The first major I-80 sinkhole in Wharton opened on Dec. 26, 2024, after an abandoned mine shaft collapsed beneath the highway. An emergency repair allowed the highway to reopen within days, but additional sinkholes and underground voids discovered in 2025 revealed a much larger problem.
NJDOT ultimately conducted extensive subsurface testing, drilling, grouting and reconstruction before fully reopening I-80 in June 2025.
New Jersey lawmakers are now considering legislation that would establish permanent abandoned-mine reclamation programs within NJDOT and NJDEP to identify, prioritize and stabilize dangerous mines before they cause another infrastructure emergency.
What began as an emergency highway repair in Morris County ultimately exposed a much larger infrastructure challenge beneath parts of New Jersey. On Dec. 26, 2024, a roughly 40-by-40-foot sinkhole opened along Interstate 80 eastbound in Wharton after the collapse of an abandoned mine shaft beneath the highway. NJDOT crews worked around the clock to stabilize the area, excavate the damaged roadway and complete emergency repairs.
The highway reopened within days, but the problem beneath I-80 was far from over. On Feb. 10, 2025, NJDOT observed another depression approximately 75 feet from the December collapse. While crews conducted soil testing that evening, the roadway collapsed, creating an approximately 11-by-11-foot sinkhole.
NJDOT began extensive geotechnical testing on both sides of I-80, including subsurface scanning, drilling, and grouting designed to identify and stabilize underground voids. The work identified approximately 150 locations requiring drilling and grouting and revealed areas where more substantial reconstruction was necessary.
The situation escalated again on March 19, when another approximately 15-by-15-foot sinkhole opened in the median. NJDOT closed I-80 westbound as a precaution, and subsequent testing identified a significant void beneath the westbound roadway.
By then, the response had evolved from repairing individual sinkholes into a major subsurface stabilization project. Crews drilled and grouted underground cavities, excavated compromised areas and constructed a new roadway foundation supported by micropiles extending into bedrock. NJDOT also incorporated quality-assurance testing and monitoring systems intended to verify the stability of the reconstructed highway.
Governor Phil Murphy declared a State of Emergency in Morris County on March 8, citing the geophysical hazards beneath I-80 and the severe transportation disruptions caused by the closure. Two eastbound lanes reopened May 21, followed by two westbound lanes on May 30. All westbound lanes reopened June 14, and the highway was fully reopened later that month. The state lifted its emergency declaration on June 21.
State budget documents estimated repairs associated with the I-80 and I-287 sinkholes at approximately $25 million at that stage of the response, with NJDOT initially using Transportation Trust Fund resources while discussing potential federal assistance.
The I-80 crisis also raised a larger question: how should New Jersey address abandoned mines before another underground collapse threatens a highway, utility or community? Lawmakers have since introduced proposals aimed at creating a more systematic answer.
In May 2026, Senators Paul Sarlo and Anthony Bucco introduced legislation that would establish separate abandoned-mine reclamation programs within NJDOT and the Department of Environmental Protection.
Rather than waiting for a collapse, the proposed framework would direct the state to identify abandoned mines, determine which pose the greatest threats to people, property, transportation and utility infrastructure, rank reclamation projects and develop plans to backfill, stabilize or otherwise make dangerous mine voids safe. The legislation would also establish dedicated reclamation funds within both departments and give state officials authority to conduct exploratory work necessary to evaluate potentially dangerous abandoned mines.
The proposal builds on legislative efforts that began following the I-80 emergency. A previous Senate bill establishing an abandoned-mine reclamation program within NJDOT passed the Senate unanimously in December 2025 before being referred to the Assembly. Separate legislation has also proposed allowing counties and municipalities to use open-space trust funds to remediate collapsed mine shafts and sinkholes on publicly owned property.
The shift is significant. For a state whose modern transportation network was built in some places above mining activity dating back generations, the lesson from I-80 may ultimately extend well beyond one stretch of highway in Wharton.
Sources:
New Jersey Department of Transportation. (2025). I-80 eastbound sinkhole. NJDOT I-80 sinkhole project page (https://www.nj.gov/transportation/commuter/roads/i80/)
New Jersey Legislature. (2026). Senate Bill No. 4142: Establishes abandoned mine reclamation programs and funding in DOT and DEP. S4142 bill text (https://pub.njleg.state.nj.us/Bills/2026/S4500/4142_I1.HTM)
New Jersey Legislature. (2025). Senate Bill No. 4833: Establishes abandoned mine reclamation program in DOT. S4833 legislative history (https://www.njleg.state.nj.us/bill-search/2024/S4833)
