No abstract

Wildlife crossing structures are gaining recognition by transportation agencies as effective measures to reduce animal–vehicle collisions and to connect wildlife habitats across transportation corridors. For the species that pose the highest risk in terms of animal–vehicle accidents in Virginia, namely, white-tailed deer and black bears, research is lacking on structural and location attributes of effective crossing structures. The Virginia Transportation Research Council began a 1-year study in June 2004 to monitor potential crossing structures and to determine the features that make a crossing successful for Virginia's large mammals. The underpasses, most not specifically designed as wildlife crossings, consist of box culverts and bridges of varying sizes. Remote cameras installed at seven underpass sites have recorded more than 2,700 wildlife photographs and documented 1,040 white-tailed deer crossings in the most heavily used structures. Underpasses with a minimum height of 12 ft were successful in facilitating deer passage. Structures that were suitable for deer passage were also heavily used by a variety of wildlife species, including coyote, red fox, raccoon, groundhog, and opossum. Structures with drainages that mimic natural waterways can encourage use by a diversity of terrestrial, semi-aquatic, and aquatic species. If even a minimal number of deer–vehicle collisions are prevented by an effective underpass, the savings in property damage alone can outweigh the construction costs of the structure.

Cured-in-place pipe (CIPP) technology is commonly used for pipe rehabilitation, and transportation agencies are increasingly using it to repair damaged pipe culverts. In typical CIPP applications, a lining tube saturated with a styrene-based thermosetting resin is installed into the damaged pipe. Subsequent curing with a heat source results in a pipe within a pipe. In this study, seven styrene-based, steam-cured CIPP installations in surface water and storm water conveyances in Virginia were identified and observed over the course of 1 year. Although the sites were not directly linked to sources of drinking water, styrene levels at five sites were higher than the Environmental Protection Agency's maximum contaminant level for drinking water of 0.1 mg/L. These concentrations were detected at these sites for a minimum of 5 days to 71 days after installation. Certain measurements were also found to exceed the concentration required to kill 50% of several freshwater aquatic indicator species. The findings suggest that the elevated styrene levels could have resulted from one or a combination of the following: ( a) installation practices that did not capture condensate containing styrene, ( b) uncured resin that escaped from the liner during installation, ( c) insufficient curing of the resin, and ( d) some degree of permeability in the lining material. In response to the preliminary findings of this study, the Virginia Department of Transportation suspended the use of styrene CIPP for conveying surface or storm water while the department further evaluated CIPP repair and subsequently developed new requirements for these installations.

Cured-in-place pipe (CIPP) technology has been used to rehabilitate sanitary sewer, storm sewer, and drinking water pipes. However, utilities, regulators, and health officials have raised environmental, occupational, and public health concerns regarding chemical emissions into air and water. To better understand emissions into water, available literature was reviewed. Water contamination has been documented in 10 states and Canada because of the release of uncured resin, solvents, manufacturing byproducts, and wastes during and after construction. Odor, fish kill, and drinking water contamination incidents have been reported. The few field-and bench-scale studies available show that a variety of volatile organic compounds and semivolatile organic compounds have been released into water and contamination was detected for several months. CIPP waste was acutely toxic to aquatic organisms. Chemical release is likely influenced by formulation, installation, and environmental conditions. CIPP installation and inspection recommendations were suggested. Studies are needed to develop evidence-based construction and monitoring practices to minimize risks.

The increase in animal–vehicle collisions (AVCs) on U.S. roadways raises significant concerns for human safety, property damage and injury costs, and viability of wildlife populations. Valuable AVC data can be obtained from documentation of instances and locations of animal carcasses on the roadway, but most transportation organizations do not systematically record these data. In 2006, accidents reported by police in Virginia represented less than 14% of the 45,000 deer–vehicle collisions (DVCs) estimated from insurance industry claims. A project was carried out to test a personal digital assistant (PDA) enabled with a Global Positioning System (GPS) receiver for the collection and analyses of animal carcass removals from the roadway and to initiate the integration of this data collection method into regular practice by the Virginia Department of Transportation (VDOT). VDOT maintenance personnel collected 8 months of spatially accurate carcass removal data by using GPS-enabled PDAs. DVC estimates from this procedure were more than nine times greater than the number reported by police. Given the findings and efforts from the study, VDOT plans to integrate collection of carcass removal data with PDAs into regular practice. The procedures described in the report can guide other states interested in implementing a systematic and spatially accurate method for collecting AVC data. Implementing mitigation in high-density AVC areas can ultimately lead to fewer AVCs and associated reductions in human deaths, injuries, and financial losses; improved traffic operations; a reduction in maintenance costs related to carcass removal and disposal; and wildlife conservation.