Land Based Watermakers

Shore-based plants span from 10,000 GPD for small island or resort applications to multi-million GPD municipal systems. The modular design allows capacity to be added in 500,000 GPD increments as demand grows. Engineering, procurement, and commissioning services are available for turnkey delivery on plants of any size in this range.

Energy recovery devices (ERDs) capture the pressure energy in the RO concentrate stream and transfer it to incoming feed water, cutting high-pressure pump energy consumption by 40 to 60 percent. For a 1 million GPD plant, this difference can exceed $200,000 per year in electricity savings. Isobaric pressure exchangers reach 97% energy transfer efficiency in large systems.

Typical pre-treatment trains include intake screening, coagulation and flocculation, dissolved air flotation or media filtration, and 5-micron cartridge filtration immediately before the high-pressure pumps. Biocide dosing controls biological fouling. Antiscalant chemical injection prevents carbonate and sulfate scale on the membrane surface. Pre-treatment design is site-specific based on raw seawater analysis.

RO permeate is slightly acidic and stripped of minerals, so post-treatment typically includes CO2 stripping, lime or calcite contactor remineralization to restore calcium hardness to 80 to 100 mg/L as CaCO3, and pH adjustment to 7.5 to 8.5. Disinfection via chlorination or UV is the final step before distribution. This meets WHO and most national drinking water standards.

Smaller plants in the 10,000 to 100,000 GPD range are typically manufactured, shipped, and commissioned within 16 to 24 weeks. Large municipal plants follow a detailed engineering and construction schedule, generally 12 to 36 months depending on civil works scope. AMPAC USA provides Gantt chart project schedules and milestone payment structures tied to delivery verification.

Seawater RO membranes require 800 to 1,000 PSI operating pressure for standard Mediterranean or ocean feed at 35,000 to 40,000 TDS. Warmer seawater, such as Red Sea or Arabian Gulf feed at 42,000 to 45,000 TDS, may require 950 to 1,100 PSI. High-efficiency vertical turbine and centrifugal pump options are sized to match site-specific feed conditions.