Editing Lake Ontario (section)

=== Water pollution ===
Lake Ontario is the most downstream lake of the Great Lakes, so the pollution from all the other lakes flows into it. Lake Ontario was ranked as the most environmentally stressed amongst the five Great Lakes in a 2015 ecological study. Some of the stresses on the lake include excess application of fertilizers in agriculture running into the lake, spillover from obsolete municipal [[sewage systems]], toxic chemicals from industries along the rivers that drain into the lake, and metropolitan drainage from big cities like Toronto, Rochester, and Hamilton.<ref>{{Cite journal |last1=Estepp |first1=Lisa R. |last2=Reavie |first2=Euan D. |date=2015-09-01 |title=The ecological history of Lake Ontario according to phytoplankton |url=https://www.sciencedirect.com/science/article/pii/S0380133015001331 |journal=Journal of Great Lakes Research |language=en |volume=41 |issue=3 |pages=669–687 |doi=10.1016/j.jglr.2015.06.005 |bibcode=2015JGLR...41..669E |issn=0380-1330|hdl=11299/186099 |hdl-access=free }}</ref>

[[Randle Reef]], the westernmost part of Lake Ontario, has been identified as one of the most contaminated areas on Lake Ontario alongside other [[Great Lakes Areas of Concern#List of areas of concern|areas of concern on Great Lakes]]. However, a $150-million cleanup project had begun in 2016 and is expected to be completed by 2025.<ref>{{Cite news |last=Rosas |first=Aura |date=7 September 2023 |title=Final stage of cleaning up contaminated Randle Reef gets underway in Hamilton Harbour |url=https://www.cbc.ca/news/canada/hamilton/randle-reef-cleaning-step-three-1.6958295 |access-date=27 December 2023}}</ref>