Milwaukee River Research Articles

Dynamic changes in the abundance and chemical speciation of dissolved and particulate phosphorus across the river-lake interface in southwest Lake Michigan

Phosphorus (P) concentrations and primary production in the Great Lakes have declined since the 1980s, but changes in biogeochemical cycling pathways of different P species remain poorly understood. Water samples were collected for the measurements of different P species to examine the dynamics of P in the water column across the river-lake interface from the Milwaukee River to open Lake Michigan. Dissolved inorganic P (DIP) concentrations were as high as 3049 nM in river waters, but decreased dramatically to as low as 11 ± 7 nM in open lake waters. Total dissolved P was mostly measured in the form of DIP in river waters (73% ± 18%), whereas dissolved organic P (DOP) became the predominant species (85% ± 18%) in lake waters. Colloidal P (>1 kDa) comprised 58% ± 16% of the bulk DOP in river waters, but decreased to 23% ± 5% in ologotrophic lake waters, showing again contrasting biogeochemical regimes between river and lake waters. Biological processes and coagulation/sedimentation were largely responsible for the removal of river-derived P species and active transformation between inorganic and organic P occurred in both dissolved and particulate phases across the river-lake interface. Increased water column P inventory over the winter of 2013–2014 likely resulted from an accumulative effect of both atmospheric and riverine inputs in the upper water column, and benthic nepheloid layer processes coupled with quagga mussels excretion for the lower water column, respectively. High partition coefficient values (logKd of 4.33–7.01) and a “particle concentration effect” on the partitioning of P between dissolved and particulate phases attested the particle-reactive nature of P in lake waters.

Sources and Variability of Cryptosporidium in the Milwaukee River Watershed

Recent well-publicized waterborne Cryptosporidium outbreaks involving large numbers of ill people and some deaths have been attributed to possible treatment deficiencies linked with source water (watershed) contamination. Understanding the occurence and variability of Cryptosporidium in a watershed is critical to the production of a safe drinking water supply. Essential to this understanding is the ability to characterize potential sources of Cryptosporidium and predict their occurrence in a watershed. The purpose of the work described in this report is to define the relative magnitude and contributions of Cryptosporidium from major non-point sources defined by urban land use, rural land use and point source wastewater discharges and to characterize contributions of each source by factors such as hydrograph timing, climatic effects and seasonal variations. Statistical models are presented that can be used to estimate the probability of high Cryptosporidium levels from a given combination of conditions and may be useful for maximising sampling strategies for watershed managers charged with understanding Cryptosporidium occurrence in a watershed. This title belongs to WERF Research Report Series ISBN: 9781843396659 (Print) ISBN: 9781780404035 (eBook)

Urbanization and Rainfall–Runoff Relationships in the Milwaukee River Basin

To understand the changing rainfall–runoff relationship, this study examined climate and streamflow data in the Milwaukee River Basin in southeastern Wisconsin, of which four catchments with different degrees of urbanization were selected for analysis. This study analyzed temperature, precipitation, and streamflow data with a range of statistical methods, including the Mann–Kendall test, double-mass technique, and quantile regression. Runoff ratios and extreme flow indexes were higher in more urbanized catchments. Catchments with long-term data (>forty years) showed significantly increasing runoff ratios and slopes in double-mass curves. Overall, there are signs of changes in the rainfall–runoff relationship, but how much they can be attributed to land use changes is uncertain.

Segmentation-based and rule-based spectral mixture analysis for estimating urban imperviousness

For detailed estimation of urban imperviousness, numerous image processing methods have been developed, and applied to different urban areas with some success. Most of these methods, however, are global techniques. That is, they have been applied to the entire study area without considering spatial and contextual variations. To address this problem, this paper explores whether two spatio-contextual analysis techniques, namely segmentation-based and rule-based analysis, can improve urban imperviousness estimation. These two spatio-contextual techniques were incorporated to a classic urban imperviousness estimation technique, fully-constrained linear spectral mixture analysis (FCLSMA) method. In particular, image segmentation was applied to divide the image to homogenous segments, and spatially varying endmembers were chosen for each segment. Then an FCLSMA was applied for each segment to estimate the pixel-wise fractional coverage of high-albedo material, low-albedo material, vegetation, and soil. Finally, a rule-based analysis was carried out to estimate the percent impervious surface area (%ISA). The developed technique was applied to a Landsat TM image acquired in Milwaukee River Watershed, an urbanized watershed in Wisconsin, United States. Results indicate that the performance of the developed segmentation-based and rule-based LSMA (S-R-LSMA) outperforms traditional SMA techniques, with a mean average error (MAE) of 5.44% and R2 of 0.88. Further, a comparative analysis shows that, when compared to segmentation, rule-based analysis plays a more essential role in improving the estimation accuracy.

Human and bovine viruses in the Milwaukee River watershed: Hydrologically relevant representation and relations with environmental variables

To examine the occurrence, hydrologic variability, and seasonal variability of human and bovine viruses in surface water, three stream locations were monitored in the Milwaukee River watershed in Wisconsin, USA, from February 2007 through June 2008. Monitoring sites included an urban subwatershed, a rural subwatershed, and the Milwaukee River at the mouth. To collect samples that characterize variability throughout changing hydrologic periods, a process control system was developed for unattended, large-volume (56–2800L) filtration over extended durations. This system provided flow-weighted mean concentrations during runoff and extended (24-h) low-flow periods. Human viruses and bovine viruses were detected by real-time qPCR in 49% and 41% of samples (n=63), respectively. All human viruses analyzed were detected at least once including adenovirus (40% of samples), GI norovirus (10%), enterovirus (8%), rotavirus (6%), GII norovirus (1.6%) and hepatitis A virus (1.6%). Three of seven bovine viruses analyzed were detected including bovine polyomavirus (32%), bovine rotavirus (19%), and bovine viral diarrhea virus type 1 (5%). Human viruses were present in 63% of runoff samples resulting from precipitation and snowmelt, and 20% of low-flow samples. Maximum human virus concentrations exceeded 300genomiccopies/L. Bovine viruses were present in 46% of runoff samples resulting from precipitation and snowmelt and 14% of low-flow samples. The maximum bovine virus concentration was 11genomiccopies/L. Statistical modeling indicated that stream flow, precipitation, and season explained the variability of human viruses in the watershed, and hydrologic condition (runoff event or low-flow) and season explained the variability of the sum of human and bovine viruses; however, no model was identified that could explain the variability of bovine viruses alone. Understanding the factors that affect virus fate and transport in rivers will aid watershed management for minimizing human exposure and disease transmission.

Evaluating impairment in Wisconsin Areas of Concern using relative abundance of Smallmouth Bass

Smallmouth Bass (Micropterus dolomieu) is an important sportfish and has been suggested as a restoration target species in degraded aquatic environments such as “Areas of Concern” in the Great Lakes basin. Determining expected relative densities of fish and wildlife populations, such as Smallmouth Bass, in least-impacted situations is central to developing effective monitoring programs, assessing the level of relative impairment, determining appropriate restoration goals, and evaluating the efficacy of restoration efforts. We tested a straightforward classification scheme of Smallmouth Bass populations in least impacted non-wadeable rivers in Wisconsin based on parameters related to substrate and geographic location as both variables have been associated with relative Smallmouth Bass density. Coarse-substrate rivers tended to have higher Smallmouth Bass catch per effort values than fine-substrate rivers and southern rivers tended to have higher catch per effort values than northern rivers in Wisconsin. We used the expected Smallmouth Bass relative density estimates to assess the level of impairment of Smallmouth Bass populations in three Areas of Concern in Wisconsin (Milwaukee River and Estuary, Sheboygan River and Estuary, and the Fox River and Green Bay). We found that Smallmouth Bass catch per effort values were significantly higher in Areas of Concern than both the minimum and 25th percentile values for least-impacted rivers and were not significantly different from the median least-impacted values. Based on abundance, it does not appear that Smallmouth Bass populations are particularly impaired in these three Areas of Concern.

Schools 2012 Serves Up Tech Tips, Midwestern Hospitality

You have accessThe ASHA LeaderASHA News1 Apr 2012Schools 2012 Serves Up Tech Tips, Midwestern Hospitality Kellie Rowden-Racette Kellie Rowden-Racette Google Scholar More articles by this author https://doi.org/10.1044/leader.AN2.17042012.9 SectionsAbout ToolsAdd to favorites ShareFacebookTwitterLinked In ASHA Schools 2012 will welcome school-based professionals and assistants to the sunny shores of Lake Michigan to learn practical, hands-on information to help their students and districts. Opening this year’s conference, scheduled for July 27–29 in Milwaukee, Wisconsin, will be Jennifer Abrams, an international educational and communications consultant for public and private schools, hospitals, universities, and non-profits. Abrams trains teachers and administrators on successful instructional practices, new employee support, supervision and evaluation, generational savvy, and effective collaboration skills. She has presented at annual conferences such as Learning Forward, the New Teacher Center Annual Symposium, and the Teachers’ and Principals’ Centers for International School Leadership. Her publications include Having Hard Conversations, published by Corwin Press in 2009; the chapter “Habits of Mind for the School Savvy Leader” in Learning and Leading with Habits of Mind: 16 Essential Characteristics for Success, by Art Costa and Bena Kallick; and contributions to Mentors in the Making: Developing New Leaders for New Teachers, published by Teachers College Press. Other presenters include Judith Maginnis Kuster speaking about Web resources for school-based SLPs; Pam Wiley addressing social skills for students with autism spectrum disorders; Laura Justice discussing emerging literacy; Mike Campbell reviewing the ins and outs of telepractice in schools; and Sam Sennott covering the latest apps to help school-based SLPs deliver effective services and streamline their heavy workloads. The conference will emphasize use of technology in the classroom, and will feature a technology session in almost every time slot. Outside of sessions, attendees can browse exhibits, participate in roundtable discussions, and speak with members of ASHA’s Board of Directors during the Member Forum. Beyond the Milwaukee Conference Center, attendees can explore the reinvigorated city of Milwaukee by strolling the Milwaukee River Walk. Once known only as a powerhouse for beer brewing and manufacturing, Milwaukee has, over the past few decades, reinvented itself as a tourist-friendly city that is home to quaint neighborhoods and a high-profile restaurant scene. Registration is now open. The early-bird deadine is June 4; regular registration closes July 14. For more information visit ASHA’s School’s webpage. Lakeside Soiree for ASHFoundation Schools Conference participants can attend a fundraising event at the Milwaukee Art Museum, an architectural landmark overlooking Lake Michigan. Sponsored by the American Speech-Language-Hearing Foundation on Friday, July 27, from 6 p.m. to 7:30 p.m., the event supports ASHFoundation research grants and scholarships. The event, which includes light fare, will take place in the Quadracci Pavilion, a sculptural, postmodern addition designed by Spanish architect Santiago Calatrava. Highlights of the building are the cathedral-like space of Windhover Hall, with a vaulted 90-foot-high glass ceiling; the Burke Brise Soleil, a moveable sunscreen with a 217-foot wingspan that unfolds and folds twice daily; and the Reiman Bridge, a pedestrian suspension bridge that connects the museum to the city. Following the reception, participants can venture out to sample nearby restaurants, brewhouses, or the weekend’s German Fest. Because of the museum’s proximity to the convention center (about 1.2 miles), participants can walk, trolley ($1 round trip), or take a cab to the event. Advance-purchase tickets (nonrefundable) are $45; on-site admission (subject to availability) is $55. Tickets may be purchased on the conference registration form or by calling 800-498-2071. Author Notes Kellie Rowden-Racette, print and online editor for The ASHA Leader, can be reached at [email protected]. Advertising Disclaimer | Advertise With Us Advertising Disclaimer | Advertise With Us Additional Resources FiguresSourcesRelatedDetails Volume 17Issue 4April 2012 Get Permissions Add to your Mendeley library History Published in print: Apr 1, 2012 Metrics Downloaded 49 times Topicsasha-topicsleader_do_tagleader-topicsasha-article-typesCopyright & Permissions© 2012 American Speech-Language-Hearing AssociationLoading ...

The effect of activated carbon on partitioning, desorption, and biouptake of native polychlorinated biphenyls in four freshwater sediments

The present study evaluated the effect of activated carbon amendment in four freshwater sediments from the Great Lakes (North America) areas of concern with a wide range of sediment geochemical characteristics (0.83-5.1% total organic carbon) and polychlorinated biphenyl (PCB) concentrations (0.33-84.7 microg/g). The work focused on understanding the impact of activated carbon amendment on PCB aqueous partitioning, PCB desorption characteristics, and PCB biouptake in a freshwater oligochaete (Lumbriculus variegatus). The results showed that PCB aqueous equilibrium concentrations, rapid desorption fractions, and biouptake by the oligochaete were reduced after activated carbon amendment. Addition of activated carbon at a dose of 0.5-fold native organic carbon reduced PCB bioaccumulation by 42% for Niagara River sediment, 85% for Grasse River sediment, 74% for Milwaukee River sediment 1, and 70% for Milwaukee River sediment 2. A linear relationship was observed between log biota-sediment accumulation factor and the first 6-h desorption fractions for each PCB homologue for treated and untreated sediments. Water-lipid bioconcentration factors for PCB congeners were largely conserved after amendment with activated carbon. Our present results suggest that at steady state, changes in the aqueous PCB concentrations can be used to predict changes in PCB bioaccumulation in deposit-feeding organisms. Thus, use of advanced pore-water measurement techniques, such as solid-phase extraction passive samplers, may be suitable for long-term monitoring of treatment performance.

Monitoring and Repair of the Milwaukee City Hall Masonry Tower

The Milwaukee City Hall was built between 1893 and 1898 and is located in downtown Milwaukee, one block east of the Milwaukee River. The 300ft(91.4m) long building, nine stories high over its main portion, is a trapezoid in plan. On the south side, there is a 393ft(119.8m) tall South Tower located above the main entrance to the building. On three sides, the South Tower rises from the street level to the 13th level and the roof above, and on the north side, it is connected to the rest of the building up to the ninth floor. The South Tower is a hybrid steel and masonry structure consisting of masonry perimeter walls and a central core, four-sided steel truss supporting the floors and roof. The building is a perimeter-load-bearing masonry structure supported on wood piles. The city of Milwaukee had been aware of distress, in the form of cracks and loose masonry, in the South Tower for a number of decades. In 2002, the city took action to investigate the causes and significance of distress, and to develop a repair program. The scope of our work included review of the available structural drawings and documents, inspection of the tower, measurement and monitoring of movements, monitoring of thermal response, structural analyses of the hybrid steel and masonry structure, and development of repair recommendations. The repair program presently is under construction. This paper describes the monitoring program, analyses of the causes for distress, and the implemented repair concepts for the observed distress in the South Tower of the Milwaukee City Hall.

A Comparison of Elastomer Marks and Fin Clips as Marking Techniques for Walleye

AbstractTwo marking techniques, fin removal and visible implant elastomer, were evaluated in walleye Sander vitreus. Although fin‐clipping is widely practiced, research results have been ambiguous as to whether the technique is harmful to fish over the long term. We attempted to determine over a 7‐year period whether elastomer marking might have significant benefits to growth and survival of walleye when compared with fish given a single fin clip. We also evaluated the long‐term detection rates of elastomer marks as well as their cost‐effectiveness. Each year for 5 years we marked and stocked an average of 8,000 extended‐growth walleye fingerlings in the lower Milwaukee River, Wisconsin, as part of a project to reintroduce walleyes to the Milwaukee River estuary. One‐half were given a single fin clip and one‐half were given an elastomer mark. Fin clips and elastomer colors were changed each year. Fish were recaptured the following year by means of electrofishing gear. We found no significant differences in survival or growth rates between the differentially marked fish. We also found that tag detection in recaptured fish over the long term was 82.5% for fish originally marked with elastomer. The cost associated with elastomer marking was US$0.40 per mark while the cost of fin clipping was $0.03 per mark. We concluded that a single fin clip was the more desirable technique for marking walleyes.

Truth, Knowledge and the Wild World

One ought not to put too much stock in the word 'philosophy'. . . . [T]here are alternative ways of intelligently engaging the world. To construe one's thinking in terms of belief is characteristic of a particular kind of world view and it remains to be seen whether those who share an indigenous world view conceive of experience in such an overtly intellectualized manner. Leroy N. Meyer and Tony Ramirez (1996, 104)1 Wilderness treats me like a human being. Tom Birch2 As Holmes Rolston III has said, "A principal characteristic of human life is that it develops into biography. In that sense, humans do not want their values in nature, any more than they want other goods in life, to come seriatim, like beads on a string. . . . Humans want a storied residence in nature where the passage of time integrates past, present, and future in a meaningful career" (Rolston 1988, 351). This is what I had hoped for: a narrative of storied residence in Midwest prairie, lake, and river country, and in the mountains and deserts of Idaho, with the history of the development of an environmental ethic (or ethos) left largely implicit within that larger narrative, leaving readers to reflect as they may on the philosophical dimensions of the journey. To leave traditional philosophical [End Page 101] modes of expression completely behind proved impossible (for now), but it has been for me a worthwhile exercise to locate my reflections on "truth, knowledge, and the wild world" in something of a narrative form. It is the lakes and rivers, prairies, mountains, and deserts that have remained implicit. They have cast their spell, however, on any attempt to impose cultural order on the relationship between truth, knowledge, and the wild world. I Looking back on it, it seems that my entire philosophical career has been implicated—in one way or another, directly and indirectly—in these two questions: "How important is truth to knowledge and epistemology?" and "What is the role of natural environments in the production of knowledge?" Furthest back, at the very origin of my philosophical life, reflections on philosophical knowledge were inevitably posed and thought about in natural environments, particularly in my meditations as I drifted in the early morning mist on the St. Croix River and several Minnesota lakes, especially Cedar Lake. Even now, when I am trying to make my way to a new understanding of some philosophical issue, I walk along the shores of Lake Michigan and the Milwaukee River, or sit by rivers and lakes in Idaho, a place that became my second home after meeting my partner, Fran. Northern White Cedars stand in our yard, front and back; Western Red Cedar holds our house in its embrace. There is no question in my mind that natural environments are the deepest sources of whatever philosophical understandings I may have come to. In terms of formal studies, however, the question of the role of natural environments in the production of knowledge did not emerge for me until, well into my teaching career, I discovered the newly-emerging field of environmental ethics. It was at that point that the deepest wellspring of my philosophy and my life came together with my professional philosophical interests—in an uneasy balance. Until that time, as I think of it now, my philosophical track through the curious environment of the academy, however well it prepared me to think about central issues in environmental ethics, was mostly marked by a fascination with glittering baubles and gemstones and did not truly touch the soil, water, and atmosphere of my life. Questions of truth, knowledge, and epistemology took center stage from the beginning of my formal philosophical studies. As an undergraduate [End Page 102] at Berkeley, Thompson Clarke introduced me (in three courses) to the skeptical implications of Ordinary Language Philosophy that had escaped the attention of J. L. Austin and others. This baptism into the rigors of skeptical philosophy left me pretty much convinced, as my partner and...

Milwaukee, WI, as a Source of Atmospheric PCBs to Lake Michigan

A field study of atmospheric PCBs in Milwaukee, WI, U.S.A. was conducted on the shore of Lake Michigan. We believe this is the first report of atmospheric PCBs in Milwaukee, although PCBs are well-known to contaminate the sediments of the Milwaukee River and Outer Harbor. Concentrations of PCBs collected during the June 2001 study are similar to concentrations in other urban-industrial areas and higher than PCBs in background air. The average sigmaPCB (sum of 88 congener groups) gas-phase concentration in Milwaukee was 1.9 ng m(-3)+/-standard deviation 0.78 ng m(-3). The average and standard deviation for the particulate-associated PCBs are 0.05+/-0.02 ng m(-3). Particulate-phase PCBs account for less than 5% of the total atmospheric concentration. PCBs in Milwaukee air are a source of PCBs to Lake Michigan. Calculated net gas exchange fluxes predicted forthe Milwaukee sampling period ranged from -60 to -400 ng m(-2) d(-1), where net deposition is indicated by the negative sign. Calculated particle-associated PCB deposition ranged from 80 to 500 ng m(-2) d(-1). Most of the particle-phase deposition flux is a result of coarse particle deposition and decreases rapidly with distance from shore. Under typical meteorological conditions, particle-associated PCBs depositional flux to the lake surface decreases by 90% within 40 km. For net gas-exchange, the flux reaches zero at about the same distance. At greater distances, particle-phase PCB deposition is negligible, and PCBs are volatilizing at a higher rate than they are being deposited. We calculated that Milwaukee air contributes about 120 kg of PCBs to Lake Michigan each year. This is about 10 times larger than the discharge of PCBs from the Milwaukee River.

Trace metal concentrations in shallow ground water.

Trace metal clean sampling and analysis techniques were used to examine the temporal patterns of Hg, Cu, and Zn concentrations in shallow ground water, and the relationships between metal concentrations in ground water and in a hydrologically connected river. Hg, Cu, and Zn concentrations in ground water ranged from 0.07 to 4.6 ng L-1, 0.07 to 3.10 micrograms L-1, and 0.17 to 2.18 micrograms L-1, respectively. There was no apparent seasonal pattern in any of the metal concentrations. Filtrable Hg, Cu, and Zn concentrations in the North Branch of the Milwaukee River ranged from below the detection limit to 2.65 ng Hg L-1, 0.51 to 4.30 micrograms Cu L-1, and 0.34 to 2.33 micrograms Zn L-1. Thus, metal concentrations in ground water were sufficiently high to account for a substantial fraction of the filtrable trace metal concentration in the river. Metal concentrations in the soil ranged from 8 to 86 ng Hg g-1, 10 to 39 micrograms Cu g-1, and 15 to 84 micrograms Zn g-1. Distribution coefficients, KD, in the aquifer were 7900, 22,000, and 23,000 L kg-1 for Hg, Cu, and Zn, respectively. These values were three to 40 times smaller than KD values observed in the Milwaukee River for suspended particulate matter.

Changes in the Habitat and Fish Community of the Milwaukee River, Wisconsin, Following Removal of the Woolen Mills Dam

We evaluated the response of fish habitat, biotic integrity, and populations of smallmouth bass Micropterus dolomieu and common carp Cyprinus carpio to the 1988 removal of the low-head Woolen Mills Dam from the Milwaukee River. After dam removal, instream habitat improvement work was done on a portion of river within the former impoundment, and a short reach just below the dam site was rerouted for bridge construction. Before dam removal in 1988, the two stations in the impounded reach of the river had fair habitat quality, few smallmouth bass, abundant common carp, and poor biotic integrity. Five years after dam removal, habitat quality was good to excellent, smallmouth bass abundance and biomass had increased substantially, common carp abundance and biomass had declined dramatically, and biotic integrity was good. A reference station on the nearby North Branch of the Milwaukee River had few major changes over the same time period, although common carp abundance and biomass did decline somewhat. Stations upstream and downstream of the impounded reach also experienced moderate declines in common carp populations, and the upstream station had a major increase in smallmouth bass abundance and biomass. Changes in size structure suggested that the smallmouth bass increases in the impounded and upstream stations were caused by increased recruitment rather than by permanent migration of fish from other areas. Habitat quality within the impounded reach increased more and faster in the station with instream improvement work, but the station without work also showed substantial gains in habitat quality through natural channel recovery processes. The station downstream from the dam experienced major declines in its smallmouth bass population and biotic integrity during channel rerouting in 1990. However, by 1993, both attributes had returned to 1988–1989 levels. We conclude that dam removal benefited habitat, fisheries potential, and biotic integrity in the Milwaukee River. Direct habitat improvement activities enhanced these benefits, but natural habitat recovery and removal of the dam as a barrier to fish movement accounted for many of the improvements we observed.

The influence of dissolved organic carbon, suspended particulates, and hydrology on the concentration, partitioning and variability of trace metals in two contrasting Wisconsin watersheds (U.S.A.)

Factors controlling the levels and forms of trace metals in streams, and transport from watersheds into streams, are poorly understood. We determined levels of filtrable ( < 0.4 μm) and particulate Al, Cd, Cu, Pb, and Zn in rivers draining two contrasting watersheds in eastern Wisconsin. Both are developed on glaciated terrain, but the North Branch Milwaukee watershed (agricultural) is characterized by gently sloping uplands with thick silt loam soils, while the Wolf River (forested) has peat loam soils on hilly terrain. Watershed differences resulted in higher mean dissolved organic carbon (DOC) concentrations under baseflow conditions in the Wolf River (7 mg 1 −1) than in the Milwaukee River (4 mg 1 −1), but higher suspended particulate. matter (SPM) levels in the Milwaukee (18 vs. 2 mg 1 −). Mean filtrable trace metal concentrations (ng 1 −). under baseflow conditions were similar in the Milwaukee and Wolf rivers (Al = 4.0 and 5.8; Cd = 4.2 and 3.2; Cu = 660 and 200; Pb = 56 and 53; Zn = 340 and 240), but particulate metal levels (ng 1 −). were higher in the Milwaukee (Al= 230 vs. 16; Cd = 14 vs. 0.8; Cu = 736 vs. 90; Pb = 750 vs. 30; Zn = 2290 vs. 180). Filtrable metal concentrations exhibited low variability (relative standard deviation) under baseflow (Milwaukee: 5–20% Cu, Pb, Zn; 20–40% Al, Cd — Wolf: 10–35% Cu, Pb, Zn; 30–60% Al, Cd), while variability in particulate metal concentrations was somewhat higher (18–73%). During events (spring melt, storms), concentrations increased 1- to 5-fold for filtrable metals and 1- to 17-fold for particulate metals. Differences between watersheds and within-watershed responses to events were related in part to SPM (particulate metals) and DOC (filtrable metals) levels in the rivers and their associated influences on metal partitioning. In the Milwaukee River (higher SPM and lower DOC), particulate metal phases were more dominant (range among the five metals in mean % particulate = 47–98% vs. 24–74% for the Wolf. Partitioning ( K d) to SPM followed the order Pb > Zn > Cd > Cu, whereas relationships to DOC indicated essentially the reverse order for metal binding to DOC. SPM was a good predictor of particulate metal levels, especially in the Milwaukee River (> 94% of variance in particulate Cd, Pb, and Zn was accounted for, vs. 44–69% in Wolf River). While DOC was able to account for a significant portion of the variation in certain filtrable metal levels ( r 2 = 0.52–0.65), other metals showed poorer correlations, probably due to variability in the composition of DOC and SPM and to variability in the forms of metal (aqueous complexes, colloid-bound) in the filtrable fraction.

Modelling impact of urban and upstream nonpoint sources on eutrophication of the Milwaukee River

This paper describes a study conducted to evaluate the impact of the absence vs. the presence of the North Avenue Damin Milwaukee, Wisconsin, on water quality in the Milwaukee River in terms of conventional constituents, such as DO, chlorophyll a, BOD, and nutrients (N and P). Phytoplanktonic primary production had been recognized earlier as a link between mostly nonpoint nutrient loads to the Milwaukee River and degradation of water quality in the River. A mathematical model of a relevant section of the River was used in the study to estimate the effect of the removal of the Dam on this primary production link. The authors established the model using WASP, which is USEPA's widely used modelling package. The modelled extent of the River included both shallow, productive upstream reaches as well as impounded downstream sections. In the impounded reach of the River where the Dam is located, the simulated removal of the Dam (1) replaced net phytoplankton decay with net phytoplankton growth because of improved light conditions and limited settling; (2) substantially increased the concentration of DO because of the increased photosynthetic production and reduced benthic consumption; and (3) somewhat increased bottle BOD5 because of the elevated phytoplankton levels. The simulated removal of the Dam eliminated the negative effects of eutrophication at the site while possibly shifting the potential for these effects further downstream towards Lake Michigan.

Modelling impact of urban and upstream nonpoint sources on eutrophicationof the Milwaukee River

This paper describes a study conducted to evaluate the impact of the absence vs. the presence of the North Avenue Damin Milwaukee, Wisconsin, on water quality in the Milwaukee River in terms of conventional constituents, such as DO, chlorophyll a, BOD, and nutrients (N and P). Phytoplanktonic primary production had been recognized earlier as a link between mostly nonpoint nutrient loads to the Milwaukee River and degradation of water quality in the River. A mathematical model of a relevant section of the River was used in the study to estimate the effect of the removal of the Dam on this primary production link. The authors established the model using WASP, which is USEPA's widely used modelling package. The modelled extent of the River included both shallow, productive upstream reaches as well as impounded downstream sections. In the impounded reach of the River where the Dam is located, the simulated removal of the Dam (1) replaced net phytoplankton decay with net phytoplankton growth because of improved light conditions and limited settling; (2) substantially increased the concentration of DO because of the increased photosynthetic production and reduced benthic consumption; and (3) somewhat increased bottle BODS because of the elevated phytoplankton levels. The simulated removal of the Dam eliminated the negative effects of eutrophication at the site while possibly shifting the potential for these effects further downstream towards Lake Michigan.

MONTE CARLO MODELING OF WATER AND SEDIMENT CONTAMINATION BY TOXIC METALS AT THE NORTH AVENUE DAM, MILWAUKEE, WI, USA

A deterministic water - sediment quality model was developed with a Monte Carlo interface and input generation. The model was used to simulate water and sediment (total and dissolved-pore water) quality of a reach of Milwaukee River that includes an urban impoundment. The sediments in the impoundments are contaminated by toxic metals and other priority pollutants. The sediment - water quality model was composed of three sequential segments each represented by three systems: water, upper sediment and lower sediment layers. The mass balance of the sediment contaminants was strongly affected by the direction of the groundwater fluxes through the sediments. Steady state was assumed for the water column and the upper sediment layer while a dynamic mass balance model was used for the lower sediment layer. The inputs of the Monte Carlo simulation were ten years long time-series of upstream flows and Combined Sewer Overflow (CSO) discharges with corresponding Monte Carlo generated concentrations. The model calculated output concentrations which were statistically similar to the probability distribution of measured concentrations.

A Source-Receptor Method for Determining Non-Point Sources of PAHs to the Milwaukee Harbor Estuary

The purpose of this work is to determine non-point sources of PAHs to the Milwaukee Harbor Estuary. Sediment samples were collected from the Milwaukee River, the Menomonee River, the Kinnickinnic River, and the Inner and Outer Harbor of the Milwaukee Harbor Estuary. Source samples were collected from a major highway, a leaking underground storage tank, and two river banks. All samples were analyzed for sixteen PAHs, which are identified as priority pollutants by the U.S. EPA. In addition to this, literature values of concentrations of PAHs in known non-point sources viz. coal tar, coal tar air emissions, No. 2 fuel oil, and gasoline engine exhaust tar were considered. A computer program, using the mathematics of least-squares, was adopted to determine the best combination of sources to the mixed PAH signature of the sediment, and to calculate the contribution of each source to the concentration of total PAHs. Chi square and the multiple correlation coefficient were used to evaluate the fits. For apportionment of sediment PAHs into sources, only those PAHs are considered whose concentrations are above the instrument's (GC-MS) detection limit. Of the 211 regressions considered, about half present good fits to the proposed sources. Highway dust is found to be a significant source in 88%, gasoline engine exhaust tar in 33%, coal tar air emissions in 23%, and coal tar in 17% of the successful regressions.

Sources and Delivery of Sediments Contaminated by Toxic Metals to the North Avenue Dam, Milwaukee, WI, USA

Sediments which have accumulated in the Milwaukee River North Avenue urban impoundment in Milwaukee, Wisconsin over a period of more than one hundred years were investigated. After the drawdown of the water level in the impoundment, extensive investigations focused on determining sediment volume, characteristics and contamination. It was found that the accumulated sediment has a fine texture and contains higher levels of toxic metals. Analysis of sources of sediments and sediment contamination considered the background sources, including impact of agriculture, and urban sources such as urban runoff and combined sewer overflow. Cadmium, copper and lead were identified as metals of concern both in the water, using log-normal statistics of the data and in the sediment by the sediment-pore water concentration partitioning. Urban runoff was found to be the most significant source of contamination. The North Avenue Dam represents a typical example of urban impoundments which have now reached the end of their usefulness.