J3- Attachment 3 - Statement of Work.pdf

US Department of Agriculture (USDA)

Statement of Work

J3 - Attachment 3 - Statement of Work

Contents Project General Information

1.0 Scope of Work

2.0 Background

Contractor Requirements

3.0 Technical Requirements / Tasks

4.0 Government Furnished

5.0 Deliverables / Schedule

6.0 Travel

7.0 Contractor’s Key Personnel

8.0 Security Requirements

9.0 Data Rights

10.0 Section 508 – Electronic and Information Technology Standards Attachment

Project Drilling Groundwater Monitoring Wells

General Information

1.0 Scope of Work

Nine ~4”diameter (minimum diameter) groundwater monitoring wells need to be dug across three forested watersheds that are in Durham County, NC to quantify deep seepage, and groundwater levels and recharge (Figure 1).

Installation of the wells shall be completed within one month after the contract is awarded.

2.0 Background

The USDA Forest Service Southern Research Station is working on a watershed scale research study in Durham County.

To gather accurate hydrology information about the forested catchments and to track seasonal groundwater levels, nine wells will be installed. The data will be used to further refine groundwater recharge in these managed forests in the Piedmont region. In addition, these results will be incorporated into broader calculations of the water budget for groundwater storage under varying forest management strategies.

Municipal stormwater leaders and consultants from the North Carolina Green Stormwater Infrastructure group are looking to use these results to further adapt silvicultural and hydrological management techniques from rural-forest to urban-forest management strategies to protect water resources.

Contractor Requirements

3.0 Technical Requirements / Tasks

The contractor needs to register SAM (https://sam.gov/content/home) to be eligible for award of the Federal government contract.

Drilling of nine 4” diameter groundwater monitoring wells across three watersheds in Durham County, NC (Note: Government will provide the 3” diameter slotted PVC screen pipe, Figure 2).

Description: Nine locations in the watershed will be marked by USDA Forest Service staff.

Specific points on this work phase include:

1. The government will provide the 3” diameter slotted PVC screen pipes and the contractor will drill the wells and install the pipes (see Figure 3 for example of well installation).

2. The wells should reach as close to the bedrock as possible at all locations. The depth at which the well will hit bedrock is unknown by Forest Service Staff but the wells on the upland slopes (~ 30 feet) will be deeper than the wells in the riparian buffer.

3. Locate wells where both morphology and hydrology are representative of the watershed soil series or component/topography.

4. The hole for the well should be wide enough to receive a 3” slotted PVC screen pipe.

5. Work with USDA Forest Service staff to determine where sediment removed from each well can be deposited.

6. Minimize stream impact where possible.

4.0 Government Furnished

The government will furnish the following:

1. PVC pipes for wells and the contractor will install the pipes in the wells.

5.0 Deliverables / Schedule

Key Deliverables

Item No. Deliverable Objective Due 1 Drilling of wells Drill nine 4” diameter groundwater monitoring wells in three watersheds and insert the provided 3” slotted PVC screen pipe into each well

No later than 30 business days after the contract is award. A timeline should be submitted with the bid for the portion of the work.

https://sam.gov/content/home

6.0 Travel

The sites are located about 20 miles north of Durham, NC. Travel cost to and from the watershed should be included as part of the overall contract.

7.0 Contractor’s Key Personnel

The work is arduous and will require personnel that can stand, dig, and be in the heat for long periods of time. Professional should also be able to construct and install water monitoring/control structures in a variety of conditions.

8.0 Security Requirements

The combination to the locked gate to the access road will be provided to the contractor.

9.0 Data Rights

N/A

10.0 Section 508 – Electronic and Information Technology Standards N/A

Attachments

Figure 1. Location of study watersheds in Durham, North Carolina. The location of the wells is approximate. Forest Service staff and the contractor will work together to determine the best location for the wells in each watershed.

Figure 2. 3" X 10' PVC Well Screen .010 Sch40

Figure 3. Example of monitoring well (source Sprecher, S.W. 2008. Installing monitoring wells in soils (Version 1.0).

National Soil Survey Center, Natural Resources Conservation Service, USDA, Lincoln, NE.)

Piezometer Installation.

1. Auger a hole in the ground with a bucket auger ~5 cm wider than the well stock to a depth approximately 2 cm deeper than the bottom of the piezometer. Be sure the auger hole is vertical.

2. Scarify the sides of the auger hole over the area to be screened, if smeared during augering.

3. Place ~2 cm of clean sand in the bottom of the hole.

4. Insert the piezometer into the hole but not through the sand.

5. Pour and gently tamp more of the same sand in the annular space around the screen and 2 to 4 cm above. Be careful not to overfill with sand. The depth of tamping for each well can be marked on the side of the tamping tool with a piece of tape.

6. Pour and gently tamp bentonite chips above the sand to the ground surface.

7. Make a mound of soil and dry bentonite around the riser at the ground surface, shaped to prevent puddling around the base of the riser. Moisten before leaving.

8. Check for clogging (Section 5.4). Reinstall and recheck if necessary.

9. Mark the side of the riser with paint at the top of the mounded soil/bentonite mixture and label the well.

10. Record height of well above ground surface and document installation.

11. Install and calibrate any water-level recording instruments.

Water-table Well Installation. Installation of a water-table well entails the same steps as above, with the modification that the filter pack extends the entire length of the well screen.