I ran across this program on a trip to Cambodia a few years ago. I saw their work in a village and on a boat trip. The small amount I give can purchase quite a few water filters. I'm also impressed by their moving into literacy programs as well.
Last year, the director called me personally to thank me for my donation. It doesn't seem like such an impersonal entity after that.
Lastly, I looked up their expenses, I am impressed that their overhead/administrative costs are very low compared to many other reputable and good charities.
Review from Guidestar