The term “Hudson (River) mustache” was popularized in the New York (NY) Times article “River Grime? Triathletes Are Swimming in It” by Lindsay Crouse, published on August 3. 2014, which began:
   
“They call it the Hudson Mustache, the thick band of silty debris that clings to a swimmer’s upper lip after a nearly mile-long paddle down the Hudson River in the New York City Triathlon.”
 
Not many people swim in the Hudson River and the term is infrequently used, but it’s entered the New York City lexicon The MSNBC story “How clean are America’s beaches?” published on August 7, 2015 stated:
   
“Most don’t get ill, but many get a ‘Hudson Mustache,’ a nickname for the finger of silt that curls over the lip of swimmers.”
   
     
New York (NY) Times
River Grime? Triathletes Are Swimming in It
By LINDSAY CROUSE AUG. 3, 2014
They call it the Hudson Mustache, the thick band of silty debris that clings to a swimmer’s upper lip after a nearly mile-long paddle down the Hudson River in the New York City Triathlon. The race is one of the few times a New Yorker will voluntarily plunge into the sometimes unsanitary waterway.
 
Gothamist
Would You Be Into A Hudson Mustache?
BY JOHN DEL SIGNORE IN NEWS ON AUG 4, 2014 3:45 PM
New York is a city fully freaky people, but perhaps the freakiest of all are those who pay good money to receive a “Hudson Mustache.” Hey, whatever you’re into. For some people, $285.00 plus a $17.50 processing fee is a small price to pay for the experience, which is known to decorate swimmers’ upper lips during the New York City Triathalon.
   
RebelMouse
New Muck City: Pollution Under the Hudson
09 May 2015
The Hudson Mustache: Swim at Your Own Risk
The ‘Hudson Mustache’ sounds like the latest New York City hipster trend, but the ‘Hudson Mustache’ is actually the term used to describe the layer of silty debris that gathers on the upper lip of someone who has braved the mile long swim across the Hudson River in the New York City Triathlon.
   
MSNBC
Rio’s not alone. How clean are America’s beaches?
08/07/15 12:50 PM—UPDATED 08/07/15 01:04 PM
By Tony Dokoupil
(...)
Dan Shapley has been monitoring New York City’s water as the manager of Hudson Riverkeepers. On a dry-weather day, he told msnbc, the water is safe for swimming. But wet-weather discharges can start after as little as a tenth of an inch of rain, turning everyday recreation into a roll of the dice. It’s not just sewage, but all the trash and toxins on city streets.
 
Almost half of the water samples that Riverkeepers recently took around the city failed federal standards for safe swimming, according to a report released last month. People still jump in, of course, thousands of them, including kayakers and triathlon participants. Most don’t get ill, but many get a “Hudson Mustache,” a nickname for the finger of silt that curls over the lip of swimmers.