Res 2011-037 - Laserfiche WebLink

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3. Identify potential contamination as a result of the Paso Robles development and associated golf course in a timely manner and ultimately help promote further investigation for the prevention of future contamination. 4. Develop a systematic water quality monitoring program for the two San Marcos National Fish Hatchery and Technology Center wells that are located down gradient of the Paso Robles site. Methods Chemical parameters (Table 2) that will be assessed prior to and throughout construction include the determination of anion/cation concentrations, which will be analyzed with Ion Chromatography, total hardness, total alkalinity, and total dissolved solids. Total coliform bacteria will also be assessed for each groundwater sample. This analysis can determine the presence of bacteria that may be found in soil, water that has been influenced by surface water, and in human or animal waste. These analytical procedures will be performed by the Edwards Aquifer Research and Data Center located at Texas State University. Water levels of structurally accommodating wells will be determined with an electric water level measurer prior to pumping of the wells. Water temperature, pH, dissolved oxygen, and specific conductance will also be measured at each site with a Hydrolab during each sampling event. Wells will be purged approximately 15 minutes to ensure a representative groundwater sample is obtained. An appropriate container will be used to acquire the water sample for Hydrolab readings, which will be taken once values become relatively stable. Table 3 lists these in -field parameters and the units of measurement to be used. Additionally, the two down gradient San Marcos National Fish Hatchery and Technology Center wells will be equipped with conductivity probes and data loggers, which will be secured to specialized airtight flow - through chambers attached to faucets at the well heads for continued monitoring. In addition, two wells owned by the City of San Marcos, one well down gradient and another within the development site, will also be equipped with the airtight flow - through chambers. The flow - through chambers at these wells, along with the two chambers installed at the National Fish Hatchery wells, will each contain a Gore survey module. As water is pumped from the well, some will be diverted into the chamber, allowing for a continuous air -tight flow of representative groundwater. In regards to the City wells, the chambers are positioned so as to receive water pumped directly from the well prior to the chlorination process. Figure 7 depicts the specially constructed chamber and explanation of each component. Each Gore survey module (approximately 0.25 inches in diameter and 13 inches in length) consists of a semi - permeable membrane surrounding a series of sorbent packets. The hydrophobic tendency of the bags will allow contaminants to pass through the membrane and bind with the inner packets. The modules will be returned to the manufacturer's laboratory for analysis (ITRC, 2005). These bags will aid in additional testing at these four sites for volatile and semi - volatile organic compounds, as well as polycyclic aromatic hydrocarbons that may be associated with the construction process and production of new roads. Table 6 lists compounds targeted in the laboratory analysis of the Gore survey modules. Precipitation will also be documented throughout the study period. Storm rainfall often results in a rapid rise of the water table in a karst aquifer and can not only dramatically affect the movement of water entering the aquifer, but also the discharge of karst springs in a relatively short amount of time. 7-