Road salt applications mobilize trace elements from roadside soil to shallow groundwater.

In regions where deicers are applied to roadways, micronutrients and toxic trace elements may be mobilized from soil material into soil porewater. These elements may subsequently migrate with soil porewater to surface waters and groundwaters, potentially leaching the soil of micronutrients or introducing toxins to water resources. Our study thus aims to quantify the timing and extent of trace element releases from soil material to soil porewater and groundwater in response to deicing events.

Floods enhance the abundance and diversity of anthropogenic microparticles (including microplastics and treated cellulose) transported through karst systems.

Microplastics (plastics <5 mm) are emerging contaminants that have been detected in virtually all environments. While microplastic research in terrestrial surface waters has been proliferating, microplastic contamination in subsurface environments remains understudied. Karst terrains may be particularly susceptible to microplastic pollution because the presence of large dissolution openings allows fast transport of water through these systems, facilitating the introduction of surface contaminants into subsurface habitats.

Cave sediment sequesters anthropogenic microparticles (including microplastics and modified cellulose) in subsurface environments.

Anthropogenic microparticles (of synthetic, semisynthetic, or modified natural compositions) are globally pervasive, yet little is known about their distribution and storage in the subsurface despite their potential threats to belowground environments. We therefore assessed their amounts and characteristics in water and sediment from a cave in the United States. During a flood, water and sediment samples were collected at 8 sites every ~25 m along the cave passageways.

Using in situ measurements of optical brighteners for rapid reconnaissance of wastewater inputs to water resources.

Untreated wastewater entering the environment through leaking infrastructure and sewer overflows threatens both human and aquatic health. Water managers therefore need low cost, in situ methods to detect sewage contamination in real time to promptly employ mitigation strategies. However, wastewater has traditionally been identified in waterbodies using chemical and microbial tracers and indicators that can be non-unique to wastewater and often require complex and expensive analyses.

Integrating land cover, point source pollution, and watershed hydrologic processes data to understand the distribution of microplastics in riverbed sediments.

Microplastics are emerging contaminants ubiquitously distributed in the environment, with rivers acting as their main mode of transport in surface freshwater systems. However, the relative importance of hydrologic processes and source-related variables for benthic microplastic distribution in river sediments is not well understood. We therefore sampled and characterized microplastics in river sediments across the Meramec River watershed (eastern Missouri, United States) and applied a hydrologic modeling approach to estimate the relative importance of river discharge, river sediment load, land cover, and point source pollution sites to understand how these environmental factors affect microplastic distribution in benthic sediments.

Local Monitoring Should Inform Local Solutions: Morphological Assemblages of Microplastics Are Similar within a Pathway, But Relative Total Concentrations Vary Regionally.

Pathways for microplastics to aquatic ecosystems include agricultural runoff, urban runoff, and treated or untreated wastewater. To better understand the importance of each pathway as a vector for microplastics into waterbodies and for mitigation, we sampled agricultural runoff, urban stormwater runoff, treated wastewater effluent, and the waterbodies downstream in four regions across North America: the Sacramento Delta, the Mississippi River, Lake Ontario, and Chesapeake Bay. The highest concentrations of microplastics in each pathway varied by region: agricultural runoff in the Sacramento Delta and Mississippi River, urban stormwater runoff in Lake Ontario, and treated wastewater effluent in Chesapeake Bay.

Road salt retention and transport through vadose zone soils to shallow groundwater.

Increasing background salinity in watersheds has largely been attributed to road salt retention in groundwaters due to their long residence times. However, laboratory studies demonstrate that soils temporarily store salts, either in porewater or adsorbed onto particles. Field studies of road salt retention in soils are nevertheless rare, and mechanisms of salt transport across multiple hydrological reservoirs (e.

An R package for correcting continuous water quality monitoring data for drift.

Continuous water quality monitoring ins- truments are used to understand the chemical and physical behaviors of aquatic environments over time. However, the data generated from these instruments are susceptible to inaccuracies due to drift that can occur between site visits. While there are several software packages available to correct drift in water quality data, these packages are often proprietary, expensive, and/or do not offer the user control over the data corrections.

Sampling, Sorting, and Characterizing Microplastics in Aquatic Environments with High Suspended Sediment Loads and Large Floating Debris.

The ubiquitous presence of plastic debris in the ocean is widely recognized by the public, scientific communities, and government agencies. However, only recently have microplastics in freshwater systems, such as rivers and lakes, been quantified. Microplastic sampling at the surface usually consists of deploying drift nets behind either a stationary or moving boat, which limits the sampling to environments with low levels of suspended sediments and floating or submerged debris.

Transport of road salt contamination in karst aquifers and soils over multiple timescales.

Road deicing has caused widespread environmental Na and Cl release for decades, yet the transport and retention of these contaminants in karst aquifers and soils are poorly understood. We examined the transport dynamics of Na and Cl from road salt in shallow groundwater during flooding and over seasonal timescales by intensively monitoring an urban and a rural karst spring over approximately 2 years. Furthermore, we used a 20-year dataset for the rural spring to determine how salt retention affected long-term geochemical trends in the shallow groundwater.

Characterizing nutrient distributions and fluxes in a eutrophic reservoir, Midwestern United States.

Harmful algal blooms are increasingly common in aquatic ecosystems and have been linked to runoff from agricultural land. This study investigated the internal nutrient (i.e.

Multiple sources of boron in urban surface waters and groundwaters.

Previous studies attribute abnormal boron (B) levels in streams and groundwaters to wastewater and fertilizer inputs. This study shows that municipal drinking water used for lawn irrigation contributes substantial non-point loads of B and other chemicals (S-species, Li, and Cu) to surface waters and shallow groundwaters in the St. Louis, Missouri, area.