Air quality monitoring is a process composed of inter-related activities which include sampling, analysis, data interpretation, and reporting. Air sampling may be generally classified into two types, namely: ambient and source sampling. In ambient air monitoring, the measurements are indicative of only a small portion of the atmosphere and cannot be assumed to be representative of the total atmosphere. In emission testing, the cross sectional area of the gas stream is fixed and the result is generally representative of the total volume of stack effluent.
Air quality monitoring data is being used for any of the following purposes:
- Establish current conditions within the a vicinity
- Assist in determining background air concentrations of the pollutants being measured
- Check compliance with air quality standards and evaluate control strategies
- Assess environmental and health risks
- Carry out assessment surveys in relation to other studies and projects
- Benchmark air dispersion modeling studies.
For ambient air monitoring, the selection of the sampling locations is primarily based on downwind proximity to the major emission source, sampler exposure to the pollutants in an open area, and location of receptors, such as residential areas.
Apercu owns hi volume samplers, di-gas bubblers, a PM10 sampler and noise meters to conduct ambient air monitoring. Weather at the time of sampling are recorded with the help of barometers, anemometers and a weather station. Sample analysis is conducted by a DENR accredited third party laboratory.
Emissions monitoring is normally subcontracted to accredited third party firms. The USEPA “Quality Assurance Handbook for Air Pollution Measurement Systems: Volume III Stationary Source-Specific Methods” is used as a guide for producing data that are complete, representative and of known precision and accuracy.