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Hazardous Waste and Biased Samples

One of our current cases deals with a question that is critical to everyone in the waste business: can biased sampling make a waste “hazardous”?

Approvals typically require waste management companies to manage wastes based on “representative samples”. Thirty years of guidance documents, and several cases, have also held that waste must be characterized as hazardous, or not, based on “representative samples”. The US Environmental Protection Agency noted, since 1986, that inaccurate and imprecise sampling can cause a solid waste to be inappropriately judged hazardous.

The Ministry of the Environment, like the US EPA, defines “representative sample” as

a sample portion of material or waste that is nearly identical in content and consistency as possible to that in the larger body of material or waste being sampled.

Hardy Wong, who helped develop Regulation 347 and Ontario’s regulatory framework for hazardous waste, testified:

Q. Now, let’s talk, then, about the whole waste or hotspot. In order to determine whether a load of waste is hazardous, is it enough to sample any one place or do you have to know about the whole load?

A. The key principle is to conduct a representative sampling.

Q. Right, in order to?

A. In order to have the result which representing the true nature of the load.

Q. The whole load or just the spot?

A. The whole load, the whole load.

Q. And if you sample just a spot, and it fails the Toxicity Characteristic Leaching Procedure (TCLP), have you proved that the whole load is hazardous?

A. No.

Q. …if you cherry-pick the parts that you choose instead of getting something that’s the whole load, does that tell you whether or not the whole load is hazardous?

A. No, it doesn’t.

Q. Now, does the mixing rule have anything to do with that?

A. No….

A. In fact, the word “hotspot” is – it’s not relevant in waste management, it’s in – only in site cleanups.

Q. Right, and in particular, is the phrase “hotspot” of any relevance to leachate toxic waste?

A. No.

This might seem obvious, especially since Regulation 347 defines, as non-hazardous waste, several types of waste that would individually fail a TCLP, including certain types of hazardous waste spill cleanup materials and the residue in the bottom of an “empty” hazardous waste container. (Up to 25 kg, in the case of a 1000 litre tote).

But the Ministry of the Environment argued in court this month that they can cherry pick “whatever interests them” out of a truck or pile of waste, even if it does not represent the truck or the pile as a whole. (This is called “biased sampling”.) And if what they choose to sample fails a TCLP, they say the waste is “hazardous”.

This “hotspot” approach creates huge risks for waste generators, as well as waste management companies. The penalties for handling “hazardous waste” as non-hazardous can include jail, and very large fines, for both companies and individuals. Yet how can any company or individual know, in advance, which parts of their waste might “interest” the Ministry, or what an analysis of that part might show? Many non-hazardous wastes are heterogeneous, and will contain some amount of hazardous materials. What kind of sampling can anyone rely on, if representative sampling is not good enough? And how can this sampling approach be reconciled with the exemptions for empty containers, spill cleanup materials, etc.?

The more that regulators jack up penalties for hazardous wastes, the more important it is that there be fair, objective and reliable ways to know what counts as “hazardous”. Abandoning representative sampling, in favour of cherry picking “whatever interests them”, would be a very dangerous step in the wrong direction.

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