Tag Archives: sustainability

Making the Most of Biosolids: Affordable Moves Toward Sustainable Biosolids Use

Based on an interview with Giovanna Forti Portiolli, Charlotte Water’s Resource Recovery Manager

Charlotte Water manages the largest public water and wastewater utility system in the Carolinas, serving more than one million people across Mecklenburg County. With five water resource recovery facilities (WRRFs) treating a combined average of 86 million gallons per day, the system also produces a significant amount of biosolids, about 120,000 wet tons per year. Traditionally, most of this material has been sent for beneficial reuse through land application, but rapid regional growth, tight storage capacity, and operational challenges have made that increasingly difficult.

I sat down with Giovanna Forti Portiolli, Charlotte Water’s Resource Recovery Manager, to discuss how Charlotte Water has navigated these hurdles without relying on significant immediate capital investments. Instead of waiting years for large-scale upgrades, her team found creative, collaborative, and cost-effective solutions that keep biosolids moving toward beneficial reuse rather than landfills.

Below are the key strategies and outcomes her team has piloted across our facilities.

Tackling Foreign Debris with a Sludge Screen Pilot at Irwin Creek WRRF

For almost two years, all of Irwin Creek’s biosolids were being landfilled out of precaution when the team started observing foreign debris finding its way to the final biosolids product. Landfilling biosolids is expensive, not sustainable, and wasteful of important nutrients and organic matter.

The operations team piloted a rental sludge screen to fine screen foreign debris out before dewatering the sludge. The impact was immediate. The utility was able to go back to beneficially reusing and recycling nutrients and organic matter from the biosolids, while also saving on landfill tipping fees. Renting the equipment also gave Charlotte Water time to test, refine, and validate the technology before purchasing and installing a permanent unit. This is a key example of how improperly disposing trash at home can have a direct negative impact in the community (e.g., higher costs and wasting important resources).

The image shows three columns of debris found in Biosolids. The columns are Nurdles/Pellets, Labels/Stickers, and Hair, from left to right.
Examples of debris causing this specific issue
Finding Storage Space

Biosolids storage is a valuable and often expensive resource to expand. Instead of launching a multimillion-dollar capital project, Charlotte Water took a more resourceful approach by looking inward at what already existed.

At Charlotte Water’s largest wastewater facility, McAlpine Creek Water Resource Recovery Facility, staff identified old, unused, or obsolete equipment inside the Residuals Management Facility that could be safely demolished to free up staging areas for future use. This newly reclaimed space eased bottlenecks and reduced the strain on limited storage. The effort generated savings of at least $135,000 every year.

A cleared-out space in the Biosolids storage. A large concrete space with barriers on the sides give potential room for biosolids. A truck has its lights on in the distant background of the facility.
Cleared out room for Biosolids storage
Strengthening Contractor Partnerships and Diversifying Outputs

Biosolids management is a shared effort. Charlotte Water works closely with its biosolids contractor to haul and land apply material, and Giovanna emphasized how important that relationship became during this transition.

Together, the team is exploring new outlets for beneficial reuse, including adding the ability to send a portion of biosolids to a composting facility. Furthermore, team is currently studying additional beneficial use outlet alternatives (e.g., alternative landfill daily cover, stormwater research). Additional reuse pathways reduce dependency on a single outlet when weather or operational conditions limits traditional land application. This adds more flexibility during challenging periods

To the right in the image a machine used to apply Biosolids onto land is spraying and distributing biosolids throughout a field. The sky is blue and there is a line of trees in the background.
Land application of Biosolids
Shifting to Seven-Day Dewatering at McAlpine Creek

For years, McAlpine operated on a five-day, twenty-four-hour dewatering schedule. This schedule created added operational pressure and challenges. The operations team transitioned to continuous seven-day operations, which streamlined biosolids flow and optimized every part of the process.

The change improved equipment efficiency, translated into a slight increase in cake solids, which help utilize storage more effectively. Even a small improvement in cake solids can reduce haul volumes and strengthen land application operations.

A Bigger Picture: Innovation Without a Giant Price Tag

All of these efforts share a commonality. Instead of waiting for long-term capital funding, staff, contractors, and consultants collaborated to identify practical, low-cost improvements that delivered benefits immediately.

Each strategy followed the same pattern:

• Start small

• Pilot first

• Measure everything

• Scale what works

And above all, stay open to ideas that come from every level of the organization.

These low-cost wins demonstrate how Charlotte Water is continuing to guide biosolids management toward higher efficiency, sustainable environmental outcomes, and reduced landfill dependency, while serving one of the country’s fastest-growing regions.

For questions, you can email Giovanna.FortiPortiolli@CharlotteNC.gov

Unlocking a New Level of Progress with a Plant: Nuvoda Pilot

Are small plant pieces key to a new level of greatness in the Queen City’s wastewater treatment process? Charlotte Water’s Sugar Creek Water Resource Recovery Facility (WRRF) has set out on a 12-month mission to learn.

Kenaf sample in an Imhoff Cone, the tool used to check how much kenaf is currently in Sugar Creek WRRF’s basins.

Nuvoda, a wastewater solutions company in Raleigh, NC, created the Mobile Organic Biofilm (MOB™) Process. The star of the show called kenaf is a fast-growing plant that can get rid of up to 10 tons of carbon dioxide per acre while growing. That’s eight times as much as evergreen trees! 

So, how does it work? Small pieces of kenaf are in all stages of Sugar Creek’s secondary treatment process. Its job is to help make space for helpful biofilms to grow.

Biofilms, a slime-like layer found in nature, grow on surfaces to eat the “waste” in wastewater and help solids settle faster.  This leads to treated water that can be safely returned to the environment.

The kenaf material is also reusable! A giant sift-like tool separates kenaf from the water. Screens inside of the filter are small enough to catch and make sure no kenaf is wasted or left to come out in your kitchen sink. Sugar Creek’s maintenance team even added some helpful features, like a ramp for it to fall out of the sift, into the bin below.

Muriel Steele, Water Process Engineer, guiding kenaf down a custom-made ramp through the final stages of the MOB cycle.

MOB and kenaf have other perks, too.

Chemicals like ammonia have to be controlled carefully while treating wastewater. The microorganisms needed to treat ammonia can be hard to grow in cold temperatures, but biofilms can provide a cozy space for these specialists to grow. Kenaf boosts the amount of space for the biofilms.

Treatment facilities need to run as smoothly as possible during storms. Improved settling thanks to the kenaf can help with higher water flows during rainy days. So, as the extra water comes into the plant from bad weather, solids settle faster and there is a lower chance of anything unwanted continuing to the next treatment stage.

Kenaf is grown in Cameron, NC, and Charlotte Water is working to include these fields in our biosolids program. Biosolids are a nutrient-rich material made from treated wastewater, used to help plant growth and keep a healthy environment.

The Nuvoda MOB pilot is a chance for Charlotte Water to improve for the future by lowering costs and getting ready for the city to grow. By exploring this new process, Sugar Creek WRRF is gathering useful data to help make decisions for improvements. All thanks to a plant! 

To learn more about MOB and kenaf, visit Nuvoda’s website.

Video | Nuvoda: The MOB™ Process

Video | Nuvoda: Natural Ballasted Media for the MOB™ Process

Charlotte Water Deputy Director Jackie Jarrell to Retire on December 31

She leaves after 38 years of service to the City and CLTWater.

Jackie Jarrell, 2013

Charlotte, N.C.– After over three decades of working for the City of Charlotte, Charlotte Water Deputy Director Jacqueline “Jackie” Jarrell, PE, is retiring after 38 years of service. Jackie, who has served in various positions since joining Charlotte Water in 1985, will retire on December 31. 

“I want to thank my family, all who I have worked with at Charlotte Water, and the many mentors and friends in the water sector for the years of partnership and guidance that allowed me to learn, grow, and succeed through my career,” says Jackie regarding her time at CLTWater and as a water sector professional. “I have constantly been inspired by how Charlotte Water, as an organization, is always looking forward to how we can continue to provide the best services possible to our community and the region through innovation, partnerships, and dedication to protecting water and the environment. I am honored to have been a part of Charlotte Water and have the opportunity to give back to my community and the water sector as a whole.”

Originally from New Jersey, Jackie moved to Charlotte to attend UNC Charlotte, becoming the first in her family to go to college and earn a degree. After graduating with a Bachelor of Science in Engineering – Urban and Environmental (Civil) program, Jackie joined Charlotte Water as an engineer (first female engineer) in the Engineering Division of Charlotte Water. While in Engineering, she worked in capital planning and completed hydraulic distribution modeling and sanitary sewer evaluations. She started the Backflow Prevention program for Charlotte Water. From there, Jackie went on to manage the System Protection Division, which included the Industrial Pretreatment Program, working with many local industries and with the Backflow Prevention program. She initiated the Industrial Excellence Awards, honoring industries in our community for excellent environmental compliance. Jackie then became a Wastewater Treatment Plant Superintendent and eventually Environmental Management Chief, managing and leading our six wastewater treatment facilities operations and the biosolids program, the largest land application program in the Southeast. From 2019-2020, she stepped into the Interim Deputy Director role before becoming a Deputy Director in 2020. She created history again when she became the first Latin American woman to serve in an executive position for Charlotte Water.

Throughout her career, Jackie has been a champion for sustainability, initiating several projects, pilots, and initiatives for Charlotte Water. She has collaborated and partnered with UNC Charlotte on research and supporting opportunities for student internships within the College of Civil and Environmental Engineering. During her time at CLTWater, Jackie became a local, state, national, and international leader in the public water sector, earning a series of accomplishments and serving in leadership roles at several organizations and professional groups.

Jackie Jarrell, 2021, Water Environment Federation, WEF Fellow

Jackie served as President of the Board of Trustees of the Water Environment Federation (WEF), an international organization of 35,000 water professionals. She was named a WEF Fellow in 2021. She is currently serving as the chair of the Diversity Equity and Inclusion Advisory to the Board. Jackie served as chair of the N.C. Water Quality Association, of which she was one of the founding members. She was also active in and was Chair of NC OneWater (formerly NC AWWA-WEA). She currently serves on the Board of Advisors for the UNC Charlotte Civil and Environmental Engineering Department College Board of Advisors. Jackie also had the opportunity to travel to Bolivia with Water for People, an international non-profit organization that promotes accessibility to high-quality drinking water and sanitation.

“There is no way I can quantify the impact that Jackie has had not only for us at Charlotte Water but the commitment and dedication she has shown in the way she has assisted in the running of a water system that supports, sustains, and grows with our region,” says Charlotte Water Director Angela Charles. “While Jackie will be sorely missed by us all, we wish her a wonderful, peaceful, and restful retirement as she embarks on this new chapter of her life.”

Jackie Jarrell (Left) and Angela Charles (Right), 2023

A Cheaper Sugar for Sweet Tooth Bugs (Substitute for Acetic Acid)

Since 2001, sugar water has been used at the McDowell plant as an acetic acid substitute.

McDowell Creek Wastewater Treatment Plant is one of the most technologically advanced in removing nutrients and enhancing downstream water quality. Sustainable innovations are nothing new to operators. Since 2001, sugar water has been used at the McDowell plant as an acetic acid substitute. It’s a win-win for Charlotte Water and local businesses when both save money by reusing a waste product.

Sugar water is produced when the soft drink manufacturers have expired or out-of-date products that they have pulled from store shelves and need to dispose of it. It is also produced when the manufacturers make a bad batch of cola and/or need to wash down the processing equipment. This sugar water is used as an organic carbon food source for microorganisms (bugs) that remove phosphorous and nitrogen during the wastewater treatment process. Because McDowell’s effluent discharges into a nutrient-sensitive creek, operators use advanced treatment techniques to also remove nutrients, nitrogen, and phosphorous from water.

The sugar water is a safe, cheap alternative that significantly reduces the use of acetic acid in the treatment process, reducing resource consumption and making use of waste that would otherwise need to be disposed of. The soft drink manufacturer gives it to CLTWater for free and CLTWater pays for the shipping. The process saves ratepayers hundreds of thousands of dollars each year.

Learn more at

Wastewater treatment plant process

Wastewater Performance Reports