On October 24, 2015, SCAQMD received the first air quality complaints resulting from sulfur type odors associated with the natural gas leak from Well SS-25.  Video recorded by SCAQMD staff using an infra-red video camera shows the infra-red images of the natural gas being released as a result of the leak. 

Through February 11, 2016, SCAQMD  received over 2340 complaints (see detail here) regarding odors from the leak. The odors are from odorant compounds (including mercaptans) that are added to natural gas and can be smelled at very low odor threshold levels (around or below 1 part per billion - ppb). The human nose is very sensitive and has the ability to detect odors that are below the detection level of any currently available device.  

SCAQMD inspectors are continuing to respond to air quality complaints and collect air samples as part of their ongoing investigation of this incident. The aerial map shows the general location of odor complaints received by SCAQMD and the location of air samples taken by SCAQMD inspectors during complaint investigation activities (see complaint air sampling data).