Statement of Work 24Q0136.pdf

Statement of Work

Submersible Carbon Dioxide Sensors

GENERAL INFORMATION

1.0 Scope of Work. The United States Department of Agriculture (USDA) Midwest Area

(MWA) Soil Drainage Research Unit (SDRU) has a requirement for the procurement of two (2) submersible carbon dioxide (CO2) sensors for continuous monitoring of CO2 concentrations within the waters of agricultural streams and ditches. The pair of CO2 sensors will be utilized to take continuous in situ measurements of CO2 concentrations at both the inlet and outlet of drainage ditches and headwater streams, allowing for the daily quantification of ecosystem metabolic rates, as well as the magnitude of CO2 fluxes between the ditch and stream ecosystems and the atmosphere. These quantities will enable improved understanding of biogeochemical cycling within agricultural drainage ditches and headwater streams, as well as quantification of greenhouse gas production potential of these ecosystems.

2.0 Background, SDRU is conducting research in Northwest and Central Ohio to understand the coupled biogeochemical and ecohydrological dynamics of agricultural drainage ditches and headwater streams and how those dynamics impact nutrient transport, transformation, retention, and export within those systems. The pair of submersible CO2 sensors will provide the capability to estimate agricultural drainage ditch and headwater stream ecosystem metabolism and greenhouse gas production, quantities that are intrinsically connected to nutrient processing within these aquatic ecosystems.

CONTRACTOR REQUIREMENTS

3.0 Technical Requirements/Tasks. Provide and deliver 2 submersible CO2 sensors for continuous monitoring of in stream/ditch CO2 concentrations with the following characteristics:

3.1 CO2 calibrated concentration measurement range of 0 to 50,000 ppmv CO2

3.2 Ability to take measurements outside of the sensor’s initial calibration range (i.e., the sensor doesn’t saturate at 50,000 ppmv), up to 2 times the calibrated measurement range (i.e., up to 100,000 ppmv)

3.3 Ability for the sensor to have the CO2 concentration measurement range be recalibrated to a different range

3.4 CO2 measurement resolution of at least 0.1% of the maximum concentration measurement range

3.5 Anti-fouling equipment for the sensor

3.6 CO2 measurement rate of 1 sample per minute or faster.

3.7 Ability to be connected to external power source for long-term deployment

3.8 Long power/data cable to allow instrument to be deployed in deep ditches while power supply remains out of flood zone (between 40-50 meter long cable)

3.9 Fast gas equilibrium rate across membrane, <4 minutes

3.10 Ability to measure total gas pressure in addition to CO2 concentration

3.11 Ability to record water temperature

3.12 Ability to log and store data internally within the instrument

4.0 Deliverables / Schedule. The pair of CO2 sensors and required accessories should be delivered before August 1st to be deployed in the field.

ITEM QTY

Submersible CO2 sensor and controller 2

Sensor anti-fouling equipment 2

Power/data cable (40 to 50 meter length) 2

Delivery location. USDA/ARS; Attn: Nathan Reaver, 590 Woody Hayes Dr., Columbus, Ohio 43146