Wastewater engineers are responsible for maintaining water quality. They are integral to infrastructure development to protect the drinking water supply.
Wastewater engineering is about designing and operating systems that collect, clean, and manage wastewater. The main goal is to protect people and the environment by safely treating and reusing or disposing of wastewater using physical, chemical, and biological methods.
Wastewater engineering is a diverse role and includes:
- Designing wastewater systems
- Managing stormwater runoff
- Conducting water quality studies
- Developing new water source
Many wastewater engineers have degrees in civil engineering, environmental engineering, chemical engineering, or bio-chemical engineering.
Wastewater engineering is constantly evolving as new technologies enter the landscape. This article explores the changing field of wastewater engineering and the importance of staying current with evolving trends.
What is Wastewater?
Wastewater is used water. It is untreated or contaminated from stormwater runoff, industrial and commercial runoff, and domestic use.
Wastewater includes stormwater, greywater, blackwater, and sewage. Stormwater results from rain or snow runoff; it runs over land surfaces and is collected in drains. Greywater is collected from bathrooms, sinks, and laundry. Blackwater comes from toilets, and sewage is a combination of greywater and blackwater. Industrial water can contain hydrocarbons, acids, and other toxic or hazardous substances. Manufacturing water and domestic water can also be polluted by pharmaceuticals. This is a growing concern for many municipalities which is caused by the public flushing unused prescriptions down the toilet creating blackwater that is infused with medications.
Wastewater contains pollutants and harmful chemicals, including nutrients, organic matter, pathogens, metals, and other contaminents.
- Nitrogen and phosphorus are the most common nutrients in wastewater. Nutrients most often come from domestic water use and farming. High nutrient levels can lead to algae blooms in lakes and rivers, depleting the water of oxygen, harming aquatic life, and threatening drinking water supplies.
- Organic matter comes from living organisms, including food scraps, grease, and oil. Like excess nutrients, organic matter consumes oxygen from water.
- Microorganisms in wastewater can cause disease, particularly gastroenteritis, cholera, and hepatitis A. Giardia can also occur in wastewater where groundwater flows through agricultural, farm, or ranch lands.
- Heavy metals, such as lead, mercury, and cadmium, result from industrial activities and pollute stormwater runoff. Heavy metals are toxic to humans and aquatic life.
- Other chemicals and pollutants found in wastewater depend on the source of runoff. Chemicals can include pesticides, herbicides, pharmaceuticals, and others.
Chemicals and other wastewater pollutants pose a direct threat to public health and the environment and must be treated before wastewater is discharged into sensitive ecosystems.
Wastewater Engineering and Treatment
Wastewater engineering focuses on the design, operation, and maintenance of collecting, treating, and disposing of contaminated or potentially contaminated water with the sole purpose of protecting the environment and public health.
There are three phases of wastewater treatment: primary, secondary, and tertiary treatment. Different technologies are used during the different treatment phases.
Primary Treatment
This phase removes large debris and solids. Often this involves storage basins that allow solids or sludge to settle and lighter substances to rise to the top. The sludge is filtered out and the resulting liquid is sent to secondary treatment.
Primary treatment in industrial complexes also serves to remove hydrocarbon liquids and solids. Hydrocarbons and chemicals call kill critical aerobic bacteria in the secondary treatment phase.
Secondary Treatment
During this phase, dissolved and suspended biological matter is removed. Secondary systems use aerobic bacteria to consume organic components of wastewater. Other technologies used in secondary treatment include fixed film systems, which act like filters, and suspended growth systems where waste is mixed with air to promote decomposition.
Tertiary Treatment
The final phase cleans the water before discharge into the environment. Tertiary treatment is necessary when treated water needs to meet high water quality standards. Different technologies are used during this stage. Sand filtration or activated carbon are used to remove particulate matter, phosphorus and nitrogen are removed using chemical precipitation and biological methods, such as nitrifying bacteria. Chlorination or UV is also used to process wastewater during this stage.
Today, automation and smart technology play a vital role in wastewater treatment. Automation improves efficiency and water quality through real-time monitoring, predictive maintenance, and automated process adjustments. Real-time continuous monitoring includes real-time decision support systems (RTDSS) and real-time controls (RTCs).
RTDSS consists of sensors and devices to measure system information using wired and wireless networks. Software processes the data so that adjustments can be made in real time. RTCs include real-time flow or level monitoring devices, computerized systems for data analysis, and automated controls, such as gates, weirs, valves, and pumps.
Other technologies include system condition and capacity tools. These tools facilitate sewer system inspections and operations. They automate data collection and evaluation to improve solutions to system issues.
Regulatory Compliance Considerations
The Clean Water Act regulates wastewater through the National Pollutant Discharge Elimination Systems (NPDES). The Clean Water Act provides the framework for wastewater and is enforced by the Environmental Protection Agency (EPA).
The EPA uses the NPDES program to regulate pollutant discharge from point sources into “waters of the United States.” Point sources include things like industrial facilities, municipal wastewater treatment plants, etc. Waters of the United States is defined under the Clean Water Act broadly as navigable waters.
In addition to federal regulations, wastewater treatment must also meet state and local regulations. In most cases, the EPA has delegated permitting authority to state and local agencies. Thus, local agencies issue and monitor NPDES permits.
It is important for wastewater engineers to understand the hierarchy of the regulatory process and emerging trends. Evolving regulations strive to improve wastewater treatment and adopt innovative technologies. Governments are tightening thresholds for wastewater pollutants, such as heavy metals and excessive nutrient loads and imposing reuse and recycle mandates.
With changing regulations comes innovation in new technologies to improve efficiency and outcomes.
Innovations & Future Trends in Wastewater Engineering
Growing demand for limited water resources is increasing the need for water recycling and reuse and a circular economy. Some advanced technologies include reverse osmosis and ultrafiltration to produce high-quality recycled water.
In-home and decentralized treatment systems offer alternatives to municipal water treatment. Decentralized systems improve efficiency and community resilience. Innovative technologies use renewable energy to desalinate water.
Recycled water is used for industrial, agricultural, and irrigation purposes. Greywater is recycled and used for non-potable purposes like toilet flushing and in-home irrigation.
Career & Continuing Education Opportunities
Ongoing innovation and environmental pressures are opening doors for wastewater engineers, civil engineers, and other engineering disciplines. Engineers are at the forefront of research and development in designing systems to meet the clean water mandates while managing this limited resource.
Continuing education is just one way for engineers to get their hands “dirty” in this growing field. Classes such as Introduction to Wastewater Treatment and Design of Onsite Wastewater Treatment Systems meet CE elective requirements while introducing engineers to wastewater treatment.
McKissock Learning is here when you’re ready to explore new trends in engineering continuing education.
