Comments on the Card/Schmidt Odor Study

Another letter to the Planning Commission…

Subject: Kind Attention – Republic Services Concealed and Mis-presented Data for Landfill Expansion Permit in Silicon Valley [PD14-014 ]

Dear Honorable Members of the Planning Commission,

We have noticed the following documents regarding Newby’s odor study that Republic Services has recently submitted for your review:

We have made the following observations about the reports included there, and would like to make some comments.

First, these documents still do not include individual odor flux measurements from the active landfill, but we can infer from the data samples from the memorandums that the Newby’s covered and closed landfill is a source of offensive odor.

From Table 2 on Page 27, we found 18 odor flux values as sampled from the inactive landfill. This is the same dataset that was included in the previous study by Card/Schmidt. (See the first data table attached at the end.)

We combined these odor flux data points with those collected from the natural resources, as found in the technical memorandum on P.75, and we charted them  together:



As you may see, one value clearly stands out, and that peak value, according to the authors, is due to surface breakthrough (P.12, second paragraph) on a dry soil surface (table on P.22), on a covered and closed landfill (P.18.).

There is an odor irritation threshold, over which most people will complain about. The peak value on the chart is clearly a source of such offensive odor. All the others should be well below the threshold. There are yet other, much higher thresholds set forth by the government for occupational safety and public health. Thankfully all these measurements are well under those levels. Dr. Schmidt’ chart was showing data points

Second, Dr. Schmidt revealed a single “Actual Measured Landfill Average” to represent the tons of historical data that the landfill has been and is still collecting. This is an irresponsible way to inform the public and decision makers.

Methane is a highly flammable gas. The government has strict requirement on methane monitoring for landfills. As a result, Newby has at least several hundreds of methane probes put in the grid cells throughout the facility (P.9. in report for sample grid location). And they set up a system to collect data at all these cells around the clock. They should also report these data to EPA.

Let’s say they have 300 probes, and they take measurements every 30 minutes. They then will have 14,400 methane measurements every day. Over a month, they would have 446,400 measurements. And they would take all these about half a million numbers and give a grand average. And that’s all they have for you and the public.

Let me explain what they are not showing.

At every 30 minutes, all about 300 probes are recorded. They can do a total or average of these 300 readings, and should also report at least the maximum, or the biggest reading out of the 300. Let’s call the average of the 300 readings “site-wide average”.

If we get the average for every 30 minutes data collection interval, and we do this for a month, we would get a time series that look like this:


As you may notice, the surges that happen from time to time are the times when Newby is cooking, and gives off foul smell. This red horizontal line is the odor threshold, above which BAAQMD would get complaints. The higher the surge, the more complaints. As you know, the landfill is not active all the time. In fact, most of the time all Newby surfaces are pretty quiet.

The catch is, if you take all this data, and find a grand average, you will get 2.80, which is the blue line near the bottom that you see. This 2.80 is exactly the same value that Dr. Schmidt reported. This graph shows what he did not show. In other words, Newby concealed a historical report like the time chart above altogether. This time chart would clearly reveal the odor outbreaks, even though the grand average is as low as 2.80.

This kind of data is very similar to earthquake data. They are what we call “skewed”, meaning most of the values are very low. But in both cases, the occasional peak values would bring big social, economical and environmental impact. Take a look at this USGS’s earthquake record from 1985, of all shakes with magnitude 2 and above.


The grand average of all these magnitudes would be lower than 3, which is not a magnitude we need to worry about. As a decision maker, will you just look at the average, and sit back and relax?

EPA would review a lot more than an average. Newby already has a capable IT team that prepares data reports to EPA on a regular basis. They don’t need to do an expensive “odor study”. They only need to publish their data report to EPA on the web, and include time charts like the above. Please urge them to do so ASAP.

Third, Dr. CE Schmidt’s data analysis of multiplying the average by surface area is really mind boggling. I wonder why he left out the entire Pacific Ocean. Even though it is not in the immediate vicinity, the Pacific Ocean is where all our wind comes from. Using Dr. Schmidt’s technique of analyzing data, by taking average and then multiplying by the area of the odor source, Dr. Schmidt will be able to conclude that the Pacific Ocean will pose a disastrous methane threat to all citizens on the west coast.

With all due respect to Dr. Schmidt, and his contribution to environmental chemistry, his data analysis techniques need to reflect some common sense, and basic understanding about statistics. EPA would not trust a data analysis report like this. Neither should you.

As a city planner making a decision that carries such enormous environmental impact and social responsibility for millions of commuters, residents and visitors from all over the world, please take careful considerations of the situation. Please do not be misguided by some unprofessional ways to conceal and manipulate data in order to blind people’s views.

The odor source is where you find the peak value in measurements of an odor substance that is over an odor irritation threshold. Undoubtedly the Newby landfill is a source of offensive odor in our area. Republic Services repeatedly denies its responsibility. It conceals relevant data. It manipulates data in unprofessional ways to mislead the public and decision makers. It makes irresponsible generalizations. It is a disgrace to the Silicon Valley. It is a neighbor we would rather not have. Please make the right decision and do not let the Newby landfill expand to new heights.

Please reject the PD zoning permit.

R. C.
Ph.D. Statistics
Milpitas Resident


Data samples from Inactive landfill:


Data from natural sources and the questioned landfill average:


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