Abstract
A new method of investigating the mode of metals transport in rivers is introduced. It is applied to the Sacramento-San Joaquin Delta, an estuary located at the mouth of the Sacramento River, which has continued to have a number of stressors causing decrease in water quality. The goal of this work is to determine the mode of transport for these and other metals in the river. Regional San (Sacrament County Regional Sanitation District) has conducted a study with AMS (Applied Marine Sciences, Inc.) and Resource Management Associates, Inc. in order to determine the fate of phytoplankton in the Sacramento River. As part of this study, collection of samples at 15 sites between Knights Landing and Isleton was done. These samples were measured for total metals and filtered metals at each of these sites. A method is developed using this data to determine if metals are transported as dissolved, within colloids, within river biota, or attached to colloid surfaces. Metals such as aluminum and iron are shown to be transported primarily as part of the colloid structures, metals such as molybdenum and sodium are shown to be transported primarily as the dissolved species, containment within river biota is not a major metals transport mechanism, and most metals such as arsenic and selenium are transported on colloid surfaces. In addition, some observations concerning the source of these metals are made, which correspond to observations in other works.