When an obstruction was discovered in the 60-year old North Gorge Interceptor (NGI), O'Brien & Gere was retained by the City of Niagara Falls, NY to provide assistance. Intermittent overflows, coupled with persistent interceptor surcharging, posed a significant hazard to the environment. The complex nature of the problem demanded innovative data collection efforts by O'Brien & Gere, as well as special attention to human safety and the welfare of the environment. From limited access to the NGI, immediately dangerous to life and health oxygen levels inside the tunnel, confined space issues, and the associated risks of working with debris and in surcharged conditions, O'Brien & Gere was facing a situation with significant safety concerns. In the end, O'Brien & Gere was able to perform investigation, develop contract documents embracing several alternatives to provide flexibility during bidding and implementation, and prepare a timely and cost-effective plan for remediation.