Mass Emission Rate Standards (MERS) for Stationary Sources

Twelve (12) years after the Clean Air Act the major provision governing the operation of industrial facilities, given below has not been clarified into an enabling regulation;

The Department shall, within two (2) years from the effectivity of this Act, and every two (2) years thereafter, review, or as the need therefor arises, revise and publish emission standards, to further improve the emission standards for stationary sources of air pollution. Such emission standards shall be based on mass rate of emission for all stationary sources of air pollution based on internationally-accepted standards, but not be limited to, nor be less stringent than such standards and with the standards set forth in this section. The standards, whichever is applicable, shall be the limit on the acceptable level of pollutants emitted from a stationary source for the protection of the public's health and welfare.

KKK has indicated to the regulatory authority its position which is consistent with the separate representations of various industry groups:That the safeguard of human health is more truly reckoned from the protection of the ambient air quality and not of the air quality at the stacks; MERS should be therefore related to ambient air quality standards.

In the illustration below (based from an actual plant operating data), although the concentration at the exit of the stack for SO2 exceeds the standard (concentration), the ambient air to which the pollutant disperse is well within the quality limits.

The case of intermittently-operating facilities also illustrates the significance of MERS versus concentration standards at stacks. A facility which operates for only certain hours in a year but which exceeds concentration limits will be less pollutive than another facility which meets the concentration standards but operates continuously since the latter discharges greater mass of pollution to the environment.