Geology topics
D. A. Rickert
Publications and source records attributed to D. A. Rickert.
Toxic Substances Hydrology Program
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Use of dissolved oxygen modeling results in the management of river quality
In 1973, the U.S. Geological Survey initiated a study of the Willamette River, Oregon, to determine the major causes of dissolved oxygen (DO) depletion, and whether advanced treatment of municipal wastewaters was needed to achieve the DO standards. The study showed that rates of carbonaceous decay were low (kr = 0.03-0.06/day) and that point-source loadings of carbonaceous biochemical oxygen demand (BOD) accounted for less than one-third of the satisfied oxygen demand. Nitrification of industrially discharged ammonia was the dominant cause of DO depletion. The study led to the calibration and verification of a steady-state DO model which was used to examine selected scenarios of BOD loading, ammonia loading, and flow augmentation. In 1976, the modeling projections for the Willamette River were presented to resource managers. A review in 1981 indicated that the State of Oregon had instituted an effluent standard on the major discharger of ammonia, rescinded an order for all municipal wastewaters to receive advanced secondary treatment by 1980, and more fully acknowledged the need for flow augmentation during summer to attain the DO standards.
Steady-state dissolved oxygen model of the Willamette River, Oregon
For nearly half a century the Willamette River in Oregon experienced severe dissolved-oxygen problems related to large loads of organically rich waste waters from industries and municipalities. Since the mid-1950 's dissolved oxygen quality has gradually improved owing to low-flow augmentation, the achievement of basinwide secondary treatment, and the use of other waste-management practices. As a result, summer dissolved-oxygen levels have increased, salmon runs have returned, and the overall effort is widely regarded as a singular water-quality success. To document the improved dissolved-oxygen regimen, the U.S. Geological Survey conducted intensive studies of the Willamette during the summer low-flow seasons of 1973 and 1974. During each summer the mean daily dissolved-oxygen levels were found to be higher than 5 milligrams per liter throughout the river. Because of the basinwide secondary treatment, carbonaceous deoxygenation rates were low. In addition, almost half of the biochemical oxygen demand entering the Willamette was from diffuse (nonpoint) sources rather than outfalls. These results indicated that point-source biochemical oxygen demand was no longer the primary cause of dissolved-oxygen depletion. Instead, the major causes of deoxygenation were nitrification in a shallow ' surface active ' reach below Salem and an anomalous oxygen demand (believed to be primarily of benthal origin) in Portland Harbor. (Woodard-USGS)
Erosional-depositional province map of the Willamette River basin, Oregon
No abstract available.
Regional analysis of the effects of land use on stream-water quality; methodology and application in the Susquehanna River Basin, Pennsylvania and New York
A framework is presented for compiling available data for assessing statistical relationships between water quality and climate, physiography and land use. Seventeen water-quality characteristics studied represent annual mean concentrations or calculated annual yields of suspended sediment, dissolved solids and various chemical species of nitrogen and phosphorus. Usable multiple-linear regressions were developed relating water-quality characteristics to basin characteristics for 14 of the 17 water-quality characteristics with standard errors of estimate ranging from 17 to 75 percent. These models can be used to estimate water quality at specific stream sites or to simulate the generalized effect of land-use characteristics on water quality. For example, observed nitrate yields were up to 20 times greater than the simulated background yields. This increase is indicated to be the result of chemical fertilizers, animal wastes, and urbanization. It was concluded that this was a viable method of assessing the relationships between water quality and basin characteristics on a regional basis. (Woodard-USGS)
Dissolved-oxygen regimen of the Willamette River, Oregon, under conditions of basinwide secondary treatment
For nearly half a century the Willamette River in Oregon experienced severe dissolved-oxygen problems related to large loads of organically rich waste waters from industries and municipalities. Since the mid-1950 's dissolved oxygen quality has gradually improved owing to low-flow augmentation, the achievement of basinwide secondary treatment, and the use of other waste-management practices. As a result, summer dissolved-oxygen levels have increased, salmon runs have returned, and the overall effort is widely regarded as a singular water-quality success. To document the improved dissolved-oxygen regimen, the U.S. Geological Survey conducted intensive studies of the Willamette during the summer low-flow seasons of 1973 and 1974. During each summer the mean daily dissolved-oxygen levels were found to be higher than 5 milligrams per liter throughout the river. Because of the basinwide secondary treatment, carbonaceous deoxygenation rates were low. In addition, almost half of the biochemical oxygen demand entering the Willamette was from diffuse (nonpoint) sources rather than outfalls. These results indicated that point-source biochemical oxygen demand was no longer the primary cause of dissolved-oxygen depletion. Instead, the major causes of deoxygenation were nitrification in a shallow ' surface active ' reach below Salem and an anomalous oxygen demand (believed to be primarily of benthal origin) in Portland Harbor. (Woodard-USGS)
Formulation and use of practical models for river-quality assessment
For nearly half a century the Willamette River in Oregon experienced severe dissolved-oxygen problems related to large loads of organically rich waste waters from industries and municipalities. Since the mid-1950 's dissolved oxygen quality has gradually improved owing to low-flow augmentation, the achievement of basinwide secondary treatment, and the use of other waste-management practices. As a result, summer dissolved-oxygen levels have increased, salmon runs have returned, and the overall effort is widely regarded as a singular water-quality success. To document the improved dissolved-oxygen regimen, the U.S. Geological Survey conducted intensive studies of the Willamette during the summer low-flow seasons of 1973 and 1974. During each summer the mean daily dissolved-oxygen levels were found to be higher than 5 milligrams per liter throughout the river. Because of the basinwide secondary treatment, carbonaceous deoxygenation rates were low. In addition, almost half of the biochemical oxygen demand entering the Willamette was from diffuse (nonpoint) sources rather than outfalls. These results indicated that point-source biochemical oxygen demand was no longer the primary cause of dissolved-oxygen depletion. Instead, the major causes of deoxygenation were nitrification in a shallow ' surface active ' reach below Salem and an anomalous oxygen demand (believed to be primarily of benthal origin) in Portland Harbor. (Woodard-USGS)
Photomosaic base map of the Willamette River basin, Oregon: A tool for land and water-resource planning
No abstract available.