The US doesn't have such a team??? I'm surprised to hear this. Pete, can you elaborate please?

we have things called aircraft carriers that produce 100's of thousands of gallons of desal water daily, multiple operating rooms, self sustaining electrical power, their own landing strip, and helicopters to deliver relief supplies

we have people called Special Forces that routinely work with indigenous people in third world countries to improve their lives as well as regular troops that provide water systems to forward deployed forces in God forsaken regions of the world

we have church groups and NGOs like the TBM that help distribute individual filters (like the Sawyer .02 micron 5 gal system)

Bingley

I could not tell you - exactly what the US Government has. Surely we must have the capability to do this. But who exactly in the military does this - and how - I am not sure. Using Navy ships might be one smart way to purify water. Especially for Puerto Rico.

I helped at a flooding disaster in Africa (Mozambique disaster, early 2000's). I saw a team in action there - from Austria. They are a military team, but organized more to provide humanitarian assistance. They are especially good at things like purifying water. They have ALL the gear ... big purifying units, hoses, tubes, all the connections. They go right into a polluted area, and start producing pure water for poor people. It's very impressive to watch. These folks would be a HUGE help to Puerto Rico right now.

Governor Of Puerto Rico Announces Major Humanitarian Crisis

http://www.msn.com/en-us/news/us/puerto-rico%E2%80%99s-governor-warns-of-%E2%80%98humanitarian-crisis%E2%80%99/ar-AAssMWv?li=AA4ZnC&ocid=spartandhp

The military will likely be employed like this:

They will go in and assess where the people are, how many and the magnitude of the need

They will set up or repair airfields, ports and helicopter landing zones in remote areas

They will set up camps with shelter, water, food and medical care

Engineer and medical units will provide the majority of the aid

Military Police may be used for security and population control

They will integrate with and assist local authorities, finding the local experts on the infrastructure and work to get it all working again

Distribution is key, and all of the population in need may not be very accessible, people will either go to the help or the help will come to them. Consolidation will be necessary in many cases for logistical reasons.

Immediate needs will be addressed first, then they will focus on a sustained effort, then on rebuilding the necessary infrastructure (water treatment, hospitals, power, food)

The US Military is already heavily involved in disaster relief in Puerto Rico:

Navy, Marine Corps Providing Around-the-Clock Hurricane Maria Relief

Military conducting multiple operations to help Hurricane Maria-struck Puerto Rico, Virgin Islands

The Marines, Navy, Army, Coast Guard, and Air Force are all involved. This includes active duty, reserve, and National Guard units.

EDIT: Note that the Marine Corps has a the capability to provide potable water, using either sea water or polluted sources. These systems are already being put to use: Joint Task Force - Leeward Islands distributes water to the people of Saint Martin

Listening to various reports on FoxNews -- per the reports: USS_Kearsarge (LHD-3) is on scene at Puerto Rico. This is an ideal ship for this situation -- it has an outstanding ability to move stuff from ship to shore, that's what it was designed to do in a war zone. Puerto Rico is a more benign environment. In keeping with it being a Naval combatant designed to support Marines in a war zone, USS Kearsarge has an extensive medical facility ...
Speaking of hospital ships, USNS Comfort may be en route, but before it arrives the port facilities will need to be restored.

Along with the military, there are NGO aide groups from the USA and Canada en-route to PR. And with some pride, I can say that my wife is once again volunteering and left early yesterday morning for a minimum 30 day deployment with a large NGO. They expect to be in PR by weeks end but that depends on the airlift and airport logistics situation which is chaos right now. It is worth noting that aide workers will have a full security briefing beforehand as the security situation in many areas of PR is not all that safe and is suspected to get worse in the coming days and weeks until food, water and shelter logistics, along with many other basics of life is established.

Also there is a call out from the American Red Cross for Ham Radio operators to assist with comms.

In the nearly 75-year association between the American Red Cross (ARC) and the American Radio Relay League (ARRL), yesterday there was an event without precedent in its scale: ARC asked ARRL for fifty amateur radio operators available for immediate deployment to Puerto Rico for disaster relief communications, especially transmitting health and welfare information.

I'm proud to be a member of ARRL. In less than twelve hours 50 highly qualified hams (General or higher licenses, previous disaster communications experience) responded to the call.

For myself, I am appropriately credentialed in both amateur radio and disaster communications, but I don't have previous experience. I'd also be a bad choice as I have almost no HF experience. Even if I'd been able to volunteer to be deployed, they wouldn't have taken me.

I know for sure that the US Army, Marine Corps and Navy all have this sort of capability.