ENVI 485 2/6/07 Introduction to Environmental Geology (cont.) Land use planning Introduction to soils

Fundamental Concepts of Environmental Geology Population growth Sustainability The earth system Uniformitarianism Hazardous earth processes Geology as a basic environmental science

Fundamental Concepts-Geology as a basic environmental science  Geology is a factor in every person’s life:  “Civilization exists by geological consent…subject to change without notice”--Will Durant

Fundamental Concepts-Geology as a basic environmental science  Branches of Environmental Geology:  Geomorphology (Geologic Landforms and Processes)  Hydrogeology (Water and soil / rock interactions)  Pedology (Soils)  Economic geology  Engineering geology  Classical geology

Fundamental Concepts-Geology as a basic environmental science  Environmental problems are interdisciplinary  Physical Geography, geologic processes, hydrology, rock types, soil types, climate  Biological  Plants, animals, biologic conditions, spatial analysis of biologic information  Human interest/use Land use, economics, aesthetics, environmental law, hazards, historical/archaeological value

Environmental Geology and Land-Use Planning There is a limited supply of land  We strive to plan so that suitable land is available for specific uses for this generation and those that follow  Comprehensive plan – designed for long-range local development based on an environmental inventory of resources and hazards

Landscape Evaluation  Environmental geologists provide geologic information and analysis to assist in planning, design, and construction Former and present land use Physical and chemical properties of earth materials –Pollutants –Engineering Properties of soil and rock Natural hazards Groundwater characteristics

Site Selection  Cost-Benefits Analysis – Assumes all relevant costs and benefits can be determined Examples: Building a shopping mall in a flood zone; Drilling oil wells in National Parks?  Physiographic Determination-applying ecological principals to planning Considers physical, social, and aesthetic data Let natural characteristics determine the choice of a site

Environmental Impact Analysis  National Environmental Policy Act (NEPA) All major federal actions which could affect the quality of the human environment must be preceded by an evaluation of the project and the potential impact to the environment Environmental Impact Statements (EIS) –Discussion of the environmental consequences of the proposed project and of the alternatives  State Environmental Impact Legislation State Environmental Policy Acts (SEPAs) –California Environmental Quality Act (CEQA)

What do Environmental Geologists do? Mostly Site Assessments (ESAs) and Brownfields Studies

What are “Brownfields”? brownfield site –“real property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant.”

Sampling/Analysis – Sampling Methods n Conventional –borings/excavation –groundwater monitoring wells –decontamination/ plugging/abandonment/ waste disposal –crude field-screening –off-site analysis n Accelerated –geophysical surveys –direct-push probes –field labs/test kits –off-site analytical confirmation –electronic data archiving/interpretation

What are ESAs? n Identify/evaluate: – environmental concerns –Magnitude and extent of contamination –Cleanup goals –Remediation options –Future land use

Phase I ESA n Identify potential environmental concerns n All Appropriate Inquiry –Records review –Site reconnaissance –Interviews –Report

Phase II ESA n Evaluates potential concerns from Phase I n Tailored to site-specific needs Limited sampling/analysis »Confirm/rule out concerns Expanded sampling/analysis »Amount and extent of contamination Recommended cleanup goals/options Increasing Costs

Phase III ESA n Corrective actions for environmental concerns

What are ESAs? – Summary Land Uses Contaminants & Related Risk Site Improvements Focus on: Past, Present & Future

Sampling/Analysis – Sampling Methods n Conventional drilling/sampling technology

Sampling/Analysis – Sampling Methods n Screening/field-based methods - Direct-push methods

Sampling/Analysis – Sampling Methods n Geophysical Methods Electromagnetic Conductivity & Magnetic Surveys Ground-Penetrating Radar

Soils  Crucial to land use planning  Waste disposal  Evaluation of natural hazards  Flooding  Landslides  Earthquakes  Evaluation building construction

Soils as a natural resource “The thin layer of soil covering the Earth’s surface represents the difference between survival and extinction of most terrestrial life”

Soil: Definition  Soil Scientist:  Solid earth material that can support rooted plant life  Engineer / Geologist:  Earth material that can be removed without blasting (any earth material that is ripable)

What sphere of the earth system includes soil?

What is soil made of?

Components of soil: 1. Minerals inorganic materials derived from weathering rocks extremely variable in size. Provide nutrients to plants Basis for soil classification

Components of soil: 2. Air Pore spaces filled with air or water comprise 1/2 the volume. The amount and composition of air in a soil are determined by the water content of the soil. Metabolic activity of roots, microbes and fauna change the composition of soil air. (Carbon dioxide greater than atmosphere).

Components of soil: 3. Water Water is the major transport agent in soil –Within the soil –To groundwater participates in geochemical cycles –weathering geological substrates –leaching materials to groundwater –moving ions and particles through the soil profile. Organisms alter the suite of solutes in percolating water

Components of soil: 4. Organic Material includes: –living organisms (soil biomass) –remains of organisms –decomposed organic compounds

What is soil? Open, dynamic, natural bodies in the landscape. exchange water and air with the atmosphere, and ions and minerals with the lithosphere Plants introduce reduced carbon to support a heterotropic biomass Decomposition of these substrates results in the cycling of nutrients

Controls on soil formation Climate Topography Parent material Time Organic Processes

Soils Soil forming process produce distinctive layers (horizons) defined by the processes that form them –Leaching –Oxidation –Accumulation of minerals