In order to make a waste determination, the generator can use either laboratory analysis results and/or apply knowledge of the waste based on the materials and processes used to generate the waste.

While representative sampling and analysis of the waste might be considered as convenient as relying solely on applying knowledge, it provides advantages.

An accurate waste determination is a critical factor in demonstrating compliance with hazardous waste regulations and reducing disposal costs by avoiding the over-classification of hazardous wastes.

Laboratory Analysis

A generator of wastes is required to use a DNR-certified laboratory to analyze waste samples for making waste determinations.

Before collecting the representative waste sample, select a lab and discuss the following: sample volumes, required containers, sample collection methods, and correct analytical test methods.

Representative Sampling

The methods and equipment used for sampling waste materials will vary based on the form and consistency of the waste. A representative sample of each waste stream must be collected and analyzed in order to provide sufficient data to make the waste determination.

The sample collected should reflect an unbiased representation of the waste, exhibit the average properties of the waste stream (or universe, such as a waste pile or lagoon) and reflect potential process variations.

According to EPA guidelines, for a sample to be representative, it needs to be collected and handled in a way that preserves its original physical form and chemical composition and prevents contamination.

For a sample to provide meaningful data, it is important that it reflect the properties of the waste from which it was obtained, that it’s physical and chemical integrity be maintained, and that it be analyzed within a dedicated quality assurance program.

Acceptable Knowledge

Use of knowledge to determine whether a waste material is hazardous waste or non-hazardous waste may be acceptable, but it must be supported with documentation.

Examples of supporting documentation include: Safety Data Sheets (SDSs), published information, process flow diagrams, chemical reaction diagrams, identified breakdown products ,and other process reactions or chemical information.

Typically, none of these documents are acceptable as stand-alone information for a waste determination as most do not state conclusively whether or not the waste is hazardous or non-hazardous. Consequently, multiple document sources may be needed to support a knowledge-based determination.

Safety Data Sheets

SDSs can provide useful information regarding ignitability (flash point), corrosivity (pH), or reactivity of the material going into the process. However, they tend to be less useful when it comes to identifying the toxic characteristics of waste generated from that process.

The SDS only lists ingredients that make up greater than 1% of the total constituents (0.1% if they are carcinogens). Ingredients that are less than 1% by mass can equal up to 10,000 parts per million (ppm).

This means that a material used in a process may contain a toxic constituent that is not listed on the SDS, but which contributes to the generation of a hazardous waste. Additionally, the process itself may chemically or physically change the properties of the materials such that the generated waste is hazardous.

Waste Profiles

A documented “waste profile” is typically generated by Treatment, Storage or Disposal (TSD) facilities as a means for them to standardize and categorize information regarding wastes they intend to accept.

The information outlined in the waste profiles regarding waste characterization needs to be supported by either laboratory analysis or acceptable knowledge.

Waste profiles are not standardized forms and may not adequately characterize the waste. The generator will likely have a better understanding of the waste materials they generate and should work with the TSD to ensure adequate characterization.

Record Keeping

Adequate written documentation (records) should include a statement regarding the waste determination for each waste stream.

It should state whether the waste is hazardous or non-hazardous waste and include copies of all information used to support the determination. Written documentation includes, but is not limited to:

A Description of each Identified Waste Stream and Process

Analytical sampling results including a description of how each representative sample was collected and managed, why the specific test method was chosen, and evidence that the laboratory was certified for the test method used.

Records that justify and support knowledge-based determinations such as SDSa, published information, process flow diagrams, chemical reaction diagrams, identified breakdown products, and other process reactions or chemical information.

During a hazardous waste generator inspection, waste determination records will be requested by the inspector to verify compliance with hazardous waste regulations, and it is recommended that this information be kept organized and readily accessible.

Re-evaluation of waste determinations should occur following process or material changes, or if the waste is highly variable, to verify that the original waste determination remains valid. Additionally, the DNR recommends a re-characterization of each waste stream be conducted every one to three years. It is the responsibility of the generator to make a correct waste determination and retain the supporting documentation.

In conclusion, from the foregoing, it can be concluded that hazardous wastes being generated from diverse businesses and institution still constitute a significant threat to human and environmental health. Accurate waste determinations have the potential to reduce the danger of indiscriminate dumping of hazardous wastes in the environment.

There are five principal steps involved in the waste determination process;

Hazardous wastes can be process wastes, chemicals or compounds designated as “listed wastes” and/or they can exhibit hazardous characteristics (ignitability, corrosivity, reactivity or toxicity);

The generator can use either laboratory analysis results and/or apply knowledge of the waste based on the materials and processes used to generate the waste; and