Daimler Trucks/Odor Nuisance Investigation
Questions and Answers
March 2016
What did DEQ decide about odors from Daimler Trucks North America LLC’s facility?
DEQ has completed its final recommendation regarding the nuisance odor investigation of Daimler
Trucks’ North Portland facility. DEQ’s final recommendation suggests that the evidence gathered through
the nuisance odor investigation of Daimler Trucks North America’s North Portland facility from October
2014 through October 2015 is sufficient to document that during the time of DEQ’s investigation the
facility was not causing a nuisance odor under Oregon law.
What was the evidence DEQ used to make this recommendation?
During the nuisance odor investigation of Daimler Trucks from Oct. 8, 2014 to Oct. 1, 2015, DEQ staff
evaluated odors at eight to ten locations on 80 days and detected an odor on 24 out of 760 individual
attempts to detect an odor. This is a detection rate of 3.2 percent.
What are the next steps in coming to a final decision?
As specified in the nuisance odor strategy, the DEQ Nuisance Odor Panel has received the
recommendation by DEQ staff that did the odor investigation. The panel consists of five DEQ executive
managers. They are in the process of reviewing the recommendation and expect to make a decision the
week of April 11, 2016. Once the decision is final, DEQ will release its decision publicly and be available
to answer questions on an as needed basis. DEQ will update the Daimler Trucks North America LLC web
page at http://www.deq.state.or.us/nwr/DaimlerTrucks.htm.
Will there be any type of public process associated with the final decision?
No. As part of how the nuisance odor strategy is structured, DEQ retains exclusive control of the decision.
What is DEQ’s nuisance odor strategy?
Oregon regulations prohibit businesses from emitting odors which cause a nuisance. DEQ is responsible
for implementing those regulations and developed a strategy for responding to odor complaints. The
strategy emphasizes recording odor complaints, voluntary cooperation from businesses and rapid
resolution of nuisance conditions related to odors and potential DEQ enforcement. For more information
go to the DEQ Nuisance Odor Strategy web page: https://www.oregon.gov/deq/Pages/NuisanceStrategy.aspx.
How does DEQ use odor data in its nuisance odor investigation to conclude that a facility
or source is causing a nuisance odor under Oregon law?
DEQ evaluates all available evidence collected in the course of its investigation. That evidence includes
odor frequency, intensity, duration and offensiveness, among other factors. Oregon law has not
established specific or objective criteria defining when the quality or quantity of the evidence must lead to
a finding that a nuisance odor does or does not exist. Instead, Oregon law requires DEQ to consider all
factors together at once in their totality, on a case by case basis, when determining whether or not a
nuisance odor exists.
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How did DEQ use odor complaint information in the odor investigation?
To determine the most effective investigation time, DEQ staff reviewed citizen complaints from the
previous month, which indicated times odors are most likely to occur. Staff averaged the complaint times
and established an investigation schedule for the next two to three weeks. Staff recalculated and averaged
complaint times at least monthly, and to the extent possible, investigated at the times that the odor was
most likely to occur. During the investigation period, the average time difference between odor
occurrences and investigations was one hour and 42 minutes.
Is DEQ still receiving odor complaints about Daimler Trucks?
Since concluding the nuisance investigation on Swan Island, DEQ has received citizen complaints
regarding paint odors coming from Daimler Trucks North America, L.L.C. From Nov. 1, 2015 to
March 23, 2016 DEQ received 67 odor complaints pertaining to paint odors. Of the 67 complaints, 26
were filed from separate individuals at separate addresses. There was a one month (February 2016)
increase in complaints filed with DEQ, with 34 paint odor complaints filed from 17 different individuals.
What actions has Daimler Trucks North America, L.L.C taken to control air emissions?
Daimler Trucks North America, L.L.C. provided a statement to DEQ identifying the following plant site
changes implemented to address and reduce odors. Daimler Trucks North America, L.L.C. indicated the
following process and equipment changes made to the facility to reduce nuisance odors.
 In 2012/2013, Daimler implemented its own neighborhood odor assessment program. This was a
rigorous sampling regime of two times per day, five days a week for one full year to try to
understand the nature of the odor complained about. Daimler ultimately collected 558 air samples
that were analyzed for a broad range of volatile organic compounds (VOCs) and 24 samples that
were analyzed for a broad range of sulfur compounds.
 In April 2012, Daimler reformulated its coating equipment cleaning solvent to replace n-Butanol
with isopropyl alcohol. N-Butanol had been identified as a solvent with a high odor potential.
 In June 2012, the Daimler sampling identified 1-methoxy 2-propyl acetate as a potential cause of
nuisance odor in the neighborhood. This chemical was used in Daimler’s clear coat at the time.
 In September 2012, Daimler reformulated its clear coat to significantly reduce the amount of 1methoxy 2-propyl acetate.
 In June 2013, Daimler changed its chassis paint reducing VOC by 12 percent and reducing odor
risk.
 In July 2013, Daimler changed its primer to a 100 percent hazardous air pollutant-free
formulation.
 In November 2015, Daimler converted to a low VOC solvent.
 In December 2015, Daimler converted the chassis booth to high volume low pressure application
equipment to optimize transfer efficiency and reduce emissions.
 In December 2015, Daimler upgraded its coating system so that two lines are employed - one
dedicated to black and one to the other color.
How does DEQ know if Daimler Trucks North America LLC has implemented the items in
their statement to DEQ?
Daimler maintains records of the volatile organic compound (VOC) and hazardous air pollutant (HAP)
content of each coating used at the facility along with the amount of coatings used and the amount per
truck. The company maintains all of these records on site which must be available for DEQ inspection.
The company’s annual reports to DEQ include the quantity of coatings used per truck, the number of
trucks, and the VOC and HAP content of those coatings.
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Daimler is required to meet specific VOC and HAP limits, but is not required to reformulate compliant
coatings, so reporting of those activities is not required by the permit or rules. Annual reports will indicate
reformulations that result in changes to VOC or HAP content of coatings.
How did results from the North Portland Air Quality Monitoring Project help with the odor
investigation?
With funding from the Oregon legislature, DEQ conducted air toxics monitoring in the Swan Island area
of North Portland from November 2014 through October 2015. The project included eight meteorology
stations that provided information about temperature, wind direction and speed to track weather
conditions associated with elevated air pollution. The monitoring showed that low wind speeds and south,
southeast, and westerly air flow conditions at Swan Island near the bluff are conducive to air movement
from Swan Island into the neighborhoods on the bluff. DEQ used this wind direction information to help
decide where to investigate odors in the neighborhoods.
What was the goal of the monitoring?
By collecting and analyzing additional monitoring and meteorology data, DEQ will gain a better
understanding of air toxics sources, exposures and risks associated with those exposures. The data can
help determine what emission reduction options might be necessary to mitigate risks from exposure to
toxic pollutants in the area.
When will DEQ release the air toxics analysis from the North Portland Air Monitoring
project?
DEQ is currently analyzing the data and expects to provide updated information by May 13.
For more information:
Keith Johnson, 503-229-6431
Louis Bivins, 503-229-6333
For North Portland Air Monitoring project:
Anthony Barnack, 503-229-5713
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