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Management of ground water and evolving hydrogeologic studies in New Jersey : a heavily urbanized and industrialized state in the northeastern United States

New Jersey is the most densely populated and one of the most industrialized states in the United States. An abundance of freshwater and proximity to major northeastern metropolitan centers has facilitated this development. Pumpage of freshwater from all aquifers in the State in 1980 was 730 million gallons per day (2.76 million cubic meters per day). Management and efficient development of the ground-water resources of the State are the responsibility of the New Jersey Department of Environmental Protection. Laws have been enacted and updated by the State legislature to manage water allocation and to control the disposal of hazardous wastes. Present resource management is guided by the New Jersey Water-Supply Master Plan of 1981. Funding for management activities is partially derived from the sale of state-approved bonds. Effective planning and regional management require accurate and up-to-date hydrologic information and analyses. The U.S. Geological Survey, in cooperation with the New Jersey Geological Survey, is conducting three intensive ground-water studies involving the collection and interpretation of hydrologic data to meet the urgent water-management needs of New Jersey. These studies are part of a long-term cooperative program and are funded through the Water-Supply Bond Act of 1981. They began in 1983 and are scheduled to be completed in 1988. The project areas are situated in the New Jersey part of the Atlantic Coastal Plain in and near Atlantic City, Camden, and South River. They range in size from 400 to 1,200 mil (1,040 to 3,120 km2). The studies are designed to define the geology, hydrology, and geochemistry of the local ground-water systems. The results of these studies will enable the State to address more effectively major problems in these areas such as declining water levels, overpumping, saltwater intrusion, and ground-water contamination resulting from the improper disposal of hazardous wastes. Specific objectives of these studies by the U.S. Geological Survey are to (1) develop an accurate and up-to-date hydrogeologic data base, (2) design and implement a data-collection program and establish a computerized information management system, (3) refine the conceptualization of the ground-water flow system, and (4) define the geochemistry of the aquifer system by conducting a water-quality appraisal. The objectives are accomplished by standard hydrogeologic methods. Information concerning hydrogeologic framework, ground-water levels, water use, hydraulic characteristics, and water quality in the study areas is compiled from all available sources. Additional data needed are collected through well inventories, surface geophysical surveys, water-quality samplings, water-level measurements, and a well-drilling program. Interpretation of the flow system is based on the use of standard analytical techniques and digital flow modeling. Calibrated flow models will provide ground-water managers with a mechanism to develop and test regional water-supply strategies. Definition of the geochemistry of the aquifer system is accomplished through a variety of methods which depend on the problems and available data in the particular study area. The approach includes statistical analysis of water-quality data, reaction-path modeling, and determination of the movement of chemical constituents using analytical and numerical modeling techniques. A combined staff of 25 to 30 professionals and technicians from the New Jersey District office of the U.S. Geological Survey is committed to the three studies. The staff has specialists in geohydrology, numerical modeling, geochemistry, geophysics, and computer science. The findings of these studies will be published in data reports, interpretive reports, instructional manuals and journal articles.

New Jersey

Comparison of pesticides in eight U.S. urban streams

Little is known of the occurrence of pesticides in urban streams compared to streams draining agricultural areas. Water samples from eight urban streams from across the United States were analyzed for 75 pesticides and seven transformation products. For six of the eight urban streams, paired agricultural streams were used for comparisons. The herbicides detected most frequently in the urban streams were prometon, simazine, atrazine, tebuthiuron, and metolachlor, and the insecticides detected most frequently were diazinon, carbaryl, chlorpyrifos, and malathion. In contrast to similar-sized agricultural streams, total insecticide concentrations commonly exceeded total herbicide concentrations in these urban streams. In general, the temporal concentration patterns in the urban streams were consistent with the characteristics of the local growing season. The insecticides carbaryl and diazinon exceeded criteria for the protection of aquatic life in many of the urban streams in the spring and summer. When the country as a whole is considered, the estimated mass of herbicides contributed by urban areas to streams is dwarfed by the estimated contribution from agricultural areas, but for insecticides, contributions from urban and agricultural areas may be similar. The results of this study suggest that urban areas should not be overlooked when assessing sources and monitoring the occurrence of pesticides in surface waters.

Connecticut, Colorado, Florida, Georgia, Maryland,

Effects of urbanization on water quality in the Kansas River, Shunganunga Creek Basin, and Soldier Creek, Topeka, Kansas, October 1993 through September 1995

A study of urban-related water-qulity effects in the Kansas River, Shunganunga Creek Basin, and Soldier Creek in Topeka, Kansas, was conducted from October 1993 through September 1995. The purpose of this report is to assess the effects of urbanization on instream concentrations of selected physical and chemical constituents within the city of Topeka. A network of seven sampling sites was established in the study area. Samples principally were collected at monthly intervals from the Kansas River and from the Shunganunga Creek Basin, and at quarterly intervals from Soldier Creek. The effects of urbanization werestatistically evaluated from differences in constituent concentrations between sites on the same stream. No significant differences in median concentrations of dissolved solids, nutrients, or metals and trace elements, or median densities offecal bacteria were documented between sampling sites upstream and downstream from the major urbanized length of the Kansas River in Topeka.Discharge from the city's primary wastewater- treatment plant is the largest potential source of contamination to the Kansas River. This discharge increased concentrations of dissolved ammonia, totalphosphorus, and densities of fecal bacteria.Calculated dissolved ammonia as nitrogen concentrations in water from the Kansas River ranged from 0.03 to 1.1 milligrams per liter after receiving treatment-plant discharge. However, most of the calculated concentrations wereconsiderably less than 50 percent of Kansas Department of Health and Environment water- quality criteria, with a median value of 20 percent.Generally, treatment-plant discharge increased calculated total phosphorus concentrations in water from the Kansas River by 0.01 to 0.04 milligrams per liter, with a median percentage increase of 7.6 percent. The calculated median densities of fecal coliform and fecal Streptococci bacteria in water from the Kansas River increased from 120 and 150colonies per 100 milliliters of water, respectively, before treatment-plant discharge to a calculated 4,900 and 4,700 colonies per 100 milliliters of water, respectively, after discharge. Median concentrations of dissolved solids were not significantly different between three sampling sites in the Shunganunga Creek Basin. Median concentrations of dissolved nitrate as nitrogen, total phosphorus, and dissolved orthophosphate were significantly larger in water from the upstream- most Shunganunga Creek sampling site than in water from either of the other sampling sites in the Shunganunga Creek Basin probably because of the site's proximity to a wastewater-treatment plant.Median concentrations of dissolved nitrate as nitrogen and total phosphorus during 1993-95 at upstream sampling sites were either significantlylarger than during 1979-81 in response to increase of wastewater-treatment plant discharge or smaller because of the elimination of wastewater-treatment plant discharge. Median concentrations of dissolved ammonia as nitrogen were significantly less during 1993-95 than during 1979-81. Median concentrations of total aluminum, iron, maganese, and molybdenum were significantly larger in water from the downstream-mostShunganunga Creek sampling site than in water from the upstream-most sampling site. This probably reflects their widespread use in the urbanenvironment between the upstream and downstream Shunganunga Creek sampling sites. Little water-quality effect from the urbanization was indicated by results from the Soldier Creek sampling site. Median concentrations of most water-quality constituents in water from this sampling site were the smallest in water from any sampling site in the study area. Herbicides were detected in water from all sampling sites. Some of the more frequently detected herbicides included acetochlor, alachlor,atrazine, cyanazine, EPTC, metolachlor, prometon, simazine, and tebuthiuron. Detected insecticides including chlordane,

Water-Resources Investigations Report

Streamflow, water quality, and aquatic macroinvertebrates of selected streams in Fairfax County, Virginia, 2007-12

Efforts to mitigate the effects of urbanization on streams rely on best management practices (BMPs) that are implemented with the intent of reducing and retaining stormwater runoff. A cooperative monitoring effort between the U.S. Geological Survey and Fairfax County, Virginia, was initiated in 2007 to assess the condition of county streams and document watershed-scale responses to the implementation of BMPs. Assessment of the data collected during the first 5 years of this monitoring program focused on characterizing the hydrologic and ecological condition of 14 monitored streams. Hydrologic, chemical, and macroinvertebrate community conditions in the streams monitored were found to be consistent, overall, with conditions commonly observed in urban streams. Hydrologically, the monitored streams were found to be flashy, with flashiness positively related to road cover in the watershed. Typical pH values of streams throughout the network centered around neutrality (pH = 7) with strong daily fluctuations apparent in the continuous data. Patterns in specific conductance were largely representative of anthropogenic disturbances—watersheds having the greatest percentage of open space and estate residential land-use had the lowest typical specific conductance values, and specific conductance variability was less than what is observed in watersheds that are more intensively developed. In watersheds having greater road coverage, and more development in general, increases in specific conductance over several orders of magnitude were observed during winter months as a result of the application of de-icing salts on impervious surfaces. Dissolved oxygen conditions were typically within the range required to support healthy biological communities, although occasional departures during summer months at some sites fell below the impairment threshold for streams in Virginia. Nitrogen (N) and phosphorus (P), concentration patterns were largely consistent across the network, with few exceptions. Nitrogen concentrations in monthly samples were generally low and dominated by nitrate. Exceptions to the generally low N concentrations occurred at Captain Hickory Run, which had a median total N concentration of approximately 4.9 milligrams per liter (mg/L), compared to the network-wide median of approximately 1.7 mg/L, and at Popes Head Creek Tributary, where total N concentrations spiked to 6–8 mg/L during low-flow periods in August or September of each year. Phosphorus concentrations in monthly samples were generally low and dominated by the dissolved fraction. Two monitoring stations in the network, Flatlick Branch and Frog Branch, are notable for having median total P concentrations that were, on average, approximately three times greater than the median total P concentration of 0.02 mg/L observed at the other 12 stations in the network. Suspended-sediment and nutrient loads and yields were similar to those of urbanized watersheds in other studies, although the yields from these urbanized basins were greater than, or within, the upper quartile of yields observed throughout the Chesapeake Bay watershed. Annual suspended-sediment loads ranged from 289–10,275 tons, with a median of 1,311 tons, and corresponding yields ranged from 107–2,827 tons per square mile (ton/mi 2 ), with a median of 277 ton/mi 2 . Annual total N loads ranged from 8,014–36,413 pounds, with a median of 21,314 pounds, and corresponding yields ranged from 3,361–8,360 pounds per square mile (lb/mi 2 ), with a median of 6,200 lb/mi 2 . Annual total P loads ranged from 380–6,558 pounds, with a median of 1,874 pounds, and corresponding yields ranged from 140–1,562 lb/mi 2 , with a median of 543 lb/mi 2 . Benthic macroinvertebrate community metrics indicated that streams throughout Fairfax County are generally of poor health. One station, Castle Creek, was an exception with results indicating relatively high quality aquatic health. Six additional monitoring stations were added to the network in 2012 to improve spatial coverage throughout Fairfax County. Monitoring activities are expected to continue at all 20 stations for the foreseeable future as BMP implementation is conducted.

Virginia

Biodiversity promotes urban ecosystem functioning

The proportion of people living in urban areas is growing globally. Understanding how to manage urban biodiversity, ecosystem functions, and ecosystem services is becoming more important. Biodiversity can increase ecosystem functioning in non-urban systems. However, few studies have reviewed the relationship between biodiversity and ecosystem functioning in urban areas, which differ in species compositions, abiotic environments, food webs, and turnover rates. We reviewed evidence of biodiversity–ecosystem functioning relationships in urban environments and assessed factors that influence the relationship direction. Based on 70 studies, relationships between biodiversity and ecosystem functioning were more positive than negative in urban areas, especially for pollination and nutrient cycling and retention. Surprisingly, positive and negative relationships between biodiversity and biomass production and storage were equally not statistically different, perhaps due to extensive plant management in urban areas. The number of studies and geographic coverage of our review was still insufficient to provide a general predictive framework for when biodiversity positively impacts ecosystem functioning. We identify gaps and opportunities to improve urban biodiversity–ecosystem functioning research and discuss how our findings can improve urban green space management.

Ecography

Urbanization of grasslands in the Denver area affects streamflow responses to rainfall events

A thorough understanding of how urbanization affects stream hydrology is crucial for effective and sustainable water management, particularly in rapidly urbanizing regions. This study presents a comprehensive analysis of changes in streamflow response to rainfall events across a rural to urban gradient in the semi-arid area of Denver, Colorado. We used 8 years of April to October instantaneous streamflow data in 21 watersheds ranging in size from 0.8 to 90 km 2 and with impervious areas ranging from 1% to 47%. With these data, we applied a semi-automated method to identify a total of 2877 streamflow responses, which were analysed for event-based metrics of peak flow, runoff depth, runoff to rainfall ratio, time to peak, duration and number of streamflow responses to rainfall events. We also determined whether streamflow responses could be predicted by a precipitation threshold. Watersheds with >10% impervious cover had a precipitation threshold of 1–2 mm/hr needed to produce a streamflow response, compared to thresholds of 4–36 mm/hr for watersheds with less than 10% impervious surface cover. This lower precipitation threshold in more impervious watersheds led to more frequent streamflow responses. On average, streamflow responses had shorter duration and higher peak flows in watersheds with more impervious surface cover. In contrast to other regions, runoff depth, runoff to rainfall ratio and time to peak either gave mixed results or did not vary significantly with imperviousness. These alterations in streamflow response to rainfall events indicate the specific ways that urban development changes how streams respond to rain events in a semi-arid setting. This work points to the need for local adaptation of stormwater management to mitigate the effects of streamflow changes with urbanization.

Colorado

Quality of shallow ground water in alluvial aquifers of the Willamette Basin, Oregon, 1993-95

The current (1993?95) quality of shallow ground water (generally, <25 meters below land surface) in Willamette Basin alluvium is described using results from two studies. A Study-Unit Survey, or regional assessment of shallow groundwater quality in alluvium, was done from June through August 1993. During the Study-Unit Survey, data were collected from 70 domestic wells chosen using a random-selection process and located mostly in areas of agricultural land use. An urban Land-Use Study, which was a reconnaissance of shallow urban ground-water quality from 10 monitoring wells installed in areas of residential land use, was done in July 1995. Concentrations of nitrite plus nitrate (henceforth, nitrate, because nitrite concentrations were low) ranged from <0.05 to 26 mg N/L (milligrams nitrogen per liter) in ground water from 70 Study-Unit-Survey wells; concentrations exceeded the U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Level (MCL) of 10 mg N/L in 9 percent of Study-Unit-Survey samples. Relationships were observed between nitrate concentrations and dissolved-oxygen concentrations, the amount of clay present within and overlying aquifers, overlying geology, and upgradient land use. Tritium (3H) data indicate that 21 percent of Study-Unit-Survey samples represented water recharged prior to 1953. Nitrogen-fertilizer application rates in the basin have increased greatly over the past several decades. Thus, some observed nitrate concentrations may reflect nitrogen loading rates that were smaller than those presently applied in the basin. Concentrations of phosphorus ranged from <0.01 to 2.2 mg/L in 70 Study-Unit-Survey wells and exceeded 0.10 mg/L in 60 percent of the samples. Phosphorus and nitrate concentrations were inversely correlated. From 1 to 5 pesticides and pesticide degradation products (henceforth, pesticides) were detected in ground water from each of 23 Study-Unit-Survey wells (33 percent of 69 wells sampled for pesticides) for a total of 51 pesticide detections. Thirteen different pesticides were detected; atrazine was the most frequently encountered pesticide. Although detections were widespread, concentrations were low (generally <1,000 ng/L [nanograms per liter]). (One ng/L is equal to 0.001 mg/L [micrograms per liter].) One detection (dinoseb, at 7,900 ng/L) exceeded a USEPA MCL. Relationships were observed between the occurrence of pesticides and the amount of clay present within and overlying aquifers, overlying geology, and land use. Between 1 and 5 volatile organic compounds (VOCs) were detected at each of 7 Study-Unit-Survey sites (11 percent of 65 sites evaluated), for a total of 14 VOC detections. One detection (tetrachloroethylene, at 29 mg/L) exceeded a USEPA MCL. Other detections were at low concentrations (0.2 to 2.0 mg/L). VOC detections generally were from sites associated with urban land use. Concentrations of arsenic ranged from <1 to 13 mg/L in 70 Study-Unit-Survey wells. Concentrations in 16 percent of samples exceeded the USEPA Risk-Specific-Dose Health Advisory of 2 mg/L. Radon concentrations ranged from 200 to 1,200 pCi/L (picocuries per liter) in 51 Study-Unit-Survey wells. All samples exceeded the USEPA Risk-Specific-Dose Health Advisory of 150 pCi/L. All urban Land-Use-Study samples were well oxygenated; thus, nitrate reduction probably did not affect these samples. Urban Land-Use-Study nitrate concentrations were similar to those of the well oxygenated, agricultural subset of Study-Unit-Survey samples. Pesticides were detected in samples from three urban Land-Use-Study sites, but concentrations were low (1 to 5 ng/L). In contrast, VOCs were detected in ground water from 80 percent of urban Land-Use-Study wells; concentrations ranged up to 7.6 mg/L. Trace-element concentrations in the urban Land-Use Study samples were low. Median concentrations consistently were <10 mg/L and frequently were <1 mg/L

Water-Resources Investigations Report

Derivation of Nationally Consistent Indices Representing Urban Intensity Within and Across Nine Metropolitan Areas of the Conterminous United States

Two nationally consistent multimetric indices of urban intensity were developed to support studies of the effects of urbanization on streams in nine metropolitan areas of the conterminous United States: Atlanta, Georgia; Birmingham, Alabama; Boston, Massachusetts; Dallas-Fort Worth, Texas; Denver, Colorado; Milwaukee-Green Bay, Wisconsin; Portland, Oregon; Raleigh, North Carolina; and Salt Lake City, Utah. These studies were conducted as a part of the U.S. Geological Survey's National Water-Quality Assessment Program. These urban intensity indices were used to define gradients of urbanization and to interpret biological, physical, and chemical changes along these gradients. Ninety census, land-cover, and infrastructure variables obtained from nationally available databases were evaluated. Only variables that exhibited a strong and consistent linear relation with 2000 population density were considered for use in the indices. Housing-unit density (HUDEN), percentage of basin area in developed land (P_NLCD1_2), and road density (ROADDEN) were selected as the best representatives of census, land-cover, and infrastructure variables. The metropolitan area national urban intensity index (MA-NUII) was scaled to represent urban intensity within each metropolitan area and ranged from 0 (little or no urban) to 100 (maximum urban) for sites within each metropolitan area. The national urban intensity index (NUII) was scaled to represent urban intensity across all nine metropolitan areas and ranged from 0 to 100 for all sites. The rates at which HUDEN, P_NLCD1_2, and ROADDEN changed with changes in population density varied among metropolitan areas. Therefore, these variables were adjusted to obtain a more uniform rate of response across metropolitan areas in the derivation of the NUII. The NUII indicated that maximum levels of urban intensity occurred in the West and Midwest rather than in the East primarily because small inner-city streams in eastern metropolitan areas are buried and converted to storm drains or sewers and because of higher density development in the Western and Central United States. The national indices (MA-NUII, NUII) were compared to indices that were derived independently for each metropolitan area (MA-UII) based on variables that were of local interest. The MA-UIIs, which were based on 5 to 40 variables, tended to overestimate urban intensity relative to the national indices particularly when the MA-UII was composed of large numbers of variables that were not linearly related to population density as in Denver, Dallas-Fort Worth, and Milwaukee-Green Bay.

Scientific Investigations Report

Incorporating future change into current conservation planning: Evaluating tidal saline wetland migration along the U.S. Gulf of Mexico coast under alternative sea-level rise and urbanization scenarios

In this study, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, quantified the potential for landward migration of tidal saline wetlands along the U.S. Gulf of Mexico coast under alternative future sea-level rise and urbanization scenarios. Our analyses focused exclusively on tidal saline wetlands (that is, mangrove forests, salt marshes, and salt flats), and we combined these diverse tidal saline wetland ecosystems into a single grouping, &ldquo;tidal saline wetland.&rdquo; Collectively, our approach and findings can provide useful information for scientists and environmental planners working to develop future-focused adaptation strategies for conserving coastal landscapes and the ecosystem goods and services provided by tidal saline wetlands. The primary product of this work is a public dataset that identifies locations where landward migration of tidal saline wetlands is expected to occur under alternative future sea-level rise and urbanization scenarios. In addition to identifying areas where landward migration of tidal saline wetlands is possible because of the absence of barriers, these data also identify locations where landward migration of these wetlands could be prevented by barriers associated with current urbanization, future urbanization, and levees.

Alabama, Florida, Louisiana, Mississippi, Texas

Physically based estimation of rainfall thresholds triggering shallow landslides in volcanic slopes of southern Italy

On the 4th and 5th of March 2005, about 100 rainfall-induced landslides occurred along volcanic slopes of Camaldoli Hill in Naples, Italy. These started as soil slips in the upper substratum of incoherent and welded volcaniclastic deposits, then evolved downslope according to debris avalanche and debris flow mechanisms. This specific case of slope instability on complex volcaniclastic deposits remains poorly characterized and understood, although similar shallow landsliding phenomena have largely been studied in other peri-volcanic areas of the Campania region underlain by carbonate bedrock. Considering the landslide hazard in this urbanized area, this study focused on quantitatively advancing the understanding of the predisposing factors and hydrological conditions contributing to the initial landslide triggering. Borehole drilling, trial pits, dynamic penetrometer tests, topographic surveys, and infiltration tests were conducted on a slope sector of Camaldoli Hill to develop a geological framework model. Undisturbed soil samples were collected for laboratory testing to further characterize hydraulic and geotechnical properties of the soil units identified. In situ soil pressure head monitoring probes were also installed. A numerical model of two-dimensional variably saturated subsurface water flow was parameterized for the monitored hillslope using field and laboratory data. Based on the observed soil pressure head dynamics, the model was calibrated by adjusting the evapotranspiration parameters. This physically based hydrologic model was combined with an infinite-slope stability analysis to reconstruct the critical unsaturated/saturated conditions leading to slope failure. This coupled hydromechanical numerical model was then used to determine intensity–duration (I-D) thresholds for landslide initiation over a range of plausible rainfall intensities and topographic slope angles for the region. The proposed approach can be conceived as a practicable method for defining a warning criterion in urbanized areas threatened by rainfall-induced shallow landslides, given the unavailability of a consistent inventory of past landslide events that prevents a rigorous empirical analysis.

Water

Evaluating groundwater quality influences from oil field operations and other anthropogenic activities in an urban setting, Santa Fe Springs, California

Groundwater quality is often affected by anthropogenic activities in urban settings. This study examines groundwater quality in and around the Santa Fe Springs Oil Field in Los Angeles County, California, where oil and gas production commonly intersects with high density industrial, commercial and residential land uses. Utilizing a combination of new and historical data, we evaluated potential pathways that would allow for oil field formation fluids to migrate into groundwater and whether mixing may have occurred based on the distribution of groundwater and oil field formation fluid tracers in samples. Samples were analyzed for a wide array of constituents including volatile organic compounds, light hydrocarbons, major ions, and various isotopic compositions. Despite evidence of oil field infrastructure providing potential pathways of migration via uncemented annular spaces, casing breaches and historical disposal of oil field formation water in surface ponds, the distribution and occurrence of stable isotopes of water, chloride, boron, and total dissolved solids do not indicate mixing of oil field formation water and groundwater. However, methane isotopic signatures and the presence of heavier alkanes suggest gas from oil-bearing formations have migrated from depth via oil field well infrastructure. Volatile organic compound detections were mainly from manufactured compounds unrelated to oil and gas production, with a relatively limited number of petroleum hydrocarbons also detected. Volatile organic compounds were generally found in wells tapping shallow, modern aged groundwater, indicating anthropogenic activities occurring at or near land surface as the source. Study results suggest that while oil field infrastructure provides migration pathways for oil field formation fluids to be introduced into groundwater, urban land uses not related to oil and gas production are the primary drivers of groundwater quality degradation.

California

Urban stormwater data management system with applications to south Florida studies

A data management system was developed to store and retrieve urban stormwater data collected from four small urban basins in south Florida. The system is event oriented in that all data from one storm are stored together on the computer file. The data include descriptive information about the storm and data on rainfall, stage, discharge, and water quality. The data management system, composed of about 20 Fortran programs, was developed to store data, retrieve tables for publication, calculate flow discharges and constituent loads, and provide for interfacing with statistical and deterministic model application programs. (Kosco-USGS)

Water-Resources Investigations Report

Floral Composition of Pollen Collected from a Rusty Patched Bumble Bee (Bombus affinis, Cresson) Nest in Southeastern Minnesota

Understanding the forage diets of imperiled bumble bees can improve conservation planning and habitat restoration efforts. In this study, we describe the taxonomic composition of bee-collected pollen from 2 Rusty Patched Bumble Bee ( Bombus affinis , Cresson) nests located in southeastern Minnesota. This is the first published reporting of pollen collected from active B. affinis nests. We also compared pollen identification via traditional palynological light microscopy with genetic identification via ITS metabarcoding. Among the 49 pollen samples analyzed, we detected 41 and 56 distinct taxa via light microscopy and metabarcoding, respectively. Furthermore, 27 of 47 total genera overlapped between the 2 methods. Bittersweet Nightshade ( Solanum dulcamara , Linnaeus) was the most detected species for both metabarcoding and microscopy identification for pollen prevalence. Pollen volume from the microscopy data showed that Lesser Burdock ( Arctium minus , Bernhardi), Alfalfa ( Medicago sativa , Linnaeus), Bittersweet Nightshade ( Solanum dulcamara , Linnaeus), Plumeless Thistle ( Carduus acanthoides , Linnaeus), and Red Clover ( Trifolium pratense , Linnaeus) together comprised more than half of the total volume of pollen. Light microscopy and metabarcoding revealed compositionally distinct plant communities when analyzed at the species level. Methodological concordance improved when analyzing pollen data at genus level, but both methods still reveal marginally distinct groupings. Our study highlights specific plant taxa that are important components of B. affinis pollen diets and provides actionable research for conservation efforts in urban systems. Our study also supports that B. affinis is a generalist forager and will collect pollen from a variety of native and non-native host plants.

Minnesota

Spatiotemporal patterns in urban nutrient and suspended sediment loads and stream response to watershed management implementation

In recent years, local governments have invested heavily in management practices to reduce nutrient and sediment loads. These practices provide localities with nutrient and sediment regulatory reduction credits; however, their effects on water quality are poorly understood at the watershed scale. Long-term watershed-scale monitoring is essential for assessing progress toward water-quality goals, yet it has historically been lacking in urban watersheds. Since 2007, Fairfax County, Virginia, has partnered with the US Geological Survey to monitor and evaluate water-quality conditions in 20 small urban streams. This study assessed nutrient and suspended sediment loads, trends in concentration, and trends in load. Trends in load are affected by streamflow-induced variability that must be removed through a process called “flow-normalization;” however, existing methods have neither been applied to small urban watersheds nor to loads computed on a sub-daily timestep. In this study, four such methods also were assessed, and an adaptation of the weighted regressions on time, discharge, and season approach was found to be most effective. Loads, concentrations, and trends in load were spatially and temporally variable. Differences were attributed to physical watershed features such as geology, soils, and channel geomorphology, as well as urban sources such as turfgrass fertilization and septic infrastructure. Most notably, flow-normalized suspended sediment, nitrogen, and phosphorus loads decreased in two watersheds with completed stream restorations and increased in those with few implemented practices.

Virginia

Variability in stream chemistry in relation to urban development and biological condition in seven metropolitan areas of the United States, 1999-2004

Beginning in 1999, the U.S. Geological Survey National Water Quality Assessment Program investigated the effects of urban development on stream ecosystems in nine metropolitan study areas across the United States. In seven of these study areas, stream-chemistry samples were collected every other month for 1 year at 6 to 10 sites. Within a study area, the sites collectively represented a gradient of urban development from minimally to highly developed watersheds, based on the percentage of urban land cover; depending on study area, the land cover before urban development was either forested or agricultural. The stream-chemistry factors measured in the samples were total nitrogen, total phosphorus, chloride, and pesticide toxicity. These data were used to characterize the stream-chemistry factors in four ways (hereafter referred to as characterizations)&mdash;seasonal high-flow value, seasonal low-flow value, the median value (representing a single integrated value of the factor over the year), and the standard deviation of values (representing the variation of the factor over the year). Aquatic macroinvertebrate communities were sampled at each site to infer the biological condition of the stream based on the relative sensitivity of the community to environmental stressors. A Spearman correlation analysis was used to evaluate relations between (1) urban development and each characterization of the stream-chemistry factors and (2) the biological condition of a stream and the different characterizations of chloride and pesticide toxicity. Overall, the study areas where the land cover before urban development was primarily forested had a greater number of moderate and strong relations compared with the study areas where the land cover before urban development was primarily agriculture; this was true when urban development was correlated with the stream-chemistry factors (except chloride) and when chloride and pesticide toxicity was correlated with the biological condition. Except for primarily phosphorus in two study areas, stream-chemistry factors generally increased with urban development, and among the different characterizations, the median value typically indicated the strongest relations. The variation in stream-chemistry factors throughout the year generally increased with urban development, indicating that water quality became less consistent as watersheds were developed. In study areas with high annual snow fall, the variation in chloride concentrations throughout the year was particularly strongly related to urban development, likely a result of road salt applications during the winter. The relations of the biological condition to chloride and pesticide toxicity were calculated irrespective of urban development, but the overall results indicated that the relations were still stronger in the study areas that had been forested before urban development. The weaker relations in the study areas that had been agricultural before urban development were likely the results of biological communities having been degraded from agricultural practices in the watersheds. Collectively, these results indicated that, compared with sampling a stream at a single point in time, sampling at regular intervals during a year may provide a more representative measure of water quality, especially in the areas of high urban development where water quality fluctuated more widely between samples. Furthermore, the use of "integrated" values of stream chemistry factors may be more appropriate when assessing relations to the biological condition of a stream because the taxa composition of a biological community typically reflects the water-quality conditions over time.

Scientific Investigations Report

Impacts of urban landuse on macroinvertebrate communities in southeastern Wisconsin streams

Macroinvertebrates were used to assess the impact of urbanization on stream quality across a gradient of watershed imperviousness in 43 southeastern Wisconsin streams. The percentage of watershed connected imperviousness was chosen as the urbanization indicator to examine impact of urban land uses on macroinvertebrate communities. Most urban land uses were negatively correlated with the Shannon diversity index, percent of pollution intolerant Ephemeroptera, Plecoptera, and Trichoptera individuals, and generic richness. Nonurban land uses were positively correlated with these same metrics. The Hilsenhoff biotic index indicated that stream quality declined with increased urbanization. Functional feeding group metrics varied across a gradient of urbanization, suggesting changes in stream quality. Proportions of collectors and gatherers increased, while proportions of filterers, scrapers, and shredders decreased with increased watershed imperviousness. This study demonstrated that urbanization severely degraded stream macroinvertebrate communities, hence stream quality. Good stream quality existed where imperviousness was less than 8 percent, but less favorable assessments were inevitable where imperviousness exceeded 12 to 20 percent. Levels of imperviousness between 8 and 12 percent represented a threshold where minor increases in urbanization were associated with sharp declines in stream quality.

Conference Paper

Lichen diversity changes along the Mississippi River in the Minneapolis-St. Paul urban area

Lichen diversity along the Mississippi River in the Minneapolis-St. Paul urban area was studied in 2008 by sampling 37 localities along the 110-kilometer river basin, resulting in 76 species, which are thought to represent 80% of the complete flora. A significant decrease in lichen diversity toward the urban part of the river basin, as well as the presence of only one cyanolichen suggests that urban factors, e.g. air pollutants and habitat destruction may be affecting lichen diversity. In addition, lichen diversity has significantly decreased from that of 112 years ago, when a study by Fink reported 113 species, and a higher number of genera represented by a single species.

Minnesota

Known and suggested quaternary faulting in the midcontinent United States

The midcontinent United States between the Appalachian and Rocky Mountains contains 40 known faults or other potentially tectonic features for which published geologic information shows or suggests Quaternary tectonic faulting. We report results of a systematic evaluation of published and other publicly available geologic evidence of Quaternary faulting. These results benefit seismic-hazard assessments by (1) providing some constraints on the recurrence intervals and magnitudes of large, prehistoric earthquakes, and (2) identifying features that warrant additional study. For some features, suggested Quaternary tectonic faulting has been disproved, whereas, for others, the suggested faulting remains questionable. Of the 40 features, nine have clear geologic evidence of Quaternary tectonic faulting associated with prehistoric earthquakes, and another six features have evidence of nontectonic origins. An additional 12 faults, uplifts, or historical seismic zones lack reported paleoseismological evidence of large. Quaternary earthquakes. The remaining 13 features require further paleoseismological study to determine if they have had Quaternary earthquakes that were larger than any known from local historical records; seven of these 13 features are in or near urbanized areas where their study could affect urban hazard estimates. These seven are: (1) the belt of normal faults that rings the Gulf of Mexico from Florida to Texas. (2) the Northeast Ohio seismic zone, (3) the Valmont and (4) Goodpasture faults of Colorado. (5) the Champlain lowlands normal faults of New York State and Vermont, and (6) the Lexington and (7) Kentucky River fault systems of eastern Kentucky. Published by Elsevier Science B.V.

Engineering Geology