Puerto Rico Desalination Hearing: RO Cost Fight, Modular Push

On September 10, the Economic Development Committee of the Puerto Rico House of Representatives held a hearing under Resolution 106 to evaluate desalination as a supplementary water source to address drought, with the Puerto Rico Aqueduct and Sewer Authority (AAA) and the legislature clashing over the cost and scale of reverse osmosis.

Ann Ventura, AAA Deputy Director of Infrastructure, stated that among the alternatives studied for the Carraízo Reservoir, a 6-million-gallon-per-day (about 23,000 m³/day) reverse osmosis plant had been proposed but was abandoned due to cost and environmental impact; preliminary studies for a new plant in Salinas likewise concluded that desalination was costly. Citing the 50-million-gallon-per-day Carlsbad desalination plant in California as an example—with an investment exceeding $1 billion and annual electricity consumption of 274 million kWh—she noted that AAA still views reverse osmosis as the most promising option, but one that is overly dependent on electricity prices.

Committee Chairman Joel Franqui, however, argued that daily water outages alone cost small and medium-sized businesses $18 million to $20 million, and 50 days of outages would equal roughly a $1 billion investment; he asked AAA to study modular scenarios of 5 million to 50 million gallons per day rather than referencing only giant single-unit plants, and suggested first building a demonstration unit at the Palo Seco power plant. The Financial Oversight and Management Board has allowed the government to apply for about $1.3 billion in drought emergency reserves, part of which could fund preliminary studies.

The core concerns of island markets toward SWRO are electricity prices, brine concentrate, and one-time mega-investments. Compared with giant single-unit plants, phased-capacity modular reverse osmosis paired with renewable-energy power supply and a pay-per-volume water supply model is more likely to pass review; for such customers, proposals should emphasize the “small-scale demonstration → gradual capacity build-out” path and per-unit electricity consumption data.