The South Coast AQMD typically collects samples as a result of an odor investigation or routine surveillance activities. Instantaneous samples (also known as grab samples) are collected when odors are present, and take less than a minute to collect. 

Odor investigation, surveillance and sample collection in the Porter Ranch area have been ongoing activities. On October 26, 2015, South Coast AQMD began taking grab samples to identify the types and concentrations of air contaminants present.  The South Coast AQMD’s sampling augmented air measurements and monitoring conducted by SoCalGas and by the California Air Resources Board.  

Instantaneous (grab) air samples were collected on the dates indicated below  (see aerial map for sampling locations).  Samples collected in SUMMA canisters were an analyzed for the presence of VOC compounds; many were also analyzed for the presence of CO (carbon monoxide), CH₄ (methane), CO₂ (carbon dioxide), C₂H₆ (ethane), and NM/NEOC (non-methane & non-ethane organic compounds). Samples collected in Tedlar bags were analyzed for TRS (total reduced sulfur).  For lab analysis results, click on the link for the type of analysis performed.