Starbucks concept storeRien Meulman Fotografie for Starbucks
Starbucks' Ethos bottled water comes from a drought-ridden county in California.
"The bottling plant that Starbucks uses for its Ethos customers in the western United States is located in Merced, California, which is currently ranked in the 'exceptional drought' category by the US Drought Monitor," writes Anna Lenzer at Mother Jones. "Its residents face steep water cuts in their homes, and surface water for the region's many farms is drying up."
The company donates 5 cents from every $1.95 bottle of Ethos to help children get clean drinking water in countries including Tanzania, Indonesia, and Colombia. Celebrities like Matt Damon have endorsed the brand for Starbucks.
Starbucks gets the water for free, according to Mother Jones.
Lenzer estimates that Starbucks has sold nearly 250 million bottles of the water. 
A Starbucks' spokesperson told Mother Jones that the company uses "a private spring source that is not used for municipal water for any communities."
ethos water descriptionethos-water.comStarbucks' often promotes Ethos water's humanitarian mission.
But a geologist tells Mother Jones that sometimes these private water sources drain the community supply by capturing the water before it reaches people downstream who might use it.
Many people are criticizing Starbucks on social media and calling for the brand to move its water plant to another location.
A separate report from Mother Jones notes that many popular bottled water brands come from California, including Nestle's Arrowhead and Pure Life brands.
There are currently no laws on the books in California to regulate how much water can be taken from underground aquifers (a.k.a. "groundwater"). The only laws that exist now govern surface water, the kind in rivers and lakes. New regulations were recently introduced for this exact purpose, but they won't kick in for serveral years.