Sludge Yield and Cash Flow Projections in Wastewater Treatment Plants
Design Calculations for a Sample Plant
When design engineers begin their projections for building a wastewater treatment plant, they calculate the expected pounds of influent BOD to determine the pounds of sludge for designing sludge storage and handling. Let’s consider a simple example:
For a one million gallon per day average flow plant with an influent BOD of 225 mg/l:
1.0 X 225 X 8.34 = 1876.5 pounds of influent BOD
This typically produces between 1688.85 and 1876.5 pounds of sludge. This “yield” shows a ONE to ONE (1876.5 to 1876.5) or ONE to .9 ratio (1876.5 to 1688.85) of influent BOD to sludge.
Annual Sludge Production and Disposal Costs
Over a year, our hypothetical plant in “TOOGUDTOBETRUE,” Florida, will need to dispose of between 300 and 350 TONS of sludge. This figure represents total pounds if processed as tonnage. For liquid disposal, the percentage of solids in the liquid and the gallonage would need to be calculated.
The cost of sludge disposal, including handling, transportation, and final disposal, varies but is never free.
Cost Savings with Biostimulation
To calculate potential cost savings:
- Determine your annual sludge disposal expenditures
- Contact us for cost and dosage requirements based on your system’s flow and influent BOD
- Apply a reasonable reduction (e.g., 35%) to your sludge expenditures
- Subtract the cost of biostimulation
For example: If you spend $100K on disposal, our product costs $20K, and your projected savings are $35K, you’re ahead by $15K. It’s that simple.
The Science Behind Biostimulation
This isn’t rocket science; we simply enhance your biology. It’s similar to how many of us take prescriptions to help our bodies overcome limiting conditions and function better.
Responsibility and Skepticism
Good operators are often skeptical, but don’t you have a responsibility to your clients and citizens? While $15K may not seem significant, it’s a start. We can prove our claims, or you can ask our clients directly.
Importance of Measurable Data
In business, it’s crucial to be aware of your costs and track measurable data. Unfortunately, many of our clients didn’t do this BEFORE we started working with them.
Case Study: City of Stuart
The City of Stuart case study demonstrated a significant cash flow opportunity from sludge cost reduction. When we did the analysis, the project became cash-flow positive with just an 18% reduction in sludge production. Their actual reductions were in the high 30% range.
Conclusion
“If you can’t measure a product’s performance with cash flow, then you’re not using biostimulation. If you can’t measure it, you can’t miss it!”
If you are running a fixed-medium secondary treatment plant, such as an RBC (rotating biological contact unit) or a Trickling filter unit, we can guarantee a positive cash flow on sludge reductions… PERIOD.