Understanding EPA Regulatory Tests

The Environmental Protection Agency (EPA) and State regulatory agencies have utilized several analytical leaching procedures in order to simulate disposal environments and to characterize a waste's toxicity to its surroundings. The use of EnviroBlend^® allows waste from contaminated sites or industrial by-products to pass these regulatory tests.

Toxicity Characteristic Leaching Procedure (TCLP)

The TCLP is most commonly used by the EPA and state regulatory agencies using a leaching solution of acetic acid to simulate co-disposal of industrial and non-industrial waste in a municipal solid waste landfill.
TCLP – Download .pdf || view as webpage

Synthetic Precipitation Leaching Procedure (SPLP)

Alternative analytical leaching methods, such as the SPLP are becoming increasingly popular with regulatory agencies. The SPLP was developed to simulate leaching under acid rain conditions, similar to an industrial waste monofill. The procedure is similar to the TCLP; however, the amount of acidity used in the test is significantly less, using a dilute nitric/sulfuric acid mixture.
SPLP – Download .pdf || view as webpage

Multiple Extraction Procedure (MEP)

Even more stringent is the use of the MEP, involving an initial extraction with acetic acid (much like the TCLP) and at least 8 subsequent extractions with a synthetic acid rain solution (sulfuric/nitric acid). This procedure simulates 1000 years of freeze and thaw cycles and a prolonged exposure to a leaching medium.
MEP – Download .pdf || view as webpage

Regulatory bodies have most often used the Toxicity Characteristics Leaching Procedure (TLCP) as a gauge of the waste's toxicity to the environment. However, most of the time, waste is directed to industrial waste monofills involving no municipal waste, making the use of the TCLP unsuitable. An EPA report on this issues (Hazardous Waste Characteristics Scoping Study, EPA, Nov. 1996 EPA530R96053) advises the use of the Synthetic Precipitation Leaching Procedure (SPLP), a test better suited for industrial wastes. Whether using the TCLP or the SPLP, EnviroBlend stabilizes the metals, ensuring that they are rendered virtually insoluble.