Introduction
Recently, one of The Conservancy Initiative’s (TCI) very loyal members wrote to TCI to report a pattern they were seeing in the odors at their home. Their astute observations motivated TCI to dive a little deeper into some of the recent landfill odor events to see how odors correlated with weather patterns.
TCI downloaded the Local Climatological Data (LCD) for the Detroit Metro Airport (DTW) weather station from the NOAA website. The date and time recorded on odor complaint records were matched to the NOAA DTW Climatological Data to determine the wind speed and direction at the time of the odor complaint. Normal wind patterns were compared to the wind patterns measured at the time of odor complaints recorded by a single conscientious family located over 3 miles from the landfill in a subdivision near Northville High School (6 Mile Road between Beck and Sheldon Road). This document presents a description of the analysis performed and the conclusions made by this investigation.
Conclusions
Wind Speed has very little effect on the probability of odors from the landfill. Odors have been detected over a wide range of wind speeds which correspond very well to the normal distribution of wind speeds observed at the DTW weather station.
Odors travel a great distance even during light or calm wind conditions. In this analysis odor complaints were made over 3 miles away from the landfill during calm and light wind conditions.
Odor complaint data track the wind direction sometimes better than The Weather Channel. Charts are available in this analysis using NOAA weather data which traces the wind direction backward from the complaint location to the landfill extremely well.
The analysis surmises that if you live within about 3 miles of the landfill, and the winds are blowing towards your home from the landfill, there is about a 1 in 3 chance that you are going to smell the landfill.
Analysis
Chart 1 shows the normal distribution of wind speeds as measured at the DTW weather station. The dataset used was approximately 2 readings per hour from January 1, 2020, through August 21, 2020 (over 9,700 data points).
Chart 2 shows the distribution of wind speeds as measured during the 31 odor complaints made a family more than 3 miles away from the landfill in a Northville subdivision near Northville High School. The distributions are almost identical which indicates wind speed has little or no impact on the probability for an odor in this subdivision. Odors may be present at any wind speed.
Chart 3 is a radar chart showing the normal distribution of the wind direction as measured at the DTW weather station. Once again, the dataset used was comprised of approximately 2 readings per hour from January 1, 2020, through August 21, 2020 (over 9,700 data points).
Chart 4 is a radar chart showing the wind directions for the 31 odor complaints made by a family more than 3 miles away from the landfill in a subdivision near Northville High School. It should be of little surprise as the landfill is located to the WSW of the Subdivision. What may be surprising is the subdivision is 3 miles from the landfill.
What does this Mean?
A single conscientious family living more than 3 miles away from the landfill, in a subdivision near Northville High School, has submitted odor complaints on 31 separate dates as of August 22nd of this year. This represents approximately 13% of the year with odors present at their home. Not a good year for a stay at home order!
Chart 5 is another depiction of the normal wind direction as measured at DTW. In this chart, we have highlighted the bars with wind directions which have resulted in odors in the Subdivision near Northville High School. Based on normal wind distribution patterns, approximately 38% of the time the wind direction has the potential for odors in the subdivision near Northville High School.
It is logical to surmise that if the wind blows in a direction that may result in odors 38% of the time and odors were reported 13% time, that there is a 1 in 3 probability of an odor when winds are blowing West to Southwest or calm (13/38 ~ 1:3) in the Northville High School subdivision. Said another way, if you live within about 3 miles of the landfill, and the winds are blowing towards your home (or calm), there is about a 1 in 3 chance that you are going to smell the landfill.
Closing Thought
On September 30, 2019, Advanced Disposal Services agreed to a Consent Agreement and Final Order (CAFO) which closed the violations issued by the USEPA in September 2016. This agreement is when ADS agreed to install a Hydrogen Sulfide meter at Ridge Wood Elementary. ADS also agreed to perform an analysis to predict the source and intensity of odors.
34. Respondent agrees to evaluate the relationship between odor monitoring conducted from 2017 through 2019 and odor complaints. The evaluation will rely on specific odor complaint locations and the recurring monitoring performed by Barr Engineering under the direction of RK Associates. The evaluation with provide a relationship between the measured level of odor and the level of odor based on the complaint. The output will include the development of quantitative methods using artificial intelligence and machine learning techniques to (i) predict the source and intensity of the odor based on complaints and/or (ii) predict the frequency and intensity of odor complaints based on odor measurements.
TCI would like to review this work in order to confirm ADS has fulfilled its commitment. We will pursue obtaining a copy from the USEPA.