Water, water everywhere but not a drop to drink: when climate changes water at the kitchen tap

Flooded streets. Beach closures. Store fronts underwater. 

These are some notable memories of New England’s 2023 summer, the second rainiest on record. 

Warmer temperatures around the globe caused rainfall to increase in the Northeast, according to experts. 

“We are getting wetter in response to climate change,” said Mary Stampone, a climatologist and Earth sciences professor at the University of New Hampshire. “When it gets warmer, there is more moisture in the air from evaporation.”

The more heat the atmosphere keeps, the more energy it can use to move water.  

Stampone explained last summer was unusual because a heat dome, a large swath of high pressure and humidity, covered the middle of the United States. This forced the Jet Stream to move around it, over Canada and New England, bringing storms carrying more moisture to the Northeast because of record-setting heat.

What’s more: there are more historic rainy years to come. Rainfall may increase by 52 percent by the year 2099. 

But what does this mean aside from canceling those weekend plans? 

Well, all this rainfall is showing up in the public drinking water, though not in the way you might expect. Sewage is what’s on tap. 

This summer’s rainfall overwhelmed an aging public water system and a watershed serving 2.6 million people, The Merrimack River. The river originates in southern New Hampshire and winds south 117 miles before emptying into the Atlantic Ocean at Newburyport, Massachusetts. It is the fourth largest watershed in New England. 

This problem has long plagued the river. More than 200 communities rely on the river for tap water. The more people who move to these cities and towns, the more sewage that needs to be processed. 

Then, add the rain. When it floods here, sewage has to be dumped into the river, or else it backs up into people’s homes. 

When it comes to heavy rain, flooding is a common concern. But heavy rain also causes soil erosion and pollution because the water picks up toxins from the surface, rather than soaking into the ground. Ecosystems respond to the changes. 

This summer about 1.6 billion gallons of raw sewage were dumped into the Merrimack River, according to non-profit Merrimack River Watershed Council. It was about twice as much as the previous record set in 2021 when 823 million gallons were discharged into the river. 

The confluence of this summer’s events resulted in bacteria 10 times the level of what the Environmental Protection declares safe for swimming, let alone for potable water.

Every day millions of people in the United States turn on their kitchen tap and pour a glass of water to drink. The EPA sets the standards for water quality and public water systems that provide tap water to about 90 percent of Americans.  It’s known as one of the largest and safest public water systems in the world.