ESBD_357589_1723754102101_RFB 2024-023 Addendum No. 2.pdf

Purchasing Services Post Office Box 2570

Waco, Texas 76702-2570 Phone: 254-750-8098

Fax: 254-750-8063 melaniew@wacotx.gov

CITY OF WACO www.waco-texas.com

Date: 08/15/2024

RFB No: 2024-023 Commodity: WMARSS Central WWTP Digester Cleaning and Improvements Purchasing Agent: Melanie Wade

Closing Time: 2:00 P.M. CST, Thursday, August 22, 2024 Opening Time: 2:01 P.M. CST, Thursday, August 22, 2024

RFB Opening Location: Via Zoom and Dial In

Addendum No: 2

1. Questions and answers

2. Revisions to previous addenda

3. Revisions to contract documents and technical specifications

The above-mentioned RFB invitation has been changed in the following manner. Sign and return addendum to the Purchasing Office by the closing time and date with your RFP response. Returning this page signed by your authorized agent will serve to acknowledge this change. All other requirements of the invitation remain unchanged. If you have any questions, please call or stop by the Purchasing Office at the above address.

Firm:

Address

Signature of Person Authorized to Sign Bid:

Signor's Name and Title (print or type):

E-mail Address:

Date: Telephone: Fax:

mailto:melaniew@wacotx.gov http://www.waco-texas.com/

Addendum No 2 Page 1 of 4

CONTRACT DOCUMENTS AND TECHNICAL SPECIFICATIONS

CITY OF WACO

WACO METROPOLITAN AREA REGIONAL SEWERAGE SYSTEM

CENTRAL WASTEWATER TREATMENT PLANT DIGESTER CLEANING AND

IMPROVEMENTS PROJECT

ADDENDUM NO. 2

Date Issued: August 15, 2024

Prepared by Allen Woelke, PE 54386

CDM Smith Inc Texas Registration No. F-3043

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 Friday April 26, 2024.

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. Bids to be submitted on the specific bid date shall conform to the additions and revisions listed herein.

Acknowledge receipt of this addendum by designating receipt of the addendum on the first page of the Bid

Proposal. Failure to do so may subject bidder to disqualification.

ADDITIONAL INFORMATION

a) The Meeting Summary from the non-mandatory Pre-Qualification meeting held at Central WWTP on

July 10, 2024 is attached.

RESPONSES TO QUESTIONS RECEIVED:

1. Is the contractor required to provide an SWPPP for this project?

Response: A stormwater pollution prevention plan (SWPPP) is only needed if more than one acre of green space is disturbed. However, per Section 1.10 Part 1C of the City of Waco Standard

Specifications for Construction, construction projects under 1 acre still need “to submit an Erosion and Sediment Control Plan, for approval to the City Environmental Department”.

2. 18819-4 says to test structures for water tightness. Is this required?

Response: Yes, we normally require water tightness so we can then do a pressure test on the covers.

Non-potable water may be used for this. This helps to test the new penetrations in the digester.

3. 400200-8 refers to stand by charges on bid form. We do not see any bid item for this.

Response: Mention of “Stand-by charges” will be removed from Section 400200, per Addendum 2.

Date Issued: August 8, 2024

Date Issued: August 5, 2024

Addendum No 2 Page 2 of 4

4. What is the % solids in the digesters?

Response: When liquids are pumped from the digesters, it is 3% solids. However, be prepared to encounter almost 100% solids during the cleaning process when the liquids are not present.

5. When was the last time the digesters were cleaned?

Response: The digesters have never been cleaned.

6. Are there any manway or access hatches in the piping gallery that would gain access in each digester side wall?

Response: No, the only points of entry are through the top of the digesters.

7. What size is the opening access hatch on top of each digester cover?

Response: There are 2-24-inch diameter and 1-36-inch diameter openings in the digester lids. See drawing D-4 for the general location of the hatches each cover.

8. D-4. How many concrete ballasts are there in the digester cover?

Response: The number of existing ballasts is unknown. For the new Digester B cover, the concrete ballasts are to be designed by the digester cover manufacturer based on the design criteria listed in

Section 467137.

9. Please advise or publish which contractors have been prequalified after the approval process.

Matous Construction, Ltd.

8602 State Highway 317

Belton, TX 76513

(254) 780-1400

Contact – Kate Richter, Kate@matousconstruction.com

Gracon Construction, Inc.

4343 Lasater Road

Mesquite, TX 75181

(972) 222-8533

Contact – Suzy Locke, slocke@gracon.biz

10. What are the digester heights from ground level?

Response: The top of wall elevation for Digesters 1A and 2A are 397.5 ft and Digesters 3A and B have a top of wall elevation of 396.00. The ground elevation at the digesters is approximately 390 ft.

Digesters 1A and 2A are approximately 7.5ft above grade, and Digesters 3A and B are approximately

6 ft above grade.

11. Is there side-portal access?

Response: See Question 6.

12. Please provide the list of pre-qualified contractors - including contact name, phone number, and e-mail address.

Response: See Question 9.

mailto:Kate@matousconstruction.com mailto:slocke@gracon.biz

Addendum No 2 Page 3 of 4

13. The water pointed out on the tour will not work for digester cleaning. We’ll need a fire hydrant that might be close or possibly pump water from their clarifier to the tanks to mix with the sludge. Can we pull water from the clarifier or where is the closest fire hydrant we can pull water from to add to the tanks for cleaning?

Response: The selected contractor can use water from the Chlorine Contact Chamber to the east of the digesters as shown on drawing G-2. The contractor will need to provide their own pumps and meter their water usage as detailed in Section 400200 paragraph 3.4.B.5. Using the on-site NPW system is not permitted, and the nearby hydrants are not sized to efficiently convey the quantity of water required for cleaning.

14. Chamberlin Waterproofing would like to propose the attached alternative Polyurethane Injection products for consideration:

Spectec PUR GT350 by Alchatek

Prime Flex 900 XLV by Prime Resins

Response: Alternative manufacturers are evaluated during the construction phase. The selected contractor would need to submit a substitution request including all of the required information outlined in the specs showing that the proposed products are better or equal then what is specified.

Only after in-depth review of the submittal then we can approve the proposed manufacturers and products.

REVISIONS TO PREVIOUS ADDENDA

a) Revise the response provided to question 2 in ADDENDUM NO. 1 to the following:

“2. The owner or engineer has software system. Spec requires contractor to purchase system for 7 license users. Is the contractor required to purchase website management software for this project?

Response: The City will provide the selected contractor with 1 license to Projectmates. This will allow multiple users access if they use the same email and login information, but not all at the same time. Additional licenses may be purchased at the contractor’s expense.”

b) Replace page 3 of ADDENDUM NO. 1 with the attached revised page. Changes include the addition of the P.E. seal and signature.

REVISIONS TO CONTRACT DOCUMENTS AND TECHNICAL SPECIFICATIONS

SECTION 013100 – PROJECT MANAGEMENT AND COORDINATION

a) Page 013100-4, Revise paragraph 1.7.B so it reads as follows:

“B. Web-Based Project Management Software Package: Use web-based Project management software package, Projectmates, for purposes of hosting and managing Project communication and documentation until Final Completion. Owner will provide one license of the software to the

Contractor. Acquiring additional software licenses is the responsibility of the Contractor.”

b) Page 013100-4, Delete paragraph 1.7.B.1 and the associated sub-list 1.7.B.1.a-1.7.B.1.l in their entirety.

c) Page 013100-5, Delete paragraph 1.7.B.2 in its entirety.

d) Page 013100-5, Delete paragraph 1.7.B.4 in its entirety.

Addendum No 2 Page 4 of 4

SECTION 460200 – TANK AND STRUCTURE CLEANING

a) Page 460200-8, Revise paragraph 3.4.B.3 so it reads as follows:

“3. Coordinate work so as to not interfere with or jeopardize the routine operation of the treatment plant or other activities of other contractors needing access to the treatment plant site.

In situations where the operation of the plant conflicts with the Contractor’s work, the operation of the plant will take precedence. Provide adequate staff to remain on site to monitor and control atmospheric conditions within the interior of the digester being cleaned during cessation of operations.”

REVISIONS TO DRAWINGS

N/A

END OF ADDENDUM NO. 2

Pre-Bid/Pre-Qualification Meeting Summary Waco Central WWTP Digester Cleaning and Improvements

Date: July 10, 2024

Time: 2:00 – 4:00 PM

Location/Call in Details: 1147 Treatment Plant Rd

Prepared by: CDM Smith

Project Name: Waco Central WWTP Digester Cleaning and Improvements

Project Number: RFP No. 2024-023; 2497-287230

Attendees: See Sign-In Sheet for meeting attendees

Meeting Objective: Non-mandatory Pre-bid/qualification meeting for the Project.

Meeting Summary:

RFB Submittal Overview

▬ Melanie Wade, the purchasing agent for the project gave an overview of the prequalification application process and timeline as outlined in Addendum 1.

▪ Pre-qualification applications need to be submitted by 5:00 pm Wednesday, July 17, 2024.

However, if more time is required, contact Melanie and the deadline may be extended.

▬ Notification of pass/fail status on the pre-qualification July 25th. Contractors may dispute their status, but it must be done in writing and received before August 1st.

▬ Deadlines for questions is August 13th, Bonfire is the preferred means of communication.

However, emailing questions is also acceptable.

▬ Bids close August 22 at 2:00 pm.

▪ Must be submitted via mail, in-person, or through Bonfire. Emailing bids is NOT acceptable.

Project Description

▬ Removal and disposal of digester contents from Digesters 1A, 2A, 3A, and B into Sludge Lagoon

#3

▬ Cleaning, inspecting, and repairing (as needed) the digesters after contents have been removed

▬ Replacing the Digester B floating gasholder cover and its appurtenances

▬ Improvements to the Digester Pump Station including replacing plug valves, modifying piping, adding tank penetrations, and installing additional plug valves.

▬ Modify digester gas piping and other work as shown in Contract documents.

Project Schedule

▬ Final selection decision will be in September.

▬ City Council meet every 1st and 3rd Tuesday of the month, aiming to present to Council during

September 17th meeting.

▬ Substantial Completion: 425 calendar days from Notice to Proceed (NTP)

▬ Final Completion: 455 calendar days from NTP

▪ CDM Smith assumed 2-week timeline for inspections.

▪ Requested that Contractors provide input on the reasonability of the schedule, if can be adjusted in future Addenda. If additional time is required during construction, it with be via Change Order.

Constraints

▬ Only one digester may be taken out of service at one time. A digester must be fully back online before taking another digester out of service.

▪ Notify plant operators three weeks prior to draining a digester.

▬ Digester 3A must be cleaned first, and Digester B must be cleaned last.

▬ Limited space for the installation of Digester B cover.

▪ There is space called out in the drawings, but that may not be enough.

▬ Valve replacements and auxiliary work inside the Digester Pump Station should be completed while the associated digester is offline for cleaning.

Addenda

▬ Addendum No. 1 has already been issued on Bonfire.

▬ Send questions through Bonfire or directly to Melanie (MelanieW@wacotx.gov).

Additional Questions/Comments

▬ City noted that they may be extended time between digester cleanings during the winter if operation problems arise.

▬ It is assumed that the plug valves will be replaced/installed while the associated digester is down. However, the plug valves have a long lead time and may not arrive in time, and the digesters may need to be taken offline and emptied a second time to install the valves.

▪ The City understands this and will start procuring equipment early on in the project. They can coordinate additional shutdowns if they are required.

▬ The specs mention Contractors providing a stormwater Pollution Prevention Plan (SWPPP).

However, this project does not disturb any of the existing ground/soil, so submission of a SWPPP may not be necessary.

▬ Supplemental Conditions mention that the Contractor is responsible for trench safety, but this

Project does not include any excavations, and it is not mentioned in the Bid Form.

▪ CDM Smith will review the documents and remove that language in the next Addendum.

▬ Section 13100 specified that the GC is responsible for the web-based project management software. What software is required?

▪ City clarified that they use ProjectMates and they will provide 1 license to the selected contractor. If additional licenses are needed, they may need to be purchased by the contractor.

mailto:MelanieW@wacotx.gov

▬ City confirmed that they are responsible for reseeding the digesters.

▬ Matous requested clarification on the intent of Section 18819 Water Tightness Testing, the process written in the spec seems quite involved and seems to be more in line for new structures rather than repairing existing ones.

▪ CDM Smith will review the specification and determine if all the testing requirements are necessary. However, CDM Smith generally expects the test to be conducted in order to ensure all cracks/leaks are addressed before the digesters are brough back online.

▬ Section 400200 mentions “Standby charges” for situations where the Owner must stop the contractors work, but there is no line item in the Bid Form for daily standby charges.

▪ CDM Smith to review language in the specification and alter the Section 400200 and/or the Bid Form accordingly.

▬ Confirmed that there is no insulation required for the digester cover.

▬ Discussion of the general process:

▪ Taking digesters offline, one at a time and convey the contents to the lagoon onsite

▪ The digesters are 90 ft in diameter with 30 ft side water depth (SWD). The City can take that down to 20 ft SWD.

▪ The bid form assumes that the contractor is getting paid by the cubic yard. How is that value getting quantified? Typically, there is a dewatering process and the contents get weighed at the landfill.

− No way to measure volume accurately once it’s been diluted. The cost will be based on the SWD measured in the digester after the City decants it.

▪ 2-3% solids flows into the digesters, but the digesters haven’t been cleaned since they were installed several decades ago. The City does not feel equipped to pump it all out themselves.

The concern is rags/grit accumulating at the bottom of the tanks.

▪ It will be confined space entry, and nitrogen gas/inert gas will be used to purge the tanks to remove any explosive gases.

▪ Large solids will be taken to the City owned landfill, the City is responsible for the tipping fees.

▬ Central WWTP has a NPW system, but it cannot accommodate the flow required for the dilution process. The contractor will need to provide their own means and methods for pumping NPW into the digesters.

▬ If the floating cover is built on the ground, the contractor needs to provide route for the plant to get chemical deliveries. The route does not have to be extensive, as long as there is room for a truck to go around the cover, can just be some temporary asphalt.

▬ There is approximately 12 million gallons of available space in Lagoon 3, more than enough space for the digester contents. Removing solids and drying them from the lagoon is an ongoing activity.

Adjourned for walk through the plant.