South Omaha Cleanup: Brown Park [ 5708 S 15th St], Upland Park [3104 Jefferson St], and Highland Park [2512 D St]
You can also find more locations: https://www.dogis.org/springcleanup/.
To find out more information: http://www.keepomahabeautiful.org/what-we-do/programs/omahaspringcleanup.html, http://omahastem.com/keep-omaha-beautiful-spring-cleanup/.