55xy/ Un At. fff- £/$ QUALITY-ASSURANCE DATA FOR ROUTINE WATER ANALYSIS IN THE NATIONAL WATER-QUALITY LABORATORY OF THE U.S. GEOLOGICAL SURVEY FOR WATER YEAR 1987 U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 89-4049 UECQSIIORX Juw egg 4tnS SITY 0F ILLINOIS AT URRAL ''HAMPAIGN QUALITY-ASSURANCE DATA FOR ROUTINE WATER ANALYSIS IN THE NATIONAL WATER-QUALITY LABORATORY OF THE U.S. GEOLOGICAL SURVEY FOR WATER YEAR 1987 By Keith J. Lucey and Dale B. Peart U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 89-4049 Denver, Colorado 1989 DEPARTMENT OF THE INTERIOR For additional information William J. Shampine U.S. Geological Survey Box 25046, Mail Stop 401 Denver Federal Center Denver, CO 80225 MANUEL LUJAN, JR., Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, Director write to: Copies of this report can be purchased from: U.S. Geological Survey Books and Open-File Reports Federal Center, Bldg. 810 Box 25425 Denver, CO 80225 CONTENTS Page Abstract . 1 Introduction. 1 Program description. 2 Statistical evaluation. 3 Quality-Assurance data for inorganic-constituent samples. 7 Precision . 7 Bias. 8 Quality-Assurance data for nutrient-constituent samples.10 Precision . 10 Bias. 10 Quality-Assurance data for precipitation samples.10 Summary and conclusions.11 References.13 Supplemental data .15 FIGURES Figures 1-148. Graphs showing: Page 1. Alkalinity, dissolved, data from the National Water-Quality Laboratory. 17 2. Aluminum, dissolved, data from the National Water-Quality Laboratory. 17 3. Antimony, dissolved, data from the National Water-Quality Laboratory. 18 4. Arsenic, dissolved, data from the National Water-Quality Laboratory. 18 5. Barium, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 19 6. Barium, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 19 7. Barium, total recoverable, data from the National Water-Quality Laboratory . 20 8. Beryllium, dissolved, data from the National Water-Quality Laboratory. 20 9. Beryllium, total recoverable, data from the National Water-Quality Laboratory. 21 10. Boron, dissolved, data from the National Water-Quality Laboratory. 21 11. Cadmium, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 22 12. Cadmium, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 22 13. Cadmium, total recoverable, data from the National Water-Quality Laboratory. 23 14. Calcium, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 23 15. Calcium, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 24 16. Chloride, dissolved, data from the National Water-Quality Laboratory. 24 17. Chromium, dissolved, data from the National Water-Quality Laboratory. 25 18. Chromium, total recoverable, data from the National Water-Quality Laboratory . 25 19. Cobalt, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 26 20. Cobalt, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 26 21. Cobalt, total recoverable, data from the National Water-Quality Laboratory. 27 22. Copper, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 27 23. Copper, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 28 24. Copper, total recoverable, data from the National Water-Quality Laboratory . 28 25. Dissolved solids, data from the National Water-Quality Laboratory. 29 in Page Figures 1-148. Graphs showing: 26. Fluoride, dissolved, data from the National Water-Quality Laboratory. 29 27. Iron, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 30 28. Iron, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 30 29. Iron, total recoverable, data from the National Water-Quality Laboratory. 31 30. Lead, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 31 31. Lead, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 32 32. Lead, total recoverable, data from the National Water-Quality Laboratory . 32 33. Lithium, dissolved, data from the National Water-Quality Laboratory. 33 34. Lithium, total recoverable, data from the National Water-Quality Laboratory. 33 35. Magnesium, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 34 36. Magnesium, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 34 37. Manganese, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 35 38. Manganese, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 35 39. Manganese, total recoverable, data from the National Water-Quality Laboratory. 36 40. Molybdenum, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 36 41. Molybdenum, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 37 42. Nickel, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 37 43. Nickel, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 38 44. Nickel, total recoverable, data from the National Water-Quality Laboratory. 38 45. Potassium, dissolved, data from the National Water-Quality Laboratory. 39 46. Selenium, dissolved, data from the National Water-Quality Laboratory . 39 47. Silica, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 40 48. Silica, dissolved, (colorimetry) data from the National Water-Quality Laboratory. 40 49. Silver, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 41 50. Silver, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 41 51. Silver, total recoverable, data from the National Water-Quality Laboratory. 42 52. Sodium, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 42 53. Sodium, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 43 54. Strontium, dissolved, data from the National Water-Quality Laboratory. 43 55. Sulfate, dissolved, data from the National Water-Quality Laboratory. 44 56. Zinc, dissolved, (inductively coupled plasma emission spectrometry) data from the National Water-Quality Laboratory. 44 57. Zinc, dissolved, (atomic absorption spectrometry) data from the National Water-Quality Laboratory. 45 58. Zinc, total recoverable, data from the National Water-Quality Laboratory. 45 59. Ammonia nitrogen as N, dissolved, data from the National Water-Quality Laboratory. 46 60. Ammonia + organic nitrogen as N, dissolved, data from the National Water-Quality Laboratory. 46 61. Nitrite + nitrate nitrogen as N, dissolved, data from the National Water Quality Laboratory- 47 62. Nitrite nitrogen as N, dissolved, data from the National Water-Quality Laboratory . 47 IV Figures 1-148. Graphs showing: Page 63. Orthophosphate phosphorus as P, dissolved, data from the National Water-Quality Laboratory. 48 64. Phosphorus as P, dissolved, data from the National Water-Quality Laboratory . 48 65. Calcium, dissolved, (precipitation) data from the National Water-Quality Laboratory . 49 66. Chloride, dissolved, (precipitation) data from the National Water-Quality Laboratory. 49 67. Fluoride, dissolved, (precipitation) data from the National Water-Quality Laboratory. 50 68. Magnesium, dissolved, (precipitation) data from the National Water-Quality Laboratory. 50 69. Ammonia nitrogen as N, dissolved, (precipitation) data from the National Water-Quality Laboratory. 51 70. Nitrate nitrogen as N, dissolved, (precipitation) data from the National Water-Quality Laboratory. 51 71. Orthophosphate phosphorus as P, dissolved, (precipitation) data from the National Water-Quality Laboratory. 52 72. Potassium, dissolved, (precipitation) data from the National Water-Quality Laboratory. 52 73. Sodium, dissolved, (precipitation) data from the National Water-Quality Laboratory. 53 74. Sulfate, dissolved, (precipitation) data from the National Water-Quality Laboratory . 53 75. Precision data for alkalinity, dissolved, at the National Water-Quality Laboratory . 54 76. Precision data for aluminum, dissolved, at the National Water-Quality Laboratory. 54 77. Precision data for antimony, dissolved, at the National Water-Quality Laboratory. 55 78. Precision data for arsenic, dissolved, at the National Water-Quality Laboratory . 55 79. Precision data for barium, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 56 80. Precision data for barium, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 56 81. Precision data for barium, total recoverable, at the National Water-Quality Laboratory . 57 82. Precision data for beryllium, dissolved, at the National Water-Quality Laboratory. 57 83. Precision data for beryllium, total recoverable, at the National Water-Quality Laboratory . 58 84. Precision data for boron, dissolved, at the National Water-Quality Laboratory. 58 85. Precision data for cadmium, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 59 86. Precision data for cadmium, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 59 87. Precision data for cadmium, total recoverable, at the National Water-Quality Laboratory. 60 88. Precision data for calcium, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 60 89. Precision data for calcium, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 61 90. Precision data for chloride, dissolved, at the National Water-Quality Laboratory . 61 91. Precision data for chromium, dissolved, at the National Water-Quality Laboratory . 62 92. Precision data for chromium, total recoverable, at the National Water-Quality Laboratory. 62 93. Precision data for cobalt, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 63 94. Precision data for cobalt, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 63 95. Precision data for cobalt, total recoverable, at the National Water-Quality Laboratory . 64 96. Precision data for copper, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 64 97. Precision data for copper, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 65 98. Precision data for copper, total recoverable, at the National Water-Quality Laboratory. 65 99. Precision data for dissolved solids at the National Water-Quality Laboratory. 66 100. Precision data for fluoride, dissolved, at the National Water-Quality Laboratory. 66 101. Precision data for iron, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 67 102. Precision data for iron, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 67 103. Precision data for iron, total recoverable, at the National Water-Quality Laboratory. 68 104. Precision data for lead, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 68 v Figures 1-148. Graphs showing: Page 105. Precision data for lead, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 69 106. Precision data for lead, total recoverable, at the National Water-Quality Laboratory. 69 107. Precision data for lithium, dissolved, at the National Water-Quality Laboratory. 70 108. Precision data for lithium, total recoverable, at the National Water-Quality Laboratory . 70 109. Precision data for magnesium, dissolved, (inductively coupled plasma emission spectrometry,) at the National Water-Quality Laboratory. 71 110. Precision data for magnesium, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 71 111. Precision data for manganese, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 72 112. Precision data for manganese, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 72 113. Precision data for manganese, total recoverable, at the National Water-Quality Laboratory. 73 114. Precision data for molybdenum, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 73 115. Precision data for molybdenum, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 74 116. Precision data for nickel, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 74 117. Precision data for nickel, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 75 118. Precision data for nickel, total recoverable, at the National Water-Quality Laboratory . 75 119. Precision data for potassium, dissolved, at the National Water-Quality Laboratory. 76 120. Precision data for selenium, dissolved, at the National Water-Quality Laboratory. 76 121. Precision data for silica, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 77 122. Precision data for silica, dissolved, (colorimetry) at the National Water-Quality Laboratory. 77 123. Precision data for silver, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 78 124. Precision data for silver, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 78 125. Precision data for silver, total recoverable, at the National Water-Quality Laboratory. 79 126. Precision data for sodium, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 79 127. Precision data for sodium, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 80 128. Precision data for strontium, dissolved, at the National Water-Quality Laboratory. 80 129. Precision data for sulfate, dissolved, at the National Water-Quality Laboratory. 81 130. Precision data for zinc, dissolved, (inductively coupled plasma emission spectrometry) at the National Water-Quality Laboratory. 81 131. Precision data for zinc, dissolved, (atomic absorption spectrometry) at the National Water-Quality Laboratory. 82 132. Precision data for zinc, total recoverable, at the National Water-Quality Laboratory. 82 133. Precision data for ammonia nitrogen as N, dissolved, at the National Water-Quality Laboratory. 83 134. Precision data for ammonia + organic nitrogen as N, dissolved, at the National Water-Quality Laboratory. 83 135. Precision data for nitrite + nitrate nitrogen as N, dissolved, at the National Water-Quality Laboratory. 84 136. Precision data for nitrite nitrogen as N, dissolved, at the National Water-Quality Laboratory _ 84 137. Precision data for orthophosphate as P, dissolved, at the National Water-Quality Laboratory. 85 138. Precision data for phosphorus as P, dissolved, at the National Water-Quality Laboratory . 85 139. Precision data for calcium, dissolved, (precipitation) at the National Water-Quality Laboratory. 86 140. Precision data for chloride, dissolved, (precipitation) at the National Water-Quality Laboratory. 86 141. Precision data for fluoride, dissolved, (precipitation) at the National Water-Quality Laboratory. 87 vi Figures 1-148. Graphs showing: Page 142. Precision data for magnesium, dissolved, (precipitation) at the National Water-Quality Laboratory. 87 143. Precision data for ammonia nitrogen as N, dissolved, (precipitation) at the National Water-Quality Laboratory. 88 144. Precision data for nitrate nitrogen as N, dissolved, (precipitation) at the National Water-Quality Laboratory. 88 145. Precision data for orthophosphate phosphorus as P, dissolved, (precipitation) at the National Water-Quality Laboratory. 89 146. Precision data for potassium, dissolved, (precipitation) at the National Water-Quality Laboratory. 89 147. Precision data for sodium, dissolved, (precipitation) at the National Water-Quality Laboratory. 90 148. Precision data for sulfate, dissolved, (precipitation) at the National Water-Quality Laboratory. 90 TABLES Table 1. Linear least-squared equations for determining the most probable standard deviation . 4 2. Total number of analyses from quality-assurance samples during water year 1987. 6 3. Results of statistical testing for lack of precision in inorganic constituent data. 8 4. Results of statistical testing for bias in inorganic constituent data. 9 5. Results of statistical testing for lack of precision in nutrient constituent data. 10 6. Results of statistical testing for bias in nutrient constituent data. 10 7. Results of statistical testing for lack of precision in precipitation constituent data. 11 8. Results of statistical testing for bias in precipitation constituent data . 11 vii Digitized by the Internet Archive in 2019 with funding from University of Illinois Urbana-Champaign Alternates https://archive.org/details/qualityassurance8940luce QUALITY-ASSURANCE DATA FOR ROUTINE WATER ANALYSIS IN THE NATIONAL WATER-QUALITY LABORATORY OF THE U.S. GEOLOGICAL SURVEY FOR WATER-YEAR 1987 By Keith J. Lucey and Dale B. Peart ABSTRACT The U.S. Geological Survey maintains a quality-assurance program based on the analysis of reference sam¬ ples for its National Water-Quality Laboratory located in Denver, Colorado. Reference samples containing selected inorganic constituents are prepared at the Survey’s Water Quality Services Unit in Ocala, Florida, disguised as rou¬ tine samples, and sent daily or weekly, as appropriate, to the laboratory through other Survey offices. Nutrient sam¬ ples and precipitation samples also were submitted as samples of unknown concentration. The results are stored permanently in the National Water Data Storage and Retrieval System (WATSTORE), the Survey’s data base for all water data. These data are analyzed statistically for precision and bias. The results of these statistical analyses are discussed for data collected during water-year 1987. An overall evaluation of the major and trace constituent data for water-year 1987 indicated a lack of precision in the National Water-Quality Laboratory for the determination of 6 out of 58 constituents: chloride; chromium; iron, total recoverable; zinc, dissolved (atomic absorption spectroscopy); zinc, (inductively coupled plasma emission spectroscopy); and zinc, total recoverable. There were fewer constituents having positive or negative bias during water-year 1987 than during water-year 1986. A lack of precision was indicated in the determination of three of the six nutrient constituents: nitrate + nitrite nitrogen as N, orthophosphate as R and phosphorus as R A biased condition was indicated in the determination of ammonia + organic nitrogen as N. There was acceptable precision in the determination of all 10 precipitation-level constituents. One precipita¬ tion-level constituent, sodium, indicated a biased condition. INTRODUCTION The National Water-Quality Laboratory (NWQL) of the U.S. Geological Survey, located in Denver, Colo¬ rado, routinely analyzes water, suspended sediment, streambed and lakebed materials for inorganic constituents, many organic substances, including common pesticides, priority pollutants as defined by the U.S. Environmental Protection Agency (Keith and Telliard, 1979), and some physical properties. Results of the quality-assurance pro¬ gram used to monitor the quality of work at the NWQL are discussed in this report. Previous reports (Peart and Thomas, 1983a, 1983b, 1984; Peart and Sutphin, 1987; Lucey and Peart, 1988,1989) document results from Febru¬ ary 1981 through September 1986. Factors that need to be considered for data interpretation for this period in conjunction with the results presented in this report include the following: 1. No effort was made to correct nonanalytical errors, even when it was obvious which corrective measures were appropriate; so the data are preserved as produced by the laboratory. These errors include any made in logging the sample into the laboratory, transcription errors by the analyst, and data entry errors. Therefore, if the data reviewer in the Survey’s office that collected the sample, is capable of detecting errors of this type, the reviewer can increase the quality of the data, when compared to those data presented in this report. For example, two samples from different sites are submitted to the laboratory on the same day and are misiden- tified, in a way that the analytical data reported for one, would actually belong to the other. A data reviewer who was familiar with the site or its historical data usually could detect the problem and correct it. 2. No quality-assurance samples had any constituents redetermined except those requested by the laboratory internal quality-assurance groups. Survey data reviewers in the offices that collected the samples are ex¬ pected to scrutinize incoming new data for discrepancies and make requests for reanalysis. These requests 1 may result in the detection of analytical and nonanalytical errors, and data quality would improve, when compared to data quality presented in this report. 3. Figures included in this report may be used to determine analytical conditions at any given time for water- year 1987. Where figures show that an analytical process has been in statistical control for most of the year, but the process also has been out of statistical control for a certain period, that period may be long enough that the statistical tests applied indicate lack of precision or significant bias for the year. The data from that period when the analytical process was in control can be considered to have acceptable precision and bias. 4. Several data points seemed to be in error because of an incorrectly applied dilution factor. Dilutions of the sample are made routinely in the laboratory to bring the sample concentration into analytical range. If the dilution factor is not applied or is applied incorrectly, the reported value will be in error by the amount of the dilution factor. For example, if several analyses of a solution result in reported values of 250 mg/L each and one analysis results in a reported value of 25 mg/L, a 10X dilution may have been used and not applied to the final results. These kinds of errors are difficult to confirm. Their detection and correction in the field offices will increase the reliability of the data above that stated in this report. Non-analytical errors for nutrient analyses can result when the samples are not maintained at the ideal temperature of 4°C during shipping and receiving. During water-year 1987, the following sample categories, containing the indicated constituents in the dis¬ solved phase were included in this quality-assurance program: Inorganic constituents—alkalinity, aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, calcium, chloride, chromium, cobalt, copper, dissolved solids (residue on evaporation at 180°C), fluoride, iron, lead, lithium, magnesium, manganese, molybdenum, nickel, potassium, selenium, silica, silver, sodium, stron¬ tium, sulfate, and zinc. Nutrients—ammonia, as nitrogen; ammonia plus organic nitrogen as nitrogen; nitrite as nitrogen; nitrite plus nitrate as nitrogen; orthophosphate as phosphorus; and phosphorus. Precipitation—minute concentrations of: ammonia, as nitrogen; calcium; chloride; fluoride; magnesium; nitrate, as nitrogen; orthophosphate, as phosphorus; potassium; sodium; and sulfate. PROGRAM DESCRIPTION Standard reference water samples (SRWS’s) (Skougstad and Fishman, 1975; Schroder and others, 1980; Jan- zer, 1985) are used as the principal component of the reference samples used in this program. The SRWS’s are diluted with deionized water, mixed in varying proportions with other SRWS’s, or used undiluted. A large range of concentrations of chemical constituents is achieved, thereby increasing the number of unique samples avail¬ able for quality-assurance purposes. This increase, in turn, decreases the probability that quality-assurance sam¬ ples will be recognized in the laboratory because of frequency of analyses or unique sample characteristics. In addition to the SRWS’s, synthetic samples made from reagent-grade chemicals are used in preparing reference samples. The reference samples are prepared in the Survey’s Water Quality Service Unit in Ocala, Fla., and are made to appear as much like environmental samples as possible. When the samples are prepared and proper forms are completed to ensure that appropriate constituents have been requested for the sample, the samples and the forms are shipped to selected Survey offices across the country. These Survey offices then ship the quality-assurance samples to the NWQL on a daily or weekly basis, as appropriate, with their regular samples. The number of quality-assurance determinations requested for inorganic constituents and nutrients are in direct proportion to the total number of requests for those determinations from all sources in the laboratory. The program goal is to have at least one quality-assurance sample analyzed daily for those constituents that are ana¬ lyzed daily, and, similarly, to have an appropriate number of quality-assurance samples analyzed for those con¬ stituents determined less frequently. Natural precipitation samples were submitted once each week. All constituents in the reference materials are in the dissolved phase because the reference materials them¬ selves have been filtered in the preparation process. Therefore, those constituents in this report that are desig¬ nated as “total recoverable” are from reference samples that have undergone a digestion process (Fishman and 2 Friedman, 1985, p 87-88) during analysis, rather than from unfiltered or whole-water samples. Differences that appear in this report between the dissolved analyses and the total recoverable analyses will be due largely or entirely to the digestion process rather than from any difference in the sampling techniques or sample source. Quality-assurance samples are processed by the NWQL as routine samples, including the normal labora¬ tory quality-control and quality-assurance procedures. The data then are stored in the Survey’s National Water Data Storage and Retrieval System (WATSTORE). After being processed by the laboratory, data from these quality-assurance samples will indicate the quality of the analytical data produced for environmental samples. STATISTICAL EVALUATION The SRWS’s initially are analyzed by many laboratories throughout the United States, using several differ¬ ent analytical methods. The results are compiled by calculating the means, standard deviations, and 95-percent confidence limits and then applying a rejection routine (American Society for Testing and Materials, 1980). Re¬ sultant means are the most probably correct values or the most probable values (MPV’s). These MPV’s are used in this quality-assurance program for comparison with laboratory data. For reference samples composed of a mixture of two SRWS’s, or SRWS’s and deionized water, the MPV’s for each constituent are weight-averaged according to their respective percentage contributions to determine a new set of MPV’s for the mixture. Standard deviations were determined by using linear least squares equations developed by regressing the means of each constituent obtained from all the SRWS’s analyzed during the last seven years against the corre¬ sponding standard deviations for those constituents. This method enabled an estimation of a most probable stan¬ dard deviation (MPSD) for each constituent on a sample-by-sample basis to ascertain whether the determination in question was statistically in or out of control. An individual reported value was considered in statistical control if it was within two standard deviations of the MPV. In certain situations, the resulting equation produced a MPSD too small for the standard deviation criterion to be met. This was true for barium, cadmium, chromium, copper, fluoride, lead, lithium, molybdenum, nickel, and selenium; and also beryllium, iron, manganese and zinc when determined by atomic absorption spectrometry or total recoverable digestion. An administrative decision was made to establish a minimum standard deviation for each of these constituents equal to three-quarters of the value of the reporting level to allow at least one reportable value on each side of the MPV to be accepted. For example, the minimum standard deviation for copper reported to the nearest 10 jig/L (micrograms per liter) is set to 7.5 pg/L; the minimum standard deviation for cadmium, reported to the nearest 1 jig/L, is 0.75 pg/L. The equations for determining the most probable stan¬ dard deviation (MPSD) for each constituent and the established minimum MPSD, if any, are listed in table 1. The number of standard deviations each constituent differs from the MPV was calculated by dividing the difference of the reported value and the MPV by the MPSD. This number was used in determining precision and bias. The results for each laboratory and each constituent are shown on control charts in figures 1 through 74 in the “Supplemental Data” section of this report. Three symbols are used in figures 1 through 58 to indicate results from the lower ( +), middle (x), and upper (o) one-thirds of the potential analytical range tested in this program for inorganic constituents. This range does not necessarily correspond with the analytical capabilities of the labo¬ ratory instrumentation or methods, but rather corresponds with the analytical range tested using the available SRWS’s or other reference samples. The three parts of this range are based on the MPV’s of the quality-assur¬ ance samples and not on the reporting policy; for example, available resources limit the maximum MPV for sul¬ fate to be 377.0 mg/L (fig. 55) and still allow a correctly reported value of 380 mg/L, based on the policy to report sulfate to the nearest 10 mg/L at this concentration. Not all figures will show all three parts of the analytical range, because some flexibility is given to the Ocala, Fla., office in sample selection and because of limited con¬ centration ranges in the available SRWS’s. Results for nutrient constituents are shown in figures 59 through 64 and results for precipitation sample results are shown in figures 65 through 74. Due to the low-level concentra¬ tions of these constituents, symbols on these plots represent the entire potential analytical range tested. Points outside the range of the plots are forced to appear at the limit (dt6 standard deviations), with the actual number of standard deviations indicated adjacent to the point (see figure 1, for example). 3 Table 1. Linear least-squared equations for determining the most probable standard deviation [MPSD, most probable standard deviation; mg/L, milligrams per liter; MPV, most probable value; t, not applicable; pg/L, micrograms per liter; ICP, inductively coupled plasma emission spectrometry; AA, atomic absorption spectrometry; TOT, total recoverable; COL, colorimetry; N, nitrogen; P, phosphorus.] Constituent (dissolved except as indicated) Units Equation to determine MPSD Minimum MPSD Inorganic constituents Alkalinity mg/L (0.021 x MPV) +1.14 t Aluminum Pg/L (0.17 x MPV) + 30.4 7.5 Antimony Pg/L (0.069 x MPV) + 1.34 $ Arsenic Pg/L (0.11 x MPV) + 1.27 0.75 Barium (ICP) Pg/L (0.16 x MPV) + 7.49 0.75 Barium (AA) Pg/L (0.17 x MPV) + 26.0 75 Barium (TOT) Pg/L (0.17 x MPV) + 26.0 75 Beryllium Pg/L (0.043 x MPV) + 1.45 t Beryllium (TOT) Pg/L (0.043 x MPV) + 1.45 7.5 Boron Pg/L (0.042 x MPV) + 33.2 t Cadmium (ICP) Pg/L (0.106 x MPV) + 0.72 0.75 Cadmium (AA) Pg/L (0.106 x MPV) + 0.72 0.75 Cadmium (TOT) Pg/L (0.106 x MPV) + 0.72 0.75 Calcium (ICP) mg/L (0.040 x MPV) + 0.54 t Calcium (AA) mg/L (0.040 x MPV) + 0.54 $ Chloride mg/L (0.026 x MPV) + 0.62 t Chromium Pg/L (0.16 x MPV) + 1.49 7.5 Chromium (TOT) Pg/L (0.16 x MPV) + 1.49 7.5 Cobalt (ICP) Pg/L (0.075 x MPV) + 2.09 t Cobalt (AA) Pg/L (0.075 x MPV) + 2.09 t Cobalt (TOT) Pg/L (0.075 x MPV) + 2.09 t Copper (ICP) Pg/L (0.046 x MPV) + 3.25 7.5 Copper (AA) Pg/L (0.046 x MPV) + 3.25 0.75 Copper (TOT) Pg/L (0.046 x MPV) + 3.25 0.75 Dissolved solids mg/L (0.022 x MPV) + 7.2 t Fluoride mg/L (0.071 x MPV) + 0.01 0.05 Iron (ICP) Pg/L (0.042 x MPV) + 8.60 t Iron (AA) Pg/L (0.042 x MPV) + 8.60 7.5 Iron (TOT) Pg/L (0.042 x MPV) + 8.60 7.5 Lead (ICP) Pg/L (0.531 x MPV) - 0.16 7.5 Lead (AA) Pg/L (0.531 x MPV)-0.16 3.75 Lead (TOT) Pg/L (0.531 x MPV) - 0.16 3.75 Lithium Pg/L (0.11 x MPV) + 1.73 7.5 Lithium (TOT) Pg/L (0.11 x MPV) + 1.73 7.5 Magnesium (ICP) mg/L (0.035 x MPV) + 0.26 t Magnesium (AA) mg/L (0.035 x MPV) + 0.26 t Manganese (ICP) Pg/L (0.044 x MPV) + 2.52 t Manganese (AA) Pg/L (0.044 x MPV) + 2.52 7.5 Manganese (TOT) Pg/L (0.044 x MPV) + 2.52 7.5 Molybdenum (ICP) Pg/L (0.081 x MPV) + 4.21 7.5 Molybdenum (AA) Pg/L (0.081 x MPV) + 4.21 0.75 4 Table 1. Linear least-squared equations for determining the most probable standard deviation. —continued Constituent (dissolved except as indicated) Units Equation to determine MPSD Minimum MPSD Inorganic constituents Nickel (ICP) Pg/L (0.109 x MPV) + 4.52 7.5 Nickel (AA) Pg/L (0.109 x MPV) + 4.52 4 Nickel (TOT) Fg/L (0.109 x MPV) + 4.52 7.5 Potassium mg/L (0.075 x MPV) + 0.07 4 Selenium Hg/L (0.347 x MPV) - 0.30 0.75 Silica (ICP) mg/L (0.038 x MPV) + 0.53 $ Silica (COL) mg/L (0.038 x MPV) + 0.53 4 Silver (ICP) Pg/L (0.260 x MPV) + 1.06 0.75 Silver (AA) Fg/L (0.260 x MPV) + 1.06 0.75 Silver (TOT) M-g/L (0.260 x MPV) + 1.06 0.75 Sodium (ICP) mg/L (0.032 x MPV) + 0.23 4 Sodium (AA) mg/L (0.032 x MPV) 4- 0.23 4 Strontium Fg/L (0.039 x MPV) + 9.30 4 Sulfate mg/L (0.045 x MPV) + 1.20 4 Zinc (ICP) M-g/L (0.039 x MPV) + 4.39 4 Zinc (AA) M-g/L (0.039 x MPV) + 4.39 7.5 Zinc (TOT) Pg/L (0.039 x MPV) + 4.39 7.5 Nutrient constituents Ammonia nitrogen, as N mg/L (0.10 x MPV) + 0.035 4 Ammonia plus organic mg/L (0.601 x MPV) - 0.06 4 nitrogen, as N Nitrate plus nitrite mg/L (0.038 x MPV) + 0.034 4 nitrogen, as N Nitrate nitrogen, as N mg/L (0.07 x MPV) + 0.003 4 Orthophosphate mg/L (0.057 x MPV) + 0.009 4 phosphorus, as P Phosphorus, as P mg/L (0.076 x MPV) + 0.007 4 Constituents in precipitation samples Calcium mg/L (0.065 x MPV) + 0.05 4 Chloride mg/L (0.073 x MPV) + 0.20 4 Fluoride mg/L (-.08 x MPV) + 0.031 4 Magnesium mg/L (0.038 x MPV) + 0.014 4 Ammonia nitrogen, as N mg/L (0.32 x MPV) + 0.008 4 Nitrate nitrogen, as N mg/L (0.23 x MPV) + 0.018 4 Orthophosphate mg/L (0.064 x MPV) + 0.008 4 phosphorus, as P Potassium mg/L (0.10 x MPV) + 0.02 4 Sodium mg/L (0.044 x MPV) + 0.04 4 Sulfate mg/L (0.037 x MPV) + 0.035 4 Precision and bias are determined by applying binomial-probability-distribution equations to the data using procedures described by Friedman, Bradford, and Peart, (1983); and by Peart and Thomas, (1983a). When preci¬ sion is determined using these procedures, it contains an element of bias because MPV’s, rather than analyzed 5 means, are used as the basis for determining the number of standard deviations each constituent deviates from that value. Therefore, in this analysis, precision, or lack of it, is based on whether or not the analytical process was statistically in or out of control (±2 standard deviations from the theoretical value). Calculation of means and relative standard deviations (Miller and Freund, 1977) were made for each major constituent with sufficient data. Because standard deviations may vary proportionally as constituent concentra¬ tion in chemical analyses varies, these calculations were done separately for individual sample mixtures; there¬ fore, they do not result in overall evaluations of the analytical processes. Relative standard deviations for inor¬ ganic, nutrient, and precipitation constituents were calculated and plotted as a percent against their mean con¬ centrations (figs. 75 through 148 in the “Supplemental data” section of this report). These plots allow a data re¬ viewer to estimate the error at any concentration shown for all constituents. For example, the precision of the alkalinity values from the NWQL are estimated to be ±2 percent from figure 75. To allow the precision charts to be used to estimate an expected error from the analytical results, outliers were deleted from the data set. An outlier was defined as being greater than 6 or less than -6 standard deviations from the MPV. The total number of analyses for each constituent processed during the water-year, the number of analyses with standard deviations greater than 2 or less than -2 from the MPV, and the number of analyses with standard deviations greater than 6 or less than -6 from the MPV are listed in table 2. If the relative standard deviation for a given mix has a value of zero, the data point will plot on the horizontal axis, as in figure 80. Because of an insufficient supply of SRWS’s for nutrients, most of the reference materials were made from reagent-grade chemicals in the Ocala, Fla., office. Preparation methods used for these samples were virtually the same as those used for preparing samples for the SRWS program. Precipitation samples were SRWS’s initially prepared from natural matrix materials (Janzer, 1985). Table 2. Total number of analyses from quality-assurance samples during water-year 1987 [ > 2SD, number of analyses greater than 2 or less than -2 standard deviations from the most probable value; >6SD, number of analyses greater than 6 or less than -6 standard deviations from the most probable value; ICP, inductively coupled plasma emission spectrometry; AA, atomic absorption spectrometry; TOT, total recoverable; COL, colorimetry; N, nitrogen; P, phosphorus.] Constituent (dissolved Number of analyses Constituent (dissolved Number of analyses except as indicated) Total > 2SD > 6SD except as indicated) Total > 2SD > 6SD Inorganic constituents Alkalinity 279 3 3 Chloride 300 44 4 Aluminum 173 1 1 Chromium 216 20 3 Antimony 9 0 0 Chromium (TOT) 36 5 1 Arsenic 211 1 0 Cobalt (ICP) 246 5 1 Barium (ICP) 240 0 0 Cobalt (AA) 19 0 0 Barium (AA) 19 0 0 Cobalt (TOT) 36 1 0 Barium (TOT) 36 0 0 Copper (ICP) 246 0 0 Beryllium 128 4 0 Copper (AA) 52 5 2 Beryllium (TOT) 17 0 0 Copper (TOT) 36 5 2 Boron 156 0 0 Dissolved solids 272 18 1 Cadmium (ICP) 246 1 0 Fluoride 299 10 8 Cadmium (AA) 52 1 0 Iron (ICP) 240 18 0 Cadmium (TOT) 36 1 0 Iron (AA) 52 7 1 Calcium (ICP) 220 11 0 Iron (TOT) 31 10 1 Calcium (AA) 61 6 3 Lead (ICP) 246 1 0 6 Table 2. Total number of analyses from quality-assurance samples during water-year 1987 —continued Constituent (dissolved Number of analyses Constituent (dissolved Number of analyses except as indicated) Total > 2SD > 6SD except as indicated) Total > 2SD > 6SD Lead (AA) 53 1 0 Potassium 280 9 4 Lead (TOT) 36 1 0 Selenium 177 8 0 Lithium 240 1 0 Silica (ICP) 220 3 2 Lithium (TOT) 17 1 1 Silica (COL) 80 4 2 Magnesium (ICP) 220 7 0 Silver (ICP) 163 1 0 Magnesium (AA) 61 2 2 Silver (AA) 20 0 0 Manganese (ICP) 240 4 0 Silver (TOT) 36 2 2 Manganese (AA) 52 1 1 Sodium (ICP) 220 2 0 Manganese (TOT) 36 4 1 Sodium (AA) 63 3 1 Molybdenum (ICP) 240 1 0 Strontium 240 1 0 Molybdenum (AA) 33 1 0 Sulfate 300 17 2 Nickel (ICP) 163 0 0 Zinc (ICP) 240 79 17 Nickel (AA) 52 0 0 Zinc (AA) 52 8 1 Nickel (TOT) 36 2 1 Zinc (TOT) Nutrient constituents 36 6 4 Ammonia nitrogen, as N 706 37 5 Nitrite nitrogen, as N 327 21 4 Ammonia + organic nitrogen, as N 702 17 7 Orthophosphate, as P 358 79 35 Nitrate + nitrite nitrogen, as N 766 90 7 Phosphorus, as P 745 160 82 Constituents in precipitation samples Calcium 39 2 0 Nitrate nitrogen, as N 34 0 0 Chloride 35 0 0 Phosphorus, as P 8 0 0 Fluoride 35 4 1 Potassium 39 0 0 Magnesium 39 2 0 Sodium 39 3 2 Ammonia nitrogen, as N 16 0 0 Sulfate 36 4 1 QUALITY-ASSURANCE DATA FOR INORGANIC-CONSTITUENT SAMPLES Precision The results of statistical testing for lack of precision for each inorganic constituent are presented in table 3. For each constituent, this table indicates significant lack of precision at the 95 percent confidence level (indicated by “LOP”) as well as all acceptable results (indicated by “ + ”). Evaluating the data for the year, chloride; chromium; iron, total recoverable; zinc (ICP); zinc (AA); and zinc, total recoverable, indicated LOP in the NWQL. Chloride; iron, total recoverable; zinc (ICP); zinc (AA); and zinc, total recoverable, all failed the precision criteria in the NWQL during water-year 1986 (Lucey and Peart, 1989) and again in 1987. Only iron, total recoverable, and zinc (ICP) have failed the precision criteria at the NWQL during each of the last three years (Lucey and Peart, 1988, 1989) In the NWQL during water-year 1987, iron (ICP), selenium, and sodium (AA) had acceptable results after failing the precision tests during water-year 1986 (Lucey and Peart, 1989). 7 Table 3. Results of statistical testing for lack of precision in inorganic constituent data [ + , acceptable results; ICP, inductively coupled plasma emission spectrometry; AA, atomic absorption spectrometry; TOT, total recoverable; LOP, significant lack of precision; COL, colorimetry] Constituent (dissolved, except as indicated Results from Oct. 1986- Sept. 1987 Constituent (dissolved, except as indicated) Results from Oct. 1986- Sept. 1987 Constituent (dissolved, except as indicated) Results from Oct. 1986- Sept. 1987 Alkalinity . .-1- Cobalt (TOT). . -1- Molybdenum (AA) .+ Aluminum . .+ Copper (ICP) . . + Nickel (ICP). .+ Antimony. .+ Copper (AA). . + Nickel (AA). .+ Arsenic. .+ Copper (TOT) .... . + Nickel (TOT). .+ Barium (ICP). .+ Dissolved solids ... . + Potassium. .-1- Barium (AA). .+ Fluoride. . + Selenium . .+ Barium, (TOT) ... .+ Iron (ICP). . + Silica (ICP). .+ Beryllium . .+ Iron (AA) . . + Silica (COL). .+ Beryllium (TOT) .. .-1- Iron (TOT) . .... LOP Silver (ICP) . .+ Boron . .+ Lead (ICP) . . + Silver (AA). .+ Cadmium (ICP) ... .+ Lead (AA). . + Silver (TOT) . .-1- Cadmium (AA) ... .+ Lead (TOT) . . + Sodium (ICP). .+ Cadmium, (TOT) . .+ Lithium . . + Sodium (AA). .+ Calcium (ICP) .... .+ Lithium (TOT)_ . + Strontium. .+ Calcium (AA) .... .+ Magnesium (ICP).. . + Sulfate . .+ Chloride . .... LOP Magnesium (AA) .. . + Zinc (ICP) . .LOP Chromium . .... LOP Manganese (ICP) .. . + Zinc (AA) . .LOP Chromium (TOT) . . + Manganese (AA) .. . + Zinc (TOT) . .LOP Cobalt (ICP). . + Manganese (TOT) . . + Cobalt (AA) . . + Molybdenum (ICP) . + Bias Results of the statistical tests for bias are shown in table 4. There were fewer constituents indicating bias for water-year 1987 than for water-year 1986 at theNWQL (Luceyand Peart, 1989). Constituents that showed nega¬ tive bias for water-years 1987 and 1986 were: antimony, barium (ICP), beryllium, boron, dissolved solids, potas¬ sium, and strontium. In addition, aluminum; magnesium (AA); nickel (AA); nickel, total recoverable; and silver (ICP) had negative bias during water-year 1987. Positively biased constituents for water-years 1987 and 1986 were: arsenic; barium (AA); barium, total re¬ coverable; chromium; iron (ICP); magnesium (ICP); molybdenum (ICP); selenium; silica (ICP); sodium (ICP); sulfate; and zinc (ICP). Additional positively biased constituents that did not have a positive bias during water- year 1986 were: alkalinity; cadmium (AA); lead (ICP); lithium; silver, total recoverable; and zinc (AA). There were no predominant patterns for bias between dissolved versus total recoverable analyses or be¬ tween ICP and AA determinations. For barium (AA); barium, total recoverable; chromium; lead (ICP); and lead (AA) an apparent biased condition occurred because the minimum reporting levels (barium, 100 pg/L; chromium, 10 pg/L; lead (ICP) 10 pg/L; and lead (AA), 5 pg/L) were greater than the MPV’s. Results for barium (ICP), boron, and potassium indicated a negative bias for each of the last three water- years (1985, 1986, and 1987). During this same period, barium (AA); barium, total recoverable; chromium; magne¬ sium (ICP); selenium; silica (ICP); sodium (ICP); sulfate; and zinc (ICP) have all had positively biased results (Lucey and Peart, 1988, 1989) 8 Table 4. Results of statistical testing for bias in inorganic constituent data [P, positive bias; N, negative bias; ICP, inductively coupled plasma emission spectrometry; AA, atomic absorption spectrometry; TOT, total recoverable; +, acceptable results; COL, colorimetry] Constituent (dissolved, except as indicated Results from Oct. 1986- Sept. 1987 Constituent (dissolved, except as indicated) Results from Oct. 1986- Sept. 1987 Constituent (dissolved, except as indicated) Results from Oct. 1986- Sept. 1987 Alkalinity. .P Cobalt (TOT). .+ Molybdenum (AA). . + Aluminum . .N Copper (ICP). .+ Nickel (ICP). . + Antimony. .N Copper (AA) . .+ Nickel (AA). . N Arsenic. .P Copper (TOT). .+ Nickel (TOT) . . N Barium (ICP). .N Dissolved solids .... .N Potassium . . N Barium (AA). .P 1 Fluoride . .P Selenium. .P Barium (TOT) .... .P 1 Iron (ICP). .P Silica (ICP). .P Beryllium. .N Iron (AA). .+ Silica (COL). . + Beryllium (TOT).. .-1- Iron (TOT). .+ Silver (ICP). . N Boron . .N Lead (ICP). .P 1 Silver (AA). . + Cadmium (ICP) ... .+ Lead (AA) . .P 1 Silver (TOT). .P Cadmium (AA) ... .P Lead (JOT). .+ Sodium (ICP). .P Cadmium (TOT) .. .+ Lithium. .P Sodium (AA). . + Calcium (ICP) .... .+ Lithium (TOT) _ .+ Strontium . . N Calcium (AA) .... .+ Magnesium (ICP) .. .P Sulfate. .P Chloride. .+ Magnesium (AA) ... .N Zinc (ICP). .P Chromium. .P 1 Manganese (ICP) .. . + Zinc (AA) . .P Chromium (TOT) . . + Manganese (AA) ... . + Zinc (TOT). . + Cobalt (ICP) . . + Manganese (TOT) . . + Cobalt (AA) . . + Molybdenum (ICP) . . P ^ias occurs because some most probable values are less than the lowest reporting limit. The control chart for dissolved solids for the NWQL (fig. 25) shows a definite positive bias in the first month of the water-year with several data points greater than plus two standard deviations from the MPV. These results are a continuation of a trend that began in the last month of water-year 1986 (Lucey and Peart, 1989). However, the results returned to an unbiased condition after the first month of the 1987 water-year. There are several analyses clustered between three and four standard deviations from the MPV for iron (ICP) during the month of October (fig. 27). This could be due to contamination of the samples during prepara¬ tion prior to analysis at the NWQL. This uncertainty could be resolved if comparable data had been available from two laboratories instead of only one. The control chart for lithium (fig. 33) indicates an abrupt change from a positive to a negative bias in the last three months of water-year 1987. This likely is due to an error in the preparation of standards in the laboratory or an error in calibration of the instruments. The lack of data for March and April on the control charts for boron (fig. 10), calcium (AA) (fig. 15), magne¬ sium (AA) (fig. 36), silica (COL) (fig. 48), and sodium (AA) (fig. 53) indicates that the reference samples were not analyzed at the NWQL during those months. These samples were misplaced in transit between the Ocala office and the NWQL. The patterns of clustered points on the control charts for chromium (fig. 17), lead (ICP) (fig. 30), molybde¬ num (ICP) (fig. 40), and silver (AA) (fig. 50) are due to variations in concentrations of the constituent in the SRWS 9 mixes and the minimum standard deviation that was established in certain situations (such as low concentrations) equal to three-fourths of the value of the reporting level. Several factors may have affected the results for other constituents that indicated occasional bias; the fac¬ tors may include deterioration of standard calibrating solutions or reagents, improper or inaccurate reagent or standard-solution preparation, undetected problems with analytical instrumentation, undefined matrix effects caused by mixing together two very different SRWS’s, reporting levels being higher than the MPV’s, or unde¬ tected contamination. When bias is indicated statistically but precision is good, the bias may have minimal effect on data interpretation and minimal practical significance. QUALITY-ASSURANCE DATA FOR NUTRIENT-CONSTITUENT SAMPLES Precision The results of statistical testing for lack of precision for each nutrient constituent are presented in table 5. Results for nitrate + nitrite nitrogen as N, orthophosphate as phosphorus, and phosphorus failed the precision test at the NWQL in water-year 1987. All nutrient constituents had passed the precision test during water-year 1986 (Lucey and Peart, 1989). Table 5. Results of statistical testing for lack of precision in nutrient constituent data [N, nitrogen; +, acceptable results; LOP, lack of precision; P, phosphorus] Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Ammonia nitrogen, as N .. + Ammonia + organic .+ nitrogen, as N Nitrite + nitrate ... nitrogen, as N Nitrite nitrogen, as N .... LOP Orthophosphate, as P Phosphorus, as P .... ... LOP ... LOP Bias Results of the statistical tests for bias are presented in table 6. Only results for ammonia + organic nitrogen as nitrogen indicated a positive bias, while the results for the other nutrient constituents did not indicate bias. During water-year 1986, ammonia as nitrogen indicated a negative bias, while nitrate plus nitrite as nitrogen and nitrite as nitrogen indicated a positive bias (Lucey and Peart, 1989). Table 6. Results of statistical testing for bias in nutrient constituent data [N, nitrogen; +, acceptable results; p, positive bias; P, phosphorus] Constituent Results from (dissolved) Oct. 1986- Sept. 1987 Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Ammonia nitrogen, as N .. + Nitrite + nitrate . .+ Orthophosphate, as P_ + Ammonia 4- organic .p nitrogen, as N Phosphorus, as P .. . + nitrogen, as N Nitrite nitrogen, as N _+ QUALITY-ASSURANCE DATA FOR PRECIPITATION SAMPLES The results for statistical testing for lack of precision and bias for each constituent in the precipitation and simulated-precipitation samples are presented in tables 7 and 8, respectively. Results for all of the constituents in 10 the precipitation samples indicated acceptable precision for water-year 1987, as they did in water-year 1986. Re¬ sults for sodium indicate a positive bias. In water-year 1986, results for ammonia as nitrogen, magnesium, and potassium indicated negative bias and results for fluoride indicated a positive bias (Lucey and Peart, 1989). Table 7. Results of statistical testing for lack of precision in precipitation constituent data [N, nitrogen; +, acceptable results; P, phosphorus] Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Ammonia nitrogen, as N .. + Magnesium . .... + Potassium . . + Calcium . .+ nitrogen, as N Sodium. . + Chloride. .+ Nitrite nitrogen, as N .... + Sulfate. . + Fluoride. .+ Phosphorus, as P ... .+ Table 8. Results of statistical testing for bias in precipitation constituent data [N, nitrogen; +, acceptable results; P, phosphorus; p, positive bias] Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Constituent (dissolved) Results from Oct. 1986- Sept. 1987 Ammonia nitrogen, as N .. + Magnesium. .... + Potassium. .+ Calcium . .+ nitrogen, as N Sodium. . P Chloride. .+ Nitrite nitrogen, as N .... + Sulfate . .+ Fluoride . .+ Phosphorus, as P ... .... + SUMMARY AND CONCLUSIONS Reference water samples that had known MPV’s were disguised as regular samples and submitted with envi¬ ronmental water samples by selected offices of the Survey to the National Water-Quality Laboratory in Denver, Colo. The resulting data were stored in WATSTORE. Data for inorganic constituents, nutrient constituents, and constituents in precipitation samples then were analyzed statistically for precision and bias by using a binomial- probability-distribution equation. An overall evaluation of the data for water-year 1987 indicates a lack of precision in results from the NWQL for chloride; chromium; iron, total recoverable; zinc (ICP); zinc (AA); and zinc, total recoverable. Chloride; iron, total recoverable; zinc (ICP); zinc (AA); and zinc, total recoverable, failed the precision crite¬ ria in the NWQL for water-years 1987 and 1986. Only iron, total recoverable, and zinc (ICP) have failed the preci¬ sion criteria during each of the last three years (Lucey and Peart, 1988, 1989) An overall evaluation of the data for water-year 1987 indicates a significant bias in results from the NWQL for alkalinity; antimony; arsenic; barium (ICP); barium (AA); barium, total recoverable; beryllium; boron; cad¬ mium (AA); chromium; dissolved solids; fluoride; iron (ICP); lead (ICP); lead (AA); lithium; magnesium (ICP); 11 magnesium (AA); molybdenum (ICP); nickel (AA); nickel, total recoverable; potassium; selenium; silica (ICP); silver, total recoverable; sodium (ICP); strontium; sulfate; zinc (ICP); and zinc (AA). Fewer constituents had biased results in water-year 1987 than in water-year 1986 at the NWQL. Constitu¬ ents having negative bias for water-years 1986 and 1987 were: antimony, barium (ICP), beryllium, boron, dis¬ solved solids, potassium, and strontium. Constituents having positively biased results for water-years 1986 and 1987 were: arsenic; barium (AA); barium, total recoverable; chromium; iron (ICP); magnesium (ICP); molybde¬ num (ICP); selenium; silica; sodium (ICP); sulfate; and zinc (ICP). Results for barium (ICP), boron, and potassium have indicated a negative bias for each of the last three years, while barium (AA); barium, total recoverable; chromium; magnesium (ICP); selenium; silica (ICP); sodium (ICP); sulfate; and zinc (ICP) have indicated positive bias during the same period (Lucey and Peart, 1988, 1989). For nutrient constituents, results for nitrate + nitrite nitrogen as N, orthophosphate as P, and phosphorus failed the precision test at the NWQL during water-year 1987. Results for ammonia + organic nitrogen as N indicate a positive bias. Results for all constituents in precipitation samples indicate acceptable precision. Results for sodium indi¬ cate a positive bias. 12 REFERENCES American Society for Testing and Materials, 1980, Annual book of ASTM standards, part 41: Philadelphia, p. 206-232. Fishman, M.J., and Friedman, L.C., 1985, Methods for determination of inorganic substances in water and fluvial sediments: Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 5, Chapter Al, Open-File Report 85-496, 709 p. Friedman, L.C., Bradford, W.L., and Peart, D.B., 1983, Application of binomial distributions to quality-assurance of quantitative chemical analyses: Journal of Environmental Science and Health, v. A18, no. 4, p. 561-570. Janzer, V.J., 1985, The use of natural waters as U.S. Geological Survey reference samples, in Thylor, J.K., and Stanley, T.W., eds.Quality assurance for environmental measurements, ASTM STP 867: American Society for Testing and Materials, Philadelphia, p. 319-333. Keith, L.H., and Telliard, W.A., 1979, Priority pollutants, I.—A perspective view: Environmental Science and Technology, v. 13 no. 4, p. 416-423. Lucey, K.J., and Peart, D.B., 1988, Quality-assurance data for routine water analysis in the laboratories of the U.S. Geological Survey for water-year 1985: U.S. Geological Survey Water-Resources Investigations Re¬ port 88-4109,121 p. -1989, Quality-assurance data for routine water analysis in the laboratories of the U.S. Geological Survey for water-year 1986: U.S. Geological Survey Water-Resources Investigations Report 89-4009,145 p. Miller, Irwin, and Freund, J.E., 1977, Probability and statistics for engineers (2d. ed.): Englewood Cliffs, New Jersey, Prentice-Hall, Inc., 529 p. Peart, D.B., and Sutphin, H.B. 1987, Quality-assurance data for routine water analysis in the laboratories of the U.S. Geological Survey for water-year 1984: U.S. Geological Survey Water-Resources Investigations Re¬ port 87-4077, 125 p. Peart, D.B., and Thomas, Nancy, 1983a, Quality-assurance data for routine water analysis in the laboratories of the U.S. Geological Survey—1981 annual report: U.S. Geological Survey Water-Resources Investigations Report 83-4090, 112 p. -1983b, Quality-assurance data for routine water analysis in the laboratories of the U.S. Geologi¬ cal Survey for water-year 1982: U.S. Geological Survey Water-Resources Investigations Report 83-4264, 112 p. -1984, Quality-assurance data for routine water analysis in the laboratories of the U.S. Geological Survey for water-year 1983: U.S. Geological Survey Water-Resources Investigations Report 84-4234, 112 p. Schroder, L.J., Fishman, M.J., Friedman, L.C., and Darlington, G.W., 1980, The use of standard reference water samples by the U.S. Geological Survey: U.S. Geological Survey Open-File Report 80-738, lip. Skougstad, M.W., and Fishman, M.J., 1975, Standard reference water samples: American Water Works Asso¬ ciation Water Quality Technology Conference, Dallas, 1974, Proceedings, p. XIX-1 -XIX-6. 13 14 SUPPLEMENTAL DATA 15 NUMBER OF STANDARD DEUIATIONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 6 5 4 3 2 l 0 -I -2 -3 -4 -5 -6 CONCENTRATION, IN MILL I GRANS PER LITER + = 8.4 - 87 ■ X = 87 - 166 o = 166 - 245 — + ' .*+ + +4H- 44 + + + + X X + -*+#• +4W- 8 4+ +H4 + 8rf> ° O +44- ++ + § + + + +4 +^S?XX "+ TT -F- -H-+ + + * * 22 $ + ++ + + 44 *88 + CD O O ***-*XX + + ■»+ >< ^>5: x 10CT 1986 1NOU 1986 IDEC 1986 1JAN 1987 inRR 1987 1NRY 1987 1JUN 1987 1JUL 1987 1RUG 1987 1SEP 1987 l OCT 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 1.—Alkalinity, dissolved, data from the National Uater Quality Laboratory. 10CT 1N0U 1986 1986 IDEC IJRN l FEB tflRR 1RPR lflRY UUN IJUL 1RUG l SEP l OCT 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 2.—Aluminum, dissolved, data from the National Uater Quality Laboratory. 17 NUMBER OF STANDARD DEUIATIONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 6 CDNCENTRRT ION, IN T 1 — -7- -7- -1- -7-"!- 5 fllCROGRRnS PER LITER '+ = 1.0 - 1.2 - x = 1.2- 1.4 4 ■ o = 1.4— 1.6 3 - 2 1 O - 0 + + + ++ l ' 2 3 - 4 • 5 - c - - 1— 1— Lmm -L. L— ■ . 1— -u _L— L. 1 OCT 1986 1MOU 1986 IDEC 1986 1JRN 1987 1FEB 1987 inflR 1987 l RPR 1987 inflY 1987 1JUN 1987 1JUL 1987 1RUG 1987 1SEP 1987 IOCT 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 3.—Antimony, dissolved, data from the National Uater Quality Laboratory. 6 5 4 3 2 l 0 -1 -2 -3 -4 -5 -6 concentration, IN fllCROGRRnS PER LITER + = 0.5- 2.4 x = 2.4 - 4.3 o = 4.3— 6.2 x x< x ac TOT" o + + + ♦ + * + +*+♦+ >X X XX * o *** o oo + IOCT 1986 1N0U 1986 IDEC 1986 IJRN 1987 1FEB 1987 inRR 1987 1RPR 1987 inRY 1987 1JUN 1987 1JUL 1987 lflUG 1987 1SEP 1987 IOCT 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 4.—Arsenic, dissolved, data from the National Uater Quality Laboratory. 18 NUMBER OF STANDARD DEUIATIONS NUMBER OF STANDARD DEU[AT TONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE lOCT 1NOU 1DEC 1JAN 1FEB lflAR 1APR 1NAY 1JUN 1JUL lfiUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 5.—Barium, dlssolued, (InductIuely coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. 6 5 4 3 2 1 0 -l -2 -3 -4 -5 -6 CONCENTRATION, IN T.T' " —!- 1 ' H . T— ” 1 1 niCROGRANS PER LITER '+ = 22,8 - 32,2 x = 32,2 - 41,6 ■o = 41,6 — 51,1 - - o o o o O O o ooo o o oo o oo ■ - ■ » _L- L. _ 1 OCT 1986 IMOU 1986 1DEC 1986 l JAN 1987 1FEB 1987 inflR 1987 1 APR 1987 inAY 1987 1JUM 1987 1JUL 1987 1 AUG 1987 1SEP 1987 10CT 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 6.—Barium, dlssolued, (atomic absorption spectrometry) data from the National Uater Quality Laboratory. 19 NUMBER OF STANDARD DEUIATIONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 6 CONCENTRATION, IN "T ’ ■- .T- -1- -1— -T-1- -1-1- nlCROGRANS PER LITER 5 '+ = 22.8 - 68.5 x = 68.5 - 114 4 - o = U4 - 160 “ 3 - 2 O 1 - XX XX X X xxxx . OO X X 0 X 0 XX X X< X XX 0 1 X X X X X X - 2 3 - 4 - 5 - C —1- \ - -L. 1- - \ - -fc—, fc— _L. 1— ■ 1 OCT 1986 1MOU 1986 IDEC 1986 1JRN 1987 1FEB 1987 inflR 1987 l APR 1987 mflv 1987 1JUN 1987 1JUL 1987 1RUG 1987 1SEP 1987 IOCT 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 7.—Barium, total recoverable, data from the National Uater Quality Laboratory. 6 5 4 3 2 1 0 -l -2 -3 -4 -5 -6 CONCENTRATION, IN niCROGRAdS PER LITER + = 4.6 - 17.6 * x = 17.6 - 30.6 -o = 30.6 - 43.7 “ . _ -r "" ++ h+ + ++ * + + + + + +J nm 4 -l -l + + + + J -H- + i + + + + ♦ *4t\ * ***** + + + + 10CT 1986 1N0U 1986 IDEC 1986 1 JAN 1987 1FEB 1987 ltlAR 1987 1 APR 1987 inAY 1987 1JUN 1987 1JUL 1987 1 AUG 1987 ISEP 1987 IOCT 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 8.—Beryllium, dissolved, data from the National Uater Quality Laboratory. 20 NUMBER OF STANDARD DEUIAT IONS NUMBER OF STANDARD DEUIAT TONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 6 6 4 3 2 l 0 -1 -2 -3 -4 -5 -6 CONCENTRATION, IN niCROGRAnS PER LITER ■+ = 25.4 - 37.2 x = 37.2 - 49.0 • o = 49.0 - 60.9 _ - + + 4+ + - ooo o o o o o o o 10CT INOU 1986 1986 IDEC 1986 1 JAN 1987 1FEB 1987 lflAR 1987 1 APR 1987 l HAY 1987 1JUN 1987 UUL 1987 1AU6 1987 1SEP 1987 1 OCT 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 9.—Beryllium, total recoverable, data from the National Uater Quality Laboratory, 10CT INOU IDEC l JAN 1FEB lflAR IAPR 1CIAY UUN 1JUL IAU6 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 10.—Boron, dissolved, data from the National Uater Quality Laboratory. 21 NUMBER OF STANDARD DEUIAT IONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE l OCT 1MOU 1DEC 1JRN 1FEB 1NRR 1RPR inflY 1JUN 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 11.—Cadmium, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. 6 S 4 3 2 1 0 -1 -2 -3 -4 -5 -6 l OCT INOU 1 DEC 1JRN 1FEB 1HRR 1RPR 1HRY 1JUN 1JUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 12.—Cadmium, dissolved, (atomic absorption spectrometry) data from the National Uater Quality Laboratory. 22 NUMBER OF STflNBRRD DEUIRTIONS NUMBER OF STRNBRRB DEUIRTIONS FROM THEORETICRL URLUE FROM THEORETICRL URLUE 10CT 1NOU 1DEC 1JAN 1FEB 1MAR l APR inflY 1JUN 1JUL 1AUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMFLE URS LOGGED INTO LRBORRTORV Figure 13.—Cadmium, total recoverable, data from the National Uater Quality Laboratory. D 5 4 3 2 1 0 -l -2 -3 -4 -5 -6 CONCENTRATION, IN flILLIGRANS PER LITER '+ = 8.4 - 39.0 x = 39.0 - 70.0 ■o = 70.0 - 101 ■ + jj; X + o + + x + + +++* + ++-£ -H- ° ^ f 1 Iftfl 1 ' Hf+ + ++ " tV - + *** # + *° ° V.-H- .. X + ++ + * o°o B 8 ** °o * X ++ +++ o ++ O o O o 4 I 1 1- + X + XXXX -HH _i_i_i_ 1 OCT INOU 1DEC 1 JAM IFEB 1MAR IAPR 1MAY IJUN 1JUL IAUG ISEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMFLE URS LOGGED INTO LRBORRTORY Figure 14.—Calcium, dissolved, ^ + + ° ° x Mh? t + + 8,9 ... .. « x fX * -T ++ + H + St + + = XX * *F + --H-+ 0 '' + + 6 + ? X x ° ° + + + + ° X + x 8 F o + XX X XX o X 0 x -H- + H + •♦**■*«*- 9.x*vy ** x * o o X X -7.8 -6.5 -■*- L -o— -T+- —1--t-1-1---1- 6.8 6.8 37. A o o o u OP o O X o o COhCEhTRflTI Oh, Ih niLLlGRflhS PER LITER + = 5.7 - 25.0 x = 25.0 - 44.0 o = 44.0 — 63.I o o o + -tf+ ~o -S-[J— o oo 24 HUMBER OF STANDARD DEUIAT TONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 6 5 4 3 2 1 0 -l -2 -3 -4 -5 -G 10CT 1MOU 1DEC 1JFIN 1FEB IHAR 1APR lflRY 1JUN 1JUL 1AU6 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 17.—Chromium, dissolved, data from the National Uater Quality Laboratory. 6 5 4 3 2 l 0 -1 -2 -3 -4 -5 -6 IOCT 1MOU 1DEC lJflli 1FEB IHAR IflPR 1HAY 1JUIT lJUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 18.—Chromium, total recoverable, data from the National Uater Quality Laboratory. COACEATRATI ON , IA 1 1 - - i - i - i - -1-1- niCROGRAnS PER LITER O '+ = 2.6 - 11.9 x = 11.9 - 21.3 - o = 21.3 - 30.4 o X XX O -++ + + + + + + +f + + ++ X X X X -CTO-O- X X + + + -__ L. 1— — . 1— i— _1. 1-L-- L - _ " I . ^ T ~ 7.5 i » i 7.6 '1 '- T - 6.2 js x>*< X XX* + + XX #4 .+ $ +++ 44 * 4 ^ -H- + ^r + + COMCENTRATioa, ia niCROGRAnS PER LITER = 1.1 - 10.9 X = 10.9 - 20.7 o = 20.7 -30.4 25 NUMBER OF STRNDRRD DEUIRTIONS NUMBER OF STRNBRRB BEUIRTIONS FROM THEORETICRL URLUE FROM THEORETICRL URLUE 6 S 4 3 2 1 0 -l -2 -3 -4 -5 -6 COMCEhTRflT IOn, TfT niCROGRflnS PER LITER + = 1.2 - 4.5 ■ X = 4.5 - 7. 8 O o = 7.8 - 11.2 O - x + + X X +M-+ X -X-X-X- -H- + + + ++ X -H- 4H- + + + + + + + + + •«<*- + + X X — K*t- x X —oar¬ s’ 0 ++H- + HH-tf + + ++tf + ++ 4f + ++ + + + + + + isir 1 OCT 1986 1NOU 1986 IDEC 1986 UflN 1987 1FEB 1987 lHFiR 1987 lflPR 1987 lHflY 1987 1JUM 1987 1JUL 1987 lflUG 1987 1SEP 1987 1 OCT 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 19.—Cobalt, dlssolued, (Induct Iuely coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. I OCT 1N0U IDEC lJflM IFEB IHflR lflPR mflY 1JUM 1JUL 1RUG 1SEP tOCT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 20.—Cobalt, dlssolued, (atomic absorption spectrometry) data from the National Uater Quality Laboratory. 26 NUMBER OF STANDARD DEUIA7I0NS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE IOCT 1NOU 1DEC URN 1FEB 1NRR lflPR 1HRY 1JUN 1JUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 21.—Cobalt, total recoverable, data from the National Uater Quality Laboratory. IOCT 1N0U l DEC 1JRN IFEB 1HRR 1RPR l DRY 1JUN 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 22.—Copper, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. 27 NUMBER OF STRNDRRD DEUIRTIONS NUMBER OF STRNBRRB DEUIRTIONS FROM THEORETICRL URLUE FROM THEORETICRL URLUE 6 5 4 3 2 1 0 -l -2 -3 -4 -5 -6 1 OCT irsou 1DEC 1JFIM 1FEB IHRR 1RPR inRY 1JUN 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMFLE URS LOGGED INTO LRBORRTORY Figure 23.—Copper, dissolved, (atomic absorption spectrometry) data from the National Uater Quality Laboratory. 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 1 OCT 1R0U 1 DEC URN l FEB IHRR 1RPR 1HRY 1JUN 1JUL IRUG 1SEP IOCT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 24.—Copper, total recouerable, data from the National Uater Quality Laboratory. 28 CONCENTRATION, IN (11 CROGRRHS PER LITER ’+ = 9.6 - 52.5 x = 52.5 - 95.3 -o = 95.3 - 138 -1-i- + -1- -1-1-- 1 T- - 1- - o " + - + + V ■ o o + ++ + + + + + + + 4- - + + + - - - • - - -13.3 -10. A ■ - , L—— ■■■ ■ —-»- L., 4, fc. -L-. L— Lm _L. L, CONCENTRATION, IN HICROGRRHS PER LITER 4- = 5.4 - 29. 1 ” X = 29. 1 - 52.8 o = 52. 8 - 76.5 ■ xx o 8 ■’•ST**" + + + X + + + + + NUMBER OF STRNBRRB BEUIRTIONS NUMBER OF STRNBRRB DEUIRTIONS FROM THEORETICRL URLUE EROM THEORETICAL URLUE IOCT INOU l DEC l JAN 1FEB IHAR IAPR IHRY 1JUN 1JUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 25.—Dissolved solids data from the National Uater Quality Laboratory. 6 5 4 3 2 l 0 -1 -2 CONCENTRATION, IN HILL I GRANS PER LITER + = 0.2 - 0-9 X = 0-9 - 1.6 o = 1.6— 2.3 37. A 8.5 + ++ o 4 * ** * ++ R o Xo* X o ++ + + + + + ++ -»x 0 § FT X + O OO 4f X X o r> r X X o X XX + 1 XX X ++ X OO O HH- +* * + + + + CD -H- <8 X OO 3 -Rare o ++ *x O X X + +* +* +«- + x° X X XXX X -SSL. 8 -3 r -4 -5 -6 - 10.0 —t- X —7 . A — 1 -1— -7.5 -11.5 — 1 —w - 1 -10.5 " +-■ ■ ■ 10CT 1986 INOU 1986 IDEC 1986 1 JAN 1987 IFEB 1987 inAR 1987 1 APR 1987 inAY 1987 l JUN 1987 1JUL 1987 1 AUG 1987 1SEP 1987 1 OCT 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 26.—Fluoride, dissolved, data from the National Uater Quality Laboratory. 29 NUMBER OF STRNDRRD BEUIRTIONS NUMBER OF STRNDRRD DEUIRTIONS FROM THEORETICRL URLUE FROM THEORETICRL URLUE 6 S 4 3 2 1 0 -1 -2 -3 -4 -5 -6 l OCT iriOU 1DEC 1JRN l FEB inflR 1FIPR 1DRY UUN lJUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMFLE URS LOGGED INTO LRBORRTORY Figure 27.—Iron, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Ulater Quality Laboratory. --T--T-1-1-1-T " ' — 1 — 1 V i » CONCENTRATION, IN nlCROGRADS PER LITER + = 8.2 - 240 x = 240 - 472 '$■%*+ ° = 472 “ 704 . x + + -d + -H- + jrt . }♦, ^ + ++ + + + + + * + + + *tr ° ° o* , ,a± + , ^ A- + —+ r 4=| T+ + + ^ 1 -l-'ffiL- » . * + +, + + . + * + + + ++ + + + + + * + * »- L i- i-1-1-L. I. 1 L. 1 OCT INOU 1BEC URN 1FEB U1RR lflPR 1HRY 1JUN 1JUL 1RUG 1SEP IOCT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 28. — Iron, dissolved, (atomic absorption spectrometry) data from the National Uater Quality Laboratory. 30 NUMBER OF STANDARD DEUIATIONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 6 5 4 3 2 1 0 -l -2 -3 -4 -5 -6 l OCT 1MOU IDEC IJfln 1FEB lflflR lflPR 1 HAY 1JUN 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 29.—Iron, total recoverable, data from the National Ulater Quality Laboratory. 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 10CT 1M0U IDEC 1JRM l FEB tHAR 1RPR 1HRY 1JUN 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 30.—Lead, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. CONCENTRATION, IN niCROGRAHS PER LITER ’ + = 2.9 - 7.5 ” X = 7.5 - 12. 1 ■ o = 12.1 - 16.7 - O o CD x»ofcx x O QD OO xooc XXX X X »CMK X XX X X XX X** XX + OO o X xocxx XXJBK nr *e%c»^ XJ#oe< X op o o X X XX 31 NUMBER OF STRNBRRB BEUIRTIONS NUMBER OF STRNBRRB BEUIRTIONS FROM THEORETICRL URLUE FROM THEORETICRL URLUE 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 10CT IMOU 1DEC lJflli 1FEB IflAR 1RPR lHRY 1JUN 1JUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 31.—Lead, dissolved, (atomic absorption spectrometry) data from the National Ulater Quality Laboratory. 6 5 4 3 2 l 0 -1 -2 -3 -4 -5 -6 l OCT INOU l DEC 1 JRM IFEB inflR lflPR inflY IJUN 1JUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 32.—Lead, total recoverable, data from the National Uater Quality Laboratory. 32 NUMBER OF STANDARD BEUIRTIONS NUMBER OF STRNBRRB BEUIRTIONS FROM THEORETICAL URLUE FROM THEORETICAL URLUE COMCEMTRRTIOM, IM niCROGRRMS PER LITER '+ = 14.5 - 181 x = 181 - 347 -o = 347 - 514 Till * ± j.± .± t* + +* + + + + 4- + , +VT* * *■+ » TT ^ TT » + + + ■ 1- U- i- L. -L. 1-I— 1- Li. L 10CT IMOU l DEC 1JRM 1FEB 1DRR IflPR 1MRY 1JUM 1JUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE LIAS LOGGED INTO LABORATORY Figure 33.—Lithium, dissolved, data from the National Hater Quality Laboratory. IOCT IMOU l DEC IJRM l FEB IMRR IflPR l DRY 1JUM 1JUL 1RUG ISEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 34.—Lithium, total recoverable, data from the National Uater Quality Laboratory. 33 NUMBER OF STRNDARD DEUIATIONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE CONCENTRATION, niLLlGRRHS PER LITER 6 '+ = 2.6 - 17.6 x = 17.6 - 32.S 4 ■o = 32.5 - 47.3 3 » + • 2 1 0 -l -2 -3 -4 -5 -6 IN -1- ■+ ■ + + . X V- x : X °2+? + + + -H+rf t 1 It lilt o X -w- + + + ++ + + + o O O >0t X X + o ° ■*-++ *+ Y * 0000 X XX + X °° + * o * ± + r # + + * OOOD 8 ° o o o o o O O o - - o X o o o * o XX O x X 1 OCT 1986 1NOU 1986 1 DEC 1986 1JRN 1987 1FEB 1987 lilRR 1987 1 APR 1987 infiY 1987 UUN 1987 IJUL 1987 1RUG 1987 l SEP 1987 1 OCT 1987 DATE SAMPLE LIAS LOGGED INTO LABORATORY Figure 35.—Magnesium, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. 10CT 1N0U 1DEC URN 1FEB inflR 1RPR 1HRY 1JDN IJUL IRUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE LIAS LOGGED INTO LABORATORY Figure 36.—Magnesium, dissolved, (atomic absorption spectrometry) data from the National Uater Quality Laboratory. 34 NUMBER OF STRNBRRD BEUIRTIONS NUMBER OF STANDARD BEUIRTIONS FROM THEORETICRL URLUE RRON THEORETICAL UALUE 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 37.—Manganese, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. 10CT 1N0U IDEC Uflli 1FEB IflflR IflPR lHflV 1JUN 1JUL lflU6 ISEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 38.—Manganese, dissolved, (atomic absorption spectrometry) data from the National Uater Quality Laboratory. 35 HUMBER OF STRNDRRD DEUIRTIONS NUMBER OF STRNBRRB DEUIRTIONS FROM THEORETICRL URLUE FROM THEORETICRL URLUE 10CT 1MOU 1DEC lJflM 1FEB lHflR IflPR lHflY 1JUN 1JUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 39.—Manganese, total recoverable, data from the National Uater Quality Laboratory. 10 CT IMOU 1 DEC lJflli 1FEB IHflR IflPR inflY 1JUN 1JUL lflUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 40.—Molybdenum, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. 36 NUMBER OF STRNBRRB BEUIRT TONS NUMBER OF STRNBRRB DEUIRTIONS FROM THEORETICRL URLUE FROM THEORETICRL URLUE 10CT 1MOU 1DEC 1JRN 1FEB IHRR lflPR 1NRY 1JUM 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 41.—Molybdenum, dissolved, (atomic absorption spectrometry) data from the National Uater Quality Laboratory. 6 5 4 3 2 1 0 -1 -2 -3 -4 -S -6 10CT INOU IDEC UflM 1FEB IHRR 1RPR lflRY 1JUN 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMPLE URS LOGGED INTO LRBORRTORY Figure 42.—Nickel, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. 37 CONCENTRATION, IN niCROGRflriS PER LITER + = 1.8 - 4. 8 X = 4.8 - 7.7 o = 7.7 - 10.5 - >£ & jQD— L4 8 ° o mm I T¥T * V NUMBER OF STANDARD DEUIATIONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 10CT 1MOU IDEC IJRN 1FEB 1I1RR 1RPR 1NRY IJUN 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 43.—Nickel, dissolved, (atomic absorption spectrometry) data from the National Uater Quality Laboratory 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 10CT 1N0U 1DEC URN 1FEB iriRR 1RPR 1HAY IJUN 1JUL IRUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 44.—Nickel, total recoverable, data from the National Uater Quality Laboratory 38 CONCENTRATION, IN niCROGRRDS PER LITER + = 3.4 - 10.6 x = 10.6 - 17.8 o = 17.8 - 25.0 11.7 T— T~ X* F x + + + + NUMBER OF STANDARD DEUIATIONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 6 s|- 4 3t- CONCENTRATION, IN nlLLlGRAHS PER LITER + = 0.2 - 2.2 x = 2.2 - 4.2 o = 4.2 - G. 2 -i- -m -r 23.6 54.A 2 1 0 -ir X + x + + +++ + X MU + + + + * + + fY o ° ■ .. ■ o +4T+ 4-P 4+H* + ++ ++o^ +44- X _o ii «■ 11 xx 9. ' +* + + oS i* * + ± X X + o ° HH- + * X X + -2 -3f -4 -5 -6 °x x ++ * + °»j§ *** 8* + + ** + -6.3 _i_ 10CT 1MOU 1986 1986 IDEC 1986 l JAN 1987 1FEB 1987 iriflR 1987 1RPR 1987 inflY 1987 1JUN 1987 1JUL 1987 1 AUG 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY ISEP 1987 1 OCT 1987 Figure 45.—Potassium, dissolved, data from the National Uater Quality Laboratory 6 S 4 3 2 1 0 -1 -2 -3 -4 -5 -6 10CT 1N0U IDEC l JAM 1FEB IflAR 1APR IflRY 1JUN lJUL IAUG ISEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY CONCENTRATION, IN niCROGRAnS PER LITER + = 1.9 - 21.3 x = 21.3 - 40.7 o =40.7—60.1 + + + -IH- + + a. + O o o _ 8 o g °% II II Ml -»o °^ ° ° + o °°l O + l x --W.- + + ++-4+ + ^ +*+• 1 1 o ® ® -^44.4.-U.° 00 W’o + + + XX X + + t + o • + Figure 46.—Selenium, dissolved, data from the National Uater Quality Laboratory 39 NUMBER OF STRNBRRB DEUIRTIONS NUMBER OF STRNDRRD BEUIRTIONS FROM THEORETICRL URLUE FROM THEORET ICRL URLUE 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 l OCT 1NOU IDEC lJflM 1FEB IHAR lflPR 1NRY 1JUN 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMFLE UIRS LOGGED INTO LRBORRTORV Figure 47.—Silica, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. ■ T-t- T 1 ■ 1 11 T-.' ■ 1 1 * CONCENTRATION, IN 2 o 2 fllLLIGRAHS PER LITER '+ = 3-5 - 8.4 x = 8.4 - 13.2 ■o = 13.2 - 18. 1 ' ' t ■■ 1 1 o °* OO o o o o ° . x9° yxx + ** * x X X ’ + "*’ + *’ o o x + X XX ++ + + 5 X X +++ X XX xx + - + 10CT 1N0U IDEC 1JRN 1FEB 1NRR 1RPR 1NRY IJUN 1JUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 54.—Strontium, dissolved, data from the National Uater Quality Laboratory. 43 NUMBER OF STRNDRRD BEUIRTIONS NUMBER OF STRNBRRB BEUIRTIONS FROM THEORET ICRL URLUE FROM THEORETICRL URLUE € 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 1 OCT 1NOU 1DEC 1 JAM IFEB 1HAR l APR 1HAY 1JUN 1JUL 1BUG 1SEP IOCT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMFLE URS LOGGED INTO LRBORRTORY Figure 55.—Sulfate, dissolved, data from the National Uater Quality Laboratory. 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 1 OCT 1NOU 1DEC 1JAN IFEB 1HRR 1APR lHFIY 1JUM 1JUL 1AUG 1SEP IOCT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMFLE URS LOGGED INTO LRBORRTORY Figure 56.—Zinc, dissolved, (Inductively coupled plasma emission spectrometry) data from the National Uater Quality Laboratory. 44 7.1 15.0 6.7 8. 6 + + * + + . + + + + + + + + M t ,* . + . + + + - ■ THU 1 |W ■ 6.7 7.5 o° ° 7 5 + + 9.5 . + o + + + + + + +^ + 4 * 1 + 1 4 + . + + * * * + + + + + t *:♦* ** * j -A- -L J- + t 4 ++ + + + Sco8*> O * X - + + J + -H- + + + t + 0 °0 o 00 + + + + CONCENTRATION, IN + ‘niCROGRAnS PER LITER + = 13,2 - 49.S -x = 49.S - 86.8 o = 85.8 - 122 CONCENTRATION, IN ‘ nILL I GRANS PER LITER + = 9.9 - 132 x = 132 - 254 o = 254 - 377 o x *■ “7 - ° -x ^ - 5—S-} >X £ . o o * °+ + x o # "* '+++ + ++ .+-»+. + + **+ + + +0 + ***+ °° °++ + + +°° + ± * -h £ * ,-H+i >* *> x + + *oo+ * ? X +>K X cP 0 + +X * + ^ ° + + S X ##*J|oX + . + +P° ° +#h- + + + * + +4+ . o o , X + * + X + X T+ + o8° x + *< ° x XX- XX o X -6.7 -1-*- NUMBER OF STANDARD DEUIAT IONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 6 S 4 3 2 1 0 -1 -2 -3 -4 -S -G 10CT 1NOU l DEC Uflfi 1FEB U1AR lflPR lHAY UUN 1JUL lflUG ISEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 57.—Zinc, dissolved, (atomic absorption spectrometry) data from the National Uater Quality Laboratory. CONCENTRATION, IN -4-*-1- 13.5 n i CROGRAns PER LITER '+ = 6.7 - 64.0 X = 64.0 - 121 ■o = 121 - 179 * - O X o x + X O X X 4 + X • CT> O + + ° 44- 4 4 4 ■ * + 4- 4 4 -H- * X X 4 + * 44 “ CD • - L- t— U - 10CT 1NOU IDEC URN 1FEB 1HRR 1RPR l HAY 1JUN UUL 1RUG ISEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 58.—Zinc, total recoverable, data from the National Uater Quality Laboratory. 45 NUMBER OF STRNDflRB BEUIRTIONS NUMBER OF STRNDRRD BEUIRTIONS FROM THEORETICRL URLUE FROM THEORETICRL URLUE 10CT INOU IDEC 1JRN 1FEB 1HRR l RPR 1HRY 1JUN IJUL 1RUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DRTE SRMFLE URS LOGGED INTO LABORATORY Figure 59.—Ammonia nitrogen as N, dissolved, data from the National Uater Quality Laboratory. 10CT INOU IDEC 1JRN IFEB II1RR 1RPR 1P1RY 1JUN IJUL IRU6 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 60.—Ammonia + organic nitrogen as N, dissolved, data from the National Uater Quality Laboratory. 46 NUMBER OF STANDARD DEUIATIONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE 10CT 1NOU IDEC l JAM 1FEB 1HAR 1APR l HAY 1JUN 1JUL 1AUG 1SEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 61.—Nitrite + nitrate nitrogen as N, dissolved, data from the National Llater Quality Laboratory. 6 5 H 3 2 1 0 -l -2 -3 -4 -5 -6 10CT 1M0U IDEC 1JAN l FEB IDAR 1APR lDRY 1JUN 1JUL 1AUG ISEP 10CT 1986 1986 1986 1987 1987 1987 1987 1987 1987 1987 1987 1987 1987 DATE SAMPLE UAS LOGGED INTO LABORATORY Figure 62.—Nitrite nitrogen as N, dissolved, data from the National Uater Quality Laboratory. CONCENTRATION, IN niLLlGRAnS PER LITER x = 0.02 - 2.32 T-*- 13.8 AO.9 X X X X X XX < wx* X^ X ^X XX X X XX X XX X *x X yxxxx x * —x > »< X »x X >x X uj ti iow o e ooo t—xx-x— it —**■ /VN /IWN /> /V*' X X M »» g xx " X XKXXXXXX^X X X * X X XX XX X xxxx XXX X v X XXX x x XXX XX xx< X X X XX -12.9 —**- -14.0 —S- 47 NUMBER OF STANDARD DEUIATIONS NUMBER OF STANDARD DEUIATIONS FROM THEORETICAL UALUE FROM THEORETICAL UALUE e 5 4 3 2 1 0 -l -2 -3 -4 -5 -6 —* ---1 39.8 45.9 40.9 X CONCENTRATI Oh, IM HILL IGRAHS PER LITER x = 0.17- 11.6 -it ix ieei—»- 6.6 39.3 40.9 35.8 38.8 37.8 . X X X X X XX * X X X X XX X X - X XX X XX x X* X x 7* x X * X v — .. X X X X X x X X X X M X x x ; 'x* X xx X >? >« \ X X X xX X XX X X xox X X X* X x *£* X x * 0 855 1710 2565 3420 4275 5130 5985 6840 7695 8550 NEAN CONCENTRATION, IN NICROGRRNS PER LITER Figure 103.—Precision data for Iron, total recoverable, at the National Uater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 2 4 6 8 10 12 14 16 18 20 HERN CONCENTRATION, IN NICROGRRNS PER LITER Figure 104.—Precision data for lead, dissolved, (Inductively coupled plasma emission spectrometry) at the National Uater Quality Laboratory. 68 RELflTIUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATI OHS, IN PERCENT IN PERCENT 100 90 80 70 60 50 40 30 20 10 0 0 2 4 6 8 10 12 14 16 18 20 NERN CONCENTRATION, IN NICROGRANS PER LITER Figure 105.—Precision data for lead, dissolved, (atomic absorption spectrometry) at the National Ulster Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 4 8 12 16 20 24 28 32 36 40 NERN CONCENTRATION, IN NICROGRANS PER LITER Figure 106.—PrecIsI on data for lead, total recoverable, at the National Ulster Quality Laboratory. 69 RELflT rUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT 100 90 80 70 GO 50 40 30 20 10 0 0 SO 100 150 200 250 300 350 400 450 500 MEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 107.—Precision data for lithium, dissolved, at the National Ulater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 25 50 75 100 125 150 175 200 225 250 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 108.—Precision data for lithium, total recoverable, at the National Uater Quality Laboratory. 70 RELRT rUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT too 90 80 70 60 50 40 30 20 10 0 0 6 12 18 24 30 36 42 48 54 60 NEAN CONCENTRATION, IN NILLIGRANS PER LITER Figure 109.—Precision data for magnesium, dissolved, (Inductively coupled plasma emission spectrometry) at the National UJater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 4 8 12 16 20 24 28 32 36 40 NEAN CONCENTRATION, IN NILL I GRANS PER LITER Figure 110.—Precision data for magnesium, dissolved, (atomic absorptI on spectrometry} at the National Uater Quality Laboratory. 71 RELRTIUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT too 90 80 70 60 50 40 30 20 10 0 0 60 120 180 240 300 360 420 480 540 600 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 111.—Precision data for manganese, dissolved, (Inductively coupled plasma emission spectrometry) at the National Uater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 40 80 120 160 200 240 280 320 360 400 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 112.—PrecIsI on data for manganese, dissolved, (atomic absorption spectrometry) at the National Uater Quality Laboratory. 72 RELHTIUE STANDARD DEUIAT IONS, RELATIUE STANDARD DEUIATIONS ; IN PERCENT IN PERCENT 100 90 80 70 60 50 40 30 20 10 0 0 30 60 90 120 150 180 210 240 270 300 NEAN CONCENTRATION, IN NICROGRANS PER LITER FIgure 113.—Precision data for manganese, at the National Uater Quality total recoverable. Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 4 8 12 16 20 24 28 32 36 40 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 114.—Precision data for molybdenum, dissolved, (Inductively coupled plasma emission spectrometry> at the National Uater Quality Laboratory. 73 RELRTIUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS IN PERCENT IN PERCENT 100 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure IIS.—Precision data for molybdenum, dlssolued, (atomic absorption spectrometry) at the National Uater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0123456789 10 MEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 116.—Precision data for nickel, dlssolued, (Induct Iuely coupled plasma emission spectrometry) at the National Uater Quality Laboratory. 74 100 90 80 70 60 50 40 30 20 10 0 100 90 80 70 60 50 40 30 20 10 0 NERN CONCENTRATION, IN NICROGRANS PER LITER Figure 117.—Precision data for nickel, dissolved, (atomic absorption spectrometry) at the National Ulater Quality Laboratory. HERN CONCENTRRTION, IN NICROGRANS PER LITER Figure 118.—Precision data for nickel, total recoverable, at the National Ulater Quality Laboratory. 75 100 90 80 70 60 50 40 30 20 10 0 100 90 80 70 60 50 40 30 20 10 0 10 HERN CONCENTRRTI Oh, IM HILLIGRRHS PER LITER Figure 119.—Precision data for potassium, dissolved, at the National Ulater Quality Laboratory. 0 10 20 30 40 50 60 70 80 90 100 HERN CONCENTRRTI ON, IN NICROGRRNS PER LITER Figure 120.—Precision data for selenium, dissolved, at the National Uater Quality Laboratory. 76 RELflTIUE STANDARD DEUIRTIONS, RELRTIUE STANDARD DEUIRTIONS, IN PERCENT IN PERCENT too 90 80 70 60 50 40 30 20 10 0 0 2 4 6 8 10 12 14 16 18 20 nERN CONCENTRATION, IN NILLIGRRNS PER LITER Figure 121.—Precision data for silica, dissolved, (Inductively coupled plasma emission spectrometry) at the National Uater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 2 4 6 8 10 12 14 16 18 20 HERN CONCENTRATION, IN NILLIGRRNS PER LITER Figure 122.—Precision data for silica, dissolved, (color 1metry) at the National Uater Quality Laboratory. 77 RELRTIUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT 100 90 80 70 GO 50 40 30 20 10 0 0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5.0 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 123.—Precision data for silver, dissolved, (Inductively coupled plasma emission spectrometry) at the National Ulater Quality Laboratory. 100 90 80 70 50 50 40 30 20 10 0 0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5.0 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 124.—Precision data for silver, dissolved, (atomic absorption spectrometry) at the National Ulater Quality Laboratory. 78 RELRT IUE STANDARD DEUIATIONS, RELAT IUE STANDARD DELATIONS, IN PERCENT IN PERCENT 100 30 80 70 60 50 40 30 20 10 0 0 2 4 6 8 to 12 14 16 18 20 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 125.—Precision data for sliver, total recoverable, at the National Uater Quality Laboratory. 100 30 80 70 60 50 40 30 20 10 0 0 15 30 45 60 75 30 105 120 135 150 NEAN CONCENTRATION, IN NILLIGRANS PER LITER Figure 126.—Precision data for sodium, dissolved, (Inductively coupled plasma emission spectrometry) at the National Uater Quality Laboratory. 79 100 90 80 70 GO 50 40 30 20 10 0 100 90 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 HERN CONCENTRATION, IN II ILL I GRANS PER LITER Figure 127.—Precision data for sodium, dissolved, (atomic absorption spectrometry) at the National Uater Quality Laboratory. - - - - m - - - - XX — *- X X _ l* _ X 0 120 240 360 480 600 720 840 960 1080 1200 NEAN CONCENTRATION, IN NICR06RANS PER LITER Figure 128.—Precision data for strontium, dissolved, at the National Uater Quality Laboratory. 80 RELRTIUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT 100 90 80 70 GO 50 40 30 20 10 0 NEAN CONCENTRATION, IN NILL I GRANS PER LITER Figure 129.—Precision data for sulfate, dlssolued, at the National Uater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 15 30 45 60 75 90 105 120 135 150 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 130.—Precision data for zinc, dlssolued, (Inductively coupled plasma emission spectrometry) at the National Uater Quality Laboratory. 81 RELAT1UE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT 100 90 80 70 60 50 40 30 20 10 0 0 20 40 60 80 100 120 140 160 180 200 NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 131.—Precision data for zinc, dissolved, (atomic absorption spectrometry) at the National Uater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 15 30 45 60 75 90 105 120 135 ISO NEAN CONCENTRATION, IN NICROGRANS PER LITER Figure 132.—Precision data for zinc, total recoverable, at the National Uater Quality Laboratory. 82 RELRTIUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT NEAN CONCENTRATION, IN NILLIGRANS PER LITER FIgure 133.—Free IsI on dIssolued. data for ammonia nitrogen as N, at the National Uater Quality Laboratory. NEAN CONCENTRATION, IN NILLIGRANS PER LITER FIgure 134.—Free IsI on dIssolued. data for ammonia + organic nitrogen as N, at the National Uater Quality Laboratory. 83 RELATIUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT NEAN CONCENTRATION, IN MILLIGRAMS PER LITER FIgure 135.—Free IsI on dlssolved. data for nitrite + nitrate nitrogen as N, at the National Uater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 0 .3 .6 .9 1.2 1.5 1.8 2.1 2.4 2.7 3 MEAN CONCENTRATION, IN MILLIGRAMS PER LITER Figure 136.—Precision data for nitrite nitrogen as N, dissolved, at the National Uater Quality Laboratory. 84 RELRTIUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT NEAN CONCENTRATION, IN HILLIGRANS PER LITER Figure 137.—Precision data for orthophosphate phosphorus as P, dlssolued, at the National Uater Quality Laboratory. NEAN CONCENTRATION, IN NILL I GRANS PER LITER Figure 138.—PrecIsI on data for phosphorus as P, dlssolued, at the National Uater Quality Laboratory. 85 RELflTIUE STANDARD DEUIATIONS, RELATIUE STANDARD DEUIAT TONS IN PERCENT IN PERCENT 100 90 80 70 60 50 40 30 20 10 0 0 .5 1 1.5 2 2.5 3 3.5 4 4.5 5 NEAN CONCENTRATION, IN MILLIGRAMS PER LITER Figure 139.—Precision data for calcium, dissolved, (precipitation) at the National UJater Quality Laboratory. too 90 80 70 60 50 40 30 20 10 0 0 .5 1.5 2 2.5 3 3.5 4 4.5 5 NEAN CONCENTRATION, IN NILLIGRANS PER LITER Figure 140.—Precision data for chloride, dissolved, (precipitation) at the National Uater Quality Laboratory. 86 RELRT IUE STANDARD DELATIONS, RELATIUE STANDARD DEUIAT IONS, IN PERCENT IN PERCENT 100 90 80 70 60 50 40 30 20 10 0 0 .03 .06 .09 . 12 . 15 . 18 .21 .24 .27 .3 NEAN CONCENTRATION, IN NILLIGRANS PER LITER Figure 141.—Precision data for fluoride, dissolved, (precIpI tat I on) at the National Uater Quality Laboratory. 100 90 80 70 60 50 40 30 20 10 0 NEAN CONCENTRATION, IN NILLIGRANS PER LITER Figure 142.—Precision data for magnesium, dissolved, (precipitation) at the National Uater Quality Laboratory. 87 RELflTIUE STANDARD DEUIAT IONS, RELATIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT too 90 80 70 60 50 40 30 20 10 0 0 .03 .06 .09 .12 .15 .18 .21 .24 .27 .3 NEAN CONCENTRATION, IN NILLIGRANS PER LITER Figure 143.—Precision data for ammonia nitrogen as N, dissolved, (precipitation) at the National Uater Quality Laboratory. • - » - ■ - ■ - - ■ - X - - m ■ X - L. * 100 90 80 70 60 50 40 30 20 10 0 0 .03 .06 .09 . 12 . 15 . 18 .21 .24 .27 .3 MEAN CONCENTRATION, IN NILLIGRANS PER LITER Figure 144.—PrecIsI on data for nitrate nitrogen as N, dissolved, (precipitation) at the National Uater Quality Laboratory. 88 RELRTIUE STANDARD DEUIATIONS, RELRTIUE STANDARD DEUIATIONS, IN PERCENT IN PERCENT 100 30 80 70 60 50 40 30 20 10 0 0 .01 .02 .03 .04 .05 .06 .07 .08 .03 .1 NERN CONCENTRATION, IN NILLIGRRNS PER LITER Figure 145.—Precision data for orthophosphate phosphorus as P, dissolved, (precipitation) at the National Uater Quality Laboratory. 100 30 80 70 60 50 40 30 20 10 0 0 .03 .06 .03 .12 .15 .18 .21 .24 .27 .3 HERN CONCENTRATION, IN NILLIGRRNS PER LITER Figure 146.—Precision data for potassium, dissolved, (precipitation) at the National Uater Quality Laboratory. 89 RELRTIUE STANDARD DEUIRTIONS, RELRTIUE STANDARD DEUIRTIONS, IN PERCENT IN PERCENT 100 30 80 70 60 50 40 30 20 10 0 0 .3 .6 .9 1.2 1.5 1.8 2.1 2.4 2.7 3 HERN CONCENTRATION, IN NILL IGRRNS PER LITER Figure 147.—Precision data for sodium, dissolved, (precipitation) at the National Uater Quality Laboratory. 100 NERN CONCENTRATION, IN NILLIGRRNS PER LITER Figure 148.—Precision data for sulfate, dissolved, (precipitation) at the National Uater Quality Laboratory, 90 *U.S. GOVERNMENT PRINTING OFFICE: 1 9 8 9-0-673-196/00020 UNIVERSITY OF ILLINOIS-URBANA 551 49UN3426W WATER-RESOURCES 89-4049 1989 C001 INVESTIGATIONS MENLO PAR 0112 026744