Sarnia was already called Chemical Valley before the world ended and reassembled itself into corporate fiefdoms. The petrochemical plants that lined the St. Clair River in the twentieth century have been replaced by something worse: bioprocessing facilities, neural-substrate refineries, and atmospheric reclamation plants that claim to clean the air while producing the chemicals that dirty it. Ouroboros Energy and Cinderfall Energy maintain competing sovereign enclaves here, their territories marked by different-colored warning lights on the stacks — red for Ouroboros, amber for Cinderfall. The rivalry is not a metaphor. Workers have died in jurisdictional gaps between the two.

The Blackpipe Corridor stretches roughly 30 kilometers along the river, a continuous industrial strip where the distinction between 'factory' and 'city' dissolved decades ago. Residential blocks are built in the shadows of processing towers, and the rent is cheap because the air isn't. Atmospheric filtration masks are standard equipment — not augmentation, not fashion, just the baseline cost of breathing here. The population is predominantly Tier 1 and Tier 2 workers bound by employment contracts that would be illegal in any jurisdiction that still enforced labor law. Cancer rates are three times the GLMZ average. The corponations attribute this to 'legacy contamination' from the pre-corporate era, which is technically true and practically a lie.

The river itself is the border. On the other side, Port Huron and the American shore. Between them, automated cargo barges move chemical precursors, refined neural substrates, and sealed containers that nobody asks about. The St. Clair River has been widened, deepened, and reinforced with automated navigation systems — it is less a river now than a liquid highway, and the things it carries are worth more per liter than the water itself. The Aamjiwnaang First Nation territory persists as a sovereign enclave within the Corridor, a legal anomaly that predates corporate sovereignty and that nobody has been able to dissolve despite decades of trying. They monitor the contamination with equipment the corponations don't control, and they publish the results.