Critical shear stress of sunken, No. 6 heavy fuel oil in fresh water.

A series of flume- and laboratory-based experiments defined and quantified the thresholds of sunken oil transport using No.6 heavy fuel oil mixed with kaolinite clay. When the sunken oil became mobile, the current-induced bed shear stress exceeded a threshold value specific to the oil, known as critical shear stress (CSS).

A spatial life cycle cost assessment of stormwater management systems.

Although widely implemented, the research and understanding of the economic impacts and benefits of green infrastructure (GI) systems remain limited. Currently, few studies have investigated the economics of GI systems from a spatial perspective and typically opportunity costs related to land and property tax were ignored. This study aims at bridging these gaps by investigating both the equivalent annual costs (EAC) and cost effectiveness of seven GI systems and compare them against local wastewater treatment facilities in five different US cities.

Upstream to downstream: stormwater quality in Mayagüez, Puerto Rico.

The focus of this research was upon consequences of urban stormwater runoff entering two streams in Mayagüez, Puerto Rico. Mayagüez is the largest urban area of the western side of the island of Puerto Rico and provides an excellent point of reference to monitor the affects of urban development on water quality in a tropical climate. The two monitored streams were Quebrada del Oro and Cano Majagual.

Polycyclic aromatic hydrocarbons in stormwater runoff from sealcoated pavements.

Coal-tar based sealcoat has been identified as a source of polycyclic aromatic hydrocarbons (PAHs) in the environment. This study measured the long-term release of PAHs in parking lot runoff and found that the presence of coal tar sealant increased the mass of PAHs released in runoff by over an order of magnitude. PAH concentrations in stormwater from two coal tar sealed parking lots and one unsealed parking lot (control) were monitored over a two-year period.

An analytical model for hydraulic fracturing in shallow bedrock formations.

A theoretical method is proposed to estimate post-fracturing fracture size and transmissivity, and as a test of the methodology, data collected from two wells were used for verification. This method can be employed before hydrofracturing in order to obtain estimates of the potential hydraulic benefits of hydraulic fracturing. Five different pumping test analysis methods were used to evaluate the well hydraulic data.

Uptake of polycyclic aromatic hydrocarbons (PAHs) in salt marsh plants Spartina alterniflora grown in contaminated sediments.

Polycyclic aromatic hydrocarbon (PAH) concentrations were measured in Spartina alterniflora plants grown in pots of contaminated sediment, plants grown in native sediment at a marsh contaminated with up to 900 microg/g total PAHs, and from plants grown in uncontaminated control sediment. The roots and leaves of the plants were separated, cleaned, and analyzed for PAHs. PAH compounds were detected at up to 43 microg/g dry weight in the root tissue of plants grown in pots of contaminated soil.