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Attachment A <br />Scope of Services: Kissing Tree groundwater monitoring project for City of San Marcos <br />Introduction/justification: <br />With the proposed work by Brookfield/Kissing Tree to monitor water quality at three on-site wells, <br />important information will be collected about ground- and surface -water on-site. However, there is still <br />a lack of information about potential contaminants of interest in adjacent up- and down -gradient <br />groundwaters, which would provide information that could be used to determine possible sources of <br />any potential contaminants. The work proposed here will build on prior work by McCalla in 2012, <br />EARDC in 2014-2019, and will complement the Kissing Tree work so that Information about potential <br />sources might be determined if contaminants are detected. <br />1) Texas State University (EARDC) will resume quarterly baseline monitoring at three groundwater <br />wells (combination of COSM and USWS wells (Figure 1), to be determined in cooperation with COSM and <br />USFWS) and will collect samples for basic water quality and chemistry parameters, VOCs, herbicides and <br />pesticides and pharmaceutical and personal care products, The three wells will be chosen so that <br />sampling will occur both up- and down -gradient of the site and the associated construction, and the <br />three on-site wells that Kissing Tree has contracted with SWCA to sample. <br />2) Sampling and monitoring will occur 4 times during the contract period at approximately <br />quarterly intervals, and will consist of basic water quality and chemistry parameters, as well as VOCs <br />using Gore Sorbers: https://www.agisurveys.net/About Us,html <br />a. Herbicides and pesticides plus pharmaceutical and personal care products will also be analyzed <br />on water samples collected during one of the four "gaurteriy events, and from the same wells. <br />Sampling for this set will occur after a significant storm event. During this sampling event, a stormwater <br />sample from the Cottonwood Creek site will also be included. Cottonwood Creek represents a small <br />surface drainage from the Kissing Tree development, if there is not a significant rain event that occurs <br />during the year, the quarterly sampling will be carried out as the previous sample events. <br />The primary purpose of this monitoring program is to continue building on the background sampling <br />and monitoring performed by EARDC in 2012 (pre -development), and to monitor for potential changes <br />in water quality during construction and buildout of Paso Robles and the associated golf course. <br />Monitoring will occur under both normal flow conditions as well as during and immediately after large <br />storm events that can cause rapid recharge into the Edwards Aquifer. <br />Sampling methods will largely duplicate those previously used by McCalla (Laura McCalla, MS Thesis, <br />Texas State University, 2012), including appropriate methods and handlingfor Gore Sorbers and <br />sampling for VOCs, Field and QA/QC methods will duplicatethose proposed to COSM by Brookfield/ <br />Kissing Tree, with one exception: Gore Sorbers (Passive Diffusion Samplers (PDS)) will be left in the <br />groundwaterfor at least 48 hours (based on information from the manufacturer, 2 hours is not long <br />enough in groundwaters with potentially very low analyte concentrations). <br />All data and findings will be reported to COSM within one month after the end of this contract, or after <br />EARDC receives the last data from sample analyses, whichever is later, <br />