Designing Contour Weep Berms to Reduce Agricultural Nonpoint Source Pollution

Nonpoint source pollution (NPS) of surface waters is a significant issue in agricultural lands, and best management practices (BMPs) are often used to reduce these impacts. Since the effectiveness of a BMP depends on a large number of widely varying factors, it is important to continue to develop BMPs in order to provide designers with more tools to use to maximize NPS removal. The contour weep berm is a new structural BMP constructed out of earth and subsequently vegetated. It is a linear BMP that is used in combination with a down-gradient vegetated filter strip or forested riparian buffer. Preliminary field evaluations of the contour weep berm indicate it is effective at reducing runoff volumes and peaks, promoting infiltration, and reducing sediment concentrations in runoff. Procedures for designing a contour weep berm are presented along with a design example. Linear BMPs, such as the contour weep berm, can provide producers with another means of effectively controlling NPS

WETLANDS AND COASTAL SYSTEMS: PROTECTING AND RESTORING VALUABLE ECOSYSTEMS

Wetlands and coastal systems are unique, highly productive, and often threatened landscapes that provide a host of services to both humans and the environment. This article introduces a five-article Wetlands and Coastal Systems Special Collection that evolved from a featured session at the 2015 ASABE Annual International Meeting in New Orleans, Louisiana. The Collection provides perspectives on tools and techniques for enhancing the protection and restoration of wetlands and coastal systems with emphasis on vegetation, hydrology, water quality, and planning. Topics span the Florida Everglades (two articles) and Virginia floodplain (one article) wetland systems and include remote sensing (one article) and geographic information system-based (one article) modeling tools developed to address wetland planning and analysis issues. The Special Collection provides valuable information to engineers, scientists, planners, and other specialists working on large-scale and small-scale wetlands and coastal systems

Development and Deployment of a Bioreactor for the Removal of Sulfate and Manganese from Circumneutral Coal Mine Drainage

Surface mining, in the form of contour mining and mountain-top removal, is a common means for retrieving coal in the Appalachian Coal Belt region of Kentucky. Overburden or excess spoil generated by these two methods is placed in valley fills. Traditionally Constructed fills have been shown to adversely impact headwater ecosystems via stream burial and through alterations to the hydrology, sediment supply, water quality and biological composition of downstream reaches. Mine drainages emanating from the toe of valley fills often contain elevated levels of total dissolved solids and heavy metals. Drainage chemistry from Guy Cove, a valley fill located in eastern Kentucky, exhibited a mean pH of 6.5 and Fe, Mn and SO4 concentrations of 1.5, 14, and 1264 mg L-1, respectively. The objective of this research was to develop an anaerobic bioreactor for the purpose of reducing Mn and SO4 concentrations in the mine drainage. Development began with batch experiments that tested five different organic carbon sources and five different inorganic substrates. A synthetic mine drainage with a pH of 6.2 and Mn and SO4 concentrations of 90 and 1,500 mg/L, respectively, was used in the experiment. Manganese and SO4 removal varied widely between treatment matrices, with removal rates \u3c 10 to 100% for Mn and \u3c 10 to \u3e 80% for SO4. The substrate sources which provided the most treatment were hardwood mulch and biosolids combined with creek sediment. Subsequent experiments were performed using the synthetic mine drainage in small bioreactors (55 liter plastic tanks) filled with creek sediment with either hardwood mulch or biosolids, each replicated three times. Over a 65 day treatment period \u3e 90% of the Mn and 70% of the SO4 was removed. There were no statistical differences between the two organic substrates. Using this information, in-situ bioreactors consisting of two 5,500 liter plastic septic tanks filled with creek sediment, hardwood mulch and manure compost were installed at Guy Cove. Mine drainage was collected in a sump and conveyed through the inline bioreactors by gravity. Gate valves were used to control flow through the bioreactors. After a 10-month monitoring period, the in-situ bioreactors removed 12, 11, and 64% of Mn, SO4 and Fe from the drainage, respectively. Results from the field differed greatly from those observed under controlled laboratory conditions. Efforts to improve the efficiency of the in-situ bioreactors are underway

Palaeoenvironmental implications of a marine geoarchaeological survey conducted in the SW Argosaronic gulf, Greece

AbstractA marine geoarcheological survey was conducted at the southwestern end of the Argosaronic gulf in Greece, an area of archaeological importance. The survey was initiated by the discovery of a Late Bronze Age (LBA) shipwreck off Modi Islet. The survey which employed echo-sounding, sub-bottom profiling, side scan sonar systems and sediment coring extended to the area between Poros Island, Modi Islet and Argolid peninsula, aiming to evaluate the changes of the coastal zone extent in the past. The evolution of the palaeo-shoreline over the last 20ka is proposed based on the interpretation of the acquired bathymetric and seismic records, the estimation of the thickness of the marine sediments and the examination of existing datasets of the relative sea level changes in the area.The produced scenarios suggest that major changes marked the extent of the coastal zone since the Paleolithics. During the Upper Paleolithic period, the coast was larger by at least 11km2 and Poros and Modi islands were connected to the Peloponnesus. The sea level rise during the Mesolithic period formed a well-protected bay between Poros Island and Peloponessus and disconnected the Modi Islet from Poros Island. The coastal zone reached the present configuration around Late Bronze Age. The detection and mapping of scarps on the seismic profiles imply that the sea level rise presented standstills at least from the Last Glacial maximum until the onset of Holocene. However, the submerged coasts could be potential areas of archaeological interest since the examined area is habited continuously from the Paleolithic period.The acoustic data sets produced high resolution geomorphological maps at the wreck site which constitute data base for the monitoring of the site. In addition, the examination of the seafloor texture at the wreck site suggests that the seafloor characteristics were unfavorable for the preservation of the shipwreck

A Review of Time Courses and Predictors of Lipid Changes with Fenofibric Acid-Statin Combination

Fibrates activate peroxisome proliferator activated receptor α and exert beneficial effects on triglycerides, high-density lipoprotein cholesterol, and low density lipoprotein subspecies. Fenofibric acid (FA) has been studied in a large number of patients with mixed dyslipidemia, combined with a low- or moderate-dose statin. The combination of FA with simvastatin, atorvastatin and rosuvastatin resulted in greater improvement of the overall lipid profile compared with the corresponding statin dose. The long-term efficacy of FA combined with low- or moderate- dose statin has been demonstrated in a wide range of patients, including patients with type 2 diabetes mellitus, metabolic syndrome, or elderly subjects. The FA and statin combination seems to be a reasonable option to further reduce cardiovascular risk in high-risk populations, although trials examining cardiovascular disease events are missing