Idaho Water Quality
Masthead
ARTICLE INDEX
Volume 1, Number 3
July 1991

FOCUS ON DRINKING WATER | FROM THE EDITOR | IDAHO'S AQUIFERS | IDAHO WATER PROJECT UPDATE PUBLISHED | 35 COMPLETE MASTER WATER WATCH TRAINING | EVALUATING YOUR DOMESTIC WATER QUALITY PROBLEM | STEEP II FOCUSES ON WATER QUALITY | DOMESTIC WATER QUALITY HANDBOOK | NITRATE EFFECTS ON LIVESTOCK | USDA WATER QUALITY RESEARCH PROGRESS | KOOTENAI WATER QUALITY FORUM | TVA DEVELOPS RESEARCH SOFTWARE | WASTE NOT . . . REDUCE!!! | SNAKE-PAYETTE RIVERS WATER QUALITY HYDROLOGIC UNIT PROJECT

Water Bar

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

FOCUS ON DRINKING WATER
Contaminants have many opportunities to reach our drinking water. The geology of an area, soil conditions, precipitation, condition of our wells and plumbing, and the characteristics and occurrence of the substances themselves are all factors that determine whether a substance reaches our water supply.

No single group of individuals is responsible for what is happening to our water supplies. Homeowners and renters, as well as farmers, city dwellers and industries, generate wastes that can eventually make their way to our drinking water sources.

There are many specific things we can do to prevent contamination. First, we must realize that water is a shared resource, used simultaneously by many individuals, municipalities, and businesses. Second, we must understand that each of us contributes to the pollution threat. Finally, we must make a conscientious decision to change the way we conduct our daily activities. Key steps we can take to protect our water include:

Protecting our water resouces will require everyone's effort. We must protect this resource to assure an adequate and safe supply of water for future use. Our children and grandchildren are depending on it.
(Source USDA-ES)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

FROM THE EDITOR
Water quality may well be one of the four or five big issues of this decade in the United States. With over 160 Idaho research and extension faculty working on water quality-related issues, the College of Agriculture stands ready to meet our state's needs. Many exciting and useful programs are currently underway in the University of Idaho College of Agriculture. A sampling of these programs appears in this issue of WATER QUALITY UPDATE. Some highlights in this issue include:

As you can see from this sampling a lot of positive activity is being generated in the water quality arena. Another observation is that the College of Agriculture is involved in many inter-agency projects. Please keep me posted as you initiate or learn of new programs gearing up across the state.
(R. L. Mahler)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

IDAHO'S AQUIFERS
Large areas which contain ground water are called aquifers. Idaho has a number of aquifers which are essential to the state's water supply. Aquifers occur in either consolidated or unconsolidated ground formations. Consolidated aquifers hold water in the cracks of solid rock and the amount of water available depends upon the size and number of cracks. Unconsolidated aquifers hold water in a mixture of sand and gravel. The Snake River aquifer in southern Idaho is an example of a consolidated aquifer and the Rathdrum aquifer in northern Idaho is an example of an unconsolidated aquifer.

Another characteristic of aquifers is whether they are confined or unconfined. Confined aquifers have impermeable surfaces on the top and bottom. Being confined often puts the water under presssure and the groundwater will rise toward the land surface when the upper layer is pierced by a well. This is often referred to as an artesian well. Unconfined aquifers are not under pressure and the water table delineates the top of the aquifer. Idaho has both confined and unconfined aquifers throughout the state.

Idaho has three major aquifer types. They are: (1) valley-filled, (2) basalt, and (3) sedimentary/volcanic aquifers. Valley-filled aquifers hold water in unconsolidated sedimentary material, usually in intermountain valleys. Basalt aquifers hold water in the cracks of underground rock (basalt), and in thin sedimentary layers which are interbedded with the basalt. Sedimentary/volcanic aquifers contain a mixture of unconsolidated sedimentary material, sedimentary rock (sandstone and shale), and basalt. Geothermal water is usually associated with sedimentary/volcanic aquifers.

Idaho map of 3 major aquifer types

Groundwater contamination can result both directly by injection of contaminants into the groundwater through wells, or when the ability of the soil to adsorb and immobilize or break down contaminants is exceeded. Under the latter conditions, contaminants applied at the land's surface move downward and may eventually reach the aquifer. For example, some wells in Idaho contain excessive levels of nitrates which may come from agricultural fertilizers, lawn and garden fertilizers, septic tanks, and/or livestock feeding operations.

The Idaho Department of Health and Welfare, Division of Environmental Quality (IDEQ), and the Idaho Department of Water Resources (IDWR) have prioritized major Idaho aquifers based on their vulnerability to pollution. Vulnerable areas exist where groundwater is shallow or where soils are thin or very permeable. Also, the potential for contamination is greater where considerable water is applied to the land surface from precipitation or irrigation water which can move contaminants below the root zone. Factors considered in the overall vulnerability ranking used by IDEQ and IDWR were population density (as a measure of land use) and intensity of ground water use. The ranking of Idaho's most important aquifers (for location see map; numbers correspond to map) from most to least vulnerable is as follows:

  1. Boise Valley
  2. Snake River Plain
  3. Rathdrum Prairie
  4. Marsh Creek/Lower Portneuf
  5. Salmon Falls Creek/Rock Creek
  6. Payette Valley
  7. Coeur d'Alene River Valley
  8. Mountain Home Plateau
  9. Moscow Basin
  10. Clearwater Uplands and Plateau
  11. Goose Creek/Golden Valley
Map of Idaho's major 
aquifers
The majority of the ongoing pollution prevention efforts in Idaho are targeted at the Boise Valley, Snake River Plain, and Rathdrum Prairie aquifer areas in Idaho. Beginning with the next issue of WATER QUALITY UPDATE I will start examining each of the 11 aquifers one at a time (in order of state priority) in more detail.
(R. L. Mahler)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

IDAHO WATER PROJECT UPDATE PUBLISHED
The Idaho Water Resources Research Institute (IWRRI) and University of Idaho Cooperative Extension System (CES) have teamed up to publish IDAHO WATER PROJECT UPDATE. The inaugural issue appeared in late June.

IDAHO WATER PROJECT UPDATE is a semi-annual newsletter for people concerned with water and water-related issues in Idaho. The importance of these issues is reflected by the involvement of over 100 federal, state, and local agencies in water quality and water management investigations and research.

Information exchange and education programs are receiving greater attention as well. Exploring solutions for problems and sharing the information is critical to good management. IDAHO WATER PROJECT UPDATE is designed to foster communication between professionals and to enhance existing and future programs by providing a resource that affords a comprehensive look at water programs in Idaho.

The inaugural issue of IDAHO WATER PROJECT UPDATE, representing contributions from over 60 agencies, contains information on more than 150 current water-related projects. An additional 20 agencies have committed to provide materials for the fall issue. The University of Idaho Agricultural Experiment Station (AES) contributed over 15 projects to this first issue. The fall issue will contain additional AES research projects and college CES projects. I will request information from faculty in the near future.

The goal of this newsletter is to let people in other agencies know the types of projects taking place in Idaho and to provide enough information so that people with mutual interests can establish a communication link. The newsletter is organized so that the reader can easily find items of interest. An index is provided and the material will probably be put into an electronic data base in the near future. By supporting this statewide effort in a major way the College of Agriculture is showing leadership and being proactive in water quality issues of importance to Idaho.
(R. L. Mahler)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

35 COMPLETE MASTER WATER WATCH TRAINING
Do you need volunteers to help with stream monitoring? or educating lake property owners on how they can minimize their impacts on water quality? or to help survey watersheds to determine best land uses to maintain good water quality? If your answer is yes to any of the above questions, or you can think of other areas in water quality education that you could use some extra hands, you may want to start a MASTER WATER WATCHERS program.

Bonner and Kootenai County Extension offices in partnership with the North Idaho Lake Association Coalition (NILAC) developed a MASTER WATER WATCHERS program patterned after the BAY WATCHERS program in Washington state. The program includes an overview of the creation and evolution of watersheds and a discussion of all the impacts on surface and ground water quality. The goal of the training is to emphasize how we can lessen those impacts. Besides the 35 hours of class time in each county, 3 joint tours were included in the training and participants had the opportunity to try water monitoring methods in a day-long workshop.

MASTER WATER WATCH instructors included representatives from the University of Idaho Colleges of Agriculture and Forestry, Range and Wildlife Sciences, Idaho Division of Environmental Quality, Idaho Department of Lands, Soil Conservation Service, Panhandle Health District, Clark Fork Coalition, 3 private consulting companies, the Idaho state legislature, and Kootenai and Bonner County Extension. The course was offered for one credit (505, recertification) through the U of I.

Those participating in the class included members of a waterways committee, planning and zoning commissioners, lake property owners, teachers, and agency people. Participants will each return 35 hours of volunteer time this summer.

For more information, contact Susan McNall, Bonner County Extension Home Economist, Vickie Parker-Clark, Kootenai County Extension Agricultural Agent, or Sue Hailey, NILAC.
(V. Parker-Clark, Kootenai County; S. McNall, Bonner County)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

EVALUATING YOUR DOMESTIC WATER QUALITY PROBLEM
If you have your private domestic water supply tested by a reliable laboratory and find that a problem does exist, then it is decision time. The decisions to be made will be based on several or all of the following:

There are five up-front options:
  1. Do nothing. If the contaminants do not present a health hazard or pose a particular threat to the water system you may rightfully choose to just "let it go." Examples might include a low to moderate water hardness problem or a slight intermittent turbidity problem.
  2. Eliminate the source(s) of contamination. The most ideal solution, if possible and practical, is to identify and eliminate the source(s) of contamination. It is certainly preferable to prevent contamination rather than having to depend on its continuous removal by treatment facilities. Examples might include providing protection for the wellhead to prevent surface contamination from entering the well, deepening the well to a new unpolluted aquifer, or drilling a new well at a location better protected from contamination sources.
  3. Install treatment facilities for the entire water supply. The presence of certain contaminants may warrant their removal from the entire household water supply. These contaminants are those that could pose a threat to people or pets or to the household water system regardless of the intended use of the water. Examples might include a sedimentation and filtration system to remove suspended materials, a chlorination system to control bacterial contamination, a neutralizing filter to control acid water, or periodic shock chlorination treatment to control iron bacteria.
  4. Install treatment facilities only for water being used for specific purposes. With most water quality problems, it is practical to provide treatment only for those uses where treatment is appropriate. This practice lowers the investment, maintenance, and operational costs associated with the treatment facility. Examples might include hard water, odor, taste, or staining problems where only the water used inside the house is treated. Other examples appropriate as point-of-use (POU) facilities could include activated carbon filters for removing volatile organic chemicals and radon, reverse osmosis (RO) or distillation units to remove total dissolved solids and nitrates (particularly important for expectant mothers and infants), or ultraviolet units to kill microorganisms.
  5. Purchase bottled water or otherwise haul water from a safe source. This alternative is used to obtain water for human consumption that is free of biological and chemical contaminants. It by-passes the need to have and maintain effective water treatment facilities capable of controlling health threatening contaminants.
(Roy Taylor, Agricultural Engineering)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

STEEP II FOCUSES ON WATER QUALITY
The newly funded tri-state (Idaho, Oregon, Washington) STEEP II project will place an emphasis on water quality considerations. Objectives of Idaho's portion of the research project which will address water quality include: (1) modification of crops, including cultivar development for erosion control, efficient capture and use of nutrients and water, and increased host plant resistance against plant pests, (2) soil, water, and crop management to maintain and improve soil productivity and safeguard water quality, (3) development of pest management systems to make maximum use of natural, physical, and/or biological controls that are environmentally safe and that utilize effective forecasting mechanisms for specific pest problems, (4) determination of the socioeconomic impacts of erosion control and water quality enhancement, and (5) development of tools for assessing the impacts of farming practices on erosion and water quality.

Over 20 AES faculty are serving as project leaders on the seven newly funded Idaho STEEP II projects. In addition to conducting the research, many of the projects address the technology transfer process necessary for adaptation by growers. STEEP II should help answer many of our most pressing questions about pesticide and fertilizer management in agricultural systems.
(R. L. Mahler)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

DOMESTIC WATER QUALITY HANDBOOK
Water is one of the most abundant and best known chemical compounds on earth. Everyone is familiar with its chemical formula, H2O. Having enough water is essential for the survival of all living things. This need for water is evident in the fact that two-thirds of the human body is water. The average person must consume 51/2 pints of water in some form each day to stay healthy. This amounts to about 16,000 gallons of water over the average person's lifetime.

Water quality is just as important as its quantity. However, people frequently take for granted that the water they use is free of contamination. Thought is seldom given to where the water comes from, what substances it may have been in contact with or whether it is indeed contaminated.

Unfortunately, high quality water is no longer something that any of us can take for granted. Reports of contaminated city supplies, rural water district supplies, and private wells have become an everyday event. Many people have had to face the unsettling reality that the water they've been using for some time may no longer be as pure as they thought.

For the person concerned about the quality of water, many questions come to mind: How do I know if my water is safe? What kinds of contaminants can get into my water? Will these contaminants make me sick? Will contaminants effect laundry results? What can I do if my water is contaminated? Where can I get more information?

In response to these questions and to raise consumer awareness concerning the issue of water quality in Idaho, a Domestic Water Quality Handbook was distributed to county faculty. Materials were purchased from other states and agencies to serve as a reference for county faculty in addressing consumer concerns in the following areas:

At your upcoming district faculty meeting this notebook will be updated. A new section on Gray Water will be added and new materials will be incorporated in selected areas of other sections. Let me know if you have any recommendations for future update materials.
(Ernestine Porter, Home Economics)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

NITRATE EFFECTS ON LIVESTOCK
Some farm animals are affected in the same way as human babies by high levels of nitrate in the water supply. Nitrate poisoning can occur in animals less than six months old. As with human babies they are susceptible to nitrate poisoning because their digestive systems contain bacteria that convert nitrate (NO3) to the toxic nitrite (NO2). Excess nitrite inhibits the oxygen-carrying capacity of blood. Without treatment this problem can be fatal. After the age of six months the acidity of the digestive system increases and conversion of nitrate to nitrite no longer occurs, thus reducing livestock susceptibility to nitrate poisoning. Nitrate is present in feed as well as in water. Crops harvested after a drought are likely to contain relatively high concentrations of nitrate.

Cows, sheep, horses, baby chickens, and baby pigs have digestive systems that support bacteria that convert nitrate to nitrite, and they are likely susceptible to methemoglobinemia (nitrate poisoning). Symptoms include bluish or brownish discoloration of the mucous membranes or the areas around the mouth or eyes, sluggishness, lack of coordination, rapid heartbeat, frequent urination, labored breathing, and abortions. If diagnosed in time animals can fully recover.

Currently there is no regulatory drinking water standard for livestock. The 10 ppm NO3-N standard used for human drinking water is safe for all animals, but research suggests that higher concentrations may be acceptable, depending on nitrate concentration in the diet. The U.S. Environmental Protection Agency has recommended that drinking water for livestock contain no more than 100 ppm nitrate-N, although most species can tolerate higher levels.
(Source: CES, Cornell University)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

USDA WATER QUALITY RESEARCH PROGRESS
A recent sampling of ARS progress under the President's Water Quality Initiative to keep pesticides and fertilizers out of ground and surface waters includes:
Tifton, GA. USDA's premier groundwater model for pesticides is being expanded to include fertilizers.
Beltsville, MD. The problem is being attacked on two fronts: a computer database helps farmers choose pesticides and a machine degrades what's left over. Also, a tiny bait minnow is being tested as an environmental sentinel for East Coast estuaries.
University Park, PA. By comparing oxygen atoms in rainwater, scientists might be able to advise farmers which fields are loosing chemicals.
Tucson, AZ. A computer program evaluates environmental/economic consequences of farming practices.
Fort Collins, CO. A computer model is being developed to show how much nitrogen fertilizer is headed toward groundwater.
Ames, IA. Well samples are helping scientists learn how chemicals move.
Morris, MN. Researchers study ways frost effects chemical movement, and search for better detection methods.
(Source: USDA)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

KOOTENAI WATER QUALITY FORUM
"Just by existing on this planet, we impact water quality. As responsible citizens of this earth (and of Kootenai County, Idaho) we should find ways to lessen our impact on water quality." That was the message of a workshop held in March in Post Falls, Idaho. The workshop theme was "Your water: the challenge is crystal clear." Emphasis was placed on both surface and groundwater.

After setting the stage with the history of the formation of the county's lakes and the Rathdrum aquifer, speakers related to the 45 participants how current practices in agriculture, tourism, recreation, forestry, urban development, and industry affect water quality. Each participant was asked to keep a list of "ah-hah's" -- information that was significant to that person in his/her own "backyard."

Not only were the impacts discussed, but each speaker gave some success stories or suggestions on how we can help maintain the quality of our water, or even improve it.

Fourteen students from Post Falls, Coeur d'Alene and Lakeland high schools participated in the 11/2 day workshop. The students received scholarships to attend the workshop and were asked to share what they learned with their classes. The scholarships were provided by USDA-ES grant monies.

An interagency group led by University of Idaho Extension Agents Vickie Parker-Clark, Kathy Wallenhaupt, and Jim Wilson planned the workshop. The other agencies involved in the planning were Panhandle Health, Idaho Division of Environmental Quality, Soil Conservation Service, Kootenai County Solid Waste Department, Coeur d'Alene Basin Interagency Group, and the University of Idaho College of Agriculture. Besides members of the planning group, workshop speakers represented other agencies and private companies including the University of Idaho College of Forestry, Range and Wildlife Sciences, Kootenai County Planning and Zoning, Idaho Department of Fish and Game, Fernan Ranger District (USFS), and Intermountain Resources.

A free nitrate water test was offered to participants during the first day of the workshop. Fifteen samples were run.

Evaluations of the workshop indicated that everyone attending listed at least one "ah-hah." Three attending this workshop later participated in the Master Water Watchers program in Kootenai County. This type of interagency program could serve as a template for water quality workshops conducted in other areas of the state.
(Vickie Parker-Clark, Kootenai County)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

TVA DEVELOPS RESEARCH SOFTWARE
Tennessee Valley Authority (TVA) engineers have developed a computer model of reservoir quality. Named BETTER, for Box Exchange Transport Temperature and Ecology of a Reservoir, the model simulates reservoir conditions to aid analysis of complex water quality patterns. The model mathematically combines reservoir geometry, weather conditions, and the quantity and quality of water going into the reservoir to predict flow patterns, temperature, dissolved oxygen levels, and other water quality patterns.

This model offers an effective tool for helping researchers and water managers understand reservoirs and to develop strategies to improve water quality. It has been used extensively in TVA studies including the recently completed Lake Improvement Plan. The BETTER model is available at no cost to scientists. For additional information on the BETTER model contact: Gill Francis, Media Relations, TVA, 400 West Summit Hill Drive, Knoxville, TN 37902.
(Source: EPA News-Notes)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

WASTE NOT . . . REDUCE!!!
Waste management and water quality are two issues of national importance that are closely related. The relationship is rather simple . . . if you reduce waste you also reduce the chance that waste will eventually pollute water supplies.

Reducing the waste stream is the most significant of all options to manage waste. To reduce the waste we produce usually means lifestyle changes. Reduce the amount you buy in the first place. In other words, buy only the amount you need. If you need a quart of paint, don't buy a gallon and then throw away the unused paint six months later. Some of the most common ways that people can simplify their lives are by accumulating less. We can also reduce the waste we generate by becoming better shoppers and by disposing of our waste in environmentally acceptable ways.

Select products that are durable, easy to repair, have good warranties, are energy efficient, functional, aesthetic, and non-polluting in both manufacture and use.

Purchasing Tips. Consider packaging. One of the best ways to reduce municipal solid waste is to cut down on packaging, which comprises about 40% of the solid waste stream, according to a 1988 survey. Packaging accounts for 50% of all paper produced in the U.S., 90% of all glass, and 11% of all aluminum. One dollar out of every $11 spent for groceries in the U.S. pays for packaging.

(Adapted from WASTEFACTS, M.S. Hammer, Univ. of Florida)

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Water Drops

SNAKE-PAYETTE RIVERS WATER QUALITY HYDROLOGIC UNIT PROJECT
The Cooperative Extension System (CES), Soil Conservation Service (SCS), and the Agricultural Stabilization and Conservation Service (ASCS) are co-leaders in a five-year water quality project located in southwestern Idaho. Extension plans to hire a multi-county agricultural agent with emphasis in water quality sometime in July to provide leadership for CES's portion of this project.

The Snake-Payette Rivers Hydrologic Unit Project is one of 74 projects funded nationally by the USDA. In addition to CES, SCS, and ASCS leadership, the Idaho Division of Environmental Quality will coordinate all water monitoring activities. The Idaho Department of Agriculture, Idaho Department of Water Resources, and the Idaho Soil Conservation Commission will also be active project participants. The Canyon, Gem, Payette, Weiser River, and Adams Soil Conservation Districts will be local partners in this effort.

All or parts of Adams, Canyon, Gem, Payette, and Washington counties comprise the Snake-Payette Hydrologic Unit. Although the selected study site is relatively small, it is anticipated that technology development efforts can be transferred elsewhere on the Snake River Plain in both Idaho and Oregon.

HUA Project Area 
Map

This hydrologic unit project is justified by the following:

  1. An extensive amount of baseline ground water data has been collected within the study area. Results show significant ground water contamination by agrichemicals.
  2. Shallow sensitive water tables exist within the study area.
  3. Intensive agriculture. Over 40 major crops are intensively grown within the study area. Canyon County ranks 33rd among all U.S. counties in terms of total farm receipts.
  4. Intensive fertilizer use within the study area. Nitrogen use ranges between 80 and 450 lb/acre depending on the crop. Average nitrogen application is 145 lb/acre. Nitrogen use efficiency by crops in the region averages 50%; however, nitrogen use efficiency is less than 20% under poor management conditions.
  5. Intensive and extensive chemical use. Over 100 different agrichemicals are used in the study area.
  6. Cooperation with Oregon. Western Idaho and eastern Oregon share similar agricultural systems and resultant water quality problems. Both states are working together to find economically and environmentally sound solutions.
Project Objectives:
  1. Determine the extent of non-point source pollution of ground water from pesticides and nutrients.
  2. Determine the nutrient and pesticide contribution of crops such as onions, potatoes, mint, corn, etc., produced under surface irrigation vs. crops such as cereals, alfalfa, pastures, etc.
  3. Develop and implement best management practices (BMPs) that will reduce to acceptable levels the loss of nutrients and pesticides from the root zone into critical groundwater aquifers.
  4. Develop an economic evaluation of BMP effectiveness in relation to a social acceptability evaluation.
  5. Develop an information and education plan evolving from information used and gathered from this project.
The following are expected results of this project:
  1. Improvement in water quality, particularly groundwater quality.
  2. Identification of areas within the study unit that have greatest groundwater quality problems.
  3. Identification of crops most responsible for degradation of groundwater quality; alternate management systems developed to produce identified high-risk crops.
  4. Improved nutrient and pesticide management, probably somewhat reduced fertilizer, pesticide, and water use.
  5. Farmer acceptance of developed and introduced BMPs within the project area; development of educational materials for farmers outside the project area.
  6. Identification of additional research needs to meet water quality goals.
  7. Improvement of farm profitability.
  8. Development of BMP programs with water quality goals that can be utilized by private consultants within the region.
  9. Establishment of good coordinated working relationships among all agencies working in water quality efforts.
This project will benefit the 3,406 farms located within the hydrologic unit. In addition, over 12,000 farms on the Snake River Plain in Idaho will have technology transferred to them from this project.

Water Bar

Next Page Previous Page Top of Page
WQ Page Ag Page UI
Page

Comments to webmistress: karenl@uidaho.edu

All contents copyright © 1997-2003.
College of Agricultural and Life Sciences, University of Idaho.
All rights reserved.

Revised: January 3, 2003
URL: http://www.uidaho.edu/wq/wqu/wqu13.html