San Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan 

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Air Monitoring Site DescriptionsSan Joaquin Valley Air Pollution Control District June 25, 2013

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Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

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### Appendix A: Monitoring Site Descriptions

Sites operated by the San Joaquin Valley Air Pollut ion Control District (SJVAPCD)

Bakersfield-Muni

The Bakersfield-Golden site was shut down for reloc ation in December 2009. The replacement site, Bakersfield-Muni, is located in t he Bakersfield, CA metropolitan area and is operated by the San Joaquin Valley Air Pollu tion Control District (SJVAPCD). The site serves as a PAMS Type 2 site, and its purp ose is to measure maximum ozone precursor emissions. The site monitors ozone, CO, NO 2 , total- and speciated-VOC, and meteorology for the PAMS program. The speciated PA MS equipment became operational in June 2012. All the other PAMS equip ment except for the NMHC equipment began operating in July 2012. The NMHC e quipment was installed and became operational in October 2012. The site monit ored PM10 and PM2.5 from July 2012 until late February 2013. However, it soon be came apparent that this site was not acceptable as a PM10 and PM2.5 site because site sp ecific emissions from nearby sources were impacting the site, and the site was t herefore not measuring ambient particulate concentrations.

Clovis-Villa Clovis, CA is located in the central part of the Sa n Joaquin Valley with mountains to the

east and northeast. North-south air flow is virtua lly unobstructed. Pollutant emissions occur locally and are also transported from upwind and nearby locations into the area by the wind. The Clovis-Villa monitoring site is operated by SJVAPCD and is located in the northeastern portion of the Fresno, CA metropol itan area. It began operating in September 1990. This site is a PAMS Type 2 site, a site intended to measure maximum ozone precursor emissions. In addition to ozone, the site also monitors PM2.5, PM10, PM2.5, CO, NO 2 , total- and speciated-VOC, and meteorology for the PAMS program. During the summer months, high tempe ratures and longer daylight hours contribute to increases in ozone during the d ay. In contrast, ozone concentrations decrease at night with the absence o f sunlight and the presence of NOx pollutants, which scavenge the ozone. During the w inter months, ozone concentrations tend to be lower due to shorter daylight hours and lower temperatures. Elevated PM2.5 concentrations are possible year round, but concent rations tend to be highest during the winter months due to moisture content in the air, w ood-burning activities, other anthropogenic activities, and atmospheric chemistry . PM2.5 concentrations can also increase during wind events, because the wind can c ause PM2.5 to become suspended in the air. On rare occasions, this area of the Sa n Joaquin Valley experiences wind events that can carry dust into the area or lift lo cal dust particles into the air. Such

events can cause PM10 concentrations to increase.

Corcoran-Patterson Corcoran, CA is located in the central part of the San Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutant emissions occur locally and are also transported from upwind locations into the area by the wind. The Corcoran-Patterson monitoring site is operated by SJVAPCD and is located 67San Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 2 miles south of the Fresno, CA metropolitan area. I t began operating in October 1996. In 2011, the site was shut down temporarily due to safety issues and repairs were made to the site. The site resumed operating in August 2012. The site measures representative concentrations of PM10 and PM2.5. T his site also monitors meteorology. Elevated PM2.5 concentrations are pos sible year round, but concentrations tend to be highest during the winter months due to moisture content in the air, wood-burning activities, other anthropogen ic activities, and atmospheric chemistry. PM2.5 concentrations can also increase during wind events because the wind can cause PM2.5 to become suspended in the air . On rare occasions, this area of the San Joaquin Valley experiences wind events that can carry dust into the area or lift local dust particles into the air. Such events can cause PM10 concentrations to
increase and sometimes exceed the NAAQS.

Fresno-Drummond Fresno, CA is located in the central part of the Sa n Joaquin Valley with mountains to the east and west. North-south air flow is virtually u nobstructed. Pollutants occur locally and are also transported from upwind locations into the area by the wind. The FresnoDrummond monitoring site is operated by SJVAPCD and is located in the Fresno, CA metropolitan area. It began operating in July 1984 . The purpose of the site is to monitor representative concentrations of hourly ozo ne responses in an urban area. In addition to ozone, the site also monitors PM10, PM2 .5, CO, NO 2 , and meteorology. During the summer months, high temperatures and lon ger daylight hours contribute to increases in ozone during the day. In contrast, oz one concentrations decrease at night with the absence of sunlight and the presence of NO x pollutants which scavenge the ozone. During the winter months, ozone concentrati ons tend to be lower due to shorter daylight hours and lower temperatures. During the winter months, ozone concentrations tend to be lower due to shorter dayl ight hours and lower temperatures. Elevated PM2.5 concentrations are possible year rou nd, but concentrations tend to be highest during the winter months due to moisture co ntent in the air, wood-burning activities, other anthropogenic activities, and atm ospheric chemistry. PM2.5 concentrations can also increase during wind events , because the wind can cause PM2.5 to become suspended in the air. On rare occa sions, this area of the San Joaquin Valley experiences wind events that can car ry dust into the area or lift local dust particles into the air. Such events can cause PM10 concentrations to increase.

Fresno-Pacific Fresno, CA is located in the central part of the Sa n Joaquin Valley with mountains to the east and west. North-south air flow is virtually u nobstructed. Pollutants occur locally and are also transported from upwind locations into the area by the wind. The FresnoPacific monitoring site is operated by SJVAPCD and is located in the Fresno, CA metropolitan area. It began operating in January 2 000. The purpose of the site is to monitor representative PM2.5 concentrations in an u rban area. Elevated PM2.5 concentrations are possible year round, but concent rations tend to be highest during the winter months due to moisture content in the air, w ood-burning activities, other anthropogenic activities, and atmospheric chemistry . PM2.5 concentrations can also increase when wind causes PM2.5 to become suspended in the air. Occasionally, windSan Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 3 will carry dust across the city or lift local dust particles into the air, and cause PM2.5 concentrations to become elevated, but PM2.5 exceed ances due to wind events are

rare.

Fresno-Sky Park Fresno, CA is located in the central part of the Sa n Joaquin Valley with mountains to the east and west. Pollutants occur locally and are al so transported from upwind locations into the area by the wind. The Fresno-Sky Park mo nitoring site is operated by SJVAPCD and is located in the Fresno, CA metropolit an area. It began operating in July 1986. The purpose of the site is to monitor r epresentative concentrations of hourly ozone responses in an urban area. In addition to o zone, the site also monitors CO,

NO 2 , and meteorology. During the summer months, high temperatures and longer daylight hours contribute to increases in ozone dur ing the day. In contrast, ozone concentrations decrease at night with the absence o f sunlight and the presence of NOx pollutants which scavenge the ozone. During the wi nter months, ozone concentrations tend to be lower due to shorter daylight hours and lower temperatures.

Hanford-Irwin Hanford, CA is located in the central part of the S an Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutants occur locally and are also transported from upwind locati ons into the area by the wind. The Hanford-Irwin monitoring site is operated by SJVAPC D and is located 51 miles south of the Fresno, CA metropolitan area. The site began o perating in October 1993 and was decommissioned in October 2007 due to plans to move it to a different part of the Irwin location. The purpose of the site is to monitor re presentative concentrations of hourly ozone, PM2.5, PM10, and NO 2 responses from upwind and nearby urban areas. The site also monitors meteorology. The PM2.5, PM10, a nd ozone monitors were temporarily moved to Corcoran during site reconstru ction. In February 2010, the ozone

and PM2.5 monitors were returned to Hanford and the site became operational again. The PM10 monitor was returned and became operationa l in July 2010. During the summer months, high temperatures and longer dayligh t hours contribute to increases in ozone during the day. In contrast, ozone concentra tions decrease at night with the absence of sunlight and the presence of NOx polluta nts which scavenge the ozone. During the winter months, ozone concentrations tend to be lower due to shorter daylight hours and lower temperatures. Elevated PM2.5 concen trations are possible year round, but concentrations tend to be highest during the wi nter months due to moisture content in the air, wood-burning activities, other anthropo genic activities, and atmospheric chemistry. PM2.5 concentrations can also increase during wind events because the wind can cause PM2.5 to become suspended in the air . On rare occasions, this area of the San Joaquin Valley experiences wind events that can carry dust into the area or lift local dust particles into the air. Such events can cause PM10 concentrations to
increase and sometimes exceed the NAAQS.

Huron Huron, CA is located in southwestern Fresno County, and is about 40 miles southwest of Fresno, CA, with the coastal mountain range just to the west. North-south air flow isSan Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 4 virtually unobstructed. This monitoring site was e stablished in January 2007 in order to comply with Assembly Bill (AB) 841. Currently, thi s site monitors PM2.5 (Non-FEM,

Lebec Lebec, CA is located in the southern-most portion o f the San Joaquin Valley. The Lebec monitoring station was initiated by the Tejon Ranch in 2004, and the District assumed responsibility for this site as of January 2009. This site allows the District to better understand pollution impacts in the southern San Emigdio Mountains. The site measures PM2.5 and meteorological parameters. This site is used for general residential wood-burning declarations for the Great er Frazier Park Area.

Madera-City Madera, CA is located in the northern part of the S an Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. The Madera-City monitoring site is located closer to the city cente r of Madera than the Madera-Pump Yard site. The Madera-City site is operated by the SJVAPCD and became operational in June 2010. The site monitors ozone, PM2.5, PM10 , and meteorology. The purpose

of this site is to measure downwind concentrations of the city of Madera which will provide needed information about the variability of air quality levels on the Valley floor of Madera County.

Madera-Pump Yard Madera, CA is located in the northern part of the S an Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. The Madera-Pump Yard Street monitoring site is operated by SJVAPCD and is located in Madera, CA. It began operating in August 1997. This site was esta blished as a PAMS Type 1 site, located in an area upwind of Fresno and not to be i nfluenced by upwind or local ozone precursor emissions. In addition to ozone, this si te also monitors CO, total- and speciated-VOC, and meteorology for the PAMS program . During the summer months, high temperatures and longer daylight hours contrib ute to increases in ozone during the day. In contrast, ozone concentrations decrease at night with the absence of sunlight and the presence of NOx pollutants which scavenge t he ozone. During the winter months, ozone concentrations tend to be lower due t o shorter daylight hours and lower
temperatures.

Manteca Manteca, CA is located in the northern part of the San Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutants are both local and up wind in origin. The Manteca monitoring site is located in Manteca, CA and operated by SJVAPCD. It became operational in Nove mber 2010. The purpose of the site is to monitor transport of and representative concentrations of ozone, PM2.5, and PM10 from upwind and nearby urban areas. The site also monitors meteorology. During the winter months, ozone concentrations tend to be lower due to shorter daylight hours and lower temperatures. Elevated PM2.5 conce ntrations are possible year round, but concentrations tend to be highest during the wi nter months due to moisture content in the air, wood-burning activities, other anthropo genic activities, and atmosphericSan Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 5 chemistry. PM2.5 and PM10 concentrations can also increase during wind events because the wind can cause PM to become suspended i n the air. Occasionally, wind will carry dust across the city and also cause PM c oncentrations to increase, but PM2.5

and PM10 exceedances due to wind events are rare.

Maricopa Maricopa, CA is located at the southern end of the San Joaquin Valley with mountains to the east, west, and south. Because the mountains block or slow down air flow pollutants can get trapped and build up in the area . The Maricopa monitoring site is operated by the SJVAPCD and is located 45 miles sou thwest of the Bakersfield, CA metropolitan area. It began operating in July 1987 . The purpose of the site is to monitor representative concentrations of hourly ozo ne in a rural area. The site also monitors meteorology. During the summer months, hi gh temperatures and longer daylight hours contribute to increases in ozone dur ing the day. In contrast, ozone concentrations decrease at night with the absence o f sunlight and the presence of NOx pollutants which scavenge the ozone. During the wi nter months, ozone concentrations tend to be lower due to shorter daylight hours and lower temperatures.

Merced-Coffee Merced, CA is located in the northern part of the S an Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutants are both local and up wind in origin. The Merced-Coffee moni toring site is operated by SJVAPCD and is located in the Merced, CA. It began operati ng in October 1991. The purpose of the site is to monitor representative concentration s of hourly ozone responses from upwind urban areas. The site also monitors PM2.5, NO 2 , and meteorology. During the summer months, high temperatures and longer dayligh t hours contribute to increases in ozone during the day. In contrast, ozone concentra tions decrease at night with the absence of sunlight and the presence of NOx polluta nts which scavenge the ozone. During the winter months, ozone concentrations tend to be lower due to shorter daylight hours and lower temperatures.

Merced-M Street Merced, CA is located in the northern part of the S an Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutants are both local and up wind in origin. The Merced-M Street mo nitoring site is operated by SJVAPCD and is located in Merced, CA. It began ope rating in April 1999. The purpose of the site is to monitor representative concentrat ions of PM2.5 and PM10 responses from upwind urban areas. Elevated PM2.5 concentrat ions are possible year round, but concentrations tend to be highest during the winter months due to moisture content in the air, wood-burning activities, other anthropogen ic activities, and atmospheric chemistry. PM2.5 and PM10 concentrations can also increase during wind events because the wind can cause PM to become suspended i n the air. Occasionally, wind will carry dust across the city and also cause PM c oncentrations to increase, but PM2.5

and PM10 exceedances due to wind events are rare.San Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 6 Parlier Parlier, CA is located in the central part of the S an Joaquin Valley with mountains to the east and west. North-south air flow is virtually u nobstructed. Pollutants are both local and up wind in origin. The Parlier monitoring site is operated by SJVAPCD and is located 20 miles southeast of the Fresno, CA metrop olitan area. It began operating in March 1983. The purpose of the site, as a PAMS Typ e 3 site, is to monitor maximum ozone concentrations and ozone responses from upwin d urban areas. The site also

monitors NO 2 , total- and speciated-VOC, and meteorology for the PAMS program. During the summer months, high temperatures and lon ger daylight hours contribute to increases in ozone during the day. In contrast, oz one concentrations decrease at night with the absence of sunlight and the presence of NO x pollutants which scavenge the ozone. During the winter months, ozone concentrati ons tend to be lower due to shorter daylight hours and lower temperatures.

Porterville Porterville, CA is located in the southeastern part of the San Joaquin Valley near the

foothills of the Sierra Nevada Mountains to the eas t. It is approximately 25 miles southeast of Visalia, CA, and so transport of pollu tants from Visalia towards Porterville is possible. The Porterville air monitoring site b ecame operational in March 2010 and is operated by the SJVAPCD. The purpose of this site is to monitor ozone, PM2.5, and meteorology, and represent air quality levels prese nt near the foothills of the southeastern portion of the Valley.

Stockton-Wagner/Holt Stockton, CA is located in the northern part of the San Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutants occur locally, but the wind can transport pollutants into the area from upwind locations or through the Sacramento Delta from the Bay Area. Th e Stockton-Wagner/Holt monitoring site is operated by SJVAPCD and is locat ed in the Stockton, CA metropolitan area. It began operating in October 1 996. The purpose of the site is to monitor representative concentrations of PM10 in an urban area. Occasionally, wind will carry dust across the city and cause PM10 conc entrations to increase, but PM10

exceedances are rare.

Tracy-Airport Tracy, CA is located in the northern part of the Sa n Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutants occur locally, but the wind can transport pollutants into the area from upwind locations or through the Sacramento Delta from the Bay Area. Th e Tracy-Airport monitoring site is operated by SJVAPCD and is located in Tracy, CA. I t began operating in January 2005. The purpose of the site is to monitor transport of ozone, PM2.5, and PM10 from upwind and nearby urban areas. The site also monitors NO 2 and meteorology. During the summer months, high temperatures and longer dayligh t hours contribute to increases in ozone during the day. In contrast, ozone concentra tions decrease at night with the absence of sunlight and the presence of NOx polluta nts which scavenge the ozone. During the winter months, ozone concentrations tend to be lower due to shorter daylightSan Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 7 hours and lower temperatures. Elevated PM2.5 conce ntrations are possible year round, but concentrations tend to be highest during the wi nter months due to moisture content in the air, wood-burning activities, other anthropo genic activities, and atmospheric chemistry. PM2.5 and PM10 concentrations can als o increase during wind events because the wind can cause PM to become suspended i n the air. Occasionally, wind will carry dust across the city and also cause PM c oncentrations to increase, but PM2.5

and PM10 exceedances due to wind events are rare.

Tranquillity Tranquillity, CA is located in western Fresno Count y, and is about 25 miles west of Fresno, CA, with the coastal mountain range just to the west. North-south air flow is virtually unobstructed. This monitoring site was e stablished in November 2009 and is operated by the SVAPCD. The purpose of this site i s to monitor ozone, PM2.5, and meteorology. The site also represents background a nd rural pollutant concentrations on the west side of the San Joaquin Valley for researc h purposes.

Turlock Turlock, CA is located in the northern part of the San Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutants occur locally, but the wind can transport pollutants into the area from upwind locations or through the Sacramento Delta from the Bay Area. Th e Turlock monitoring site is operated by SJVAPCD and is located in the Turlock, CA. It began operating in April 1992. The purpose of the site is to monitor repres entative concentrations of hourly ozone, PM2.5, and PM10 from upwind urban areas. Th e site also monitors CO, NO 2 , and meteorology. During the summer months, high te mperatures and longer daylight hours contribute to increases in ozone during the d ay. In contrast, ozone concentrations decrease at night with the absence o f sunlight and the presence of NOx pollutants which scavenge the ozone. During the wi nter months, ozone concentrations tend to be lower due to shorter daylight hours and lower temperatures. Elevated PM2.5 concentrations are possible year round, but concent rations tend to be highest during the winter months due to moisture content in the air, w ood-burning activities, other anthropogenic activities, and atmospheric chemistry . PM2.5 and PM10 concentrations can also increase during wind events because the wi nd can cause PM to become suspended in the air. Occasionally, wind will carr y dust across the city and also cause PM concentrations to increase, but PM2.5 and PM10 e xceedances due to wind events

are rare.

Visalia-Airport Visalia, CA is located where the central and southe rn parts of the San Joaquin Valley meet. The Sierra Nevada mountain range is approxim ately 20 miles east of Visalia. North-south air flow is virtually unobstructed. Th e Visalia-Airport monitoring site is operated by SJVAPCD and serves as a wind profiler m onitoring surface wind speed and wind direction. It also monitors air temperature, and relative humidity at the surface. It began reporting official meteorological data in Jan uary 2001. Meteorological parameters have a direct influence on how and where pollutants are transported and how much pollutant concentrations increase or decre ase.San Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 8 Sites Operated by the California Air Resources Boar d (CARB)

Arvin-Di Giorgio Arvin, CA is located at the southern end of the San Joaquin Valley with mountains to the east, west, and south. Because the mountains block or slow down air flow pollutants can get trapped and build up in the area. Pollutan ts occur locally and are also transported from upwind locations into the area by the wind.

The Arvin-Bear Mountain Boulevard ozone monitoring site was established by the Air Resources Board (ARB) in 1989 and has periodically been the Valley’s ozone design site. Due to circumstances beyond ARB’s control, A RB was unable to renew the lease at this location, and monitoring had to be disconti nued at the end of the 2010 ozone season. The loss of this monitoring site has impli cations for determining the ozone attainment status of the region. The ARB is active ly working with the United States Environmental Protection Agency on an appropriate s olution to address this situation.

The Di Giorgio site is located 18 miles southeast o f the Bakersfield, CA metropolitan area. The purpose of the site, as a PAMS Type 3 si te, is to monitor maximum ozone concentrations and transport from upwind urban area s. The site also monitors NO 2 , NMOC, NMHC, and meteorology and CARB plans to insta ll methane/CO 2 and trace CO analyzers for special purpose monitoring. In addit ion, a NOy monitor will be added to the Arvin-Di Giorgio air monitoring site to comply with the latest regulation for PAMS Type 3 sites. During the summer months, high tempe ratures and longer daylight hours contribute to increases in ozone during the day. I n contrast, ozone concentrations decrease at night with the absence of sunlight and the presence of NOx pollutants which scavenge the ozone. During the winter months , ozone concentrations decrease due to shorter daylight hours and lower temperature s. Pollutants occur locally and are also transported into the area by wind.

Bakersfield-Planz Bakersfield, CA is located at the southern end of t he San Joaquin Valley with mountains to the east, west, and south. Because the mountains block or slow down air flow pollutants can get trapped and build up in the area . Pollutants occur locally, and are transported from upwind locations into the area by the wind. The Bakersfield-Planz monitoring site is operated by CARB and is located 6 miles north of the Bakersfield, CA metropolitan area. It began operating in September 2000. The purpose of the site is to monitor representative concentrations of PM2.5 from upwind and nearby urban areas. Elevated PM2.5 concentrations are possible year rou nd, but concentrations tend to be highest during the winter months due to moisture co ntent in the air, wood-burning activities, other anthropogenic activities, and atm ospheric chemistry. PM2.5 concentrations can also increase during wind events because the wind can cause PM2.5 to become suspended in the air.San Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 9 Bakersfield-California Bakersfield, CA is located at the southern end of t he San Joaquin Valley with mountains to the east, west, and south. Because the mountains block or slow down air flow pollutants can get trapped and build up in the area . Pollutants occur locally, and are transported from upwind locations into the area by the wind. The Bakersfield-California monitoring site is operated by CARB and is located in the Bakersfield, CA metropolitan area. It began operating in March 1994. The purpo se of the site is to monitor representative concentrations of hourly and daily o zone, PM10, and PM2.5 in an urban

area. After the shutdown of the Bakersfield-Golden site, the District requested CARB’s permission to temporarily operate a real time PM10 monitor at the Bakersfield-California site (06-029-0014). The temporary PM10 monitor was used for daily AQI forecasting purposes. This temporary monitor was later moved t o the Bakersfield-Muni site, however the monitor is no longer operating at Baker sfield-Muni (see Appendix C for details). The Bakersfield-California site also mon itors NO 2 and meteorology. During the summer months, high temperatures and longer dayligh t hours contribute to increases in ozone during the day. In contrast, ozone concentra tions decrease at night with the absence of sunlight and the presence of NOx polluta nts which scavenge the ozone. Elevated PM2.5 concentrations are possible year rou nd, but concentrations tend to be highest during the winter months due to moisture co ntent in the air, wood-burning activities, other anthropogenic activities, and atm ospheric chemistry. PM2.5 concentrations can also increase during wind events because the wind can cause PM2.5 to become suspended in the air.

Edison Edison, CA is located at the southern end of the Sa n Joaquin Valley with mountains to the east, west, and south. Because the mountains b lock or slow down air flow pollutants can get trapped and build up in the area . Pollutants occur locally, and are transported from upwind locations into the area by the wind. The Edison monitoring site is operated by CARB and is located 9 miles east of the Bakersfield, CA metropolitan area. It began operating in January 1980. The pur pose of the site is to monitor representative concentrations of hourly ozone from upwind and nearby urban areas.

The site also monitors NO 2 and meteorology. During the summer months, high temperatures and longer daylight hours contribute t o increases in ozone during the day. In contrast, ozone concentrations decrease at night with the absence of sunlight and the presence of NOx pollutants which scavenge the ozone . During the winter months, ozone concentrations decrease due to shorter daylig ht hours and lower temperatures.

Fresno-Garland Fresno, CA is located in the central part of the Sa n Joaquin Valley with mountains to the east and west. North-south air flow is virtually u nobstructed. Pollutants occur locally, and are transported from upwind locations into the area by the wind. In December 2011, CARB moved the Fresno-First monitoring site t o Garland Avenue which is two

blocks north of the Fresno-First site. The new sit e is now referred to as Fresno-Garland and became operational on December 31, 2011. The F resno-Garland monitoring site is a National Core (NCore) site operated by CARB and i s located in the Fresno, CA metropolitan area. The purpose of the site is to m onitor representative concentrationsSan Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 10 of hourly ozone, PM2.5, and PM10 in an urban area. The site also monitors CO, NO 2 , SO 2 , NMOC, NMHC, toxics, and meteorology. During the summer months, high temperatures and longer daylight hours contribute t o increases in ozone during the day. In contrast, ozone concentrations decrease at night with the absence of sunlight and the presence of NOx pollutants which scavenge the ozone . During the winter months,

ozone concentrations tend to be lower due to shorte r daylight hours and lower temperatures. Elevated PM2.5 concentrations are po ssible year round, but concentrations tend to be highest during the winter months due to moisture content in the air, wood-burning activities, other anthropogen ic activities, and atmospheric chemistry. PM2.5 concentrations can also increase during wind events because the wind can cause PM2.5 to become suspended in the air . On rare occasions, this area of the San Joaquin Valley experiences wind events that can carry dust into the area or lift local dust particles into the air. Such events can cause PM10 concentrations to

increase.

Modesto-14 th Street Modesto, CA is located in the northern part of the San Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutants occur locally, but the wind can transport pollutants into the area from upwind locations or through the Sacramento Delta from the Bay Area. Th e Modesto-14 th Street monitoring site is operated by CARB and is located in the Mode sto, CA metropolitan area. It began operating in January 1981. The purpose of the site is to monitor representative concentrations of hourly ozone, PM2.5, and PM10 in local and upwind urban areas. The site also monitors CO and meteorology. During the summer months, high temperatures and longer daylight hours contribute t o increases in ozone during the day. In contrast, ozone concentrations decrease at night with the absence of sunlight and the presence of NOx pollutants which scavenge the ozone . During the winter months,

ozone concentrations tend to be lower due to shorte r daylight hours and lower temperatures. Elevated PM2.5 concentrations are po ssible year round, but concentrations tend to be highest during the winter months due to moisture content in the air, wood-burning activities, other anthropogen ic activities, and atmospheric chemistry. PM2.5 concentrations can also increase during wind events because the wind can cause PM2.5 to become suspended in the air . Occasionally, wind will carry dust across the city and cause PM10 concentrations to increase, but PM10

exceedances are rare.

Oildale Oildale, CA is located at the southern end of the S an Joaquin Valley with mountains to the east, west, and south. Because the mountains b lock or slow down air flow pollutants can get trapped and build up in the area . Most pollutants occur locally, however, a small amount are also transported from u pwind locations into the area by the wind. The Oildale monitoring site is operated b y CARB and is located 6 miles north of Bakersfield, CA within the metropolitan area. I t began operating in January 1980. The purpose of the site is to monitor representativ e concentrations of hourly ozone concentrations, and PM10 every 6 days in an urban a rea. The site also monitors meteorology. During the summer months, high temper atures and longer daylight hoursSan Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 11 contribute to increases in ozone during the day. I n contrast, ozone concentrations decrease at night with the absence of sunlight and the presence of NOx pollutants which scavenge the ozone. Not only does the metrop olitan area generate its own pollution, it is also the recipient of pollutants t hat get transported by wind. On rare occasions, this area of the San Joaquin Valley expe riences wind events that can carry dust into the area or lift local dust particles int o the air. Such events can cause PM10

concentrations to increase.

Shafter Shafter, CA is located at the southern end of the S an Joaquin Valley with mountains to the east and west, and 58 miles to the south. Becau se the mountains to the south are further away, southward air flow is less obstructed through Shafter so pollutant build-up is less pronounced compared to Bakersfield and the towns further south. Pollutants occur locally and wind can transport pollutants int o and through Shafter from nearby and upwind areas. The Shafter monitoring site is a shared site operated by CARB and

the SJVAPCD and is located 18 miles northwest of th e Bakersfield, CA metropolitan area. It began operating in January 1989. This si te was established as a PAMS Type 1 site, located in an area upwind of Bakersfield and not to be influenced by upwind or local ozone precursor emissions. In addition to oz one, the site also monitors NO 2 , totaland speciated-VOC and meteorology for the PAMS prog ram. During the summer months, high temperatures and longer daylight hours contribute to increases in ozone during the day. In contrast, ozone concentrations decrease at night with the absence of sunlight and the presence of NOx pollutants which s cavenge the ozone. Being located upwind of Bakersfield, the Shafter site tends to ha ve lower ozone concentrations than does the metropolitan area to the south.

Stockton-Hazelton Stockton, CA is located in the northern part of the San Joaquin Valley with mountains to

the east and west. North-south air flow is virtual ly unobstructed. Pollutants occur locally, but the wind can transport pollutants into the area from upwind locations or through the Sacramento Delta from the Bay Area. Th e Stockton-Hazelton monitoring site is operated by CARB and is located in the Stoc kton, CA metropolitan area. It began operating in June 1976. The purpose of the site is to monitor representative concentrations of ozone, PM2.5, and PM10 in an urba n area. The site also monitors CO, NO 2 , toxics, and meteorology. During the summer month s, high temperatures and longer daylight hours contribute to increases in oz one during the day. In contrast, ozone concentrations decrease at night with the abs ence of sunlight and the presence of NOx pollutants which scavenge the ozone. During the winter months, ozone concentrations tend to be lower due to shorter dayl ight hours and lower temperatures. Elevated PM2.5 concentrations are possible year rou nd, but concentrations tend to be highest during the winter months due to moisture co ntent in the air, wood-burning activities, other anthropogenic activities, and atm ospheric chemistry. PM2.5 concentrations can also increase during wind events because the wind can cause PM2.5 to become suspended in the air. On rare occa sions, wind will carry dust across the city and cause PM10 concentrations to increase, but PM10 exceedances are rare.San Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 12 Visalia-Church Visalia, CA is located where the central and southe rn parts of the San Joaquin Valley meet. The Sierra Nevada mountain range is approxim ately 20 miles east of Visalia. North-south air flow is virtually unobstructed. Po llutants occur locally, and can be transported from upwind locations into the area by the wind. The Visalia-Church monitoring site is operated by CARB. It began oper ating in July 1979. The purpose of the site is to monitor representative concentration s of hourly ozone, PM2.5, and PM10 from upwind and nearby urban areas. The site also m onitors NO 2 and meteorology. During the summer months, high temperatures and lon ger daylight hours contribute to increases in ozone during the day. In contrast, oz one concentrations decrease at night with the absence of sunlight and the presence of NO x pollutants which scavenge the ozone. During the winter months, ozone concentrati ons tend to be lower due to shorter daylight hours and lower temperatures. Elevated PM 2.5 concentrations are possible year round, but concentrations tend to be highest d uring the winter months due to moisture content in the air, wood-burning activitie s, other anthropogenic activities, and atmospheric chemistry. PM2.5 concentrations can al so increase during wind events because the wind can cause PM2.5 to become suspende d in the air. On rare occasions, wind will carry dust across the city and cause PM10 concentrations to increase, but PM10 exceedances are rare.

Sequoia and Kings National Park and Forest Monitori ng Sites

Sequoia-Ash Mountain The Ash Mountain monitoring station is operated by Sequoia National Forest and is located at the southern entrance of Sequoia Nationa l Park at a 1,500-foot elevation. It originally began operating in 1985, though the site has been relocated several times over the years. The site demonstrates the hourly o zone concentrations in the foothills. The site also monitors PM2.5 and meteorology. On s ummer days, ozone and precursors can be transported to Ash Mountain from other locations. At this location, there are significantly lower hourly emissions of N Ox as compared to urban areas such as Bakersfield, or Fresno, CA. The amount of avail able NOx at Ash Mountain to scavenge the ozone is much lower. Because the ozon e scavenging at Ash Mountain is much less than the ozone scavenging in urban areas, Ash Mountain can experience elevated ozone concentrations for a 24-hour period during ozone episodes. Since the ozone concentration is already fairly high at dawn, only a relatively small amount of additional ozone can cause levels in the atmosphere to exceed federal standards.

Sequoia-Lower Kaweah The Lower Kaweah monitoring station is operated by Sequoia National Forest and is located at the southern entrance of Sequoia Nationa l Park at a 6,200-foot elevation. It began operating in April 1987. The site demonstrat es the hourly ozone concentrations in a rural area. The site also monitors meteorolog y. On summer days, ozone and precursors can be transported to Ash Mountain from other locations. At this location, there are significantly lower hourly emissions of N Ox as compared to urban areas such as Bakersfield, or Fresno, CA. The amount of avail able NOx at Lower Kaweah to scavenge the ozone is much lower. Because the ozon e scavenging at Lower KaweahSan Joaquin Valley Air Pollution Control District June 25, 2013

Appendix A: Air Monitoring Site Descriptions Annual Air Monitoring Network Plan A

- 13 is much less than the ozone scavenging in urban are as, Lower Kaweah can experience elevated ozone concentrations for a 24-hour period during ozone episodes. Since the ozone concentration is already fairly high at dawn, only a relatively small amount of additional ozone can cause levels in the atmosphere to exceed federal standards.