FOG Definitions

Biochemical Oxygen Demand(BOD): is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period.  It’s often used as a robust substitute of the degree of organic pollution of water.

Chemical Oxygen Demand (COD): is commonly used to indirectly measure the amount of organic compounds in water. Most applications of COD determine the amount of organic pollutants found in surface water (e.g. lakes and rivers) or wastewater, making COD a useful measure of water quality.

Effluent:  treated wastewater coming from a water treatment facility that is typically returned to a nearby waterway.

Force main:  a pressurized sewer line usually connected to a pump station. It moves wastewater discharged from the pump station either to a gravity sewer or to a water reclamation facility.

Gravity sewer:  sewer line that slopes downward relying on gravity to convey wastewater to a force main, interceptor sewer, pump station, or reclamation facility. Sewer laterals typically extend from private property to a gravity sewer, which is the most common type of sewer line in use.

Influent:  wastewater, untreated or partially treated, from everyday activities that flows into a basin, treatment process, or water reclamation facility. Influent from homes and businesses is called “domestic” wastewater while wastewater from industrial and manufacturing facilities is known as “industrial” wastewater. Industrial wastewater goes through a pre-treatment process before it goes to the water reclamation facility.

Interceptor sewer: a large sewer line that collects flows from force mains and gravity sewers and carries it to a water reclamation facility. During heavy rains, leaks within the system sometimes add stormwater to interceptor sewers. An interceptor sewer’s larger diameter helps to protect against overflows during wet weather.

Pump or Lift station: an assembly of pumps contained in some type of housing that moves flow from a gravity sewer up a hill or changing land grade where gravity cannot move the flow. The flow from the gravity sewer typically comes into the wet well, which is essentially a tank or compartment for collecting the wastewater. Pumps are either connected to the wet well or if they are submersible pumps, they may be placed inside the well.  Force mains are used to move the flow from pump stations to other parts of the collection system.

Sewer lateral: a small diameter pipeline that runs from the foundation of a home or business to the sewer main, which is usually under the street. Maintenance of the sewer lateral is the responsibility of the property owner.

Water reclamation facility: a facility that receives wastewater from the collection system and through a combination of physical, chemical, and biological processes removes organic matter so the highly treated effluent can be returned to local waterways, which helps maintain river, stream, aquifer and lake levels.