Code of Practice for Cost Effective Boreholes

Abstract: Drinking water supplies are based on ground water resources all over the world. At some localities problems with higher concentrations of iron and manganese found in ground water. These higher concentration of these metals result in metallic taste of water, effect color and flavor of food and cause staining of different products like paper, cloths, and plastics. Therefore World Health Organization has approved the treatment of water if concentrations of iron and manganese are higher than 0.3mg/L and 0.1 mg/L. Several techniques have been applied to remove iron and manganese from groundwater. The issue of higher concentrations of iron and manganese in groundwater wells at Grindalsmoen in Elverum Municipality in the south eastern part of Norway has been investigated by a PHREEQC geochemical model. The aim of this investigation was to analyze the relationships between oxygen levels and precipitation rates of iron and manganese. For this purpose geochemical simulations were performed with PHREEQC model with radial and linear flow. Results proved that concentration of oxygen at the water works (at its corresponding partial pressure) is high enough to precipitate the level of iron and manganese found in groundwater. The concentration of oxygen in equilibrium air at our desired temperature of 6 degree centigrade was 12.3 mg/l calculated by PHREEQC. Geochemical simulations were performed by the one dimensional column flow and radial flow towards well. The phenomenon of sorption was also included in model to see the adsorption behavior of iron and manganese. Overall this geochemical study has provided satisfactory results.

Introduction: The atoms of a particular element must have the same number of protons and electrons, but they can have different numbers of neutrons. When atoms differ only in the number of neutrons, they are referred to as isotopes of each other. If a particular isotope is not radioactive, it is called a stable isotope. Because they differ in the number of neutrons, isotopes differ in mass, and they can be separated using a mass spectrometer. In recent years mass spectrometers have been joined to gas chromatographs to allow separation of individual organic compounds in a mixture, followed by combustion of each separate organic compound to carbon dioxide, and then determination of the ratio of isotopes in the carbon dioxide with a mass spectrometer. Even more recently, new techniques of sample preparation, such as purge and trap or solid phase micro-extraction, have made it possible to obtain adequate material for analyses from water with low concentrations of organic contaminants. For the first time, it is possible to perform Compound Specific Isotope Analysis (CSIA) on dissolved organic contaminants such as chlorinated solvents, aromatic petroleum hydrocarbons, and fuel oxygenates, at concentrations in water that are near their regulatory standards. Biodegradation can come about through natural biological processes, or through active in situ bioremediation. When organic contaminants are degraded in the environment, the ratio of stable isotopes will often change, and the extent of degradation can be recognized and predicted from the change in the ratio of stable isotopes; CSIA has great promise to improve our understanding of the behavior of organic contaminants at hazardous waste sites. Better understanding can lead to better decisions on the remedies that are selected. CSIA can also be used to monitor the progress of natural attenuation or active biological remediation, and identify remedies that are not performing as expected. The U.S. Environmental Protection Agency requires that data quality objectives be developed for the methods and procedures that are used to characterize hazardous waste sites. The U.S. EPA also requires that the data that are used to make decisions must meet predetermined goals for data quality, including the accuracy, precision, and sensitivity of the measurement, and the extent to which the sample submitted for analysis are representative of the environmental medium being sampled. Other regulatory agencies world-wide have similar expectations. Because CSIA is a new approach in environmental investigations, there are no widely accepted standards for accuracy, precision and sensitivity, and no established approaches to document accuracy, precision, sensitivity and representativeness. This Guide is intended for managers of hazardous waste sites who must design sampling plans that will include CSIA and specify data quality objectives for CSIA analyses, for analytical chemists who must carry out the analyses, and for staff of regulatory agencies who must review and approve the sampling plans and data quality objectives, and who must review the data provided from the analyses. This Guide provides recommendations and suggestions to site managers, chemists and regulators. The recommendations and suggestions in this Guide are not legal guidance, and the site managers, chemists, and regulators may negotiate among themselves to develop objectives and approaches that are most appropriate for their site.

1. Purpose: The purpose of this manual is to provide guidance to Corps of Engineers personnel who are responsible for groundwater-related projects.

2. Applicability: This manual applies to all USACE Commands having responsibility for design of civil works projects.

3. Distribution Statement: Approved for public release, distribution is unlimited.