Where:
[DELTA]ci = The fenceline concentration, corrected for background, at measurement location i, micrograms per cubic meter ([MICRO]g/m3).
MFCi = The measured fenceline concentration at measurement location i, [MICRO]g/m3.
NFSi = The near-field source contributing concentration at measurement location i determined using the additional measurements and calculation procedures included in the site-specific monitoring plan, [MICRO]g/m3. For monitoring locations that are not included in the site-specific monitoring plan as impacted by a near-field source, use NFSi = 0 [MICRO]g/m3.
UB = The uniform background concentration determined using the additional measurements included in the site-specific monitoring plan, [MICRO]g/m3. If no additional measurements are specified in the site-specific monitoring plan for determining the uniform background concentration, use UB = 0 [MICRO]g/m3.
40 C.F.R. §63.658