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general northeastern flow of the Edwards Aquifer (Murray, Straud, Hammond, 2007; Schindel et al.,
<br />2009; Smith, Hunt, Schindel, 2005). Methods to assess water quality will include Ion Chromatography
<br />to determine the presence and concentrations of cations and anions, Gas Chromatography Mass
<br />Spectrometry (GC -MS) and Liquid Chromatography Mass Spectrometry (LC -MS) to assess the
<br />presence of compounds from the City's effluent as well as chosen pesticides and herbicides, and the
<br />use of semi -permeable Gore survey modules within airtight flow -through chambers to detect the
<br />presence of volatile organic carbons, semi -volatile organic carbons and polycyclic aromatic
<br />hydrocarbons that may be byproducts of the construction process. Analysis of total alkalinity, total
<br />dissolved solids, total hardness, and total colifonm bacteria will also be performed. Field parameters
<br />such as pH, dissolved oxygen, water temperature, and specific conductance will be obtained for the
<br />wells upon each collection event. Water level of structurally accommodating wells will be assessed
<br />with an electronic water level meter. Measurements will be taken prior to well pumping at the time of
<br />sampling.
<br />In addition, an ISCO-6712 Portable Storm water sampler will be deployed at the base of an observed
<br />drainage, known as Cottonwood Creek, that runs through the Paso Robles development site toward
<br />Hunter Road (Figure 6). Each surface runoff sample collected will be analyzed for total suspended
<br />solids, nitrate, calcium, magnesium, sodium, potassium, sulfate, chloride, dissolved organic carbon,
<br />alkalinity, and conductivity (Table 7). In addition, a rough estimate of flow will be determined with
<br />the use of a flow meter and the construction of a weir. This data will aid in the evaluation of surface
<br />runoff which may enter the aquifer as Paso Robles and the associated golf course are being
<br />constructed.
<br />Baseline water quality data, acquired prior to development, will be compared to that collected during
<br />development of Paso Robles as a means of tracking water quality. Ultimately, this thesis project will
<br />enhance the likelihood of timely identification of potential contamination and promote further
<br />investigation of the effects of anthropogenic surface activity on subsurface aquatic environments such
<br />as the Edwards Aquifer. The project may also aid in expediting corrective management practices for
<br />Paso Robles and its associated golf course if needed, and help protect crucial environmental aspects of
<br />the aquifer and its sources of recharge from future contamination.
<br />Statement of Need
<br />There are over 40 specialized surface and subsurface aquatic species associated with the Edwards
<br />Aquifer and connected streams. Of these, seven are listed as endangered (Longley, 1986). They
<br />include the fountain darter (Etheostoma fonticola), Texas blind salamander (Eurycea rathbuni), Comal
<br />Springs riffle beetle (Heterelmis comalensis), Comal Springs dryopid beetle (Stygoparnus comalensis),
<br />Peck's Cave amphipod (Stygobromus pecki), and Texas wild rice (Zizania texana). The San Marcos
<br />salamander (Eurycea nana) inhabits San Marcos Springs, which discharges from the Edwards Aquifer,
<br />and is listed as threatened under the US Fish and Wildlife Service's endangered and threatened species
<br />report (U.S. Fish and Wildlife Service, 2010).
<br />Groundwater from the Edwards Aquifer, which encompasses sections of Kinney, Uvalde, Zavala,
<br />Medina, Frio, Atascosa, Bexar, Comal, Guadalupe, and Hays counties (Figure 1); is heavily used for
<br />municipal, agricultural, and recreational purposes (Longley, Jordan, 1996; Schindel et al., 2009).
<br />Historically, the high -quality water of the Edwards Aquifer prompted the cities of New Braunfels,
<br />Uvalde, San Antonio, and San Marcos to be founded near the springs that discharge from the aquifer
<br />(Schindel et al., 2009). The two largest spring groups in the state of Texas, Comal and San Marcos
<br />Springs, are sustained by water discharged from the Edwards Aquifer. Additional springs that
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