I live in a community on the Pacific Coast of Nicaragua and I do not recommend drinking the water from the tap. While other comments on this site have suggested the water is "generally" safe, I think its important to consider your water source very carefully.
The body needs significantly more water here in Nicaragua, which means you should be drinking about double what you drink in a normal climate. Now, your body will be digesting the water differently as well since it will use it to cool off.
I experimented with drinking the local "aquifer" water for about a week. While I was not sick with obvious ailments one may witness in the bathroom, there was a very heavy feeling in my lower abdomen which was caused by the heavy metals that are not cleansed from the underground source.
The best option is too buy a reverse osmoses purifier and hook it up in your house. My boss has this system, and it is great. It is cost effective as well. I just use the large 5 gallon bottles currently, but once I move to a permanent location I will be using a reverse osmoses system as well.