toolbox
Home / Energy & Sustainability / Water Treatment Treatment Cost Estimator

Water Treatment Treatment Cost Estimator

The Water Treatment Treatment Cost Estimator combines annual treated volume, variable treatment cost, energy intensity, electricity price, and fixed annual expense into a single operating-cost estimate. It is designed for early budgeting and scenario comparison when a facility wants to see how throughput and energy use affect the cost of producing treated water.

The calculator separates variable treatment expense from electricity and fixed cost so the user can see which component drives the result. The unit-cost result divides the annual total by the treated volume, making it easier to compare operating scenarios at different throughputs. It does not attempt to replace a full cost model that includes financing, depreciation, labor escalation, residuals handling, taxes, or capital replacement unless those items are deliberately included in the fixed or variable inputs.

Annual treatment cost

gal/yr
$/1k gal
kWh/1k gal
$/kWh
$ /yr
Result
—
Estimated annual treatment cost
Variable treatment cost—
Energy cost—
Total unit cost—

1. Enter annual treated volume
Use the expected finished-water throughput for one year.

2. Add non-energy variable cost
Enter chemicals, consumables, disposal, or other variable expense on a per-1,000-gallon basis.

3. Enter energy intensity
Provide electricity use per 1,000 gallons of treated water.

4. Set the electricity price
Use the expected average energy price paid per kilowatt-hour.

5. Add fixed annual cost
Enter annual expenses that do not vary directly with treated volume, then review total and unit cost.

Annual cost = Fixed cost + (Volume/1,000 × Variable cost) + (Volume/1,000 × Energy intensity × Electricity price)

Where:

  • Volume: treated water in gallons per year
  • Variable cost: non-energy dollars per 1,000 gallons
  • Energy intensity: kilowatt-hours per 1,000 gallons
  • Electricity price: dollars per kilowatt-hour
  • Fixed cost: annual dollars independent of throughput

Assumption: This is an operating-cost model. Capital recovery and other ownership costs are excluded unless the user incorporates them into the entered cost values.

What the result means

The main result is a planning estimate derived directly from the entered operating assumptions and should be interpreted within the stated system boundary.

Use project-specific design criteria, equipment data, and applicable requirements before making final engineering or procurement decisions.

Given:

  • Annual treated volume = 12,000,000 gal
  • Non-energy variable cost = $1.80/1,000 gal
  • Energy intensity = 1.20 kWh/1,000 gal
  • Electricity price = $0.14/kWh
  • Fixed annual cost = $45,000

Calculation:
Volume basis = 12,000 thousand gal.
Variable cost = 12,000 × $1.80 = $21,600.
Energy cost = 12,000 × 1.20 × $0.14 = $2,016.
Total = $45,000 + $21,600 + $2,016 = $68,616.

Result:
$68,616 per year, or about $5.72 per 1,000 gallons.

At this throughput, fixed cost is the largest of the three modeled cost components.

What belongs in non-energy variable cost?

Use costs that increase with treated volume, such as treatment chemicals, media consumption, routine disposal, or similar consumables. Avoid double counting anything already included in fixed cost.

Why is energy entered separately?

Separating energy makes it possible to test changes in electricity price or process efficiency without changing every other variable expense.

What happens when annual volume is zero?

The total can still include fixed annual cost, but the calculator reports a zero unit cost instead of dividing by zero. A meaningful unit cost requires positive treated volume.

Does the result include capital cost?

Not by default. Include annualized capital or lease expense in fixed annual cost only if that is consistent with the budgeting question you are answering.

Can I compare two treatment technologies with this tool?

Yes, if you run the calculator separately with technology-specific energy, variable, fixed, and throughput assumptions. Keep the scope of included costs consistent across the scenarios.