Excavation. Function: EHS Number: HAN-EHS-SPI-0278 Page: 1 of 18 Original Effective Date: Reviewed 07/03/18 Effective: Supersedes: 03/17/17

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1 Number: HAN-EHS-SPI-0278 Page: 1 of 18 Preparer: Owner: Approver: EHS Specialist EHS Team Leader Site Director J. Hooker (Electronic Approval via MOC) J. Walker (Electronic Approval via MOC) P. Waddington (Electronic Approval via MOC) Rev. No. Rev. Date Change Control Document ID Description of Revision /25/ TESH Implemented new documented procedure and included the environmental/industrial hygiene expectations for excavation on the Hannibal site. The following changes were completed: Updated Form to include Corrective Action Management Zone HAN- EHS-PAU-056, Updated Daily Checklist HAN-ENG-FRM-0005 as a requirement for all excavations, updated Permit HAN-ENG-FRM /17/ S&H Added definitions, reformatted and organized for clarity /03/ S&H Added Section 2.2 Competent Person & deleted Section 2.10 Qualified Person definition. Changed daily excavation permit requirement to duration of excavation and added daily revalidation of excavation permit. 1. PURPOSE To establish minimum requirements to ensure safe excavation, reduce the potential of underground pipes or cables, and ensure proper handling of excavated soil in accordance with environmental regulations by establishing guidelines for excavation. 2. DEFINITIONS 2.1. Area of Concern (AOC) An area of soil or groundwater contamination specifically delineated within the site s RCRA Corrective Action RCRA Facility Assessment Competent Person An individual who is capable of identifying existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous or dangerous to workers and who is authorized to take prompt corrective measures to eliminate them Confined Space A space, (such as tanks, vessels, silos, storage bins, hoppers, vaults, pits, ditches and sewers) that: Is large enough and so configured that a person can Bodily Enter and perform assigned work; and

2 Number: HAN-EHS-SPI-0278 Page: 2 of 18 Has Limited or Restricted Means of Entry or Exit; and Is not designed for continuous employee occupancy Any man-made cut, cavity, trench, or depression in the earth surface formed by earth removal Work Grass stripping, power auguring, concrete drilling, concrete/asphalt sawing, breaking/removal of concrete (where earth is directly under the concrete), earth removal and relocation, installation/maintenance of underground utility system, new pipe installation, new foundation, well drilling, horizontal boring, vegetation removal, trenching, installation of sign posts, etc Field Representative Unit/department representative following the job in the field during construction/project Hazardous Atmosphere An atmosphere that may expose personnel to the risk of death, incapacitation, impairment of the ability to self-rescue, injury, or acute illness from one or more of the following causes: Flammable gas, vapor or mist in any detectable concentration using a calibrated combustible gas indicator operating in the percent range of sensitivity. Airborne combustible dust at a concentration that meets or exceeds its lower flammable limit. This concentration may be approximated as a condition in which the dust obscures vision at a distance of 5 feet (1.52 m) or less. Atmospheric oxygen concentration below 19.5 percent or above 21.0 percent. Atmospheric concentration of any substance that could result in employee exposure in excess of its occupational exposure limit. Any other atmospheric condition that is immediately dangerous to life or health Oxygen Deficiency An atmosphere containing less than 19.5% oxygen Protective System A method of protecting employees from cave-ins, material that could fall or roll from an excavation face or into an excavation, or from the collapse of adjacent structures. Protective systems include support systems, sloping and benching systems, shield systems, and other systems that provide the necessary protection Requestor Person initiating the Permit Form Shield System A structure capable to withstand the forces imposed on it by a cave-in and thereby protect employees within the structure. Shields can be permanent structures or can be designed to be portable and moved along as work progresses. Additionally, shields can be either premanufactured or job-built in accordance with (c)(3) or (c)(4).

3 Number: HAN-EHS-SPI-0278 Page: 3 of 18 Shields used in trenches are usually referred to as "trench boxes" or "trench shields." Shoring System Structure composed of such materials as metal hydraulic, mechanical, or timber, that supports the sides of an excavation and which is designed to prevent cave-ins Sloping System Method of protecting employees from cave-ins by excavating to form sides of an excavation that is inclined away from the excavation. The angle of incline inquired to prevent cave-in varies with differences in such factors as soil type, environmental conditions of exposure, and application of surcharge loads Support system Underpinnings, bracing or shoring that provide support to an adjacent structure, underground installation, or the sides of an excavation Trench (Trench ) A narrow excavation (in relation to its length) made below the surface of the ground. In general, the depth is greater than the width, but the width of a trench (measured at the bottom) is not greater than 15 feet. If forms or other structures are installed or constructed in the excavation, so as to reduce the dimension measured from the forms or structure to the side of the excavation to 15 feet or less (measured at the bottom of the excavation), the excavation is also considered to be a trench. 3. SCOPE This procedure applies to BASF Employees, contract employees, or contractors involved in any planned ground penetrating activity that extends below the ground surface at the Hannibal Site. Exceptions: Hand dug excavations do not normally require an Permit HAN-ENG- FRM-0004, but must be considered on a case-by-case basis. Surface maintenance with road graders or box blades that does not include repair or modifications below road grade does not require an Permit. During emergency clean-up of spills, it may be necessary to remove contaminated soil in a timely manner. For this reason, excavations may take place up to 12 inches deep without the use of a permit. The incident commander responsible for the spill must approve this practice. 4. PROCEDURE 4.1. General Requirements All ground penetrating activities must include a completed Permit HAN-ENG-FRM-0004 and the work must adhere to the requirements of this procedure. Emergency situations will be reviewed on a case-by-case basis, but at a minimum requires verbal approval of the Unit/Facility Manager or designee All employees signing the Permit, HAN-ENG-FRM-0004, shall verify

4 Number: HAN-EHS-SPI-0278 Page: 4 of 18 it is filled out completely. Each person signing the Permit, HAN- ENG-FRM-0004, must inspect the excavation area prior to approving the permit using the Daily Checklist, HAN-ENG-FRM If performing subsurface work in or near Corrective Action Management Zone, Areas of Concern (AOC), or in areas where potential exposure exists an EHS review and approval is required For excavations outside the plant fence perimeter or at the discretion of the Permit approver, the Project Manager is responsible for contacting or ensuring the Contractor has contacted the buried line and cable location service at least two days prior to planned start date. Missouri One Call System: 800-DIG-RITE ( ) or 811 or mocall1.com of materials shall only be performed under authorization by BASF personnel responsible for the scope of work Before any excavation begins the location of utility installations (i.e. sewer, telephone, fuel, electric, water lines, or any other underground installations) that may be encountered during digging shall be identified. BASF Site Utilities, outside utility companies or owners involved shall be notified at least forty-eight (48) hours before work is to begin The BASF Project Manager and Permit Approver shall ensure all locates have been performed as noted on the Permit, HAN-ENG- FRM If the locating party cannot identify the exact location of the utility installations, the BASF representative may issue the permit and have the responsible party proceed with caution To find the exact location of underground installations, workers must use safe and acceptable means If underground installations are exposed, they shall be protected or properly supported Each trenching, shoring and back filling job shall be approached with the utmost care and preparation Refer to Appendix A for procedural steps and responsibilities for all excavation activities On the Job Evaluation s and adjacent areas shall be inspected daily by a competent person for possible cave-ins, failures of protective systems and equipment, hazardous atmospheres, or other hazardous conditions If these conditions are encountered, exposed employees must be removed from

5 Number: HAN-EHS-SPI-0278 Page: 5 of 18 the hazardous area until the necessary safety precautions have been taken Inspections are required after natural (i.e. heavy rains) or manmade events such as blasting that may increase the potential for hazards Project Managers and Competent Persons shall conduct inspections, investigate accidents, and anticipate hazards If evidence of soil or groundwater contamination is discovered during the excavation, contact EHS for disposition of contaminated material Inspections shall be documented using HAN-ENG-FRM-0005, Inspection Cave-In and Protective Support System OSHA requires excavations where employees are exposed to potential caveins, employees must be protected by sloping, or benching the sides of the excavation, supporting the sides of the excavation, or placing a shield between the side of the excavation and the work area. This is regardless of the depth of the excavation s deeper than four (4) feet require a means of protective system to be utilized prior to employees accessing the excavation One method of ensuring the safety and health of workers in an excavation is to slope the sides to an angle not steeper than one and one-half horizontal to one vertical (34 degrees measured from the horizontal). These slopes must be excavated to form configurations that are according to the soil type tested for in the pre-excavation assessment. Any soil not evaluated shall be considered Type C soil. Refer to the information found in OSHA Appendix B - Sloping and Benching. A slope of this gradation or less is considered safe for any type of soil (see Figure 1). Figure 1. s Made in Type C Soil All simple slope excavations twenty feet or less in depth shall have a maximum

6 Number: HAN-EHS-SPI-0278 Page: 6 of 18 allowable slop of 1 ½: A second design method, which can be applied for both sloping and shoring, involves using tabulated data, such as tables and charts, approved by a registered professional engineer. Data shall be in writing and include sufficient information to enable the user to make adequate decisions based upon the limits of the data. At least one copy of the information, including the identity of the registered professional engineer who approved the data, must be kept at the worksite during construction of the protective system. A trench box or shield that is either designed or approved by a registered professional engineer or is based on tabulated data prepared or approved by a registered professional engineer may be used. Timber, aluminum, or other suitable materials may also be used Safety Precautions Support systems such as shoring, bracing, or underpinning to ensure the stability of adjacent structures such as, buildings, walls, sidewalks, or pavements shall be used as needed No excavation below the level of the base or footing or any foundation or retaining wall shall be performed unless: A support system such as underpinning is provided; A registered professional engineer determines that the structure is sufficiently removed from the excavation and that excavation will not pose a hazard to employees s under sidewalks, roads or other paved areas are also prohibited unless an appropriately designed support system by a registered professional engineer is provided, or another effective method is used Installation and Removal of Protective systems The following procedures for the protection of employees when installing support systems shall be followed: The system is designed to resist the forces calculated for the full depth of the trench. There are no indications, while the trench is open, of a possible cave-in below the bottom of the support system. Also, the installation of support systems must be closely coordinated with the excavation of trenches Materials and Equipment The Project Manager and Contractor Competent Person are responsible for the safe condition of materials and equipment used for protective systems To avoid possible failure of a protective system, the Competent Person must ensure that: Materials and equipment are free from damage or defects. Manufactured materials and equipment are used and maintained in a manner consistent with the recommendations of the manufacturer and that will prevent employee exposure to hazards. While in operation, damaged materials and equipment are examined by a

7 Number: HAN-EHS-SPI-0278 Page: 7 of 18 Competent Person to determine if they are suitable for continued use If materials and equipment are not safe for use, they must be removed from service. These materials cannot be returned to service without the evaluation and approval of a registered professional engineer or Manufacturer s Representative written authorization Falls and Equipment Hazards In addition to cave-in hazards and secondary hazards related to cave-ins, there are other hazards from which workers must be protected during excavationrelated work. These hazards include exposure to falls, falling loads, and mobile equipment The contractor performing the excavation work is responsible for erecting proper barricading around the excavation and installing the proper shoring and/or creating the proper slope in the excavation. Refer to Appendix.B The Competent Person and Project Managers shall ensure the following precautions are followed: Keep materials or equipment that might fall or roll into excavation at least two feet from the edge of excavations, have retaining devices, or both. Provide warning systems for mobile equipment to include barricades, hand or mechanical signals, or stop logs to alert operators of the edge of an excavation. If possible, keep the grade away from the excavation. Provide scaling to remove loose rock or soil or install protective barricades/ protection protect employees against falling materials. Prohibit employees from working on faces of sloped/ benched excavations above other employees unless employees at lower levels are adequately protected from the hazard of falling, rolling, or sliding material or equipment. Prohibit employees from being under elevated loads to include any spillage or falling materials. Drivers shall stand away from vehicles being loaded or unloaded or if cab protectors are used the operators may remain in cabs Water Accumulation Employees shall not work in excavations where water has accumulated or is accumulating unless adequate protection has been taken If water removal equipment is used to control or prevent water from accumulating, the equipment and operations of the equipment must be monitored by a competent person to ensure proper use If water accumulating in the excavation is believed to be contaminated (e.g., in the Corrective Action Management Zone) it must be analyzed for contamination before it is removed. If found to be contaminated, the water must be collected and disposed of through the site incineration facilities, under the direction of EHS and the Incineration/Utilities Department Equipment used to pump out contaminated water must be decontaminated after use Diversion ditches, dikes, or other suitable means may be used to prevent surface water from entering an excavation and to provide adequate drainage of the area adjacent to the excavation. Also, a competent person shall inspect excavations subject to runoffs from heavy rains.

8 Number: HAN-EHS-SPI-0278 Page: 8 of Access and Egress Supervisors shall ensure that safe access and egress to all excavations is maintained. This includes wearing of appropriate PPE specified by EHS if the excavation is occurring in a contaminated or suspected contamination area When employees are required to be in trench excavations four feet deep or more, adequate means of exit, such as ladders, steps, ramps or other safe means of egress must be provided and be within twenty-five feet of lateral travel Any structured ramps used solely for worker access or egress must be designed by a competent person. Structural ramps used for access or egress of equipment must be designed by a competent person qualified in structural design. Also, structural members used for ramps or runways must be uniform in thickness and joined in a manner to prevent tripping or displacement The project manager must make certain that documentation of the exact location of all obstructions and new installations underground is made during and after the excavation. This may include taking photos of the underground obstructions and flagging the area above them. All documentation must be submitted with the permit to the engineering department for filing and redrafting of excavated area Any excavation that exceeds 4 feet in depth requires a confined space permit; with the following exceptions: If no one will be entering the excavation. If there is a low potential for a hazardous atmosphere to exist. Consult with EHS for determination if an excavation would meet the low potential requirement Restrictions and Guidelines An excavation permit, HAN-ENG-FRM-0004, shall be issued for the duration of excavation work. The excavation permit must be revalidated each day by the safe work permit issuer and documented on the back of the excavation permit. permits do not require reissue except for the following: change in work scope, change in work area conditions, or at the request of Owning/Operating Department When obstructions exist, it is recommended that an employee be provided to assist the equipment operator with locating obstructions Inspection of excavations, adjacent areas and protective systems must be performed by a competent person daily or after each weather event All soils on the BASF Hannibal Site are Class C Do not enter an excavation greater than 4 feet without proper shoring or sloping Contact EHS before entering an excavation greater than 4 feet in depth to determine if a confined space permit is required Personnel working within barricading and adjacent to vertical excavations greater than 4 feet are required to use fall protection Do not stand on the edge of the excavation Stay clear of machine operation and remain in the operator s view Obtain other pertinent permits such as Confined Space Entry, HAN-EHS- FORM-0002, and Safe Work Permit.

9 Number: HAN-EHS-SPI-0278 Page: 9 of All excavations must be barricaded in a manner to stop someone from accidentally walking into the excavation. Temporary fencing is recommended around all excavations. Danger and caution tape is not considered to be a sufficient means of barricading excavations left unattended Do not undermine any structures or poles Soil Disposition Generally, soil removed during an excavation can be returned to the excavation location, or applied as fill elsewhere on site, unless contamination is discovered (by visual or olfactory indication, or by soil analysis, etc.) Any soil removed from the Corrective Action Management Zone must be held for analysis, if it is not going to be returned directly to the excavation zone Contaminated soil that cannot be returned to the excavated area will be disposed of under the direction of EHS Emergency s Emergency excavations may be performed when the time constraints associated with this procedure threaten employee safety, the environment or property loss The following actions must be taken prior to an emergency excavation: Contact either the EHS Team Leader or EHS Specialist On-Call and inform them that an emergency excavation needs to be performed. Contact the Locator Service ( or 811) and inform them that an emergency excavation needs to be performed. Complete the Permit, HAN-ENG-FRM-0004, with as much information as possible. An emergency excavation does not remove the threat of underground obstructions. Therefore, it is necessary to assure excavation safety while still addressing the time constraints associated with the emergency. 5. Training 5.1. All BASF Safe Work Permit Issuers, Project Managers and Contractors will have awareness training on this procedure. 6. Responsibilities 6.1. Site Director The Site Director has the primary responsibility for the implementation of this procedure for the Hannibal Site BASF Project Manager The BASF Project Manager has the primary responsibility for the following: Assure Safe Work Permit, HAN-EHS-FORM-0303, has been issued. Initiate Permit, HAN-ENG-FRM-0004, process by filling it out and obtaining proper approvals before proceeding with excavation activities. Clearly define the excavation limits and ensure all underground obstructions are located and marked. Obtain EHS approval for excavations performed within Corrective Action Management Zone.

10 Number: HAN-EHS-SPI-0278 Page: 10 of 18 Coordinate with EHS to perform industrial hygiene monitoring during excavation in the Corrective Action Management Zone. Proper shoring and/or slope of the excavation walls. Refer to Appendix B. Contact EHS for soil disposition if excavation is within Corrective Action Management Zone. Ensure barricades remain in place for duration of excavation. Record changes in underground contents EHS Site Services EHS has the primary responsibility for the initiation, re-issuance, administration, and/or interpretation of this procedure, as well as the following: Confined space evaluation of all excavations greater than four feet in depth prior to any personnel entering excavation. Evaluation of emergency situations when time constraints associated with this procedure threatens employee safety, the environment or property loss. Ensure conditions stated in have been met Operation Managers, Production Managers and Supervisors The Operation Mangers, Production Managers and Supervisors have the primary responsibility for the implementation and enforcement of this procedure in their units BASF Employees, Contract Employees and Contractor Employees BASF Employees, Contract Employees, and Contractor Employees has the primary responsibility to comply with the requirements of this procedure. 7. Related Documents OSHA 29 CFR 1926 Subpart P - s HAN-ENG-FRM-0004 Permit HAN-ENG-FRM-0005 Inspection HAN-EHS-SPI-0231 Safe Work Permit HAN-EHS-SPI-0203 Confined Space HAN-EHS-SPI-0216 Contractor EHS Management HAN-EHS-PAU-056 Corrective Action Management Zone

11 Number: HAN-EHS-SPI-0278 Page: 11 of 18 Appendix A Table of Procedure Steps STEP PROCEDURE RESPONSIBLE PARTY 1 Obtain blank Permit HAN-ENG-FRM BASF Project Manager 2 Obtain all available drawings of the excavation area. BASF Project Manager Contact buried line and cable location service DIG-RITE ( ) or 811 at least two days prior to start date. Contact all persons required to sign the permit and let them know the time and area of the excavation. This will give them time to evaluate the area prior to signing the permit. Acquire signatures on permit of ALL personnel affected by the excavation including contractor performing the excavation. Determine the exact location of buried obstructions. If a metal probing rod is used to probe the dirt, the probe handles must be electrically insulated. If excavation is in Corrective Action Management Zone (HAN- EHS-PAU-056), arrange with EHS to issue IH monitoring plan, specify PPE requirements, and determine any soil sampling and special disposition requirements (e.g. offsite disposal if soil is contaminated). Perform excavation work. Ensuring that confined space procedures are followed and proper barricading is erected. BASF Project Manager/ Contractor BASF Project Manager BASF Project Manager Contractor BASF Project Manager Contractor 9 Record any changes in underground contents with Engineering. BASF Project Manager Ensure Permit is completed and underground infrastructures have been adequately located before permit approval. Complete Inspection and maintain copy at excavation site. Unit Permit Approver Contractor Competent Person *Completed Permits shall be posted and/or retained as follows: Posted with the original Safe Work Permit in the unit/department issued and in other affected units/departments, if applicable. The Safe Work Permit and Permit copy must be posted in area of the excavation; ideally on the piece of equipment doing the excavation work, if possible. A copy must be retained by the BASF Project Manager for future reference and documentation.

12 Number: HAN-EHS-SPI-0278 Page: 12 of 18 APPENDIX B Safe and Shoring Training A. INTRODUCTION This program outlines specific recommendations and procedures for safe excavation and shoring. This program complies with the applicable codes of Federal OSHA 29 CFR Part 1926 Subpart P, for the most common types of trenching and shoring. For more complete information, refer to the actual codes. This program is designed for safe working conditions within an open trench that is shallower than twenty feet. In excavations exceeding twenty feet, the codes require the shoring system be designed by a professional engineer. This program contains only a summary of suggestions that one could take to increase the safety of trenching operations. No attempt was made in this program to provide a complete listing neither of the codes nor of common shoring practices. B. GENERAL In the excavation of a trench, many factors should be considered to prevent accidents. Walls of earth may look quite safe and harmless, but can be extremely dangerous if not properly sloped or shored. Therefore, a system of proven rules and formal procedures must replace subjective judgment or rules-of-thumb when designing and performing excavation work. into the ground permits forces previously held in equilibrium to act upon the exposed cut. These forces must be counteracted in some manner or a cave-in could occur. This can be done by trench shoring or sloping. C. BEFORE EXCAVATING 1. Locate hidden obstructions. 2. Obtain plans of as-builds to locate any underground pipes or utilities that would interfere with the trench. 3. Be aware that these records may not be accurate. Therefore, these obstructions should be physically located and either removed or protected from damage. D. BEWARE OF DISTURBED GROUND 1. Take precautions when excavating in previously back filled or disturbed soil. 2. Trenches in disturbed soil may require additional sheeting and bracing, as will hard compact ground, if there is filled ground nearby. 3. For example, a trench wall that is near another previously filled trench is unstable, although it might appear to be hard compact material.

13 Number: HAN-EHS-SPI-0278 Page: 13 of 18 Reviewed 03/17/17 Effective: 06/19/17 Supersedes: 10/25/11 E. WHEN TO USE SHORING 1. Per OSHA, all trenches over five feet in depth must be shored, sloped, or shields provided to protect workers. 2. The depth of the excavation is to be measured at its greatest vertical dimension. For example, when the trench is in a hillside, the depth should be measured on the uphill side. 3. Although a three-foot trench is less than the height of a worker, it can still pose a threat, since workers often work in a stooped or kneeling position. This makes them vulnerable even in such a shallow trench. F. SLOPING A TRENCH 1. One of the three methods of safeguarding workers in a trench is sloping. 2. Sloping involves cutting back the trench walls to an appropriate angle of repose. (See OSHA table B-1) 3. These angles vary from site to site depending on soil classification, water conditions, previous soil disturbances, etc. 4. The proper angle should be independently determined by a competent person for each site, and even each trench at the same site, if the conditions so warrant. 5. The angle of repose shall be flattened when the excavation has water conditions, silty material, loose boulders, and areas where erosion, deep frost action, and slide planes appear. G. SHORING OF TRENCHES 1. The function of trench shoring is to resist or replace the force on the excavation face. 2. The shoring of a trench can be accomplished with the use of wood timbers, screw jacks, hydraulic rams, or combinations of these methods. 3. Timbers should be in sound condition, free of major defects and equal to the grade size specified. Structural timber normally gives some warning by splintering or separation of wood fibers if failure is imminent. Workers should be alert for these warnings. 4. Steel shoring components give little warning before failure. Workers should watch for bent or otherwise damaged members. 5. If using hydraulic shoring, pressure gauges, cylinders and rails must all be in good condition. Signs of fluid leakage should be looked for and corrected. H. TRENCH SHORING

14 Number: HAN-EHS-SPI-0278 Page: 14 of 18 Reviewed 03/17/17 Effective: 06/19/17 Supersedes: 10/25/11 1. The type of shoring is dependent upon soil type and soil conditions. 2. Before excavating and shoring, determine the type of soil and design an appropriate shoring method considering the possibility of changing soil conditions. 3. Ground water and water intrusion can weaken the soil face, as well as adding weight, exerting additional force on the shores. 4. If the excavation is below the water line, shoring should be driven below the bottom surface of the trench to prevent undermining. Tight sheeting should be provided where seepage occurs. 5. The excavation should be kept dry twenty-four hours a day to avoid the possibility of saturation and possible failure of the excavation wall. I. SHORING IN HARD COMPACT SOIL 1. Struts must be placed in a true horizontal position and square to the sides of the trench at a maximum vertical spacing not to exceed OSHA Tables C1.1-C1.3, C2.1-C2.3, D1.1-D1.3, or manufacturers tabulated data. 2. Ends should be secured to prevent slippage of kick outs. 3. The lateral spacing between struts should not exceed manufacturers tabulated data, a professional engineer s specifications or OSHA Tables C , C , D All struts should be inspected daily for movement or decreased bearing pressure, and repairs, replacement or reinstatement completed before workers are allowed to enter the excavation. J. SHORING IN LOOSE UNSTABLE SOIL 1. The pressure exerted on shoring by unstable soil can be considerably greater than in stable soil. 2. Unstable soil may require increased strut size and/or decreased strut spacing. 3. Very loose soil requires closed (solid) sheeting with tight edge-to-edge contact. 4. Either wood or locking steel sheeting may be used when joints are required to be watertight. K. SHORING PROTECTION 1. All workers in a trench shall be protected by a shoring system (or shields) when depths exceed five feet. 2. Any shoring system used below twenty feet in depth must be designed by a registered professional engineer.

15 Number: HAN-EHS-SPI-0278 Page: 15 of 18 Reviewed 03/17/17 Effective: 06/19/17 Supersedes: 10/25/11 3. The placement of shores must be done promptly before anyone enters the trench. 4. Back filling should take place as soon as the shoring is removed. 5. All workers should be provided protective equipment dictated by the environment in which work is being performed. L. INSTALLATION OF SHORING SYSTEMS 1. The installation of shoring should be in a top down method. 2. Struts should be in a true horizontal position with ends secured to prevent slipping or sliding. 3. The uppermost shores should be placed first. 4. If possible, the next shores should be lowered from above before a worker enters the trench to set them. 5. When possible, installation work should be done from outside the trench, thereby not exposing workers to an unsupported trench. 6. Shore installation should follow the excavation work as close as possible. Dirt walls not shored can slough off causing dangerous overhangs. 7. The longer a trench is left unsupported, the greater the chance of a cave-in. M. REMOVAL OF SHORING SYSTEMS 1. Removal of shoring should proceed by a bottom up method. 2. A worker removing shoring must always remain in the protected zone. 3. Premature removal of the shoring leaves a worker totally unprotected. 4. Hydraulic shoring can be removed from above. 5. Timber or steel jacks are usually removed while inside the trench. 6. Before their removal, some force must replace that of the shores against the trench face. 7. For example, bottom and intermediate struts should not be removed until they have been effectively replaced by back fill material. N. WEATHER CONDITIONS 1. Changing weather conditions can affect the water content of the soil.

16 Number: HAN-EHS-SPI-0278 Page: 16 of 18 Reviewed 03/17/17 Effective: 06/19/17 Supersedes: 10/25/11 2. Excess water from rain or melting snow can liquefy firm soil and increase pressure on the shores. 3. Beware of shoring in frozen ground where a sudden thaw can undermine a shoring system and cause its failure. 4. Provisions must be made in the design of a shoring system to consider these increased loads. O. SOIL CHANGES 1. Some soils change their properties merely from exposure to air. 2. This softening is called air-slaking and will turn hard, solid soil to soft, slippery soil. 3. To prevent slaking, the time a trench is left open should be limited. This will also limit the exposure to detrimental weather changes. 4. In large excavations, which may need to be kept open, an application of a protective coating to the face, such as gunite, and added shoring will provide protection. P. VIBRATION 1. Vibration from nearby machinery, highways, or explosives will cause increased loads on a shoring system, and extra sheeting and shoring may be needed. 2. Loose rocks and chunks of earth that could fall in the trench should be removed. Q. SPOIL BANK LOCATION 1. Where the spoil is deposited can also affect the pressure on a shoring system. 2. These deposits should be no closer than two feet from the trench. 3. This distance should be increased when site conditions or size of the spoil pile warrant it. R. TRENCH ACCESS 1. Some means of access (most often ladders) into an open trench should be within twenty-five linear feet of every worker. 2. Ladders should be in good condition, extend three feet over the trench top, and be secured to prevent movement while in use. 3. Access should be provided for all excavations exceeding four (4) feet deep.

17 Number: HAN-EHS-SPI-0278 Page: 17 of 18 Reviewed 03/17/17 Effective: 06/19/17 Supersedes: 10/25/11 4. Walkways, runways, and sidewalks shall be kept clear of excavated material or other obstructions. 5. No sidewalk or road shall be undermined unless shored. S. EDGE PROTECTION 1. The edges of all open trenches must be protected. 2. If possible, bumpers should be provided to prevent equipment from falling in as well as barricades for the public s protection. 3. Excavated material, tools, and machinery must be secured or stored far enough away to prevent falling into the trench. 4. Good housekeeping creates a clean and safer jobsite. 5. Workers should not walk close to edges as their weight may cause localized failures and they may fall into the excavation. 6. Trenches must be crossed only where safe crossing nave been provided. T. INSPECTIONS 1. Daily inspections of the excavations shall be made by a competent person. 2. Checks of the system, soil conditions, and construction methods help detect unsafe conditions before they cause them. 3. Should an unsafe condition be discovered, work must stop immediately in the affected area, and corrective action taken. 4. Inspections should also be done after rainstorms, any other weather event or any change in the affected area (i.e. thawing of ground) and corrective action taken. U. EXCAVATION EQUIPMENT 1. All equipment must be operated only by a trained person, and at a safe speed. 2. Equipment should always be shut off when the operator leaves the cab. 3. If the operator does not have total view of the operation, a signalman shall be used who knows the standard signals used in construction. 4. No person shall be allowed under loads. V. CONCLUSION

18 Number: HAN-EHS-SPI-0278 Page: 18 of 18 Reviewed 03/17/17 Effective: 06/19/17 Supersedes: 10/25/11 The best method of accident prevention is a well-followed safety program that has the support of every worker on the jobsite. It should be the responsibility of every worker on the site to keep the job a safe one. REMEMBER: 1. Every shovelful of material dug from an excavation helps to create an unnatural condition in the ground. 2. This situation can be remedied by using shoring properly and promptly. 3. Proper trenching and shoring requires careful attention to details. 4. The design of a trenching and shoring system should consider hidden obstructions, disturbed ground, soil type, water conditions, weather conditions, soil changes, vibrations, and equipment usage. 5. Everyone concerned must plan, have adequate materials available, and be forever vigilant. 6. Doing a job right means doing it safely. 7. Plan what you dig -- follow your plan.