Calculator Inputs
Designed for temporary or permanent treatment systems on active sites.
Formula Used
Each component inventory is calculated from concentration and liquid volume.
How to Use This Calculator
- Enter the number of basins and the volume of each aeration zone.
- Input the default MLSS concentration, or set zone-specific values.
- Optionally include clarifier, RAS, and WAS volumes with concentrations.
- Press Calculate to see totals and a component breakdown.
- Use CSV or PDF buttons in the results card for exports.
Example Data Table
Example values below demonstrate typical temporary treatment sizing.
| Scenario | Basins | Zone 1 (m³) | Zone 2 (m³) | MLSS (mg/L) | Clarifier (m³) | Estimated Total (kg) |
|---|---|---|---|---|---|---|
| Balanced two-basin setup | 2 | 320 | 160 | 2,800 | 90 | 2,940 |
| Compact single-basin with RAS | 1 | 250 | 120 | 2,200 | 60 | 1,010 |
| High-rate three-basin with Zone 3 | 3 | 400 | 220 | 3,200 | 120 | 7,194 |
Inventory visibility for construction treatment systems
On active projects, packaged plants and temporary basins are often moved, resized, or shared between work fronts. A running MLSS inventory turns daily sampling into a practical number: kilograms of solids on site. That total supports chemical dosing, blower loading, and contingency planning when flows spike after dewatering or rainfall events. It also helps teams compare performance between shifts using one consistent metric.
Data inputs that most influence the total
Volume drives inventory as strongly as concentration. Confirm zone volumes from as-built drawings or calibrated level readings, then apply the best representative MLSS for each zone. If zones behave differently, use zone-specific concentrations rather than one average. Small errors in a large basin can shift totals by hundreds of kilograms, changing hauling and polymer forecasts.
Using totals to forecast hauling and disposal
Inventory helps convert “how much sludge is in the system” into truckloads and disposal costs. For example, two basins with 320 m³ and 160 m³ zones, at 2,800 mg/L, contain 2,688 kg in aeration volume. Adding a 90 m³ clarifier at the same concentration adds 252 kg, for 2,940 kg total. If your dewatering target is 20% solids, this total frames realistic cake production.
Operational checks with weighted concentration
The weighted average MLSS is a consistency check across mixed volumes. If the average is far below expected, you may be missing a storage volume or using a diluted sample. If it is far above, verify if concentrated blankets, RAS wells, or WAS holding tanks are included and measured correctly. Pair the check with trend graphs from your lab sheet.
Documentation for audits and construction turnover
Exports create a repeatable record for compliance, commissioning, and handover. Store weekly CSVs with sampling notes, then attach PDFs to progress reports. When operations shift from temporary to permanent equipment, your inventory history helps explain process stability and supports smoother operator training and startup troubleshooting. Keep a brief change log when tanks are isolated or re-plumbed.
| Example item | Volume (m³) | MLSS (mg/L) | Inventory (kg) |
|---|---|---|---|
| Aeration volume (2 basins, zones 1–2) | 960 | 2,800 | 2,688 |
| Clarifier / storage volume | 90 | 2,800 | 252 |
| Total inventory | 1,050 | — | 2,940 |
FAQs
1) What does this calculator estimate?
It estimates the total mass of suspended solids held in selected liquid volumes by converting MLSS concentration and volume into kilograms, pounds, and tonnes for planning and reporting.
2) Why is a weighted average MLSS shown?
It reflects the overall concentration across all included volumes. It is useful for quick checks, especially when zones or storage tanks have different sizes.
3) Should I include a clarifier blanket?
Include it if the blanket holds a meaningful solids mass. Use an estimated blanket-average concentration, not the mixed liquor value, to avoid underestimating inventory.
4) How often should I update the inputs?
Update after major flow changes, wasting events, tank cleanouts, or equipment moves. For stable systems, weekly updates aligned with routine sampling are usually adequate.
5) My lab reports MLSS in g/L. What do I enter?
Convert g/L to mg/L by multiplying by 1,000. For example, 3.0 g/L equals 3,000 mg/L.
6) Can I model basins that have different volumes?
Use the basin count with representative average zone volumes, or run the calculator multiple times per basin group and add the totals for a combined inventory.
7) What is included in the CSV and PDF exports?
Both exports capture your inputs, component breakdown, total volume, weighted concentration, and total inventory. They are formatted for quick sharing with site management and compliance teams.