Wastewater Utility

Biochemical Oxygen Demand (BOD) measures how much oxygen is needed by aerobic microorganisms to break down organic matter in water—typically from pollution sources like sewage. It’s a key indicator of water pollution, showing how much oxygen will be used to fully digest the remaining organic material in treated wastewater. In ideal conditions, BOD would be zero.

BOD is one of the most widely used indicators of organic pollution in water. It reflects the amount of biodegradable material present: low BOD means cleaner water, while high...

Biochemical Oxygen Demand (BOD) measures how much oxygen is needed by aerobic microorganisms to break down organic matter in water—typically from pollution sources like sewage. It’s a key indicator of water pollution, showing how much oxygen will be used to fully digest the remaining organic material in treated wastewater. In ideal conditions, BOD would be zero.

BOD is one of the most widely used indicators of organic pollution in water. It reflects the amount of biodegradable material present: low BOD means cleaner water, while high BOD points to higher pollution levels. When water contains a lot of organic waste, bacteria use up dissolved oxygen (DO) to decompose it. DO is the oxygen naturally dissolved in water and is vital for aquatic life.

If DO levels drop too low, fish and other aquatic organisms struggle to survive. This oxygen depletion can lead to fish kills and overgrowth of invasive aquatic plants, causing major ecological changes in rivers, lakes, and streams. Since energy is produced through oxidation, BOD helps determine how strong or concentrated the sewage is. For example, reducing BOD from 500 to 50 means a 90% reduction—showing significant treatment progress.

Nitrogen is an essential ingredient in the formation of proteins for cell growth. From complex organisms like animals to the simple bacteria used to treat wastes in an activated sludge treatment facility, every living thing needs some form of nitrogen to survive.

But too much nitrogen freely available in the environment can be a bad thing. Excess nitrogen discharged into our waterways can contribute to the gradual change of water bodies into marshes, meadows, and forests. It can also contribute to massive algae blooms leading...

Nitrogen is an essential ingredient in the formation of proteins for cell growth. From complex organisms like animals to the simple bacteria used to treat wastes in an activated sludge treatment facility, every living thing needs some form of nitrogen to survive.

But too much nitrogen freely available in the environment can be a bad thing. Excess nitrogen discharged into our waterways can contribute to the gradual change of water bodies into marshes, meadows, and forests. It can also contribute to massive algae blooms leading to oxygen depletion in water and its associated problems. Certain forms of nitrogen can cause specific problems too. Ammonia is toxic to fish, and nitrates at high enough dosages in the drinking water cause illness in infants.

In the wastewater field we are concerned with several forms of nitrogen: ammonia, organic, nitrate, and nitrite. Under the right conditions, each of these forms is biologically convertible to one of the other forms. This creates certain challenges in the treatment of nitrogen in wastewater. Because of these challenges, it is important to properly collect, preserve, and analyze samples for the specific forms of nitrogen so that the appropriate treatment of these wastes can be made.

Total Phosphorus is the total concentration of phosphorus found in the wastewater.

Phosphorus is a nutrient and acts as a fertilizer, increasing the growth of plant life. Phosphorus comes from several sources: human wastes, animal wastes, industrial wastes, and human disturbance of the land and its vegetation. Sewage from wastewater treatment plants and septic tanks is one source of phosphorus in rivers and lakes.

Phosphorus can be removed from wastewater by various means. The Racine Wastewater Treatment Plant removes phosphorus with ferric chloride, greatly reducing...

Total Phosphorus is the total concentration of phosphorus found in the wastewater.

Phosphorus is a nutrient and acts as a fertilizer, increasing the growth of plant life. Phosphorus comes from several sources: human wastes, animal wastes, industrial wastes, and human disturbance of the land and its vegetation. Sewage from wastewater treatment plants and septic tanks is one source of phosphorus in rivers and lakes.

Phosphorus can be removed from wastewater by various means. The Racine Wastewater Treatment Plant removes phosphorus with ferric chloride, greatly reducing the amount of phosphorus discharged to the lake.

Total Suspended Solids is a water quality measurement usually abbreviated as TSS. It is listed as a conventional pollutant in the U.S. Clean Water Act. It is a measure of the amount of small, particulate solid pollutants that are suspended in wastewater after treatment. Ideally, suspended solids would be zero.

These particles suspended in water will not pass through a filter. Suspended solids are present in sanitary wastewater and many types of industrial wastewater. TSS can include a wide variety of organic and inorganic material,...

Total Suspended Solids is a water quality measurement usually abbreviated as TSS. It is listed as a conventional pollutant in the U.S. Clean Water Act. It is a measure of the amount of small, particulate solid pollutants that are suspended in wastewater after treatment. Ideally, suspended solids would be zero.

These particles suspended in water will not pass through a filter. Suspended solids are present in sanitary wastewater and many types of industrial wastewater. TSS can include a wide variety of organic and inorganic material, such as silt, decaying plant and animal matter, industrial wastes, and sewage.