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I � E F a t '� P,,, C�?i1NQw,4't'ER MoN_IT�.LS`r Ate?sAMPLtNG_PRQ��l]URl~,�, x t Prior to sampling, the depth :o water was measured in all monitoring wells using an electronic immersion probe, All measurements were read to the nearest 0.01 foot. if free product was present, the depth to free product and the depth to water were measured using an interface probe and an # observation sample was collected with a clear teflon bailer for confirmation. No analytical samples were collected from monitoring wells containing more than 0.25 inch of free product. The monitoring wells were sampled on.tune 8, 1990. Prior to purging, each well was checked with a cl--z teflon bailer in order to observe the possible presence of floating hydrocarbons. Purging was accomplished using a stainless steel or teflon bailer. The bailer was thoroughly cleaned prior to each sampling using a trisodium phosphate solution followed by a 10% methylalcohol solution,and then l rinsed twice with potable water. The wells were purged prior to sampling until pH,conductivity,and + . temperature values stabilized. Generally, this resulted in the removal of approximately 3 to 5 well volumes of ground water from each wall during the purging process. The water obtained from purging was placed in labeled 55-gallon drums and stored on-site, The bailer line was replaced after each I sampling. Samples recovered from each well were decanted )'hto two appropriatelyprepared and labeled 40-m1 volatile organic analysis (VOA)bottles. A travel blank (numbered as NM A) and a c duplicate sample from MW-20 were also submitted for quality assurance. The sample bottles were immediately placed in an ice chest and maintained at 4°C until delivery to a State of California licensed laboratory. Routine chain-of-custody procedures were employed. g, t .s,. ,f 1 w of � -.• X-�"{i" �-"�r^a..-.. ...�. +..e P ,.T„; . ,a°,k.p:({y r:k' _ '-6+'ccb.t. ..z> s r Y