Plant Utilities worked example

Water Reuse Payback with water reuse project cost of 32,500 $: a worked example in plant utilities

Here is what the math looks like when conditions slip. We hold every other input steady and drop water reuse project cost to 32,500 $, then walk the calculation through step by step. Estimate payback for a water reuse project using installed cost, annual sewer and water savings, and support cost.

The inputs for this scenario

  • Water reuse project cost: 32,500 $ (the input this scenario stresses; the baseline uses 65,000)
  • Annual water and sewer savings: 28,000 $ / yr (held at the documented default)
  • Annual filter and maintenance cost: 4,500 $ / yr (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Net annual savings = annual water and sewer savings - annual filter and maintenance cost.
  • Water Reuse Payback payback works out to 1.38 yr at these inputs, and this is the headline figure for the scenario.
  • Net annual savings works out to 23,500 $ / yr at these inputs.
  • Project or backlog investment works out to 32,500 $ at these inputs.
  • Five year net works out to 85,000 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where water reuse project cost sits at 65,000 $ and the headline result is 2.77 yr, this scenario comes in 50% below the baseline at 1.38 yr.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to water reuse project cost, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes today's water and sewer rates hold; since those rates often rise faster than inflation, the tool tends to be conservative and the real payback may be shorter than shown.

Results at a glance

  • Water Reuse Payback payback: 1.38 yr (headline result)
  • Net annual savings: 23,500 $ / yr
  • Project or backlog investment: 32,500 $
  • Five year net: 85,000 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Water Reuse Payback calculator, set water reuse project cost to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.