Important Chemical Speciation Network (CSN) documents can be found below, including current sampling calendars, a master site list and historical documents from the beginning of the program.

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Current Network Information

• List of CSN Sites Using National Contract for Analysis (PDF)(4 pp, 162 K) 
• 2020 CSN 1 in 6 Day Sampling Schedule (PDF) (13 pp, 182 K)
• 2020 CSN 1 in 3 Day Sampling Schedule (PDF) (14 pp, 192 K)

Background Information and Documentation

• Particulate Matter (PM2.5) Speciation Guidance (PDF) (70 pp, 216 K)
• Recommendations of the Expert Panel on the EPA Speciation Network Final Summary (PDF) (16 pp, 61 K)
• Data Quality Objectives for the Trends Component of the PM2.5 Speciation Network (PDF) (25 pp, 641 K)
• Strategic Plan Development of PM2.5 Quality System for CSN (PDF) (15 pp, 136 K)