Decontamination of filed Decontamination of filed equipment used in equipment used in environmental site environmental site

characterization and ground-characterization and ground-water monitoring projectswater monitoring projects

University of ArkansasUniversity of Arkansas

11/13/200611/13/2006

By : Ruwaya AlkendiBy : Ruwaya Alkendi

IntroductionIntroduction

contamination on field equipment contamination on field equipment influence the quality of a sample.influence the quality of a sample.

Contamination of a sample make it Contamination of a sample make it hard to:hard to: Have representative data.Have representative data. Make important decisions.Make important decisions.

Objectives of Equipment Objectives of Equipment decontaminationdecontamination

Prevent cross-contamination between sites.Prevent cross-contamination between sites. Prevent contamination of areas on site.Prevent contamination of areas on site. Prevent cross-contamination of individual Prevent cross-contamination of individual

sampling locations at single site.sampling locations at single site. Ensure proper operation of equipment.Ensure proper operation of equipment. Prevent accidental exposure of workers to Prevent accidental exposure of workers to

contamination.contamination. Prevent cross-contamination of individual Prevent cross-contamination of individual

samples from a single sampling location.samples from a single sampling location.

Preparing Preparing Decontamination protocols Decontamination protocols

For field equipment For field equipment decontamination protocol must include:decontamination protocol must include:

What equipment should be cleaned.What equipment should be cleaned. Whether disposable equipment can be used.Whether disposable equipment can be used. When & where it should take place.When & where it should take place. What cleaning protocols should be used on What cleaning protocols should be used on

a parameter and equipment- specific basis.a parameter and equipment- specific basis. What should be done with any waste What should be done with any waste

materials generated from the cleaning.materials generated from the cleaning.

What equipment requires What equipment requires field decontamination?field decontamination?

List of equipments.List of equipments. Potential contact of equipment with Potential contact of equipment with

the sample.the sample. Direct contact with sample.Direct contact with sample. Facilitate sample collection.Facilitate sample collection. Measurement or analysis of some Measurement or analysis of some

parameters.parameters. Table 20.1, page 1266.Table 20.1, page 1266.

Disposable equipmentsDisposable equipments Advantages:Advantages:

Save time.Save time. Reduces the # of field QC samples.Reduces the # of field QC samples. Minimizes the potential for cross-contamination Minimizes the potential for cross-contamination

of samples and sampling locations.of samples and sampling locations. Reduces the volume of liquid waste.Reduces the volume of liquid waste. Equipment is generally simple to operate.Equipment is generally simple to operate. Precleaned equipment options may be available.Precleaned equipment options may be available. Some equipment is available in a variety of Some equipment is available in a variety of

different materials.different materials. Convenience.Convenience.

Disposable equipmentsDisposable equipments

Limitations:Limitations: Large number of samples (expensive).Large number of samples (expensive). Limited selection of types of disposable Limited selection of types of disposable

equipments available.equipments available. Reuse disposable equipments (save money).Reuse disposable equipments (save money). Increase volume of solid waste.Increase volume of solid waste. Potential for contamination if not Potential for contamination if not

precleaned.precleaned. Not all samples can be collected using the Not all samples can be collected using the

disposable equipment.disposable equipment.

Types of equipment Types of equipment decontaminationdecontamination

Remote Equipment cleaning.Remote Equipment cleaning. Field equipment cleaning.Field equipment cleaning.

Remote equipment Remote equipment cleaningcleaning

Clean in a remote location (e.g. Lab).Clean in a remote location (e.g. Lab). Cleaning and shipping are continues Cleaning and shipping are continues

during the investigation.during the investigation.

Field equipment cleaningField equipment cleaning

Advantages:Advantages: Ability to clean equipment accidentally Ability to clean equipment accidentally

contaminated.contaminated. Improve the cleaning protocol.Improve the cleaning protocol. Sampling team assure of cleaning.Sampling team assure of cleaning. Less expensive.Less expensive. No shipping of equipment.No shipping of equipment.

Field equipment cleaningField equipment cleaning

Disadvantages:Disadvantages: Time consuming.Time consuming. Poor weather.Poor weather. Poor facilities (unsuitable water, lack of Poor facilities (unsuitable water, lack of

electricity).electricity). Extra personnel (more cost).Extra personnel (more cost).

Selecting a Selecting a decontamination protocoldecontamination protocol

Factors need to be evaluated:Factors need to be evaluated: The purpose of the investigation (level The purpose of the investigation (level

of QA/QC demand).of QA/QC demand). Identifying the suspected contaminants.Identifying the suspected contaminants. Establishing a list of parameters to be Establishing a list of parameters to be

analyzed.analyzed. Evaluate the number of contaminant-Evaluate the number of contaminant-

specific physical and chemical specific physical and chemical properties. properties.

Cont.Cont.

if more than one contaminant if more than one contaminant (complicated ).(complicated ).

Relative concentrations of Relative concentrations of contaminants.contaminants.

Identifying physical limitations Identifying physical limitations (time, budget, inconvenience, (time, budget, inconvenience, inability to manage the waste inability to manage the waste generated).generated).

Decontamination Decontamination protocolsprotocols

Available decontamination protocols:Available decontamination protocols: Methods for larger support equipmentMethods for larger support equipment

High pressure, hot-water wash system.High pressure, hot-water wash system. e.g. Drilling rigs, support vehicles.e.g. Drilling rigs, support vehicles. Disadvantages:Disadvantages:

Lack of adequate pressureLack of adequate pressure Difficult to generate sufficient source of steam Difficult to generate sufficient source of steam

under filed conditions.under filed conditions. High temperature affect seals on equipments.High temperature affect seals on equipments.

Decontamination Decontamination protocolsprotocols

Methods for sample collection or Methods for sample collection or analysis equipment.analysis equipment.

Usually, one or a combination of Usually, one or a combination of several of five solutions are typically several of five solutions are typically specified in field decontamination specified in field decontamination procedures:procedures: Tap water, dilute acid, solvent, distilled or Tap water, dilute acid, solvent, distilled or

deionized water, and laboratory grade deionized water, and laboratory grade phosphate-free detergent.phosphate-free detergent.

Table 20.5, page 1278. (physical & Table 20.5, page 1278. (physical & chemical methods)chemical methods)

SolventsSolvents

Cause interference in analyses.Cause interference in analyses. Degrade flexible parts on some field Degrade flexible parts on some field

equipments.equipments. Damage sensitive hydrocarbon Damage sensitive hydrocarbon

sensorssensors

ProblemsProblems

Problems associated with Problems associated with decontamination procedures include:decontamination procedures include: Use of contaminated portable water Use of contaminated portable water

supplies.supplies. Use of contaminated supplies of Use of contaminated supplies of

commercially prepared distilled water.commercially prepared distilled water. Residues of fluids used for decontamination Residues of fluids used for decontamination

such as dilute acids or solvents.such as dilute acids or solvents. Oil spray from unfiltered exhaust from Oil spray from unfiltered exhaust from

generators used as power sources.generators used as power sources.

Cont.Cont.

Volatile organic contamination Volatile organic contamination associated with equipment exhaust associated with equipment exhaust systems.systems.

Use of ethylene glycol in Use of ethylene glycol in decontamination equipment to prevent decontamination equipment to prevent freezing in extremely cold weather.freezing in extremely cold weather.

Hydraulic fluids, oils, gasoline, or diesel Hydraulic fluids, oils, gasoline, or diesel fuel used to operate generators and fuel used to operate generators and other support equipment.other support equipment.

QA/QC components of QA/QC components of decontamination protocolsdecontamination protocols

Several issues must be addressed:Several issues must be addressed: Location of decontamination area.Location of decontamination area. Movement of clean & contaminated Movement of clean & contaminated

equipment.equipment. Preliminary cleaning of all equipment.Preliminary cleaning of all equipment. Segregation of clean & contaminated Segregation of clean & contaminated

equipmentequipment Controls to ensure equipment do not get Controls to ensure equipment do not get

contaminated prior to use.contaminated prior to use. Controls to ensure equipment that are used in Controls to ensure equipment that are used in

decontamination are not source of it.decontamination are not source of it.

Cont.Cont.

Chemical verification of suitability of Chemical verification of suitability of potable water supply.potable water supply.

Use of rinse blanks & ‘wipe’ samples to Use of rinse blanks & ‘wipe’ samples to verify effectiveness of decontamination verify effectiveness of decontamination procedure.procedure.