Arlington Heights reviews December CNG garbage-truck explosion; fire chief urges safer battery disposal and new response rules

Arlington Heights — At a Feb. 18 Arlington Heights Village Board meeting, Fire Chief Lance Harris delivered an internal review of a Dec. 6 incident in which a contracted Groot garbage truck caught fire and exploded, injuring members of the responding public-safety crews but not causing any life-threatening injuries to residents.

Harris told the board the department is treating the presentation as an internal review while Groot’s own investigation remains open, and said the department is sharing lessons learned with the contractor and neighboring departments.

The presentation focused on how CNG (compressed natural gas) systems behave in fire, how pressure-relief devices (PRDs) are intended to operate, the timeline of the December event and immediate operational changes the Village and Groot have agreed to. Harris said the explosion is not ‘‘normal behavior of a CNG storage system during a fire’’ and explained how PRDs are designed to vent upward to prevent catastrophic failure.

The review described CNG as primarily methane, lighter than air and flammable, and noted that odorant (mercaptan) is added to aid leak detection. Harris said Groot has operated CNG vehicles in the community since 2010 and that its Elk Grove fleet includes about 165 vehicles, of which about 15 run on CNG and about 50 run on diesel. He described CNG cylinders as composite-wrapped tanks with pressure-relief devices located in openings along each side of the truck. On the truck involved in December, Harris said, there were five PRD openings per side — ten PRDs total — and that only one PRD needs to operate to vent the entire daisy‑chained system.

Harris reviewed the December timeline and response: the truck had completed a morning route, emptied at the transfer station around noon, returned to Arlington Heights about 1 p.m. for a recycling pickup, and the explosion occurred roughly 4 minutes 10 seconds after first firefighting units arrived on scene. Fire crews attempted to have the driver dump the load (the department trains to have a load dumped to remove the fuel for the fire), but the driver was unable to do so. Harris said crews deployed a hose line and were ‘‘lobbing water’’ into the compactor because direct water on CNG cylinders is not an effective tactic; while crews discussed next steps, the truck exploded.

Harris told the board the department believes ‘‘there’s a very high suspicion that this fire was started because [of] the improper disposal of a lithium‑ion battery in a recycling bin’’ and noted that thermal runaway in such batteries can produce temperatures near 750°F, which would rapidly fuel and intensify a compactor/load fire. He also said the department had not observed PRDs operating at the scene and that the cylinders are designed to withstand fire for roughly 8–10 minutes before failing if not vented.

Taking lessons from the incident, the Village and Groot have agreed to operational changes Harris said include: instructing drivers to dump the load immediately if a fire is detected rather than attempting to compact it; training drivers to explicitly notify dispatch that they are driving a CNG truck when reporting a fire; Northwest Central Dispatch asking callers whether a truck is a CNG vehicle and whether the load has been dumped; and tactical changes for responders including establishing a 300‑foot evacuation radius for large compactor fires, setting a command post with police coordination, deploying the police drone to observe venting, and positioning hose lines to protect structures rather than attacking the cylinders. Harris said the department will ‘‘let the truck burn’’ when the CNG cylinders are involved unless it is clearly a smoldering load that can be extinguished.

Harris said Arlington Heights firefighters were trained on CNG incidents in February 2024 and that the department has handled six garbage‑truck fires since 2017. He said the department has been in contact with the Los Angeles Fire Department, which experienced a similar garbage‑truck explosion in February 2024, to compare tactics and lessons learned.

Board members and the village manager praised the department’s response and training. Village Manager Randy Reclaus said, ‘‘I want to commend Chief Harris and his entire team on both the response to this incident, and the conscientious way with which they reviewed this incident with Groot.’’ Mayor (President) Hayes thanked the department and said the presentation ‘‘focused on lessons learned and how we can perhaps prevent this or at least minimize the damage if it does occur.’’

Several trustees pressed for further follow-up with Groot on equipment maintenance, driver training and safety records; Trustee Bertucci said the board should consider asking about contractor safety records and whether the failure to dump the load derived from a mechanical problem, an operator issue, or training gaps. Trustee Shirley asked whether PRDs are periodically inspected and whether they ‘‘expire’’; Harris said those are questions for Groot. Staff said they would reach out to Groot and share any additional information that the contractor can provide consistent with ongoing litigation and investigation.

Harris and trustees urged residents not to put batteries—especially lithium‑ion batteries—into curbside recycling or trash. Harris cited national numbers in his presentation that he said show batteries cause thousands of fires annually and listed local options for battery recycling: Arlington Heights Village Hall and Health & Human Services collection, Best Buy, Home Depot (Mount Prospect) and online locators. Harris also mentioned a state Senate bill (Senate Bill 3686) he said will take effect in 2026, but noted it does not address the immediate risk.

Two nearby residents who spoke during citizens’ comments thanked the department. Resident Philip Bankston, who said he and neighbors were ‘‘ground zero’’ for the explosion, thanked firefighters for their work and noted property damage and a continuing recovery process. Resident Bill Manganera thanked the board for prior pension funding decisions that support emergency workers and said he had been ‘‘at the scene’’ of the budget discussion that funded those pensions.

What the Village will do next: staff said they will continue to coordinate with Groot and Northwest Central Dispatch, review whether additional inspection or oversight steps are appropriate, and expand public communications about accepted battery‑recycling options. Chief Harris said the department will update operational guidelines for CNG fires and continue training.

Chief Harris’s presentation and subsequent board discussion emphasized that the investigation on Groot’s side remains open; Harris repeatedly framed the Village review as operational and informational rather than investigative.

Ending — Practical guidance and local impact: the department urged residents to use designated battery‑recycling drop‑offs and to avoid disposing of rechargeable or damaged batteries in curbside trash or recycling. Residents with questions about battery drop‑off options were told to consult the Village website or the list Harris provided at the Feb. 18 meeting.