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Arq turns coal waste and other carbon materials into activated carbon products used to clean water, air, and other industrial streams.
Arq is a specialty materials company that makes activated carbon — a highly porous form of carbon that acts like a sponge at the molecular level, grabbing pollutants and impurities out of water, air, and industrial processes. Its customers are utilities, water treatment plants, and industrial firms that need to strip contaminants like mercury, PFAS "forever chemicals," and other toxins from what they release or what they sell.
The company's twist is where it gets its raw material. Instead of buying virgin carbon, Arq takes coal waste — the fine leftover bits that coal mines and power plants discard — and processes it into a marketable carbon product. That turns an environmental liability into a saleable good, which is both the business idea and the environmental pitch. Its main product line, sold under the Flueguard brand, is used by coal-fired power plants to capture mercury before it leaves the smokestack. It also produces activated carbon for water treatment, and it has been pushing into higher-value markets like removing PFAS from drinking water, where regulations are tightening and demand is growing. The clean-water angle is the growth story here. As governments crack down on PFAS and other contaminants, water utilities need more activated carbon, and Arq is positioning itself as a domestic supplier with a lower-cost, waste-derived feedstock. That matters in a market historically dominated by imports and virgin-carbon producers.
Arq started in 1996 as a holding company in Greenwood Village, Colorado, selling equipment that helped power plants control pollution and emissions. The basic idea was simple: as the world demanded cleaner air, someone had to supply the hardware that made it possible.
In early 2004 the company sold shares to the public and listed on NASDAQ. That gave a young environmental technology business access to outside money to grow with.
In February 2023 the company bought the assets of Arq Limited, a move that flipped it from an industrial manufacturer into an environmental technology company. The prize was a feedstock made from bituminous coal waste and a set of patented products built on it.
A year after the acquisition, the company renamed itself Arq, Inc. and switched its ticker from ADES to ARQ. The new name was meant to signal that this was no longer the old industrial manufacturer but a North American environmental technology company.
In November 2025 the company reported a quarterly loss and admitted its granular activated carbon plant in Corbin, Kentucky was running far below capacity because of design problems. Investors reacted hard, and the stock lost more than a third of its value in a single day.
By March 2026 the full picture came out: a full-year loss of $50 million, and a decision to pause the granular activated carbon project entirely for an engineering review. Management called the plant's design flaws fundamental and said no GAC would be produced in 2026. The stock fell by nearly half in a day.
Rather than keep pouring money into the troubled plant, Arq pointed its growth plans at a new product: PAC for PFAS, a treatment for the hazardous chemicals known as PFAS. The best part was that it was a small extension of its existing powdered activated carbon business, needing little to no new spending on equipment. The clock driving demand was a federal monitoring deadline for PFAS in 2027.
In the third quarter of 2026 Arq posted record revenue of $38.2 million, up 9% from a year earlier, with gross margin jumping from under 29% to nearly 40%. It was the tenth straight quarter of positive adjusted EBITDA, and the company raised the low end of its profit guidance. None of it depended yet on PAC for PFAS, which made the core business and the PFAS opportunity look like the real path forward after the GAC disappointment.
The business is small and has had a bumpy financial history — it has spent years losing money while building out capacity — so it is best understood as a bet on tightening environmental rules meeting a clever supply chain. The company is headquartered in Greenwood Village, Colorado, and trades on Nasdaq.
Saved answer · last researched 6 Nov 2026