Geology topics

Steven W. Geis

Publications and source records attributed to Steven W. Geis.

4 recordsLinked to original sources

USGS2025

Comparative toxicity of aircraft deicers, runway deicers, and road salt in winter airport runoff

Aircraft deicer and anti-icer formulations and airfield pavement deicer formulations are commonly used at airports that experience freezing precipitation. In addition, road salt is often applied in urban areas surrounding airports. This mixture of deicers in receiving streams can be toxic to aquatic organisms. A 17-year study of deicers and toxicity in runoff samples from sites in and near Milwaukee Mitchell International Airport included bioassay testing of Ceriodaphnia dubia , Pimephales promelas , Raphidocelis subcapitata , and Aliivibrio fischeri concurrently with quantification of freezing-point depressants that represent presence of the various deicers. Propylene glycol was monitored to represent aircraft deicers and anti-icers, acetate and formate were monitored to represent airfield pavement deicers, and chloride was monitored to represent road salt. Toxicity endpoints (e.g., lethal concentrations and inhibitive concentrations) were compiled for 19 airport deicer products and sodium chloride. Comparison of freezing-point depressant concentrations with toxicity endpoints indicated that propylene glycol, acetate, and chloride exceeded endpoint concentrations in multiple samples: more than 70% of 492 runoff samples exceeded at least one endpoint concentration with exceedances of propylene glycol and acetate-based deicer endpoints as well as road salt endpoints. Validation of these results were observed with measured toxic effects on C. dubia , P. promelas , and R. subcapitata in bioassays conducted on undiluted samples: samples with multiple deicers exceeding endpoint thresholds had greater toxicity than samples with individual deicer endpoint exceedances, and samples with no endpoint exceedances typically exhibited less toxicity than samples with only one endpoint exceedance. A comparison of additivity of toxicity quotients with bioassay results fit a log-logistic regression curve, indicating that the condition of tested organisms degraded with increasing deicer presence. These findings suggest that concurrent reduction of runoff from aircraft, airfield pavement, and road salt deicers will be needed to eliminate aquatic toxicity in adjacent watersheds.

Wisconsin↗

USGS2013

Organic waste compounds in streams: Occurrence and aquatic toxicity in different stream compartments, flow regimes, and land uses in southeast Wisconsin, 2006–9

An assessment of organic chemicals and aquatic toxicity in streams located near Milwaukee, Wisconsin, indicated high potential for adverse impacts on aquatic organisms that could be related to organic waste compounds (OWCs). OWCs used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewage overflows, among other sources. Many of these compounds are toxic at elevated concentrations and (or) known to have endocrine-disrupting potential, and often they occur as complex mixtures. There is still much to be learned about the chronic exposure effects of these compounds on aquatic populations. During 2006–9, the U.S. Geological Survey, in cooperation with the Milwaukee Metropolitan Sewerage District (MMSD), conducted a study to determine the occurrence and potential toxicity of OWCs in different stream compartments and flow regimes for streams in the Milwaukee area. Samples were collected at 17 sites and analyzed for a suite of 69 OWCs. Three types of stream compartments were represented: water column, streambed pore water, and streambed sediment. Water-column samples were subdivided by flow regime into stormflow and base-flow samples. One or more compounds were detected in all 196 samples collected, and 64 of the 69 compounds were detected at least once. Base-flow samples had the lowest detection rates, with a median of 12 compounds detected per sample. Median detection rates for stormflow, pore-water, and sediment samples were more than double that of base-flow samples. Compounds with the highest detection rates include polycyclic aromatic hydrocarbons (PAHs), insecticides, herbicides, and dyes/pigments. Elevated occurrence and concentrations of some compounds were detected in samples from urban sites, as compared with more rural sites, especially during stormflow conditions. These include the PAHs and the domestic waste-water-indicator compounds, among others. Urban runoff and storm-related leaks of sanitary sewers and (or) septic systems may be important sources of these and other compounds to the streams. The Kinnickinnic River, a highly urbanized site, had the highest detection rates and concentrations of compounds of all the sampled sites. The Milwaukee River near Cedarburg—one of the least urban sites—and the Outer Milwaukee Harbor site had the lowest detection rates and concentrations. Aquatic-toxicity benchmarks were exceeded for 12 of the 25 compounds with known benchmarks. The compounds with the greatest benchmark exceedances were the PAHs, both in terms of exceedance frequency (up to 93 percent for some compounds in sediment samples) and magnitude (concentrations up to 1,024 times greater than the benchmark value). Other compounds with toxicity-benchmark exceedances include Bis(2-ethylhexyl) phthalate (a plasticizer), 2-Methylnapthalene (a component of fuel and oil), phenol (an antimicrobial disinfectant with diverse uses), and 4-Nonylphenol (sum of all isomers; a detergent metabolite, among other uses). Analyzed as a mixture, the suite of PAH compounds were found to be potentially toxic for most non-base-flow samples. Bioassay tests were conducted on samples from 14 streams: Ceriodaphnia dubia in base-flow samples, Ceriodaphnia dubia and Hyallela azteca in pore-water samples, and Hyallela azteca and Chironomus tentans in sediment samples. The greatest adverse effect was observed in tests with Chironomus tentans from sediment samples. The weight of Chironomus tentans after exposure to sediments decreased with increased OWC concentrations. This was most evident in the relation between PAH results and Chironomus tentans bioassay results for the majority of samples; however, solvents and flame retardants appeared to be important for one site each. These results for PAHs were consistent with assessment of PAH potency factors for sediment, indicating that PAHs were likely to have adverse effects on aquatic organisms in many of the streams studied.

Wisconsin↗

USGS2008

Formulations for aircraft and airfield deicing and anti-icing: aquatic toxicity and biochemical oxygen demand

The Airport Cooperative Research Program (ACRP) has sponsored research on environmental characteristics of aircraft and pavement deicers and anti-icers focusing primarily on biochemical oxygen demand (BOD) and aquatic toxicity of formulated products and individual chemical components of formulations. This report presents a background of issues leading to this research, objectives of this document, and a description of the efforts and findings of this research. Except when the distinction among products is necessary for clarity, “deicer” will refer to aircraft-deicing fluids (ADFs), aircraft anti-icing fluids (AAFs), and pavement-deicing materials (PDMs) generally. The efforts of this project have included the following: A review of regulations and specifications related to the performance and environmental characteristics of deicer formulations A review of issues related to the impact that deicers have on aquatic systems and causes of those impacts Laboratory testing of current-use deicers to establish benchmark values for aquatic toxicity, BOD, and chemical oxygen demand (COD) A review of deicer formulations under development and their relevant performanceand environmental-related characteristics A review of operational and infrastructure considerations A synopsis of current analytical methods used in environmental characterization of airport deicing runoff A toxicity-based investigation of current-use deicers to determine components responsible for toxicity and identify component classes to focus a search for alternative components Identification of gaps in knowledge and data pertaining to the above topics

Report↗

USGS2001

Aircraft and runway deicers at General Mitchell International Airport, Milwaukee, Wisconsin, USA. 2. Toxicity of aircraft and runway deicers

Streams receiving runoff from General Mitchell International Airport (GMIA), Milwaukee, Wisconsin, USA, were studied to assess toxic impacts of aircraft and runway deicers. Elevated levels of constituents related to deicing (propylene glycol, ethylene glycol, and ammonia) were observed in stream samples. The LC50s of type I deicer for Ceriodaphnia dubia, Pimephelas promelas, Hyalela azteca , and Chironimus tentans and the EC50 for Microtox® were less than 5,000 mg/L of propylene glycol. Concentrations up to 39,000 mg/L were observed at airport outfall sites in samples collected during deicing events. The IC25s of type I deicer for C. dubia and P. promelas were less than 1,500 mg/L of propylene glycol. Concentrations up to 960 mg/L were observed in low‐flow samples at an airport outfall site. Measured toxicity of stream water was greatest during winter storms when deicers were applied. Chronic toxicity was observed at airport outfall samples from low‐flow periods in the winter and the summer, with the greater toxic impacts from the winter sample. All forms of toxicity in stream‐water samples decreased as downstream flows increased.

Wisconsin↗