April 6, 2014 was the latest "ARM Sunday" here in Massachusetts. For the past 31 years, volunteers have helped the Water Resources Research Center keep track of the effects of acid precipitation on the Commonwealth's surface waters.
After visiting most of Massachusetts' 4500 ponds and streams in the early years of the project, we now monitor 150 sites statewide once a year in April, in order to catch the worst case scenario - that is, the most acidic situation in our surface waters when the snowpack melts.
Nitric acids are stored in snow all winter, and when meltwaters reach streams and ponds, they bring along an "acid pulse" that lowers the pH to levels that can be damaging to aquatic life.
Without our volunteers, who collect those 150 samples simultaneously on ARM Sunday and bring them to volunteer laboratories around the state, we would be unable to keep this long-term monitoring effort alive. So, a big THANK YOU to all our volunteers, and a special thought for Bill Elliott, who helped us for so many years before passing away a couple of weeks ago.