Frequently Asked Questions About Sugar Factory Odors
This web page answers some of the most common questions regarding odor from our operations. We welcome any comment or question you may have.
The sugarbeet industry has a reputation for creating occasional odors in the communities where factories and storage facilities are located. This is the case not only in the Red River Valley, but other sugarbeet producing areas in the United States as well. Usually, odor issues occur in the spring and summer as we are completing the processing of sugarbeets and treating the water in our holding ponds. We apologize for any unpleasantness this may cause.
What causes odors at sugar beet factories?
In general, seasonal odors are associated with the decay of organic material. Beets are perishable vegetables and can be subject to decay. Odors from American Crystal operations come from three primary sources: deteriorating beets in storage, beet processing, and industrial water ponds. The magnitude of the odors can be impacted by weather, wind direction, atmospheric conditions, and storage conditions.
Why do odors start in the spring?
Similar to refrigeration, the normally cold Red River Valley winter climate assists with the preservation of the beets. When temperatures rise in the spring, the beets are vulnerable to degradation. This degradation results in premature 'juicing' of the beets which generates a high organic content liquid. This liquid is collected and stored in a number of large ponds for treatment. These ponds are also used to store industrial water from beet processing. As long as the ponds are covered with ice, there is minimal odor risk. However, when the ice starts to melt in the spring and the pond surface opens, odors may begin to generate. In most years, this starts approximately mid-May. However, warmer or cooler spring temperatures my advance or delay odor development.
Why do I sometimes smell odors and sometimes do not?
Weather conditions influence the migration and concentration of odors. As a result, weather represents the major cause of intermittent odor issues. Wind direction is an obvious weather consideration. Another is temperature inversions - when a warm evening is followed by a cool, still morning, odors can get trapped in the lower atmosphere and concentrated in a small areas.
How does weather affect beet storage?
As mentioned earlier, cold winter weather is beneficial for beet preservation. Several weeks of very cold weather - below zero degrees Fahrenheit - are needed to freeze the beets for storage through the winter until processing time in the spring. Early warm weather or a series of freeze/thaw cycles can cause beet piles to deteriorate prematurely, resulting in a strong fermentation odor. Weather also plays an important role during harvest. If beets have been damaged by frost during harvest, they do not store well in piles and begin to deteriorate quickly.
What happens when the beets deteriorate?
Beets in poor conditions start to 'juice', creating a large amount of high organic content liquid. The organic material in the liquid decays, resulting in increased levels of odor. Also, rain can flush the juice from deteriorating beet piles into storm water ponds, contributing to the odor.
What has American Crystal done to minimize odors from sugarbeet storage and processing?
American Crystal has recently completed a variety of odor reduction activities. Significant effort has been placed toward source identification and reduction, resulting in infrastructure additions, operational changes, improved management practices, and others.
- Approximately half of the ponds that were odor sources have been eliminated.
- Remaining odor risk ponds are covered, either with membranes or 8" to 12" straw mats that act as odor bio-filters.
- Odor neutralizing systems have been installed.
- Treatment capacity has been increased.
- Management practices relating to collection and land application of 'juice' from pile stations have been improved.
- Beets that are deteriorating significantly are removed to farms and tilled into the soil.
- High organic material stockpiles are managed by quickly removing the material from factory locations.
- Improved storage techniques involving beet pile covers, enclosures, insulation, artificial cooling, and others assist with limiting deterioration.
What is American Crystal doing about future improvements?
The improvements listed above have resulted in a significant reduction in odor generation. Although we have increased our odor risk profile, we recognize that additional opportunities remain. Many initiatives are underway to identify and mitigate odor sources from factory and pile locations. These include conducting research on the specific substances that cause odors in our ponds, storage piles, and operations. In addition, we are collecting pertinent data and information from the improvements that have been made thus far. This information will be used to continue the trend of odor reduction.
Can the odors be completely eliminated?
Unfortunately, the answer is no. Sugar beets are 70 percent water, and will always generate some strong organic liquid that needs to be stored prior to treatment. Weather conditions also have a major impact on the ponds and stored beets. That means odors will occur from time to time in spite our efforts, and we truly regret any inconvenience this may cause.
Are any health hazards associated with the odors?
Based on current knowledge, the chemicals causing odors do not have a serious impact on health at the levels experienced in neighborhoods close to American Crystal plants. One of the chemicals, hydrogen sulfide, gives off a "rotten egg" smell. We are currently working with the Minnesota Pollution Control Agency on how best to approach this matter.
What is the outlook for the spring of 2012?
One of the mildest winters and record-breaking warm springs has been beneficial on a number of fronts. However, beet storage is not one of them. Without the typical cold winter weather, freezing of storage piles was not as effective as it has been in previous years. In most years, at the end of March, there would be little concern about pile temperatures. The recent run of unseasonably high temperatures significantly increases the risk of early deterioration of stored beets. Our storage techniques and investments made over recent years are reducing the risk, but we anticipate significant challenges relating to odor generation this spring and into summer.
While each of our factories is working diligently to deploy their odor abatement plans, we are committed to search for additional methods to control odors and reduce their impact on our communities and the environment.