Delta Regional Monitoring Program (RMP) - Water Quality Monitoring

  Water Quality Monitoring & Studies

Pesticides & Toxicity

2018 is Year 1 of a multi-year study of current-use pesticides and aquatic toxicity in the Sacramento-San Joaquin Delta. A rotating basin monitoring design with monitoring at two fixed sites will begin in October 2018, the “option 2” described in the 2018-19 DRMP Pesticides and Toxicity Monitoring Proposal. This proposal describes a 4-year monitoring program covering six Delta sub-regions after which an interpretive report will inform adaptive management and improve future monitoring.


Stations for Model Assessment
Stations with data that will be used for the modeling analysis.
Stations with data that will be used for the modeling analysis. Model verification plots will be made for a subset of these stations covering all areas of the Delta.

Data Synthesis and Modeling
For this study, we propose to combine a hydrodynamic-biogeochemical model of the Delta in WY2016 with water quality measurements in order to understand what caused large phytoplankton blooms in this year. The approach will be to apply a biogeochemical model developed for WY2011 to WY2016 and then to compare the model predictions to measurements made throughout the Delta. Comparisons between the model and observations will provide insight into important mechanisms for phytoplankton productivity including physical and other influencing factors. The study will be a first step toward implementing priority research recommendations in the Delta Nutrient Research Plan. The study design leverages in-kind modeling resources from the Department of Water Resources and takes advantage of studies being funded by other parties. Finally, this project implements a recommendation to increase data sharing among different models and monitoring programs.

Intercalibration Study for Chlorophyll Fluorescence Sensors in the Bay-Delta
Chlorophyll is an important water quality parameter for assessing the effects of nutrients and for fisheries management in the Bay-Delta. This study is the second phase of a multi-year effort to improve the accuracy, precision, and comparability of chlorophyll data collected in the Bay-Delta. Phase I planning has shown that variability in the methods used for measurement chlorophyll across the Bay-Delta is significant and that reducing this variance is of interest to a wide variety of monitoring agencies. In FY18/19, we propose to tackle a portion of the problem with a series of tasks to help understand and reduce the variance in the measurements of chlorophyll by in-situ sensors and laboratory methods. The proposed tasks for 2018 include: (1) assessing methods used by different monitoring programs; (2) performing field intercalibration exercises between programs; (3) organizing a laboratory intercalibration study; and (4) preparing a summary report through technical workgroup discussion. The study leverages in-kind support from the Department of Water Resources and the US Bureau of Reclamation.


Continued monitoring of sport fish and water will address the highest priority information needs related to implementation and revision of the Methylmercury TMDL (re-opening of the TMDL is tentatively scheduled for 2020). Annual monitoring of sport fish will firmly establish baseline concentrations and interannual variation in support of monitoring of long-term trends as a critical performance measure for the TMDL. Monitoring of water on a near-monthly basis will solidify the linkage analysis (the quantitative relationship between methylmercury in water and methylmercury in sport fish) in the TMDL and contribute to verifying trends and patterns predicted by a numerical model of methylmercury transport and cycling being developed for the Delta and Yolo Bypass by the California Department of Water Resources (DWR). The 8 water sampling event option was selected for 2018-19 monitoring described in the proposal below.

Graphic of Large Mouth Bass - Saber Tooth Co.

Mercury Sampling Sites

Map of Delta Regional Monitoring Program 2018-19 Mercury Monitoring
Click image for larger version of map


The two-year Pathogen Study was completed in April 2017. It was designed to fulfill the dual purpose of characterizing ambient conditions for pathogens (Cryptosporidium and Giardia) throughout the Sacramento-San Joaquin Delta, and satisfying Basin Plan requirements. The study coordinates water agency intake sample collection for the United States Environmental Protection Agency (USEPA) Long Term 2 Enhanced Surface Water Treatment Rule (LT2) between April 2015 and April 2017 with ambient sample collection. The Delta RMP collected ambient samples at twelve locations through in-kind field support by the Municipal Water Quality Investigations (MWQI) section of the Department of Water Resources (DWR), and in-kind contributions from Workgroup members to oversee sample collection and data assessment. The study was phased to perform a Year 1 assessment of characterization data and then a more targeted Delta subarea evaluation of infectibility, source tracking, hydrodynamics, and decay and growth. However, monitoring results were all below threshold values in the first year and targeted studies were not necessary during the second year.

Contaminants of Emerging Concern (CEC)

In 2018-19, the Delta RMP will develop a Quality Assurance Program Plan (QAPP) and plan for program implementation of the CEC Pilot Study. Program implementation will include optimization of the pilot study work plan, logistics planning, sample collection and analysis vendor selection process administration, contract set-up with vendors, coordination with other monitoring programs, facilitation of the Technical Advisory Committee CEC Subcommittee, and start-up mobilization for 2019-2020 sample collection.