What Is Waste Water: A Complete Guide

Wastewater, also known as sewage, refers to any used water.

It can be generated from three main sources: domestic activities, industrial activities, and rainwater runoff.

Wastewater contains many pollutants and contaminants, including human waste, food scraps, oils, and chemicals from homes, businesses, and industries.

When wastewater is collected, it is conveyed to wastewater treatment plants for treatment and reuse.

What Are the Main Sources of Waste Water

Wastewater is categorized based on where the discharged water comes from the following:

1: Domestic Sewage

This wastewater is produced from residential and domestic sources like homes and apartments. It's also known as sanitary sewage.

It results from HUMAN ACTIVITIES, including:

• Toilet flushing
• Bathing
• Dishwashing
• Laundry

Domestic sewage contains chemicals like phosphorus, nitrogen, organic matter, and disease-causing pathogens.

Residential wastewater is further categorized into two types: grey water and black water.

Some states in the U.S. permit homes to use an innovative treatment system that can safely treat wastewater for reuse in toilets or irrigation.

2: Industrial Wastewater

Industrial wastewater comes from discharges produced by commercial and manufacturing industries.

This wastewater comes from restaurants, hospitals, farms, and other non-residential institutions.

Commercial and industrial enterprises use water for many purposes, such as:

• Processing
• Manufacturing
• Cleaning
• Rinsing

Industrial water use is harder to treat and process than domestic wastewater because it can contain hazardous materials.

The characteristics of this type of wastewater can vary depending on the industry.

A restaurant discharges huge quantities of oil and grease. On the other hand, a laundromat can produce large amounts of used water containing lint and microfiber.

It's important to ASSESS the sources of non-residential sewage to ensure that it undergoes adequate wastewater treatment.

3: Rainwater

Stormwater or rainwater is a type of wastewater that comes from precipitation.

It picks up debris, nutrients, and chemicals and washes off impervious surfaces into storm sewers and drains.

Rainwater is conveyed to the nearest source of groundwater, like a river or lake.

If improperly treated, it can pose a great risk of CONTAMINATION to local water bodies.

What Are the Effects of Waste Water Pollutants?

There is no 100% clean water in nature. However, the amount of pollutants determines whether water is fit or unfit for drinking, swimming, or fishing.

Without proper disposal, wastewater can lead to WATER POLLUTION, contaminating groundwater and waterways.

Harmful substances in wastewater can lead to:

• Increased concentrations of nutrients like phosphorus and nitrogen (ammonia) in water can result in excessive algal blooms, reducing the available oxygen for aquatic life.
• Decaying organic matter can use up the oxygen in the water, making it difficult for fish to survive.
• Chlorine is toxic to most aquatic animals and plants.
• Disease-causing pathogens can contaminate fish populations and local recreational sites like beaches, limiting recreation and consumption.

Wastewater MUST be properly treated in treatment plants to mitigate these effects.

How to Treat Waste Water

A wastewater treatment plant removes the suspended solids in wastewater before releasing the effluent back into irrigation systems.

There are two solutions to treat polluted water:

1. Septic system - Uses an underground tank and discharges sewage using a drain field
2. Lagoon system - Uses an open pool and discharges sewage using slow evaporation

Wastewater treatment plants are composed of sewer pipes that flow into a centralized treatment facility.

The treatment plant includes pumping systems that pump the water to the point that it collects most of the sewage.

Primary Treatment

The primary treatment involves removing 60% of suspended solids that enter the settling tank.

Heavier solids settle at the bottom, and lighter solids float to the tank's surface.

After the settled solids are EXTRACTED, it is followed by the secondary treatment, which removes around 90% of the dissolved solids.

Secondary Treatment

The secondary treatment uses biological processes involving microorganisms that feed on the organic matter in the sewage.

Microorganisms need oxygen to convert organic substances into a cellular mass, which is then removed.

Some treatment plants optimize their operations by reducing energy demand and chemical use to minimize nutrient loads.

The sewage then undergoes disinfection to remove phosphorus and nitrogen before it's released.

What Are the Different Types of Waste Water

Wastewater is also categorized into THREE MAIN TYPES based on its specific source:

1: Black Water

Black water refers to sewage water from toilets and urinals.

Kitchen sinks are sometimes considered black water due to the grease and pathogens present in this type of wastewater.

Black water contains high levels of disease-causing bacteria that can harm public health and aquatic wildlife.

Due to the presence of fecal matter and urine, black water CANNOT be reused for domestic purposes.

Black water can be treated using wastewater treatment facilities such as:

• Sewage treatment facilities
• Aerated wastewater treatment systems

2: Grey Water

Grey water comes from non-toilet plumbing such as baths, washing machines, and sinks.

This type of wastewater has not come in contact with fecal matter, making it easy to process during treatment.

Since grey water has LOWER levels of bacteria and chemicals than black water, it can still be reused and recycled.

It can be introduced into the environment to bring nutrients to the soil or reused to flush toilets.

IMPORTANT: Both grey water and black water are NOT suitable for drinking.

Grey water can be treated using biological methods like coarse or sand filtration techniques.

3: Storm Water

Stormwater refers to water from rain, and ice melts that runs off any impervious surface like concrete pavements and rooftops.

This wastewater picks up different substances and POLLUTANTS along its path, such as:

• Sediment
• Grease
• Animal feces
• Chemicals

Stormwater flows into combined sewers, which is conveyed either to a treatment plant or to the ocean.

It can also be discharged into the local groundwater that flows into water supply dams. This wastewater can pose a significant risk to our drinking water quality.

Proper wastewater treatment is important to prevent water pollution and environmental degradation.

What Is Sewage?

Sewage is another term for wastewater.

It is any water, such as freshwater or drinking water, used for domestic or industrial applications.

Sewage needs to be treated in wastewater treatment plants to keep the environment clean and improve local conditions.

What Is an Onsite Sewage Facility?

An onsite sewage treatment facility (OSSF) is a septic system designed to treat, process, and discharge wastewater from homes and businesses.

This septic system is common in areas where residences are far from one another.

An OSSF consists of a septic tank that holds sewage (e.g., human waste) until solids settle to the bottom of the container.

The tank includes an effluent filter that keeps suspended solids out of the effluent.

The wastewater then flows out of the tank and into a distribution box. It will flow into the soil absorption field, where it undergoes final treatment and disposal.

Frequently Asked Questions

Below are commonly asked questions related to wastewater and wastewater treatment:

Why Should You Treat Waste Water?

Without proper wastewater treatment, wastewater can negatively impact our health and environment.

Proper wastewater treatment can help prevent the spread of water-borne diseases. Also, wastewater treatment is important for fishing industries and local residents

Rivers, lakes, and oceans are VITAL for hundreds of fish and other aquatic life species.

The organic matter in wastewater can cause oxygen depletion in bodies of water, which can be destructive to the local fish and plant population.

Wastewater also brings with it phosphorus and nitrogen into water bodies.

Nutrients like phosphorus and nitrogen can result in eutrophication, which is harmful to any aquatic system.

Where Does the Waste Water Go After Treatment?

Treated wastewater is discharged into local waterways after treatment.

Wastewater resource recovery can benefit the community in many ways. Treated effluent can be reused for other purposes like irrigating crops and sustaining aquatic habitats.

Conclusion

Wastewater is any residential and non-residential water use.

It contains several contaminants that can pose health risks to human and animal life if left untreated.

The main objective of sewage treatment plants is to REMOVE as many pollutants as possible before the wastewater is reintroduced to the environment.

Small amounts of water pollution can be found in nature, but ensuring water quality is important to protect public health and local wildlife.