Follow-Up: Landfill Northeast Station
The sustained elevated readings at the Landfill Northeast Ajax air quality monitoring location are being investigated to determine whether the readings are a result of sensor signal shift, or an actual elevation in VOCs in the area.
This judgement can be difficult, as the sensor on the station is responding to levels over 900 VOCs, but the CSU laboratory is only measuring ~50 in the canister. There is a possibility that real VOCs are being detected, but aren’t able to be collected or quantified.
Analysis of the specific canister samples collected in response to this event are forthcoming and will likely yield greater understanding of the nature of the event. In the meantime, the Landfill Northeast sensors (canister trigger threshold) have been raised to 700 mV, as this is a sustained elevated reading. There is not a value in triggering too many sample collections with this single event (two have been collected already).
The threshold will be lowered back down once understanding of the event can be gained and/or the signal drops back down to baseline. More information will be shared as it becomes available.