The buyers of Oasis Pet Spa in Castle Rock discovered during pre-purchase due diligence that the property's cast iron sewer service line had multiple bellies and cracked joints. Before the sale could proceed, the line needed to be fully replaced — beneath an active parking lot, with minimal disruption to the surrounding asphalt and no delays to the ownership transfer.

The line ran beneath the parking lot and required excavation down to the building's foundation wall and back to the sanitary main. As depth increased, the team encountered highly unstable, sandy soil that began caving aggressively — a hazard that threatened both crew safety and the structural integrity of the surrounding pavement. The goal was a clean, fully compliant replacement while preserving as much existing asphalt as possible.

CJB's Excavation pulled all required permits with the Town of Castle Rock, submitted traffic control plans, and received approval before mobilizing. Proper shoring was installed immediately upon encountering the unstable soil — protecting both the crew and the adjacent pavement from further undermining. The line was replaced to the main, a new tap installed, and inspection passed. Rather than standard compaction backfill — which would have required workers in an unsafe trench — CJB's Excavation specified CDOT flow-fill, a free-flowing cementitious material that fills every void and self-compacts, eliminating future settlement risk. A two-way cleanout was installed near the building. Once cured, the team saw-cut and patched the asphalt to match the original surface and repainted all parking lot striping.