Brooklyn's Sea Gate Beach, Staten Island's South Beach, Midland Beach and Cedar Grover Beach are now all back open.
Recreational activities can also resume in the Hudson, Harlem and East Rivers.
An additional engine at the plant, making three of five, is back up and running.
Officials on both sides of the Hudson have been testing water samples since a wastewater treatment plant in Harlem was crippled by fire last week Wednesday.
The New York City Department of Environmental Protection will be providing updates on the situation as needed at http://www.nyc.gov/html/dep/html/home/home.shtml.