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5 <br /> 12/24/03 <br /> water temperatures will be low and small sized planktonic microorganisms are likely to <br /> be less abundant. <br /> Task 1. Basic sampling plan: <br /> The Contractor shall collect samples every two weeks during the summer stratified period <br /> and monthly during the time of the year when the reservoir is mixed (i.e. late fall, winter, <br /> and early spring). Based on thermal stratification patterns seen in Lake Washington <br /> which is larger than Lake Chaplain but also lower elevation,it is likely that the period of <br /> most intense thermal stratification in Lake Chaplain would occur from the beginning of <br /> June to the end of September. Thus the Contractor would be sampling Lake Chaplain <br /> biweekly 4 months each year, and monthly the remaining 8 months. Sampling will be <br /> initiated January 2004 and will continue through December 2004. Vertical profiles will <br /> be collected in the vicinity of the intake structure and at a station located above the <br /> deepest point in Lake Chaplain. Plankton and water chemistry samples will be collected <br /> at 2-meter increments throughout the water column as well as at the depth of the intake <br /> structure at the intake structure sampling site. Samples will be collected at 3 m <br /> increments at the deep water site. The Contractor will also collect vertical profiles at 1 <br /> meter increments at both sites using an in situ multi-probe which simultaneously <br /> determines depth, temperature,dissolved oxygen, conductivity and algal fluorescence. <br /> The Contractor will also do a vertical net tow to collect zooplankton at each site on each <br /> sampling date. <br /> Samples for chemical characterization, will be analyzed for total dissolved and total <br /> phosphorus (i.e. TDP and TP), nitrate and ammonia, chlorophyll, and total suspended <br /> solids according to Standard Methods The Contractor will use a Sequoia Scientific <br /> LISST Portable-particle size analyzer to measure the size distribution of suspended <br /> particles in these samples. The Contractor will also determine a proxy for the"filter <br /> clogging time" for these samples by measuring the amount of water from each depth that <br /> can be passed through a GF/F filter(i.e. a glass fiber filter with a 0.45 µm pore size) in 15 <br /> minutes time. The Contractor will collect zooplankton samples. However, the City shall <br /> identify and enumerated the zooplankton samples. <br /> To determine if lake level has an effect on nutrient concentrations, the City and the <br /> Contractor shall attempt to arrange the sampling dates so that sampling occurs at a range <br /> of lake levels. The Snohomish County PUD controls the level of Lake Chaplain. The City <br /> shall work with the Snohomish County PUD and request a specific lake level for each <br /> sampling date. The Contractor shall adjust their sampling date by one or two days, if <br /> necessary, to ensure that sampling occurs at the desirable lake level. The City shall give <br /> the Contractor at least one-week notice if a sampling date needs to be adjusted. <br /> Task 2. Report Writing <br /> At the end of the project the Contractor will provide the City of Everett with all of the <br /> raw data and a preliminary report. This report will describe how detrital and planktonic <br /> particle abundance and size distributions vary with thermal stratification, depth and <br /> season in Lake Chaplain and how this relates to the depth of the intake structure. The <br /> 17 <br />