A ground water quality monitoring network is proposed for Idaho. The network comprises 565 sites, 8 of which will require construction of new wells. Frequencies of sampling at the different sites are assigned at quarterly, semiannual, annual, and 5 years. Selected characteristics of the water will be monitored by both laboratory- and field-analysis methods. The network is designed to: (1) Enable water managers to keep abreast of the general quality of the State 's ground water, and (2) serve as a warning system for undesirable changes in ground-water quality. Data were compiled for hydrogeologic conditions, ground-water quality, cultural elements, and pollution sources. A ' hydrologic unit priority index ' is used to rank 84 hydrologic units (river basins or segments of river basins) of the State for monitoring according to pollution potential. Emphasis for selection of monitoring sites is placed on the 15 highest ranked units. The potential for pollution is greatest in areas of privately owned agricultural land. Other areas of pollution potential are residential development, mining and related processes, and hazardous waste disposal. Data are given for laboratory and field analyses, number of site visits, manpower, subsistence, and mileage, from which costs for implementing the network can be estimated. Suggestions are made for data storage and retrieval and for reporting changes in water quality.
5 Summary 8 References cited 8 ILLUSTRATIONS 1-2.Maps showing: 1. Location of study area, Gibson Terrace, and surrounding areas 2 2. Location and identification of wells on or near the Gibson Terrace in which water levels were measured in March or April 1990 3 I 3-5.Hydrographs showing: 3
Concentrations of dissolved radon-222, a naturally occurring radioactive gas, are found in water in Idaho. The U.S. Geological Survey collected water samples for radon-222 analyses from 338 Idaho wells and springs during 1989-91. These water samples were collected as part of ongoing monitoring programs with the Idaho Department of Water Resources and the U.S. Department of Energy. Concentrations of dissolved radon-222 in 372 of the water samples ranged from -58{+-}30 to 5,715{+-}66 picocuries per liter; the mean and median concentrations were 446{+-}35 and 242{+-}25 picocuries per liter, respectively.
This report presents June 1987 water-quality data, principally dissolved chloride and dissolved nitrite plus nitrate (as nitrogen), for water samples from 45 wells in the Murtaugh Lake area, south-central Idaho. Chloride concentrations ranged from 23 to 320 milligrams per liter; the median concentration was 70 milligrams per liter. Nitrogen concentrations ranged from less than 0.1 to 11.0 milligrams per liter; the median concentration was 3.7 milligrams per liter. Chloride concentrations in 6 samples and nitrogen concentrations in 3 samples equaled or exceeded the U.S. Environmental Protection Agency public drinking-water limits of 250 and 10 milligrams per liter, respectively.
The Idaho statewide surface-water-quality monitoring network consists of 56 sites that have been monitored from 1989 through 2002 to provide data to document status and changes in the quality of Idaho streams. Sampling at 33 sites has covered a wide range of flows and seasons that describe water-quality variations representing both natural conditions and human influences. Targeting additional high- or low-flow sampling would better describe conditions at 20 sites during hydrologic extremes. At the three spring site types, sampling covered the range of flow conditions from 1989 through 2002 well. However, high flows at these sites since 1989 were lower than historical high flows as a result of declining ground-water levels in the Snake River Plain. Summertime stream temperatures at 45 sites commonly exceeded 19 and 22 degrees Celsius, the Idaho maximum daily mean and daily maximum criteria, respectively, for the protection of coldwater aquatic life. Criteria exceedances in stream basins with minimal development suggest that such high temperatures may occur naturally in many Idaho streams. Suspended-sediment concentrations were generally higher in southern Idaho than in central and northern Idaho, and network data suggest that the turbidity criteria are most likely to be exceeded at sites in southern Idaho and other sections of the Columbia Plateaus geomorphic province. This is probably because this province has more fine-grained soils that are subject to erosion and disturbance by land uses than the Northern Rocky Mountains province of northern and central Idaho has. Although erodable soils are likely a cause of elevated turbidities, suspended-sediment concentrations were not strongly correlated with turbidities. Dissolved-solids and hardness concentrations were strongly correlated. This is probably because the limestones present in some basins are more soluble than the igneous rocks that predominate in others. Low hardness in streams of northern Idaho, where watersheds are underlain by resistant igneous rocks, enhances the toxicity of some trace elements to aquatic life in these streams. Only a few measurements of dissolved-oxygen concentrations at six sites were less than 6.0 milligrams per liter, the Idaho minimum criterion for protection of aquatic organisms. High supersaturations of dissolved oxygen at four sites suggest excessive photosynthetic activity by algal communities. Nighttime monitoring would help determine whether dissolved-oxygen concentrations at these sites might fall below the Idaho criterion. Data from four sites suggest that dissolved-oxygen concentrations may have decreased over time. The pH at 15 sites sometimes fell outside the range specified (6.5-9.0) for the protection of aquatic organisms in Idaho streams. Values exceeded 9.0 at 10 sites, probably because of excessive algal photosynthetic activity in waters where carbonate rocks are present. Values were sometimes less than 6.5 at five sites in areas of mountain bedrock geology where pH is likely to be naturally low. Mining activities also may contribute to low pH at some of these sites. Inorganic nitrogen and total phosphorus concentrations commonly exceeded those considered sufficient for supporting excess algal production (0.3 and 0.1 milligrams per liter, respectively). Data from a few sites suggest that nitrogen and(or) phosphorus concentrations might be changing over time. Low concentrations of nitrogen and phosphorus at six sites, most representing forested basins, might make them good candidates as reference sites that represent naturally occurring nutrient concentrations. Trace elements examined for this report were cadmium, copper, lead, mercury, selenium, and zinc. In water, many trace-element concentrations were below the minimum analytical reporting levels. Concentrations of cadmium, copper, lead, and zinc generally were highest in mined and other mineral-rich basins in northern Idaho. Concentrations of mercury were
Selected well-inventory and water-chemistry data for 718 thermal-water wells and springs in Idaho were compiled.A total of 1,319 chemical analyses are presented.Analyses were performed at U.S. Geological Survey laboratories from 1921 through 1991.Most data are for sites in southwest and south-central parts of the State. WELL-AND SPRING-NUMBERING SYSTEMThe well-and spring-numbering system used by the U.S. Geological Survey in Idaho indicates the location of wells and springs within the official rectangular subdivision of public land, with reference to the Boise base line and Meridian.The first two segments of the number designate the township (north or south) and range (east or west).The third segment gives the section number; four letters, which indicate the 1/4 section (160-acre tract), 1/4-1/4 section (40-acre tract), 1/4-1/4-1/4 section (10-acre tract), and serial number of the well or spring within the tract.Some locations also include a 1/4-1/4-1/4-1/4 section (2 l/2-acre tract) letter within the section number.Quarter sections are designated by the letters A, B, C, and D in counterclockwise order from the northeast quarter of each section.Forty-acre, 10-acre, and 2 i/2-acre tracts within each quarter section are lettered in the same manner.Well 3S-6E-27DDD1 (fig. 1) is in the SEl/4 SE1/4SE1/4 sec.27, T. 3 S., R. 6 E., and was the first well inventoried in that tract.Springs are designated by the letter "S" following the last numeral; for example 21N-IE-23ABA1S.
Water samples were collected from 903 wells in the Boise River Valley, Idaho, from January 1990 through December 1995. Selected well information and analyses of 1,357 water samples are presented. Analyses include physical properties ad concentrations of nutrients, bacteria, major ions, selected trace elements, radon-222, volatile organic compounds, and pesticides.
As part of a study to obtain groundwater quality data in areas of Idaho were land- and water-resource development is expected to increase, water quality, geologic, and hydrologic data were collected for 74 wells in the Payette River basin, west-central Idaho, from July to October 1982. Historical (pre-1982) data from 13 wells were compiled with more recent (1982) data to define, on a reconnaissance level, water quality conditions in major aquifers and to identify factors that may have affected groundwater quality. Water from the major aquifers generally contains predominantly calcium, magnesium, and bicarbonate plus carbonate ions. Sodium and bicarbonate or sulfate are the predominant ions in groundwater from 25% of the 1982 samples. Areally, groundwater from the upper Payette River basin has proportionately lower ion concentrations than water from the lower Payette River basin. Water samples from wells < 100 ft deep generally have lower ion concentrations than samples from wells > 100 ft deep. Variations in groundwater quality probably are most affected by differences in aquifer composition and proximity to source(s) of recharge. Groundwater in the study area is generally suitable for most uses. In localized areas, pH and concentrations of hardness, alkalinity, dissolved solids, or dissolved nitrite plus nitrate as nitrogen, sulfate, fluoride, iron, or manganese exceed Federal drinking water limits and may restrict some uses of the water.
This report presents data collected during January through September 1989 from 86 thermal-water wells and 5 springs in the Indian Bathtub area, southwestern Idaho. The data include well and spring locations, well-construction and water level information, hydrographs of water levels in 9 wells, hydrographs of discharges in 4 springs, and chemical and isotopic analysis of water from 33 thermal-water wells and 5 springs. These data were collected as part of a continuing study to determine the cause or causes of decreased discharge at Indian Bathtub Spring and other thermal springs along Hot Creek.