Devils Lake Trench Drain

Added: Apr 27, 2016 3:58 pm The purpose of this Amendment is to provide responses to questions asked regarding the contract and to extend the closing date to 3 May 2016 at 10AM CDT

Questions and responses:

QUESTIONS & RESPONSES
1. Page 9 of 50 Paragraph 12 A - Discusses the items that are to be incidental to the Trench Drain line item.

a. Stripping vegetation, topsoil ..., stockpiling stripped material on‐site for later use, dewatering, topsoil, soil amendments, seed, ...

i. On a recent site visit it appears that there isn't much topsoil currently onsite in the areas that are to be disturbed, it appears that there is a more clayey material. So is it to be understood that we should plan to import 4" of topsoil for the roughly 2 acres of area that will be disturbed and restored?

RESPONSE: It wasn't expected there would be enough topsoil, and what topsoil is in place will be difficult to strip and reuse due to the soft conditions, thus the paragraph about importing topsoil. Please verify quantity as the trench drain area is approx. 1 ac.

ii. It also states that soil amendments are incidental. I don't see any type of soil amendments required further in the specs. to be done on either the existing or imported topsoil, if soil amendments are desired we will need more direction as to what type and how much?

RESPONSE: Soil amendments will not be necessary for imported topsoil.

2. Page 15 of 50 Paragraph 15 - Trench Drain Backfill Material

a. Is there a particular reason to utilize the sand material to backfill the trench rather than a "Pearock" which is the type of material normally used around a trench drain?

RESPONSE: Yes, this gradation was chosen to meet filter requirements with the surrounding soils

3. Page 13 of 50 Paragraph 19a - Backfilling and Compaction

a. ... shall be mechanically compacted to 100 percent of standard Proctor maximum density ASTM D698... It seems to us that compacting the trench drain material to 100% would be unreasonable due to the fact that the purpose of the material is to allow water to flow through it to the trench drains. If compacted to 100% I believe that the material would become tight and in the long run not allow the water to flow as desired. It would also be tough to get 100% compaction in a "jello" trench, I don't believe this would be very achievable. Please review with comments?

RESPONSE: Paragraph 19a is titled "PVC pipe" and only pertains to the PVC discharge pipe and not to the corrugated HDPE pipe in the trench drain (see CS101 and CS501). As stated in paragraph 19c, compaction is not required for the trench drain backfill material if a trencher machine is used to install the HDPE, otherwise 92 percent of standard proctor density is required.

4. Page 33 of 50 - Completion dates for the project don't seem to correspond with the normal seeding dates. This raises some concerns for the watering and getting the seed to grow during the hottest months of the year. It would seem more reasonable to adjust the completion dates to having the interim work completed by September 15 and the final completion date could remain the same or be adjusted slightly. Please comment?

RESPONSE: The dates that are mentioned in the specs are adequate. According to NDDOT Specs seeding with the late season permanent seed mix can be done after Aug 10. This will allow adequate time to seed and water until the completion date of Sept 30.

SECTION 00010 - SOLICITATION CONTRACT FORM
The required response date/time has changed from 28-Apr-2016 10:00 AM to 03-May-2016 10:00 AM.