M3.1. Sampling and Laboratory Issues

Stage

M3

Sampling and Laboratory Issues

START

Sampling and Laboratory Issues

Materials found in an inspection may be:

To discover if they are:

• Harmful

• Sample the material

• Regulated

• Analyze it in a laboratory

• Prohibited

Sample

Why Sample?

Help identify materials encountered in the inspection

Show that a requirement applies

Define extent of contamination

Provide background information

Verify self-monitoring program

• Facilities sample themselves to show compliance
• Inspection can validate accuracy of facility’s analysis and reports

Prove a violation

• Most common reason to sample in an inspection
• Sample and analysis results become evidence

Sampling Considerations (1)

Follow strict guidelines to show that the sample results are credible to use as evidence

Need to be credible to:

• Court
• Public
• Regulated community
• Government officials

Physical samples taken in an inspection are evidence that:

• Substantiates a violation
• Demonstrates compliance

To be reliable evidence, samples must be:

• Of known quality and providing specific data
• Collected using sound technical procedures (using agency’s protocol, if available)
• Representative of materials and/or population
• Results provided by certified laboratories, that are different from those used by the audited company

Sampling Considerations (2)

Store in the right type and size sample container

• Know which container is required for each analysis, and the minimum quantities required
• Allow for duplicates and extra containers in the case of loss or breakage
• Be aware of required preservation requirements and check to make sure you achieved the proper pH
• Wear gloves to prevent cross-contamination

Document chain of custody

Representative Samples

Selecting a truly representative sample provides the strongest foundation for demonstrating evidence of compliance or of violation.

• A small amount of something that truly reflects the whole

• Accurate and similar to the rest

• Reproducible, where anyone can get

• A comparable sample

• Similar results

• Equivalent to the total population in

• Composition

• Physical and chemical properties

• Collect representative samples and be able to prove that they are representative

• Properly mix samples, if required, before placing in jars

What Defines a Representative Sample?

Consider differences in:

• Operating conditions

• Waste type and contaminants(materials in drums, soils, or lagoons)

• Statistical conditions that affect concentrations of contaminants

• Spatial variability(both vertical and horizontal)

• Variability over time

• System aberrations

Random Samples

In statistics, a random sample is a portion of the whole, with the same probability as any other sample.

Non-representative samples can be used for compliance purposes:

• May not be random, but purposely selected

• Prove characteristics in at least part of the whole

Representative samples are not always random. Sampling may intend to reflect:

What may be enough to prove a violation?

• Likely violations

• Operating conditions: normal, maximum normal, and average

Proving the Sample is Representative

To help prove that the samples are representative, create a Sampling Plan that includes:

• Project description

• Project responsibilities

• Procedures for:

• Sampling

• Laboratory

• Calibration

• Custody of samples

• Shipping requirements

• Safety

• Control samples

Sampling Plan

A document within the inspection plant which identifies the who, why, when, where, what, and how of the sampling collection

Standard Operating Procedures (SOPs): Regulations on how to collect the samples

• May apply in some sectors or materials

• Provide initial guidance

• Can be used as basis for creating an individual plan

Keep in mind:

• Sampling objectives determine:

• How and from where samples were collected

• Representative sampling plans to reflect specific conditions

• Design of representative sampling plan must be clearly documented.

• Plan will be part of the investigation legal record.

If there are any changes or exceptions, document how and why

Key Elements of Sampling Plan

Project description

Project responsibilities

Sampling procedures

Project description

Laboratory requirements

Calibration procedures

Sample custody procedures

Shipping requirements

Safety

Download an example of a Sampling and Quality Assurance Project Plan

Activity

Representative samples:

That’s right! A truly representative sample provides the strongest foundation for demonstrating evidence of compliance or of violation.

Are always random

Demonstrate evidence of compliance or violation

Can be reproduced only under certain conditions

Are taken at the same time each day to ensure the same conditions

For more details about field equipment and its use, see the downloadable PDF in this module

For example, like taking a sample of a “suspicious” stain

• One person is working without a contract

• One person working at heights is not wearing a harness

• Mercury in the top layer of soil is above regulated levels. No need to measure elsewhere

Including changes in:

• Process
• Schedule
• Manufacturing

• Raw materials
• Management practice
• Seasonal

For more details about field equipment and its use, see the downloadable PDF in this module Field Equipment and Supplies (downloadable PDF)

You may need to filter before preservation.

That is incorrect. Please review the definition of a representative sample and think of the conditions that apply for each of the cases presented.

• Uneven dispersion from a discharge point
• Settling of particles on obstructions
• Waste constituents moving at different speeds

Sample: A portion of the total that represents the whole

That is incorrect. Please review the definition of a representative sample and think of the conditions that apply for each of the cases presented.

• Seasonal or off-peak
• Night vs day shift

That is incorrect. Please review the definition of a representative sample and think of the conditions that apply for each of the cases presented.

Example: Waste requires special treatment if it contains high levels of heavy metals (as lead).

• Changes in manufacturing schedule
• Peak and off-peak production rates
• Waste generated at different points of manufacturing cycle