35586 Site Narrative.pdf

DATE: February 7, 2023

TO: Jim Scholtes ODOT R4 District 10 Manager

Ramon Alonso ODOT R4 Maintenance & Operations Liaison

CC: Russ Frost, C.E.G.

ODOT R4 Geology Manager

Scott Billings, C.E.G.

ODOT R4/5 Senior Engineering Geologist

FROM: Micah Lederer, C.E.G.

ODOT R4 Associate Geologist

SUBJECT: Agency Provided Prospective Material Source Narrative ODOT R4 District 10 Maintenance Gap (M.P. 87) Quarry Chip Rock Production Central Oregon Hwy. 007 (US20) M.P. 87.16, Harney County, OR ODOT Source No. OR-13-061-5, DOGAMI No. 13-0003

Introduction This memo and attachments should be duplicated and distributed to all bidders that inquire about this prospective material source, in accordance with Section 00120.25 of the Oregon Standard Specifications for Construction, 2021 edition. ODOT Region 4 is offering Gap (M.P. 87) Quarry as a prospective material source for the production of 10,500 cubic yards of 3/8” graded chip seal aggregate for use by ODOT District 10 Maintenance. The accompanying quarry development plans identify an Excavation Area adequate to supply the volume of aggregate materials needed to complete the project. The Contractor should review the information provided in this application package and the Plans and all Specifications and consider variables in production and implementation to produce the stated material quantities based on their knowledge of the project-specific development plan and experience with like materials. Any changes to the development plan or special provisions for the material source must receive written approval of the Engineer.

Any Contractor interested in viewing documents or information not summarized or provided herein should contact the Project Manager’s office and schedule an appointment to review the material. An ODOT Region 4 Geology staff representative must be present when information is being reviewed to ensure that content is disseminated accurately, fairly, and consistently throughout the bid process.

Background and Source-Use History Gap (M.P. 87) Quarry is located in the N ½ of Section 33, T. 23 S., R.24 E., W.M. adjacent north of the Central Oregon Highway (US20) at MP 87.16, approximately 17 miles west of Riley and 43 miles west of Burns. The quarry is BLM-owned and is controlled by ODOT through a Material Source Right of Way Easement. The site has been used by ODOT since the 1930s, both as a quarry and as a material stockpile site. It has historically produced AC-quality aggregate for Agency paving and resurfacing projects, including most recently in 2009 when approximately 113,275

Department of Transportation Region 4 Geology/Environmental Unit

63055 N Hwy. 97 Bldg. M Bend, OR 97703

Phone: (541) 388-6186 cubic yards were removed from the source for EAC paving and chip seal projects (US 20 Harney County Line - Hines, MCS No. 9 Chip Seal and US 20 Bulger Creek Road - Riley Junction Sections).

A significant quantity of excess shot material, including some oversize, was generated during the 2009 rock production and remains stockpiled in the excavation floor area. Special consideration should be given to the preparation of the bid and the blast plan, taking into account the possible need to handle or reduce oversize material to a usable size as stated in the specifications. Even with a successfully executed blast, special equipment or equipment setup may be necessary for secondary size reduction, or to enable the Contractor to handle the larger material where it exists in the source. Rock productions at Gap Quarry have also historically generated a significant amount of scalpings and crusher fines. Scalping/screening operations can be particularly challenging during the winter months and in wet weather.

Source Geology The material source is in the High Lava Plains Physiographic Province, where the regional geology is dominated by volcanic flows and volcaniclastic sedimentary deposits associated with Cascade Range volcanism. However, the quarry source material is mapped as the Olivine Basalt of Gum Boot Canyon (Tobg), which erupted from vents in the northern Basin and Range Province during the middle Miocene epoch (5 to 10 million years bp)1. The unit consists of basalt and andesite lava flows, as well as some stratified volcaniclastic deposits.

Exploration History Geotechnical rock core drilling occurred at Gap Quarry in 1993, 1996, and 2006, and exploratory air track drilling was performed in 2008. The most recent subsurface exploration of the site, an air track drilling investigation of the existing quarry floor and high walls, was completed by ODOT R4 Geology staff in 2018. The upper portion of the rock mass is weathered, and has historically required scalping to remove abundant silt and clay joint infill and other unsuitable weathering products. Prior subsurface investigations have also identified rock of variable quality at depth in the existing quarry high walls, including some zones of predominantly decomposed rock. The 2008 exploration identified a zone of decomposed rock immediately to the west of the former Excavation Area, which was avoided during the 2009 US 20 Harney County Line - Hines, MCS No.

9 Chip Seal rock production and now forms a peninsular outcrop near the center of the north wall of the quarry.

Hard rock was encountered to depths of at least 22 feet below the quarry floor in or adjacent to the Excavation Area identified in the accompanying quarry development plans, and representative samples of shot rock collected from the west side of the quarry floor in 2018 were found to meet ODOT specifications for AC aggregate. The ODOT Materials Testing Laboratory results (Laboratory Report No. 18-003803) and relevant drill hole logs are attached. Note that the characteristics of materials in the subsurface can vary between and beyond drill hole locations.

hole

Project-Specific Development Plan The development concept for this entry is to deepen the quarry floor in the southwestern region of the source area by excavating a depression in a manner that maximizes the use of the resource, as shown in the development Plans. The operating plan provides for removal of rock products required for this Project, and will leave the site in a condition that facilitates systematic development in the future. To this end, the proposed bench access road must be properly constructed after blasting and maintained for the duration of the rock production. When the current operation is completed, the site must be left in a stable and safe condition.

1 Greene, R.C., Walker, G.W., and Corcoran, R.E., 1972, Geologic map of the Burns quadrangle, Oregon: Reston, Va., U.S.

Geological Survey Interpretive Map I-680, scale 1:250,000.

The accompanying material source Plan sheets identify an Excavation Area sufficient to supply the volume of material required to meet the contract requirements, which specify a production quantity of 10,500 cubic yards of 3/8” graded chip rock. Note that existing loose shot material in the quarry floor area was not included in the volume estimates, and no swell (or “bulking”) factor was applied to the volume calculations. Waste material quantities generated during aggregate production can vary significantly depending on Contractor implementation and operations, and the excavation limits should be determined by the Contractor in the field based on their knowledge of the contract specifications and experience with like materials.

Development Plan Description The proposed development plan will establish a uniform and level quarry floor at an elevation of approximately 4,615 feet (all elevations NAVD88). Upon completion, the existing quarry floor will form a mid-slope bench between the proposed Excavation Area and the former working slopes of the existing quarry, and a safety berm will be constructed on the northern and eastern sides of the Excavation Area as shown, at an elevation of approximately 4,640 feet. The final northern and/or eastern extent(s) of the excavation may be reduced or expanded as needed to produce the required quantity of material. All interior quarry slopes should be 4V:1H. The proposed bench access road, which is required to establish and maintain access to floor of the proposed Excavation Area, may be constructed from loose material, crusher fines, or some combination thereof, and must be a minimum of 12 feet wide and stable as constructed (no steeper than 1V:6H). The Contractor should generate floor space as needed by relocating and/or processing existing loose material and oversize currently stockpiled in the source area.

The Contractor should anticipate encountering previously loosened shot rock materials as well as in-place hard rock. Ground loss and reject materials previously used as access ramps will also be encountered in the Excavation Area. All material loosened during prior entries, including oversize material that is currently stockpiled in the quarry floor and in the berm between the quarry floor and Processing Area, may be used for the production of the specified aggregate product at the discretion of the Contractor. Previously shot rock should be removed from the Excavation Area and Processing Area as needed to generate floor space and facilitate safe, unencumbered blasting and quarry operations; these materials shall be stockpiled with similar material in the Oversize stockpile or incorporated with the stockpile in the northwest corner of the quarry floor. The contract specifications limit oversize material loosened/generated from this rock production to 50 cubic yards. Special equipment or equipment setup may be required for secondary reduction, or to handle the larger material that currently exists in the source. Scalpings and reject fines shall be placed in separate and accessible stockpiles at the site as shown on the material source Plan sheets.

No Work Areas The contractor should be aware that all areas beyond the Project Boundary are designated as No Work Areas, as shown on the Plans. These areas shall not be entered or disturbed by persons, vehicles or equipment. The contractor should also be aware that Federal law prohibits persons from knowingly disturbing Native American Indian-made features, historic and prehistoric archaeological sites, or for collecting artifacts of any kind, including historic items and/or arrowheads, on Federal lands.

General Information Contractors should make an on-site visit to this prospective material source to familiarize themselves with the existing conditions and appearance of the site in advance of preparing their bids. As per Section 00120 - Bidding Requirements and Procedures of the Oregon Standard Specifications for Construction, 2021 ed., all prospective Bidders shall carefully examine the Site of the proposed work to familiarize themselves with the appearance and conditions at the prospective material source and to visually inspect the existing quarry faces and surrounding ground surface in advance of bid preparation. Based on this and review of all available information, Contractors will then be able to use their best judgment to prepare a bid based upon existing site conditions, the conditions they expect to encounter at the time of the proposed operation, and on the most accurate information available for the source. Documentation contained within this material source narrative is for informational purposes only. Contractors shall carefully examine the available information for the prospective material source. Based on the on-site visits and review of all available information, the Contractor will then be able to prepare a bid based on the existing site conditions, the conditions they expect to encounter at the time of the proposed operation, and on the most accurate information available for the source.

Attachments

1) ODOT Drill Hole Logs

a. 2018 Air Track Drill Hole Logs (AT18-01 to -06 and AT18-12 to -17)

b. 1996 Core Hole Field Logs (TH-3-96, TH-4-96, and TH-5-96)

2) ODOT Materials Testing Laboratory Report No. 18-003803

3) DOGAMI Operating Permit (ID No. 13-0003)

Oregon Department of Transportation Region 4 Geology Unit, Bend

Air Track Drill Log

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-01 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18 Driller: Matt – Quality Drilling Logged by: Kris Iverson Page 1/1 Backfill: Cuttings/Soil EA: PE003018-000 Total Depth: 34 ft.

Depth Feet

Time (m:s)

Advancement Rate Fast Mod. Slow

Dust Color

Voids

Water

Comments and Material Description

X DK BRN Overburden

4 X DK GRY Rock, some gray chips

6 X DK BRN 6’ – 8’ soft cindery

8 X DK GRY Rock, gray fresh chips, some gray dust

14 X x DK BRN X Boulder/Cinder, fast unsteady drilling, some voids, lost air/cuttings return to surface

23 X No Return Hard rock at 23’, no dust or cuttings return

26 X No Return Soft at 26’, no cuttings return

30-34 x x No Return

Hard rock at 30’. Driller remark ”may have followed vertical joint”. 24’ of rod and bit stock in hole.

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-02 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Backfill: Cuttings/Soil EA: PE003018-000 Total Depth: 22 ft.

Time (m:s)

Advancement Rate Fast Mod. Slow

X Added Added water, unsteady drill action, wet basalt chips

3 X GRY Rock, gray basalt chips/gray dust, steady drill action

22 3’ – 22’ good rock, steady drill action

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-03 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Time (m:s)

Advancement Rate Fast Mod. Slow

X Added Added water, unsteady drill action, wet basalt

3 X GRY Rock, gray basalt chips/gray dust, steady drill

22 3’ – 22’ good rock

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-04 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Time (m:s)

Advancement Rate Fast Mod. Slow

X Added Rejects on surface. Added water, wet basalt

1 X GRY Rock, gray basalt chips/gray dust, steady drill

22 1’ – 22’ good rock

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-05 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Time (m:s)

Advancement Rate Fast Mod. Slow

X Added Added water, wet basalt chips

1 X GRY Fractured or Vesicular Rock, gray-gray brown dust, slightly faster drill rate

22 1’ – 22’ good rock, , few thin seams 0.5’ – 1’ of brown gray dust

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-06 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18 Driller: Matt – Quality Drilling Logged by: Bobby Voeks Page 1/1 Backfill: Cuttings/Soil EA: PE003018-000 Total Depth: 12 ft.

Time (m:s)

Advancement Rate Fast Mod. Slow

0 2 s/ft X BRN GRY X Boulder/cobble in matrix, shot rock?

12 No rock encountered. Drill stem stuck in hole.

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-12 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Backfill: Cuttings/Soil EA: PE003018-000 Total Depth: 40 ft.

Time (m:s)

Advancement Rate Fast Mod. Slow

0 2 s/ft X Lt BRN Rejects at surface. Shot rock & rejects to 2’

2 10 s/ft X Lt GRY X Voids or loose rock 5’-7’

Good Rock 2’-40’

24 15 s/ft X Lt GRY

29 10 s/ft X LT GRY

40 End hole 40’

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-13 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Time (m:s)

Advancement Rate Fast Mod. Slow

0 2 s/ft X GRY

1 7 s/ft X Lt GRY

4 3s/ft X BRN GRY Hole keeps collapsing

12 End Hole 12’

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-14 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Backfill: Cuttings/Soil EA: PE003018-000 Total Depth: 24 ft.

Time (m:s)

Advancement Rate Fast Mod. Slow

0 3 s/ft X BRN

GRY

1 5 s/ft X BRN

GRY

12 10 s/ft X LT GRY Good rock, Hole keeps collapsing

24 Drill string keeps getting stock in hole. End Hole 24’

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-15 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Time (m:s)

Advancement Rate Fast Mod. Slow

0 3 s/ft X BRN

9 10 s/ft X LT GRY Good Rock. Void at 17‘, back break related?

19 25 s/ft X LT GRY Good rock

22 12 s/ft X LT GRY Hole frequently plugs, fractured rock?

34 End hole 34’

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-16 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Time (m:s)

Advancement Rate Fast Mod. Slow

0 3 s/ft X BRN Rock/soil at surface. Caliche encrusted soils and rock fragments.

4 7 s/ft X BRN GRY Dark red brown/brown silty sand clogs bit

12 Bit stuck, end hole

Quarry: Gap Quarry (MP87) County: Harney Hole No.: AT 18-17 Highway: US20 (COH MP87) Source No.: OR-13-061-5 Date: 11/20/18

Time (m:s)

Advancement Rate Fast Mod. Slow

0 3 s/ft X BRN Fill/rejects?

11 7 s/ft X LT GRY BRN Cobbles w/ rejects or fill. Boulder/basalt?

15 11 s/ft X LT GRY Boulder or basalt flow rock?

29 3 s/ft X X GRY X Loosened basalt? Backbreak voids?

33 X

34 Hole collapses. End hole 34’