While all the rain might be good for gardeners, it’s bad news for beach bums. After a very wet week in the Ocean State, seven of our best beaches are currently closed for swimming.

“It’s not unusual to see elevated bacteria counts after heavy rain, which explains this week’s closures to swimming,” said Dara Chadwick, the spokeswoman for the state Health Department.

She directed me to this really cool interactive map where you can see for yourself which beaches are closed. From north to south, they are: Barrington Beach, Conimicut Point, City Park, Oakland, Goddard Park, North Kingstown and Narragansett town beaches. (note: some inaccuracies on map)

So why do we get bacteria in the Bay after wet weather?

Rhode Island doesn’t have to worry about big factories dumping pollutants directly into the Bay anymore, but it does still suffer from what’s called “non-point source pollution.” All sorts of lawn fertilizers, oils and other environmental toxins – even pet poop – gets washed from our roads and lawns into Narragansett Bay. When we get a lot of rain, the Bay becomes too polluted to swim in; all that bacteria can make us pretty sick.

If the bacteria level gets too high, the effects become catastrophic for the native species, rather than just inconvenient for human recreation – as happened in the infamous 2003 Greenwich Bay fish kill.

Rep. Teresa Tanzi introduced a bill this year that would lower non-point source pollution by phasing out septic tanks in Rhode Island.

Save The Bay spokesman Peter Hanney said, “This is important because cesspools – simple drums in the ground with no treatment of waste – pollute ground and surface water, well and drinking water supplies, and beaches where people swim.”