Surface Changes in Well Casing Pipe Exposed to High Concentrations of Organics inAqueous Solution

摘要

Prior to 1985 polyvinyl chloride (PVC) was the most commonly used well casing material for ground water monitoring. In 1985 the EPA published the initial draft of the Resource Conservation and Recovery Act (RCRA) Ground-Water Monitoring Technical Enforcement Guidance Document. This document stated that 'steel casings deteriorated in corrosive environments; PVC deteriorated in contact with ketones, esters and aromatic hydrocarbons...' and recommended that either Teflon or stainless steel 316 be used for constructing wells. The EPA's concerns were that PvC and the casing materials commonly used for ground water monitoring either altered the ground water samples or did not meet the long-term structural characteristics required of RCRA monitoring wells. While we have found many studies that have examined the effects of well casing materials on ground water sample, little information exists on the long-term stability of casing materials exposed to extreme environmental conditions such as highly salinity or pH, or to either pure of high concentrations of organic of organic solvents. (JES)