CH 15 - Material Sampling Flashcards
Sampling
The purpost is to determine the characterists of a source material based on testing a small selected amount.
In order for those characterists to tryly describe the source, sampling procedures must be carefully planned and performed and the sample be be representative of the wast from which it was taken.
EPA specifies how to determine where to take spamples so that they are representative of the entire area or container.
A sample can come from one of two sources;
1 - The environment
2. Hazardous waste
Environmental Samples
Taken from the environment sorrounding a hazardous waste site, eg. ground water, surface water and soil
Results can be used to determine the extent of remedial / corrective action needed as well as adjusting the necessary site boundaries.
The environmental samples contain dilute concentrations of pollutants and are not as hazardous as the hazardous waste samples.
Hazardous waste samples
taken from the source of the contamination
They are very hazardous
require special handling.
Provide exact information converning the contaminants present and are the basis for taking specific remedial actions.
Samples may also be required for litigation or for submission to the proposed hazardous waste disposal site.
Sampling Plan
Sampling can be one of the most dangerous activities on a hazardous waste site.
The process of opening and sampling a hazardous waste container can placea worker in direct contact with unidentified waste. In order to reduce the potential for injury, a detailed written complrehsive sampling plan must be developed. This is incorporated in the site specific safety and health plan.
Written Plan
must contain the following:
- backgrouind information
- sample collection details
- selection of sampling equipment
- personal protective equipment
- Decontamination
- Standard operating procedures
- sample integrity
- recordkeeping
- Packaging and shipping
Background iNformation
Various sources should be researched to determine the possible types of hazardous waste on site.
Sources of information include
EPA and State agency records
Local health department
Local fire and police departments
Interview of past or present employees of firms involved with the site
Interview with those living or working near the site.
Sample collection details
Specific details include:
- mapped locations of on and offic site
- random sampling of hazardous waste containers is necessary - and a diagram of where hazardous waste samples are to be taken
- Number of samples to be taken at each point
- Volume of sample to be taken
- Type of sample container to be used based on the nature of the sample, compatibility of the sample with the container, volume and laboratory requirement.s.
Selection of Sampling Equipment
Various kinds of sampling euipment.
Selection is dependent on the type of material to be sampled
Limitations of the device
Decontamination plans.
The sampling plan should include recommendations for
- equipment selection based on the situation
- samples should be given unique names which include the date
site name
matrix
sample numbner
depth at which the sample was collected
They should be named in a way that is easy to sory and arrange quickly.
Personal protective Equipment
Trained health and safety professional should determine from the sie informaiton the personal protective equpment to be used by sampling personnel.
Decontamination
Sampling equipment must be thoroughly decontaminated after each use.
Process:
- washing with soapy water
- followed by tap water rinse
- mild solvent rinse
- final rinse of triple de-ionized water.
Decontamination and rinse solutions must be properly discarded.
In some cases the monitoring and sampling equipment can be partially wrapped in a plastic bag to minimize contamination of instruments.
Disposable equipment can be used to eliminate the need for decontamination. Procedures should also be established for the decontamination of the outside of sample containers.
Sample procedure also usually calls for a clean pair of disposable gloves between each sample to reduce any cross contamination.
Standard Operating Procedures (SOP)
A sampling standard operating procedure sop shoud ne developed to ensure safety and efficiency during teh sampling process. A well-organized approach to sampling can reduce many of the dangers associated with the procedure. Sampling personnel must be informed of their roles and be required to comple with the safe work practices written in the SOPs.
Sample Integrity
Most samples have a limited amount of time that they can be kept before the characteristics of the sample become altered. If samples are not analyzed within tht time, the resuls may not be accurate. For this reason , all samples should be refrigerated or placed in a cooler with the ice until they are received by the laboratory or packaged for the shipment. The analytical laboratory to be used can provide information on preserving samples and packaging in ice. Refrigeration at 4Degrees Celcius with a minimal holding time is the best approach. Samples should be protecrted from direct light.
