Washington ( CNN ) -- Nearly a billion people worldwide have limited access to clean water , the State Department says , and the crisis disproportionately affects women and girls . `` On average , women in developing countries walk 6 kilometers a day to collect water '' because there is not enough of it nearby , Undersecretary of State for Democracy and Global Affairs Maria Otero told CNN . The chore keeps girls out of school and women from more productive economic activities , Otero said . Otero spoke at a Washington , D.C. , event Wednesday organized to bring awareness to the issue . Several hundred people gathered outside the State Department for the `` Earth Day 6K Walk for Water , '' a 3.5-mile walk around the city to support the many women who have to carry containers on long treks every day to fetch water for their families . Nearly 1 billion people in the developing world walk on average 3.5 miles to get water to drink . The United Nations ' refugee agency estimates that more than half of the world 's refugee camps do n't have the recommended minimum daily water requirement of 20 liters per person , and about 30 % of camps do n't have adequate waste disposal and latrine facilities , according to its website . Elynn Walter , the sustainability director with the Washington-based WASH Advocacy Initiative , which works to raise and funds and awareness to address the problem , said women in many developing countries are expected to supply water while men tend to other chores . Walter stood before two large containers called jerry cans commonly used in third-world countries to carry water collected from far-away locations . When filled , she said the cans weigh a hefty 55 pounds . `` They often put it on their shoulder and carry it above their head , '' Walter told CNN . Rachel Schneller , a foreign service officer who lived for two years in Mali in the mid-1990s as a Peace Corps volunteer , said she joined the walk to raise awareness about the problem . She lived in a village in a nut hut in Mali , with a grass roof , no running water and no electricity . She said she carried her water in a jerry can . `` When you need that water to do everything from washing your body , brushing your teeth , cooking your meals , washing your clothes , water for bathing ... you count every single drop , Schneller said . `` You realize how important water is , especially if you 're the one that has to go collect it and bring it back -- every single drop . '' Secretary of State Hillary Clinton has elevated water to one of her key issues , providing $ 770 million through USAID in 2009 toward increasing access to water and sanitation , particularly for people living in developing countries . Otero said water problems are not limited to the third world , however . Every region of the world is affected , including the United States , especially in the Southwest . Water scarcity has even become a security consideration , she said . `` Wars can start , conflict can start , tension can happen , and being able to help countries manage this and address it in a collaborative way is part of our effort in working this , '' Otero said . CNN 's Jill Dougherty contributed to this report .
Nearly a billion people worldwide have limited access to clean water . The State Department is working to raise awareness about the issue . Score: 6