Wastewater treatment plants are vital to our health, sanitation, and water supply. But effective wastewater management comes at a cost.
Every year, municipal wastewater treatment operations account for at least 30 terawatt hours of electricity, costing nearly $2 billion. As climate concerns rise and industrial operating budgets fluctuate, reducing energy consumption and increasing efficiency are top priorities.
Goals to make wastewater treatment plants (WWTPs) more efficient and sustainable are important, as 40% of WWTP operating costs come from electricity alone. Fortunately, energy efficiency is an attainable goal thanks primarily to the subject matter (sewage) containing energy-available components upon treatment.
To learn of the current methods that help encourage energy efficiency in wastewater treatment plants, keep reading.
Operational Efficiency at a Wastewater Treatment Plant
Water and wastewater treatment plants hold a large demand for power systems every day. The sewer system never sleeps, so WWTP equipment and heavy machinery must run 24/7 to ensure standard water treatment continues. Industrial motors, hydraulic-powered lifts and heavy-duty pumps can operate nonstop at municipal facilities.
The operational costs of WWTPs have great social, environmental and economic impacts. Sewage treatment plants, depending on size and location, demand careful design and process implementation when considering efficiency.
New Challenges in WWTP Operation
Today, sewage and human waste are no longer the only materials WWTPs remove. The increased use of chemicals and microplastics in modern society has put larger demands on WWTP operations. Removing microplastics is a growing concern regarding both public health and wastewater treatment plant efforts.
During wastewater treatment, the primary and secondary treatment phases are most efficient at removing harmful microplastics, particularly during grease removal. However, even the most effective treatment plants only remove up to 90% of microplastics from the water before being released back into natural water sources. This leaves a concerning amount of plastic particles untreated, potentially re-entering wild food and water sources.
From equipment to waste removal, operational efficiency at WWTPs depends on better energy efficiency.
Energy Efficiency of Wastewater Treatment
Based on projections for population growth and greater climate efforts to minimize non-renewable energy consumption, wastewater efficiency initiatives focus on energy.
WWTPs rely heavily on several key energy methods:
Electricity: Pumps, motors, computer systems, control rooms, etc.
Thermal energy: Aeration, heating, drying, etc.
Chemical energy: Biochemical treatment, UV/chlorination, lab testing, etc.
Manual energy: Physical labor, manual turnkeys, chemical preparation, etc.
Fossil fuels: Greenhouse gas emissions from purifying water, waste disposal, etc.
The benefits of attaining energy-efficient practices in WWTPs include:
Fewer emissions of greenhouse gasses.
Reduced operational costs.
Increased job opportunities.
Improved water management systems and water security.
Leadership rollout of environmental sustainability.
Greater protection of public health.
How can wastewater treatment plant operators and employees implement greater efficiency, both energetically and operationally? Here’s how an initial assessment typically works.
Efficiency Assessment for Operators and Staff
Retrofitting a wastewater treatment plant for efficiency begins with a thorough, honest assessment. Everything from facility layout to equipment to daily workflows requires consideration.
Benchmark WWTP Processes
Daily evaluations of wastewater treatment processes ensure the productivity of equipment and employees, from automated systems to manual tests and maintenance. Ongoing benchmarks are necessary to create, observe, improve and achieve operational targets as well as increase efficiency.
If you notice a gap in performance or an area of operation that consistently fails to meet targets, it’s time to reevaluate the WWTP processes with an outside wastewater professional.
Audit Facility Equipment
Without efficient plumbing or processing equipment, wastewater treatment plants take a huge hit to their operating costs. Treatment plant operators and leadership should be aware of the latest technology available for optimal performance.
Consider switching WWTP equipment that uses high amounts of energy consumption. Upgrade to more efficient options, such as:
Smart meter systems like AMR and AMI
Smart control systems
High-density sludge processes
Variable frequency drives (VFDs)
Accurate, automated data acquisition systems
Energy-efficient lights throughout the facility
Dual-channel grinders for larger solids
Combined heat and power (CHP) systems
Equipment audits are especially important for WWTPs that are ten years or older. Contact a wastewater operations and management company to get optimal equipment suggestions for your facility.
Implement or Improve Biogas Conversion
There is a significant opportunity for renewable energy usage from the wastewater treatment process: the organic matter in wastewater can be used as energy. Many WWTPs in the U.S. already streamline this process to convert solid waste into gas for energy, and it’s continuing to expand.
Using anaerobic digesters, organic waste from wastewater is broken down and converted into potent methane gas. Cogeneration engines— ideal for improved energy efficiency— use the available biogas as fuel, converting it into electric and thermal energy to be used in plant operation.
Biogas is used to power WWTPs in several ways. It can power digester heating, facility temperature regulation, electricity, pipeline injection and more. Ultimately, implementing the biogas process has the potential to convert wastewater plants into net-zero energy operations in the future.
Join Ongoing Community Initiatives
Whether you’re a wastewater system operator or you work in the water utility sector, here are some notable resources for further self-assessment of efficiency:
Note: it’s not always feasible or helpful to limit your WWTP to self-assessment. To develop a long-term wastewater treatment plant efficiency protocol, get an expert operations analysis.
Get an Efficiency and Operations Analysis for Your Wastewater Treatment Plant
Real efficiency begins at the local level. Systematically, all WWTPs in a jurisdiction would benefit the greater community by undergoing operations and efficiency analysis from wastewater treatment consulting experts. Combining updated operation standards, improved performance tracking and multi-facility oversight results in larger energy and cost savings.
At O&M Solutions, our extensive experience in optimizing WWTP efficiency has helped facilities improve operation costs, reduce harm to the environment and achieve greater efficiency in the scaling economy. We’ve led many recent projects for wastewater treatment plants in both public and private sectors with much success.
To retrofit your water management or wastewater treatment plant in New Jersey, Pennsylvania or New York, schedule an efficiency assessment. This provides your facility and team with the consulting you need before implementing the best practices. To get a consultation, contact Greg Seaman at O&M Solutions.