Amendment_0001.docx

Solicitation No. W9128F-17-Q-0083

Left Tailrace Waterline Replacement Big Bend Dam, SD

Amendment 0001 25 August 2017

A. Specifications. (Descriptive Changes.)

1) Section 31 00 00 page 10, paragraph 3.2.5.5 Jacking, Boring, and Tunneling. Delete the forth sentence reading: “Guidance for horizontal directional drilling is provided in an attachment to this specification.” and substitute the following: “Guidelines for horizontal directional drilling are provided in attachments to this specification (NWDR 1110-1-1, ER 1110-1-1807 and Directional Drilling paper). These attachments are included for reference only. Provided that the contractor complies with the plans and specifications including approval by USACE of the required Work Plan, Drilling Plan (see attached Drill Plan Requirements), Dewatering Plan and Shoring Plan a Contractor provided geotechnical engineer will not be required to be on site during the directional drilling work, as stated in the reference documents.”

2) Section 33 11 00 pages 6 & 7, paragraph 2.1.2.1 Gate Valves on Buried Piping, add the following to the end of the paragraph: "Valves less than 3 inches in size shall conform to ANSI/AWWA C800 - Underground Service Line Valves and Fittings and may be either gate or ball type valves so long as they meet or exceed all other requirements and specifications herein specified for valves 3 to 12 inches in size, and can meet the configuration requirements specified in the drawings and specifications for placement and surface operation at the specified depth of the vault. Ball valves shall be quarter turn limited and not allow 360 degree operation.”