert depth of the sewer lateral at SS MH-01 is approximately 58 inches below finished grade. This depth is provided for estimating purposes only and shall be field verified during excavation.

The original design profile indicates a minimum gravity slope of 2.0 percent.

Settlement of SS MH-01 and/or deficient backfill has resulted in deformation and splitting of the 4-inch sewer pipe immediately outside the manhole structure. In addition, improper invert channel construction within the manhole has created misalignment and inadequate slope at the pipe connection, resulting in surcharge and sewage backup into the comfort station.

This project restores proper grade, alignment, invert geometry, structural backfill conditions, and surface restoration in accordance with the requirements of Section 33 31 00 – Sanitary Utility Sewerage Piping, originally issued under Contract No. P17PC00299 and reissued as part of this contract.

1.2 Work Covered by the Contract Documents

BASE BID – 10 LINEAR FEET SEWER REPLACEMENT

Work includes, but is not limited to:

1. Provide traffic control in accordance with the MUTCD and maintain continuous ADA/ABA-compliant pedestrian access between the parking lot and Visitor Center entrance.

Attachment 4 ONPVC Sewer SOW 140P8326Q0022

ONPVC Sewer Line Repair Olympic National Park

2. Provide temporary public sanitation facilities in accordance with Item 10 of this Section.

3. Sawcut and remove asphalt pavement adjacent to SS MH-01 using full-depth, straight saw cuts. Protect adjacent pavement and concrete surfaces.

4. Provide engineered trench protective system compliant with OSHA 29 CFR 1926 Subpart P. Trench protection shall be appropriate for Type B or Type C soils and shall prevent undermining of adjacent pavement, sidewalk, and manhole structures.

5. Excavate trench to expose existing 4-inch PVC SDR-35 sewer lateral and tracer wire.

6. Carefully hand expose pipe and tracer wire at the manhole penetration and upstream tie-in location.

7. Remove approximately 10 linear feet of existing PVC sewer pipe and dispose of off-site in accordance with applicable regulations.

8. Trim and shape trench bottom to provide uniform, stable subgrade free of loose or disturbed material.

9. Provide pipe bedding in accordance with ASTM D2321, Class B bedding, with minimum 6-inch compacted bedding layer.

10. Furnish and install 4-inch PVC SDR-35 sewer pipe conforming to ASTM D3034 with elastomeric gasket joints per ASTM F477.

11. Install pipe at a uniform minimum slope of 2.0 percent (1/4 inch per foot), as confirmed by field measurement in accordance with Part 3 – Execution.

12. Install new resilient pipe connector at manhole wall per ASTM C923, or verify integrity of existing connector as directed by the COR.

13. Remove defective grout and reconstruct manhole channel and bench using 3000 psi concrete per ACI 318. Apply ASTM C881 epoxy bonding agent between existing and new concrete. Restore invert channel to provide smooth transition between upstream and downstream pipe inverts with no offsets or standing water.

14. Protect and reinstall existing tracer wire where feasible. If damaged, splice or install new tracer wire directly above the pipe. Install detectable warning tape 12 inches below finished grade.

15. Compact backfill in maximum 8-inch lifts to 95% Modified Proctor per ASTM D1557.

Provide third-party in-place density testing to verify trench backfill and aggregate base course compaction immediately prior to asphalt placement.

16. Restore asphalt pavement to match existing thickness and section. Provide minimum 6-inch crushed base (or match existing thickness), apply tack coat to all

Attachment 4 ONPVC Sewer SOW 140P8326Q0022 vertical and horizontal joints, and install hot-mix asphalt in lifts. Compact using vibratory roller meeting WSDOT standards.

CONTRACT OPTION 1 – ADDITIONAL 10 LINEAR FEET AND CONCRETE RESTORATION

If field-measured invert elevations, obtained in accordance with Part 3 – Execution, demonstrate that the Base Bid repair limits are insufficient to achieve a minimum 2.0 percent gravity slope, the Contracting Officer may authorize the following additional work in writing:

1. Sawcut and remove concrete curb and a portion of adjacent sidewalk as required to extend trench limits.

2. Provide engineered trench protective system in accordance with Base Bid requirements.

3. Excavate trench to expose an additional 10 linear feet of 4-inch PVC SDR-35 sewer lateral.

4. Remove additional existing PVC sewer pipe as required.

5. Trim and shape trench bottom to provide uniform, stable subgrade free of loose or disturbed material.

6. Provide pipe bedding in accordance with ASTM D2321, Class B bedding, with minimum 6-inch compacted bedding layer.

7. Furnish and install additional 4-inch PVC SDR-35 sewer pipe with elastomeric gasket joints.

8. Install pipe at a uniform minimum slope of 2.0 percent (1/4 inch per foot), as confirmed by field measurement.

9. Protect and reinstall existing tracer wire where feasible, or install new tracer wire as required.

10. Backfill and compact trench in accordance with Base Bid requirements.

11. Replace concrete curb and sidewalk with 3000 psi concrete per ACI 318. Match existing curb profile, joint spacing, control joints, and surface finish. Provide broom finish on sidewalk surfaces.

Concrete restoration shall match existing thickness and section unless otherwise directed by the COR.

1.3 Period of Performance:

The period of performance shall be 21 calendar days from Notice to Proceed.

Contractor shall mobilize within 7 calendar days of NTP.

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Authorization of Contract Option 1 shall not automatically extend the period of performance unless approved in writing by the Contracting Officer.

ITEM 2 – EXISTING UTILITIES

Contractor shall notify the Washington Utility Notification Center (811) prior to excavation and shall verify the location of all public and private utilities within the work area.

Contractor shall field-verify marked utility locations prior to excavation. Hand excavation shall be performed within the tolerance zone of marked utilities and where utility crossings are suspected.

The Contractor is responsible for identifying and protecting all utilities within the work limits, including private utilities, park-owned utilities, and service laterals not identified through 811 notification.

Excavation operations shall be conducted in a manner that prevents damage to existing utilities and prevents undermining of SS MH-01 or adjacent pavement and structures.

Any damage to utilities caused by construction operations shall be immediately reported to the COR and repaired at no additional cost to the Government.

ITEM 3 – CONTRACTOR’S USE OF PREMISES

Work occurs in a high-visibility, high-traffic public area directly outside the Visitor Center entrance.

Contractor shall:

• Maintain continuous ADA-compliant pedestrian access.

• Maintain continuous emergency vehicle access at all times.

• Install temporary fencing and barricades around excavation.

• Maintain site cleanliness daily.

• Coordinate work activities such that activities producing noise above ambient levels shall be conducted between two hours after sunrise and two hours before sunset during marbled murrelet nesting season.

Environmental Protection

Contractor shall implement the following environmental protection measures:

Attachment 4 ONPVC Sewer SOW 140P8326Q0022

• Remove all materials, including trash and food wastes, from project sites daily to reduce attraction of marbled murrelet predators such as crows and jays.

• Reuse suitable excavated material as backfill where appropriate. If additional fill, rock, or topsoil is required, it shall be weed-free and approved by park vegetation staff prior to import.

• Comply with NPS invasive species prevention protocols. Equipment shall be pressure washed prior to arrival at the park and shall be free of weeds, seed, debris, and mud.

• Hazardous spill clean-up material shall be maintained onsite at all times. Any spill shall be immediately contained and reported to the COR.

Restoration & Clean-up

All excess materials and debris, including visible concrete and metal pieces, shall be removed from the park to an approved disposal location. Upon project completion, all tools, equipment, barricades, signs, surplus materials, and rubbish shall be removed from the project limits.

Any asphalt or concrete surfaces damaged due to work on the project shall be repaired to match existing thickness, section, and finish.

ITEM 4 – COMMENCEMENT, PROSECUTION, AND COMPLETION

Contractor shall submit the following for review and acceptance by the COR a minimum of five (5) working days prior to mobilization:

• Construction schedule identifying sequence of work, duration of each phase, mobilization date, trench excavation duration, anticipated restroom closure period, and surface restoration activities.

• Product data for PVC pipe, resilient connectors, tracer wire, asphalt mix, and concrete mix designs.

Work shall not commence until submittals have been reviewed and accepted.

ITEM 5 – EXAMINATION OF SITE

Contractor shall field verify rim elevations, surface conditions, and other visible site features prior to excavation.

Invert elevations shall be verified in accordance with Part 3 – Execution after exposure of existing pipe.

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Contractor is responsible for examining the site and becoming familiar with existing conditions affecting the work. No claims for visible site conditions will be accepted.

ITEM 6 – ABBREVIATIONS AND APPLICABLE STANDARDS

The following standards are referenced in this Section and shall govern materials, installation, and safety requirements. Where applicable, standards shall be consistent with the editions referenced in Section 33 31 00 – Sanitary Utility Sewerage Piping.

• ASTM D3034 – Standard Specification for Type PSM Poly(Vinyl Chloride) (PVC) Sewer Pipe and Fittings (SDR-35 gravity sewer pipe)

• ASTM D2321 – Standard Practice for Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow Applications (bedding and backfill requirements)

• ASTM F477 – Standard Specification for Elastomeric Seals (Gaskets) for Joining Plastic Pipe

• ASTM C923 – Standard Specification for Resilient Connectors Between Reinforced Concrete Manholes and Pipes

• ASTM C881 – Standard Specification for Epoxy-Resin-Base Bonding Systems for Concrete

• ASTM D1557 – Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (Modified Proctor compaction testing)

• ACI 318 – Building Code Requirements for Structural Concrete

• OSHA 29 CFR 1926 – Safety and Health Regulations for Construction (excavation, trenching, confined space entry, and personal protective equipment)

• NFPA 241 – Standard for Safeguarding Construction, Alteration, and Demolition

Operations

• MUTCD – Manual on Uniform Traffic Control Devices (temporary traffic control)

• ABA Accessibility Standards – Architectural Barriers Act Accessibility Standards

(accessible routes and portable sanitation accessibility)

• WSDOT Standard Specifications – Road, Bridge, and Municipal Construction

(asphalt placement and compaction requirements)

ITEM 7 – ACCIDENT PREVENTION

Contractor shall submit a site-specific Accident Prevention Plan (APP) for review and acceptance a minimum of five (5) working days prior to mobilization. Work shall not commence until the APP has been accepted.

The APP shall include, at a minimum:

• Trench safety plan compliant with OSHA 29 CFR 1926 Subpart P, including designation of a Competent Person responsible for daily excavation inspections.

Attachment 4 ONPVC Sewer SOW 140P8326Q0022

• Confined Space Entry Permit program compliant with OSHA 29 CFR 1926 Subpart AA, if manhole entry is required.

• Continuous atmospheric monitoring procedures for any manhole entry operations.

• Traffic control safety procedures addressing pedestrian protection and emergency vehicle access.

• Spill prevention and response plan addressing fuels, oils, and hydraulic fluids.

• Emergency procedures, including emergency contact numbers and identification of the nearest medical facility.

Daily tailgate safety meetings shall be conducted and documented for the duration of field operations.

ITEM 8 – PRECONSTRUCTION CONFERENCE

Contractor shall attend a mandatory preconstruction conference prior to commencement of field work. At a minimum, the Contractor shall present and review the following:

• Project schedule with key dates, including anticipated restroom closure period and surface restoration milestones.

• Subcontractor list and key personnel assignments.

• Accepted Accident Prevention Plan (APP).

• Traffic control plan and pedestrian routing.

• Portable sanitation plan and servicing schedule.

• Utility verification status.

• Site access, staging, and restoration strategy.

• Procedures for documenting invert elevations and determining whether Contract

Option 1 is required.

Work shall not commence until the preconstruction conference has been conducted.

ITEM 9 – SUBMITTALS

Required submittals shall be submitted via NPS CM-16 form.

Prior to Mobilization

• PVC pipe product data.

• Asphalt mix design.

• Concrete mix design (if needed).

During Construction

• Signed Grade Verification Report documenting measured invert elevations and installed slope. Report shall be submitted and accepted prior to backfill.

Attachment 4 ONPVC Sewer SOW 140P8326Q0022

• Tracer wire continuity test results, if new tracer wire is installed.

• Density test reports demonstrating compliance with 95% Modified Proctor compaction requirement.

Work shall not proceed beyond applicable construction phases until required submittals have been reviewed and accepted by the COR.

ITEM 10 – TEMPORARY SERVICES

During construction operations, the Contractor shall provide temporary portable sanitation facilities for public use for the full duration of construction while the following facilities are secured and taken out of service:

• Comfort Station Building (for the duration of the project) o Women’s: 4 toilets, 2 lavatories o Men’s: 2 toilets, 2 urinals, 2 lavatories o Family Restroom: 1 toilet, 1 lavatory

• Visitor Center Main Building Restrooms (during active manhole repair operations) o Women’s: 3 toilets, 2 lavatories o Men’s: 1 toilet, 2 urinals, 2 lavatories

Portable sanitation facilities shall be installed and operational prior to securing permanent restroom facilities.

The Comfort Station Building shall remain locked and out of service during sewer repair operations to prevent flow into the affected sanitary line and manhole. The Visitor Center Main Building Restrooms shall be locked and out of service during active manhole repair operations.

Contractor shall provide a sufficient number of portable restroom units to accommodate public demand typical of the Visitor Center. At a minimum:

• Four (4) standard portable toilet units

• One (1) ADA-compliant accessible portable toilet unit meeting ABA Accessibility

Standards

• One (1) standalone handwashing station equipped with potable water, soap, paper towels, and contained wastewater tank

Locations of all units shall be approved by the COR. The accessible unit shall be placed on firm, stable, level ground and connected to an accessible route from the parking lot and Visitor Center entrance.

The COR reserves the right to require additional units if visitor demand warrants.

Contractor shall provide full servicing and cleaning of all portable restroom units no less than two (2) times per week. Additional servicing shall be provided as necessary during

Attachment 4 ONPVC Sewer SOW 140P8326Q0022 periods of high visitation. Units shall be maintained in a clean, odor-free, and fully stocked condition at all times.

Overflowing, unsanitary, or vandalized units shall be addressed within 24 hours of notification.

Upon completion of sewer repairs and reactivation of permanent restroom facilities, the Contractor shall remove all portable units and restore staging areas to original condition.

ITEM 11 – PROJECT CLOSEOUT

Prior to Final Acceptance, Contractor shall provide:

• Signed Grade Verification Report documenting installed invert elevations and confirmed slope.

• Density test reports demonstrating compliance with 95% Modified Proctor compaction requirements.

• Tracer wire continuity test results, if new tracer wire was installed.

• Confirmation that all temporary facilities, including portable sanitation units, have been removed and staging areas restored.

All surface restoration shall be complete and accepted by the COR prior to Final Acceptance.

Contractor shall provide a one-year warranty covering materials and workmanship, beginning on the date of Final Acceptance.

PART 2 – PRODUCTS

Not Used – Replacement materials must match existing specifications.

PART 3 – EXECUTION

Phase 1: Pre-Construction Survey and Layout

• Establish benchmark referenced to rim elevation of SS MH-01.

• Verify rim elevation and ground elevations in the work area.

Phase 2: Surface Removal and Excavation

• Sawcut asphalt or concrete full depth within Base Bid limits.

• Install trench protective system in accordance with OSHA 29 CFR 1926 Subpart P as excavation progresses.

Attachment 4 ONPVC Sewer SOW 140P8326Q0022

• Excavate to expose the existing 4-inch sewer lateral while protecting adjacent utilities and preventing undermining of SS MH-01.

• Carefully expose the manhole penetration and upstream lateral using hand excavation near the pipe barrel and tracer wire.

Phase 3: Invert Verification (After Exposure, Before Removal)

• Measure and record invert elevation at:

o The pipe invert at SS MH-01 connection.

o The invert of the exposed upstream lateral at the proposed tie-in location.

• Calculate existing slope across the exposed segment.

• Submit field measurements to the COR prior to pipe removal.

• Confirm whether Base Bid limits are sufficient to achieve a minimum 2.0 percent slope.

If measured elevations indicate that a 2.0 percent minimum slope cannot be achieved within Base Bid limits, Contractor shall suspend further work and notify the COR. No additional excavation beyond Base Bid limits shall occur without written authorization from the Contracting Officer under Contract Option 1.

Phase 4: Pipe Removal and Installation

• Remove damaged pipe within authorized limits.

• Trim and shape trench bottom to provide uniform, stable subgrade free of loose or disturbed material.

• Place Class B bedding in accordance with ASTM D2321 with minimum 6-inch compacted bedding layer.

• Install new 4-inch PVC SDR-35 pipe beginning at downstream manhole connection with bells facing upstream.

• Install resilient pipe connector at manhole wall or verify integrity of existing connector as directed by the COR.

• Reconstruct manhole channel and bench using epoxy bonding agent and 3000 psi concrete. Restore smooth, continuous flow line with no offsets or standing water.

• Confirm installed slope using laser level immediately after placement and prior to backfill. Submit signed Grade Verification Report documenting slope and elevations.

• Tracer Wire:

o If existing tracer wire remains intact, reconnect and reuse.

o If damaged, remove damaged sections and install new #12 AWG solid copper tracer wire with HDPE insulation rated for direct burial.

o Provide waterproof direct-bury splices.

o Test tracer wire continuity prior to backfill and document results.

Attachment 4 ONPVC Sewer SOW 140P8326Q0022

• All joints, resilient connectors, and manhole channel reconstruction shall be visually inspected by the Contractor and COR prior to backfill.

Phase 5: Backfill and Surface Restoration

• Place initial backfill to springline and haunching in accordance with ASTM D2321.

• Complete trench backfill in maximum 8-inch lifts.

• Install detectable warning tape 12 inches below finished grade.

• Compact to 95% Modified Proctor with third-party density testing as specified.

• Restore base course and asphalt or concrete surfaces in accordance with Base Bid or Option 1 requirements.

Phase 6: Final Inspection and Closeout

• Provide complete documentation package, including grade verification and compaction reports.

• Correct punch list items.

• Restore site to preconstruction condition.

END OF SECTION 01 10 00

Attachment 4 ONPVC Sewer SOW 140P8326Q0022