Q782. What does the majority of the landfill refer to when determining which oxidation fraction to use in Table HH-4?

A782. The phrase ‘majority of the landfill’ in Table HH-4 refers to more than 50 percent of the landfill area that contains waste meeting the specified cover criteria.  There are three different cover types that are included in five conditions (C2, C4, C5, C6, and C7) in Table HH-4.  These three different cover types include:

• Landfills that have a geomembrane (synthetic) cover with less than 12 inches of cover soil for the majority of the landfill area containing waste (C2 in Table HH-4)
• Landfills that do not meet the requirements in C2 and that do not have a soil cover of at least 24 inches for the majority of the landfill area containing waste (C4 in Table HH-4)
• Landfills that have a soil cover of at least 24 inches for the majority of the landfill area containing waste (C5, C6, and C7 in Table HH-4).

In the instance where a facility has cover types that meet all three of the conditions mentioned above and none are greater than 50 percent, the “majority of the landfill area containing waste” would be the cover type (from the three categories listed above) with the largest area.