5.7 Preparing a QAPP or WAP In this activity, the outputs of the DQO Process and the sampling design are combined in a planning document such as a QAPP or WAP. The Agency has developed detailed guidance on how to prepare a QAPP (see USEPA 1998a) or WAP (see USEPA 1994a). The minimum requirements for a WAP are specified at 40 CFR §264.13. The following discussion is focused on the elements of a QAPP; however, the information can be used to help develop a WAP. For additional guidance on selecting the most resourceefficient design, see ASTM standard D 6311 98, Standard Guide for Generation of Environmental Data Related to Waste Management Activities: Selection and Optimization of Sampling Design. 85 Additional EPA Guidance on Preparing a QAPP or WAP ° Chapter One, SW 846 ° EPA Requirements for Quality Assurance Project Plans, EPA QA/ R 5 (replaces QAMS 005/ 80) (USEPA 2001b)

° EPA Guidance for Quality Assurance Project Plans, EPA QA/ G 5 (EPA/ 600/ R 98/ 018) (USEPA 1998a)

° Guidance for Choosing a Sampling Design for Environmental Data Collection, EPA QA/ G 5S  Peer Review Draft (EPA QA/ G 5S) (USEPA 2000c)

° Waste Analysis at Facilities That Generate, Treat, Store, And Dispose Of Hazardous Wastes, a Guidance Manual (USEPA 1994a) The QAPP is a critical planning document for any environmental data collection operation because it documents project activities including how QA and QC activities will be implemented during the life cycle of a project. The QAPP is the "blueprint" for identifying how the quality system of the organization performing the work is reflected in a particular project and in associated technical goals. QA is a system of management activities designed to ensure that data produced by the operation will be of the type and quality needed and expected by the data user. QA, acknowledged to be a management function emphasizing systems and policies, aids the collection of data of needed and expected quality appropriate to support management decisions in a resource efficient manner.

The activities addressed in the QAPP cover the entire project life cycle, integrating elements of the planning, implementation, and assessment phases. If the DQOs are documented (e. g., in a memo or report format), include the DQO document as an attachment to the QAPP to help document the technical basis for the project and to document any agreements made between stakeholders.

As recommended in EPA QA/ G 5 (USEPA 1998a), a QAPP is composed of four sections of project related information called "groups," which are subdivided into specific detailed "elements." The elements and groups are summarized in the following subsections.

5.7.1 Project Management The QAPP (or WAP) is prepared after completion of the DQO Process. Much of the following guidance related to project management can be excerpted from the outputs of the DQO Process.

The following group of QAPP elements covers the general areas of project management, project history and objectives, and roles and responsibilities of the participants. The following elements ensure that the project's goals are clearly stated, that all participants understand the goals and the approach to be used, and that project planning is documented:

° Title and approval sheet ° Table of contents and document control format ° Distribution list ° Project/ task organization and schedule (from DQO Step 1) ° Problem definition/ background (from DQO Step 1) ° Project/ task description (from DQO Step 1) ° Quality objectives and criteria for measurement data (DQO Step 3) 86 ° Special training requirements/ certification ° Documentation and records.

For some projects, it will be necessary to include the names and qualifications of the person( s) who will obtain the samples (e. g., as required under 40 CFR §261.38( c)( 7) in connection with testing for the comparable fuels exclusion).

5.7.2 Measurement/ Data Acquisition This group of QAPP elements covers all aspects of measurement system design and implementation, ensuring that appropriate methods for sampling, analysis, data handling, and QC are employed and thoroughly documented. Apart from the sample design step (DQO Step 7), the following information should be included in the QAPP or incorporated by reference:

° Sampling process design/ experimental design (DQO Steps 5 and 7) ° Sampling methods and SOPs ° Sample handling and chain of custody requirements ° Analytical methods and SOPs (DQO Step 3) ° QC requirements; ° Instrument/ equipment testing, inspection, and maintenance requirements ° Instrument calibration and frequency ° Inspection/ acceptance requirements for supplies and consumables ° Data acquisition requirements (non direct measurements) ° Data management.

For some projects, under various circumstances it may be appropriate to include hard copies of the SOPs in the QAPP, rather than incorporate the information by reference. For example, under the performance based measurement system (PBMS) approach, alternative sampling and analytical methods can be used. Such methods can be reviewed and used more readily if actual copies of the SOPs are included in the QAPP. Hard copies of SOPs also are critically important when field analytical techniques are used. Field personnel must have detailed instructions available to ensure that the methods are followed. If it is discovered that deviation from an SOP is required due to site specific circumstances, the deviations can be documented more easily if hard copies of the SOPs are available in the field with QAPP.

5.7.3 Assessment/ Oversight The purpose of assessment is to ensure that the QAPP is implemented as prescribed. The elements below address the activities for assessing the effectiveness of the implementation of the project and the associated QA/ QC activities:

° Assessments and response actions ° Reports to management.

5.7.4 Data Validation and Usability Implementation of these elements ensures that the data conform to the specified criteria, thus enabling reconciliation with the project's objectives. The following elements cover QA activities that occur after the data collection phase of the project has been completed: 87 ° Data review, verification, and validation requirements ° Verification and validation methods ° Reconciliation with DQOs.

5.7.5 Data Assessment Historically, the focus of most QAPPs has been on analytical methods, sampling, data handling, and quality control. Little attention has been paid to data assessment and interpretation. We recommend that the QAPP address the data assessment steps that will be followed after data verification and validation. While it may not be possible to specify the statistical test to be used in advance of data generation, the statistical objective (identified in the DQO Process) should be stated along with general procedures that will be used to test distributional assumptions and select statistical tests. EPA's Guidance for Data Quality Assessment (USEPA 2000d) suggests the following five step methodology (see also Section 8 for a similar methodology):

1. Review the DQOs 2. Conduct a preliminary data review 3. Select the statistical test 4. Verify the assumptions of the test 5. Draw conclusions from the Data.

The degree to which each QAPP element should be addressed will be dependent on the specific project and can range from "not applicable" to extensive documentation. The final decision on the specific need for these elements for project specific QAPPs will be made by the regulatory agency. Documents prepared prior to the QAPP (e. g., SOPs, test plans, and sampling plans) can be appended or, in some cases, incorporated by reference. 88 6 CONTROLLING VARIABILITY AND BIAS IN SAMPLING The DQO Process allows you to identify the problem to be solved, set specific goals and objectives, establish probability levels for making incorrect decisions, and develop a resourceefficient data collection and analysis plan. While most of the sampling designs suggested in this guidance incorporate some form of randomness so that unbiased estimates can be obtained from the data, there are other equally important considerations (Myers 1997). Sampling and analysis activities must also include use of correct devices and procedures to minimize or control random variability and biases (collectively known as "error") that can be introduced in field sampling, sample transport, subsampling, sample preparation, and analysis. Sampling error can lead to incorrect conclusions irrespective of the quality of the analytical measurements and the appropriateness of the statistical methods used to evaluate the data.

This section is organized into three subsections which respond to these questions:

1. What are the sources of error in sampling (Section 6.1)?

2. What is sampling theory (Section 6.2)?

3. How can you reduce or otherwise control sampling error in the field and laboratory (Section 6.3)?

6.1 Sources of Random Variability and Bias in Sampling In conducting sampling, we are interested in obtaining an estimate of a population parameter (such as the mean, median, or a percentile); but an estimate of a parameter made from measurements of samples always will include some random variability (or variances) and bias (or a systematic shift away from the true value) due primarily to (1) the inherent variability of the waste or media (the "between sampling unit variability") and (2) imprecision in the methods used to collect and analyze the samples (the "within sampling unit variability") (USEPA 2001e).

Errors caused by the sample collection process can be much greater than the preparation, analytical, and data handling errors (van Ee, et al. 1990, Crockett, et al 1996) and can dominate the overall uncertainty associated with a characterization study (Jenkins, et al. 1996 and 1997). In fact, analytical errors are usually well characterized, well understood, and well controlled by laboratory QA/ QC, whereas sampling and sample handling errors are not usually well characterized, well understood, or well controlled (Shefsky 1997). Because sampling error contributes to overall error, it is important for field and laboratory personnel to understand the sources of sampling errors and to take measures to control them in field sampling.

The two components of error  random variability and bias  are independent. This concept is demonstrated in the "target" diagram (see Figure 7 in Section 2), in which random variability (expressed as the variance, ) refers to the "degree of clustering" and bias ( ) relates   2 µ   x to the "amount of offset from the center of the target" (Myers 1997).

Random variability and bias occur at each stage of sampling. Variability occurs due to the heterogeneity of the material sampled and random variations in the sampling and sample handling procedures. In addition, bias can be introduced at each stage by the sampling device (or the manner in which it is used), sample handling and transport, subsampling, and analysis. 89 MSE(x bias )() = +   2 2 Systematic Error (Bias) Random Variability where bias = Sum of all biases Analytical variability Between sampling unit variability (population variability)

Sampling and subsampling variability including Analytical bias Sampling bias (e. g., improper selection and use of sampling devices; loss or gain of constituents during sampling, transport, storage, subsampling, and sample preparation)

Statistical bias Mistakes, blunders, sabotage h h h   b 2 =

  s 2 =

  a 2 = h      22 2 2 = + + b sa Figure 23. Components of error and the additivity of variances and biases in sampling and analysis While it is common practice to calculate the variability of sample analysis results "after the fact," it is more difficult to identify the sources and potential impacts of systematic sampling bias. As discussed in more detail below, it usually is best to understand the potential sources of error "up front" and take measures to minimize them when planning and implementing the sampling and analysis program.

Even though random variability and bias are independent, they are related quantitatively (see Figure 23). Errors expressed as the variance can be added together to estimate overall or "total study error." Biases can be added together to estimate overall bias (though sampling bias is difficult to measure in practice). Conceptually, the sum of all the variances can be added to the sum of all biases (which is then squared) and expressed as the mean square error () MSE x () which provides a quantitative way of measuring the degree of representativeness of the samples. In practice, it is not necessary to try to calculate mean square error, however, we suggest you understand the sources and impacts of variability and bias so you can take steps to control them in sampling and improve the representativeness of the samples. (See Sections 5.2.4 and 5.2.5 of EPA's Guidance for Data Quality Assessment, EPA QA/ G 9  QA00 Update (USEPA 2000d) for a more detailed discussion of how to address measurement variability and bias in the sampling design).

The relatively new science of sampling theory and practice (Myers 1997) provides a technically based approach for addressing sampling errors (see Section 6.2). Sampling theory recognizes that sampling errors arise from or are related to the size and distribution of particles in the waste, the weight of the sample, the shape and orientation of the sampling device, the manner 90 in which the sample is collected, sample handling, and the manner in which subsampling is performed within the laboratory. Sampling theory applies to particulate solids, liquids, and mixtures of solids and liquids. Understanding sampling theory does not allow us to completely eliminate sampling and analytical errors, but sampling theory does allow us to identify the sources and magnitudes of sampling errors so we can take steps to minimize those that are the largest. In doing so, samples will be more precise and unbiased (i. e., more "representative"), thus reducing the number of samples required (lowering costs) and improving our ability to achieve the decision error rate specified in the DQOs.

6.2 Overview of Sampling Theory A number of environmental scientists have recognized a set of sampling theories developed by Dr. Pierre Gy (Gy 1982 and 1998) and others (Ingamells and Switzer 1973; Ingamells 1974; Ingamells and Pitard 1986; Pitard 1989; and Visman 1969) as one set of tools for improving sampling. These researchers have studied the sources of sampling error (particularly in the sampling of particulate matter) and developed techniques for quantifying the amount of error that can be introduced by the physical sampling process. The theories were originally developed in support of mineral exploration and mining and more recently were adopted by EPA for soil sampling (van Ee, et al. 1990; Mason 1992). Under some conditions, however, the theories can be applied to waste sampling as a means for improving the efficiency of the sampling and analysis process (Ramsey, et al. 1989).

As discussed in the context of this guidance, Gy's theories focus on minimizing error during the physical collection of a sample of solid and liquid media and should not be confused with the statistical sampling designs such as simple random, stratified random, etc. discussed in Section 5. Both sampling theory and sampling design, however, are critical elements in sampling: Gy's theories facilitate collection of "correct" individual samples, while statistical sampling designs allow us to conduct statistical analyses and make conclusions about the larger mass of waste or environmental media (i. e., the decision unit).

The following three subsections describe key aspects of sampling theory including heterogeneity, sampling errors, and the concept of sample support. The descriptions are mostly qualitative and intended to provided the reader with an appreciation for the types and complexities of sampling error. Detailed descriptions of the development and application of sampling theory can be found in Sampling for Analytical Purposes (Gy 1998), Geostatistical Error Management (Myers 1997), Pierre Gy's Sampling Theory and Sampling Practice (Pitard 1993), and in EPA's guidance document Preparation of Soil Sampling Protocols: Sampling Techniques and Strategies (Mason 1992).

6.2.1 Heterogeneity One of the underlying principles of sampling theory is that the medium to be sampled is not uniform in its composition or in the distribution of constituents in the medium, rather, it is heterogeneous. Heterogeneity causes the sampling errors.

Appropriate treatment of heterogeneity in sampling depends on the scale of observation. Largescale variations in a waste stream or site affect where and when we take samples. Small scale variations in a waste or media affect the size, shape, and orientation of individual field samples and laboratory subsamples. Gy's theory identifies three major types of heterogeneity: (1) short 91 range (or small scale) heterogeneity, (2) long range (or large scale) heterogeneity, and (3) periodic heterogeneity:

Short range heterogeneity refers to properties of the waste at the sample level or in the immediate vicinity of a sample location. Two other types of heterogeneity are found within short range heterogeneity: one reflected by differences in the composition between individual particles, the other having to do with the distribution of those particles in the waste. Composition heterogeneity (also known as constitution heterogeneity) is constant and cannot be altered except by particle size reduction (e. g., grinding or crushing the material). The distribution heterogeneity plays an important role in sampling because particles can separate into groups. Distribution heterogeneity can be increased (e. g., by gravitational segregation of particles or liquids) and can be reduced by homogenization (mixing) or by taking many small increments to form a sample.

Large scale heterogeneity reflects local trends and plays an important role in deciding whether to divide the population into smaller internally homogenous decision units or to use a stratified sampling design. See Appendix C for a detailed description of largescale heterogeneity.

Periodic heterogeneity, another larger scale phenomena, refers to cyclic phenomena found in flowing streams or discharges. Understanding periodic heterogeneity can aid in dividing a waste into separate waste streams or in establishing a stratified sampling design.

Forming a conceptual model of the heterogeneity of a waste will help you to determine how to address it in sampling.

6.2.2 Types of Sampling Error Gy's theory (see also Mason 1992, Pitard 1993, and Gy 1998) identifies a number of different types of error that can occur in sampling as a result of heterogeneity in the waste and failure to correctly define the appropriate shape and volume of material for inclusion in the sample. Understanding the types and sources of the errors is an important step toward avoiding them. In qualitative terms, these errors include the following:

° Fundamental error, which is caused by differences in the composition of individual particles in the waste ° Errors due to segregation and grouping of particles and the constituent associated with the particles ° Errors due to various types of trends including small scale trends, large scale trends, or cycles ° Errors due to defining (or delimiting) the sample space and extracting the sample from the defined area ° Errors due to preparation of the sample, including shipping and handling. [Note that the term "preparation," as used here, describes all the activities that take 92 Sample A Sample B "Population"

Figure 24. Effects of sample size on fundamental error. Small samples such as "A" cause the constituent of interest to be under represented in most samples and over represented in a small proportion of samples. Larger samples such as "B" more closely reflect the parent population. place after the primary sample is obtained in the field and includes sample containerization, preservation, handling, mixing, grinding, subsampling, and other preparative steps taken prior to analysis (such as the "sample preparation methods" as described in Chapters Three, Four, and Five of SW 846).]

Errors that can occur during sampling are described below.

<IP_ADDRESS> Fundamental Error The composition of a sample never perfectly matches the overall composition of the larger mass from which is was obtained because the mass of an individual sample is always less than the mass of the population and the population is never completely homogeneous. These conditions result in a sampling error known as fundamental error. The error is referred to as "fundamental" because it is an incompressible minimum sampling error that depends on the composition, shape, fragment size distribution, and chemical properties of the material, and it is not affected by homogenization or mixing. It arises when the constituent of interest is concentrated in constituent "nuggets" in a less concentrated matrix, especially when the constituent is present at a trace concentration level (e. g., less than 1 percent). This type of sampling error occurs even when the nuggets are mixed as well as possible in the matrix (so long as they are not dissolved). The fundamental error is the only error that remains when the sampling operation is "perfect"; that is, when all parts of the sample are obtained in a probabilistic manner and each part is independent.

As a conceptual example of fundamental error, consider a container filled with many white marbles and a few black marbles that have been mixed together well (Figure 24). If a small sample comprising only a few marbles is picked at random, there is a high probability they would all be white (Sample "A" in Figure 24) and a small chance that one or more would be black. As the sample size becomes larger, the distribution in the sample will reflect more and more closely the parent population (Sample "B" in Figure 24). The situation is similar in a waste that contains rare highly concentrated "nuggets" of a constituent of concern. If a small sample is taken, it is possible, and even likely, that no nuggets of the constituent would be selected as part of the sample. This would lead to a major underestimate of the true parameter of interest. It also is possible with a small sample that a gross overestimate of the parameter of interest will occur if a nugget is included in the sample because the nugget would comprise a relatively large proportion of the analytical sample compared to the true population. To minimize fundamental error, the point is not to simply "fish" for a black marble (the contaminant), but to sample for all of the fragments and constituents such that the sample is a representation of the lot from which it is derived. 1 This approach should not be confused with composite sampling, in which individual samples from different times or locations are pooled and mixed into a single sample.

93 (A) (B) Increments Increments Grouping Segregation Figure 25. How grouping and segregation of particles can affect sampling results. Grouping and segregation error can be minimized by taking many small increments. The fundamental error is never zero (unless the population is completely homogeneous or the entire population is submitted for analysis) and it never "cancels out." It can be controlled by taking larger physical samples; however, larger samples can be difficult to handle in the field and within the laboratory, and they may pose practical constraints due to increased space needed for storage. Furthermore, small samples (e. g., less than 1 gram) generally are required for analytical purposes. To preserve the character of a large sample in the small analytical sample, subsampling and particle size reduction strategies should be employed (see also Section 7.3).

<IP_ADDRESS> Grouping and Segregation Error Grouping and segregation results from the short range heterogeneity within and around the area from which a sample is collected (i. e., the sampling location) and within the sample container. This small scale heterogeneity is caused by the tendency for some particles to associate into groups of like particles due to gravitational separation, chemical partitioning, differing moisture content, magnetism, or electrostatic charge. Grouping and segregation of particles can lead to sampling bias.

Figure 25 depicts grouping of particles (at "A") and segregation of particles (at "B") within a sample location. The grouping of particles at location "A" could result from an affinity between like particles (for example, due to electrostatic forces). Analytical samples formed from just one group of particles would yield biased results.

The segregation of particles at location "B" could result from gravitation separation (e. g., during sample shipment). If the contaminant of interest was associated with only one class of particle (for example, only the black diamond shapes), then a sample collected from the top would result in a different concentration than a sample collected from the bottom, thus biasing the sample.

Grouping and segregation error can be minimized by properly homogenizing and splitting the sample. As an alternative, an individual sample can be formed by taking a number of increments (small portions of media) in the immediate vicinity of the sampling location and combining them into the final collected sample. 1 Pitard (1993) suggests collecting between 10 and 25 increments as a means to control grouping and segregation error. These increments are then combined to form an individual sample to be submitted to the laboratory for analysis. 94 The approach of taking multiple increments to form a sample is not recommended when volatile constituents are of interest and may have practical limitations when sampling highly heterogeneous wastes or debris containing very large fragments.

<IP_ADDRESS> Increment Delimitation Error Increment delimitation error occurs when the shape of the sampling device excludes or discriminates against certain portions of the material to be sampled. For example, a sampling device that only samples the top portion of a liquid effluent as it is leaves a discharge pipe (leaving a portion of the flow unsampled) causes increment delimitation error. This type of error is eliminated by choosing a sampling device capable of obtaining all of the flow for a fraction of the time (see also Sections 6.3.2 and 6.3.3).

<IP_ADDRESS> Increment Extraction Error Increment extraction error occurs when portions of the sample are lost or extraneous materials are included in the sample. For example, if the coring device is too small to accommodate a large fragment of waste, particles that should be in the sample might get pushed aside, causing sampling bias. Extraction error can be controlled through selection of devices designed to accommodate the physical characteristics of the waste.

<IP_ADDRESS> Preparation Error This error results from the incorrect preservation, handling, mixing, grinding, and subsampling that can result in loss, contamination, or altering of the sample such that it no longer is an accurate representation of the material being sampled. Proper choice and implementation of preparation methods controls this error.

6.2.3 The Concept of "Sample Support"

The weight, shape (length, width and height dimensions), and orientation of a sample describe the "sample support." The term "support" has been used in sampling and statistical literature in various ways, such as to describe the mass or volume of an "exposure unit" or "exposure area" in the Superfund program  similar to the "decision unit" described in the DQO Process.

Conceptually, there is a continuum of support from the decision unit level (e. g., an exposure area of a waste site or a drum of solid waste) to the sample and subsample level down to the molecular level. Because it is not possible to submit the entire decision unit for analysis, samples must be submitted instead. For heterogeneous media, the sample support will have a substantial effect on the reported measurement values.

Measures can be taken to ensure adequate size, shape, and orientation of a sample:

° The appropriate size of a sample (either volume or mass) can be determined based on the relationship that exists between the particle size distribution and expected sampling error  known as the fundamental error (see Section <IP_ADDRESS>). In the DQO Process, you can define the amount of fundamental error that is acceptable (specified in terms of the standard deviation of the fundamental error) and estimate the volume required for field samples. The sampling tool should 95 have dimensions three or more times larger than that of the diameter of the largest particles. Proper sizing of the sampling tool will help ensure that the particle size distribution of the sampled material is represented in the sample (see discussion at Section 6.3.1).

° The appropriate shape and orientation of the sample are determined by the sampling mode. For a one dimensional waste (e. g., liquid flowing from a discharge pipe or solids on a conveyor belt), the correct or "ideal" sample is an undisturbed cross section delimited by two parallel planes (Pitard 1993, Gy 1998) (see discussion at Section <IP_ADDRESS>). For three dimensional waste forms (such as solids in a roll off bin, piles, thick slabs, soil in drums, liquids in a tank, etc.), the sampling problem is best treated as a series of overlapping two dimensional problems. The correct or ideal sample is an undisturbed core (Pitard 1993) that captures the entire thickness of the waste (see discussion at Section <IP_ADDRESS>).

6.3 Practical Guidance for Reducing Sampling Error This section describes steps that can be taken to control sampling error. While the details of sampling theory may appear complex and difficult to explain, in practice most sampling errors can be minimized by observing a few simple rules that, when used, can greatly improve the reliability of sampling results with little or no additional costs (Gy 1998):

° Determine the optimal mass of each field sample. For particulate solids, determine the appropriate sample weight based on the particle size distribution and characteristics, and consider any practical constraints (see Section 6.3.1). Also, determine additional amounts of the sampled material needed for split samples, for field and laboratory quality control purposes, or for archiving.

° Select the appropriate shape and orientation of the sample based on the sampling design model identified in DQO Step 7 (see Section 6.3.2).

° Select sampling devices and procedures that will minimize grouping and segregation errors and increment delimitation and increment extraction errors (see Sections 6.3.3 and 7.1).

Implement the sampling plan by obtaining the number of samples at the sampling locations and times specified in the sampling design selected in DQO Step 7, and take measures to minimize preparation errors during sample handling, subsampling, analysis, documentation, and reporting. When collecting samples for analysis for volatile organic constituents, special considerations are warranted to minimize bias due to loss of constituents (see Section 6.3.4).

Table 7 provides a summary of strategies that can be employed to minimize the various types of sampling error. 96 Table 7. Strategies for Minimizing Sampling Error Type of Sampling Error Strategy To Minimize or Reduce Error Fundamental Error ° To reduce variability caused by fundamental error, increase the volume of the sample. ° To reduce the volume of the sample and maintain low fundamental error, perform particle size reduction followed by subsampling. ° When volatile constituents are of interest, do not grind or mix the sample. Rather, take samples using a method that minimizes disturbances of the sample material (see also Section 6.3.4).

Grouping and Segregation Error ° To minimize grouping error, take many increments. ° To minimize segregation error, homogenize the sample (but beware of techniques that promote segregation)

Increment Delimitation/ Extraction Errors ° Select sampling devices that delimit and extract the sample so that all material that should be included in the sample is captured and retained by the device (Pitard 1993, Myers 1997). ° For one dimensional wastes (e. g., flowing streams or waste on a conveyor), the correct or "ideal" sample is an undisturbed cross section delimited by two parallel planes (Pitard 1993, Gy 1998). To obtain such a sample, use a device that can obtain "all of the flow for a fraction of the time" (Gy 1998) (see also Section <IP_ADDRESS>). ° For three dimensional wastes (e. g., solids in a roll off bin), the waste can be considered for practical purposes a series of overlapping twodimensional wastes. The correct or "ideal" sample is an undisturbed vertical core (Pitard 1993, Gy 1998) that captures the full depth of interest.

Preparation Error ° Take steps to prevent contamination of the sample during field handling and shipment. Sample contamination can be checked through preparation and analysis of field quality control samples such as field blanks, trip blanks, and equipment rinsate blanks. ° Prevent loss of volatile constituents through proper storage and handling. ° Minimize chemical transformations via proper storage and chemical/ physical preservation. ° Take care to avoid unintentional mistakes when labeling sample containers, completing other documentation, and handling and weighing samples.

6.3.1 Determining the Optimal Mass of a Sample As part of the DQO Process (Step 4  Define the Boundaries), we recommend that you determine the appropriate size (i. e., the mass or volume), shape, and orientation of the primary field sample. For heterogeneous materials, the size, shape, and orientation of each field sample will affect the analytical result. To determine the optimal mass (or weight) of samples to be collected in the field, you should consider several key factors:

° The number and type of chemical and/ or physical analyses to be performed on each sample, including extra volumes required for QA/ QC. (For example, SW846 Method 1311 (TCLP) specifies the minimum sample mass to be used for the extraction.)

° Practical constraints, such as the available volume of the material and the ability to collect, transport, and store the samples 2 In this section, we use the "relative variance" ( ) and the "relative standard deviation" ( ). The s x 2 2 s x values are dimensionless and are useful for comparing results from different experiments.

97 ° The characteristics of the matrix (such as particulate solid, sludge, liquid, debris, oily waste, etc.)

° Health and safety concerns (e. g., acutely toxic, corrosive, reactive, or ignitable wastes should be transported and handled in safe quantities)

° Availability of equipment and personnel to perform particle size reduction (if needed) in the field rather than within a laboratory.

Often, the weight (or mass) of a field sample is determined by "whatever will fit into the jar." While this criterion may be adequate for some wastes or media, it can introduce serious biases – especially in the case of sampling particulate solids.

If a sample of particulate material is to be representative, then it needs to be representative of the largest particles of interest (Pitard 1993). This is relevant if the constituent of concern is not uniformly distributed across all the particle size fractions. To obtain a sample representative of the largest particles of interest, the sample must be of sufficient weight (or mass) to control the amount of fundamental error introduced during sampling.

If the constituent( s) of concern is uniformly distributed throughout all the particle size fractions, then determination of the optimal sample mass using Gy's approach will not improve the representativeness of the sample. Homogeneous or uniform distribution of contaminants among all particle sizes, however, is not a realistic assumption, especially for contaminated soils. In contaminated soils, concentrations of metals tend to be higher in the clay and silt size fractions and organic contaminants tend to be associated with organic matter and fines in the soil.

The following material provides a "rule of thumb" approach for determining the particle size sample weight relationship sufficient to maintain fundamental error (as measured by the standard deviation of the fundamental error) within desired limits. A detailed quantitative method is presented in Appendix D. Techniques for calculating the variance of the fundamental error also are presented in Mason (1992), Pitard (1993), Myers (1997), and Gy (1998).

The variance of the fundamental error ( ) is directly proportional to the size of the largest sFE 2 particle and inversely proportional to the mass of the sample. 2 To calculate the appropriate mass of the sample, Pitard (1989) proposed a "Quick Safety Rule" for use in environmental sampling based on a standard deviation of the fundamental error of 5 percent ( ): sFE = ± 5%

MS   10000 3 d Equation 18 where is the mass of the sample in grams (g) and of the diameter of the largest particle MS d in centimeters (cm). 98 Direction of Flow Taking all of the flow part of the time.

Taking part of the flow all of the time.

Taking part of the flow part of the time. A B C Figure 26. Three ways of obtaining a sample from a moving stream. "A" is correct. "B" and "C" will obtain biased samples unless the material is homogeneous (modified after Gy 1998). Alternatively, if we are willing to accept , we can use sFE = ± 16%

MS   1000 3 d Equation 19 An important feature of the fundamental error is that it does not "cancel out." On the contrary, the variance of the fundamental error adds together at each stage of subsampling. As pointed out by Myers (1997), the fundamental error quickly can accumulate and exceed 50 percent, 100 percent, 200 percent, or greater unless it is controlled through particle size reduction at each stage of sampling and subsampling. The variance, , calculated at each stage of sFE 2 subsampling and particle size reduction, must be added together at the end to derive the total . A example of how the variances of the fundamental error can be added together is sFE 2 provided in Appendix D.

6.3.2 Obtaining the Correct Shape and Orientation of a Sample When sampling heterogeneous materials, the shape and orientation of the sampling device can affect the composition of the resulting samples and facilitate or impede achievement of DQOs. The following two subsections provide guidance on selecting the appropriate shape and orientation of samples obtained from a moving stream of material and a stationary batch or unit of material.

<IP_ADDRESS> Sampling of a Moving Stream of Material In sampling a moving stream of material, such as solids, liquids, and multi phase mixtures moving through a pipe, on a conveyor, etc., the material can be treated as a one dimensional mass. That is, the material is assumed to be linear in time or space.

The correct or "ideal" sample is an undisturbed cross section delimited by two parallel planes (Pitard 1993, Gy 1998). The approach is depicted in Figure 26 in which all of the flow is collected for part of the time. In practice, the condition can be met by using "cross stream" sampling devices positioned at the discharge of a conveyor, hose, duct, etc. (Pitard 1993). Alternatively, in sampling solids from a conveyor belt, a transverse cutter or flat scoop (with vertical sides) can be used to obtain a sample, preferably with the conveyor stopped (though this condition may not be practical for large industrial conveyors).

For sampling of liquids, if the entire stream cannot be obtained for a fraction of the time (e. g., at the discharge point), then it may be necessary to introduce turbulence in the stream using baffles and to obtain a portion of the mixed stream part of the time (Pitard 1993). 99 Different Size Devices Different Shape and Orientation C B A Decision Unit Different Orientation of Coring Device D Figure 27. Sampling a three dimensional waste by treating the sampling problem as a series of overlapping two dimensional wastes. Only device "A" provides the correct size, shape, and orientation of the sample. <IP_ADDRESS> Sampling of a Stationary Batch of Material Sampling of a stationary batch of material, such as filter cake in a roll off bin, soil in a drum, or liquid in a tank can be approached by viewing the threeCoring

dimensional space as a series of overlapping two dimensional (i. e., relatively flat) masses in a horizontal plane. The correct or "ideal" sample of a is a core that obtains the full thickness of the material of interest.

For example, Figure 27 shows a bin of granular waste with fine grain material in the upper layer and larger fragments in the bottom layer. The entire batch of material is the "decision unit." Coring device "A" is correct: it is wide enough and long enough to include the largest fragments in the waste. Coring device "B" is too narrow. It either fails to capture the larger particles or simply pushes them out of the way (causing increment delimitation error). Device "C," a trowel or small shovel, can collect an adequate volume of sample, but it preferentially selects only the finer grained material near the top of the bin. Device "D" is the correct shape, but it is not in the correct orientation. Devices "B," "C," and "D" yield incorrect sample support.

6.3.3 Selecting Sampling Devices That Minimize Sampling Errors As part of the project planning process, you should establish performance goals for the sampling devices to be used and understand the possible limitations of any candidate sampling devices or equipment. The performance goals can then be used to select specific sampling devices or technologies with a clear understanding of the limitations of those devices in the field. Detailed guidance on the selection of specific sampling devices is provided in Section 7 and Appendix E of this document.

<IP_ADDRESS> General Performance Goals for Sampling Tools and Devices Selection of the appropriate sampling device and sampling method will depend on the sampling objectives, the physical characteristics of the waste or media, the chemical constituents of concern, the sampling location, and practical concerns such as technology limitations and safety issues (see also Section 7). The following general performance goals apply to the selection of sampling devices for use in those situations in where it is desirable to control or otherwise minimize biases introduced by the sampling device:

° The device should not include or exclude portions of the waste that do not belong in the sample (in other words, the device should minimize delimitation and extraction errors). 100 ° If volatile constituents are of interest, the device should obtain samples in an undisturbed state to minimize loss of volatile constituents.

° The device should be constructed of materials that will not alter analyte concentrations due to loss or gain of analytes via sorption, desorption, degradation, or corrosion.

° The device should retain the appropriate size (volume or mass) and shape of sample, and obtain it in the orientation appropriate for the sampling condition

preferably in one pass.

Other considerations not related to performance follow:

° "Ease of use" of the sampling device under the conditions that will be encountered in the field. This includes the ease of shipping to and from the site, ease of deployment, and ease of decontamination.

° The degree of hazard associated with the deployment of one sampling device versus another (e. g., consider use of an extension pole instead of a boat to sample from a waste lagoon).

° Cost of the sampling device and of the labor (e. g., single vs. multiple operators) for its deployment (including training) and maintenance.

<IP_ADDRESS> Use and Limitations of Common Devices Unfortunately, many sampling devices in common use today lack the properties required to minimize certain types of sampling error. In fact, there are few devices available that satisfy all the general performance goals stated above. Pitard (1993), however, has identified a number of devices that can help minimize delimitation and extraction error (depending on the physical form of the waste to be sampled). These devices include:

° COLIWASA (or "composite liquid waste sampler")  for sampling free flowing liquids in drums or containers ° Shelby tube or similar device  for obtaining core samples of solids ° Kemmerer depth sampler  for obtaining discrete samples of liquids ° Flat scoop (with vertical walls)  for subsampling solids on a flat surface.

Some devices in common use that can cause delimitation and extraction errors include the following: auger, shovel, spoon, trowel, thief, and trier. In spite of the limitations of many conventional sampling devices, it is necessary to use them under some circumstances encountered in the field because there are few alternatives. When selecting a sampling tool, choose the one that will introduce the least sampling error. In cases in which no such tool exists, document the approach used and be aware of the types of errors likely introduced and their possible impact on the sampling results. To the extent possible and practicable, minimize sampling errors by applying the concepts presented in this chapter. 101 6.3.4 Special Considerations for Sampling Waste and Soils for Volatile Organic Compounds In most contaminated soils and other solid waste materials, volatile organic compound (VOCs), when present, coexist in gaseous, liquid, and solid (sorbed) phases. Of particular concern with regard to the collection, handling, and storage of samples for VOC characterization is the retention of the gaseous component. This phase exhibits molecular diffusion coefficients that allow for the immediate loss of gas phase VOCs from a freshly exposed surface and continued losses from well within a porous matrix. Furthermore, once the gaseous phase becomes depleted, nearly instantaneous volatilization from the liquid and sorbed phases occurs in an attempt to restore the temporal equilibrium that often exists, thereby allowing the impact of this loss mechanism to continue.

Another mechanism that can influence VOC concentrations in samples is biological degradation. In general, this loss mechanism is not expected to be as large a source of determinate error as volatilization. This premise is based on the observation that losses of an order of magnitude can occur on a time scale of minutes to hours due solely to diffusion and advection, whereas losses of a similar magnitude due to biological processes usually require days to weeks. Furthermore, under aerobic conditions, which is typical of most samples that are transported and stored, biological mechanisms favor the degradation of aromatic hydrocarbons over halogenated compounds. Therefore, besides the slower rate of analyte loss, biodegradation is compound selective.

To limit the influence of volatilization and biodegradation losses, which, if not addressed can biased results by one or more orders of magnitude, it is currently recommended that sample collection and preparation, however not necessarily preservation, follow one or the other of these two protocols:

° The immediate in field transfer of a sample into a weighed volatile organic analysis vial that either contains VOC free water so that a vapor partitioning (purge and trap or headspace) analysis can be performed without reopening or that contains methanol for analyte extraction in preparation for analysis, or ° The collection and up to 2 day storage of intact samples in airtight containers before initiating one of the aforementioned sample preparation procedures.

In both cases, samples should be held at 4± 2 o C while being transported from the sampling location to the laboratory.

The Standard Guide for Sampling Waste and Solids for Volatile Organics (ASTM D 4547 98) is recommended reading for those unfamiliar with the many challenges associated with collecting and handling samples for VOC analysis. 102 For additional guidance on the selection and use of sampling tools and devices, see:

° 40 CFR 261, Appendix I, Representative Sampling Methods ° Standard Guide for Selection of Sampling Equipment for Waste and Contaminated Media Data Collection Activities (ASTM D 6232) 7 IMPLEMENTATION: SELECTING EQUIPMENT AND CONDUCTING SAMPLING This section provides guidance on selecting appropriate sampling tools and devices (Section 7.1), conducting field sampling activities (Section 7.2), and using sample homogenization, splitting, and subsampling techniques (Section 7.3).

7.1 Selecting Sampling Tools and Devices The tools, devices, and methods used for sampling waste materials will vary with the form, consistency, and location of the waste materials to be sampled. As part of the DQO Process, you identify the location (type of unit or other source description) from which the samples will be obtained and the "dimension" of the sampling problem (such as "one dimensional" or "two dimensional"). In the DQO Process, you also specify the appropriate size, shape, orientation and other characteristics for each sample (called the "sample support"). In addition to the DQOs for the sample, you will identify performance goals for the sampling device. You may need a device that meets the following qualifications:

° Minimizes delimitation and extraction errors so that it does not include material that should not be in the sample, nor exclude material that should be in the sample ° Provides a largely undisturbed sample (e. g., one that minimizes the loss of volatile constituents, if those are constituents of concern)

° Is constructed of materials that are compatible with the media and the constituents of concern (e. g., the materials of construction do not cause constituent loss or gain due to sorption, desorption, degradation, or corrosion)

° Is easy to use under the conditions of the sampling location, and the degree of health or safety risks to workers is minimal ° Is easy to decontaminate ° Is cost effective during use and maintenance.

Unfortunately, few devices will satisfy all of the above goals for a given waste or medium and sampling design. When selecting a device, try first to choose one that will introduce the least sampling error and satisfy other performance criteria established by the planning team, within practical constraints.

Figure 28 summarizes the steps you can use to select an optimal device for obtaining samples. 1 ASTM is a consensus standards development organization. Consistent with the provisions of the National Technology Transfer and Advancement Act of 1995 (NTTAA), Public Law 104 113, Section 12( d), which directs EPA to use voluntary consensus standards to the extent possible, this guidance supports the use of and provides references to ASTM standards applicable to waste sampling.

103 Step 1 Identify the medium (e. g., liquid or sludge) in Table 8 that best describes the material to be sampled.

Step 2 Select the location or point of sample collection (e. g., conveyor, drum, tank, etc.) in Table 8 for the medium selected in Step 1.

Step 3 Identify candidate sampling devices in the third column of Table 8. For each, review the information in Table 9 and the device summaries in Appendix E.

Step 4 Select a sampling device based on its ability to (1) obtain the correct size, shape, and orientation of the samples, and (2) meet other performance goals specified by the planning team. Step 1 Identify the medium (e. g., liquid or sludge) in Table 8 that best describes the material to be sampled.

Step 2 Select the location or point of sample collection (e. g., conveyor, drum, tank, etc.) in Table 8 for the medium selected in Step 1. Step 2 Select the location or point of sample collection (e. g., conveyor, drum, tank, etc.) in Table 8 for the medium selected in Step 1.

Step 3 Identify candidate sampling devices in the third column of Table 8. For each, review the information in Table 9 and the device summaries in Appendix E. Step 3 Identify candidate sampling devices in the third column of Table 8. For each, review the information in Table 9 and the device summaries in Appendix E.

Step 4 Select a sampling device based on its ability to (1) obtain the correct size, shape, and orientation of the samples, and (2) meet other performance goals specified by the planning team. Step 4 Select a sampling device based on its ability to (1) obtain the correct size, shape, and orientation of the samples, and (2) meet other performance goals specified by the planning team.

Figure 28. Steps for selecting a sampling device Using the outputs from the DQO Process, a description of the medium to be sampled, and knowledge of the site or location of sample collection, Tables 8 and 9 (beginning on pages 109 and 115 respectively) can be used to quickly identify an appropriate sampling device. For most situations, the information in the tables will be sufficient to make an equipment selection; however, if you need additional guidance, review the more detailed information provided in Appendix E or refer to the references cited.

If desired, you can refer to the documents (such as ASTM standards) referenced by Table 8 for supplementary guidance specific to sampling a specific medium and site, or refer to those referenced by Table 9 for supplementary guidance on a device. 1 The contents of the ASTM standards are summarized in Appendix J. (For more information on ASTM or purchasing their publications, including the standards referenced in this chapter, contact ASTM at: ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428 2959, or by telephone at 610 832 9585, via the World Wide Web at http:// www. astm. org.)

In particular, we recommend that you review the guidance found in ASTM Standard D 6232, Standard Guide for Selection of Sampling Equipment for Waste and Contaminated Media Data Collection Activities. Most of the information on sampling devices found in this chapter and in Tables 8 and 9 came from that standard. As noted by the standard, it covers criteria that should be considered when selecting sampling equipment for collecting environmental and waste samples for waste management activities. It also describes many of the typical devices used during such sampling. Because each sampling situation is unique, the guidance in this chapter may not adequately cover your specific sampling scenario. You may have to modify a part of the device or modify the device application to improve its performance or to facilitate sample collection. For 104 example, you might use a rope or an extension handle on a device to access a particular location within a waste management unit. In other cases, you may need auxiliary equipment that will increase the cost or complexity of sampling operation (such as a drill rig to drive a split barrel sampler or a power supply to run a pump). The physical state of the waste or design of the unit also may affect how the equipment is deployed. You should address such variations as part of your sampling plan and make sure that any modifications do not cause sampling bias.

Finally, other sampling devices not addressed in this chapter can and should be used if appropriate (e. g., if the device meets the performance goals and is more practical). New or innovative devices not discussed in this chapter also should be considered for use if they allow you to meet the sampling objectives in a more cost effective manner. In other words, we encourage and recommend a performance based approach for selecting sampling equipment.

7.1.1 Step 1: Identify the Waste Type or Medium to be Sampled The first column of Table 8 (page 109) lists the media type or waste matrix commonly sampled under RCRA. These media may include liquids, sludges or slurries, various unconsolidated solids, consolidated solids and debris, soil, ground water, sediment, soil gas, and air. In general, the types of media describe the physical state of the material to be sampled. The physical characteristics of the waste or medium affect many aspects of sampling, including the volume of material required, selection of the appropriate sampling device, how the device is deployed, and the containers used for the samples. Table 10 provides an expanded description of the media listed in Table 8.

7.1.2 Step 2: Identify the Site or Point of Sample Collection In the second column of Table 8, identify the site or point of sample collection that best describes where you plan to obtain the samples. The "site or point of sample collection" may include (1) the point at which the waste is generated (e. g., as the waste exits a pipe, moves along a conveyor, or is poured or placed into a container, tank, impoundment or other waste management unit); (2) the unit in which the waste is stored (such as a drum, collection hopper, tank, waste pile, surface impoundment, sack or bag) or transported (such as a drum, tanker truck, or roll off box); or (3) the environmental medium to be sampled (such as surface soil, subsurface soil, ground water, surface water, soil gas, or air).

When testing a solid waste to determine if it should be characterized as a hazardous waste or to determine if the waste is restricted from land disposal, such a determination must be made at the point of waste generation.

<IP_ADDRESS> Drums and Sacks or Bags Drums and sacks or bags are portable containers used to store, handle, or transport waste materials and sometimes are used in waste disposal (e. g., drums in a landfill). "Drums" include metal drums and pails, plastic drums, or durable fiberboard paper drums or pails (USEPA 1994a). Drums and pails may contain nearly the full range of media  liquids (single or multilayered sludges, slurries, or solids. Sacks or bags include less rigid portable containers and thus can contain only solids. The sampling approach (including number of samples, locations of samples, sampling device, depth of samples) for these containers will depend on the number of 105 containers to be sampled, waste accessibility, physical and chemical characteristics of the waste, and component distribution within the containers.

Review ASTM Standards D 6063, Guide for Sampling Drums and Similar Containers by Field Personnel, and D 5679, Practice for Sampling Consolidated Solids in Drums or Similar Containers, for more information on the sampling of drums and sacks or bags. Other useful guidance on sampling drums includes "Drum Sampling" (USEPA 1994b), issued by EPA's Environmental Response Team.

<IP_ADDRESS> Surface Impoundments Surface impoundments include natural depressions, manmade excavations, or diked areas that contain an accumulation of liquids or wastes containing free liquids and solids. Examples of surface impoundments are ponds, lagoons, and holding, storage, settling, and aeration pits (USEPA 1994a). The appropriate sampling device for sampling a surface impoundment will depend on accessibility of the waste, the type and number of phases of the waste, the depth, and chemical and physical characteristics of the waste.

<IP_ADDRESS> Tanks A tank is defined at § 260.10 as a stationary device, designed to contain an accumulation of hazardous waste which is constructed primarily of non earthen materials which provide structural support. A container is defined at § 260.10 as a portable device, in which a material is stored, transported, treated, disposed of, or otherwise handled. The distinction that a tank is not a container is important because the regulations at 261.7 set forth conditions to distinguish whether hazardous waste in a container is subject to regulation. Nevertheless, for the purpose of selecting an appropriate sampling device, the term "tank" as used in Table 8 could include other units such as tank trucks and tanker cars even though they are portable devices.

The selection of equipment for sampling the pipes and sampling ports of a tank system is covered separately under those categories. The equipment used to sample a pipe or spigot can be very different from that used to sample an open tank.

Tanks usually contain liquids (single or multi layered), sludges, or slurries. In addition, suspended solids or sediments may have settled in the bottom of the tank. When sampling from a tank, one typically considers how to acquire a sufficient number of samples from different locations (including depths) to adequately represent the entire content of the tank.

Waste accessibility and component distribution will affect the sampling strategy and equipment selection. In addition to discharge valves near the bottom, most tanks have hatches or other openings at the top. It is usually desirable to collect samples via a hatch or opening at the top of the tank because of the potential of waste stratification in the tank (USEPA 1996b). In an open tank, the size of the tank may restrict sampling to the perimeter of the tank. Usually, the most appropriate type of sampling equipment for tanks depends on the design of the tanks and the media contained within the tank.

You can find additional guidance on sampling tanks in "Tank Sampling" (USEPA 1994c), issued by the EPA's Environmental Response Team. 106 <IP_ADDRESS> Pipes, Point Source Discharges, or Sampling Ports For the purpose of this guidance, pipes or point source discharges include moving streams of sludge or slurry discharging from a pipe opening, sluice, or other discharge point (such as the point of waste generation). Sampling ports include controlled liquid discharge points that were installed for the purpose of sampling, such as may be found on tank systems, a tank truck, or leachate collection systems at waste piles or landfills.

A dipper also is used to sample liquids from a sampling port. Typically, it is passed through the stream in one sweeping motion so that it is filled in one pass. In that instance, the size of the dipper beaker should be related to the stream flow rate. If the cross sectional area of the stream is too large, more than one pass may be necessary to obtain a sample (USEPA 1993b). Besides the use of a dipper or other typical sampling devices, sometimes the sample container itself is used to sample a spigot or point source discharge. This eliminates the possibility of contaminating the sample with intermediate collection equipment, such as a dipper (USEPA 1996b).

See ASTM D 5013 89 Standard Practices for Sampling Wastes from Pipes and Other Point Discharges for more information on sampling at this location. Also see Gy (1998) and Pitard (1989, 1993).

<IP_ADDRESS> Storage Bins, Roll Off Boxes, or Collection Hoppers Discharges of unconsolidated solids from a process, such as filter cakes, often fall from the process into a collection hopper or other type of open topped storage container. Sometimes the waste materials are combined into large a storage bin, such as a roll off box or collection hopper. A storage bin also may be used to collect consolidated solids, such as construction debris. The waste can be sampled either as it is placed in the container or after a certain period of accumulation, depending on the technical and regulatory objectives of the sampling program.

<IP_ADDRESS> Waste Piles Waste piles include the non containerized accumulation of solid and nonflowing waste material on land. The size of waste piles can range from small heaps to large aggregates of wastes. Liners may underlie a waste pile, thereby preventing direct contact with the soil. As with other scenarios, waste accessibility and heterogeneity will be key factors in the sampling design and equipment selection. Besides the devices listed in this chapter, excavation equipment may be needed at first to properly sample large piles. Waste piles may present unique sample delimitation problems (Pitard 1993 and Myers 1997), and special considerations related to sampling design may be necessary (such as the need to flatten the pile).

We recommend a review of ASTM Standard D 6009, Guide for Sampling Waste Piles for more information. Another source of information on sampling waste piles is "Waste Pile Sampling" (USEPA 1994d), issued by EPA's Environmental Response Team.

<IP_ADDRESS> Conveyors Solid process discharges are sometimes sampled from conveyors such as conveyor belts or screw conveyors. Conveyor belts are open moving platforms used to transport material 107 between locations. Solid or semi solid wastes on a conveyor belt can be sampled with a flat scoop or similar device (see also Section <IP_ADDRESS>). Screw conveyors usually are enclosed systems that require access via a sampling port, or they can be sampled at a discharge point. See also ASTM D 5013 and Gy (1998, pages 43 through 56).

<IP_ADDRESS> Structures and Debris This guidance assumes that the sampling of structure or debris typically will include the sampling of consolidated solids such as concrete, wood, or other structure debris. Appendix C provides supplemental guidance on developing a sampling strategy for such heterogeneous wastes. See also AFCEE (1995), Koski, et al. (1991), Rupp (1990), USEPA and USDOE (1992), and ASTM Standard D 5956, Standard Guide For Sampling Strategies for Heterogeneous Wastes.

<IP_ADDRESS> Surface or Subsurface Soil Selection of equipment for sampling soil is based on the depth of sampling, the grain size distribution, physical characteristics of the soil, and the chemical parameters of interest (such as the need to analyze the samples for volatiles). Your sampling strategy should specify the depth and interval (e. g., "0 to 6 inches below ground surface") of interest for the soil samples.

Simple manual techniques and equipment can be used for surface or shallow depth sampling. To obtain samples of soil from greater depths, powered equipment (e. g., power augers or drill rigs) will be required; however, those are not used for actual sample collection, but are used solely to gain easier access to the required sample depth (USEPA 1996b). Once at the depth, surface sampling devices may be used.

ASTM has developed many informative standards on the sampling of soil, including D 4700, Standard Guide for Soil Sampling from the Vadose Zone, and D 4220, Standard Practices for Preserving and Transporting Soil Samples. In addition, see EPA published guidance such as Preparation of Soil Sampling Protocols: Sampling Techniques and Strategies (Mason 1992) and Description and Sampling of Contaminated Soils  A Field Pocket Guide (USEPA 1991b).

7.1.3 Step 3: Consider Device Specific Factors After you identify the medium and site of sample collection, refer to the third column of Table 8 for the list of candidate sampling devices. We listed common devices that are appropriate for the given media and site. Next, refer to the information in Table 9 for each of the candidate devices to select the most appropriate one for your sampling effort.

Table 9 provides device specific information to help you choose the appropriate device based on the study objective and the DQOs established for volume (size), shape, depth, and orientation of the sample, and sample type (discrete or composite, surface or at depth).

For easy reference, the devices are listed alphabetically in Table 9. Appendix E contains a summary description of key features of each device and sources for other information. Under the third column in Table 9, "Other Device Specific Guidance," we have identified some of those sources, especially relevant ASTM standards (see summaries of ASTM standards in Appendix J). 108 <IP_ADDRESS> Sample Type The column "Sample Type" Table 9 identifies whether the device can sample at surface only, shallow or at a deeper profile (depth), and whether the device can obtain a discrete sample or a composite sample. For example, a COLIWASA or drum thief can be used to sample a container that is 3 feet deep, but a Kemmerer sampler may be required to sample the much deeper depth of an impoundment. We also identify in this column whether the device collects a undisturbed or disturbed solid sample. Also, the actual depth capacity may depend on the design of the device. Some devices can be modified or varied to collect at different depths or locations in a material. You should refer to the device summary in Appendix E if you need specifics regarding the sampling depth available for a given device.

<IP_ADDRESS> Sample Volume The column for volume in Table 9 identifies the range of sample volume, in liters, that the device can obtain. It may be possible to increase or decrease this value through modification of the device. During the planning process, you should determine the correct volume of sample needed. Volume is one of the components of sample "support" (that is, the size, shape, and orientation of the sample).

<IP_ADDRESS> Other Device Specific Considerations The last column of Table 9 notes other considerations for device selection. The comments focus on those factors that may cause error to be introduced or that might increase the time or cost of sampling. For some devices, the column includes comments on how easy the equipment is to use, such as whether it needs a power source or is heavy, and whether it can be decontaminated easily. The table also mentions whether the device is appropriate for samples requiring the analysis of volatile organic constituents and any other important considerations regarding analyte and device compatibility. The equipment should be constructed of materials that are compatible with the waste and not susceptible to reactions that might alter or bias the physical or chemical characteristics of the sample of the waste.

7.1.4 Step 4: Select the Sampling Device Select the sampling device based on its ability to (1) obtain the correct size, shape, and orientation of the samples (see Sections 6.3.1 and 6.3.2) and (2) meet any other performance criteria specified by the planning team in the DQO Process (see Section <IP_ADDRESS>). In addition, samples to be analyzed for volatile organic constituents should be obtained using a sampling technique that will minimize the loss of constituents and obtain a sample volume required for the analytical method (see Section 6.3.4). 109 Table 8. Device Selection Guide  Media and Site of Sample Collection Media (See Section 7.1.1) Site or Point of Sample Collection (See Section 7.1.2) Candidate Devices (Listed Alphabetically. For Device Specific Information, See Table 9) Other Related Guidance Liquids, no distinct layer of interest Examples: Containerized spent solvents, leachates or other liquids discharged from a pipe or spigot Drum COLIWASA Dipper Drum thief Liquid grab sampler Peristaltic pump Plunger type sampler Settleable solids profiler Swing jar sampler Syringe sampler Valved drum sampler ASTM D 5743 ASTM D 6063 EPA/ ERT SOP 2009 (USEPA 1994b)

Surface impoundment Automatic sampler Bacon bomb Bailer Bladder pump Centrifugal sub pump Dipper Displacement pump Kemmerer sampler Liquid grab sampler Peristaltic pump Plunger type sampler Settleable solids profiler Swing jar sampler Syringe sampler ASTM D 6538 USEPA (1984, 1985, and 1989c)

Tank Bacon bomb Bailer COLIWASA Dipper Drum thief Kemmerer sampler Liquid grab sampler Peristaltic pump Plunger type sampler Settleable solids profiler Submersible pump Swing jar sampler Syringe sampler ASTM D 6063 ASTM D 5743 EPA/ ERT SOP 2010 (USEPA 1994c)

* Copies of EPA/ ERT SOPs are available on the Internet at http:// www. ert. org/ 110 Table 8. Device Selection Guide  Media and Site of Sample Collection (Continued)

Media (See Section 7.1.1) Site or Point of Sample Collection (See Section 7.1.2) Candidate Devices (Listed Alphabetically. For Device Specific Information, See Table 9) Other Related Guidance Liquids, no distinct layer of interest (continued) Pipe, point source discharge Automatic sampler Bladder pump Centrifugal submersible pump Dipper Displacement pump Liquid grab sampler Plunger type sampler Sample container Swing jar sampler ASTM D 5013 ASTM D 5743 ASTM D 6538 Gy 1998 Sampling port (e. g., spigot) Beaker, bucket, sample container Swing jar sampler Gy 1998 Liquids, multi layered, with one or more distinct layers of interest Examples: Non aqueous phase liquids (NAPLs) in a tank; mixtures of antifreeze in a tank. Drum COLIWASA Discrete level sampler Drum thief Plunger type sampler Settleable solids profiler Swing jar sampler Syringe sampler Valved drum sampler ASTM D 6063 Surface impoundment Automatic sampler Bacon bomb Bailer (point source bailer) Bladder pump Centrifugal submersible pump Discrete level sampler Displacement pump Peristaltic pump Plunger type sampler Settleable solids profiler Swing jar sampler Syringe sampler ASTM D 6538 USEPA (1989c)

Tank COLIWASA Centrifugal submersible pump Bacon bomb Bailer Discrete level sampler Peristaltic pump Plunger type sampler Settleable solids profiler Swing jar sampler Syringe sampler Valved drum sampler ASTM D 6063 ASTM D 5743 EPA/ ERT SOP 2010 (USEPA 1994c) Table 8. Device Selection Guide  Media and Site of Sample Collection (Continued)

Media (See Section 7.1.1) Site or Point of Sample Collection (See Section 7.1.2) Candidate Devices (Listed Alphabetically. For Device Specific Information, See Table 9) Other Related Guidance 111 Sludges, slurries, and solidliquid suspensions Examples: Paint sludge, electroplating sludge, and ash and water slurry. Drum COLIWASA Dipper Liquid grab sampler Plunger type sampler Settleable solids profiler Swing jar sampler Syringe sampler ASTM D 6063 Tank COLIWASA Dipper Lidded sludge/ water sampler Liquid grab sampler Plunger type sampler Ponar dredge Settleable solids profiler Swing jar sampler Syringe sampler ASTM D 6063 EPA/ ERT 2010 (USEPA 1994c)

Surface impoundment Dipper Lidded sludge/ water sampler Liquid grab sampler Peristaltic pump Plunger type sampler Ponar dredge Settleable solids profiler Swing jar sampler USEPA (1989c)

Pipe or conveyor Dipper or bucket Scoop/ trowel/ shovel Swing jar sampler ASTM D 5013 Granular solids – unconsolidated Examples: Filter press cake, powders, excavated (ex situ) soil, incinerator ash Drum Bucket auger Coring type sampler (w/ valve) Miniature core sampler Modified syringe sampler Trier Scoop/ trowel/ shovel ASTM D 5680 ASTM D 6063 EPA/ ERT SOP 2009 (USEPA 1994b)

Sack or bag Concentric tube thief Miniature core sampler Modified syringe sampler Scoop/ trowel/ shovel Trier ASTM D 5680 ASTM D 6063 Table 8. Device Selection Guide  Media and Site of Sample Collection (Continued)

Media (See Section 7.1.1) Site or Point of Sample Collection (See Section 7.1.2) Candidate Devices (Listed Alphabetically. For Device Specific Information, See Table 9) Other Related Guidance 112 Granular solids – unconsolidated (continued) Storage bin, rolloff box, or collection hopper Bucket auger Concentric tube thief Coring type sampler (w/ valve) Miniature core sampler Modified syringe sampler Scoop/ trowel Trier ASTM D 5680 ASTM D 6063 Waste pile Bucket auger Concentric tube thief Coring type sampler (w/ valve) Miniature core sampler Modified syringe sampler Scoop/ trowel/ shovel Thin walled tube Trier ASTM D 6009 EPA/ ERT SOP 2017 (USEPA 1994d)

Pipe (e. g., vertical discharge from cyclone centrifuge or baghouse) or conveyor Bucket, dipper, pan, or sample container Miniature core sampler Scoop/ trowel/ shovel Trier ASTM D 5013 Gy (1998) Pitard (1993)

Other solids – unconsolidated Examples: Waste pellets, catalysts, or large grained solids. Drum Bucket auger Scoop/ trowel/ shovel ASTM D 5680 ASTM D 6063 EPA/ ERT SOP 2009 (USEPA 1994b)

Sack or bag Bucket auger Scoop/ trowel/ shovel ASTM D 5680 ASTM D 6063 Storage bin, rolloff box, or collection hopper Bucket auger Scoop/ trowel/ shovel ASTM D 5680 ASTM D 6063 Waste pile Bucket auger Scoop/ trowel/ shovel Split barrel Thin walled tube ASTM D 6009 EPA/ ERT SOP 2017 (USEPA 1994d)

Conveyor Scoop/ trowel/ shovel ASTM D 5013 Gy (1998) Pitard (1993) Table 8. Device Selection Guide  Media and Site of Sample Collection (Continued)

Media (See Section 7.1.1) Site or Point of Sample Collection (See Section 7.1.2) Candidate Devices (Listed Alphabetically. For Device Specific Information, See Table 9) Other Related Guidance 113 Soil and other unconsolidated geologic material Examples: In situ soil at a land treatment unit or in situ soil at a SWMU Surface Bucket auger Concentric tube thief Coring type sampler Miniature core sampler Modified syringe sampler Penetrating probe sampler Scoop/ trowel/ shovel Thin Walled Tube Trier ASTM D 5730 ASTM E 1727 ASTM D 4700 EISOPQA Manual (USEPA 1996b)

Subsurface Bucket auger Coring type sampler Miniature core sampler Mod. syringe sampler Penetrating probe sampler Shovel/ scoop/ shovel Split barrel Thin walled tube ASTM D 4700 ASTM D 5730 ASTM D 6169 ASTM D 6282 USEPA (1996b) USEPA (1993c)

Solids – consolidated Examples: Concrete, wood, architectural debris* Storage bin (e. g., roll off box) Penetrating probe sampler Rotating coring device ASTM D 5679 ASTM D 5956 ASTM D 6063 USEPA and USDOE (1992)

Waste pile Penetrating probe sampler Rotating coring device Split barrel ASTM D 6009 USEPA and USDOE (1992)

Structure Rotating coring device (See also Appendix C, Section C. 5) AFCEE (1995) Koski, et al (1991) USEPA and USDOE (1992)

* The term "debris" has a specific definition under 40 CFR 268.2( g) (Land Disposal Restrictions regulations) and includes "solid material exceeding a 60 mm particle size that is intended for disposal and that is a manufactured object; or plant or animal matter; or natural geologic material." § 268.2( g) also identifies materials that are not debris. In general, debris includes materials of either a large particle size or variation in the items present. 114 Table 8. Device Selection Guide  Media and Site of Sample Collection (Continued)

Selected References for Sampling of Other Media Air Example: BIF emissions Chapter Ten SW 846 EISOPQA Manual (USEPA 1996b)

Sediment Example: Surface impoundment sediment QA/ QC Guidance for Sampling and Analysis of Sediments, Water, and Tissues for Dredged Material Evaluations (USEPA 1995d)

Superfund Program Representative Sampling Guidance Volume 5; Water and Sediment, Part I – Surface Water and Sediment, Interim Final Guidance (USEPA 1995e)

Region 4 EISOPQA Manual (USEPA 1996b)

Sediment Sampling (USEPA 1994e)

ASTM D 4823; ASTM D 5387 Soil Gas or Vapor Examples: Soil, soil water, or gas in the vadose zone at a waste disposal site Subsurface Characterization and Monitoring Techniques  A Desk Reference Guide (USEPA 1993c)

ASTM Standard Guide for Soil Gas Monitoring in the Vadose Zone (ASTM D 5314)

Soil Gas Sampling (USEPA 1996c)

Ground Water Example: Ground water monitoring wells at a landfill RCRA Ground Water Monitoring Draft Technical Guidance (USEPA 1992c)

Low Flow (Minimal Drawdown) Ground Water Sampling Procedures (Puls and Barcelona 1996)

ASTM D4448 01 Standard Guide for Sampling Ground Water Monitoring Wells ASTM D 5092 90 Standard Practice for Design and Installation of Ground Water Monitoring Wells in Aquifers ASTM D 6286 98 Standard Guide for Selection of Drilling Methods for Environmental Site Characterization ASTM D 6282 Standard Guide for Direct Push Soil Sampling for Environmental Site Characterizations ASTM D 6771 02 Standard Practice for Low Flow Purging and Sampling for Wells and Devices Used for Ground Water Quality Investigations 115 Table 9. Device Selection Guide – Device Specific Factors Sampling Device (Listed in Alphabetical Order) Description, Appendix E,

Section No. Other Device Specific Guidance (in Addition to ASTM D 6232) Sample Type Volume (Liters per Pass) Comments (For Example: Effects on Matrix, Operational Considerations, Typical Uses)

Automatic sampler E. 1.1 ASTM D 6538 EISOPQA Manual (USEPA 1996b) Shallow (25 in.), discrete or composite Unlimited Auto samplers are available to collect samples for volatile organics analysis, provide a grab or composite sample, and may be unattended. Need power source/ battery. Commonly used at waste water treatment plants. Must be knowledgeable of compatibility of waste and sampler components.

Bacon bomb E. 3.1 USEPA 1984 USEPA 1994c Depth, discrete 0.1 to 0.5 For parameters that do not require a polytetrafluroethylene (PTFE) sampler. Recommended for sampling of lakes, ponds,

large tanks, or lagoons. May be difficult to decontaminate and materials of construction may not be compatible with sample matrix.

Bailer E. 7.1 ASTM D 4448 USEPA 1992c USEPA 1994c Depth, discrete 0.5 to 2.0 Bailers are not recommended for sampling ground water for trace constituent analysis due to sampling induced turbidity (USEPA 1992c and Puls and Barcelona 1996). Unable to collect samples from specific depths (unless a point source bailer is used). Available in a variety of sizes as either reusable or single use devices. May be chemically incompatible with certain matrices unless constructed of resistant material.

Bladder pump E. 1.2 ASTM D 4448 USEPA 1992c USEPA 1996b Depth, discrete Unlimited For purging or sampling of wells, surface impoundments, or point discharges. Contact parts are made of PTFE, PVC and stainless steel. Requires a power source, compressed gas, and a controller. Difficult to decontaminate (based on design).

Suitable for samples requiring VOAs. May require a winch or reel.

Bucket auger E. 5.1 ASTM D 1452 ASTM D 4700 ASTM D 6063 Mason 1992 USEPA 1993c Surface or depth, disturbed 0.2 to 1.0 Easy and quick for shallow subsurface samples but not recommended for VOAs. Requires considerable strength and labor and destroys soil horizons. 116 Table 9. Device Selection Guide – Device Specific Factors (Continued)

Sampling Device (listed in alphabetical order) Description, Appendix E,

Section Other Device Specific Guidance (in addition to ASTM D 6232) Sample Type Volume (Liters Per Pass) Comments (For Example: Effects on Matrix, Operational Considerations, Typical Uses)

Centrifugal submersible pump E. 1.4 ASTM D 4448 ASTM D 4700 USEPA 1992c Depth, discrete Unlimited For purging or sampling wells, surface impoundments, or point discharges. Contact parts are made of PTFE and stainless steel. Requires a power source. Adjustable flow rate and easy to decontaminate. Not compatible with liquids containing high percent solids. May require a winch or reel.

COLIWASA E. 6.1 ASTM D 5495 ASTM D 5743 ASTM D 6063 USEPA 1980 Shallow, composite 0.5 to 3.0 Reusable and single use models available. Inexpensive. Glass type devices may be difficult to decontaminate. Collects undisturbed sample. For mixed solid/ liquid media will collect semi liquid only. Not for high viscosity liquids.

Concentric tube thief E. 4.3 ASTM D 6063 USEPA 1994d Surface, relatively undisturbed, selective 0.5 to 1.0 Recommended for powdered or granular materials or wastes in piles or in bags, drums or similar containers. Best used in dry,

unconsolidated materials. Not suitable for sampling large particles due to narrow width of slot.

Coring type sampler (with or without valve) E. 4.6 ASTM D 4823 USEPA 1989c Surface or depth, disturbed 0.2 to 1.5 Designed for wet soils and sludge. May be equipped with a plastic liner and caps. May be used for VOAs. Reusable and easy to decontaminate.

Dipper (or "pond sampler") E. 7.2 ASTM D 5358 ASTM D 5013 USEPA 1980 Shallow, composite 0.5 to 1.0 For sampling liquids in surface impoundments. Inexpensive.

Not appropriate for sampling stratified waste if discrete characterization needed.

Discrete level sampler E. 3.5 Depth, discrete 0.2 to 0.5 Easy to decontaminate. Obtains samples from a discrete interval. Limited by sample volume and liquids containing high solids. Can be used to store and transport sample.

Displacement pumps E. 1.5 ASTM D 4448 Depth, discrete Unlimited Can be used for purging or sampling of wells, impoundments, or point discharges. Contact parts are made of PVC, stainless steel, or PTFE to reduce risk of contamination when trace levels or organics are of interest. Requires a power source and a large gas source. May be difficult to decontaminate (piston displacement type). May require a winch or reel to deploy. Table 9. Device Selection Guide – Device Specific Factors (Continued)

Sampling Device (listed in alphabetical order) Description, Appendix E,

Section Other Device Specific Guidance (in addition to ASTM D 6232) Sample Type Volume (Liters Per Pass) Comments (For Example: Effects on Matrix, Operational Considerations, Typical Uses)

117 Drum thief E. 6.2 ASTM D 6063 ASTM D 5743 USEPA 1994b Shallow, composite 0.1 to 0.5 Usually single use. If made of glass and reused,

decontamination may be difficult. Limited by length of sampler,

small volume of sample collected, and viscosity of fluids.

Kemmerer sampler E. 3.2 Depth, discrete 1.0 to 2.0 Recommended for lakes, ponds, large tanks or lagoons. May be difficult to decontaminate. Materials may not be compatible with sample matrix but all PTFE construction is available. Sample container exposed to media at other depths while being lowered to sample point.

Lidded sludge/ water sampler E. 3.4 Discrete, composite 1.0 1 L sample jar placed into device (low risk of contamination).

May sample at different depths and samples up to 40 percent solids. Equipment is heavy and limited to one bottle size.

Liquid grab sampler E. 7.3 Shallow, discrete, composite suspended solids only 0.5 to 1.0 For sampling liquids or slurries. Can be capped and used to transport sample. Easy to use. May be lowered to specific depths. Compatibility with sample parameters is a concern.

Miniature core sampler E. 4.7 ASTM D 4547 ASTM D 6418 Discrete 0. 01 to 0.05 Used to retrieve samples from surface soil, trench walls, or sub

samples from soil cores. O rings on plunger and cap minimize loss of volatiles and allow device to be used to transport sample.

Designed for single use. Cannot be used on gravel or rocky soils must avoid trapping air with samples.

Modified syringe sampler E. 4.8 ASTM D 4547 Discrete 0. 01 to 0.05 Made by modifying a plastic, medical, single use syringe. Used to collect a sample from a material surface or to sub sample a core. The sample is transferred to a vial for transportation.

Inexpensive. Must ensure device is clean and compatible with media to be sampled. Table 9. Device Selection Guide – Device Specific Factors (Continued)

Sampling Device (listed in alphabetical order) Description, Appendix E,

Section Other Device Specific Guidance (in addition to ASTM D 6232) Sample Type Volume (Liters Per Pass) Comments (For Example: Effects on Matrix, Operational Considerations, Typical Uses)

118 Penetrating probe sampler E. 4.1 USEPA 1993c Discrete, undisturbed 0.2 to 2.0 Used to sample soil vapor, soil, and ground water (pushed or hydraulically driven). Versatile, make samples available for onsite analysis and reduces investigation derived waste. Limited by sample volume and composition of subsurface material.

Peristaltic pump E. 1.3 ASTM D 4448 ASTM D 6063 USEPA 1996b Shallow, discrete or composite suspended solids only Unlimited Possible to collect samples from multiple depths up to 25 feet.

Decontamination of pump is not required and tubing is easy to replace. Can collect samples for purgeable organics with modified equipment, but may cause loss of VOAs.

Plunger type sampler E. 6.4 ASTM D 5743 Surface or depth, discrete 0.2 to Unlimited Made of high density polyethylene (HDPE) or PTFE with optional glass sampling tubes. Used to collect a vertical column of liquid. Either a reusable or single use device.

Decontamination may be difficult (with glass tubes).

Ponar dredge E. 2.1 ASTM D 4387 ASTM D 4342 USEPA 1994e Bottom surface, rocky or soft, disturbed 0.5 to 3.0 One of the most effective samplers for general use on all types of substrates (silt to granular material). May be difficult to repeatedly collect representative samples. May be heavy.

Rotating coring device E. 5.2 ASTM D 5679 Surface or depth, undisturbed 0.5 to 1.0 May obtain a core of consolidated solid. Requires power and water source and is difficult to operate. Sample integrity may be affected.

Scoop E. 7.5 ASTM D 5633 ASTM D 4700 ASTM D 6063 Surface, disturbed, selective <0. 1 to 0.6 Usually for surface soil and solid waste samples. Available in different materials and simple to obtain. May bias sample because of particle size. May exacerbate loss of VOCs.

Settleable solids profiler E. 6.5 Depth, composite suspended solids only 1.3 to 4.0 Typically used at waste water treatment plants, waste settling ponds, and impoundments to measure and sample settleable solids. Easy to assemble, reusable and unbreakable under normal use. Not recommended for caustics or high viscosity materials. Table 9. Device Selection Guide – Device Specific Factors (Continued)

Sampling Device (listed in alphabetical order) Description, Appendix E,

Section Other Device Specific Guidance (in addition to ASTM D 6232) Sample Type Volume (Liters Per Pass) Comments (For Example: Effects on Matrix, Operational Considerations, Typical Uses)

119 Shovel E. 7.5 ASTM D 4700 Surface, disturbed 1.0 to 5.0 Used to collect surface material or large samples from waste piles. Easy to decontaminate and rugged. Limited to surface use and may exacerbate the loss of samples for VOAs.

Split barrel sampler E. 4.2 ASTM D 1586 ASTM D 4700 ASTM D 6063 Discrete, undisturbed 0.5 to 30.0 May be driven manually, or mechanically by a drill rig with trained personnel. May collect a sample at depth. A liner may be used in the device to minimize disturbance or for samples requiring VOAs.

Swing jar sampler E. 7.4 Shallow, composite 0.5 to 1.0 Used to sample liquids, powders, or small solids at a distance up to 12 feet. Adaptable to different container sizes. Not suitable for discrete samples. Can sample a wide variety of locations.

Syringe sampler E. 3.3 ASTM D 5743 ASTM D 6063 Shallow, discrete, disturbed 0.2 to 0.5 Recommended for highly viscous liquids, sludges and tar like substances. Easy to decontaminate. Obtains samples at discrete depths but limited to length of device. Waste must be viscous enough to stay in sampler.

Thin walled tube E. 4.5 ASTM D 1587 ASTM D 4823 ASTM D 4700 Surface or depth, undisturbed 0.5 to 5.0 Useful for collecting an undisturbed sample (depends on extension). May require a catcher to retain soil samples.

Inexpensive, easy to decontaminate. Samples for VOAs may be biased when sample is extruded.

Trier E. 4.4 ASTM D 5451 ASTM D 6063 Surface, relatively undisturbed, selective 0.1 to 0.5 Recommended for powdered or granular materials or wastes in piles or in bags, drums, or similar containers. Best for moist or sticky materials. Will introduce sampling bias when used to sample coarse grained materials.

Trowel E. 7.5 ASTM D 5633 ASTM D 4700 ASTM D 6063 Surface, disturbed, selective 0.1 to 0.6 Usually for surface soil and solid waste samples. Available in different materials and simple to obtain. May bias sample because of particle size, and may exacerbate loss of VOAs.

Valved drum sampler E. 6.3 Shallow, composite 0.3 to 1.6 Used to collect a vertical column of liquid. Available in various materials for repeat or single use. High viscosity liquids may be difficult to sample. 120 Table 10. Descriptions of Media Listed in Table 8.

Media Description Examples Liquids  no distinct layer of interest Liquids (aqueous or nonaqueous) that are or are not stratified and samples from discrete intervals are not of interest. Sampling devices for this medium do not need to be designed to collect liquids at discrete depths. Containerized leachates or spent solvents; leachates or other liquids released from a spigot or discharged from a pipe.

Liquids  one or more distinct layers of interest Liquids (aqueous or nonaqueous) that are stratified with distinct layers and collection of samples from discrete intervals is of interest. Sampling devices for this media do need to be designed to collect liquids at discrete depths. Mixtures of antifreeze and used oil; light or dense non

aqueous phase liquids and water in a container, such as a tank.

Sludges or slurries Materials that are a mixture of liquids and solids and that may be viscous or oily. Includes materials with suspended solids. Waste water treatment sludges from electroplating; slurry created by combining solid waste incinerator ash and water.

Granular solids, unconsolidated Solids which are not cemented, or do not require significant pressure to separate into particles, and are comprised of relatively small particles or components. Excavated (ex situ) soil in a staging pile; filter press cake;

fresh cement kiln dust; incinerator ash.*

Other solids, unconsolidated Solids with larger particles than those covered by granular solids. The sampling device needs to collect a larger diameter or volume of sample to accommodate the larger particles. Waste pellets or catalysts.

* For EPA published guidance on the sampling of incinerator ash, see Guidance for the Sampling and Analysis of Municipal Waste Combustion Ash for the Toxicity Characteristic (USEPA 1995f). 121 Table 10. Descriptions of Media Listed in Table 8 (Continued).

Media Description Examples Soil (in situ) and other unconsolidated geologic material Soil in its original undisturbed location or other geologic material that does not require significant pressure to separate into particles. In situ soil sampling may be conducted at subsurface or surface depths. Surface soils generally are defined as soils between the ground surface and 6 to 12 inches below the ground surface (USEPA 1996b); however, the definition of surface soils in State programs may vary considerably from EPA's. Subsurface soil at a land treatment unit; surface soil contaminated by a chemical spill on top of the ground or soil near a leak from an excavated underground storage tank.*

Solids, consolidated Cemented or otherwise dense solids that require significant physical pressure to break apart into smaller parts. Concrete, wood, and architectural debris.

Air For the purpose of RCRA sampling, air includes emissions from stationary sources or indoor air. Emissions from boilers and industrial furnaces (BIFs).**

Sediment Settled, unconsolidated solids beneath a flowing or standing liquid layer. Sediment in a surface water body.

Soil gas or vapor Gas or vapor phase in the vadose zone. The vadose zone is the hydrogeological region extending from the soil surface to the top of the principal water table. Soil gas overlying a waste disposal site.

Ground water "Water below the land surface in a zone of saturation" (40 CFR 260.10). Water can also be present below the land surface in the unsaturated (vadose) zone. Ground water in monitoring wells surrounding a hazardous waste landfill.***

* Detailed guidance on soil sampling can be found in Preparation of Soil Sampling Protocols: Sampling Techniques and Strategies (Mason 1992), which provides a discussion of the advantages and disadvantages of various sample collection methods for soil.

** See Chapter Ten of SW 846 for EPA approved methods for sampling air under RCRA.

*** Detailed guidance on ground water sampling can be found in RCRA Ground Water Monitoring  Draft Technical Guidance (USEPA 1992c), which updates technical information in Chapter Eleven of SW 846 (Rev. 0, Sept. 1986) and the Technical Enforcement Guidance Document (TEGD). 122 7.2 Conducting Field Sampling Activities This section provides guidance on performing field sampling activities that typically are performed during implementation of the sampling plan. Additional guidance can be found in Waste Analysis at Facilities That Generate, Treat, Store, and Dispose of Hazardous Wastes, a Guidance Manual (USEPA 1994a), Environmental Investigations Standard Operating Procedures and Quality Assurance Manual, U. S. EPA Region 4, May 1996 (USEPA 1996b), other USEPA guidance cited in the reference section of this chapter, and various ASTM standards summarized in Appendix J of this guidance. See also Appendix C of EPA's Guidance for Quality Assurance Project Plans (USEPA 1998a). The latter document includes extensive checklists, including the following:

° Sample handling, preparation, and analysis checklist ° QAPP review checklist ° Chain of custody checklist.

In this section, we provide guidance on the following topics:

° Sample containers (Section 7.2.1) ° Sample preservation and holding times (Section 7.2.2) ° Documentation of field activities (Section 7.2.3) ° Field quality control samples (Section 7.2.4) ° Sample identification and chain of custody procedures (Section 7.2.5) ° Decontamination of equipment and personnel (Section 7.2.6) ° Health and safety (Section 7.2.7) ° Sample packaging and shipping (Section 7.2.8).

7.2.1 Selecting Sample Containers All samples should be placed in containers of a size and construction appropriate for the volume of material specified in the sampling plan and as appropriate for the requested analyses. If sufficient sample volume is not collected, the analysis of all requested parameters and complete quality control determinations may not be possible. In addition, minimum sample volumes may be required to control sampling errors (see Section 6). Chapters Two, Three, and Four of SW 846 identify the appropriate containers for RCRA related analyses by SW 846 methods.

It is important to understand that a single "sample" may need to be apportioned to more than one container to satisfy the volume and preservation requirements specified by different categories of analytical methods. Furthermore, the analytical plan may require transport of portions of a sample to more than one laboratory.

Factors to consider when choosing containers are compatibility with the waste components, cost, resistance to breakage, and volume. Containers must not distort, rupture, or leak as a result of chemical reactions with constituents of waste samples. The containers must have adequate wall thickness to withstand handling during sample collection and transport. For analysis of non volatile constituents, containers with wide mouths are often desirable to facilitate Chapters Two, Three, and Four of SW 846 identify some of the appropriate containers for RCRA related analyses by SW 846 methods. 2 For example, when inspections are conducted under Section 3007 of RCRA (42 U. S. C. § 6927), and samples are obtained, EPA must provide a split sample to the facility, upon request.

123 transfer of samples from the equipment. The containers must be large enough to contain the optimum sample volume specified in the DQO Process.

You should store samples containing light sensitive organic constituents in amber glass bottles with Teflon® lined lids. Polyethylene containers are not appropriate for use when the samples are to be analyzed for organic constituents because the plastics could contribute organic contaminants and potentially introduce bias. If liquid samples are to be submitted for analysis of volatile compounds, you must store the samples in air tight containers with zero head space. You can store samples intended for metals and other inorganic constituent analyses in polyethylene containers with polyethylene lined lids. We recommend that you consult with a chemist for further direction regarding chemical compatibility of available containers and the media to be sampled. We recommend that an extra supply of containers be available at the sampling location in case you want to collect more sample material than originally planned or you need to retain splits of each sample. 2 Always use clean sample containers of an assured quality. For container cleaning procedures and additional container information, refer to the current iteration of Specifications and Guidance for Contaminant Free Sample Containers (USEPA 1992d). You may wish to purchase pre cleaned/ quality assured bottles in lieu of cleaning your own bottles (USEPA 2001g).

7.2.2 Sample Preservation and Holding Times Samples are preserved to minimize any chemical or physical changes that might occur between the time of sample collection and analysis. Preservation can be by physical means (e. g., kept at a certain temperature) or chemical means (e. g., with the addition of chemical preservatives). If a sample is not preserved properly, the levels of constituents of concern in the sample may be altered through chemical, biological, or photo degradation, or by leaching, sorption, or other chemical or physical reactions within the sample container.

The appropriate method for preserving a sample will depend on the physical characteristics of the sample (such as soil, waste, water, etc.), the concentration of constituents in the sample, and the analysis to be performed on the sample. Addition of chemical preservatives may be required for samples to be analyzed for certain parameters. You should not chemically preserve highly concentrated samples. Samples with low concentrations, however, should be preserved. You should consult with a chemist at the laboratory regarding the addition of chemical preservatives and the possible impact on the concentration of constituents in the sample. Also, be aware that addition of some chemical preservatives to highly concentrated waste samples may result in a dangerous reaction.

Regardless of preservation measures, the concentrations of constituents within a sample can degrade over time. Therefore, you also should adhere to sample holding times (time from sample collection to analysis), particularly if the constituents of concern are volatiles in low concentrations. Analytical data generated outside of the specified holding times are considered to be minimum values only. You may use such data to demonstrate that a waste is hazardous 124 where the value of a constituent of concern is above the regulatory threshold, but you cannot use the data to demonstrate that a waste is not hazardous. Exceeding a holding time when the results are above a decision level does not invalidate the data.

Appropriate sample preservation techniques and sample holding times for aqueous matrices are listed in Chapters Two, Three, and Four of SW 846. You should also consult the methods to be used during analysis of the sampled waste. In addition, Standard Guide for Sampling Waste and Soil for Volatile Organic Compounds (ASTM D 4547 98) provides information regarding the preservation of volatile organic levels in waste and soil samples.

7.2.3 Documentation of Field Activities This section provides guidance on documenting field activities. Records of field activities should be legible, identifiable, retrievable and protected against damage, deterioration, and loss. You should record all documentation in waterproof, non erasable ink. If you make an error in any of these documents, make corrections by crossing a single line through the error and entering the correct information adjacent to it. The corrections should then be initialed and dated. Stick on labels of information should not be removable without evidence of the tampering. Do not put labels over previously recorded information.

Keep a dedicated logbook for each sampling project with the name of the project leader, team members, and project name written inside the front cover. Document all aspects of sample collection and handling in the logbook. Entries should be legible, accurate, and complete. The language should be factual and objective.

You also should include information regarding sample collection equipment (use and decontamination), field analytical equipment and the measurements, calculations and calibration data, the name of the person who collected the sample, sample numbers, sample location description and diagram or map, sample description, time of collection, climatic conditions, and observations of any unusual events. Document the collection of QC samples and any deviations from procedural documents, such as the QAPP and SOPs.

When videos, slides, or photographs are taken, you should number them to correspond to logbook entries. The name of the photographer, date, time, site location, and site description should be entered sequentially into the logbook as photos are taken. A series entry may be used for rapid aperture settings and shutter speeds for photographs taken within the normal automatic exposure range. Special lenses, films, filters, or other image enhancement techniques must be noted in the logbook. Chain of custody procedures for photoimages depend on the subject matter, type of film, and the processing it requires. Adequate logbook notations and receipts may be used to account for routine film processing. Once developed, the slides or photographic prints should be serially numbered corresponding to the logbook descriptions and labeled (USEPA 1992e).

7.2.4 Field Quality Control Samples Quality control samples are collected during field studies to monitor the performance of sample collection and the risk of sampling bias or errors. Field QC samples could include the following: 125 [Name of Sampling Organization]

Sample Description Plant:

Date:

Time:

Media:

Sample Type:

Sampled By:

Sample ID No.: Location:

Station:

Preservative:

Figure 29. Sample label Equipment blank: A rinse sample of the decontaminated sampling equipment using organic/ analyte free water under field conditions to evaluate the effectiveness of equipment decontamination or to detect sample cross contamination.

Trip blank: A sample prepared prior to the sampling event and stored with the samples throughout the event. It is packaged for shipment with the samples and not opened until the shipment reaches the laboratory. The sample is used to identify any contamination that may be attributed to sample handling and shipment.

Field blank: A sample prepared in the field using organic/ analyte free water to evaluate the potential for contamination by site contaminants not associated with the sample collected (e. g., airborne organic vapors)

Field split sample: Two or more representative portions taken from the same sample and submitted for analysis to different laboratories. Field split samples are used to estimate interlaboratory precision.

In addition to collecting field QC samples, other QC procedures include sample storage, handling, and documentation protocols. These procedures are covered separately in the following sections. In addition, Chapter One of SW 846, entitled "Quality Control", contains guidance regarding both field and laboratory QA/ QC. We also recommend reviewing the following for information on field QA/ QC:

° EPA Guidance for Quality Assurance Project Plans (USEPA 1998a)

° Standard Practice for Generation of Environmental Data Related to Waste Management Activities: Quality Assurance and Quality Control Planning and Implementation (ASTM D 5283 92).

7.2.5 Sample Identification and Chain of Custody Procedures You should identify samples for laboratory analysis with sample tags or labels. An example of a sample label is given in Figure 29. Typically, information on the sample label should include the sample identification code or number, date, time of collection, preservative used, media, location, initials of the sampler, and analysis requested. While not required, you may elect to seal each sample container with a custody seal (Figure 30).

You should use chain of custody procedures to record the custody of the samples. Chain of custody is the custody of samples from time of collection through shipment to analysis. A sample is in one's custody if: 126 Figure 30. Custody seal ° It is in the actual possession of an investigator ° It is in the view of an investigator, after being in their physical possession ° It is in the physical possession of an investigator, who secures it to prevent tampering ° It is placed in a designated secure area.

All sample sets should be accompanied by a chain of custody form. This record also serves as the sample logging mechanism for the laboratory sample custodian. Figure 31 illustrates the content of a chain of custody form. When the possession of samples is transferred, both the individual relinquishing the samples and the individual receiving the samples should sign, date, and note the time on the chain of custody document. If you use overnight shipping service to transport the samples, record the air bill number on the chain of custody form. This chain ofcustody record represents the official documentation for all transfers of the sample custody until the samples have arrived at the laboratory. The original form of the chain of custody record should accompany each shipment. A copy should be retained by a representative of the sampling team.

When sample custody is transferred between individuals, the samples or coolers containing the samples are sealed with a custody seal. This seal cannot be removed or broken without destruction of the seal, providing an indicator that custody has been terminated.

EPA's Superfund Program has developed software called Field Operations and Records Management System (FORMS) II Lite™ that automates the printing of sample documentation in the field, reduces time spent completing sample collection and transfer documentation, and facilitates electronic capture of data prior to and during field sampling activities. For information on FORMS II Lite™, see http:// www. epa. gov/ superfund/ programs/ clp/ f2lite. htm.

For additional information on chain of custody procedures, we recommend ASTM D 4840, Standard Guide for Sampling Chain of Custody Procedures. 127 Figure 31. Chain of custody form 128 7.2.6 Decontamination of Equipment and Personnel Decontamination of sampling equipment refers to the physical and chemical steps taken to remove any chemical or material contamination. Equipment decontamination helps prevent sampling bias. All equipment that comes in contact with the sampled material should be free of components that could influence (contaminate) the true physical or chemical composition of the material. Besides the equipment used to collect the samples, any containers or equipment used for sample compositing or for field subsampling should be free of contamination.

Equipment decontamination also prevents cross contamination of samples when the equipment is used to collect more than one sample. Disposable equipment or the use of dedicated equipment provides the most effective means of avoiding cross contamination; however, the use of such equipment is not always practical.

You should decontaminate equipment to a level that meets the minimum requirements for your data collection effort. Your decontamination steps (e. g., use of solvents versus use of only soap and water), therefore, should be selected based on the constituents present, their concentration levels in the waste or materials sampled, and their potential to introduce bias in the sample analysis results if not removed from the sampling equipment. You should describe the projectspecific decontamination procedures in your planning document for the sampling effort. In addition, items used to clean the equipment, such as bottle brushes, should be free of contamination.

The following procedure is an example of one you could use to decontaminate a sampling device to be used for collecting samples for trace organic or inorganic constituent analyses (from USEPA 1996b):

1. Clean the device with tap water and soap, using a brush if necessary to remove particulate matter and surface films.

2. Rinse thoroughly with tap water.

3. Rinse thoroughly with analyte or organic free water.

4. Rinse thoroughly with solvent. Do not solvent rinse PVC or plastic items.

5. Rinse thoroughly with organic/ analyte free water, or allow equipment to dry completely.

6. Remove the equipment from the decontamination area. Equipment stored overnight should be wrapped in aluminum foil and covered with clean, unused plastic.

The specifications for the cleaning materials are as follows (you should justify and document the use of substitutes):

° "Soap" should be a phosphate free laboratory detergent such as Liquinox®. It must be kept in clean plastic, metal, or glass containers until used and poured directly from the container when in use. 129 ° "Solvent" should be pesticide grade isopropanol. It must be stored in the unopened original containers until used. It may be applied using the low pressure nitrogen system fitted with a Teflon® nozzle, or using Teflon® squeeze bottles. For equipment highly contaminated with organics (such as oily waste), a laboratory grade hexane may be a more suitable alternative to isopropanol.

° "Tap water" may be used from any municipal water treatment system. Use of an untreated potable water supply is not an acceptable substitute. Tap water may be kept in clean tanks, hand pressure sprayers, squeeze bottles, or applied directly from a hose or tap.

° "Analyte free water" (deionized water) is tap water treated by passing it through a standard deionizing resin column. At a minimum, it must contain no detectable heavy metals or other inorganic compounds as defined by a standard ICP (or equivalent) scan. It may be obtained by other methods as long as it meets the analytical criteria. Analyte free water must be stored in clean glass, stainless steel, or plastic containers that can be closed prior to use. It can be applied from plastic squeeze bottles.

° "Organic/ analyte free water" is tap water that has been treated with activated carbon and deionizing units. A portable system to produce such water under field conditions is available. At a minimum, the water must meet the criteria of analyte free water and not contain detectable pesticides, herbicides, or extractable organic compounds, and no volatile organic compounds above minimum detectable levels as determined for a given set of analyses. Organic/ analyte free water obtained by other methods is acceptable, as long as it meets the analytical criteria. It must be stored in clean glass, Teflon®, or stainless steel containers. It may be applied using Teflon® squeeze bottles or with the portable system.

Clean the field equipment prior to field use. Designate a decontamination zone at the site and, if necessary, construct a decontamination pad at a location free of surface contamination. You should collect wastewater from decontamination (e. g., via a sump or pit) and remove it frequently for appropriate treatment or disposal. The pad or area should not leak contaminated water into the surrounding environment. You also should collect solvent rinses for proper disposal.

You should always handle field cleaned equipment in a manner that prevents recontamination. For example, after decontamination but prior to use, store the equipment in a location away from the cleaning area and in an area free of contaminants. If it is not immediately reused, you should cover it with plastic or aluminum foil to prevent recontamination.

Decontamination will generate a quantity of wastes called investigation derived waste (IDW). You should address the handling and disposal of IDW in your sampling plan. You must handle this material in accordance with whether it is nonhazardous or suspected of, or known to be, hazardous. You should minimize the generation of hazardous IDW and keep it separated from nonhazardous IDW. For example, you should control the volume of spent solvents during equipment decontamination by applying the minimum amount of liquid necessary and capturing 130 it separately from the nonhazardous washwater. For additional guidance on handling IDW, see Management of Investigation Derived Wastes (USEPA 1992f).

Decontamination of personnel and their protective gear also is often necessary during hazardous waste sampling. This important type of decontamination protects personnel from chemical exposure and prevents cross contamination when personnel change locations. The level or degree of such decontamination will depend on site specific considerations, such as the health hazards posed by exposure to the sampled waste. You should address these decontamination procedures in your health and safety plan.

For additional information regarding decontamination, see ASTM D 5088, Standard Practice for Decontamination of Field Equipment Used at Nonradioactive Waste Sites. Another source of additional information is "Sampling Equipment Decontamination" (USEPA 1994f), issued by EPA's Environmental Response Team.

7.2.7 Health and Safety Considerations Regulations published by the Occupational Safety and Health Administration (OSHA) at 29 CFR Part 1910.120 govern workers at hazardous waste sites and include requirements for training, equipment, medical monitoring, and other practices. Many sampling activities covered by this guidance may require compliance with OSHA's health and safety regulations. Specific guidance on worker health and safety is beyond the scope of this chapter; however, development and use of a project specific health and safety plan may be required. It is the responsibility of the sampling team leader and others in charge to ensure worker safety.

Some important health and safety considerations follow:

° Field personnel should be up to date in their health and safety training.

° Field personnel should have a medical examination at the initiation of sampling activities and routinely thereafter, as appropriate and as required by the OSHA regulations. Unscheduled examinations should be performed in the event of an accident or suspected exposure to hazardous materials.

° Staff also should be aware of the common routes of exposure at a site and be instructed in the proper use of safety equipment and protective clothing and equipment. Safe areas should be designated for washing, drinking, and eating.

° To minimize the impact of an emergency situation, field personnel should be aware of basic first aid and have immediate access to a first aid kit.

The guidance manual Occupational Safety and Health Guidance Manual for Hazardous Waste Site Activities (OSHA 1985, revised 1998) was jointly developed by the National Institute for Occupational Safety and Health (NIOSH), OSHA, the United States Coast Guard (USCG), and EPA. Its intended audience is those who are responsible for occupational safety and health programs at hazardous waste sites. 131 7.2.8 Sample Packaging and Shipping During transport of waste samples, you should follow all State and Federal regulations governing environmental sample packaging and shipment and ship according to U. S. Department of Transportation (DOT) and International Air Transportation Association (IATA) regulations. Minimum guidelines for sample packaging and shipping procedures follow in the next subsections; however, the rules and regulations for sample packaging and shipping are complex, and for some samples and shipping situations the procedures outlined below may need to be exceeded.

<IP_ADDRESS> Sample Packaging You should package and label samples in an area free of contamination. You also should ship or transport samples to a laboratory within a time frame that meets recommended sample holding times for the respective analyses. Additional guidelines follow:

° Aqueous samples for inorganic analysis and volatile organic analysis may require chemical preservation. The specific preservation requirements will depend on the analytical method to be used.

° Make sure all lids/ caps are tight and will not leak.

° Make sure sample labels are intact and covered with a piece of clear tape for protection.

° Enclose the sample container in a clear plastic bag and seal the bag. Make sure the sample labels are visible. If bubble wrap or other wrapping material will be placed around the labeled containers, write the sample number and fraction (e. g., "BLH01 VOCs") so that it is visible on the outside of the wrap, then place the wrapped container in a clear plastic bag and seal the bag.

° Make sure that all samples that need to be kept cold (4 ± 2 o C) have been thoroughly cooled before placing in packing material so that the packing material serves to insulate the cold. Change the ice prior to shipment as needed. Ideally, pack the cooled samples into shipping containers that have already been chilled. (Of course, these precautions are not necessary if none of the samples in the shipping container need to be kept cold.)

° Any soil/ sediment samples suspected to be of medium/ high concentration or containing dioxin must be enclosed in a metal can with a clipped or sealable lid (e. g., paint cans) to achieve double containment of those samples. Place suitable absorbent packing material around the sample container in the can. Make sure the sample is securely stored in a can and the lid is sealed. Label the outer metal container with the sample number and fraction of the sample inside.

°Use clean waterproof metal or hard plastic ice chests or coolers that are in good repair for shipping samples.

° Remove the inapplicable previous shipping labels. Make sure any drain plugs 132 are shut. Seal plugs shut on the inside and outside with a suitable tape such as duct tape. Line the cooler with plastic (e. g., large heavy duty garbage bag) before inserting samples.

° Ship samples at 4 ± 2 o C, place double bagged ice on top of samples. Ice must be sealed in double plastic bags to prevent melting ice from soaking the packing material. Loose ice should not be poured into the cooler.

° Conduct an inventory of sample numbers, fractions, and containers when placing samples into the coolers. Check the inventory against the corresponding chainof custody form before sealing the cooler to make sure that all samples and containers are present.

° Pack the lined shipping containers with noncombustible absorbent packing material, such as vermiculite or rock wool. Place the packing material on the bottom of the shipping container (inside the plastic liner) and around sample bottles or metal cans to avoid breakage during shipment. Never use earth, ice, paper, or styrofoam to pack samples. Earth is a contaminant, melted ice may cause complications and allow the sample containers to bang together when the shipping container is moved, and styrofoam presents a disposal problem (it also may easily blow out of the shipping container at the site).

° For samples that need to be shipped at 4 ± 2º C, place double bagged ice on top of samples and fill remaining space with packing material. If sample bottles have been protected with packaging material such as bubble wrap, then some doublebagged ice or ice packs also may be placed between samples.

° Use tape to securely fasten the top of the plastic used to line the shipping container. It is a good idea to then place a completed custody seal around the top of the bag that contains the sample in case the outer seals placed across the cooler lid are inadvertently damaged during shipment.

° Enclose all sample documentation (i. e., chain of custody forms and cooler return shipping documents) in a waterproof plastic bag, and tape the bag to the underside of the cooler lid. This documentation should address all samples in the cooler, but not address samples in any other cooler.

° If more than one cooler is being used, place separate sample documentation in each cooler. Instructions for returning the cooler should be documented inside the cooler lid. Write a return name and address for the sample cooler on the inside of the cooler lid in permanent ink to ensure return of the cooler.

° Tape the cooler shut using strapping tape over the hinges. Place completed custody seals across the top and sides of the cooler lid so that lid cannot be opened without breaking the seal.

° Place clear tape over the seal to prevent inadvertent damage to the seal during shipment. Do not place clear tape over the seals in a manner that would allow the seals to be lifted off with the tape and then reaffixed without breaking the 133 seal.

For additional detailed guidance on sample documentation, packaging, and shipping, we recommend the Contract Laboratory Program (CLP) Guidance for Field Samplers  Draft Final (USEPA 2001g).

<IP_ADDRESS> Sample Shipping In general, samples of drinking water, most ground waters and ambient surface waters, soil, sediment, treated waste waters, and other low concentration samples can be shipped as environmental samples; however, shipment of high concentration waste samples may require shipment as dangerous goods (not as "hazardous waste"). Note that RCRA regulations specifically exempt samples of hazardous waste from RCRA waste identification, manifest, permitting, and notification requirements (see 40 CFR §261.4( d)). The shipment of samples to and from a laboratory, however, must comply with U. S. DOT, U. S. Postal Service, or any other applicable shipping requirements. If a sample is a hazardous waste, once received at the laboratory, it must be managed as a hazardous waste.

In recent years, commercial overnight shipping services have adopted the regulations of the IATA for shipment of dangerous goods by air. The IATA Dangerous Goods Regulations contain all provisions mandated by the International Civil Aviation Organization and all rules universally agreed to by airlines to correctly package and safely transport dangerous goods by air. Contact IATA for a copy of the IATA Dangerous Goods Regulations and for assistance in locating suppliers of specialized packaging for dangerous goods.

When shipping samples, perform the following activities:

° Clearly label the cooler and fill out appropriate shipping papers.

° Place return address labels clearly on the outside of the cooler.

° If more than one cooler is being shipped, mark each cooler as "1 of 2," "2 of 2," etc.

° Ship samples through a commercial carrier. Use appropriate packaging, mark and label packages, and fill out all required government and commercial carrier shipping papers according to DOT and IATA commercial carrier regulations.

° Ship all samples by overnight delivery in accordance with DOT and IATA regulations. For information on shipping dangerous goods visit the International Air Transport Association (IATA) Dangerous Goods Information Online at http:// www. iata. org/ cargo/ dg/ index. htm or call 1 800 716 6326. 134 7.3 Using Sample Homogenization, Splitting, and Subsampling Techniques 7.3.1 Homogenization Techniques The objective of homogenization (mixing) is to minimize grouping and segregation of particles so they are randomly distributed within the sample. While homogenization can reduce grouping and segregation of particles, it will not eliminate it and will not make the material "homogeneous." If homogenization is successful, subsamples of the homogenized material will show less variability than if the material was not homogenized. Homogenization, combined with a composite sampling strategy, can be an efficient method for improving the accuracy and precision in sampling of particulate material (Jenkins, et al. 1996). Homogenization can be applied to solids, liquids, slurries, and sludges.

Pitard (1993) recognizes two processes for homogenization: