Born as the youngest of the five children to farmers Jan and Berta (maiden name: Hebel), between 1914 and 1921 he attended elementary school in Mirachowo (first in German, later in the Polish language).

Along with Labuda and A. Stoltmann, Trepczyk organized a teachers' conference in Kartuzy which culminated in the establishment of the regional Association of the Kashubians.

In 1930, Trepczyk married Jan Rompski's sister Aniela, with whom he fathered Bogusława, Mirosława, Damroka, Sława, Świętopełek, and Mestwin.

In 1934, Trepczyk was ordered to move to Rogoźno and a year later, to Tłukawy in Wielkopolska, as a result of the Polish government's attempt to weaken the local Kashubian establishment accused of separatist tendencies.

Following his post-World War II return to Kashubia Trepczyk supported local cultural and social affairs.

Finding for it a suitable downtown location, he expanded its engagement to include drama, music, lectures, and exhibitions.

He asked to be relieved from his position at the Kashubian-Pomeranian Association in 1961, following the accusations of holding separatist sentiments and sympathizing with German revisionists.

Consequently, the organization he helped to establish, issued him a formal reprimand, thus temporarily crippling his cultural and artistic endeavors.

He commenced with a volume of poems Mòja stegna (1970) followed by two song collections based on the work of a Lębork-native musician, Juliusz Mowiński, entitled Rodnô Zemia (1974).

However, his main accomplishment of this period was a substantial volume of poetry titled "Òdecknieni", published in 1977 and consisting of more than 80 poems.

In 1979, the author was honored by the publication of Pasja twórczego życia, dedicated to Marian Mokwa and Aleksander Labuda.

He conducted various choruses, often performing solo or in small groups with his wife, daughter Zofia, and son-in-law, Edmund Kamiński.

In 2008, his biography was released in "Feliks Marszalkowski i inni Zrzeszincy a rozwój jezyka oraz literatury kaszubskiej."

At the same time an anthology was released, titled "Jubileusz Ogólnopolskich Festiwali Piesni o Morzu w Wejherowie (1966-2008)", summing the songs performed at various festivals with the sea theme.

He has made important contributions to the revival of Kashubian as a written language, and greatly influenced the cultural milieu in Kashubia.