There's no need. All of our biological waste (e.g. wood) will provide reliable carbon dates within the range of ~50k years. Radioisotope ratios in our metals and construction materials can be used to date our inorganic ruins on geologic time scales.

Radioisotope dating doesn't work for stone structures like the one described in this article, because it would date the age of the stone, not the structure. But concrete is poured, and steel forged or reforged at or close to its actual use date. So radioisotope ratios in these materials ought to give a reliable dating mechanism on very long timescales.