Two projects with the same daily wastewater volume may need different treatment arrangements. A hotel with a short morning peak, a construction camp with changing occupancy and a permanent residential community should not be specified from population alone. Build a design basis that separates measured conditions, estimates and requirements still awaiting confirmation.
1. Establish hydraulic flow and organic load separately
Record average daily volume, maximum daily volume and the hourly arrival profile. State whether the figures are metered or calculated, the monitoring dates and the occupancy represented. Check for stormwater connections or infiltration: EPA identifies large flow changes as a challenge for biological treatment. Do not apply a generic peak factor without recording its basis.
Organic load combines flow with concentration. For an illustrative calculation only, 100 m³/day at 200 mg/L BOD₅ corresponds to 20 kg BOD₅/day: load = flow × concentration ÷ 1,000. This is arithmetic, not a BOKAWATER equipment rating. A laboratory result from an unusually quiet day should not silently become the entire design basis.
2. Turn the treatment target into an acceptance checklist
Ask the project engineer to identify the actual discharge or reuse destination and the applicable project limits. List each required parameter, sampling location, test method and acceptance period. Separate normal operation from startup and seasonal restart. Nutrient removal, disinfection and reuse storage should be explicit decisions in the scope, with a named party responsible for each.
Compare candidate treatment routes against the same influent and target. Ask how flow balancing, solids separation, sludge removal and operator attendance are addressed. A technology acronym alone does not establish the required footprint, operating effort or effluent performance.
3. Close the site and handover interfaces
Mark inlet and outlet elevations, power supply, access for sludge removal, lifting space and the distance to occupied buildings on the site plan. Identify who supplies civil works, connecting pipes and storage. Ask for a proposed equipment list, layout, electrical load list, control description and operation documentation before finalizing an order.
For commissioning, agree who provides seed material where required, laboratory testing, operator training and the acceptance record. Record exclusions alongside the price. Send the completed data sheet with the project location and the latest available water analysis so the quotation can describe a defined scope.
Data to collect before comparing proposals
| Parameter / interface | Unit / format | Why it matters |
|---|---|---|
| Average / maximum daily flow | m³/day | Provide both values with the measurement or estimation basis. |
| Peak hourly inflow | m³/h and duration | Describe morning, evening and intermittent discharge peaks. |
| BOD₅ / COD / TSS | mg/L | Attach laboratory results with sampling date and location. |
| Nitrogen / phosphorus / pH | mg/L; pH | Identify the parameters required by the project treatment target. |
| Wastewater temperature / occupancy | °C; seasonal profile | Describe cold conditions and periods of low or zero loading. |
| Effluent target and sampling point | Project requirement | Attach the project limits and define how acceptance is measured. |
| Sludge route / site utilities | Site plan and responsibility | Identify disposal access, electrical supply and civil-work boundaries. |
Technical references
Prepared with AI assistance from the references below and original project-planning checklists. General engineering guidance; project specifications require confirmation by the responsible engineer.