Start with the intended use
Specify the receiving process, seasonal demand and the water-quality envelope it can accept. Cooling, irrigation and process make-up have different constraints. Separate the target concentration from the required reliability: a good average does not describe the frequency or consequence of an excursion.
Describe the salt and contaminant mixture
Bring together conductivity, total dissolved solids, major ions, relevant organics, suspended solids and variability. Ask which measurements explain scaling, fouling, corrosion or biological inhibition in the proposed process. Conductivity is a useful indicator; it does not identify every constituent that matters.
Close the water and residual balances
Compare feed, product, reject, cleaning streams and losses on the same time basis. For reverse osmosis, high recovery changes the composition of the remaining concentrate. A zero-liquid-discharge (ZLD) proposal still needs an account of solids, energy, chemicals, downtime and final outlets.
Make the comparison decision-ready
Request feed limits, pretreatment assumptions, product criteria and a residual-management route for each option. Flag which claims are demonstrated on a comparable stream and which remain to be tested. A useful output is an options matrix with explicit exclusions and the evidence needed for the next stage.
Sources & context
Background reading checked 9 October 2026. The review questions and structures above are BGF editorial guidance; the references are not BGF project evidence or endorsements. Apply them to the relevant site, data and agreed scope.