2023 Clean Water Report Card

In this section:  About StreamWatch ,  StreamWatch Teams , and  Monitoring Locations .

StreamWatch is a citizen science program that employs the watchful eyes and willing hands of volunteers to help protect water quality and habitat in Central New Jersey. It was developed after research showed that no public agency was monitoring our waterways on a consistent basis. Since government agencies cannot control all the collective and individual actions that affect our environment, it is important for everyone to play a role in the stewardship of the natural world. The Chemical Action Team (CAT) of StreamWatch, the first of our water quality monitoring programs, was developed in the spring of 1992 by Watershed staff as our response. Volunteers Lesley Barnhorn and Tim McDermott implemented it that summer.

StreamWatch has four overall project goals:  

• To characterize the water quality in Central New Jersey,
• To involve citizens in observing, monitoring, recording, and reporting stream conditions,
• To motivate the public to initiate change in their use of the land and drainage systems that will enhance water quality, and
• To provide quality data to decision-makers which may bring about improvement in water quality.

The goals will be achieved by establishing short and long-term objectives, including the compilation of information gathered by other sources on watershed water quality, the publication of progress reports, and sharing of collected data with local government.

Each of the nine parameters we score has three maps detailing individual site scores, subwatershed scores, and municipal scores. These maps are arranged horizontally under each parameter heading and can be accessed by using the arrows in the map interface. Pan and zoom to find points of interest, such as a nearby stream or your home municipality. Clicking anywhere on a map will show a pop-up with additional information about that location, including recent sampling dates, detailed scoring data, and land usage statistics. Site pop-ups may have multiple tabs, which can be viewed using the arrows at the bottom left corner. The nine parameters ( Temperature ,  Turbidity ,  pH ,  Dissolved Oxygen ,  Nitrate ,  Phosphate ,  Chloride ,  Macroinvertebrates ,  E. coli ) fall under three main categories, which can be accessed quickly in the main menu above.

The Watershed Institute supplies this information for educational and informational purposes only, and it is not intended to be a substitute for federal or state recommendations regarding local water. This includes advisories around safe drinking, boating, fishing, or swimming in New Jersey lakes and streams.

Click on the green box (below) to see how we determine how our watershed fares across the different parameters measured by StreamWatch from January 2019 - December 2023. Sites have been assessed on a scale of “Excellent”, “Good”, “Fair”, or “Poor” for each parameter individually, then used to determine if each subwatershed or municipality meets or fails the applicable  NJ DEP Surface Water Quality Standards .

Subwatersheds and municipalities whose scores are calculated based on a single site are made more transparent. This serves to indicate the preliminary results for that area as well as the need for more data collection.

Our overall scores act as a summary of the individual scores for each parameter that we measure. Expanding our monitoring efforts will help us to collect data in these areas and others so that we can build a clearer picture of water quality in central New Jersey.

Sites are scored on a four-unit scale: Excellent, Good, Fair, and Poor. These scores have been assigned a value of 4, 3, 2, and 1, respectively. For subwatersheds and municipalities with multiple sites, the geometric mean of scored values is calculated to determine the score for the subwatershed as a whole according to the table shown in the  2024 Assessment Framework .

Physical parameters we measure include  Water Temperature  and  Turbidity . Click on each parameter to jump to the corresponding maps.

Although temperature may be one of the easiest measurements to perform, it is probably one of the most important parameters to be considered. It dramatically affects the rates of chemical and biological reactions within water. Elevated water temperatures, known as thermal pollution, can decrease the capability of water to hold dissolved oxygen, crucial to aquatic organisms.  Thermal pollution can also impair feeding, growth, and reproduction and can cause death to aquatic organisms. Fish species vary in the level of thermal pollution they can withstand.  Even a small change in temperature can drastically affect a fish's life cycle. Spawning activities, metamorphosis, and migration can be triggered at the wrong time of the year by a slight change in temperature.  This, in turn, can decrease or destroy a species’ chance of survival.

Sedimentation is the process by which streams, storm runoff, and other forms of moving water carry sand, silt, clays, organic matter, and other substances into streams and lakes from the surrounding watershed. In general, the amount of material deposited into a lake or stream is directly related to the use of watershed land. Activities that clear the land and expose soil to winds and rain (i.e., agriculture, site development) may greatly increase sedimentation.

Sediment material eroded from the watershed tends to fertilize algae and aquatic plants because essential nutrients are attached to incoming sediment particles. Further, sedimentation can ruin the lake bottom for aquatic insects and bottom dwelling creatures and negatively affect fish spawning beds by filling in or covering crucial habitat space. 

Turbidity measures how much the sediment particles suspended in the water affect the passage of light through the water. The presence of suspended sediment may cause the water to be cloudy and brownish in appearance. Suspended particles block light from penetrating into the water and may interfere with the gills of fish and the breathing mechanisms of other creatures.

Chemical parameters we measure include  pH ,  Dissolved Oxygen ,  Nitrate ,  Phosphate , and  Chloride . Click on each parameter to jump to the corresponding maps.

A measure of acidity or alkalinity of the water, pH is based on a scale of 0.0 to 14.0 standard pH units. A pH of 0.0 is the most acidic, a pH of 14.0 is the most alkaline, and a pH of 7.0 is neutral.  Normal rainwater is slightly acidic with a pH ranging from 5.5 to 6.0. 

Each organism requires a certain pH range to survive, and most organisms are very susceptible to changes in pH. The pH of unpolluted water depends on the local geology and physical conditions. For example, streams draining wooded swamps usually have a pH between 5.5 and 6.5, while streams in limestone areas may have a pH as high as 9.0.

Human-driven sources of pH-influencing pollution include industrial runoff, landfill leaching, and agricultural waste. Depending on their composition, these inputs can cause surface water to become either too acidic or too alkaline, which damages soft tissues of aquatic organisms, weakens invertebrate exoskeletons, and prevents aquatic plants and algae from developing.

Dissolved oxygen (DO) is one of the most important indicators of the quality of water for aquatic life. It is essential for all plants and animals inhabiting the stream. When oxygen levels in the water fall below about 3.0 – 5.0 ppm, fish species become stressed. At a level below 2.0 – 3.0 ppm, they cannot survive. Oxygen is a sensitive constituent because other chemicals present in the water, biological processes, and temperature exert a major influence on its availability during the year. 

Oxygen is transferred directly from the atmosphere into the surface waters by the aerating action of the wind and wave action. It is also added at or near the surface as a by-product of plant photosynthesis. As a result, floating and rooted aquatic plants increase dissolved oxygen levels. Since the presence of aquatic plants and algae also depends on the availability of light, dissolved oxygen levels can be affected by turbidity and sedimentation.

Nitrogen makes up about 80% of the air we breathe. It's an essential component of proteins and is found in the cells of all living things. Inorganic nitrogen may exist in the "free" state as a gas, or as nitrites, nitrates, or ammonia. Organic nitrogen is found in proteins and other compounds. The most common source of nitrate pollution in water is from fertilizer used in agriculture, which is washed into rivers and streams during rain events. Other sources include mismanaged sewage or some types of manufacturing waste. These nitrates can accumulate in a process known as eutrophication, and high levels of dissolved nitrates can cause harmful algal blooms (HABs) that kill other aquatic organisms and contaminate drinking water.

Acceptable nitrate levels for drinking water have been established as less than 10.0 milligrams of nitrate in one liter of water (mg/l). Unpolluted water generally has a nitrate reading of less than 2.0 mg/l. The nitrate test measures nitrate-nitrogen levels in parts per million (ppm). Ppm is equivalent to mg/l.

Eutrophication is the natural aging process of a body of water. However, an excess of nutrients such as nitrates and phosphates can greatly accelerate this natural process by stimulating excessive plant growth. These plants die more quickly than they can be decomposed, and the dead plant matter builds up. Together with the sediment entering the water, the plant matter results in a filling of the bed of the water body making it progressively shallower. Although the process of eutrophication may take hundreds or even thousands of years naturally, human impacts may reduce this time period to tens of years.

Like nitrate pollution, phosphate pollution can come from agriculture, sewage, or industrial waste. As phosphates are often the limiting factor for algal growth in freshwater systems, excess phosphate can also cause eutrophication, rapidly degrading freshwater ecosystems.

Increased chloride levels in freshwater systems can be attributed to human impacts. Since the widespread adoption of the use of road salts in the 1970s, chloride concentrations have risen dramatically. Excessive chloride concentrations can lead to a multitude of biological effects from smaller animal body sizes and changing sex ratios to cellular desiccation and death. In lakes stratified by salt, denser salty water sinks to the bottom and avoids vertical mixing with the layers above, preventing dissolved oxygen from replenishing the deeper parts of the lake. Chloride concentrations have increased over time since there are few methods to filter it from surface and groundwater, compromising drinking water supplies. Salty drinking water may taste bad for some, but it can be harmful to those on low-salt diets, sometimes without them even knowing. Saltier water also corrodes infrastructure, increasing the likelihood of heavy metals like lead and copper leaching into drinking water.

Biological parameters we measure include  Macroinvertebrates  and  E. coli . Click on each parameter to jump to the corresponding maps.

Freshwater macroinvertebrates, ranging from the fully aquatic snails, clams, and mussels to the larval stages of terrestrial insects like dragonflies and mosquitoes, are vital parts of food webs in lakes and streams. In addition to serving as prey for larger organisms like fish and frogs, they also help to decompose and process decaying organic matter that would otherwise build up and fill in the bed of a water body.

A survey of the abundance and diversity of macroinvertebrate species at a site is a good approximation of that site's water quality, since an unhealthy system is generally unable to support the same biodiversity as a healthy one.

E. coli is a species of gut bacteria found in the digestive system of many animals, including humans. They aid in the digestion of certain components of food and provide their hosts with nutrients like vitamin K, which would otherwise be difficult to obtain. While they primarily live in the lower intestine of a host organism, they can survive for a period outside the body, living off of environmental nutrients instead.

High levels of E. coli in water can be dangerous, however, and may cause disease after exposure through activities like swimming or wading or via contaminated drinking water. The most common cause of elevated E. coli in water is untreated sewage, though a baseline population of E. coli is normal because of waste from other animals.

Water monitoring and research are the foundations of The Watershed Institute’s efforts to protect streams and rivers in central New Jersey. Understanding the health and quality of our waters helps us to protect and restore our water and natural environment through conservation, advocacy, science, and education. Becoming a StreamWatch volunteer is an easy and fun way to contribute to the health of your watershed.

The Watershed Institute also offers River-Friendly Certification! These programs promote clean water and a healthy environment through voluntary action by individuals and institutions. To achieve these goals we work one-on-one with residents, businesses, golf courses, and schools to improve land stewardship practices. The program works to reduce pollution, conserve water, restore habitat for wildlife and educate the public about becoming better environmental stewards.

The Watershed Institute and the New Jersey Watershed Watch Network work with about 300 community volunteers who help monitor and assess the salinity of freshwater streams in the winter throughout New Jersey. They share their results with state officials and contribute to a nationwide study, Winter Salt Watch, conducted by the Izaak Walton League of America.