SWAP - Frequently Asked Questions

q1. What is a Public Water System?

a1. A public water system is a system of pipes or other constructed material that provides water to the public for consumption. To be classified as a public water system, the water system must contain at least fifteen service connections or regularly serve at least twenty-five individuals. If a water system does not fall within this definition, it is considered a private water system. For example a home which contains its own well is not a public water system. For different types of public water systems please refer to question number two.

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q2. What are the different types of public water systems?

a2. There are two types of public water systems: community and noncommunity. A community water system has at least 15 service connections used by year around residents, or regularly serves at least twenty-five year around residents. Examples of a community water system are mobile home communities and municipalities.

A noncommunity water system is a public water system used by individuals other than year around residents for at least sixty days of the year. A noncommunity water system can be either transient or nontransient. A nontransient noncommunity water system serves at least twenty-five of the same people over a period of six months during the year, such as schools, factories, and office buildings. A transient noncommunity water system is a system that serves year around for at least sixty days of the year, but does not serve the same individuals during that time period. Transient noncommunity water systems include rest stop areas, restaurants, and motels.

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q3. Where do public water systems get the drinking water?

a3. There are two sources of drinking water: ground water and surface water. Ground water is water that has infiltrated into the ground and is stored in aquifers, the soil and rock below the surface. Aquifers typically consist of gravel, sandstone, sand, or fractured rock. An aquifer can be confined or unconfined. A confined aquifer is when the ground water is bounded between layers of impermeable layers, such as clay. An unconfined aquifer is an aquifer that is not bounded by impermeable layers, but instead has a water table that rises and falls over time.

Ground water is obtained by pumping water from an aquifer or a spring through a well. A well is a hole drilled into an aquifer in which a pipe and pump are used to extract water from the ground. In 2002, public wells in New Jersey ranged from a depth of 15 feet to 1,984 feet.

Surface water is water collected from streams, rivers, lakes, and reservoirs. Precipitation that does not infiltrate into the ground or evaporate into the atmosphere runs off into these surface waters.

A link exists between ground water and surface water. Ground water may discharge into a lake or stream. During periods of low precipitation New Jersey's natural streamflow is from ground water. Some of the streams in New Jersey may also lose water to ground water.

Community water systems in New Jersey receive drinking water from both ground water and surface water. With the exception of three noncommunity water systems, noncommunity water systems obtain drinking water from ground water sources.

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q4. How many New Jersey Public Water Systems were assessed in 2004?

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q5. What is a source water assessment?

a5. A source water assessment is the determination of a public water system's vulnerability to contamination. A source water assessment is completed for a public water system through four steps:

1. Delineate the source water assessment area for a public drinking water source.


2. Inventory the potential contaminant sources within the source water assessment area.


3. Determine the public water system's susceptibility to contamination.


4. Public participation and outreach.

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q6. What is a source water assessment area for ground water?

a6. A source water assessment area for ground water sources in New Jersey is the area from which water flows to a well within a certain time period. Each ground water source water assessment area in New Jersey contains three tiers, labeled as Tier 1, Tier 2, and Tier 3. Tier 1 is a two year time of travel, which means the ground water within this tier flows to the well within a two year time period. Tier 2 is a five year time of travel; the ground water within this tier will flow and reach the well within five years. The final tier, Tier 3, is a twelve year time of travel, in which the ground water within this tier will flow and reach the well within twelve years.

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q7. What is a source water assessment area for surface water?

a7. For surface water sources, such as a river, the source water assessment area is the area upstream of a surface water intake including the tributaries and headwaters.

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q8. How did the New Jersey Department of Environmental Protection delineate the source water assessment areas for ground water sources (wells)?

a8. New Jersey Department of Environmental Protection has performed ground water source delineations using the Combined Model/Calculated Fixed Radius Method for all community water systems. Public noncommunity water systems were delineated using the Calculated Fixed Radius Method. For a detailed description of the delineation methods please refer to "Guidelines for Delineation of Well Head Protection Areas in New Jersey" - adobe pdf.

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q9. How did the New Jersey Department of Environmental Protection delineate the source water assessment areas for surface water intakes?

a9. The source water assessment area delineations were performed using United States Geological Survey's hydrologic unit code 14. The source water assessment area for surface water intakes contains the entire drainage area that flows past the intake. This area includes the headwaters and tributaries. For more information concerning the surface water assessment areas please refer to the SWAP Plan.

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q10. What contaminant categories were addressed in the SWAP?

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q11. What does a Potential Contaminant Source Inventory consist of?

a11. Within the source water assessment area all potential contaminant sources were identified to assist in determining a public water system source's susceptibility to contamination. Potential contaminant sources within the source water assessment area were identified using existing Geographic Information System (GIS) data sets. The Potential Contaminant Source Inventory focuses on two contaminant groups: point and nonpoint sources. Nonpoint sources, primarily land use sources, include runoff from roadways, pesticide and herbicide application, storage facilities, and landfills. Point sources include known contaminated sites, leaking underground storage tanks, storage facilities, and New Jersey Pollution Discharge Elimination Systems (NJPDES) discharges.

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q12. How was a public water system's susceptibility to potential contamination determined?

a12. The New Jersey Department of Environmental Protection contracted with the United States Geological Survey to provide susceptibility assessments for all of the public water systems for each of the contaminant categories.

To determine susceptibility, the United States Geological Survey developed susceptibility models. Models were created for each of the contaminant categories and for ground water and surface water. Susceptibility is determined on several factors: location, use, ground water or surface water, and amount and type of potential contaminants within the source water assessment area.

The susceptibility models were created using existing analytical data and a selected set of public water system wells and intakes located throughout the state. Following the development of the models, the United States Geological Survey tested and validated the models using additional public water system wells and intakes. These models were then applied to the remaining public water systems to determine the drinking water source's susceptibilities. Each drinking water source received a high, medium, or low rating to each contaminant category.

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q13. How did the New Jersey Department of Environmental Protection incorporate public education and participation into SWAP?

a13. As a result of the 1996 Amendments' strong emphasis on public outreach, the New Jersey Department of Environmental Protection developed a Source Water Assessment Advisory Committee. The advisory committee consists of approximately 50 members who come from various interests including water purveyors, municipalities, health departments, and environmental organizations. Source Water Assessment Advisory Committee is responsible for assisting the New Jersey Department of Environmental Protection with addressing concerns and questions that arise during the SWAP. The advisory committee will also ensure the information gained from the source water assessments is presented to the public in an understandable form.

In addition, the New Jersey Department of Environmental Protection presented SWAP to various groups throughout the state including water purveyors, watershed management areas, environmental organizations, and other interested groups. The New Jersey Department of Environmental Protection also kept the public informed through a series of newsletters, fact sheets, and other educational materials. The New Jersey Department of Environmental Protection anticipates hosting training sessions for the water purveyors to ensure they understand the material provided in their source water assessment report.

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q14. When were the source water assessments completed?

a14.The SWAP began when the United States Environmental Protection Agency approved New Jersey's SWAP Plan in November of 1999. New Jersey Department of Environmental Protection completed the community water system source water assessments in January 2005. The noncommunity water system source water assessments were finished by June 2005. All the source water assessments are available on the SWAP web page.

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q15. How did the New Jersey Department of Environmental Protection report the results of the source water assessments?

a15. A source water assessment document was created for each public water system in New Jersey. The New Jersey Department of Environmental Protection met with the Source Water Assessment Advisory Committee to discuss several source water assessment report formats and decided to develop three separate documents. The results of the source water assessments are reported in the following documents.

Community Water System Source Water Assessment Report: primarily intended for the public water system's reference and use, although the report is also available to the public. Individuals, environmental organizations, and municipalities interested in source water protection may also utilize the Community Water System Source Water Assessment Report for protection activities. The report is a large document consisting of seven sections providing general SWAP information and system specific information such as contact information, source susceptibility ratings, and entry point to the distribution system susceptibility ratings. Several attachments are also included in the report, such as source water assessment area maps, potential contaminant source inventories, and treatment.

Community Water System Source Water Assessment Summary: a short (4 page) informative document created for the general public. The Community Water System Source Water Assessment Summary is a synopsis of the Source Water Assessment Report and provides the source susceptibility ratings for the community water system and a source water assessment area map. The State is requesting water systems to provide its customers with a copy of the summary either as a bill insert or with their Consumer Confidence Report.

Noncommunity Water System Source Water Assessment Report: developed for the respective noncommunity water system. The report is similar to the community water system summary. It is approximately six pages in length, with the first two pages containing general information and then the remaining pages being system specific.

Noncommunity Water System Source Water Assessment Report - Municipality Based: developed for each municipality that contains at least one noncommunity water system. There are 296 municipalities in New Jersey that contain one or more noncommunity water systems. This report is similar to the Community Water System Source Water Assessment Report and includes all of the individual Noncommunity Water System Source Water Assessment Reports for the systems within the municipality.

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q16. Who do I contact for more information on the SWAP?

a16.Please contact the Bureau of Safe Drinking Water at (609) 292-5550 or email us

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