Res 2016-012/interlocal agreement with Texas State University (Edwards Aquifer Research and Data Center) providing for groundwater quality monitoring services in the vicinity of the Paso Robles Development site for an amount not to exceed $34,999.98

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Attachment A Scope of Services: Kissing Tree groundwater monitoring project for City of San Marcos Introduction /justification: With the proposed work by Brookfield /Kissing Tree to monitor water quality at three on -site wells, important information will be collected about ground- and surface -water on -site. However, there is still a lack of information about potential contaminants of interest in adjacent up- and down - gradient groundwaters, which would provide information that could be used to determine possible sources of any contaminants. The work proposed here will build on prior work by McCalla in 2012, and will complement the Kissing Tree work so that information about potential sources might be determined if contaminants are detected. 1) Texas State University ( EARDC) will resume baseline monitoring at three groundwater wells (combination of COSM and USWS wells (Figure 1), to be determined in cooperation with COSM and USFWS) and will collect samples for basic water quality, VOCs, and herbicides and pesticides. The three wells will be chosen so that sampling will occur both up- and down - gradient of the site and the associated construction, and the three on -site wells that Kissing Tree has contracted with SWCA to sample. 2) Routine /baseline monitoring will occur 4 times during the contract period at approximately quarterly intervals, and will consist of basic water quality and chemistry parameters, as well as VOCs using Gore Sorbers: https: / /www.agisurveys.net /About Us.html a. Herbicides and pesticides will be analyzed in one set of three routine /baseline samples from the same wells. 3) Post -storm sampling will occur after one large storm. Basic water quality and chemistry and VOCs will be measured at all three wells, as well as in surface water discharging from Paso Robles via a small surface drainage. a. Herbicides and pesticides will be analyzed in one set of stormwater samples at the three wells, and in a sequence of six samples collected across a storm hydrograph at the surface water sampling site. The primary purpose of this monitoring program is to continue and build on the background sampling and monitoring performed by EARDC in 2012 (pre - development), and to monitor for potential changes in water quality during construction and buildout of Paso Robles and the associated golf course. Monitoring will occur under both normal flow conditions as well as during and immediately after large storm events that can cause rapid recharge into the Edwards Aquifer. Sampling methods will largely duplicate those previously used by McCalla (Laura McCalla, MS Thesis, Texas State University, 2012), including appropriate methods and handling for Gore Sorbers and sampling for VOCs. Field and QA /QC methods will duplicate those proposed to COSM by Brookfield /Kissing Tree, and which will be used by their contractor SWCA to perform monitoring work (see Brookfield /Kissing Tree document), with one exception: Gore Sorbers (Passive Diffusion Samplers (PDS)) will be left in the groundwater for at least 48 hours (based on information from the manufacturer, 2 hours is not long enough in groundwaters with potentially very low analyte concentrations).