Stormwater drives seasonal geochemical processes beneath an infiltration basin
Andres, Scott A.
Sturchio, Neil C.
Journal of Environmental Quality
Deicing salt is an important component of road safety during winter storms. Stormwater infiltration best management practices aim to prevent the salt from polluting streams and waterways, but this may shift pollutants to groundwater resources. In response to limited field studies investigating groundwater quality impacts caused by input of salt from stormwater infiltration best management practices, we monitored water levels and quality of groundwater at various depths in an unconfined aquifer around a stormwater infiltration basin using in situ sensors coupled with grab sampling. Our observations revealed differences in groundwater chemistry with depth in the aquifer and processes that were driven by the seasonal changes in the chemistry of stormwater (salt-impacted in winter and fresh in non-winter) recharging the aquifer. Water–matrix interactions in the vadose zone beneath the basin affected the transport of sodium (Na) into groundwater following non-winter recharge. Sodium movement through the aquifer was delayed relative to chloride (Cl), indicating a longer residence time of Na in the vadose zone. Radium (Ra) concentrations were correlated with Cl concentrations, suggesting salt-impacted recharge caused desorption of Ra into groundwater because of increased salinity. Stormwater-influenced groundwater followed a preferential flow path due to heterogeneity of the aquifer materials, and water chemistry varied with time and location along the flow path. These results highlight the importance of well screen length, placement and depth, and frequency of observations when designing a monitoring network.
This is the peer reviewed version of the following article: McQuiggan, R., Andres, A. S., Roros, A., & Sturchio, N. C. (2022). Stormwater drives seasonal geochemical processes beneath an infiltration basin. Journal of Environmental Quality, 51, 1198– 1210. https://doi.org/10.1002/jeq2.20416, which has been published in final form at https://doi.org/10.1002/jeq2.20416. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited. This article will be embargoed until 10/11/2023.
stormwater , infiltration , groundwater , chloride , road salt , deicer , water quality , Delaware
McQuiggan, R., Andres, A. S., Roros, A., & Sturchio, N. C. (2022). Stormwater drives seasonal geochemical processes beneath an infiltration basin. Journal of Environmental Quality, 51, 1198– 1210. https://doi.org/10.1002/jeq2.20416