SECTION 3.0 MONITORING PLAN APPROACH
The interim GBP is intended to remove unusable water from wetland water supply conveyance channels. The project, by combining drainage flow within the SLD, will provide the opportunity for more focused monitoring which may in turn result in improved management of those flows. The project should allow for better measurement of the selenium load being discharged from the Grassland Basin. Further, the monitoring program will provide data which may elucidate the selenium flux (e.g. in-transit losses) between the water column, biota and sediment. Finally, the results of this monitoring program, coupled with information about concurrent drainage management techniques that may be employed by the SLD-MWA, may aid in the identification of effective means by which to improve drainage management in the Basin and attain regulatory water quality standards.
3.2 Monitoring Plan Objectives
Table 3.1 outlines the monitoring plan objectives and the tasks which are intended to address each objective. The monitoring plan is designed as a working document. The results of the monitoring effort will be reviewed on a regular basis to determine whether modifications to the tasks are necessary. Such modifications might include reduction or expansion of the sampling effort.
The following are the working hypotheses underlying the monitoring plan objectives.
1. The GBP monitoring plan will provide the opportunity to collect information, which, if supplemented and augmented with information collected by the water districts themselves and related ongoing and additional agency investigations, will permit greater understanding of the interactions between a) agricultural drainage management and water quality; and b) selenium fate and transport and environmental health.
2. The re-routing of agricultural drainage flows to the SLD and Mud Slough is predicted to degrade environmental conditions in Mud Slough initially. A long-term program of selenium load reductions, however, is predicted to improve environmental conditions over time. Monitoring will be critical in determining environmental conditions in Mud Slough, and documenting changes over time.
3. The re-routing of agricultural drainage flows to Mud Slough is predicted to improve environmental conditions in Salt Slough and the Grasslands channels and to provide improved water management for wetland managers. Monitoring biota, water quality, and sediment in Salt Slough and water quality in the Grasslands channels will document the changes.
4. The re-routing of agricultural drainage flows into the SLD and Mud Slough is predicted to have little impact on the water quality of the San Joaquin River. A long-term program of selenium load reductions, however, is predicted to improve environmental conditions over time. Monitoring will be critical in determining environmental conditions in the San Joaquin River and documenting changes due to the Project over time.
5. Not all of the findings and commitments are of such a nature that they can be measured by environmental sampling.
The monitoring objectives were formulated with these hypotheses in mind and are intended to provide the information necessary to determine whether project commitments are being met.
Monitoring Plan Objectives
The primary objective of the Monitoring Plan is to meet the first goal of the project articulated in Section 1.4.1; i.e., to measure compliance with the environmental commitments included in the Use Agreement, the Environmental Assessment, the Supplemental EA, the FONSI, and the consensus letter to the Regional Board.
The specific objectives of the Monitoring Plan are:
1. to assess environmental conditions in the SLD by measuring selenium concentrations and other parameters in water, sediment and biota.
2. to assess the changes in environmental conditions in Mud Slough from pre-project conditions which are related to discharges from the SLD by measuring selenium concentrations and other parameters in water, sediment and biota.
3. to assess the changes in environmental conditions in Salt Slough from pre-project conditions which are related to the removal of agricultural drainage water from these water bodies by measuring selenium concentrations and other parameters in water, sediment and biota and to verify that poor quality agricultural drainage water is removed from GWD channels by measuring water quality in these channels.
4. to assess the changes in environmental conditions in the San Joaquin River from pre-project conditions which are related to the re-routing of agricultural drainage water from the Grasslands channels and Salt Slough to the SLD and Mud Slough by measuring selenium concentrations and other parameters in water and biota.
5. to assess event-driven selenium concentration changes in sediment, water and biota which are related to the project as they are coincident with collecting data to meet other monitoring plan objectives, and by collection of data during unique events as possible.
To achieve these objectives, existing data describing pre-project conditions will be assembled into a readily available database, for comparison with data collected after the GBP is implemented.
Data quality objectives (DQO) for the project are defined in the Quality Assurance Project Plan (QAPP) that accompanies the Monitoring Plan. Each agency has established DQOs for every field and laboratory parameter it is responsible for measuring. Agency DQOs are discussed in detail in the text of the QAPP (Section 2.5), and summarized collectively in Table 3 of that document. Discussion of DQOs includes definitions for the quantitative goals of precision, accuracy and completeness, and the qualitative goals of representativeness and comparability. Not all objectives are relevant to each type of data collected by the various agencies.
The quantitative DQOs include precision, accuracy and completeness. Precision is defined as the agreement among a set of replicate measurements with no assumption that a true value is known. Accuracy is the closeness of agreement between an observed value and an accepted reference value. A stated percent of samples collected properly and analyzed acceptably constitutes a complete data set.
The qualitative DQOs include representativeness and comparability. In the discussion of representativeness of a sample site, the rationale for the sampling design is provided. Demonstration of sample representativeness involves a description of the steps by which the sample is collected. Comparability refers to the methods used to collect and analyze the sample. The Standard Operating Procedures (SOPs) should outline methods commonly used by laboratories or, if the methods are modified for the project, these changes should be documented. Finally, the results should be available to be included in an inter- or intra-laboratory data base.
Overall, the GBP monitoring tasks are designed to measure compliance with selenium load levels and to detect impacts due to the GBP. Another overall goal of the Project, as described in Section 1.4.1, is to improve, where possible, the current scientific understanding of selenium fate and transport. The monitoring approach provides the opportunity to increase the general understanding of selenium mass balance within the SLD (Grassland Bypass), Mud and Salt Slough and the San Joaquin River. The plan was developed and the tasks assigned to minimize duplication of effort, maximize cost effectiveness, and to coordinate reporting so that the GBP may have timely information to make informed decisions regarding the management of the GBP.
The plan provides for the collection of data that will monitor the selenium load from the GBP that is delivered to the San Joaquin River. The selenium load targets that must be achieved in the compliance program for the next five years are presented in Section 1.0, Table 1.1. Flow, salinity, selenium, and boron discharged to the San Joaquin River from the GBP area will also be monitored and compared to historic discharges from the area to evaluate and verify that the project does not adversely affect water quality in the San Joaquin River. The biological data will be compared to the ecological risk guidelines developed by USFWS (USFWS, 1995) and other relevant information.
3.4.2 Selenium Mass Balance in the System
The basis for any resource monitoring plan is a conceptual model of how the resource system operates. Mass balance is an appropriate conceptual model for the GBP. It is not the objective nor design of the monitoring plan in and of itself to determine definitive mass balances for selenium or other constituents; nevertheless, a mass balance approach to the GBP MP provides a valuable framework and philosophical rationale for various elements of the program. The mass balance approach will help to identify deficiencies and redundancies in data gathering, help to identify the need for adjustments to the monitoring program, and facilitate cooperation and coordination of data gathering and integration with related research or investigations that may be undertaken.
Review of data collected during the monitoring
program, particularly if coupled with investigations that
could be undertaken in conjunction with monitoring, will help
develop a better understanding of the fate of selenium within
and between the several media (sediment, water, biota) in the
environment. The physical, chemical, biological and toxicity
analyses will allow for the tracking of selenium input and
output, and will provide a stronger scientific basis for
predicting effects.
Use of the data base produced by the monitoring tasks, especially if coupled with data from other existing programs and related investigations that might be undertaken, will increase understanding of the mass balance of selenium throughout the study area. The data base will provide opportunities for further coordinated efforts to identify and understand the relevant components of a mass balance model including; 1. sources of selenium and salts to the SLD from surface and subsurface agricultural drainage and groundwater, 2. fluxes of selenium and salts among water, sediment, and biota in the GBP and receiving waters, 3. transport of selenium and salts in the SLD to receiving waters, and 4. fate and effect of selenium and salts in these receiving waters. Additionally, information from the monitoring program will be available and can be consulted by the GBD when interpreting the effect of irrigation events and other actions on drainage flows. An effort will be made to collect data during unusual events, such as storm-related flooding, which may or may not coincide with scheduled monitoring. Finally, an effort could also be made to determine the dominant selenium species within the study area, both temporally and spatially, as possible.
The defined tasks of the monitoring plan will provide some of this information, but it will need to be supplemented through separate, specifically focused investigations.
3.4.3 Integration with Research/Investigations Activities
The distinction between compliance monitoring needs for the GBP, and research/investigation needs to improve selenium and drainage management, has been and will likely continue to be blurred. The compliance monitoring plan is designed to measure whether the GBP meets the commitments made in the UA, EA/FONSI, and consensus letter to the CVRWQCB and to improve, where possible through the monitoring program, the current scientific understanding of selenium fate and transport. However, additional research and investigations will be required to address questions related to selenium mobilization, fate, and transport in order to better predict and prevent impacts, to develop, implement and evaluate improved drainage management techniques, and through these efforts develop and implement a long term drainage management plan.
The comprehensive data collection effort undertaken
for the monitoring program may allow more in-depth,
interagency research projects to be performed than might have
been otherwise possible.
The data collection, reporting and dissemination process will be implemented to foster close cooperation and coordination, not only with the agencies and organizations involved in the monitoring program but also with the research community.
The monitoring plan is designed as a coordinated effort among USBR, USFWS, USGS, CVRWQCB, CDFG, and SLD-MWA. The monitoring plan has been designed to incorporate, where possible, the existing monitoring efforts of participating agencies. The monitoring plan is conceived as a working document which will be modified periodically, based on a review of the data relative to the project objectives and commitments. Should certain monitoring efforts appear to add little to the understanding of conditions resulting from this project, they may be reduced or eliminated. Conversely, should monitoring objectives or project commitments not be met or satisfactorily evaluated by the current plan, the effort may be expanded.
Each agency has responsibility for collecting and analyzing the data associated with its particular area of expertise. USBR will collect sediment data. USGS and USBR will collect flow data. USFWS and CDFG will collect biological data. CVRWQCB will collect water quality data. SLD-MWA will, through its consultant, perform sediment quantity surveys and collect toxicity data. The monitoring effort of USFWS and CDFG will overlap with that of other agencies in those cases where USFWS or CDFG collect water and sediment data concurrently with their biota collections.
An independent data manager will be contracted to ensure that the results of the monitoring efforts of all agencies are compiled into monthly, quarterly and annual reports. The data manager will perform additional quality control/quality assurance tasks and develop and manage an accessible data base, in order to prepare accurate and timely data reports.