Boston beaches close due to water concerns (7/10/2009)

The Globe reports today:

The state Department of Conservation and Recreation is recommending that people stay out of the water at several Boston-area beaches, warning that they could get sick if they take a dip.

Red flags are flying, signs are posted, and lifeguards are urging people not to swim at Tenean Beach in Dorchester, Carson Beach in South Boston, and parts of Wollaston Beach in Quincy.

The probable culprit is the recent rains, which have washed animal waste, such as dog and bird droppings, into storm sewers that dump into the water, said DCR spokeswoman Wendy Fox. That can lead to the enterococcus bacteria entering the water, which can cause gastrointestinal illness for those who come in contact with it, she said.

The full story is here.

The Charles has typically experienced a deterioration in water quality after heavy rains.  Knowing just how much rain is going to cause a problem is a different matter though.  As MWRA projects advance to completion the capacity of the river to handle rain events improves.  The Stony Book Sewer Separation, for example, was a $45 million project that has reduced CSO (Combined Sewage Overflow) events from 22 times per year to 2.  This has resulted in a reduction of 44.5 million gallons of CSO per year to 0.13 million.  Not bad!