COORDINATED APPROACH TO REMEDIATION OF ABANDONED MINE HAZARDS l T.G. Carter, W.O. Mackasef and C.M. Steed 2 Abstract: Developing a strategy for dealing with the complex problems of remediating hazardous mine sites in municipal areas calls for an integrated approach where planners, engineers and municipal and government authorities can work together to organize, fund and then construct appropriately engineered remedial works. In Cobalt, the sudden collapse of a highway into an old mine working necessitated immediate assessment and investigation of the problem and development of a mechanism for fast release and allocation of appropriate government level funding to expedite the emergency remediation works required to make the area safe. In addition to the many novel engineering solutions that were developed to investigate and remediate the hazard sites, remediation of the Cobalt problems saw the landmark creation of an Inter-Ministry Abandoned Mines Hazard Committee charged with the responsibility of expediting the remediation works. With this authority vested in members of the committee, not only were innovative engineering ideas spawned from the thinking but various new approaches and methods were also developed for expediting and obtaining emergency funding. Keywords: Mine Hazards, Stopes, Crown Pillars, Highways, Remediation, Collapses, Cave-Ins, Subsidence, Liability, Abandoned Mines. Introduction Dealing with abandoned mine hazards and developing cost-effective remediation measures often calls for innnovation in developing optimum solutions within a framework of ensuring public safety. Generally where abandoned hazard sites need remediation but are located close to Municipal infrastructure, in addition to compliance requirements that have to be achieved by the Mining Company, Government and Municipal needs also have to be met; immediate and long term safety issues have to be addressed; future land use requirements have to be considered and costs for the remediation measures have to be kept within reasonable proportions. Optimizing the decisions of whether or not to fix the problem or take other action is often complex, (Figure 1). In this paper, the procedure that was developed and followed for dealing with the severe mining hazards that existed in Cobalt are described as a model for dealing with other problem sites elsewhere. lPaper presented at Sudbury '95, Conference on Mining and the Environment, Sudbury, Ontario, May 28th - June 1, 1995 2T.G. Carter, Principal, C.M. Steed, Associate, Golder Associates Ltd., 2180 Meadowvale Blvd., Mississauga, Ontario, LSN 5S3 3W.O. Mackasey, Provincial Supervisor, Mining and Land Management Branch, Ministry of Northern Development and Mines, 933, Ramsey lake Rd., Sudbury, Ontario, P3E 6B5