Recharge and other solutions for the water supply

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By Roger Snodgrass

Recharge and other solutions for the water supply

Zooming down from a high-angle view of the earth to one watershed and one facet of a set of interrelated environmental problems, the geologist focused on sustaining clean water in this century.

A supercomputing specialist in hydrological sciences from California’s Lawrence Livermore National Laboratory, Andrew Tompson painted some of the big-picture symptoms related to fresh water resources in the world and then plunged into the role science played in a tough situation.

Tompson spoke at an Earth and Environmental Sciences Division colloquium Monday in the Physics Auditorium on the campus of Los Alamos National Laboratory

Water supplies in many areas are increasingly tapped out, impaired or polluted. Five million people die in the world each year from water-borne illnesses. By 2025, 2.7 billion people will face water shortages.

“We’re in a red area of physical scarcity,” Tompson said.

What role, then, can science play? What do we need most, new supplies, better treatment technologies or improved operations of natural systems?

The questions are not easy to answer in the Golden State, which Tompson considers a microcosm of the world predicament.

As in many other places in the world and even in New Mexico, urban growth is driving what is becoming an unsupportable demand.

When the result is not actual water shortages or pollution, as in the agricultural areas of the Central Valley, the demand is managed through a jumble of solutions that are becoming more and more difficult to patch together and more and more expensive to build and manage.

“It’s a complicated systems problem to manage it all,” Tompson said, citing uncertainties related to how much water the state can expect for replenishment, further complicated by a new wave of unknowns linked to climate change, not to mention political boundaries and policy shortcomings.

California is warming; there is less snowfall, a lighter snow pack, and a dwindling snowmelt across the West.

To make matters worse, it has been observed that the precipitation falls in the winter but is needed in the summer. It doesn’t come down where most people are but where the population is sparse.

“There’s always somewhere else to go for water,” said Tompson, but there are also built-in contradictions between protecting people from floods by building constraints and the need to store and convey water supplies to distant users.

The specific contributions science and technology can provide, Tompson said, are in areas like improving reliability of long-term forecasts on the regional scale and developing better treatment technologies to deal with pollution and salt.

Science and technology can do more to improve storage and recovery efforts, like banking water supplies in underground aquifers.

Toward the end of a presentation Monday, Tompson delved into a particularly sensitive situation involving an aquifer storage and recovery project in Southern California.

The question was how to qualify a stream of treated water, 100 percent treated, from upstream uses in the Santa Ana River Basin that is collected in infiltration basins for aquifer storage.

The scientists served the project by modeling the geology and testing observations to validate the model in ways that could be used for validating compliance standards.

In conclusion, Tompson returned to the high-level view, noting the integral relationship between water and energy at the heart of the earth system.

“We need water to make energy and we need energy to move the water.”

Huge technical projects could be accomplished, “if you have enough money,” but we also need “micro-technologies for areas without money.”

Scientists, he cautioned, need to keep in mind, “We’re working, not in an ideal world, but in a polluted and energy-starved world.”