Established in 1925, Chas. H. Sells is an engineering and design firm that serves clients throughout the United States. It maintains a staff of engineers, landscape designers and technicians. The firm provides planning and construction services for clients in the public and private sectors. Chas. H. Sells undertakes various construction projects for bridges, highways, roads and railroads. It offers landscape architecture, inspection and transportation services. In addition, the firm provides stormwater management, drainage analysis and hydraulic design services. Its landfill services include land surveying and erosion control. The company is a subsidiary of the WSP Group. Chas. H. Sells maintains one of its locations in Briarcliff Manor, N.Y.