Most of us do not think much about what happens after we flush the toilet. But there is a world of infrastructure out there that may come with a $20,000.00 price tag per Island household in the near future.
To be well informed about the issue, we thought we would begin with a brief primer on central sewer. These are the three types of central sewer systems, all of which are used to transport raw sewage through pipelines to a treatment facility.
Gravity sewers use large pipes trenched in a slow downgrade to move sewage. They are used in extreme high-density areas, such as you would find in major cities and municipalities – not applicable on the Island.
A Vacuum Sewer system maintains a partial vacuum inside the pipe network and vacuum station. A single central vacuum station (also called a lift station) can collect the wastewater of several thousand individual homes, depending on terrain and the local situation. Vacuum systems can be found in flat areas which have a high water table. Pipework is laid relatively flat in the ground and the whole intention of this type of system is to ensure that construction remains as shallow as possible. This reduces costs, time and environmental impacts.
Low Pressure Sewer Systems (Grinder Pumps) use a small pump station located at each house to move wastewater through the transmission system. Low-pressure systems (grinder pumps) can often be used when connecting outlying homes or developments to municipal central sewer. However, there are downside considerations with grinder pumps:
Sewer System Comparisons: Vacuum or Low Pressure Pumps