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§ 20415. SWRCB--General Water Quality Monitoring and System Requirements. [C15: § 2550.7 // T15...

27 CA ADC § 20415Barclays Official California Code of Regulations

Barclays California Code of Regulations

Title 27. Environmental Protection

Division 2. Solid Waste (Refs & Annos)

Subdivision 1. Consolidated Regulations for Treatment, Storage, Processing or Disposal of Solid Waste

Chapter 3. Criteria for All Waste Management Units, Facilities, and Disposal Sites

Subchapter 3. Water Monitoring (Refs & Annos)

Article 1. SWRCB--Water Quality Monitoring and Response Programs for Solid Waste Management Units

27 CCR § 20415

§ 20415. SWRCB--General Water Quality Monitoring and System Requirements. [C15: § 2550.7 // T15: § 17783.5(d)]

Currentness

(a) The discharger shall comply with the requirements of this section for any water quality monitoring program developed to satisfy § 20420, § 20425, or § 20430 of this article.

(b) Ground Water Monitoring System.

(1) General--Except as provided under ¶(e)(3), the discharger shall establish a ground water monitoring system for each Unit. This ground water monitoring system shall include:

(A) For All Programs--for all monitoring and response programs, a sufficient number of Background Monitoring Points (as defined in § 20164) 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 Unit;

(B) For DMP--for a detection monitoring program under § 20420:

1. a sufficient number of Monitoring Points (as defined in § 20164) 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 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 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 ¶(b)(1)(B)1. and ¶(b)(1)(B)2., to provide the best assurance of the earliest possible detection of a release from the 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 Unit; and

5. Monitoring Point locations and depths that include the zone(s) of highest hydraulic conductivity in each ground water body monitored pursuant to this subsection [i.e., under ¶(b), inclusive].

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 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 ¶(b)(1)(C)1., to provide the data needed to evaluate changes in water quality due to the release from the Unit; and

3. 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 Unit; and

(D) For CAP--for a corrective action program under § 20430:

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 ¶(b)(1)(D)1., to provide the data needed to evaluate the effectiveness of the corrective action program; and

3. 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) Alternate Background Locations--The ground water monitoring system may include Background Monitoring Points that are not hydraulically upgradient of the Unit if the discharger demonstrates to the satisfaction of the RWQCB that sampling at other Background 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 Background Monitoring Points.

(3) Drillers' Logs--Copies of drillers' logs which the Department of Water Resources requires to be submitted pursuant to § 13751 of the California Water Code shall be submitted to the RWQCB.

(4) Monitoring Well Performance Standards.

(A) 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.

(B) 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.

(C) 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.

(D) All monitoring wells shall be adequately developed to enable collection of representative ground water samples.

(1) General--The discharger shall establish a surface water monitoring system to monitor each surface water body that could be affected by a release from the Unit.

(2) Each Monitored Surface Water Body--Each surface water monitoring system shall include:

(A) Background Monitoring Points--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 Unit;

(B) For DMP--for a detection monitoring program (under § 20420), 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 Unit;

(C) For EMP--for an evaluation monitoring program (under § 20425), 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 Unit; and

(D) For CAP--for a corrective action program (under § 20430), 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 Standard (of § 20390) and to evaluate the effectiveness of the corrective action program.

(d) Unsaturated Zone Monitoring System.

(1) Except as otherwise provided in ¶(d)(5), the discharger shall establish an unsaturated zone monitoring system for each Unit.

(2) The unsaturated zone monitoring system shall include:

(A) Background Monitoring Points--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 Unit;

(B) For DMP--for a detection monitoring program (under § 20420), 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 Unit;

(C) For EMP--for an evaluation monitoring program (under § 20425), 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 Unit; and

(D) For CAP--for a corrective action program (under § 20430), 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 Standard (of § 20390) and to evaluate the effectiveness of the corrective action program.

(3) Background Plot--Background Monitoring Points shall be installed at a background plot having soil characteristics similar to those of the soil underlying the Unit.

(4) Alternate Methods--Liquid recovery types of unsaturated zone monitoring (e.g., the use of lysimeters) are required unless the discharger demonstrates to the satisfaction of the RWQCB that such methods of unsaturated zone monitoring cannot provide an indication of a release from the Unit. The RWQCB shall require complementary or alternative (non-liquid recovery or remote sensing) types of unsaturated zone monitoring to provide the best assurance of the earliest possible detection of a release from the Unit.

(5) Exemption--Unsaturated zone monitoring is required at all new Units unless the discharger demonstrates to the satisfaction of the RWQCB that there is no unsaturated zone monitoring device or method designed to operate under the subsurface conditions existent at that Unit. For a 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 RWQCB that either there is no unsaturated zone monitoring device or method designed to operate under the subsurface conditions existent at that 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) Boring Logs--All monitoring wells and all other borings (including but not limited to gas monitoring wells) drilled to satisfy the requirements of this division shall be drilled by a licensed drilling contractor (or by a drilling crew under the direct supervision of the design engineer or engineering geologist), and shall be logged during drilling under the direct supervision of a person who is a registered geologist or a registered civil engineer, and who has expertise in stratigraphic well logging. These logs shall be submitted to the RWQCB upon completion of drilling.

(A) Soil shall be described in the geologic log in accordance with current industry-wide practices [e.g., American Society for Testing and Materials (ASTM) Designation “D2488-93 Method for Visual Classification, Standard Practice for Description and Identification of Soils (Visual-Manual Procedure)” for field work, with initial determinations backed up by laboratory work under ASTM Designation “D2487-93 Standard Classification of Soils for Engineering Purposes (Unified Soil Classification System),” available from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959].

(B) Rock shall be described in the geologic log in a manner appropriate for the purpose of the investigation.

(3) Shared Systems--If a facility contains contiguous Units, separate ground water monitoring systems are not required for each such Unit if the discharger demonstrates to the satisfaction of the RWQCB that the water quality monitoring program for each Unit will enable the earliest possible detection and measurement of a release from that Unit.

(4) QA/QC--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, including purging techniques, sampling equipment, and decontamination of sampling equipment;

(B) sample preservation and shipment;

(D) chain of custody control.

(5) Sampling & Analytical Methods--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 COC and the concentration or value of each Monitoring Parameter.

(6) Initial Background Sampling--For each Unit, the discharger shall collect all data necessary for selecting the appropriate data analysis methods pursuant to ¶(e)(7-9) and for establishing the background values specified pursuant to ¶(e)(10). 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 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) Propose Data Analysis Method(s)--Based on data collected pursuant to ¶(e)(6), the discharger shall implement data analysis methods allowed in ¶(e)(8) for each COC and for each Monitoring Parameter. The data analysis methods shall be used in evaluating water quality monitoring data. The specifications for each data analysis method shall include a detailed description of the criteria to be used for determining “measurably significant” (as that term is defined in § 20164) evidence of any release from the Unit and for determining compliance with the Water Standard. Each statistical test specified for a particular COC or Monitoring Parameter shall be conducted for that COC or Monitoring Parameter at each Monitoring Point. Where practical quantitation limits (PQLs) are used in any of the following data analysis methods to comply with ¶(e)(9)(E), the discharger shall identify the PQL to the RWQCB. The discharger shall:

(A) continue using the methods specified in the existing M&RP or

(B) submit to the RWQCB, before implementing the selected methods, a comprehensive technical report, certified by an appropriately registered professional, documenting that use of the proposed data analysis methods will comply with the performance standards outlined in ¶(e)(9, 10, & 12):

1. the RWQCB shall audit selected reports submitted pursuant to this subdivision for compliance and applicability, as deemed necessary by the RWQCB; and

2. the discharger shall not change the data analysis methods developed pursuant to this subdivision until the next review/update of the M&RP, unless directed to make changes by the RWQCB; or

(C) use any water quality data analysis software the SWRCB or RWQCB deems appropriate for such use, provided that the manner of such use is consistent with the manner of usage the SWRCB or RWQCB has deemed appropriate (without the need for additional substantiation), for that software, and further provided that the discharger notifies the RWQCB before initiating such use.

(8) Allowable Data Analysis Methods--The statistical data analysis requirement in this article do not preclude the use of a particular non-statistical method which can achieve the goal of the particular monitoring program at least as well as will the most appropriate statistical method. If statistical methods cannot meet these goals, the discharger's proposed non- statistical method must achieve the goal of the particular monitoring program adequately [see ¶(e)(12)(A)1.-3.]. For those monitoring data analyses in which statistical methods are used, the discharger shall use one of the following methods:

(A) Parametric ANOVA--a parametric analysis of variance (ANOVA) followed in all instances by a multiple comparisons procedure to identify “measurably significant” (see § 20164) evidence of a release from the 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) Nonparametric ANOVA--an ANOVA based on ranks followed in all instances by a multiple comparisons procedure to identify “measurably significant” (see § 20164) evidence of a release from the 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) Tolerance Interval--a tolerance or prediction interval procedure in which an interval for each COC or Monitoring Parameter is established from the distribution of the background data, and the value for each COC or Monitoring Parameter at each monitoring point is compared to the upper tolerance or prediction limit;

(D) Control Chart--a control chart approach that gives control limits for each COC or Monitoring Parameter; or

(E) Other Statistical Methods--any statistical test method submitted by the discharger including, but not limited to, any statistical method which includes a procedure to verify that there is “measurably significant” (see § 20164) evidence of a release from the 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 ¶(e)(9):

1. Discrete Retest Rule--if the verification procedure consists of discrete retests, rejection of the null hypothesis for any one of the retests shall be considered confirmation of “measurably significant” (see § 20164) evidence of a release;

2. Retest Sample Size--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 WDRs for that COC or Monitoring Parameter pursuant to ¶(e)(7). The number of additional samples (obtained at the indicating Monitoring Point for the indicating COC or Monitoring Parameter) shall be greater than or equal to the number of samples specified in the WDRs for that constituent or parameter pursuant to ¶(e)(12)(A);

3. 30-Day Resampling Window--if resampling at the interval identified for use in the initial statistical test pursuant to ¶(e)(12)(B) 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 “measurably significant” (see § 20164) evidence of a release pursuant to § 20420(g or i);

4. Data Mix (for Composite Retest)--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. Retest Effects on Type I Error Rate--the Type I error for statistical methods employing a retest procedure shall be as follows:

a. When Initial Test = Retest--in cases where the discharger proposes to use the same statistical test for both the initial test and the retest, either:

i. α for Composite Retest--for a verification procedure containing a composite retest, the statistical test method 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; or

ii. α for Discrete Retest (& Original Test Too)--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 ¶(e)(9), 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 (or COCs, as appropriate) being tested by statistical methods during that Reporting Period; W = the total number of Monitoring Points at the Unit (considering all monitored media); S = the number of times that suites of monitoring data from the Unit are subjected to initial statistical analysis within a period of six months (i.e., for Monitoring Parameter testing, S≥1, but for COC testing, S=1); and R = the number of discrete retests that are to be conducted at a Monitoring Point for a given COC or Monitoring Parameter whose initial statistical analysis, at that Monitoring Point, has indicated the presence of a release (i.e., R≥2); or

b. When Retest Differs From Initial Test Method--in cases where the discharger proposes to use a different statistical test for the composite or discrete retest than that which provided the initial indication of a release (e.g., parametric Tolerance Limit test facility-wide, following by a parametric Prediction Limit retest for any indicating Monitoring Point), the individual Monitoring Point error level requirements of ¶(e)(9)(B) do not apply. Nevertheless, the discharger shall demonstrate that the initial and retest method, in combination, provide:

i. a facility-wide false positive rate of ≥5%, for the indicated COC or Monitoring Parameter; and

ii. a statistical power equivalent to or better than the USEPA Reference Power Curve (see Section 5 and Appendix B of “Statistical Analysis of Ground-Water Monitoring Data at RCRA Facilities -- Addendum To Interim Final Guidance”, USEPA Office of Solid Waste, Washington, D.C., July, 1992), which is hereby incorporated by reference.

6. Reporting--the discharger shall report to the RWQCB 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; and

7. Scope--the verification procedure shall only be performed for the constituent(s) or parameters which has shown “measurably significant” (see § 20164) evidence of a release, and shall be performed for those Monitoring Points at which a release is indicated.

(9) Data Analysis Method Performance Standards--In cases where the discharger proposes to use a non-statistical data analysis method, the discharger shall demonstrate that it meets the performance standard given in the leading paragraph of ¶(e)(8). Each statistical method chosen under ¶(e)(7) for specification in the WDRs shall comply with the following performance standards for each six-month period:

(A) Fit & Performance--the statistical method used to evaluate water quality monitoring data shall be appropriate for the distribution of the COC 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 Unit. If the distribution of a COC 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 COC or Monitoring Parameters differ, more than one statistical method may be needed;

(B) α Level--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 Standard or with a background Monitoring Parameter value, the test shall be done at a Type I error rate (α, as a decimal fraction) no less than 0.01. If a multiple comparisons procedure is used, the Type I experiment-wise error rate (experiment- wise α) 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, control charts, or any method using discrete retests [for α levels applicable to the latter case, see ¶(e)(8)(E)5.b.];

(C) Control Chart Rate--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 included in the supporting documentation under ¶(e)(7). The discharger shall use the procedure only if the discharger's supporting documentation under ¶(e)(7) shows 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) Tol. Int./Pred. Int. Rate--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 included in the technical documenation submitted to the RWQCB pursuant to ¶(e)(7). The discharger can use the parameters only if the documentation submitted under ¶(e)(7) shows 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 COC 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) Addressing Censored Data--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 validated pursuant to ¶(e)(7) 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 WDRs for routine laboratory operating conditions that are available to the facility. The discharger's technical report, under ¶(e)(7) 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 WDRs;

(F) Seasonal/Spatial Variability--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) Outliers--any quality control procedure that is declared for use, in the technical report under ¶(e)(7), 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) Background Values/Procedures--Based on the data collected pursuant to ¶(e)(6) and the data analysis methods addressed in the technical report under ¶(e)(7), the discharger shall justify the use of a procedure for determining a background value for each COC and for each Monitoring Parameter specified in the WDRs. These procedures shall be proposed for ground water, surface water, and the unsaturated zone. The discharger shall declare and substantiate one of the following methods in the technical report under ¶(e)(7):

(A) By Reference to Historical Data--a procedure for determining a background value for each constituent or parameter that does not display appreciable variation; or

(B) By Using a Formula/Procedure--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 data analysis method for that constituent or parameter.

(11) [Reserved]

(12) Sampling Methods--For each COC and Monitoring Parameter listed in the WDRs, the discharger shall verify, in the technical report under ¶(e)(7), that the sampling methods to be used to establish background values and the sampling methods to be used for monitoring pursuant to this article are consistent with the following:

(A) Sample Size--the number and kinds of samples collected shall be appropriate for the form of data analysis employed and, in the case of statistical data analysis shall follow generally accepted statistical principles. The “sample size” (i.e., the number of water quality data points representing a given Monitoring Point or Background Monitoring Point) approved for the data analysis method shall be as large as necessary to ensure with reasonable confidence that:

1. for a detection monitoring program, a release from the Unit will be detected;

2. for an evaluation monitoring program, changes in water quality due to a release from the Unit will be recognized; and

3. for a corrective action program, compliance with the water quality protection standard and effectiveness of the corrective action program will be determined; and

(B) Data Collection & Analysis--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. For ground water, the discharger can use a post-sampling purge to assure sample independence whenever the time between successive sampling events (for a given COC or Monitoring Parameter) is insufficient to assure sample independence, in which case 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 collection of at least the appropriate number of new data points [pursuant to ¶(e)(12)(A)] at least semi-annually from each Monitoring Point and background monitoring point and data analysis carried out at least semi-annually. The RWQCB shall require more frequent sampling and statistical analysis than is stated in the discharger's technical report under ¶(e)(7) where necessary to protect human health or the environment.

(13) Elevation & Field Parameters--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) Annual Data Graphs--The discharger shall graph all analytical data from each Monitoring Point and Background Monitoring Point and shall submit these graphs to the RWQCB 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 RWQCB 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) G.W. Flow Direction--In addition to the water quality sampling conducted pursuant to the requirements of this article, the discharger shall measure the water elevation 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 ¶(b)(1) at least quarterly, including the times of expected highest and lowest elevations of the water levels in the wells.

(16) Operating Record--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 RWQCB shall specify in the WDRs when the data shall be submitted for review.

Credits

Note: Authority cited: Section 1058, Water Code. Reference: Sections 13172, 13263 and 13267, Water Code; and Section 43103, Public Resources Code.