B09 140G0221R0007-1 Attch 5 Q and As 01-10_0001.docx

Solicitation 140G0221R0007 Amendment 0001 Attachment 5 (PR 0040516860) Construct (4) Wells Questions and Answers 01 to 10

1. Can you further define plumbness procedure. What is acceptable procedure to determining plumbness? The USGS needs to be able to raise and lower a 15 ft long 3-inch diameter stiff rod to the bottom of the well and back up without binding.

2. On temporary fencing, is orange snow fence acceptable? Yes

3. On the steel casing, are you requiring galvanized or black pipe? Wall thickness? Ohio code is minimum .188 wall, standard sch 40 steel is .258 wall Galvanized sch 40 steel pipe.

4. Screen size availability. Can we predetermine a suitable size say 0.0015 for the wells? To have multiple sizes ranging from 0.0010- 0.0060in a 1 piece 10’ screen for each well would be a large expense to have on hand that would have to be past along to project. Screens of this length would be custom and non-returnable. As of February 17th there was a 2 week lead time so not something we could drill, custom order and install in a timely fashion per well. Or would threading 2-5’ screens together be a possibly? That would give us the versatility to have multiple slot size screens available and not required to predetermine a slot size or custom ordering screens. Carrying multiple size 5 foot screens and threading 2 screens together to accommodate the encountered materials during drilling is acceptable.

5. Is there any pumping test required upon completion? If so flow rates and duration? A 2 to 4 hour pump test is expected. The onsite USGS representative can work with the contractor to identify the length and flow rate.

6. Please determine diameter and length of protective risers to be installed. Protective risers need to a minimum of 8-inches in diameter, extend 2.5 to 3 ft above ground and set at least 3 ft in the ground.

7. In the case that a borehole needs to be backfilled, what is the required procedure and approved material needed to backfill? Follow regulations and guidance provided by the Ohio Water Resources council at https://epa.ohio.gov/Portals/28/documents/wellsealguide-2015.pdf. Pea gravel in the aquifer interval and bentonite chips to the surface is likely adequate for this area of the State.

8. Sampling and techniques. This is the portion that is going to be time consuming. Typically split spoon sampling and mud rotary don’t go hand in hand. This is due to bit design and time. Typically mud rotary would use Shelby tubes and pushing to get raw samples. This requires tripping drilling tools completely out of borehole, tripping Shelby tubes and tooling back in, pushing tubes for sampling and removing from borehole. Then tripping drilling tools back in and commence drilling again till next required sampling. This will be timely and expense. How often do you truly anticipate sampling the borehole? Shelby tubes can be used in place of split spoon sampling techniques if the technique is preferred. The onsite USGS representative will work with the contractor to identify intervals that require sampling. It is anticipated that only the projected screened interval of the borehole will be sampled.

9. Please define nesting procedure required and odds of completing a nested well. We don’t typically keep smaller flush joint pipe and screens in stock and unaware of availability. The likelihood of nested wells is low. Since the statement of work was prepared, additional wells were identified near the drilling sites that will allow for the measurement of vertical gradients eliminating the need for nested wells.

10. Is REDACTED required to have and carry any form of bonding for this project? Say a Surety Bond or anything other than our current bonding required to be registered with the State of Ohio? Answer found on Solicitation Page 19 (snipped/pasted) image1.png