Water from the Sacramento-San Joaquin Delta contains high concentrations of disinfection byproduct-forming (DBP-forming) materials when treated for potable use. DBPs form when dissolved organic compounds (DOC) in water react with disinfectants such as chlorine and ozone during the water treatment process. The amount of DBPs that form is a function of both the amount and source of the DOC, both of which can vary significantly over a period of days. Epidemiological studies have linked several DBPs to increased occurrence of bladder cancer, miscarriages, and leukemia. Treated Delta water frequently exceeds DBP concentrations permitted by U.S. Environmental Protection Agency regulations.
A variety of natural and anthropogenic processes affect the concentration and composition of DOC in the Delta, some of which are likely to be affected by CalFed actions. Presently, there is little information available regarding historic levels and trends in the amount and composition of DOC released from, for example, in-channel biological production, wetlands, agricultural sources, island drains and the myriad of other DOC sources present in a system as large and complex as the Delta and its watersheds. A quantitative understanding of these processes is an important part of a CalFed solution to drinking water issues. In addition, assessment of the impact of CalFed Delta changes and integrated storage solutions on water users requires that DOC changes be monitored. To quantify potential changes, the baseline levels and current trends must be characterized and understood.
These goals are achieved by analysis of existing time-series data of a variety of types. The techniques used to analyze the data include spectral analysis and multiple parameter regression. Published reports include information on the baseline, trends, and major factors affecting DOC in the Delta, and on evaluating predictive/statistical models for quantitative assessment of changes and recommending effective monitoring solutions.
Below are publications associated with this project.
Chemically enhanced treatment wetland to improve water quality and mitigate land subsidence in the Sacramento-San Joaquin Delta: Cost and design considerations
Sequestration and transformation in chemically enhanced treatment wetlands: DOC, DBPPs and Nutrients
Procedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter
Wetlands receiving water treated with coagulants improve water quality by removing dissolved organic carbon and disinfection byproduct precursors
Optical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation
How reservoirs alter drinking water quality: Organic matter sources, sinks, and transformations
Landscape scale controls on the vascular plant component of dissolved organic carbon across a freshwater delta
Assessing the contribution of wetlands and subsided islands to dissolved organic matter and disinfection byproduct precursors in the Sacramento-San Joaquin River Delta: A geochemical approach
- Overview
Water from the Sacramento-San Joaquin Delta contains high concentrations of disinfection byproduct-forming (DBP-forming) materials when treated for potable use. DBPs form when dissolved organic compounds (DOC) in water react with disinfectants such as chlorine and ozone during the water treatment process. The amount of DBPs that form is a function of both the amount and source of the DOC, both of which can vary significantly over a period of days. Epidemiological studies have linked several DBPs to increased occurrence of bladder cancer, miscarriages, and leukemia. Treated Delta water frequently exceeds DBP concentrations permitted by U.S. Environmental Protection Agency regulations.
A variety of natural and anthropogenic processes affect the concentration and composition of DOC in the Delta, some of which are likely to be affected by CalFed actions. Presently, there is little information available regarding historic levels and trends in the amount and composition of DOC released from, for example, in-channel biological production, wetlands, agricultural sources, island drains and the myriad of other DOC sources present in a system as large and complex as the Delta and its watersheds. A quantitative understanding of these processes is an important part of a CalFed solution to drinking water issues. In addition, assessment of the impact of CalFed Delta changes and integrated storage solutions on water users requires that DOC changes be monitored. To quantify potential changes, the baseline levels and current trends must be characterized and understood.
These goals are achieved by analysis of existing time-series data of a variety of types. The techniques used to analyze the data include spectral analysis and multiple parameter regression. Published reports include information on the baseline, trends, and major factors affecting DOC in the Delta, and on evaluating predictive/statistical models for quantitative assessment of changes and recommending effective monitoring solutions.
- Publications
Below are publications associated with this project.
Chemically enhanced treatment wetland to improve water quality and mitigate land subsidence in the Sacramento-San Joaquin Delta: Cost and design considerations
Water quality impairment and land surface subsidence threaten the viability of the Sacramento-San Joaquin Delta (Delta), a critical component of California’s water conveyance system. Current day irrigation drainage through Delta island peat soils impacts drinking water treatment and is linked to mercury transport, potentially posing both ecological and public health concerns. Hybrid coagulation-trAuthorsPhilip A. M. Bachand, Tamara E. C. Kraus, William R. Horwath, Nathan R. Hatch, Sandra M. BachandSequestration and transformation in chemically enhanced treatment wetlands: DOC, DBPPs and Nutrients
We examined the effectiveness of chemically enhanced treatment wetlands (CETWs), wetlands that received water treated with coagulants, to remove dissolved organic carbon (DOC), disinfection byproduct precursors (DBPPs), nutrients and metals from agricultural drain water. Wetlands consisted of controls with no coagulant addition, ferric sulfate dosed and polyaluminum chloride dosed treatments. CETWAuthorsPhilip A. M. Bachand, Sandra M. Bachand, Tamara E. C. Kraus, Dylan Stern, Yan Ling Liang, William R. HorwathProcedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter
Advances in spectroscopic techniques have led to an increase in the use of optical measurements (absorbance and fluorescence) to assess dissolved organic matter composition and infer sources and processing. Although optical measurements are easy to make, they can be affected by many variables rendering them less comparable, including by inconsistencies in sample collection (for example, filter porAuthorsAngela M. Hansen, Jacob Fleck, Tamara E. C. Kraus, Bryan D. Downing, Travis von Dessonneck, Brian A. BergamaschiWetlands receiving water treated with coagulants improve water quality by removing dissolved organic carbon and disinfection byproduct precursors
Constructed wetlands are used worldwide to improve water quality while also providing critical wetland habitat. However, wetlands have the potential to negatively impact drinking water quality by exporting dissolved organic carbon (DOC) that upon disinfection can form disinfection byproducts (DBPs) like trihalomethanes (THMs) and haloacetic acids (HAAs). We used a replicated field-scale study locaAuthorsAngela M. Hansen, Tamara E. C. Kraus, Sandra M. Bachand, William R. Horwath, Philip A.M. BachandOptical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation
Advances in spectroscopic techniques have led to an increase in the use of optical properties (absorbance and fluorescence) to assess dissolved organic matter (DOM) composition and infer sources and processing. However, little information is available to assess the impact of biological and photolytic processing on the optical properties of original DOM source materials. We measured changes in commAuthorsAngela Hansen, Tamara E. C. Kraus, Brian Pellerin, Jacob Fleck, Bryan D. Downing, Brian A. BergamaschiHow reservoirs alter drinking water quality: Organic matter sources, sinks, and transformations
Within reservoirs, production, transformation, and loss of dissolved organic matter (DOM) occur simultaneously. While the balance between production and loss determines whether a reservoir is a net sink or source of DOM, changes in chemical composition are also important because they affect DOM reactivity with respect to disinfection by-product (DBP) formation. The composition of the DOM pool alsoAuthorsTamara E.C. Kraus, Brian A. Bergamaschi, Peter J. Hernes, Daniel H. Doctor, Carol Kendall, Bryan D. Downing, Richard F. LoseeLandscape scale controls on the vascular plant component of dissolved organic carbon across a freshwater delta
Lignin phenol concentrations and compositions were determined on dissolved organic carbon (DOC) extracts (XAD resins) within the Sacramento-San Joaquin River Delta (the Delta), the tidal freshwater portion of the San Francisco Bay Estuary, located in central California, USA. Fourteen stations were sampled, including the following habitats and land-use types: wetland, riverine, channelized waterwayAuthorsRobert S. Eckard, Peter J. Hernes, Brian A. Bergamaschi, Ramunas Stepanauskas, Carol KendallAssessing the contribution of wetlands and subsided islands to dissolved organic matter and disinfection byproduct precursors in the Sacramento-San Joaquin River Delta: A geochemical approach
This study assesses how rivers, wetlands, island drains and open water habitats within the Sacramento-San Joaquin River Delta affect dissolved organic matter (DOM) content and composition, and disinfection byproduct (DBP) formation. Eleven sites representative of these habitats were sampled on six dates to encompass seasonal variability. Using a suite of qualitative analyses, including specific DBAuthorsT.E.C. Kraus, B.A. Bergamaschi, P.J. Hernes, R.G.M. Spencer, R. Stepanauskas, C. Kendall, R.F. Losee, R. Fujii