Urbanization typically results in increased imperviousness which alters suspended sediment yield and impacts geomorphic and ecological processes within urban streams. Therefore, there is an increasing interest in the ability to predict suspended sediment yield. This study assesses the combined impact of urban development and increased precipitation on suspended sediment yield in the Cuyahoga River using statistical modeling. Historical satellite-based land-cover data was combined with precipitation and suspended sediment yield data to create a Multiple Linear Regression (MLR) model for the Cuyahoga watershed. An R² value of 0.71 was obtained for the comparison between the observed and predicted results based on limited land-use and land-cover data. The model also shows that every 1 mm increase in the mean annual precipitation has the potential to increase the mean annual suspended sediment yield by 860 tons/day. Further, a 1 km² increase in developed land area has the potential to increase mean annual suspended sediment yield by 0.9 tons/day. The framework proposed in this study provides decision makers with a measure for assessing the potential impacts of future development and climate alteration on water quality in the watershed and implications for stream stability, dam and flood management, and in-stream and near-stream infrastructure life.

Apparent diffusion coefficients, D_a, were measured for two soil–bentonite (SB) backfills characteristic of those used in SB vertical cutoff walls for subsurface control of contaminant migration. The base soils for the backfills comprised either a natural lean clay or sand–bentonite mixtures. The base soils were mixed with 5% bentonite–water slurry to obtain a slump of 125 mm, resulting in total bentonite contents ranging from 4.76% to 7.31%. Values of D_a for sodium chloride were measured using a recently developed dialysis-leaching test method. The D_a values for the clay–bentonite and sand–bentonite backfills ranged from 2.5 × 10⁻¹⁰ to 5.3 × 10⁻¹⁰ m²/s and from 1.4 × 10⁻¹⁰ to 8.1 × 10⁻¹⁰ m²/s, respectively. Values of D_a for both backfills increased with increasing average salt concentration in the specimen (C_ave). Values of D_a decreased by ≤50% with increasing backfill bentonite content. For all C_ave values, the clay backfills exhibited lower D_a than the sand–bentonite backfills, likely due to additional fines from the lean clay. Results of this study enhance understanding of solute diffusion through SB cutoff walls, as well as support future use of the dialysis-leaching test method to measure diffusion properties of SB backfills.

Bioinfiltration systems for stormwater management rely on the ability of the engineered media to adequately infiltrate, filtrate, and store water to reduce runoff volumes and improve water quality. However, the potential clogging of the soil over time due to the migration of fines and deposition of sediment and debris has raised concerns regarding system longevity. To quantify temporal and spatial changes in textural and hydraulic properties of bioinfiltration media infiltrating runoff from an interstate, a comprehensive field and laboratory study was completed for two sites over a two-year period. Despite observed sediment deposition within both basins, there were no statistically significant trends in the saturated hydraulic conductivity of the media over the study period. Soil core sampling and analysis confirmed fines did not migrate through the soil column. Susceptibility to future clogging of the well-graded, loamy sand used at both sites was evaluated based on the collected data and permeability and retention criteria commonly used in geotechnical design of graded filters. Based on the results of this study and the current literature, soils proposed for use in bioinfiltration systems should be evaluated for filter compatibility with the anticipated sediment load and include maximum limits on the plasticity index to help enhance system lifespan and reduce necessary maintenance.

Reclaimed Asphalt Pavement (RAP) has been extensively studied for potential use as a recycled material in infrastructure construction. There is consensus that utilization of RAP provides environmental and economic benefits for most projects. However, impacts to engineering performance are less known, owing to the highly variable nature of RAP sources with different asphalt pavement mixtures and milling processes, which has limited the adoption of RAP as fill material in geotechnical infrastructure. This study conducted a comprehensive review of geotechnical properties reported for RAP in the experimental literature. The gradation, specific gravity, density, moisture content, hydraulic conductivity, leaching, shear strength, and creep properties of different RAP sources are summarized and compared. These geotechnical properties, as well as recent investigations into the effects of temperature and aggregate mixing, were used to identify the potential reuse of RAP in highway transportation applications beyond just asphalt mixture design, such as embankments. Additionally, correlations between gradation properties (C_u, D₁₀, D₈₅), asphalt content, and the geotechnical properties of maximum dry density, saturated hydraulic conductivity, and shear strength were identified.