A suspected oxidant event needs a traceable investigation, not an immediate conclusion from a conductivity trend. This checklist helps an owner prepare records for the responsible operator, plant designer and element supplier. It is not an emergency operating sequence, a chemical dosing recipe or a decision that a membrane is damaged. Use the installed plant's approved response procedure while the evidence is reviewed.
1. Reconstruct the event and the water path
FilmTec guidance identifies oxidants as a membrane-protection concern. Start the file with exact installed models, element positions and the current process diagram. Mark chemical injection points, any dechlorination stage, sample points and the route toward the membrane. Distinguish a measurement upstream of pretreatment from one at the actual RO inlet; they do not establish the same exposure.
Retain chemical product name, active ingredient, batch and preparation records where available, together with pump status, settings, relevant flow and alarm history. Record last confirmed normal condition, first indication, actions and next verified condition with timestamps and time zone. State gaps explicitly. A dosing-pump command is not a measured residual concentration, and an assumed event duration is not proof of the dose reaching each element.
2. Preserve what each measurement actually reports
Label residual tests by the actual reported analyte, including free or total chlorine where applicable, method, unit, sample point and collection time. Keep original result, reporting limit, instrument verification and reagent information when relevant. Ask the laboratory or instrument specialist to identify interferences and sampling limitations. A result below a reporting limit should retain that qualifier rather than being rewritten as an exact zero.
Keep ORP readings in mV distinct from concentration results in mg/L, and retain sensor location, status and the approved monitoring basis. Do not turn a generic threshold into this site's acceptance criterion. Attach synchronized temperature, pH, water analysis, flows, pressures, recovery and feed/permeate quality, with dosing, maintenance and shutdown events. Preserve raw records alongside any normalized comparison so the reviewer can separate measurement and operating changes from a proposed damage mechanism.
3. Agree the investigation and release decision
Submit the file with a named reviewer and written questions: what is confirmed, which measurements need checking, and whether additional sampling or specialist examination is justified. Reclamation describes membrane forensic and laboratory examination as specialist services. If an element is removed for an approved investigation, agree its identification, handling, preservation and custody before dispatch. Do not infer a cleaning remedy, remaining life, warranty decision or replacement approval from the event log alone.
For reference, BOKAWATER BW-4040 lists 2500 GPD (9.5 m³/d) and 99.60% stabilized salt rejection at 225 psi (1.55 MPa), 2000 mg/L NaCl, 25 °C, pH 7.5–8.0 and 15% recovery. This complete catalog test is not an oxidant-exposure test. Have the responsible parties document corrective actions, required water checks, unresolved items and authorization to return to the intended duty; keep the original incident evidence after closure.
Data to collect before comparing proposals
| Parameter / interface | Unit / format | Why it matters |
|---|---|---|
| Review record | Evidence to retain | Question to resolve |
| Installed identity | Model, serial/lot and vessel position | Which elements are under review? |
| Water path | Dosing, treatment and sample-point diagram | Where was exposure actually measured? |
| Chemical history | Product, ingredient, preparation and pump records | Which entries are measurements or assumptions? |
| Timeline | Normal, indication, actions and verified recovery times | Where are the record gaps? |
| Residual result | Analyte, units, method, reporting limit and timestamp | What does the result establish? |
| Online monitoring | Sensor location, verification and raw trend | Is the monitoring basis approved? |
| Operating context | Temperature, pH, flows, pressures and quality | Are comparisons made at matched conditions? |
| Catalog reference | Model plus complete test conditions | Is an unrelated test being misapplied? |
| Investigation and release | Authorized checks, findings and signed actions | Who closes the case and approves operation? |
Technical references
- DuPont — FilmTec Chlorination/Dechlorination, 45-D01569-en, Rev. 11, February 2026 ↗Source checked:
Evidence scope — original English record
Pages 1–4 discuss oxidant exposure, chlorine forms, dechlorination and monitoring in the FilmTec context. No exposure allowance, ORP threshold, reducing-agent dose, operating instruction or warranty rule is transferred to BOKAWATER. The incident worksheet is original evidence-organizing guidance, not a damage diagnosis or emergency response procedure.
- Bureau of Reclamation — Water Treatment Services ↗Source checked:
Evidence scope — original English record
Membrane Autopsies section describes forensic and laboratory examination as specialist work. Does not confirm an oxidation cause or prescribe tests for an individual BOKAWATER element.
- BOKAWATER — BW-4040 brackish-water RO membrane, item BK-BW-4040 ↗Source checked:
Evidence scope — original English record
Existing model, stated flow/rejection and complete catalog test conditions checked together. These data do not establish resistance to an incident, an exposure duration, remaining life, warranty outcome or replacement compatibility. Other generic operating-limit fields are not adopted as incident acceptance criteria.