Arq is an environmental technology company that makes and sells activated carbon (AC) products used to remove pollutants from air, water, and soil. AC is a highly porous material that adsorbs contaminants, and Arq's products are consumables — customers buy repeatedly as the material is used up in pollution control systems. Arq's two core product forms are Powdered Activated Carbon (PAC), a fine powder injected into flue gas or water streams to capture mercury and other contaminants, and Granular Activated Carbon (GAC), a coarser form used in fixed-bed water filters, particularly relevant for removing PFAS ("forever chemicals") from drinking water. PAC is the established revenue base, while GAC is the growth initiative. Arq's key end markets are coal-fired power generation (utilities inject PAC to comply with EPA mercury standards), municipal water treatment (utilities use PAC and GAC to remove contaminants including PFAS), and industrial applications including cement plants and renewable natural gas producers. Arq sells primarily through a direct sales force under one-to-five year contracts. Arq is vertically integrated — it owns a lignite coal mine in Louisiana that supplies raw material for PAC production, providing cost control and insulation from import tariffs. Arq's GAC growth ambitions have been delayed by design flaws in its new production facility, with no material GAC revenue expected in 2026. Arq also has early-stage, pre-revenue initiatives exploring uses for its proprietary carbon feedstock in asphalt additives and semiconductor materials.