Sample Improvement Survey An Improvement Survey has the same features as an ILC (Improvement Location Certificate) except: It shows all property corners properly marked and certified to be correct,   It is used to determine boundary lines. See also: Improvement Land Certificate (ILC) ALTA/ACSM Survey   Home | Land Surveys - Questions and Answers | Our Services | Our Experience | Find Us | Contact Us Emerald Mountain Surveys, Inc. PO Box 774812 2851 Riverside Plaza, Suite 7D Steamboat Springs, CO 80477 Phone: 970-879-8998 Fax: 970-871-8009 Email: bear@emeraldmtn.net