ADDENDUM NO. 2 - Laredo, Texas

1 2517-96098 City of Laredo - South Laredo Wastewater Treatment Plant 12 MGD to 18 MGD Expansion Project ADDENDUM NO. 2 2016 CDM Smith ADD-1 ADDENDUM NO. 2 All Rights Reserved August 2, 2016 ADDENDUM NO. 2 Date of ADDENDUM : August 2, 2016 PROJECT NAME: South Laredo Wastewater Treatment Plant 12 MGD to 18 MGD Expansion Project Bidders on this project are hereby notified that this ADDENDUM shall be attached to and made a part of the above named Contract Documents and Technical Specifications, dated July 2016. The following items are issued to add to, modify, and clarify the Contract Documents and Technical Specifications and Drawings. These items shall have full force and effect as the Contract Documents and Technical Specifications, and cost involved shall be included in bid prices.

2 Bids to be submitted on the specific bid date shall conform with the additions and revisions listed herein. Acknowledge receipt of this ADDENDUM by designating receipt of the ADDENDUM on the Bid Form. Failure to do so may subject bidder to disqualification. CHANGES TO PROJECT MANUAL DIVISION A 1. Proposal and Affidavit. Remove pages PA-15 and PA-16 and replace with the attached pages PA-15 and PA-16. SPECIFICATION SECTIONS 1. Section 05500 Miscellaneous Metals. Remove page 05500-7 and replace with the attached page 05500-7. 2. Section 11355 Weirs. Remove Section 11355 in its entirety and replace with the revised attached Section 11355. 3. Section 11370 Positive Displacement Blowers. Remove page 11370-8 and replace with the attached page 11370-8. 4. Section 16196 Low Voltage AC Surge Protective Devices (SPDs).

3 Add Section 16196 in its entirety. 5. Section 16425 480 Volt Switchboards. Remove page 16425-18 and replace with the attached page 16425-18. 2517-96098 City of Laredo - South Laredo Wastewater Treatment Plant 12 MGD to 18 MGD Expansion Project ADDENDUM NO. 2 2016 CDM Smith ADD-2 ADDENDUM NO. 2 All Rights Reserved CHANGES TO DRAWINGS 1. Drawing MC-5. Remove Drawing MC-5 and replace with attached Drawing MC-5. 2. Drawing MC-6. Remove Drawing MC-6 and replace with attached Drawing MC-6. 3. Drawing ME-4. Remove Drawing ME-4 and replace with attached Drawing ME-4. 4. Drawing MG-1. Remove Drawing MG-1 and replace with attached Drawing MG-1. 5. Drawing MZ-1. Remove Drawing MZ-1 and replace with attached Drawing MZ-1. 6. Drawing E-4. Remove Drawing E-4 and replace with attached Drawing E-4.

4 CLARIFICATIONS 1. Question: Specification 05500 Miscellaneous Metals. Page 05500-7, paragraph Aluminum Fabrications, subparagraph Finishes. STATEMENT: Apply a coat of methacrylate lacquer to all aluminum before shipment. 1. This is a very expensive coating, not really environmental friendly. Is this finish truly required? Requesting confirmation. 2. For embedded aluminum fabrications Is this finish applied only to exposed surfaces? 3. Is this finish applicable to embedded aluminum angles, which support grating edges? 4. Is this finish applicable to aluminum grating, aluminum stair treads? 5. Is this finish applicable to aluminum ladders? 6. We are assuming this finish is NOT applicable to aluminum Handrails and Guardrails. If required, please provide a surface preparation specification, list of approved manufacturers or suppliers and required number of coats and/or DFT.

5 We could not locate a specific or definitive specification in Division 9 Painting and Protective Coating. Answer: The lacquer coating of aluminum is only required at aluminum surfaces that will be in contact with concrete (embedded aluminum). Other aluminum protective coating system specified in Spec Section can be used in lieu of methacrylate lacquer. 2. Question: Spec. Sec. 05500 MISCELLANEOUS METALS. Page 05500-7, B. ALUMINUM NOSINGS FOR CONCRETE STAIRS. The specified Wooster Products Type 116 Abrasive Cast Aluminum Nosing are not available with concealed stainless steel integral anchors. Anchors are aluminum , stainless steel is NOT available. Wooster does not provide any integral stainless steel anchors for any of their products. Please advise. Answer: Corrosion resistant integral aluminum anchors are acceptable.

6 3. Question: Spec. Sec. 05515 - ALUMINUM LADDERS AND ACCESSORIES. Page 05515-1, Part 2: PRODUCTS, paragraph The O Keeffe's Inc. Model 520-CH (Standard) is a "Ships Ladder . Are Model Nos. 502 or 504 Acceptable or a Better Selection? Answer: O'Keeffe's Inc. Model 504 is acceptable. Ladder requirements shown on Detail A/SZ-6 need to be met. 2517-96098 City of Laredo - South Laredo Wastewater Treatment Plant 12 MGD to 18 MGD Expansion Project ADDENDUM NO. 2 2016 CDM Smith ADD-3 ADDENDUM NO. 2 All Rights Reserved 4. Question: Spec. Sec. 11355 WEIRS, Page 11355-3, Part 2: PRODUCTS, paragraph - STAINLESS STEEL WEIRS. It appears that paragraphs B, C and D relate to Fiberglass specifications? Are there other specific requirements required but not listed? Are paragraphs , H, I and J applicable to Stainless Steel Weir Plates?

7 Answer: Refer to revised Specification 11355, Sheet MZ-1 and Sheet ME-4 for detailed requirements. 5. Question: Weir Plate Detail - Detail "AH / MZ-1". Could not locate a Structural (SZ) Detail - Is this detail applicable to both Stainless Steel and FRP Weir Plates? Detail note indicates all weir fabrications to be FIBERGLASS . Specification page 11355-2 indicates Stainless Steel and Fiberglass Weir Plates? Are ALL Weir Plates 3/8-Inch Thick x 12-Inch Height? Detail "AH" indicates two sizes of gasket material - 1/8-Inch and 3/8-Inch. Specification indicates 1/4-Inch x 5-Inch gasket material? Which is the correct gasket thickness? Do ALL Weir Plates have beveled edge as shown in Detail B? Can post-installed adhesive HAS Rod anchors be used in lieu of "cast-in-place" anchors? Answer: This detail applies to weir plates and baffles at aeration basin splitter box, aeration basin effluent channel, clarifier splitter box, and chlorine contact basin splitter box.

8 Secondary clarifier weir plate detail is included on Sheet ME-4. Refer to revised sheets MC-5, MC-6, ME-4, MG-1, MZ-1 and revised Specification 11355. Provide cast-in-place anchors. 6. Question: Sheet No. MA-3 - INFLUENT PUMP STATION TO HEADWORKS FLOW METER BOX. Please confirm there is no associated "SA" Structural Drawing for this structure. Could not locate this Structure on the Bid/Proposal Form. Are construction costs to be included in Bid Item 13 - Miscellaneous? Answer: This is a pre-cast concrete meter box. Include this work in Bid Item 12 Plant Yard Piping Improvements. 7. Question: Sheet Nos. SG-5, SG-6 - CHLORINE CONTACT BASIN SPLITTER BOX. Are ALL Grating areas to have checkered plate covers, or only the interior 23 x 23' area? Sheet No. SG-6 indicates "2-1/2" MIN.". Is this the minimum Grating-Plate thickness acceptable?

9 Will a smaller Grating-Plate configuration, which meets load design criteria, be acceptable? Answer: Only the interior basin (23'X23') area will have cover plate on top of grating. 2 1/2" is the minimum grating+cover plate thickness. Thinner than 2 1/2" is not acceptable. 8. Question: One-Line Drawing ED-2 shows that spare breakers are required for SWBD-D. How Many Spare Breakers are required and ratings? Answer: Two, 400A spare breakers. 9. Question: One-Line Drawing ED-2 shows that space for future breakers are required for SWBD-D. How much Spaces are required and or ratings of spaces? Answer: Spaces to fill out the section. Spaces to be set up to accept 100A breakers. 2517-96098 City of Laredo - South Laredo Wastewater Treatment Plant 12 MGD to 18 MGD Expansion Project ADDENDUM NO.

10 2 2016 CDM Smith ADD-4 ADDENDUM NO. 2 All Rights Reserved 10. Question: One-Line Drawing ED-2 shows another SPD Device on the distribution section after the Main and Gen Mains, is this required? Answer: SPD on the distribution section can be eliminated. 11. Question: Elevation Drawing ED-3 has the SWBD as 19 -2 (230 ) Wide. We can provide the Switchboard at a width of 168 Wide worst based on the breakers shown not including spares and spaces. Will 168 wide be acceptable? Answer: Contractor is responsible for providing equipment that will fit within the allotted space and maintain required clearances. 168 width is acceptable. 12. Question: Elevation Drawing ED-3 has a bus transition section between the Gen Main and the distribution section. We do not require a transition section, would this be acceptable?