S.D. Admin. R. 74:36:07:101
The owner or operator of an existing municipal solid waste landfill shall install at least two sample probes per hectare, evenly distributed over the landfill surface that has retained waste for at least two years. If the landfill is larger than 25 hectares in area, only 50 samples are required. The probes should be evenly distributed across the sample area. The sample probes should be located to avoid known areas of nondegradable solid waste. The owner or operator shall collect and analyze one sample of landfill gas from each probe to determine the nonmethane organic compound concentration using 40 C.F.R. Part 60, Appendix A, Method 25 or 25C (July 1, 2018). Taking composite samples from different probes into a single cylinder is allowed; however, equal sample volumes shall be taken from each probe. For each composite, the sampling rate, collection times, beginning and ending cylinder vacuums, or alternative volume measurements shall be recorded to verify that composite volumes are equal. Composite sample volumes should not be less than one liter unless evidence can be provided to substantiate the accuracy of smaller volumes. Terminate compositing before the cylinder approaches ambient pressure where measurement accuracy diminishes. If more than the required number of samples is taken, all samples shall be used in the analysis. The landfill owner or operator shall divide the nonmethane organic compound concentration from Method 25 or 25C by six to convert from nonmethane organic compound concentration as carbon to nonmethane organic compound concentration as hexane. If the landfill has an active or passive gas removal system in place, Method 25 or 25C samples may be collected from these systems instead of surface probes provided the removal system can be shown to provide sampling as representative as the two sampling probe per hectare requirement. For active collection systems, samples may be collected from the common header pipe. The sample location on the common header pipe shall be before any gas moving, condensate removal, or treatment system equipment. For active collection systems, a minimum of three samples shall be collected from the header pipe. The owner or operator shall determine the site-specific nonmethane organic compound concentration using the following sampling procedure:
S.D. Admin. R. 74:36:07:101
General Authority: SDCL 34A-1-6.
Law Implemented: SDCL 34A-1-18.