Geochemical mole-balance models are sets of chemical reactions that quantitatively account for changes in the chemical and isotopic composition of water along a flow path. A revised mole-balance formulation that includes an uncertainty term for each chemical and isotopic datum is derived. The revised formulation is comprised of mole-balance equations for each element or element redox state, alkalinity, electrons, solvent water, and each isotope; a charge-balance equation and an equation that relates the uncertainty terms for pH, alkalinity, and total dissolved inorganic carbon for each aqueous solution; inequality constraints on the size of the uncertainty terms; and inequality constraints on the sign of the mole transfer of reactants. The equations and inequality constraints are solved by a modification of the simplex algorithm combined with an exhaustive search for unique combinations of aqueous solutions and reactants for which the equations and inequality constraints can be solved and the uncertainty terms minimized. Additional algorithms find only the simplest mole-balance models and determine the ranges of mixing fractions for each solution and mole transfers for each reactant that are consistent with specified limits on the uncertainty terms. The revised formulation produces simpler and more robust mole-balance models and allows the significance of mixing fractions and mole transfers to be evaluated. In an example from the central Oklahoma aquifer, inclusion of up to 5% uncertainty in the chemical data can reduce the number of reactants in mole-balance models from seven or more to as few as three, these being cation exchange, dolomite dissolution, and silica precipitation. In another example from the Madison aquifer, inclusion of the charge-balance constraint requires significant increases in the mole transfers of calcite, dolomite, and organic matter, which reduce the estimated maximum carbon 14 age of the sample by about 10,000 years, from 22,700 years to 12,600 years.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97WR01125","usgsCitation":"Parkhurst, D.L., 1997, Geochemical mole-balance modeling with uncertain data: Water Resources Research, v. 33, no. 8, p. 1957-1970, https://doi.org/10.1029/97WR01125.","productDescription":"14 p.","startPage":"1957","endPage":"1970","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":487270,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/97wr01125","text":"Publisher Index Page"},{"id":228012,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"33","issue":"8","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a1689e4b0c8380cd551ac","contributors":{"authors":[{"text":"Parkhurst, David L. 0000-0003-3348-1544 dlpark@usgs.gov","orcid":"https://orcid.org/0000-0003-3348-1544","contributorId":1088,"corporation":false,"usgs":true,"family":"Parkhurst","given":"David","email":"dlpark@usgs.gov","middleInitial":"L.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":383473,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019649,"text":"70019649 - 1997 - Historical trends in organochlorine compounds in river basins identified using sediment cores from reservoirs","interactions":[],"lastModifiedDate":"2020-01-07T12:45:31","indexId":"70019649","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Historical trends in organochlorine compounds in river basins identified using sediment cores from reservoirs","docAbstract":"This study used chemical analyses of dated sediment cores from reservoirs to define historical trends in water quality in the influent river basins. This work applies techniques from paleolimnology to reservoirs, and in the process, highlights differences between sediment-core interpretations for reservoirs and natural lakes. Sediment cores were collected from six reservoirs in the central and southeastern United States, sectioned, and analyzed for 137Cs and organochlorine compounds. 137Cs analyses were used to demonstrate limited post-depositional mixing, to indicate sediment deposition dates, and to estimate sediment focusing factors. Relative lack of mixing, high sedimentation rates, and high focusing factors distinguish reservoir sediment cores from cores collected in natural lakes. Temporal trends in concentrations of PCBs, total DDT (DDT + DDD + DDE), and chlordane reflect historical use and regulation of these compounds and differences in land use between reservoir drainages. PCB and total DDT core burdens, normalized for sediment focusing, greatly exceed reported cumulative regional atmospheric fallout of PCBs and total DDT estimated using cores from peat hogs and natural lakes, indicating the dominance of fluvial inputs of both groups of compounds to the reservoirs.This study used chemical analyses of dated sediment cores from reservoirs to define historical trends in water quality in the influent river basins. This work applies techniques from paleolimnology to reservoirs, and in the process, highlights differences between sediment-core interpretations for reservoirs and natural lakes. Sediment cores were collected from six reservoirs in the central and southeastern United States, sectioned, and analyzed for 137Cs and organochlorine compounds. 137Cs analyses were used to demonstrate limited post-depositional mixing, to indicate sediment deposition dates, and to estimate sediment focusing factors. Relative lack of mixing, high sedimentation rates, and high focusing factors distinguish reservoir sediment cores from cores collected in natural lakes. Temporal trends in concentrations of PCBs, total DOT (DDT+DDD+DDE), and chlordane reflect historical use and regulation of these compounds and differences in land use between reservoir drainages. PCB and total DDT core burdens, normalized for sediment focusing, greatly exceed reported cumulative regional atmospheric fallout of PCBs and total DDT estimated using cores from peat bogs and natural lakes, indicating the dominance of fluvial inputs of both groups of compounds to the reservoirs.","language":"English","publisher":"ACS","doi":"10.1021/es960943p","issn":"0013936X","usgsCitation":"Van Metre, P., Callender, E., and Fuller, C.C., 1997, Historical trends in organochlorine compounds in river basins identified using sediment cores from reservoirs: Environmental Science & Technology, v. 31, no. 8, p. 2339-2344, https://doi.org/10.1021/es960943p.","productDescription":"6 p.","startPage":"2339","endPage":"2344","numberOfPages":"6","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":227878,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"31","issue":"8","noUsgsAuthors":false,"publicationDate":"1997-07-30","publicationStatus":"PW","scienceBaseUri":"505a31a8e4b0c8380cd5e0fe","contributors":{"authors":[{"text":"Van Metre, P. C.","contributorId":92999,"corporation":false,"usgs":true,"family":"Van Metre","given":"P. C.","affiliations":[],"preferred":false,"id":383443,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Callender, E.","contributorId":72528,"corporation":false,"usgs":true,"family":"Callender","given":"E.","email":"","affiliations":[],"preferred":false,"id":383442,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Fuller, C. C.","contributorId":29858,"corporation":false,"usgs":true,"family":"Fuller","given":"C.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":383441,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019645,"text":"70019645 - 1997 - The design of sampling transects for characterizing water quality in estuaries","interactions":[],"lastModifiedDate":"2019-02-04T10:31:20","indexId":"70019645","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1587,"text":"Estuarine, Coastal and Shelf Science","active":true,"publicationSubtype":{"id":10}},"title":"The design of sampling transects for characterizing water quality in estuaries","docAbstract":"The high spatial variability of estuaries poses a challenge for characterizing estuarine water quality. This problem was examined by conducting monthly high-resolution transects for several water quality variables (chlorophyll a, suspended particulate matter and salinity) in San Francisco Bay (California, U.S.A.). Using these data, six different ways of choosing station locations along a transect, in order to estimate mean conditions, were compared. In addition, 11 approaches to estimating the variance of the transect mean when stations are equally spaced were compared, and the relationship between variance of the estimated transect mean and number of stations was determined. The results provide guidelines for sampling along the axis of an estuary: (1) choose as many equally-spaced stations as practical; (2) estimate the variance of the meanyby var (y)=(1/10n2)Σnj=2(yj−yj−1)2, wherey1, . . .,ynare the measurements at thenstations; and (3) attain the desired precision by adjusting the number of stations according to var(y)α1/n2. The inverse power of 2 in the last step is a consequence of the underlying spatial correlation structure in San Francisco Bay; more studies of spatial structure at other estuaries are needed to determine the generality of this relationship.
We have developed an approach which examines ecosystem function and the potential effects of climatic shifts. The Lake McDonald watershed of Glacier National Park was the focus for two linked research activities: acquisition of baseline data on hydrologic, chemical and aquatic organism attributes that characterize this pristine northern rocky mountain watershed, and further developing the Regional Hydro-Ecosystem Simulation System (RHESSys), a collection of integrated models which collectively provide spatially explicit, mechanistically-derived outputs of ecosystem processes, including hydrologic outflow, soil moisture, and snowpack water equivalence. In this unique setting field validation of RHESSys, outputs demonstrated that reasonable estimates of SWE and streamflow are being produced. RHESSys was used to predict annual stream discharge and temperature. The predictions, in conjunction with the field data, indicated that aquatic resources of the park may be significantly affected. Utilizing RHESSys to predict potential climate scenarios and response of other key ecosystem components can provide scientific insights as well as proactive guidelines for national park management.
","language":"English","publisher":"American Water Resources Association","doi":"10.1111/j.1752-1688.1997.tb04103.x","issn":"1093474X","usgsCitation":"Fagre, D., Comanor, P., White, J., Hauer, F.R., and Running, S.W., 1997, Watershed responses to climate change at Glacier National Park: Journal of the American Water Resources Association, v. 33, no. 4, p. 755-765, https://doi.org/10.1111/j.1752-1688.1997.tb04103.x.","productDescription":"11 p.","startPage":"755","endPage":"765","numberOfPages":"11","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":506113,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1111/j.1752-1688.1997.tb04103.x","text":"Publisher Index Page"},{"id":227677,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"33","issue":"4","noUsgsAuthors":false,"publicationDate":"2007-06-08","publicationStatus":"PW","scienceBaseUri":"505bcf79e4b08c986b32e902","contributors":{"authors":[{"text":"Fagre, D.B.","contributorId":52135,"corporation":false,"usgs":true,"family":"Fagre","given":"D.B.","email":"","affiliations":[],"preferred":false,"id":383397,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Comanor, P.L.","contributorId":47103,"corporation":false,"usgs":true,"family":"Comanor","given":"P.L.","email":"","affiliations":[],"preferred":false,"id":383395,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"White, J.D.","contributorId":42923,"corporation":false,"usgs":true,"family":"White","given":"J.D.","email":"","affiliations":[],"preferred":false,"id":383394,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hauer, F. Richard","contributorId":76892,"corporation":false,"usgs":true,"family":"Hauer","given":"F.","email":"","middleInitial":"Richard","affiliations":[],"preferred":false,"id":383398,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Running, S. W.","contributorId":51257,"corporation":false,"usgs":false,"family":"Running","given":"S.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":383396,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70019606,"text":"70019606 - 1997 - Statistical modeling of agricultural chemical occurrence in midwestern rivers","interactions":[],"lastModifiedDate":"2019-02-14T06:49:45","indexId":"70019606","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2342,"text":"Journal of Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Statistical modeling of agricultural chemical occurrence in midwestern rivers","docAbstract":"Agricultural chemicals in surface water may constitute a human health risk or have adverse effects on aquatic life. Recent research on unregulated rivers in the midwestern USA documents that elevated concentrations of herbicides occur for 1-4 months following application in late spring and early summer. In contrast, nitrate concentrations in unregulated rivers are elevated during fall, winter, and spring months. Natural and anthropogenic variables of fiver drainage basins, such as soil permeability, amount of agricultural chemicals applied, or percentage of land planted in corn, affect agricultural chemical concentration and mass transport in rivers. Presented is an analysis of selected data on agricultural chemicals collected for three regional studies conducted by the US Geological Survey. Statistical techniques such as multiple linear and logistic regression were used to identify natural and anthropogenic variables of drainage basins that have strong relations to agricultural chemical concentrations and mass transport measured in rivers. A geographic information system (GIS) was used to manage and analyze spatial data. Statistical models were developed that estimated the concentration, annual transport, and annual mean concentration of selected agricultural chemicals in midwestern rivers. Multiple linear regression models were not very successful (R2 from 0.162 to 0.517) in explaining the variance in observed agricultural chemical concentrations during post-planting runoff. Logistic regression models were somewhat more successful, correctly matching the observed concentration category in 61-80% of observations. Linear and multiple linear regression models were moderately successful (R2 from 0.522 to 0.995) in explaining the variance in observed annual transport and annual mean concentration of agricultural chemicals. Explanatory variables that were commonly significant in the regression models include estimates of agricultural chemical use, crop acreage, soil characteristics, and basin topography.","language":"English","publisher":"Elsevier","doi":"10.1016/S0022-1694(97)00011-5","issn":"00221694","usgsCitation":"Battaglin, W., and Goolsby, D.A., 1997, Statistical modeling of agricultural chemical occurrence in midwestern rivers: Journal of Hydrology, v. 196, no. 1-4, p. 1-25, https://doi.org/10.1016/S0022-1694(97)00011-5.","productDescription":"25 p.","startPage":"1","endPage":"25","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":227797,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205996,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/S0022-1694(97)00011-5"}],"volume":"196","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9732e4b08c986b31b940","contributors":{"authors":[{"text":"Battaglin, W.A.","contributorId":16376,"corporation":false,"usgs":true,"family":"Battaglin","given":"W.A.","email":"","affiliations":[],"preferred":false,"id":383307,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Goolsby, D. A.","contributorId":50508,"corporation":false,"usgs":true,"family":"Goolsby","given":"D.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":383308,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019598,"text":"70019598 - 1997 - Use of 234U and 238U isotopes to evaluate contamination of near-surface groundwater with uranium-mill effluent: A case study in south-central Colorado, U.S.A.","interactions":[],"lastModifiedDate":"2012-03-12T17:19:27","indexId":"70019598","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1539,"text":"Environmental Geology","active":true,"publicationSubtype":{"id":10}},"title":"Use of 234U and 238U isotopes to evaluate contamination of near-surface groundwater with uranium-mill effluent: A case study in south-central Colorado, U.S.A.","docAbstract":"The 234U/238U alpha activity ratio (AR) was determined in 47 samples of variably uraniferous groundwater from the vicinity of a uranium mill near Canon City, Colorado. The results illustrate that uranium isotopes can be used to determine the distribution of uranium contamination in groundwater and to indicate processes such as mixing and chemical precipitation that affect uranium concentrations. Highly to moderately contaminated groundwater samples collected from the mill site and land immediately downgradient from the mill site contain more than 100 ??g/l of dissolved uranium and typically have AR values in the narrow range of 1.0-1.06. Other samples from the shallow alluvial aquifer farther downgradient from the mill contain 10-100 ??g/1 uranium and plot along a broad trend of increasing AR (1.06-1.46) with decreasing uranium concentration. The results are consistent with mixing of liquid mill waste (AR ??? 1.0) with alluvial groundwater of small, but variable, uranium concentrations and AR of 1.31.5. In the alluvial aquifer, the spatial distribution of wells with AR values less than 1.3 is consistent with previous estimates of the probable distribution of contamination, based on water chemistry and hydrology. Wells more distant from the area of probable contamination have AR values that are consistently greater than 1.3 and are indicative of little or no contamination. The methodology of this study can be extended usefully to similar sites of uranium mining, milling, or processing provided that local geohydrologic settings promote uranium mobility and that introduced uranium contamination is isotopically distinct from that of local groundwater.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s002540050201","issn":"09430105","usgsCitation":"Zielinski, R.A., Chafin, D.T., Banta, E.R., and Szabo, B.J., 1997, Use of 234U and 238U isotopes to evaluate contamination of near-surface groundwater with uranium-mill effluent: A case study in south-central Colorado, U.S.A.: Environmental Geology, v. 32, no. 2, p. 124-136, https://doi.org/10.1007/s002540050201.","startPage":"124","endPage":"136","numberOfPages":"13","costCenters":[],"links":[{"id":205963,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s002540050201"},{"id":227675,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"32","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbe55e4b08c986b32952c","contributors":{"authors":[{"text":"Zielinski, R. A. 0000-0002-4047-5129","orcid":"https://orcid.org/0000-0002-4047-5129","contributorId":106930,"corporation":false,"usgs":true,"family":"Zielinski","given":"R.","email":"","middleInitial":"A.","affiliations":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true}],"preferred":false,"id":383282,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Chafin, D. T.","contributorId":57893,"corporation":false,"usgs":true,"family":"Chafin","given":"D.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":383280,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Banta, E. R.","contributorId":63038,"corporation":false,"usgs":true,"family":"Banta","given":"E.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":383281,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Szabo, Barney J.","contributorId":6848,"corporation":false,"usgs":true,"family":"Szabo","given":"Barney","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":383279,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":1015833,"text":"1015833 - 1997 - Nesting season food habits of 4 species of herons and egrets at Lake Okeechobee, Florida","interactions":[],"lastModifiedDate":"2023-11-18T14:20:35.045574","indexId":"1015833","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1272,"text":"Colonial Waterbirds","printIssn":"07386028","active":false,"publicationSubtype":{"id":10}},"title":"Nesting season food habits of 4 species of herons and egrets at Lake Okeechobee, Florida","docAbstract":"Based on the composition of nestling regurgitations collected during 3 breeding seasons, fish were the most important prey group for Great Egrets (Ardea alba: N = 200 nest-day samples; aggregate percent biomass [APB] = 73.4%), Snowy Egrets (Egretta thula: N = 115; APB = 91.4%), and Tricolored Herons (E. tricolor: N = 68; APB = 97.3%). For Little Blue Herons (E. caerulea: N = 57), grass shrimp (Palaemonetes paludosus; APB = 39.7%) ranked higher in overall importance than all fishes combined (APB = 36.5%). Dietary overlap, as measured by Schoener's Similarity Index, was greatest between Snowy Egrets and Tricolored Herons (77%) and lowest between Tricolored Herons and Little Blue Herons (30%). Diet diversity, as measured by Shannon's Index, was highest for Great Egrets (2.04), intermediate for Snowy Egrets (1.71) and Tricolored Herons (1.68), and lowest for Little Blue Herons (1.60). Great Egrets ate a wider variety of fish species and sizes, especially larger fishes, and more crayfish than the other species. Little Blue Herons ate fewer fish and more grass shrimp and insects, and ate smaller forage fishes than Tricolored Herons but similar-sized fish as Snowy Egrets. The coarse-scale trophic composition of Snowy Egret and Tricolored Heron diets did not differ significantly, but Tricolored Herons ate larger forage fishes than Snowy Egrets. Pronounced interannual and intercolony variation in diet composition suggested that Great Egrets and Little Blue Herons switched prey types as hydrologic conditions and habitat availability changed. Conversely, lack of such variation suggested that Snowy Egrets and Tricolored Herons adjusted their foraging tactics to ensure continued encounters with preferred prey despite changing habitat conditions. These results are generally consistent with other published data, help confirm some generalizations about foraging strategies and patterns of niche differentiation among these ecologically similar species, and have implications for managing the Lake Okeechobee ecosystem.","language":"English","publisher":"Waterbird Society","doi":"10.2307/1521686","usgsCitation":"Smith, J., 1997, Nesting season food habits of 4 species of herons and egrets at Lake Okeechobee, Florida: Colonial Waterbirds, v. 20, no. 2, p. 198-220, https://doi.org/10.2307/1521686.","productDescription":"23 p.","startPage":"198","endPage":"220","numberOfPages":"23","costCenters":[{"id":290,"text":"Forest and Rangeland Ecosystem Science Center","active":false,"usgs":true}],"links":[{"id":134401,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Florida","otherGeospatial":"Lake Okeechobee","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -81.38184578069523,\n 27.37177026751857\n ],\n [\n -81.38184578069523,\n 26.490243449146305\n ],\n [\n -80.31617195257014,\n 26.490243449146305\n ],\n [\n -80.31617195257014,\n 27.37177026751857\n ],\n [\n -81.38184578069523,\n 27.37177026751857\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"20","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b25e4b07f02db6af44e","contributors":{"authors":[{"text":"Smith, Jeff P.","contributorId":79852,"corporation":false,"usgs":true,"family":"Smith","given":"Jeff P.","affiliations":[],"preferred":false,"id":323212,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019585,"text":"70019585 - 1997 - Kinetics of DCE and VC mineralization under methanogenic and Fe(III)- reducing conditions","interactions":[],"lastModifiedDate":"2019-02-13T06:38:58","indexId":"70019585","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Kinetics of DCE and VC mineralization under methanogenic and Fe(III)- reducing conditions","docAbstract":"The kinetics of anaerobic mineralization of DCE and VC under methanogenic and Fe(III)-reducing conditions as a function of dissolved contaminant concentration were evaluated. Microorganisms indigenous to creek bed sedi ments, where groundwater contaminated with chlorinated ethenes continuously discharges, demonstrated significant mineralization of DCE and VC under methanogenic and Fe(III)-reducing conditions. Over 37 days, the recovery of [1,2-14C]VC radioactivity as 14CO2 ranged from 5% to 44% and from 8% to 100% under methanogenic and Fe(III)-reducing conditions, respectively. The recovery of [1,2-14C]DCE radioactivity as 14CO2ranged from 4% to 14% and did not vary significantly between methanogenic and Fe(III)-reducing conditions. VC mineralization was described by Michaelis−Menten kinetics. Under methanogenic condi tions, Vmax was 0.19 ± 0.01 μmol L-1 d-1 and the half-saturation constant, km, was 7.6 ± 1.7 μM. Under Fe(III)-reducing conditions, Vmax was 0.76 ± 0.07 μmol L-1 d-1 and km was 1.3 ± 0.5 μM. In contrast, DCE mineralization could be described by first-order kinetics. The first-order degradation rate constant for DCE mineralization was 0.6 ± 0.2% d-1 under methanogenic and Fe(III)-reducing conditions. The results indicate that the kinetics of chlorinated ethene mineralization can vary significantly with the specific contaminant and the predominant redox conditions under which mineralization occurs.
On July 21 or 22, 1984, debris flows triggered by rainfall occurred on the southern hillslope of Jake Ridge, about 6 km east of the crest of Yucca Mountain, Nevada. Rain gages near Jake Ridge recorded 65 mm and 69 mm on July 21, and 20 mm and 17 mm on July 22. Rates of rainfall intensity ranged up to 73 mm/h on the twenty-first, and 15 mm/h on the twenty-second. Digital elevation models with 2.0 m grid-node spacing, measured from pre-storm and post-storm aerial stereo-photographs, were used to map hillslope erosion and the downslope distribution of debris. Volumetric calculations indicate that about 7040 m3 of debris was redistributed on the 49,132 m2 hillslope study area during the two-day storm period. About 4580 m3 (65%) of the eroded sediment was deposited within the study area and the remaining 35% was deposited outside the study area in a short tributary to Fortymile Wash and in the wash itself. The maximum and mean depths of erosion in the study area were about 1.8 m and 5 cm, respectively. The mean depths of erosion on the upper and middle hillslope were 27 cm and 4 cm, respectively. The mean depth of deposition on the lower hillslope was 16 cm.
Analysis of the values of cumulative precipitation in the context of the precipitation-frequency atlas of the National Oceanic and Atmospheric Administration indicates that precipitation from the main storm on July 21 was more than double that expected, on average, once during a 100-year-period. The relations of precipitation intensity/duration, developed from data recorded at a nearby precipitation gage, indicate a storm interval of 500 years or greater. The amount of erosion caused by such a storm is primarily dependent on three variables; storm intensity, development of the drainage network on the hillslope, and the amount of available colluvium. Additionally, the erosive ability of successive storms of equal intensity will decrease because such storms would tend to progressively isolate and reduce the amount of colluvium available. The preservation of Pleistocene deposits on hillslopes of Yucca Mountain, in general, indicates that erosional events that strip 5% of the available hillslope colluvium must be quite rare. We conclude that the recurrence interval of an erosional event comparable to the July, 1984 event is probably much longer than 500 years.
The spatial distribution of source areas and associated residence times of water in the catchment are significant factors controlling the annual cycles of dissolved organic carbon (DOC) concentration in Deer Creek (Summit County, Colorado). During spring snowmelt (April-August 1992), stream DOC concentrations increased with the rising limb of the hydrograph, peaked before maximum discharge, then declined rapidly as melting continued. We investigated catchment sources of DOC to streamflow, measuring DOC in tension lysimeters, groundwater wells, snow and streamflow. Lysimeter data indicate that near-surface soil horizons are a primary contributor of DOC to streamflow during spring snowmelt. Concentrations of DOC in the lysimeters decrease rapidly during the melt period, supporting the hypothesis that hydrological flushing of catchment soils is the primary mechanism affecting the temporal variation of DOC in Deer Creek. Time constants of DOC flushing, characterizing the exponential decay of DOC concentration in the upper soil horizon, ranged from 10 to 30 days for the 10 lysimeter sites. Differences in the rate of flushing are influenced by topographical position, with near-stream riparian soils flushed more quickly than soils located further upslope. Variation in the amount of distribution of accumulated snow, and asynchronous melting of the snowpack across the landscape, staggered the onset of the spring flush throughout the catchment, prolonging the period of increased concentrations of DOC in the stream. Streamflow integrates the catchment-scale flushing responses, yielding a time constant associated with the recession of DOC in the stream channel (84 days) that is significantly longer than the time constants observed for particular locations in the upper soil.
","language":"English","publisher":"Wiley","doi":"10.1002/(SICI)1099-1085(19971015)11:12<1635::AID-HYP494>3.0.CO;2-H","issn":"08856087","usgsCitation":"Boyer, E., Hornberger, G., Bencala, K., and McKnight, D.M., 1997, Response characteristics of DOC flushing in an alpine catchment: Hydrological Processes, v. 11, no. 12, p. 1635-1647, https://doi.org/10.1002/(SICI)1099-1085(19971015)11:12<1635::AID-HYP494>3.0.CO;2-H.","productDescription":"13 p.","startPage":"1635","endPage":"1647","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":227794,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"11","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aaa11e4b0c8380cd86110","contributors":{"authors":[{"text":"Boyer, E.W.","contributorId":56358,"corporation":false,"usgs":false,"family":"Boyer","given":"E.W.","email":"","affiliations":[{"id":6738,"text":"The Pennsylvania State University","active":true,"usgs":false}],"preferred":false,"id":383174,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hornberger, G.M.","contributorId":68463,"corporation":false,"usgs":true,"family":"Hornberger","given":"G.M.","email":"","affiliations":[],"preferred":false,"id":383176,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bencala, K.E.","contributorId":105312,"corporation":false,"usgs":true,"family":"Bencala","given":"K.E.","email":"","affiliations":[],"preferred":false,"id":383177,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"McKnight, Diane M.","contributorId":59773,"corporation":false,"usgs":false,"family":"McKnight","given":"Diane","email":"","middleInitial":"M.","affiliations":[{"id":16833,"text":"INSTAAR, University of Colorado","active":true,"usgs":false}],"preferred":false,"id":383175,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019560,"text":"70019560 - 1997 - Stream bed temperature profiles as indicators of percolation characteristics beneath arroyos in the middle Rio Grande Basin, USA","interactions":[],"lastModifiedDate":"2019-02-12T06:33:09","indexId":"70019560","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"Stream bed temperature profiles as indicators of percolation characteristics beneath arroyos in the middle Rio Grande Basin, USA","docAbstract":"Stream bed temperature profiles were monitored continuously during water year 1990 and 1991 (WY90 and 91) in two New Mexico arroyos, similar in their meteorological features and dissimilar in their hydrological features. Stream bed temperature profiles between depths of 30 and 300 cm were examined to determine whether temporal changes in temperature profiles represent accurate indicators of the timing, depth and duration of percolation in each stream bed. These results were compared with stream flow, air temperature, and precipitation records for WY90 and 91, to evaluate the effect of changing surface conditions on temperature profiles. Temperature profiles indicate a persistently high thermal gradient with depth beneath Grantline Arroyo, except during a semi-annual thermal reversal in spring and autumn. This typifies the thermal response of dry sediments with low thermal conductivities. High thermal gradients were disrupted only during infrequent stream flows, followed by rapid re-establishment of high gradients. The stream bed temperature at 300 cm was unresponsive to individual precipitation or stream flow during WY90 and 91. This thermal pattern provides strong evidence that most seepage into Grantline Arroyo failed to percolate at a sufficient rate to reach 300 cm before being returned to the atmosphere. A distinctly different thermal pattern was recorded beneath Tijeras Arroyo. Low thermal gradients between 30 and 300 cm and large diurnal variations in temperature, suggest that stream flow created continuous, advection-dominated heat transport for over 300 days, annually. Beneath Tijeras Arroyo, low thermal gradients were interrupted only briefly during periodic, dry summer conditions. Comparisons of stream flow records for WY90 and 91 with stream bed temperature profiles indicate that independent analysis of thermal patterns provides accurate estimates of the timing, depth and duration of percolation beneath both arroyos. Stream flow loss estimates indicate that seepage rates were 15 times greater for Tijeras Arroyo than for Grantline Arroyo, which supports qualitative conclusions derived from analysis of stream bed temperature responses to surface conditions.
","language":"English","publisher":"Wiley","doi":"10.1002/(SICI)1099-1085(19971015)11:12<1621::AID-HYP493>3.0.CO;2-X","issn":"08856087","usgsCitation":"Constantz, J., and Thomas, C.L., 1997, Stream bed temperature profiles as indicators of percolation characteristics beneath arroyos in the middle Rio Grande Basin, USA: Hydrological Processes, v. 11, no. 12, p. 1621-1634, https://doi.org/10.1002/(SICI)1099-1085(19971015)11:12<1621::AID-HYP493>3.0.CO;2-X.","productDescription":"14 p.","startPage":"1621","endPage":"1634","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":227793,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"11","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9a63e4b08c986b31c8f4","contributors":{"authors":[{"text":"Constantz, J.","contributorId":29953,"corporation":false,"usgs":true,"family":"Constantz","given":"J.","email":"","affiliations":[],"preferred":false,"id":383172,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Thomas, C. L.","contributorId":43802,"corporation":false,"usgs":true,"family":"Thomas","given":"C.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":383173,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019550,"text":"70019550 - 1997 - Organic and inorganic nitrogen pools in talus fields and subtalus water, Green Lakes Valley, Colorado front range","interactions":[],"lastModifiedDate":"2024-03-27T10:59:46.446932","indexId":"70019550","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"Organic and inorganic nitrogen pools in talus fields and subtalus water, Green Lakes Valley, Colorado front range","docAbstract":"Organic and inorganic pools of nitrogen (N) were measured in talus fines or ‘soils’ and subtalus water during the summer of 1995 in the alpine Green Lakes Valley catchment of the Colorado Front Range. Nineteen talus soil samples were divided into four classes: subtalus dry, subtalus wet, surface vegetated and surface bare. The size of the individual talus soil patches ranged from 0·5 to 12·0 m2 in area, with bulk density ranging from 0·98 to 1·71 kg m−3 and soil texture ranging from sandy gravel in the subsurface talus to a loam in the vegetated surface. All samples contained KCl-extractable NH+4 and NO−3, organic N and carbon (C), and 17 of 19 samples contained microbial biomass. The mean subtalus values for KCl-extractable NH−4, of 3·2 mg N kg−1, and NO−3, of 1·0 mg N kg−1, were comparable with developed alpine soils on Niwot Ridge. Average microbial biomass in subtalus soils of 5·4 mg N kg−1 and total N of 1000 mg N kg−1 were about an order of magnitude lower than alpine tundra soils, reflecting the reduced amount of vegetation in talus areas. However, these measurements in surface-vegetated patches of talus were comparable with the well-developed soils on Niwot Ridge. These measurements in talus of microbial biomass, total N and KCl-extractable NH+4 and NO−3, show that there is sufficient biotically conditioned ‘soil’ within talus fields to influence the solute content of interstitial waters. Mean NO−3 concentrations of 20 μeq l−1 from 29 samples of subtalus water were significantly higher than the 6·7 μeq l−1 in snow, while NH+4 concentrations in subtalus water of 0·7 μeq l−1 was significantly lower than in snow at 5·2 μeq l−1 (p = 0·001). Nitrate concentrations in subtalus water were significantly (p < 0·0001) correlated with concentrations of geochemical weathering products such as Ca2+ (r2 = 0·84) and silica (r2 = 0·49). The correlation of NO−3 in subtalus water with geochemical weathering products suggests that NO−3 concentrations in subtalus water increased with increased residence time, consistent with a biological source for this subtalus water NO−3. The high NO−3 concentrations in subtalus water compared with atmospheric deposition of NO−3 suggests that NO−3 in talus fields may contribute to NO−3 in stream waters of high-elevation catchments.
In the mantled karst terrane of northern Florida, the water quality of the Upper Floridan aquifer is influenced by the degree of connectivity between the aquifer and the surface. Chemical and isotopic analyses [18O/16O (δ18O), 2H/1H (δD), 13C/12C (δ13C), tritium (3H), and strontium‐87/strontium‐86 (87Sr/86Sr)] along with geochemical mass‐balance modeling were used to identify the dominant hydrochemical processes that control the composition of ground water as it evolves downgradient in two systems. In one system, surface water enters the Upper Floridan aquifer through a sinkhole located in the Northern Highlands physiographic unit. In the other system, surface water enters the aquifer through a sinkhole lake (Lake Bradford) in the Woodville Karst Plain. Differences in the composition of water isotopes (δ18O and <δD) in rainfall, ground water, and surface water were used to develop mixing models of surface water (leakage of water to the Upper Floridan aquifer from a sinkhole lake and a sinkhole) and ground water. Using mass‐balance calculations, based on differences in δ18O and δD, the proportion of lake water that mixed with meteoric water ranged from 7 to 86% in water from wells located in close proximity to Lake Bradford. In deeper parts of the Upper Floridan aquifer, water enriched in 18O and D from five of 12 sampled municipal wells indicated that recharge from a sinkhole (1 to 24%) and surface water with an evaporated isotopic signature (2 to 32%) was mixing with ground water.
The solute isotopes, δ13C and 87Sr/86Sr, were used to test the sensitivity of binary and ternary mixing models, and to estimate the amount of mass transfer of carbon and other dissolved species in geochemical reactions. In ground water downgradient from Lake Bradford, the dominant processes controlling carbon cycling in ground water were dissolution of carbonate minerals, aerobic degradation of organic matter, and hydrolysis of silicate minerals. In the deeper parts of the Upper Floridan aquifer, the major processes controlling the concentrations of major dissolved species included dissolution of calcite and dolomite, and degradation of organic matter under oxic conditions. The Upper Floridan aquifer is highly susceptible to contamination from activities at the land surface in the Tallahassee area. The presence of post‐ 1950s concentrations of 3H in ground water from depths greater than 100 m below land surface indicates that water throughout much of the Upper Floridan aquifer has been recharged during the last 40 years. Even though mixing is likely between ground water and surface water in many parts of the study area, the Upper Floridan aquifer produces good quality water, which due to dilution effects shows little if any impact from trace elements or nutrients that are present in surface waters.
","language":"English","publisher":"Wiley","doi":"10.1111/j.1745-6584.1997.tb00174.x","issn":"0017467X","usgsCitation":"Katz, B., Coplen, T., Bullen, T., and Hal Davis, J., 1997, Use of chemical and isotopic tracers to characterize the interactions between ground water and surface water in mantled karst: Ground Water, v. 35, no. 6, p. 1014-1028, https://doi.org/10.1111/j.1745-6584.1997.tb00174.x.","productDescription":"15 p.","startPage":"1014","endPage":"1028","numberOfPages":"15","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":228236,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"35","issue":"6","noUsgsAuthors":false,"publicationDate":"2005-08-04","publicationStatus":"PW","scienceBaseUri":"505bbed3e4b08c986b3297da","contributors":{"authors":[{"text":"Katz, B. G.","contributorId":82702,"corporation":false,"usgs":true,"family":"Katz","given":"B. G.","affiliations":[],"preferred":false,"id":383141,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Coplen, T.B.","contributorId":34147,"corporation":false,"usgs":true,"family":"Coplen","given":"T.B.","affiliations":[],"preferred":false,"id":383138,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Bullen, T.D.","contributorId":79911,"corporation":false,"usgs":true,"family":"Bullen","given":"T.D.","email":"","affiliations":[],"preferred":false,"id":383140,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Hal Davis, J.","contributorId":70947,"corporation":false,"usgs":true,"family":"Hal Davis","given":"J.","email":"","affiliations":[],"preferred":false,"id":383139,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019539,"text":"70019539 - 1997 - Microbial reduction of iodate","interactions":[],"lastModifiedDate":"2019-02-14T06:39:11","indexId":"70019539","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3728,"text":"Water, Air, & Soil Pollution","onlineIssn":"1573-2932","printIssn":"0049-6979","active":true,"publicationSubtype":{"id":10}},"title":"Microbial reduction of iodate","docAbstract":"The different oxidation species of iodine have markedly different sorption properties. Hence, changes in iodine redox states can greatly affect the mobility of iodine in the environment. Although a major microbial role has been suggested in the past to account for these redox changes, little has been done to elucidate the responsible microorganisms or the mechanisms involved. In the work presented here, direct microbial reduction of iodate was demonstrated with anaerobic cell suspensions of the sulfate reducing bacterium Desulfovibrio desulfuricans which reduced 96% of an initial 100 ??M iodate to iodide at pH 7 in 30 mM NaHCO3 buffer, whereas anaerobic cell suspensions of the dissimilatory Fe(III)-reducing bacterium Shewanella putrefaciens were unable to reduce iodate in 30 mM NaHCO3 buffer (pH 7). Both D. desulfuricans and S. putrefaciens were able to reduce iodate at pH 7 in 10 mM HEPES buffer. Both soluble ferrous iron and sulfide, as well as iron monosulfide (FeS) were shown to abiologically reduce iodate to iodide. These results indicate that ferric iron and/or sulfate reducing bacteria are capable of mediating both direct, enzymatic, as well as abiotic reduction of iodate in natural anaerobic environments. These microbially mediated reactions may be important factors in the fate and transport of 129I in natural systems.","language":"English","publisher":"Kluwer ","doi":"10.1023/A:1018370423790","issn":"00496979","usgsCitation":"Councell, T., Landa, E.R., and Lovley, D.R., 1997, Microbial reduction of iodate: Water, Air, & Soil Pollution, v. 100, no. 1-2, p. 99-106, https://doi.org/10.1023/A:1018370423790.","productDescription":"8 p.","startPage":"99","endPage":"106","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":267628,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1023/A:1018370423790"},{"id":228082,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"100","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a565be4b0c8380cd6d52b","contributors":{"authors":[{"text":"Councell, T.B.","contributorId":44187,"corporation":false,"usgs":true,"family":"Councell","given":"T.B.","email":"","affiliations":[],"preferred":false,"id":383102,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Landa, E. R.","contributorId":100002,"corporation":false,"usgs":true,"family":"Landa","given":"E.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":383103,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lovley, Derek R.","contributorId":107852,"corporation":false,"usgs":true,"family":"Lovley","given":"Derek","middleInitial":"R.","affiliations":[],"preferred":false,"id":383104,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019521,"text":"70019521 - 1997 - Concentration and transport of chlordane and nonachlor associated with suspended sediment in the Mississippi River, May 1988 to June 1990","interactions":[],"lastModifiedDate":"2020-02-21T10:59:44","indexId":"70019521","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":887,"text":"Archives of Environmental Contamination and Toxicology","active":true,"publicationSubtype":{"id":10}},"title":"Concentration and transport of chlordane and nonachlor associated with suspended sediment in the Mississippi River, May 1988 to June 1990","docAbstract":"Technical chlordane, a formerly widely used organochlorine pesticide, has become widespread in the environment. The distribution of technical chlordane in riverine environments may be due in part to resuspension and aqueous transport of contaminated bed sediment. To test this hypothesis, the Mississippi River was sampled for suspended sediment five times over a two- year period, at up to 17 sites from St. Louis to below New Orleans, including major tributaries. The ratio of chlordane to nonachlor concentrations averaged 3.6 during May-June 1988 for the Mississippi River below its confluence with the Ohio River. During March-April 1989, the ratio was 0.6, suggesting weathered technical chlordane contributions to the suspended sediment. During June 1989, the ratio averaged 1.1, indicating some input of less weathered technical chlordane. During February-March and May-June 1990, the ratios again shifted, from 0.8 to 1.3. This shifting ratio is likely due to resuspension of weathered technical chlordane associated with bed sediment during spring runoff. Annual transport by suspended sediment from the Mississippi River to the Gulf of Mexico was estimated to be 110 kg of chlordane and 100 kg of nonachlor.","language":"English","publisher":"Springer","doi":"10.1007/s002449900266","issn":"00904341","usgsCitation":"Rostad, C., 1997, Concentration and transport of chlordane and nonachlor associated with suspended sediment in the Mississippi River, May 1988 to June 1990: Archives of Environmental Contamination and Toxicology, v. 33, no. 4, p. 369-377, https://doi.org/10.1007/s002449900266.","productDescription":"9 p.","startPage":"369","endPage":"377","numberOfPages":"9","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226428,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","otherGeospatial":"Mississippi River","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -95.361328125,\n 46.76996843356982\n ],\n [\n -95.2294921875,\n 46.6795944656402\n ],\n [\n -96.15234375,\n 46.76996843356982\n ],\n [\n -95.2734375,\n 45.79816953017265\n ],\n [\n -93.779296875,\n 44.68427737181225\n ],\n [\n -92.5048828125,\n 43.99281450048989\n ],\n [\n -91.93359375,\n 42.71473218539458\n ],\n [\n -92.021484375,\n 41.57436130598913\n ],\n [\n -92.28515625,\n 40.38002840251183\n ],\n [\n -91.93359375,\n 39.842286020743394\n ],\n [\n -91.7578125,\n 39.470125122358176\n ],\n [\n -91.1865234375,\n 38.61687046392973\n ],\n [\n -90.966796875,\n 36.70365959719456\n ],\n [\n -91.93359375,\n 34.08906131584994\n ],\n [\n -92.2412109375,\n 32.509761735919426\n ],\n [\n -92.28515625,\n 31.316101383495624\n ],\n [\n -91.49414062499999,\n 29.916852233070173\n ],\n [\n -90.5712890625,\n 28.806173508854776\n ],\n [\n -89.384765625,\n 28.729130483430154\n ],\n [\n -88.8134765625,\n 30.06909396443887\n ],\n [\n -89.736328125,\n 30.675715404167743\n ],\n [\n -90.65917968749999,\n 30.86451022625836\n ],\n [\n -90.3955078125,\n 32.879587173066305\n ],\n [\n -89.7802734375,\n 34.161818161230386\n ],\n [\n -88.9892578125,\n 35.53222622770337\n ],\n [\n -88.8134765625,\n 37.125286284966805\n ],\n [\n -89.20898437499999,\n 38.238180119798635\n ],\n [\n -90.5712890625,\n 40.01078714046552\n ],\n [\n -89.6044921875,\n 41.21172151054787\n ],\n [\n -89.912109375,\n 42.94033923363181\n ],\n [\n -91.669921875,\n 45.058001435398275\n ],\n [\n -95.361328125,\n 46.76996843356982\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"33","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f97ce4b0c8380cd4d61f","contributors":{"authors":[{"text":"Rostad, C.E.","contributorId":50939,"corporation":false,"usgs":true,"family":"Rostad","given":"C.E.","email":"","affiliations":[],"preferred":false,"id":383047,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70019508,"text":"70019508 - 1997 - Marine bacterial degradation of brominated methanes","interactions":[],"lastModifiedDate":"2019-02-13T05:44:25","indexId":"70019508","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Marine bacterial degradation of brominated methanes","docAbstract":"Brominated methanes are ozone-depleting compounds whose natural sources include marine algae such as kelp. Brominated methane degradation by bacteria was investigated to address whether bacterial processes might effect net emission of these compounds to the atmosphere. Bacteria in seawater collected from California kelp beds degraded CH2Br2 but not CHBr3. Specific inhibitors showed that methanotrophs and nitrifiers did not significantly contribute to CH2Br2 removal. A seawater enrichment culture oxidized 14CH2Br2 to 14CO2 as well as 14CH3Br to 14CO2. The rates of CH2Br2 degradation in laboratory experiments suggest that bacterial degradation of CH2Br2 in a kelp bed accounts for <1% of the CH2Br2 produced by the kelp. However, the half-life of CH2Br2 due to bacterial removal appears faster than hydrolysis and within an order of magnitude of volatilization to the atmosphere.Brominated methanes are ozone-depleting compounds whose natural sources include marine algae such as kelp. Brominated methane degradation by bacteria was investigated to address whether bacterial processes might effect net emission of these compounds to the atmosphere. Bacteria in seawater collected from California kelp beds degraded CH2Br2 but not CHBr3. Specific inhibitors showed that methanotrophs and nitrifiers did not significantly contribute to CH2Br2 removal. A seawater enrichment culture oxidized 14CH2Br2 to 14CO2 as well as 14CH3Br to 14CO2. The rates of CH2Br2 degradation in laboratory experiments suggest that bacterial degradation of CH2Br2 in a kelp bed accounts for <1% of the CH2Br2 produced by the kelp. However, the half-life of CH2Br2 due to bacterial removal appears faster than hydrolysis and within an order of magnitude of volatilization to the atmosphere.","language":"English","publisher":"ACS","doi":"10.1021/es970165g","issn":"0013936X","usgsCitation":"Goodwin, K., Lidstrom, M., and Oremland, R., 1997, Marine bacterial degradation of brominated methanes: Environmental Science & Technology, v. 31, no. 11, p. 3188-3192, https://doi.org/10.1021/es970165g.","productDescription":"5 p.","startPage":"3188","endPage":"3192","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":205732,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es970165g"},{"id":226472,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"31","issue":"11","noUsgsAuthors":false,"publicationDate":"1997-10-29","publicationStatus":"PW","scienceBaseUri":"505a51cbe4b0c8380cd6bf3d","contributors":{"authors":[{"text":"Goodwin, K.D.","contributorId":45472,"corporation":false,"usgs":true,"family":"Goodwin","given":"K.D.","email":"","affiliations":[],"preferred":false,"id":383000,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lidstrom, M.E.","contributorId":93207,"corporation":false,"usgs":true,"family":"Lidstrom","given":"M.E.","email":"","affiliations":[],"preferred":false,"id":383001,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Oremland, R.S.","contributorId":97512,"corporation":false,"usgs":true,"family":"Oremland","given":"R.S.","email":"","affiliations":[],"preferred":false,"id":383002,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019504,"text":"70019504 - 1997 - Identification of ionic chloroacetanilide-herbicide metabolites in surface water and groundwater by HPLC/MS using negative ion spray","interactions":[],"lastModifiedDate":"2019-02-12T09:47:17","indexId":"70019504","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":761,"text":"Analytical Chemistry","active":true,"publicationSubtype":{"id":10}},"title":"Identification of ionic chloroacetanilide-herbicide metabolites in surface water and groundwater by HPLC/MS using negative ion spray","docAbstract":"Solid-phase extraction (SPE) was combined with high-performance liquid chromatography/high-flow pneumatically assisted electrospray mass spectrometry (HPLC/ESP/MS) for the trace analysis of oxanilic and sulfonic acids of acetochlor, alachlor, and metolachlor. The isolation procedure separated the chloroacetanilide metabolites from the parent herbicides during the elution from C18 cartridges using ethyl acetate for parent compounds, followed by methanol for the anionic metabolites. The metabolites were separated chromatographically using reversed-phase HPLC and analyzed by negative-ion MS using electrospray ionization in selected ion mode. Quantitation limits were 0.01 μg/L for both the oxanilic and sulfonic acids based on a 100-mL water sample. This combination of methods represents an important advance in environmental analysis of chloroacetanilide−herbicide metabolites in surface water and groundwater for two reasons. First, anionic chloroacetanilide metabolites are a major class of degradation products that are readily leached to groundwater in agricultural areas. Second, anionic metabolites, which are not able to be analyzed by conventional methods such as liquid extraction and gas chromatography/mass spectrometry, are effectively analyzed by SPE and high-flow pneumatically assisted electrospray mass spectrometry. This paper reports the first HPLC/MS identification of these metabolites in surface water and groundwater.
","language":"English","publisher":"ACS","doi":"10.1021/ac9704671","issn":"00032700","usgsCitation":"Ferrer, I., Thurman, E., and Barcelo, D., 1997, Identification of ionic chloroacetanilide-herbicide metabolites in surface water and groundwater by HPLC/MS using negative ion spray: Analytical Chemistry, v. 69, no. 22, p. 4547-4553, https://doi.org/10.1021/ac9704671.","productDescription":"7 p.","startPage":"4547","endPage":"4553","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226432,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205724,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/ac9704671"}],"volume":"69","issue":"22","noUsgsAuthors":false,"publicationDate":"1997-11-15","publicationStatus":"PW","scienceBaseUri":"505a382de4b0c8380cd6148c","contributors":{"authors":[{"text":"Ferrer, Imma","contributorId":68606,"corporation":false,"usgs":true,"family":"Ferrer","given":"Imma","affiliations":[],"preferred":false,"id":382991,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Thurman, E.M.","contributorId":102864,"corporation":false,"usgs":true,"family":"Thurman","given":"E.M.","affiliations":[],"preferred":false,"id":382992,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Barcelo, Damia","contributorId":189407,"corporation":false,"usgs":false,"family":"Barcelo","given":"Damia","email":"","affiliations":[],"preferred":false,"id":382990,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019503,"text":"70019503 - 1997 - The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater","interactions":[],"lastModifiedDate":"2019-02-12T06:37:55","indexId":"70019503","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater","docAbstract":"Infiltration and dispersion (including molecular diffusion) can transport volatile organic compounds (VOCs) from urban air into shallow groundwater. The gasoline additive methyl-tert-butyl ether (MTBE) is of special interest because of its (1) current levels in some urban air, (2) strong partitioning from air into water, (3) resistance to degradation, (4) use as an octane-booster since the 1970s, (5) rapidly increasing use in the 1990s to reduce CO and O3 in urban air, and (6) its frequent detection at low microgram per liter levels in shallow urban groundwater in Denver, New England, and elsewhere. Numerical simulations were conducted using a 1-D model domain set in medium sand (depth to water table = 5 m) to provide a test of whether MTBE and other atmospheric VOCs could move to shallow groundwater within the 10−15 y time frame over which MTBE has now been used in large amounts. Degradation and sorption were assumed negligible. In case 1 (no infiltration, steady atmospheric source), 10 y was not long enough to permit significant VOC movement by diffusion into shallow groundwater. Case 2 considered a steady atmospheric source plus 36 cm/y of net infiltration; groundwater at 2 m below the water table became nearly saturated with atmospheric levels of VOC within 5 y. Case 3 was similar to case 2, but considered the source to be seasonal, being “on” for only 5 of 12 months each year, as with the use of MTBE during the winter fuel-oxygenate season; groundwater at 2 m below the water table became equilibrated with 5/12 of the “source-on” concentration within 5 y. Cases 4 and 5 added an evapotranspiration (ET) loss of 36 cm/y, resulting in no net recharge. Case 4 took the ET from the surface, and case 5 took the ET from the capillary fringe at a depth of 3.5 m. Net VOC mass transfer to shallow groundwater after 5 y was less for both cases 4 and 5 than for case 3. However, it was significantly greater for cases 4 and 5 than for case 1, even though cases 1, 4, and 5 were all no-net recharge cases. The mechanism responsible for this effect was the dispersion acting on each downward infiltration event, and also on the ET-induced flow. The ability of MTBE to reach groundwater in cases 2−5 is taken as evidence of the potential importance of urban air as a non-point source for VOCs in shallow urban groundwater. Two subcases were run for both case 4 and case 5: subcase a (water and VOCs move with ET) and subcase b (water only moves with ET).
","language":"English","publisher":"ACS Publication","doi":"10.1021/es970040b","usgsCitation":"Pankow, J.F., Thomson, N., Johnson, R.L., Baehr, A.L., and Zogorski, J., 1997, The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater: Environmental Science & Technology, v. 31, no. 10, p. 2821-2828, https://doi.org/10.1021/es970040b.","productDescription":"8 p.","startPage":"2821","endPage":"2828","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226344,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"31","issue":"10","noUsgsAuthors":false,"publicationDate":"1997-09-30","publicationStatus":"PW","scienceBaseUri":"505bb155e4b08c986b3252d9","contributors":{"authors":[{"text":"Pankow, J. F.","contributorId":20917,"corporation":false,"usgs":true,"family":"Pankow","given":"J.","email":"","middleInitial":"F.","affiliations":[],"preferred":false,"id":382985,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Thomson, N.R.","contributorId":51027,"corporation":false,"usgs":true,"family":"Thomson","given":"N.R.","email":"","affiliations":[],"preferred":false,"id":382987,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Johnson, Richard L.","contributorId":169575,"corporation":false,"usgs":false,"family":"Johnson","given":"Richard","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":382986,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Baehr, A. L.","contributorId":59831,"corporation":false,"usgs":true,"family":"Baehr","given":"A.","email":"","middleInitial":"L.","affiliations":[],"preferred":false,"id":382988,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Zogorski, J.S.","contributorId":108201,"corporation":false,"usgs":true,"family":"Zogorski","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":382989,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70019499,"text":"70019499 - 1997 - Water quality functions of riparian forest buffers in Chesapeake bay watersheds","interactions":[],"lastModifiedDate":"2012-03-12T17:19:13","indexId":"70019499","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1547,"text":"Environmental Management","active":true,"publicationSubtype":{"id":10}},"title":"Water quality functions of riparian forest buffers in Chesapeake bay watersheds","docAbstract":"Maryland, Virginia, and Pennsylvania, USA, have agreed to reduce nutrient loadings to Chesapeake Bay by 40% by the year 2000. This requires control of nonpoint sources of nutrients much of which comes from agriculture. Riparian forest buffer systems (RFBS) provide effective control of nonpoint source (NPS) pollution in some types of agricultural watersheds. Control of NPS pollution is dependent on the type of pollutant and the hydrologic connection between pollution sources, the RFBS, and the stream. Water quality improvements are most likely in areas of where most of the excess precipitation moves across, in, or near the root zone of the RFBS. In areas such as the Inner Coastal Plain and Piedmont watersheds with thin soils RFBS should retain 50%-90% of the total loading of nitrate in shallow groundwater sediment in surface runoff and total N in born surface runoff and groundwater. Retention of phosphorus is generally much less. In regions with deeper soils and/or greater regional groundwater recharge (such as parts of the Piedmont and the Valley and Ridge), RFBS water quality improvements are probably much less. The expected levels of pollutant control by RFBS are identified for each of nine physiographic provinces of the Chesapeake Bay Watershed. Issues related to of establishment sustainability, and management are also discussed.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Springer-Verlag New York","publisherLocation":"Secaucus, NJ, United States","doi":"10.1007/s002679900060","issn":"0364152X","usgsCitation":"Lowrance, R., Altier, L., Newbold, J., Schnabel, R., Groffman, P., Denver, J.M., Correll, D., Gilliam, J., Robinson, J., Brinsfield, R., Staver, K., Lucas, W., and Todd, A., 1997, Water quality functions of riparian forest buffers in Chesapeake bay watersheds: Environmental Management, v. 21, no. 5, p. 687-712, https://doi.org/10.1007/s002679900060.","startPage":"687","endPage":"712","numberOfPages":"26","costCenters":[],"links":[{"id":205701,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s002679900060"},{"id":226300,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"21","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bc894e4b08c986b32c9dc","contributors":{"authors":[{"text":"Lowrance, R.","contributorId":6198,"corporation":false,"usgs":true,"family":"Lowrance","given":"R.","email":"","affiliations":[],"preferred":false,"id":382961,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Altier, L.S.","contributorId":43116,"corporation":false,"usgs":true,"family":"Altier","given":"L.S.","email":"","affiliations":[],"preferred":false,"id":382967,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Newbold, J.D.","contributorId":55582,"corporation":false,"usgs":true,"family":"Newbold","given":"J.D.","email":"","affiliations":[],"preferred":false,"id":382968,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Schnabel, R.R.","contributorId":81259,"corporation":false,"usgs":true,"family":"Schnabel","given":"R.R.","email":"","affiliations":[],"preferred":false,"id":382970,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Groffman, P.M.","contributorId":21904,"corporation":false,"usgs":true,"family":"Groffman","given":"P.M.","affiliations":[],"preferred":false,"id":382965,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Denver, J. M.","contributorId":100356,"corporation":false,"usgs":true,"family":"Denver","given":"J.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":382972,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Correll, D.L.","contributorId":20478,"corporation":false,"usgs":true,"family":"Correll","given":"D.L.","email":"","affiliations":[],"preferred":false,"id":382964,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Gilliam, J.W.","contributorId":42369,"corporation":false,"usgs":true,"family":"Gilliam","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":382966,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Robinson, J.L.","contributorId":13283,"corporation":false,"usgs":true,"family":"Robinson","given":"J.L.","email":"","affiliations":[],"preferred":false,"id":382963,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Brinsfield, R.B.","contributorId":78484,"corporation":false,"usgs":true,"family":"Brinsfield","given":"R.B.","email":"","affiliations":[],"preferred":false,"id":382969,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Staver, K.W.","contributorId":91997,"corporation":false,"usgs":true,"family":"Staver","given":"K.W.","email":"","affiliations":[],"preferred":false,"id":382971,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Lucas, W.","contributorId":107439,"corporation":false,"usgs":true,"family":"Lucas","given":"W.","email":"","affiliations":[],"preferred":false,"id":382973,"contributorType":{"id":1,"text":"Authors"},"rank":12},{"text":"Todd, A.H.","contributorId":9409,"corporation":false,"usgs":true,"family":"Todd","given":"A.H.","email":"","affiliations":[],"preferred":false,"id":382962,"contributorType":{"id":1,"text":"Authors"},"rank":13}]}} ,{"id":70019493,"text":"70019493 - 1997 - Practical considerations for measuring hydrogen concentrations in groundwater","interactions":[],"lastModifiedDate":"2019-02-08T16:56:36","indexId":"70019493","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Practical considerations for measuring hydrogen concentrations in groundwater","docAbstract":"Several practical considerations for measuring concentrations of dissolved molecular hydrogen (H2) in groundwater including 1 sampling methods 2 pumping methods and (3) effects of well casing materials were evaluated. Three different sampling methodologies (a downhole sampler, a gas- stripping method, and a diffusion sampler) were compared. The downhole sampler and gas-stripping methods gave similar results when applied to the same wells, the other hand, appeared to The diffusion sampler, on overestimate H2 concentrations relative to the downhole sampler. Of these methods, the gas-stripping method is better suited to field conditions because it is faster (~ 30 min for a single analysis as opposed to 2 h for the downhole sampler or 8 h for the diffusion sampler), the analysis is easier (less sample manipulation is required), and the data computations are more straightforward (H2 concentrations need not be corrected for water sample volume). Measurement of H2 using the gas-stripping method can be affected by different pumping equipment. Peristaltic, piston, and bladder pumps all gave similar results when applied to water produced from the same well. It was observed, however, that peristaltic-pumped water (which draws water under a negative pressure) enhanced the gas-stripping process and equilibrated slightly faster than either piston or bladder pumps (which push water under a positive pressure). A direct current(dc) electrically driven submersible pump was observed to produce H2 and was not suitable for measuring H2 in groundwater. Measurements from two field sites indicate that iron or steel well casings, produce H2, which masks H2 concentrations in groundwater. PVC-cased wells or wells cased with other materials that do not produce H2 are necessary for measuring H2 concentrations in groundwater.Several practical considerations for measuring concentrations of dissolved molecular hydrogen in groundwater including sampling methods, pumping methods, and effects of well casing materials were evaluated. The downhole sampler and gas-stripping methods gave similar results when applied to the same wells. The diffusional sampler appears to overestimate H2 concentrations relative to the downhole sampler. Gas-stripping method is better for a single analysis and the data computations are more straightforward. Measurement of H2 using the gas-stripping method can be affected by different pumping equipment.","language":"English","publisher":"ACS","doi":"10.1021/es970085c","issn":"0013936X","usgsCitation":"Chapelle, F.H., Vroblesky, D., Woodward, J., and Lovley, D.R., 1997, Practical considerations for measuring hydrogen concentrations in groundwater: Environmental Science & Technology, v. 31, no. 10, p. 2873-2877, https://doi.org/10.1021/es970085c.","productDescription":"5 p.","startPage":"2873","endPage":"2877","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226339,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":205705,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1021/es970085c"}],"volume":"31","issue":"10","noUsgsAuthors":false,"publicationDate":"1997-09-30","publicationStatus":"PW","scienceBaseUri":"505a80a9e4b0c8380cd7b11f","contributors":{"authors":[{"text":"Chapelle, F. H.","contributorId":101697,"corporation":false,"usgs":true,"family":"Chapelle","given":"F.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":382942,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Vroblesky, D.A.","contributorId":101691,"corporation":false,"usgs":true,"family":"Vroblesky","given":"D.A.","affiliations":[],"preferred":false,"id":382941,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Woodward, J.C.","contributorId":62590,"corporation":false,"usgs":true,"family":"Woodward","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":382940,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lovley, Derek R.","contributorId":107852,"corporation":false,"usgs":true,"family":"Lovley","given":"Derek","middleInitial":"R.","affiliations":[],"preferred":false,"id":382943,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019491,"text":"70019491 - 1997 - Groundwater record of halocarbon transport by the Danube River","interactions":[],"lastModifiedDate":"2020-01-08T06:26:41","indexId":"70019491","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Groundwater record of halocarbon transport by the Danube River","docAbstract":"Groundwater dating studies have supported the concept that aquifers with low coefficients of dispersion may contain coherent records of past conditions in recharge areas. Groundwater records can provide unique information about natural or anthropogenic changes in the atmosphere and hydrosphere where long-term monitoring data are not available. Here we describe a 40-year record of halocarbon contamination in the Danube River that was retrieved from a shallow aquifer in northwest Hungary. The time scale is based on 3H and He isotope dating of groundwaters that were recharged by the Danube River and moved horizontally away from the river in a surficial gravel aquifer with minor dispersion at a maximum rate of at least 500 m/yr. Analyses of dated groundwaters along a flow path indicate that the river loads of selected compounds (including CFC-12, CFC-113, and trichloroethane) were negligible before about 1950, rose rapidly to peak values in the 1960s and 1970s, and then decreased by varying degrees to the present. Peak concentrations are tentatively attributed to point sources in upstream urban-industrial centers; while recent decreases presumably resulted from declining manufacturing rates and(or) improvements in control of urban- industrial runoff and sewage effluent entering the river in upstream areas.","language":"English","publisher":"ACS","doi":"10.1021/es970336h","issn":"0013936X","usgsCitation":"Böhlke, J., Revesz, K., Busenberg, E., Deak, J., Deseo, E., and Stute, M., 1997, Groundwater record of halocarbon transport by the Danube River: Environmental Science & Technology, v. 31, no. 11, p. 3293-3299, https://doi.org/10.1021/es970336h.","productDescription":"7 p.","startPage":"3293","endPage":"3299","numberOfPages":"7","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226297,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"Hungary, Slovakia ","otherGeospatial":"Danube River","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n 17.05078125,\n 47.68018294648414\n ],\n [\n 19.51171875,\n 47.68018294648414\n ],\n [\n 19.51171875,\n 48.20271028869972\n ],\n [\n 17.05078125,\n 48.20271028869972\n ],\n [\n 17.05078125,\n 47.68018294648414\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"31","issue":"11","noUsgsAuthors":false,"publicationDate":"1997-10-29","publicationStatus":"PW","scienceBaseUri":"505a2dc0e4b0c8380cd5bff1","contributors":{"authors":[{"text":"Böhlke, J.K. 0000-0001-5693-6455","orcid":"https://orcid.org/0000-0001-5693-6455","contributorId":96696,"corporation":false,"usgs":true,"family":"Böhlke","given":"J.K.","affiliations":[],"preferred":false,"id":382937,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Revesz, K.","contributorId":95202,"corporation":false,"usgs":true,"family":"Revesz","given":"K.","affiliations":[],"preferred":false,"id":382936,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Busenberg, E.","contributorId":56796,"corporation":false,"usgs":true,"family":"Busenberg","given":"E.","affiliations":[],"preferred":false,"id":382933,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Deak, J.","contributorId":63184,"corporation":false,"usgs":true,"family":"Deak","given":"J.","affiliations":[],"preferred":false,"id":382934,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Deseo, E.","contributorId":42730,"corporation":false,"usgs":true,"family":"Deseo","given":"E.","affiliations":[],"preferred":false,"id":382932,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Stute, M.","contributorId":67234,"corporation":false,"usgs":true,"family":"Stute","given":"M.","affiliations":[],"preferred":false,"id":382935,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70019490,"text":"70019490 - 1997 - Bacterial oxidation of methyl bromide in fumigated agricultural soils","interactions":[],"lastModifiedDate":"2023-01-12T22:00:23.77647","indexId":"70019490","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":850,"text":"Applied and Environmental Microbiology","active":true,"publicationSubtype":{"id":10}},"title":"Bacterial oxidation of methyl bromide in fumigated agricultural soils","docAbstract":"The oxidation of [14C]methyl bromide ([14C]MeBr) to 14CO2 was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCl3NO2). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or several days after injection. No oxidation of MeBr occurred in heat-killed soils, indicating that microbes were the causative agents of the oxidation. Degradation of MeBr by chemical and/or biological processes accounted for 20 to 50% of the loss of MeBr during fumigation, with evasion to the atmosphere inferred to comprise the remainder. In laboratory incubations, complete removal of [14C]MeBr occurred within a few days, with 47 to 67% of the added MeBr oxidized to 14CO2 and the remainder of counts associated with the solid phase. Chloropicrin inhibited the oxidation of MeBr, implying that use of this substance constrains the extent of microbial degradation of MeBr during fumigation. Oxidation was by direct bacterial attack of MeBr and not of methanol, a product of the chemical hydrolysis of MeBr. Neither nitrifying nor methane-oxidizing bacteria were sufficiently active in these soils to account for the observed oxidation of MeBr, nor could the microbial degradation of MeBr be linked to cooxidation with exogenously supplied electron donors. However, repeated addition of MeBr to live soils resulted in higher rates of its removal, suggesting that soil bacteria used MeBr as an electron donor for growth. To support this interpretation, we isolated a gram-negative, aerobic bacterium from these soils which grew with MeBr as a sole source of carbon and energy.
","language":"English","publisher":"American Society for Microbiology","doi":"10.1128/aem.63.11.4346-4354.1997","issn":"00992240","usgsCitation":"Miller, L., Connell, T., Guidetti, J., and Oremland, R., 1997, Bacterial oxidation of methyl bromide in fumigated agricultural soils: Applied and Environmental Microbiology, v. 63, no. 11, p. 4346-4354, https://doi.org/10.1128/aem.63.11.4346-4354.1997.","productDescription":"9 p.","startPage":"4346","endPage":"4354","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":489714,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1128/aem.63.11.4346-4354.1997","text":"Publisher Index Page"},{"id":226932,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","county":"Monterey County, Orange County","otherGeospatial":"Gavilan Berry Farm, 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L.G.","contributorId":32522,"corporation":false,"usgs":true,"family":"Miller","given":"L.G.","email":"","affiliations":[],"preferred":false,"id":382928,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Connell, T.L.","contributorId":96024,"corporation":false,"usgs":true,"family":"Connell","given":"T.L.","email":"","affiliations":[],"preferred":false,"id":382930,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Guidetti, J.R.","contributorId":72001,"corporation":false,"usgs":true,"family":"Guidetti","given":"J.R.","email":"","affiliations":[],"preferred":false,"id":382929,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Oremland, R.S.","contributorId":97512,"corporation":false,"usgs":true,"family":"Oremland","given":"R.S.","email":"","affiliations":[],"preferred":false,"id":382931,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70019487,"text":"70019487 - 1997 - Effects of exchanged cation and layer charge on the sorption of water and EGME vapors on montmorillonite clays","interactions":[],"lastModifiedDate":"2019-02-04T10:54:07","indexId":"70019487","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1245,"text":"Clays and Clay Minerals","onlineIssn":"1552-8367","printIssn":"0009-8604","active":true,"publicationSubtype":{"id":10}},"title":"Effects of exchanged cation and layer charge on the sorption of water and EGME vapors on montmorillonite clays","docAbstract":"The effects of exchanged cation and layer charge on the sorption of water and ethylene glycol monoethyl ether (EGME) vapors on montmorillonite have been studied on SAz-1 and SWy-1 source clays, each exchanged respectively with Ca, Na, K, Cs and tetramethylammonium (TMA) cations. The corresponding lattice expansions were also determined, and the corresponding N2 adsorption data were provided for comparison. For clays exchanged with cations of low hydrating powers (such as K, Cs and TMA), water shows a notably lower uptake than does N2 at low relative pressures (P/P0). By contrast, EGME shows higher uptakes than N2 on all exchanged clays at all P/P0. The anomaly for water is attributed to its relatively low attraction for siloxane surfaces of montmorillonite because of its high cohesive energy density. In addition to solvating cations and expanding interlayers, water and EGME vapors condense into small clay pores and interlayer voids created by interlayer expansion. The initial (dry) interlayer separation varies more significantly with cation type than with layer charge; the water-saturated interlayer separation varies more with cation type than the EGME-saturated interlayer separation. Because of the differences in surface adsorption and interlayer expansion for water and EGME, no general correspondence is found between the isotherms of water and EGME on exchanged clays, nor is a simple relation observed between the overall uptake of either vapor and the cation solvating power. The excess interlayer capacities of water and of EGME that result from lattice expansion of the exchanged clays are estimated by correcting for amounts of vapor adsorption on planar clay surfaces and of vapor condensation into intrinsic clay pores. The resulting data follow more closely the relative solvating powers of the exchanged cations.
","language":"English","publisher":"The Clay Minerals Society","doi":"10.1346/CCMN.1997.0450611","usgsCitation":"Chiou, C.T., and Rutherford, D.W., 1997, Effects of exchanged cation and layer charge on the sorption of water and EGME vapors on montmorillonite clays: Clays and Clay Minerals, v. 45, no. 6, p. 867-880, https://doi.org/10.1346/CCMN.1997.0450611.","productDescription":"14 p.","startPage":"867","endPage":"880","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226337,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"45","issue":"6","noUsgsAuthors":false,"publicationDate":"2024-02-28","publicationStatus":"PW","scienceBaseUri":"505a06e2e4b0c8380cd51476","contributors":{"authors":[{"text":"Chiou, Cary T. 0000-0002-8743-0702","orcid":"https://orcid.org/0000-0002-8743-0702","contributorId":189558,"corporation":false,"usgs":true,"family":"Chiou","given":"Cary","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":382920,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rutherford, David W. dwruther@usgs.gov","contributorId":1325,"corporation":false,"usgs":true,"family":"Rutherford","given":"David","email":"dwruther@usgs.gov","middleInitial":"W.","affiliations":[],"preferred":true,"id":382919,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70019480,"text":"70019480 - 1997 - Logistic model of nitrate in streams of the upper-midwestern United States","interactions":[],"lastModifiedDate":"2019-02-04T10:58:09","indexId":"70019480","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2262,"text":"Journal of Environmental Quality","active":true,"publicationSubtype":{"id":10}},"title":"Logistic model of nitrate in streams of the upper-midwestern United States","docAbstract":"Nitrate in surface water can have adverse effects on aquatic life and, in drinking-water supplies, can be a risk to human health. As part of a regional study, nitrates as N (NO3-N) was analyzed in water samples collected from streams throughout 10 Midwestern states during synoptic surveys in 1989, 1990, and 1994. Data from the period immediately following crop planting at 124 sites were analyzed during logistic regression to relate discrete categories of NO3-N concentrations to characteristics of the basins upstream from the sites. The NO3-N data were divided into three categories representing probable background concentrations (<3 mg L-1), elevated concentrations (3-10 mg L-1), and concentrations that exceeded the U.S. Environmental Protection Agency maximum contaminant level (MCL) for drinking water (>10 mg L-1). Nitrate-N concentrations were positively correlated to streamflow, upstream area planted in corn (Zea mays L.), and upstream N- fertilizers application rates. Elevated NO3-N concentrations were associated with poorly drained soils and were weakly correlated with population density. Nitrate-N and streamflow data collected during 1989 and 1990 were used to calibrate the model, and data collected during 1994 were used for verification. The model correctly estimated NO3-N concentration categories for 79% of the samples in the calibration data set and 60% of the samples in the verification data set. The model was used to indicate where NO3-N concentrations might be elevated or exceed the NO3-N MCL in streams throughout the study area. The potential for elevated NO3-N concentrations was predicted to be greatest for streams in Illinois, Indiana, Iowa, and western Ohio.","language":"English","publisher":"ACSESS","doi":"10.2134/jeq1997.00472425002600050005x","issn":"00472425","usgsCitation":"Mueller, D., Ruddy, B.C., and Battaglin, W., 1997, Logistic model of nitrate in streams of the upper-midwestern United States: Journal of Environmental Quality, v. 26, no. 5, p. 1223-1230, https://doi.org/10.2134/jeq1997.00472425002600050005x.","productDescription":"8 p.","startPage":"1223","endPage":"1230","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226930,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"26","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4949e4b0c8380cd684b2","contributors":{"authors":[{"text":"Mueller, D. K.","contributorId":93525,"corporation":false,"usgs":true,"family":"Mueller","given":"D. K.","affiliations":[],"preferred":false,"id":382876,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ruddy, B. C.","contributorId":65098,"corporation":false,"usgs":true,"family":"Ruddy","given":"B.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":382875,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Battaglin, W.A.","contributorId":16376,"corporation":false,"usgs":true,"family":"Battaglin","given":"W.A.","email":"","affiliations":[],"preferred":false,"id":382874,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70019475,"text":"70019475 - 1997 - Constant-concentration boundary condition: Lessons from the HYDROCOIN variable-density groundwater benchmark problem","interactions":[],"lastModifiedDate":"2019-02-13T05:55:59","indexId":"70019475","displayToPublicDate":"1997-01-01T00:00:00","publicationYear":"1997","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Constant-concentration boundary condition: Lessons from the HYDROCOIN variable-density groundwater benchmark problem","docAbstract":"In a solute-transport model, if a constant-concentration boundary condition is applied at a node in an active flow field, a solute flux can occur by both advective and dispersive processes. The potential for advective release is demonstrated by reexamining the Hydrologic Code Intercomparison (HYDROCOIN) project case 5 problem, which represents a salt dome overlain by a shallow groundwater system. The resulting flow field includes significant salinity and fluid density variations. Several independent teams simulated this problem using finite difference or finite element numerical models. We applied a method-of-characteristics model (MOCDENSE). The previous numerical implementations by HYDROCOIN teams of a constant-concentration boundary to represent salt release by lateral dispersion only (as stipulated in the original problem definition) was flawed because this boundary condition allows the release of salt into the flow field by both dispersion and advection. When the constant-concentration boundary is modified to allow salt release by dispersion only, significantly less salt is released into the flow field. The calculated brine distribution for case 5 depends very little on which numerical model is used, as long as the selected model is solving the proper equations. Instead, the accuracy of the solution depends strongly on the proper conceptualization of the problem, including the detailed design of the constant-concentration boundary condition. The importance and sensitivity to the manner of specification of this boundary does not appear to have been recognized previously in the analysis of this problem.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/97WR01926","usgsCitation":"Konikow, L.F., Sanford, W., and Campbell, P., 1997, Constant-concentration boundary condition: Lessons from the HYDROCOIN variable-density groundwater benchmark problem: Water Resources Research, v. 33, no. 10, p. 2253-2261, https://doi.org/10.1029/97WR01926.","productDescription":"9 p.","startPage":"2253","endPage":"2261","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":226927,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"33","issue":"10","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fa03e4b0c8380cd4d896","contributors":{"authors":[{"text":"Konikow, Leonard F. 0000-0002-0940-3856 lkonikow@usgs.gov","orcid":"https://orcid.org/0000-0002-0940-3856","contributorId":158,"corporation":false,"usgs":true,"family":"Konikow","given":"Leonard","email":"lkonikow@usgs.gov","middleInitial":"F.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":382861,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sanford, W. E. 0000-0002-6624-0280","orcid":"https://orcid.org/0000-0002-6624-0280","contributorId":102112,"corporation":false,"usgs":true,"family":"Sanford","given":"W. E.","affiliations":[],"preferred":false,"id":382863,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Campbell, P.J.","contributorId":56393,"corporation":false,"usgs":true,"family":"Campbell","given":"P.J.","email":"","affiliations":[],"preferred":false,"id":382862,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ]}