Federal, state, and local governments have worked to clean up the legacy of municipal and industrial pollution in Onondaga Lake. In 1896, the city built sewers and banned backyard privies, but sewage flowed directly into Onondaga Creek and Harbor Brook. In 1970, Onondaga County established an annual lake monitoring program, and in 1972 the Federal Clean Water Act was passed. In 1979, the Metropolitan Syracuse Wastewater Treatment Plant, which serves Syracuse and surrounding communities and discharges into Onondaga Lake, was upgraded. A 1989 legal agreement in Federal court required Onondaga County to study and upgrade Metro and reduce sewage pollution from combined sewer overflows. In 1991, pump stations at Liverpool and Ley Creek were upgraded to reduce raw sewage overflows into the lake. In 1994, Onondaga Lake was added to the Federal Superfund List, making polluters responsible for cleanup of industrial contamination. In 1995, projects began to reduce excessive sediment flowing to Onondaga Creek from the Tully Valley Mudboils. A revised 1998 legal agreement required additional water quality monitoring and a reduction of combined sewer overflows into Onondaga Lake tributaries. In 2001, oil tanks were removed from Oil City near the Inner Harbor. In 2004, the final stage of Metro improvements for ammonia reduction began, and Onondaga County achieved ammonia reduction goals eight years ahead of schedule. In 2005, more than eight tons of mercury were removed by Honeywell from the Linden Chemical and Plastics property under a legal agreement, cutting off a major source of mercury to the lake. In 2006, Metro upgrades reduced phosphorus released into the lake by 75 percent, from 200 pounds to 50 pounds per day. In 2008, the Midland Avenue facility was completed, allowing sewage and stormwater from three combined sewer overflows to be treated before release into Onondaga Creek. In 2009, a fourth revision to the legal agreement was approved by the Federal court, allowing Onondaga County to incorporate green infrastructure to reduce combined sewer overflows, and Honeywell continued construction of a barrier wall to capture and treat polluted groundwater before it reached the lake. In 2010, Onondaga County launched the Save the Rain program to improve water quality through green roofs, rain gardens, porous pavement parking lots, and rain barrels. In 2011, cleanup began at Geddes Brook and Ninemile Creek, including wetland and creek habitat enhancements. In 2012, Honeywell began removing polluted sediments from the bottom of the lake. Today, Onondaga Lake is the cleanest it has been in over 100 years, and fish, plants, and birds are reinhabiting the area while the lake draws over 1.3 million visitors annually, though more remains to be done.