A small New York ad agency is making a big difference in the lives of third world children who lack access to clean drinking water. Droga5’s Tap Project, a pro bono ad campaign, partners with restaurants that donate $1 to Project Tap each time a diner chooses tap water over bottled during the week of March 16th. With World Water Day coming up on March 22nd, the Tap Project is raising awareness of–and money for–the cause of clean water in undeveloped nations.

The first Tap Project, last March, raised about $100,000 through the participation of  300 or so New York restaurants and thousands of patrons; this year, as the New York Times reports, the Tap Project’s going nationwide:

Additional markets scheduled to take part are Boston; Chicago; Cincinnati; Dallas; Los Angeles; Milwaukee; New Orleans; Portland, Ore.; Richmond, Va.; San Diego; San Francisco; Seattle; and several cities in South Carolina. 

Thirteen additional ad agencies and the Adcenter at Virginia Commonwealth University have signed on to donate their time and ingenuity to help create ad campaigns geared towards the individual cities. The campaign is expanding with approval and support from Unicef. Jay Aldous, vice president for marketing, communications and corporate partnerships at the United States Fund for Unicef in New York, called the ad campaign “remarkable:”

The expansion of the campaign “illustrates the power of how when people take an idea and put their own imprint on it, it grows faster”If we as an organization, with all our rules and regulations, were managing this, we’d be one fraction of where we are now.”

Learn more about the Tap Project here.