Arizona Water Resource Newsletter
Water Resources Research Center
College of Agriculture and Life Sciences
The University of Arizona, Tucson AZ

Recharging Treated Water May Alter Groundwater Quality

A recent U.S Geological Survey study found that recharging an aquifer with treated surface water may affect groundwater quality. The study sounds a warning to officials who are considering injecting and storing treated water underground to improve water supply and availability. The process may affect the future usability of the water.

History repeats itself. In 1934, Arizona Governor B.B. Moeur sent a contingent of National Guardsmen to prevent the building of a dam on the Colorado River. In pursuit of is battle objectives it requisitioned a ferryboat, and newspapers gleefully dubbed the contingent the “Arizona Navy.” Above is a leaner, meaner Arizona navy, with the “Gov. B.B Moeur” submarine gliding under London Bridge in Lake Havasu. The digitally composed photo was used by Herb Guenther in a power point presentation at the Water Resources Research Center Prescott conference. California take note. (Photo: Arizona Department of Water Resources).

The study found that when treated surface water recharges an aquifer, the by-products of the water disinfection process accumulate in the aquifer. Included among the by-products are trihalomethanes (THMs), formed when chlorine reacts with organic matter in an aquifer. Further, extracted water still contained measurable concentrations of THMs long after a greater volume of water had been pumped than injected.

THMs are carcinogenic compounds, and their concentrations in drinking water are regulated by the U.S. Environmental Protection Agency. The mean total concentration of THMs in the aquifer was estimated to be 58 micrograms per liter. The EPA’s stated maximum level for THMs is an annual average of 0.08mg/l.
According to the study THMs continued to form in the aquifer until the residual disinfectant (chlorine) in the injected surface water is used up, and that bacteria in the aquifer does not consume significant amounts of THMs. THM concentrations in the water extracted from the aquifer decreased over time as the injected water mixed with the native groundwater in the aquifer.

The researchers say THMs formed in the aquifer are very difficult to remove completely. In the course of the study, only 67 percent of the chloride and THMs injected into the aquifer system were recovered after 132 percent of the volume of the injected water had been extracted. With 250 percent of the volume of injected water removed from the aquifer 80 percent of the injected THMs had been recovered. Miranda Fram, lead author of the study, says the accumulation of THMs could be minimized by removing the residual chlorine in the water before injection or by modifying the extraction program.

The USGS report, “Processes Affecting the Trihalomethane Concentrations Associated with the Third Injection, Storage, and Recovery Test at Lancaster, Antelope Valley, California, March 1998 through April 1999” by Miranda S. Fram, Brian A. Bergamaschi, Kelly D. Goodwin, Roger Fujii, and Jordan F. Clark can be found at: http://water.usgs.gov/pubs/wri/wri034062/.

Environmental Industry Provides Profits, Jobs

Recently released U.S. Department of Commerce statistics profile the economic health of the water/environmental industry. Statistics show current annual revenues for the entire industry at $200+ billion for more than 115,000 revenue-generating enterprises that employ 1.4 million workers.

Municipalities are the largest segment of the marketplace, with more than 80,000 local government divisions acquiring approximately $65 billion in environmental technologies every year. But domestic sales are virtually flat with only 3-5 percent growth a year.

In terms of gross revenue and employment, environmental technology is larger than such industries as aerospace, computer hardware, paper, steel, textiles and chemicals. Environmental technology also employs more than six times the workers than motor vehicle and car body manufacturing and nearly equals that sector’s revenues.

In 2003, exports of environmental technology goods and services will top $21 billion, representing a positive trade balance of $10 billion and creating 170,000 new jobs. Currently the global environmental technology market is slightly over $500 billion per year and is projected to grow to $564 billion by 2005 and to $1 trillion by 2010.

Experts predict a 10 percent annual growth rate in parts of Asia, E. Europe and Latin America. Considering the current situation — US companies have less than a 5 percent share of the non-US market. — US companies may not be in position to take advantage of the opportunities.

Proposed San Juan Pipeline Raises Complex Legal Issue

Two tribes and a city located within two states are working on a water supply project made additionally complicated since its completion would entail delivering upper basin Colorado River water for use in the lower basin.

The project involves constructing a 250-mile pipeline to deliver about 36,000 acre-feet of San Juan River water to Gallup, New Mexico as well as to the Navajo Nation capitol of Window Rock and Navajo communities in New Mexico and Arizona. The Jicarilla Apache of New Mexico also would benefit from the proposed project.

First discussed about 1970, the plan made little headway until 2000 when New Mexico legislators voted some funding for the proposed project, and the U.S. Bureau of Reclamation got involved in the steering committee and suggested several project alternatives. The steering committee selected a preferred plan, and an environmental impact statement was initiated.

The communities that stand to benefit from the project rely on groundwater, with the San Juan River, the identified source of water for the project, the closest surface water supply. The 1,200 acre-feet delivered to the Jicarilla Apaches would come from the tribe’s water rights to the river. Navajo’s water rights are being looked to for supplying the rest of the water for the project. Complicating the situation, however, is that Navajo water rights to the San Juan River have not yet been settled.

Navajo negotiations for San Juan River water include 27,000 acre-feet of depletion rights for use in this project, to be delivered to the reservation. Gallup has several options to secure a source of water for its needs. The city can request through the Secretary of the Interior uncontracted water from the Navajo Reservoir or the city can negotiate with the Navajo Tribe, once its water rights are settled, or with the Jicarilla Apaches for tribal waters to supply its needs.

Much obviously depends upon the settlement of Navajo water rights to the San Juan, not only to supply water for the project, but also to provide the means to construct it. Rege Leach, reclamation team leader of the U.S. Bureau of Reclamation western Colorado Office, says “At this point, we are looking at this project as wrapped around the Navajo settlement on the San Juan in New Mexico. There is the likelihood that the Navajo piece would be repaid through the settlement. We are assuming at this time that Gallup’s piece and the Jicarilla Apache piece would be fully repaid by those entities.”

Further complicating the situation is that water pumped from the San Juan to supply the designated locations would entail moving water from the Upper Colorado River Basin for use in the lower basin. The San Juan is located in New Mexico in the upper basin. The project proposes using the water in three river basins, with a portion used in the upper Colorado River basin in New Mexico, another portion used in the Rio Grande basin and a portion for the lower basin in areas of New Mexico and Window Rock, Arizona. This plan bristles with legal complexities. Leach says, “It is a contentious issue. Some read the Colorado River Compact to prohibit moving water between basins.” What is being proposed is unprecedented and resolving the issue will require negotiations and evaluating the law of the river.

Leach also explains they are in the process of completing a draft environmental impact statement, and they hope that pending water issues will be resolved in the meantime, with the resolution reflected in the completed EIS.

New ASU Center Studies Urban Environment

Arizona State University’s newly established Consortium for the Study of Rapidly Urbanizing Areas will have a 486-square mile laboratory as it focuses on the City of Phoenix. One of the fastest growing urban regions in the country, the Phoenix area is suited for the role, its rapid urbanization raising demographic, environmental and other issues. Water resources will be one of the areas to be studied.

The consortium will coordinate ASU research in urban development currently underway in various academic fields. A prime intent is to combine the university’s environmental science and engineering research in metropolitan Phoenix with other related university fields. The goal is to bring an interdisciplinary approach to problem solving and to broaden the research focus to include analysis of global urban affairs.

The consortium builds upon ASU’s established commitment to urban studies. Its Center for Environmental Studies receives National Science Foundation support to participate in its Long Term Ecological Research program, to study ecological processes occurring over long periods of time in the Phoenix area. The new consortium will be housed at the center, with center director, Charles Redman, heading it.