IWRA Proceedings

In the United States, desalination has considerably expanded since the 1950s, reaching a daily production capacity of 2 BGD (billion gallons per day) with around 1,336 operating plants as of 2013 (GWI, 2013). The steady increase in the number of new desalination plants online as well as the production capacity in the US indicates long-term trends in the desalination sector (Gasson, 2013). Despite this continuous growth, a steady increase in desalination investments and growing demand for water, in many regions, the costs of desalination are still prohibitive for its quick uptake. At the same time, the technology offers a tremendous potential for ‘enormous supply expansion that exceeds all likely demands’ (Chowdhury et al., 2013). Moreover, research on long-term desalination trends, socio-economic impacts and potentials for additional water supply is still limited, mainly due to data paucity and a regional differentiation of the desalination plants in the US.

This paper provides answers to those questions by developing interactive geospatial models and a multi-dimensional analysis of desalination trends in the time span 1950-2013. The analysis is based on data from Global Water Intelligence (GWI, 2013). The models use the Keyhole Markup Language (KML) and the C++ computing language to represent desalination trends over time and space in virtual globes environment. Thus, the results of the analysis and the models themselves can be viewed in any virtual globe (e.g., Google Earth, Google Maps, ArcGIS).

The analysis shows that more than 90% of all the plants in the US are small-scale plants with the capacity below 4.31 MGD. Most of the plants (and especially larger plants with the capacity above 4.31 MGD – million gallons per day) are located on the US East Coast, as well as in California, Texas, Oklahoma, and Florida. Some larger plants are also present inland in Illinois and Colorado. The vast majority of plants in the country operate with a capacity in the range between 0.31 MGD and 1.80 MGD. Despite the geographical proximity to the sea, most of the plants use brackish groundwater due to economic factors related to the desalination process itself and the disposal of the highly saline byproduct - brine. The models provide information about economic feasibility of a potential new plant based on the access to feed water, energy sources, water demand, and experiences of other plants in that region. The models also evaluate correlations between population density and the developments of desalination plants in different US regions, which directly determines the necessity for a reliable water supply.

The analysis and models can be used both for educational and interdisciplinary research purposes and help with determining socio-economic viability of establishing prospective desalination plants in different regions in the future. They can also help support decision makers in solving emergency questions related to water shortages and preparing for long-term water scarcity in different regions.