ARQ · CIK 1515156
What Arq, Inc. told the SEC could break it.
Arq's disclosures concentrate on a narrow operating base: its revenue leans on a handful of accounts — two customers individually topped 10% (24% and 11%), its top three were about 42% and its top five about 50% — and all of its activated-carbon products come from a single plant, the Red River Plant in Coushatta, Louisiana, so a disruption there would materially hurt the business. Both ends of its market are governed by regulation: demand for its mercury-removal carbon hinges on EPA MATS standards, which the EPA moved to weaken by finalizing repeal of the 2024 MATS amendment in February 2026, while its pricing against low-cost Chinese imports depends on anti-dumping duties and tariffs holding up.
4 self-disclosed vulnerabilities, pulled from its own filings, each in the company’s words, with the source. This is the risk register almost nobody reads.
In its own words
What could break it.
Regulatory & policy
- anti-dumping duties / tariffs on Chinese activated-carbon importsmedium
Arq competes against low-priced Chinese AC imports; if anti-dumping duties and tariffs fail to adequately offset unfairly-traded imports, demand and pricing for Arq's products could suffer.
“The failure of tariffs or duties placed on U.S. imports of Chinese AC to adequately address the impact of low-priced imports from China could have a material adverse effect on the competitiveness and financial performance of our business.”
SEC filing →As of 2026 - EPA MATS mercury rule drives AC demand (2024 amendment repealed)medium
Demand for Arq's mercury-removal activated carbon depends on EPA MATS standards; the EPA finalized repeal of the 2024 MATS amendment (Feb 2026) and repealed the GHG endangerment finding, which could reduce demand and coal-unit operation.
“This, and any other action taken by the EPA related to MATS that decreases demand for our products for mercury removal may have a negative effect on our financial results.”
SEC filing →As of 2026
Customer concentration
- top 3 customers = 42% (one at 24%); top 5 = 50%high
Arq's revenue is concentrated: two customers individually exceeded 10% (24% and 11%) in 2025, its top three were ~42% and its top five ~50%; losing any large customer would materially hurt results.
“Revenue from our top three customers comprised approximately 42% of our revenue for the year ended December 31, 2025, and the loss of any of these customers would have a material adverse effect on our operating results.”
SEC filing →As of 2026
Geographic concentration
- Red River Plant is the sole AC manufacturing planthigh
Arq's Red River Plant in Coushatta, Louisiana is its sole manufacturing plant for activated-carbon products; a disruption there would materially affect the business.
“We own and operate the Red River Plant, which is our sole manufacturing plant for producing and selling AC products to our customers.”
SEC filing →As of 2026
The hidden graph
Who it depends on, and who depends on it.
Relationships surfaced from filings, including ones disclosed by the other side, which is how the non-obvious ones come to light.
Its suppliers
North American Coal Company (subsidiary)
“The Five Forks Mine is operated for us by a subsidiary of the North American Coal Company.”
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