Air Monitoring Glossary
An amount of a substance established by regulatory agencies that is protective of public health. Action levels are used during the work at Ascon to guide mitigation actions, stop work actions, and prompt increased actions to control potential odor, emissions or dust.
The air occurring at a particular time and place outside of structures. Often used interchangeably with “outdoor air”.
The periodic or continuous sampling and analysis of air pollutants in ambient air or from individual pollution sources.
The lead State regulatory agency for the cleanup at Ascon, responsible for protecting people and the environment from harmful effects of chemicals.
In the direction the wind is blowing. The majority of the time at Ascon the wind blows from the southwest toward the northeast, so the downwind air monitoring stations are in the northern and eastern zones of the Site. Data from the downwind air monitoring stations is analyzed to understand if impacts are being generated at the Ascon site or from offsite sources.
A SCAQMD rule designed to reduce the amount of particulate matter (dust) in ambient air by requiring actions to prevent, reduce or control dust from activities onsite.
A SCAQMD rule designed to minimize offsite dust from earth-moving activities at hazardous waste sites by establishing dust control measures.
The level considered to be health-protective by state and federal regulatory agencies for airborne chemicals. These levels have a built-in margin of safety which means that a short-term exposure above a health-protective screening level does not mean that adverse health effects will occur.
Conducted with hand-held instruments during active field work to evaluate total VOCs both at the property boundary and in active work areas.
The regulatory agency with direct oversight of air quality and odors at Ascon, responsible for protecting air quality for the majority of Los Angeles, Orange County, Riverside and San Bernardino counties.
A stainless steel electro polished (or “summa” polished) vessel used to collect whole air samples. Summa canisters are located in multiple places around the perimeter of Ascon.
This is obtained by subtracting the upwind data (or dust blowing onto the Site from other sources) from the downwind data. This helps us to better understand what impacts on air quality are being created on the Site and determine if dust control actions to protect public health are effective.
The direction from which the wind is coming. At Ascon, most of the time the wind comes from the ocean onto the southwest portion of the Site. One upwind monitor is located in the southwest zone of Ascon to collect data about airborne dust and air chemicals blowing onto the Site from other sources.
Any of thousands of organic, carbon-containing chemicals that are usually gases at room temperature. VOCs are both man-made and naturally occurring. VOCs are released from burning fuel such as gasoline, wood, coal, or natural gas and can be released from solvents, cigarettes, paints, and other consumer products.
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