This is a link to an NGO that focuses on sanitation in India.  http://www.sulabhinternational.org/ 

Not necessarily rapid response for a disaster but certainly development related.  I've also attached a powerpoint slide show that I pulled off their website.

From a recent article in the Economist

"Sulabh, a charity, has developed an ingeniously simple one, costing around $100, that empties into one pit, and then, when it is full, another. It flushes with two litres of water, compared with the ten litres required by a standard cistern toilet. It takes ten people two years to fill one pit, by which time the waste in the other has turned into composted manure, clean enough for growing vegetables.

Sulabh has built 1.2m of the latrines across India and helped 60,000 scavengers find new work. “The toilet is a tool of social change,” declares Bindeshwar Pathak, a (high-caste) brahmin who started the charity in 1970 and has developed a passion for lavatorial technology. "