mispecs3-final1a.pdf

UNITED STATES DEPARTMENT OF THE INTERIOR

OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT

OSMRE/TSD/Pittsburgh Three Parkway Center

Pittsburgh, Pennsylvania 15220

Michigan Reclamation Project– Group 5 Problem Areas MI-065, MI-002, MI-18-001

SPECIFICATIONS

General Specifications

GS NO. 1 LOCATION, BACKGROUND, AND SCOPE OF WORK Page 2

GS NO. 2 GENERAL INFORMATION Page 4

Technical Specifications

TS NO. 1 MOBILIZATION & DEMOBILIZATION Page 7

TS NO. 2 ANCHORING SYSTEM AND TETHER LINE INSTALLATION Page 9

TS NO. 3 WATER CONTAINMENT Page 10

TS NO. 4 DRILLING AND PREPARATION OF COREHOLES Page 10

TS NO. 5 GROUTING COREHOLES Page 17

TS NO. 6 BACKFILLING Page 23

TS NO. 7 FOUNDATION/STRUCTURE REMOVAL AT Page 26

ROBERT GAGE NO. 7 SITE

TS NO. 8 SITE RESTORATION Page 29

TS NO. 9 WATER DISPOSAL Page 23

Attachment No. 1- Drill Log- Buena Vista Attachment No. 2- Drill Log- Pere Marquette Attachment No. 3- Location Aerial of Pere Marquette Attachment No. 4- Location Aerial of Buena Vista Attachment No. 5- Location Aerial of Standard No. 1 Attachment No. 6- Location Aerial of Robert Gage No. 7

STATEMENT OF WORK SPECIFICATIONS

Michigan Reclamation Project – Group 5 PADs MI-065, MI-002, and MI-059

MI-18-001

GS NO. 1 - LOCATION, BACKGROUND, AND SCOPE OF WORK

There are three separate project sites: the property at 1470 Treanor Street, Saginaw, Saginaw County, (Standard No. 1 PA MI 065), latitude 430 23’31”, longitude 830 55’41” (Figure 1); the property 508 Malzahn Street, Saginaw, Saginaw County, (Pere Marquette No.2 PA-MI-065), latitude 430 25’7.7”, longitude 830 59’19” (Figure 2); the property at South 7 Mile Road, Bay City, Bay County,(Robert Gage No. 7 Mine PA MI-002), latitude 43°35 43.6 longitude 84°02’28” (Figure 3) and the property at 2704 Hampshire Street, Saginaw Saginaw County (Buena Vista Mine, MI 065),latitude 430, 23’, 36.58”, longitude 830, 55’, 53.12” (Figure 4) .

Based on the available maps, the main shaft at the Standard No. 1 is located in a wooded lot behind homes. Access will be off of Bagshaw Drive, in Saginaw. Wood and chain link fences will need to be partially dismantled to gain access. They are to be replaced when work is completed. The site is heavily vegetated. A large gully exist very near where we feel the shaft may be located. The mining was conducted from the early 1900’s until about 1907. The shaft is about 50 feet from the nearest residence and 100 feet from a public street. The overburden is reported to consist of approximately 80’-90’ of unconsolidated material and the rest rock, although this is indicative of the geographical location and is not site specific. The actual depth to the coal bed (and of the shafts) can only be determined upon drilling a vertical hole at this site. The available mine mapping indicates room and pillar mining at a rate of approximately 60 percent. Depth to groundwater at the site is reported to vary from 2’ to 5’. The mine is about 130-140 feet below the surface.

Based on the available maps, the shaft at the Pere Marquette II site is located near the corner of Malzahn and Kollen Streets in an area of open grass and sidewalk. Some trees and electrical lines are in the area to be drilled. The mining was conducted from the early 1900’s until about 1909.

The shaft is near a residence and within 25 feet of the street. The overburden is reported to consist of approximately 80’-90’ of unconsolidated material and the rest rock, although this is indicative of the geographical location and is not site specific. The available mine mapping indicates room and pillar mining at a rate of approximately 60 percent. Depth to groundwater at the site is reported to vary from 2’ to 5’. The mine is about 140 feet or more below the surface. We previously attempted to find this shaft in 2017. We were not successful at the previous location. Further investigation indicates the shaft may actually be in the area now proposed to be drilled. The previous vertical hole drill information is attached to this contract. No vertical hole will be needed at this site. Drilling operations at this site will be limited a start time no earlier than 7:30 AM and end time not later than 5:30 PM.

The two mine shafts within a wooded and field area surrounded by farm fields off South 7 mile road, near Bay City, Bay County was last mined by the Robert Gage No. 7 mine which ceased operations in 1936. The Robert Gage Coal Company last operated the mine. The main shaft is reported to be a vertical, double-compartment, timbered structure, with surface dimensions of roughly 12’ by 16’. The shaft accessed a single, three-foot, coal strata at an approximate depth of 170-180’. The 150-170’of overburden is reported to consist of approximately 80’-90’ of unconsolidated material and about 80 feet of rock, although this is indicative of the geographical location and is not site specific. The available mine mapping indicates room and pillar mining at a rate of approximately 60 percent. Depth to groundwater at the site is reported to vary from 2’ to 6’. The air shaft was reported to about 8 X 12 feet in dimension.

The shaft at 2704 Hampshire Street, Saginaw, Saginaw County, (Buena Vista PA MI-065) was utilized by the Buena Vista Coal Company prior to 1920.

Its actual date of abandonment is unknown. The shaft is reported to be a vertical, double-compartment, timbered structure, with surface dimensions of roughly 12 by 16’. The shaft supposedly accessed a single, three-foot, coal strata at an approximate depth of 130-140 feet. The overburden is reported to consist of approximately 80’-90’ of unconsolidated material and the rest rock, although this is indicative of the geographical location and is not site specific. The available mine mapping indicates room and pillar mining at a rate of approximately 60 percent. Depth to groundwater at the site is reported to vary from 2’ to 6’. We previously attempted to locate this shaft as part of work performed in 2016.

Additional information obtained indicates the shaft is north of where we previously explored. Attached to this contract is the drill log for the vertical hole previously drilled on this lot. No vertical hole will be needed at this site. Drilling operations at this site will be limited to a start time no earlier than 7:30 AM and end time not later than 5:30

PM.

The work covered by these technical specifications (TS) consists of drilling and casing vertical and angled core holes in the vicinity of and into the abandoned shafts, in order to locate them, determine their condition of their sidewalls, determine whether they are backfilled, and for grouting the shafts to provide stability. The drilling plan calls for one vertical core (where required), followed by angled coring.

The vertical core will verify the geologic section and the remaining angled core holes will penetrate the shaft sidewalls. Additional angled holes may be required to help locate the shaft. The condition of the shafts’ sidewalls is unknown. The shafts appear to have been backfilled to the surface with miscellaneous material and interior conditions are unknown. Angled core drilling is expected to have a maximum inclination of 45 degrees from the vertical. Samples of the overburden and rock cores will be required. Due to the many unknowns associated with this work, we make no assurances regarding the final quantities realized.

The stability of the overburden and bedrock surrounding the project area is unknown. The nature and condition of backfill is unknown. The Contractor shall exercise necessary caution when working in this area. The Contractor shall be responsible for informing employees of the dangers related to this project. The employees shall be under the Contractor's supervision at all times.

GS NO. 2 - GENERAL INFORMATION

2.1 Underground Utilities and Other Obstructions - It shall be the sole responsibility of the Contractor to locate and avoid all underground utilities and other structures and obstructions and, for that purpose, shall employ all necessary precautions and methods to insure avoidance of damage to such underground conditions.

In the event damage does occur to any buried or overhead utilities at the four sites, the Contractor shall be solely liable; therefore, he/she shall notify the appropriate authority and Contracting Officer's Representative (COR) immediately and make or have made all necessary repairs and bear the expense thereof and all resulting damage caused thereby. On the basis of utility locations, the boring locations can be changed with the consent of the COR. The toll free number to have member MISS DIG SYSTEM, Inc. utility locations marked is (1-800-482-7171 or 811). For Robert Gage No. 7 an underground petroleum pipe line(s) will need to be crossed over to access the air shaft at the site. The right of way is owned by the Wolverine Pipe Line Company. The contact person is Fred Hipshear at 269-357-6002. No permit is required if ground is dry and hard. If wet or soft where any vehicle is causing rutting the use of metal road plates or wooden planks manufactured to help distribute vehicle weight will be required for any crossing point over the lines.

2.2 Easements and Work Area - The Contractor shall confine project operations to the properties for which OSMRE has received written authorization for right-of-entry from the landowner(s). The Contractor shall consult the COR if he/she is uncertain about where access has been obtained. As an agent of OSMRE, the Contractor is forbidden to use other properties where OSMRE has not received written permission, and the Contractor shall be solely liable for its actions if he/she trespasses onto properties where consents for right-of-entry have not been obtained. During the course of the work, the site shall be neatly maintained and free of litter and other debris, with site cleanup performed daily. All properties affected by the Contractor's activities shall be restored to a condition as good or better and is acceptable to the COR and property owner.

2.3 Coordination with OSMRE - Work schedule, including specific daily work hours, shall be presented to the Contracting Officer (CO) at the pre-construction meeting. The Contractor shall coordinate a date and time for work start-up with the CO. The Contractor shall also provide prompt notification of delays as soon as they become known. This allows the COR or appointed representative, the Construction Inspector (CI), to minimize unproductive time, yet be at the work site during ALL project operations.

The performance period established for this contract is based upon all work being conducted during regular working hours. If the Contractor desires to carry on work outside regular hours, including weekends and Federal holidays, the contractor must contact the COR for prior approval.

To ensure the COR has on-site representation during working hours, the Contractor shall be limited to working on no more than one site at a time.

Some latitude on that requirement maybe made when work is being done on Buena Vista and Standard No. 1. Those sites are less than a half mile apart.

2.4 Safety - The Contractor, subcontractors, and their employees shall abide by all safety rules applicable at the site of the work and shall comply with all Federal, State, OSHA, and municipal laws, ordinances, orders, codes, rules, regulations, etc. The Contractor shall furnish employees, including those of subcontractors, with MSHA approved safety equipment, devices, and enforce compliance in their use consistent with accepted practices and applicable rules. Specifically, HARD HATS AND STEEL-TIPPED SHOES shall be worn by all workmen, supervisors, inspectors, and visitors while on the project site.

The depth to the top of bedrock and the unknown subsurface condition of the shaft sidewalls and interior indicate a potential for movement of the unconsolidated material surrounding the shaft. In order to provide personnel safety at the site, the contractor will construct a tether line attached to pre-approved anchors at the work site to which all personnel will be attached while performing work. This will be done prior to any angle drilling into the shaft. The specifics of the tether line are contained in TS No. 2.

Delineation of a collapse zone - A collapse zone shall be established around the perimeter of the shaft in accordance with direction provided by the COR in the field. This estimated zone is delineated as an area extending outward from the shaft perimeter, projected to the surface, within which access of personnel and equipment is restricted due to potential for collapse. For this project the collapse zone shall extend upwards of 50 feet beyond the perimeter of the shaft projected to the surface. The limit of the collapse zone shall be well fenced and maintained by the Contractor, presenting a visible barrier to all personnel. Although OSMRE has estimated the limit of the collapse zone, OSMRE does not guarantee that a larger area may not be affected.

It shall be the responsibility of the Contractor to implement appropriate, OSHA compliant, safety restrictions within the collapse zone.

During the course of the work, the Contractor shall be responsible for monitoring the ground surface and nearby structures to determine if movement is taking place. During operations, work shall cease periodically to allow for inspection of the ground surface and structures. Should any signs of instability appear in the ground, shaft or structures, or should any signs of water or grout appear on the ground surface or in structures, the Contractor shall suspend work immediately and inform the on-site monitor, Contracting Officer’s Representative (COR) and the OSMRE Contracting Officer. The Contracting Officer will then consult with appropriate personnel to determine the appropriate course of action.

2.5 Environmental Compliance - The Contractor shall perform this work to minimize the possibility of air, water, and land pollution. The contractor is reminded that the water table is close to the surface and it is the contractor’s responsibility to control surface water created by drilling to the work site. The contractor shall comply with all applicable environmental laws and regulations concerning environmental protection.

The Contractor will be solely responsible for securing required permits and for compliance thereto. Contractor shall determine what, if any, local ordinances, codes, and regulations apply to this work. The contractor shall comply with all such ordinances, codes, and regulations.

When it is necessary to construct access roads or otherwise disturb the surface, care shall be taken to avoid causing undue erosion. This specifically includes implementation of erosion control measures if soil is being adversely affected by the project work.

2.6 Review of Mine Maps and Drill Logs – OSMRE affords no guarantee, expressed or implied, regarding the accuracy or completeness of this information, nor the interpretation thereof by OSMRE, OSMRE’s consultant or any of their representatives. The Contractor shall make his/her own interpretations regarding subsurface information and, at his/her own expense, make any surveys and investigations deemed necessary to evaluate conditions that may affect performance of the work.

The vertical drill logs for the previous Buena Vista and Pere Marquette number 2 mine is included as attachments. There will be no need for vertical hole at Buena Vista or Pere Marquette. A vertical hole will be drilled at the other two sites.

TECHNICAL SPECIFICATIONS

TS NO. 1 - MOBILIZATION AND DEMOBILIZATION

1.1 Description:

a. Mobilization: Upon receipt of notice to proceed, the Contractor shall initiate and complete measures necessary to commence work described herein. This includes all costs and activities related to establishing and maintaining site access. In performing site access, the Contractor shall always attempt to minimize the disturbance to landowners' property and minimize inconvenience to the public (i.e. noise, litter, parking spaces, traffic flow, dust, runoff water, etc.). For this contract, the contractor will be required to establish and maintain a work area safety fence, with signage, approximately 50’ off the shaft and enclosing the work area. The safety fence shall be comprised of orange plastic, 4 feet in height. Signage shall read “Danger, Keep Out.”

b. Mobilization shall also consist of delivering to the site and assembling in working order all necessary equipment, materials, and supplies.

Prior to the commencement of work, the Contractor's equipment shall be subject to approval of the COR. Equipment shall be maintained in first-class operating condition at all times. Mobilization shall include the storage of all materials and supplies. No additional payment shall be made for movement of the drill and associated equipment around the property where the shaft locations have been marked. Shaft locations indicated on the attached Figures (1-4) are only estimates. Mobilization also includes providing drinking water, a workable cell phone, and toilet facilities. The portable toilet must be on each individual site within 1 day from the time work begins on each of the four sites. The portable toilets shall be left at the site until all drilling and grouting work is completed.

c. Each of the five sites has their own site access concerns. For the Pere Marquette No. 2 Mine, sidewalks and trees are located in the area. In addition, the overhead utility lines shall be avoided while drilling. The contractor will need to coordinate traffic control with the City of Saginaw if the street needs to be closed or traffic restricted in anyway. At the end of the work day all equipment will be moved off the road, or proper signage erected to warn motorists that some traffic restrictions exists around the work area. Also, a water retention and dispersal system will be set up at the Pere Marquette site to insure all water discharges are adequately controlled and filtered. Permission from the city must be obtained prior to discharging into any storm sewer. For the Standard No. 1 site work shall be performed off of Bagshaw Drive. A chain link/wooden fence exists parallel to the street which will have to be temporarily removed to gain access. The area around the shaft is heavily wooded.

All trees/limbs taken down for access must ultimately be removed from the site. Trees that can’t be disturbed, due to possible bat habitat, will be marked by the COR. The street shall be kept open to at least one lane of traffic at all times. At the end of the work day all equipment will be moved off the road to insure it is completely open during non-work hours. For the Robert Gage No. 7 Mine site, there is an access road off Seven Mile which will be used to get to the shafts.

It is a dirt farm road. This road shall be maintained during work activities. Some small trees may have to be removed at this site. All trees and brush are to be hauled off site when work is completed. For Robert Gage No. 7 an underground petroleum pipe line(s) will need to be crossed over to access the air shaft at the site. The right of way is owned by the Wolverine Pipe Line Company. The contact person is Fred Hipshear at 269-357-6002. No permit is required if the ground is dry and hard. If wet or soft where any vehicle is causing rutting the use of metal road plates or wooden planks manufactured to help distribute vehicle weight will be required for any crossing point over the lines. The contractor shall insure that all safety standards required by Wolverine to cross over the lines are being met.

d. For the Buena Vista site, (PA MI-065), an overhead utility line located along Livingston Drive needs to be avoided, as well as coordinating traffic control with the City of Saginaw if the street is closed. A large tree at the site near the shaft shall not be disturbed, except for trimming branches less than 4 inches in diameter. Also, a water retention and dispersal system will be set up at the Buena Vista site to insure all water discharges are adequately controlled and filtered.

Permission form the city must be obtained prior to discharging into any storm sewer. The contractor is responsible for obtaining all necessary traffic control permits required by the Saginaw City road departments for the Buena Vista, Standard and Pere Marquette sites.

Finally, for all properties, no dead or dying standing trees with loose bark can be removed until authorized by the COR. No other disturbances, except for trimming of limbs 4 inches in diameter or less, to trees marked by the COR are permitted.

At the Robert Gage No. 7 site some concrete foundations pieces exist around the air shaft. All concrete pieces removed to clear these foundations shall be hauled off site to an approved location. See Section 8 for more detailed explanation of the work related to these structures. Once the structures are removed the resulting holes/depressions shall be filled with topsoil.

It is the sole responsibility of the Contractor to protect motorists, pedestrians, and the curious public from the dangers of work activities during working and nonworking hours. The Contractor shall not be limited in its use of flagmen, warning signs, fencing, and watchmen to protect the public from the project site.

It is the Contractor's responsibility to legally obtain any water that is needed for this project. The cost of permits for removal of hydrant water, water meters, and the water itself shall be borne by the Contractor. If the Contractor desires to use water, electric, garden hoses, wheelbarrows, hand tools, or other items from a landowner, the

Contractor must obtain written approval from the owner prior to using the item(s), and negotiate in advance a means of compensation that is satisfactory to the owner. All such agreements must be submitted to the COR for review.

e. Demobilization - Demobilization shall consist of removing all plant, equipment, supplies, debris and waste material upon completion of work.

All damage to public or private property outside the drilling and access area shall be promptly corrected/repaired to its preconstruction condition.

1.2 Method of Measurement and Basis of Payment: Mobilization, demobilization, site preparation and site access work will be measured combined along with the anchoring system, and water containment, as a single unit, acceptably performed, per drill site. Payment shall be included in the lump sum for each site as bid under Contract Bid Items, Standard Nol. 1, Pere Marquette NO. 2, Robert Gage No. 7 and Buena Vista, known as Contract Bid Item Nos. 10, 20, 30, and 40, on the Bid Form and shall include the cost of all items described previously, as well as all associated and incidental costs. All costs related to satisfying any bonding requirements shall be included in these bid items.

TS NO. 2 – ANCHORING SYSTEM AND TETHER LINE INSTALLATION

2.1 General Requirements: The Contractor shall provide all tools, equipment, and labor to carry out the work and furnish all the required facilities and services. All work done under this item shall be performed in a safe and professional manner.

2.2 Description: The contractor shall provide a safe and effective anchoring system, complete with tether lines and full body harnesses for each drill site. The anchors and tether lines shall be set up and in use prior to any angle drilling to explore the shaft locations. The anchoring system shall be capable of supporting the weight of all contractor personnel working on-site in the event of a shaft collapse. The system shall support full movement of personnel within the collapse zone. The system must be in-place and usable during all work hours. The tether line will consist of a minimum ¼-inch diameter stranded steel cable. The anchors should be a minimum of 25-50 feet away from the shaft perimeter, as access allows.

All personnel within the collapse zone shall wear a full body harness that is securely tied to the tether line at all times. The collapse zone is identified as a 25-50-foot perimeter from the shaft. The perimeter shall be marked by the Contractor, re-established as needed and fenced until all work is done. The anchoring system and tether line installation plan must be submitted to the COR for review and prior approval. As a minimum, the plan shall include the number of personnel to be tied off to the cable at one time, the cable length, a description of the anchors, and the location of the anchors. Although all drill sites shall have an anchoring system, different systems are permissible for each drill site as long as all anchoring system plans are approved by the COR prior to starting work.

2.3 Method of Measurement and Basis of Payment: The anchoring system and tether line installation will be measured combined along with the mobilization, demobilization, site access, and water containment, as a single unit, acceptably performed, per drill site. Payment shall be included in the lump sum for each site as bid under Contract Bid Items Standard No. 1, Pere Marquette No. 2, Robert Gage No. 7 and Buena Vista.

known as Contract Bid Item Nos. 10, 20, 30, and 40, on the Bid Form and shall include the cost of all items described previously, as well as all associated and incidental costs.

TS NO. 3 – WATER CONTAINMENT

3.1 General Requirements: The Contractor shall provide all tools, equipment, and labor to carry out the work and furnish all the required facilities and services. All work done under this item shall be performed in a safe and professional manner. The contractor must have a working test kit that will at a minimum measures PH and Iron levels in the field.

3.2 Description: The contractor shall provide safe and reliable water containment system for each site. When needed the system shall collect all water that is released as grout is pumped into each shaft. It is anticipated that water will discharge from the cased holes as grout is pumped into the shaft. Each shaft shall have a minimum of two shallow holes, one of which is designated for water discharge. The Contractor shall install a secure cap on one of the shallow hole casings in order to provide the ability to regulate and stop the flow, if necessary, during grouting operations. If water starts exiting a lower hole during grouting then a secure cap can be moved in order to insure there is adequate control of the discharge. All casings, while not in use for grouting or water discharge, shall be securely capped (Taping is not an acceptable substitute). This water must be contained/controlled, so as not to disturb the site, until it can be disposed of. The water containment system must be in-place and usable during all grouting work hours. If on-site dispersal of the water is available, the containment system can be a distribution system to relay the water from the casing to a pre-designated area on-site. If the COR can designate an area on-site to discharge the water, this water must be tested and filtered through straw/hay bales. It must meet all applicable Federal and State effluent limitations for pH, iron, and sediment (pH between 6.0-9.0 standard units and iron less than

6.0 mg/l). It is the COR’s intent to discharge this water on-site, if at all possible, rather than off-site disposal. Although all grouting sites shall have a water containment system, different systems are permissible for each grouting site.

3.3 Method of Measurement and Basis of Payment: The water containment system will be measured and combined along with the mobilization, demobilization, site access, and anchoring system, as a single unit, acceptably performed, per drill site. It will include all costs for controlling, containing, distributing, and testing the water, as well as all other associated and incidental costs. Payment shall be included in the lump sum for each site as bid under Contract Bid Items Standard No. 1, Pere Marquette No. 2, Robert Gage No. 7 and Buena Vista known as Contract Bid Item Nos. 10, 20, 30, and 40, on the Bid Form and shall include the cost of all items described previously, as well as all associated and incidental costs.

TS NO. 4 - DRILLING AND CASING OF COREHOLES

4.1 General Requirements: This work consists of conventional coring (vertical holes only) and sonic drilling and casing core holes at sites, to the depths and inclinations, designated by the COR. The layout/sites of the holes will be established by the COR. The maximum inclination of sonic core holes shall be 45 degrees from vertical. The number of core holes will be determined by the COR during the course of the work, however, drilling of no fewer than 10 angle holes per shaft per site is anticipated. In addition, one vertical hole shall be drilled at the Standard NO. 1 and Robert Gage sites, down to the mine level of the site. This vertical hole shall be used to determine the depth to the mine interval. A vertical hole shall be any hole drilled at an inclination of 5 degrees or less. This hole can be drilled by a conventional coring drill rig.

The Contractor shall provide all tools, equipment, material and labor to carry out the work and furnish all the required facilities and services.

All work under this item shall be performed in a safe and professional manner. The contractor shall provide drilling rig(s) capable of accessing the desired core hole locations, drilling to the specified depths, and installing casing.

4.2 Drilling Equipment and Supplies: Equipment for sonic, continuous-core drilling shall include sonic drill rig with hydraulic powered drill head capable of generating high frequency vibration and rotation, together with all accessories, for taking complete and continuous cores, to the depths specified.

Equipment for conventional core drilling shall include hydraulic feed-core drilling machinery, complete with pressure gauge for measuring down pressure, water-pressure gauge, and relief-valve assembly, together with all other accessories for taking complete and continuous rock cores, to the depths specified. Core size shall be NX or NQ.

Supplies for sonic and conventional core drilling shall include all casing, drill rods, bits, piping, pumps, water, tools, power, and all boxes and containers required for core samples, and all other items not specifically herein described but required for satisfactory performance of the required work.

4.3 Materials: The Contractor shall furnish all materials required for the drilling of soil and rock and casing and capping of holes as described herein:

a. Casing: The Contractor shall provide steel or schedule 40 PVC casing for each hole of a sufficient length to case through the soil zone and into the shaft interior. The vertical depth of the unconsolidated column is expected to be at least 80 feet and possibly more and comprised mostly of clay. Casing shall be of a sufficient inside diameter to allow the drilling through rock with the required diameter bit.

b. Caps: The Contractor shall provide airtight caps that fit securely on the casing and are made of the same material as the pipe for each casing. The caps shall fit snugly over the pipe. No type of taping to close the top of the pipes will be allowed.

c. Approval: All materials used for the casing and capping of core holes shall be the same material as the actual casing. They must fit tightly so that they can meet the approval of the COR.

4.4 Description: This work consists of drilling and casing vertical and angled core holes at specified locations, for the ultimate purpose of determining the composition of the overburden strata and the stability of the shaft and the ground surrounding the shaft column. The intent is to drill into the shafts to locate them, determine their configuration, the condition of the sidewalls, and whether or not they are backfilled. On the basis of utility locations, the core hole location may be changed with the approval of the COR. Actual drilling results may necessitate changes to subsequent core hole specifics by the COR. Additional holes may be required by the COR. The majority of the core drilling will involve angled drilling. One vertical hole shall be placed per site, except Buena Vista and Pere Marquette, for the sole purpose of determining depth to the mine or coal level. Angles will vary to a maximum of 45° from the vertical and involve working in confined conditions.

It is the intention not to delay the work for the checking of core hole locations, temperatures, or depths; but, if necessary, work shall be suspended for such reasonable time as the COR may require. No special compensation shall be paid for the cost to the Contractor of any of the work or delay occasioned by making necessary inspections. The Contractor shall keep the COR informed a reasonable time in advance of the times and places at which the Contractor intends to do work in order that necessary checking or inspections can be made with the minimum of inconvenience to the COR or to the Contractor.

4.5 Construction Requirements:

a. The final inside diameter of the borehole shall be large enough to accept a minimum 3 inch inside diameter casing. All of the grout mixtures listed in Section 5.3 (b) must be able to be pumped through the casing selected by the contractor.

b. Drilling of Holes: The holes shall be drilled in an orderly sequence to the depths and at the angles requested by the COR. Drilling shall be performed in such a manner as to minimize sidewall collapse, such as by vibration frequency, etc. The Contractor shall be responsible for drilling a plumb hole. All drill-rod sections shall be tightly sealed to each other by means of commercial seals made for this purpose or by the application of wicking to the joints. The holes shall be drilled with bits and stabilizers that will provide full-diameter, straight holes.

Any water encountered in the drilling process and carried to the surface with cuttings shall be contained and filtered by the use of straw bales/wattles or silt fence. Cuttings and dust sludge shall be cleaned daily from the hole area after drilling. Water shall be tested and shall meet all applicable Federal and State effluent limitations if it is to be discharged from the immediate work area.

Water shall then be discharged to a grassy, wooded area or closest storm sewer if properly filtered, subject to approval of the COR, or otherwise disposed of off-site.

c. Drill and Case Holes through Soil Overburden and the Sidewalls and Interior of the Shaft: Each hole drilled shall be protected from caving and/or becoming clogged or obstructed. Holes drilled through the overburden shall be cased through the shaft wall and into the interior of the shaft keyed into rock sufficient to exclude all overburden and be watertight to prevent any migration of grout from the cased core hole into the soil layer, utilities, etc. The casing must fall freely down into the hole with only minimum pressure. This casing shall then be capped as described in 4.3 (b). Casing shall be capped for possible future use in grouting. Any hole that becomes clogged or obstructed for any reason before completion of operations shall be cleaned out at the Contractor's expense, or a replacement hole shall be provided at the Contractor's expense. Further, any incidental expenses required for cleaning out a hole or providing a replacement hole shall be the responsibility of the Contractor.

All pipe and fittings required for casing holes shall be furnished, handled, and installed by the Contractor.

Casing shall be kept a maximum of 6 inches above the grade. Casing shall be left in the hole and capped if shaft is encountered.

d. Drilling and Casing Holes through Rock: The minimum diameter of drilled holes in rock shall be as specified in TS No. 4.5.a. Casing will be required if the core hole intersects the shaft. In coring rock (including shale and indurated clays), the Contractor shall operate the drill at such speed and frequency so as to ensure maximum core recovery.

A minimum core recovery of 70% for the entire hole shall be required as high percentage of recovery is considered necessary for proper interpretation of subsurface conditions. When a "run" is made which results in complete core loss, the tools shall be double checked for damage or malfunction. Failure to obtain 70% recovery could constitute justification for the COR to require re-drilling of the hole at the Contractor's expense. It is further understood that when coring within the shaft recovery levels may be less due to the consistency of the materials within the shafts. The 70% requirement will not be required within the shafts if conditions do not allow a good recovery.

Inasmuch as the function of core boring includes the determination of the width, orientation, extent, and spacing of rock fractures, the Contractor shall exercise particular care in recording noteworthy events such as rod jerks, drops, etc., which, supplementing the core record, will yield information regarding the nature and extent of the fracturing.

Upon completion of drilling a hole, the hole shall be temporarily capped with a secure, air tight cap and otherwise protected from entry of foreign material until grouting operations are initiated.

When the Contractor believes the core hole is completed, he/she shall notify the Inspector before the drill steels are removed so that the Inspector can witness the removal of the drill steels and the depth drilled. Casing shall be installed as soon as possible after the drill rods are removed when the shaft has been encountered to insure holes do not close off due to expansion of shaft lining.

The Contractor and the OSMRE inspector shall confer daily regarding the quantity of drilling performed. Any disagreement shall be brought to the attention of the COR within 24 hours.

The Contractor shall sign off on the inspector's daily construction logs signifying agreement or disagreement daily.

e. Casing Anchored and Left in Place: If the COR desires the drilled core hole be kept for grouting under this contract, he/she will instruct the Contractor to furnish and install minimum 3-inch I.D.

casing to the prescribed depth. The Contractor's temporary standpipe casing may be removed, providing the finished casing is anchored on the surface to prevent it from falling down the hole.

The casing shall be either steel or schedule 40 PVC, dependent upon the Contractor’s preference. Steel casing shall be removed from the ground after grouting and may be reused to case future holes. PVC casing shall not be reused on future holes and may be left in the ground, provided it is grouted in place. PVC casing grouted in place must be cut-off a minimum of one foot (12 inches) below the surface and disposed of off-site. Measurement for payment for casing left in place shall be made by the OSMRE Inspector from the top of casing near the ground surface to the actual depth cased.

Payment will be made at the contract unit price per linear foot as listed as Contract Bid Item No. 60 on the Bid Form. The Contractor and the OSMRE inspector shall confer daily regarding the quantity of casing installed. Any disagreement shall be brought to the attention of the COR within 24 hours. The Contractor shall sign off on the inspector's daily construction logs signifying agreement or disagreement daily.

f. Completion of Holes:

(1) After drilling, the holes shall be washed to remove all mud and cuttings adhering to the coring sidewalls. Washing may be done by using water from a hose directed into the top of the hole, or some other method acceptable to the COR. The amount of water used shall be subject to COR approval.

(2)It shall be the responsibility of the Contractor to cap and protect all drilled and cleaned holes from obstruction by debris. Any required cleaning of the hole after initial drilling and cleaning shall be performed, as necessary, at the Contractor's expense. It is important to place casing as quickly as possible after the hole has been drilled and washed.

(3) The pipe casing is to remain for grouting if the shaft is encountered.

(4) All unsuitable material shall be legally disposed offsite by the Contractor. Unsuitable material shall include, but not be limited to drill cuttings, old pavement, and soils designated by the COR as unsuitable for backfill. Any cores that the COR deems acceptable for backfill may be used as backfill on sites with existing depressions at the shaft locations. Some sites do not have depressions and the soil cores will need to be disposed of off-site. The compensation for this work, whether it is on-site backfilling/grading or off-site disposal, shall be included under these drilling bid items of the contract, as noted in TS No. 4 DRILLING AND PREPARATION OF COREHOLES, Paragraph 4.7. No separate compensation will be made for this work. If the cores are disposed of off-site in a landfill, OSMRE will not sign the waste manifest forms as the generator of the waste.

g. Core hole Logs: The Contractor shall keep accurate logs of all core holes vertical or angled that are drilled. A legible, handwritten copy of the core hole logs shall be presented to the OSMRE on-site inspector as soon as possible after drilling of a hole is completed.

Typewritten core hole logs shall be presented to the COR within two weeks from which drilling has taken place.

The fact that an inspector shall be present and keeping a record of the drilling shall not relieve the Contractor from the requirements of keeping an accurate log as described above. Drilling logs shall be provided to the COR prior to abandonment of any core hole that intercepts a shaft.

The log must include, at a minimum, the following information:

(1)Project name, contract number, coring number, location of coring, ground elevation, total length of hole, time-date of starting, time-date completion, driller's name, and logger's name.

(2)Size and depth of casing and size and type of drilling tools used to advance the hole.

(3)Depth to top and bottom of each run.

(4)Total length of core recovered plus the maximum and average length of individual core fragments for each run.

(5)Color changes in drill-water returned.

(6)Depths at which sudden losses or gains of return drill-water occur and estimated quantities involved.

(7)Visual classification of rock type (lithology), including color, grain size, and inclination of beds or layers as measured from the horizontal.

(8)Nature and extent of fracturing of the rock, as determined by a field examination of the core and the "feel" of the drill during coring.

(9)Depth to the top of firm, fresh rock and all other contacts between dissimilar materials.

(10)Location of soft zones or "break-through," as indicated by rod chatter or changes in the rate of penetration.

(11)Notes, remarks, and information on noteworthy events pertinent to the drilling operation, to include encountering the shaft.

i. Core Samples: The contractor shall provide these items:

(1)Longitudinally partitioned wooden/card board core boxes or plastic sleeves shall be used for all vertical exploratory hole cores. As many core boxes or plastic sleeves as may be necessary shall be provided for storage of each core hole core or group of cores. Cores boxes, including partitions, shall be substantially constructed of dressed lumber or durable cardboard.

(2)All vertical hole cores shall be arranged neatly in the partitioned boxes, in the sequence in which they occurred prior to removal from the hole. Facing the open box, cores shall be arranged in descending sequence, beginning with the left end of the partition nearest the hinges and continuing in other partitions, from left to right. Wood spacers shall be inserted at beginning and end of each run, and depths shall be shown on the blocks. If voids are encountered, a spacer block shall be inserted and marked to clearly indicate the depth to the top and bottom of the void.

(3)During the course of the drilling contract, the Contractor shall be responsible for storing the cores and taking adequate precautions to protect the cores from mechanical damage as well as from extreme temperature changes. Once recovered and cleaned, the core shall be kept dry.

(4)After vertical hole drilling has been completed, the cores shall be logged and color photographed by the OSMRE inspector.

When that is completed, the cores shall be discarded by the Contractor.

4.6 Method of Measurement: Measurement for payment for drilling and casing core holes shall be made by the OSM Inspector from the ground surface to the actual depth drilled and the amount of casing successfully placed within the hole.

4.7 Basis of Payment:

a. General: Payment will include the cost of furnishing all labor, tools, materials, pipe, casing caps, and equipment required for drilling the core holes, casing the core holes, removing all materials from the casing, maintaining the core holes open and clean until the core holes are no longer required, removing and/or cutting the casing, handling the core samples, disposing of and/or using cores as backfill, and all associated incidental work. All costs associated with developing type written drill logs for all vertical and angle holes will be included with this item.

Payment will not be made for any core hole which has been drilled with the wrong size bit, at the wrong location, or at the wrong angle of inclination, or any hole which is not accepted as satisfactory by the COR for that core hole’s intended use.

b. Drill Core holes: Payment for drilling both sonic and conventional coring will be made at the contract unit price per linear foot, satisfactorily completed and accepted by the COR, and listed as Contract Bid Item “Sonic Core Drilling” known as Contract Bid Item No. 50 on the Bid Form. Casing shall be paid for under Payment for casing will be made at contract unit price per linear foot, satisfactorily completed and accepted by the COR, and listed as Bid Item 60 “Casing” on the bid form. No separate payment will be made for drilling soils vs. rock vs.

grout.

TS NO. 5 - GROUTING COREHOLES

5.1 Description: This work shall consist of pumping specified grout mixtures within drilled sonic core holes to backfill the shafts.

5.2 Equipment: All equipment used for injecting grout shall be furnished by the Contractor and shall be maintained in first-class operating condition at all times. The equipment shall be capable of placing all grout or aggregate mixtures contained within these specifications. The equipment shall be capable of grouting service, to include the agitating, pumping, and injecting of a cement-pozzolan-sand-aggregate grout mix. The Contractor's grout pump shall include the following:

a. All hoses and/or pipes, injection tubes/pipes and fittings required for grouting. The inside diameter of the hoses, supply lines, injection tubes/pipes, and other grout/aggregate mixture conveyors shall be selected by the Contractor. The Contractor is responsible for selecting an inside diameter which allows the Contractor to properly execute the work, meet the overall objectives of the contract, and convey the grout and/or aggregate mixes specified at the required slump or consistency for the final placement.

b. Such valves, pressure hoses, pressure gauges, pipe, fittings, and small tools as may be necessary to provide a continuous supply of grout and accurate control of the pressure and volume of grout being injected. The pressure gauge shall be graduated to ensure accuracy of ±1 psi. The pressure gauge shall be placed at the head of the grout supply pipe so that the downhole grout pressure can be accurately measured. Payment will not be made for excessive grout injected due to the inaccuracy of the Contractor's control.

5.3 Materials: Grout mixes shall be composed of a combination of water, cement, sand, fly ash, and gravel. The COR may also require the addition of accelerator or admixtures to the grout. Only pre-mixed grout delivered to the site in concrete mixer trucks will be acceptable for this project. Any other materials needed for this item shall be considered incidental to this type of work. All delivery tickets for concrete/grout mixtures delivered to the site shall be signed and certified as accurate by the batch plant owner, manager, or weigh master and indicate the actual weight (in pounds) for the following components:

dry cement, pozzolans (fly ash), sand, coarse aggregate, and accelerator (calcium chloride) for the mix contained in the truck. Water shall be shown in gallons. Delivery of any concrete/grout ordered by the Contractor where the ticket is hand written and not generated from the batch plant computer system shall be rejected and not paid for by OSMRE.

OSMRE may also take samples of the mixtures for laboratory analysis, slump tests, or other field tests to assess the cohesiveness and flow-characteristics of the grout underwater. If requested by the COR, the Contractor shall supply the COR with letters of certification that all materials to be used meet the requirements of this technical specification prior to commencing grouting activities.

a. Grout Mix Components

1. Water: The water used in the grout shall be furnished by the Contractor and shall be clean and free from injurious amounts of sewage, oil, acid, alkali, salts, organic matter, or other foreign solids deemed by the COR as deleterious to the grout mix.

2. Cement: Cement used in grout shall meet the requirements of ASTM C150-84 Type I or II. Cement shall be free from lumps due to storage. In the event the cement is found to contain lumps or foreign matter, in an amount the COR considers deleterious, screening through U.S. Standard 100 mesh screen shall be required. No additional payment will be made for such screening.

3. Sand for Grout Admixture: The sand shall consist of hard, dense, durable, uncoated rock fragments obtained from a river or quarry with not more than 5% of any deleterious substances. The fineness of the sand required for grouting shall be as follows: 45 to 80% shall pass a Standard No. 16 sieve and approximately 10 to 30% shall pass a No. 50 sieve.

4. Type "A" Coarse Aggregate for Grout Admixture:…