A

• Activated sludge: Microorganisms used in biological wastewater treatment.

• Aerobic: Occurring with oxygen present.

• Alkalinity: Ability of a substance to neutralize acids.

• Aquifer: Underground layer storing and transmitting groundwater.

• Backflow prevention: Devices or methods to prevent contaminated water backflow.

• Biochemical oxygen demand (BOD): Oxygen needed by microbes to decompose organic matter in water.

• Chlorination: Adding chlorine to water for disinfection.

• Coagulation: Process of causing water particles to clump and settle.

• Collection system: Network of pipes collecting wastewater from homes and businesses.

• Combined sewer overflow (CSO): Untreated/partially treated wastewater discharge point in heavy rainfall.

• Cross-connection: Physical link between a contaminated source and clean water supply.

B

• Bar screen: Tool used to remove large debris from wastewater.

• Biochemical methane potential (BMP): Estimate of methane production from organic matter.

• Biosolids: Treated and stabilized sewage sludge used as fertilizer or fuel.

• Blending: Mixing raw water with treated water to adjust specific parameters.

• Bypass: Channel allowing water or wastewater to flow around a treatment process.

C

• Catch basin: Underground structure collecting surface runoff and debris.

• Caustic soda: Chemical used for pH adjustment and grease removal in wastewater.

• Centrifugation: Separation process using high-speed rotation to separate particles from liquids.

• Chloramination: Disinfection using both chlorine and ammonia.

• Clarifier: Tank used to settle out suspended solids from water or wastewater.

D

• Demand management: Strategies to reduce peak water demand and conserve water.

• Demineralization: Removal of minerals from water, often via reverse osmosis.

• Desalination: Removing salt from water to produce freshwater.

• Detention basin: Temporary storage for stormwater to control flow and prevent flooding.

• Digestion: Process of breaking down organic matter by microorganisms in anaerobic conditions.

E

• Effluent: Treated wastewater discharged from a treatment plant.

• Emerging contaminant: Newly detected contaminants with unknown health effects.

• Erosion: Wearing away of land surface by wind or water.

• Evapotranspiration: Combined loss of water from land surface through evaporation and plant transpiration.

• Fecal coliform bacteria: Group of bacteria used as indicator organisms for potential fecal contamination.

F

• Floc: Clump of particles formed during coagulation.

• Flocculation: Process of causing flocs to form in water or wastewater.

• Flowmeter: Device that measures the flow rate of water or wastewater.

• Fluoridation: Adding fluoride to water for dental health benefits.

• Gravity sewer: Sewer system relying on gravity to move wastewater downhill.

G

• Grease trap: Device that traps grease in kitchen wastewater before it enters sewer system.

• Groundwater: Water stored underground in saturated rock or unconsolidated materials.

• Hydrant: Valve for accessing water supply for firefighting or other purposes.

• Hydraulic retention time (HRT): Average time water or wastewater spends in a specific treatment unit.

I

• Infiltration: Entry of water from the ground into a sewer system.

• Influent: Untreated water entering a treatment plant.

• Irrigation: Applying water to land to support plant growth.

J

• Jetting: Cleaning pipes using high-pressure water to remove blockages.

K

• Kinetic settling velocity: Rate at which particles settle through water.

L

• Lagoon: Large open pond used for wastewater storage and treatment.

• Leakage: Loss of water from a pipe or other infrastructure.

• Level of service: Expected quality and reliability of water or wastewater service provided to customers.

M

• MBR (Membrane Bioreactor): Wastewater treatment system combining activated sludge with membrane filtration.

• Membrane filtration: Process using membranes to remove impurities from water.

• Meter: Device that measures the amount of water or wastewater used by a customer.

• Microfiltration: Membrane filtration removing particles larger than 0.1 microns.

• Microwaves: Emerging technology for wastewater sludge disinfection and pathogen reduction.

N

• Nanofiltration: Membrane filtration removing particles larger than 0.001 microns.

• Non-revenue water: Water lost through leaks, breaks, or unauthorized use.

• Nitrification: Process by which microorganisms convert ammonia to nitrite and nitrate.

• Nitrogen cycle: The nitrogen cycle follows the different stages of biogeochemical evolution of the component. It leads to the formation of nitrogen gas (nitrogen N2) starting with organic nitrogen, and passing by: ammonia, nitrite, nitrate.

O

• Odor control: Methods used to prevent or remove unpleasant odors from treatment facilities.

• Overflow: Discharge of untreated or partially treated wastewater from a sewer system.

• Oxidation: Chemical reaction where an electron is lost. Used in wastewater treatment for pollutant removal.

• Ozone disinfection: Disinfection process using ozone gas to kill microorganisms.

P

• pH: Measure of acidity or alkalinity of water.

• Phosphorus removal: Removing phosphorus from wastewater to prevent eutrophication in receiving waters.

• Pretreatment: Removing large particles and harmful substances from wastewater before primary treatment.

• Primary treatment: First stage of wastewater treatment removing large solids and organic matter.

• Pump station: Facility using pumps to lift water or wastewater to a higher elevation.

Q

• Quality assurance/quality control (QA/QC): Procedures for ensuring accuracy and consistency of data and processes.

R

• Rainwater harvesting: Collecting and storing rainwater for later use.

• Reclamation: Treatment of wastewater to produce water suitable for non-potable uses like irrigation or industrial processes.

• Reverse osmosis: Membrane filtration process removing dissolved salts and other impurities from water.

• Reservoir: Large body of water stored for later use like drinking water or hydropower generation.

• Residual chlorine: Amount of chlorine remaining in water after disinfection.

S

• Sanitary sewer: Sewer system collecting only wastewater from homes and businesses.

• Sedimentation: Process of allowing particles to settle out of water or wastewater.

• Scum: Layer of floating material often forming on the surface of wastewater.

• Secondary treatment: Second stage of wastewater treatment removing dissolved organic matter and nutrients.

• Septic system: Small-scale on-site system for treating wastewater from individual homes or businesses.

T

• Tertiary treatment: Advanced wastewater treatment beyond secondary treatment for further pollutant removal.

• Total coliform bacteria: Group of bacteria used as indicators of potential fecal contamination, broader than fecal coliform.

• Total dissolved solids (TDS): Measure of the combined amount of dissolved minerals and organic matter in water.

• Transmissivity: Measure of the ease with which water flows through an aquifer.

• Turbidity: Measure of the cloudiness of water caused by suspended particles.

U

• Ultrafiltration: Membrane filtration process removing particles larger than 0.01 microns.

• Ultraviolet (UV) disinfection: Disinfection process using UV radiation to kill microorganisms.

V

• Valve: Device for controlling the flow of water or wastewater.

• Venturi meter: Device for measuring the flow rate of water or wastewater based on the pressure difference caused by a constriction in the pipe.

W

• Wastewater treatment plant (WWTP): Facility for treating wastewater before discharge to receiving waters or reuse.

• Water conservation: Strategies to reduce water use and prevent waste.

• Water distribution system: Network of pipes delivering treated water to customers.

• Water pressure: Force exerted by water at a specific point in a pipe system.

• Watershed: Area of land where all surface water drains to a common point.

X

• Xerostorm: Landscape design minimizing water use and promoting drought resistance.

Y

• Yard hydrant: Above-ground access point for water supply, often used for outdoor watering.

Z

• Zero liquid discharge (ZLD): Treatment process where all wastewater is treated and converted into solids or valuable byproducts, resulting in no liquid discharge.