SOW FY25 HAHD Relief Tunnel Drain Maintenance DRAFT.pdf

STATEMENT OF WORK (SOW)

Howard Hanson Dam Relief Tunnel Drain Maintenance US Army Corps of Engineers, Seattle District

Part 1

General Information

1. GENERAL: This is a non-personnel services contract to supply all supervision, labor, equipment, and materials to perform all work in strict accordance with this Statement of Work, all Federal, State and Local codes and regulations to complete camera inspections, cleaning or decommissioning of vertical and horizontal drains in the drainage tunnel constructed within the right abutment of Howard A. Hanson Dam (HAHD) with optional tasks for additional vertical and horizontal drain camera inspections, cleaning, or end plug replacement. The Government does not exercise any continuous supervision or control over the contract service providers performing the services herein. Such contract service providers shall be accountable solely to the prime Contractor. See Part 5 of the SOW for Specific Tasks.

1.1 Description of Services/Introduction: The contractor shall supply all supervision, labor, equipment, and materials to perform all work in strict accordance with this Statement of Work, all Federal, State and Local codes and regulations to provide drainage tunnel drain camera inspections, cleaning, decommissioning and repairs as described herein.

1.2 Background: HAHD is located on the Green River, in southeast King County, near Palmer, Washington in Section 28, Township 21 North, Range 8 East, Willamette Meridian. The dam is located approximately 35 miles southeast of Seattle and 25 miles east of Tacoma, at river mile (RM) 64. HAHD is a multiple purpose project for flood risk management, low flow augmentation and municipal and industrial water supply. The project also provides municipal and industrial water supply to the City of Tacoma and several other municipalities in the area.

General site map of Howard Hanson Dam is identified in Figure 3 of Attachment C.

The focus of this work will be the drains inside the HAHD drainage tunnel. The drainage tunnel was designed to control seepage through the right abutment. Lighting is provided throughout the tunnel but contractors should expect no electrical outlet availability and no source of water or compressed air if needed. Radon gas has been detected at low levels within the tunnel and is constantly monitored for safety with continuous ventilation provided by two over-drain fan systems located at the back of the tunnel that pull fresh air in from the tunnel portal. The 640 foot long tunnel was constructed in 1969 and included eleven original vertical drains and an 18-inch thick gravel drain beneath the floor. The vertical drains were constructed of unfiltered, torch-cut, slotted steel. The gravel drain contained an eight-inch perforated concrete pipe to direct flow toward the tunnel outlet. In 2011, a full tunnel rehabilitation was completed to reduce the risk of internal erosion due to the incompatible filter materials. The original vertical drains were re-lined, 25 new vertical drains were installed, and the concrete pipe in the gravel drain was decommissioned. All under-drains were developed by over-pumping.

The vertical drain configuration includes an over-drain above the tunnel and an under-drain aligned with the over-drain extending across the gravel drain and into the aquifer beneath the tunnel. Each vertical drain is 8-inches in diameter, covered with an iron grate flush with the tunnel floor and positioned at regular intervals near the centerline of the tunnel. The vertical drains consist of a one-foot stainless steel riser and multiple sections of 0.020 stainless steel vee wrapped screen with an end cap at the bottom. The vertical drain depths range from approximately 26 to 48.5 feet below the tunnel floor. The current tunnel drain configuration is shown in Figure 1 of Attachment C. A cross-section showing the drains is identified in Figure 2 of Attachment C. In addition, 32 horizontal drains have been installed at regular intervals in the tunnel wall as shown in Figure 1 of Attachment C.

The horizontal drains are constructed using 1.5-inch inside diameter (ID) stainless steel pipe, stainless steel screen in various lengths and locations and end plugs at the end of the drains. Some of the horizontal drain outlet pipes are connected to removable PVC drain pipes or hoses directed to aluminum weirs stationed throughout the tunnel.

Attachment D and Attachment E contain some as-builts of the tunnel drains.

1.3 Period of Performance: The period of performance shall be 180 days. The Government may exercise any or all optional items within 90 days after the initial contract award provided that the Government gives the Contractor a preliminary written notice of its intent at least 10 days before exercising any or all options.

Note: Period of Performance will be extended 30 calendar days for each option exercised; however, the total time extension for exercising optional item(s) will not exceed 120 calendar days.

1.4 General Information

1.4.1 Quality Control: The contractor shall develop and maintain an effective quality control program to ensure services are performed in accordance with this SOW. The contractor shall develop and implement procedures to identify, prevent, and ensure non-recurrence of defective services. The contractor’s quality control program is the means by which they assure that work complies with the requirement of the contract. Quality Control Program (QCP) is to be delivered within 30 days after contract award, three copies of a comprehensive written QCP shall be submitted to the KO and QAR within 5 (five) working days when changes are made thereafter. After acceptance of the quality control plan the contractor shall receive the contracting officer’s acceptance in writing of any proposed change to their QC system.

1.4.2 Quality Assurance: The government shall evaluate the contractor’s performance under this contract in accordance with the Quality Assurance Surveillance Plan. This plan is primarily focused on what the Government must do to ensure that the contractor has performed in accordance with the performance standards.

It defines how the performance standards will be applied, the frequency of surveillance, and the minimum acceptable defect rate(s).

1.4.3 Recognized Holidays: Contractor is not required to perform services on holidays.

New Year’s Day Labor Day Martin Luther King Jr.’s Birthday Columbus Day President’s Day Veteran’s Day Memorial Day Thanksgiving Day Independence Day Christmas Day Juneteenth National Independence Day

1.4.4 Hours of Operation: The contractor is responsible for coordinating hours for conducting business with HAHD. HAHD staff hours are generally available between the hours of 07:00 and 16:00, Monday thru Friday except Federal holidays or when the Government facility is closed due to local or national emergencies, administrative closings, or similar Government directed facility closings. For other than firm fixed price contracts, the contractor will not be reimbursed when the government facility is closed for the above reasons. The Contractor must at all times maintain an adequate workforce for the uninterrupted performance of all tasks defined within this SOW when the Government facility is not closed for the above reasons. When hiring personnel, the Contractor shall keep in mind that the stability and continuity of the workforce are essential.

1.4.5 Place of Performance: The work to be performed under this contract will be:

- Howard Hanson Dam,

- 36932 S.E. Green River Headworks Road

- RAVENSDALE, WA 98051

1.4.6 Type of Contract: The government will award a Firm Fixed Price Contract.

1.4.7 Security Requirements:

All contractor and all associated sub-contractors employees shall comply with applicable installation, facility and area commander installation/facility access and local security policies and procedures (provided by government representative). The contractor shall also provide all information required for background checks to meet installation/facility access requirements to be accomplished by installation Provost Marshal Office, Director of Emergency Services or Security Office. Contractor workforce must comply with all personal identity verification requirements (FAR clause 52.204-9, Personal Identity Verification of Contractor Personnel) as directed by DOD, HQDA and/or local policy. In addition to the changes otherwise authorized by the changes clause of this contract, should the Force Protection Condition (FPCON) at any installation or facility change, the Government may require changes in contractor security matters or processes.

Contractor and all associated sub-contractors employees shall comply with adjudication standards and procedures using the National Crime Information Center Interstate Identification Index (NCIC-III) and Terrorist Screening Database (TSDB) (Army Directive 2014-05 / AR 190-13), applicable installation, facility and area commander installation/facility access and local security policies and procedures (provided by government representative, as NCIC and TSDB are available), or, at OCONUS locations, in accordance with status of forces agreements and other theater regulations.

The Contractor must pre-screen Candidates using the E-verify Program (http://www.uscis.gov/e-verify) website to meet the established employment eligibility requirements. The Vendor must ensure that the Candidate has two valid forms of Government issued identification prior to enrollment to ensure the correct information is entered into the E-verify system. An initial list of verified/eligible Candidates must be provided to the QAR no later than 3 business days after the initial contract award." *When contracts are with individuals, the individuals will be required to complete a Form I-9, Employment Eligibility Verification, with the designated Government representative. This Form will be provided to the Contracting Officer and shall become part of the official contract file.

All contract employees, including subcontractor employees who are not in possession of the appropriate security clearance or access privileges, will be escorted in areas where they may be exposed to classified and/or sensitive materials and/or sensitive or restricted areas.

1.4.7.1 Physical Security: The contractor shall be responsible for safeguarding all government equipment, information and property provided for contractor use. At the close of each work period, government facilities, equipment, and materials shall be secured.

1.4.7.2 Key Control: The Contractor shall establish and implement methods of making sure all keys/key cards issued to the Contractor by the Government are not lost or misplaced and are not used by unauthorized persons.

NOTE: All references to keys include key cards. No keys issued to the Contractor by the Government shall be duplicated. The Contractor shall develop procedures covering key control that shall be included in the Quality Control Plan. Such procedures shall include turn-in of any issued keys by personnel who no longer require access to locked areas. The Contractor shall immediately report any occurrences of lost or duplicate keys/key cards to the Contracting Officer.

The Contractor shall prohibit the use of Government issued keys/key cards by any persons other than the Contractor’s employees. The Contractor shall prohibit the opening of locked areas by Contractor employees to permit entrance of persons other than Contractor employees engaged in the performance of assigned work in those areas, or personnel authorized entrance by the Contracting Officer.

1.4.7.3 Lock Combinations: NOT APPLICABLE

1.4.8 Special Qualifications: At a minimum, contractor must be able to identify one project that demonstrates their experience working at a government owned dam and one project that demonstrates their experience cleaning seepage drains.

1.4.9 Post Award Conference/Periodic Progress Meetings: The Contractor agrees to attend any post award conference convened by the contracting activity or contract administration office in accordance with Federal Acquisition Regulation Subpart 42.5. The contracting officer, Quality Assurance Representative (QAR), and other Government personnel, as appropriate, may meet periodically with the contractor to review the contractor's performance. At these meetings the contracting officer will apprise the contractor of how the government views the contractor's performance and the contractor will apprise the Government of problems, if any, being experienced. Appropriate action shall be taken to resolve outstanding issues. These meetings shall be at no additional cost to the government. No more than one, one hour, meeting will be held on a given week.

1.4.10 Quality Assurance Representative (QAR): The QAR monitors all technical aspects of the contract and assists in contract administration. The QAR is authorized to perform the following functions: assure that the Contractor performs the technical requirements of the contract: perform inspections necessary in connection with contract performance: maintain written and oral communications with the Contractor concerning technical aspects of the contract: issue written interpretations of technical requirements, including Government drawings, designs, specifications: monitor Contractor's performance and notifies both the Contracting Officer and Contractor of any deficiencies: coordinate availability of government furnished party, and provide site entry of Contractor personnel. The QAR is not authorized to change any of the terms and conditions of the resulting order.

1.4.11 Key Personnel: The following personnel are considered key personnel by the government: Contract Manager/Alternate Contract Manager. The contractor shall provide a contract manager who shall be responsible for the performance of the work. The name of this person and an alternate who shall act for the contractor when the manager is absent shall be designated in writing to the contracting officer. The contract manager or alternate shall have full authority to act for the contractor on all contract matters relating to daily operation of this contract.

The contract manager or alternate shall be available between 7:00 a.m. to 3:00p.m., Monday thru Friday except Federal holidays or when the government facility is closed for administrative reasons.

1.4.12 Identification of Contractor Employees: All contract personnel attending meetings, and working in other situations where their contractor status is not obvious to third parties are required to identify themselves as such to avoid creating an impression in the minds of members of the public that they are Government officials. They must also ensure that all documents or reports produced by contractors are suitably marked as contractor products or that contractor participation is appropriately disclosed.

1.4.13 Contractor Travel: NOT APPLICABLE

1.4.14 Other Direct Costs: NOT APPLICABLE

1.4.15 Data Rights: Government Rights: The Government has unlimited rights to all documents/material produced under this contract. All documents and materials produced under this contract shall be Government owned and are the property of the Government with all rights and privileges of ownership/copyright belonging exclusively to the Government. These documents and materials may not be used or sold by the contractor without written permission from the Contracting Officer. All materials supplied to the Government shall be the sole property of the Government and may not be used for any other purpose. This right does not abrogate any other Government rights.

1.4.17 PHASE IN /PHASE OUT PERIOD: NOT APPLICABLE

PART 2

DEFINITIONS & ACRONYMS

2. DEFINITIONS AND ACRONYMS:

2.1. DEFINITIONS:

2.1.1. CONTRACTOR. A supplier or vendor awarded a contract to provide specific supplies or service to the government. The term used in this contract refers to the prime.

2.1.2. CONTRACTING OFFICER. A person with authority to enter into, administer, and or terminate contracts, and make related determinations and findings on behalf of the government. Note: The only individual who can legally bind the government.

2.1.4. DEFECTIVE SERVICE. A service output that does not meet the standard of performance associated with the Performance Work Statement.

2.1.5. DELIVERABLE. Anything that can be physically delivered, but may include non-manufactured things such as meeting minutes or reports.

2.1.6. KEY PERSONNEL. Contractor personnel that are evaluated in a source selection process and that may be required to be used in the performance of a contract by the Key Personnel listed in the PWS/SOW. When key personnel are used as an evaluation factor in best value procurement, an offer can be rejected if it does not have a firm commitment from the persons that are listed in the proposal.

2.1.7. PHYSICAL SECURITY. Actions that prevent the loss or damage of Government party.

2.1.8. QUALITY ASSURANCE. The government procedures to verify that services being performed by the Contractor are performed according to acceptable standards.

2.1.9. QUALITY ASSURANCE SURVEILLANCE PLAN (QASP). An organized written document specifying the surveillance methodology to be used for surveillance of contractor performance.

2.1.10. QUALITY CONTROL. All necessary measures taken by the Contractor to assure that the quality of an end product or service shall meet contract requirements.

2.1.11. SUBCONTRACTOR. One that enters into a contract with a prime contractor. The Government does not have privity of contract with the subcontractor.

2.1.12. WORK DAY. The number of hours per day the Contractor provides services in accordance with the contract.

2.1.12. WORK WEEK. Monday through Friday, unless specified otherwise.

2.2. ACRONYMS:

AR Army Regulation ATO Antiterrorism Officer CFR Code of Federal Regulations CONUS Continental United States (excludes Alaska and Hawaii) COTR Contracting Officer's Technical Representative COTS Commercial-Off-the-Shelf

DA Department of the Army DD250 Department of Defense Form 250 (Receiving Report) DD254 Department of Defense Contract Security Requirement List DFARS Defense Federal Acquisition Regulation Supplement DMDC Defense Manpower Data Center DOD Department of Defense EM Engineering Manual FAR Federal Acquisition Regulation FPCON Force Protection Condition HAHD Howard A Hanson Dam HQDA Headquarters Department of the Army HIPAA Health Insurance Portability and Accountability Act of 1996 KO Contracting Officer OCI Organizational Conflict of Interest OCONUS Outside Continental United States (includes Alaska and Hawaii) ODC Other Direct Costs POC Point of Contact PRS Performance Requirements Summary PWS Performance Work Statement QA Quality Assurance QAP Quality Assurance Program QASP Quality Assurance Surveillance Plan QC Quality Control QCP Quality Control Program RM River Mile RA Requiring Activity TE Technical Exhibit TPU Tacoma Public Utilities TSDB Terrorist Screening Database

PART 3

GOVERNMENT FURNISHED PRTY, EQUIPMENT, AND SERVICES

3. GOVERNMENT FURNISHED ITEMS AND SERVICES:

3.1. Services: The Government will not provide any services under this contract.

3.2 Facilities: The Government will provide loading and unloading area along with short term storage (laydown) area for supplies and access to a settling pond for drain water disposal – all located on the HAHD property.

Coordinate with appropriate POC listed in the solicitation.

3.3 Utilities: The Government will not provide any utilities for this contract. There are lights within the drainage tunnel but electrical service via generator will be the responsibility of the contractor. Water for drain cleaning can be obtained on-site as described in Part 5, Specific Tasks.

3.4 Equipment: The Government will not provide any equipment for this contract.

3.5 Materials: The Government will not provide any new material(s) for this contract.

PART 4

CONTRACTOR FURNISHED ITEMS AND SERVICES

4. CONTRACTOR FURNISHED ITEMS AND RESPONSIBILITIES:

4.1 General: The Contractor shall furnish all supplies, equipment, materials, facilities and services required to perform work under this contract that are not listed under Section 3 of this SOW.

4.2 Secret Facility Clearance: NOT APPLICABLE

4.3. Materials: The Contractor shall furnish all materials, supplies, equipment necessary to meet the requirements under this SOW.

4.4. Equipment: The Contractor shall supply all equipment necessary to comply with this contract.

PART 5

SPECIFIC TASKS

5. Specific Tasks:

5.1. Base Item 1. Work Plan. The Contractor shall provide a description of activities to be performed in sufficient detail in order to achieve mutual understanding with the government on the work being accomplished during each task. See Section 5.1.1, 5.1.2, and 5.1.3 for additional work requirements. Qualified personnel or subcontractors shall be identified for tasks that require specialized training. A flowchart may be used as an aid to describe the general work flow process. The work plan shall be submitted as draft and finalized after receipt of Government comments. Two weeks shall be given for government review after the draft version is received. The work plan at a minimum, shall also include the following information:

Type of equipment, locations, and procedures for work;

Drain cleaning, decommissioning and end plug replacement procedures;

Schedule for completing the work;

Water Quality Management Plan;

Emergency Demobilization Plan;

Accident Prevention Plan.

Water Quality Management Plan shall describe procedures to control and contain debris and turbid, bio-fouled drain water pumped from the vertical drains before it is transferred to the settling ponds as part of the work described in this contract. Procedures shall include methods to prevent debris and turbid, bio-fouled drain water from entering the HAHD reservoir or river downstream of the tunnel portal. In addition, procedures shall include temporary installation of dams, barriers, covers or other effective means of preventing water from vertical drain cleaning activities from entering adjacent and downstream drains. See Section 5.1.4 for additional water quality requirements.

Emergency Demobilization Plan shall describe procedures to be completed in the event of a high reservoir pool flood event or other government requirement requiring an emergency demobilization from the drainage tunnel.

Emergency demobilization may be required in the event of natural precipitation events that result in a rise in reservoir water elevation. Emergency demobilization response time may be as short as 24 hours.

Accident Prevention Plan shall be completed in accordance with EM 385-1-1 to include, but not limited to safety procedures associated with non-permit required confined space work inside tunnels.

5.1.1 General Requirements

Access to HAHD is restricted. Access to Howard Hanson Dam is controlled at an entrance guard station operated by Tacoma Public Utilities (TPU). TPU will issue permits for the Contractor’s vehicles on the first occasion they come to the guard station. Access can be expedited by notifying the Tacoma control station, at (206) 502-8346, and the Corps of Engineers Project Office at (206) 764-6975, in advance. Incoming traffic will be restricted from entering the controlled area until proper identification is provided. Access on a regular basis and during other than established working hours will require prior coordination and approval by the Contracting Officer. Access to the Green River Watershed will be permitted only to those persons actually engaged in operations authorized by the Contractor by permit from TPU. Access to the watershed is permitted only at such times as personnel are on direct work assignment. Wandering from the work area or engaging in any activity other than that authorized is not permitted.

Minimal room is available at the project site for equipment lay down and material storage. Staging areas for equipment and supplies are shown on the attached drawings. The primary access road to the project site is a two-lane gravel road that is used by logging trucks. Snow, ice, and mud are common in the watershed during the winter and early spring months.

Radio communication on CB bands (channel 10) for all vehicles is mandatory for travel along the access road to the dam. Cell phone reception is poor to nonexistent at the project site. Landline telephones at the HAHD project office shall not be used by the Contractor except in the event of an emergency. Handheld radios shall be required for communication between crews while on-site.

The Contractor is required to pay to TPU the rate of $25.00/trip for hauling heavy equipment (vehicles over 14,000 lbs.) on the Tacoma Headworks Access road from Kanasket-Cumberland Road (Access Road “A”) to the dam. In addition, the Contractor shall pay to TPU the rate of $3.57/trip for hauling to the Project Disposal Site for all construction vehicles over 14,000 lbs. The fees are to reimburse TPU for required road repair. The Contractor is required to maintain the road from the dam to the staging and stockpile area in the same condition as that prior to construction throughout the contract period. The Contractor shall keep records of road use in the watershed and provide 3 copies of road use trip and mileage records to the Government project manager. The Contractor is required to coordinate with TPU’s Watershed Manager, Jarod Kaiser, (253)-502-8808 for forms and frequency of payment.

TPU will inspect all equipment used for drain cleaning and decommissioning activities for invasive weed seeds before the Contractor is permitted to mobilize this equipment into the drainage tunnel. Contractor will thoroughly steam clean all equipment before arriving on site to ensure TPU requirements are met and site access is granted.

All equipment used at the site shall be thoroughly cleaned before arriving on site. Appropriate means of sediment and oil containment shall be used for work near the reservoir, river and in the watershed. The Contractor shall ensure that all equipment cleaning, maintenance, lubrications, etc. are in compliance with required regulations, and meet the requirements of the City of Tacoma for work in the watershed and for work adjacent to a water supply reservoir. While working in the drainage tunnel, the Contractor shall clean and sterilize all downhole equipment between holes so as not to spread biofouling bacteria. Disinfection and cleaning specifications, mandated for the equipment utilized by the contractor for work identified in this SOW, are included as Attachment A. Biodegradable hydraulic fluid must be utilized by all onsite hydraulic operated equipment.

5.1.2 Drainage Tunnel Access

Access to the tunnel is made via an unpaved road off of the main access road to the dam with a steep uphill grade to a limited parking area near the tunnel portal. Entry to the tunnel portal is made by climbing a steel stairway to a steel grated platform in front of the steel grated access door. HAHD staff will unlock the portal entry door for access to the tunnel. The first approximately 200 feet of tunnel contains a raised, grated catwalk and left turn ending in a ramp down to the concrete tunnel floor continuing to the back of the tunnel. The contractor should expect foot traffic access only within the tunnel with less than 7 feet of vertical and less than 6 feet of horizontal clearance within the first 200 feet of tunnel, then less than 6 feet of vertical and horizontal clearance within the remaining 440 feet of tunnel. Aluminum weir boxes and other materials are staged in several areas within the tunnel that may limit movement and access to complete this work. The contractor shall verify that the equipment selected for this work can operate and fit within the tunnel. Access and laydown areas are shown on the attached drawings. The contractor is responsible for coordinating all access with project personnel.

5.1.3 Site Restoration:

The work site shall be left in a clean and safe condition at the end of each shift. Sediment, debris, or other waste generated by the work shall be removed at the contractor’s expense. After completion of the work, tools, appliances, surplus materials, temporary drainage, rubbish, and debris incidental to work shall be removed and disposed of by the Contractor. Site cleanup shall be to the requirements and to the satisfaction of the Government.

All solid debris from the drain cleaning process can be disposed of on-site at the spoils area identified on the drawings. All debris must be free from contaminants to include, but not limited to, fuels, oils, or other chemical compounds. Wastewater shall be disposed off-site.

5.1.4 Water Quality Restrictions

The Contractor shall manage all water, cleaning debris and other waste to prevent degradation of the river as a municipal water source during the course of the specified activities. The Contractor shall take such precautions as may be necessary to prevent cleaning debris, equipment exhaust oil, wash water, from defacing or damaging the permanent structure. The Contractor will be required to furnish such equipment as may be necessary to care for waste water from his operations and prevent turbid and/or contaminated water from entering the Green River which is used by the City of Tacoma for municipal water supply.

The Contractor shall supply all water for the work specified in this contract. Water must be potable or it can be pumped from the reservoir or stilling basin. Access to the reservoir can be attained at the boat launch south of the gate tower. Alternatively, pending availability/accessibility, water may be obtained downstream from the stilling basin. It shall be the responsibility of the Contractor to provide a pumps, trucking, and any necessary supply line connections and extensions to draw water. Water level of the reservoir and the stilling basin fluctuate based on the weather and the dam’s water control requirements. Therefore, access to the water sources may change over time. If the contractor choses to draw water from either location, they are solely responsible for all aspects of that operation. For refueling a water pump, the Contractor shall move the pump to an area where runoff does not enter the water supply. Plastic sheeting shall be used beneath the pump in the refueling area and also while pumping water from the reservoir.

5.2 Base Item 2. Drainage Tunnel Vertical Drain Cleaning

Based on recent downhole camera inspections conducted by the Government, the following 10 vertical drains have been selected for cleaning under Base Item 2: TW-275, TW-276, TW-278, TW-279, TW-282, TW-283, TW-286, TW-287, TW-288 and TW-289. Refer to Attachments C, D, and E for additional detail on the tunnel drains. Drainage tunnel vertical drain cleaning shall include an inspection of the specified tunnel drains following procedures identified in Section 5.2.1, Drain Inspection Procedures. All 10 drains located along the floor of the tunnel shall be cleaned according to Section 5.2.2, Drain Cleaning Procedures.

5.2.1 Vertical Drain Inspection Procedures

Drain inspection shall be completed using a downhole camera collecting digital video recordings showing horizontal and vertical views displaying drain screen and bottom conditions before and after drain cleaning. The Contractor shall record the date of inspection, drain number, as-built drain length, measured drain length, estimate of flow from drain, and drain condition (e.g. debris depth, bio-fouling or mineral buildup with color, etc.). All drain inspection records shall be submitted to the Government. Copies of all videos collected during inspections shall be provided to the Government using a Microsoft Windows compatible file format. Copies of the videos shall submitted on a portable hard drive. The portable hard drive shall be furnished by the contractor.

5.2.2 Vertical Drain Cleaning Procedures

Vertical drain cleaning within the HAHD drainage tunnel will consist of mechanical cleaning to remove as much bio-fouling, mineral scale, sand and sediment from the drain as possible. Chemical treatment is not authorized for this work. The process outlined below will continue until the water is free and clear of biological matter and other fines. If it appears that sediment is entering the drain through the screen from the surrounding material/filter pack during development, the development shall stop immediately and the Government geologist shall be contacted for further guidance.

The following steps shall be followed for the mechanical cleaning:

1. Mechanically scrub the entire length of the drain with a brush of appropriate diameter and stiffness to remove bio-foul and mineral scale within the 8-inch ID casing and screen without causing damage to the casing and screen. Before any actual scrubbing is initiated, a pre-pass test shall be conducted which consists of the brush assembly being slowly lowered the entire length of the drain to determine if the brush assembly will pass without binding or encountering obstructions. The results of the pre-pass test and depths of any obstructions shall be documented on the Vertical/Horizontal Drain Cleaning Log (Attachment B). The brush assembly should be periodically removed and cleaned to prevent binding in the drain. Pertinent details of the brushing process shall be recorded on the Vertical/Horizontal Drain Cleaning Log.

2. Once brushing is complete, the water column in the drain shall be pumped utilizing an airlift or other appropriate method until the drain is clear of biomass and sediment. The discharge water shall be directed by hose or piping into a water storage tank outside of the tunnel portal (truck mounted or stationary) for later disposal into nearby settling ponds.

3. At the completion of brushing, the drain shall be surged with an appropriately sized and functioning surge block (with built-in relief valve) to entrain any loose bio-foul or mineral scale within the filter pack. Prior to performing the surging, a pre-pass test with the surge block assembly shall be conducted. During this pre-pass test, the surge block shall be slowly lowered the entire length of the drain to verify free passage. Upon completion of the successful pre- pass test, the drain screen shall be surged in sections. The stroke length of the surge block action shall not exceed 10 feet and maintain a stroke rate of no more than 4 feet/second. Each 10-foot length of cleaning zone shall proceed for 15 minutes. Care shall be taken while surging at the bottom of the drain as to not damage the drain bottom. If a cleaning zone less than 10 feet is encountered (such as at the top of the drain screen), then a shorter stroke length shall be used that will allow proper surging to proceed.

Any portion of the surge block assembly shall not come within 1 foot of the bottom of the drain.

4. At the completion of surging, the water column in the drain shall be pumped utilizing an airlift or other appropriate method until the drain is clear of bio-fouling and sediment. The discharge water shall be directed by hose or piping into a water storage tank outside of the tunnel portal (truck mounted or stationary) for later disposal into nearby settling ponds.

A record of cleaning methods and final inspection results for each drain shall be submitted to the Government.

Copies of all videos collected during final inspections shall be provided to the Government using a Microsoft Windows compatible file format. Copies of the videos shall submitted on a portable hard drive. The portable hard drive shall be furnished by the contractor.

5.3 Base Item 3. Drainage Tunnel Horizontal Drain Cleaning

Based on recent downhole camera inspections conducted by the Government, horizontal drain THD-19 has been selected for cleaning to include an inspection following procedures identified in Section 5.3.1, Drain Inspection Procedures. THD-19 shall be cleaned according to Section 5.3.2, Drain Cleaning Procedures. Refer to Attachments C, D, and E for additional detail on the tunnel drains.

5.3.1 Drain Inspection Procedures

Drain inspection shall be completed using a downhole camera collecting digital video recordings showing horizontal and vertical views displaying drain screen and end cap conditions before and after drain cleaning. The Contractor shall record the date of inspection, drain number, as-built drain length, measured drain length, estimate of flow from drain, and drain condition (e.g. debris depth, bio-fouling or mineral buildup with color, etc.). All drain inspection records shall be submitted to the Government. Copies of all videos collected during inspections shall be provided to the Government using a Microsoft Windows compatible file format. Copies of the videos shall submitted on a portable hard drive. The portable hard drive shall be furnished by the contractor.

5.3.2 Drain Cleaning Procedures

Horizontal drain cleaning within the HAHD drainage tunnel will consist of mechanical cleaning to remove as much bio-fouling, mineral scale, sand and sediment from the drain as possible. Chemical treatment is not authorized for this work. The process outlined below will continue until the water is free and clear of biological matter and other fines. If it appears that sediment is entering the drain through the screen from the surrounding material/filter pack during development, the development shall stop immediately and the Government geologist shall be contacted for further guidance.

The following steps shall be followed for the mechanical cleaning:

1. Mechanically scrub the entire length of the drain with a brush of appropriate diameter and stiffness to remove bio-foul and mineral scale within the 1.5-inch ID casing and screen without causing damage to the casing and screen. Before any actual scrubbing is initiated, a pre-pass test shall be conducted which consists of the brush assembly being slowly lowered the entire length of the drain to determine if the brush assembly will pass without binding or encountering obstructions. The results of the pre-pass test and depths of any obstructions shall be documented on the Vertical/Horizontal Drain Cleaning Log (Attachment B). The brush assembly should be periodically removed and cleaned to prevent binding in the drain. Pertinent details of the brushing process shall be recorded on the Vertical/Horizontal Drain Cleaning Log.

2. Once brushing is complete, the water column in the drain shall be pumped utilizing an airlift or other appropriate method until the drain is clear of biomass and sediment. The discharge water shall be directed by hose or piping into a water storage tank outside of the tunnel portal (truck mounted or stationary) for later disposal into nearby settling ponds.

3. At the completion of brushing, the drain shall be surged with an appropriately sized and functioning surge block (with built-in relief valve) to entrain any loose bio-foul or mineral scale within the filter pack. Prior to performing the surging, a pre-pass test with the surge block assembly shall be conducted. During this pre-pass test, the surge block shall be slowly lowered the entire length of the drain to verify free passage. Upon completion of the successful pre- pass test, the drain screen shall be surged in sections. The stroke length of the surge block action shall not exceed 10 feet and maintain a stroke rate of no more than 4 feet/second. Each 10-foot length of cleaning zone shall proceed for 15 minutes. Care shall be taken while surging at the bottom of the drain as to not damage the drain bottom. If a cleaning zone less than 10 feet is encountered (such as at the top of the drain screen), then a shorter stroke length shall be used that will allow proper surging to proceed.

Any portion of the surge block assembly shall not come within 1 foot of the bottom of the drain.

4. At the completion of surging, the water column in the drain shall be pumped utilizing an airlift or other appropriate method until the drain is clear of biomass and sediment. The discharge water

A record of cleaning methods and final inspection results for each drain shall be submitted to the Government.

Copies of all videos collected during final inspections shall be provided to the Government using a Microsoft Windows compatible file format. Copies of the videos shall submitted on a portable hard drive. The portable hard drive shall be furnished by the contractor.

5.4 Base Item 4. Drainage Tunnel Horizontal Drain Decommissioning

The Government has selected drainage tunnel horizontal wells THD-10, THD-11, THD-12 and THD-16 for decommissioning. THD-10 is approximately 37.5 feet in length with stainless steel screen set at approximately

22.5 to 27.5 feet from tunnel wall. THD-11 is approximately 200 feet in length with screen set at approximately 100 to 200 feet from tunnel wall. THD-12 is approximately 200 feet in length with screen set at approximately 120 to 200 feet from tunnel wall. THD-16 is approximately 100 feet in length with screen set at approximately 30 to 100 feet from tunnel wall. Refer to Attachments C, D, and E for additional detail on the tunnel drains.

Drain decommissioning shall be done according to the requirements of the State of Washington, ASTM D 5299, and the requirement of these specifications. The screened interval of the drains must be pressure grouted in one continuous operation. Enough pressure shall be used to force grout through the screen and into the formation but not exceed 25 psi. Grout shall be injected until twice the calculated volume of the borehole annulus has been injected or until grout cannot be injected at the allowed pressure. The drain pipe shall be cut 1 inch behind the surface of the tunnel liner and the hole patched with cement leveled smooth with the existing tunnel liner.

The drains shall be decommissioned using a grout composed of neat cement with 2-8 percent bentonite. A grout pump and tremie pipe shall be used for delivering grout to the ends of each well. The Contractor shall utilize the best method of completing the decommissioning by bringing the cement-bentonite mixture flush with the inner concrete tunnel wall. Grout for decommissioning shall consist of a homogenous, pumpable, stable mixture of non-shrink cementaceous grout. The mixture water content shall be the minimum possible for proper placement and penetration through the screen and filter pack, and the water-cement ratio shall not exceed 0.45 by weight, or as recommended by the grout manufacturer if a prepackaged non-shrink cementaceous grout is used. The grout mix shall have 0 percent bleed at 3 hours at 70 degrees F, when tested in accordance with ASTM C 940. The pressure filtration coefficient shall not exceed 0.09 𝑚𝑖𝑛 when tested in accordance with API method API RP 13B-1, low pressure / low temperature. A record of grout mix materials, material volumes used and mixture test results shall be submitted to the Government.

Drain decommissioning records shall be maintained for each drain that is decommissioned. Drain decommissioning records shall include project name, drain hole number, location, depth, diameter, date of decommissioning, method of decommissioning, description of materials and quantity of materials used, and items left in hole (casing, screen, etc.).

5.5 Optional Item 1. Additional Vertical Drain Cleaning

Based on recent downhole camera inspections conducted by the Government, the following 7 vertical drains have been selected for cleaning under Optional Item 1: TW-280, TW-281, TW-284, TW-285, TW-290, TW-291 and TW-292. Refer to Attachments C, D, and E for additional detail on the tunnel drains. Drainage tunnel vertical drain cleaning shall include an inspection of the specified tunnel drains following procedures identified in Section 5.5.1, Drain Inspection Procedures. All 7 drains located along the floor of the tunnel shall be cleaned according to Section 5.5.2, Drain Cleaning Procedures.

5.5.1 Vertical Drain Inspection Procedures

Drain inspection shall be completed using a downhole camera collecting digital video recordings showing horizontal and vertical views displaying drain screen and bottom conditions before and after drain cleaning. The Contractor shall record the date of inspection, drain number, as-built drain length, measured drain length, estimate of flow from drain, and drain condition (e.g. debris depth, bio-fouling or mineral buildup with color, etc.). All drain inspection records shall be submitted to the Government. Copies of all videos collected during inspections shall be provided to the Government using a Microsoft Windows compatible file format. Copies of the videos shall submitted on a portable hard drive. The portable hard drive shall be furnished by the contractor.

5.5.2 Vertical Drain Cleaning Procedures

Vertical drain cleaning within the HAHD drainage tunnel will consist of mechanical cleaning to remove as much bio-fouling, mineral scale, sand and sediment from the drain as possible. Chemical treatment is not authorized for this work. The process outlined below will continue until the water is free and clear of biological matter and other fines. If it appears that sediment is entering the drain through the screen from the surrounding material/filter pack during development, the development shall stop immediately and the Government geologist shall be contacted for further guidance.

The following steps shall be followed for the mechanical cleaning:

1. Mechanically scrub the entire length of the drain with a brush of appropriate diameter and stiffness to remove bio-foul and mineral scale within the 8-inch ID casing and screen without causing damage to the casing and screen. Before any actual scrubbing is initiated, a pre-pass test shall be conducted which consists of the brush assembly being slowly lowered the entire length of the drain to determine if the brush assembly will pass without binding or encountering obstructions. The results of the pre-pass test and depths of any obstructions shall be documented on the Vertical/Horizontal Drain Cleaning Log (Attachment B). The brush assembly should be periodically removed and cleaned to prevent binding in the drain. Pertinent details of the brushing process shall be recorded on the Vertical/Horizontal Drain Cleaning Log.

2. Once brushing is complete, the water column in the drain shall be pumped utilizing an airlift or other appropriate method until the drain is clear of biomass and sediment. The discharge water shall be directed by hose or piping into a water storage tank outside of the tunnel portal (truck mounted or stationary) for later disposal into nearby settling ponds.

3. At the completion of brushing, the drain shall be surged with an appropriately sized and functioning surge block (with built-in relief valve) to entrain any loose bio-foul or mineral scale within the filter pack. Prior to performing the surging, a pre-pass test with the surge block assembly shall be conducted. During this pre-pass test, the surge block shall be slowly lowered the entire length of the drain to verify free passage. Upon completion of the successful pre- pass test, the drain screen shall be surged in sections. The stroke length of the surge block action shall not exceed 10 feet and maintain a stroke rate of no more than 4 feet/second. Each 10-foot length of cleaning zone shall proceed for 15 minutes. Care shall be taken while surging at the bottom of the drain as to not damage the drain bottom. If a cleaning zone less than 10 feet is encountered (such as at the top of the drain screen), then a shorter stroke length shall be used that will allow proper surging to proceed.

Any portion of the surge block assembly shall not come within 1 foot of the bottom of the drain.

4. At the completion of surging, the water column in the drain shall be pumped utilizing an airlift or other appropriate method until the drain is clear of bio-fouling and sediment. The discharge water

A record of cleaning methods and final inspection results for each drain shall be submitted to the Government.

Copies of all videos collected during final inspections shall be provided to the Government using a Microsoft Windows compatible file format. Copies of the videos shall submitted on a portable hard drive. The portable hard drive shall be furnished by the contractor.

5.6 Optional Item 2. Drainage Tunnel Horizontal Drain End Plug Replacement

The Contractor shall remove the damaged/corroded end plug at horizontal drain THD-41and replace with a new end plug matching or compatible with the original plug for that drain. TDH-41 is a 1.5 inch ID steel cased drain approximately 52.5 feet in length with corroded rivets protruding into the drain that may complicate the plug replacement work. Refer to Attachments C, D, and E for additional detail on the tunnel drains.

PART 6

APPLICABLE PUBLICATIONS

6. APPLICABLE PUBLICATIONS (CURRENT EDITIONS)

6.1. The Contractor must abide by all applicable regulations, publications, manuals, local policies and procedures;

and EM 385-1-1 USACE Safety and Health Requirements.

TECHNICAL EXHIBIT 1

QUALITY ASSURANCE SURVEILLANCE PLAN

For Drainage Tunnel Drain Maintenance

U.S. Army Corps of Engineers Seattle District (USACE-NWS) Howard A Hanson Dam

Contract Description: A non-personnel services contract to complete camera inspections, cleaning or decommissioning of vertical and horizontal drains in the drainage tunnel constructed within the right abutment of Howard A. Hanson Dam (HAHD) with optional tasks for additional vertical and horizontal drain camera inspections, cleaning, or end plug replacement as specified by the Government.

1. PURPOSE

This Quality Assurance Surveillance Plan (QASP) provides a systematic method to evaluate performance for the stated contract. This QASP explains the following:

• What will be monitored

• How monitoring will take place

• Who will conduct the monitoring

• How monitoring efforts and results will be documented

This QASP does not detail how the contractor accomplishes the work.