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The Pre-Conference Workshop on November 1 covered the topics of basic groundwater hydrology, regional groundwater quantity issues, state policies on surface water-groundwater interactions, groundwater issues in rural residential and urbanizing areas, public drinking water issues, and source water protection planning.

Michael Barber (State of Washington Water Research Center) covered groundwater essentials and introduced the concept of Aquifer Storage and Recovery (ASR). In ASR, water not being used is pumped into an aquifer and stored until needed. Although ASR avoids most of the environmental impacts associated with above-ground storage, it is a relatively new tool. Potential issues include the cost of the required pilot phase of a project, mitigation plans, and groundwater quality regulations.

Robert Mahler (University of Idaho) discussed the complicated administration of water use, a complication at least partly due to the fact that surface water and groundwater often interact. Pumping groundwater may eventually impact surface water, but the definition of “eventually” is variable. The challenge for the states is balancing the need to administer an understandable policy with the fact that science needs to fit into the equation somewhere. In Idaho, water quantity is regulated by the Idaho Department of Water Resources, while quality is regulated by the Idaho Department of Environmental Quality. The law, however, is not well developed. Both agencies have rules that indicate the state recognizes the connection between groundwater and surface water, but groundwater mining is a problem in southern Idaho.

Gail Andrews (Oregon State University) said that in Oregon, “First in time, first in right” is the basic rule for water quantity. Oregon’s Groundwater Act allows groundwater use if reasonable levels are maintained, but individual basins also have rules. Surface water-groundwater interference is regulated largely by the distance separating well and surface water (i.e., by geometry).
Barber said that in Washington, senior water rights are protected from all junior rights. Currently, water right applications are evaluated in the context of water availability in the watershed. The widely debated “one molecule” standard is used--if no further surface water diversions can be permitted, no matter how small, then the same holds for groundwater withdrawals. In summary, Barber said that the differences in water laws makes management of interstate watersheds like the Columbia Plateau area extremely complicated. What may seem like a good solution in one state may, in fact, be illegal in another.

Andrews said that one quarter to one third of the population of Oregon has a well, a septic system, or both. Yet there is no census of them, and no regulations with respect to testing wells or pumping septic tanks and maintaining drain fields. Regulations for the placing of both are again geometric, and not all sites are suitable for septic systems or wells. One interesting aspect of septic design is that groundwater dilution actually is the final treatment--by design.

Mahler presented the results of a Pacific Northwest survey on drinking water, and outlined the standards that protect central water supplies serving 25 or more residences. Individual, exempt wells, however, are not regulated. The primary national standards, which are those that are enforced, include organic chemicals, inorganic chemicals, microorganisms, turbidity and radionuclides. Elevated nitrates, common in agricultural areas, may also indicate that other contaminants are present.

Barber concluded the workshop by discussing source water protection in watershed management, the use of zoning or policy to keep high-risk activities away from the drinking water supply, and monitoring to insure existing operations do not negatively impact supply. Land uses allowed vary according to travel time considerations. Management focuses largely on shallow aquifers, which may be deemed nonsensitive or sensitive. The latter classification requires a determination of wellhead protection areas, which can be produced using the wellhead analytic element model WhAEM2000. It is important, however, not to overlook the importance of routine monitoring and public participation in the process.

Summary by Mary Aegerter, Technical Writer, Washington State University