Walk outside and take a deep breath. How did it go? Was it up to your standards? Was it up to the government’s standards?  

Well, federally speaking, Santa Clarita’s air was just fine today. It was yesterday as well, and should be tomorrow if predictions are correct.  

You can check for yourself at airnow.gov, the Environmental Protection Agency website which provides the public with daily air quality values by zip code, city or state.  

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The website, updated hourly, uses a six-level scale (good, moderate, unsafe for sensitive groups, unhealthy, very unhealthy and hazardous) to grade levels of ozone, fine and course particulate matter, carbon monoxide and nitrogen dioxide. The data is combined to determine an area’s Air Quality Index, which is based off federal standards.  

As of 8 a.m. today, the SCV’s Air Auality Index read, “37, Good.”

The website also gives a reading of the day’s highest score on the index, of which the SCV currently has a one of “64, Moderate.”  

“Moderate” is the second level in the scale and carries the health message, “Unusually sensitive people should consider reducing prolonged or heavy exertion.”  

The EPA retrieves this data for the SCV from the South Coast Air Quality Management District, which monitors much of Southern California. The District is broken down into 31 air monitoring areas, comprising all or parts of the Los Angeles, San Bernadino, Riverside and Orange counties.  

Most of the Santa Clarita Valley is located within Air Monitoring Area 13, while Castaic falls within No. 15. The SCAQMD retrieves air quality data using a single monitoring station for both of these areas. The station, which has changed location over the years, is currently in Newhall.  

According to Sam Atwood, Media Relations Manager for the SCAQMD, the stations are meant to typify a community.  

“They’re not meant to gauge the pollution from freeways or a particular business or factory,” said Atwood. “Overall, we try to generate air quality data that is not affected by emissions made from a particular source.”  

Other factors are considered when choosing a location, including the relative seclusion and safety of the area, as well as the need to acquire a long-term lease.  

In 2003, the SCV’s monitoring station recorded the highest official 1-hour ozone reading in Los Angeles County. Its ozone concentrations also exceeded the federal 1- and 8- hour standards on 35 and 69 days, respectively. This prompted the SCAQMD to compile its Santa Clarita Subregional Analysis Plan in 2004.  

The report is the latest thorough analysis the SCQAMD has conducted for the SCV, providing expanded data on the area’s air quality. The data presented obvious concerns, concluding that Santa Clarita had excesses of both ozone and particulate matter.  

Most striking, however, was that Santa Clarita’s own emissions hardly contributed to its combined pollution.  

“The Subregional Plan showed that 2 percent of the sources of our pollution comes from Santa Clarita,” said Travis Lange, Environmental Services Manager for the City of Santa Clarita. “The vast majority comes from the L.A. Basin.”  

Consisting of nearly 15 million people, the Los Angeles Basin is the plain located between coastal and inland mountain ranges in Southern California, containing central Los Angeles as well as its southern and southeastern suburbs.  

“With the truck corridor, goods movement and the weigh station, pollution levels are certainly higher within a quarter-and-a-half mile of the freeway,” said Heather Merenda, Sustainability Planner for the City of Santa Clarita.  

Much of this pollution comes from out of the area, which can force the City to shut down outdoor activities, said Merenda.  
According to Atwood, pollution from the basin is blown by sea breeze and prevailing winds through natural routes and corridors. This transient ozone and particulate matter eventually makes its home in Santa Clarita.  

“As this plume of pollutants is being transported, photochemical reactions are taking place. One of the primary reactions turns hydrocarbons, oxides and nitrogen into ozone,” said Atwood.  

Given increased levels of sunlight – which Santa Clarita certainly has – the ozone concentration can violate standards set by the EPA.  

The SCAQMD monitoring station in the SCV records violations each time they occur. The district then notifies the EPA and City staff.  

“We really depend on the AQMD and their experts for air quality,” said Lange. “(The City) isn’t operating the air monitoring station or doing the enforcing.”  

The enforcing Lange is referring to is the fines levied on businesses for emission violations as well as the dialogue with other local governments to curb pollution that directly affects the City of Santa Clarita.  

“It’s largely outside of our control. If we don’t have the AQMD standing up for us and doing this work our air quality gets worse,” said Merenda.