In keeping with Ft. Pierce’s vigilant protection of its alluring coastal environment and robust tourism, the City engaged NuTerra to develop a wastewater treatment/biosolids management alternative to aerobic digestion to reduce energy costs, greenhouse gas emissions, nutrient pollution and odors.
- Protection of the Florida coastal environment (greenhouse gas
and nutrient pollution)
- Long-term control of escalating energy and operating costs
- Effect of unpleasant odors on tourism and the public
Long-Term Successes Achieved:
- $242,166.87 reduction in annual biosolids treatment and disposition costs
- 34% reduction in polymer usage
- 27% increase in cake solids for centrifuge-dewatered biosolids
- 70% (76 tons) reduction in nutrients and biosolids returned via filtrate
- 21% (52) fewer truckloads hauled annually
- $53,891.74 annual reduction in energy costs
- Virtually odorless wastewater treatment plant operation
- Significant reduction in nutrient pollution (92% less nitrogen, 66% less phosphorous)
- Energy/GHG emission savings equates to 50.8 cars per year or 86.4 tons of waste sent to the landfill
The hub of St. Lucie County, Florida, Ft. Pierce, is one of oldest communities on the east coast of Florida, having been incorporated in 1901, and one of the densest, with 41,000 residents inhabiting only 29 square miles. The popular tourist destination’s historic downtown waterfront provides contemporary shopping, dining, great fishing, and live entertainment.
Having earned the City of Excellence Award from the Florida League of Cities for overall excellence in city government, Ft. Pierce is committed to providing responsible government that protects the City’s coastal environment. Demonstrating this commitment, the City engaged NuTerra to address the challenges listed above with a complete wastewater treatment/biosolids management solution that was more environmentally and economically beneficial than its previous aerobic digestion process.
NuTerra Solution Delivers
In 2014, NuTerra installed a CleanB® system and centrifuge at the Ft. Pierce wastewater treatment facility, which began wasting directly from the clarifier through the CleanB treatment system and new centrifuge for dewatering. Eliminating wasting to a DAF unit for thickening and holding sludge in an aerobic holding tank prior to contract dewatering and landfill disposition substantially reduced energy consumption and costs, greenhouse gas emissions and nutrient pollution, and eliminated odors associated with digestion and dewatering.
The CleanB system has resulted in approximately $242,000 in annual operating cost savings. The elimination of the 75-horsepower aerobic digestion blower alone saves $0.11 per kilowatt-hour on 8,760 hours for an annual savings of $53,891.74. Energy costs for the CleanB system of $18,648 for a net energy cost savings of $37.02 per dry ton.
Better Nutrient Control, Better Soil, Better Environment
In addition to these advantages, the wastewater treatment facility (WWTF) logged improved nutrient and solids capture rates. Total nitrogen leaving with the biosolids increased by: 182% increase, or 35 tons per year, and phosphorous increased by 476%, or 20 tons per year
The benefits of reducing the amount of nutrients returning to the plant are twofold:
- Less reprocessing within the liquid treatment train frees up between 20-30% plant capacity. The high capture rate of nitrogen in the biosolids reduced 45 tons of nitrogen being returned to the head works per year. Total phosphorous returned via the centrate was reduced by 9 tons per year or 66%.
- Increased nutrient content in the biosolids result in a much more valuable soil amendment.
Additionally, the CleanB system produced a much drier cake, with a 27% increase in cake solids for the dewatered biosolids that equates to a 21% reduction in wet weight and 52 fewer truckloads hauled each year (assuming 44,000 lbs. per truckload). The CleanB system also reduced polymer consumption by 40%.
Dewatering and Hauling Cost Benefits
Ft. Pierce’s WWTF used to dilute its stream from the digester in order to dewater. They were paying 5.39 cents per gallon dewatered. This cost included dewatering, hauling and disposition. With an annual output of 952 dry tons per year, their dewatering, hauling, and disposition costs amounted to $492,209 per year, approximately $517.03 per dry ton. The CleanB system reduced these costs to $180.18 per dry ton, a savings of $336.85 per dry ton.
Find Out More About Your Costs/Risks
Complete a free biosolids/organic waste management assessment questionnaire.
For more information, visit www.nuterra.green or call 904-819-9170.
What Makes NuTerra a Trusted Partner?
NuTerra designs, builds, and assumes full project accountability for long-term, sustainable wastewater treatment/organic waste and biosolids management solutions that deliver municipalities on average savings of 40-plus percent in operating costs and 90-plus percent in energy consumption. Our partnerships meet capital and operating expense constraints, assure regulatory compliance, buoy public sentiment, and enhance environmental stewardship.
- Only provider using patented, scalable, low-cost solutions certified nationally by the U.S. EPA that provide high quality end products for beneficial reuse/land application
- Only company with economically viable solutions for <15MGD / <15 DTPD operations
- Only fully integrated platform with proven technologies and 100% project success
- Only progressive project delivery approach with financial and risk analysis models designed specifically for biosolids and organics operations/management
- Only system that produces documented Class A and Class B biosolids 100% of the time
About the CleanB® Solution
CleanB is a simple process that meets pathogen and vector attraction reduction requirements as defined by 40 CFR Part 503. The system is highly scalable, has a small footprint, and may be mobilized or permanently installed onsite. Every CleanB system is outfitted with a control system and monitoring devices to record process parameters and ensure efficient operation.