Decontamination of filed equipment used in environmental site characterization and ground-water monitoring projects University of Arkansas 11/13/2006 By : Ruwaya Alkendi

Introduction contamination on field equipment influence the quality of a sample. contamination on field equipment influence the quality of a sample. Contamination of a sample make it hard to: Contamination of a sample make it hard to: Have representative data. Have representative data. Make important decisions. Make important decisions.

Objectives of Equipment decontamination 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 sampling locations at single site. Prevent cross-contamination of individual sampling locations at single site. Ensure proper operation of equipment. Ensure proper operation of equipment. Prevent accidental exposure of workers to contamination. Prevent accidental exposure of workers to contamination. Prevent cross-contamination of individual samples from a single sampling location. Prevent cross-contamination of individual samples from a single sampling location.

Preparing Decontamination protocols For field equipment Preparing Decontamination protocols 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 a parameter and equipment- specific basis. What cleaning protocols should be used on a parameter and equipment- specific basis. What should be done with any waste materials generated from the cleaning. What should be done with any waste materials generated from the cleaning.

What equipment requires field decontamination? List of equipments. List of equipments. Potential contact of equipment with the sample. Potential contact of equipment with the sample. Direct contact with sample. Direct contact with sample. Facilitate sample collection. Facilitate sample collection. Measurement or analysis of some parameters. Measurement or analysis of some parameters. Table 20.1, page Table 20.1, page 1266.

Disposable 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 of samples and sampling locations. Minimizes the potential for cross-contamination 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 different materials. Some equipment is available in a variety of different materials. Convenience. Convenience.

Disposable equipments Limitations: Limitations: Large number of samples (expensive). Large number of samples (expensive). Limited selection of types of disposable equipments available. Limited selection of types of disposable 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 precleaned. Potential for contamination if not precleaned. Not all samples can be collected using the disposable equipment. Not all samples can be collected using the disposable equipment.

Types of equipment decontamination Remote Equipment cleaning. Remote Equipment cleaning. Field equipment cleaning. Field equipment cleaning.

Remote equipment cleaning Clean in a remote location (e.g. Lab). Clean in a remote location (e.g. Lab). Cleaning and shipping are continues during the investigation. Cleaning and shipping are continues during the investigation.

Field equipment cleaning Advantages: Advantages: Ability to clean equipment accidentally contaminated. Ability to clean equipment accidentally 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 cleaning Disadvantages: Disadvantages: Time consuming. Time consuming. Poor weather. Poor weather. Poor facilities (unsuitable water, lack of electricity). Poor facilities (unsuitable water, lack of electricity). Extra personnel (more cost). Extra personnel (more cost).

Selecting a decontamination protocol Factors need to be evaluated: Factors need to be evaluated: The purpose of the investigation (level of QA/QC demand). The purpose of the investigation (level of QA/QC demand). Identifying the suspected contaminants. Identifying the suspected contaminants. Establishing a list of parameters to be analyzed. Establishing a list of parameters to be analyzed. Evaluate the number of contaminant-specific physical and chemical properties. Evaluate the number of contaminant-specific physical and chemical properties.

Cont. if more than one contaminant (complicated ). if more than one contaminant (complicated ). Relative concentrations of contaminants. Relative concentrations of contaminants. Identifying physical limitations (time, budget, inconvenience, inability to manage the waste generated). Identifying physical limitations (time, budget, inconvenience, inability to manage the waste generated).

Decontamination protocols Available decontamination protocols: Available decontamination protocols: Methods for larger support equipment Methods 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 pressure Lack of adequate pressure Difficult to generate sufficient source of steam under filed conditions. Difficult to generate sufficient source of steam under filed conditions. High temperature affect seals on equipments. High temperature affect seals on equipments.

Decontamination protocols Methods for sample collection or analysis equipment. Methods for sample collection or analysis equipment. Usually, one or a combination of several of five solutions are typically specified in field decontamination procedures: Usually, one or a combination of several of five solutions are typically specified in field decontamination procedures: Tap water, dilute acid, solvent, distilled or deionized water, and laboratory grade phosphate-free detergent. Tap water, dilute acid, solvent, distilled or deionized water, and laboratory grade phosphate-free detergent. Table 20.5, page (physical & chemical methods) Table 20.5, page (physical & chemical methods)

Solvents Cause interference in analyses. Cause interference in analyses. Degrade flexible parts on some field equipments. Degrade flexible parts on some field equipments. Damage sensitive hydrocarbon sensors Damage sensitive hydrocarbon sensors

Problems Problems associated with decontamination procedures include: Problems associated with decontamination procedures include: Use of contaminated portable water supplies. Use of contaminated portable water supplies. Use of contaminated supplies of commercially prepared distilled water. Use of contaminated supplies of commercially prepared distilled water. Residues of fluids used for decontamination such as dilute acids or solvents. Residues of fluids used for decontamination such as dilute acids or solvents. Oil spray from unfiltered exhaust from generators used as power sources. Oil spray from unfiltered exhaust from generators used as power sources.

Cont. Volatile organic contamination associated with equipment exhaust systems. Volatile organic contamination associated with equipment exhaust systems. Use of ethylene glycol in decontamination equipment to prevent freezing in extremely cold weather. Use of ethylene glycol in decontamination equipment to prevent freezing in extremely cold weather. Hydraulic fluids, oils, gasoline, or diesel fuel used to operate generators and other support equipment. Hydraulic fluids, oils, gasoline, or diesel fuel used to operate generators and other support equipment.

QA/QC components of decontamination protocols Several issues must be addressed: Several issues must be addressed: Location of decontamination area. Location of decontamination area. Movement of clean & contaminated equipment. Movement of clean & contaminated equipment. Preliminary cleaning of all equipment. Preliminary cleaning of all equipment. Segregation of clean & contaminated equipment Segregation of clean & contaminated equipment Controls to ensure equipment do not get contaminated prior to use. Controls to ensure equipment do not get contaminated prior to use. Controls to ensure equipment that are used in decontamination are not source of it. Controls to ensure equipment that are used in decontamination are not source of it.

Cont. Chemical verification of suitability of potable water supply. Chemical verification of suitability of potable water supply. Use of rinse blanks & ‘wipe’ samples to verify effectiveness of decontamination procedure. Use of rinse blanks & ‘wipe’ samples to verify effectiveness of decontamination procedure.