SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

DALES & MOORE , T01 I-Ik)NAI 1 �Al I 1 1) , Renown Enterprises, Inc• October 3, 1988 Page Two 2esponse: Discussion with the chemists at our contract lab (Curtis & 'Dins) indicated that PAH's are difficult to detect in oily soil samples as were anticipated at the Renown site. We resolved that the samples would be extracted using EPA Method 3510 with a silica gel cleanup stage and analyzed using EPA Method 8100 to improve detection limits. The detection limits subsequently reported for analysis of ten soil samples from the Renown property ranged from 0.05 to 0.25 mg/kg. DHS Ooaranent: "may are rising head (slug?) tests proposed instead of pimping tests to measure the hydraulic conductivity of the shallow ground u7at- _ rv_-tc t-li n, that T,mm t°s� results would give a more precise value of the hydraulic conductivity than rising head tests." : We recognize that pumping tests generally provide a more accurate estimate of aquifer parameters including hydraulic conductivity. However, we proposed conducting rising head tests to obtain a preliminary estimate of aquifer parameters and minimize the volume of waste water produced. Rmjping tests should probably not be conduc.-ted at the site until etxx2gh data is available to estimate the volume and chemical character of water likely to be produced during pumping. DHS Cap t: "How many rounds of groundwater sampling are You anticipating? DHS believes that, at a minimum, three consecutive months of sampling should be conducted." : only one groundwater sampling round was planned for this investigation. Based on the results of that first sampling rand, water level monitoring data, and other pertinent site data, Dames & Moore may remmiend additional sampling to evaluate seasonal changes in water quality or to assess the possible offsite extent of contamination. pHs : "Doax erning the required data to coMletre a hazard ranking: be sure that references are supplied with the data and that you include data oax erning the distanoe to the nearest sensitive environment." : Sources of data will be cited in the text of our final report as appropriate. The Department of Fish and Game has been contacted regarding available data on the distance to the nearest sensitive . Z-lese findings will be presented in our final report. EHS : ,Will sieve analyses data be used to select the monitoring well screen slot size and the filter pack grain size distribution? DHS recorrends that the scram slot size and the filter pack grain size distribution be selected using the sieve analyses data for the finest grained soil in the horizon to be screened."