Surface Water‐Ground Water Interaction: Herbicide Transport into Municipal Collector Wells

Abstract

During spring runoff events, herbicides in the Platte River are transported through an alluvial aquifer into collector wells located on an island in the river in 6 to 7 d. During two spring runoff events in 1995 and 1996, atrazine [2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine] concentrations in water from these wells reached approximately 7 µg/L, 70 times more than the background concentration in ground water. Concentrations of herbicides and metabolites in the collector wells generally were one‐half to one‐fifth the concentrations of herbicides in the river for atrazine, alachlor [2‐chloro‐2′‐6′‐diethyl‐N‐(methoxymethyl)‐acetanilide], alachlor ethane‐sulfonic acid (ESA) [2‐((2,6‐diethylphenyl) (methoxymethyl)amino)‐2‐oxoethane‐sulfonic acid], metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl)acetamide], cyanazine [2‐((4‐chloro‐6‐(ethylamino)‐1,3,5 triazin‐2‐yl)‐amino)‐2‐methylpropionitrile], and acetochlor [2‐chloro‐N‐(ethoxymethyl)‐N‐(2‐ethyl‐6methyl‐phenyl) acetamide], suggesting that 20 to 50% river water could be present in the water from the collector wells, assuming no degradation. The effect of the river on the quality of water from the collector wells can be reduced through selective management of horizontal laterals of the collector wells. The quality of the water from the collector wells is dependent on the (i) selection of the collector well used, (ii) number and selection of laterals used, (iii) chemical characteristics of the contaminant, and (iv) relative mixing of the Platte River and a major upstream tributary.

Peer Reviewed: The Promise of Bank Filtration

“…However, Schwarzenbach and colleagues also identified a group of organic chemicals (chloroform, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene) that were resistant to biological transformation and thus ineffectively removed by riverbank filtration. Indeed, some compounds are less affected by natural filtration, such as certain pesticides (24,29,31), pharmaceuticals (2,30,32), and halogenated organic compounds (23,28).…”

Occurrence, Characteristics, Transport, and Fate of Pesticides, Pharmaceuticals, Industrial Products, and Personal Care Products at Riverbank Filtration Sites

“…In some cases, the presence of numerous herbicides and other organic compounds in groundwater has been attributed to surface water that was contaminated with herbicides by periodic flooding, bank storage of river water, artificial recharge by impoundments, and induced infiltration (Exner, 1990;Duncan et al, 1991;Thurman et al, 1991;Taylor, 1994;Wang and Squillace, 1994;Frycklund, 1998;Burkart et al, 1999a;Verstraeten et al, 1999b;Lange et al, 2000;Mazounie et al, 2000;Verstraeten et al, in press). In other cases, pesticides have been identified in surface water during base-flow conditions and have been attributed to inflow from contaminated groundwater (Barbash and Resek, 1996).…”

“…Pesticides (Verstraeten et al, 1999b). Personal care products, like fragrance compounds (Jüttner, 1999).…”

“…Tracer studies with these reacting chemicals can establish the adsorption/desorption characteristics locally and can show the heterogenous nature of the hydraulic properties of the aquifer, sometimes indicating the presence of preferential flow paths (Verstraeten et al, 1999b).…”

“…Marine environments (Buser et al, 1998;Siegener and Chen, 2000). Groundwater (Stan and Linkerhägner, 1992;Burkart and Kolpin, 1993;Heberer, 1995;Barbash and Resek, 1996;Dünnbier et al, 1997;Kolpin et al, 1998;Burkart et al, 1999aBurkart et al, , 1999bHeberer and Dünnbier, 1999;Hodiaumont et al, 1999;Verstraeten et al, 1999b;Lange et al, 2000;Heberer, in press). Drinking water (Ang et al, 1989;Jani et al, 1991;Stan et al, 1994;Heberer and Stan, 1996;Tsipi and Hiskia, 1996;Kalajzic et al, 1998;Verstraeten et al, 1999b;Lange et al, 2000;Heberer, in press.…”