CITY OF NEWBURGH CONTACT TANK AT WASHINGTON LAKE FILTRATION PLANT

Newburgh, New York

Site Number 336022

July 2016

ADDENDUM No. 2

TO CONTRACT D010238

Prepared by:

Arcadis CE, Inc. 855 Route 146, Suite 210 Clifton Park, NY 12065

ADDENDUM No. 2

JULY 2016 CONTRACT DOCUMENTS CITY OF NEWBURGH CONTACT TANK

AT WASHINGTON LAKE FILTRATION PLANT NEWBURGH, NEW YORK CONTRACT NO. D010238

JULY 2016 TO ALL HOLDERS OF THE CONTRACT DOCUMENTS: Your attention is directed to the following changes and additions to the July 2016 Contract Documents for the City of Newburgh Contact Tank at Washington Lake Filtration Plant. This addendum has been prepared in accordance with the provisions of the Contract Documents.

PART A. Questions and Answers Q1 The General Conditions call for full-time supervision. Please confirm that the tank

manufacturer’s subcontractor superintendent may be assigned by the tank builder as their superintendent representative when the tank manufacturer is not on site.

Please refer to Article 5 of the General Conditions. The site superintendent, or their

representative on site in their absence, must able to act on behalf of the Contractor. Q2 Specification Section X, Standard Specification, Section 00011, Site Security – Please

confirm a full time uniform watchman is not required. The City of Newburgh Washington Lake Filtration Plant is staffed 24 hours a day, seven

days a week and has an existing perimeter fence for security. If there are temporary breaches in the perimeter fence the Contractor should expect to take necessary actions to maintain the current level of security through temporary fencing or other methods including a watchman if necessary to secure the worksite. Specifically a watchman is not required, but maintaining the existing site security is required.

Q3 Specification Section X, Standard Specification, Section 0009, Traffic Control – Please

confirm a traffic control plan is required for this project. A traffic control plan is not required for the Site, but Contract deliveries and workflow must

be coordinated with the City and Engineer. Q4 Specification Section 31 23 05, Excavation and Fill, Paragraph 3.5.H.3 – Please clarify

how the removal of unsuitable foundation soils will be paid for and directed if excavations are required below the limits of excavation. There is a unit price item for granular fill beneath the tank but payment of that item does not include the removal of unsuitable soils below the limits of excavation.

Please see Addendum No 2, Part B.15 for revisions to Section XII for suitable fill. Q5 Specification Section V, Bid Form – Please clarify if the 1,000 CY unit price item for

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granular fill beneath the tank includes the 6-inches of granular fill as shown on Sheet C-08 of the plans or if it is for additional granular fill, if required.

Please see Addendum No 2, Part B.15 for revisions to Section XII Measurement and Payment.

Q6 Specification Section 31 23 16.26, Rock Removal, Paragraph 1.1.D.1.c states the limits for rock removal are to extend 12-inches outside of the footing. Please increase these limits to include the required working area outside of the tank footing in order to construct the tank. We would recommend an 18-foot track for construction work performed during potential inclement weather.

Please see Addendum No 2, Part B.2 for revisions to Section XI, Specification 31 23 16.26, paragraph D.

Q7 Specification Section 33 16 13.16, Paragraph3.11.C.1 states special inspections shall be provided for this project. Please clarify what responsibility the Tank Contractor will have so the cost may be carried in the bid. IBC, Chapter 17, indicates that the Owner provides Special Inspection services for the project.

The Contractor will be responsible for testing services required by Paragraph 3.11 of Section XI, Specification 33 16 13.16 and Paragraph 3.14 of Section XI, Specification 31 23 05.Please refer to Section XI, Specification 01 45 33.00.CH. The Coordinating Special Inspector will be employed by the Department. They will be responsible for visual inspections and reviewing the testing documentation provided by the Contactor, which combined achieve the requirements for special inspection.

Q8 Specification Section 33 16 13.16, Paragraph 2.11.L.2 states that 316 S.S. bracing is required for the baffle wall. Other appurtenances inside the tank are required to be 304 S.S. material. Please confirm 304 S.S. bracing is acceptable.

Please see Addendum No 2, Part B.5 for revisions to Section XI, Specification 33 16 13.16.

Q9 Specification Section 33 16 13.16, Paragraph2.12.B.1.b indicates that aluminum in contact with dissimilar materials should be coated. Please confirm in lieu of providing this coating, isolation kits can be utilized.

Bid as specified.

Q10 Specification Section 33 16 13.16, Paragraph 3.5 – Please confirm AWWA C652 Method 3 disinfection can be utilized on the prestressed concrete water tank in lieu of the disinfection procedure outlined in this section.

Bid as specified.

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Q11 Drawing G-01, General Notes 13 and 14 state the Contractor shall topsoil and seed the site. Please clarify if importing and spreading topsoil is required as part of this contract. Due to the lack of space on site, all topsoil stripped prior to the tank excavation is intended to be hauled offsite. Additionally, please confirm that seeding is only required as an erosion control measure and that the final seeding will be part of the follow-up on the building contract.

Please see addendum No 2, Part B.16, B.17, B.18 and B.26 for revisions to notes on the

drawings. Q12 Drawing C-03 – Please confirm the 20-foot measurement from the property line to the tank

is measured to the outside diameter of the tank foundation. The 20-foot measurement is from the property line to the outside face of the contact tank. Q13 Drawing C-03 indicated the rain garden as future work. Please clarify if the rain garden is

to be included in the bid contract for this project. The rain garden with plants is not required and will be in a subsequent Contract by Others,

however, the detail shown on Sheet C-06 is part of the work. Please refer to Addendum No 2, Part B.22.

Q14 Drawing C-08, Dome Plan, indicates a dome Saf-T-Line system is required on the tank

dome. However, Specification Section 33 16 13.16 does not include a dome Saf-T-Line system. Please confirm a dome Saf-T-Line system is required for this tank.

A Saf-T-Line system is required for the Project. Please refer to Addendum No 2, Part B.10

for revisions to Section XI, Specification 33 16 13.16 for details. Q15 Drawing C-08, Note 17 states that no cold weather construction or hot weather

construction is permitted on this project as defined in Specification Section 03300. Please confirm this note is not applicable for this project or provide a copy of this specification section as it is not present in the documents.

Note and reference to Section 03300 has been deleted, please refer to Addendum No 2,

Part B.23 for revisions to Drawing C-08. Q16 Drawing C-09, 36” Inlet Detail shows the inlet encasement from the tank wall extending to

the tank floor. Please confirm this can be terminated above the tank floor to allow free radial movement of the tank wall.

The concrete encasement can be terminated prior to the floor as demonstrated by the 36-

inch flexible coupling connecting the inlet piping and inlet riser. Please refer to Addendum No 2, Part B.24 to Drawing C-09.

Q17 Drawing C-09, 18” Overflow Detail indicates a through-wall overflow above grade with a

centerline elevation of 276.42. Please note this is below the tank’s lowest adjacent finish grade. Please confirm the overflow should penetrate through the tank wall above finish grade. Additionally, please confirm the overflow can penetrate the tank wall at the manway centerline elevation to reduce the amount of un-banded area in the prestressing.

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Please refer to Addendum No 2, Part B.24 for revisions to Drawing C-09, 18” Overflow Detail.

Q18 Drawing C-09, Roof Vent Detail shows a fiberglass vent cap with a 20” x 20” mesh screen

for the vent. Specification Section 33 16 13.16, Page 17, Paragraph 2.11.H.1 indicates a 16-mesh screen is required. Please confirm the required mesh type. Additionally, can an aluminum fail safe vent be provided in lieu of the fiberglass?

Please refer to Addendum No 2, Part B.24 for revisions to the Roof Vent Detail and

Addendum No 2 Part B.9 for revisions to the specification. Q19 Drawing C-09, Wall Manway Detail indicates a 304 stainless steel ladder is required.

Specification Section 33 16 13.16, Page 17, Paragraph 2.11.F.2 indicates either an aluminum, fiberglass, or stainless steel ladder is required. Please confirm the ladder material can be aluminum or fiberglass as indicated in the specification.

Please refer to Addendum No 2, Part B.9 for revisions to Section XI, Specification 33 16

13.16. Q20 On Drawing C-10, Precast Concrete Baffle Wall Detail, shows a baffle wall height of 25’-

6”. We recommend the baffle wall height be 6-inches above the design liquid level (30’-6”). Please confirm the required baffle wall height.

Please refer to Addendum No 2, Part B.25 for revisions to Drawing C-10, Precast

Concrete Baffle Wall Detail. Q21 Please confirm an interior ladder is required for this tank. Specification Section 33 16

13.16, Page 18, Paragraph 2.11.I indicates an interior ladder is required; however, an interior ladder is not shown in the drawings.

An interior ladder is required to be located under the manway, please refer to Drawing C-

09, Wall Manway Detail. Q22 We recommend a perimeter drain to be located below the foundation bearing elevation

and at the bottom of the cut for subgrade soil removal. Please confirm if this would be acceptable.

Please refer to Addendum No 2, Part B.20, Part B.21 and Part B.23 for revisions to

include a perimeter drain. Q23 Addendum 1, page 8 added the following language, “All on-site personnel are required to

have 40 hour OSHA training plus a current eight-hour refresher, baseline medical monitoring plus a current yearly physical and training and current fit testing for respirator use.” Please confirm that this requirement only applies for when respirator use is required.

This provision only applies to personnel required to wear a respirator for the Work. Q24 Is there a site groundwater remediation spec associated with this project? No groundwater remediation is anticipated at the Site.

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Q25 Please confirm that the Contractor for the Contact Tank is NOT responsible for installing the rain garden?

The rain garden topsoil and plantings are not required and will be in a subsequent

Contract by Others, however, the detail shown on Sheet C-06 is part of the work. Please refer to Addendum No 2, Part B.22.

Q26 Can we assume that it is not necessary to consider buoyancy effects during tank-empty

conditions when designing the tank floor? The draft geotechnical report that was included in the revised Limited Site Data does not

indicate the presence of high groundwater, however a perimeter drain was added to the Work. Please refer to Addendum No 2, Part B.20, Part B.21 and Part B.23 for revisions to include a perimeter drain.

Q27 Section 33 16 13.16 Prestressed Concrete Aboveground Water Utility Storage Tanks 1.4

QUALITY ASSURANCE C. Regulatory Requirements 3. Please revise: “All supplementary cementitious materials, admixtures, curing compounds, and other industrial-produced materials used in concrete, or for curing or repairing of concrete, that can contact potable water or water that will be treated to become potable shall be listed in NSF/ANSI 61” to “All coatings, sealants, and repair materials that can contact potable water or water that will be treated to become potable shall be NSF/ANSI 61 compliant.” It is our experience that admixtures, curing compounds, and Portland cement that are NSF 60/61 compliant can be difficult, sometimes impossible, to obtain locally. Due to the extremely fast track nature of the project, this requirement may unduly delay the concrete procurement.

Please refer to Addendum No 2, Part B.6 for revisions to Section XI, specification 33 16

13.16 Paragraph 1.4.C. Q28 Section 33 16 13.16 Prestressed Concrete Aboveground Water Utility Storage Tanks 2.1

SYSTEM PERFORMANCE A. System Description 4. Tank dome roof c. Please revise: “Dome design shall be based on elastic spherical shell analysis and shell thickness shall be governed by buckling or maximum stress considerations in accordance with ANSI/AWWA D110, but not less than 4 inches to provide a minimum concrete cover of 1.5 inches at each face in accordance with ACI 350” to “Dome design shall be based on elastic spherical shell analysis and shell thickness shall be governed by buckling or maximum stress considerations in accordance with ANSI/AWWA D110, but not less than 4 inches by the precast placement method and not less than 3 inches by the cast-in-place method”

The more stringent of the ANSI/AWWA D110 and ACI 350 standards were selected for

the dome minimum thickness and concrete cover, which results is a minimum dome thickness of 4 inches and 1.5 inch concrete cover.

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PART B. Changes to Contract Documents The following changes are to be made to the Contract Documents:

1. Changes to the Contact Documents in all references:

Insurance:

The City of Newburgh, in addition to others previously identified, shall be named as additionally insured in policies and upon certificates of insurance provided by the Contractor for Commercial General Liability Insurance, Workers’ Compensation Insurance, and Commercial Automobile Liability Insurance.

Increased Coverages:

Commercial General Liability Insurance – Each Occurrence limit of not less than $3,000,000. Owners and Contractors Protective Liability Policy – Each Occurrence limit of not less than $3,000,000. General Aggregate limit of not less than $5,000,000.

Bonding:

The City of Newburgh shall be added as an additional obligee on the Performance Bond, and, Labor and Material Payment Bond. The Contractor will provide a dual obligee rider to the bond as evidence of the addition.

2. Section XI, Specification 31 23 16.26: Add Paragraph 1.1.D.4 to read as follows:

“4. Precast Concrete Tanks: Limit for all precast concrete tanks shall be bounded by the following: a. Bottom of footing, drainage course material, or compacted backfill.b. Pre-construction rock face.c. Vertical planes located 18 feet outside of footing.”

3. Section XI, Specification 31 23 16.26: Replace Paragraph 2.1.B.2.h in its entirety to readas follows:

“h. Backfill Pressure: The lateral pressure from earth backfill and surcharge, including those caused by unequal fill, shall be determined by rational methods of soil mechanics and shall be in line with the recommendations of geotechnical report. 1) Backfill pressure shall not be used to reduce the amount of required pre-stressing.2) Minimum vertical surcharge load shall be 300 psf.3) Soil parameters for lateral earth pressure on walls for compacted fill:

i. Angle of internal friction = 32°ii. At rest earth pressure coefficient for horizontal backfill, Ko = 0.47iii. Passive earth pressure coefficient, Kp = 3.26iv. Coefficient of base friction = 0.15v. Total unit weight of soil = 120 pcf

4) Passive resistance should be neglected within the zone of frost penetration (4 ft).”

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4. Section XI, Specification 31 23 16.26: Replace Paragraphs 2.1.B.2.J.1.v and

2.1.B.2.J.1.vi to read as follows: “v. SDS: 0.23 vi. SDI: 0.13” 5. Section XI, Specification 31 23 16.26: Revise Paragraph 2.11.L.2 to read as follows: “2. Bracing members shall be aluminum, stainless steel type 304, or concrete. Bracing

hardware shall be stainless steel type 316.” 6. Section XI, Specification 33 16 13.16: Revise Paragraph 1.4.C.3 to read as follows: “3. All coatings, sealants, and repair materials that can contact potable water or water that will

be treated to become potable shall be NSF/ANSI 61 compliant.” 7. Section XI, Specification 33 16 13.16: Add Paragraph 1.4.A.6 to read as follows: “6. The baffle wall system shown on the Drawings is expected to achieve a baffling factor of

0.5 in accordance with the research performed on circular contact tanks and published in “Improving Clearwell Design for CT Compliance”. Computational Fluid Dynamic (CFD) simulation software is expected to model the baffling factor for this layout to be at least 0.3 as required by New York State Department of Health (NYSDOH). CONTRACTOR shall perform CFD simulations, as required herein, to demonstrate that the baffling factor is greater than 0.3 for review by the ENGINEER as an Action Submittal. Should the CFD simulations show the baffling factor is less than 0.3, CONTRACTOR shall make appropriate design recommendations to achieve the minimum 0.3 baffling factor and confirm with a CFD simulations.

a. CFD Simulation Scenario 1:

1) Tank Steady State Flow Rate = 8.85 MGD 2) Liquid Depth = 299.67 ft.

b. CFD Simulation Scenario 2: 1) Tank Steady State Flow Rate = 4.7 MGD 2) Liquid Depth = 287.17 ft.”

8. Section XI, Specification 33 16 13.16: Paragraph 2.11.H.1, first sentence after the word

“Fiberglass” add the words “or aluminum”. 9. Section XI, Specification 33 16 13.16: Delete the words “aluminum, fiberglass or” from

Paragraph 2.11.F.2. 10. Section XI, Specification 33 16 13.16: Add Paragraph 2.11.J.2 to read as follows: “2. Provide rail system to roof ventilator as shown on the Drawings compatible with the

sliding, locking mechanism and safety belt. Provide two safety sleeves compatible for use with the rails. Sleeves shall be cast bronze with five zinc-plated steel roller bearings. Sleeves shall travel smoothly on straight or curved rail. Provide two safety harnesses that attach to sleeves. Provide two shock-absorbing Y-lanyards no longer than six feet and complying with ANSI Z359.1. Provide Miller Saf-T-Climb system or equal.”

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11. Section XI, Specification 33 16 13.16: Delete Paragraphs 3.12.B.2, 3.12.B.3 and

3.12.B.4. 12. Section XI, Specification 33 16 13.16: Add Paragraph 3.12.B.2 to read as follows: “5. The water used for disinfection shall remain in the tank to be later utilized in the leakage

test and distribution system after the tank has been completely filled and the biological test has been conducted and passed, as approved by the Engineer.”

13. Section XI, Specification 33 16 13.16: Delete Paragraph 3.12.C in its entirety and

replace with the following: “C. Disinfection of prestressed concrete tanks shall comply with Section 01 45 53, Cleaning,

Testing and Disinfecting Hydraulic Structures, and as specified herein. 1. City will only furnish water for initial filling of the prestressed concrete tanks and

absorption make-up period. Additional water required for retesting shall be furnished at Contractor’s expense. The prestressed concrete tank filling operation will be subject to scheduling and approval by Engineer and City.

2. Damp spots which glisten on the surface of the tank and spots where moisture can be picked up on a dry hand will not be allowed. The source of water movement through the wall shall be located and permanently sealed in a manner acceptable to Engineer. No leakage that includes visible flow through the wall-floor joint shall be allowed. Damp spots on the footing will be accepted.

3. If prestressed concrete tank does not meet these criteria, the Engineer may require prestressed concrete tank to be repaired and retested. If such repairs and retesting are required, they shall be performed by Contractor at no additional cost to the Department.

4. Disinfect tank prior to conducting the hydrostatic test. 5. Water from accepted disinfection test may be used for hydrostatic test. Additional

water or chlorine required for retesting shall be furnished at Contractor’s expense. The prestressed concrete tank filling operation will be subject to scheduling and approval by Engineer and City.

14. Section XI, Specification 40 05 53: Replace Paragraph 2.4.B in its entirety to read as

follows: “B. General: 1. Application: Reduce higher, fluctuating upstream pressure to a lower, steady,

downstream pressure within specified range of flow variations. 2. Rated Working Pressure: 250 psi 3. Sizing Data High Service: a. Maximum Flow Rate: 4,167 gpm. b. Minimum Flow Rate: 250 gpm. c. Maximum Upstream Pressure: 190 feet. d. Minimum Upstream Pressure: 150 feet. e. Setpoint Downstream Pressure: 40 feet. f. Setpoint downstream pressure shall be field-adjustable over range of near-

zero to 110 percent. 4. Sizing Data Low Service: a. Maximum Flow Rate: 15,375 gpm.

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b. Minimum Flow Rate: 500 gpm. c. Maximum Upstream Pressure: 132 psig. d. Minimum Upstream Pressure: 120 psig. e. Setpoint Downstream Pressure: 120 psig. f. Setpoint downstream pressure shall be field-adjustable over range of near-

zero to 110 percent. 5. Valves shall not suffer cavitation damage within five-year period from date of

Substantial Completion when exposed to specified operating conditions.” 15. Section XII, Measurement and Payment: Replace Part 3 D to read as follows: “D. Bid Item UP-2 – Select Granular Fill 1. Payment: Bid Item UP-2 shall be bid unit cost price per cubic yard, as quantified by

the in place measure and comparison of before and after surveys as approved by the Department’s Representative. Provide all labor, materials, equipment and incidentals necessary to furnish, place, and compact select granular fill for the tank foundation not otherwise shown or specified. Specifically, this items includes the quantity of select granular fill as equal to the in place volume of bedrock removed. In addition this item will include any additional undercut of unsuitable soils beyond the typical or specified limits of excavation as ordered or directed by the Engineer. Payment will also include the removal and off-site disposal of any unsuitable soils removed under this payment item.

2. Measurement for payment of Bid Item UP-2 – Select Granular Fill shall be the actual number of in place cubic yards approved by the Department’s Representative.”

16. Drawing G-01: Delete General Notes 12, 14 and 16. 17. Drawing G-01: Revise General Note 14 to read as follows: “14. The Contractor shall remove topsoil from the site and haul to the location shown on

Addendum No 2, SK-0X. Contractor shall seed and mulch the stockpile and provide silt fence and hay bales as required to prevent sediment runoff into Washington Lake. The stockpile shall be inspected after each precipitation event and implement additional measures to prevent erosion. The City will provide access to the Contractor and the gate must be locked at times the Contractor is not present. Topsoil will be used by others.”

18. Drawing G-01: Add Detail 1 shown on Addendum No 2, SK-01. 19. Drawings C-01 and C-02: Revise contract limit lines as shown in Addendum No 2,

reissued Drawings C-01 and C-02. 20. Drawing C-03: Revise contract limit lines and add perimeter drain and notes shown on

Addendum No 2, reissued Drawing C-03. 21. Drawing C-04: Add perimeter drain and notes shown on Addendum No.2, reissued

Drawing C-04. 22. Drawing C-06: Replace the Rain Garden Detail, removed Perimeter Drain Detail, add

Sewer Separation Detail, and revise Drain Outlet Manhole Detail as shown on Addendum No 2, reissued Drawing C-06.

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23. Drawing C-08: Replace Section 2, replace Note 17 and replace Plan @ El. 217 as shown

on Addendum No 2, reissued Drawing C-08. 24. Drawing C-09: Add note to 36” Inlet Detail, revise Replace Roof Vent Detail and replace

18” Overflow Detail as shown on Addendum No 2, reissued Drawing C-09. 25. Drawing C-10: Revise Precast Concrete Baffle Wall Detail as shown on Addendum No 2,

reissued Drawing C-10. 26. Drawing C-11: Revise General Erosion and Sediment Control Notes as shown on

Addendum No 2, reissued Drawing C-11. 27. Drawing E-01: Replace Plan and replace Typical Underground Conduit Detail as shown

on Addendum No 2, reissued Drawing E-01 This ADDENDUM No 2, including Attachment A, becomes part of the Contract Documents.

Daniel J. Loewenstein, P.E., BCEE

Dated: August 5, 2016

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ATTACHMENT A

ADDENDUM No. 2

City of Newburgh Contact Tank at Washington Lake Filtration Plant Site No. 336022

CONTRACT NO. D010238

Contract Sketches

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C

E

C

E

C

E

C

E