A Four Legged Stool and A Water Scarcity

After three weeks in Santorini, Greece, my homesick heart aches for the smell of pines, the Grand Canyon’s plateaus, and the queen, herself, the Colorado River. When I think of home, the ocean does not first come to my mind. I think of the river, which once carved through rock; the river that we so heavily depend on in the South West region of the U. S. for water and agriculture.

After observing the desalination plant on the northern part of Santorini’s crescent, I questioned the scarcity of such plants in the United States. Desalination plants, which convert seawater into potable drinking water, may not be the only solution to Santorini’s high demand for water. In an effort to explore other options for potable water in Santorini, I propose that the island utilize an array of methods to harvest water for drinking, farming, and energy, rather than simply relying on one limited resource, such as the Colorado River, in the Southwestern part of the U.S., or the Aegean Sea, in Greece.

Here in Santorini, “water demand… has been increased due to increase in per capita water consumption, and due to a sharp rise of tourists during the hot months of the year” [1]. Santorini relies solely on three desalination plants, distributed strategically to accommodate communities in and around population centers, for potable water (Figure 1) Typically, the Greek government would subsidize the shipment of water to islands in need, but due to Santorini’s and many other Greek Island’s sizes and permeable land composition, storing potable water in groundwater reservoirs has proven to be a less sustainable option (Figure 2). The extremely permeable composition of Santorini, containing only a small percentage of metamorphic rock and the rest volcanic, can result in seawater intrusions when ground water is extracted. [1].

(Figure 1) Map with Population Centers and Desalination Plants

(Figure 2) Map displaying Santorini’s composition and Gracie

Santorini, unfortunately, does not receive adequate rainfall for precipitation to be used as a reliable water source. Luckily, the amount of “water product” distributed by desalination plants cannot easily be altered by local weather or a changing climate. In addition to having a consistent output, desalination plants (Figure 3 and 4) also produce high quality water that has been filtered through a reverse osmosis process [2].

(Figure 3 and 4) Building and Box

Below, I will briefly explore some alternative water collection, treatment, and distribution ideas that could be incorporated into Santorini’s already existing infrastructure. First, I believe we cannot sustainably support a community for a prolonged period of time, if only one major water resource method is utilized. In addition to desalination, “the water needs of Santorini and Thirasia are currently partially satisfied by groundwater abstraction, while water reclamation is not practiced” [1]. Although we do not yet know the long-term effects of ingesting reclaimed water, it would be extremely beneficial to introduce an additional water source, such as the aforementioned, to Santorini and other islands struggling with similar scarcity issues.

Similarly to the water reclamation process, desalination also lies within its infant phase. Although many innovations have been made thus far, a demand for advancements within this technology remains. Still, a desalination plant can cost millions to billions of dollars to construct; operating one can cost just as much. A tremendous amount of energy and power are required to pump water up the caldera walls (Figure 5). Reclaimed water facilities are considerably less expensive and would utilize wastewater that would otherwise be sent to sea [2].

(Figure 5) plant on the water

As I learned about the hydrothermal reservoirs that reside below Nea Kameni, I began to wonder if it could be used as a unique water or energy source for Santorini. Since higher risks of earthquakes exist in geologic hotspots, such as Santorini’s active resurgent dome volcano, tampering with the geography could be a very poor decision. The hot water that is pumped from underground hydrothermal reservoirs contains high levels of sulfur and many other minerals that would require an excessive amount of energy to extract [3]. Gasses such as hydrosulfide, hydrogen, carbon dioxide, and methane are released from the hydrothermal reservoir as the magma chamber below boils the groundwater above (Figure 6).

It appears to me, hydrothermal reservoirs may not be a sustainable or safe addition to Santorini’s water resource plans. However, it could be utilized as a source of energy to power existing desalination plants and future water reclamation plants. In fact, most of the funding for volcano monitoring on Nea Kameni is from private companies interested in geothermal energy.

(Figure 6) Active Dome Sketch

After investigating the desalination process, water reclamation process, and the possibility of tapping into Santorini’s hydrothermal reservoir, it is apparent that one other water resource is necessary to sustain the island’s population due to economic and environmental reasons. An example of this could be that desalination plants are large contributors to carbon dioxide emissions and may be damaging ecosystems near pumping and dumping sites [2]. In addition, they are less cost effective than reclamation plants [1]. Typically, finding alternative water and energy sources that are both economically and environmentally friendly, can prove to be extremely difficult.

An ideal water resource system would incorporate four parts. Imagine a community’s water resource system as a four-legged stool, where each leg is a different source. One leg would be surface water, a supposedly renewable source such as the Colorado River. The second leg would be groundwater, a “savings account” for emergencies. The third leg would be demand management (i.e. water conservation). The fourth would be, desalinization. Without one leg, the stool will fall; the community will not thrive. Since Santorini does not have a renewable water source, one leg is missing. As a replacement leg, I believe water reclamation is worth consideration.

Sources

[1] Konstantopoulou, Flora. Liu, Songsong, Papageorgiou, Lazaros. Gikas, Petros. The utilization of non-conventional water resources to subsidize insufficient water balances: Case study for Santorini Island, Greece. (2012) http://www.ucl.ac.uk/~ucecsol/pdf/FK_SL_LGP_PG_ENCON2012.pdf (June 2015)

[2] Lebwohl, Beth. Heather Cooley on Reasons for and Against Desalination (2011). http://earthsky.org/earth/heather-cooley-on-the-advantages-and-drawbacks-of-desalination (June 2015)

[3] Environmental Impacts of Geothermal Energy. http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/environmental-impacts-geothermal-energy.html#.VYJYTktbTwI (June 2015)

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One thought on “A Four Legged Stool and A Water Scarcity”

  1. Good job on incorporating more geology into your post (after our first edit). I would still like to know more about how the rock types control groundwater (or the lack thereof). If you email me your pictures, or give them to me on a flash drive. I can add them when the wifi cooperates.

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