The western massasauga (Sistrurus tergeminus) and the timber rattlesnake (Crotalus horridus) are protected under Nebraska Statute 37-801-811 and listed as threatened species. These species occur in the right-of-way (ROW) along several roads in Jefferson, Gage, Pawnee, and Richardson Counties which necessitates the need for added Environmental Review (ER) from Nebraska Department of Transportation (NDOT) staff and onsite surveys prior and during maintenance and construction to roadways. This project sought to minimize ER time, staff time, and increase the knowledge of these species in southeast Nebraska by: a) Identifying precise locations of western massasauga brumation sites; b) Mapping travel corridors from brumation site to active (summer) sites and explore how they relate to NDOT ROW; c) Developing standardized survey/search protocols; d) Documenting materials used by snakes as basking and/or refuge locations; e) Providing recommendations to avoid or minimize impacts to protected snakes for future NDOT maintenance and construction practices. Only western massasaugas were captured during this project and were tagged with GPS and radio transmitters to elucidate their movements through NDOT ROW. Thirteen massasaugas were captured and tagged with transmitters; one individual was never recovered so the authors only have data for 12 snakes. Overall, the massasaugas stayed very close to their capture location and only moved into surrounding fields occasionally and the authors rarely noted them on NDOT materials (besides the road itself). To limit take of these species, NDOT should clear vegetation the winter before work begins, ensure water connectivity and wetlands are maintained, ensure NDOT and contractor vehicles/equipment only drive and park on the staging area – which needs to be included in the pre-construction surveys, erect signage warning drivers of snakes on the road and continue to work closely with NGPC biologists.
The purpose of this project was to provide a data driven process to identify sensor technologies with the potential for detecting and identifying low levels of contaminants that may occasionally be present in aircraft engine bleed air supplies. Bleed air from a ground-based aircraft propulsion engine and an auxiliary power unit (APU) were used to supply air through an ozone/volatile organic compound (VOC) converter to the environmental control system on a Boeing 747, while injecting controlled amounts of fluid contaminants (i.e., aircraft engine oil, hydraulic fluid, and deicing fluid). Measurements of contaminants were performed at the ozone/VOC converter inlet and exit, and at the air conditioning pack exit. Ultrafine particles (UFP) were found to be a sensitive marker for engine oil contamination with measurements at all three locations showing similar, highly elevated UFP concentrations with a mean diameter near 40nm and smaller when the sample stream was cooled to near room temperature. In situ measurements showed that UFPs are generated by condensation and high UFP concentrations were not detected in uncooled bleed air. Oil contamination VOC levels were very low upstream of the ozone/VOC converter at bleed air temperatures up to 220˚C and increased at bleed temperatures of around 315˚C; however, oil contamination VOC levels remained at sub-ppmv levels. Fine particle concentrations also increased with oil contamination at lower bleed air temperatures, but not with temperatures around 315 ˚C. Secondary contaminants including pentanoic acid, heptanoic acid, acetic acid, formaldehyde, and acetaldehyde formed in the ozone/VOC converter as the oil aerosol oxidized. Consideration must be given to contaminant deposition within the bleed air system and sample lines as this deposition may lead to delayed responses and contaminant release during temperature transients. Of the sensor technologies assessed, spectrometers provided the best opportunity to detect and identify contaminants. Carbon monoxide (CO) measurements confirmed that CO is not generated in sufficient quantities to be of value as a marker for engine oil or hydraulic fluid contamination of bleed air. CO may be useful as a marker for ingestion of engine exhaust in some cases. However, carbon dioxide (CO2) is a much better marker for engine exhaust ingestion.
Cabin air quality within commercial aircraft has persisted as an area of concern, specifically with regard to potential exposures of and health impacts to flight crew and/or passengers. Many efforts have focused on understanding quality of the air within aircraft and the potential risks of exposure to chemicals within cabin or engine bleed air; however, variability in collection and analytical methods, and samples themselves, in addition to the lack of validated sensors for accurate in-cabin measurements have left many questions unanswered. This study was designed to assess engine bleed air for chemical contaminants following engine fluid contamination events and evaluate the potential risks for health-related effects should human exposure occur at the reported concentrations. Contamination events were simulated by injecting a variety of aircraft fluids, including oils, hydraulic fluids and a deicing fluid into an engine (for off aircraft engine stand tests) or a propulsion engine or APU (for ground-based on aircraft tests). A vast variety of chemical compounds were identified across the study, including volatile organic compounds, carbonyls and organophosphates. Interestingly, despite the study simulating contamination events by actively injecting aircraft fluids, the chemical compounds, while many, were identified at relatively low concentrations – on the order of parts per billion (ppb) or less – with none reaching the level of parts per million (ppm) where many exposure recommendations, limits and guidelines would start to restrict exposure in an effort to prevent the risk of potential health effects. Only two compounds were found to have exceeded health exposure recommendations, limits, values and/or guidelines. Tridecane, a potential dermal irritant, was found at a very low concentration (14.86 ppb). This value exceeded tridecane’s only established guideline, although the justification for the extremely low guideline could not be scientifically validated. The other compound that was found in concentrations that exceeded one exposure recommendation was formaldehyde; however, those formaldehyde concentrations (reaching ~100 ppb) did not exceed established/accepted exposure limits and guidelines, and likely present little to no health risk at concentrations ~100 ppb.
The purpose of this project was to provide a data driven process to identify sensor technologies with the potential for detecting and identifying low levels of contaminants that may occasionally be present in aircraft engine bleed air supplies. Bleed air from a ground-based aircraft propulsion engine and an auxiliary power unit (APU) were used to supply air through an ozone/volatile organic compound (VOC) converter to the environmental control system on a Boeing 747, while injecting controlled amounts of fluid contaminants (i.e., aircraft engine oil, hydraulic fluid, and deicing fluid). Measurements of contaminants were performed at the ozone/VOC converter inlet and exit, and at the air conditioning pack exit. Ultrafine particles (UFP) were found to be a sensitive marker for engine oil contamination with measurements at all three locations showing similar, highly elevated UFP concentrations with a mean diameter near 40nm and smaller when the sample stream was cooled to near room temperature. In situ measurements showed that UFPs are generated by condensation and high UFP concentrations were not detected in uncooled bleed air. Oil contamination VOC levels were very low upstream of the ozone/VOC converter at bleed air temperatures up to 220˚C and increased at bleed temperatures of around 315˚C; however, oil contamination VOC levels remained at sub-ppmv levels. Fine particle concentrations also increased with oil contamination at lower bleed air temperatures, but not with temperatures around 315 ˚C. Secondary contaminants including pentanoic acid, heptanoic acid, acetic acid, formaldehyde, and acetaldehyde formed in the ozone/VOC converter as the oil aerosol oxidized. Consideration must be given to contaminant deposition within the bleed air system and sample lines as this deposition may lead to delayed responses and contaminant release during temperature transients. Of the sensor technologies assessed, spectrometers provided the best opportunity to detect and identify contaminants. Carbon monoxide (CO) measurements confirmed that CO is not generated in sufficient quantities to be of value as a marker for engine oil or hydraulic fluid contamination of bleed air. CO may be useful as a marker for ingestion of engine exhaust in some cases. However, carbon dioxide (CO2) is a much better marker for engine exhaust ingestion.
The Federal Railroad Administration (FRA) manages billions in taxpayer funding to develop and support a safe and efficient rail network, and has initiated several research efforts to provide resiliency information to rail owners and operators. This document introduces the threats to the rail network, provides tools and resources such as Climate Mapping for Resilience and Adaptation (CMRA), summarizes a recent weather-oriented FRA Safety Advisory, and provides a case study of experiences in Maine to highlight issues faced by the rail industry.
Locomotives, trucks, and cargo-handling equipment in and around railyards contribute to air pollution concerns for surrounding communities and railyard workers. The Federal Railroad Administration (FRA) is exploring a Technology Innovation for Energy-Efficient Railyards (TIEER) Initiative, which would focus on implementing zero-emissions projects. This report discusses the concept of TIEER, the benefits of replacing or retrofitting equipment to zero-emission versions, including the opportunity to modernize and optimize equipment tailored to the railyard’s needs, and considerations for conducting a TIEER pilot study. This report also provides an overview of zero-emissions technologies, funding opportunities for zero-emission equipment, and case studies of select zero-emissions projects.
The objective of this project was to conduct experimental testing on fence designs that are effective in preventing diamondback terrapins (Malaclemys terrapin) from entering roadways to prevent the species from being impacted by road mortality. The diamondback terrapin is listed as a State Species of Concern in the State of Georgia. They are the only native brackish-water dwelling turtle species along the eastern seaboard of the United States and are facing population declines as a result of human encroachment and habitat modification. Specifically, this species experiences widespread road impacts throughout their range around coastal transportation infrastructure. This conflict between wildlife and transportation infrastructure occurs most frequently with nesting females, a critical demographic to the long-term viability of populations. Therefore, the authors' goal was to devise an affordable structural option to prevent terrapins from entering US-80 (the Tybee Island Causeway) that aligns with the Georgia Department of Transportation construction, maintenance, and driver safety protocols. Specifically, the authors determined the height and angle specifications for the exclusion fencing implementation by testing three reverse curb designs: 90º flat surface, 90º with a 3” lip, and 70º reverse angle. Each curb had 2’ sections of 4 different heights: 6”, 8”, 10”, and 12”. The most effective heights were 12”, successfully excluding 100% of animals attempting to climb the barrier for the 90-degree, 98% of animals for the 70-degree reverse angle & 100% for 90 degree with 3” lip. Next, the 10” height successfully excluded 96% of animals for the 90-degree, 100% for the 70-degree reverse angle, and 100% for the 90-degree with 3” lip. At the 8” height, 70% of animals were excluded from the 90-degree, 97% from the 70-degree reverse angle, and 96% from the 90-degree with 3” lip. Lastly at the shortest 6” curb, only 64% of animals were excluded from the 90-degree, 96% were excluded from the 70-degree reverse angle, and 87% were excluded from the 90-degree with 3” lip. Overall, the 10” and 12” heights of the 70-degree reverse angle curb and the 90-degree with 3” lip curb were most successful at excluding terrapins. This research can guide GDOT towards adapting a concept into an effective barrier design that will be permanent, reduce maintenance costs, and increase safety on US-80 and future causeway or coastal projects where impacts to terrapins need to be mitigated. These results have broader application to diamondback terrapins throughout their range and to other hard-shelled chelonids on a global scale.
Many migratory amphibians make annual population-level migrations among breeding wetlands and over-wintering and/or summer foraging upland terrestrial habitats. To reduce the negative impacts from road mortality on these vulnerable populations, it has been standard practice to build safe crossings in the form of small passages connected by barrier fencing as mitigation. The permeability of crossing structures is dependent upon the proportion of migrating animals that even reach the passages. In Phase 1 of this project, California tiger salamanders (Ambystoma californiense; CTS) were shown to move an average of approximately 40m along a barrier fence before giving up (90% tolerance interval of 12.5m). CTS that came in contact with fencing and initially moved the ‘wrong’ way (away from a passage) had a very low probability of reaching the passage system. In another study, turnarounds, often placed at fence ends, were shown to be effective in changing the trajectory of amphibians and reptiles. In this Phase 2 study, the authors tested if multiple turnarounds along the length of barrier fencing would increase the probability reaching the passage system. At the study site in Stanford, CA, the authors installed turnarounds every 25m, with an additional turnaround 12.5m from the passage system. Individual CTS movements were monitored using active-trigger cameras, documenting speed, direction, use of turnarounds, and success at reaching the passage system for 3 years prior and 2 years after the multiple turnarounds were in place. The results showed that an average of 36% of CTS initially turned in the ‘wrong’ direction. Prior to installation of multiple turnarounds, 5% of CTS that initially turned in the ‘wrong’ direction made it to the passage system. After installation of the turnarounds, 96% of CTS that initially turned in the ‘wrong’ direction interacted with one or more turnarounds and their probability of reaching the passage system increased to that of CTS that initially moved in the ‘right’ direction (mean 66% success rate); with probabilities increasing in relation to initial distance from passage. To the authors' best knowledge, this is the first study of multiple turnarounds and their impacts on passage system permeability. In addition to increasing the number and quality of passages along migratory pathways, the authors believe this is promising and cost-effective method to increase overall permeability of passage-barrier systems to migrating amphibians.
Caltrans Division of Research Innovation and System Information (DRISI) initiated the Fish Passage Engineering Project with the objective of evaluating the implementation of recent fish passage road crossings. Crossings that span the bankfull channel width, referred to as full span crossings, were of primary interest given their recognized benefits of maintaining geomorphic continuity, providing passage for aquatic and terrestrial species other than fish, lower maintenance costs and resilience to extreme events. Seventeen sites consisting of both full and partial span crossings were identified by Caltrans and regulatory agency (California Department of Fish and Wildlife, National Marine Fisheries Services) personnel serving on the project advisory board for inclusion in the study. This report describes the methods used to assess the study sites current performance and presents the findings from the site assessments and detailed site surveys. These findings are synthesized to identify project elements that have worked well for all sites and causes and lessons learned from elements that have underperformed. Detailed site assessments and observations are provided in Appendix A, and completed Caltrans Expert Fish Passage Site Assessment forms for each study site are included in Appendix B.
This research developed a robust set of quantitative performance metrics, measures, and methodologies to assess project alignment with the Climate Action Plan for Transportation Infrastructure (CAPTI). The literature review included documenting measures and metrics in published reports, peer-reviewed journals, textbooks, and presentations. Subsequently, a Caltrans System Investment Strategy (CSIS) Project Evaluation Tool was developed to evaluate projects by quantifying performance measures and metrics across eleven criteria as follows: Mode shift (active transportation, transit, and rail elements), Vehicle Miles Traveled (VMT), Zero Emission Charging & Fueling Infrastructure, Safety, Climate Adaptation and Resiliency, Natural Resources and Ecosystems, Infill Development, Freight Benefit - (Throughput, Velocity, and Reliability), Congestion Relief, Public Engagement, and Benefits to Disadvantaged Communities. The outcome of this research will allow for a data- and performance driven approach to project nomination and evaluation.
