MPA Project No. M545-C1 Project Title: New Berth 10 & Berth 11 Deepening Project Phase I Location: Conley Terminal, South Boston, Massachusetts

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1 MPA Project No. M545-C1 Project Title: New Berth 10 & Berth 11 Deepening Project Phase I Location: Conley Terminal, South Boston, Massachusetts RESPONSES TO QUESTIONS and/or RFI s Date: 04/27/18 The attention of Contractors submitting General Bids for the above referenced project is called to the following Responses to Questions and/or RFI s. Responses to Questions and/or RFI s: (Cashman Dredging & Marine Contracting Company, LLC) electronic mail to CPBidQuestions from (Drew Clark) dated 04/23/2018; Item #1 Specification Section Dredging by Mechanical Method, paragraph 3.05.E.1 states The Contractor shall assume that blasting will not be permitted for rock removal until such time as the Contractor demonstrates that dredging to project limits cannot be completed using conventional dredging equipment. The requirement that the Contractor demonstrates that dredging to project limits cannot be completed using conventional dredging equipment is broad and subject to varied interpretation. There are no qualitative or quantitative measurements presented in the plans or specifications that would lead a reasonable Contractor to gauge the risk involved with convincing the Authority that a reasonable effort has been undertaken to remove material and that blasting is required. Question: We respectfully request that the Authority provide specific guidance on what will be required from the Contractor to demonstrate that dredging to the project limits cannot be completed using conventional dredging equipment. Design Team Response: The materials to be dredged include overburden soils ranging from soft organic soils to very dense stratified drift and glacial till and medium hard to hard argillite bedrock. Specification Section E.2. requires use of appropriate equipment such as a large cutter head or a hydraulic excavator to loosen material prior to removal. With the exception of areas within 45 feet of Berth 11 structures, there is no intent to mechanically fracture rock for removal. It is anticipated that the conventional dredging equipment mobilized will include a large excavator type dredge with significant digging capacity (at least 15 tons) at the required dredge depth and equipped with a rock ripping bucket. The Contractor will need to make a reasonable effort to remove the dredge material using non-blasting methods. A reasonable effort 1

2 consists of multiple digging attempts for each approximately 400-square-foot area for at least one ½ hour (not including moving the barge) with the dredge positioned at different angles from the materials to be dredged. Documentation of the Contractor s efforts shall include the northing and easting of approximately the center of the 400-square-foot area, elevation of the top of the material attempted to be dredged before and after the attempt, and a brief description of the Contractor s means and methods. Item #2 Specification Section Dredging by Mechanical Method, paragraph 3.05.E.1 states The Contractor shall assume that blasting will not be permitted for rock removal until such time as the Contractor demonstrates that dredging to project limits cannot be completed using conventional dredging equipment. A review of the available contract documents combined with a practical view of what can be removed by dredging via hydraulic excavator confirms that blasting will be required to achieve grade on this project. Based on the data presented it is reasonable to conclude that blasting will be required to achieve grade on the project, and the requirement to demonstrate that dredging to project limits cannot be completed using conventional dredging equipment may function to increase the cost of the project by requiring Bidders to include significant cost to their bids to account for an extended effort to prove this to the Authority. Question: We respectfully request that the Authority modify Dredging by Mechanical Method, paragraph 3.05 to allow for a more practical transition from dredging to blasting. We request that the Authority introduce less restrictive and more clear approach to transitioning between defining the limits to dredging with respect to rock and the beginning of drilling and blasting to remove rock. Design Team Response: See response to Question #1. Item #3 Specification Section Dredging by Mechanical Method, paragraph 3.05.E.2 states Methods of rock and hard material removal are anticipated to include, but not be limited to, excavation, ripping, cutting and scraping. It appears that this language is broadening the language presented in Dredging by Mechanical Method, paragraph 3.05.E.1 to include not only conventional dredging equipment, by introducing the broad descriptions of ripping, cutting and scraping. Paragraph 3.05.E.1 previously required that the Contractor demonstrates that dredging to project limits cannot be completed using conventional dredging equipment. The addition of Methods of rock and hard material removal are anticipated to include, but not be limited to, excavation, ripping, cutting and scraping in 3.05.E.2 without mention of drilling and blasting essentially broadens the Contractors burden in demonstrating that dredging to project limits cannot be completed using conventional dredging equipment. The standard of proof required in 3.05.E.1 and 3.05.E.2 creates a difficult dilemma from which there appears no solution because of mutually conflicting conditions: Drilling and blasting will be required to achieve grade in the footprint of this project Before blasting is allowed, an indeterminate level of effort will have to be expended to prove that drilling and blasting is required. 2

3 Question: Please modify the contract to present a clear path with definable and measurable features which describe the transition from dredging rock to drilling and blasting rock as a means to achieve grade. Design Team Response: See response to Question #1. Item #4 Specification Section Dredging by Mechanical Method, paragraph 3.05.E.3 states In the event that refusal is reached prior to reaching project limits, the Contractor shall notify the Authority but shall continue to dredge to the maximum extent of equipment capability until the entire project footprint has been completed. Our review of the available contract documents, Geotechnical data, and contract drawings combined with significant industry experience with the types of material which can be removed by dredging via hydraulic excavator confirms that blasting will be required to achieve grade on this project. Based on the data presented it is reasonable to conclude that blasting will be required to achieve grade on the project, and the requirement that the Contractor to continue to dredge to the maximum extent of equipment capability until the entire project footprint has been completed may function to increase the cost of the project by requiring Bidders to include significant cost to their bids to account for an extended effort to prove this to the Authority. Question: We respectfully request that the Authority modify Dredging by Mechanical Method, paragraph 3.05 to allow for a more practical transition from dredging to blasting. We request that the Authority particularly clarify 3.05.E.3 which could be read that regardless of the type of material encountered the Contractor will be required to dredge all rock encountered in the required prism as opposed to drill and blast the rock. Design Team Response: See response to Question #1. Item #5 Specification Section Dredging by Mechanical Method, paragraph 3.05.E.4 states A verification survey shall be performed on completion of conventional dredging (rock removal) operations and submitted to the Authority with documentation of methods and time spent in an effort to remove rock. Based on available data it is reasonable to conclude that blasting will be required to achieve grade on the project. Paragraph 3.05.E.1 previously required that the Contractor demonstrates that dredging to project limits cannot be completed using conventional dredging equipment. Paragraph 3.05.E.2 adds Methods of rock and hard material removal are anticipated to include, but not be limited to, excavation, ripping, cutting and scraping, and paragraph 3.05.E.3 generates further questions regarding the ability of the successful bidder to drill and blast on the project. Paragraph 3.05.E.4 adds to the general sense that the specifications may be effectively prohibiting any drilling and blasting on the project by requiring that the Contractor provide documentation of methods and time spent in an effort to remove rock without also providing any metrics or standards the will be used by the Authority to decide if the Contractors efforts are sufficient for the Authority to grant permission to perform drilling and blasting. 3

4 Question: We respectfully request that the Authority modify Dredging by Mechanical Method, paragraph 3.05 to clarify and simplify the precise steps, level off effort, and submittals as well as the standards for which those steps, level of effort, and submittals will be measured against before the contractor is allowed to perform drilling and blasting. Design Team Response: See response to Question #1. Item #6 Specification Section Dredging by Mechanical Method, paragraph 3.05.E.6 states Blasting will be subject to approval by the Authority following satisfactory documentation of efforts made to remove rock by non-blasting techniques. Previous paragraphs 3.05.E.1, 2, 3, and 4 generate significant questions regarding whether or not the Contractor will be able to gain approval by the Authority to drill and blast. Paragraph 3.05.E.6 adds to the concern that approval for drilling and blasting may not be granted on the project by restating that blasting will be subject to approval by the Authority following satisfactory documentation of efforts made to remove rock by non-blasting techniques without describing what specifically constitutes a satisfactory effort. The extreme case is that if after significant Contractor effort to remove rock is completed, if even one small piece of rock is removed on a subsequent attempt to prove that satisfactory efforts have been made to remove rock, the contractor is forced to continue to struggle to remove rock when the more practical method of drilling and blasting could be employed with immediate positive effect. Question: We respectfully request that the Authority modify all of Dredging by Mechanical Method, paragraph 3.05 to either prohibit drilling and blasting or to provide a reasonable and measurable path to transition between dredging and drilling / blasting as a means of achieving grade on the contract. Design Team Response: See response to Question #1. Item #7 Specification Section Blasting, paragraph 1.07.G.1 states Blasting will be Submit design and layout of each individual blast round at least 24 hours before drilling the blast holes. Loading of explosives will not be permitted until the blast round design has been reviewed and accepted. The submittal shall include the information listed in Paragraph 1.07.C.10. The plan layout shall show the locations of nearby structures, buildings and utilities. We understand this requirement to mean that for each shot (which normally occur twice per day) a plan layout must be submitted, reviewed, and accepted by the Authority or the Authorities designated representatives. We are concerned that if this is the case, the progress of a drilling and blasting effort will be hindered and will require additional time to complete. Marine drilling and blasting is accomplished differently from land-based drilling and blasting. Land based drilling and blasting enjoys the freedom to drill holes during one operation using one set of equipment and then during a separate and distinct operation load the holes using a separate set of equipment. Marine drilling and blasting is different in that during marine drilling and blasting the drilling and loading of holes occurs as one continuous operation. Once a hole is drilled, its depth is confirmed and the hole is immediately loaded before the drill moves to 4

5 the next hole in the pattern and repeats the process. Because in marine drilling and blasting the holes cannot be drilled during one operation and loaded in another later operation, the requirement that explosives will not be permitted until the blast round design has been reviewed and accepted will produce significant delay and add significant cost to the drilling and blasting effort that will be required for this project since no drilling or loading will be allowed until each blast round design has been reviewed and accepted. The time for the Authority or their representatives to review and accept the blast round design is not stated. Question: We respectfully request that the Authority reconsider the submission of a plan layout which must be reviewed and accepted before each shot. The layout and means and methods for drilling and blasting required by Blasting 1.07.C.1 through Blasting 1.07.C.13 should be sufficient to provide the Authority or the Authorities designated representatives the level of detail to approve the drilling and blasting program. Design Team Response: The Contractor may submit individual blast round design more than 24 hours before drilling blast holes to avoid any impact on productivity. Alternately, the Contractor may submit a full blasting plan before blasting begins, that outlines individual blast round designs, and provide periodic updates with 24 hour notice, as necessary, during construction. Either option would satisfy the requirements of Section 02900, paragraph 1.07.G.1. Item #8 Specification Section Blasting, paragraph 2.01 does not currently require dual-path initiation. Dual path initiation is typical for drilling and blasting efforts of this type. Dual Path initiation ensures a fully redundant initiation path for the initiation system and would provide a greater level of safety for the Massachusetts Port Authority, the drilling and blasting Contractor, the USCG, the Boston Fire Department, and the USACE. Question: We respectfully request that the Authority consider requiring dual path initiation for all drilling and blasting performed on this project. Design Team Response: The Contractor may use dual-path initiation at his or her discretion. Item #9 Specification Section Blasting, paragraph may require the use of a bubble curtain to enclose the blast area. We believe that a requirement to install a bubble curtain around an active drilling and blasting operation will pose hazard to navigation and create safety issues associated with the installed infrastructure to operate the bubble curtain. In addition to potential safety issues, the cost would not be what would normally be considered as incidental to the work. Question: We respectfully request that in order to maintain a level bidding opportunity for all bidders, that the Authority revise paragraph to either require or not require a bubble curtain during drilling and blasting operation. Design Team Response: The use of a bubble curtain will be as directed by the Authority if required to mitigate blasting impacts. It is understood that the cost of bubble curtains is not incidental to 5

6 the work and, if bubble curtains are required by the Authority, payment will be made under Pay Item Bubble Curtains for Blasting Mitigation. Item #10 Specification Section Blasting, paragraph may require the use silt curtains to enclose the blast area. We strongly believe that a requirement to install silt curtains around an active drilling and blasting operation will pose a significant hazard to navigation, create safety issues associated with ingress and egress from the drilling and blasting platform, and create an unsafe condition relating to the potential of downlines becoming entangled in the silt curtain or the silt curtain anchoring system. Question: We respectfully request that the Authority revise paragraph to remove the potential requirement to use silt curtains around the drilling and blasting operation. Design Team Response: The Authority will not require use of a silt curtain where it creates a hazard to navigation or an unsafe condition. In the event that a silt curtain could be safely deployed, payment would be made under Pay Item Additional Turbidity Curtains. Item #11 Specification Section Blasting, paragraph 3.04.D states Do not drill blast holes ahead of the test blast area until the test blast results are evaluated. After test blasting has been performed for the USACE NY and the USACE New England (Portland, Maine), drilling and blasting has continued in a confirmation blasting state until the results of the test blast program have been approved by the USACE. Confirmation blasting re-uses shots used during the test blast which produced vibration and environmental results which were inside of the predicted parameters. Question: We respectfully request that the Authority modify paragraph 3.04.D to allow confirmation blasting to continue as the results of the test blast are evaluated. Design Team Response: The regulatory approvals require submission and pre-approval of a blasting monitoring plan prior to any blasting activities. The approved blasting monitoring plan may require submission of test results to regulatory agencies and it has yet to be determined how much time the agencies will require for review. It also has yet to be determined whether the regulatory agencies will allow blasting to continue, regardless of what was allowed on previous projects. Therefore, the Authority cannot make such an allowance at this time. Item #12 6

7 Specification Section Blasting, paragraph 3.04.D states Do not drill blast holes ahead of the test blast area until the test blast results are evaluated. Section paragraph 3.04.D is not specific regarding the amount of time which will elapse between the submission of the test blast results and the completion of the Authorities evaluation of the test blast results. Question: We respectfully request that the Authority modify paragraph 3.04.D to define the time it will take to evaluate the test blast results. Design Team Response: The regulatory approvals require submission and pre-approval of a blasting monitoring plan prior to any blasting activities. The approved blasting monitoring plan may require submission of test results to regulatory agencies and it has yet to be determined how much time the agencies will require for review. Item #13 Specification Section Blasting, paragraph 3.06.E.3 states Each blast round shall be limited to a maximum of 50 blast holes containing explosives. Limitations regarding blast size are typically referenced to pounds per delay as opposed to the number of holds in a particular shot. Using the commercially available delay systems available in 2018, each hole is set to detonate 25 milliseconds after the previous hole. This effectively divides the shot into a series of smaller detonations spaced 25 milliseconds apart. The pounds per delay, or put a different way the pounds per hole, controls first order vibration generation caused by the detonation of a shot. The vibration limitations for the project (peak particle velocity, airblast overpressure, and water overpressure) are defined in Blasting 3.05.F. The Contractor will be responsible for maintaining these blasting limit criteria. The limit of 50 holes per shot is significantly less than our normal production shot which are typically comprised of between holes. The limitation on the number of holes per shot will limit the Contractors operational flexibility, increase the cost of drilling and blasting, while not producing the effect of limiting the environmental response to drilling and blasting which is driven primarily by pounds per delay (before +/ pounds per hole and holes per delay were the primary factors in vibration generation, however now that all holes are separated by 25 milliseconds only the pounds per hole is a contributing factor). Question: We respectfully request that the Authority modify paragraph 3.06.E.3 to remove shot size restrictions from the contract while allowing 3.05.F, which defines environmental response limitations from blasting, to function as the control on vibration and overpressure. Design Team Response: The limit on the number of holes per shot is specified for safety reasons and to limit potential impacts to fisheries and will not be changed; however, the selected Contractor may propose an alternate number of holes per shot which may or may not be accepted at the discretion of the Authority. In order for such alternate maximum number of holes per shot to be accepted by the Authority, the selected Contractor shall be required to demonstrate to the satisfaction of the Authority that the larger number of holes per shot can be completed safely and will not result in fish kills that may be of concern to the regulatory agencies, and without interference with marine traffic. 7

8 Item #14 Specification Section Blasting, paragraph 3.06.I states Provide a muffler to reduce the noise from the drilling. All engines on our drillboat have proper mufflers installed and the drills are hydraulically operated. The hydraulic drills are quieter than older style pneumatic drills. We are confused by the requirement of 3.06.I to provide a muffler to reduce noise from the drilling. Question: We respectfully request that the Authority clarify what is meant by provide a muffler to reduce the noise from the drilling. Design Team Response: The intent of Specification Section Blasting, paragraph 3.06.I is to limit off-site noise impacts especially during overnight drilling operations. All internal combustion engines shall be equipped with mufflers. Item #15 Specification Section Blasting, paragraph 3.07.A states Special control shall be used to provide a smooth and stable final rock cut at the perimeter of the excavation parallel to and in front of the existing Berth 11 and the proposed Berth 10. Question: We respectfully request that the Authority revise paragraph 3.07.A to either detail an exact requirement or allow the dredging Contractor to determine means and methods to transition the perimeters of Berths 11 and 10 while maintaining stable slopes. Design Team Response: The Contractor is referred to Specifications Section Blasting, paragraph B and Drawings D-101 through D-107. Item #16 Specification Section Blasting, paragraph 3.07.B states Line drilling shall be used for the perimeter excavation plane. Limit hole spacing to no greater than 2 to 3 times the hole diameter, with hole diameters limited to 5 inches. and Drawing D-104 detail D shows line drilling at 12 on center. There are a limited number of operating drillboats in the US and both of them utilize 4 ½ casings. A spacing of 3x the hole diameter would result in a hole to hole clearance of 9. This spacing may result in a high percentage of holes which slip into previously drilled holes. We have successfully performed line boring to isolate structures from vibration with spacing on 22.5 on center (vs. the 13.5 spacing which 3x the diameter yields). Question: We respectfully request that the Authority revise paragraph 3.07.B to allow hole spacing of up to 20 on center. Design Team Response: The line drilling is specified to maintain a stable vertical face at the 8

9 perimeter of the rock excavation along the Berths and will not be changed; however, the selected Contractor may propose an alternate hole spacing which may or may not be accepted at the discretion of the Authority. In order for such alternate hole spacing to be accepted, the selected Contractor shall be required to demonstrate to the satisfaction of the Authority that the larger spacing is adequate to provide a smooth and stable vertical rock cut at the perimeter of the excavation. If the Contractor cannot control the over breakage and fails to provide a smooth stable final rock cut with the larger hole spacing, the Contractor shall reduce the hole spacing to the specified limit. Contractor will be required to remedy any over-breakage that threatens and or undermines the Berth 11 pile foundations and sheet piles. Item #17 Specification Section Dredging by Mechanical Method, paragraph 3.01.A.3 states The Contractor shall place and maintain markers at the limits of the dredge area. Markers shall not be located to cause an obstruction or other hazard for vessels using the Cruise Terminal, Container Terminal or Reserved Channel. Specification Section Dredging by Mechanical Method, paragraph 3.01.B.3 states The Contractor shall perform all survey for layout, placement and maintenance of markers, as well as the verification survey. Survey control baseline(s), markers and tide boards shall be established and maintained at all times during the project for the dredging area. Any marker or buoy employed on the project would be fixed to the bottom with an anchor and a mooring line which has a sufficient length to allow the marker or buoy to remain above water throughout the tidal cycle. The length of line required to fix the marker or buoy to the bottom causes the buoy the freedom of motion to move within a watch circle at the surface. The limits of the dredge area include the dredge material within a 100 buffer from the Eversource Cable. The dredge material within a 100 buffer from the Eversource Cable is adjacent to the Reserved Channel. Any dredge anticipated to be used on this project should have electronic positioning capable of displaying the buffer zone for the Eversource Cable as well as real time monitoring and display of the 3-D bucket position and the location of the barge and spuds. Question: We respectfully request that the Authority reconsider the requirement to install a buoy to mark the limits of the dredge area as they will create a hazard to navigation for vessels transiting in and around the project site. Design Team Response: It is not anticipated that buoys would be installed because of the hazard to navigation. Suitable visual indicators (range markers) should be utilized to define the limits of the dredge area. Item #18 Specification Section Dredging by Mechanical Method, paragraph 3.03.C states The Contractor shall have the berth open for use a minimum of 4 hours prior to all vessel arrivals and may resume dredging immediately following a vessel departure. Specification Section Dredging by Mechanical Method, paragraph 3.03.D states The Authority will perform surveys 9

10 before vessel arrivals and following vessel departures as noted above and the Contractor shall coordinate movement of his plant and equipment with the Authority s Surveyor. There seems to be a conflict with dredging operations after a vessel departs. Question: Is it the intent of the Authority to allow the Contractor to immediately resume dredging operations once a vessel departs or is it the intent of the Authority to have the Contractor begin dredging operations only after the Authority has performed surveys? Design Team Response: Unless otherwise agreed by the Authority, it is the intent to have the Contractor begin dredging operations only after the Authority has performed a survey. This condition will only apply to the dredge footprint within Berth 11. (McDonald Electrical Corp) electronic mail to CPBidQuestions from (Chafic Eldamaa) dated 04/23/2018; Item #19 On drawing E102, the pedestal detail showing communication access. Please clarify if this unit need communication cable, if so please provide detail or online for this feed Design Team Response: No communications equipment is required. (Caldwell Marine) electronic mail to CPBidQuestions from (Edward Kehoe) dated 04/19/2018; Item #20 Caldwell Marine would like to officially request a 3 week extension of the bid date. Design Team Response: See Addendum #4. (Cashman Dredging & Marine Contracting Company, LLC) electronic mail to CPBidQuestions from (Drew Clark) dated 04/17/2018; Item #21 We respectfully request a 2 week extension to the bid date. Design Team Response: See Addendum #4. (Great Lakes Dredge & Cock Company, LLC) electronic mail to CPBidQuestions from (Eric McDade) dated 04/23/2018; 10

11 Item #22 Due to the nature and complexity of this project, we respectfully request a two week extension to the May 2 nd bid date in order to more thoroughly review all of the provided bid documents and addendums. Design Team Response: See Addendum #4. (Construction Industries of Massachusetts, Inc.) letter to Mr. Houssam Sleiman, Director of Capital Programs from (John Pourbaix) letter dated 04/23/2018; Item #23 At the request of the majority of members of Construction Industries of Massachusetts intending to bid on the above referenced project we are seeking a 2 week postponement of the current bid date of May 2 nd. Design Team Response: See Addendum #4. - End of Responses - 11