John Allman, head of Trinity School, read the following dedication out loud during the final faculty and staff luncheon of the 2010-2011 academic year: "The year was 1974. Richard Nixon had just become the first President to resign from office. The cost of a gallon of gas was fifty-five cents, and the cost of a year in Trinity’s Kindergarten was $1350. And, after working for five years as a college professor, Walter Ostapiak came to Trinity to teach math in what was then called our Upper Middle division. A few years later, Walter added to his responsibilities the task of serving as the Eighth Grade Form Master, a precursor of our class deans today, and eventually Walter’s teaching responsibilities moved from Middle to Upper School. As his history at Trinity suggests, Walter quickly became known as a teacher who demonstrated a 'total commitment to Trinity' and who 'could be counted on to carry out any extra assignment.' One of his numerous department heads repeatedly described him as a 'mainstay of the department' known for his 'deep concern for students.' Another of his colleagues saw in Walter the essence and embodiment of faculty excellence at Trinity School—'he sets high standards for his students and always does everything he can to help them reach those standards.' As any of his students or colleagues will quickly report when asked about what they appreciate about Mr. O, Walter was also blessed with a distinctive sense of humor that he used to enliven his work with us. A man of mirth, he is also a man of quiet, yet fervent faith, and, in Walter, I suspect that the two are related, for I think he, like Karl Barth, understands in a profound way that 'laughter is the closest thing to the grace of God.' Walter, for thirty-seven years, you have graced us with your humor, your dedication to Trinity, your care for others—students and colleagues—and your total commitment to teaching. We are so grateful for your time with us. Please join me in thanking Mr. O for his thirty-seven years of distinctive service to Trinity School."

Upon his retirement, Walter donated two books to the Trinity School library: Personal Recollections of Joan of Arc by Mark Twain and The Complete C.S. Lewis Signature Classics by C.S. Lewis.

Personal Recollections of Joan of Arc is the story of the fifteenth-century martyred teenage patron saint of France. Twain said of this work: "I like Joan of Arc best of all my books; and it is the best; I know it perfectly well. And besides, it furnished me seven times the pleasure afforded me by any of the others; twelve years of preparation, and two years of writing. The others need no preparation and got none." Twain considered this book—his last finished novel—to be his most significant.

C. S. Lewis was one of the intellectual giants of the 20th century and arguably the most influential Christian writer of his day. His major contributions in literary criticism, children's literature, fantasy literature, and popular theology brought him international renown and acclaim. The Chronicles of Narnia was for decades the world's bestselling fantasy series for children. Although it was eventually superseded by Harry Potter, the series still holds a firm place in children's literature and the culture at large. The Complete C. S. Lewis Signature Classics contains his seven most popular works.

After enjoying his thirty-seventh year of teaching at Trinity School, Walter decided to retire at the end of the 2010-2011 academic year. He is grateful for the many rewarding years he has taught at Trinity, and he will miss the students, fellow teachers, administrators, and staff.