Watec is the Northwest leader in developing customized desalination plants for individual property owners, communities and commercial sites. The state-of-the-art reverse osmosis (RO) technology that we utilize filters water based on particle size. Pure water passes through the membrane’s surface while larger particles are filtered out—even particles that are invisible to the human eye.

Reverse Osmosis (RO) water filtration is essentially the filtering out of particles based on their size. The chart above indicates the particles filtered out using differing filtration techniques. Although the term “particle filtration” is used as a specific filtration process, all the processes are types of particle filtration with the difference being the varying membranes, materials and pressures used to differentiate the process terms. In reading the chart, note that one thousand microns equal 1 millimeter and 25.4 millimeters equal 1 inch.

• Particle filtration–Filters out particles between 1 to 1000 microns.
• Microfiltration–Filters out particles 0.1 micron to 10 microns.
• Ultrafiltration–Filters out particles 0.007 micron to 0.15 microns.
• Nanofiltration–Filters out particles 0.0005 micron to 0.01 microns.
• Reverse Osmosis–Filters out particles 0.0001 micron to 0.004 microns.

Economical, reliable and eco-friendly water production.
RO desal plants offer major advantages to older thermal desalination systems. They are much less energy dependent than distillation methods since energy is only used to pump the water through the membranes. Smaller systems producing 5 to 50 gallons per minute (GPM) require an energy expenditure of 0.1 to 0.3 cents per gallon. Larger plants delivering over 50 GPM have a combined energy and capital cost ranging from 0.2 to 0.4 cents per gallon produced.

Watec RO desal systems have proven to be environmentally benign, requiring only the responsible management of brine concentrate discharge. In assessing environmental impact, one must also consider the benefit of RO in creating new water resources compared to the detrimental impact of overdrawing groundwater or surface water sources.

The photos show two views of the RO desalination mechanical room at Lopez Water LLC. The system specifications are:

• 34 Gallon Per Minute (GPM) seawater intake
• 10 GPM potable product water production
• Energy costs–3.3 Gallons/Cent or 330 Gallons/Dollar
• Programmable computer controlled
• Remote monitoring and control via DSL modem