Topographic surveys are most commonly conducted prior to the design phase of land development or construction projects, installation of septic systems, residential lot grading and development, landscaping projects, swimming pool installation or utility projects. Includes measurement and mapping of locations and elevations of all visible above ground features, structures and utilities and development of elevation contours. Resulting "base" plans or maps are generally compiled using a combination of field data in conjunction with record data and the Pennsylvania One Call System for underground utility plotting.