Sewage discharges – Untreated sewage from leaks and overflows of sanitary sewer lines has many negative impacts on our waterways including:
- Bacteria eat the organic matter in sewage which uses up oxygen in the waterway. This can result in the death of fish and other aquatic life.
- Sewage provides nutrients which leads to growth of algae and other plants. Excessive algae and plant growth can disrupt the aquatic food chain and the balance of plant and animal species.
- Introducing antibiotics and hormones that come from livestock and humans disrupts the natural processes that take place in the water and also negatively affects the growth and reproduction of aquatic animals.
Petroleum discharges and spills – Gas, oil and other petroleum materials are poisonous to aquatic plants and animals and waterfowl, sometimes resulting in their death.
Heavy metals can kill aquatic organisms.
- Heavy metals like cadmium, mercury, and lead are absorbed by fish and other aquatic life which negatively affects their activity, growth, body processes, and reproduction.
- In high enough concentrations, some heavy metals can kill aquatic organisms.
Fertilizers can negatively impact water quality.
- Fertilizers can negatively impact water quality when too much of it enters our waterways in stormwater runoff.
- Nutrients in fertilizers, such as nitrogen and phosphorus, can cause excessive algae and weed growth.
- Besides being unsightly and causing odor problems, too many weeds and algae can deplete the oxygen in water and cause fish and other aquatic life to die. This is most common in the summer when temperatures and sunlight are at their peak.
Pesticides have been linked to the death of many fish and other aquatic life.
- When pesticides are not used according to label instructions or are used in excessive amounts, they can enter waterways in stormwater runoff and harm fish and other aquatic life.
- Organisms at the lower end of the aquatic food chain are very intolerant of pesticides, so when they die off, that impacts the rest of the aquatic food chain.
Yard waste (leaves, grass clippings) can harm aquatic life when disposed of in storm drains.
- While many people may not think of yard waste as a pollutant because it is made up of natural materials, too much of it improperly disposed of into storm drains or surface waters can add too many nutrients and cause unwanted algae to grow.
- As algae decomposes, it uses up oxygen that aquatic life need.
Pollutants in other types of discharges.
- All kinds of products used at households and businesses are used that, when discharged improperly to a storm drain or directly to surface waters, can harm or kill aquatic life.
- These include uncured concrete, chlorinated pool water, paint, and many other materials.
– For instance, concrete has a high pH and can burn (like an acid burn) fish and other animals living in the water.
– Pool water where chlorine concentration has not been lowered can also burn and kill aquatic life.