Pace® Analytical Services Introduces New TCLP Center of Excellence


The world generates about 400 million tons of hazardous waste annually. Regulations require facilities producing this waste to know its composition and manage it properly to protect the health of their employees, the environment, and the public.

In the United States, the Resource Conservation and Recovery Act (RCRA) of 1976 led to the establishment of federal standards for the disposal of solid waste and hazardous waste. RCRA requires that industrial and other waste be characterized following testing protocols published by the EPA. Toxicity Characteristic Leaching Procedure, also known as TCLP, is one of these tests.

Sherri Lloyd, Product Marketing Manager at Pace® spoke with Valerie Slaven, Director of Laboratory Operations for Pace®, to discuss the TCLP Center of Excellence and why Pace® dedicated a lab to this procedure.


So Val, let’s start with the basics. What is TCLP?

landfill (2)Toxicity Characteristic Leaching Procedure, also known as TCLP, is used to ensure the safety of the environment when handling, transporting, or disposing of potentially hazardous materials.
Simply put, TCLP simulates what happens to a waste product during leaching. It’s an extraction process used to determine whether there are hazardous compounds present in the waste.  

Analyzing leachate tells you a few things. First, the tests show which EPA-listed contaminants, organic and inorganic, are present and at what levels. TCLP testing also shows the mobility of these contaminants. These results give you a pretty strong indication of what’s likely to migrate to local soil and groundwater from the landfill. At a high level, this can also tell you whether the types of wastes in the landfill are hazardous and need proper handling.


You mentioned leaching, so how does leaching occur?

Leaching occurs when rainwater or other liquids filter through solid or liquid waste. As they pass through the landfill, these liquids can draw out or leach potentially harmful chemicals or other contaminants.


Can you give us a quick overview of the TCLP procedure?

Before the TCLP extraction process can be started, the laboratory must classify the sample received as liquid or solid waste by determining the percent of solids.

If the sample is greater than 0.5% solid, the sample is characterized as solid waste. A sample with less than 0.5% is characterized as liquid waste. Samples characterized as liquid waste become the sample extract and are prepped for analytical testing of the requested RCRA analytes.

Solid and multi-phase samples require a more complex testing process. The solid material is blended with an extraction liquid equal to 20 times the weight of the original sample. Next, the brew mixes in a tumbler for a minimum of 18 hours to simulate the leaching action of precipitation seeping through the landfill.

When the tumbling process is complete, the solid portion is removed and discarded. The liquid portion is then combined with any liquid filtered from the original sample. We then analyze this mixture using specific methods for metals and chemical compounds. The test results which we reported in milligrams per liter (mg/L) must fall below TCLP regulatory limits to ensure that all waste is TCLP compliant and able to be processed to a landfill without special considerations for public health and safety. If the concentration of any individual contaminant is greater than the TCLP limit, the waste is then considered a “toxicity characteristic” hazardous waste.


Pace® recently opened a TCLP Center of Excellence. Tell us a little bit about the background behind this decision.

tumblersMost businesses are concerned with adhering to regulatory standards and laws to avoid stiff penalties and fines, not to mention any reckless contamination of the environment. To mitigate their risks, they need to know, in-depth, what’s in their waste they send to a municipal or private landfill as well as any landfill they manage themselves.

Since we’re dealing with such a wide variety of waste products, TCLP is not a straightforward test. It requires an experienced team that can handle and manage some pretty challenging characterization projects. Pace® has provided testing services to industry and waste management organizations for 30 years. It made sense to concentrate this expertise at our Pace® TCLP Center of Excellence so our customers have easy access to in-depth expertise and can feel confident in their results.


Val, thanks for the context (background). Can you highlight some of the benefits that working with Pace® provides to organizations requiring TCLP testing and analysis?

Sure, as I just mentioned, our extensive experience working within the waste/landfill business provided the team with intimate knowledge of the TCLP process and regulatory landscape. This also means our team has the technical know-how to perform difficult extractions, such as sub-sampling of stratified waste or challenging multi-phasic material, and the specialized knowledge to manage difficult non-aqueous waste samples.

Our state-of-the-art TCLP facility also has a segregated temperature control room and a prep area designed for maximum TCLP efficiency. Our instrumentation is optimized and calibrated to handle the most difficult TCLP samples. For our customers, that means we have the capacity and capability to process up to 200 samples per day and can offer rush services if needed.


Thanks, Val. Can you expand upon why the availability of TCLP RUSH services are important?

Sure. Companies often find themselves in a position where they need lab results quickly. One situation we run into a lot is when companies find themselves waiting for lab results while their drivers are sitting with full trucks of waste awaiting instructions. Every day of waiting can cost them tens of thousands of dollars. These customers need a lab that can turn the results quickly.

Pace® TCLP Center of Excellence has rush services available, including for complex TCLP samples.


Val, any concluding statements?
Just that I can’t stress enough the importance of choosing a lab with the right experience and expertise. Labs often have strengths and weaknesses, and just because a lab says they can do TCLP testing does not mean it’s a forte of theirs.

Got questions?
Contact the Pace® TCLP Now