Soils and Geological Resources (including Seismicity and Geo Hazards) Mitigation Measures

Mitigation measures to avoid or reduce impacts on soils and geological resources from oil and gas production.

The following are examples of mitigation measures that could be applied to reduce impacts of a project on soils and geological resources depending upon site- and project-specific conditions. Impacts to soils and geological resources are related to the project footprint (e.g., land disturbance, erosion) and the extraction of raw materials for project use. Many impacts can be reduced or avoided when considered during the siting and design phase.

Develop a final set of mitigation measures for any project in consultation with the appropriate federal resource management agencies and stakeholders. Conduct these consultations early in the project development process and preferably prior to final project siting and design.

Siting and Design Mitigation Measures

• Identify and avoid areas with unstable slopes and local factors that can cause slope instability (groundwater conditions, precipitation, seismic activity, slope angles, and geologic structure).
• Minimize the amount of land disturbed as much as possible. Use existing roads, disturbed areas, and borrow pits and quarries. Minimize vegetation removal.
• Place access roads to follow natural topography, and avoid or minimize side hill cuts. New roads should avoid going straight up grades in excess of 10%. Design roads with eventual reclamation in mind.
• Design runoff control features to minimize soil erosion.
• Construct drainage ditches only where necessary. Use appropriate structures at culvert outlets to prevent erosion.
• Use special construction techniques in areas of steep slopes, erodible soils, and stream crossings.

General Mitigation Measures

• Reclaim or apply protective covering on disturbed soils as quickly as possible.
• Apply erosion controls to prevent/minimize soil erosion from vehicular traffic and during drilling/development activities (e.g., jute netting, silt fences, and check dams).
• Maintain vegetative cover within road rights-of-way (ROWs) to prevent erosion and periodically monitor ROWs to assess erosion.
• Clean and maintain catch basins, drainage ditches, and culverts regularly.
• During all phases of the project, keep equipment and vehicles within the limits of the initially disturbed areas.
• In areas of potential wind erosion, apply gravel to access road surfaces.

Project Phase-Specific Mitigation Measures

Mitigation measures specific to a particular phase of an oil and gas project include:

Drilling/Development Practices

• Avoid creating excessive slopes during excavation and blasting operations.
• Obtain borrow material from authorized and permitted sites.
• Dispose of excess excavation materials in approved areas to control erosion and minimize leaching of hazardous materials.
• Save topsoil removed during drilling and development activities and use to reclaim disturbed areas upon completion of those activities. Apply interim reclamation measures to non-travel surfaces of roads and to well pad areas not needed for production purposes.
• Minimize the occurrence and velocity of flyrock during blasting activities (e.g., by use of blasting mats) and keep ground vibration to safe levels.

Decommissioning/Site Reclamation

• Backfill any foundations and trenches, preferably with excess excavation material generated during the drilling/development phase.
• Use topsoil removed during the beginning of the project or during decommissioning activities to reclaim disturbed areas.
• Reestablish the original grade and drainage pattern to the extent practicable.
• Stabilize all areas of disturbed soil using weed-free native shrubs, grasses, and forbs.