Barack and Michelle Obama spend vacation day by a pond ‘fouled by human urine’

Cape Cod has its own urgent water problems made worse by tourist invasion

Back on Martha's Vineyard for the first family's summer break (AP)

America’s first couple, Barack and Michelle Obama, spent Tuesday on a Martha’s Vineyard beach backing onto a huge and well-loved pond that is being killed slowly by human urine.

The visit with friends to a glistening beach under perfect skies on a thin sand bar that separates the Atlantic Ocean from the Edgartown Great Pond, a brackish body of water with precious wildlife, was the highlight for the Obama’s on the fourth day of their two-week holiday.

It was a change of pace for President Obama, in particular, who, true to form, spent most of his first days on the island hitting the golf links. For his traditional summer break, he has also been joined by his daughter, Sasha and Malia.

The plight of the pond, which has been officially designated compromised because of unacceptably high levels of nitrogen, stood in stark contrast to the beauty of the clear-blue day and the southern vista out towards the ocean.

It was the object of scholarly research by reporters who found themselves stuck for the afternoon in a bus in the beach parking lot while the first family frolicked. While they could boast being entirely aware of the compromised nature of the pond them before them, it isn’t clear that the Obama’s had any idea.

While excessive nitrogen is a common ecological problem that has caused widespread harm in sensitive watersheds in America, including in Chesapeake Bay and southern Florida, in most cases it is traced back to run-off from agricultural land and the fertilisers used to enrich them.

But for Edgartown Great Pond, human urine is the most important culprit. Indeed, according to the website of Great Pond Foundation, which was formed to help address the crisis, “by far the greatest source of ‘manageable’ (i.e. non-atmospheric) source of nitrogen pollution in our ponds comes from the urine in wastewater.”

And that arises, of course, because Martha’s Vineyard, an island off Cape Cod in Massachusetts and eight miles from its sister island of Nantuckett, in the summer attracts hordes of beach-loving tourists, the first family included who have visited it each of the last seven summers - every August, in fact, since Mr Obama became president.

The island has just 15,000 year-round residents but sees its population soar to 100,000 in the peak summer months.

Added to that is the problem that almost none of its homes are on mainline sewage. Nine out of ten dwellings depend on septic systems to deal with human waste. And those systems, the foundation’s site says, “deal well with pathogens but have little impact on nitrogen” in urine.

According to the US Geographical Survey, excessive nitrogen levels "can cause excessive growth of algae and other plants, leading to accelerated eutrophication or 'aging' of lakes, and occasional loss of dissolved oxygen".

Overwhelming tourist numbers as well as commerical development is also causing strains to the water supply on Cape Cod itself, which is dependent on a single underground aquifer for nearly all of its fresh water supply. On Cape Cod, four fifths of all homes also depend on in-ground septic tanks to treat their human waste.

In their small bus, the White House reporters, who offer a ‘pooled report’ of the day’s events to media outlets that our interested, determined they were not about to add to the problem. “Your pool is holding in a bus nearby with plenty of bottled water,” wrote New York Times reporter Gardiner Harris.

“Horrified at playing even a small role in this unfortunate cycle, your pooler promises to drink abstemiously."