Four key steps are taken to assess public water systems. They are:

1) Delineate the drinking water source protection area. This is the area around the water intake that could contribute water or pollutants to the water supply. For wells, this area is a 500-foot or 1000-ft. radius for smaller water systems and a five-year ground water travel time for larger water systems. For surface water systems, the assessment area is determined by the upstream watershed.

2) Inventory known or potential sources of contamination. The inventory takes place within the delineated source water protection area. This inventory only identifies potential sources of contamination. It does not mean that these sites are actively causing contamination of the drinking water source.

Examples of some potential contaminants sources could include landfills, underground or aboveground fuel storage tanks, dry cleaning facilities, and wastewater disposal areas.

3) Determine the susceptibility of the water supply to the contaminants. This analysis will tell how likely it is that these potential sources could affect your source of drinking water. Each potential source of contamination will be given a score that will indicate whether it has a high, moderate or low risk of affect the drinking water source.

4) Notify the public about the threats identified in the contaminant source inventory.  DEP will create summaries that will help communities to understand the potential threats to their water supply.  This information will be sent to utilities, provided to interested parties and posted on the SWAPP website.  Whether your tap water comes from surface or ground water, all drinking water sources are vulnerable to a variety of contaminants from a variety of activities.  The origin of contaminants might be in your neighborhood or many miles away.  When  rain falls, it picks up and carries away pollutants, depositing them into lakes, rivers, wetlands, coastal and even underground sources of drinking water.  Because we know these activities have the potential to contaminate the source of our drinking water, we have created four major barriers to protect our source water from contamination.  Preventing pollution is critical to protecting drinking water from contamination and reducing the need for costly treatment.  Community involvement and individual action are key to providing a safe supply of drinking water.