Why the Emphasis on Runoff When We Know that Sewage is the Sound's Biggest Pollutant?
Controlling runoff and reducing the amount of pollution is runoff is sort of important, but I’m surprised at the emphasis it has gotten, both in the survey and in the news accounts of the survey.
By far the biggest source of pollution in Long Island Sound is treated sewage. It is the source of the vast majority of the nitrogen that triggers the low levels of dissolved oxygen that make much of the western end of the Sound uninhabitable for marine life in late summer.
The second biggest source of nitrogen is air pollution. Nitrogen emitted from car tailpipes and power plants falls into the Sound and adds to the nitrogen from sewage plants.
And of the important sources of nitrogen, the smallest and the most difficult to control is runoff from streets and driveways and septic systems in the Sound’s watershed. Not only is it hard to control, it’s hard to measure. It’s been a while since I’ve asked, but the last time I did I was told that less than 10 percent of the nitrogen that damages the Sound comes from runoff.
So to me it’s not that huge of a deal if people don’t realize that runoff contributes to the Sound’s problems and if, because they don’t realize that, they don’t do the few small things that may or may not reduce the tiny amount of pollution they are personally responsible for.
Far more troubling to me is that most people don’t know that treated sewage and sewage plants are the biggest polluters of Long Island Sound (the survey is here). Presumably they also don’t realize that upgrading sewage plants is the single best thing we as a society can do for the Sound. And that perhaps explains why Connecticut for years was allowed to get away with ignoring its responsibility to upgrade sewage plants by failing to put money in its Clean Water Fund.
Convincing people not to wash their cars in the driveways is important, I suppose, but it’s a drop in the bucket compared to sewage plants. We really should keep our priorities straight.
Labels: Long Island Sound survey