Further description:-  Sampling and analysis 

Glossary Entry
the collection and analyses of soil, water, air, building samples as well as geological, hydrogeological, 
and hydrological data. Sampling is to describe the contamination, the soil, and the groundwater
to such an extent that risk analyses may be carried out, and so that there is an adequate foundation
for planning and executing necessary remediation. Analysing soil and water samples is to identify
the degree of contamination in the area being investigated. The collection depends entirely on the
result of the initial survey as well as the requirements for the data which are to be used in connection
with the subsequent risk assessment.
Investigation: Sampling and Analysis

Investigation: Sampling and Analysis

 

1. Summary

 

In site investigation sampling as well as physical and chemical analysis are required to:

 

  • Determine nature and extent of existing contaminations,
  • Estimate fate and transport of contaminants of concern,
  • Characterize exposure pathways of concern.

 

Appropriate tools and methods are selected according to data quality levels, which shall be achieved by the site investigation. These quality levels are defined in a data quality objective plan.

 

2. Description of Sampling Technologies

 

Technologies for sampling with respect to investigation of contaminated land and groundwater can be distinguished in the following categories:

 

  • Access tools for direct access to environmental media,
  • Collection tools to physically remove samples,

 

These tools are used to collect solids samples or cores for lithologic logging and chemical analysis. Additionally access tools can be used for lithologic and hydrogeologic characterization (e.g., borehole geophysical logging; installation of piezometers or monitoring wells.

 

In detail the access tools comprise

  • Power driven drilling methods for unconsolidated materials (clays, sands, silts, and gravel),
  • Power driven drilling methods for consolidated materials (drilling in heavier materials and at greater depths),
  • Drive methods using a hydraulic device to penetrate the ground,
  • Sampling installations for portable samplers,
  • Portable In-situ ground water samplers,
  • Fixed in-situ samplers.

 

The collection tools are based on the following methods:

  • Hand-held sampling methods,
  • Power-driven soil samplers usually operated in conjunction with a drill rig,
  • Portable displacement pumps placed below the static water level of a well,
  • Other portable pumps for sampling ground water,
  • Portable grab samplers manually operated methods for collecting ground water samples,
  • Extractive collection Methods for soil water extraction from the vadose zone and the use of biological indicators,
  • Gas/air collection methods for collecting soil-gas samples and ambient air samples.

 

3. Description of Analysis Procedures

 

Analysis procedures include a qualitative analysis to identify substances present in a sample and a quantitative analysis to determine the amount of substances in the sample. Commonly used technologies in sample taken from contaminated land and groundwater are:

 

  • Ex-situ and in-situ methods for analyzing organic substances (e.g. volatile/semi-volatile organics, pesticides, polycyclic organics, etc.),
  • Ex-situ methods for analyzing metals,
  • Ex-situ and in-situ methods for analyzing radionuclides,
  • Ex-situ methods for analyzing explosives.

 

In-situ technologies are based on direct measurements in environmental compartments conducted without taking samples. Ex-situ methods require the removal of samples from or analysis conducted on the surface of the ground.

 

The following table presents an overview on the relevant analysis methods for organics, metals, and explosives:

 

Table 1: On-Site and Off-site Analysis Methods

Location

Analyte

Method

In-situ

Organics

Laser-Induced Fluorescence (LIF)

 

 

Solid/Porous Fiber Optic

 

Radionuclides

Gamma Radiation

 

Ex-situ

Organics

Field Bioassessment

 

 

Free Product Sensors

 

 

Gas Chromatography (GC)

 

 

Ground Penetration Radar

 

 

Immunoassay Colorimetric Kits

 

 

Infrared Spectroscopy

 

 

Mass Spectrometry (MS)

 

 

Toxicity Tests

 

 

Ultraviolet (UV) Fluorescence

 

Metals

Atomic Absorption (AA) Spectroscopy

 

 

Chemical Colorimetric Kits

 

 

Immunoassay Colorimetric Kits

 

 

Inductively-Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES)

 

 

Ion Chromatography

 

 

Toxicity Tests

 

 

X-Ray Fluorescence

 

Radionuclides

Gamma Ray Spectrometry

 

 

Nuclear Magnetic Resonance

 

 

Radiation Detectors

 

Explosives

Chemical Colorimetric Kits

 

 

Field Bioassessments

 

 

Gas Chromatography (GC)

 

 

Toxicity Tests

 

4. Data Quality Objectives for Sampling and Analysis

 

Data Quality Objectives (DQO) are necessary to:

 

  • Ensure that Quality Assurance (QA) and Quality Control (QC) measures are conducted to match the analytical effort of a site investigation,
  • Determine what practical limits are to be placed on the use of analytical and field data.

 

The DQO process is used for planning of field investigations so that the quality of generated data matches a sufficient level depending on the investigation objectives. DQO are qualitative and quantitative statements defined in the DQO process.

 

Data collected in the field include samples and site information and can be divided in the following categories and levels, respectively:

 

  • Field screening data at this level data are acquired by portable instruments providing real-time data to assist in the optimization of sampling locations. Generated data indicate whether specific contaminates are present at the site or not.
  • Field analytical data at this level, portable analytical instruments are used on site, or in mobile laboratories. Depending upon the types of contaminants, sample matrix, and technical equipment, qualitative and quantitative are can be acquired.
  • Screening data with definitive confirmation -- data at this level are generated by rapid, less precise analytical methods. Screening data provides qualitative information on substances present at the site and semi-quantitative information on the amount of identified. A certain portion of that data (e.g., 10 %) should be confirmed using appropriate analytical methods and QA/QC procedures and criteria associated with definitive data (see below).
  • Definitive Data -- These data are generated using exact analytical methods, such as reference methods. Definitive data are substance-specific, with confirmation of substance identity and concentration. Data may be generated at the site or at an off-site location, as long as the QA/QC requirements are satisfied. To be definitive, either the analytical or total measurement error must be determined.

 

The DQO process should establish the data requirements for the site investigation by definition of specific procedures that will be followed for sampling and analysis of samples. In detail the DQO press addresses the:

 

  • Selection of sampling locations including background and/or control samples,
  • Selection of sampling procedures in accordance to technical protocols and standard operation procedures,
  • Determination of the environmental compartments where samples need to be taken (e.g., surface water, ground water, soil, ambient air, vegetables, etc.),
  • Determination of data use (e.g., to adjust sample locations or to characterize nature and extent of a contamination),
  • Determination of required data types (e.g., field screening data, field analytical data, etc.),
  • Definition of field QA/QC measures (e.g., percentage of split and duplicate samples, trip blanks, rinse blanks, etc.).

 

5. Information Sources

 

Information on sampling and analysis methods including requirements with respect to QA/QC measure can be found in the following sources:

 

  • Technical guidelines,
  • Technical protocols,
  • Reference guides,
  • Method databases.

 

6. Literature

 

U.S. Army Corps of Engineers (2001):

Environmental Quality. Requirements for the Preparation of Sampling and Analysis Plans. Washington D.C. EM 200-1-3.

 

U.S. Environmental Protection Agency (1997):

Federal Facilities Forum Issue. Field Sampling and Selecting On-Site

Analytical Methods for Explosives in Soil. Office of Research and Development. Washington D.C. EPA/540/R-97/501.

 

U.S. Environmental Protection Agency (1998):

Quality Assurance Guidance for Conducting Brownfields Site Assessments. Office of Research and Development. Washington D.C. EPA/540/R-98/038.

 

U.S. Environmental Protection Agency (2001):

Resources for Strategic Site Investigation and Monitoring. Office of Solid Waste and Emergency Response. Washington D.C. EPA/542/F-01-0030b.

 

U.S. Environmental Protection Agency (2001):

Innovations in Site Characterization Technology Evaluation: Real-time VOC Analysis Using a Field Portable GC/MS. Office of Solid Waste and Emergency Response. Washington D.C. EPA/542/R-01/011.

 

U.S. Environmental Protection Agency (2003):

Field Analytic Technologies Encyclopedia (FATE). Office of Superfund Remediation and Technology Innovation (OSRTI). http://fate.clu-in.org.

 

 

 

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