At approximately 3:15 Saturday afternoon, Station 2 was alerted for a vehicle collision in the 43-11 box on Mount Carmel Road. Truck 2, with a crew of five, was the first unit to arrive and found a van over the embankment in a stream. The lone occupant had self-extricated prior to arrival. Part of the truck’s crew began patient care of the driver while the remainder of the crew checked the vehicle to verify it was in a safe state. According to witnesses, the van drove onto the guard rail, rode on top of it for a distance during which time the engine oil pan and fuel tank were compromised, hit a utility pole, and rolled down the hill into the stream. The driver stated he was not wearing a seatbelt. A medic unit was requested. At the same time, the crew near the vehicle discovered that the van was leaking both engine oil and fuel into the stream. A hazmat response was also requested. Medic 28 arrived and requested a Medevac helicopter for the driver. Utility 2-1 responded to the scene with absorbent booms to help contain the fluids leaking into the stream. Using a roof ladder and salvage cover from Truck 2 and the absorbent booms delivered by U2-1, crews built a dam to contain and absorb the fluids until the Baltimore County Fire Department Hazmat Unit and Maryland Department of the Environment Emergency Response unit arrived. After the Hazmat and MDE teams determined that the hazard had been mitigated, Truck 2 cleared the scene.