On the evening of Oct. 8, 2017, more than 250 wildfires erupted and burned throughout Northern California -- in Napa, Lake, Mendocino, Solano, Yuba and Butte counties. In total, officials say nearly 9,000 structures were destroyed and more than 40 people were killed. Damages exceeded $9 billion. The President signed a federal disaster declaration on October 10, setting into motion the largest debris cleanup in the state's history since the 1906 San Francisco earthquake. As the lead agency for Emergency Support Function #3, FEMA called upon the U.S. Army Corps of Engineers to execute the massive program in partnership with the California Governor's Office of Emergency Services. On Oct. 19 USACE received the direct federal assistance mission for Private Property Debris Removal in Lake, Mendocino, Napa and Sonoma counties, with the state conducting operations in the other affected counties."The work that is getting accomplished following the devastating fires of 2017 is truly staggering and spread across extremely diverse areas," said Cal OES Director Mark Ghilarducci. "Our joint partnership between the local, state and federal agencies has been moving at an amazing speed to adjudicate each of the hurdles of this massive recovery."Six months later, the program is more than 92 percent complete. Crews have removed 2.2 million tons debris, more than double the weight of the iconic Golden Gate Bridge. By the time operations are completed, more than 4,500 properties will have been cleared. "Our mission in Northern California is debris removal -- getting the stuff off the property so that survivors are ready for the next step, whether that's rebuilding or sale. The goal was to leave a clean, safe lot," said LTC Travis Rayfield, commander of the USACE Sonoma Recovery Field Office. The two-phase process of debris removal was a shared federal and state responsibility. The US EPA moved in first to remove Household Hazardous Waste. USACE and CalRecycle crews were then responsible for clearing the lots of ash and fire-related debris. Three prime contractors -- ECC of Burlingame, Ca.; AshBritt Environmental of Deerfield Beach, Fl., and CERES of Minneapolis, Minn. -- were awarded contracts for debris removal. It is estimated that more than 90 percent of sub-contractors working on the mission are from the state of California. "The fire debris removal program has been enormous and reflects a huge investment in the affected communities, by federal, state and local partners," said Bill Roche, federal coordinating officer for the October wildfires across the state. "As the debris operations conclude, we are excited to see more evidence of smart redevelopment and recovery." Although USACE is often assigned debris removal missions following hurricanes or floods, the Northern California PPDR program has presented new challenges. Typically contractors will remove wet debris from the right-of-way. In this case, each property owner was required to opt-in to the federal/state debris removal program by submitting a Right of Entry to their county, which was then reviewed and forwarded to USACE and FEMA. Additionally, the terrain of the area as well as the types of homes that were destroyed made debris removal more difficult. Many homes were large custom builds, constructed into the side of hills, with unique features. The guidelines of the PPDR called for removing foundations while leaving retaining walls and other features needed for erosion control. Some of the hardest-hit areas in Sonoma County were densely-populated neighborhoods in Santa Rosa like Coffey Park, where nearly 1300 homes were destroyed. Other parcels were remote and required engineering solutions, like temporary bridge installation, before crews could even reach the sites for assessments and clearance. "Most of the time the Corps is dealing with one job site," said Rayfield. "In this case we had more than 4,500 job sites, each one unique. We had to balance our responsibility to property owners' rights while working within the scope of our authorities and contracts." The process didn't end when crews cleared the last of the ash and concrete from as site. After scraping three to six inches of soil, the next step in the process was soil sampling, to ensure that all contaminated material and soil had been removed. If the soil samples came back clear, there were other final prep activities to be completed, including removal of burned vehicles, installation of erosion control and final Quality Assurance check. As of April 19, six months since receiving the mission assignment, USACE and its contractors are left with just a handful of complex properties left to clear of debris. Working with its federal and state partners, another 500 parcels with additional eligible debris were identified and the Corps is offering homeowners the opportunity to have contractors return to the property to have the additional debris removed. Even as debris removal activities are ramping down, there is still a large administrative workload for USACE, as they will compile a Parcel Completion Report to be provided to FEMA for each property. When the field work ends, the Corps will transition from field offices in the affected areas back to the Sacramento District, who has the lead for the mission. Since October, approximately 850 USACE employees have deployed from more than 30 districts and divisions to support the mission. Many of these individuals also deployed in response to Hurricanes Harvey, Irma and Maria in 2017, which proved to be a busy year for the USACE disaster response efforts."At the end of the day, the real story is the here is the people - from our outstanding Corps team members who placed their home-district duties on hold and surged from across the country to Northern California, to our construction contractors who answered our call for this Herculean task, to our Federal, State, and local partners who rallied together for the common goal of supporting survivors by rebuilding as soon as possible," said BG Peter Helmlinger, South Pacific Division commander. "These people are the heroes whose hard work ensured mission success."