Independent Ozone Baseline Monitoring

With funding from the Greater Yellowstone Coalition, and the Wilderness Society, combined with my own, we have formed a partnership in establishing an independent ozone monitoring station at my location 21 miles north of Pinedale and 12 miles north of the DEQ-Daniel monitor. 

   The tower was constructed and sited to comply with EPA's requirements as stipulated in 40CFR, Part 58. The monitor is an EPA approved "equivalent method" Dasibi Model 1000-PC.  As much as is practical, compliance with the intent of plans and protocol descriptions in 40CFR, Part 51 is practiced.  At a minimum, calibration and operation of the monitor is in compliance with recommendations spelled out in the manufacturer's operation manual.

   The system went through "shakedown" operation in January and full operation in February 2008.  Initially, the system is operated in daytime only, when ozone is being produced, in the hope of extending the lifetime of the monitor.  The unit is 30 years old, long since out of production, and therefore will be difficult to repair.  This operating strategy has already been modified as a result of a spectacular ozone exceedence event in the Upper Green River Valley on Feb 23, 2008 (discussed below).  In the future, when an ozone event appears to be building, the monitor will be kept in operation for the duration of the event, night and day.  This will better produce a series of 8-hour averages which are the basis for federal regulatory  response.

  High Ozone Event

  Between Feb 20-23rd, 2008, local weather conditions combined with continuous snow cover on the ground and high intensity sun illumination to produce an ozone level that resulted in WYO-DEQ issuing a hazardous air quality warning for the Upper Green River Valley.  This was the first time in history that such an action has been necessary.(click Warning)  DEQ monitors situated around the southwest quadrant of Wyoming all registered ozone levels that were somewhat elevated into the low 50 ppb (part per billion) where readings in the mid-to-low 40s are the norm.  However, the monitors in the Jonah and Anticline (Boulder) gas fields registered dramatically higher levels.  The table below is a snapshot of readings for times noted.  One of the most striking aspects of the event was the persistence of high ozone readings through midnight at the gas field monitors.....ozone normally declines after sunset. 

  Another aspect must be noted....namely, that the gas fields, by themselves, seem to have doubled the ozone reading in their local area as well as my own location some 30 and 50 miles north of the gas fields.  My own monitor registered a peak reading of 92 ppb around 4:00 P.M. for a short while.

                                               

  It is worth noting that around 1:00 P.M., a light wind between 5-10 mph, out of the southeast began blowing and did so until about 5:00 P.M.  This was also happening at the Jonah and Boulder monitors.  My monitor began to climb in readings shortly after 2:00 P.M. and continued on that trend until the wind slowed and the sun was low in the sky.  This behavior supports my long stated theory that wind can run northward along the foothills of the Wind River Mountain Range and act as a conveyor of gas field air pollutants toward the Class I & II air sheds to the north.