The Onondaga Lake Cleanup Corporation (OLCC) was formed in 1990 as a not-for-profit organization to administer the Onondaga Lake Management Conference (OLMC), created by the US Congress; and managed and implemented projects and programs of the OLMC through its transition to the Onondaga Lake Partnership (OLP) in 1999.

Since August 2001, the OLCC operated as an independent not-for-profit institution dedicated to public education, scientific research, and remediation of Onondaga Lake and its surrounding lands.

In August 2006, the OLCC changed its name to the Onondaga Environmental Institute (OEI); and in December 2006, expanded its mission beyond Onondaga Lake.