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Contaminated Ground Water (contaminated + ground_water)

Distribution by Scientific Domains

Engineering	50%

Selected Abstracts

A Probabilistic Method for Estimating Monitoring Point Density for Containment System Leak Detection

GROUND WATER, Issue 4 2000
Randall R. Ross
The use of physical and hydraulic containment systems for the isolation of contaminated ground water and aquifer materials associated with hazardous waste sites has increased during the last decade. The existing methodologies for monitoring and evaluating leakage from hazardous waste containment systems rely primarily on limited hydraulic head data. The number of hydraulic head monitoring points available at most sites employing physical containment systems may be insufficient to identify significant leaks from the systems. A probabilistic approach for evaluating the performance of containment systems, based on estimations of apparent leakage rates, is used to introduce a methodology for determining the minimum number of monitoring points necessary to identify the hydraulic signature of leakage from a containment system. The probabilistic method is based on the principles of geometric probability. The method is demonstrated using three-dimensional ground water flow modeling results of leakage through a vertical barrier. The results indicate that the monitoring point spacing used at many hazardous waste sites likely is inadequate to detect the hydraulic signatures of all but the largest leaks. [source]

Vapor Intrusion in Homes over Gasoline-Contaminated Ground Water in Stafford, New Jersey

GROUND WATER MONITORING & REMEDIATION, Issue 1 2006
Paul F. Sanders
The potential for chemical vapor intrusion from contaminated ground water to the interior of homes was investigated at a site with a leaking underground gasoline storage tank in Stafford Township, New Jersey. This location exhibited conditions favorable to vapor intrusion, with sand soil and a water table depth of 3.3 m. Concentrations of volatile organic chemicals in the ground water were as high as 82 mg/L for total benzene, toluene, ethylbenzene, and xylene (BTEX) and up to 590 mg/L for methyl- t -butyl ether (MTBE). Soil vapor samples at multiple depths were taken adjacent to several homes. Inside the homes, air samples were taken on the main floor, in the basement, and under the foundation slab. Despite high ground water concentrations, only one home had measurable impacts to indoor air quality attributable to some of the ground water contaminants. In this house, the BTEX chemicals were not detected in the basement, indicating a lack of indoor air impacts from the ground water for these chemicals. Oxygen measurements suggested that degradation attenuated these chemicals as they diffused through the vadose zone. However, MTBE, 2,2,4-trimethylpentane (isooctane), and cyclohexane were found in the indoor air. The first two of these chemicals served as gasoline-specific tracers and indicated that vapor intrusion was occurring. Attenuation factors (the ratio of the indoor air concentration to a source soil vapor concentration) for the BTEX chemicals between the ground water and the indoor air were <1 × 10,5, and for MTBE was 1.2 × 10,5. Attenuation factors between the deep-soil vapor and the basement air were as follows: BTEX compounds, <1 × 10,5; MTBE, 2.2 × 10,5; 2,2,4-trimethylpentane, 3.6 × 10,4; and cyclohexane, 1.2 × 10,4. Attenuation factors between the subslab vapor and the basement air were 7 to 8 × 10,3. [source]

As(III) Determination in the Presence of Pb(II) by Differential Alternative Pulses Voltammetry

ELECTROANALYSIS, Issue 15 2010
Roumen Zlatev
Abstract Differential Alternative Pulses Voltammetry (DAPV), introduced by the authors earlier, was applied with HMDE for direct As(III) determination in the presence of Pb(II) in natural water without sample pretreatment. Distinguishable peaks of As(III) and Pb(II) were registered in 1,M HCl supporting electrolyte at a concentration ratio as high as 1,:,6, while complete peak overlapping occurs applying DPP at any concentration ratio at the same experimental conditions. In-situ As(III) determinations in the presence of Pb(II) in contaminated ground waters in Mexico were performed, using especially designed disposable safe mercury drop electrodes. [source]

In vivo genotoxic effects of industrial waste leachates in mice following oral exposure

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 5 2006
Saurabh Chandra
Abstract Contamination of ground water by industrial waste poses potential health hazards for man and his environment. The improper disposal of toxic wastes could allow genotoxic chemicals to percolate into ground waters, and these contaminated ground waters may produce toxicity, including mutation and eventually cancer, in exposed individuals. In the present study, we evaluated the in vivo genotoxic potential of leachates made from three different kinds of industrial waste (tannery waste, metal-based waste, and waste containing dyes and pigments) that are disposed of in areas adjoining human habitation. Three different doses of test leachates were administered by oral gavage for 15 consecutive days to Swiss albino mice; their bone marrow cells were examined for chromosome aberrations (CAs), micronucleated polychromatic erythrocytes (MNPCEs), and DNA damage using the alkaline Comet assay. Exposure to the leachates resulted in significant (P < 0.05 or P < 0.001) dose-dependent increases in chromosome and DNA damage. Fragmented chromosomes and chromatid breaks were the major CAs observed. Chemical analysis of the leachates indicated that chromium and nickel were elevated above the limits established by health organizations. The highest levels of genotoxicity were produced by the metal-based leachate and the tannery-waste leachate, while the dye-waste leachate produced weaker genotoxic responses. The cytogenetic abnormalities and DNA damage produced by the leachates indicate that humans consuming water contaminated with these materials are at increased risk of developing adverse health consequences. Environ. Mol. Mutagen., 2006. © 2006 Wiley-Liss, Inc. [source]