PVC Unit role time Depth Design debris trends Purpose dip tape sediment sampling Materials pollution information water entry instruments well casing data loggers Construction contaminants Water samples allegianceindia stainless steel land use changes specialized type Screened Section production wells aquifer behavior observation wells chemical analysis potential impacts electronic sensors static water level Monitoring Process groundwater levels seasonal variations groundwater quality Regular measurements pressure transducers Monitoring Equipment chemical composition continuous monitoring Allegiance Enterprise groundwater chemistry Environmental Studies Groundwater Monitoring Water Quality Assessment Allegiance Water Management environmental impact assessments other hydrogeological parameters