ARTICLE INDEX
Volume 3, Number 6
December 1993

IDAHO WELLHEAD SURVEY 1993 UPDATE
The Idaho Private Wellhead Sampling program for nitrates was initiated in 1990 by the Idaho Farm Bureau Federation. This program is a cooperative effort as seven different government agencies and the Idaho Farm Bureau have united to make the program a success. The Idaho Department of Agriculture, Soil Conservation Service, and the University of Idaho Cooperative Extension System assist with program logistics, sample bottle distribution, and dissemination of information. The University of Idaho College of Agriculture's Analytical Laboratory has major roles in planning and designing the quality assurance phase of the analytical part of the program and analyzes all samples for nitrates. The Idaho Division of Environmental Quality designs the quality assurance plan for the field effort, the questionnaire, and sampling procedures for the public. The United States Geological Survey and local health districts assist with the collection of samples for quality assurance.

So far, 2,178 samples from private wells and 1,194 control and quality assurance samples have been collected from 18 Idaho counties. County participation to date is as follows: Cassia, Minidoka, and Jerome (September 1990); Canyon (February 1991); Gem and Payette (March 1991); Ada (April 1991); Twin Falls (August 1991); Latah and Benewah (September 1991); Bonner (November 1991); Bonneville (March 1992); Elmore and Owyhee (November 1992); Fremont (April 1993); and Jefferson, Madison, and Teton (October 1993).

What Do the Sampling Results Mean?
This study shows that:

• 94 percent of sampled wells do not contain excessive levels of nitrate based on U.S. Public Health Service drinking water standards.
• 41 percent of sampled wells contain less than 2 ppm NO₃-N.
• 6 percent of sampled wells contain more than 10 ppm NO₃-N.

Northern Idaho
According to this sampling, water quality is better in northern Idaho than other regions of the state. In Benewah, Bonner, and Latah counties, 142 water samples were collected from wells. Less than 3 percent of the wells contained NO₃-N values that exceeded the drinking water standard. In addition, 76 percent of the wells contained less than 2.0 ppm NO₃-N; 13 percent of the wells contained NO₃-N values between 2.0 and 5.0 ppm; and 11 percent had values greater than 5.0 ppm (50 percent of the drinking water standard).

Southwestern Idaho
Nitrate values in groundwater were higher in southwestern Idaho than other regions of the state. Still, 93 percent of the samples did not exceed the drinking water standard. In Ada, Canyon, Elmore, Gem, Owyhee, and Payette counties, 1,117 samples were collected from wells. About 7 percent of the wells exceeded the 10.0 ppm NO₃-N drinking water standard. More than 58 percent of the wells had NO₃-N levels above 2.0 ppm; 36 percent contained NO₃-N values between 2.0 and 5.0 ppm; and 22 percent of the wells had values greater than 5.0 ppm.

Southcentral Idaho
In Cassia, Jerome, Minidoka, and Twin Falls counties, 541 water samples were collected from wells. Four percent of the wells contained NO₃-N values that exceeded the drinking water standard. Conversely, 21 percent of the wells contained NO₃-N values less than 2.0 ppm; 54 percent of the wells contained NO₃-N values between 2.0 and 5.0 ppm; and 25 percent had values greater than 5.0 ppm (50 percent of drinking water standard). Ninety-six percent of the wells meet the drinking water standard in the region; however, man has impacted the nitrate content in at least 79 percent of the wells.

Southeastern Idaho
In Bonneville, Fremont, Jefferson, Madison, and Teton counties, 378 water samples were collected from wells. Four percent of the wells contained NO₃-N values that exceeded the drinking water standard. Conversely, 60 percent of the wells contained NO₃-N values less than 2.0 ppm; 27 percent of the wells contained NO₃-N values between 2.0 and 5.0 ppm; and 13 percent had values greater than 5.0 ppm (50 percent of drinking water standard). Ninety-six percent of the wells meet the drinking water standard in the region; however, man has impacted the nitrate content in at least 40 percent of the wells.

For the most part, the results of this survey are to date reassuring to Idahoans. To deal with specific and geographic problems, use proactive approaches that will protect and enhance water quality while ensuring the survival of Idaho's number one industry -- agriculture. Where NO₃-N levels are high, use BMPs to apply N-containing materials.

This program is one of the largest wellhead sampling programs in the United States. When completed in the next 2 to 3 years, it will provide an extensive data base for Idahoans to effectively analyze the quality of groundwater and plan for the future.
(R. L. Mahler)

HOW EXTENSIVE IS GROUNDWATER CONTAMINATION?
(This is the fourth in a series of articles on the causes of groundwater contamination.)
Assessment of the extent of groundwater contamination is difficult, due to such factors as limited and inconsistent access to the water (usually dependent on wells and springs), the potential for bias in existing data (if originally collected to explore a particular water quality problem), incomplete information about the well (did the well draw from more than one aquifer?), and inconsistent methods of sampling and analysis.

It is also important to keep in mind that the trend of increasing reports of detections of contaminants in groundwater is largely due to the intensive search for contaminants now under way by many state agencies, as well as continued improvements in the sensitivity of analytical methods used to measure the concentration of contaminants.

The volume of groundwater within 2,500 feet of the surface has been estimated at 100 quadrillion gallons, or about 16 times the volume of the Great Lakes. Of this amount, at least half is too saline from natural causes to use for drinking water, although some of it may be suitable for other uses. The total amount of the remaining groundwater that is contaminated is unknown, although EPA estimates the amount contaminated by point sources to be 2 to 3 percent.

Recent U.S. Geological Survey studies have made the following assessments:

• The United States has large amounts of potable water available for use. Locally, however, high concentrations of a variety of toxic metals, organic chemicals, and petroleum products form plumes around such point sources as leaking underground storage tanks, waste disposal sites, and chemical or waste handling areas. These types of problems generally occur in urban or industrialized areas, although they are found occasionally in rural areas.
• Large regions have been identified in which contaminants, derived from nonpoint sources and often at minimum detectable levels, are present in many shallow wells throughout a given area. In a small percentage of wells, contaminants such as nitrate may exceed drinking water standards or health advisories. Generally, such nonpoint source contamination is associated with densely populated urban areas, agricultural land uses, and concentrations of septic systems. However, such contamination commonly affects only the shallowest aquifers.
• Twenty percent of 124,000 wells sampled over the past 25 years contained a maximum nitrate-nitrogen concentration greater than 3 ppm, suggesting the effects of human activities. Six percent of the samples exceeded the federal drinking water standard for nitrate-nitrogen of 10 ppm.
• Although 44 state summaries in the U.S. Geological Survey's 1986 National Water Summary on groundwater quality mention detection of pesticides in groundwater, data are insufficient to draw conclusions about the extent of contamination. The state summaries do, however, express widespread concern that the frequency of detections and the concentrations of pesticides will increase over time.

FOREST WATER QUALITY VIDEO AVAILABLE
A new forest water quality videotape is available from the University of Idaho. "Forest Water Quality" was jointly funded and produced by the University of Idaho Cooperative Extension System, the Idaho Department of Lands, and the Idaho Forest Stewardship program. It is targeted at the thousands of nonindustrial, private owners of woodlands in Idaho. This group of people owns over 2,000,000 acres of trees in the state.

"Forest Water Quality" shows the private forest owner ways to improve and maintain water quality during, and after, any forest practice, whether it's timber harvest, road-building, or homesite construction.

"Forest Water Quality" contains two 22-minute segments. Part One shows how water moves through the forest, how forest activities affect that water, and ways to enhance water quality. Part Two takes a close look at the Idaho Forest Practices Act -- the law that sets "Best Management Practices" to guide activities that can affect forest water quality.

Whether you own 5 acres or 5,000, you'll find these programs invaluable for helping you steward one of Idaho's most precious resources. This video is available from the University of Idaho Agricultural Communications Center, University of Idaho, Moscow, Idaho 83844-2332. This VHS format video is priced at $29.95 plus $3.00 for shipping.

BLUE THUMB FACT
The average family turns on the tap to use water between 70 and 100 times per day.

IRON BACTERIA IN WELL WATER
The occurrence of iron bacteria has long been known as a problem for rural homeowners and for operators of water supplies that rely on groundwater. Although many other concerns about drinking water have been in the headlines for the past 20 years, iron bacteria is still a major headache causing restricted flows as well as taste and odor problems. Iron bacteria do not make people ill, but they can pit and corrode pipes, cause discolored, turbid water, and lower the pH of the water.

Iron bacteria are widespread in the environment. They can be found anywhere that both dissolved iron and dissolved oxygen are present. They occur naturally in soil, streams, cool surface waters, and shallow aquifers. They prefer a pH range of 6 to 10 and a temperature range of 40 to 60 F. Usually the first indication of the presence of iron bacteria is a sudden discoloration or iron staining (rust colored). A rust colored gelatinous slime in the toilet tank or in filter housing is another key indicator of iron bacteria.

If the slime growth is in a water filter or in the pump or pipes, it could cause clogging of the system. If there is any indication that a water supply has iron in it, pressure drops should be investigated to see if iron bacteria are plugging the system.

As a precaution, and to prevent all types of bacterial contamination of wells, all tools and materials should be disinfected with chlorine before they are inserted into a well. After drilling operations or any maintenance on a well, the well and water system should be thoroughly chlorinated.

Once a system has iron bacteria growing in it, periodic shock chlorination or continuous chlorination may be necessary. Slimy bacterial growth should be removed from pipes or equipment, and shock chlorination should follow. A second shock chlorination is recommended in the case of iron bacteria.
(Ernestine Porter)

WATER MANAGEMENT BMPs FOR YOUR GARDEN
Most people intensively manage their backyard flower and/or vegetable gardens. Inputs such as pesticides, fertilizers, and water when used incorrectly may adversely impact surface and/or groundwater quality. To protect the environment and water quality you should use BMPs, which are defined as implemented strategies that eliminate or minimize environmental pollution. BMPs are designed to be compatible with garden ecosystems. BMPs can protect the environment without compromising the productivity of large or small gardens.

Why should you be concerned about water use in your garden? Americans use a lot of water. In fact, a typical American today uses four times as much water as a great-grandparent did at the turn of the century. In urban areas of the Pacific Northwest water use often doubles when the gardening season arrives.

There are many reasons why water should not be over-used in your garden. Some potential adverse effects include:

• Depletion of groundwater resources cause water tables to fall,
• Excess water causes leaching -- a process that may contaminate groundwater with nitrates and pesticides,
• Excess surface water runoff may cause erosion and pollute streams, rivers, and lakes.

1. Use water wisely in the garden!
• Repair all leaks in hoses and faucets.
• Water your garden at optimal times:
• early in the morning,
• late at night.
• Never over-water.
• Don't put water below plant roots:
• saves money,
• reduces chemical leaching.
• Advantages of wise water use include:
• save water needed for drier days,
• decrease the peak demand for water,
• help meet the needs of an increasing population,
• reduce negative environmental impact from fertilizer and pesticide run-off,
• decrease time in maintaining gardens,
• increase plant success rate in times of drought.
2. Protect your soil from water erosion!
• Use mulches to cover soils.
• Reduce intensity of water droplets on soil surface.
• Improve the waterholding capacity of soil by incorporating compost and using mulch.
3. Design your garden irrigation system for maximum efficiency!
• Drip lines are better than sprinklers.
• Sprinklers are better than hoses.
• Strive for uniform water applications.

LAND USE PLANNING AS A TOOL TO PROTECT GROUNDWATER QUALITY
(This is the first in a series of articles on protecting groundwater quality by managing local land use.)
Since over 90 percent of Idahoans obtain their drinking water from groundwater it makes sense to consider different options to protect this resource. One option for county and city governments to consider is land use planning.

In most areas local land use activities can influence groundwater quality greatly. This close relationship between land use and groundwater quality means that local government, in exercising the traditionally local function of managing land use, can play a significant role in protecting this resource.

Local governments can effectively protect groundwater quality through control of local land use activities. Higher levels of government often are unable to consider unique local characteristics in land use management because of their need to generalize across broad geographic areas. Local governments, however, can attempt to fashion management decisions that do reflect unique local needs.

Developing a groundwater management plan involves many choices. No set formula applies to all local groundwater protection decisions. The variability in the natural resource base, institutional framework, perceptions of groundwater problems, and management and fiscal capabilities suggest the importance of selecting the management technique most suited to the particular setting at hand. Understanding a few general principles, however, can help local governments fashion appropriate management decisions.

Land uses and the pollution sources they generate vary widely in their potential to contaminate groundwater. Substances range from the relatively innocuous to those listed as hazardous by federal and state agencies. There is also wide variability in terms of soil, subsoil, and bedrock conditions affecting the susceptibility of different land areas to contamination. Another factor to consider is the number of people affected.

Regulatory vs. nonregulatory approaches. There are two categories of groundwater protection techniques. Regulatory approaches involve placing a system of legal constraints on land uses and potentially contaminating activities. Nonregulatory approaches include public education and involvement; voluntary best management practices; land acquisition programs; facility siting procedures and capital facility and infrastructure planning; inspection and training programs; monitoring; emergency spill plans; community waste management and minimization programs; and governmental coordination efforts. To be most effective, local protection programs generally should employ a mixture of regulatory and nonregulatory techniques.

Some important potential pollution sources are regulated at the state and federal levels. In these cases, state law sets the basic framework. Local governments must take these regulations into consideration so that their actions complement, rather than conflict with, state regulations.

Local land use controls. Many land use control techniques are important to local groundwater quality protection programs. Such techniques can include prohibiting uses that have the potential to cause serious contamination, permitting other uses only under certain conditions, limiting density of development, and regulating locations within which various uses are permitted.

Measures to require that new land uses protect groundwater quality can include conventional zoning, flexible zoning devices, subdivision regulations, and extraterritorial controls. Since these regulations deal primarily with prospective land uses, however, it may be necessary to enact special-purpose ordinances that address existing land uses and specific pollution sources connected with them. Since a number of pollution sources are controlled at state and federal levels, it is important to consider whether the local unit is authorized to adopt source control regulations and how best to coordinate controls at various governmental levels. Local officials also must consider whether a proposed ordinance meets state and federal constitutional requirements.
(Adapted from Groundwater and Public Policy. Series No. 6 by D. A. Yanggen and S. M. Born from the University of Wisconsin-Madison)

HARD WATER -- A PROBLEM IN THE LAUNDRY
Hard water is a water quality problem that may adversely affect the laundering of clothing. Hard water often results in problems such as: dinginess or graying, yellowing, general soil buildup, white or gray streaks on colored fabrics, and/or a stiff, harsh feel to fabrics.

To prevent hard water problems, use adequate amounts of heavy duty liquid detergent and water as hot as is safe for the fabric. Soften the water with nonprecipitating water conditioner or install a water softening system. Note however, that water softening systems may increase the amount of sodium in the drinking water and cause problems for people on salt-restricted diets.

A general prescription to reduce hard water impacts would be as follows: Fill the washer with the hottest water appropriate for the fabric. Add four times the normal amount of liquid laundry detergent and 1 cup of nonprecipitating water conditioner such as Calgon® or Spring Rain®. Agitate just long enough to wet the clothes. Soak overnight or about 12 hours. Drain and spin without agitating. Launder, using regular cycle, no detergent, and 1 cup of nonprecipitating water conditioner. Repeat laundering with no detergent and 1 cup of nonprecipitating water conditioner until no suds appear during the rinses. To remove all dinginess, launder with nonprecipitating water conditioner and bleach safe for the fabric.

A new Pacific Northwest Bulletin, PNW 440, "Stain Removal Guide for Washable Fabrics," is now available from your local county Extension office. This guide contains useful hints that will help you deal with some potential water quality problems as well as stains caused by everyday activities.
(Ernestine Porter)

HOW MUCH DO WE DEPEND ON GROUNDWATER?
According to government figures, nationally groundwater provides an estimated:

• 22 percent of all freshwater withdrawals,
• 53 percent of drinking water for the total population and 97 percent of drinking water for the rural population,
• 40 percent of public water supply withdrawals,
• 46 percent of domestic and commercial use,
• 24 percent of industrial and mining use,
• 34 percent of agricultural use (mostly for irrigation).

WATER QUALITY 2000 CONFERENCE
Water Quality 2000, a state-level agricultural water quality conference, will be held January 24-26, 1994, at the Red Lion-Riverside in Boise. This conference is co-sponsored by the Idaho Association of Soil Conservation Districts, the Environmental Protection Agency, and the University of Idaho Cooperative Extension System. As a follow-up to the successful 1990 conference this forum will review, examine, and discuss agricultural nonpoint source pollution control efforts and programs.

The two-and-one-half day conference will consist of both general sessions and concurrent sessions. General sessions will highlight state water quality objectives, existing programs, emerging initiatives, and technical support.

There will be eight concurrent sessions on the following topics: conservation, monitoring, best management practices (BMPs), watersheds, agrichemical management, state agricultural water quality projects, public policy, and riparian areas and wetlands.

As in 1990, this conference has been designed to benefit a variety of audiences including: farmers and user groups, concerned organizations and citizens, water quality professionals, and local, state, and federal government officials.

Over 500 people are expected in attendance. To receive registration information contact Kathleen Pidjeon at the Idaho Soil Conservation Commission (1215 West State St., Boise, ID 83720; phone 208/334-0220).

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