Please visit NRDC's Action Center and get busy with those letters to Congress.
You might also want to visit Heather Allen's blog at NRDC here. Quoting from her latest post:
It's budget season in Washington, an opportunity to help shape how the U.S. will spend millions and sometimes billions of funds to improve the lives of the poor around the world.
Safe drinking water and adequate sanitation can have the most profound impact on improving lives and preventing disease, allowing people to focus on other issues like getting their children to school, growing food and doing other daily tasks.
Please take a moment to call upon Congress to increase funding for safe water and sanitation programs which promote health and healthy ecosystems.
So please do take five minutes out of your busy schedules and encourage the US Congress to do more for safe drinking water and sanitation around the developing world.