What is Hexavalent Chromium?


Image from https://www.hrwc.org/our-watershed/. Image edited by Chuck Colby to show the locations of Tribar Technologies and Wixom Water Treatment facility in retrospect to Norton Creek, the location of the chemical dump, and the current affected area.

By Michelle Colby, STN Reporter

"Those that fail to learn from history, are doomed to repeat it,” ~Winston Churchill. History is repeating itself. Think Industrial Revolution. Think the Great Smog of 1952 (London) and the Deadly Smog of Donora, Pennsylvania. Do you remember, or have you heard of, the days when humans excreted their waste into waterways? Oh yeah...that was WAY back in the day. There are farmers that I have spoken with that remember their childhood days of people defecating in the Huron River! Not too far off. The Industrial Revolution started in the midst of this practice. Hence, the introduction and the “accepted” practice of Industries dumping their “bologna” into water. The Clean Water Act was passed by our United States Congress in 1972. Yet, industries still have the ability to negatively impact our waterways. 

TRIBAR Technologies, Inc. is at it again. They were identified as the source of PFAS contamination to the Huron River System in 2018. Since then, they have installed filters at Adept Plastic Finishing (Wixom Plant 4). On Monday, August 1, at 3:21pm, The Michigan Department of Environment, Great Lakes, and Energy (EGLE) was notified by TRIBAR (Wixom Plant 5) that it had released several thousand gallons of a liquid containing 5% hexavalent chromium to the Wixom Sewage Treatment Facility. The release may have started the previous Saturday morning. Water from the sewer feeds the Wixom wastewater treatment plant. After treatment, the water is discharged to Norton Creek, which flows into the Huron River System.

What is hexavalent chromium? First, let’s explore chromium (symbol Cr and atomic number 24). It is an abundant metallic element that naturally occurs in the Earth’s crust, rocks, animals, plants, soil, along with volcanic dust and gases. It is a hard, shiny (think chrome), steel-gray, and brittle transition metal that is valued for its high corrosion resistance, hardness, and lustrous polishing qualities. 

Image from https://periodictable.vom/Elements/024/index.html

 Chromium is considered an essential trace mineral that we can get from consuming broccoli, liver, and brewers’ yeast. Being a transition metal means that chromium can come in different forms/compounds. The 2 most common forms are chromium (III) (trivalent) and chromium (VI) (hexavalent). Both are a form of chromium, but they behave differently.

According to enviroforensics.com, Trivalent chromium has relatively low toxicity, low solubility, and low mobility in the environment. By contrast, hexavalent chromium is toxic, has a higher solubility and greater mobility in the environment. Hexavalent chromium has historically been used in chrome plating operations because it is less costly than plating with trivalent chromium.

Products manufactured at TRIBAR Technologies, Inc. Photo from https://tribar.com/products/

Hexavalent chromium compounds are commonly used in electroplating, stainless steel production, leather tanning, textile manufacturing, and wood preservation. 

Hexavalent chromium is a known human cancer-causing poison. Exposure can occur through breathing it in, ingesting it from food or water, and direct contact with the skin. Some of the adverse health effects include nasal and sinus cancers, kidney and liver damage, nasal and skin irritation and ulceration, along with eye irritation and damage.

Have you watched the movie Erin Brockovich? The 2000 biographical legal drama is about a multi-billion dollar industry with corrupt practices. There is a lot of information about hexavalent chromium, as well. The ground water in Hinkley, California, was affected. A fact found by an “uneducated” person who had a passion for humans and the environment. Thus, she became an academic, a consumer advocate, and an environmental activist. She mentioned in an interview that the movie was 98% accurate. 

What can we do to prevent exposure? We will be dependent on EGLE and our local cities to remain transparent, and to also test for the presence of hexavalent chromium in our areas. Water, air, and soil can be affected. If anybody finds that their water has hexavalent chromium, reverse osmosis systems remove that poison, along with several other pollutants. But, it is not a concern right now.

Can hexavalent chromium be remediated? According to enviroforensics.com, Since hexavalent chromium is an element that cannot be destroyed, it has to either be physically removed by excavating soil or pumping and treating groundwater or transformed to the less toxic trivalent form and stabilized within the subsurface environment by forming insoluble and immobile trivalent hydroxide precipitates and iron and sulfide complex co-precipitates. Luckily, this transformation can be performed using many of the same injectable chemicals that are used at chlorinated sites for in-situ chemical reduction (ISCR) and enhanced reductive dechlorination (ERD).

Ok, back to the story. Here is what we know so far. TRIBAR Technologies, Inc. released thousands of gallons of a liquid, containing 5% hexavalent chromium, into the Wixom sewer system over a period of 2-3 days! Unfortunately, the treated water does make its way to the Huron River System. “This is a significant release into a large, much-loved waterway,” said Liesl Clark, EGLE Director, “Our teams are in the field now assessing the situation. We will stay on the job as long as it takes to ensure residents are safe and impacts to the ecosystem are minimized.” 

The infraction was reported on Monday, 8/1/22. EGLE personnel began testing the waterway on Tuesday. As of Thursday, over a span of 42 river miles (the Huron River is 130 miles), 69 samples have been collected and tested. 3 detections of hexavalent chromium have been discovered, located in Milford’s Hubbell Pond and in the middle of Kent Lake.*

On Thursday, officials took samples from the Wixom Wastewater Plant. Let’s all hope that the sludge that remains has captured most of this poison. 

Barton Pond is next on the list. This is where the city of Ann Arbor gets their drinking water. This is being done as a necessary precaution and to help with getting baseline data as to when the contaminant may reach that pond. For now, state officials have stressed that there is no immediate threat to drinking water. 

Ann Arbor has the closest water intake. Modeling suggests that the time-of-travel would take the contaminant several weeks or more to make its way to the city’s water intakes. The city of Ann Arbor has been notified and is taking steps to monitor incoming water.

The city of Dexter sent an informative letter to help the residents understand where their water comes from. That letter is included in this issue, in an earlier article.

Officials have assured that properly constructed and permitted drinking water wells should be safe. Surface water does not tend to directly influence these structures. This type of release also does not tend to affect the groundwater. However, it is important to know that if you use unpermitted driven sand points and submerged irrigation pumps, you are at risk.

The Michigan Department of Health and Human Services (MDHHS) has recommended that people and pets avoid contact with the Huron River System between North Wixom Road, in Oakland County, and Kensington Road, in Livingston County. Norton Creek, Hubbell Pond, and Kent Lake are included. For this area:

Don’t swim in, wade in, play in, or drink water directly from the Huron River.

Don’t water your plants or lawn with Huron River water.

Don’t eat fish caught in this section, a PFAS advisory has already been in affect.

“This recommendation is being made to help protect the health and safety of families who live, work and play in the Huron River in the affected area,” said Elizabeth Hertel, MDHHS Director. “As we gather additional information, through sampling, this recommendation may change or be expanded.”

EGLE and MDHHS are preparing for a long road of water testing and public awareness/preparedness. This is necessary to keep up with the progression of this toxin. Until test results come back, it is too difficult to make guesses as to how much and how many will be affected. 

MDHHS has offered a MI Toxic Hotline for questions regarding the potential health effects and/or exposures at 800-648-6942 (Monday-Friday: 8am-5pm). 

In the meantime, can we allow ourselves to be more conscientious about how we treat our water-side properties and waterways when we use them? This is about us, too. The big industries and their accidents are concerning, but all of the fertilization and pet waste causes toxic algae blooms, which are also dangerous to wildlife, humans, and pets. The Huron River System is vulnerable to all of the actions that we all take. 

*The state’s chronic aquatic life value is 11 parts per billion (ppb) of hexavalent chromium – designed to protect organisms from long-term exposure harm. Its Acute Aquatic Life Value is 16 ppb, designed to protect from short-term exposures. The samples at Hubbell Pond registered 11 ppb at the surface, and 9 ppb near the bottom. The Kent Lake sample, at between 6 and 12 inches deep, registered 5 ppb. The limit at which testing is not able to detect the chemical is 5 ppb.

Image from https://www.hrwc.org/our-watershed/. Image edited by Michelle Colby to show direction of flow of the Huron River. The Huron River System starts from Big Lake (green star), near Pontiac. Roughly 1200 miles of creeks and streams flow into the system. Everything that occurs in the Huron River Watershed will affect the river system, for this serves as the fundamental and inseparable connection between water and land. The Huron River Watershed spans more than 900 square miles. Because it empties into Lake Erie, it is also part of the Lake Erie and Great Lakes Watersheds.

Information about hexavalent chromium was obtained here: https://www.niehs.nih.gov/health/topics/agents/hex-chromium/index.cfm https://www.enviroforensics.com/blog/how-do-you-remediate-hexavalent-chromium-crvi/  https://periodictable.com/Elements/024/index.html

Information in this article was mostly obtained via press releases obtained here: https://www.michigan.gov/egle/newsroom/press-releases 

Information on Erin Brockovich was obtained here: https://www.brockovich.com

Information about the Huron River System and the Huron River Watershed were obtained here: https://www.hrwc.org 

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