Questions_Answers Updated 5.4.21_0002.pdf

Question 1: Would the owner or owner’s representative be open to allowing alternate trenchless rehabilitation methods for the two manholes scheduled to be replaced?

Alternate Method 1 would include the installation of modular flow channels at the base.

Alternate Method 2 would include application of a high strength corrosion resistant lining to all exposed manhole surfaces including barrel sections, cones, and chimneys.

Government Answer: If we use the alternatives, we are changing the scope of work. At this time, the government wants the manholes replaced.

Question 2: To replace the 2 manholes bypass pumping will be required to isolate the structure. Can the Park Service provide a map showing where the nearest manholes up and down gradient of the ones to be replaced?

Government Answer: Please see attached map below.

Question 3: Seeding: I didn’t find a specification for seeding the disturbed areas.

Do we need to reseed the disturbed areas? Will the park supply the seed mix?

Will the park supply fertilizer? Can we use erosion blankets in place of mulch?

Is there a watering or maintenance period?

Government Answer: Specifications did not include seeding of disturbed areas therefore seeding of disturbed areas are not required.

Question 4: Can you clarify the scope for each manhole/location:

CPHH Manhole 19- can we reuse the existing frame & cover? Does the park require any type of seal on the adjusting rings such as an internal chimney seal, or external wrap to seal water from infiltration?

Government Answer: All risers, lids, extension rings associated with manholes will need to be installed new. See pages 18 & 19 manhole specifications/technical specifications. Manhole sections and joints will be sealed inside and out with one of the approved methods. Manhole joints would be all joints within the manholes including risers/rings.

CPHH Manhole 20- can we reuse the existing frame & cover? Does the park require any type of seal on the adjusting rings such as an internal chimney seal, or external wrap to seal water from infiltration?

Government Answer: All risers, lids, extension rings associated with manholes will need to be installed new. See pages 18 & 19 manhole specifications/technical specifications. Manhole sections and joints will be sealed inside and out with one of the approved methods. Manhole joints would be all joints within the manholes including risers/rings.

DIV-V-2- can we reuse the existing frame & cover? Does the park require any type of seal on the adjusting rings such as an internal chimney seal, or external wrap to seal water from infiltration?

Government Answer: The Riser lid ring on these are broken and would need new precast riser lid rings.

See page 19 under technical specifications. Manhole sections and joints will be sealed inside and out with one of the approved methods. Manhole joints would be all joints within the manholes including risers/rings.

DIV-V-3- can we reuse the existing frame & cover? Does the park require any type of seal on the adjusting rings such as an internal chimney seal, or external wrap to seal water from infiltration?

Government Answer: The Riser lid ring on these are broken and would need new precast riser lid rings.

See page 19 under technical specifications. Manhole sections and joints will be sealed inside and out with one of the approved methods. Manhole joints would be all joints within the manholes including risers/rings.

CPL-MH-2- can we reuse the existing frame & cover? Does the park require any type of seal on the adjusting rings such as an internal chimney seal, or external wrap to seal water from infiltration? With adding 24” of concrete risers, do we need to import any fill to raise the elevation around the MH frame?

Government Answer: If existing frame and cover are not damaged in removal, they can be reused as the government specs do not say to replace the ring. If damaged does occur, then they would need replaced with new. See page 19 under technical specifications. Manhole sections and joints will be sealed inside and out with one of the approved methods. Manhole joints would be all joints within the manholes including risers/rings. Fill would need hauled in to meet the spec on page 20 for non-traffic areas.