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Describe your goal, effluent limit or sludge volume and receive a technology shortlist plus a sizing proposal – by email, no phone call required.
Key Facts
- Label
- Value
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- Core metric
- Dry solids content (TR) drives disposal volume
- Economic lever
- Higher TR means fewer truckloads and lower tipping fees
- Decision method
- Compare annual savings against capital + operating cost of new dewatering equipment
- Typical improvement
- Each 1 percentage point TR gain can materially reduce transport and disposal volume
| Parameter | Current case | After upgrade |
|---|---|---|
| Annual dry solids mass | 500 t DS/year | 500 t DS/year |
| Current TR | 18% | 22% |
| Wet sludge mass to dispose | 2,778 t/year | 2,273 t/year |
| Reduction in wet mass | - | 505 t/year |
| Assumed truck payload | 20 t/load | 20 t/load |
| Truckloads per year | 139 loads | 114 loads |
| Loads avoided | - | 25 loads/year |
| Unit disposal + transport cost | 180 EUR/load | 180 EUR/load |
| Annual cost | 25,020 EUR | 20,520 EUR |
| Annual saving | - | 4,500 EUR |
How to build the break-even model
A sound break-even calculation should include both direct and indirect costs. Direct annual benefit - fewer truckloads - lower tipping or gate fees - reduced haulage charges - lower handling and site storage costs Annual cost of the new equipment - capital recovery over chosen payback period - energy - polymer - maintenance and wear parts - operator time Break-even logic If annual savings are greater than annualised equipment cost, the project is justified. If not, the TR target or operating assumptions need refinement. A useful sensitivity test is to vary TR in 1% increments. In many applications, the model shows a threshold where one additional percentage point of dry solids pushes the project from marginal to attractive. That is the exact break-even point you should present to management.
Financial modelling steps
- 1. Measure current sludge throughput in wet tonnes or cubic metres.
- 2. Verify current TR with representative samples, not a single lab result.
- 3. Calculate annual dry solids mass.
- 4. Estimate target TR after improved dewatering.
- 5. Convert target TR into annual wet mass and truckloads.
- 6. Apply all transport, disposal, and handling costs per load or per tonne.
- 7. Add annualised cost of the screw press and related systems.
- 8. Run sensitivity cases for TR, haulage distance, and disposal tariff.
- 9. Identify the lowest TR improvement that delivers payback inside your target period.
reduce sludge volume before disposal+
Reduce sludge volume by increasing TR before transport, because the dry solids mass remains constant while the water fraction falls. In practice, that means better dewatering can cut wet tonnes, truckloads, and disposal fees at the same time.
sludge disposal cost per tonne dry solids+
To model sludge disposal cost per tonne dry solids, divide total annual disposal and transport cost by annual dry solids mass. This normalises the cost base and makes different dewatering options directly comparable.
sludge dewatering payback calculation+
Calculate annual savings from avoided truckloads, lower tipping fees, and reduced handling, then subtract the annualised cost of the equipment. Payback equals investment cost divided by net annual savings, with TR improvement as the main performance driver.
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Engineering Hub: get this sized for your plant
Describe your goal, effluent limit or sludge volume and receive a technology shortlist plus a sizing proposal – by email, no phone call required.