Grenga's appointment to metallurgy professor in 1968 opened the door to many more distinguished women faculty members and students at Georgia Tech.

While she came to Georgia Tech as a postdoctoral fellow in chemistry, Grenga retired a professor and administrator. During her time at Tech, Grenga held several administrative positions on campus, including director in the Office of Graduate Studies and Research.

She was secretary, vice president and then president of the national Society of Women Engineers (SWE) in addition to being longtime faculty advisor for the student chapter of SWE. She also served as professor emeritus in the School of Materials Science and Engineering.

At Georgia Tech, she held the office of president of Sigma Xi and Phi Kappa Phi. She was a recipient of numerous awards, including the prestigious Georgia Tech ANAK Faculty Award and the Georgia Tech Women's Leadership Conference's Women of Distinction Outstanding Faculty Member Award.

Grenga obtained her B.A. in chemistry in 1960 from Shorter College and her Ph.D. in physical chemistry from the University of Virginia in 1967. She was employed by the Food and Drug Administration for a few years until she began her career in academia.

In 2001, Grenga published a book entitled Movies on the Fantail, a compilation of the diary writings of her brother, James Grenga, and other sailors' accounts while aboard the destroyer USS Barr.