Mixed Gasoline and Acid Load at a Rural Intersection
At 02:00 a tank truck carrying 32,000 L of gasoline in three compartments and 20,000 L of a corrosive acidic inorganic liquid (UN 3264) in eight IBCs is struck at a rural intersection. One IBC has toppled and is leaking at an estimated 5 L/min toward a storm drain 8 m away. The driver is uninjured but has no visible placards on the rear; the shipping papers are in the cab. Wind is 2 m/s toward a motel 60 m away. The intersection has no lighting; a bystander is smoking 40 m upwind. The local fire department is 12 minutes away and has foam but no acid suit. The storm drain discharges to a creek 400 m downstream.
1. Establish the initial isolation and identify the primary hazards from both loads.
Read the worked answer
Reasoning: The scene has two different hazard classes that require different protective measures. Gasoline is a flammable liquid with a low flash point and vapors that can travel; the UN 3264 liquid is corrosive and can cause severe tissue damage. The missing rear placards mean responders must rely on the shipping papers, the driver, and the UN numbers rather than assuming the load is benign.
Initial isolation: approach from upwind and uphill; stop the bystander from smoking and move that person away; establish an initial isolation zone of at least 100 m in all directions and consider a larger downwind zone because the motel is 60 m away. Use the current Emergency Response Guidebook for UN 1203 and UN 3264 to refine distances. Deny entry and eliminate ignition sources. Do not touch the leaking IBC. Only responders in SCBA and acid-protective clothing should enter the hot zone; firefighter turnout gear is not acid protection.
Primary hazards: gasoline flammability and vapor accumulation; corrosive acid contact and inhalation; potential contamination of the storm drain and creek; poor lighting and traffic. The two products should be kept separate during containment.
2. What environmental protection actions should be taken before the fire department arrives?
Read the worked answer
Reasoning: The storm drain is 8 m away and the leak is moving toward it, so the first environmental action is to stop the pathway, not to dilute the product. Water spray on gasoline can spread the flammable liquid; water on the acid can also spread contamination.
Actions: place absorbent socks, sand, or earth to divert the acid away from the drain; cover the drain inlet if it can be done safely from outside the hot zone; do not flush the drain. Use compatible containers and a pump rated for the product only if trained personnel are available. Keep gasoline and acid absorbents separate. Notify the downstream water utility, the creek owner, and the environmental regulator; warn the motel. If product has entered the drain, build a containment dike or underflow dam at the creek outfall and deploy booms. Sample the creek and document the plume. The fire department should bring foam for gasoline and acid-compatible protective equipment; the incident commander should be told the drain pathway and the creek distance on arrival.
3. What documentation and notifications are required, and what would you tell the fire department on arrival?
Read the worked answer
Reasoning: A mixed load with a release creates regulatory, contractual, and safety documentation duties. The fire department needs a concise hazard and action brief, not a recital of regulations.
Tell the fire department: products and UN numbers; estimated quantities (32,000 L gasoline, 20,000 L acid); leak rate of about 5 L/min; one toppled IBC; storm drain 8 m away and creek 400 m downstream; wind toward the motel; missing rear placards; no acid suit on scene. Recommend foam for the gasoline, acid-compatible PPE and SCBA for the acid, upwind approach, and drain containment before firefighting water is used.
Documentation: shipping papers, driver statement, photos, placards, UN numbers, quantities, leak estimates, weather, isolation zones, and chain-of-custody for samples. Notify emergency services, the environmental regulator, the sewer/water authority, downstream users, the insurer, and the carrier's emergency number. If the release meets a reportable quantity, follow the applicable reporting rule. Record all notifications with times and names.