Raybestos Memorial Field (OU4) and Additional Properties (OU6) Air Monitoring

Air monitoring is one of several safety controls in place at Raymark cleanup sites to protect site personnel and the surrounding community from airborne dust.  Perimeter air monitoring will be conducted at all Raymark cleanup sites during remedial activities that disturb soil.  Air monitoring meters measure airborne dust (particulate matter) in real time.  Dust “action levels” have been calculated based on chemicals known to be in the soil and potential routes and durations of exposure.  These action levels are meant to be protective of public health.  If the level of dust in air exceeds the action level, site management will be immediately notified to modify their activity and increase dust control before the dust reaches a level that can harm human health.  In addition, samples are sent to the lab for chemical analysis to ensure that the action levels set for airborne dust are preventing unacceptable amounts of hazardous chemicals from entering the air.  In addition to the U.S. Army Corps of Engineers and the on-site air monitoring and sampling technician, the Stratford Health Department reviews air monitoring results to ensure the community is protected.  Results will be posted to this website.  You can view the Raymark remedial contractor’s full Perimeter Air Monitoring Plan here.  


Summary of Air Monitoring Program at OU4 and OU6 sites:

  • ·         Dust monitors operate continuously from approximately 7:00am until site shutdown each day of operation (not operating when raining).
  • ·         5 DustTrak monitors stationed at OU4, 2 at upwind locations, 2 around the immediate work area and 1 downwind location.
  • ·         2 DustTrak monitors are stationed at each OU6 site, 1 upwind and 1 downwind from the work area.
  • ·         Each DustTrak monitor is set at 0.020 mg/m3 (continuous measurement over 15 min) notification for dust generation and field actions to be conducted; meters monitored continuously by onsite contractor and USACE personnel.
  • ·         The 8-hour Daily Average dust concentration was derived specific to the site soil at OU4 and OU6 sites.  EPA screening concentrations for 12 chemicals detected at OU4 and OU6 sites were used to calculate a human health-based protection Action Level (OU4 8-hour Daily Average = 0.014 mg/m3, OU6 8-hour Daily Average = 0.019 mg/m3).
  • ·         The health-based protection Action Levels for both OU4 and OU6 include a safety factor of 10 (0.14 mg/mdivided by 10 = 0.014 mg/m3) to be further protective.
  • ·         Measured 8-hour Daily Average subtracts measured site background (including offsite sources, e.g. ongoing construction, mowing of lawns, etc.) to verify 8-hour Daily Average is below the health-based Action Levels. 
  • ·         Dust samples are collected for chemical analyses from each meter location when soil is being disturbed; samples include personnel air samples.  Samples are analyzed for asbestos, metals and PCBs. 
  • ·         Chemical data is available approximately 3 days following sample collection, then evaluated for worker health and safety and further protection of abutters. 
  • ·         The dust sample IDs coincide with the Meter #s (e.g. S-1 = DustTrak Meter 1) and P-1 is personnel monitoring. 
  • ·         Meteorological monitoring station is located on top of the construction trailer at OU4; data is collected 4 times/day.

Properties and Results: