Casella Waste Systems is a regional solid waste services company serving the Northeastern and Mid-Atlantic U.S. Casella collects, transfers, and disposes of non-hazardous solid waste from residential, commercial, municipal, and industrial customers across eleven states, with its legacy markets in Vermont, New Hampshire, New York, Massachusetts, Connecticut, and Maine, and more recent expansion into Pennsylvania, Delaware, New Jersey, Maryland, and West Virginia. Collection is the largest part of the business, with commercial and industrial customers on multi-year service agreements and residential customers on municipal contracts. Casella also owns nine landfills and a network of transfer stations, forming a vertically integrated model where collected waste flows through Casella's own disposal infrastructure rather than third-party sites. This "internalization" is the primary driver of profitability — the more waste Casella collects and disposes in its own landfills, the more margin it captures. Beyond collection and disposal, Casella operates ten materials recovery facilities for recycling, a biosolids and organics processing business, and a National Accounts brokerage that serves large multi-site commercial customers. Casella has completed 76 acquisitions since 2018, targeting owner-operated businesses that enter at below-average margins and improve over two to three years as Casella integrates routes and converts rear-load trucks to automated side-loaders. Casella is also actively expanding landfill capacity in New York and developing the McKean Landfill in Pennsylvania as a rail-served disposal site for the broader Northeast.