CHESTER COUNTY SOLID WASTE AUTHORITY LEACHATE PLANT IMPROVEMENTS PROJECT

7224 DIVISION HWY. NARVON PA 17555

ADDENDUM NO. 3

December 5, 2019

The above-referenced Contract Documents shall be amended as indicated in detail below. The Certification page of this Addendum is being furnished in two copies. One signed copy of the Certification page shall be enclosed in the sealed, marked envelope containing the Bid. The inclusion of this Addendum will be noted in the Agreement, and the execution of the Contract shall indicate full acceptance by all parties of the provisions contained herein. All other provisions of the Plans, Specifications, and other Contract Documents not noted in the Addendum shall remain unchanged and in full effect. This Addendum shall be attached to and become a part of the Plans and Specifications for the project.

Item #1 – Written Questions Submitted by Contractors and Vendors

The answers to questions submitted to the Engineer in writing by the prospective bidders are provided below.

1. On drawing E5 there are two runs of heat trace. Who supplies and installs the heat trace? If it is the electrical contractor we will need a spec for the heat trace. The electrical contractor will supply and install the heat trace. A specification for the heat trace was provided with Addendum No. 2, issued on December 4, 2019.

2. Who supplies the level switches and level transmitters for the project? I did not see a

spec on either of these.

The level switches and level transmitters will be supplied under the General contract.

3. Are the new underground conduits to be in a concrete encased duct bank? Yes, the conduits are to be installed in a concrete-encased duct bank. For purposes of preparing the cost estimate, assume that the depth of cover will be 24”.

4. Can we use a quazite manhole in the underground conduit installation instead of a

precast concrete? Substitutions may be requested through the submittal process. Only those submittals approved by the Engineer are permitted for use in the project.

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5. The existing RO permeate tanks, are we to remove them to install new house keeping pads? No, it is not necessary to install new housekeeping pads under the existing RO permeate tanks.

6. Drawing S-01, shows all housekeeping pads to have the stone hard coating? Not normally done. Stonhard coating is to be applied to all housekeeping pads, as shown on Drawing S-01.

7. Bid form item #4, concrete pad removal. The plant demolished all pads except a large

one downstairs in front of the overhead door. Is the contractor responsible for this one? Yes. Demolition is to include break-up and removal of the lower level concrete pad and curb, filling of the trench drain, and creation of a smooth, even surface.

8. Drawing M-14 shows the aeration system to be reused. I saw no equipment there on

the site visit. Did the plant dispose of it?

No, the aeration system equipment is still located at the leachate treatment plant and is available for re-use.

9. Can you please mark the tank ID numbers on drawing, PFD-01? The tank ID numbers have been marked on drawing PFD-01. The revised drawing is provided with this Addendum in Attachment A.

10. Spec, 15110-5, H. Pump P-700. Spec says to match existing. Does the plant not have

any literature on it? The existing is on the bottom of the tank, I can’t ID it. There is no additional information available for this pump. If the Contractor cannot match existing, under the provisions of the specification, an “approved equal” is allowed for substitution. Based on a 2-inch PVC line from the effluent equalization tank to the outfall and a design flow rate of 30 gpm, total head (accounting for elevation and friction loss) was calculated to be 53 ft. One such pump meeting these specifications is Flygt 3057. Contractor is to verify actual pump requirements based on field conditions and coordination with the equipment manufacturer regarding treatment system requirements for flow rate.

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11. Drawing D-07 calls the tank “effluent EQ” on drawing M-15, it’s permeate settlingtank. Is it the same tank?

Yes, the tank shown on drawing M-15 is the effluent equalization tank. The label onDrawing M-15 has been changed to be consistent with Drawing D-07. The reviseddrawing is included with this Addendum in Attachment A.

12. I am looking at detail 05 on S01. Can you confirm that we are only chipping out 1” ofthe concrete around the grate per note 1 and reusing the existing grate after the concreteis repaired?

The specified depth of 1” is an estimate. The actual depth of concrete to be removedin order to access the grate will need to be field verified by the Contractor. Onceremoved, the former grate will be discarded and replaced with a new grate.

13. Is there a repair method preferred to fill in the holes in the existing floor. I don’t seethis damaged area called out on the plans anywhere or a detail on how to fix it beforewe install the Stonehard coating.

Repair of this damaged area (i.e., the cracked floor) is not included in the scope of work for the Leachate Treatment Plant Improvements project. CCSWA will address this repair under a different contract.

14. I have not been able to find the 3” x 18” Rubberform containment berm. Do you knowof a local distributor? If not, would the 4” high barrier by pig be an acceptable equal?See the link below. Is there really a need to remove the existing floor 10” deep andreplace with concrete to epoxy down a containment berm?https://www.grainger.com/ec/pdf/45GP18_1.pdf

If Contractor is unable to locate the specified berm, a request can be made forsubstitution of an equal product through the submittal process. Only those submittalsapproved by the Engineer are permitted for use in the project.

15. Please confirm, as stated during the pre-bid meeting, that the equipment layout in theexisting building can be altered to best fit the space.

Yes, the equipment layout in the building can be altered to best fit the space. A set ofdrawings will be issued for construction after bid award, based on the treatmentsystem that is to be installed.

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16. Please confirm that all the equipment shown to be located in the building must be provided. The equipment to be located in the building, as shown in the Contract Documents, is an estimation based upon a preliminary UF/RO Treatment System design. The Contractor should coordinate with his preferred vendor in order to procure the equipment necessary to install a properly functioning, complete treatment system as proposed in his bid.

17. Drawing C–02 shows a UF & RO CIP skid but we do not find any details for pump, level control, piping or electrical related to that system; please provide details for what is expected. The UF & RO CIP system components will be specific to the particular treatment system that is proposed. The Contractor should coordinate with the equipment manufacturer to determine the needs for the pump and level control, piping and electrical as related to the proposed system.

18. Drawing D-05 is labeled (lower right corner) as “Draft – Progress Print 08/13/2019” - is this drawing released for construction? As issued, Drawing D-05 is a P&ID for a suggested RO/UF treatment system. In the bid process for this project, the Contractor has the flexibility to work with equipment manufacturers to select an appropriate treatment system (i.e., a system that meets the performance standards outlined in specification 11380) and provide the equipment necessary to install a fully functioning treatment system. Therefore, certain details have not provided with the Contract Documents, as these items will be specific to the treatment system proposed in the bid. The Engineer will issue a set of drawings for construction after bid award, based on the treatment system that is to be installed. • Drawing D-05 shows what we guess is a feed tank for the second pass reverse

osmosis system; this is not shown on any of the layout drawings nor are there any details associated with it. Please provide what is expected. The Contractor should coordinate with the equipment manufacturer to determine specific system requirements.

• Drawing D-05 shows the CIP system along with what appears to be a tank. Are there details associated with this. For instance, is there a pump in CIP–100?

Contractors are to coordinate with the equipment manufacturer to determine the CIP system requirements that are specific to the selected treatment system, including pumps.

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• Drawing D-05 shows lots of pipes from what appears to be a tank associated with CIP – 100. Without details for the UF and RO systems, how will we know where the pipes begin and terminate? Final piping layout will be determined based on treatment system that is selected. As mentioned above, the Engineer will issue a set of drawings for construction after bid award, based on the treatment system that is to be installed.

• Drawing D-05 shows anti-scale and added to the final pH adjustment tank. Is this correct and why? Addition of anti-scalant, if required, should be made to the RO feed line and not to the final pH adjustment tank. Drawing D-05 has been revised to show this change. The revised drawing is provided with this Addendum in Attachment A. The Contractor should coordinate with the equipment manufacturer to determine the specific requirements for the treatment system selected for installation.

• Drawing D-05 shows the addition of sulfuric acid into the final pH adjustment tank. Caustic only should be required. Please comment. Addition of sulfuric acid and caustic to the final pH adjustment tank is preferred. The Contractor should coordinate with the equipment manufacturer to determine the specific requirements for the treatment system selected for installation.

19. The drawings note that the UF and two RO systems will be provided by others but in

the meeting you to confirm that they are to be included in the bid. Please confirm. Costs for provision of the treatment system equipment should be included in the bid. Drawings D-04 and D-05 have been revised to reflect this information and are included with this Addendum in Attachment A.

20. Will mounting of transmitters, level switches, etc. be part of the mechanical scope or

the electrical scope? Mounting of transmitters, level switches, etc. will be conducted by the mechanical contractor.

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21. There is no biocide addition shown for the RO feed tank. Will there be biocide feed? Addition of biocide to the RO feed tank is up to the discretion of the Bidder. The Contractor should coordinate with the equipment manufacturer to determine the specific requirements for the treatment system selected for installation.

22. There is no antiscalant addition shown for the reverse osmosis systems. Will there be antiscalant addition for the feed? Provisions for the addition of antiscalant to the RO system is preferred. The Contractor should coordinate with the equipment manufacturer to determine the specific requirements for the treatment system selected for installation.

23. There are no chemical feed pump shown for cleaning chemicals. With the chemicals be added by hand or is it expected to require pumps? Contractor should provide pumps on the CIP skid. Specific pump requirements, including number and type, should be coordinated with the equipment manufacturer.

24. Can air be used to mix the final pH adjustment tank?

The use of air to mix the final pH adjustment tank was not considered but may be used if the Contractor confirms that the leachate treatment plant blower system can accommodate this function.

25. P–105 is shown as a flat bottom tank. Should a cone bottom tank be considered to effectively purge solids that are removed by the ultrafilter? The flat bottom tank shown for use was selected based upon space considerations (i.e., the ceiling height of the treatment plant) and ease of alignment with existing equipment. The Contractor may propose a feasible substitution through the submittal process. Only those submittals approved by the Engineer are permitted for use in the project.

26. Drawing D–03 shows a 6 inch pipe from the UF suction pipe to the CIP skid. Is this correct? The 6” pipe shown has been selected based on the treatment system identified in the project specifications and is subject to change based on the treatment system proposed by the Bidder. The piping requirements will be finalized based on the actual treatment system that is selected for installation. At that time, a set of drawings will be issued for construction which will include final piping system details.

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27. Section 11380 Part 2.4.C.3 specifies a “RO break tank” for feed water to the second pass RO Feed Pump. A line item for this tank is not included in the Schedule of Values. Should the cost be included in the RO System price or be included in another line item? The price for the RO break tank should be included in the line item for the RO System price in the Schedule of Values.

28. Section 11380 Part 2.7.A.1 and Part 2.7.A.2 state the RO frame to be stainless steel while Part 2.7.A.11.h states the RO frame to be constructed of powder coated carbon steel. There is no specification for the UF frame. What should the unit frames be constructed of? The Contractor can elect to use either stainless steel or powder coated carbon for the RO and UF frames.

29. Section 11380 Part 2.6.B.4 states “Each membrane frame shall be fitted with a minimum of two lifting points…” Are lifting points for forklift access or for lifting via crane? The lifting points are for forklift access.

30. Section 11380 Part 3.3.D.3.d references a specified frequency for the Maintenance Clean – what is the specified frequency? The specified frequency refers to that which is included in the equipment manufacturer’s specifications for the treatment system.

31. Section 11380 Part 3.3.D.3.e references a specified frequency for the Recovery Clean – what is the specified frequency? The specified frequency refers to that which is included in the equipment manufacturer’s specifications for the treatment system.

32. Section 11380 Part 3.3.D – will the plant operators operate the system during the Acceptance Test period or is it the Vendor’s responsibility? The plant operator will operate the system during the Acceptance Test period. It is the vendor’s responsibility to continuously monitor the operation of the system over this 30-day period.

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33. Suction piping from the feed tanks for the UF and RO systems is not shown and based upon the specified layout suction piping will be extended a relatively long distance and present a tripping hazard. Please clarify what is expected. The piping layout in the building can be altered to best fit the space, prior to Bid Award. The Engineer will issue a set of drawings for construction based on the selection of the treatment system. Any changes made to system design and/or layout after Bid Award must be approved by the Engineer and the Owner.

34. The specified layout shows the reverse osmosis system close to the electrical panel on the north wall. What is the space required between the electrical panel and the reverse osmosis unit? The RO system is to be installed at least three (3) feet from the electrical panel.

35. Acid and caustic chemicals are located next to each other in the specified layout. What provisions are required to ensure that the chemicals do not come in contact one with the other? If the Engineer deems it necessary at the time of system installation, locations of the chemical storage can be adjusted to ensure that the acid and caustic chemicals do not come in contact with one another. Final storage location is subject to approval by the Engineer and Owner.

36. Based upon the feed TDS and an overall recovery of 67% from a two pass reverse

osmosis system 450 psi is not adequate. Please advise.

Information provided in the Contract Documents is based on a preliminary UF/RO system design. The Contractor is to coordinate with the equipment manufacturer to determine the actual design conditions necessary to allow for a treatment system that meets the performance standards outlined in Specification 11380 and revised in Addendum No. 2.

37. If the feed rate to the first pass reverse osmosis system is 27 GPM is the specification correct in calling for the same feed rate to the second pass reverse osmosis system. Refer to the response to Question #36.

38. Why is the second pass reverse osmosis system rated at 450 psi when a 300 psi rating is

more than adequate? Is a 300 psi design acceptable? Refer to the response to Question #36.

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39. Is it necessary to provide one turbidity monitor for each UF module or is one turbidity monitor acceptable for the UF system? Refer to the response to Question #36.

40. The specification calls for the PLC and the low voltage components packaged in the same enclosure with the three-phase high-voltage starters and drives. Today most specifications require 2 panels to isolate the low voltage which is usually 24 V from the three-phase power for our flash protection. Please comment. The 480 volt 3-phase, 60 Hz power panel and any VFD panel(s) shall be separate from any low voltage PLC panel. Equipment supplier shall conform this requirement unless the vendor provides written guarantee that panel containing high voltage (480 volt/3 phase /60 Hz) and low voltage (24V DC) devices will work properly.

41. The specification shows one CIP system on the layout but the specification has separate descriptions for CIP for UF and RO systems as though there are two CIP systems each dedicated to UF and RO systems.

One CIP system for both the UF and RO systems is preferred. However, the Contractor should coordinate with the equipment manufacturer to determine the specific CIP requirements for the system to be installed.

42. I spoke with the company that does liner work for us. They looked at the details on S-01 of the liner repair where the concrete pump support is. They don’t normally use batten strips on a round concrete support. Their typical detail is attached. Would this be acceptable? If batten strips are required, could the concrete support be changed from round to square? In order to avoid structural changes, the round concrete support should remain in-place. However, the use of a field-fabricated 60 mil HDPE boot and skirt should be used to seal the penetration. The boot should be secured to the concrete with stainless steel banding in conjunction with neoprene or other suitable cushion material to avoid damaging the boot, and the top of the boot should be caulked. The HDPE skirt should be secured to the existing 60-mil HDPE containment liner using standard extrusion welding methods and non-destructively tested (e.g. vacuum box) tested following completion. Drawing S-01 detailing the liner repair with additional special instructions will be revised and included in the set of drawings to be issued for construction after bid award.

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43. Will the bid date be extended? Numerous questions have been asked and no answers have been given and it is now less than one week to bid time? In order to maintain the schedule provided in the Contract Documents, the bid date cannot be extended.

44. If any answers to our questions need to be clarified, can they be submitted after today? In order to maintain the schedule provided in the Contract Documents, written questions will not be accepted after December 3, 2019.

45. Do you have a Bid Bond or Bid Security form that is required for this bid? Also do you have a Bidder’s Qualification statement form or list of what is needed? The Contractor should use the form provided by the surety company. The Owner will not be issuing a specific form that must be used. Refer to Addendum No. 2 for additional information. Bidders should refer to Article 4 in the Instructions to Bidders section of the Contract Documents to determine the information to be provided to demonstrate Contractor qualifications.

Attachments to this Addendum

Attachment A Revised Drawings: PFD-1, D-04, D-05 and M-15

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CERTIFICATION OF RECEIPT AND ACCEPTANCE OF ADDENDUM NO. 3

CHESTER COUNTY SOLID WASTE AUTHORITY LEACHATE PLANT IMPROVEMENTS PROJECT

The undersigned hereby acknowledges receipt of Addendum No. 2 prior to the submission of their bid; and hereby agrees to the inclusion of this Addendum in the Agreement and in the Contract Documents; and further agrees that the other provisions of the Contract Documents shall remain unchanged and in full effect.

______________________ Contractor

________________________ Date

Chester County Solid Waste Authority

Bid and Contract Documents - Addendum No. 3

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December 2019

ATTACHMENT A

Revised Drawings: PFD-1, D-04, D-05 and M-15

FROMLANDFILL

EX. GRITCHAMBER EX. MIX TANK

EX. UFFEEDTANK

EX. STORAGE TANK

UF UNIT

EX. RO FEED TANK

RO UNIT

EX. POST-PERMEATE

TANK

ROCONCENTRATE

TANKS(1 & 2 PROPOSED)

DUPLEX STRAINERS(800 MICRON)

(30 GPM EACH)

EX. ROPERMEATE

TANK

EX. BLOWERACID FEED

TO OFFSITEDISPOSAL

TO OFFSITEDISPOSAL

TO STREAMDISCHARGE

TO OFFSITEDISPOSAL

EX. INFLUENT PUMPS (2)30 GPM

DUPLEX BAG FILTERS( 600 MICRON)

(30 GPM EACH)EX. STORAGE TANK

EX. ROPERMEATE

TANK

CHEMICAL FEEDCHEMICAL FEED(S)

EX.BLOWERS

EX. LOADOUTPUMP

EX. LEACHATETRANSFER

PUMP

EFFLUENTSTORAGE

TANK

OVERFLOW TO EX.MIXING TANK

FROM RO FEED TANKOVERFLOW

OVERFLOW TO EX.MIXING TANK

OVERFLOW TO EX.MIXING TANK

T-101 T-115

T-100T-105

T-111T-500

T-620 & 640

DRAFT - PROGRESS PRINT 12/05/2019

B

A

C

D

E

5 64321

B

A

C

D

E

5 64321

DRAFT - PROGRESS PRINT 12/05/2019

B

A

C

D

E

5 64321

B

A

C

D

E

5 64321

DRAFT - PROGRESS PRINT 12/05/2019

DRAFT - PROGRESS PRINT 12/05/2019