Why pre-screen desalination engineers before the technical panel
Two numbers decide whether a desalination project works: energy per cubic metre produced, and what the brine discharge does to the receiving environment. Both are easy to state optimistically at design stage and hard to hold in operation, because membranes foul, recovery drops and the discharge plume behaves differently from the model. Engineers worth hiring have operated a plant and know the real figures. A short screen asks for them.
What actually matters when screening Desalination Systems Engineer candidates
- 01
Technical depth
Check command of SWRO train design: intake screening, pretreatment (DAF, UF), membrane flux and recovery limits, energy recovery devices, and brine density plume modelling with CORMIX or Delft3D.
- 02
Work that shipped
Probe plants they took from feasibility to commissioning: capacity in m3/day, intake type chosen, entrainment mitigation fitted, and measured post-commissioning receiving water salinity.
- 03
Diagnosis under uncertainty
Assess how they chased causes of unexplained differential pressure rise, biofouling blooms, red tide intake shutdowns, or seagrass decline near an outfall with ambiguous baseline data.
- 04
Working across the org
Look for work alongside marine biologists, regulators on NPDES or equivalent brine permits, plant operators, and EPC contractors during design reviews and stakeholder hearings.
Pre-screening questions to ask Desalination Systems Engineer candidates
12 questions grouped by what they test. Ask the same set in every screen and score answers on a consistent scale, or send them as an async video screen and compare answers side by side.
Plants they ran
3 questions01What experience do you have designing, building or maintaining desalination systems?
Listen forPlants with capacity named and their own role, distinguishing design work from commissioning and operation.
Studies and feasibility work only, or no plant that reached operation.
02Can you describe any large-scale desalination projects you have worked on?
Listen forCapacity, technology and their scope stated, with what the plant actually achieved against its design figures.
Projects described by design capacity with no operating performance.
03Which desalination technologies are you most familiar with?
Listen forTechnologies compared on energy, feed water quality and where each is appropriate, from actual experience.
Technologies listed with no comparison, or membrane processes assumed suitable for every feed water.
Fouling managed
4 questions04How do you address scaling and fouling in membranes?
Listen forPretreatment designed for the feed water, with cleaning triggered by measured performance rather than a calendar.
Cleaning on a fixed schedule regardless of performance, or pretreatment treated as a standard package.
05Can you discuss a time when you had to troubleshoot a problem at a plant?
Listen forA performance decline diagnosed from operating data, with the cause confirmed before membranes were replaced.
Membranes replaced as a first response, or performance loss attributed with no data behind it.
06Can you describe your experience with water quality testing and monitoring?
Listen forFeed and product water monitored continuously with the parameters that predict fouling tracked.
Water quality tested only at the product end, or feed variability not monitored.
07What steps do you take to ensure the reliability and longevity of equipment?
Listen forMembrane life and pump wear planned for, with replacement budgeted rather than treated as a failure.
Equipment life assumed from specifications, or no allowance for degradation in operating cost.
Brine addressed
2 questions08How do you approach brine disposal and its environmental impact?
Listen forDischarge design with dilution modelled and the receiving environment monitored after commissioning.
Brine treated as a disposal line item, or discharge effects assumed rather than monitored.
09What strategies do you use to minimise the environmental footprint of a plant?
Listen forIntake design considered for marine life alongside discharge, with measures that were actually built.
Environmental measures described in principle, or intake impacts never considered.
Cost per cubic metre
3 questions10Can you provide an example of optimising the energy efficiency of a process?
Listen forEnergy per cubic metre before and after, with the specific measure and what it cost to implement.
Efficiency claimed with no figures, or energy recovery described as standard with no measurement.
11What measures do you take to ensure the cost-effectiveness of a project?
Listen forWhole-life cost understood including membranes, chemicals and energy, not just capital cost.
Cost assessed at capital stage only, or operating cost assumptions taken from a vendor.
12How do you ensure a plant complies with local and international regulations?
Listen forDischarge consents and drinking water standards named specifically, with monitoring designed to demonstrate both.
Compliance treated as a permit obtained once, or discharge limits not known for the jurisdiction.
How to score responses
Score every candidate on the same four criteria immediately after the screen. At this stage you are shortlisting for panel interviews, not making the final call.
Technical depth
35%5Quotes real flux, recovery and salinity figures; explains diffuser port spacing and dilution ratios against local benthic tolerance limits.
Work that shipped
30%5Names specific plants and their role in each, with before and after monitoring data and permit conditions actually met.
Diagnosis under uncertainty
20%5Walks through autopsy of membranes, SDI trends and ambient sampling, separating plant impact from natural variability before acting.
Working across the org
15%5Describes translating ecological monitoring requirements into contractor specifications and defending outfall design to regulators and coastal communities.
Two numbers decide these projects: energy per cubic metre and what the brine does. A one-way video screen asks for both from a plant they worked on.
Try it on HirevireScreening FAQ
Process basics
How long should a pre-screening round for this role take?
Fifteen minutes across eight to ten questions, answered async. Enough to establish what they designed or operated, test their fouling and brine thinking, and hear operating cost figures.
How much should operations experience matter?
A great deal. Design experience alone produces optimistic assumptions about recovery, cleaning frequency and membrane life. An engineer who has operated a plant knows what those look like after two years.
Evaluating answers
What is the strongest signal when screening this role?
Actual energy and cost per cubic metre from a plant they worked on. Engineers with operating experience know these; design-only candidates quote figures from a specification.
How do I judge their environmental thinking?
Ask what happens to the brine. Real answers cover discharge design, dilution and monitoring of the receiving environment. Anyone who treats brine as a disposal line item has not faced a consenting process.
Go deeper on this role
Sanat has been hiring since 2012 and watching the recruitment industry change up close ever since, and turned that screening process into Hirevire's video screening platform. LinkedIn
