Sewerline_Questions_Answers.pdf

Eielson AFB Repair Sewerline on Flightline Avenue PH1

Questions

1. Is there on site disposal for waste generated during sewer line cleaning operations?

NO. CONTRACTOR MUST REMOVE WASTE.

2. How many service laterals are located on each segment?

MAP PROVIDED WITH UPDATED LATERALS.

3. Is there any additional information as to the services that tie into the mainline to be lined? i.e.:

cleanouts, manholes, etc.

MAP PROVIDED WITH UPDATED LATERALS.

4. Will the as‐built and CCTV data be made available?

YES.

5. How many cured liner samples will the government need for testing?

CIPP SPECS SECTION 02537 – PART 3.E.2

6. Have the missing manholes been located and if so where. i.e.: grass, pavement

YES. MANHOLE 13 IS IN AN ADJACENT FIELD AND 14 IS NEXT TO THE SIGN. 12 IS STILL UNKNOWN AND

WILL BE DESCOPED FROM THE PROJECT.

7. Is the project scheduled to be completed in 2017? Materials would not be on site until late

August or early September which could push the work into inclement weather conditions. The work can be completed but at a much higher cost in cold or freezing conditions.

WORK SHALL BE COMPLETED IN 2018.

8. Are the damaged concrete rings which the casting sit on to be replaced?

NO.

9. Is there a contractor lay down area available?

YES. ONE WILL BE PROVIDED.

10. This project bids on July 25th and has a 180 day bid acceptance period. Additionally, the contract performance time is specified as 90 days after notice to proceed. Based on the bid date and a reasonable estimate regarding the acceptance period (assuming the full 180 days would not be used) this project would probably be awarded sometime in September. Performing this work in the winter

(any time after Sept 15th) would be unreasonable due to the need to bypass the existing sewer lines above grade and the need to coat the existing manholes. We would suggest either establishing a fixed completion date (July 31, 2018) or extending the completion time to 360 days.

WORK SHALL BE COMPLETED IN 2018.

11. A specific statement of work is listed as a stand‐alone specification item Oust after the contract clause section and just before the Technical Specification table of contents). In the SOW no reference is made to in‐situ grouting. In section 01100 in‐situ grouting is referenced for sewer main joints, service lateral connections and other defects. Typically, if a line is relined (CIPP lined) grouting is not required as the lining is a stand‐ alone new pipe. I think the inclusion of this reference in this spec section is a possible oversite and was listed as an option to CIPP lining. If joint grouting is required this is a specialized and costly activity and an actual quantity of joints requiring grouting will need to be provided to establish a price for this work.

NO LINING IS REQUIRED AS LONG AS SUFFICIENT COVERAGE IS MADE.

12. The stand‐alone Statement of work (item 2.4) calls for "rehabilitation of all affected manholes using a polyuria spray liner method". We could not find any specification information pertaining to this statement (which manholes, spalling repairs prior to coating, bottom 4 feet/full height, millage, etc.). If manhole coating is required I would suggest the inclusion of a specification similar to the attached specification that was included for a project on Elmendorf AFB. Also, if coating is required we would request clarification as to the extent, for example some of the "manholes" are actually vaults or vaults over manholes. The "manhole" at 702 is an enclosed box inside of a larger vault and appears to be just a flow‐thru junction area with very limited access. Please define coating scope for these areas if coating is applicable.

ONLY MANHOLE IS REQUIRED TO BE LINED, NOT THE VAULT OVER THE MANHOLE. I RECOMMEND

USING SPEC USED FOR ELMENDORF AFB.

13. Spec section 01100 also indicates the requirement for CCTV "inspection of the sewer service laterals identified as contributing to the l&I". Service laterals were not identified on the drawings or specs and no specific laterals were identified as contributing to the l&I. Is this a requirement for this contract and if so can the lateral locations and sizes be identified? See also next question.

MAP PROVIDED WITH UPDATED LATERALS.

14. Specification section 02537 page 5 section D deals with lateral seals, lateral seals are normally installed in services to mains that are not relined and for smaller mainline systems. The mains for this system are going to be completely relined and then the services reinstate. Installation of service lateral

"top hats" for this size main would require manual installation from inside the 24" main. This specification also states the services will be lined up the lateral a distance as specified by the owner.

Again, this is the typical wording of a small ms:iinline project where only the service laterals are rehabilitated. For larger lines where service laterals are lined the standard way (and in most cases the only way) is to access the lateral upstream and then line back into the main. Is that the intent for this project?

UP TO CONTRACTOR ON HOW TO COMPLETE WORK, AS LONG AS IT FOLLOWS SPEC.

15. Spec section 02537 page 10 indicates a liner thickness tolerance of minus 5% and plus 10%. We typically design our liners with at least 10% over to avoid having any sections coming out under designed. Additionally liners typically come in 1.5mil increments which if the actual design calls for a 9.2 mil liner the closest fabricated size would be a 10.5 mil liner which would be over the 10% variance.

Based on this it would not be unlikely that some sections could be more than 10% over. Can the over percentage be increase or removed to allow for this type of design.

THAT IS FINE, AS LONG AS OVERALL PIPE OPENING IS NOT IMPEDED.

13. MANHOLE Lining:

13.1. This section shall govern all work, materials and equipment required for manhole rehabilitation for the purpose of eliminating infiltration, providing corrosion protection, repair of voids and restoration of the structural integrity of the manhole as a result of spray‐applying a monolithic fiber‐reinforced ultra‐high build epoxy liner to the wall and bench surfaces of brick, concrete or any other construction material.

13.2. Described are procedures for manhole preparation, cleaning, application and testing. The applicator, approved and trained by the manufacturer, shall furnish all labor, equipment and material for applying a two part ultra‐high build epoxy to form a monolithic liner to a n average thickness of 125 mils on brick manholes and 80 mils on concrete manholes, using a system specially designed for the application. All aspects of the installation shall be in accordance with the manufacturer's recommendations and with the following specifications which include: The elimination of active infiltration prior to making the application.

a. Minor repair and sealing of the benches.

b. The removal of any loose and unsound material.

c. The spray application of a pre‐blended epoxy mix to form a monolithic liner. Inspection and touch‐up.

13.3. Site Preparation:

13.3.1. The surface to be lined shall be cleaned and abraded to ensure a clean and rough surface with sufficient profile to provide a good bond between the epoxy lining and the substrate. This can be done with mechanical cleaning such as sandblasting or water blasting with equipment capable of a minimum of 3,500 psig for brick. Concrete may require up to 10,000 psig.

13.3.2. Appropriate barricades and flags shall be erected around the manholes and work areas to comply with Base, and OSHA regulations.

13.3.3. All extraneous flows into the sewer above the invert shall be plugged until the epoxy, has set a minlfJJJJm of three hours after application. As an option hot air may be added to the manhole which will reduce set time to 1to 2 hours.

13.4. PATCHING

13.4.1. The area between the brick and the manhole ring and any other area that might exhibit movement or cracking due to expansion and contraction, shall be grouted with Raven

MACC TORFP FXSB 11‐2830 Repair/Replace Sewer Pipe Sijan‐Wewak‐20th Attachment 2 ‐ Statement of

Work

02722‐11

821 Flexible Caulk Sealant, or equivalent.

13.4.2. The area between the brick and the manhole ring and any other area that might exhibit movement or cracking due to expansion and contraction, shall be grouted with Raven

821 Flexible Caulk Sealant, or equivalent.

13.4.3. All holes and cracks to be patched shall be filled with 100°/0 solids, high‐build, nonsagging epoxy grout such as Raven 810 High Build Epoxy Coating and Grout, or equivalent. Holes should not be filled in lifts greater than 2" in depth.

13.4.4. In brick manholes where loss of mortar has created gaps greater than 1/4 inch in diameter between the bricks, the voids can be filled using Raven 810, Raven 821, or close d cell foam backing rod.

Whenever structural integrity is questioned, foam backing rod shall not be used.

13.4.5. In structures less than 36 inches in diameter, caulking or sealing of each individual mortar joint may not be practical or possible. In this instance,2 or 3 coats of epoxy may be required to provide a monolithic lining.

13.5. LINING

13.5.1. The interior surface of the brick manhole will be lined with a 100°/o solid, self‐priming, ultra‐ high build epoxy applied to a minimum thickness of 100 mils and an average thickness of 125 mils.

Sound concrete and steel surfaces will be lined with a minimum 60 mils and an average thickness of 80 mils. Material shall be Raven 405 by Raven Lining system or equal.

13.5.2. Epoxy shall be applied per manufacturer's recommendations.

13.5.3. If the sloped surface of the floor is to be lined, it shall be made non‐skid by broadcasting aluminum oxide, sand or gravel into the surface prior to gelation. Depending on flow levels and how long flow can be stopped, inverts may be lined with Raven 405, Raven 825 or equivalent, or quick setting cementitious materials.

13.5.4. Lined manholes shall be allowed to cure as recommended by the manufacturer. For some manholes, if flow diversion cannot be made to last the length of the curing period, then the contractor shall reduce the curing time by applying heat to the lined surface.

13.6. INSPECTION:

13.6.1. Visual Inspection: After the liner has set (hard to touch), it will be visually inspected and any pinholes repaired. Repairs shall be made by lightly abrading the surface by hand and brushing over the area with a mixture of the same material used for the liner per manufacturer's instructions.

13.6.2. Final Inspection: The inspector shall visually check the applied coating for evidence of blisters and confirm even coloring, proper mix ratio, coverage and cure. Deficiencies in the finished coating shall be marked and repaired in strict accordance with the manufacturer's recommendations.

13.7. APPLICATOR: The applicator will have a minimum of 1year experience with the application of 100% solids high‐build epoxy coatings or be trained and approved for application by the manufacturer.