Odor Regulations Stink

Posted on September 6, 2012 by Kevin Finto

Federal and state regulators have, over the years, frequently received complaints about odor.  Because the problem is a common one -- and because the origins of environmental law lie, in part, in the common law of public nuisance -- one might think we would have developed a consistent, practical way of regulating odor.  We haven’t.  No federal laws address odor, and the  various state laws and rules addressing odor are a hodge-podge of not fully-considered  ideas. 

This is likely due in part to the subjective nature of odor:  one person’s stench may be another person’s sweet smell of success.  More importantly, though, there is no commonly accepted way of quantifying or measuring odor.  If you cannot define something precisely and cannot agree on how to measure it, it necessarily follows that you will have a hard time regulating it.    There have been attempts to use odor measurement technologies including the scentometer or field olfactometer, but they ultimately rely on subjective human olfactory assessment.  While some states allow them as a guide, it does not appear that any statutory or regulatory scheme has adopted their use, and in fact, some states legislatures have adopted resolutions prohibiting their agencies from using such technologies for enforcement purposes.

So what is a regulator to do?  Consider the efforts made by one state, my beloved Commonwealth.  Virginia has tried to cram the square peg of odor into the round hole of the Best Available Control Technology (“BACT”) requirement of the Clean Air Act’s prevention of significant deterioration of air quality (“PSD”) preconstruction permitting program.  Applying the BACT process to odor may have sounded like a good idea back in the day when the PSD rules were first adopted and BACT was a sexy new acronym, but implementation of the BACT approach for odor has not been easy. 

At the outset, there is the difficulty that the BACT process applies only to things that are “pollutants” under the Clean Air Act.  Not everything that regulators want to regulate under the Clean Air Act, however, is considered a “pollutant” under the Act.  (If you doubt this, recall that it took many years of agency action and litigation and decisions by the United States Courts of Appeals and the Supreme Court before it was generally accepted that carbon dioxide is a pollutant under the Clean Air Act.)  And so it is with odor, which is defined by Webster’s Dictionary as  “a quality of something that stimulates the olfactory nerves or the stimulation itself.  In short, odor is definitely not a “typical” Clean Air Act pollutant.  (Interestingly, certain substances that are pollutants, also carry the name “aromatic” if they also happen to be organic compounds with a cyclical structure, but I digress.) 

Even if one can accept that “odor” is a “pollutant,” though, can the BACT process be applied to it?  Not really.  ”Best available control technology” means “an emission limitation based on the maximum degree of reduction of [a pollutant . . .] which the permitting authority . . . , taking into account energy, environmental, and economic impacts and other costs, determines is achievable . . . .” Clean Air Act § 169(3).  And typically BACT is determined through a top-down approach, i.e., one starts with the most stringent emission limitation theoretically achievable and then moves down from there only if the various costs of that approach are too high.  How can such an approach work for odor, though, when we do not have a unit measure for odor, much less a quantitative scale for objectionable scent.  Without such a measure or scale, it is effectively impossible to evaluate whether the environmental, economic or energy costs of reducing odor are reasonable or cost-effective.

So, if my beloved Commonwealth doesn’t now have the answer, let me cast my net more broadly and ask if anyone knows of a good practical scheme for regulating odor.

Comments (1) -

David Lansdale United States
5/4/2018 3:45:23 PM #

To develop an air quality standard with measurable results;
1. List all known chemicals, compounds, mixtures, elements which have been (proven)determined to be dangerous to humans.
2. Determine maximum safe exposure limits in parts per million (ppm).
3. When measuring a specific location for odor, determine if any of the above substances are present and in what quantity in (ppm) if they exceed the maximum safe exposure level then exposure is unsafe, possibly creating an unpleasant or unwanted odor and therefore the source would be unlawful or may fall under state statutes as a "Nuisance" either "Public" or "Private". If the measured levels are below the maximum safe exposure limits, no law violation is noted, however this would not preclude the filing of action by a plaintiff against the responsible party.

Add comment

  Country flag
  • Comment
  • Preview