Natural Catchments as Sources of Background Levels of Storm-Water Metals, Nutrients, and Solids

Influence of Clay Mineralogy on Soil Dispersion Behavior and Water Quality

“…Monterey Formation, which is present in the study area, has been shown to be a source of phosphate loadings (Bisson et al, 1987;Egli et al, 2008;Horowitz and Elrick, 1987;Richards, 1982;Trefry and Metz, 1985;Yoon and Stein, 2008). The high CECs in study area soils indicate that the phyllosilicates will bind with phosphates from the parent material, and are capable of being carried into the surrounding surface waters as suspended sediment.…”

“…In this review I will concentrate on the sources of sediment carrying phosphorus and the negative effects they have on water quality. The type of soil parent material has an impact on the presence of metals and nutrients in eroded sediments (Yoon and Stein, 2008). Watersheds underlain by sedimentary rock generally have higher concentrations of metals, nutrients, and total suspended solids as compared to watersheds underlain by igneous rock.…”

“…Clay colloids have powerful adsorption properties, which means that the strong negative charge on the surface of a clay particle attracts cations to attach to their surface (Hillel, 1998). The nutrients and contaminants likely to be carried via adsorption by clay colloids include ammonia, phosphorus, copper, nickel, selenium, and most metals with the exception of arsenic (Calero et al, 2008;Harper, 1992;Wang et al, 2006;Yoon and Stein, 2008). In this review I will concentrate on the sources of sediment carrying phosphorus and the negative effects they have on water quality.…”

“…Watersheds underlain by sedimentary rock generally have higher concentrations of metals, nutrients, and total suspended solids as compared to watersheds underlain by igneous rock. In southern California, the Monterey Formation (mostly sedimentary rock) has been shown to be a source of phosphate loadings, which may contribute to algal growth in streams due to the decreased availability of oxygen (Bisson et al, 1987;Egli et al, 2008;Horowitz and Elrick, 1987;Richards, 1982;Trefry and Metz, 1985;Yoon and Stein, 2008). Calero et al, (2008) studied clay dispersivity in relation to phosphorus concentration, and found that the water dispersible clay portion of the soil carried 1/10 th of the soil's total phosphorus.…”

“…The studied soils are mostly Haploxerolls, and smectites dominate clay mineralogy (Table 4- (Bisson et al, 1987;Egli et al, 2008;Horowitz and Elrick, 1987;Richards, 1982;Trefry and Metz, 1985;Yoon and Stein, 2008).…”