Solicitation Number: 140R4026Q0105 Page 1 of 2

DETERMINATION TO SOLICIT FROM A SINGLE SOURCE

1. Agency and Contracting Activity. U.S. Department of the Interior, Bureau of Reclamation, Acquisition Management Division, UCB Regional Office.

2. Name and Address of Single Source.

Rumbolt Manufacturing Company 875 Tollgate Road, Elgin, IL 60123.

3. Description of Supplies/Services and Estimated Cost.

The Erosion Function Apparatus (EF A) is flume-type soil erosion test that extrudes a soil sample into the bottom of a flume with flowing water at a set velocity. As the soil surface erodes, the scour depth is measured. This is repeated with several velocities to create a suite of results. Valuable design parameters that can be obtained from the EF A, which include:

• Critical velocity (water velocity at which erosion initiates)

• Critical shear str·ess (the shear str·ess on the soil required to detach a paiiicle)

• Erosion rate

• Maximum depth of scour

These data ai·e critical for evaluating a dam's susceptibility to internal erosion or scour erosion, critical info1mation for a Dam Safety Office (DSO) evaluation of an eaiihen embankment dam. This device is a complement to the existing laborato1y capabilities. The device is used commonly for bridge pier scour evaluations but is also critical for evaluating soil erodibility for dam safety.

4. Description of Circumstances, including why only one source is reasonably available.

Specific chai·acteristics of the Humboldt EF A system that limit the availability to a sole source is the utilization the Scour Rate in Cohesive Soils (SRICOS) methodology, providing accurate evaluation of soil erodibility and dependable scour prediction data. Only this suggested source can furnish the requirements, to the exclusion of other sources, because of the unique design and manufacturing by Humboldt, providing an "out of the box" and "plug and play" system that meets all of the requirements in ASTM Work Item 67195, "New Standard for Measuring the Erosion Function of a Soil." Humboldt also offers dedicated technical suppo1i, including ongoing assistance via phone and email, ensuring suppo1i helps proper equipment operation, efficient t:I'oubleshooting, and constituent, reliable testing perfo1mance throughout the life of the instrument.

Solicitation Number: 140R4026Q0105

5. Determination of Fair and Reasonable Price.

Page 2 of2

Humboldt offers the lowest overall cost, since the required equipment is proprieta1y and provides an "out of the box" and "plug and play" solution, whereas custom-f a bricated alternatives would require extended manufacturing time and higher associated costs in relation to components and labor.

6. Description of Market Research.

Humboldt is cmTently the sole source manufacturer and supplier of the EF A and are the only commercial source that produces a "plug-and-play" EF A system. The Humboldt device is the most widely used in the industry; subsequent Google searches and communication with Humboldt sales representatives did not yield an identified, approved reseller of the EF A system. While a professor at the University of Texas at Austin also constrncts a similar device, no other commercially available manufacturers offers an EF A system with minimal assembly.

SIGNATURES

CONTRACTING OFFICER (CO) (RFO 12.102(a)):

X

Name: ConnieAnn A. Tudela-Kately

Date: