A line marked drain on a desalination drawing is not a complete waste-management scope. Before purchasing equipment, ask for a register that follows each proposed waste stream to an identified receiving interface. Use it to compare supplier and site responsibilities without assuming that every stream can share the same outlet. This is a procurement checklist, not a discharge design or permission to release water.
1. Give each stream an identity and operating state
Reclamation's historical Report 69 distinguishes membrane concentrate, backwash and intermittent cleaning wastes. Use that distinction as a starting point for the proposed package, not as a statement of current discharge rules. Give each actual stream an identifier: normal RO concentrate; pretreatment backwash where fitted; cleaning-solution drain; rinse or preservation drain; and diverted startup or off-spec water. Mark which streams are absent or supplied by another contractor.
For each identifier request its origin, generating equipment, operating state, collection point and proposed destination. Ask whether events can overlap and which streams are accounted for in the supplier's water balance. A separate entry does not automatically require a separate pipe; routing and any proposed combination need a documented project assessment. For an enquiry referencing SWRO-3, obtain the configuration-specific drawing rather than treating the catalog name as a complete drainage package.
2. Describe event peaks as well as daily totals
Request normal and maximum instantaneous flow, batch volume, duration, frequency and the basis of each estimate. As an arithmetic illustration only, a hypothetical 2.4 m³ batch averaged over 8 hours is 0.3 m³/h; emptying that batch in 10 minutes instead requires 14.4 m³/h on average during the event. Neither number is a BOKAWATER rating or a pipe-sizing recommendation. Ask the designer to address the actual event profile, simultaneous loads and any proposed buffering.
Define a characterization sheet for each stream: water source, expected salinity or conductivity, pH, temperature, relevant suspended solids, process-added chemicals and the evidence behind those values. For chemical batches request product names, safety data sheets, intended concentration and volume, and possible contaminants removed during service. Agree sampling location and operating state, laboratory scope and how estimates will be checked during commissioning. Reclamation's service description specifically includes mass balances and water sampling; conductivity or pH alone is not a complete characterization.
3. Close the receiving interface before accepting the package
Assign who evaluates the receiving route, obtains project-specific acceptance and defines any required collection or treatment. Identify the boundary location, connection, hydraulic conditions, monitoring, isolation and responsibility for abnormal batches. Ask who approves any proposed mixing or conditioning and which evidence that approval requires. A neutral pH, an ocean location or an existing drain does not by itself establish an acceptable route; use the current site-specific assessment and applicable local decisions.
Make handover evidence measurable: updated stream register, approved drawings, responsibilities, instrument checks, available analyses and a signed list of unresolved items. Agree how routing and alarms are demonstrated safely under the approved commissioning plan, without releasing an unaccepted batch for a test. Record who authorizes waste transfer and who responds to a failed quality check or unavailable receiver. Send the register with the equipment enquiry so collection tanks, treatment, pumps, monitoring and site discharge works are explicitly included or excluded.
Data to collect before comparing proposals
| Parameter / interface | Unit / format | Why it matters |
|---|---|---|
| Interface | Record to request | Decision to close |
| Stream identity | Origin and operating state | Which contractor generates it? |
| Normal concentrate | Water-balance basis and flow profile | Which conditions are represented? |
| Backwash | Installed stage and event schedule | Can events overlap? |
| Chemical batch | Chemical identity, volume and duration | Who accepts this batch? |
| Peak loading | Instantaneous flow and simultaneous events | Is buffering proposed? |
| Characterization | Composition, sampling point and state | Which values remain estimates? |
| Receiving boundary | Connection, conditions and named owner | Is the route accepted? |
| Abnormal event | Isolation, hold and escalation plan | Who authorizes transfer? |
| Handover | Signed register and remaining actions | Are exclusions explicit? |
Technical references
- Bureau of Reclamation — Membrane Concentrate Disposal: Practices and Regulation, Report 69, September 2001 ↗Source checked:
Evidence scope — original English record
Section 6.1.1, printed page 51, distinguishes concentrate, backwash and intermittent cleaning wastes. Historical process context only; its regulatory discussion, classifications, disposal options and numerical examples are not adopted as current or universal requirements. The stream register and purchasing questions are original planning guidance.
- Bureau of Reclamation Technical Service Center — Water Treatment Services ↗Source checked:
Evidence scope — original English record
The official service description identifies mass balances for product and waste-stream quantities and composition, plus water monitoring and sampling. This supports requesting a characterized stream register, not a site discharge approval or a BOKAWATER equipment rating.
- BOKAWATER — Small desalination plant, item SWRO-3 ↗Source checked:
Evidence scope — original English record
Confirms existing item SWRO-3 only. Generic capacities and other model tables are not adopted. Its catalog identity does not establish included collection tanks, waste treatment, sampling, discharge works or a permitted disposal route.