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James L. Gray

Publications and source records attributed to James L. Gray.

50 records · Page 3Linked to original sources

Steroid hormone runoff from agricultural test plots applied with municipal biosolids

The potential presence of steroid hormones in runoff from sites where biosolids have been used as agricultural fertilizers is an environmental concern. A study was conducted to assess the potential for runoff of seventeen different hormones and two sterols, including androgens, estrogens, and progestogens from agricultural test plots. The field containing the test plots had been applied with biosolids for the first time immediately prior to this study. Target compounds were isolated by solid-phase extraction (water samples) and pressurized solvent extraction (solid samples), derivatized, and analyzed by gas chromatography&ndash;tandem mass spectrometry. Runoff samples collected prior to biosolids application had low concentrations of two hormones (estrone <0.8 to 2.23 ng L -1 and androstenedione <0.8 to 1.54 ng L -1 ) and cholesterol (22.5 &plusmn; 3.8 &mu;g L -1 ). In contrast, significantly higher concentrations of multiple estrogens (<0.8 to 25.0 ng L -1 ), androgens (<2 to 216 ng L -1 ), and progesterone (<8 to 98.9 ng L -1 ) were observed in runoff samples taken 1, 8, and 35 days after biosolids application. A significant positive correlation was observed between antecedent rainfall amount and hormone mass loads (runoff). Hormones in runoff were primarily present in the dissolved phase (<0.7-&mu;m GF filter), and, to a lesser extent bound to the suspended-particle phase. Overall, these results indicate that rainfall can mobilize hormones from biosolids-amended agricultural fields, directly to surface waters or redistributed to terrestrial sites away from the point of application via runoff. Although concentrations decrease over time, 35 days is insufficient for complete degradation of hormones in soil at this site.

Environmental Science & Technology↗

Pharmaceuticals, hormones, anthropogenic waste indicators, and total estrogenicity in liquid and solid samples from municipal sludge stabilization and dewatering

The ubiquitous presence of pharmaceuticals and other emerging contaminants, or trace organic compounds, in surface water has resulted in research and monitoring efforts to identify contaminant sources to surface waters and to better understand loadings from these sources. Wastewater treatment plant discharges have been identified as an important point source of trace organic compounds to surface water and understanding the transport and transformation of these contaminants through wastewater treatment process is essential to controlling their introduction to receiving waters.

Open-File Report↗

Determination of steroid hormones and related compounds in filtered and unfiltered water by solid-phase extraction, derivatization, and gas chromatography with tandem mass spectrometry

A new analytical method has been developed and implemented at the U.S. Geological Survey National Water Quality Laboratory that determines a suite of 20 steroid hormones and related compounds in filtered water (using laboratory schedule 2434) and in unfiltered water (using laboratory schedule 4434). This report documents the procedures and initial performance data for the method and provides guidance on application of the method and considerations of data quality in relation to data interpretation. The analytical method determines 6 natural and 3 synthetic estrogen compounds, 6 natural androgens, 1 natural and 1 synthetic progestin compound, and 2 sterols: cholesterol and 3--coprostanol. These two sterols have limited biological activity but typically are abundant in wastewater effluents and serve as useful tracers. Bisphenol A, an industrial chemical used primarily to produce polycarbonate plastic and epoxy resins and that has been shown to have estrogenic activity, also is determined by the method. A technique referred to as isotope-dilution quantification is used to improve quantitative accuracy by accounting for sample-specific procedural losses in the determined analyte concentration. Briefly, deuterium- or carbon-13-labeled isotope-dilution standards (IDSs), all of which are direct or chemically similar isotopic analogs of the method analytes, are added to all environmental and quality-control and quality-assurance samples before extraction. Method analytes and IDS compounds are isolated from filtered or unfiltered water by solid-phase extraction onto an octadecylsilyl disk, overlain with a graded glass-fiber filter to facilitate extraction of unfiltered sample matrices. The disks are eluted with methanol, and the extract is evaporated to dryness, reconstituted in solvent, passed through a Florisil solid-phase extraction column to remove polar organic interferences, and again evaporated to dryness in a reaction vial. The method compounds are reacted with activated -methyl--trimethylsilyl trifluoroacetamide at 65 degrees Celsius for 1 hour to form trimethylsilyl or trimethylsilyl-enol ether derivatives that are more amenable to gas chromatographic separation than the underivatized compounds. Analysis is carried out by gas chromatography with tandem mass spectrometry using calibration standards that are derivatized concurrently with the sample extracts. Analyte concentrations are quantified relative to specific IDS compounds in the sample, which directly compensate for procedural losses (incomplete recovery) in the determined and reported analyte concentrations. Thus, reported analyte concentrations (or analyte recoveries for spiked samples) are corrected based on recovery of the corresponding IDS compound during the quantification process. Recovery for each IDS compound is reported for each sample and represents an absolute recovery in a manner comparable to surrogate recoveries for other organic methods used by the National Water Quality Laboratory. Thus, IDS recoveries provide a useful tool for evaluating sample-specific analytical performance from an absolute mass recovery standpoint. IDS absolute recovery will differ and typically be lower than the corresponding analyte’s method recovery in spiked samples. However, additional correction of reported analyte concentrations is unnecessary and inappropriate because the analyte concentration (or recovery) already is compensated for by the isotope-dilution quantification procedure. Method analytes were spiked at 10 and 100 nanograms per liter (ng/L) for most analytes (10 times greater spike levels were used for bisphenol A and 100 times greater spike levels were used for 3--coprostanol and cholesterol) into the following validation-sample matrices: reagent water, wastewater-affected surface water, a secondary-treated wastewater effluent, and a primary (no biological treatment) wastewater effluent. Overall method recovery for all analytes in these matrices averaged 100 percent, with overall relative standard deviation of 28 percent. Mean recoveries of the 20 individual analytes for spiked reagent-water samples prepared along with field samples and analyzed in 2009–2010 ranged from 84–104 percent, with relative standard deviations of 6–36 percent. Concentrations for two analytes, equilin and progesterone, are reported as estimated because these analytes had excessive bias or variability, or both. Additional database coding is applied to other reported analyte data as needed, based on sample-specific IDS recovery performance. Detection levels were derived statistically by fortifying reagent water at six different levels (0.1 to 4 ng/L) and range from about 0.4 to 4 ng/L for 16 analytes. Interim reporting levels applied to analytes in this report range from 0.8 to 8 ng/L. Bisphenol A and the sterols (cholesterol and 3-beta-coprostanol) were consistently detected in laboratory and field blanks. The minimum reporting levels were set at 100 ng/L for bisphenol A and at 200 ng/L for the two sterols to prevent any bias associated with the presence of these compounds in the blanks. A minimum reporting level of 2 ng/L was set for 11-ketotestosterone to minimize false positive risk from an interfering siloxane compound emanating as chromatographic-column bleed, from vial septum material, or from other sources at no more than 1 ng/L.

Techniques and Methods↗

Demasculinization of male fish by wastewater treatment plant effluent

Adult male fathead minnows ( Pimephales promelas ) were exposed to effluent from the City of Boulder, Colorado wastewater treatment plant (WWTP) under controlled conditions in the field to determine if the effluent induced reproductive disruption in fish. Gonadal intersex and other evidence of reproductive disruption were previously identified in white suckers ( Catostomus commersoni ) in Boulder Creek downstream from this WWTP effluent outfall. Fish were exposed within a mobile flow-through exposure laboratory in July 2005 and August 2006 to WWTP effluent (EFF), Boulder Creek water (REF), or mixtures of EFF and REF for up to 28 days. Primary (sperm abundance) and secondary (nuptial tubercles and dorsal fat pads) sex characteristics were demasculinized within 14 days of exposure to 50% and 100% EFF. Vitellogenin was maximally elevated in both 50% and 100% EFF treatments within 7 days and significantly elevated by 25% EFF within 14 days. The steroidal estrogens 17β-estradiol, estrone, estriol, and 17α-ethynylestradiol, as well as estrogenic alkylphenols and bisphenol A were identified within the EFF treatments and not in the REF treatment. These results support the hypothesis that the reproductive disruption observed in this watershed is due to endocrine-active chemicals in the WWTP effluent.

Colorado↗

Endocrine active chemicals, pharmaceuticals, and other chemicals of concern in surface water, wastewater-treatment plant effluent, and bed sediment, and biological characteristics in selected streams, Minnesota: Design, methods, and data, 2009

This report presents the study design, environmental data, and quality-assurance data for an integrated chemical and biological study of selected streams or lakes that receive wastewater-treatment plant effluent in Minnesota. This study was a cooperative effort of the U.S. Geological Survey, the Minnesota Pollution Control Agency, St. Cloud State University, the University of St. Thomas, and the University of Colorado. The objective of the study was to identify distribution patterns of endocrine active chemicals, pharmaceuticals, and other organic and inorganic chemicals of concern indicative of wastewater effluent, and to identify biological characteristics of estrogenicity and fish responses in the same streams. The U.S. Geological Survey collected and analyzed water, bed-sediment, and quality-assurance samples, and measured or recorded streamflow once at each sampling location from September through November 2009. Sampling locations included surface water and wastewater-treatment plant effluent. Twenty-five wastewater-treatment plants were selected to include continuous flow and periodic release facilities with differing processing steps (activated sludge or trickling filters) and plant design flows ranging from 0.002 to 10.9 cubic meters per second (0.04 to 251 million gallons per day) throughout Minnesota in varying land-use settings. Water samples were collected from the treated effluent of the 25 wastewater-treatment plants and at one point upstream from and one point downstream from wastewater-treatment plant effluent discharges. Bed-sediment samples also were collected at each of the stream or lake locations. Water samples were analyzed for major ions, nutrients, trace elements, pharmaceuticals, phytoestrogens and pharmaceuticals, alkylphenols and other neutral organic chemicals, carboxylic acids, and steroidal hormones. A subset (25 samples) of the bed-sediment samples were analyzed for carbon, wastewater-indicator chemicals, and steroidal hormones; the remaining samples were archived. Biological characteristics were determined by using an in-vitro bioassay to determine total estrogenicity in water samples and a caged fish study to determine characteristics of fish from experiments that exposed fish to wastewater effluent in 2009. St. Cloud State University deployed and processed caged fathead minnows at 13 stream sites during September 2009 for the caged fish study. Measured fish data included length, weight, body condition factor, and vitellogenin concentrations.

Minnesota↗

Determination of the anionic surfactant di(ethylhexyl) sodium sulfosuccinate in water samples collected from Gulf of Mexico coastal waters before and after landfall of oil from the Deepwater Horizon oil spill, May to October, 2010

On April 22, 2010, the explosion on and subsequent sinking of the Deepwater Horizon oil drilling platform resulted in the release of crude oil into the Gulf of Mexico. At least 4.4 million barrels had been released into the Gulf of Mexico through July 15, 2010, 10 to 29 percent of which was chemically dispersed, primarily using two dispersant formulations. Initially, the dispersant Corexit 9527 was used, and when existing stocks of that formulation were exhausted, Corexit 9500 was used. Over 1.8 million gallons of the two dispersants were applied in the first 3 months after the spill. This report presents the development of an analytical method to analyze one of the primary surfactant components of both Corexit formulations, di(ethylhexyl) sodium sulfosuccinate (DOSS), the preliminary results, and the associated quality assurance/quality control (QA/QC) from samples collected from various points on the Gulf Coast between Texas and Florida. Seventy water samples and 8 field QC samples were collected before the predicted landfall of oil (pre-landfall) on the Gulf Coast, and 51 water samples and 10 field QC samples after the oil made landfall (post-landfall). Samples were collected in Teflon(Registered) bottles and stored at -20(degrees)C until analysis. Extraction of whole-water samples used sorption onto a polytetrafluoroethylene (PTFE) filter to isolate DOSS, with subsequent 50 percent methanol/water elution of the combined dissolved and particulate DOSS fractions. High-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) was used to identify and quantify DOSS by the isotope dilution method, using a custom-synthesized 13C4-DOSS labeled standard. Because of the ubiquitous presence of DOSS in laboratory reagent water, a chromatographic column was installed in the LC/MS/MS between the system pumps and the sample injector that separated this ambient background DOSS contamination from the sample DOSS, minimizing one source of blank contamination. Laboratory and field QA/QC for pre-landfall samples included laboratory reagent spike and blank samples, a total of 34 replicate analyses for the 78 environmental and field blank samples, and 11 randomly chosen laboratory matrix spike samples. Laboratory and field QA/QC for post-landfall samples included laboratory reagent spike and blank samples, a laboratory 'in-bottle' duplicate for each sample, and analysis of 24 randomly chosen laboratory matrix spike samples. Average DOSS recovery of 89(+/-)9.5 percent in all native (non-13C4-DOSS ) spikes was observed, with a mean relative percent difference between sample duplicates of 36 percent. The reporting limit for this analysis was 0.25 micrograms per liter due to blank limitations; DOSS was not detected in any samples collected in October (after oil landfall at certain study sites) above that concentration. It was detected prior to oil landfall above 0.25 micrograms per liter in 3 samples, but none exceeded the Environmental Protection Agency aquatic life criteria of 40 micrograms per liter.

Alabama, Florida, Louisiana, Mississippi, Texas↗

Lagrangian sampling of wastewater treatment plant effluent in Boulder Creek, Colorado, and Fourmile Creek, Iowa, during the summer of 2003 and spring of 2005— Hydrological and water-quality data

This report presents methods and data for a Lagrangian sampling investigation into chemical loading and in-stream attenuation of inorganic and organic contaminants in two wastewater treatment-plant effluent-dominated streams: Boulder Creek, Colorado, and Fourmile Creek, Iowa. Water-quality sampling was timed to coincide with low-flow conditions when dilution of the wastewater treatment-plant effluent by stream water was at a minimum. Sample-collection times corresponded to estimated travel times (based on tracer tests) to allow the same "parcel" of water to reach downstream sampling locations. The water-quality data are linked directly to stream discharge using flow- and depth-integrated composite sampling protocols. A range of chemical analyses was made for nutrients, carbon, major elements, trace elements, biological components, acidic and neutral organic wastewater compounds, antibiotic compounds, pharmaceutical compounds, steroid and steroidal-hormone compounds, and pesticide compounds. Physical measurements were made for field conditions, stream discharge, and time-of-travel studies. Two Lagrangian water samplings were conducted in each stream, one in the summer of 2003 and the other in the spring of 2005. Water samples were collected from five sites in Boulder Creek: upstream from the wastewater treatment plant, the treatment-plant effluent, and three downstream sites. Fourmile Creek had seven sampling sites: upstream from the wastewater treatment plant, the treatment-plant effluent, four downstream sites, and a tributary. At each site, stream discharge was measured, and equal width-integrated composite water samples were collected and split for subsequent chemical, physical, and biological analyses. During the summer of 2003 sampling, Boulder Creek downstream from the wastewater treatment plant consisted of 36 percent effluent, and Fourmile Creek downstream from the respective wastewater treatment plant was 81 percent effluent. During the spring of 2005 samplings, Boulder Creek downstream from the wastewater treatment plant was 40 percent effluent, and Fourmile Creek downstream from that wastewater treatment plant was 28 percent effluent. At each site, 300 individual constituents were determined to characterize the water. Most of the inorganic constituents were detected in all of the stream and treatment-plant effluent samples, whereas detection of synthetic organic compounds was more limited and contaminants typically occurred only in wastewater treatment-plant effluents and at downstream sites. Concentrations ranged from nanograms per liter to milligrams per liter.

Colorado, Iowa↗

A role for analytical chemistry in advancing our understanding of the occurrence, fate, and effects of Corexit Oil Dispersants

On April 24, 2010, the sinking of the Deepwater Horizon oil rig resulted in the release of oil into the Gulf of Mexico. As of July 19, 2010, the federal government's Deepwater Horizon Incident Joint Information Center estimates the cumulative range of oil released is 3,067,000 to 5,258,000 barrels, with a relief well to be completed in early August. By comparison, the Exxon Valdez oil spill released a total of 260,000 barrels of crude oil into the environment. As of June 9, BP has used over 1 million gallons of Corexit oil dispersants to solubilize oil and help prevent the development of a surface oil slick. Oil dispersants are mixtures containing solvents and surfactants that can exhibit toxicity toward aquatic life and may enhance the toxicity of components of weathered crude oil. Detailed knowledge of the composition of both Corexit formulations and other dispersants applied in the Gulf will facilitate comprehensive monitoring programs for determining the occurrence, fate, and biological effects of the dispersant chemicals. The lack of information on the potential impacts of oil dispersants has caught industry, federal, and state officials off guard. Until compositions of Corexit 9500 and 9527 were released by the U.S. Environmental Protection Agency online, the only information available consisted of Material Safety Data Sheets (MSDS), patent documentation, and a National Research Council report on oil dispersants. Several trade and common names are used for the components of the Corexits. For example, Tween 80 and Tween 85 are oligomeric mixtures.

Environmental Science & Technology↗

Evaluating the behavior of gadolinium and other rare earth elements through large metropolitan sewage treatment plants

A primary pathway for emerging contaminants (pharmaceuticals, personal care products, steroids, and hormones) to enter aquatic ecosystems is effluent from sewage treatment plants (STP), and identifying technologies to minimize the amount of these contaminants released is important. Quantifying the flux of these contaminants through STPs is difficult. This study evaluates the behavior of gadolinium, a rare earth element (REE) utilized as a contrasting agent in magnetic resonance imaging (MRI), through four full-scale metropolitan STPs that utilize several biosolids thickening, conditioning, stabilization, and dewatering processing technologies. The organically complexed Gd from MRIs has been shown to be stable in aquatic systems and has the potential to be utilized as a conservative tracer in STP operations to compare to an emerging contaminant of interest. Influent and effluent waters display large enrichments in Gd compared to other REEs. In contrast, most sludge samples from the STPs do not display Gd enrichments, including primary sludges and end-product sludges. The excess Gd appears to remain in the liquid phase throughout the STP operations, but detailed quantification of the input Gd load and residence times of various STP operations is needed to utilize Gd as a conservative tracer.

Environmental Science & Technology↗

Fate of estrogenic compounds during municipal sludge stabilization and dewatering

This project brought together a team of experts in the fields of environmental engineering, analytical chemistry and hydrogeology, and biological assay analysis to evaluate the occurrence and fate of estrogenic compounds and the estrogenicity of biosolids derived from wastewater treatment. The primary objective of the study was to provide key baseline information concerning the estrogenicity (measured with in vitro bioassays) and concentrations of individual estrogenic compounds and other trace organic chemicals through common wastewater treatment processes. This research is important for developing information critical to the assessment of the potential risks associated with biosolids land application. Published by WERF. 178 pages. Soft cover and online PDF. (2010)

Report↗

Biodegradation of 17β-estradiol, estrone and testosterone in stream sediments

Biodegradation of 17&beta;-estradiol (E2), estrone (E1), and testosterone (T) was investigated in three wastewater treatment plant (WWTP) affected streams in the United States. Relative differences in the mineralization of [4- 14 C] substrates were assessed in oxic microcosms containing saturated sediment or water-only from locations upstream and downstream of the WWTP outfall in each system. Upstream sediment demonstrated significant mineralization of the &ldquo;A&rdquo; ring of E2, E1, and T, with biodegradation of T consistently greater than that of E2 and no systematic difference in E2 and E1 biodegradation. &ldquo;A&rdquo; ring mineralization also was observed in downstream sediment, with E1 and T mineralization being substantially depressed relative to upstream samples. In marked contrast, E2 mineralization in sediment immediately downstream from the WWTP outfalls was more than double that in upstream sediment. E2 mineralization was observed in water, albeit at insufficient rate to prevent substantial downstream transport. The results indicate that, in combination with sediment sorption processes which effectively scavenge hydrophobic contaminants from the water column and immobilize them in the vicinity of the WWTP outfall, aerobic biodegradation of reproductive hormones can be an environmentally important mechanism for nonconservative (destructive) attenuation of hormonal endocrine disruptors in effluent-affected streams.

Colorado, Iowa↗

Reproductive disruption in fish downstream from an estrogenic wastewater effluent

To assess the impact of an estrogenic wastewater treatment plant (WWTP) effluent on fish reproduction, white suckers ( Catostomus commersoni ) were collected from immediately upstream and downstream (effluent site) of the city of Boulder, CO, WWTP outfall. Gonadal intersex, altered sex ratios, reduced gonad size, disrupted ovarian and testicular histopathology, and vitellogenin induction consistent with exposure to estrogenic wastewater contaminants were identified in white suckers downstream from the WWTP outfall and not at the upstream site. The sex ratio was female-biased at the effluent site in both the fall of 2003 and the spring of 2004; the frequency of males at the effluent site (17–21%) was half that of the upstream site (36–46%). Intersex white suckers comprised 18–22% of the population at the effluent site. Intersex fish were not found at the upstream site. Chemical analyses determined that the WWTP effluent contained a complex mixture of endocrine-active chemicals, including 17β-estradiol (E 2 ) 17α-ethynylestradiol, alkylphenols, and bisphenol A resulting in an estimated total estrogen equivalence of up to 31 ng E 2 L −1 . These results indicate that the reproductive potential of native fishes may be compromised in wastewater-dominated streams.

Colorado↗

Occurrence of organic wastewater compounds in drinking water, wastewater effluent, and the Big Sioux River in or near Sioux Falls, South Dakota, 2001-2004

The U.S. Geological Survey (USGS) in cooperation with the city of Sioux Falls conducted several rounds of sampling to determine the occurrence of organic wastewater compounds (OWCs) in the city of Sioux Falls drinking water and waste-water effluent, and the Big Sioux River in or near Sioux Falls during August 2001 through May 2004. Water samples were collected during both base-flow and storm-runoff conditions. Water samples were collected at 8 sites, which included 4 sites upstream from the wastewater treatment plant (WWTP) discharge, 2 sites downstream from the WWTP discharge, 1 finished drinking-water site, and 1 WWTP effluent (WWE) site. A total of 125 different OWCs were analyzed for in this study using five different analytical methods. Analyses for OWCs were performed at USGS laboratories that are developing and/or refining small-concentration (less than 1 microgram per liter (ug/L)) analytical methods. The OWCs were classified into six compound classes: human pharmaceutical compounds (HPCs); human and veterinary antibiotic compounds (HVACs); major agricultural herbicides (MAHs); household, industrial,and minor agricultural compounds (HIACs); polyaromatic hydrocarbons (PAHs); and sterol compounds (SCs). Some of the compounds in the HPC, MAH, HIAC, and PAH classes are suspected of being endocrine-disrupting compounds (EDCs). Of the 125 different OWCs analyzed for in this study, 81 OWCs had one or more detections in environmental samples reported by the laboratories, and of those 81 OWCs, 63 had acceptable analytical method performance, were detected at concentrations greater than the study reporting levels, and were included in analyses and discussion related to occurrence of OWCs in drinking water, wastewater effluent, and the Big Sioux River. OWCs in all compound classes were detected in water samples from sampling sites in the Sioux Falls area. For the five sampling periods when samples were collected from the Sioux Falls finished drinking water, only one OWC was detected at a concentration greater than the study reporting level (metolachlor; 0.0040 ug/L). During base-flow conditions, Big Sioux River sites upstream from the WWTP discharge had OWC contributions that primarily were from nonpoint animal or crop agriculture sources or had OWC concentrations that were minimal. The influence of the WWTP discharge on OWCs at downstream river sites during base-flow conditions ranged from minimal influence to substantial influence depending on the sampling period. During runoff conditions, OWCs at sites upstream from the WWTP discharge probably were primarily contributed by nonpoint animal and/or crop agriculture sources and possibly by stormwater runoff from nearby roads. OWCs at sites downstream from the WWTP discharge probably were contributed by sources other than the WWTP effluent discharge, such as stormwater runoff from urban and/or agriculture areas and/or resuspension of OWCs adsorbed to sediment deposited in the Big Sioux River. OWC loads generally were substantially smaller for upstream sites than downstream sites during both base-flow and runoff conditions.discharge had OWC contributions that primarily were from nonpoint animal or crop agriculture sources or had OWC concentrations that were minimal. The influence of the WWTP discharge on OWCs at downstream river sites during base-flow conditions ranged from minimal influence to substantial influence depending on the sampling period. During runoff conditions, OWCs at sites upstream from the WWTP discharge probably were primarily contributed by nonpoint animal and/or crop agriculture sources and possibly by stormwater runoff from nearby roads. OWCs at sites downstream from the WWTP discharge probably were contributed by sources other than the WWTP effluent discharge, such as stormwater runoff from urban and/or agriculture areas and/or resuspension of OWCs adsorbed to sediment deposited in the Big Sioux River. OWC loads generally were substantially smaller for

South Dakota↗

Occurrence of organic wastewater compounds in wastewater effluent and the Big Sioux River in the Upper Big Sioux River basin, South Dakota, 2003-2004

The U.S. Geological Survey (USGS) in cooperation with the East Dakota Water Development District conducted a reconnaissance study to determine the occurrence of organic wastewater compounds (OWCs) in wastewater effluent and the Big Sioux River at or near the cities of Watertown, Volga, and Brookings in the upper Big Sioux River Basin during August 2003 through June 2004. For each city, samples were collected from the wastewater treatment plant (WWTP) effluent and from Big Sioux River sites upstream and downstream from where the wastewater effluent discharges to the Big Sioux River. For Watertown and Brookings, samples were collected during a low-flow period (August 2003) and a runoff period (June 2004). For Volga, samples were collected during two low-flow periods (August 2003 and October 2003) and a runoff period (June 2004). A total of 125 different OWCs were analyzed for and were classified into six compound classes-human pharmaceutical compounds (HPCs), human and veterinary antibiotic compounds (HVACs), major agricultural herbicides (MAHs), household, industrial, and minor agricultural compounds (HIACs), polyaromatic hydrocarbons (PAHs), and sterol compounds (SCs). Of the 125 different OWCs, 45 had acceptable analytical method performance, were detected at concentrations greater than the study reporting levels, and were included in analyses and discussion related to occurrence of OWCs in wastewater effluents and the Big Sioux River. OWCs in all six compound classes were detected in water samples from sampling sites in the Watertown area. The Watertown WWTP discharged continuously to the Big Sioux River during both the low-flow August 2003 and runoff June 2004 sampling periods. Total OWC concentrations for Big Sioux River sites upstream from the Watertown WWTP discharge generally were small, less than 6 micrograms per liter (µg/L) for both sampling periods. SCs accounted for nearly all of the total OWC concentrations for upstream Big Sioux River sites for the low-flow August 2003 sampling period, and MAHs accounted for nearly all of the total OWC concentrations for the runoff June 2004 sampling period. Total OWC concentrations for samples collected from the Watertown wastewater effluent were relatively large for both sampling periods (estimated concentrations ranged from 20 to 41 µg/L), and primarily consisted of HIACs, SCs, and HVACs. Total OWC concentrations for Big Sioux River sites downstream from the Watertown WWTP discharge were relatively large for the low-flow August 2003 sampling period (estimated concentrations ranged from 6.9 to 19 µg/L) and smaller for the runoff June 2004 sampling period (estimated concentrations ranged from 3.3 to 6.5 µg/L), a pattern that probably reflects a greater fraction of the total flow of the Big Sioux River being derived from WWTP discharge during the low-flow sampling period. Major OWC classes contributing to total OWC concentrations for Big Sioux River sites downstream from the Watertown WWTP were HIACs, SCs, and HVACs. Total OWC concentrations decreased substantially between the two downstream Big Sioux River sites. Although confident conclusions could not be made primarily due to possible effects of non-Lagrangian sampling, OWC results for the Watertown area might indicate that (1) OWCs for upstream Big Sioux River sites probably were primarily contributed by nonpoint agricultural sources, with livestock agriculture accounting for most of the total OWC concentration for the low-flow August 2003 sampling period, and crop agriculture accounting for most of the total OWC concentration for the runoff June 2004 sampling period; (2) OWCs for downstream Big Sioux River sites were substantially influenced by contributions from the Watertown WWTP during both the low-flow and runoff sampling periods; and (3) contributions of OWCs that might be derived from nonpoint livestock agricultural sources increased in proportion for the most downstream site for both the low-flow and runoff sampling periods. Suspected endocrine-disrupting compounds (EDCs) were detected in all Big Sioux River samples in the Watertown area. For both the low-flow and runoff sampling periods, the numbers of EDCs detected, and EDC concentrations and loads generally were larger for downstream Big Sioux River sites than for upstream Big Sioux River sites. Combined EDC concentrations for downstream Big Sioux River sites consisted mostly of HIACs for the low-flow sampling period and both HIACs and MAHs for the runoff sampling period. OWCs in all compound classes except PAHs were detected in samples from sites in the Volga area. The Volga WWTP was not discharging to the Big Sioux River during the low-flow August 2003 and runoff June 2004 sampling periods, but was discharging continuously to the Big Sioux River during the low-flow October 2003 sampling period. For the low-flow August 2003 sampling period, the upstream Big Sioux River site had larger total OWC concentrations and loads than downstream Big Sioux River sites, and SCs accounted for most of the total OWC concentration for all Big Sioux River sites. For the low-flow October 2003 sampling period, when the Volga WWTP was discharging to the Big Sioux River, total OWC concentrations and loads were larger for the downstream Big Sioux River site than for the upstream site, and the increase in load corresponded well with the load contributed by the Volga wastewater effluent discharge, especially for HIACs. HIACs and SCs accounted for most of the total OWC concentrations for Big Sioux River sites for the October 2003 sampling period. For the June 2004 runoff sampling period, the upstream Big Sioux River site had smaller total OWC concentrations and loads than downstream Big Sioux River sites, and MAHs accounted for most of the total OWC concentrations for all Big Sioux River sites. Although confident conclusions could not be made due to possible effects of non-Lagrangian sampling, the data might indicate that (1) for the low-flow August 2003 sampling period, nonpoint livestock agricultural and/or human wastewater sources might have been the primary contributors to occurrence of OWCs at Big Sioux River sampling sites; (2) for the low-flow October 2003 sampling period, nonpoint livestock sources and upstream human wastewater sources primarily contributed to occurrence of OWCs at Big Sioux River sampling sites; (3) for the runoff June 2004 sampling period, nonpoint crop agricultural sources primarily contributed to occurrence of OWCs at Big Sioux River sampling sites; (4) for the low-flow August 2003 and runoff June 2004 sampling periods, seepage of water from the Volga WWTP had little effect on downstream OWC concentrations; and (5) for the low-flow October 2003 sampling period, the Volga wastewater effluent discharge contributed to downstream OWC concentrations. EDCs were detected in all samples collected from sampling sites in the Volga area. For all sampling periods, total EDC concentrations generally were similar between upstream and downstream Big Sioux River sites and consisted of HIACs and MAHs. HIACs accounted for most of the total EDC concentrations for the low-flow August 2003 and October 2003 sampling periods, and MAHs accounted for most of the total EDC concentrations for the runoff June 2004 sampling period for all Big Sioux River sites. OWCs in all compound classes except PAHs were detected in water samples from sampling sites in the Brookings area. The Brookings WWTP discharged continuously to the Big Sioux River during all sampling periods. For the low-flow August 2003 sampling period, the upstream site had slightly smaller total OWC concentrations and loads compared to the downstream Big Sioux River sites. SCs and HIACs accounted for most of the total OWC concentration in all Big Sioux River sampling sites, but the proportion of SCs increased at the most downstream site. For the runoff June 2004 sampling period, the upstream site generally had smaller total OWC concentrations and loads than downstream Big Sioux River sites. MAHs accounted for most of the total OWC concentration for all Big Sioux River sites, but the proportion of SCs increased at the most downstream site. Although confident conclusions could not be made due to possible effects of non-Lagrangian sampling, the data might indicate that (1) for the low-flow August 2003 sampling period, nonpoint livestock agricultural sources probably primarily contributed to occurrence of OWCs at all Big Sioux River sampling sites, and the Brookings WWTP wastewater effluent discharge contributed but did not have a substantial effect on concentrations at downstream sites; and (2) for the runoff June 2004 sampling period, nonpoint crop agricultural sources primarily contributed to occurrence of OWCs at all Big Sioux River sites, contributions of OWCs that might be derived from nonpoint livestock agricultural sources increased in proportion to other sources for the most downstream site, and the Brookings WWTP wastewater effluent discharge probably did not substantially contribute to total OWC concentrations at downstream sampling sites. EDCs were detected in all samples collected from sampling sites in the Brookings area. Total EDC concentrations for the upstream site consisted entirely of MAHs. Total EDC concentrations for downstream sites consisted of MAHs and HIACs. HIACs accounted for most of the total EDC concentrations for the low-flow August 2003 sampling period, and MAHs accounted for most of the total EDC concentrations for the runoff June 2004 sampling period for downstream Big Sioux River sites. The city of Watertown is located near the upstream part of the Big Sioux River Basin, where the mean annual flow of the Big Sioux River is less than 100 cubic feet per second (ft 3 /s). Watertown WWTP discharges can account for a substantial part of the flow in the Big Sioux River, especially during low-flow periods. Effects of the Watertown WWTP wastewater effluent discharges on the occurrence of OWCs in the Big Sioux River downstream were apparent during both the low-flow and runoff sampling periods. For Volga and Brookings, which are farther downstream and where the mean annual flow of the Big Sioux River exceeds 400 ft 3 /s, wastewater effluent discharges from the Volga and Brookings WWTPs probably influenced the occurrence of OWCs in the Big Sioux River, but probably did not substantially contribute to total OWC concentrations, especially during the runoff sampling period.

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