Conference Papers

Limestone drains were constructed in 1995, 1997, and 2000 to treat acidic mine drainage (AMD) from the Orchard, Buck Mtn., and Hegins discharges, respectively, in the Swatara Creek Basin, Southern Anthracite Coalfield, east-central Pennsylvania. This report summarizes the construction characteristics and performance of each of the limestone drains on the basis of influent and effluent...

Currently 20-30 billion barrels of formation water are co-produced annually in the USA with conventional oil and natural gas. The large database on the geochemistry of this produced water shows salinities that vary widely from ~5,000 to >350,000 mg/L TDS. Chloride, Na and Ca are generally the dominant ions, and concentrations of Fe, Mn, B, NH3 and dissolved organics, including, BTEX...

In 1950 when Cherry Creek dam, which is located in Denver. Colorado, was completed, the design flood was 5,126 m3/s. Two recent probable maximum flood (PMF) estimates for the dam range from 14,840 to 18,750 m 3/s demonstrate the uncertainty in estimating extreme flooding in eastern Colorado. PMF difference is due in part to a lack of extreme rainfall and flood data in eastern Colorado. A

Biological and physical properties of rivers and streams are inherently difficult to sample and visualize at the resolution and extent necessary to detect fine-scale distributional patterns over large areas. Satellite imagery and broad-scale fish survey methods are effective for quantifying spatial variability in biological and physical variables over a range of scales in marine...

Samples from two streams (Kisco River and the Middle Branch of the Croton River) in the Croton Reservoir system in south-eastern New York State, USA were sampled from May 2000 through to February 2001 in order to document the effect of land use, streamflow and seasonal patterns of application on pesticide concentrations in runoff from developed watersheds. Many of the pesticides detected...

The Virgin River in southwestern Utah and adjacent Arizona and Nevada is habitat for a number of endangered and threatened species of fish. The river also has significant loads of sediment that change the characteristic of the stream channel with time. The Virgin River transports large quantities of sand. Some sections of the river store the sand in the stream bed following a high stream...

Cost-effective methods are needed to detect contamination near radioactive-waste and other contaminated sites. Such methods should be capable of providing an early warning of contaminant releases and should be accurate and robust enough for assessing the long-term performance of waste-isolation facilities and remediation measures. Recently, a simplified method for detecting tritium...

The fundamental force behind population change is the balance between age-specific survival and reproductive rates. Thus, understanding population demographics is crucial when trying to interpret trends in population change over time. For many species, demographic rates change as the population’s status (i.e., relative to prey resources) varies. Indices of body condition indicative of...

The benefits of gradually removing a dam (through multiple notches) are to reduce the total project cost and reduce possible environmental effects by allowing the impounded sediment to slowly move downstream, and a stable stream and revegetated floodplain to form upstream. Notching, in this study of a dam on Brewster Creek, near St. Charles, Illinois, involves cutting a given height (in...

The recent availability of spatially-dense airborne lidar data makes assessment of the vulnerability of beaches and dunes to storm impacts practical over long reaches of coast. As an initial test, elevations of the tops (D high) and bases (Dlow) of foredune ridges along a 55-km reach on the northern Outer Banks, NC were found to have considerable spatial variability suggesting that...

Reclaimed asphalt pavement (RAP) and portland cement concrete (RPCC) are abundant and available substitutes for natural aggregate in many areas. This paper presents an overview of factors that affect recycled aggregate cost, availability, and engineering performance, and the results of a survey of business practices in the Mid-Atlantic region. For RAP, processing costs are less than...

Global warming, or the increasing of earth's temperatures, leads to rising sea level as polar ice caps and mountain glaciers melt and ocean water undergoes thermal expansion. Tidal records collected by the U.S. Army Corps of Engineers (COE), Mobile District, at Gulfport, Biloxi, and Pascagoula, Mississippi, and at Mobile, Alabama, indicate trends of water-surface elevations increasing...