Water Quality Issues

Credit: Jim Lukach

The Great Swamp Watershed and Passaic River face a range of water quality threats. Below are some water quality issues and what you can do to help:


Have you ever seen a pond or lake that has a layer of green algae on top? That water body is most likely impaired as a result of excessive fertilizer, failing septic tanks, or other nutrient rich pollution. When excessive amounts of nutrients, like nitrogen and phosphorous, enter waterways in runoff from storm events, they cause unicellular and filamentous algae to grow.  This rapid growth of life is called an algal bloom. As the algae dies, bacteria in the water begin to break it down, depleting the water’s supply of dissolved oxygen in the process. Just like humans, aquatic life needs oxygen to survive. Poorly oxygenated water can harm and even kill animals that live in the water. This entire process is called eutrophication, and can be prevented by making smart choices in the products you use around your home.

  1. Avoid using fertilizer, especially before it rains.
  2. If you have a septic tank, make sure it does not leak.
  3. Check your cleaning products, such as laundry detergent, to make sure they don’t contain phosphates.
  4. If you have a water body on your property, plant trees or shrubs around it to protect it from run off.


E. coli is a type of bacteria normally found in the intestines of mammals (including humans) and birds. Most strains of E. coli are harmless but can indicate the presence of fecal matter, which may contain harmful viruses. No natural body of water will ever be entirely free of E. coli because of the animal life surrounding it, but high levels can indicate fecal contamination which could be due to a failing septic system, broken sewer pipe, or stormwater runoff carrying fecal matter deposited by wildlife and pets into the water. To ensure that the water we interact with is free of harmful bacteria, make sure you:

  1. Always pick up after your dog, even in your yard. Remember that stormwater runoff flowing from your yard eventually ends up in a water body.
  2. If you have a septic system, be sure to perform regular maintenance on it to ensure that it is working properly.

pH Levels

pH is a measure of how acidic or alkaline (basic) water is. The pH scale ranges from 0 to 14. Water with a low pH is considered acidic, while a high pH is considered alkaline or basic. Although 7 is considered neutral, streams in our area have an expected pH between 6.5 and 8.5. If the water in a stream is too acidic or basic, fish, plants, and other life forms cannot survive. The habits of watershed homeowners can have an effect on the water’s pH levels. To keep things neutral you can:

  1. Conserve energy. Power plants release chemicals into the air which can cause acid rain (which then falls into our streams), so reducing the amount of energy you use in your home reduces the pollution output of the power plants.

Road Salt

Road Salt is the primary pollutant in Great Swamp Watershed streams. Winter use of road salt easily contaminates streams (through runoff from impervious roads, driveways, parking lots, and sidewalks). It can be deadly to aquatic life and plants on stream banks. Fish, insects, and macroinvertebrates often cannot tolerate high levels of road salt and may die when the levels are too high. Non-aquatic animals can also be negatively affected by road salt as they drink the contaminated water. As a homeowner, you can help to decrease road salt in the environment by:

  1. Using less or no road salt on driveways and walkways in the wintertime.
  2. If you must use salt, apply according to package directions and choose a product that is more environmentally benign. Sodium chloride has the highest environmental impact and should be avoided, while calcium magnesium acetate has the lowest environmental impact.
  3. Support municipal efforts to utilize lower salt alternatives such as brining.

Water Temperature

Water Temperature is critical because the fish, amphibians, and invertebrates that live in streams are cold-blooded, and the temperature of the stream can dictate whether they can survive and thrive. Different species of fish live best in different temperatures of water, and water that is consistently too hot or too cold for the native fauna will not support an ecosystem well. For example, trout are very sensitive to water temperature and cannot live in streams that are too warm. High water temperatures can also decrease dissolved oxygen levels, further negatively impacting aquatic life. To make sure any water bodies that are on your property can support a healthy ecosystem, make sure you:

  1. Plant trees and shrubs along streams to provide shade.

Water Clarity

Fish have trouble navigating when water clarity is poor. Underwater plants serve many purposes in a stream ecosystem, from providing food for animals to oxygenating the water. However, plants need sunlight in order to thrive, and muddy, opaque water does not let light in. Additionally, poor water clarity frequently is a sign of excess sediment which can impact aquatic life by burying stream bottom habitat. To help improve water clarity, you can:

  1. Allow natural vegetation to grow along stream banks by planting trees and shrubs or simply reducing or eliminating mowing there. Taller vegetation acts as a filter, catching sediment before it enters the stream and slowing runoff down to reduce stream bank erosion.
  2. If you have large areas of exposed soil due to construction, use silt fencing to keep it in place.

Combined Sewer Overflows

Combined Sewer Overflows or CSO’s for short, are outdated wastewater systems that utilize sewage pipes for stormwater drainage. During heavy rain events, these systems over flow (the added stormwater runoff can overtax the wastewater treatment plant capacity, at which point, flow is redirected into the river, bypassing the wastewater treatment plant all together. This results in raw sewage entering the waterways.

Improper Disposal of Trash

Trash and other man-made pollution can enter our waters in runoff during storm events or from illegal dumping. The presence of trash in the water is harmful to wildlife because they can ingest it, it can contaminate and degrade habitats, and make it so there’s no where to live. In addition, toxic chemicals used in plastics can leach into the water. Every single piece of plastic that has ever been produced is still in existence. You can help keep trash out of the water by:

  1. Securing your trash
  2. Not dumping illegally
  3. Avoiding microplastics
  4. Disposing of larger trash items in designated landfill areas