Water quality advocates say the state of South Dakota acted prematurely in reporting last week that human health was not at risk from high ammonia releases at the Smithfield Foods plant in Sioux Falls.
The Department of Environment and Natural Resources filed limited public notice before the violations stopped and before the ammonia releases had reached their peak.
A wastewater treatment system failure at Smithfield’s pork processing plant in Sioux Falls last week led to a nearly weeklong release of exceedingly high levels of ammonia into the Big Sioux River. At one point the levels were more than 21 times higher than the daily limit.
State DENR officials issued a statement on the elevated ammonia releases on Friday, saying there would be no risk to humans, though fish in the river could be threatened.
The ammonia releases well over the permitted amount began on Wednesday, Aug. 15 and continued through Monday, Aug. 20. The plant that processes 20,000 hogs per day released more ammonia in a 4-day period than would be allowable in a more than 4-month period.
The highest ammonia release came on Saturday, Aug. 18 when 2,199 pounds of ammonia were released; the single-day limit in the plant’s permit allows 102 pounds of ammonia to be released, and the daily average over a month is capped at 58 pounds per day.
Water quality advocates are angry not only over the high levels of ammonia released in such an extended period of time, but also over the state’s response and limited public announcement about the pollution violations.
The state DENR published a press release on the state website Friday, Aug. 17, noting that Smithfield had an “upset” in its system and that ammonia violations had taken place. The release went on to say that, “levels could pose threats to fish life, but no risks to human health.”
The statement on human health, attributed to DENR Secretary Steven Pirner, was released before the ammonia violations had stopped and before the cause of the problem had been determined. Furthermore, the statement came out the day before the ammonia releases reached their peak the next day. They continued above permit limits for three days after the notice. In the statement, Pirner said that “at this point it appears” that Smithfield was taking appropriate internal steps to solve the problem.
“That’s an inadequate response from the DENR, because they didn’t have the data to make that statement one way or the other and should have erred on the side of human health,” said Dana Loseke, a leader of the Friends of the Big Sioux River advocacy group. “The amount of ammonia that was released, and that they were allowed to continue to release that amount, was obscene.”
Ammonia is a compound of hydrogen and nitrogen that is used in industrial processes and at times in water treatment. In gaseous form, it can cause lung and airway illnesses. It is highly soluble in water and in very high doses can cause neurological and liver problems, according to the National Institutes of Health. Ammonia is likely used in Smithfield’s processes to break down blood from animals processed there.
Kelli Buscher, administrator for the state’s Surface Water Quality Program, said the state took immediate and appropriate action after Smithfield officials reported the high ammonia discharge levels.
Buscher said the state worked with Smithfield to reduce ammonia discharges and sent inspectors to Sioux Falls to take water samples several times daily at four locations including upstream from the plant, just below the plant and further down river. She ordered Smithfield, which is required to test for ammonia levels three times a week, to begin testing daily and to immediately report results to the state.
Though she wasn’t sure what plant officials did internally, she was told the plant reduced flows through its wastewater system to limit ammonia releases.
Buscher said heavy flows in the Big Sioux this time of year helped dilute the ammonia and that the overall safety limit of ammonia in the river was never reached. Buscher said state employees also did not see any dead fish or wildlife during their testing efforts.
“What we were concerned about were the ammonia levels, and the ammonia levels of toxicity is a concern for fish,” Buscher said Wednesday. “In terms of a human health impact, we did not feel based on our experience that it was going to create a human health hazard.”
But according to state data, the overall safe ammonia limit in the Big Sioux was nearly breached during the Smithfield releases. On Saturday, Aug. 18, the allowable ammonia limit for the Big Sioux at 200 feet below the Smithfield plant is 10.13 milligrams per liter, and the level that day reached 7.3 milligrams per liter. On most other days, the limit was not nearly reached, the data show.
Once the ammonia releases became known, and were continuing without a known cause, the state should have required Smithfield to stop discharging wastewater in order to protect the Big Sioux River, people who may have entered the river and communities downstream, said Jay Gilbertson, manager of the East Dakota Water Development District that works to protect water quality in 10 counties including Minnehaha County.
“The fact that fish didn’t immediately go belly up, I wouldn’t necessarily agree with Ms. Buscher that more drastic measures wouldn’t have been appropriate,” Gilbertson said. “The standards are there and they need to be adhered to. The absence of immediate adverse results shouldn’t be a justification for simply ignoring it, especially for the people downstream.”
Smithfield has had a clean inspection record of its wastewater process over the past few years, but has a history of discharge violations including for ammonia. The state fined the plant $44,000 in 2011 for consistent violations of several permit limits, including 26 ammonia release violations in 2010.
Smithfield officials released two brief statements regarding the ammonia releases but refused to answer questions or grant an interview.
“Smithfield takes environmental compliance very seriously and strives for 100 percent compliance, 100 percent of the time,” the company said. “There was no risk to human health and no reports of impact to fish or other area wildlife.”
Buscher said Smithfield will likely face enforcement actions from the state for the ammonia releases. She said the state will take more samples through Thursday and require daily ammonia reports from Smithfield through the end of the week.
Loseke said any fines issued should cover the costs of state inspection efforts and that Smithfield should now be required to test for and report ammonia releases every day.
“They’re dumping 126 days’ worth of ammonia in four days; how can any business leader live with that?” Loseke said. “This cannot continue, this has got to stop, and this is an example of why you have agencies like the DENR that are supposed to stop this."
Excessive ammonia releases from Smithfield Foods
According to its state permit, the allowable amounts of ammonia release from Smithfield are 102 pounds in any single day and a month-long average of 58 pounds per day. During the recent violations, the plant exceeded the daily limit by as many as 21 times on a single day. Ammonia discharge amounts into the Big Sioux River during the system failure were as follows:
- 1,478 pounds, Wed., Aug. 15
- 1,867 pounds, Thur., Aug. 16
- 1,762 pounds, Fri., Aug. 17
- 2,199 pounds, Sat., Aug. 18
- 164 pounds, Sun., Aug. 19
- 122 pounds, Mon., Aug. 20
- 57 pounds, Tues., Aug. 21 (back in compliance)
Source: South Dakota Department of Environment and Natural Resources