Purpose
All boats that have running water, a toilet or other types of plumbing must have a holding tank to store water. Most holding tanks are permanent structures within the boat and are mounted somewhere in the boat; however, some holding tanks are temporary structures. The purpose of a holding tank is to have a place to store all water from the boat. This includes fresh water, waste water or wash water.
Law
The Clean Water Act of 1972 addresses the issues of water pollution issues. Through this act, boats are not allowed to discharge any type of water or liquids into lakes or other waters. This act was created for several purposes, but the primary reason was to control the amount of sewage and wastewater boats were placing into water areas.
Maintenance
If you have a holding tank in your yacht, you must rinse and flush it out after the tank is pumped out. Many people may perform this process after each boat trip; however, if you use the boat quite often, you may not need to do this after each trip. This helps reduce odors and dilutes any remaining materials left in the tank. At the end of the boating season, pump and rinse the tank and allow it to dry. After this, the boat is ready to be winterized.
Details
In order to have plumbing that is usable in your yacht, you must also fill up the reservoir with fresh water for other uses such as a sink or for flushing the toilet. Wastewater can hold many types of bacteria, so if you have a yacht that has running water, be sure to install a holding tank in it if it does not have one already.