DRAFT_SOW_5_05_26_1.pdf

Prosser Creek Dam Spillway Stilling Basin Cleanout Lahontan Basin Area Office – Washoe Project - California

STATEMENT OF WORK

SPILLWAY STILLING BASIN CLEANOUT

PROSSER CREEK DAM

DEFINITIONS

CO Contracting Officer COR Contracting Officer’s Representative LBAO Lahontan Basin Area Office OGR On-site Government Representative Reclamation U.S. Bureau of Reclamation

1.0 BACKGROUND

Prosser Creek Dam is located in Nevada County, California; approximately 1½ miles upstream of the Truckee River and about four miles northeast of Truckee, California. The dam is a zoned earthfill structure with a structural height of 165.6 feet, a hydraulic height of 141.4 feet, a crest width of 30 feet, and a crest length of 1,830 feet. The spillway is in the left abutment and consists of an unlined approach channel, a crest structure with a 15-foot-wide uncontrolled ogee crest at elevation 5745.2, a concrete-lined chute, and a stilling basin. The spillway has a capacity of 2,750 cubic feet per second at the original maximum water surface elevation of 5758.5 feet. The Prosser Creek Dam spillway stilling basin is directly at the bottom of the spillway and will only receive flows during high water years. In turn, the stilling basin flows into Prosser Creek, ultimately joining the Truckee River further downstream.

Prosser Creek Dam is defined as a high and significant hazard potential dam and therefore requires annual, periodic and comprehensive reviews to occur following Reclamation Directives and Standards FAC 01-07 Review and Examination Program for High and Significant Hazard Potential Dams. In 2011, the Reclamation Dive Team completed a routine dive inspection of the spillway stilling basin and discovered a significant amount of material on the floor of the basin.

This prevented the dive team from completing a comprehensive inspection of the concrete floor as well as other critical stilling basin features. A Category 2 Recommendation to “remove the debris located within the spillway stilling basin and clear accumulated sediments from the under-drain outfalls” (Recommendation 2011-2-A) was issued as a result. Additional dive inspections have been completed following the issuance of this recommendation and all continue noting an increase in accumulated sediments and recommend their removal.

Reclamation has obtained an Exclusion Category 516 DM 14.5 D (1) permit for maintenance, rehabilitation, and replacement of existing facilities which may involve a minor change in size, locations, and/or operation. All work completed under this contract must comply with the National Environmental Protection Act (NEPA) and exclusion category as listed in this Performance of Work Statement. Additionally, all work completed under this contract shall be done in accordance with applicable federal safety practices. Federal and safety practices include, but are not limited to items outlined in the Reclamation Directives and Standards (https://www.usbr.gov/recman/), Reclamation Safety and Health Standards (RSHS)

DRAFT

(https://www.usbr.gov/ssle/safety/), and the Occupational Safety and Health Administration Standards (OSHA) (https://www.osha.gov).

2.0 SCOPE

This Statement of Work (SOW) describes the objectives, tasks, and deliverables needed to successfully fulfill cleanout and inspection of the spillway stilling basin at Prosser Creek Dam.

The contractor will be required to complete the following:

1. Remove all materials from the spillway stilling basin. These materials include, but are not limited to fine sediments, gravels, cobbles, boulders, chain link fence materials, and large woody materials.

2. Remove material that is present in the 6-inch drains on two of the chute blocks to the greatest extent possible.

3. Perform an inspection of the concrete floor and all other spillway stilling basin features upon completion of the sediment and materials removal.

3.0 OBJECTIVES

a) Removal of materials from the spillway stilling basin:

The contractor shall removal materials from the spillway stilling basin including fine sediments, gravels, cobbles, boulders, chain link fence materials, and large woody material.

The contractor shall complete a site visit to determine accessibility, staging areas, and all necessary equipment required to successfully complete the removal of any material. The contractor shall also provide a Work Plan describing the means and methods for removing the materials. The Work Plan shall include safety measures, site use maps, methods for preserving as-is site conditions, equipment, describe Best Management Practices (BMPs), and a tentative schedule and duration for all activities. All materials removed from the spillway stilling basin must be completely removed from the site and will no longer be considered Government property.

b) Remove material that is present in the 6-inch drains on two chute blocks:

The contractor shall remove the material from the 6-inch drains to the greatest extent possible, taking care not to cause damage or further move the material into the drains. After initial removal of material present at the 6-inch drains, the contractor shall verify if the drainpipe is free of material. The contractor shall probe approximately 12 feet of length of the drainpipe to verify the area is clear of material. Refer to the drawings provided in Section 11.0 Attachments.

c) Inspect the concrete floor and all other spillway stilling basin features:

The contractor shall complete an inspection of the concrete floor and all other spillway stilling basin features upon completion of all materials being removed. The contractor shall take measurements of any concrete deterioration, note any abnormalities observed on the concrete floor, walls, or other features, and provide photos or documentation of all findings.

The contractor shall provide the results of the inspection as outlined in Section 5.0 Tasks.

4.0 TYPE OF CONTRACT

The Government will award a firm-fixed price construction contract.

5.0 TASKS

A. Construction Requirements

1. Attend Post Award preconstruction meeting with Contracting Officer (CO) and

Contracting Officer’s Representative (COR).

2. Attend preconstruction safety meeting before work begins.

3. Provide acceptable submittals outlining the work to be performed.

4. Remove and dispose of all materials removed from the spillway stilling basin.

5. Remove and dispose of all materials in the 6-inch drain on two chute blocks in the spillway stilling basin.

6. Inspect the concrete floor and all other spillway stilling basin features and provide one (1) detailed inspection report summarizing findings.

B. Spillway Stilling Basin Cleanout Requirements

This specification defines the requirements for completing the spillway stilling basin cleanout.

1. Removal of materials in the spillway stilling basin:

a. Spillway Stilling Basin Material Removal Plan:

i. The Spillway Stilling Basin Material Removal Plan (Plan) shall, at a minimum, identify the following information:

1. Develop a baseline schedule for when removal activities will take place and expected duration.

2. Provide a Safety Plan for how the material will be removed.

The Safety Plan must clearly identify potential hazards, risks, and proper mitigations. Multiple Safety Plans may be required depending on equipment, timing, and methodology of activities.

3. Prepare Site Use Maps identifying access routes, equipment staging areas, haul routes, etc. Allowable work areas will be limited to previously disturbed areas that will be identified during the site visit and must withing the Reclamation Zone (refer to Figure 2).

4. Describe methods to clean out and probe the 6-inch drains on the spillway chute blocks.

5. Describe methods to preserve, protect, and repair if damaged, vegetation (such as trees, shrubs, and grass) and other landscape features on or adjacent to the jobsite, which are not to be removed and which do not interfere with the work required under this contract.

6. Include methods to mark work area limits, protect disturbed areas, and prevent erosion.

7. Identify all equipment that shall be used for the purpose of removing material from the stilling basin. The equipment and specific use shall be clearly identified in the Plan.

8. Provide the name, location, and/or business where removed material will be properly disposed of.

9. If water is to be disposed of at an approved adjacent upland site area, BMPs to minimize erosion to adjacent land or features and ensure water is not returning to the Prosser Creek shall be clearly described. All BMPs shall be properly disposed of once work is complete.

10. Provide the name and contact information of the job supervisor and any information for emergency notification in case of injury onsite to employees.

b. Material Removal from Stilling Basin:

i. The following material quantities are estimates based off the results summarized in the 2023 Inaccessible Feature Review, Prosser Creek Dam Report (refer to Section 11. Attachments).

1. Six-inch layer of sediment on the concrete floor

2. 18-inch diameter, semi-angular cobble

3. A three (3)-foot boulder

4. A five (5)-foot boulder

5. Several cobble piles measuring 12-18 inches

6. Woody debris.

ii. It is estimated there are 55 cubic yards of sediment and 10 cubic yards of boulders and other debris.

iii. All material and items removed from the spillway stilling basin shall be properly disposed of offsite.

iv. Water that is expected to be pumped from the spillway stilling basin shall either be hauled offsite or disposed of at an approved adjacent upland site using approved BMPs.

c. Material Removal from 6-inch Chute Block Drains:

i. Remove and dispose of material present in the two (2), 6-inch chute block drains to the greatest extent possible.

ii. After initial removal of material present in the two (2), 6-inch chute block drains, verify drainpipe is free of material by probing approximately 12 feet of the length of the drainpipe. Refer to Drawing 320-D-9, Detail U located in Section 11.0 Attachments.

2. Inspection Report:

a. Complete an inspection of the concrete floor and all other spillway stilling basin features at Prosser Creek Dam.

i. Inspection report shall cover all requirements listed in the Reclamation Directive and Standard FAC 01-07 Review and Examination Program for High and Significant Hazard Potential Dams, Section E.

Examinations of Normally Inaccessible Features, (7) Documentation.

ii. Measurements of any concrete deterioration, abnormalities observed on the concrete floor, walls, or other features must be photographed and documented. Note: Visibility may be a challenge. Previous inspections have noted the visibility depth to be between 0 and six (6) inches.

iii. Inspection items include, but are not limited to:

1. Condition of eight (8) chute blocks

2. Condition of two (2), 6-inch drain outlet chute blocks

3. Condition of the concrete floor. Attention should be given to

Station 17+50 and Station 18+50.

4. Condition of the concrete sloped floor from the top of water surface elevation to Station 17+50.

5. Condition of the four (4) energy dissipating dentates.

6. Condition of the cutoff wall located downstream of the dentates.

7. General condition of the left and right spillway walls below the water surface elevation.

C. Required Submittals

1. Include the following information in each submittal:

a. Contract number, Contract title, Required Submittal Numbers (RSNs).

2. Submittal review will require 14 days for review of each submittal or resubmittal.

3. Submittals will be returned either Approved, Conditionally Approved, Accepted, Conditionally Accepted, Not Approved or Not Accepted.

4. Provide an electronic copy of each submittal in PDF file to the COR and Task Manager as listed in Section 6.

5. Contractor shall not begin any field work until RSN-1, RSN-2, RSN-4, and RSN-5 have been submitted, reviewed, and accepted in writing by Reclamation.

6. Submit RSNs in accordance with Table 1 below.

Table 1: Submittal Table

RSN

No. Section Submittal Title Due date

1 Use of Site Use of Site Plan At least 28 days before use of Government land

2 Construction Program Baseline Schedule Submitted and approved prior to mobilization

3 Construction Program Updated Schedule Within 14 days of request from OGR

4 Safety and Health Safety Program Submitted and accepted prior to mobilization

5 Contractor’s Onsite Safety Personnel Safety Resumes Submitted and accepted prior to mobilization

6 Spillway Stilling Basin Removal Plan Approval Data Submitted and accepted prior to mobilization

7 Inspection Report Final Data Within 14 days after inspection is completed

1. RSN-1, Use of Site Plan:

a. Show use location and extent of impact. Uses include but are not limited to the following:

i. Buildings and service areas

ii. Parking areas

iii. Areas for processing and storing materials from constructions operations.

b. Describe methods to preserve, protect, and repair if damaged, vegetation (such as trees, shrubs, and grass) and other landscape features on or adjacent to the jobsite, which are not to be removed and which do not interfere with the work required under this contract. Include methods to mark work area limits, protect disturbed areas, and prevent erosion.

c. Describe methods to protect, and repair if damaged, existing improvements and utilities at or near the jobsite.

d. Describe methods for removing temporary structures and facilities, cleanup, and rehabilitating site after completion of construction activities.

2. RSN-2, Baseline Schedule:

a. Gantt chart for project.

3. RSN-3, Updated Schedule:

a. Required only if requested by OGR

b. Gantt chart for project.

4. RSN-4, Safety Program:

a. In the form and time intervals prescribed in Section 1.03 of RSHS (https://www.usbr.gov/safety/rshs/index.html).

b. Cover all aspects of on-site and applicable off-site operations and activities associated with this contract.

c. Follow the outline in Appendix B of RSHS.

https://www.usbr.gov/safety/rshs/index.html

d. A generic Company Safety Plan is not acceptable. The Safety Program shall be site specific for this contract.

5. RSN-5, Safety Resumes:

a. Contractor’s Onsite Safety Representative

6. RSN-6, Approval Data:

a. Detailed, step-by-step plan for removing the material from the spillway stilling basin.

b. Detailed, step-by-step plan for removing the material from the 6-inch chute block drains.

c. Include set up details, name and qualifications of personnel performing checkout and testing, equipment required, and any other pertinent details of the test procedures.

7. RSN-7, Final Data:

a. Detailed report clearly documenting the observed conditions and identifying areas of deficiencies.

b. Documented procedures and results of the contractor inspection.

6.0 CONTRACTING OFFICER’S REPRESENTATIVE AND TASK MANAGER

In accordance with Section G.2 (CAR Clause 1352.201-72, Contracting Officer’s Technical Representative and Assistant COTR), the designated Contracting Office Representative (COR) for this order will be provided at time of award. The COR and Task Manager (TM), specified below, shall serve as the primary points of contact for the duration of this contract and shall receive all required submittals as listed in Section 5 – C. Required Submittals.

COR: Jason Villarreal, LBAO Email: jvillarreal@usbr.gov Phone: 775.884.8391

Task Manager: Sara Horgen, LBAO Email: shorgen@usbr.gov Phone: 775.546.3396

7.0 DELIVERY

The Contractor shall deliver to the site and install all materials/equipment as required. All materials/equipment are subject to inspection and approval by the Government. Delivery of any equipment utilized to meet the general requirements of this contract shall be coordinated with LBAO staff.

8.0 SECURITY

Work shall not proceed without a Government Inspector on the site. Contractor Employees shall be accompanied by a Government Inspector during the work. Contractor employees shall wear vests, T-shirts, or other identifiable clothing with the Contractor’s Company Name clearly visible at a minimum of 50 feet.

Information Marking, Handling, and Safeguarding All information (drawings, data, text, photos, etc.) received or produced under this contract shall be treated in accordance with Reclamation Directive and Standard SLE 02-01 “Identifying and Safeguarding FOR OFFICIAL USE ONLY (FOUO) Information.” A copy of the memorandum is available upon request via the CO or at the following web address:

http://www.usbr.gov/recman/sle/SLE02-01.pdf

All information Drawings, designs, specifications, and other engineering data related to specific security systems or measures associated with this contract shall be designated as “Highly Sensitive – For Official Use Only.”

9.0 PLACE OF PERFORMANCE

The place of performance shall be at Prosser Creek Dam, California. The address to the facility is provided below:

Prosser Creek Dam Truckee, CA 96161

During the contract work, the Contractor shall minimize the impact on the employees to the greatest extent possible. Delivery of any heavy equipment utilized to meet the general requirements of this contract shall be coordinated with LBAO staff. It is expected that the contractor provides their own mobile generator(s) to supply the power required to complete all tasks. In addition, restroom facilities ARE NOT available onsite, and it is expected that the contractor provide restroom facilities and hand wash stations as appropriate to complete all tasks.

10.0 PERIOD OF PERFORMANCE

The Period of Performance shall be 364 days from issuance of Notice to Proceed. Saturday work and other work outside of normal business hours shall be coordinated with the COR two weeks in advance to allow the COR to arrange for inspection.

11.0 ATTACHMENTS

List of Figures

a) Figure 1: Prosser Creek Dam General Location Map

b) Figure 2: Prosser Creek Dam Site Location Map

c) Figure 3: Prosser Creek Dam Proposed Water Spread Area

d) Figure 4: Prosser Creek Dam Access Map

e) Figure 5: Prosser Creek Dam Spillway Stilling Basin

f) Figure 6: Spillway Stilling Basin Debris Distribution

Reference Drawings

a) General arrangement drawings. Reference drawings:

i. 320-D-9

ii. 320-D-29

Additional drawings can be provided at the request of the contractor.

Reference Documents

a) 2023 Inaccessible Feature Review, Prosser Creek Dam Report

Figure 1: Prosser Creek Dam General Location Map.

Prosser Creek Dam

Figure 2: Prosser Creek Dam Site Location Map

Figure 3: Prosser Creek Dam Proposed Water Spread Area

Figure 4: Prosser Creek Dam Access Map.

Figure 5: Prosser Creek Dam Spillway Stilling Basin

Figure 6: Spillway Stilling Basin Debris Distribution.

END OF STATEMENT OF WORK