Laserfiche WebLink
04ARCADIS <br /> • A YSI 3560 Water Quality Meter° (or equivalent) was used to measure pH, specific <br /> conductance (EC), temperature, and turbidity. After approximately every casing volume of <br /> purging, field parameters were recorded on a Well Data Sheet. Sampling was performed <br /> when the total estimated purge volume was reached. <br /> • The pumping rate is reduced during evacuation of the last casing volume so that sampled water <br /> is not subject to unnecessary agitation. If a bailer is used, the bailer is slowly lowered to <br /> minimize agitation of the water column. <br /> Groundwater Sampling Using Low-Flow (Micro Purge) Methods <br /> For groundwater monitoring wells at the Austin Unit equipped with dedicated bladder pumps, groundwater <br /> sampling was performed using low-flow (micro purge) methods described below. <br /> • In order to minimize a decline in water level, the bladder pump was operated at a discharge rate of 1 <br /> liter per minute or less. <br /> • A weighted water-level meter was used to measure water levels in the well during purging. Water levels <br /> were recorded on a Well Data Sheet along with water quality parameters. <br /> • To assess the presence of fresh water coming into the well, discharged water was routed <br /> through a flow cell attached to a YSI 3560 Water Quality Meter° (or equivalent) equipped <br /> with probes for measuring pH, specific conductance, temperature, and turbidity. When three <br /> consecutive readings of these field parameters had stabilized to within the established <br /> criteria listed in the table below, the water quality was considered to be stable and samples <br /> were collected. <br /> CONSTITUENT CRITERIA <br /> Turbidity t 10%of reading <br /> Specific Conductance t 10%of reading <br /> Temperature t 0.2 degrees Celsius <br /> pH t 0.2 units, <br /> Domestic Well Sampling Methods <br /> For domestic wells the water was left to run for approximately 30 minutes prior to sample <br /> collection. At the time of sampling, a YSI 3560 Water Quality Meter° (or equivalent) was used to <br /> measure field parameters (EC, pH, temperature, and turbidity) and recorded on a Well Data Sheet. <br /> Surface-Water Sampling <br /> Surface water sampling is performed by submerging laboratory-supplied sample containers or a <br /> decontaminated sampling dipper into the surface water channel at the designated sampling <br /> stations. At the time of sampling, a YSI 3560 Water Quality Meter° (or equivalent) was used to <br /> measure field parameters (EC, pH, temperature, and turbidity) and recorded on a Well Data Sheet. <br />