Section 2550.7 - General Water Quality Monitoring and System Requirements(a) The discharger shall comply with the requirements of this section for any water quality monitoring program developed to satisfy sections 2550.8, 2550.9, or 2550.10 of this article.(b) Ground Water Monitoring System. (1) Except as provided under subsection (e)(3) of this section, the discharger shall establish a ground water monitoring system for each waste management unit. This ground water monitoring system shall include: (A) for all monitoring and response programs, a sufficient number of background monitoring points installed at appropriate locations and depths to yield ground water samples from the uppermost aquifer that represent the quality of ground water that has not been affected by a release from the waste management unit;(B) for a detection monitoring program under section 2550.8 of this article: 1. a sufficient number of monitoring points installed at appropriate locations and depths to yield ground water samples from the uppermost aquifer that represent the quality of ground water passing the point of compliance and to allow for the detection of a release from the waste management unit;2. a sufficient number of monitoring points installed at additional locations and depths to yield ground water samples from the uppermost aquifer to provide the best assurance of the earliest possible detection of a release from the waste management unit;3. a sufficient number of monitoring points and background monitoring points installed at appropriate locations and depths to yield ground water samples from portions of the zone of saturation, including other aquifers, not monitored pursuant to subsections (b)(1)(B)1. and (b)(1)(B)2. of this section to provide the best assurance of the earliest possible detection of a release from the waste management unit;4. a sufficient number of monitoring points and background monitoring points installed at appropriate locations and depths to yield ground water samples from zones of perched water to provide the best assurance of the earliest possible detection of a release from the waste management unit; and5. monitoring point locations and depths that include the zone(s) of highest hydraulic conductivity in each ground water body monitored pursuant to this subsection.(C) for an evaluation monitoring program under section 2550.9 of this article: 1. a sufficient number of monitoring points installed at appropriate locations and depths to yield ground water samples from the uppermost aquifer that represent the quality of ground water passing the point of compliance and at other locations in the uppermost aquifer to provide the data needed to evaluate changes in water quality due to the release from the waste management unit;2. a sufficient number of monitoring points and background monitoring points installed at appropriate locations and depths to yield ground water samples from portions of the zone of saturation, including other aquifers, not monitored pursuant to subsection (b)(1)(C)1. of this section to provide the data needed to evaluate changes in water quality due to the release from the waste management unit; and3. a sufficient number of monitoring points and background monitoring points installed at appropriate locations and depths to yield ground water samples from zones of perched water to provide the data needed to evaluate changes in water quality due to the release from the waste management unit; and(D) for a corrective action program under section 2550.10 of this article: 1. a sufficient number of monitoring points installed at appropriate locations and depths to yield ground water samples from the uppermost aquifer that represent the quality of ground water passing the point of compliance and at other locations in the uppermost aquifer to provide the data needed to evaluate the effectiveness of the corrective action program;2. a sufficient number of monitoring points and background monitoring points installed at appropriate locations and depths to yield ground water samples from portions of the zone of saturation, including other aquifers, not monitored pursuant to subsection(b)(1)(D)1. of this section to provide the data needed to evaluate the effectiveness of the corrective action program; and3. a sufficient number of monitoring points and background monitoring points installed at appropriate locations and depths to yield ground water samples from zones of perched water to provide the data needed to evaluate the effectiveness of the corrective action program.(2) The ground water monitoring system may include background monitoring points that are not hydraulically upgradient of the waste management unit if the discharger demonstrates to the satisfaction of the regional board that sampling at other monitoring points will provide samples that are representative of the background quality of ground water or are more representative than those provided by the upgradient monitoring points.(3) Copies of drillers' logs which the Department of Water Resources requires to be submitted pursuant to section 13751 of the California Water Code shall be submitted to the regional board.(4) All monitoring wells shall be cased and constructed in a manner that maintains the integrity of the monitoring well bore hole and prevents the bore hole from acting as a conduit for contaminant transport.(5) The sampling interval of each monitoring well shall be appropriately screened and fitted with an appropriate filter pack to enable collection of representative ground water samples.(6) For each monitoring well, the annular space (i.e., the space between the bore hole and well casing) above and below the sampling interval shall be appropriately sealed to prevent entry of contaminants from the ground surface, entry of contaminants from the unsaturated zone, cross contamination between portions of the zone of saturation, and contamination of samples.(7) All monitoring wells shall be adequately developed to enable collection of representative ground water samples.(c) Surface Water Monitoring Systems.(1) The discharger shall establish a surface water monitoring system to monitor each surface water body that could be affected by a release from the waste management unit.(2) Each surface water monitoring system shall include:(A) a sufficient number of background monitoring points established at appropriate locations and depths to yield samples from each surface water body that represent the quality of surface water that has not been affected by a release from the waste management unit;(B) for a detection monitoring program under section 2550.8 of this article, a sufficient number of monitoring points established at appropriate locations and depths to yield samples from each surface water body that provide the best assurance of the earliest possible detection of a release from the waste management unit;(C) for an evaluation monitoring program under section 2550.9 of this article, a sufficient number of monitoring points established at appropriate locations and depths to yield samples from each surface water body that provide the data to evaluate changes in water quality due to the release from the waste management unit; and(D) for a corrective action program under section 2550.10 of this article, a sufficient number of monitoring points established at appropriate locations and depths to yield samples from each surface water body that provide the data to evaluate compliance with the water quality protection standard and to evaluate the effectiveness of the corrective action program.(d) Unsaturated Zone Monitoring System. (1) Except as otherwise provided in subsection (d)(5) of this section, the discharger shall establish an unsaturated zone monitoring system for each waste management unit.(2) The unsaturated zone monitoring system shall include: (A) a sufficient number of background monitoring points established at appropriate locations and depths to yield soil-pore liquid samples or soil-pore liquid measurements that represent the quality of soil-pore liquid that has not been affected by a release from the waste management unit;(B) for a detection monitoring program under section 2550.8 of this article, a sufficient number of monitoring points established at appropriate locations and depths to yield soil-pore liquid samples or soil-pore liquid measurements that provide the best assurance of the earliest possible detection of a release from the waste management unit;(C) for an evaluation monitoring program under section 2550.9 of this article, a sufficient number of monitoring points established at appropriate locations and depths to yield soil-pore liquid samples or soil-pore liquid measurements that provide the data to evaluate changes in water quality due to the release from the waste management unit; and(D) for a corrective action program under section 2550.10 of this article, a sufficient number of monitoring points established at appropriate locations and depths to yield soil-pore liquid samples or soil-pore liquid measurements that provide the data to evaluate compliance with the water quality protection standard and to evaluate the effectiveness of the corrective action program.(3) Background monitoring points shall be installed at a background plot having soil characteristics similar to those of the soil underlying the waste management unit.(4) Liquid recovery types of unsaturated zone monitoring (e.g., the use of lysimeters) are required unless the discharger demonstrates to the satisfaction of the regional board that such methods of unsaturated zone monitoring cannot provide an indication of a release from the waste management unit. The regional board shall require complimentary or alternative (non-liquid recovery) types of unsaturated zone monitoring to provide the best assurance of the earliest possible detection of a release from the waste management unit.(5) Unsaturated zone monitoring is required at all new waste management units unless the discharger demonstrates to the satisfaction of the regional board that there is no unsaturated zone monitoring device or method designed to operate under the subsurface conditions existent at that waste management unit. For a waste management unit that has operated or has received all permits necessary for construction and operation before 7-1-91, unsaturated zone monitoring is required unless the discharger demonstrates to the satisfaction of the regional board that either there is no unsaturated zone monitoring device or method designed to operate under the subsurface conditions existent at that waste management unit or that installation of unsaturated zone monitoring devices would require unreasonable dismantling or relocating of permanent structures.(e) General Monitoring Requirements. (1) All monitoring systems shall be designed and certified by a registered geologist or a registered civil engineer.(2) All monitoring wells and all other borings drilled to satisfy the requirements of this article shall be logged during drilling under the direct supervision of a registered geologist. These logs shall be submitted to the regional board upon completion of drilling. (A) Soil shall be described in the geologic log according to the Unified Soil Classification System as presented in Geotechnical Branch Training Manuals No. 4, 5, and 6, published by the United States Bureau of Reclamation in January of 1986 (available from Bureau of Reclamation, Engineering and Research Center, Attention: Code D-7923-A, P.O. Box 25007, Denver, Colorado 80225).(B) Rock shall be described in the geologic log in a manner appropriate for the purpose of the investigation.(C) Where possible, the depth and thickness of saturated zones shall be recorded in the geologic log.(3) If a facility contains contiguous waste management units, separate ground water monitoring systems are not required for each such unit if the discharger demonstrates to the satisfaction of the regional board that the water quality monitoring program for each unit will enable the earliest possible detection and measurement of a release from that unit.(4) The water quality monitoring program shall include consistent sampling and analytical procedures that are designed to ensure that monitoring results provide a reliable indication of water quality at all monitoring points and background monitoring points. At a minimum, the program shall include a detailed description of the procedures and techniques for:(A) sample collection (e.g., purging techniques, sampling equipment, and decontamination of sampling equipment);(B) sample preservation and shipment;(C) analytical procedures; and(D) chain of custody control.(5) The water quality monitoring program shall include appropriate sampling and analytical methods for ground water, surface water, and the unsaturated zone that accurately measure the concentration of each constituent of concern and the concentration or value of each monitoring parameter.(6) For each waste management unit, the discharger shall collect all data necessary for selecting the appropriate statistical methods pursuant to subsections (e)(7), (e)(8), and (e)(9) of this section and for establishing the background values specified pursuant to subsection (e)(11) of this section. At a minimum, this data shall include analytical data obtained during quarterly sampling of all background monitoring points for a period of one year, including the times of expected highest and lowest annual elevations of the ground water surface. For a new waste management unit, this data shall be collected before wastes are discharged at the unit and background soil-pore liquid data shall be collected from beneath the unit before the unit is constructed.(7) Based on data collected pursuant to subsection (e)(6) of this section, the discharger shall propose one of the statistical methods specified in subsection (e)(8) of this section for each constituent of concern and for each monitoring parameter. These methods, upon approval by the regional board, shall be specified in the waste discharge requirements and shall be used in evaluating water quality monitoring data. The specifications for each statistical method shall include a detailed description of the criteria to be used for determining statistically significant evidence of any release from the waste management unit and for determining compliance with the water quality protection standard. Each statistical test specified for a particular constituent of concern or monitoring parameter shall be conducted separately for that constituent of concern or monitoring parameter at each monitoring point. Where practical quantitation limits are used in any of the following statistical methods to comply with subsection (e)(9)(E) of this section, the practical quantitation limit shall be proposed by the discharger for approval by the regional board. The discharger shall demonstrate that use of the proposed statistical methods will comply with the performance standards outlined in subsection(e)(9) of this section.(8) The discharger shall propose one of the following statistical methods: (A) a parametric analysis of variance (ANOVA) followed in all instances by a multiple comparisons procedure to identify statistically significant evidence of a release from the waste management unit. The method shall include estimation and testing of the contrasts between each monitoring point's mean and the background mean value for each constituent or parameter;(B) an ANOVA based on ranks followed in all instances by a multiple comparisons procedure to identify statistically significant evidence of a release from the waste management unit. The method shall include estimation and testing of the contrasts between each monitoring point's median and the background median values for each constituent of concern or monitoring parameter;(C) a tolerance or prediction interval procedure in which an interval for each constituent of concern or monitoring parameter is established from the distribution of the background data, and the value for each constituent of concern or monitoring parameter at each monitoring point is compared to the upper tolerance or prediction limit;(D) a control chart approach that gives control limits for each constituent of concern or monitoring parameter; or(E) any statistical test method submitted by the discharger for approval by the regional board including, but not limited to, any statistical method which includes a procedure to verify that there is statistically significant evidence of a release from the waste management unit. If the statistical test method includes a verification procedure, this procedure shall include either a single "composite" retest (i.e., a statistical analysis that augments and reanalyzes the data from the monitoring point that indicated a release) or shall consist of at least two "discrete" retests (i.e., statistical analyses each of which analyzes only newly-acquired data from the monitoring point that indicated a release). The verification procedure shall comply with the following requirements in addition to the statistical performance standards under subsection (e)(9) of this section: 1. if the verification procedure consists of discrete retests, rejection of the null hypothesis for any one of the retests shall be considered confirmation of significant evidence of a release;2. the number of additional samples collected and analyzed for use in the verification procedure shall be appropriate for the form of statistical test specified in the waste discharge requirements for that constituent of concern or monitoring parameter pursuant to subsection (e)(7) of this section. The number of additional samples shall be greater than or equal to the number of samples specified in the waste discharge requirements for that constituent or parameter pursuant to subsection (e)(12)(A) of this section;3. if resampling at the interval identified for use in the initial statistical test pursuant to subsection (e)(12)(B) of this section would cause the entire resampling effort to take longer than 30 days, the sampling interval for use in the verification procedure shall be reduced to ensure that all samples are collected and submitted for laboratory analysis within 30 calendar days from the time that the discharger determines statistically significant evidence of a release pursuant to subsection 2550.8(g) or (i) of this article;4. for a verification procedure containing a composite retest, the statistical verification procedure shall be based on all data obtained from the initial sampling event combined with all data obtained during the resampling event. For a verification procedure containing discrete retests, each retest shall analyze data obtained during its respective resampling event(s) and no data shall be shared between retests;5. the Type I error for statistical methods employing a retest procedure shall be as follows: a. for a verification procedure containing a composite retest, the statistical test method used shall be the same as the method used in the initial statistical comparison, except that the statistical test used in the verification procedure shall be conducted at a Type I error rate of no less than 0.05 for both the experiment-wise analysis (if any) and the individual monitoring point comparisons. Therefore, if a control chart approach is used to evaluate water quality monitoring data, the upper limit on an X-Bar or R-Chart must be set at no more than 1.645 standard deviations of the statistic plotted for a one-sided statistical comparison or at no more than 1.96 standard deviations of the statistic plotted for a two-sided statistical comparison;b. For a verification procedure containing discrete retests, the statistical test method used shall be the same as the method used in the initial statistical comparison. Notwithstanding any provision of subsection (e)(9) of this section, the critical value for the tests shall be chosen so that the Type I error rate for all individual monitoring point comparisons is the same, whether for an initial test or for a retest, and is equal-to-or-greater-than either (1-[0.95]1/M*W*S)0.5 * (1/R)0.5 or
1-(0.99)1/S,
whichever is larger, where: M = the number of monitoring parameters; W = the number of monitoring points at the waste management unit; S = the number of times that suites of monitoring data from the waste management unit are subjected to initial statistical analysis within a period of six months (i.e., S >
1) ; and R = the number of discrete retests that are to be conducted at a monitoring point whose initial statistical analysis for a given constituent of concern or monitoring parameter has indicated the presence of a release (i.e., R >6. the discharger shall report to the regional board by certified mail the results of both the initial statistical test and the results of the verification procedure, as well as all concentration data collected for use in these tests within seven days of the last laboratory analysis of the samples collected for the verification procedure; and7. the verification procedure shall only be performed for the constituent(s) which has shown statistically significant evidence of a release, and shall be performed for those monitoring points at which a release is indicated.(9) Each statistical method chosen under subsection 2550.7(e)(7) of this article for specification in the waste discharge requirements shall comply with the following performance standards for each six-month period: (A) the statistical method used to evaluate water quality monitoring data shall be appropriate for the distribution of the constituent of concern or monitoring parameter to which it is applied and shall be the least likely of the appropriate methods to fail to identify a release from the waste management unit. If the distribution of a constituent of concern or monitoring parameter is shown by the discharger to be inappropriate for a normal theory test, then the data shall be either transformed so that the distribution of the transformed data is appropriate for a normal theory test or a distribution-free theory test shall be used. If the distributions for the constituents of concern or monitoring parameters differ, more than one statistical method may be needed;(B) if an individual monitoring point comparison procedure is used to compare an individual monitoring point constituent concentration or monitoring parameter value with a concentration limit in the water quality protection standard or with a background monitoring parameter value, the test shall be done at a Type I error rate no less than 0.01. If a multiple comparisons procedure is used, the Type I experiment-wise error rate shall be no less than 0.05; however, a Type I error rate of no less than 0.01 for individual monitoring point comparisons shall be maintained. This performance standard does not apply to tolerance intervals, prediction intervals, or control charts;(C) if a control chart approach is used to evaluate water quality monitoring data, the specific type of control chart and its associated statistical parameter values (e.g., the upper control limit) shall be proposed by the discharger and submitted for approval by the regional board. The regional board may approve the procedure only if it finds the procedure to be protective of human health and the environment. Any control charting procedure must have a false-positive rate of no less than 1 percent for each monitoring point charted (e.g., upper control limits on X-bar or R-Charts used only once every six months must be set at no more than 2.327 standard deviations of the statistic plotted for a one-sided statistical comparison or at no more than 2.576 standard deviations of the statistic plotted for a two-sided statistical comparison);(D) if a tolerance interval or a prediction interval is used to evaluate water quality monitoring data, the levels of confidence and, for tolerance intervals, the percentage of the population that the interval must contain shall be proposed by the discharger and submitted for approval by the regional board. The regional board may approve the parameters only if it finds these statistical parameters to be protective of human health and the environment. These statistical parameters shall be determined after considering the number of samples in the background data base, the data distribution, and the range of the concentrations or values for each constituent of concern or monitoring parameter. The coverage of any tolerance interval used shall be no more than 95 percent and the confidence coefficient shall be no more than 95 percent for a six-month period. Prediction intervals shall be constructed with an experiment-wise error rate of no less than 5 percent and an individual monitoring point error rate of no less than 1 percent;(E) the statistical method shall account for data below the practical quantitation limit with one or more statistical procedures that are protective of human health and the environment. Any practical quantitation limit approved by the regional board pursuant to subsection (e)(7) of this section that is used in the statistical method shall be the lowest concentration (or value) that can be reliably achieved within limits of precision and accuracy specified in the waste discharge requirements for routine laboratory operating conditions that are available to the facility. The regional board shall consider the practical quantitation limits listed in Appendix IX to Chapter 14 of Division 4.5 of Title 22, California Code of Regulations (Appendix IX) for guidance when specifying limits of precision and accuracy in the waste discharge requirements;(F) if necessary, the statistical methods shall include procedures to control or correct for seasonal and spatial variability as well as temporal correlation in the data; and(G) any quality control procedure that is approved by the regional board for application to water quality data from downgradient monitoring points for a monitored medium shall also be applied to all newly-acquired background data from that medium. Any newly-acquired background monitoring datum that is rejected by an approved quality control procedure shall be maintained in the facility record but shall be excluded from use in statistical comparisons with downgradient water quality data.(10) Based on the data collected pursuant to subsection (e)(6) of this section and the statistical methods proposed under subsection (e)(7) of this section, the discharger shall propose and justify the use of a procedure for determining a background value for each constituent of concern and for each monitoring parameter specified in the waste discharge requirements. These procedures shall be proposed for ground water, surface water, and the unsaturated zone. The discharger shall propose one of the following for approval by the regional board: (A) a procedure for determining a background value for each constituent or parameter that does not display appreciable variation; or(B) a procedure for establishing and updating a background value for a constituent or parameter to reflect changes in the background water quality if the use of contemporaneous or pooled data provides the greatest power to the statistical method for that constituent or parameter.(11) Upon approval of the procedures for determining background values, proposed pursuant to subsection (e)(10) of this section, the regional board shall specify in the waste discharge requirements one of the following for each constituent of concern and for each monitoring parameter: (A) a background value established by the discharger using the procedure proposed pursuant to subsection (e)(10)(A) of this section; or(B) a detailed description of the procedure to be used by the discharger for establishing and updating a background value as proposed pursuant to subsection (e)(10)(B) of this section.(12) For each constituent of concern and monitoring parameter listed in the waste discharge requirements, the discharger shall propose, for approval by the regional board, the sampling methods to be used to establish background values and the sampling methods to be used for monitoring pursuant to this article. Upon approval by the regional board, sampling methods consistent with the following shall be specified in waste discharge requirements:(A) the number and kinds of samples collected shall be appropriate for the form of statistical test employed, following generally accepted statistical principles. The sample size shall be as large as necessary to ensure with reasonable confidence that: 1. for a detection monitoring program, a release from the waste management unit will be detected;2. for an evaluation monitoring program, changes in water quality due to a release from the waste management unit will be recognized; and3. for a corrective action program, compliance with the water quality protection standard and effectiveness of the corrective action program will be determined; and(B) the sampling method (including the sampling frequency and the interval of time between successive samples) shall be appropriate for the medium from which samples are taken (e.g., ground water, surface water, and soil-pore liquid). For ground water, sampling shall be scheduled to include the times of expected highest and lowest elevations of the potentiometric surface. The sampling method shall assure, to the greatest extent possible, that independent samples are obtained. In addition to any pre-sampling purge prescribed in the sampling and analysis plan, ground water monitoring wells shall be purged immediately after sampling is completed in order to remove all residual water that was in the well bore during the sampling event so as to assure the independence of samples from successive sampling events. The volume of well water to be withdrawn from the well bore for the post-sampling purge shall be determined by the same method used to determine adequate pre-sampling purging. The sampling method selected shall include either:1. a sequence of at least four samples collected at least semi-annually from each monitoring point and background monitoring point and statistical analysis carried out at least semi-annually. The regional board shall require more frequent sampling and statistical analysis where necessary to protect human health or the environment; or2. not less than one sample collected quarterly from each monitoring point and background monitoring point and statistical analysis performed at least quarterly.(13) The ground water portion of the monitoring program shall include an accurate determination of the ground water surface elevation and field parameters (temperature, electrical conductivity, turbidity, and pH) at each well each time ground water is sampled.(14) The discharger shall graph all analytical data from each monitoring point and background monitoring point and shall submit these graphs to the regional board at least once annually, except that graphs are not required for constituents for which no new data has been collected since the previous graph submittal. Graphs shall be at a scale appropriate to show trends or variations in water quality. All graphs for a given constituent shall be plotted at the same scale to facilitate visual comparison of monitoring data. Unless the discharger receives written approval from the regional board to use an alternate procedure that more effectively illustrates trends or variations in the data, each graph shall represent data from one monitoring point or background monitoring point and one constituent of concern or monitoring parameter.(15) In addition to the water quality sampling conducted pursuant to the requirements of this article, the discharger shall measure the water level in each well and determine ground water flow rate and direction in the uppermost aquifer and in any zones of perched water and in any additional portions of the zone of saturation monitored pursuant to subsection (b)(1) of this section at least quarterly, including the times of expected highest and lowest elevations of the water levels in the wells.(16) Water quality monitoring data collected in accordance with this article, including actual values of constituents and parameters, shall be maintained in the facility operating record. The regional board shall specify in the waste discharge requirements when the data shall be submitted for review.Cal. Code Regs. Tit. 23, § 2550.7
1. New section filed 5-24-91; operative 7-1-91 (Register 91, No. 22). Note: Authority cited: Section 1058, Water Code. Reference: Sections 13172, 13263, and 13267, Water Code.
1. New section filed 5-24-91; operative 7-1-91 (Register 91, No. 22).