attmt3_IBM10B0002_amend A003 Hatch_Mesilla_Canutillo_Questions_set1.pdf

BIDDER QUESTIONS SUMMARY

Project: Rehabilitation of Improvements for the Rio Grande Canalization Protective Levee System

River Segment Upper Rio Grande Hatch/ Mesilla/Canutillo Task Order: IBM09T0030 By: S&B Infrastructure, Ltd.

Client: IBWC Date: 12/15/2009

Ite m

N o.

B id

P kg

Date Contractor Contractor Comment S&B Response Comments Date Responded Set No.

1 All 12/10/09 Jobe Co.

In situations where the bench excavation actually requires a fill to construct can this be done with material excavated from an adjacent bench? If so how will this be accounted for in the measurement and payment? One good example of this condition can be seen in the Mesilla project cross sections station 55+00 sheet 10.002.

All material must meet specifications for embankment.

12/15/2009 1

2 All 12/10/09 Jobe Co.

Can the material excavated from the benches be used on the land side of the levees or does the entire embankment have to meet the clay specification.

Material has to meet specifications 12/15/2009 1

3 All 12/11/09 Skanska USA Civil West RMD

Item 35 43 00 TOE DRAIN, states "For the gravel, the material should be composed of at least 90% silica or other material insoluble in hydrochloric acid." Meaning no limestone should be used. This requirement is typically specified when the leach ate is anticipated to be acidic and could decompose carbonate aggregate. This should not be the case for the levee water seepage, the USGS shows the Rio Grande in the area to have a pH typically above 7 or basic. By eliminating competitive sources or having to import material to meet the specification, the cost of construction goes up. Can the use of permeable, clean, hard, durable rock, meeting the requirements of ASTM C 33 Size 57 or 67, and L.A. Abrasion, soundness requirements be allowed for the pervious toe drain?

No change can be made to the material specifications 12/15/2009 3