31_Jan_2022_SOW_Sediment_Revised.pdf

PERFORMANCE-BASED WORK STATEMENT

I. GENERAL INFORMATION

A. Introduction

This work will be conducted as part of a project administered by the USGS Grand Canyon

Monitoring and Research Center. This project is in support of needs requested by the

National Park Service in Big Bend National Park in order to understand the sediment transport/geomorphology dynamics within the Rio Grande and its tributaries. This science is used to make science-based decisions regarding binational river management. This project includes a large field component whereby state-of-the art instrumentation (Acoustic Doppler

Current Profilers - ADCPs) currently installed in the Rio Grande needs to be programmed, maintained, downloaded, and repaired on a regular basis. These ADCPs are used to calculate sediment concentration, load, and transport rate at high temporal resolution (i.e. 15 min).

Physical sediment samples need to be collected during both high and low flows to calibrate, or update the calibrations of these instruments. These physical samples are collected from a boat using specialized USGS sediment samplers, as well as by automatic pump samplers installed alongside the ADCPs. Pump samplers also require special expertise to program and operate in order to be used in ADCP calibration. In addition, field measurements of geomorphic change will be collected at 68 established river cross sections in the vicinity of three study reaches using total station, or RTK GPS technology. Completion of these tasks will be dependent upon funding on a year to year basis.

B. Background

This project has been in place since 2010, and is part of a comprehensive river science program implemented in Big Bend National Park. Flows within the Rio Grande have been drastically reduced over the last half century leading to widespread changes to the morphology of the river. These physical changes are negatively affecting the riparian and aquatic ecosystem, and this project provides the information park managers need in order to develop environmental flow protocols, and other river rehabilitation actions designed to maintain and improve essential riverine habitats.

C. Scope

The general purpose is to conduct sediment sampling, instrument maintenance, data retrieval, and channel surveys needed in order to complete the science objectives outlined in the project.

II. WORK REQUIREMENTS

A. Technical Requirements.

Project Element 1: Sediment Sampling and Sediment Gage Maintenance

1. Contractor must make site visits twice per year to 4 sediment monitoring stations:

Rio Grande above Castolon, TX, Rio Grande above Rio Grande Village, TX, Terlingua Creek near Terlingua, TX, and Tornillo Creek near Langford Hot

Springs, TX. Contractor must have experience installing, programming, and downloading sidelooking acoustic Doppler profilers made by Nortek, including the

Nortek EZQ and Aquadopp. At the Rio Grande stations, acoustic instrumentation in both frequencies (1 and 2 mhz) must be downloaded, reprogrammed, and relaunched. Downloaded files must be converted to acoustic beam and velocity files. For Nortek EZQ profilers, .EZQ files must be converted into .DAT, .HDR, .RA1, .RA2, .RA3, .RA4, and .SEN files. For Nortek Aquadopp profilers, .PRF files must converted to .SEN, .SSL, .V1, .V2, .WAD, .WHD, .A1, .A2 files.

Contractor must analyze files in field to verify that instrument operated correctly during the entire period of record, and that the entire period of record was downloaded.

The frequency of visits (i.e. twice per year) to the sites may be modified in out years depending on available funding. In years with additional funding, the frequency will be increased, and the USGS will work with the contractor to determine the adequate frequency in these cases.

2. During each site visit, contractor must check all electronic connections, test battery voltage, investigate noise and voltage within downloaded files. Acoustic instrument heads must be cleaned upon each download if flow conditions allow.

3. During each site visit, contractor must retrieve all samples from the automatic pump samplers at each station, properly recording the data that accompanies each sample. All pump tube intakes need to be cleaned. Pump samplers need to be reprogrammed upon retrieval. For Rio Grande pump samplers, this requires that the program operates based on input from attached pressure transducers, such that samples are collected based on the flow stage and volume of each flood event.

Power supply and voltage must be checked. Pump sample data must be compiled in a summary.

4. Contractor must have experience installing, maintaining, and downloading Hobo, In-Situ, and Campbell Scientific SR-50 transducers and stage-measurement devices. Stage measurement devices at each of Rio Grande, Terlingua Creek, and

Tornillo Creek stations need to be downloaded, backed up, and verified for accuracy.

5. Depth-integrated suspended-sediment samples must be collected at the Rio Grande above Castolon, and Rio Grande above Rio Grande Village at a minimum of 5 times per year. One of these samples needs to be collected at low flow with a DH-

48 sampler. The remaining four samples need to be collected at high flow (>1000 cfs) from a boat mounted with a crane using a D74 or D96A1 sampler. Samples will need to be collected using U.S. Geological Survey depth-integrated sampling protocols (Edwards and Glysson, 1988, 1999). Contractor should be trained in

USGS suspended-sediment sampling procedures at the time the contract is awarded, and be able to sample using required suspended-sediment sampling equipment including DH-48 and D-74 bottle samplers, and D-96A1 bag-type sampler. For each flow sampled, bed-sediment needs to be sampled with a BMH-

60 or BM-54 at three locations across the channel. Depth-integrated suspended-sediment samples must be collecting using the Equal-Width-Increment method at a minimum of 10 stations across the channel. Average surface flow velocity, sampler transit rate at each station, and total transit time for each of the 10 stations must be recorded and entered into a spreadsheet. All sampling needs to be conducted using approved USGS protocols. Two grab-samples must be collected using the pump sampler and must be collected before and after each high-flow suspended-sediment sample. Boat (motorized cataraft and/or jetboat), sampling frame, and crane must be supplied by contractor.

The number of samples may be modified based on an agreement between the contractor and the PI in years where few high flows occur, or where many high flows occur.

6. High flows on the Rio Grande occur episodically during the thunderstorm season from spring to fall. Many, if not all of these flows occur for extremely short durations (less than 12 hours). The rise of these floods generally occurs between midnight and 6 am, depending on the location of the thunderstorms that generated the floods; the recession of these floods often occur before midnight of the next day. Therefore, the contractor must be flexible, and must be able to respond to high flow events in an extremely short time frame such that depth-integrated samples are collected before the recession of these floods occur. This requires identification that a flood has occurred, travel to the field sites, launching boats, and collection of samples during the same day the flood occurs. If this condition is not satisfied, it is likely that the required sampling requirements will also not be satisfied.

7. All acoustic data files, transducers and stage-measurement files, pump sampler datasheets, suspended-sediment and bed-sediment sample datasheets must be emailed to the USGS PI within 5 days after data collection.

B. Deliverables.

1. Data files from 4 acoustic instruments emailed to USGS PI within 5 days of data collection. Files specified in Project Element 1.1.

2. Summary sheets from pump samplers, and transducers at the four sediment stations must be emailed to USGS PI within 5 days after data collection.

3. Summary sheets of suspended- and bed-sediment samples must be compiled and emailed to USGS PI within 5 days after data collection.

4. Bottles obtained from EWI sampling, and sample bags obtained by bed sampling at the Rio Grande sediment gages will be retrieved annually or bi-annually by project

PI during site visits. There must be a minimum of 100 bottles associated with the 6 samples at each site (10 bottles/sample). In the event there is a not a sufficient number of high flows to sample, an additional low flow sample may be collected, or the sampling regime may be re-evaluated by the USGS PI.

2. A summary of all work must be included in a report and delivered to the USGS PI by the end of the year/contract.

C. Quality Assurance and Surveillance Plan.

A performance assessment plan is based on the premise that the contractor, not the government, is responsible for managing and ensuring that quality controls meet the terms of the contract.

Contractor and the Contracting Officer’s Representative (COR) shall monitor the working relationship between the Government and Contractor personnel to ensure that services do NOT develop into a personal service relationship as defined in FAR 37.104. Questions concerning this matter shall immediately be referred to the Contracting Officer.

The Government, through its COR or other designated technical representative, will monitor the Contractor’s performance. The Government may monitor the Contractor’s performance of routine functional requirements and outputs, as well as the milestones and deliverables of specific project requirements as deemed necessary to ensure acceptable progress and compliance with contract requirements. The Government shall use a variety of methods to evaluate the Contractor’s performance including monthly task summary reports that shall be delivered to the Government.

Required Service (1) Performance Standard (2) Monitoring method (3)

Downloading, maintenance, and reprogramming of ADCP data

Downloaded files are converted to .DAT, .HDR, .RA1, .RA2, .RA3, .RA4, and

.SEN files for EZQ instruments, or .PRF files must converted to .SEN, .SSL, .V1, .V2, .WAD, .WHD, .A1, .A2 for Aquadopp instruments. Files are emailed to USGS upon download.

Visual inspection of data files, and reduce data down to beam and velocity files, and verified that all data since last download exists at 15 minute intervals.

Quality control project-level acoustic data

Data is examined and evaluated to ensure instrumentation is working correctly

Review work progress and periodically inspect for data quality through the processing of the data into sediment attenuation and backscatter data.

Summary sheets of pump samples

Emailed documents stating station location, bottle number, time, and date of sample. This data must also be included on individual bottle labels.

Review status reports.

Individual bottles will be collected by the USGS annually, or bi-annually

Summary sheets of depth integrated suspended- and bed-sediment samples

Emailed summary sheets of depth-integrated samples include the sampling location, the station name, date, personnel who collected sample, sampler type, nozzle size, station number for each bottle, tagline distance of each station, depth at each station, transit time of each vertical sample, transit velocity, mean surface flow velocity at least 3 stations, start time and end time of sample, and tape-down measurements at the

Evaluation of the collected samples will be inspected by the USGS GCMRC sediment lab, and grain size distributions will be analyzed to verify that samples do not contain bed-sediment contamination. If no bed-contamination exists, and concentration and grain size data agree favorably with our database of past samples, performance will be satisfied.

instruments. Bed sampling summary sheets must include the station name, date, time, and the tagline distance of each sample.

III. SUPPORTING INFORMATION

A. Place of Performance.

Rio Grande Village, Terlingua Creek, Tornillo Creek, Castolon, Big Bend National Park.

B. Period of Performance.

Base: 14 Feb 2022 - 2022-Dec 31, 2022 with (4) Option Periods:

Option 1: 01/01/2023 – 12/31/2023

Option 2: 01/01/2024 – 12/31/2024

Option 3: 01/01/2025 – 12/31/2025

Option 4: 01/01/2026 – 12/31/2026

C. Government Furnished Property (GFP):

The following property already exists at the monitoring sites:

Suspended-sediment samplers ($3,535)

Bed-sediment samplers ($2,500)

B-reel ($1,970)

Qty (4) ADCPs ($54,000)

Qty (4) ISCO 3712 pump samplers ($14,000)

Wiring/Cabling ($4,000)

SR-50 stage sensor ($1,200)

Qty (4) solar panels ($1,000)

Qty (10) deep cycle batteries ($1,000)

Total = $83,000.

D. Special Considerations.

1. Data Rights, Safety, Environment.

No Data is to be transferred to anyone except the USGS PI (David Dean), without PI written consent to do so.

2. Invoicing Structure.

Invoices shall be submitted upon monthly report submission.