NuTerra upgraded Haines City’s wastewater treatment plant from Class B biosolids to a Class AA/ EQ fertilizer product. The new BCR Environmental (BCR) Neutralizer® system delivered significant cost savings and expanded beneficial reuse options for Haines City’s fertilizer product.
CHALLENGING SITUATION
Serving 20,000 residents and its businesses, Haines City’s 3 MGD (million of gallons per day) wastewater treatment plant treated secondary sludge through aerobic digestion and subsequently hauled the Class B residuals to a landfill or land application site. The operation presented the following costs and risks:
- Escalating energy costs
- Citizen complaints about odors (next to baseball field)
- Digester capacity limitations
- Stringent environmental regulations
- Rising operating expenses
- Limited capital for process enhancements
“We are ahead of the curve as far as compliance issues,” notes Nathan Silveira, licensed operator and interim pretreatment coordinator at the plant. “We had a lot of odors because of the digesters and that’s something that’s been eliminated.”
NUTERRA SOLUTION DELIVERS
Through value engineering, NuTerra was able to deliver a design-build biosolids treatment solution that met Haines City’s financial and Class AA/EQ product goals. Installation of the dual-train Neutralizer system with a centrifuge for sludge dewatering was completed in a new 5,000-square-foot building on the site of the plant’s unused drying beds in late 2011. Since becoming fully operational in early 2012, the solution has delivered the following results:
- Residuals that now meet Class AA/EQ standards
- Treated nutrient-rich residuals registered as a commercial fertilizer with the Florida Department of Agriculture
- Elimination of $2.75 million in capital expenditures for digester rehabilitation and dewatering equipment
- Twenty-year reduction in total annual biosolids treatment and disposition costs of approximately $133,000 per year (includes financing costs of the Neutralizer equipment)
- Reduced energy costs for biosolids treatment of around 97 percent compared to previous aerobic digestion
- Virtually odor-free wastewater treatment plant operation
Not only are residuals free from foul odors, but the pH can also be adjusted to suit the needs of fertilizer customers. Neutralizer residuals meet the strict nutrient and pollutant limits of the State of Florida with an extremely low Phosphorus Source Coefficient. In a Penn State University study, the Phosphorus Source Coefficient of Neutralizer residuals was 0.1.
ABUNDANT OPERATING AND PROJECT COST SAVINGS
NuTerra’s unique before-and-after models based on real/verifiable operational and financial data demonstrate that Haines City’s Neutralizer system delivers an estimated $4.8 million in cumulative operating cost savings over the initial twenty-year project period. Net capital cost savings to the city, including avoided capital costs for digester upgrades, were estimated initially at $2.8 million. This cost savings translates to a $1.8 million present value economic benefit based on a twenty-year net present value.
Instead of the city having to pay the cost to haul and dump the sludge from the traditional system in the landfill, Stripling said the City uses the concentrated fertilizer on all municipal rights-of-way, parks, and at various city facilities. The fertilizer also can be sold to other fertilizer companies.
ENERGY COST SAVINGS
Projected energy costs at Haines City dropped 97 percent, from an average approximately $333,000 per year to approximately $9,000 per year with Neutralizer. The Neutralizer system relies on chemistry rather than on energy-intensive treatment with digesters, dryers, incinerators, or gasifiers. The entire process is designed using energy efficient equipment to minimize electrical consumption. Process automation ensures maximum energy efficiency every time the batch flow system operates.
According to Haines City Public Works Director Mike Stripling, “Shutting down the plant’s three digesters, which used to process the waste solids, means a terrific energy savings. We no longer have to run two 125-horsepower motors 24/7.”
The chemical systems automatically inject a mixture of sulfuric acid, sodium chlorite, sodium hydroxide, ferric chloride and sodium nitrite in two processing steps.
WHAT’S NEXT
Haines City has engaged NuTerra to design, build, and maintain a new organics recycling facility at its current wastewater treatment property site. The city will own the building, which will blend residents’ yard waste with wastewater treatment biosolids and other organic waste accepted from surrounding communities and commercial interests. NuTerra will market the resulting federal- and state-approved Class AA/EQ compost product for unrestricted reuse locally and in surrounding communities. ◆
Aaron Zahn is president and CEO of NuTerra. NuTerra designs, builds, and assumes full project accountability for long-term, sustainable wastewater treatment/organic waste/biosolids management solutions that deliver municipalities on average savings of 40-plus percent in operating costs and 90-plus percent in energy consumption. For more information, visit www.nuterra.green or call 904.819.9170.
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MODERN PUMPING TODAY, September 2015
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