Plastics and other floating debris cause unsightly slicks on the water. Floatables are frequently the most visible evidence of polluted water. They include toilet paper, condoms, and tampon applicators, as well as oil and grease. While obviously aesthetically offensive, floatables can include plastic bags or six-pack rings which can entangle or be mistakenly eaten by marine life.
Combined sewer overflows, a major source of floatable pollution, have been greatly reduced in both volume and frequency by an increased pumping capacity at the treatment plant, and better overall sewer system performance. The Interim Improvements to the scum handling facilities and the landfilling of scum instead of mixing it with sludge, greatly reduced the discharge of scum to the Harbor starting in the late 1980's. The removal of sludge discharges in 1991 and the start-up of the new primary plant in 1995 also reduced the amount of floatables entering the Harbor. CSO improvements being phased in over the next several years will decrease floatables even more.
To complement the decrease in sewage-related floatables, conscientious
attention to litter prevention and removal is important to prevent debris
from streets or boats from entering the Harbor.