Lake Improvement

Steven Effler

Steven Effler

Honeywell has finished implementing New York State’s cleanup plan for Onondaga Lake. Onondaga Lake is now becoming a source of pride and optimism for local residents and an economic driver for the region. The cleanup, together with upgrades made by Onondaga County to its wastewater treatment plant and the County’s Save the Rain program, has resulted in the best water quality in more than 100 years.

“Upstate Freshwater Institute has been studying Onondaga Lake for more than 30 years. Implementation of state-of-the-art wastewater treatment by Onondaga County and Honeywell’s lake cleanup have gone a long way to enhance water quality in Onondaga Lake. The improvement is truly remarkable. Onondaga Lake is experiencing a renaissance that few thought possible,” said Steven Effler, Ph.D., former Chief Executive Officer and Director of Research, Upstate Freshwater Institute, Syracuse.


  • About 2.2 million cubic yards of material removed from the lake
  • 475 acres of lake bottom capped with more than 3 million cubic yards of natural material consisting primarily of sand, activated carbon, and stone, creating a new, clean lake bottom
  • Honeywell’s approximately 1.5 mile underground barrier intercepts contaminated groundwater from former factory sites so it can be treated to meet DEC standards before it is returned to the lake
  • Water quality in northern two-thirds of Onondaga Lake has achieved public health criteria for swimming (Source: DOH)
  • 65 species of fish documented, up from nine to 12 counted in 1970s (Source: DEC)
  • Aquatic plant community expanded from less than 12 percent of shallow-water lake areas to about 80 percent (Source: SUNY-ESF)
  • Methylmercury in deep-water portions decreased 98 percent since 2009 (Source: Upstate Freshwater Institute)
  • Concentrations of dissolved mercury significantly lower in surface water samples (Source: EPA)
  • Natural recovery in the lake is progressing faster than predicted (Source: EPA)
  • About 90 acres of wetlands restored in and around the lake
  • More than 250 wildlife species, some not seen in decades, identified in restored areas
  • More than 120 unique bird species documented at or near Onondaga Lake, a priority Audubon Important Bird Area