Hurricane Preparedness for Wastewater Facilities

As Hurricane Ian left swaths of Florida without water and wastewater services at the end of September, the New York Times was already reporting on potential environmental impacts of the storm hitting South Carolina. Beyond the acute hazards of exposure to untreated wastewater, the biggest concern in hurricane-impacted areas is nutrient pollution and the potential for harmful algal blooms.

As extreme weather events impact larger stretches of the country, the water sector (including regional watershed protection entities) will need to anticipate greater consequences in the emergency response planning process. Florida DEP's Hurricane Preparedness for Domestic Wastewater Facilities and FEMA's Hurricane and Flood Mitigation Handbook for Public Facilities offer some helpful recommendations.

FEMA divides its recommended (primarily anticipatory) mitigation strategies into four categories: elevate or relocate, protect or divert, floodproof, provide redundant systems. The fact sheet identifies which of these strategies are appropriate for each major component of a wastewater facility. For example, installing "backflow prevention devices such as valves on lines that flow into the lift station and emergency overflow lines" is an option for floodproofing a lift station.

FEMA also provides a similar framework for drinking water systems.

Florida DEP's suggestions for before and after a hurricane can provide an update to an existing baseline checklist, particularly for minimizing these concerning downstream impacts. For example, it is recommended to "drain wastewater holding ponds as completely as practical after receiving a hurricane warning" as well as ensure that biosolids for land application have been "spread or stored in a secure manner."

With the frequency and severity of hurricanes and other extreme weather events increasing, facilities may need to adopt new strategies to prevent costly cleanup efforts and even legal battles.

Additional Resources for Management of Dissolved Oxygen in Activated Sludge Plants

Below is a list of free resources on the management of dissolved oxygen in activated sludge plants to supplement our previous article Managing Dissolved Oxygen in Activated Sludge Plants. 

Troubleshooting Noncompliance at Small Wastewater Treatment Plants

This is a 171-page presentation from the Ohio EPA on Troubleshooting Noncompliance at Small Wastewater Treatment Plants that features information on activated sludge process control.  

Operating Tools and Measurement Techniques for Troubleshooting Activated Sludge Systems

This 29-slide presentation discusses tools that can be used to troubleshoot activated sludge systems. The presentation will introduce some simple tools, talk about some that are a little more advanced, and show operators that this is not the realm of only the laboratory or the engineer.

Activated Sludge Process Control Manual

This is a 106-page Activated Sludge Training Manual that was prepared by the Michigan Department of Environmental Quality with information on operating the activated sludge process, including nutrient removal, and troubleshooting. 

Holistic Aeration and Chemical Optimization Saves Big Money from 1 MGD to 600 MGD

This 36-slide presentation outlines automated dissolved oxygen control, which includes reduced operator labor/attention, improved process stability, and energy savings; automated biomass control; and automated chemical feed control for P removal, which includes a 95 percent reduction in chemical usage. 

Troubleshooting Activated Sludge Processes

This 32-slide presentation discusses how to troubleshoot activated sludge processes and covers process types & kinetics, influent monitoring, process monitoring, and control and nitrification.

Convert Activated Sludge to BPR

This 48-slide presentation discusses improving Bio-P performance by getting to know the system, initial assessment, expanding a zone for increased BPR performance, learning D.O. control, and more.

Efficient Nutrient Removal under Low Dissolved Oxygen Concentrations

This 25-slide presentation discusses the City of St. Petersburg Southwest WRF, City of Rochester WWTF, and more. 

Activated Sludge- It’s About Efficiency and Optimization

Doom & Bloom: Biochemical Oxygen Demand (BOD) in Wastewater Treatment

This website from the Environmental Finance Center Network provides an overview of the function of biochemical oxygen demand in wastewater treatment plants. 

A Tale of Two Filaments: BNR System Recovery from a Major Process Upset

This 7-page article discusses the Glendale Wastewater Treatment Plant in Lakeland, Florida that had a power outage that caused the dissolved oxygen concentrations in the aeration basins to drop very low. 

These resources and more can be found in our document library.

COVID-19 in Wastewater Surveillance

Over the past two years, researchers have turned to wastewater to find out more about the trajectory of the COVID-19 pandemic.

In September of 2020 the CDC developed the National Wastewater Surveillance System (NWSS) to help monitor and better understand the spread of COVID-19 throughout communities. The NWSS works directly with public health departments to track the presence of the SARS-CoV-2 virus in the wastewater of communities across the country. They are able to do this because humans infected with the SARS-CoV-2 virus shed the virus in their feces making it detectable within community wastewater systems. The CDC has been able to gather a large amount of data because 80 percent of households in the United States are served by municipal wastewater collection systems. Wastewater surveillance programs have been implemented across the country in places like Utah, Washington D.C., Massachusetts, Connecticut, and Illinois. Programs have also been implemented internationally. 

Wastewater surveillance technology has proven to be very beneficial to communities because it is able to detect the virus even before people start showing symptoms. This is helpful because once health departments are aware, communities can immediately take stricter precautions to prevent the spread of the virus. You can stay up to date on the presence of COVID-19 in your community by checking the COVID Data Tracker which provides regularly updated information on the presence of SARS-CoV-2 levels in wastewater at testing sites across the country. 

SURE! Sustainable Utilities Research and Education

SURE! is a program within the Cal Poly School of Civil and Environmental Engineering that seeks to find solutions within the water-energy nexus that will provide sustainable solutions to wastewater recycling and resource recovery. The mission of the SURE! program is to help expand the wastewater recycling workforce and develop new sustainable technologies. The program received a WEF award for its commitment to water treatment education and research. The SURE team has worked on algae-based wastewater treatment, algae biofuels, conversion of wastewater solids to energy, potable re-use, and dairy wastewater treatment. 

Decentralized Wastewater Infrastructure Challenges in the Alabama Black Belt

A quarter of Americans rely on decentralized wastewater systems, including septic tanks, because they are too far away from municipal sewers or the local environment cannot support a wastewater treatment plant.

Decentralized wastewater treatment facilities can offer economic and environmental benefits to a community, but they can also be dangerous to public health and the local ecosystem if they are not designed properly.

In the Black Belt region of Central Alabama, the rural landscape and heavy clay soils make it difficult to establish a traditional wastewater facility. These communities have struggled with wastewater management for years and the U.S. EPA (with many partners) has been working to help develop long-term solutions.

Impermeable soil, high rates of poverty, and no sewer access can result in difficult choices. Some communities in this region use straight pipes to carry wastewater to a nearby location like a ditch or woods, where residents can then be exposed to raw sewage.

Decentralized wastewater treatment systems can use a variety of different approaches to process a community’s wastewater, but there are also financial and managerial solutions that can be explored. Responsibilities can be better distributed and organized with community leadership. Individuals who attend community meetings and communicate with their state and local government officials are more likely to have their voice heard. 

The newly passed infrastructure bill is set to contribute $150 million in decentralized household grants over five years to help low-income homeowners construct or repair failing septic systems. Investments are also needed in cost-effective treatment technologies and innovative approaches to help municipal wastewater systems reach rural communities. 

Dig Deep, an organization that helps bring running water and adequate sanitation to communities across the United States, created a decentralized wastewater innovation cohort to help connect rural communities with innovative solutions. 

The Alabama Black Belt is just one of many regions of the United States that are struggling, with a history of environmental injustice compounding logistical challenges. Roughly 2.2 million Americans across the United States still do not have running water or adequate sanitation. 

The information in this blog post was presented at a U.S. EPA webinar in May 2021. A recording is available to explore this topic in more depth:

Are Solar Powered Water Treatment Plants the Future?

Clean water and clean energy are both essential on the road to a more sustainable future. To be able to tackle two issues at once and provide clean water using clean energy is exactly the kind of innovation that the world needs. A few wastewater treatment plants across the country are taking matters into their own hands and converting their plants to solar-powered energy. 

The solar farm for the Wastewater Treatment Plant in New Stanton was just finished. The Federalsburg Wastewater Treatment Plant just received over one million dollars in grant funding for the construction of a solar panel system. The city of Danbury, Connecticut is also considering a solar installation that would power their city’s wastewater treatment plant. The Diablo Water District also installed a solar power system in their facility to help them achieve their ambitious goal of being carbon neutral by 2027.

Powering water treatment plants with solar power helps the environment and it can help facilities save money because it can lock in electrical rates. It also makes facilities more resilient to power outages from natural disasters or other power grid failures. Utilities that convert their water treatment facility to solar power help their community and country work towards achieving the renewable energy goals the world is striving towards. 

Elevating Women in Water

Contributed by Margaret Golden

Women make up over half of the population, but account for less than 20% of workers in the water industry. The work that women contribute to the water industry is necessary and important, offering valuable insight to bring the industry into the future.

With a new generation of workers on the rise, it is important that women feel empowered to work in the water. Brianna Huber, chemist with the City of East Moline, is on a mission to not only recruit women into the industry but see equity in their opportunities. Her non-profit, Her2O, is currently seeking members who are ready to forge lasting change.

Women across the country are already making great impacts, breaking glass ceilings and blazing their path to the top of the water world. Two leaders in the water industry recently discussed what it means to them to be a woman in the water industry.

Newsha Ajami, the Director of Urban Water Policy at Water in the West at Stanford University, discussed in a podcast what we need to do to transition to 21st century sustainable water management. Michelle Harrison talked about her favorite parts about working as a wastewater treatment operator at the Northwestern Water & Sewer District.

Many organizations take the time to specifically acknowledge the women in their work place during women's history month. Last spring the U.S. EPA highlighted Sandhya Parshionikar, Director of the Water Infrastructure Division, Center for Environmental Solutions and Emergency Response. Rural Communities Assistant Partnership highlighted Ines Polonius, CEO of Communities Unlimited.

Cuyamaca College in El Cajon also hosts an annual symposium dedicated to Women in Water.

Wastewater Collection System Components

Contributed by Phil Vela

A wastewater collection system is a series of pipes, tunnels, conduits and other devices that transport wastewater from homes, businesses and industries to a central treatment plant. Transport of the wastewater is either by gravity (the preferred method) or with the use sanitary lift or pump stations to either a location that gravity can be used or to another lift or pump station and finally to the wastewater treatment plant. In either case, the collection system has many functioning parts as shown and described below.

Figure 1 (source) shows the different types and sizes of sewer lines in a typical wastewater collection system. They range from the smallest (approximately 4 inches) located at the home or business to the large truck mains (minimum 12 inches and can be as large as 27 ft tunnels in large cities) that carry the sewerage to the waste treatment plant. A brief description of each follows.

Here's house the Louisville Metropolitan Sewer District describes each of the components:

House Sewer conveys the sewerage from a building to the lateral or branch lines.

Lateral & Branch Sewers are the upper ends of the municipal sewer system. Laterals dead-end at their upstream end with branch sewers collecting the wastewater from several lateral sewer lines.

Sub-main Sewers are collectors for numerous lateral and branch sewers from an area of several hundred acres or a specific neighborhood or housing development They convey the wastewater to larger trunk sewer lines, to lift stations or to a neighborhood package water quality treatment center.

Trunk/Main Sewers serve as the main arteries of the wastewater collection system. They collect and convey the wastewater from numerous main sewer lines either to a water quality treatment center or to a interceptor sewer.

Interceptor Sewers receive the wastewater numerous from trunk sewers and convey it to a water quality treatment center. These are the largest diameter lines in the sewer system and the furthest downstream in the system.

Lift or Pump Stations are utilized in gravity sewer systems to lift (pump) wastewater to a higher elevation when the route followed by a gravity sewer would require the sewer to be laid at an insufficient slope or at an impractical depth. Lift stations vary in size and type depending upon the quantity of wastewater to be handled and the height it must be lifted.

This video from American Water College describes the components of a wastewater collection system:

Using Willow Trees to Treat Wastewater

This article was featured in a recent edition of Innovations for Small Systems, our monthly water technology newsletter.

Researchers at University of Montreal, Canada have found a way to filter the waste from municipal wastewater through the roots of willow trees while also producing renewable bioenergy and 'green' chemicals. The study, which was published in Science of the Total Environment, details the experiment conducted in Quebec, Canada to investigate the potential for sustainable wastewater treatment through phytofiltration, an emerging method to remove contaminants from water through the use of plants, to be integrated with renewable biorefinery. 

Phytofiltration plantation is an alternative wastewater treatment method where root systems from non-food crops, such as fast-growing trees, are used to capture contaminants and nutrients from wastewater. Short rotation coppice (SRC) willow has been considered as a promising renewable bioenergy crop due to its natural tolerance to contamination and the roots ability to filter out nitrogen in sewage, which can then be harvested for renewable lignocellulosic biofuels. This concept of a biorefinery illustrate the potential of multifunctional biotechnologies to address environmental challenges caused by human activities.

Photo Credit: Katy Walters

Studies Track PFAS Through Wastewater Facilities

This article was featured in a recent edition of Innovations for Small Systems, our monthly water technology newsletter.

University of New Hampshire (UNH) researchers have conducted two of the first studies in New England to show that per- and polyfluoroalkyl substances (PFAS) are ending up in the environment differently after being processed through wastewater treatment facilities, making it more challenging to set acceptable screening levels.

Researchers including Paula Mouser, associate professor of civil and environment engineering at UNH, aimed to highlight the gaps around contaminants of emerging concerns (CECs) in wastewater residuals and to stress that more research is needed to assess the impact of facility design and operation on the treatment of CECs before costly upgrades are implemented to comply with stricter drinking water standards. 

The first study, which was recently published in The Royal Society of Chemistry, investigated the distribution and fate of 24 different PFAS through six New Hampshire wastewater treatment facilities to examine how they are distributed after being treated. The study aimed to characterize PFAS in wastewater treatment influent, sludge, and effluent discharging into the Great Bay Estuary in southeastern New Hampshire. 

The second study, which was featured in the New England Water Environment Association Journal, evaluated the changes in 24 PFAS and 21 pharmaceutical and personal care products (PPCPs) during wastewater treatment and assessed the composition of PFAS in biosolids post-stabilization treatment. Recent studies have suggested PPCPs and PFAS from land-applied biosolids may accumulate in soils, agricultural crops, and food products. This study compares the composition and concentration of PFAS from 39 biosolid samples collected from WWTFs in New Hampshire and Vermont.

Photo Credit: Conservation Law Foundation