Watershed Report Card
Through a grant from the Watershed Institute, the Lake Hopatcong Foundation working in cooperation with the Musconetcong Watershed Association, with assistance from Princeton Hydro, the lake’s environmental consultant, developed a “Watershed Report Card” for Lake Hopatcong and the Musconetcong River.
Here we will post updated water quality indicators from beaches around the lake as well as from the in-lake monitoring sites in the newly developed Watershed Report Card format.
Lake Hopatcong is monitored five times a year monthly from May to September by Princeton Hydro. Some of the water quality data collected during these sampling events are total phosphorus, nitrates, chlorophyll a, and water clarity. The sampling locations are done at 16 stations throughout Lake Hopatcong.
Additionally, all public beaches need to be tested on a routine basis over summer recreational months and warnings need to be posted if E. coli counts exceed State levels. Sustained counts in excess of legal parameters could also lead to beach closings until counts decline.
Thank you to the beach clubs and public beaches for providing the information, for us to gather in one easy place.
What is E. Coli?
E.Coli or Escherichia coli is a form of bacteria that is found in human and animal intestines. E. Coli is found in the environment through feces contamination and is the number one reason for beach closing. Sources of this contamination come from birds (geese), dogs and cats, humans (through septic systems, sewage treatment, and storm drains) and agricultural run-off. E.Coli attaches itself to grains on beach sand and multiples. The highest levels of E. Coli will typically be present after a storm, this is because rainwater runoff flows into the lake around the shoreline. In New Jersey, E.Coli counts should not exceed a maximum of 235/100 mLs. This means 235 organisms per 100 milliliters of water.
With this very high number there is usually concern for public health and the beach is closed until the count declines. Beaches on Lake Hopatcong are required to test on a weekly basis for this bacteria. The New Jersey Department of Environmental Protection (NJDEP) has set the parameter of 126/100mLs as a good benchmark. If the number is greater than 126 additional testing is required. E. Coli also has an effect on the lakes aquatic life because it takes available oxygen necessary for the aquatic life, which can kill them and other organisms. This beach data was collected from the various beach clubs on Lake Hopatcong.
More information available is available in the E-coli and Fecal Coliform Guide.
What else is included in the Watershed Report Card?
The water quality data from the five monthly in-lake sampling events is included in the Watershed Report card. The other parameters included are water clarity, chlorophyll a, total phosphorus, and nitrates.
Water clarity or transparency is measured at each in-lake monitoring station with a Secchi disk. Generally for lakes in northern New Jersey, water clarity is considered acceptable for recreational activities when the Secchi depth is equal to or greater than 1.0 meter (3.3 ft). Pictured below are examples of the secchi disk in use.
Total Phosphorus is the primary nutrient for algal and plant growth in Lake Hopatcong. Lake Hopatcong is considered a eutrophic lake. This means it has high levels of productivity for plant and algae growth which is moderate to high nutrient levels. In terms of total phosphorus (TP) greater than 0.03 mg/L and less than 0.06 mg/L is categorized as eutrophic. TP is found in fertilizers that runoff from lawns and streets into the Lake. Phosphorus has natural sources too, such as air, soil, and rocks. A little bit of phosphorus goes a long way. One pound of phosphorus has the potential to generate up to 1,100 pounds of wet algae goo. This goo is typically surface scum or filamentous mats. Since this nutrient has such a large impact on fresh water systems a long term restoration plan for the Lake was approved in 2006. The plan is to keep total phosphorus (TP) average concentrations at or below 30ppb or 0.03mg/L. If this concentration exceeds 60ppb or (0.06 mg/L) goo and algal blooms, lower water quality is expected. Since phosphorus has such a large effect on the Lake’s quality, the towns surrounding the lake and the State have adopted rules that limit the use of fertilizers around.
Nitrates (or NO3-n) are very dangerous to aquatic life in large amounts. Algae and weeds use nitrates as their source of food, like a fertilizer, so large amounts of it will cause them to grow rapidly. This will decrease the available oxygen in the water for the fish. This is produced by sewage and other chemical fertilizers that run-off into the lake.
For more information view the Lake Hopatcong Water Quality Guide.
How Can We Help?
Here are some simple steps we all can do even if we don’t live directly on the lake to improve the water quality!
- Plant native plants along the shoreline and in places susceptible to erosion
- Reduce the amount of fertilizer and always use phosphorus free fertilizers
- Sweep up excessive fertilizer and other debris from pavement
- Do not dispose of lawn waste near a source of water
- Clean up and properly dispose of pet waste
- Do not put anything in the storm drains
- Properly maintain septic systems and pump out every three years
- Bring your vehicles to a carwash or wash vehicles on the lawn instead of pavement to prevent direct runoff into storm drains
- Educate your friends and neighbors about the watershed and lake health
- Volunteer to clean up litter in your neighborhood or around the lake