Laserfiche WebLink
1 <br /> City of Stockton - Van Buskirk Park Golf Course TL 394-0074-01 <br /> July 29, 1994 Page A-6 <br /> Monitoring well construction details are recorded on the field well construction form. <br /> Construction information is transferred to Monitoring Well construction schematics for <br /> presentation in final reports. <br /> A-9 Standard Operating Procedures for Groundwater Monitoring Well Development <br /> When possible, initial well development is performed during installation of the sand pack. <br /> ' A minimum of 48 hours following installation, groundwater monitoring wells are developed <br /> in order to remove sediment that may accumulate in the well during installation, and to <br /> settle the filter pack. Groundwater monitoring well development is performed using a <br /> combination of either bailing, pumping, and surging. <br /> The development of each groundwater monitoring well continues until a minimum of five <br /> well casing volumes of water have been removed, and the displaced water is relatively clear, <br /> free of sediment, and the values of Ph, temperature, and specific electrical conductance <br /> (EC) have stabilized. Well development data is recorded on the Well Development Log. <br /> ' r i containerized in Department of Transportation-approved drums and stored <br /> Purged Ovate s p , <br /> on site in an area inaccessible to the general public. The purged water is typically <br /> characterized either by sampling it, or on the basis of the groundwater sample analytical <br /> results. Twining can recommend an appropriate method for disposition of the purged water. <br /> Disposal will be the responsibility of the client. <br /> A-10 Standard Operating Procedures for Groundwater Monitoring Well Sampling <br /> ' Groundwater sampling is performed a minimum of 24 hours following development,or when <br /> the post-development water level in the well has returned to the static level. Before purging <br /> ' and sampling is performed, the depth to water and the total well depth is measured. If <br /> floating hydrocarbons are suspected, a bottom-filling clear bailer or hydrocarbon-detecting <br /> paste bailer may be used to record floating hydrocarbon thickness. Depth to water is <br /> measured with an electric sounder, according to Twining's "Standard Operating Procedures <br /> for Measuring Depths to Water and Calculating Groundwater Elevations". <br /> i <br /> Prior to.sampling a monitoring well, a minimum of 3 well casing volumes is purged using <br /> a clean, stainless steel submersible pump or a disposable bailer equipped with a length of <br /> new rope. Disposable bailers and rope lengths will be used once, and discarded. After 3 <br /> casing volumes of water have been removed from the well, purging continues until measured <br /> field parameters (Ph, specific electrical conductivity, and temperature) have stabilized. <br /> Purging data is recorded on the Well Sampling log. <br /> Some monitoring wells are expected to be evacuated to dryness after removing fewer than <br /> three casing volumes. These low-yield monitoring wells are allowed to recharge for as long <br /> as 24 hours. Samples are collected as soon as the monitoring wells have recharged <br /> sufficiently to allow sample collection. If insufficient water has recharged after 24 hours, <br /> the monitoring well is recorded as "dry" for the sampling event. <br /> 1 <br />