Effects of Waste‐Water Irrigation on Aqueous Geochemistry Near Paris, Texas

Abstract

A comprehensive assessment of the environmental impact of a full‐scale, operating overland flow (OLF) land treatment system was made at the Campbell Soup (Texas), Inc. facility in Paris, Texas. The system treats over 16,000 m3/d of waste water and has been in operation for over 25 years. Field samples of soil, waste water, OLF runoff, and ground water collected during the study and detailed long‐term process records maintained by Campbell Soup were used as part of the evaluation. Geochemical data indicated that sulfate‐chloride facies were dominant for the ground water collected at the OLF site. Field data and calculations indicated that the evapotranspirative concentration of salts in the applied waste water would be insufficient to produce the measured concentrations in the ground water. A pattern of increasing ionic concentration over time (1968 to 1989) with small changes in ionic ratios suggested a trend toward the dissolution and concentration of naturally present minerals (such as gypsum and sodium chloride) in the slow moving ground water. Predictions made with the aid of MINTEQA2, a thermodynamic equilibrium model, indicated that precipitation of carbonates and simultaneous ion exchange on clays could represent a significant mechanism for the removal of calcium and magnesium from solution and the addition of sodium. The development of a slightly saline, semiconfined aquifer was strongly suggested by the ground‐water geochemical data, soil data, the estimated rate of infiltration, field hydraulic conductivity, MINTEQA2 model predictions and the magnitude of the volume of waste water applied.

Chemical composition of groundwater and brines as a result of hydrogeochemical processes in arid zones: an example from Albaji plain, Khuzestan, Iran

“…Salt precipitation occurs related to irrigation water evaporation, and precipitated salts can subsequently be leached by later irrigation or precipitation (Law 1987;Tedaldi and Loehr 1992). Practically, higher evapotranspiration rate in cultivated areas caused to more enrichment of dissolved ions and precipitating salts in these parts of the study area.…”

Assessment of hydrogeochemical characteristics of groundwater in parts of Hindon–Yamuna interfluve region, Baghpat District, Western Uttar Pradesh

“…Its addition to some extent may occur due to cation exchange but definitely not to such level. Such high K values (22 out of 110 samples with concentration of >30 mg/l), averaging 16 (pre-monsoon) to 23 mg/l (post-monsoon), may have manifested as a result of partial or deficient fixation in the soil (Tedaldi and Lohar 1992;Tyagi 2003) of potassium applied in the form of fertilizers.…”

“…Ion exchange is common when groundwater flows through a clay bearing aquifer. Calcium and Na are often involved in ion exchange (Tedaldi and Lohar 1992;Tyagi 2003), the former replacing the latter. This exchange results in Ca depletion and proportionate enrichment of Na in groundwater.…”

“…Some Mg could have been added as a consequence of cation exchange in smectiterich zones within clay beds (Tedaldi and Lohar 1992). Mg-HCO 3 > Ca-HCO 3 > Mg-HCO 3 > Ca-HCO 3 = Na-HCO 3 = Na-SO 4 > Na-Cl Na-SO 4 > Na-Cl > Na-HCO 3…”

Physico-chemical processes in a vadose zone during the infiltration of treated wastewater used for irrigation: application of the NETPATH model

“…With appropriate techniques of sampling of soils and/or soil water (Boulding 1995;Wilson and others 1995) the migration may be controlled in a real context, where the characteristics must be known. Examples of this type of ®eld study on leaching of pesticides can be found in Beltran and others (1993) and Azevedo and others (1997); on the transport of nitrates in Jemison and Fox (1994), Jabro and others (1995), and Morell and others (1996); and studies on puri®cation of wastewater through vadose zone in Bustamante (1990), Tedaldi and Loehr (1992), Esteller and others (1994), and Shahalam and others (1998). In arid or semiarid countries it is becoming more and more common to use urban wastewater for irrigation, and this is not always subjected to even a primary puri®cation process prior to being used.…”