@article{kranz_rivers_mclaughlin_heitman_2022, title={Influence of compost application rate on nutrient and heavy metal mobility: Implications for stormwater management}, volume={9}, ISSN={["1537-2537"]}, url={https://doi.org/10.1002/jeq2.20403}, DOI={10.1002/jeq2.20403}, abstractNote={AbstractAmending soils with compost has become increasingly common in stormwater management practices. Compost can be a source and sink for nutrients and heavy metals, and it is important to understand the effect of compost on pollutant leaching under different hydrologic conditions. The objectives of this study were (a) to quantify the distribution coefficient (Kd) of PO4–P and metals (Cd, Cr, Cu, Ni, Pb, Zn) for compost–soil blends and (b) to examine how compost rate alters leaching patterns of nutrients (NH4–N, NO3–N, PO4–P) and metals from compost–soil blends. Material consisted of a sandy loam subsoil, a yard‐waste compost, and compost–soil blends at 20 or 50% compost by volume. Materials were tested in sorption–desorption experiments using simulated stormwater (SW); columns with the materials were also leached with either SW or deionized (DI) water. As compost rate increased, the Kd decreased for PO4–P and Cr but increased for Cd, Cu, Ni, and Zn. The addition of compost reduced the sorption of PO4–P and Cr, potentially making it a source of these pollutants. Simulated stormwater did not increase the amount of pollutants retained compared with DI water for compost blends, except for 100% compost columns. Nitrate was the only constituent that had a negative removal efficiency, suggesting the compost was a source of NO3–N. Column media retained >70% of the metals from the added stormwater solution. These results suggest that yard‐waste compost blends at ≤50% have the potential to retain certain pollutants from infiltrating stormwater, but this effect may decline after several storm events.}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Kranz, Christina N. and Rivers, Erin N. and McLaughlin, Richard A. and Heitman, Joshua L.}, year={2022}, month={Sep} }
 @article{rivers_morse_2022, title={Variability of Potential Soil Nitrogen Cycling Rates in Stormwater Bioretention Facilities}, url={https://doi.org/10.3390/su14042175}, DOI={10.3390/su14042175}, abstractNote={Low-impact development (LID) is a common management practice used to infiltrate and filter stormwater through vegetated soil systems. The pollutant reduction potential of these systems is often characterized by a single pollutant removal rate; however, the biophysical properties of soils that regulate the removal of pollutants can be highly variable depending on environmental conditions. The goal of this study was to characterize the variability of soil properties and nitrogen (N) cycling rates in bioretention facilities (BRFs). Soil properties and potential N cycling processes were measured in nine curbside bioretention facilities (BRFs) in Portland, OR during summer and winter seasons, and a subset of six sites was sampled seasonally for two consecutive years to further assess temporal variability in soil N cycling. Potential N cycling rates varied markedly across sites, seasons, and years, and higher variability in N cycling rates was observed among sites with high infiltration rates. The observed seasonal and annual changes in soil parameters suggest that nutrient removal processes in BRFs may be highly variable across sites in an urban landscape. This variability has important implications for predicting the impacts of LID on water quality through time, particularly when estimated removal rates are used as a metric to assess compliance with water quality standards that are implemented to protect downstream ecosystems.}, journal={Sustainability}, author={Rivers, Erin N. and Morse, Jennifer L.}, year={2022}, month={Feb} }
 @article{rivers_heitman_mclaughlin_howard_2021, title={Reducing roadside runoff: Tillage and compost improve stormwater mitigation in urban soils}, volume={280}, ISSN={["1095-8630"]}, url={https://doi.org/10.1016/j.jenvman.2020.111732}, DOI={10.1016/j.jenvman.2020.111732}, abstractNote={Soils adjacent to urban surfaces are often impaired by construction activities that degrade the natural structure and function of the soil, resulting in altered physical, hydraulic, and vegetative properties that limit the infiltration, storage, and filtration of stormwater runoff. A management approach to enhance the efficacy of vegetated roadside soils for runoff control is the use of compost in conjunction with tillage to improve soil conditions and facilitate improved hydrological function, the establishment of vegetative biomass, and increased nutrient and pollutant attenuation. The purpose of this study was to determine the efficacy of soil improvement measures to reduce runoff volumes and improve water quality along roadsides over time. The effects of tillage with and without compost on 1) bulk density and infiltration rates, 2) runoff volumes, and 3) runoff water quality were evaluated during multiple storm events along two long-established interstate roadsides in North Carolina during 2015 and 2017. Experimental plots were established in the grassed areas adjacent to roads and consisted of an untreated control, tillage only, and tillage amended with compost. Tillage alone did not reduce runoff in roadside soils, however, tillage with compost did improve runoff capture. The patterns in hydrologic performance within and among sites suggests that the incorporation of compost in tilled soils may influence storage potential through different effects on soil properties, such as decreasing bulk density or improving vegetation establishment, thereby increasing evapotranspirative withdrawals, depending on soil texture. Tillage increased sediment concentrations in runoff, however, net export of sediments was reduced with the inclusion of compost due to the reduction of runoff quantities compared to undisturbed areas and tillage alone. Control and treatment plots were equally effective in reducing dissolved nutrient and metal concentrations, however, the improved hydrologic performance in plots with compost decreased net nutrient and metal export in most storms. The results of this study suggest that the incorporation of compost in compacted urban soils may provide significant improvements for biological and physical soil properties that affect stormwater interception and infiltration.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, publisher={Elsevier BV}, author={Rivers, Erin N. and Heitman, Joshua L. and McLaughlin, Richard A. and Howard, Adam M.}, year={2021}, month={Feb} }