Amendment No. 0002 Continuation page.pdf

AMENDMENT NO. 0002 TO ADVERTISED IFB W912DR-20-B-0020

EFFECTIVE DATE: OCTOBER 16, 2020 PAGE 1 of 5 PAGES

SOLICITATION:

1) Section 00010 - STANDARD FORM 1442, Block 11: Change “332 calendar days” to read

“362 calendar days”.

SPECIFICATIONS:

2) Section 01 14 00 WORK RESTRICTIONS, Paragraph 1.2 SEQUENCING

REQUIREMENTS : Replace Paragraph 1.2 in its entirety with the following:

“1.2 SEQUENCING REQUIREMENTS

The Contractor shall provide the Contracting Officer with a detailed workplan that shows exactly how he intends to proceed with work in each clearwell prior to each scheduled outage. The Contractor shall also provide the Government with a minimum of 30 calendar days’ notice when requesting a clearwell outage. The Contractor shall ensure his sequencing is in accordance with the following:

a. Work during 30 MG Clearwell Outage No. 1: The Government shall isolate and dewater the 30 MG Clearwell down to finished floor elevation 96.33. The Contractor shall perform all required work associated with modifications to mixing chamber and associated equipment installation and commissioning. The Contractor shall also verify all sluice gate measurements prior to shop drawing fabrication. The Contractor shall plan to run at least two 6-inch pumps continuously to handle leakage from the existing sluice gates. Clearwell outage not to exceed 10 weeks and must occur during the dates of November 1, 2020 and April 30, 2021. Mixing performance will need to undergo successful testing for 21 days prior to April 30, 2021 before any additional clearwell outages will be permitted. Work on this facility's overflow piping, grading, and sample drain discharge can occur while the clearwell is in service.

b. Work during 15 MG Clearwell Outage: The Government shall isolate and dewater the

15 MG Clearwell. The Contractor shall perform all required activities, including modifications to the drainage chamber, new gate installation, and flow meter installation in the venturi vault. Clearwell outage not to exceed 10 weeks; there is no seasonal limitation to outages for this clearwell. Work on this facility's grading and membrane replacement can occur while the clearwell is in service.

c. Leak repair work in the Visitor Center requires the 15 MG Clearwell to be dewatered.

Remaining work, including building mechanical work, basement trench covering, finishings in the visitor center, and electrical ductbank installation may occur whether clearwells are in service or not.

d. Work during 30 MG Clearwell Outage No. 2: The Government shall isolate and dewater the 30 MG Clearwell down to finished floor elevation 96.33. The Contractor shall perform all remaining activities, including modifications to the drainage

EFFECTIVE DATE: OCTOBER 16, 2020 PAGE 2 of 5 PAGES chamber, re-seating of baffles, and gate replacement and rehabilitation as described in the Contract Documents. The Contractor shall plan to run at least two 6” pumps continuously to handle leakage from the existing sluice gates. Clearwell outage not to exceed 10 weeks; there is no seasonal limitation to this outage. Work on this facility's overflow piping, grading, and sample drain discharge can occur while the clearwell is in service.”

3) Section 03 01 00 REHABILITATION OF CONCRETE: ADD Section 2.6.3 REPAIR

MORTAR to read as follows:

“2.6.3 Repair Mortar

a. Repair mortar shall be site mixed.

b. Repair mortar shall be Portland cement based, fast curing, and non-sag mortar.

c. Mortar shall be applicable for overhead and vertical surfaces.

d. Shall be approved compliant for ANSI/NSF Standard 61 potable water.

e. The minimum 28-day compressive strength shall be at least 5,000 psi.

f. The minimum modulus of elasticity in compression for the mortar shall be at least

2,900,000 psi.

g. The minimum flexural strength at 28 days shall be at least 900 psi.

h. The tensile adhesion strength at 28 days shall be at least 2,000 psi.

i. At 28 days, the maximum shrinkage for a 1”x1”x11-1/4” specimen shall be less than 0.05%.

j. At 28 days, the rapid chloride permeability shall be less than 500 C.”

4) Section 03 01 00 REHABILITATION OF CONCRETE, Paragraph 3.3.2.4 Placement of

Other Repair Materials: CHANGE the fifth sentence to read as follows: “Comply with the repair material manufacturer's requirements for substrate preparation, batching, mixing, placing and curing repair materials.”

5) Section 05 50 13 MISCELLANEOUS METAL FABRICATIONS: ADD section 2.6 PORTABLE DAVIT CRANES to read as follows:

“2.6 PORTABLE DAVIT CRANES

a. Provide a portable davit crane to be used at all locations shown on plans. Davit crane shall not weigh more than 500 lbs fully assembled and shall not have

EFFECTIVE DATE: OCTOBER 16, 2020 PAGE 3 of 5 PAGES individual parts, excluding wheel bases, that weigh more than 100 lbs each. Davit crane shall be easily disassembled into sections for ease of transport or storage.

Crane disassembly shall be achievable without tools and through use of quick-release connections. All parts shall be factory fabricated and shall not be modified during installation.

b. Davit crane and supplementary parts shall have galvanized, 304 or 316 stainless steel, or corrosion-resistant epoxy finishes.

c. Load requirements shall meet the requirements as indicated on plans. Minimum load required shall be achieved with boom position fully extended and in horizontal orientation. Davit crane shall be factory tested for 125% of maximum rated load, prior to shipping.

d. Crane and hook clearances shall meet the requirements as indicated on plans.

Provide base extension sections as required to meet the height and clearance requirements at all locations on plans.

e. Permanently installed base plates shall be flush mount base plates. Provide at all locations indicated on plans.

f. One wheel base shall be provided for use at all locations indicated on the plans.

Wheel base shall be adjustable to allow for crane hook to be located directly over openings. Provide locking system for wheels when crane is in use.

g. Provide worm gear or spur gear hand winch. Hand winch must include desc brake for load control and gear covers.

h. For base plate mounted applications, provide ball or roller bearing that allows for 360 degree rotation under load. Provide lock assembly with bearing that can lock crane into position during winch operation or when not in use.

i. Provide rotation handle that does not interfere with crane and boom operation.

j. Provide galvanized, 304 stainless steel or 316 stainless steel wire rope that meets

150% the maximum load requirement indicated on plans. Wire rope shall be continuous and shall meet the maximum length indicated on plans.”

6) Section 05 50 13 MISCELLANEOUS METAL FABRICATIONS: ADD section 3.11

PORTABLE DAVIT CRANES to read as follows:

“3.11 PORTABLE DAVIT CRANES

EFFECTIVE DATE: OCTOBER 16, 2020 PAGE 4 of 5 PAGES

Provide flush mounted base plates level with finished concrete surface. Provide base cap with lanyard at each flush mounted base plate to keep water and debris out when crane is removed.”

DRAWINGS:

1) Plate 2, CONSTRUCTION NOTES: Add Note 7 to read as follows: “The Contractor is advised that the 30 MG and 15 MG Clearwells and Visitor Center Basement may be classified as confined spaces per OSHA. The Contractor shall provide all equipment and personnel required to satisfy OSHA requirements as related to confined space entry.”

2) Plate 3, Detail 1, C-101/S-109: Change call-out to “Detail 1, C-101/S-121”

3) Plate 4, Detail 1, C-102/C-104: Change annotation of “New Wingwall” with “Reconstructed

Splash Pad and Wingwall”.

4) Plate 5, NOTES: Add Note 9 to read as follows: “The Clearwell roof slopes approximately 3" per 100ft with a top of concrete elevation of 145.4 ft at the North end of the Clearwell and a top of concrete elevation of 146.5 ft at the South end of the Clearwell.”

5) Plate 6, Detail 1, CONCRETE HEADWALL WITH FLAP VALVE, NOTES: Add Note 4 to read as follows: “Flap gate to have materials as stated in Section 33 11 00 and to be flat-back style with minimum 10-ft opening head.

6) Plate 18, GATE SCHEDULE: Replace note “Maximum Outage to be 10 Weeks, Must be

Between November 1 and March 1” with the following:

“Refer to Section 01 14 00 WORK RESTRICTIONS for Sequencing Requirements.”

7) Plate 18, NOTES: Add Note 5 to read as follows: “The Contractor shall plan to run at least two 6" dewatering pumps continuously to handle leakage from the existing sluice gates during each Clearwell outage.”

8) Plate 20, NOTES: Add Note 6 to read as follows: “New valves to have both electric motor actuators and handwheel operators for backup. Actuators are specified in 40 95 00, Process Control. Additional electrical descriptions are provided on E-101.”

9) Plate 21, NOTES: Add Note 8 to read as follows: “New valves to have both electric motor actuators and handwheel operators for backup. Actuators are specified in 40 95 00, Process Control. Additional electrical descriptions are provided on E-101.”

10) Plate 21, NOTES: Change Note 6 to read as follows: “SEAL EXISTING VAULTS TO

WATER TIGHT OPERATION (EPOXY SEAL BOTTOM 2" OF WALL AND ALL

EFFECTIVE DATE: OCTOBER 16, 2020 PAGE 5 of 5 PAGES

CRACKS). CONTRACTOR SHALL ASSUME 10 GALLONS OF CRACK INJECTION

EPOXY IS REQUIRED.”

11) Plate 25, NOTES: Add Note 4 to read as follows: “Existing ammonia feed pipe is 1-inch schedule 40 stainless steel pipe. Contractor to match existing coating system for new 50-feet of installed pipe.”

12) Plate 44, NOTES: Add Note 9 to read as follows: “Contractor to assume a total of 200 sq.ft.

of the chase wall in the Visitor Center Theater is required to be replaced.”

13) Plate 44, NOTES: Change Note 4 to read as follows: “REPAIR UNDERSIDE OF FLOOR

SLAB ABOVE WITH MORTAR REPAIR MATERIAL. CONTRACTOR SHALL

ASSUME 5 CUBIC FEET OF MORTAR REPAIR IS REQUIRED.”

14) Plate 45, NOTES: Add Note 1.1 to read as follows: “Contractor to assume a total of 25 conduit penetrations need epoxy.”

15) Plate 45, NOTES: Add Note 1.2 to read as follows: “Contractor to repair around the conduit through the wall and floor with an assumed 5 cubic feet of mortar repair material required.”

16) Plate 49, GENERAL NOTES, Note 8: Remove “IF EXISTING HVAC SYSTEM

DRAWINGS ARE NEEDED FOR PRICING THE CLEANING AND DISINFECTION

WORK, THEY WILL BE MADE AVAILABLE UPON REQUEST.”

17) Plate 49, GENERAL NOTES: Add Note 9 to read as follows: “The existing ductwork and insulation in the Visitor's Center Basement was installed between 2002 and 2004. Site inspection indicates this ductwork to be of galvanized steel construction with 2-inch thick fiberglass insulation.”

GENERAL:

18) Pre-Proposal Site Visit: Attached for information only is the sign in sheet for the Pre- Proposal Site Visit dated Oct. 08, 2020.

ATTACHMENT:

1) October 08, 2020 Prospective Bidders Sign-in Sheet