Groundwater and soil protection

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Groundwater and soil protection

• Environmental remediation

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Hydrologic cycle
When rain falls to the ground, the water does not
stop moving. Some of it flows along the surface
in streams or lakes, some of it is used by
plants, some evaporates and returns to
the atmosphere, and some sinks into the ground
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Groundwater flow
Groundwater is water that is found underground in
cracks and spaces in soil, sand, and rocks. The
area where water fills these spaces is called the
saturated zone. The top of this zone is called
the water table...just remember the top of the
water is the table. The water table may be only a
foot below the grounds surface or it may be
hundreds of feet down.
Groundwater is stored inand moves slowly
throughlayers of soil, sand, and rocks called
aquifers. The speed at which groundwater flows
depends on the size of the spaces in the soil or
rock and how well the spaces are connected.
Aquifers typically consist of gravel, sand,
sandstone, or fractured rock like limestone.
These materials are permeable because they have
large connected spaces that allow water to flow
through.
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Aquifers

• Aquifers are soil or rock layers that are good
  reservoirs that are easy to produce
• High porosity lots of pore space between grains
  to store water
• High permeability good connectivity between pore
  spaces so water can easily flow into and out of
  the reservoir.

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Above and below the water table

• The Water Table is the depth to the part of the
  soil or rock that is saturated with water
• Storage capacity (also related to specific yield)
  is how much water we can drain from an aquifer
• Saturated zone a portion of the soil profile
  where all pores are filled with water. Aquifers
  are located in this zone. There may be multiple
  saturation zones at different soil depths
  separated by layers of clay or rock.
• Unsaturated zone a portion of the soil profile
  that contains both water and air the zone
  between the land surface and the water table. The
  soil formations do not yield usable amounts of
  freeflowing water. It is also called zone of
  aeration and vadose zone
• Capillary Zone the transition between vadose
  phreatic (only a few cm thick, at most). Water
  can be wicked from phreatic to vadose zone.
  Deep phreatic zone can keep a shallower vadose
  zone productive in drought

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The contamination of groundwater and soil
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Legislative background

• Important international legislation on
  groundwater
• The Water Framework Directive of EUmaintain the
  balance of withdrawal and recharge and to prevent
  or reverse the deterioration of the qualitative
  status of groundwater
• Groundwater Protection Directive (80/68/EEC)
  deals with the protection of groundwater against
  pollution caused by certain dangerous substances.
  It classifies dangerous substances into List I
  and List II depending on the level of danger
  caused by the relevant substances
• The Nitrate Directive (911676/EEC) covers the
  protection of waters against pollution caused by
  nitrates from agricultural sources.
• The directive 85/337/EEC on the assessment of the
  effects of certain public and private projects on
  the environment
• The directive 96/61/EC concerning integrated
  pollution prevention and control
• The most important home legislation regarding the
  groundwater
• Act LIII of 1995 on the general rules of
  environmental protection
• The Government Decree No. 219/2004. (VII. 21.) on
  the protection of groundwater
• And in your country how does it works?

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Remediation process
Remediation is a procedure including technical,
economic and administrative activities aimed at
gaining knowledge about threatened, polluted and
damaged groundwater and geological media as well
as at ceasing or reducing contamination, damage
and risk, and at the monitoring thereof
Quantitative risk assessment means a detailed
assessment procedure based on the sitespecific
investigations of a given contaminated site. The
result is represented by risk ratio value,
expressing the proportion of the actual level of
pollution in the environmental elements
(especially in groundwater) and the levels of
pollution acceptable for the environment,
ecosystem and human beings
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Site investigation

• In the course of site-specific investigations
• the spatial occurrence of any such pollutant
  shall be investigated that may likely to be
  present as a result of activities and
  technologies applied on the site
• detailed chemical investigations shall be carried
  out in both the geological medium and groundwater
  to enable the detection of the occurrence of each
  pollutant causing the contamination.

• Report on site investigation
• Presentation of the affected area
• Methodology of site investigation
• Findings of the investigation
• Results of the risk assessment
• Presentation, characterisation of possible
  options for technical interventions
• Results of the cost-benefit and
  cost-effectiveness analyses
• Presentation and justification of the proposed
  option
• Plan of monitoring for the period following the
  site investigation

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Technical intervention
Treatment of soils, sediments and sludge In situ
technologies Bioventing , Enhanced
bioremediation , Landfarming , Natural
attenuation , Phytoremediation , Electrokinetic
remediation, Fracturing , Soil flushing , Soil
vapour extraction, Solidification/Stabilisation ,
Soil vapour extraction thermally enhanced Ex
situ technologies Biopiles , Composting ,
Degradation by fungi , Agrotechnical soil
treatment , Slurry phase bioremediation ,
Chemical extraction , Chemical oxidation-reduction
, Dehalogenation, Separation , Soil washing ,
Soil vapour extraction , Solar detoxification ,
Solidification, stabilisation , Hot gas
decontamination , Incineration , Open
burning/Open detonation , Pyrolysis , Thermal
desorption , Capping , Capping, drainage and
recultivation , Excavation, transport and
deposition with soil replacing Treatment of
shallow groundwater, surface water and leachate
In situ technologies Cometabolic degradation,
Enhanced bioremediation , Natural attenuation ,
Phytoremediation , Soil vapour extraction , Air
sparging , Vacuum-enhanced free-product recovery
and bioventing , Directional wells , Dual phase
extraction , In-well air stripping , Hot water or
gas stripping , Hydrofracturing, Passive/active
treatment walls Ex situ technologies Bioreactor
, Constructed wetlands , Adsorption, absorption ,
Air stripping , Activated carbon adsorption , Ion
exchange, Precipitation, coagulation , Separation
, UV oxidation, Groundwater pumping , Barriers
Treatment of exit gas (emission into air)
Biofiltration , High energy destruction ,
Membrane separation , Oxidation , Activated
carbon adsorption
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After the technical intervention

• Report on technical intervention
• Presentation of the completed technical
  intervention and remedial technology/technologies
  applied
• Results of the technical intervention
• Presentation of the remediation monitoring
  operated in the course of technical Intervention
• Draft proposal for remedial monitoring
• The responsible authority shall make a decision
  upon
• continuing the technical intervention if it is
  considered inefficient
• additional investigation or
• completion of the technical intervention and
  adoption of the final report also
• remedial monitoring and/or
• termination of remediation.

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Remedial monitoring

• Determination of the installations of the
  monitoring systems
• Scope of the monitored parameters in different
  environmental elements.
• Frequency of monitoring.
• Methodology of the measurements, observations,
  detection and sampling.
• Registration of the measured, detected and
  observed data, and order of data processing.
• Order of data evaluation and reporting. Results
  of the evaluation shall include outcomes on
  the following
• the condition of the monitoring installations
• sampling regularity
• sampling reliability
• the reliability of field analyses
• the reliability of laboratory analyses
• the correlation between data and the relevant
  limit values
• trend analyses and the identifiability of trends
• proposal for eventual modifications.
• Short overview of monitoring results,
  specifically detailing as to what part of the
  polluted area was spatially delimited by
  monitoring.

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Environmental risk
Effect In this instance, the influence of soil
contamination on human beings and the
environment. The effect can be a measurable
change in the soil or recipient in relation to
the expected condition as a result of the
influence from the contaminated site. The effect
includes concentrations above the natural
background level and the influence on life
generally. Effects may be negative, positive or
neutral with respect to life and health.
Exposure Contact between a chemical substance
and a receptor (human beings or the ecosystem).
Source Location and content of priority
pollutants in the ground, supplied by deposition
or contamination from anthropogenic activities.
The source refers to the original placement and
contents of the contaminant, independent of
distribution and degradation.
Risk Risk designates the danger that undesirable
events represent for humans, the environment
(ecosystem) or material values. Risk is expressed
as the probability and consequences of the
undesirable events.
Transport (mechanism) The different mechanisms
leading to the migration of the contaminant (for
example in the air, soil or water phase).
Receptors General description of human beings,
animals, birds, plants, fungi, algae, fish,
crustaceans, shellfish and bacteria.
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Risk assessment investigation

• The following parameters
• must be determined
• all relevant exposure pathways.
• expected contaminant concentrations in all the
  different exposure pathways (load/dosage).
• which receptors (humans, animals, fish,
  shellfish, birds, plants, mushrooms, algae,
  bacteria, etc.) are most likely exposed to the
  contaminant and those whose protection is desired
  (environmental objective).
• which tolerance concentrations (acceptance
  criteria) exist for the relevant receptors.
• the probability that the contaminant may spread
  such that other receptors or additional exposure
  pathways must be considered

This tiered approach for risk assessments makes
it possible to provide the same degree of safety
and protection to humans and the environment when
determining the course of action, even when the
available information is limited.
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Tiered risk assessment
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Problem description

• Information about the site
• Description of the source (expected contaminants)
• Migration/transport related information
• Effect related information (based on the present
  land use and planned land use)

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Description of the source

• Primary sources (based on present and earlier
  land use)
• Contaminant (amount, environmentally related
  substance information)
• Secondary sources (contaminated surface soil (lt 1
  m deep), mineral soil (gt 1 m deep), groundwater,
  free-phase, surface water, sediment
  (freshwater/marine))
• Possible location of primary and secondary
  sources
• Other relevant information (time aspects for
  possible contamination and other activities that
  may have influenced primary and secondary
  sources)
• References/uncertainty in available information

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Migration/transport related information
Possible migration routes (soil, water, air)
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Migration/transport related information
Site specific data
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Migration/transport related information
Pollutant specific data regarding the transport
process

• Molar weight
• Analytical detection limit
• Density
• Mobility (diffusion factors in water and air)
• Solubility
• Vapor pressure
• Henrys constant
• Sorption parameters (Kd, Kp, Koc, Kow)
• Degradability
• Viscosity
• Bioconcentration factors

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Effect related information
Receptors
Land use and existing conditions
Exposure pathways
Toxicitiy parameters
Ecotoxicological data LC50/LD50 EC50/ED50 NOEC PN
EC
Human toxicological data RfC RfD SF UR
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Exposure and effect
ingestion of soil or dust. dermal contact to
soil or dust. inhalation of dust. inhalation
of soil vapour through indoor air intake of
drinking water from a groundwater well
consumption of vegetables and crops grown at the
contaminated site. consumption of fish or
shellfish from a nearby recipient contaminated by
gw dermal contact to drinking water (by
showering). inhalation during showering.
dermal contact during outdoor bathing.
Dose-effect curve of the carcinogenic pollutants
Dose-effect curve of the non- carcinogenic
pollutants
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Calculation of human risk for non-carcinogenic
materials

• The exposure can be expressed with average
• daily dose (ADD)
• ADD (C ADI fexp) / BW mg/kgd
• Where
• C the pollutant concentration in the media
  mg/kg, mg/l
• ADI average daily intake kg/d, l/d
• fexp fraction exposure time d/d
• BW body weight kg

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Calculation of human risk for non-carcinogenic
materials

• In case of dermal contact
• ADI SA AF DA
• Where
• SA Surface Contact Area cm2
• AF Soil Adherence Factor mg/cm2/d
• DA Dermal Adsorption Factor -
• In case of inhalation we determine the Average
  Inhalated
• Exposure Concentration
• AIEC C fexp
• Where
• C the pollutant concentration in the media
  mg/m3
• fexp fraction exposure time d/d

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Evaluation of the calculated risk for non
carcinogenic materials
RQ ADD / Rfdo
RQ AIEC / Rfc
RQ ADD / Rfdd
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Calculation of human risk for carcinogenic
materials

• As for the carcinogenic materials we are taking
  into account the life-span dose
• LADD ADD ED/AL
• LAIEC AIEC ED/AL
• Where
• ED exposure duration year
• AL average life year

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Calculation of human risk for carcinogenic
materials

• CR1-exp-(SFLADD)
• Where
• SF slope factor 1/(mg/kgd)
• LADD life-span average daily
• dosemg/kgd
• CR1-exp-(UFLAIEC)
• Where
• UF unit of risk -
• LAIEC life- span average inhalated
• exposure concentration-

• Evaluation
• For one substance
• CRgt10-5 /yr
• (10 µrisk/yr) ? risk
• Cumulative value
• CRgt10-6 /yr
• (1 µrisk/yr) ? risk

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Thank you for your attention !

• The next time
• Petroleum Hydrocarbons in groundwater and soil
  and the applicable remediation technologies
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