Photochemical Assessment Monitoring Station (PAMS)

Section 182(c)(1) of the 1990 Clean Air Act Amendments required EPA to promulgate rules for the enhanced monitoring of ozone, oxides of nitrogen (NOx), and volatile organic compounds (VOC). The subsequent revisions to Title 40, Code of Federal Regulations, Part 58 (40 CFR 58) required States to establish Photochemical Assessment Monitoring Stations (PAMS) as part of their SIP monitoring networks in ozone non-attainment areas classified as serious, severe, or extreme for more comprehensive and representative data on ozone air pollution. The database will be used in evaluating, tracking the progress of, and, if necessary, refining control strategies for attaining the ozone National Air Quality Standards (NAAQS).

PAMS Type I (Corbin, VA):

In 1993, the Department of Environmental Quality established a PAMS Type I at Corbin in Caroline County. This site is part of the Enhanced Ozone Monitoring Network for the Washington, D.C. Consolidated Metropolitan Statistical Area (CMSA) which is classified as a severe ozone non-attainment area. The objective of this PAMS Type I site is to characterize the upwind background and transported concentration of ozone and its precursors entering the Washington, D.C. area.

Integrated ambient air samples are collected in evacuated, six liter stainless steel canisters by a manual method using the Xontech air sampler. The collected air samples are analyzed by the Division of Consolidated Laboratory Services (DCLS) for volatile organic ozone precursors and Total Non-methane Organic Compound (TNMOC).

From 1993 through 2001, the sampling frequencies for volatile organic ozone precursors were eight 3-hour samples every third day and one 24-hour sample every sixth day during the core ozone season (June-August). At the end of August, sampling was switched to one 24-hour sample every sixth day. From 2002, in accordance to the revised PAMS for the Washington, D.C. area, the episodic sampling frequency for volatile organic ozone precursors in the summer are eight 3-hour samples in the ozone warning days (Code Red) and one 24-hour sample every sixth day.

PAMS Type II-A (Fairfax, VA):

In 1998, the Department of Environmental Quality established a PAMS Type II-A at Lee District Park in Fairfax County. This site is part of the Enhanced Ozone Monitoring Network for the Washington, D.C. severe ozone non-attainment area. The objective of this PAMS Type II-A site is to measure maximum ozone precursor concentrations in the secondary downwind direction on days conducive to ozone formation.

Hourly volatile organic ozone precursors samples were collected and analyzed by the Perkin Elmer Auto Gas Chromatograph (AutoGC). Integrated 24-hour ambient air samples were collected in evacuated, six liter stainless steel canisters by a manual method using the Xontech air sampler. The Air Laboratory of the Maryland Department of the Environment analyzed the collected canister samples. Carbonyl Compound was collected by DNPH coated cartridges and analyzed by the Air Management Laboratory of Philadelphia.

From 1998 though 2001, hourly samples were collected everyday and one 24-hour canister sample was collected for every sixth day during the core ozone season (June-August). At the end of August, sampling was switched to one canister 24-hour sample every sixth day. Sampling frequencies for Carbonyl Compound were four 3-hour samples every third day and one 24-hour every sixth day.

At the end of 2001, in accordance to the revised PAMS for the Washington, D.C. area, the PAMS Type II-A at Lee District Park was shut down and the AutoGC was moved to the new PAMS Type II in Richmond.

PAMS Type II (Richmond, VA):

From 2002, the Department of Environmental Quality established a new PAMS Type II at the Math & Science Center in Henrico County to enhance the PAMS Network by extending the spatial coverage area to North Carolina. The objective of this PAMS Type II site is to measure maximum ozone precursor concentrations in the primary downwind direction on days conducive to ozone formation for the Richmond area.

Hourly volatile organic ozone precursors samples are collected and analyzed by the Perkin Elmer Auto Gas Chromatograph (AutoGC). Integrated 24-hour ambient air samples are collected in evacuated, six liter stainless steel canisters by a manual method using the Xontech air sampler. The Air Laboratory of the Maryland Department of the Environment analyzed the collected canister samples. Carbonyl Compound was collected by DNPH coated cartridges and analyzed by the Air Management Laboratory of Philadelphia.

Hourly samples are collected everyday and one 24-hour canister sample is collected for every sixth day during the core ozone season (June-August). A collocated canister sample is collected every twelfth day. At the end of August, sampling is switched to one 24-hour canister sample every sixth day. Sampling frequency for Carbonyl Compound is four 3-hour samples every third day and one 24-hour every sixth day.

Questions concerning the DEQ PAMS Program should be directed to:

Brian King
Office of Air Quality Monitoring
4949-C Cox Road
Glen Allen, VA 23060

Voice: 804-527-5186
Fax: 804-527-5160
Email: Brian.King@deq.virginia.gov

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Virginia Department of
Environmental Quality
P.O. Box 1105
Richmond, VA 23218
(804) 698-4000


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