ASTM D5092/D5092M-16

1.1 This practice describes a methodology for designing and installing conventional (screened and filter-packed) groundwater monitoring wells suitable for formations ranging from unconsolidated aquifers (that is, sands and gravels) to granular materials having grain-size distributions with up to 50 % passing a #200 sieve and as much as 20 % clay-sized material (that is, silty fine sands with some clay). Formations finer than this (that is, silts, clays, silty clays, clayey silts) can be monitored but the well may not yield sufficient water required for sampling, and fine filter pack and screen requirements are difficult and costly to install. Use of coarser filter/screens in fine formations will result in wells with unstable filter packs and associated elevated sample turbidity that may adversely affect sample accuracy and data quality objectives. This practice is not applicable in fractured or karst rock conditions, but may be applicable for other porous rock formations.