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Kansas Geological Survey, Open-file Report 1999-45


Preliminary Assessment of the Distribution and Sources of Nitrate-Nitrogen in Kansas Ground Water

by
M. A. Townsend and D. P. Young

KGS Open-file Report 1999-45

Abstract

Nitrate in ground water is a potential problem in many parts of Kansas. From 1989 to 1998, 747 water samples were collected from domestic, irrigation, monitoring, and public water supply wells and analyzed for nitrate-nitrogen by the Kansas Geological Survey. Of all the samples 29% have nitrate-N values less than or equal to 3 mg/L; 51% have values between 3 and 10 mg/L; and 20% have values greater than or equal to 10 mg/L.

Nitrogen-15 isotope values were used in several studies to determine sources of the observed nitrate-N. Of the 112 samples analyzed in this data set, 29% of the samples indicate a fertilizer source, 22% indicate mixed sources, 42% indicate an animal waste source, and 7% indicate denitrification processes have occurred.

Factors that show a statistically significant relationship with the occurrence of nitrate in Kansas ground water in the preliminary stages of this study include geographic area of the state, depth of well, and age of well.

Introduction

Ground water is the major source of drinking water for 70% of the residents of Kansas. In rural areas, 85% of the population relies on ground water. Contaminants in ground water that may cause health problems, such as nitrate, are of significant concern.

Nitrate is the most common inorganic contaminant of ground water in Kansas. Background level for the natural occurrence of nitrate-N is considered less than or equal to 3 mg/L (Madison and Brunett, 1985). Values above 3 mg/L are considered indications that man-induced sources of contamination have occurred. Areas that are heavily agricultural, such as much of the Midwest, appear to have a greater number of detections of nitrate-N above the background level in the ground water (Spalding and Exner, 1993; Kolpin et al., 1994).

The objectives of this preliminary assessment were to evaluate available ground-water nitrate-N data for the time period of 1990 to 1998 to determine if any trends in concentrations within the state existed, or if there were any factors that appeared to have an impact on the observed distribution of nitrate in ground water. The work also has been useful in identifying areas where more study is needed.

Methods

Sources of Data

The Kansas Geological Survey (KGS) is in the process of evaluating the occurrence of nitrate-N in ground water throughout the state. The sources of the data for this preliminary assessment were studies where the chemical analyses were done by KGS and the sampling dates were from 1990 through 1998. Agencies contributing to the work include the five ground-water management districts and the Kansas Department of Agriculture (KDA).

Distribution by well type shows 472 irrigation wells, 206 domestic wells, 40 monitoring wells, and 29 public water supply wells. Additional information was obtained from water well completion forms (WWC-5s) on file at KGS, Water Information Management and Analysis System (WIMAS) database (Wilson, 1998) and field notes.

Because some of the data were collected for specific site studies where nitrate contamination was observed or suspected, there is some bias in the overall evaluation. However, there are a number of samples from more regional sampling events, such as those performed by the KDA chemigation program.

Sample Collection and Chemical Analyses

Samples were collected from wells after the well was purged for 3 to 5 well volumes and/or the temperature, pH, and specific conductance had stabilized for three consecutive readings at 3 to 5 minute intervals. Notes concerning land use around the well and farmstead were recorded to use in the evaluation of sources of nitrate in the water samples.

Samples for nitrate analysis were stored on ice in 250-ml polyethylene bottles with 2 ml HCl as preservative. Samples were transferred to a refrigerator upon return to KGS. Nitrate analyses were performed by the KGS Analytical Services section within one month of sample time. The method used was the UV screening method developed by Hathaway (1990).

Samples for nitrogen-15 isotope analysis were collected in 125-ml polyethylene bottles. These samples were stored on ice until return to the Survey, where they were frozen. Samples were shipped frozen by next day delivery to the isotope lab at the University of Virginia, Charlottesville. Samples were stored frozen until thawed and analyzed on GC Mass Spectrophotometer.

Statistical Methods

SAS statistical package for UNIX systems (SAS Institute, 1996, v. 6.2) was used to evaluate the data for this study. Because of the lack of normality in the data set, non-parametric methods were used. The specific tests used were Spearman rho rank correlation test, the Kruskal-Wallis test (analysis of variance equivalent) and the Mann-Whitney t-test equivalent. All statistical tests were performed at the 90 percent level of confidence (α = 0.10). Tests with values greater than the α = 0.10 are considered not significant.

Minimum values of 0.02 mg/L nitrate-N indicate concentrations below the detection limit of the nitrate analysis. Because only 1% of the data set (8 samples) had values below the detection limit, the simple substitution method discussed by Helsel and Hirsch (1992) was used. Substitution of 0.02 mg/L for the non-detects was used in calculation of the mean and median values reported in Table 1 in the Results and Discussion section and in all other statistical analyses.

Results and Discussion

Distribution of Sampling Points and Nitrate-N Concentrations

The distribution of sampling points for this study is shown in Figure 1 for irrigation wells, and Figure 2 for non-irrigation wells, which include domestic, public water supply, and monitoring wells. The data set was divided into irrigation and non-irrigation wells because of the difference in depth of the wells in some parts of the state and also because in some parts of the state the wells sampled were predominantly either irrigation or non-irrigation type. Evaluation of these figures indicates the areas where detailed site studies were undertaken (indicated by high data density) and the more regional areal surveys.

Figure 1. Distribution of nitrate-nitrogen in groundwater from irrigation wells in Kansas. A larger version of this figure is available as an Acrobat PDF file.

Samples are primarily from western (along Ark R. and in Sherman Co.) and south-central Kansas.

Figure 2. Distribution of nitrate-nitrogen in groundwater from non-irrigation wells (domestic, stock, monitoring, and public-water supply) in Kansas. A larger version of this figure is available as an Acrobat PDF file.

Samples are primarily from south-central Kansas, Sherman Co., and along Solomon R. in Smith and Osborne counties.

Figures 1 and 2 also show the geographic distribution of nitrate-N concentrations throughout the state. As can be seen from these two figures nitrate concentrations in most of the samples are greater than the background level of 3 mg/L. This indicates that much of Kansas' ground water has been impacted by anthropogenic sources of nitrate.

Results of chemical analyses and other physical data for the sites are presented in Appendix A. Table 1 is a summary of simple statistics for parameters evaluated in this study. The mean, median, and range of the sample values (minimum and maximum) are reported. Data were grouped a number of ways to ascertain possible relationships between nitrate-N concentrations and different independent variables. Table 1 includes the nitrate-N values for different groupings of the data. The principal groups are depth of well, well type, age of irrigation wells, and the three geographic areas that were evaluated in this assessment.

Nitrate-N concentrations in samples from irrigation wells ranged from less than 0.02 to 43.3 mg/L, with a mean of 6.5 and median of 4.8 mg/L. Concentrations from domestic wells ranged from less than 0.02 to 77.4 with a mean of 8.7 and a median of 5.7 mg/L. The range of nitrate-N values for public water supply was 0.2 to 58.4 mg/L with a mean of 8.6 and median of 6.3 mg/L. The range of nitrate-N values for monitoring wells was less than 0.02 to 20.1 with a mean of 3.9 and a median of 1.8 mg/L.

Although the reported means suggest the possibility of discernable differences in concentrations among the groups, the statistical tests used, which are based on the median values (see Methods section), indicate that the variation between the well types is not statistically significant. Well type is one of the factors that will be reevaluated as more data become available.

Variables that did have statistically significant relations with nitrate-N concentrations are discussed in the section: Factors Affecting the Occurrence of Nitrate in Ground Water.

Table 1. Summary of Simple Statistics.

Variable Number of
Samples
Mean Median MinimumMaximum
Nitrate-N (mg/L) 747 7.0 4.9 0.02 77.4
Nitrate-N (mg/L)
Domestic Wells
206 8.7 5.7 0.02 77.4
Nitrate-N (mg/L)
Irrigation Wells
472 6.5 4.8 0.02 43.3
Nitrate-N (mg/L)
Public Water Supply
29 8.6 6.3 0.2 58.4
Nitrate-N (mg/L)
Monitoring Wells
40 3.9 1.8 0.02 20.1
Nitrogen-15 ‰ 112 10.1 9.8 2.2 22.4
Depth of All Wells
with Known Depths (ft)
536 157 108 20 740
Depth Irrigation
Wells (ft)
297 219 200 30 740
Depth Domestic
Wells (ft)
177 76 70 25 284
Depth Monitoring
Wells (ft)
37 109 90 20 223
Depth of Public
Water Supply Wells (ft)
25 74 63 36 190
Nitrate-N All Wells
≤ 108 ft (Median Depth)
270 8.5 6.0 0.02 61.4
Nitrate-N All Wells
> 108 ft (Median Depth)
266 5.8 4.4 0.02 69.7
Nitrate-N All Wells
Western KS (Area 1)
358 6.1 4.3 0.02 69.7
Nitrate-N All Wells
South-central KS (Area 2)
333 7.5 5.7 0.02 77.4
Nitrate-N All Wells
North-central and
Northeastern KS (Area 3)
56 10.6 7.7 0.1 58.4
Nitrate-N Pre-1975
Irrigation
272 7 5.2 0.02 43.3
Nitrate-N Post-1975
Irrigation
200 5.7 4.5 0.02 28.7
* Minimum values of 0.02 indicate values below detection limit of test.
Value of 0.02 used as a proxy value for statistical tests.

Potential Sources of Nitrate-Nitrogen

Figure 3 illustrates the various sources and destinations for nitrogen throughout the nitrogen cycle. The major sources of nitrate are from surface activities including application of fertilizer, human and animal wastes and plant decay. The major destinations for nitrogen in different forms are incorporation by soil microorganisms as food, storage as organic nitrogen in plants or dead microorganisms that have not yet decayed, adsorption of ammonium ion to clay particles, volatilization of ammonia, denitrification (conversion of nitrate to nitrogen gases), and leaching of nitrate to ground water.

Figure 3. Nitrogen cycle illustrating sources and sinks for different forms of nitrogen. Figure illustrates that many different processes can lead to the formation of nitrate.

Diagram showing cycle of delta15N moving through environment.

Two major sources of anthropogenic nitrogen for the formation of nitrate are animal waste and fertilizer. Animal waste sources of nitrogen include feedlots, manure applied as fertilizer, and septic systems. Roughly 30 percent of the population of Kansas disposes of its waste through use of septic systems. Table 2 lists an estimate of the potential volume of nitrogen available from various animals commonly raised in Kansas and also from septic systems.

Table 2. Potential nitrogen loads from animal wastes in Kansas. Population statistics from 1990 U. S. Census; Animal Statistics from KDA 1997 Farm Facts.

  Amount of
Nitrogen
Approx. Number of
Animals/Humans
Tons of Potential
Available N/year
Dairy Cattle 10 lb./ton manure 79,000 4,680
Beef Cattle 14 lb./ton manure 2.35 million 180,000
Swine 10 lb./ton manure 1.3 million 9,530
Humans Using
Septic Systems
14.5 lb./person/yr. 765,000 5,550

Nitrate in ground water is frequently associated with agriculture, the largest industry in Kansas. Plants have basic needs: water, nitrogen, and other nutrients. Although there are other sources of nitrogen for crops, nitrogen is commonly applied as chemical fertilizer. Figure 4 shows the quantity of nitrogen-based fertilizers sold from 1945-1997, providing an estimate of the quantity used. The striking upward trend indicates the potential for a continuous and growing source of nitrate available for leaching from the unused portion of the fertilizer. The figure also shows the cumulative water rights issued mainly for irrigation wells since 1945. The increase in the number of water rights reflects the increase in irrigated farming. Generally, more fertilizer is applied to irrigated cropland compared with non-irrigated cropland. The extra irrigation water applied increases the potential for leaching of water and nitrate.

Figure 4. Relationship between the increase in irrigated farming (as illustrated by the increase in irrigation water rights) and the quantity of nitrogen fertilizer sold.

Water rights increase steadily, slight acceleration in 1970s; nitrogen sales rise sharply in 1960-1970s, flatter since then.

Factors Affecting the Occurrence of Nitrate in Ground Water

Many studies have identified a variety of factors that affect the occurrence of nitrate in ground water. Some of these factors include depth of well, well construction, depth to water, soil type, precipitation, land use, farming practices (such as irrigated versus dryland farming, timing of fertilizer application, use of manure versus chemical fertilizer), and many others (Hallberg, 1989; Kolpin and others, 1994; Spalding and Exner, 1993). The next few sections describe the findings from this preliminary assessment concerning some of the factors that are related to the occurrence of nitrate in Kansas' ground water.

Geographic Area

Across the state of Kansas, characteristics such as geology, precipitation, soils and land use vary widely. For example, mean annual precipitation varies from 16 inches/year in western Kansas to over 40 inches/year in southeastern Kansas. Consideration of the above factors may be important in evaluating the occurrence of nitrate in ground water. One way to encompass the influence of these factors is to evaluate the occurrence of nitrate in ground water by dividing the state into geographic sub-units.

Figure 5 shows the subdivisions of the state used in this assessment. Areas 1 and 2 overlie the High Plains aquifer and the great majority of wells sampled in these areas tap the High Plains aquifer. More specifically, Area 1 overlies the Ogallala portion of the High Plains aquifer in western Kansas, and Area 2 overlies the Great Bend Prairie and Equus Beds portions of the aquifer in south-central Kansas. The aquifer in Area 2 is generally shallower and soils are sandier compared with Area 1. Wells in Area 3 are typically screened in relatively shallow and narrow alluvial aquifers in the Solomon and portions of the Kansas River basins. No samples were collected in southeastern Kansas during the period of study.

Figure 5. Geographical subdivisions used in evaluation of occurrence of nitrate in ground water. Area 1 is representative of western High Plains, primarily the Ogallala aquifer. Area 2 represents the south-central High Plains aquifer. Area 3 represents the alluvial aquifers of the Solomon and portions of the Kansas River basins.

Area 1 is western counties from Clark-Norton and west; Area 2 is south-central from Rush-McPherson and south; Area 3 is north-central and north-east, Phillips-Rooks-Ellis east to Missouri.

Figure 6 illustrates the variation of nitrate concentration in ground-water samples in the three areas. Nitrate-N concentrations were generally higher in Area 2 (south-central Kansas) compared with Area 1 (western Kansas). This is attributed primarily to the shallower aquifer (shallower wells and shallower depth to water) and sandier soils in Area 2. Also, the greater amount of precipitation may enhance the amount of nitrate leached to ground water. It is also possible that the presence of caliche zones in the unsaturated zone in western Kansas may permit decreases in nitrate concentration by either chemical or biological reduction (Herbel and Spalding, 1993). Future work will examine these questions as well as potential differences in land use (such as fertilizer and irrigation rates), occurrence of feedlots, and other potential point sources in the two Areas.

Figure 6. Box plots of ground-water nitrate-N concentrations in different areas of the state. Values of 0.02 mg/L are proxy values for nitrate-N values below detection limit.

Area 1 has narrowest band, mean above median; Area 2 has wier band, mean near top, median near center of band; Area 3 has widest band, mean above median but both near top.

Concentrations in Area 3 tended to be higher than those in the High Plains regions (Table 1). These higher concentrations are probably related to the limited aquifer extent (in both depth and width), the permeable sediments, the higher rate of precipitation, and the land uses along the river corridors. For example, flood irrigation is more common in this area than in the western parts of the state. Elevated concentrations may also be related to the length of time that potentially polluting activities have occurred along the river corridors. The majority of the samples from public water supply wells came from Area 3, which may explain the relatively high concentrations observed in these wells (Table 1). Future work will examine these variables in more detail.

Depth of Well

Many studies on nitrate contamination of ground water have found a negative correlation between the concentration of nitrate and the depth of well, indicating that shallower wells are more likely to be contaminated than deeper wells (Spalding, 1988). In this assessment shallower wells tended to show more nitrate contamination than deeper wells. This result was expected, as the source of nitrate is normally at the land surface. As indicated previously, shallower well depths in Area 2 compared with Area 1 are as least partly responsible the higher concentrations in Area 2. Future work will examine other relations within the individual regions such as depth to water and vadose zone characteristics.

Figure 7 shows the distribution of nitrate for the 536 samples with reliable depth measurements. A higher percentage of shallower wells (≤ the median depth of 108 ft; Table 1) have concentrations greater than 10 mg/L. The graph also illustrates that the majority of the samples overall have nitrate-N greater than 3 mg/L, which indicates that nitrate contamination may be more widespread than previously suspected.

Figure 7. Nitrate-N ranges from wells less than and greater than the median depth of 108 ft. Number of samples in each group shown above bar.

Same numbers of deep and shallow wells have low Nitrate-N values; a few more deep wells have middle-range Nitrate-N values; twice as many shallow wells have Nitrate-N greater than or equal to 10.

Age of Well

Age of well may be an indicator of at least two factors that may affect nitrate concentrations in ground water: 1) well construction and 2) length of time potentially polluting activities may have occurred near a well. Both of these factors would favor higher concentrations in older wells.

Poor well construction is frequently cited as a possible pathway for movement of nitrate from land surface to ground water (Kolpin and others, 1994; Steiken and others, 1988). In Kansas, legislation was passed in 1975 which required more stringent well construction methods, primarily to mitigate movement of surface water to ground water via the annular space of wells. The 1975 legislation required that the annular space of wells be grouted from land surface to a minimum of 20 ft or to a minimum of five ft into the first clay or shale layer if one is present, whichever is greater.

Wells installed prior to 1975 frequently have a gravel packed well bore from land surface to the bottom of the well. The presence of this gravel may permit rapid flow of surface water to ground water. In addition, the gravel provides a highly permeable zone that may permit flow of perched water from clay or caliche zones to ground water. Multiple well screens, common in irrigation wells in some areas, may permit mixing of different zones of ground water.

Because of the 1975 legislation, the irrigation well data, based on water right issuance date, were divided into pre- and post-1975 categories to see if a statistically significant difference in nitrate-N concentrations exists. The age division based on water right issuance date assumes that the well was installed near the time that the water right was issued, which may not be true for all wells. Preliminary analysis shows that for irrigation wells, the older (pre-1975) wells do tend to have higher concentrations than newer wells. As Figure 8 shows, a higher percentage of newer (≥ 1975) wells have concentrations less than or equal to the background concentration of 3 mg/L. Further analysis of the distribution of age of water rights throughout the state may provide further insight as to the potential relationship that length of time farming in a given area has with the observed nitrate concentrations.

Figure 8. Comparison of age of irrigation wells with observed nitrate-N concentrations. Number of wells in each group shown above bars.

More newer wells than older have low Nitrate-N values; a few more older wells have middle-range Nitrate-N values; the same number of older and newer wells have Nitrate-N greater than or equal to 10.

Variation of Nitrate Concentrations with Time

Increasing nitrate-N concentration in ground water over time is a growing concern. One way to evaluate possible increases is to compare data sampled from the same well at different time periods. Figure 9 shows a comparison of samples collected from the same irrigation wells in both the 1970's and the 1990's. The diagonal line in the figure represents the line of no change in concentration. If the values were the same in both time periods the point would fall on the line. The figure shows that many of the points fall above the line suggesting that the nitrate values have increased from the 1970's to the 1990's. This graph echoes Figure 4 in that increasing nitrate in ground water appears to follow the trend of increased irrigated farming in Kansas.

Figure 9. Comparison of nitrate-N concentrations from the same wells in the 1970's and 1990's. Values below line indicate decreased nitrate concentration from the 1970's to 1990's. Values above the line indicate increased nitrate concentration from 1970's to 1990's. Maximum Contaminant Level for nitrate-N in drinking water shown (10 mg/L). Most of the samples in graph show an increase in nitrate-N with time (Townsend and Young, 1999).

Five wells sow nitrate-N values lower on their second measurement; most have values that rise over the two measurement times.

One potential problem with this graph is that these are single samples collected at different times from the same well. There is no continuous record available to help determine if there was a fluctuation due to rainfall, drought, season, change in land use practices, possibilities of spills etc. However, the utility of the figure is that as a snapshot it indicates that at least at these locations nitrate-N concentration has generally increased over time.

Nitrogen-15 Isotope Method for Identification of Nitrate Sources

Nitrogen-15 isotope values are used to determine the sources for nitrate-nitrogen in water (Townsend et al., 1994; Kreitler, 1975; Kreitler, 1979; Gormly and Spalding, 1979). The method uses the relation between nitrogen-14 (14N), which is common in air, and nitrogen-15 (15N), which is present at approximately 0.3% in air, as an indicator of sources of nitrogen for the measured nitrogen in water. The following equation shows the ratio used in the method:

Delta15N is equal to the 15/14 ratio of the sample minus the ratio of the standard, all divided by the ratio of the standard.

In this equation, the standard is air; the sample is the water to be tested. The ‰ sign means parts per thousand or "per mil" as researchers using isotopic methods commonly report the units.

Figure 10 shows the ranges of nitrogen-15 observed for different sources of nitrogen and processes discussed previously. Heaton (1986) compiled the data from various studies. The figure shows that fertilizer ranges generally from δ15N of -2 to +8 ‰ while animal waste ranges from δ15N of +9 to greater than +20 ‰. Denitrification, the process of breaking down nitrate by bacteria to form nitrogen gases, also results in a δ15N range of +10 to greater than +20 ‰ in ground water. The concentration of observed nitrate-N is a strong indicator of whether animal waste or denitrification is the cause of the observed high δ15N value. As indicated in Figure 10, animal waste sources generally result in relatively high nitrate-N concentrations and denitrification processes generally result in relatively low nitrateN concentrations.

Figure 10. Range of δ15N values from selected references (after Heaton, 1986).

Animal waste is far more positive than rain (negative), soil (neutral), or ferilizers (slightly negative to positive).

Figure 11 shows the distribution of nitrate-N and δ15N values for the samples collected in Kansas. The majority of wells shown in the figure have nitrate-N values greater than 3 mg/L (background level shown by gray dashed line). Most of the non-irrigation wells, particularly those with high nitrate-N concentrations, fall within the animal and human waste area of the graph (above +10 ‰). Many of these samples were collected from site study areas where elevated nitrate-N concentrations occurred.

Figure 11. Graph shows ranges of δ15N and nitrate-N (mg/L) values from areas in Kansas. Possible sources of nitrate are indicated: fertilizer and animal waste. Denitrification is illustrated as a sink for nitrate removal. Background and drinking water limits for nitrate are also indicated.

About half of the samles are above the drinking water limit, half below; about half fall inthe animal waste zone, half in the fertilizer zone; few cross into the denitrification zone.

The majority of irrigation wells with nitrate-N above 10 mg/L plot within the fertilizer source range (+8 ‰ or less). Samples from wells that have nitrate-N less than 3 mg/L but an enriched (high positive value) δ15N value may indicate that denitrification of nitrogen by bacteria has occurred. The areas in the state where this has occurred, particularly in Harvey County, generally have reducing water chemistry. Samples with concentrations between 3 and 10 mg/L showed either one or the other of the sources or mixed/combined sources.

In summary, nitrogen-15 values indicate that 29% of all samples indicate a fertilizer source, 22% of all samples indicate mixed sources, 42% of all samples indicate an animal waste source, and 7% of all samples indicate denitrification processes have occurred. Nearly all the samples with δ15N values in the animal waste range are all from domestic and public water supply wells with high nitrate-N concentrations. Also, wells with the highest nitrate-N concentrations were non-irrigation wells with animal waste sources, which is indicative of point-source contamination typically from either septic systems or confined animal operations. Nitrogen-15 results indicate those irrigation wells with nitrate-N values greater than 10 mg/L typically have a fertilizer source for nitrate.

Conclusions

This preliminary assessment of nitrate in Kansas ground water indicates that much of the ground water has indications of nitrate present above the background level of 3 mg/L. The presence of measurable nitrate indicates that human activities are having an impact on the overall ground-water quality in the state.

South-central Kansas has higher mean and median nitrate-N concentrations than western Kansas, at least in part because of the sandier soils and shallower aquifer in south-central Kansas. Sampled wells in north-central and northeastern Kansas wells are sited in alluvium and are generally shallower than those in other parts of the state. Nitrate values from this area are higher than other parts of the state partly due the to permeable alluvium, higher precipitation, and to the possibility of a higher concentration of point sources such as septic systems or small farmstead feedlots located near wells, and differences in farming practices.

As expected, shallower wells in general had higher nitrate-N concentrations than deeper wells. Also, shallower wells had a greater percentage of nitrate-N above 3 mg/L, suggesting that the shallower portions of the aquifers within the state are more prone to contamination than the deeper portions of the aquifers.

Age of well may be an indicator of both well-construction practices used and length of time farming has occurred at a site. Older wells tend to have gravel pack to the surface and no grout across clay or perching zones, thus permitting contaminated surface and/or perched water to migrate down the well bore to ground water. Irrigation wells also may have multiple screen intervals that can permit mixing of different quality of water. In this assessment, older (pre-1975) irrigation wells generally had higher concentrations than newer wells and a higher percentage of the older irrigation wells had nitrate-N concentrations above 3 mg/L, suggesting that age of well may be an indicator of areas with potential problems.

Older irrigation well water right numbers give an indication of how long farming has occurred in different parts of the state. Further analysis of the distribution of age of water rights throughout the state may provide further insight as to the potential relationship that length of time farming in a given area has with the observed nitrate concentrations. Future work will also examine other relations within the individual regions, which might be indicators of potential contamination.

Nitrogen-15 values from non-irrigation wells typically indicate an animal waste source for nitrate: either septic systems or farmstead feedlots. Approximately 44% of the non-irrigation wells tested for nitrogen-15 had values in the animal waste range. This suggests that point source contamination may be more common, especially for shallower wells, than was previously thought. Nitrogen-15 from irrigation wells suggests a fertilizer source for nitrate, which may be a broader indication of nonpoint source contamination in areas where crop production dominates.

Because this is a preliminary assessment only a limited number of factors were considered. Future work will examine the effects of differences in precipitation and unsaturated zone characteristics as well as potential differences in land use (such as fertilizer and irrigation rates), occurrence of feedlots, and other potential point sources on the distribution of nitrate in Kansas ground water.

Recommendations

To prevent against further nitrate contamination from anthropogenic sources, proper management of all nitrate sources is essential. Many recommendations for fertilizer and irrigation water management are available from Agricultural Extension offices. Some of these recommendations include: split application of fertilizer, preplanting soil testing to determine nitrogen load, accounting for nitrate content in irrigation water as part of the fertilizer used during the growing season, and evaluating the efficiency of water application rates to prevent excess leaching of applied fertilizer.

To reduce the risks for point-source contamination, wells must be designed and installed properly. Also recommended are: proper plugging of abandoned wells, storing and mixing chemicals and fertilizers away from wells, and locating areas of livestock confinement away from wells (and vice versa).

References

Conover, W.J., 1980, Practical Nonparametric Statistics. 2nd Edition: John Wiley and Sons, New York, 493 p.

Gormly, J. R. and Spalding, R. F., 1979. Sources and concentrations of nitrate-nitrogen in ground water of the central Platte region, Nebraska: Ground Water, 17:291-301.

Hallberg, G. R., 1989, Nitrate in ground water in the United States. in Follet, R.F. (ed.), Nitrogen Management and Ground Water Protection: Developments in Agricultural and Managed-forest Ecology 21, Elsevier, New York, p. 35-74.

Heaton, T. H. E., 1986, Isotopic studies of nitrogen pollution in the hydrosphere and atmosphere: a review: Chemical Geology, 59:87-102.

Helsel, D. R., and Hirsch, R. M., 1992, Statistical methods in water resources: Studies in Environmental Science 49, Elsevier, New York, p. 357-376.

Herbel, M. J. and Spalding, R. F., 1993, Vados zone fertilizer-derived nitrate and δ15N extracts: Ground Water, 31:3:376-382.

Kansas Department of Agriculture, 1997, Kansas Farm Facts: Topeka, KS., 118 p.

Kolpin, D.W., Burkart, M.R., and Thurman, E.M., 1994, Herbicides and nitrate in near-surface aquifers in the midcontinental United States, 1991: U.S. Geological Survey, Water-Supply Paper 2413. [available online]

Kreitier, C. W., 1975, Determining the source of nitrate in groundwater by nitrogen isotope studies: Texas Bureau of Economic Geology, Report Investigations, No. 83. 57 p.

Kreitler, C. W. and Jones, D. C., 1975, Natural soil nitrate: the cause of the nitrate contamination of groundwater in Runnels County, Texas: Ground Water, 13:53-61.

Kreitler, C. W., 1979, Nitrogen-isotope ratio studies of soils and groundwater nitrate from alluvial fan aquifers in Texas: Journal Hydrology, 42: 147-170.

Madison, R. J., and Brunett, J. O., 1985, Overview of the occurrence of nitrate in ground water of the United States; in, National Water Summary 1984: U.S. Geological Survey, Water-Supply Paper 2275, p. 93-105.

SAS Institute., 1996, Master index to SAS system documentation, Version 6.12: SAS Institute, Gary, N.C.

Siegel, S., 1956, Nonparametric Statistics for the Behavioral Sciences: McGraw-Hill Book Co., New York. 312 p.

Spalding, M. E., 1984, Implication of temporal variations and vertical stratification of groundwater nitrate-nitrogen in the Hall County special use area: Nebraska Water Resources Research Institute, v. 372906, 44 p.

Spalding, R. F. and Exner, M. E., 1993. Occurrence of nitrate in groundwater--a review: Journal of Environmental Quality, v. 22, p. 392-402.

Steichen, J. Koelliker, J. Grosh, D. Heiman, A. Yearout, R. and Robbins, V., 1988, Contamination of farmstead wells by pesticides, volatile organics, and inorganic chemicals in Kansas: Ground Water Monitoring Review, v. 8, no. 3, p. 153-160.

Townsend, M. A., Macko, S. A., Young, D. P., and Sleezer, D. O., 1994, Natural 15N isotopic signatures in ground water: a cautionary note on interpretation: Kansas Geological Survey, Open-file Report 94-29, 24 p.

Townsend, M. A. and Young, D. P., 1999, Nitrate in Kansas ground water: Kansas Geological Survey, Public Information Circular 14, 4 p. [available online]

U.S. Census Bureau., 1999, 1990 Population Census Data; http://www.census.gov/.

Wilson, B. B., 1998, Water Information Management and Analysis System (WIMAS), version 4, for ArcView--Users Manual: Kansas Department of Agriculture, Division of Water Resources, 35 p.

Appendix A

Chemical and Physical Data for Kansas Ground-Water Samples, 1990-1998

ID Legal Location
T-R-Sec
County Area
ID
Year
Sampled
NO3-N
(mg/L)
δ15N
Sp. C.
(μmhos/cm)
SO4
(mg/L)
Cl
(mg/L)
Well
Type
Depth of
Well (ft)
Age of
Well
1 03S-16E-17 BR 3 1994 20.2   630     D 140 1977
2 19S-14W-32 BT 2 1997 13.6   1405 184.0 124.0 I 106 1975
3 20S-12W-29 BT 2 1996 1.3   917 34.2 141.0 I 100 1963
4 20S-14W-28 BT 2 1996 13.5   654 76.5 34.5 I 86 1984
5 33S-23W-29 CA 1 1997 3.0   1075 308.0 57.1 I 172 1975
6 05S-02W-20 CD 3 1994 4.3   700     D 45 1974
7 05S-02W-30 CD 3 1994 2.5   1100     D 42 1976
8 05S-02W-32 CD 3 1994 16.2   1030     D 60 1976
9 32S-18W-05 CM 1 1995 4.5   240 7.1 2.8 I 250 1976
10 32S-20W-26 CM 1 1997 6.3   792 144.0 26.8 I 88 1991
11 32S-20W-27 CM 1 1997 0.6   582 68.0 16.1 I 130 1976
12 32S-20W-27 CM 1 1997 0.3   499 27.3 15.2 I 91 1976
13 32S-20W-35 CM 1 1997 11.6   1150 248.0 36.1 I 87 1969
14 03S-37W-15 CN 1 1997 8.5   473 27.5 8.7 I   1974
15 05S-38W-20 CN 1 1996 5.5 12.0 515 47.3 19.2 I 275 1968
16 07S-02E-25 CY 3 1994 13.7   1170     D 56 1984
17 07S-02E-27 CY 3 1994 0.1   1140     D 60 1979
18 07S-03E-29 CY 3 1994 0.3   2001     D 70 1974
19 08S-02E-18 CY 3 1994 30.0   1980     D 57 1984
20 08S-03E-22 CY 3 1994 1.9   780     D 120 1984
21 02S-28W-28 DC 1 1995 1.0   1485 271.0 107.0 I 72 1956
22 12S-19E-09 DG 3 1997 2.2   773 36.3 7.2 I 50 1987
23 12S-20E-35 DG 3 1994 0.5   790     D 85 1973
24 13S-02E-29 DK 3 1994 0.7   790     P 58 1990
25 24S-16W-19 ED 2 1995 11.9   480     I 92 1979
26 24S-17W-24 ED 2 1994 8.5   530     D 76 1983
27 24S-18W-36 ED 2 1997 18.9   775 29.6 20.7 I 80 1976
28 25S-16W-27 ED 2 1994 9.3   550     D 64 1983
29 25S-16W-35 ED 2 1996 13.0   619 23.6 37.9 I 100 1976
30 25S-18W-01 ED 2 1996 13.9   668 21.0 9.4 I 80 1984
31 25S-18W-18 ED 2 1990 9.9 4.5       D 54 1981
32 25S-19W-31 ED 2 1997 11.8   2070 784.0 61.9 I   1974
33 25S-20W-26 ED 2 1996 1.4   2000 613.0 146.0 I 124 1996
34 26S-16W-02 ED 2 1994 2.1   390     D 76 1984
35 26S-16W-04 ED 2 1996 9.3   482 19.4 18.2 I 102 1975
36 26S-16W-04 ED 2 1994 15.3   530     D    
37 26S-17W-05 ED 2 1996 10.1   638 38.9 33.8 I   1966
38 26S-18W-06 ED 2 1996 5.1   502 41.0 18.6 I 160 1985
39 26S-19W-04 ED 2 1996 12.6   869 236.0 31.3 I 98 1977
40 26S-20W-01 ED 2 1997 19.1   2275 847.0 102.0 I 59 1975
41 26S-20W-01 ED 2 1995 38.1   1984     I 90 1974
42 26S-20W-14 ED 2 1996 36.1 9.5 1910 470.0 61.7 I   1974
43 23S-31W-25 FI 1 1997 43.3   2100 216.0 258.0 I   1971
44 23S-31W-31 FI 1 1995 6.0   875 147.0 73.4 I   1975
45 23S-02W-19 FI 1 1994 4.1   3600 1688.0 147.0 I   1955
46 23S-32W-21 FI 1 1998 3.2   778 169.0 40.6 I   1954
47 23S-32W-22 FI 1 1998 4.0   700 129.0 36.7 I 240 1977
48 23S-32W-28 FI 1 1998 3.7   1690 584.0 121.0 I   1973
49 23S-32W-36 FI 1 1998 4.8   780 149.0 42.6 I   1967
50 23S-33W-35 FI 1 1994 7.0   3730 1782.0 170.0 I 370 1965
51 23S-34W-17 FI 1 1996 4.9 14.3 805 152.0 65.0 I 336 1973
52 23S-34W-17 FI 1 1997 6.3   1570 560.0 117.0 I 310 1957
53 23S-34W-26 FI 1 1997 8.4   3430 1703.0 180.0 I 339 1980
54 23S-34W-36 FI 1 1997 3.5   968 304.0 28.2 P   1955
55 23S-34W-36 FI 1 1997 4.8   1070 332.0 47.2 P   1955
56 24S-31W-06 FI 1 1997 3.9   814 178.0 32.4 I   1974
57 24S-31W-18 FI 1 1998 4.2   865 209.0 31.5 I 280 1972
58 24S-31W-18 FI 1 1998 4.6   942 245.0 35.5 I 280 1966
59 24S-32W-01 FI 1 1998 4.2   738 149.0 28.9 I   1965
60 24S-32W-01 FI 1 1995 4.1   783 169.0 26.8 I   1978
61 24S-32W-01 FI 1 1998 5.1   850 178.0 47.6 I   1956
62 24S-32W-03 Fi 1 1994 15.2   2820 1109.0 139.0 I   1954
63 24S-32W-10 FI 1 1998 4.3   2090 806.0 137.0 I 270 1971
64 24S-32W-11 FI 1 1998 5.5   928 221.0 41.9 I 250 1964
65 24S-32W-13 FI 1 1998 3.8   1115 348.0 44.5 I 278 1972
66 24S-32W-25 FI 1 1994 4.5   3250 1532.0 139.0 I   1956
67 24S-32W-28 FI 1 1998 8.1   2730 1298.0 101.0 I   1975
68 24S-32W-29 FI 1 1994 2.6   485 81.9 13.7 I   1979
69 24S-32W-36 FI 1 1998 16.3   1420 549.0 58.1 I   1976
70 24S-33W-07 FI 1 1997 2.1   561 100.0 12.8 P   1961
71 24S-33W-07 FI 1 1997 2.1   720 175.0 17.3 P   1961
72 24S-33W-14 FI 1 1994 2.6   1780 665.0 56.2 I 290 1980
73 24S-33W-16 FI 1 1997 6.1   3790 1982.0 145.0 I 220 1972
74 24S-33W-21 FI 1 1994 7.7   627 127.0 16.2 I 300 1975
75 24S-33W-22 FI 1 1994 2.5   681 173.0 14.5 I 320 1972
76 24S-33W-22 FI 1 1997 3.7   1960 863.0 66.2 I 373 1972
77 24S-33W-27 FI 1 1995 1.6   1625 640.0 64.2 I 360 1972
78 24S-33W-27 FI 1 1997 32.5   975 152.0 53.6 I 360 1972
79 24S-33W-34 FI 1 1995 0.5   555 26.6 21.0 I 350 1972
80 24S-33W-34 FI 1 1995 0.5   437 34.0 7.2 I 435 1972
81 24S-33W-36 FI 1 1997 9.9   1360 505.0 54.0 I   1967
82 24S-34W-06 FI 1 1997 4.2   972 296.0 36.3 I   1955
83 24S-34W-11 FI 1 1997 4.4   2250 1056.0 87.1 I   1965
84 24S-34W-12 FI 1 1997 2.2   679 167.0 16.5 I 336 1968
85 24S-34W-13 FI 1 1995 2.8   803 220.0 21.2 I 440 1975
86 24S-34W-13 FI 1 1996 17.1   2630 1165.0 113.0 I   1975
87 24S-34W-14 FI 1 1997 6.0   1460 538.0 56.9 I 380 1967
88 24S-34W-14 FI 1 1997 15.2   2750 1258.0 121.0 I 380 1976
89 24S-34W-17 FI 1 1994 6.4   2050 880.0 81.2 I 366 1972
90 24S-34W-18 FI 1 1997 9.2   4312 2225.0 162.0 I 59 1976
91 24S-34W-20 FI 1 1997 6.2   1680 706.0 62.9 I   1967
92 24S-34W-20 FI 1 1997 15.4   1900 755.0 68.2 I   1973
93 25S-31W-02 FI 1 1998 3.6   980 295.0 39.5 I 265 1968
94 25S-31W-05 FI 1 1997 3.3   1785 749.0 60.3 I   1976
95 25S-31W-13 FI 1 1995 4.3   3700 1851.0 142.0 I 175 1964
96 25S-32W-03 FI 1 1996 22.1   535 20.0 18.5 I 242 1973
97 25S-32W-17 FI 1 1994 4.0   368 23.9 4.5 I 437 1977
98 25S-33W-12 FI 1 1998 6.1   411 31.9 6.1 I 496 1977
99 25S-33W-29 FI 1 1996 3.0   380 34.2 3.9 I   1973
100 25S-34W-18 FI 1 1996 2.2   373 41.0 4.6 I   1975
101 26S-31W-09 FI 1 1996 7.4   448 32.1 8.4 I 290 1976
102 26S-32W-07 FI 1 1998 4.5   488 42.2 22.7 I   1978
103 26S-32W-29 FI 1 1996 2.7   351 19.3 6.9 I   1978
104 26S-33W-06 FI 1 1994 2.1   342 20.8 1.8 I 375 1979
105 26S-33W-19 FI 1 1998 4.2   325 17.0 3.0 I   1976
106 26S-33W-20 FI 1 1996 2.5   318 10.8 3.0 I   1955
107 26S-34W-22 FI 1 1996 1.9   295 16.8 2.0 I 392 1980
108 26S-24W-28 FO 1 1994 1.2   450 12.6 6.3 I 221 1964
109 26S-25W-25 FO 1 1994 6.3   910     P 190 1955
110 26S-25W-32 FO 1 1995 8.6   1330 431.0 32.9 I   1970
111 26S-25W-35 FO 1 1994 4.9   940     P 165 1955
112 26S-26W-33 FO 1 1998 20.8   708 43.7 25.3 I   1971
113 27S-22W-13 FO 1 1997 5.8   557 27.1 19.1 I 358 1973
114 27S-24W-06 FO 1 1997 7.2   472 33.1 12.4 I   1967
115 27S-24W-06 FO 1 1994 3.9   450     D 183 1981
116 27S-24W-06 FO 1 1994 5.4   432 28.0 8.2 I 190 1978
117 27S-24W-09 FO 1 1998 19.2   512 18.0 18.1 I 201 1972
118 27S-24W-24 FO 1 1994 3.8   426 19.7 7.4 I   1976
119 27S-25W-01 FO 1 1997 5.4   468 26.9 11.0 I 176 1975
120 27S-25W-04 FO 1 1995 5.6   659 95.6 17.0 I   1970
121 27S-25W-04 FO 1 1997 4.2   549 69.9 14.3 I   1957
122 27S-25W-05 FO 1 1995 6.8   582 47.5 21.3 I 164 1976
123 27S-25W-24 FO 1 1995 6.5   708 56.0 55.2 I 164 1975
124 27S-26W-04 FO 1 1995 5.9   550 33.6 16.5 I   1973
125 27S-26W-33 FO 1 1998 4.4   537 33.7 33.8 I   1976
126 28S-23W-31 FO 1 1994 1.8   411 18.3 7.3 I 240 1976
127 28S-24W-01 FO 1 1996 3.2   428 28.7 8.6 I   1974
128 11S-5E-35 GE 3 1994 0.2   680     P 63 1975
129 08S-21W-16 GH 3 1994 5.8   1360 411.0 52.2 I 55 1973
130 17S-40W-17 GL 1 1998 3.4   548 84.0 26.0 I   1973
131 17S-40W-17 GL 1 1998 3.7   560 92.3 29.9 I   1965
132 11S-26W-18 GO 1 1995 4.2   470 17.0 13.1 I 250 1969
133 12S-29W-10 GO 1 1995 3.1   487 30.6 13.0 I 125 1975
134 27S-35W-16 GT 1 1996 1.9   320 18.4 5.6 I 150 1976
135 27S-37W-12 GT 1 1996 3.6   657 115.0 32.1 I   1973
136 28S-37W-20 GT 1 1997 1.1   708 178.0 17.0 I   1976
137 28S-37W-20 GT 1 1995 2.8   878 238.0 23.4 I   1959
138 29S-38W-29 GT 1 1995 3.3   602 125.0 16.1 I 520 1977
139 30S-35W-09 GT 1 1996 4.2   823 177.0 34.4 I 295 1970
140 25S-28W-31 GY 1 1994 4.2   844 213.0 36.7 I   1972
141 25S-28W-31 GY 1 1998 3.3   802 199.0 34.7 I   1971
142 25S-29W-07 GY 1 1994 5.2   910 239.0 36.7 I 300 1973
143 25S-29W-14 GY 1 1994 5.2   881 194.0 48.7 I   1955
144 25S-29W-29 GY 1 1995 19.3   2235 920.0 71.2 I 180 1975
145 25S-29W-32 GY 1 1994 7.0   870 235.0 19.4 I   1974
146 25S-29W-33 GY 1 1994 15.5   2650 1162.0 82.9 I   1971
147 25S-30W-17 GY 1 1994 14.4   1830 699.0 67.9 I 110 1965
148 25S-30W-22 GY 1 1994 19.3   2360 926.0 99.3 I 218 1968
149 25S-30W-25 GY 1 1994 8.3   3170 1510.0 108.0 I 185 1965
150 25S-30W-27 GY 1 1997 10.2   2135 926.0 82.2 I   1967
151 25S-30W-35 GY 1 1996 9.4   470 30.8 7.7 I 226 1976
152 26S-27W-18 GY 1 1994 2.4   1300 422.0 44.4 I   1968
153 26S-27W-24 GY 1 1995 1.6   934 202.0 15.5 I   1972
154 26S-28W-13 GY 1 1995 5.7   1955 750.0 60.7 I 152 1972
155 26S-28W-13 GY 1 1998 6.2   749 172.0 10.5 I   1968
156 26S-28W-13 GY 1 1997 6.9   687 124.0 11.5 I 152 1968
157 26S-28W-14 GY 1 1998 8.8   1135 367.0 19.6 I   1971
158 26S-28W-16 GY 1 1995 2.7   510 81.0 6.9 I   1974
159 26S-28W-23 GY 1 1998 16.1   563 33.7 13.0 I   1972
160 26S-29W-02 GY 1 1998 10.5   2220 906.0 77.5 I 300 1969
161 26S-29W-02 GY 1 1998 12.2   853 176.0 20.2 I 300 1969
162 26S-29W-15 GY 1 1995 0.6   454 28.7 7.6 I 201 1979
163 26S-29W-25 GY 1 1997 4.0   437 33.8 7.2 I   1973
164 26S-30W-06 GY 1 1995 4.9   453 25.0 13.1 I 230 1973
165 26S-30W-08 GY 1 1996 11.9 7.4 518 37.4 11.6 I 305 1973
166 26S-30W-12 GY 1 1996 7.4   481 29.8 12.9 I   1973
167 26S-30W-17 GY 1 1994 6.9   650 62.5 36.3 I   1968
168 27S-27W-36 GY 1 1996 3.3   445 26.0 12.3 I 240 1967
169 27S-28W-01 GY 1 1995 3.6   428 29.2 6.5 I 195 1972
170 27S-28W-23 GY 1 1995 3.1   400 21.3 4.0 I 160 1972
171 27S-28W-26 GY 1 1998 10.4   530 20.4 9.7 I 237 1972
172 27S-28W-31 GY 1 1996 4.3   426 28.9 8.1 I 190 1978
173 27S-29W-06 GY 1 1997 5.0   438 31.3 6.7 I 200 1975
174 27S-30W-28 GY 1 1996 3.8   445 39.6 13.3 I 370 1964
175 23S-42W-19 HM 1 1994 9.8   5460 2699.0 234.0 I   1974
176 23S-42W-34 HM 1 1994 3.7   5070 2706.0 184.0 I 80 1966
177 23S-43W-28 HM 1 1995 4.8   5670 2878.0 321.0 I 80 1975
178 24S-39W-30 HM 1 1994 3.0   4490 2253.0 170.0 I   1955
179 24S-39W-30 HM 1 1994 7.0   5500 2769.0 221.0 I   1955
180 24S-40W-17 HM 1 1994 6.5   5060 2427.0 266.0 I   1944
181 24S-42W-08 HM 1 1995 1.0   723 171.0 18.2 I 130 1977
182 27S-31W-34 HS 1 1997 2.2   351 30.5 9.1 I 570 1950
183 27S-32W-11 HS 1 1995 4.4   412 28.8 10.2 I 360 1973
184 27S-32W-13 HS 1 1997 2.3   352 30.8 4.5 I   1955
185 27S-32W-20 HS 1 1996 3.0   357 20.0 14.9 I 486 1972
186 27S-32W-28 HS 1 1994 1.9   305 15.1 6.8 I 402 1955
187 27S-33W-22 HS 1 1994 2.4   322 12.3 4.5 I 516 1976
188 27S-34W-11 HS 1 1996 4.4   312 11.6 2.5 I 344 1979
189 29S-33W-36 HS 1 1994 3.0   504 65.5 19.1 I   1965
190 29S-34W-16 HS 1 1996 6.2   673 109.0 29.7 I 600 1976
191 22S-01W-16 HV 2 1994 6.4   960     D 35 1979
192 22S-03W-23 HV 2 1993 0.1         D 78 1979
193 22S-03W-29 HV 2 1997 0.02   483 13.0 6.5 M   1981
194 22S-03W-30 HV 2 1993 4.6 16.2       D 55 1984
195 23S-01W-18 HV 2 1993 6.4         M 135 1987
196 23S-01W-19 HV 2 1993 16.6 11.7       D 70 1975
197 23S-01W-19 HV 2 1993 9.8 13.8       D 105 1975
198 23S-01W-19 HV 2 1993 2.0         M 164 1987
199 23S-01W-19 HV 2 1994 9.1   310     D 91 1994
200 23S-01W-19 HV 2 1993 32.3         D 50 1975
201 23S-01W-30 HV 2 1993 5.2         D 123 1983
202 23S-01W-31 HV 2 1993 9.0 12.6       D 90 1975
203 23S-01W-31 HV 2 1993 2.3         D 80 1975
204 23S-02W-19 HV 2 1993 9.9 14.6       D 110 1980
205 23S-02W-19 HV 2 1993 8.5 12.6       D 75 1975
206 23S-02W-19 HV 2 1993 10.2 13.4       D 73 1978
207 23S-02W-19 HV 2 1993 0.1         I 226 1984
208 23S-02W-25 HV 2 1993 6.9         I 96 1955
209 23S-02W-25 HV 2 1993 6.4         D 85 1975
210 23S-02W-25 HV 2 1993 13.7 11.3       D 65 1975
211 23S-02W-29 HV 2 1994 0.02   340 17.8 6.6 I   1968
212 23S-02W-30 HV 2 1994 17.3   550     D 120 1968
213 23S-02W-32 HV 2 1993 0.2         D 110 1990
214 23S-02W-36 HV 2 1993 4.2         D 101 1987
215 23S-03W-16 HV 2 1993 7.7 13.3       D 25 1975
216 23S-03W-23 HV 2 1993 0.1         D    
217 23S-03W-23 HV 2 1993 2.7         I   1968
218 23S-03W-26 HV 2 1993 0.04         D 58 1981
219 23S-03W-26 HV 2 1993 13.8         I 130 1980
220 23S-03W-35 HV 2 1993 6.1         D 48 1980
221 23S-03W-36 HV 2 1993 6.6 14.0       D 58 1975
222 23S-03W-36 HV 2 1993 7.5 11.1       D 68 1975
223 23S-03W-36 HV 2 1993 2.4         I 143 1979
224 24S-01W-04 HV 2 1993 2.8         D    
225 24S-01W-06 HV 2 1993 5.5         M 74 1975
226 24S-01W-06 HV 2 1993 3.7 16.3       D 80 1975
227 24S-01W-07 HV 2 1993 6.0         D 48 1978
228 24S-01W-07 HV 2 1997 4.7   403 22.4 4.1 I 124 1977
229 24S-01W-08 HV 2 1993 0.2         D 93 1985
230 24S-01W-08 HV 2 1993 5.3         I 169 1980
231 24S-01W-08 HV 2 1993 9.4 16.6       D 82 1984
232 24S-01W-17 HV 2 1993 12.3 10.7       D    
233 24S-02W-01 HV 2 1993 0.6         I   1977
234 24S-02W-01 HV 2 1993 5.2 8.4       D 74 1975
235 24S-02W-06 HV 2 1993 0.03         D    
236 24S-02W-07 HV 2 1993 0.05         D 80 1976
237 24S-02W-08 HV 2 1993 0.07         D 135 1975
238 24S-02W-16 HV 2 1993 0.1         I 111 1982
239 24S-02W-16 HV 2 1993 0.2         D 77 1982
240 24S-02W-21 HV 2 1993 0.06         D    
241 24S-02W-21 HV 2 1993 0.09         I 221 1976
242 24S-02W-21 HV 2 1993 0.14         I 30 1977
243 24S-02W-21 HV 2 1993 0.07         D 92 1987
244 24S-02W-21 HV 2 1997 0.10   884 181.0 39.0 M 201 1980
245 24S-02W-22 HV 2 1993 0.05         D 50 1975
246 24S-02W-22 HV 2 1993 0.08         D 112 1983
247 24S-02W-22 HV 2 1993 0.6         I 200 1983
248 24S-02W-29 HV 2 1993 0.12         D 73 1981
249 24S-02W-29 HV 2 1993 0.09         I 234 1975
250 24S-02W-29 HV 2 1993 0.1         D 88 1988
251 24S-02W-29 HV 2 1997 0.2   1030 227.0 42.5 I 222 1975
252 24S-02W-31 HV 2 1993 1.4         I 162 1974
253 24S-02W-31 HV 2 1993 0.02         D 49 1991
254 24S-02W-33 HV 2 1993 0.07         D 106 1992
255 24S-02W-33 HV 2 1993 1.4         I 140 1976
256 24S-03W-01 HV 2 1993 0.07         I 117 1981
257 24S-03W-01 HV 2 1993 0.02         I 236 1991
256 24S-03W-05 HV 2 1993 0.11         I 52 1976
259 24S-03W-05 HV 2 1993 0.04         D 32 1985
260 24S-03W-06 HV 2 1993 12.9 12.7       D 38 1990
261 24S-03W-08 HV 2 1993 0.06         M 43 1979
262 24S-03W-08 HV 2 1993 0.7         M 75 1979
263 24S-03W-08 HV 2 1993 0.07         I 50 1980
264 24S-03W-13 HV 2 1993 0.6         D 135 1980
265 24S-03W-15 HV 2 1993 0.05         I 85 1979
266 24S-03W-16 HV 2 1994 0.1   1320     D    
267 24S-03W-16 HV 2 1993 0.02         I 72 1979
268 24S-03W-17 HV 2 1993 0.08         D 68 1975
269 24S-03W-17 HV 2 1993 0.09         M 46 1979
270 24S-03W-17 HV 2 1993 0.7         M 79 1979
271 24S-03W-17 HV 2 1993 0.14         M 196 1979
272 24S-03W-22 HV 2 1993 1.8         D 55 1975
273 24S-03W-22 HV 2 1993 0.11         I 68 1981
274 24S-03W-22 HV 2 1993 0.08         M 20.5 1981
275 24S-03W-22 HV 2 1993 0.02         M 86 1981
276 24S-03W-22 HV 2 1994 0.2   1090     D 40 1960
277 24S-03W-22 HV 2 1993 1.4         I 120 1981
278 24S-03W-22 HV 2 1993 0.2         D    
279 24S-03W-24 HV 2 1993 0.06         D 64 1984
280 24S-03W-24 HV 2 1993 0.09         D 120 1975
281 24S-03W-24 HV 2 1997 5.5   1335 266.0 109.0 I 117 1977
282 24S-03W-28 HV 2 1993 1.3         D 25 1975
283 24S-03W-30 HV 2 1994 12.0   1020     D 60 1981
284 24S-03W-36 HV 2 1993 1.2         I 104 1981
285 24S-03W-36 HV 2 1993 0.08         D    
286 26S-07W-03 HV 2 1994 11.6   240     M 65 1992
287 26S-07W-08 HV 2 1994 16.8   720     M 20 1992
288 26S-07W-13 HV 2 1994 6.0   240     M 34 1992
289 26S-07W-15 HV 2 1994 19.1   320     M 64 1992
290 23S-35W-24 KE 1 1995 4.7   1575 601.0 80.1 I 360 1976
291 23S-35W-25 KE 1 1994 5.3   2250 954.0 119.0 I 360 1954
292 23S-35W-27 KE 1 1998 8.3   3280 1545.0 136.0 I 375 1981
293 23S-35W-28 KE 1 1998 5.0   2800 1405.0 104.0 I 360 1980
294 24S-35W-10 KE 1 1998 5.2   2610 1169.0 120.0 I 340 1973
295 24S-35W-11 KE 1 1998 9.6   3610 1789.0 169.0 I 305 1973
296 24S-35W-13 KE 1 1997 5.6   3295 1629.0 130.0 I   1975
297 24S-35W-13 KE 1 1994 5.5   2920 1387.0 107.0 I   1954
298 24S-35W-22 KE 1 1994 6.6   2830 1347.0 114.0 I   1966
299 24S-35W-23 KE 1 1995 2.4   825 225.0 19.7 I   1973
300 24S-35W-23 KE 1 1997 4.6   3440 1714.0 118.0 I   1954
301 24S-35W-24 KE 1 1997 14.8   3080 1483.0 123.0 I   1967
302 24S-35W-25 KE 1 1997 17.8   1860 737.0 83.6 I 337 1976
303 24S-35W-33 KE 1 1995 1.4   2830 1318.0 96.9 I 310 1993
304 24S-35W-35 KE 1 1995 4.7   1090 374.0 36.0 I 345 1992
305 24S-36W-23 KE 1 1994 4.2   27900 1266.0 126.0 I 260 1944
306 24S-36W-29 KE 1 1994 1.8   466 31.1 10.8 I 170 1976
307 24S-36W-29 KE 1 1994 4.5   460 35.1 17.7 I 158 1976
308 24S-36W-32 KE 1 1995 4.0   3650 1751.0 149.0 I 110 1971
309 25S-35W-10 KE 1 1997 10.5   672 138.0 26.0 I 335 1975
310 25S-35W-12 KE 1 1996 5.8   408 34.1 8.2 I 275 1973
311 25S-35W-22 KE 1 1996 5.6 11.2 396 37.8 6.3 I 240 1989
312 25S-35W-33 KE 1 1996 6.6   320 12.6 6.0 I 389 1968
313 25S-36W-01 KE 1 1995 5.8   3880 1915.0 154.0 I 373 1945
314 25S-36W-11 KE 1 1994 4.4   3360 1672.0 135.0 I 120 1984
315 25S-36W-18 KE 1 1994 3.3   3730 1813.0 136.0 I   1969
316 25S-36W-21 KE 1 1995 0.5   490 104.0 11.4 I 500 1967
317 25S-36W-24 KE 1 1996 12.3 5.8 635 117.0 24.6 I 380 1976
318 25S-37W-24 KE 1 1994 2.8   3840 1910.0 151.0 I 160 1976
319 25S-37W-24 KE 1 1997 1.6   2400 1119.0 89.8 I 298 1987
320 25S-38W-22 KE 1 1994 9.8   449 27.4 6.2 I   1970
321 26S-35W-13 KE 1 1996 3.3   292 6.0 14.2 I 440 1980
322 26S-35W-27 KE 1 1995 6.9   342 14.6 4.6 I 390 1980
323 26S-36W-01 KE 1 1996 10.8   344 11.3 3.7 I   1973
324 27S-08W-16 KM 2 1994 27.8   560     D 80 1966
325 27S-10W-01 KM 2 1994 2.7   180     D 76 1973
326 27S-10W-02 KM 2 1996 10.8   489 13.6 25.1 I   1973
327 27S-10W-05 KM 2 1994 9.8   310     D   1970
328 28S-09W-31 KM 2 1994 3.6   470     D 75 1975
329 27S-17W-01 KW 2 1996 9.6 9.5 345 10.2 29.5 I   1972
330 27S-17W-15 KW 2 1994 13.1   390     D 100 1991
331 27S-17W-21 KW 2 1994 4.3   290     D 80 1989
332 27S-17W-34 KW 2 1994 8.9   300     D   1964
333 27S-18W-04 KW 2 1996 5.9 15.2 344 13.1 4.7 I 150 1976
334 27S-18W-36 KW 2 1994 8.1   380     D 80 1970
335 27S-19W-01 KW 2 1996 9.4 10.2 557 17.2 22.6 I 195 1974
336 27S-19W-01 KW 2 1997 8.7   505 17.4 23.2 I 195 1974
337 27S-20W-26 KW 2 1996 7.5   415 11.8 15.3 I 101 1978
338 28S-16W-09 KW 2 1995 5.6   300 10.7 6.4 I   1965
339 28S-18W-02 KW 2 1995 5.6   357 14.3 5.7 I 142 1991
340 17S-29W-01 LE 1 1997 10.8   1015 97.5 121.0 I 155 1975
341 11S-32W-02 LG 1 1998 6.9   590 36.5 33.0 I   1975
342 11S-32W-04 LG 1 1998 4.9   520 33.5 17.4 I   1976
343 11S-32W-04 LG 1 1998 4.4   501 28.1 12.9 I   1963
344 11S-32W-04 LG 1 1998 6.4   580 56.7 25.6 I   1963
345 11S-32W-04 LG 1 1996 7.6   620 62.4 29.4 I   1972
346 30S-26W-32 ME 1 1994 5.2   450 14.5 9.2 I 180 1976
347 31S-30W-02 ME 1 1996 1.9   385 36.5 4.4 I   1975
348 32S-30W-21 ME 1 1998 3.0   546 77.7 19.5 I   1978
349 17S-05W-26 MP 2 1994 5.6   960     D    
350 18S-03W-31 MP 2 1997 0.02   565 27.0 12.5 M   1981
351 19S-04W-23 MP 2 1997 0.1   703 60.4 15.7 M   1981
352 19S-04W-24 MP 2 1996 2.1   662 18.6 49.6 I 245 1977
353 20S-01W-15 MP 2 1994 2.7   360     D 72 1977
354 20S-03W-19 MP 2 1997 0.5   449 20.5 21.1 M 223 1977
355 20S-04W-01 MP 2 1994 9.9   950     D 110 1976
356 21S-02W-24 MP 2 1996 77.4 22.4 2020 136.0 233.0 D   1981
357 14S-06E-34 MR 3 1994 10.7   900     P 120 1936
358 14S-06E-36 MR 3 1994 15.1   860     D 60 1993
359 15S-06E-02 MR 3 1994 8.6   750     D 75 1993
360 31S-40W-29 MT 1 1997 5.1   724 134.0 37.3 I 400 1955
361 34S-39W-17 MT 1 1994 2.2   698 168.0 9.8 I 475 1992
362 02S-22W-33 NT 3 1997 1.1   1355 92.4 85.2 I 70 1977
363 06S-11W-21 OB 3 1996 15.5 8.9 1035 78.8 65.3 P 93 1976
364 06S-12W-05 OB 3 1996 15.0 13.1 1525 230.0 132.0 P 49 1940
365 06S-12W-08 OB 3 1996 10.2 11.9 1100 89.8 65.7 D 45 1976
366 06S-13W-07 OB 3 1996 24.7 13.4 1495 202.0 118.0 D 60 1940
367 06S-13W-11 OB 3 1996 2.3 10.9 1045 229.0 44.9 D 90 1981
368 07S-12W-19 OB 3 1996 21.9 8.1 1370 202.0 99.6 P 50 1957
369 07S-12W-23 OB 3 1996 14.8 9.1 1520 274.0 150.0 D 30 1975
370 07S-13W-18 OB 3 1996 13.7 14.3 1780 417.0 152.0 D 60 1977
371 07S-14W-08 OB 3 1996 5.0 9.4 1180 214.0 77.5 D 30 1930
372 07S-15W-08 OB 3 1996 13.3 6.2 1125 164.0 83.2 P 36 1969
373 07S-15W-08 OB 3 1996 20.2 8.2 1810 372.0 160.0 D 25 1880
374 07S-15W-11 OB 3 1996 58.4 12.1 1800 260.0 139.0 P 48 1920
375 04S-16W-25 PL 3 1996 24.9 10.9 1850 586.0 69.5 D   1970
376 04S-16W-27 PL 3 1996 8.2 13.7 1485 276.0 88.4 P 74 1968
377 04S-16W-36 PL 3 1996 10.0 10.4 1290 291.0 55.8 I   1977
378 21S-16W-23 PN 2 1990 9.0 5.6       D 50 1975
379 22S-16W-04 PN 2 1997 0.5   1320 427.0 56.2 I   1956
380 22S-16W-10 PN 2 1997 7.1   513 17.3 29.2 I   1970
381 22S-16W-16 PN 2 1996 12.6 7.9 550 17.1 17.1 I   1979
382 23S-15W-01 PN 2 1996 9.8 8.8 546 17.5 34.4 I 98 1977
383 23S-16W-34 PN 2 1996 8.2   539 24.7 20.4 I 83 1980
384 23S-17W-32 PN 2 1990 8.6 7.2       D 45 1975
385 26S-11W-01 PR 2 1997 4.7   1070 28.8 199.0 I 90 1979
386 26S-11W-22 PR 2 1994 6.6   632 17.1 53.2 I 140 1990
387 26S-11W-30 PR 2 1994 11.7   570     P 80 1933
388 26S-12W-02 PR 2 1995 7.5   624 21.9 60.3 I 135 1956
389 26S-12W-36 PR 2 1995 3.6   617 18.0 58.3 I 130 1978
390 26S-13W-09 PR 2 1996 18.6 5.8 530 17.3 20.8 I 92 1978
391 26S-13W-09 PR 2 1994 10.0   510     D 64 1979
392 26S-13W-28 PR 2 1995 5.7   831 28.2 144.0 I 150 1967
393 26S-14W-02 PR 2 1997 3.4   368 8.2 10.9 I   1971
394 26S-14W-03 PR 2 1997 4.6   510 9.0 41.3 I 136 1973
395 26S-14W-11 PR 2 1994 9.9 9.3 1100 33.0 105.0 M 30 1987
396 26S-14W-11 PR 2 1994 20.1   899 17.0 89.0 M 50 1987
397 26S-14W-11 PR 2 1994 13.7   804 16.0 40.0 M 70 1987
398 26S-14W-11 PR 2 1994 7.5 3.8 664 28.0 232.0 D 65 1976
399 26S-14W-11 PR 2 1997 8.4   529 14.1 34.6 I 160 1969
400 26S-14W-11 PR 2 1996 23.9 5.8 834 18.0 81.8 I 161 1969
401 26S-14W-12 PR 2 1994 18.0 5.9 505 18.3 181.0 I 108 1975
402 26S-14W-12 PR 2 1994 2.6   390     D 93 1991
403 26S-14W-12 PR 2 1997 16.3   737 15.8 71.7 I 149 1969
404 26S-14W-13 PR 2 1997 17.4   610 17.7 25.4 I 91 1974
405 26S-14W-16 PR 2 1995 5.8   408 12.8 20.0 I 124 1968
406 26S-14W-31 PR 2 1996 23.9 6.3 564 20.6 9.8 I 111 1957
407 26S-15W-02 PR 2 1994 16.8   590     D 66 1981
408 26S-15W-13 PR 2 1997 10.2   387 10.9 10.3 I 160 1982
409 27S-11W-36 PR 2 1995 8.6   498 9.9 23.8 I 99 1989
410 27S-12W-06 PR 2 1993 1.5   41760 1539.0 14840.0 M 196 1982
411 27S-12W-06 PR 2 1993 1.8   1110 28.0 232.0 M 151 1982
412 27S-12W-06 PR 2 1993 4.3   1020 18.3 181.0 M 90 1982
413 27S-13W-05 PR 2 1997 5.1   783 13.2 44.3 I   1975
414 27S-13W-08 PR 2 1997 4.7   785 32.2 126.0 I   1960
415 27S-13W-09 PR 2 1995 9.8   744 24.4 95.0 I   1960
416 27S-15W-10 PR 2 1994 6.3   270     D 80 1987
417 28S-12W-34 PR 2 1996 2.8 17.7 412 11.6 17.2 I 226 1981
418 28S-15W-02 PR 2 1995 4.8   301 8.6 11.3 I 150 1980
419 28S-15W-11 PR 2 1995 3.3   341 14.6 28.2 I 180 1989
420 29S-11W-06 PR 2 1995 4.6   466 12.2 11.9 I 140 1976
421 29S-11W-26 PR 2 1994 9.8   480     D 85 1976
422 29S-11W-33 PR 2 1995 4.6   457 10.0 7.0 I 180 1976
423 29S-12W-02 PR 2 1996 3.3 14.3 430 15.3 20.7 I 187 1979
424 29S-12W-22 PR 2 1994 2.0   340     D 120 1985
425 10S-08E-08 PT 3 1994 0.5   1040     P 76 1969
426 10S-08E-09 PT 3 1994 0.5   560     P 68 1969
427 10S-08E-09 PT 3 1994 0.5   470     P 65 1985
428 10S-08E-09 PT 3 1994 0.5   560     P 68 1969
429 10S-08E-09 PT 3 1994 0.7   660     P 67 1969
430 21S-09W-08 RC 2 1996 28.7 7.3 1485 251.0 133.0 I 35 1989
431 10S-08E-09 RL 3 1994 1.8   780     D 50 1993
432 22S-09W-03 RN 2 1995 9.5   620 20.6 45.3 I 105 1973
433 23S-05W-31 RN 2 1994 2.8   1860     D 30 1979
434 23S-07W-13 RN 2 1995 18.6   450 29.2 12.0 I 100 1954
435 23S-09W-01 RN 2 1990 32.0 13.6       M 31.5 1981
436 23S-10W-06 RN 2 1993 0.07   66560 2660.0 25130.0 M 100 1981
437 23S-10W-06 RN 2 1993 0.2   61340 2590.0 22830.0 M 49 1981
438 24S-04W-05 RN 2 1997 4.7   770     D 70 1977
439 24S-04W-10 RN 2 1994 2.9   1360     D 30 1986
440 24S-04W-30 RN 2 1997 10.5   1445 28.4 234.0 I 52 1984
441 24S-04W-30 RN 2 1997 19.6   1705 39.0 285.0 D 30 1947
442 24S-04W-31 RN 2 1997 2.8 8.9 645 19.4 25.9 D 107 1986
443 24S-04W-31 RN 2 1997 18.3   910     D 30 1975
444 24S-04W-31 RN 2 1997 9.0 9.6 800 33.8 43.4 I 61 1968
445 24S-04W-32 RN 2 1997 8.7 7.9 720 24.5 34.7 D 51 1976
446 24S-04W-32 RN 2 1997 10.1 9.4 920 36.8 76.1 D 35 1975
447 24S-06W-30 RN 2 1994 10.6   850     D   1944
448 24S-10W-17 RN 2 1995 6.7   550 19.9 75.4 I   1972
449 25S-04W-04 RN 2 1997 6.0 6.9 650 26.9 27.5 D 40 1978
450 25S-04W-04 RN 2 1997 7.4 10.5 1280 57.8 150.0 D 60 1974
451 25S-04W-04 RN 2 1997 5.7   1140 52.1 119.0 M 45 1981
452 25S-04W-04 RN 2 1997 3.0 3.2 1675 25.9 285.0 I 60 1997
453 25S-04W-05 RN 2 1997 6.7 10.0 1395 72.3 240.0 P 58 1992
454 25S-04W-05 RN 2 1997 10.3   1020 49.4 87.4 D 60 1978
455 25S-04W-05 RN 2 1997 5.9 12.9 917 34.2 71.5 P 55 1975
456 25S-04W-05 RN 2 1997 5.8 10.1 988 40.3 88.4 D 45 1975
457 25S-04W-05 RN 2 1997 12.1 9.0 1330 72.6 191.0 P 52 1966
458 25S-04W-05 RN 2 1997 12.5 10.8 1005 59.2 59.6 P 54 1973
459 25S-04W-05 RN 2 1997 61.4 9.2 2360 183.0 260.0 D 30 1940
460 25S-04W-05 RN 2 1997 33.0 7.6 1090 47.5 41.9 D 30 1975
461 25S-04W-05 RN 2 1997 5.6 7.1 780 20.0 28.8 D 35 1969
462 25S-04W-05 RN 2 1997 5.8 2.3 1030     D 75 1984
463 25S-04W-05 RN 2 1997 21.6 8.6 980 30.1 53.6 D 54 1982
464 25S-04W-05 RN 2 1997 20.6 9.3 1050     D 35 1975
465 25S-04W-05 RN 2 1997 30.9 10.0 1320 36.3 120.0 D 70 1988
466 25S-04W-06 RN 2 1997 4.4 11.5 1610     D 65 1975
467 25S-04W-08 RN 2 1997 11.3 9.2 938 29.2 63.3 I 95 1978
468 25S-04W-08 RN 2 1997 47.0 10.5 2260 332.0 180.0 D 30 1975
469 25S-04W-09 RN 2 1997 9.5 6.7 840 25.8 13.5 D 52 1997
470 25S-04W-18 RN 2 1997 3.9 8.7 800 13.6 50.1 D 43 1997
471 24S-04W-33 RN 2 1997 4.9 6.2 1310 22.1 218.0 I 116 1996
472 25S-05W-02 RN 2 1997 0.2   2965 1718.0 70.7 D 200 1992
473 25S-07W-36 RN 2 1996 8.1 11.1 335 11.7 7.2 I 95 1969
474 25S-08W-01 RN 2 1994 7.0   520     D 45 1947
475 25S-10W-16 RN 2 1997 7.1   648 20.0 73.5 I   1984
476 26S-06W-07 RN 2 1995 12.4   403 20.8 8.6 I   1968
477 26S-06W-18 RN 2 1994 8.2   320     P 97 1994
478 26S-07W-03 RN 2 1994 18.1   350     D 37 1981
479 26S-09W-31 RN 2 1995 9.2   642 18.0 59.4 I   1986
480 26S-09W-31 RN 2 1996 13.8 8.4 623 15.8 42.4 I   1981
481 26S-10W-20 RN 2 1997 9.0   766 17.5 89.5 I 78 1979
482 26S-10W-31 RN 2 1995 6.9   565 14.9 35.9 I 110 1974
483 26S-10W-36 RN 2 1994 8.8   565 18.0 54.0 I 160 1985
484 07S-16W-09 RO 3 1996 6.7 7.2 905 77.8 44.6 P 64 1959
485 07S-16W-16 RO 3 1996 7.0 7.4 1005 128.0 60.7 D 35 1973
486 07S-17W-20 RO 3 1996 2.8 12.8 2920 509.0 518.0 D 60 1974
487 07S-18W-21 RO 3 1996 7.2 7.9 1960 587.0 150.0 D 80 1990
488 07S-18W-23 RO 3 1996 2.9 17.2 1050 195.0 64.3 P 42 1950
489 09S-18W-34 RO 3 1994 11.4   2001     P 61 1951
490 09S-18W-34 RO 3 1994 18.6   1490     D 47 1981
491 09S-18W-34 RO 3 1994 6.4   1940     D 65 1984
492 17S-32W-14 SC 1 1997 10.7   797 119.0 57.8 I   1968
493 18S-32W-20 SC 1 1998 9.0   900 116.0 57.3 I 198 1955
494 18S-33W-10 SC 1 1997 11.7   985 157.0 89.2 I   1970
495 18S-33W-12 SC 1 1998 7.3   660 65.1 34.0 I   1947
496 18S-33W-14 SC 1 1997 28.2   1425 302.0 73.9 I   1975
497 20S-32W-18 SC 1 1997 3.5   1385 410.0 40.2 I   1975
498 06S-29W-05 SD 1 1998 2.3   439 13.0 4.6 I 200 1966
499 07S-28W-34 SD 1 1996 2.9 19.1 448 25.3 8.4 I 230 1974
500 07S-30W-36 SD 1 1994 4.0   458 23.5 13.1 I   1976
501 08S-28W-05 SD 1 1995 5.6   495 28.6 17.8 I 260 1972
502 08S-28W-08 SD 1 1995 3.7   489 33.4 15.8 I 260 1974
503 08S-28W-17 SD 1 1998 3.9   500 34.1 16.3 I 220 1969
504 09S-28W-27 SD 1 1994 1.8   420 20.9 6.3 I 198 1989
505 09S-30W-11 SD 1 1997 2.8   447 16.7 14.2 I 205 1976
506 09S-30W-12 SD 1 1997 7.6   645 36.2 39.8 I   1956
507 25S-13W-26 SF 1 1996 12.1   755 22.7 57.0 I   1978
508 21S-11W-04 SF 2 1993 14.2 10.0       D 42 1976
509 21S-11W-04 SF 2 1993 8.5         D 85 1978
510 21S-11W-04 SF 2 1993 6.5         S 58 1975
511 21S-11W-07 SF 2 1995 3.5   1035 30.2 192.0 I 122 1984
512 21S-12W-02 SF 2 1993 5.0         I 123 1976
513 21S-12W-02 SF 2 1993 4.2         I 108 1981
514 21S-12W-06 SF 2 1996 10.0   689 20.3 77.3 I   1975
515 21S-12W-06 SF 2 1993 0.7         I 115 1983
516 21S-12W-09 SF 2 1993 3.0         D 70 1976
517 21S-12W-09 SF 2 1993 10.9     20.0 86.0 I 85 1975
518 21S-12W-11 SF 2 1993 6.0         I 109 1976
519 21S-12W-14 SF 2 1993 5.9 8.9       I 100 1978
520 21S-12W-15 SF 2 1993 11.1 9.9       I 115 1975
521 21S-12W-15 SF 2 1993 8.0         I 115 1977
522 21S-12W-16 SF 2 1993 3.3         I 131 1985
523 21S-12W-18 SF 2 1994 8.1   650 16.0 43.0 D 80 1984
524 21S-12W-19 SF 2 1993 5.4 6.9       D 74 1985
525 21S-12W-21 SF 2 1993 3.4         D 67 1981
526 21S-12W-23 SF 2 1993 23.0 11.1       S 81 1977
527 21S-12W-23 SF 2 1993 8.1 6.3       I 140 1978
528 21S-12W-23 SF 2 1993 7.0         I 142 1975
529 21S-12W-23 SF 2 1993 4.5         I 140 1977
530 21S-12W-26 SF 2 1994 4.4   660     D 102 1981
531 21S-12W-26 SF 2 1994 3.7   1000     D 85 1966
532 21S-12W-26 SF 2 1993 5.1         I 136 1977
533 21S-12W-26 SF 2 1994 40.2   1000     D 96 1981
534 21S-12W-26 SF 2 1993 10.5         D 90 1975
535 21S-12W-27 SF 2 1993 5.7 8.3       S 90 1978
536 21S-12W-27 SF 2 1993 8.7 8.3       I 120 1976
537 21S-12W-27 SF 2 1993 8.1         I 101 1975
538 21S-12W-28 SF 2 1993 6.0 13.2       I 102 1980
539 21S-12W-31 SF 2 1993 0.5   82500 3740.0 31870.0 M 203 1981
540 21S-12W-31 SF 2 1993 0.6   480 13.5 18.8 M 85 1981
541 21S-12W-32 SF 2 1993 1.1         I 115 1989
542 21S-12W-32 SF 2 1993 5.5         D 94 1989
543 21S-12W-35 SF 2 1993 8.8 4.7       D 90 1982
544 21S-12W-35 SF 2 1994 11.0   520     D 90 1982
545 21S-12W-36 SF 2 1993 0.8         S 49 1988
546 21S-12W-36 SF 2 1993 0.09   24330 989.0 8024.0 M 107 1980
547 21S-12W-36 SF 2 1993 3.7   680 19.3 63.8 M 46 1980
548 21S-13W-04 SF 2 1993 6.0         I 86 1980
549 21S-13W-05 SF 2 1993 4.3         D 80 1982
550 21S-13W-05 SF 2 1993 5.0         I 108 1976
551 21S-13W-06 SF 2 1995 4.8   570 26.2 39.6 I 85 1978
552 21S-13W-10 SF 2 1993 1.6         D 90 1980
553 21S-13W-10 SF 2 1993 3.4         D 56 1986
554 21S-13W-27 SF 2 1993 1.1         I 85 1976
555 21S-13W-31 SF 2 1995 9.1   624 22.9 29.6 I 102 1975
556 21S-13W-34 SF 2 1993 4.6         D 65 1986
557 21S-13W-36 SF 2 1993 4.7         D 60 1979
558 21S-13W-36 SF 2 1993 5.8         D 65 1981
559 21S-14W-8 SF 2 1996 5.7   588 23.2 19.3 I 52 1976
560 22S-11W-19 SF 2 1993 1.2     3740.0 31870.0 S 52 1988
561 22S-12W-04 SF 2 1993 5.3     19.3 63.8 D 80 1979
562 22S-12W-05 SF 2 1993 1.7         D 80 1985
563 22S-12W-06 SF 2 1993 0.1         D 89 1989
564 22S-12W-06 SF 2 1993 0.2         D 80 1977
565 22S-12W-08 SF 2 1993 7.2     13.5 18.8 D 92 1978
566 22S-12W-08 SF 2 1993 5.7     989.0 8024.0 D 125 1989
567 22S-12W-10 SF 2 1993 5.2         D 92 1978
568 22S-12W-12 SF 2 1993 6.8         D 70 1988
569 22S-12W-15 SF 2 1993 2.8         D 83 1985
570 22S-12W-21 SF 2 1993 3.0         D 93 1985
571 22S-12W-21 SF 2 1993 3.9     35.0 96.0 D 100 1977
572 22S-12W-24 SF 2 1993 2.5         S 118 1981
573 22S-12W-31 SF 2 1994 6.5   500     D 80 1973
574 22S-13W-03 SF 2 1993 1.7         I 85 1980
575 22S-13W-10 SF 2 1993 1.3         I 92 1981
576 22S-13W-11 SF 2 1993 1.5         I 100 1984
577 22S-13W-13 SF 2 1993 7.6 12.0   22.0 34.0 D 80 1979
578 22S-13W-13 SF 2 1993 4.8         I 93 1982
579 22S-13W-19 SF 2 1993 4.9 5.3   18.0 94.0 D 95 1982
580 22S-13W-20 SF 2 1997 5.9   708 21.2 60.4 I 115 1978
581 22S-13W-24 SF 2 1993 5.9         I 96 1976
582 22S-13W-25 SF 2 1993 8.5         I 90 1979
583 22S-13W-26 SF 2 1993 4.7         I 85 1978
584 22S-14W-15 SF 2 1996 17.3   677 27.0 20.4 I 94 1976
585 23S-12W-36 SF 2 1990 11.5 5.8       D 54  
586 23S-13W-27 SF 2 1996 10.7 13.6 1075 28.7 193.0 I   1964
587 23S-13W-36 SF 2 1997 5.3   561 19.1 49.7 I 80 1976
588 23S-14W-25 SF 2 1995 5.6   576 22.8 29.6 I 86 1976
589 24S-13W-04 SF 2 1995 12.2   502 21.0 32.0 I   1973
590 24S-13W-16 SF 2 1994 10.7   530     D 80 1975
591 24S-13W-36 SF 2 1994 3.5   937 34.4 146.0 M 154 1978
592 24S-14W-36 SF 2 1995 4.0   508 18.1 41.0 I 142 1989
593 25S-13W-31 SF 2 1997 14.1   603 14.0 22.6 I   1973
594 25S-13W-36 SF 2 1995 13.0   684 20.9 49.5 I 99 1973
595 25S-15W-17 SF 2 1996 4.7   446 15.3 28.0 I 100 1976
596 29S-01E-22 SG 2 1994 0.1   870     D 50 1990
597 07S-39W-28 SH 1 1994 9.8   488 26.9 13.6 I   1968
598 07S-39W-30 SH 1 1994 19.2   795 129.0 27.7 I   1957
599 07S-39W-31 SH 1 1994 11.9   559 46.5 24.3 I   1963
600 07S-40W-24 SH 1 1994 3.9   400 29.4 9.9 I 300 1975
601 07S-40W-24 SH 1 1994 4.1   355 18.2 6.2 I 300 1955
602 07S-40W-24 SH 1 1994 2.7         I 300 1968
603 07S-40W-25 SH 1 1994 2.5         I   1975
604 07S-40W-36 SH 1 1994 5.8         I   1971
605 07S-40W-36 SH 1 1997 6.3   589 28.5 34.8 I   1964
606 08S-37W-10 SH 1 1994 3.4   406 23.4 6.2 I   1969
607 08S-38W-17 SH 1 1996 2.9 2.2 378 22.8 5.0 I 280 1976
608 08S-38W-27 SH 1 1995 3.4   390 24.7 6.0 I 275 1967
609 08S-39W-02 SH 1 1994 3.9         I   1964
610 08S-39W-16 SH 1 1997 0.02   392 22.1 6.0 I   1976
611 08S-39W-31 SH 1 1998 21.7   835 131.0 60.4 I 280 1961
612 08S-39W-31 SH 1 1998 17.7   673 72.8 44.6 I 290 1961
613 08S-39W-31 SH 1 1998 3.8   392 25.6 7.0 I 285 1961
614 08S-39W-31 SH 1 1998 2.8   381 23.9 5.0 I 288 1961
615 08S-40W-01 SH 1 1994 9.4         I   1956
616 08S-40W-07 SH 1 1994 3.5   442 38.0 12.1 I   1968
617 08S-40W-11 SH 1 1994 8.9         I   1954
618 08S-40W-11 SH 1 1994 15.0   624 66.1 32.5 I   1963
619 08S-40W-14 SH 1 1994 2.3         I    
620 08S-40W-14 SH 1 1994 13.9   618 75.1 24.3 I 290 1964
621 08S-40W-14 SH 1 1994 16.7   694 94.1 26.2 I   1976
622 08S-40W-14 SH 1 1994 15.9   689 68.1 30.2 I 320 1976
623 08S-40W-21 SH 1 1994 12.8   490 37.2 15.0 I 280 1976
624 08S-40W-22 SH 1 1994 5.3         D    
625 08S-40W-26 SH 1 1994 2.3         D    
626 08S-40W-30 SH 1 1994 0.7 8.2 450     M 139 1991
627 08S-40W-30 SH 1 1994 1.8 10.1 1180     M 105 1991
628 08S-40W-35 SH 1 1994 20.0         I 275 1956
629 08S-41W-01 SH 1 1994 2.4   330 16.1 7.8 I 290 1974
630 08S-41W-18 SH 1 1994 3.5   409 23.9 6.9 I   1968
631 08S-41W-25 SH 1 1994 2.1         D    
632 08S-41W-34 SH 1 1994 6.0         I 302 1979
633 08S-41W-34 SH 1 1994 2.1         D    
634 08S-41W-36 SH 1 1994 2.5         I    
635 08S-39W-31 SH 1 1998 5.0   420 23.8 13.5 I 272 1977
636 09S-40W-03 SH 1 1994 4.5         I   1973
637 09S-40W-04 SH 1 1994 13.9         I   1975
638 09S-40W-05 SH 1 1994 5.7         I 314 1968
639 09S-40W-08 SH 1 1994 2.7         I 245 1973
640 09S-40W-18 SH 1 1994 2.8         I 267 1967
641 09S-40W-19 SH 1 1994 4.4         I   1964
642 09S-40W-29 SH 1 1994 29.5         D 240 1994
643 09S-41W-02 SH 1 1994 2.3         D    
644 09S-41W-03 SH 1 1994 6.2         I 253 1966
645 09S-41W-06 SH 1 1994 3.9         I 290 1962
646 09S-41W-07 SH 1 1994 5.7         D    
647 09S-41W-07 SH 1 1997 5.3   450 44.2 18.2 I 285 1963
648 09S-41W-08 SH 1 1994 7.8         I 290 1965
649 09S-41W-09 SH 1 1994 3.8         I 290 1959
650 09S-41W-09 SH 1 1994 2.4         D    
651 09S-41W-09 SH 1 1994 3.1         I 295 1965
652 09S-41W-10 SH 1 1994 2.2   380     M 209 1991
653 09S-41W-10 SH 1 1994 3.2         I 252 1976
654 09S-41W-10 SH 1 1994 7.1   550     M 110 1991
655 09S-41W-10 SH 1 1994 2.3         I 258 1975
656 09S-41W-11 SH 1 1994 2.2         D    
657 09S-41W-11 SH 1 1994 2.3 7.1 370     M 153 1991
658 09S-41W-11 SH 1 1994 13.6   563 54.1 21.6 I 301 1955
659 09S-41W-11 SH 1 1997 5.5   412 27.6 6.9 I   1968
660 09S-41W-11 SH 1 1994 2.2 6.8       M 214 1991
661 09S-41W-12 SH 1 1994 9.1   481 30.0 18.2 I   1968
662 09S-41W-12 SH 1 1994 15.2   657 73.5 32.3 I 290 1975
663 09S-41W-12 SH 1 1994 6.8         I 290 1961
664 09S-41W-12 SH 1 1994 16.1         I 290 1965
665 09S-41W-13 SH 1 1994 2.5         I   1969
666 09S-41W-13 SH 1 1994 2.8         D    
667 09S-41W-14 SH 1 1994 5.6   460     M 197 1991
668 09S-41W-14 SH 1 1994 4.8         I   1965
669 09S-41W-15 SH 1 1994 5.6         I 291 1968
670 09S-41W-16 SH 1 1994 2.3         D    
671 09S-41W-16 SH 1 1994 2.7         I 260 1977
672 09S-41W-18 SH 1 1994 5.8         I 285 1963
673 09S-41W-19 SH 1 1994 4.5         I   1971
674 09S-41W-20 SH 1 1994 4.2         I   1966
675 09S-41W-21 SH 1 1994 6.4         D 284 1976
676 09S-41W-22 SH 1 1994 8.2         I   1969
677 09S-41W-23 SH 1 1994 3.5         I   1963
678 09S-41W-24 SH 1 1994 2.9         D 255 1976
679 09S-41W-27 SH 1 1994 13.0         I   1976
680 09S-41W-27 SH 1 1994 2.4         D    
681 09S-41W-31 SH 1 1994 3.6         I   1964
682 09S-41W-33 SH 1 1994 6.0         I   1958
683 09S-41W-33 SH 1 1994 5.3         I   1958
684 09S-41W-33 SH 1 1994 4.0         I 295 1973
685 09S-41W-36 SH 1 1994 2.9         I   1972
686 09S-42W-11 SH 1 1994 15.4         I   1958
687 09S-42W-11 SH 1 1994 9.3         I   1961
688 09S-42W-14 SH 1 1994 69.7   1340     D 280 1975
689 09S-42W-22 SH 1 1994 3.2         I   1969
690 09S-42W-24 SH 1 1994 3.0         I   1974
691 09S-42W-34 SH 1 1994 5.0         I   1963
692 10S-40W-04 SH 1 1994 2.7         D    
693 10S-40W-08 SH 1 1994 3.2         I 256 1963
694 10S-41W-03 SH 1 1997 2.8   323 16.3 4.2 I 205 1981
695 10S-41W-08 SH 1 1994 2.8         I 285 1968
696 10S-41W-08 SH 1 1994 2.4         D    
697 10S-42W-12 SH 1 1994 2.8         I 297 1966
698 05S-13W-17 SM 3 1996 18.4 13.5 1430 296.0 53.6 D 65 1982
699 05S-14W-01 SM 3 1996 9.4 12.7 1155 169.0 64.9 D 55  
700 05S-14W-12 SM 3 1996 15.6 11.1 1360 262.0 77.0 D 60 1986
701 05S-15W-05 SM 3 1996 38.4 13.5 1720 181.0 167.0 D 47 1971
702 11S-13E-01 SN 3 1994 1.4   640     D 75 1974
703 11S-15E-20 SN 3 1994 0.7   640     I 66 1972
704 29S-40W-10 ST 1 1994 1.7   513 97.2 10.5 I   1973
705 29S-40W-29 ST 1 1997 3.3   505 77.3 18.8 I   1970
706 31S-35W-08 SV 1 1994 2.3   630 122.0 16.3 I   1970
707 31S-36W-02 SV 1 1996 3.5   680 110.0 35.1 I   1961
708 31S-37W-25 SV 1 1996 2.7   740 162.0 19.8 I   1970
709 32S-35W-13 SV 1 1996 3.3   696 135.0 25.5 I 474 1976
710 32S-36W-06 SV 1 1997 2.6   570 93.9 17.0 I 529 1956
711 32S-37W-02 SV 1 1997 2.8   525 69.8 19.5 I   1974
712 33S-35W-16 SV 1 1996 2.4   740 171.0 14.5 I   1973
713 33S-35W-33 SV 1 1994 3.7   607 134.0 15.2 I 740 1986
714 33S-37W-21 SV 1 1997 3.5   693 160.0 17.4 I 585 1990
715 33S-37W-30 SV 1 1997 5.9   718 125.0 36.0 I   1976
716 33S-38W-18 SV 1 1996 3.4   587 108.0 12.2 I 429 1988
717 34S-36W-03 SV 1 1996 3.3   559 103.0 14.5 I   1969
718 32S-33W-32 SW 1 1996 3.2   627 118.0 13.1 I   1976
719 32S-33W-25 SW 1 1994 2.2   602 107.0 11.8 I 234 1977
720 32S-34W-21 SW 1 1994 3.4   645 107.0 21.4 I 414 1977
721 33S-31W-16 SW 1 1994 3.4   705 156.0 16.2 I   1982
722 33S-32W-01 SW 1 1997 5.5   755 127.0 41.0 I   1974
723 33S-33W-30 SW 1 1997 4.2   725 150.0 28.3 I   1972
724 33S-34W-21 SW 1 1997 2.9   758 184.0 14.5 I 460 1990
725 34S-32W-10 SW 1 1997 3.4   2340 153.0 563.0 I 415 1976
726 07S-31W-07 TH 1 1997 3.1   442 19.1 6.6 I 206 1968
727 07S-31W-26 TH 1 1994 3.8   450 24.9 11.2 I   1968
728 07S-36W-16 TH 1 1997 4.4   435 19.8 6.9 I 275 1968
729 08S-31W-15 TH 1 1994 2.7   443 21.2 7.0 I 218 1979
730 08S-33W-34 TH 1 1997 6.7   549 35.4 23.5 I   1974
731 08S-34W-24 TH 1 1995 3.7   468 28.8 9.1 I   1973
732 09S-33W-15 TH 1 1997 3.0   453 24.5 11.0 I   1956
733 09S-33W-30 TH 1 1996 4.2   447 17.3 8.6 I   1965
734 09S-34W-25 TH 1 1994 1.8   428 15.5 4.8 I   1974
735 12S-23W-21 TR 1 1998 5.1   638 27.3 32.1 I 98 1963
736 13S-40W-07 WA 1 1994 2.8   917 214.0 25.1 I   1982
737 14S-40W-36 WA 1 1996 9.1   598 85.5 34.0 I   1955
738 14S-42W-10 WA 1 1997 4.3   428 39.6 18.4 I   1968
739 15S-38W-29 WA 1 1994 3.9   450 42.9 15.1 I   1969
740 15S-38W-33 WA 1 1994 8.0   589 68.1 33.2 I 223 1967
741 15S-39W-21 WA 1 1997 4.8   500 52.4 20.0 I 226 1977
742 15S-40W-23 WA 1 1996 2.9   410 35.4 6.3 I   1968
743 16S-38W-27 WH 1 1996 8.1   785 123.0 42.5 I   1954
744 18S-36W-18 WH 1 1998 4.9   510 51.4 28.5 I   1971
745 05S-02E-11 WS 3 1994 32.1   860     D 78 1977
746 05S-02E-12 WS 3 1994 10.2   340     D 98 1980
747 05S-02E-25 WS 3 1994 5.8   780     D 138 1991

Kansas Geological Survey, Geohydrology
Placed online Nov. 15, 2007; original report dated Dec. 1999
Comments to webadmin@kgs.ku.edu
The URL for this page is http://www.kgs.ku.edu/Hydro/Publications/1999/OFR99_45/index.html