Land Measurement and Site Analysis

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Land Measurement and Site Analysis
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Introduction

• Environment awareness is increasing.
• Two reasons

• People are becoming more aware that we only have
  one place to live
• More people are accepting the fact that
  historically human activities have had a negative
  impact on the environment.

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The Results of Human Activities

• Increased industrial gasses
• Grass and trees converted to concrete and
  buildings
• Reduction of rainforests
• Increased energy use
• Habit changes
• Species extinction
• Environmental pollution

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Environmental Pollution

• In an industrialized society a wide variety of
  compounds are released to the environment every
  day from residential, commercial and industrial
  sources.
• These releases are referred to as discharges.
• Many of these releases pose no potential harm for
  the environment.
• Hazardous substances pose potential harm to the
  environment.
• A hazardous substance is defined as any substance
  that is a physical hazard or a health hazard
  (i.e., compressed gases, explosives, flammables,
  oxidizers, carcinogens, toxins, irritants, or
  corrosives)1.
• Hazardous substances generally have a material
  safety data sheet (MSDS) provided by the
  manufacturer.

1www.doc.state.ok.us/offtech/op150310.pd
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Hazardous Substance

• Determining the existence of a hazardous
  substance in the environment does not necessarily
  mean it needs to be or can be corrected.
• Many measurable hazardous substances are
  naturally occurring.
• Metals
• Salts
• Nitrates
• Sediment
• Oil seeps

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Probability of Occurrence

• All industrial and natural processes have a
  probability of an incident releasing compounds
  into the environment.
• The greater the use or quanity -- the greater the
  probability of accidental or intentional release.
• The greater the resources (cost) required for
  proper desposial -- the greater the probability
  of inadequate disposal or intentional release.
• Modern societies use a large quantity of organic
  and inorganic compounds.
• High probability that organic and inorganic
  chemicals will be released into the environment.

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Environmental Standards

• When it is impossible to prevent hazardous
  substances from reaching the environment, then
  standards of acceptability must be established.
• The setting of standards has become the
  responsibility of local, state and federal
  governments.
• Not all stakeholders will agree on standards of
  acceptability.
• Requires compromise and in most cases,
  legislation to cause a change.
• Whenever the standards are exceeded, the extent
  of the contamination must be determined. Such
  things as
• Area
• Depth
• Concentration
• Mobility
• Transport mechanisms
• Surrounding affected areas

All of these require measurements.
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Forms of Hazardous Substances

• Hazardous substances enter the environment in
  three common forms
• Liquid
• Solid
• Vapor

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Sources of Hazardous Substances

• Sources of contaminants divided into to two (2)
  categories.
• Point source
• Non point source.
• Point source
• Small scale localized.
• Once source is identified measurements can be
  completed.
• Non point source
• Large scale not localized.
• Difficult to locate and collect information.

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Examples of Point Sources

• Waste pit
• Buried waste
• Mine waste
• Chemical spill
• Industrial drain

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Examples of Non Point Sources

• Agricultural runoff
• Polluted runoff
• Polluted rainfall
• Air pollution

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Natural Remediation

• The environment is capable of remediating many
  chemicals.
• There are several limitations to natural
  remediation.
• Can be a slow process.
• Pollutant concentration can overpower organisms.
• May be a time delay before the natural organisms
  concentration is high enough for the contaminate
  concentration.
• One problem with natural remediation is than many
  chemical pollutants are compounds -- not single
  chemicals.
• Compounds are harder to identify.
• The effects of compounds are not as clear.
• Remediation of compounds is more complex.

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Risk Assessment

• Environmental risk assessment involves the
  collection of sampling and monitoring data.
• Statistical analysis is used to characterize the
  data and provide input values to be used in the
  evaluation process.
• Once collected an analyzed, the nature, magnitude
  and likelihood of adverse effects on human health
  or the environment can be assessed.
• Must consider the concentration, hazardous limit,
  pathway of exposure and transport mechanisms.

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Sources of Information

• Soil samples
• Air samples
• Observations
• Measurements
• Monitoring wells

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Data to Collect

• Area
• Slope
• Identification of contaminate(s)
• Chemical
• Radioactive
• Biological
• Quantity of contaminate
• Total amount
• Concentration

• Pathways
• Contact
• Inhalation
• Ingestion
• Transport processes
• Transport agent
• Direction of any movement
• Rate of movement

Requires measuring and recording many different
parameters
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Three (3) Transport Mechanisms

• Advection The movement of a chemical by virtue
  of its presence in a medium, which happens to be
  flowing.
• Common advection processes
• Outflow and inflow of air.
• Inflow and outflow of water.
• Inflow and outflow of aerosol particles in air.
• Inflow and outflow of particles, dissolved
  chemicals and biota in water.
• Vertical transport of air.
• Flow of water from surface soil to groundwater.
• Out gassing of soil vapor.
• Others?

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Three (3) Transport Mechanisms--cont

• 2. Diffusion Redistribution of a chemical
  within a media because there is a tendency for
  the chemical to move from areas of high
  concentration to areas of low concentration.
• The rate of chemical diffusion varies
• Chemical properties
• The properties of the medium
• Soil
• Water
• Aerosol
• Size of molecule
• Large molecules tend to diffuse at a slower rate
  than small ones.
• Temperature
• Diffusion rates are usually faster at higher
  temperatures

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Three (3) Transport Mechanisms--cont

• 3. Dispersion (turbulent diffusion) any
  deviation in the mean flow, mixing.
• Sources of dispersion
• Difference in temperature
• Mechanical
• Suppression of dispersion
• Temperature
• Density differences
• Viscosity

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Richard Corsi Transport Model
B Biosphere L Lithosphere H Hydrosphere A
Atmosphere D Discharge R Recharge
These reactions can change the concentrations of
a chemical or transform a chemical into another
chemical species
http//www.ce.utexas.edu/prof/maidment/risk/lectur
e/Lect3/LN3973.html
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Risk Management

• Def Eliminating or controlling the risk
  associated with a hazardous substance with the
  goal of reducing the risk to an acceptable level.
• Elimination
• May require physically removing contaminant(s)
  (oil spill)
• May mean isolation of the contaminant(s)
• Control is through remediation
• Neutralizing the contaminant(s)
• Diluting contaminant(s)

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First Step in Risk Management--Discovery
You cant fix it if you dont know its broken.

• 1. Discovery process is varied and may be
  unpredictable and unreliable.
• Highway accident
• Real estate inspection
• Government inspection
• Anonymous complaint
• Personal observation

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Second Step in Risk Management--Site
Investigation.

• Purpose of site investigation is to determine the
  nature of the problem, the area involved and to
  gather information for risk assessment.
• May depend on historical information.
• Governmental agency or industry previously using
  site.
• May require investigative work at county court
  house, newspaper office, neighbors, etc.
• A minimum of a three (3) step process.
• Desktop study
• Walkover survey
• Detailed site investigation

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Site Investigation--Three steps
Step one and two

• 1. Desktop study
• 2. Walkover survey Look for visual clues
• Unusual looking soil
• Old foundations
• Back fill areas
• Subsidence and/or poor drainage
• Trees in a pattern
• Dead plants or animals

Location, area and pertinent features will need
to be recorded.
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Site Investigation--Third step
Step three

• 3. Detailed site investigation
• Pitting, trenching and drilling reveal the
  sub-surface characteristics.
• Soil and water samples are taken for chemical
  analysis.
• Geophysical surveys can yield valuable
  information about sub-surface features.
• Must be conducted by qualified individual.
• Qualifications for inspector is determined by the
  nature of the contaminant.
• The acceptability of the results is dependent on
  the reputation of the inspector.
• Should follow acceptable methods and techniques.

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Site Investigation--Third step--cont.

• Inspector must protect themselves against
  contamination.
• Personal protection equipment
• Must have correct equipment for the contaminant
  and it must be disposed of properly when done.
• Inspector must insure they do not increase
  transport of the contamination.
• Site investigation may be under adverse
  conditions.
• Land owner resistance
• Environmental conditions

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Third Step in Risk Management--Remedial Plan

• Once the nature, concentration and hazards of the
  site are known, a remedial plan can be developed.
• May involve several stake holders.
• Land owner
• Neighbors
• Local government
• Federal government
• Must meet current standards and requirements.
• Must be economically feasible.

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Fourth Step in Risk Management--Monitoring

• Remedial plans require monitoring.
• Cost must be budgeted in initial proposal.
• Reporting procedures must be part of initial
  plan.

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Summary

• Evaluate the nature and extent of site
  contamination
• Determine alternatives and overseeing cleanup.
• Developing a monitoring program.
• Establish and administer laboratory quality
  assurance management program to ensure
  high-quality, defensible analytical data and
  supporting documentation

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Questions ?