Through land application of waste, anaerobic digesters in ag have re-created a dead zone in Lake Michigan that had been mostly gotten rid of through the Clean Water Act in the early 1970’s. Ag digesters in Iowa are adding more ag pollution to Iowa’s already number one ranked contributor of ag pollution to the dead zone in the Gulf of Mexico. There have been leaks, explosions, fires, people injured, and a death recently in Iowa ag digesters.
We are here today because the ag digester industry is justifying, in part, digester use in ag by using the fact that the wastewater industry has used anaerobic digesters for years with success. That assumes that digesters in ag are the same as digesters in wastewater. They are not and I will list for you today the many ways that they are not. This presentation should be useful for you if you ever get involved in a conversation about this issue. We do not create dead zones as ag does, we do not increase our pollution yearly as ag does, and we do have regulations, which ag doesn’t, that protect workers, the public, urban and rural neighborhoods, and the larger environment. The wastewater industry is not an unregulated, technically uneducated, and unlicensed industry, and should not be associated with that kind of industry. Ag has adopted wastewater digesters, but they have not adopted the regulations, education, and protections for the workers, the public, and the environment that wwtp digesters have matured with.
The easiest way to show you the differences is to discuss some recent incidents that have involved ag digesters in Iowa. I will discuss the incidents, from least harmful to most harmful, and then compare what, why, and how these incidents would have been different, or never happened, if they happened in a wastewater treatment plant.
A Colorado company built an ag digester in Western Iowa a couple years ago. Shortly after start up, it was reported that the digester had leaked 376,000 gallons of manure into waters of the state. For some reason the DNR would not let their head ag engineer go and find out what caused the leak. At your wwtp, you would not have filled a digester being constructed before you submitted a construction certification form, or a similar form, noting that the construction had been done correctly. The ag digester construction company didn’t check the construction first to make sure all construction was done correctly, and didn’t send in the required certification form to the DNR before they pumped manure into the digester. The digester then had a leak of 376,000 gallons because of faulty construction. After the leak the digester construction company corrected the construction and paid a fine of $10,000 to the state. This would not have happened at your wastewater treatment plant during construction. Ag digesters and wwtp digesters are not treated the same.
There was a rumor that there had been an explosion and a fire at an Iowa ag digester. I called the State Fire Marshall’s office and asked about that. The answer I got was the State Fire Marshall’s office had not heard anything about an explosion and a fire. A journalist, with the help of locals, did an investigation and found that there had been a methane explosion and a fire with two workers being injured. If that would have happened at your wwtp, you would have had the DNR and OSHA doing an immediate investigation into the explosion, the fire, and the injuries to the workers. Again, a report, a demand to fix the reason for the incident happening, and probably a fine would have been issued by the DNR and OSHA. None of that happened for the same reasons I mentioned in the leak incident. No DNR or OSHA regulatory oversight happens with ag digesters.
At a SE Iowa digester, a diver was contracted to fix a problem that was occurring in the digester. Because there are no regulations, and their education components, the diver did not know what he was getting into. There was no Standard Operating Procedure that he could work off of, and he was told that the temperature would be 99 to 105 degrees. When he went into the digester liquid, he radioed to his girlfriend who was helping him, that he was having trouble and taking his helmet off. She started pulling on the air lines, this was a hard hat diver, there was not a safety line or safety equipment, and all that came up was his helmet. They brought in 3 professional divers from Chicago to retrieve the body. They found that the temperature was 120 degrees and not the 105 that he was told. They had to add 100,000 gallons of water to cool the liquid down and get rid of the foam before they could go in and get his body. From the Cedar Rapids Gazette article, ‘Frank Frosolone, owner of the company that recovered the body, said it did not appear Baenziger had on the proper gear for a dive into liquids contaminated with manure and food waste. “It’s a contaminated dive, so we had to use specialized suits with double seals and triple backup air supply and communications. You got to have the right stuff,” he said. Frosolone said he did not believe Baenziger was using protective equipment, such as a harness or a backup air source. “He didn’t have any of that stuff,” he said.’ The local law enforcement said that because there was no OSHA regulatory department involved there would be no investigation of what happened. And, the death was simply ruled an accident.
For many reasons, this probably would not have happened at a wwtp. If this happened at a wwtp, DNR and OSHA would have been involved doing an investigation, a report on what went wrong, a demand that problems be fixed, and a fine. The ag industry cannot say that ag and wwtp digesters are the same when ag digesters have none of the regulations protecting workers, the public, and the environment. And have no education of workers that is required to be a licensed wwtp operator.
Iowa is the major contributor of ag pollution creating the dead zone in the Gulf of Mexico. The first attempt at lowering that ag pollution was the Iowa Plan, a forerunner by five years of the Iowa Nutrient Reduction Strategy. Since the introduction of those voluntary to ag plans, Iowa’s agricultural pollution has doubled. As part of the INRS, wastewater treatment plants were given more strict discharge limits that we had to meet which lowered out pollution contribution. Because most existing dairies have to expand their herds to meet the amount of waste needed for ag digesters to operate efficiently, each ag digester adds to this already doubled pollution going into our surface and ground waters when ag waste is land applied. By expanding herds, ag digesters will add to the already record ag pollution. Because of the stricter limits, wwtp digesters lower the pollution that wwtp’s discharge. In fact, to meet the stricter limits on wwtp’s discharge permits, many plants are going away from anaerobic digesters to aerobic digesters, and/or going to tertiary treatment. The ag industry does not use either of those technologies.
15 to 20 years ago the percentage of pollution added to Iowa’s waters was 92% from ag, 4% from wastewater, and 4% from others (parking lots, roads, lawns, golf courses, cities, etc.). Because ag’s contribution has doubled during that time, and because wastewater’s contribution is smaller due to stricter discharge limits, the percentages today are approximately 96.5% from ag, 1.5% from wastewater, and 2% from others.
More differences:
1. Feedstock. Your sewer systems hold and transport human waste to your treatment systems. In that sewer system, do you leave the tops of manhole covers off manholes, put blowers down into those manholes and blow all the sewer gasses up into your city neighborhoods? I’m pretty sure that is against both federal and state regulations. And, your city wouldn’t allow it anyway.
Most ag digester waste comes from pigs and dairy cows. That waste comes from confinements with either pits below slatted floors, or lagoons and tanks outside storing that waste. In order to keep the pigs, dairy cows, and workers alive and healthy, all those sewer gasses, and other pollutants, created in the confinements are constantly, 24/7/365, blown out of the confinements into rural neighborhoods and the larger environment. Those pollutants – hydrogen-sulfide – ammonia – methane – particulates – antibiotic resistant organisms – VOC’s – harm the human central nervous system, the digestive system, the respiratory system, eyes and skin, and as we know, hydrogen-sulfide will kill you. Our lawsuit asking the DNR to regulate the air pollution coming from confinements had 867 peer-reviewed journal studies showing the harm that pollution causes. A rural school that two of my granddaughters went to was part of a study focused on asthma and children based on proximity to confinements. Ammonia can cause asthma. That school had hog confinements upwind of it. In that school, the students’ rate of asthma was almost four times the state’s average rate of asthma.
The difference is we don’t blow sewer gasses into our neighborhoods. In ag, you cannot regulate confinement air pollution. The DNR has no regulations for confinement air pollution, as I know from suing them. And in Iowa, OSHA cannot regulate agriculture, so rural neighborhoods, by law, must endure this health harming pollution, where city neighborhoods don’t.
2. WWTP digesters are part of a multi-step treatment process. Do any of you use digesters as the only technology in your wastewater treatment system? In wastewater, digesters are only one part of a multi-step treatment process. Anaerobic digesters are a stand-alone technology in agriculture. There is little difference between the pollution kinds and amounts that go into an ag digester, and what is land applied after being in the digester. WWTP’s treat waste to limits that result in our discharges being cleaner than the existing ag pollution in the streams and rivers that we discharge into. Many operators who fish will fish below the discharge pipe as that area of rivers and streams are the cleanest areas of rivers and streams as we have seen from the percentages of contributing pollution. So the difference in digester use is multi-step treatment at wwtp’s, versus one step stand alone digester technology in ag.
3. Wastewater treatment plants and their digesters are run by licensed, think education levels, operators who need to pass tests in order to attain different levels of licenses, and need to attend CEU classes to keep their licenses up to date. There is no requirement to have licensed operators running ag digesters. I know that for a fact as I was on the DNR TAC committee (when they still had TAC committees) that was writing regulations for ag digesters. When the Iowa Legislature found out we were writing those regs, they passed Senate File 534 in 2019 that said the DNR couldn’t regulate agricultural digesters, and the committee was disbanded.
4. Wastewater operators have to follow federal OSHA occupational safety and health regulations. OSHA cannot, by law, regulate agriculture in Iowa. So there are no federal or state regulations that would protect workers and people who live, work, or go to school in proximity to ag digesters.
5. OSHA considers digesters a “confined space”. Confined spaces are the most dangerous places in the treatment process. Confined spaces protection does not exist in ag because confined spaces, because of no regulations, do not exist in ag.
6. Hazardous wastes exist in wastewater treatment plants and have to be dealt with carefully. In ag, there are no hazardous waste designations. My first contribution to the DNR TAC committee writing digester regulations was mentioning that even though the draft regulations said that no hazardous waste was to be allowed in these ag digesters, hog confinement and dairy confinement waste, major waste streams for these digesters, fit Iowa’s definition of hazardous waste to a “T”.
Iowa Code 455B.411 subsection 3:
3.
a. “Hazardous waste” means a waste or combination of wastes that, because of its quantity, concentration, biological degradation, leaching from precipitation, or physical, chemical, or infectious characteristics, has either of the following effects:
(1) Causes, or significantly contributes to an increase in mortality or an increase in serious irreversible, or incapacitating reversible, illness.
(2) Poses a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of, or otherwise managed. “Hazardous waste” may include but is not limited to wastes that are toxic, corrosive or flammable or irritants, strong sensitizers or explosives.
The gasses hydrogen-sulfide and ammonia, the green house and explosive gas methane (which is what ag digesters are after), antibiotic-resistant organisms, particulates, and toxic VOC’s are cooked up during anaerobic digestion in hog and dairy confinements and are contained in that confinement waste. This pollution is blown or vented out of hog and dairy confinements 24/7/365 so the pigs and cows inside won’t die.
High concentrations of hydrogen-sulfide can cause respiratory paralysis and may cause coma after a single breath and may be rapidly fatal. Also convulsions, acute conjunctivitis with pain, lacrimation, and photophobia; rhinitis, pharyngitis, bronchitis, and pneumonitis among others are mentioned. Ammonia vapor is a severe irritant of the eyes, especially the cornea, the respiratory tract, and skin. Also mentioned are dyspnea, bronchospasm, chest pain and pulmonary edema which may be fatal; bronchitis, pneumonia, and asthma are also problems. There can be health problems when people are colonized by antibiotic-resistant organisms such as MRSA. There are respiratory problems from particulates. And the 100 or so toxic VOC’s also are harmful to human health. These fit the Iowa hazardous waste definition.
These health problems, and deaths, of Iowans from hog and dairy confinement waste should give you serious pause because hog and dairy confinement waste is the major feedstock of these ag digesters. Similar to other bandaids for industrial ag like CO2 pipelines, edge of field practices, and ethanol, ag digesters used this way are a bandaid that tries to give industrial hog and dairy confinements relevance, but actually enable those confinements to continue polluting no matter the inherent ongoing human health and environmental problems that exist by using them.
When I made the DNR Chair of the committee aware of this hazardous waste problem, his answer to me was that the feds and the state say that because this is ag, this waste cannot be described as hazardous. I quote: “The Code citation is a legislative decision and matches the federal exclusion. I don’t believe Iowa DNR can do anything contrary to the state and federal statutes.”
So something that is known to be a hazardous waste is not a hazardous waste in ag just because the feds and the state say it isn’t. Think about that for a second. Are people whose health is affected by these hazardous wastes told they are not really affected? Are Iowa families who have lost family members told that the deaths were not from a hazardous waste? The statement that “this is not really hazardous waste so we don’t protect you from it” is not really a satisfactory response for families who have had members die, and for people who have serious health issues from this waste. Historically, the wastewater industry made relevant changes to its processes when they discovered health problems associated with how we processed our waste.
7. Before you land apply digester waste in the wastewater industry that waste needs to be tested. Because of the law that was passed by the Legislature, the DNR told me that waste from digesters cannot be tested. So we have no idea what is being land applied from digesters in ag.
8. We know we are environmentalists. The Iowa Governor has signed a proclamation each year for the last 15 years honoring the work that we do to keep people and the environment as clean and safe as possible as we can. Ag digester people have said ag digesters are an environmentally positive technology. That is hard to justify when ag digesters enable more hog and dairy confinements. Those digesters and confinements contribute to Iowa’s ever growing ag pollution through air emissions, and through land application of waste. Again, that ag pollution has doubled in the last 20 years.
Dairies and ag digesters, through land application of waste in NE Wisconsin, have recreated a dead zone in the Green Bay of Lake Michigan that was pretty much cleaned up by the Clean Water Act in the early 70’s. Today that dead zone is back with a vengeance. A study showed that some 47% of that dead zone is from phosphorus from confinement dairies and ag digesters land application of their waste. If you add in nitrogen from those sources, it ends up that some 90% of the pollution in the dead zone is from confinement dairies and ag digesters. Hardly an environmental positive.
Ag doesn’t even need digesters to capture methane. I ended my EPA ag digester presentation by identifying an unlimited, and unregulated, source of methane from industrial agriculture which can be accessed without building new digesters or transporting any waste streams.
In our DNR lawsuit asking that the DNR regulate air emissions coming from hog confinements, the judge wrote in the “Order Granting Motion To Dismiss” this: “Section 459.207 is one of many “Air Quality” protections contained in Subchapter II. Section 459.207 expressly addresses the emission of “airborne pollutants,” including the emission of “ammonia” and “hydrogen sulfide,” from “confinement feeding operation structure[s].” And it expressly authorizes the DNR to take various measures to “control” and “reduce” the emission of those pollutants “from animal feeding operations.”
But, in May 2003 the Iowa Legislature repealed the ambient air standards for hydrogen-sulfide and ammonia. So the law exists on the books, but the DNR can’t enforce it. Essentially it is illegal to regulate the air emissions coming out of hog confinements which happens 24/7/365 and includes methane.
Therefore, there is an unlimited, unregulated supply of methane that can be captured at the some 13,000 hog and dairy confinements that exist in Iowa. You don’t have to build new taxpayer subsidized ag digesters. You don’t have to transport any waste. Just put your methane capture equipment on any hog confinement you want.
So I have gone over the differences between ag digesters and wwtp digesters. I hope this will help you explain the differences if you are ever involved in conversations where ag digester people are comparing their use of digesters with our successful use over the years. We should not let them use us to justify their different use of digesters.
This document will be on my website if you want to review or copy it, www.civandinc.com . Just click on the title “2025 IAWEA digester presentation” at the top of the website page.
I’ll leave you with this thought, using anaerobic digesters in ag is a moral and ethical quagmire.
Thank you. Questions and comments?
Bob Watson