debris. Environmental issues On January 30, 1986, four underground storage fuel tanks were excavated and removed from the 150 First Street site. Each of these tanks had a capacity of 1,000 gallons (Earth Metrics, 1989). Eight soil samples showed the existence of total petroleum hydrocarbons in levels ranging from 20 to 9,000 parts per million. On February 3, 1986, the excavation was backfilled. Demolition and replacement The City and County of San Francisco, the Alameda – Contra Costa Transit District (AC Transit), and the Peninsula Corridor Joint Powers Board (Caltrain) proposed to replace the underused original Transbay Terminal with an entirely new and more functional building at roughly the same location. The final Environmental Impact Report (EIR) was published in 2004, and construction began in August 2010 on Phase 1, the new Transbay Transit Center (TTC) building. A new outdoor temporary terminal was opened nearby to serve commuters during construction of the new transit center. The last bus departed the Transbay Terminal early on , just after ownership of the building was transferred from Caltrans to TJPA. Demolition by wrecking ball commenced in December 2010, and demolition was declared complete on . It was announced in March 2011 that a sculpture to be assembled from Transbay Terminal debris by Tim Hawkinson would be erected on the corner of Mission and Fremont Streets after completion of the new Transbay Transit Center. However, the sculpture project was cancelled on June 7, 2017 due to cost and engineering concerns. Temporary Transbay Terminal The Temporary Transbay Terminal was the San Francisco terminus for Transbay and regional buses for most of the 2010s. It was in operation from August 2010 through August 2018, when the new Transbay Transit Center opened, and again from September 2018 to August 2019 during a temporary closure of the new center. It occupied the city block bounded by Howard, Main, Folsom, and Beale Streets. Closure & reopening The Temporary Transbay Terminal initially ceased operations on August 12, 2018, with the opening of the new Salesforce Transit Center, only to be reopened weeks later, on September 25, 2018, following the discovery of support beam cracks at the Salesforce Transit Center. By December 5, 2018, Clipper card kiosks were reinstalled at the temporary terminal due to the continued closure of the Transit Center. In April 2019, repairs were finished and it was determined that the cause of the cracking was partly caused