B09_Atch_1_Questions_Answers_0001.pdf

140P6325Q0008 Theodore Roosevelt NP-Culvert Cleaning Questions and Answers

Question 1:

In Line item #2 for work consists- Creating access approaches to culvert inverts- are we making approaches to get the dump trucks off payment for loading or is there another reason for access approaches- are the approaches to be removed ?

NPS Response: The approaches are being placed to allow for the continued access to the work site remaining clear of visitor traffic and reduce the need for flagging / signing. The approaches may be left behind at end of work in an mutually acceptable condition. The government assumes that the road redevelopment project to be completed by 2029-30 as anticipated will alter, repair or replace these culverts being excavated and cleared to assess conditions at this time.

Question 2:

Culvert #2 has a lot of sediment on the downstream side- 70 feet may not be enough for cutting drainage is 120’ or more acceptable if needed?

NPS Response: The government will consider allowing adjustment of the range of cut slopes for instance sliding the zone from the upstream end toward the downstream end to ensure adequate inspection and basic operations.

Question 3:

How wide of area is allowed to be cut for drainage down or upstream- is a 6-10 foot bottom acceptable and what slopes are wanted on the drainage area?

NPS Response: Contour restoration is a consideration of the site. Adjust to a point of balance looking at head and toe wall construction, do not excavate beyond original construction limits of those features.

Question 4:

Do the drainages need to be topsoiled, seeded or just install wattle?

NPS Response: Install wattle(s) considerations for potential erosion control wattles upstream of culverts to impound sediments may be proposed. Natural forb regeneration is intended to reduce impacts of invasive specimens. All 100% biodegradable non synthetic curlex may be a prudent consideration for contractors to assure stability of finished work.

Question 5:

Would rip rap be better to install to reduce future erosion?

NPS Response: The NPS is not designing long term plans., As described in the SOW, the US DOT will be assessing the locations and providing permanent design. This work is to provide near term access, and basic operations again.

Question 6:

Warranties- says for 1 year- if there’s a major rainfall event and there is sediment (4plus inches for example) that fills in the area is contractor required to clean culvert again?

NPS Response: No, contingent the stabilization and placement of wattles assurs a minimal required stability when done.

Question 7:

Are flaggers required or what signage is required?

NPS Response: Flaggers will be required to manage traffic operating continuously in the Roadway, hence the motive for creating basic truck access points off road of the culvert areas. This work is a stop gap measure to provide access to engineers for the longer-term culvert repairs.

Question 8:

What is the expectation for clean- every square inch is wash? Flushed with a little dirt left on walls/ floor.

NPS Response: The culverts will be cleared of debris and returned to basic flowable conditions. The residue of surface films of mud will be okay, but clumps of dirt, rock, clay and sand will be removed to maximum extent.

Question 9:

Are the bottoms of culvert stone like the sides or flat cement?

NPS Response: The culverts are believed to be stone. Consistent with installations elsewhere on the property and in the broader park from that era. However, some locations have been found to consist of dirt floors. In that case, follow guidance pertaining to excavation and protection of arch spring lines.

Question 10:

Now that we are actually getting rain, want to understand what is considered weather days and who declares them under what conditions. Figured this is important for this job.

NPS Response: Per the Statement of Work (SOW). The period of performance is inclusive of ten (10) weather days. If there are weather related environment factors affecting the service performance towards the end of the project where unexpected adverse weather conditions may delay progress. The CO will work with the contractor to adjust the performance period at no additional cost to the government.