groundwater and soil protection

8/13/2019 Groundwater and Soil Protection

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GROUNDWATER AND SOILPROTECTION

Environmental remediation


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Hydrologic cycle

When rain falls tothe ground, thewater does notstop moving.

Some of it flowsalong the surfacein streams orlakes, some of itis used by plants,some evaporates

and returns to theatmosphere, andsome sinks intothe ground


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Groundwater flow

Groundwater is water that is foundunderground in cracks and spacesin soil, sand, and rocks. The areawhere water fills these spaces iscalled the saturated zone. The topof this zone is called the water

table...just remember the top ofthe water is the table. The watertable may be only a foot below thegrounds surface or it may behundreds of feet down.

Groundwater is stored inand moves slowly throughlayers of soil, sand, androcks called aquifers. The speed at which groundwater flows depends on the sizeof the spacesin the soil or rock and how well the spaces are connected. Aquiferstypically consist of gravel, sand, sandstone, or fractured rock like limestone. Thesematerials are permeable because they have large connected spaces that allowwater to flow through.


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Aquifers

Aquifersare soil or rocklayers that are goodreservoirs that are easy toproduce

High porosity: lots of porespace between grains tostore water

High permeability: goodconnectivity between porespaces so water can easilyflow into and out of thereservoir.


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Above and below the water table

The Water Tableis the depth to the part of thesoil or rock that is saturated with water Storage capacity (also related to specific yield)

is how much water we can drain from anaquifer

Saturated zone: a portion of the soil profilewhere all pores are filled with water. Aquifersare located in this zone. There may be

multiple saturation zones at different soildepths separated by layers of clay or rock.

Unsaturated zone: a portion of the soil profilethat contains both water and air; the zonebetween the land surface and the water table.The soil formations do not yield usableamounts of freeflowing water. It is also calledzone of aeration and vadose zone

Capillary Zone the transition betweenvadose & phreatic (only a few cm thick, atmost). Water can be wickedfrom phreatic tovadose zone. Deep phreatic zone can keep ashallower 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 EU:

maintain the balance of withdrawal and recharge and to prevent or reverse the deterioration ofthe qualitative status of groundwater

Groundwater Protection Directive (80/68/EEC): deals with the protection ofgroundwater against pollution caused by certain dangerous substances. It classifiesdangerous substances into List I and List II depending on the level of danger caused by therelevant substances

The Nitrate Directive (911676/EEC): covers the protection of waters against pollutioncaused 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

Quantitative risk assessment means a detailed assessment procedure based on thesitespecific investigationsof a given contaminated site. The result is represented byrisk ratio value, expressing the proportion of the actual level of pollution in theenvironmental elements (especially in groundwater) and the levels of pollution

acceptablefor the environment, ecosystem and human beings

Remediation is a procedure including technical, economic and administrativeactivities aimed at gaining knowledge about threatened, polluted and damagedgroundwater and geological mediaas well as at ceasing or reducingcontamination,damage and risk, and at the monitoringthereof

Environmental remediation

Site investigation Technical intervention Remedial monitoring

Risk assessment

The remediation target limit value

Remained risk after thetechnical intervention


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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 carriedout 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 areaMethodology of site investigationFindings of the investigationResults of the risk assessmentPresentation, characterisation of possible options for technicalinterventionsResults of the cost-benefit and cost-effectiveness analysesPresentation 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 sludgeIn situ technologiesBioventing , 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 , Chemicalextraction , Chemical oxidation-reduction , Dehalogenation, Separation , Soil washing , Soil vapour extraction , Solardetoxification , Solidification, stabilisation , Hot gas decontamination , Incineration , Open burning/Open detonation ,Pyrolysis , Thermal desorption , Capping , Capping, drainage and recultivation , Excavation, transport and deposition with soilreplacing

Treatment of shallow groundwater, surface water and leachateIn situ technologies

Cometabolic degradation, Enhanced bioremediation , Natural attenuation , Phytoremediation , Soil vapour extraction , Airsparging , Vacuum-enhanced free-product recovery and bioventing , Directional wells , Dual phase extraction , In-well airstripping , Hot water or gas stripping , Hydrofracturing, Passive/active treatment walls

Ex situ technologiesBioreactor , 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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Report on technical intervention

Presentation of the completed technical intervention and remedialtechnology/technologies applied

Results of the technical intervention

Presentation of the remediation monitoring operated in the course oftechnical 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 finalreport; also

remedial monitoring; and/or

termination of remediation.

After the technical

intervention


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Remedial monitoring

Determination of the installations of the monitoring systemsScope 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, andorder 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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Source: Location and content of prioritypollutants in the ground, supplied bydeposition or contamination fromanthropogenic activities. The source refers tothe original placement and contents of thecontaminant, independent of distribution anddegradation.

Receptors: Generaldescription of human beings,animals, birds, plants, fungi,algae, fish, crustaceans,shellfish and bacteria.

Transport(mechanism):The different mechanisms leading tothe migration of the contaminant (forexample in the air, soil or waterphase).

Risk: Risk designates thedanger that undesirable eventsrepresent for humans, theenvironment (ecosystem) ormaterial values. Risk isexpressed as the probabilityand consequences of theundesirable events.

Effect: In this instance, the influenceof soil contamination on human beingsand the environment. The effect can bea measurable change in the soil orrecipient in relation to the expectedcondition as a result of the influence

from the contaminated site. The effectincludes concentrations above thenatural background level and theinfluence on life generally. Effects maybe negative, positive or neutral withrespect to life and health.

Exposure: Contactbetween a chemicalsubstance and a receptor(human beings or theecosystem).

Receptors

TransportSource

Exposure

RiskEffect

Environmental risk


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Risk assessment investigation

The following parametersmust 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 likelyexposed to the contaminant and thosewhose protection is desired

(environmental objective). which tolerance concentrations

(acceptance criteria) exist for therelevant receptors.

the probability that the contaminantmay spread such that other receptorsor 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

Tier 3: Expanded risk assessment

(measurement of exposure)

Tier 2: Expanded risk assessment

(calculation of exposure)

Tier 1:Simplified risk assessment

(use of soil quality guidelines)


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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 useand planned land use)


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Description of the source

Primary sources (based on present andearlier land use)

Contaminant (amount, environmentallyrelated substance information)

Secondary sources (contaminated surfacesoil (< 1 m deep), mineral soil (> 1 m deep),groundwater, free-phase, surface water,sediment (freshwater/marine))

Possible location of primary and secondarysources

Other relevant information (time aspectsfor possible contamination and otheractivities that may have influenced primaryand secondary sources)

References/uncertainty in availableinformation


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Migration/transport related

informationPossible migration routes (soil, water, air)


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informationSite specific data


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informationPollutant 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 relatedinformation

Land use andexistingconditions

Exposurepathways Receptors Toxicitiy parameters

Ecotoxicological data:LC50/LD50EC50/ED50

NOECPNEC

Human toxicological data:

RfC

RfDSFUR


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Exposure and effect

Dose-effect curve of the

carcinogenic pollutants

Dose-effect curve of the non-

carcinogenic pollutants

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 bygw

dermal contact to drinking water (by showering).

inhalation during showering.

dermal contact during outdoor bathing.

continuous periodic

stochastic concentrated

time

time time

time

Effect

%

Dose

Extra-

polated

rangeObserved range

Extrapolation

mg/kg/dayDose

No

effect

Maximum

effect

Limit dose

Effect

%

mg/kg/day


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Calculation of human risk for

non-carcinogenic materials

The exposure can be expressed with average

dailydose (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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non-carcinogenic materialsIn 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 fexpWhere:

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

Risk quotient (RQ) Scale of the risk

10 very highRQ = ADD / Rfdd

RQ = AIEC / Rfc

RQ = ADD / Rfdo


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carcinogenic materials

As for the carcinogenic materials we aretaking 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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carcinogenic materials

CR=1-exp-(SFLADD)Where:SF: slope factor [1/(mg/kgd)]

LADD: life-span average daily

dose[mg/kgd]

CR=1-exp-(UFLAIEC)

Where:UF: unit of risk [-]

LAIEC: life- span average inhalated

exposure concentration[-]

Evaluation

For one substance

CR>10-5 /yr

(10 risk/yr)risk

Cumulative value

CR>10-6 /yr

(1 risk/yr)risk


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Thank you for your

attention!

The next time:

Petroleum Hydrocarbons in groundwater and

soil and the applicable remediationtechnologies thereof

groundwater and soil protection

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