Plant Utilities worked example

Water Reuse Payback with water reuse project cost of 162,500 $: a worked example in plant utilities

What does the result look like when water reuse project cost reaches 162,500 $? The full calculation is worked below with real intermediate numbers. Use it when reviewing water reuse payback for a utility budget, maintenance priority, capacity check, energy project, or production support plan.

The inputs for this scenario

  • Water reuse project cost: 162,500 $ (raised for this scenario; the documented default is 65,000)
  • Annual water and sewer savings: 28,000 $ / yr (unchanged)
  • Annual filter and maintenance cost: 4,500 $ / yr (unchanged)

Working through the calculation

  • Applying the documented formula (Net annual savings = annual water and sewer savings - annual filter and maintenance cost) to the inputs above produces each figure below.
  • At this operating point the engine returns 6.91 yr for water reuse payback payback, the number this scenario is built around.
  • At this operating point the engine returns 23,500 $ / yr for net annual savings.
  • At this operating point the engine returns 162,500 $ for project or backlog investment.
  • At this operating point the engine returns -45,000 $ for five year net.

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 150% above the baseline at 6.91 yr.
  • A figure at this level is achievable when water reuse project cost is genuinely sustained, not just peaked for a shift. 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: 6.91 yr (headline result)
  • Net annual savings: 23,500 $ / yr
  • Project or backlog investment: 162,500 $
  • Five year net: -45,000 $

Run it with your numbers

  • Every input above is editable in the live Water Reuse Payback calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.