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Home My Public Portal AboutWatertown 19-01S Addendum 1 Addendum No. 1 June 26, 2019 Pagel Town of Watertown, MA CIP Project 1 Rehabilitations Addendum No. 1 To be considered as part of the contract drawings and specifications for the Watertown, MA CIP Project 1 Rehabilitations (Contract 19-01 S). Bidders are advised that this Addendum must be acknowledged in the appropriate space provided on the Form for General Bid. SPECIFICATIONS SECTION 01270.1.02.2 ADD "removal and disposal of existing sewer concrete encasement" to the first sentence after "including removal and disposal of existing sewers where necessary," QUESTIONS Q1. Sheet C-4 of the plan shows segments of open cut sewer main replacement with insulated 8" and 6" DI pipe but there is no detail, spec or payment item(s) for the insulation. Al. Regarding payment, Specification section 01270.1.02.2 states "The unit prices under the appropriate subdivisions of this item shall constitute full compensation for constructing the sewers, complete in place, as indicated on the drawings and as specified, including ... insulation of pipe where shown on the drawings Regarding the specification of work,ADD Attachment 1 -Specification Section 02513 Insulation for Buried Pipelines to Division 2 of the specifications. Q2. Sheet C-10 of the plan shows the proposed pipe bursting of the segment of 15" clay sewer on North Beacon St. The plans show a bursting pit downstream of SMH 14- 1667 and calls for the replacement of that manhole. Will the connection to the 15" clay sewer downstream of the manhole be made with 15" SDR 35 pipe and a Fernco coupling? Will that pipe be measured for payment separately or is it to be considered incidental to the manhole installation? A2. ADD the following note to C-10 regarding pipe bursting: "7. Contractor shall replace a minimum of 3-feet of the incoming and outgoing pipes, with the exception of the new HDPE pipe, with SDR 35 PVC, connected to each manhole being replaced. Diameters shall match existing pipes. Connections from the new SDR 35 PVC to the existing pipes shall be made with leak-proof flexible couplings and considered incidental to the manhole installation." Q3. Manhole 14-1645 is not shown to be replaced. Paragraph 3.03 B of spec section 02225 states "where manholes are used as access pits, the Contractor shall replace such manholes." If the pipe bursting can be performed using a reversible pneumatic tool into that manhole will the existing MH 14-1645 be able to remain in place and be modified from within? A3. It is assumed manhole 14-1645 will be left in place and modified from within if manhole 14-1667 is used for bursting access. Addendum No. 1 June 26, 2019 Page 2 Q4. Will an INSERTA TEE be acceptable for reconnecting the one active service shown to be at STA 0+44? Paragraph 2.01 H 3 of spec section 02624 lists INSERTA TEE as an acceptable product but the bid item 2C and spec section 02225 spell for fusion saddle. A4. An electro-fusion or classic fusion saddle shall be used to connect PVC building connections to HDPE pipe. DELETE the second sentence from section 02442.2.04.2 "The adapters shall be Inserta Tee or approved equal." DELETE specification section 02624.2.01.H.3. 05. Regarding the contract time, a significant portion of the 200 contract days will occur after November 15. Will winter shutdown be excluded from the contract time? If not, can the contract time be extended to allow for additional work to be completed in the Spring? A5. In the event of a winter shutdown, the contract duration will be put on hold and resumed upon completion of the winter shutdown. 06. Can the bypass spec. of 1.25 times the pipe capacity be relaxed as this is small diameter pipe lining with relatively low flow? A6. Specification Section 3.01.13 states "The Contractor shall protect against surcharging of the existing system upstream of the work area by installing adequate temporary by-pass pumping to handle dry weather and wet weather flows." 07. Is it the Owners intent to line the siphons after they are cleaned and inspected? A7. The intent of cleaning and performing television inspection of the Spring Street Siphon is to assess the condition of the siphon. ATTACHMENTS Attachment 1 —Specification Section 02513 END OF ADDENDUM NO. 1 \\wse03.local\WSE\Projects\MA\Watertown MA\2180169-CIP 1-Subareas 1 and 9\DESIGN\AS-BID\Addendum 1 ATTACHMENT A SPECIFICATION SECTION 02513 .................................................................................................................................................................... westonandsampson.com Weston®Sampson SECTION 02513 INSULATION FOR PIPELINES PART 1 - GENERAL 1.01 WORK INCLUDED: This Section covers the furnishing of all material, accessories, labor, and equipment necessary to insulate the pipelines where shown on the drawings and where so required by the Engineer. 1.02 RELATED WORK: A. Section 02080, DUCTILE IRON PIPE AND FITTINGS B. Section 02300, EARTHWORK 1.03 REFERENCES: A. The following standards form a part of this specification as referenced: American Society for Testing and Materials (ASTM) ASTM C552 Specification for Cellular Glass Block and Pipe Thermal Insulation 1.04 SUBMITTALS: IN ACCORDANCE WITH REQUIREMENTS OF SECTION 01330 SUBMITTALS, SUBMIT THE FOLLOWING: A. Manufacturer's literature of the materials of this section and installation instructions for the products being provided for the project. B. A sample of the insulation. PART 2 - PRODUCTS 2.01 INSULATION: DIRECT BURIED PIPE A. Insulation shall be cellular glass type. The insulation shall be a cellular glass product that is made specifically for thermal insulation of piping and is compatible with the piping material. Insulation shall be a minimum of two (2) inches thick, unless otherwise shown on the drawings. 01/24/2019 02513-1 B. Insulation shall be composed of all glass sealed cells having no binders or fillers. The completed product shall be rigid and impermeable, with an ultimate compressive strength of at least 90 psi. The thermal conductivity of the cellular glass shall be no higher than 0.29 BTU-in./hr• ft2• °F @ 75°F and 0.28 BTU-in./hr• ft2• °F @ 50°F. C. The cellular glass insulation shall comply with all requirements of ASTM C552. The cellular glass shall be fabricated in half sections whenever possible. D. Bands for securing the insulation to the pipe shall be 0.5 inches wide by 0.020 inches thick made of stainless steel. E. The jacketing for the insulation shall be one of the following methods: 1. A 125 mil (3mm) thick, heat sealed high polymer asphaltic membrane with an integral glass scrim and integral I mil (.02mm) aluminum foil and a thin Mylar film on the surface, equal to Pittwrap Jacketing as manufactured by Pittsburgh Corning or equal. 2. Mastic - asphalt cutback mastic, equal to Pittcote 300 Finish, as manufactured by Pittsburgh Corning or equal. 3. Reinforcing fabric - an open mesh polyester fabric with a 6 x 5.5 mesh/inch configuration, equal to PC Fabric 79, as manufactured by Pittsburgh Corning or equal. F. The insulation shall be "Foamglass" with jacketing as manufactured by Pittsburgh Corning Corporation, Pittsburgh, PA, or an approved equal. A minimum of 6" layer of fine sand shall surround the insulated pipe before rock free backfill is used in the trench. G. The Foamglass and jacketing shall be installed per the manufacturer instructions included in the approved shop drawings. H. Tees, valves, and bends shall be covered with form fitting factory made sections. PART 3 - EXECUTION 3.01 INSTALLATION: A. Cellular glass shall not be applied to the piping until the piping has been wiped clean and supported so that there is adequate space to apply the full thickness of insulation and the covering completely around the pipe. The Contractor must obtain the Engineer's approval before the installation begins. B. Cellular glass insulation and jacketing shall be applied in accordance with the manufacturer's installation procedures included in the approved shop drawings. C. There shall be at least three 0.50-inch wide stainless steel bands secured around each joint and these bands shall be placed not over 9 inches on center on straight sections of pipe. 01/24/2019 02513-2 D. Tees, valves, and bends shall be covered with form fitting factory made sections. E. All testing of the piping system, such as hydrostatic, x-ray or other such testing, shall be accomplished prior to application of insulation. END OF SECTION \\wse03.local\WSE\Projects\MA\Watertown MA\2180169-UP 1-Subareas 1 and 9\DESIGN\AS-BID\Addendum 1 01/24/2019 02513-3