Geology topics

D.W. Owens

Publications and source records attributed to D.W. Owens.

4 recordsLinked to original sources

USGS2001

Evaluation of nonpoint-source contamination, Wisconsin: water year 1999

The objective of the watershed-management evaluation monitoring program in Wisconsin is to evaluate the effectiveness of best-management practices (BMPs) for controlling nonpoint-source pollution in rural and urban watersheds. This progress report provides a summary of the data collected by the U.S Geological Survey for the program and a discussion of the results from several different detailed analyses conducted within this program. A land-use and best-management-practice inventory is ongoing for each evaluation monitoring project to track the different sources of nonpointsource pollution in each watershed and to document implementation of best-management programs that may cause changes in the water quality of streams. Updated information is gathered each year, mapped, and stored in a geographic-information-system database. Summaries of BMP-implementation data collected through the 1999 water year are presented in this report. Suspended sediment and total phosphorus storm-load and annual-load data are summarized for eight rural sites. For all 8 rural sites a sufficient number of pre-BMP storm samples have been collected; for two of the sites (Brewery and Garfoot Creeks), a sufficient number of post-BMP storm samples have been collected to allow for a final assessment of the effectiveness of the BMPs. For the remaining sites, numerous transitional storm samples have been collected, but in all cases BMP implementation has lagged such that there are insufficient post-BMP storm samples for final analysis. For two sites (Rattlesnake and Kuenster Creeks) there are not enough planned BMPs to warrant further data collection. Continuous dissolved-oxygen data collected at 5 rural sites are summarized. In terms of instantaneous concentrations when comparing pre-BMP data to transitional and post-BMP data, the general trend is a reduction in the number of days that the dissolved oxygen concentration was less than the state standard. These results are anecdotal, however; the differences have not been rigorously tested statistically. For a level of dissolved oxygen sustained over a continuous hour, the results are mixed. In general the number of days with standard violations has decreased, but there are notable exceptions. For the four urban streams, the pre-BMP data were examined to determine the level of improvement that could potentially be detected with a statistical analysis. Regression analyses were performed relating constituent loads of suspended solids, total phosphorus and total copper to various independent variables, including seasonal terms and variables related to rainfall. On the basis of the residuals from the regressions, there is a wide range of potential change that could be detected with an analysis of pre- and post-BMP loads. This is likely a result of the high degree of variability in the data, particularly from site to site. For suspended solids, total phosphorus, and total recoverable copper the minimum detectable changes ranges from 20-80, 30-70 and 30-90 percent, respectively. For two of the eight rural streams (Rattlesnake and Kuenster Creeks) minimal BMP implementation has occurred, hence a comparison of pre- BMP and data collected after BMP implementation began is not warranted. For two other rural streams (Brewery and Garfoot Creeks), BMP implementation is complete. For the four remaining rural streams (Bower, Otter, Eagle, and Joos Valley Creeks), the pre-BMP load data were compared to the transitional data to determine if significant reductions in the loads have occurred as a result of the BMP implementation to date. For all sites, the actual constituent loads for suspended solids and total phosphorus exhibit no statistically significant reductions after BMP installation. Multiple regressions were used to remove some of the natural variability in the data. Based on the residual analysis, for Otter Creek, there is a significant difference in the suspended-solids regression residuals between the pre-BMP and transitional periods, indicating a potential reduction as a result of the BMP implementation after accounting for natural variability. For Joos Valley Creek, the residuals for suspended solids and total phosphorus both show a significant reduction after accounting for natural variability. It is possible that the other sites will also show statistically significant reductions in suspended solids and total phosphorus if additional BMPs are implemented.

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USGS1997

Evaluation of Nonpoint-Source Contamination, Wisconsin: Selected Topics for Water Year 1995

The objective of the watershed-management evaluation monitoring program in Wisconsin is to evaluate the effectiveness of best-management practices (BMP's) for controlling nonpoint-source contamination in eight rural and four urban watersheds. This report, the fourth in an annual series of reports, presents a summary of the data collected for the program by the U.S. Geological Survey and the results of several detailed analyses of the data. To complement assessments of water quality, a land-use and BMP inventory is ongoing for 12 evaluation monitoring projects to track nonpoint sources of contamination in each watershed and to document implementation of BMP's that were designed to cause changes in the water quality of streams. Each year, updated information is gathered, mapped, and stored in a geographic-information-system data base. Summaries of land-use, BMP implementation, and water-quality data collected during water years 1989-95 are presented. Storm loads, snowmelt-period loads, and annual loads of suspended sediment and total phosphorus are summarized for eight rural sites. Storm-load data for suspended solids, total phosphorus, total recoverable lead, copper, zinc, and cadmium are summarized for four urban sites. Quality-assurance and quality-control (QA/QC) samples were collected at the eight rural sites to evaluate inorganic sample contamination and at one urban site to evaluate sample-collection and filtration techniques for polycyclic aromatic hydrocarbons (PAR's). Some suspended solids and fecal coliform contamination was detected at the rural sites. Corrective actions will be taken to address this contamination. Evaluation of PAR sample-collection techniques did not uncover any deficiencies, but the small amount of data collected was not sufficient to draw any definite conclusions. Evaluation of PAR filtration techniques indicate that water-sample filtration with O.7-um glass-fiber filters in an aluminum filter unit does not result in significant loss of PAR.

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USGS1995

Evaluation of nonpoint-source contamination, Wisconsin; selected streamwater-quality data, land-use and best-management practices inventory, and quality assurance and quality control, water year 1993

The objective of the watershed-management evaluation monitoring program in Wisconsin is to evaluate the effectiveness of the best-management practices (BMPs) for rural streams, urban streams, and urban storm sewers. This report is an annual summary of the data collected for the program and a report of the results from several different special studies conducted within this program. Suspended sediment and total phosphorus storm-load data are summarized for eight rural sites and suspended sediment, total phosphorus, total recoverable lead, total recoverable copper, total recoverable zinc, and total recoverable cadmium storm-load data are summarized for four urban sites. Dissolved-oxygen data is summarized and compared with Wisconsin's waterquality standards for summer 1993 for seven rural sites. The dissolved-oxygen concentrations declined to levels below these standards at least one time at all seven sites during summer 1993. Total-recoverable hardness concentrations were compared with dissolved-hardness concentrations at two urban streams and two urban storm sewers. Least-squared linear regressions resulted in stronger relations for low-flow conditions than for high-flow conditions, indicating that most hardness during low flow is dissolved hardness. Pesticide data are summarized for four urban sites and six rural sites. Herbicides were detected at urban and rural sites; whereas insecticides were detected only at urban sites. A land-use and best-management-practice inventory is ongoing for each evaluation monitoring project to track the different sources of nonpoint pollution in each watershed and to document implementation of best-management programs that may cause changes in water quality of streams. Updated information is gathered each year, mapped, and stored in a geographic-information-system data base. The quality-assurance/quality-control plan for the urban watershed-management evaluation program consisted of a series of blank samples. These blank samples were used to identify and isolate contamination by inorganic and organic components throughout the collection and processing of urban streamwater samples. A dissolved trace-metal contamination problem was identified and resolved by using different laboratory- supplied sample bottles. A special study was done to determine the effect of holding time on fecal coliform colony counts. A linear regression indicated that the mean decrease in colony counts over 72 hours was 8.2 percent per day. Results after 24 hours showed that colony counts increased in some samples and decreased in others.

Wisconsin↗

USGS1995

Evaluation of nonpoint-source contamination, Wisconsin: Land-use and Best-Management-Practices inventory, selected streamwater-quality data, urban-watershed quality assurance and quality control, constituent loads in rural streams, and snowmelt-runoff analysis, water year 1994

The objective of the watershed-management evaluation monitoring program in Wisconsin is to evaluate the effectiveness of best-management practices (BMP) for controlling nonpoint-source contamination in rural and urban watersheds. This report is an annual summary of the data collected for the program by the U.S Geological Survey and a report of the results of several different detailed analyses of the data. A land-use and BMP inventory is ongoing for 12 evaluation monitoring projects to track the sources of nonpoint-source pollution in each watershed and to document implementation of BMP's that may cause changes in the water quality of streams. Updated information is gathered each year, mapped, and stored in a geographic-information-system data base. Summaries of data collected during water years 1989-94 are presented. A water year is the period beginning October 1 and ending September 30; the water year is designated by the calendar year in which it ends. Suspended-sediment and total-phosphorus data (storm loads and annual loads) are summarized for eight rural sites. For all sites, the annual suspended-sediment or suspended-solids load for water year 1993 exceeded the average for the period of data collection; the minimum annual loads were transported in water year 1991 or 1992. Continuous dissolved-oxygen data were collected at seven rural sites during water year 1994. Data for water years 1990-93 are summarized and plotted in terms of percentage of time that a particular concentration is equaled or exceeded. Dissolved-oxygen concentrations in four streams were less than 9 mg/L at least 50 percent of the time, a condition that fails to meet suggested criterion for coldwater streams. The dissolved-oxygen probability curve for one of the coldwater streams is markedly different than the curves for the other streams, perhaps because of differences in aquatic biomass. Blank quality-assurance samples were collected at two of the urban evaluation monitoring sites to isolate contamination in the sample bottle, the automatic sampler and splitter, and the filtration system. Significant contamination caused excessive concentrations of dissolved chloride, alkalinity, and biochemical oxygen demand. The level of contamination may be large enough to affect data for water samples in which these analytes are present at low concentration. Further investigation is being done to determine the source of contamination and take measures to minimize its effect on the sampling. A preliminary regression analysis was done for the rural sites using data collected during water years 1989-93. Loads of suspended solids and total phosphorus in stormflow were regressed against various precipitation-related measures. The results indicate that, for most sites, changes in constituent load on the order of 40 to 50 percent could be detected with a statistical test. For two sites, the change would have to be 60 to 70 percent to be detected. A detailed comparison of snowmelt runoff and rainfall stormflow in urban and rural areas was done using data collected during water years 1985-93. For the rural sites where statistically significant differences were found between constituent loads in snowmelt and storm runoff, the loads of suspended solids and total phosphorus in snowmelt runoff were greater than those in storm runoff. For the urban sites where statistically significant differences were found between snowmelt and storm runoff, the loads of suspended solids and total phosphorus in storm runoff were greater than those in snowmelt runoff. The importance of including snowmelt runoff in designing and analyzing the effects of BMP's on streamwater quality, particularly in rural areas, is emphasized by these results.

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