Editor's note: This letter was sent in April.

It shouldn't stink

John,

Regarding your comments about odor and hydrogen sulfide gas (H 2S) in the April 2006 Up Front "2006: A Gypsum Odyssey":

Disposing gypsum board in a landfill does not create odor problems when the landfill is properly constructed and correctly managed. Proper management techniques would include the practice of not placing gypsum scrap in areas that have a propensity to be covered with standing water for extended periods of time. This and other sensible landfill management techniques will greatly mitigate the potential for the creation of H2S.

In addition, while it is true that under specific anaerobic and other environmental conditions gypsum can undergo a limited chemical change that will occasionally result in a sulfur-containing material, numerous environmentally stressed conditions must occur simultaneously for H 2S to be produced. These include wet conditions or standing water; the presence of organic material and sulfate ions; anaerobic (no oxygen) conditions; the presence of sulfate reducing bacteria, and; a conducive soil pH and soil temperature. The simple existence of a moist organic or sulfur-containing material in a landfill does not cause the production of H2S-many conditions must exist for the gas to be produced.

Michael Gardner,
Executive Director/CEO,
Gypsum Association