o I! L: all. .4-.. .x . :34: flu! “Ht-La- . .i. )5‘ en. wit. .II: “Sr I :.. Mg2+ and K+ > NaI). However, the specific cations that form on a mineral’s exchange complex depend on the type and concentration of cations in solution. Cation exchange in a soil/water system can be influenced or controlled by several methods, including increasing solution pH or changing the composition or concentration of cations in solution. Equations showing the mechanisms involved in cation exchange are included in Table A-4 in Appendix A. 1.1.3 Chemical adsorption Similar to cation exchange, chemical adsorption refers to a bonding process between an ion and a mineral surface. However, unlike the electrostatic bonds for cation exchange, the chemical bonds that form during chemical adsorption may be nearly permanent. Chemical adsorption of heavy and trace metals to soils is one reason the aqueous concentration of metals is typically much lower than expected (Drever, 1997). As groundwater pH increases, trace metal adsorption generally impacts the only the concentration of metals in solutions, but not the major geochemical interactions between soil and water. Equations showing the mechanisms involved in chemical adsorption are included in Table A-5 in Appendix A. 1.2 Groundwater systems In aquifers, as in any soil/water system, the total buffering capacity includes both contributions from both the solid (minerals) and aqueous (groundwater) phases. Appelo (1994) showed that even in extremely sandy soils mineral equilibria and ion exchange play important roles in controlling changes to groundwater chemistry. Environmental factors like pH, solution chemistry, contact time, and temperature, to name a few, may also control both the magnitude and involvement of each geochemical process. Pratt (1961) and Griffioen (1993) both demonstrated that the CEC of soils is a function of the pH Of the system (i.e., CEC increases with increasing pH). Therefore the involvement of each of these processes (i.e., mineral equilibria, cation exchange, and chemical adsorption) on pH change must be evaluated for the site-specific conditions of a particular aquifer. 1.3 Schoolcraft Field Bioaugmentation Experiment For the past several years, researchers from Michigan State University (MSU), in cooperation with the Michigan Department of Environmental Quality (MDEQ), have been working to develop and implement an in situ process capable of removing dissolved carbon tetrachloride (CCl4) present in an aquifer in Schoolcraft, Michigan. In situ bioremediation using the bacterium, Pseudomonas stutzeri strain KC (PKC), was selected as the preferred remedial approach. PKC is a denitrifying bacterium capable of degrading CCl4 without producing harmful degradation-by-products like chloroform (Criddle et al., 1990; Tatara et al., 1993; Lewis et al., 1993; Dybas et al., 1995). Other microorganisms also have the ability to transform CCl4, but chloroform is typically produced under denitrifying conditions. The high nitrate concentrations present in the Schoolcraft Aquifer (see Chapter 3) create a situation that idea] for PKC, however iron-limiting conditions are required for rapid transformation of dissolved CCl4 (Criddle et al., 1990; Tatara et al., 1993). One way of creating iron-limiting conditions in groundwater is by increasing pH, through the addition of an alkali (base). As the groundwater pH increases, dissolved iron becomes less soluble and precipitates out of solution (see Section 1.1.1). The lower iron concentrations, which result from this mineral precipitation, allow PKC to compete for food and nutrients with other microorganisms in an aquifer. The geochemical changes that occur as groundwater pH increases may have significant impacts on both the composition and/or reactivity of aquifer solids and CCl4 transformation by PKC. 1.4 Experimental approach In order to evaluate the potential impact of each of the three geochemical processes (mineral equilibria, cation exchange, and chemical adsorption), the capacity and degree of involvement of each process must be quantified. A series of one-dimensional (l-D) column experiments were used to simulate the addition of base to a soil/water system. Water present in the pore spaces of the aquifer solids was displaced by alkaline water (solution with a positive ANC) that was injected into the columns. Just as with any other plug flow reactor, the displaced water had little chance to mix and react with the bulk of the displacing solution. However, reactions immediately began to occur between the alkaline water and solid phase in an effort to reach a new chemical equilibrium. Under these conditions, cations present in the alkaline water may leave solution and be stored on the soil exchange complex and/or precipitate as the solubility of minerals are exceeded (Ulrich and Sumner, 1991). The geochemical changes that occurred on the solids and in the groundwater were monitored and are presented in subsequent chapters and the appendices. This thesis evaluates that involvement of each of these processes on Schoolcraft solids and groundwater as the pH increased due to base addition. CHAPTER 2 SCHOOLCRAFT AQUIFER SOLIDS 2.0 Introduction Groundwater is continually seeking to equilibrate with the minerals that compose an aquifer. Depending upon the pH and geochemistry of the surrounding solution, these minerals may: . Precipitate or dissolve (mineral equilibria), . Act as ion exchangers (cation exchange), or . Act as adsorption sites for metals (chemical adsorption). The impact of each of these mechanisms during the pH—adjustment of groundwater was experimentally determined by comparing the properties of pH-adjusted solids with untreated solids that served as a control (see Chapter 6 and Appendices B and E). This section summarizes the geologic framework and baseline conditions of the solids that compose the Schoolcraft Aquifer. 2.1 Geologic framework The Schoolcraft Aquifer is unconfined and composed of unconsolidated, glacial deposits (USGS, 1990). The aquifer solids are primarily fine- to medium- grain sand with occasional silt and clay regions (SFBE, 1997). The top of the water table is about 15 feet below ground surface (bgs) and the average saturated thickness of the aquifer ranges from 70 to 90 feet (Mayotte, et. al., 1996). The aquifer porosity is approximately 25 % and the hydraulic conductivity in the aquifer is approximately 10'1 to 10'2 centimeters per second (cm/s), yielding a groundwater flow velocity of about 15 centimeters per day (cm/day) (Mayotte, et. al., 1996). 2.2 Aquifer mineralogy In order to identify the major minerals that compose the aquifer, one sample of Schoolcraft aquifer solids collected from soil boring, SB-8, at a depth of about 71 feet. SB-8 is located several hundred feet upgradient from the region of the aquifer targeted for biotreatment using PKC. The locations of SB-8, well MW34A (discussed in subsequent sections), and the PKC biotreatment zone in relation to the CCl4 plume in Schoolcraft, Michigan are shown on Figure 2-1. West W Ave. BIOTREATMENT ZONE 00 83-8 MW34 . o 13 South 14th St. 6 5 Q ~. 41*. o 6’ 0: 5:0 q: S 0 o 853 . . D7 : .. DJ : .. _,..«-"“-.- ...... Rai'road DI NOT TO SCALE LEGEND a . . M25 Monitoring well 0 . D13 Delivery well Figure 2-1. Sampling locations in the Schoolcraft (Michigan) Aquifer 10 The mineral grains were mounted on a slide, polished, and then examined under a petrographic microscope for light refraction, color, shape, cleavage, and crystalline form (SSSA, 1986). These observations enabled identification of the specific minerals that compose the individual grains. The grains were grouped into the following three classifications: . Silicates (including quartz, feldspar, schist, and rock fragments), . Calcite, and . Dolomite. Although, some of the grains contained more that one mineral, each grain was classified according to which mineral was most abundant. Results from the petrographic observations are included in Table 2-1. Table 2-1. Mineral composition of Schoolcraft aquifer solids (Sibley, 1997) Mineral Percent (°/o) Silicates 90 i 4 Calcite 6 i 3 Dolomite 4 i 3 As shown in Table 2-1, roughly 90% of the sample of aquifer solids fiom SB-8 are silicates and the remaining 10% are the carbonate minerals, calcite (CaCO3) and dolomite (CaMg(CO3)2). While this one evaluation of aquifer solids does not even begin to describe the complete mineral composition of the aquifer it does provide general information on the type of minerals present in the aquifer. This information is useful when trying to predict which chemical processes may occur between the groundwater and aquifer solids as pH changes. 11 Silicates are relatively geochemically stable minerals in most pH regimes, while carbonate minerals typically serve as the primary pH buffer in near neutral pH systems (Ulrich and Sumner, 1991), like the Schoolcraft Aquifer. As discussed in Section 1.1.2, silica minerals may serve as a primary matrix for cation exchange. As will be illustrated in Chapters 4 and 5, calcite precipitation had a significant impact on pH response as base was added to the groundwater. 2.3 Grain texture Samples of approximately 275 feet of aquifer solids (2-inch-diameter) were collected during the installation of 15 groundwater delivery wells in July 1997 using a Waterloo cohesionless soil sampler. These 15 wells (labeled D1 through D15, see Figure 2-1) were constructed to deliver base, nutrients, and PKC across a 50 foot section of the aquifer. This region referred to, as the biotreatment zone (see Figure 2-1) is the primary focus of the field-scale bioremediation activities discussed in Section 1.3. Core from six of the delivery wells (D2, D4, D6, D8, D10, and D14) were logged, photographed, and divided into homogeneous segments based upon the following visually observed differences in particle size or texture: . Silty sand, . Fine sand, . Medium sand, . Coarse sand, and . Very coarse sand. 12 It should be noted that these classifications were based upon visual Observations only and may not necessary be similar to formal classification methods that utilize sieves to determine particle texture (SSSA, 1986). A total of 79 core segments were examined and classified as shown in Table 2-2. Table 2-2. Solids texture in 79 samples of Schoolcraft aquifer solids Grain No. of Percent of Texture Samples Total Silty sand 1 1.3 Fine sand 23 29.1 Medium sand 37 46.8 Coarse sand 17 21.5 Very coarse sand 1 1.3 Total 79 100 As shown in Table 2-2, fine-, medium-, and coarse-grained sands account for over 97 % of the total number of samples collected, since there was only one sample each of silty-sand and very-coarse-grained sand. These findings are similar to the historical description Of aquifer minerals discussed in Section 2.1. Since the silty- sand and very-coarse- grained sand comprise less than 3 % of the total number of core samples, only the fine-, medium-, and coarse-grained sands will be discussed in subsequent sections. The relative position below ground surface of each of the core samples is shown on Figure 2-2. 13 l 2 3 4 5 6 7 8 9 10 ll 12 13 14 15 30 “L L :1 a la .3 - - 401TTBTT T TAT “—‘A—T—TT T —ATT * T “a 6? 1 A A 3’ j E A a A 0 50-?“ 7- .v I--- .-..__ - - ______ #_* __ I ..____ '1?) . A 2 I A A . . Silty sand A o E '8 . o A A gFine sand 3 60 4 9 ‘ E‘o 14”““1 "" 73' A“ A "' *2" “Medium sand .5 A A 3 A A A ; .Coarse sand n 1 E 70 73—, M”. We . — --_f_______—,____________ lgVerycoarse sand. ‘5. * : o A 9 ° l 8 o o , 9 o 80 ;__ A °___u _ a -1 . o 6 g: 0 90 i o Figure 2-2. Observed particle size distribution in Schoolcraft aquifer cores As shown in Figure 2-2, there are three observable layers of material in the aquifer near the 15 delivery wells. The aquifer is primarily fine-grained sand fiom 30 feet to 40 feet bgs, medium-grained sand from 40 feet to 70 feet bgs, and coarse- grained sand from 70 feet to 90 feet bgs. Solids samples were not collected in the clay layer that serves as a no-flow boundary at an average depth of 90 feet bgs. Figure 2-2 also shows that the sand layers are not entirely homogeneous, as indicated by the intermingling of other sand textures in the layers discussed above. Each homogeneous core segment was also subdivided into smaller samples for characterization in terms of porosity, hydraulic conductivity, surface area, CCl4 concentration, microbial characterization, and potential for geochemical 14 interaction. This thesis includes data only on the potential for geochemical interaction of the aquifer solids, and not the other parameters discussed above. The potential for geochemical interaction was defined in terms of: . Solids pH, . Base exchange capacity (BBC), and . Chemical surface adsorption capacity (SAC). 2.4 Solids pH The pH of Schoolcraft aquifer solids was measured using an Orion® SA 720 pH meter calibrated using two standard pH buffers (pH 7.00 d: 0.01 and pH 10.00 i 0.01). The pH of aquifer solids was measured using two methods described in ASTM Standard D 4972-95a (ASTM, 1996). The methods were followed as outlined in the standard, except that in an effort to conserve the amount of solids for other experiments, only 5 grams (g) of solids and 5 milliliters (mL) of water were used instead Of 10 g of solids and 10 mL of water. The first method used to measure solids pH involved measuring the pH in a soil/water slurry made using one part aquifer solids to one part distilled deionized water (DDW). The second method measuring the pH in a 0.01 molar (M) calcium chloride (CaClz) sluny made by adding one drop of l M CaClz to the DDW slurry already prepared. The average pH of the aquifer core samples is shown in Table 2-3. 15 Table 2-3. Average pH of Schoolcraft aquifer solids Grain No. of Solids pH Solids pH Texture Samples in DDW in 0.01 M CaClz Fine sand 23 9.2 :h 0.1 8.2 d: 0.1 Medium sand 36 9.4 i 0.1 8.3 i 0.1 Coarse sand 10 9.4 i 0.1 8.2 :l: 0.1 As shown in Table 2-3, there does not appear to be a statistical difference in the pH measured for the different grain textures of Schoolcraft aquifer solids. The similarity in pH values for the different grain textures of solids suggests that the initial ANC of the solids is similar. Table 2-3 also shows that the pH of solids measured in DDW (pH 9.1-9.5) was about one pH unit higher than the value measured in the 0.01 M CaClz slurry (pH 8.1-8.4). This difference in pH readings is due to the increased concentration of ions resulting from adding the CaClz solution. The presence of soluble salts in the DDW slurry may affect the pH readings. Adding CaClz to the slurry helps reduce the impact of these soluble salts by increasing the total salt concentration (N CR, 1988). Soil scientists typically agree thatsolids pH values measured in the CaClz solution are more representative of actual in situ pH values. 2.5 Base exchange capacity The concentrations of four exchangeable bases, Ca2+, Mg2+, Na+, and K“, present on the cation exchange complex of Schoolcraft aquifer solids were measured using a strontium chloride (SrClz) displacement method modified from 16 Appelo (1990). Sr2+ was selected over other displacing cations (N a+, KI, and NH4+) since is behaves similar to both Ca2+ and Mg”, the main exchangeable cations in most types of soils (Sullivan, 1977). A known mass of aquifer solids (approximately 3 g) was placed in a 15-mL plastic centrifuge tube with 10 mL of 0.25 M SrClz. The tube was shaken overnight on a shaker table to order to provide mixing between the solids and SrClz solution. The concentration of Sr2+ in the 0.25 M Ser solution is typically a 100 times the concentration of Ca2+ in the groundwater that was equilibrated with the aquifer solids. The high concentration of Sr2+ in solution displaces cations (Ca2+, Mg”, and KI) from the surface of the aquifer solids and forces them into solution (see Figure 1-1). The sample was then centrifuged at 2,100 revolutions per minute (rpm) for 5 minutes to separate the solids from the liquids. The supernatant was decanted and analyzed for Ca2+, Mgr", Na+, and K+ using inductively coupled plasma-atomic emission spectrometry (ICP-AES) (Method 3120 B, APHA, et. al., 1995). One drawback with using SrClz displacement to measure BBC is that the method does not correct for carbonate dissolution that may occur during displacement. The potential dissolution of calcium carbonate minerals during displacement may result in overestimating the amount of Ca2+ originally present on the surface exchange complex. In order to reduce the potential for carbonate dissolution, the pH of the SrClz solution was maintained at or above pH 8, the point where calcite typically remains a precipitate. l7 The concentration of cations in the supernatant and the mass of the solids extracted were then used to calculate the BEC of the core samples. The average BEC of the Schoolcraft core samples (grouped by grain texture) is included in Table 2-4. Table 24. Base exchange capacity of Schoolcraft aquifer solids Grain No. of Ca2+ Mg“ Na+ and K+ Total Texture Samples (meq/100 g) (meq/100 g) (meq/100 g) (mqu 100 g) Fine sand 23 3.3 :1: 1.8 0.29 i 0.08 < 0.02 3.6 :L- 1.9 Medium sand 37 3.5 i 1.1 0.25 :I: 0.05 < 0.02 3.8 at 1.1 Coarse sand 17 3.7 i 1.0 0.35 :I: 0.26 < 0.02 4.1 :1: 1.1 As shown in Table 2-4, Ca2+ occupies about one order-of-magnitude more cation exchange sites on the aquifer solids than MgZI. However, as will be illustrated in Chapters 4 and 5, both cations play important roles during groundwater pH adjustment. Table 2-4 shows the average total BEC ranges from 3.6 i 1.9 millieqivalents (meq) per 100 g to 4.1 i 1.1 meq/ 100 g indicating that there is little difference (approximately 12 %) in the BEC capacity measured for the three soil grain textures. The impact of Na+ and K+ on BBC in these core samples is considered to be negligible as indicated by the low concentrations of both cations (< 0.02 meq/ 100 g). 18 2.6 Chemical surface adsorption capacity The potential for chemical adsorption is partly a fimction of the activity of surface exchange sites on the aquifer solids. The amount of chemical adsorption sites on the aquifer solids was measured using a sodium fluoride (NaF) displacement method (McBride, 1994). The number of reactive OH' sites on the mineral surfaces is measured by monitoring the pH change in a concentrated NaF (approximately 1 M) solution after adding a known mass of soil. Fluoride (F') ions displace OH' from the mineral surfaces and free OH' ions cause the pH to increase. The number of OH' ions displaced, as measured by the resulting increase in pH, corresponds to the amount of sites available for cation adsorption. The average SAC of the Schoolcraft core samples is shown in Table 2-5. Table 2-5. Surface adsorption capacity of Schoolcraft aquifer solids Grain No. of SAC Texture Samples (meq/ 100g) Fine sand 13 9.4E-05 Medium sand 17 4.9E-05 Coarse sand 4 3.9E—05 As shown in Table 2-5, it appears that SAC decreases with increasing particle size (i.e., fine- to coarse-grained). Assuming that the concentration of surface exchange sites per unit area of a mineral is constant, the greater the surface area, the greater the number of surface exchange sites. Small particles like fine- grained sands have a larger surface per unit volume of material than coarse-grained sands l9 and therefore a greater SAC. The concentration Of surface exchange sites is about five order of magnitude less that the concentration of base exchange sites (see Table 2-4), suggesting that BBC is a more important process when it comes to geochemical changes in Schoolcraft aquifer solids. 20 CHAPTER 3 SCHOOLCRAFT GROUNDWATER CHEMISTRY 3.0 Introduction During the biotreatment phase of the Schoolcraft Field Bioaugmentation Project, NaOH was periodically injected into the aquifer in order to raise groundwater pH from about 7.2 to 8.2. The addition ofNaOH has significant impacts on the geochemistry of the aquifer due to increased pH and concentration of Na" in solution. The water chemistry of the Schoolcraft Aquifer or any aqueous solution must be understood in order to predict and explain geochemical changes that occur as pH changes. Chemical properties that were used to describe the composition of Schoolcraft groundwater include pH, alkalinity, and the concentration of major cations, 810;, major anions, and trace metals. The methods used to collect and quantify each of these properties in groundwater samples are outlined in the following sections. 3.1 Groundwater sampling During September 1997, 81 groundwater samples were collected from monitoring locations in the biotreatment area of the Schoolcraft Aquifer. Dedicated in-well sample tubing and peristaltic pumps were used to collect samples from a network of multi-level monitoring wells shown on Figure 3-1. 21 e 4 M4 M8 4 4 M3 M7 Direction of ¢ groundwater flow M31 > ¢ 1? M2 M6 4» 4» M1 M5 0 1 2 E APPROXIMATE SCALE (meters) O O D15 O O D14 O O D13 O O D12 O O D11 O O D10 BIOTREATMENT ZONE .¢. M11 4, M10 ¢ M9 ¢ M16 M30 4 e e 4 M13 M20 M24 M26 .¢. M15 4 e e 4» M12 M19 M23 M25 ¢. M29 ¢ M14 LEGEND ¢ . . M25 Monitoring well O O - D13 Delivery well Figure 3-1. Location of monitoring wells near the biotreatment zone 22 Sixty-seven (67) of the 81 groundwater samples collected were used to characterize the pretreatment or baseline chemistry of the aquifer. The data for the remaining 14 samples were rejected due to equipment malfunction or analytical results being outside acceptable limits (see Section 3.7). The average value of each chemical property (e. g. pH, alkalinity, cation concentration) for the baseline groundwater samples are presented in the following sections. 3.2 Groundwater pH The pH Of Schoolcraft groundwater samples was measured using an Orion® SA 720 pH meter. The pH meter was calibrated between two standardized pH buffers (pH 7.00 i 0.01 and pH 10.00 d: 0.01). The pH of each groundwater sample was measured immediately afier collection in the field, or samples were sealed in plastic bottles with zero headspace, stored in a cooler at 4 degrees Celsius (°C), and transported to the laboratory for analysis. Typically, all pH measurements were performed within 10 hours of sample collection. The pH of all samples was recorded to the nearest hundredth (0.01) after the readings had stabilized. The average pH of the 67 baseline groundwater samples was determined to be 7.32 i 0.03. 3.3 Alkalinity At the average groundwater pH of 7.32, HCO3' is the only major component of alkalinity (Snoeyink and Jenkins, 1980). Alkalinity was quantified 23 by measuring the equivalents of a standardized acid required to lower a specific volume of groundwater to pH 4.5 (Method 2320 B, APHA, et. al., 1995). The standardized acid was dispensed using a Fisher® digital burette with a display precision Of 0.01 mL. An Orion® SA 720 pH meter calibrated between two standard buffers (pH 4.00 3: 0.01 and pH 7.00 :I: 0.01) was used to measure the pH of the titrated sample. The average alkalinity of the 67 baseline samples is 417 i 26 milligrams per liter (mg/L) in terms of mass or 6.83 i 0.42 milliequivalents per liter (meq/L) in terms of charge. 3.4 Major cations Major cations are those that are present in relatively large concentrations or those that have significant impacts on the geochemistry of the system. The major cations in Schoolcraft groundwater include Ca2+, MgZI, Na+, and KI. The concentration of each cation and SiOz in groundwater were measured ICP-AES, as discussed in Section 2-5 (Method 3120 B, APHA, et. al., 1995). The average concentrations of Ca2+, Mg”, NaI, KI, and SiOz, in the baseline groundwater samples are shown in Table 3-1. 24 Table 3-1. Major cations and silica in Schoolcraft groundwater Chemical No. of Concentration Concentration Percent of Property Samples (mg/L) (meq/L) Positive Charge Ca2+ 67 99.4 :t 9.5 4.95 a 0.47 56.1 Mg2+ 67 31.7 :1: 3.0 2.60 :I: 0.24 29.4 Na+ 67 26.8 :t 8.9 1.16 :1: 0.38 13.1 K+ 67 4.2 :t 2.2 0.10 i 0.05 1.1 SiOz 67 13.6 :t 1.6 Not applicable Not applicable Total 8.83 :I: 0.83 99.7 As shown in Table 3-1, Ca2+ accounts for 56.1 % of the total positive charge in the baseline Schoolcraft groundwater samples. Mg”, Na+, and KT provide 29.4 %, 13.1 %, and 1.1 % of total cationic charge. SiOz is a neutral compound and does not contribute a charge (positive or negative) to groundwater. Table 3-1 also shows that the sum of the positive charge resulting from major cations is 99.7 %. The sum of positive charges does not add up to 100 % due to rounding errors and neglecting standard deviations when calculating the percent of total positive charge. 3.5 Major anions The major anions in Schoolcraft groundwater are bicarbonate (HCO3'), chloride (Cl’), nitrate (N 03'), and sulfate (8042'). The concentrations of all anions, except HCO3', were measured using ion chromatography (IC) as described in Standard Method: 4110 B (APHA, et. al., 1995). As discussed in Section 3.2, the 25 concentration of HCO3‘ was determined by measuring the alkalinity of the groundwater samples. The average concentrations of major anions (including HCO3'), in the baseline groundwater samples are shown in Table 3-2. Table 3-2. Major anion concentrations in Schoolcraft groundwater Major N o. of Concentration Concentration Percent of Anion Samples (mg/L) (meq/L) Negative Charge HCO3' 67 417 i 26 6.83 i 0.42 68.9 C1' 67 55.6 :t 15.1 1.56 :4: 0.42 15.7 N03' 67 54.1 :t 13.8 0.87 d: 0.22 8.8 so} 67 30.8 :I: 8.3 0.64 i 0.17 6.5 Total 9.92 :I: 0.69 99.9 As shown in Table 3-2, HCO3' accounts for 68.9 % of the total negative charge in the baseline Schoolcraft groundwater samples. Cl', NO3', and 8042’ provide 15.7 %, 8.8 %, and 6.5 % of total cationic charge. Table 3-2 also shows that the total negative charge resulting from major anions is 99.9 %. The sum of negative charges does not add up to 100 % due to rounding errors and neglecting standard deviations when calculating the percent of total negative charge. 3.6 Trace metals The average concentrations of nine trace metals, aluminum (Al), barium (Ba), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), strontium (Sr), and zinc (Zn), were also quantified using ICP-AES, as discussed in Section 26 2-5 (Method 3120 B, APHA, et. al., 1995). The average concentrations of the trace metals analyzed in the 67 baseline groundwater samples are shown in Table 3-3. Table 3-3. Trace metals concentrations in Schoolcraft groundwater Trace Samples Samples Concentration Concentration Metal Analyzed Above MDL (mg/L) (meq/L) Al 67 62 0.16 i 0.06 < 0.01 Ba 67 66 0.05 i 0.01 < 0.01 Cu 67 0 < 0.03 < 0.01 Fe 67 6 0.19i0.14 <0.01 Ni 67 13 0.03 i 0.01 < 0.01 Mn 67 14 0.07 :t 0.12 < 0.01 Pb 67 37 0.05 d: 0.03 < 0.01 Sr 67 67 0.12 i 0.02 < 0.01 Zn 67 45 0.04 :1: 0.01 < 0.01 Total < 0.10 The third column in Table 3-3 shows how many of the 67 baseline samples had concentrations above the method detection limit (MDL). Cu was the only trace metal analyzed that did not have measurable concentrations in any of the baseline groundwater samples. The concentration of Cu was reported as less than the MDL (i.e., < 0.03 mg/L). Table 33 also shows the charge concentration for each of the trace metals that were analyzed. All of the nine trace metals had charge concentrations less than 0.01 meq/L. The positive charge from all trace metals analyzed is less than 0.1 meq/L. When compared to the total positive charge in the groundwater samples (8.83 meq/L, see Table 3-1) the charge contribution, from the trace metals analyzed, is approximately 1 %. 27 The presence of trace metals in high concentrations may affect the activity and viability of microorganisms like PKC (Tatara et al., 1993). High concentrations of Zn (0.83 mg/L) were observed in groundwater samples collected in May 1997 from well MW34A (see Figure 2-1) for a bench-scale experiment. It was later determined, by reviewing field records, that the groundwater samples were collected before the steel-cased well was sufficiently purged. PKC would not grow in any of these groundwater samples even though pH and food concentrations appeared ideal. A series Of serial dilutions was performed to determine if high concentrations of Zn inhibited grth of PKC. After inoculation in diluted groundwater samples, PKC grew normally. These experiments help verify that the high concentrations of Zn were toxic to PKC. It was hypothesized that the concentration of Zn in groundwater would decrease due to surface adsorption of the metals by the aquifer solids (see Figure 1-1 and Section 2.6) and enable PKC to grow in the groundwater. Approximately 1 g of Schoolcraft aquifer solids was placed in three SO-mL Erlenmeyer flasks with 10 mL of groundwater. The flasks containing the soil/water slurry and a control flask containing only 10 mL of groundwater were then placed on a shaker table operating at approximately 90 rpm, for three days. The slurry was centrifuged at 4,800 rpm for 30 minutes and the decanted supernatant was analyzed for trace metals using ICP-AES. The concentrations of Zn in the samples are shown in Table 3-4. 28 Table 3-4. Concentrations of Zn in groundwater exposed to aquifer solids Sample Before Exposure After Exposure Percent No. (mg/L) (mg/L) Decrease 1 0.80 < 0.01 > 98.8 2 0.93 0.03 96.8 3 0.88 0.03 96.6 Average 0.87 i 0.07 0.02 i 0.01 97.4 As shown in Table 3-4, the concentration of Zn decrease by an average 97.4% when the groundwater was exposed to Schoolcraft aquifer solids. The average concentration of Zn after exposure to aquifer solids (0.02 :I: 0.01 mg/L) is about 50% less than the average concentration in the baseline samples (0.04 i 0.01 mg/L, see Table 3-3). This decrease in the Zn concentration was due to adsorption of the trace metals on the surface sites of the aquifer solids (see Section 2-6). PKC inoculated into the groundwater exposed to aquifer solids grew normally without any further trace metal toxicity problems. 3.7 Charge balance An aqueous solution must be electrically neutral in order for the system to be in equilibrium. As shown in Tables 3-1, 3-2, and 3-3, the concentration of each chemical constituent (cations, anions, and trace metals) was expressed in terms of both mass (mg/L) and charge (meq/L). Electroneutrality requires that the sum of the positive (cation) charges equal the sum of the negative (anion) charges. Analyses of the baseline groundwater samples that produced a cation-anion charge difference greater than 20 % were rejected and not included when characterizing 29 the groundwater chemistry. The average charge concentrations for major cations, anions, and trace metals in the baseline Schoolcraft groundwater samples are included in Table 3-5. Table 3-5. Average concentration in Schoolcraft groundwater samples Chemical Cation Concentration Anion Concentration Property (meq/L) (meq/L) Major Cations 8.83 d: 0.83 N/A Anions N/A 9.92 i 0.69 Trace Metals < 0.10 N/A Total 8.83 :t 0.83 9.92 :t 0.69 As shown in Table 3-5, the total cation concentration in 8.83 meq/L and the average total anion concentration is 9.92 meq/L. The ration of cation concentration to anion concentration is 8.83/9.92 or approximately 89 %, resulting in a charge difference of approximately 11 %. This 11 % cation-anion charge difference is within the 20 % acceptance criteria discussed earlier. One reason for the 11 % difference in charge concentration is due to the fact that all these values are averages concentrations from 67 samples. Therefore the 11 % charge difference does not reflect values for all baseline samples. A cation-anion charge difference of only 1.5 % resulted from an evaluation of the groundwater chemistry fi'om well MW34A (see Figure 2-1). This small error indicates that the analytical methods employed to quantify the concentration of 30 major cations and anions are adequate, and may be used describe some of major geochemical properties of Schoolcrafi groundwater. Another reason for the 11 % cation-anion charge difference is due to human error while performing alkalinity titrations (see Section 3.3). Due to the large concentration of alkalinity (6.83 meq/L, see Table 3-2), a strong acid was used to reduce the total volume of acid required for each titration. Even though the automatic burette is capable of delivering standardized acid to an accuracy of 0.01 mL, the operator may still unintentionally dispense more acid than needed to reach the pH 4.5 endpoint. One extra drop of 0.1 normal (N) acid will titrate the sample beyond the pH 4.5 endpoint, and if unaccounted, will cause the alkalinity of the sample to be overestimated. 3.8 Hydrochemical facies Hydrochemical facies are classification schemes based on the dominant cation and/or anion in water (Wahrer, 1993). A cation or an anion is considered dominant when it comprises more than 50 % of the total charge concentration. If no one cation and/or anion compose more than 50 % of the charge, then no facies are considered dominant. As shown in Tables 3-1 and 3-2, Ca” and HCO3' account for at least 50 % of the charge from cations and anions in the groundwater samples, respectively. Therefore the baseline Schoolcraft groundwater samples may be classified as calcium-bicarbonate. 31 3.9 Piper diagrams One method of visually determining the facies classification of a water is by using a Piper diagram. Ion concentrations for a water sample are plotted on cation (Ca2+, MgZI, Na+ and KI) and anion (HCO3' and CO32’, Cl', SO42") triangles and a central diamond-shaped diagram. The plotting locations on the diagram automatically determine whether any cation or anion is dominant. Two waters that have different total ion concentrations will be plotted on the same location on the diagram if the relative concentrations between the ions are similar. This allows quick comparison of water chemistry when two or more waters have very different ionic strengths. One drawback of using conventional Piper diagrams for Schoolcraft groundwater is that NO; is not included in the diagram. This omission is usually not a problem since most natural waters have small NO3' concentrations when compared to other anions like HCO3°, Cl‘, and 8042'. However, if a water like the Schoolcraft Aquifer has a significant NO3' concentration (see Table 3-2), the anion facies derived from using a Piper diagram will be inaccurate. One solution to this problem is creating a modified Piper diagram that plots the concentration of N03' with another anion (whichever has the smallest concentration). As shown in Table 3-2, HCO3' and Cl' have the highest percent of total anionic charge, 68.9 % and 15.7 %, respectively. Table 3-2 also shows that NO3’ accounts for 8.8 % of the total anionic charge while 8042' accounts for only 6.5 % of the total average anionic charge in the Schoolcraft baseline samples. In order to 32 include NO; on a Piper diagram, all groundwater samples will be displayed on modified diagrams that combine nitrate with sulfate (N03 + 804) since 8042‘ is present in the smallest concentration. Figure 3-2 is a modified Piper diagram for the baseline Schoolcraft groundwater samples. . 99 9999 a 998? ’9’9‘9 9‘9‘9’9’9’9’9’ . ,9,9,9,9,9,9 .9... 9,999 A2; O [WAVAVAVAVAVA ', AVAVAVAVAVAVA It, ,AVAv-‘IAVAVAVAVA. JAVAVAVAVAVAVA. AVAVAVAVAVAVAVAVA 0" AV... 'IVAVAVAVAVAVA V vvvvvvvvv c. .0 oo '__.40 20 Na+K H003+C03 20 40 _,oo so 0. Calcium (Ca) Chloride (CI) CATIONS *M’L ANIONS Figure 3-2. Modified Piper diagram of baseline groundwater samples Figure 3-2 shows by the plotting position of baseline samples that groundwater from the Schoolcraft Aquifer may be classified as calcium-bicarbonate. The composition of groundwater in the biotreatment zone will change as NaOH is injected into the subsurface to raise groundwater pH. The expected changes include increased NaI concentrations from the NaOH and decreased Ca2+ 33 and HCO3', concentrations due to the expected precipitation of calcium carbonate minerals. It is expected that the groundwater will change from calcium- bicarbonate dominated to sodium-bicarbonate dominated. The geochemical changes that occur as groundwater in the biotreatment zone are discussed in Chapter 4. 34 CHAPTER 4 EF F LUENT CHEMISTRY OF l-D COLUMNS 4.0 Introduction As mentioned earlier, significant geochemical changes occur in the treatment zone as the pH Of the groundwater is increased. A series of bench scale experiments was performed on Schoolcraft aquifer solids. Glass columns packed with Schoolcraft aquifer solids were flushed with groundwater that had been adjusted to pH 8.2. The ion concentration and pH of each column’s effluent were monitored in order to determine the geochemical changes that occur as the solids were titrated. The flow through the columns represents a one-dimensional (l-D) titration of the solids that was used to represent and understand how the aquifer solids react during base addition. 4.1 Materials and methods The following two sizes of Kontes® glass HPLC columns were to perform the solids titration experiments: . Diameter: 1.5 centimeters (cm), Length: 15 cm, Volume: 24 mL, and . Diameter: 1.5 cm, Length: 30 cm, Volume: 53 mL. All columns were wet packed using aquifer solids collected from the biotreatment zone during the installation of the injection/extraction wells (see Figure 2-1). The sides of the columns were tapped periodically during filling to 35 enhance packing. Schoolcraft groundwater was then pumped through each column using a syringe pump until at least three pore volumes (as defined by a conservative tracer) of water had been exchanged or moved through the column. Schoolcraft groundwater, adjusted to pH 8.2 using 1 M NaOH, was then pumped through each column and the effluent collected in 12-24 mL aliquots. Each aliquot was monitored for pH, alkalinity, major cations, major anions, and SiOz, using the analytical methods discussed in Chapters 2 and 3. The results of only one l-D column experiment are discussed in this chapter. The impact on pH and ion concentrations in other columns is included in Appendix D. The relative response in terms of pH change and, chemical makeup of the effluent was similar is all columns (see Appendix D). 4.2 Effluent pH The pH of each effluent aliquot was measured immediately after collection in order to determine the number of pore exchanges required for pH breakthrough, or when effluent pH equals 95 % of the difference between the influent pH and original pH. Figure 4-1 shows the shape of a typical pH breakthrough curve for an experimental column packed with Schoolcraft aquifer solids. 36 ooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo 8.2 . pH 8.36 breakthrough (1 1-12 PVE) 8.0 ; 7.8 -. pH (units) 7.6 7.4 . 0123456789101112131415 Pore volumes exchanged (PVE) Figure 4-1. Typical pH breakthrough curve for an experimental column Figure 4-1 illustrates that breakthrough at pH 8.36 occurred after about 11-12 pore exchanges. 4.3 Cation concentration in column effluent The concentrations of major cations in the effluent of all l-D columns were affected by pH as shown in Figure 4.2. 37 . pH breakthrough Concentration (meq/L) N w A J z/ ”3.. + Z >I 9+\‘ 0 x mIx) l + f a—vm + — + i \l \l 00 00 O\ 00 O N pH (units) ." A ." N O "_‘r""T‘ T' “"“ " '—“"'— ' “' "" ' ' ""‘_*" "‘ ' " "f r I I . l T r -'j 0123456789101112131415 Pore volumes exchanged (PVE) Figure 4-2. Major cations in effluent of a typical l-D column Figure 4-2 shows that the concentration of Na+ increased with increasing pH. This increase in Na+ concentration from 1.3 meq/L to 4.0 meq/L is due to the NaOH that was used to raise pH of the influent solution. Figure 4-2 shows that the concentration of Ca2+ decreased from 4.5 meq/L to 1 meq/L with increasing pH. The concentration of Mg2+ also decreased fi'om 2.9 meq/L to 1.3 meq/L in the column effluent for about two pore exchanges before returning to its background concentration after about nine pore exchanges. There was less than 5 % change in the concentration of K+ in the effluent during pH adjustment. 38 4.4 Anion concentration in column effluent The anion concentration in the effluent of a typical l-D column is shown in Figure 4-3. 12 -- 8.6 pH breakthrough _ 10 \ .. 8.4 .................................................................................. 8.2 S Er 8 I a l E ; 3.0 :5 .§ 6 - 5 g . 7.8 :1: 5 a. 8 4 * 8 . 7.6 cr _‘ 2 M f ‘ fi‘ ‘* 7'4 . - so 2' O .. ..-_ _ :_ . . _ --_- 2 . “I; 2...._. .._I“ L 7.2 0123456789101112131415 Pore volumes exchanged (PVE) Figure 4-3. Major anions in effluent of a typical l-D column As shown in Figure 4-3, there were no significant changes in the concentrations of Cl', N03” or 3042’ as pH increased in column effluent. However, as pH increased, effluent alkalinity (HCO3') decreased below background concentrations. This decrease in HCO3' concentration is most likely due to the formation of carbonate minerals (see Chapter 5). 39 4.5 Piper diagram The concentrations of ions in the 1-D column effluent were plotted using a modified Piper diagram (see Section 3.9). One advantage of using Piper diagrams, is that when two waters having very different chemistries are mixed in any proportion, the concentrations of the ions in the mixture will plot on a straight line between the two waters. The chemical composition of each effluent sample for Column B4 was plotted on a Piper diagram as shown in Figure 4-4. 9 9 . 99999999 . 9392939393939393939 A I .... ....... ”~50. “1 9992499 99 . N N/ .9: ‘ ‘ . WNW? : “ /A A\ AAA . AVAVAVAVAV» ,AVAVAVAVAV . , A. .9; AVAVAVAVAVA. ., AVAVAVAVAVAVA A . a AVAVAVAVAVAVA a .AVAVAVAVAVAVAVA. a: AVAVAVAVAVAVAVA. *1 9’ MAVAVAVAVA vvvvvvvvv C. fl GOV—40 20 N.+K HCO3+CO3 20 40—-—r so so C| Column (Ce) Chloride (Cl) CATIONS *M’L ANIONS Figure 44. Modified Piper diagram showing l-D column effluent The points on the figure represent the effluent water chemistry from a ID column as the pH increases. Point A represents background water chemistry (see Figure 40 3-2) and point E represents pH-adjusted conditions. Figure 4-4 shows that fi'om points A to C, the concentrations of Ca2+ and Mg2+ are both decreasing. These changes correspond to Region 1, where carbonate precipitation is occurring. From Points C to E, the concentration of Ca2+ is still decreasing, but the concentration of Mg2+ is increasing. Points C to E show the geochemical changes in Region 2 due to cation exchanged. The data from Figure 4-4, also shows that the water moves from being calcium-bicarbonate dominated (A) to sodium-bicarbonate dominated (C, D, E). The dramatic change in shape of a series of lines drawn through Points A through E suggests that two separate processes are controlling geochemical response as the pH increases. Points A through C may represents one process and Points C through E represent another. The two geochemical processes that control the concentration of cations in the effluent are discussed in Chapter 5. 41 CHAPTER 5 GEOCHEMICAL MECHANISMS 5.0 Introduction The mechanisms that control geochemical changes that occur as base is added to thel-D columns (see Chapter 4) may predicted by evaluating the interaction between cations and anions and the surface of the aquifer solids. The precipitation of three carbonate minerals (aragonite, calcite, and dolomite) and cation exchange involving Ca2+ and Mg“, were evaluated. 5.1 Geochemical regions Upon examining the shapes of the cation effluent curves for the 1-D column (see Figure 4-2), three regions that exhibited similar geochemical features were identified. These regions are shown on Figure 5-1. 42 T Region: Region Region I 7 l ! 2 3 5 ...................................................... ’ ................. :7 8'4 ‘ : pH + ‘ pH breakthrough r g Na ..5 .. .— 8.2 3' T” é . 8.0 9* -§ Mg” . E ‘g : 4.7JIIE 5 : - Q o ; ._ 5 r 7 6 U , i * - Ca2+ 1 T ' $ $ ; a #1 fi; w 7.4 _ Kf l 0 "T? 3. -Ti . , ..°. _ -4. 2 3 T :-_:-. ?.i_._,__-__.___‘_. -__+ 7.2 0123456789101112131415 Pore volumes exchanged (PVE) Figure 5-1. Geochemical regions in 1-D column effluent As shown in Figure 5-1, the approximate ranges for the three regions are: . Region 1: 0 to 1.5 pore volumes; . Region 2: 1.5 to 11 pore volumes; and . Region 3: 11 to 13 pore volumes. 5.1.1 Region 1 Figure 5-1 shows that the concentration of Na+ reached its maximum effluent concentration of approximately 4 meq/L in Region 1. Na+ acted similar to a conservative tracer during the ID experiments. The mixing or dispersion front that occurs as fluids travel through porous media has left the column in Region 1, since Na+ has nearly reached its influent concentration. Since the dispersion front 43 had passed through the column at the end of Region 1, it is expected that any changes in water chemistry in Regions 2 and 3 are results of geochemical interactions and not dispersion. The concentrations of Ca2+ and Mg2+ decrease at approximately the same rate, which may suggest that, the geochemical processes affecting both of the cations may be related. 5.1.2 Region 2 Figure 5-1 shows that in Region 2, Na+ has reached its maximum concentration of 4 meq/L and the concentration of Ca2+ continues to decrease. Mg2+ reached a minimum concentration of 1.3 meq/L at approximately 1.5 pore volumes, but then began to increase again. The concentrations Ca2+ and Mg” throughout all of Region 2 are nearly mirror images of each other. 5.1.3 Region 3 Figure 5-1 shows that at approximately 11 pore volumes, pH breakthrough has finally occurred (see Chapter 4). The effluent pH and cation concentrations are approximately equal to influent conditions and the system is in a state of near equilibrium. 5.2 Carbonate formation Carbonate minerals are the principle buffering mechanism in most natural waters. When alkali is added to a carbonate water system, Ca2+, Mg": and HCO3' 44 may combine to form calcium- and magnesium carbonates. As the solubility limits of these carbonates are exceeded, they may form minerals that precipitate out of solution. The three commonly occurring carbonate minerals are: . Aragonite (C3CO3), . Calcite (CaCO3), and . Dolomite (CaMg(CO3)2). The potential for each carbonate minerals to form in the ID column is discussed in the following sections. 5.2.1 Aragonite and calcite Aragonite and calcite have the same molecular formula, CaCO3, and are formed through similar processes. The presence and formation of calcite and aragonite are partially controlled by groundwater pH and the ratio of the concentration of Mg2+ with respect to Ca2+ (MgZI/Ca2+ ratio). High aqueous concentrations of Mg2+ inhibit the formation of calcite, but not aragonite (Drever, 1997). Therefore, waters with high Mg2+ concentrations (e.g., seawater) typically form aragonite and not calcite. In freshwaters (e.g., Schoolcraft groundwater), where the MgZI/Ca2+ ratio is low, calcite is typically the most abundant carbonate mineral (see Table 2-1). In order to determine which mineral was most likely to form in Schoolcraft groundwater, Figure 5-2 was developed to show the Mg24'/Ca2+ ratio for the 1-D column effluent. 45 5 ............. ........................................................................... ........................ ".j. K pH breakthrough i 8.0 8.2 pH (units) 2. 7.8 Mg2+/Ca2+ ratio . 7.6 .. 7.4 o___w i . -____._.. ._, . . . 7.2 012 34 5 67 89101112131415 Pore volumes exchanged (PVE) Figure 5-2. MgZIICa2+ratio in 1-D column effluent As shown in Figure 5-2, the MgzI/Ca2+ ratio in Region 1 is approximately 0.6. The MgZI/Ca2+ ratio remains constant during this period even through the concentrations both Mg2+ and Ca2+ are decreasing. The ratio remains constant since the concentrations of both cations are decreasing at the same rate (see Figures 4-2 and 5-1). The low MgZI/Ca2+ ratio of 0.6 calculated in Region 1, Mg2+ does not inhibit calcite precipitation (Drever, 1997), therefore calcite is more likely to form in the 1-D column than aragonite. 46 5.2.2 Dolomite Dolomite is very unreactive at low temperatures (about 25 °C) and nearly impossible to form in the laboratory (Drever, 1997). Typically, dolomite forms only by the chemical alteration of an existing mineral like calcite or aragonite and not through direct precipitation. In addition, dolomite has much slower precipitation kinetics than calcite and aragonite and is therefore less likely to precipitate (Drever, 1997). Therefore, it is unlikely that the decrease in Ca2+, Mg”, and HCO3' concentrations in Region 1 were due to the precipitation of dolomite. 5.2.3 Calcite precipitation One way of determining if carbonate minerals are precipitating, is by examining the relative concentrations of Ca2+, Mg“, and HCO3' as solution pH increases. Figure 5-3 shows the concentration of Ca2+, Mg”, and HCO3' in the effluent of the 1-D column. 47 1 .11 ;10 Cation Concentration (meq/L) + W HCO3' Concentration (meq/L) 0 HAT—..rfie . —r"’——*' . .. . . . - ._-. . 7%.. r 7 T— . T" . 7‘ 0123456789101112131415 ._._7___ Hfififi.__ .._“ + _ .._ Pore volumes exchanged (PVE) Figure 5-3. Concentrations of Ca2+, Mg“, and HCO3' in l-D column effluent As shown on Figure 5-3, the concentrations of Ca2+ decreases at approximately the same rate as HCO3'. This stoichiometric decrease in the concentrations of Ca2+ and HCO3', suggests that calcite is the lone carbonate mineral that precipitates as the pH increases in Region 1. The sawtooth-shaped variations in HCO3' concentration during Regions 2 and 3 are most likely due to measurement inaccuracies and therefore may not reflect the occurrence of other chemical processes. Equations describing this process are included in Tables A-2 and A-3 in Appendix A. 48 5.3 Cation exchange The decrease in Mg2+ concentration observed in Region 1 cannot be described by the precipitation of carbonate minerals discussed in Section 5.2, therefore another geochemical process must be considered. Cation exchange can explain these changes in Mg2+ concentration in solution is due to cation exchange on the mineral surfaces. In Region 1, the concentration of Ca2+ decreases due to calcite precipitation (see Section 5.2). During Region 2, the increase in the MgZ‘L/Ca2+ ratio (see Figure 5-2) suggests that the cation exchange affinity for Mg2+ will increase, with respect to Ca2+. This increased exchange affinity enables Mg2+ ions to replace Ca2+ ions present on the exchange complex. Figure 5-3 shows that this process actually occurs. During Region 2, the effluent concentration of Mg2+ remains lower than the influent concentration as Mg2+ ions leave solution and replace Ca2+ on the exchange complex. The effluent concentration of Mg2+ remains lower than the influent concentration until all available sites have been occupied by Mg2+ and the solution reaches equilibrium (Region 3). The concentration of Ca2+ during Region 2 is higher than the influent concentrations due to displaced Ca2+ ions leaving the cation exchange complex and therefore increasing the concentration of Ca2+ in solution. The effluent concentration of Ca2+ is higher than influent concentrations until all available Ca2+ sites have been occupied by Mg2+ and the solution reaches equilibrium (Region 3). 49 A simple depiction of how the composition of the base-exchange complex changes during the 1-D bench scale is included on Figure 5-4. 1.2 . , , . 12 Region; Region 2 Region 7 1 : 2 f 3 :- l.0 7 . 10 6 ~ * E 1 0 “ .- 1 1- A *5 - 3 ! ..1 .§ 0-3“ 3 8 E" O ; 1 5 11.1 0.6 »~ . + 6 .5 E 1 g o : 5 ,8 0.4 -- . 4 8 E 8 IL 0 o O o 9 Q 0‘ JL 2 + 2 MgXZ i — —~ — — ~ —~— 0 0123456789101112131415 Pore volumes exchanged (PVE) Figure 5-4. Estimated composition of base-exchange complex The letter “X” in Figure 5-4 represents a cation exchange site on the mineral surface. Figure 5-4 illustrates that at zero pore volumes (Region 1), the base- exchange complex is composed of CaXZ and HX. As alkali is added to the system, calcite begins to precipitate thus lowering the concentration of Ca2+ and HCO3' in the water. The hydrogen ions (HI) associated with HCO3‘ and the base- exchange complex, begin to react with the OH' provided by the alkali (NaOH). The Mg2+ ions in water then have a greater affinity for the HX sites begin to 50 displace the H+ from the available sites on the solids. These displaced HI ion serve to buffer the water by neutralizing OH', and thus decrease the potential rate of pH adjustment. As shown on Figure 5—4, by the end of Region 1, Mg2+ has displaced HI from the available sites on the surface of the solids. As the concentration of Ca2+ decreased in Region 1, the relative affinity for maintaining the CaXz sites also decreased. This lower affinity for base-exchange sites enables Mg2+ to displace Ca2+ from the CaX2 sites on the aquifer solids. The shape of the lines in Table 5-3 illustrates this 1:1 stoichiometric replacement. As the concentration of Ca2+ decreased, the concentration of Mg2+ increased by the same magnitude. The influent concentrations of Ca2+ and Mg2+ are approximately 1 meq/L and 3 meq/L, respectively. The effluent concentration of Ca2+ is higher than the influent due to Ca2+ ions being displaced from the solids by Mg”. The effluent concentration of M g2+ is lower than the influent concentration due to the Mg2+ ions leaving solution and occupying newly available sites on the base- exchange complex. The concentrations of Ca2+ and Mg2+ approach influent concentrations when Mg2+ has occupied all of the available CaXz sites. The physical changes that occur on the aquifer solids as a result Of calcite precipitation and base cation exchange are discussed in Chapter 6. It should be noted that Figure 5-4 is a simple depiction and it provides only general information that illustrates what happens to the base-exchange complex during pH adjustment. It is not meant to provide accurate values for BBC since the locations and shapes of the regions were empirically determined by comparing 51 effluent water chemistry with influent water chemistry. Differences in Mg2+ concentrations between the two were assumed to be due to Mg2+ exchange on the aquifer solids. 52 CHAPTER 6 IMPACT OF pH ADJUSTMENT ON AQUIFER SOLIDS 6.0 Introduction The impact of pH adjustment on the aquifer solids was determined by comparing the properties of pH-adjusted samples (pH, base-exchange capacity and surface adsorption capacity) with a control and the characteristics of original core samples (Chapter 2). 6.1 Materials and methods Experimental columns (Kontes®, Diameter: 1.5 cm, Length: 15 cm, Volume: 24 mL) were wet packed with aquifer solids from each core sample. Where practical, these columns were the same columns used in the 1-D column experiments. For each core sample, one column acted as a control and received only Schoolcraft groundwater (pH 7.4 i 0.2), while the remaining column(s) received pH-adjusted groundwater (pH 8.3 :1: 0.2). Initially, each column was flushed with Schoolcraft groundwater using a Harvard® syringe pump operating at a flow rate of 90 mL/hour. Flushing continued until three pore-volumes Of water had been exchanged through each column or the effluent pH was constant. Two hundred microliters (1.1L) of tritium (3 H) labeled water was injected at the inlet of each pH-adjusted column and two more pore volumes of water were flushed through the column. Tritium activity in l-mL effluent aliquots was 53 measured in 10 mL of Safety-Solve® scintillation cocktail using a liquid scintillation counter. The porosity of each column was determined using the tritium concentration profile in the effluent samples. Porosity in the columns ranged from 35 % to 45 %, or pore volumes of 9 mL and 13 mL, respectively. The pH-adjusted columns were then flushed with groundwater adjusted to pH 8.3 i 0.2 using 1 M NaOH. The effluent was collected in 12-mL aliquots and immediately analyzed for pH. The composition and chemistry of these effluent samples is discussed in Chapter 4. The control columns were flushed with pH 7.4 groundwater until five additional pore water exchanges had occurred. NO significant changes occurred in the effluent pH or chemistry of any of the control columns, indicating that any geochemical change in the pH-adjusted columns was a function of base addition and the resulting increase. When the experiment was completed, the remaining water was forced out of the column using an air-filled syringe attached to the inlet of the column. The solids were then removed from the column, placed in an open plastic bag and allowed to air dry at room temperature for approximately one week. The impact of base addition (N aOH) on the aquifer solids was determined by comparing the properties opr-adjusted solids sample with solids from the control column and the measurements from the original core samples (see Chapter 2). 54 6.2 Solids pH The pH of the solids from the control and pH-adjusted columns was measured in order to determine solid pH changes that resulted from the column experiments and may be expected during field base addition. Selected solids pH values are included in Table 6-1. Table 6-1. Solid pH values of pH-adjusted columns Core Grain Cores Control pH-Adjusted Sample Texture pH (units) Solids pH Solids pH D6-3111 Fine sand 9.03 :1: 0.04 9.04 :1: 0.05 9.08 :t 0.04 D4-7810 Medium sand 9.17 i 0.05 9.08 i 0.02 9.29 i 0.02 D2-6608 Medium sand 9.17 i 0.05 9.21 i 0.04 9.40 :1: 0.02 As shown in Table 6-1, there was no significant difference in the pH values for the core sample and the control column. However, the pH Of the pH-adjusted medium sand is about 0.2 pH units higher than the control solids and thus statistically different from both the original core sample and control column. The higher pH of pH-adjusted solids suggests that composition and reactivity of solid surfaces was altered by pH adjustment and changes may be expected in total BBC and SAC. 6.3 Base exchangeable cations Base-exchange capacity in soils typically increases with increasing pH (Pratt, 1961). As neutral exchange sites are converted to negatively charged sites 55 due to the increase concentration of OH‘. These newly available negatively charges site become available for cation exchange and thus increase the total BEC of the solids. However, to simplify the evaluation of the results, the total BEC of the solids was assumed to be constant. Table 6-2 contains selected information on the magnitude and composition of the base-exchange complex for Schoolcraft core samples, control solids and pH-adjusted solids. Table 6-2. Base exchange composition of pH-adjusted solids Cores Control pH-Adjusted Cation (meq/100 g) (meq/100 g) (meq/100 g) Ca2+ 3.44 1.24 1.51 Mg2+ 0.24 0.15 0.22 Na+ Not measured Not measured Not measured K+ < 0.02 < 0.02 < 0.02 As Table 6-2 shows, the base exchange capacity of the aquifer cores for Ca2+ is over two times larger than the capacity for both the control and pH-adjusted solids. This difference in BBC is an artifact of column preparation as demonstrated by similar Ca2+ BBC for the control and pH-adjusted solids. When packing the columns (Chapter 4), the fine sand and clay particles tend to settle more slowly than larger particles. As a result, the larger grained solids tend to occupy most of the available space in the columns and smaller particles like clay minerals are excluded fi'om the column. Clay-sized minerals typically have a higher surface 56 area per unit volume than sand-sized minerals. In addition, clay minerals may also participate in isomorphous substitution of ions in the structure of the clays. The substituted ions may increase the total BEC of a mineral. Table 6-2 also shows that Mg2+ BBC is about 30% higher in the pH-adjusted solids (0.22 meq/ 100 g) than the control solids (0.15 meq/ 100g). As discussed in Section 5.3, the increased concentration on the exchange complex is due to Mg2+ occupying newly available sites due to Ca2+ displacement. The reported increase in Ca2+ BEC is not consistent with information obtained from water chemistry, therefore the dissolution of calcite during SrClz displacement may have resulted in overestimating the amount of Ca2+ BBC on the solids. Similar BEC responses were also observed in other samples as shown in Table E4 in Appendix E. However the total BEC for the control and pH-adjusted solids was also less than the BEC for the original core samples due to loss of fine-grained solids when packing the columns. 6.4 Carbonate content Carbonate minerals like (calcite) are the primary pH buffers in the pH range that exists in the aquifer during groundwater pH-adjustment since bgthmbegin to precipitate at pH 8 (Drever, 1997). Carbonate precipitation helps control groundwater pH and concentration of Ca2+ and HCO3’ during pH-adjustment. The total mass of carbonates that precipitate during pH-adjustment are negligible when compared to the total mass of carbonates in the solids (Schoolcraft Field 57 Bioaugmentation Experiment, 1997). Though immeasurable after, the concentration of calcite in the aquifer solids is expected to increase slightly due to mineral precipitation occurring in Region 1 (Chapters 4 and 5). 6.5 Surface adsorption capacity The activity of surface adsorption sites for the core samples, control solids and pH-adjusted solids were measured using the NaF displacement method discussed in Chapter 2. The changes in surface complexing capacity on the surface of aquifer solids, before and after pH adjustment were not measurable using NaF . 58 CHAPTER 7 GEOCHEMICAL MODELING 7.0 Introduction In order to validate explanations derived from the data collected from the 1- D column experiments, PHREEQC (Parkhurst, 1995), a geochemical equilibrium model was used to help describe the changes in the water chemistry. This model was used to predict the changes in pH and aqueous concentration of target components (Ca2+, Mg2+ and HCO3') as field groundwater pH-adjustment. The model may then be used as a tool to predict the response of another groundwater system subjected to similar remediation strategies based upon the solids composition and chemistry of the aquifer. The approach to quantify and model the impact of geochemical mechanisms may also be useful when predicting changes in groundwater chemistry during seawater intrusion. 7.1 Solid phase input parameters PHREEQC allows users considerable flexibility when entering data into input files. The conceptual model consisted of a 1-D column containing solids with a porosity of 0.45. The magnitude of cation exchange capacity was defined for each cation based on measurements on the aquifer solids (Chapters 4 and 6) and is included in Table 7.1. 59 Table 7-1. Solid phase input parameters for PHREEQC data input file Parameter Actual Modeled Actual/Modeled Porosity 0.45 0.45 1.0 Volume 53 cm3 53 cm3 1.0 Ca-exchange 0.0124 0.0124 1.0 Mg-exchange 0.0015 0.0015 1.0 Hfo_w 5.0E-6 0.0025 0.002 The magnitude of hydrous ferric oxides (Hfo) that are used to define surface complexing surfaces in the model helps control the number of pore volumes required for pH breakthrough (Chapter 4). The amount of hydrous ferric oxide was used as a calibration parameter to fit the simulated pH curve to the points generated during the experiment. Initially, Hfo was empirically determined by matching the shape of the modeled pH breakthrough curve with experimental data. For the 1-D column that was modeled in this experiment, a Hfo concentration that was 500 (1/0.002) times higher than the number of surface sites measured by NaF displacement (Chapter 2) was required for the modeled data to match the experimental results. 7.2 Liquid phase input parameters The composition of at least two solutions must be defined when using the advective transport capabilities in PHREEQC. Solution “1” represents the groundwater chemistry at baseline conditions (pH 7.3-7.5) and solution “0” 60 represents pH-adjusted water that will be injected into the aquifer (pH 8.2-8.4). The chemical compositions of the waters used to define the solutions for the PHREEQC input file are shown in Table 7 -2. Table 7-2. Liquid phase input parameters for PHREEQC data input file Input Pore Displacing Parameter Format Solution Solution Solution Solution 1 0 pH (units) pH 7.56 8.39 Temperature (°C) Temp 25.0 25.0 Units -units ppm ppm Calcium Ca 90.1 17.1 Magnesium Mg 34.9 33.9 Sodium Na 30.2 94.7 Potassium K 7.0 7.3 Alkalinity Alkalinity 613 442 Chloride CI 56.8 61.4 Nitrate N(5) 20.1 22.8 Sulfate S(6) 20.2 21.5 Silica Si 14.2 13.5 The actual input file used in the simulations is included in Table F-l in Appendix F. Chloride, nitrate, sulfate, and silica were not needed to simulate the geochemical changes in the 1-D column, but they were included to maintain charge balance. As mentioned earlier, groundwater is continually trying to equilibrate with minerals that it is in contact with. However, in nearly all situations, the concentration of dissolved minerals are either undersaturated or supersatured with respect to equilibrium conditions. Saturation indices (SI) are one way to represent 61 the concentration conditions at a given pH, temperature and pressure. When log S1 is greater than 0, the mineral is supersaturated and when log S1 is less than 0, the mineral is undersaturated. The SI for selected minerals for the two solutions (before and after titration) are shown in Table 7 -3. Table 7-3. Saturation indices for effluent groundwater samples Pore Solution Displacing Solution Mineral (log SI) (log SI) pH (units) 7.56 8.3 Aragonite -2.54 -3.7 1 Calcite 0.82 0.78 Dolomite 1 .59 2.23 Quartz 0.35 0.32 Table showing SI for the minerals are included in Tables F-2 and F -3 in Appendix F. As shown in Table 7-3, both solutions are supersaturated with respect to calcite, dolomite and quartz. The log SI for calcite decreases as the pH of the water increases. As mentioned earlier (Chapters 4 and 5), carbonate minerals precipitate from solution as groundwater pH increases. This precipitation of carbonate minerals results in a lower concentration of minerals in solution and thus a lower log SI. Dolomite will not precipitate and therefore maintains a higher SI than calcite. Table 7-3 also shows that the log SI for dolomite increased with increasing pH. Since the solution reaches saturation at lower concentrations at increasing pH, log SI for dolomite will increase, assuming the same mass of dolomite in solution. 62 Log SI for quartz remains fairly constant (0.3 5) for both baseline and pH-adjusted groundwater, suggesting that quartz and other silicate minerals do not undergo significant changes during base addition. 7.3 Simulated and experimental pH and cation concentrations Experimental and simulated pH values and major cation concentrations for a 1-D column experiment are shown in Figure 7.1. Experimental data are shown as points, while solid lines represent simulated data. 05 9° 05 . I H breakthrou h 5 4p g - - e 0 .vTu - T 8.4 pH 0 0 ° _ A ‘ 0 Na‘“ 32 d 4 r x “ I! g “l x X x E. 8.0 35 c: o 'E .2 3 - o :3 ..- + 4- 7 8 :1: 5 7 Mg2 x :1. g 2 _ ’ A A X I 8 I 7.6 .' x A 1 ’ Ca A A A A A A A -~>— 7.4 K+ 1‘ fit- 9 e e c c c c c 4.5 c 4% o o 0 (I) I r . r 1 1 r 1 r 1 T T 1 n 1 . I—r T I I T 1 7'2 0123456789101112131415 Pore volumes exchanged (PVE) Figure 7-1. Experimental and simulated pH and concentrations of cations 63 As shown in Figure 7-1, the simulated values are very close to the measured pH and cation concentrations in the effluent of column B-4. The concentration of Na+ and K+ are also simulated well by this model. The simulation predicted pH values to within 0.1 pH units of the experimental data. The model predicted concentrations of Ca2+, Mg2+, Na": and K+ to within, 0.4, 0.4, 0.2, and 0.1 meq/L, respectively. The differences between experimental and simulated concentrations are most likely due to two reasons. One reason is the error associated with the analytical methods used to quantify the potential for involvement of cation exchange and surface complexation. The second and perhaps the most important difference stems from using a chemical equilibrium model to describe a system that has some kinetic response. In the PHREEQC model, mineral equilibria, cation exchange, and surface adsorption are all assumed to occur instantaneously, when in reality that is not the case. Each process takes time to occur. A model that incorporates kinetic parameters could be developed, but little information is available on the rates of most of the geochemical processes (NRC, 1990). In addition, the improved but small accuracy that may result from incorporating kinetic parameters is not justified when considering the additional time and expense required to develop such a model. 64 CHAPTER 8 SUMMARY AND APPLICATIONS 8.0 Summary Mineral equilibria and cation exchange are important geochemical processes that control pH response as alkali is added to a solids and groundwater system (Chapter 1). The minerals that compose the solids portion of the system are primarily silicates and calcium carbonates (Chapter 2). Schoolcraft has an average pH of about 7.32 and is classified as calcium-bicarbonate (Chapter 3). Calcite was the only major carbonate mineral observed to precipitate during pH-adjustment of the 1-D columns. Aragonite did not form during the experiment due to low Mg2+ concentrations and dolomite was prevented from precipitating by the environmental conditions and kinetic limitations. The precipitation of calcite resulted in an initial decrease in concentration of Ca2+ and HCO3' (Region 1). However the effluent concentration of Ca2+ remained above the influent concentrations until about 11 pore volumes (end of Region 2) of pH-adjusted water had passed through the l-D columns (Chapters 4 and 5). As the solution concentration of Ca2+ decreased, the Mg2+/Ca2+ ratio increased. Mg2+ was then able to replace some of Ca2+ ions that occupied a portion of the cation exchange sites on the surface of the aquifer solids. Mg2+ ions left the displacing solution to occupy newly available exchange sites, resulting in the effluent concentration of Mg2+ being less than the influent concentration 65 during Regions 1 and 2. The Ca2+ ions displaced from the exchange sites by Mg2+ resulted in a Ca2+ effluent concentration that was higher than the influent concentration (Chapter 5). The changes that occurred on the aquifer solids as a result of pH-adjustment indicated that the solids pH and BEC were both increased by base addition (Chapter 6). The geochemical impacts of pH-adjustment were simulated using mineral equilibria and cation exchange in the PHREEQC computer code. The PHREEQC simulation was able to effectively predict cation concentration to within 0.4 meq/L and pH to within 0.1 units. 8.1 Application The results of this thesis indicate that cation exchange is an important process in even sandy soils, which are typically assumed to have very little geochemical reactivity. This thesis also provides a substantial source of site specific information on the: . Equations that describe geochemical changes as a function of pH (Appendix A) . Geochemical attributes of Schoolcraft Aquifer solids including solids pH (Chapter 2 and Appendix B) . Geochemical attributes of Schoolcrafi Aquifer solids including solids pH (Chapter 2 and Appendix B) . Chemical makeup of Schoolcraft groundwater, including depth specific chemistry (Chapter 3 and Appendix C) 66 . Approach and methods that may be used to quantify geochemical changes that result from pH changes (Chapters 2 through 6) . Changes that occur in groundwater chemistry as a result of pH adjustment (Chapter 4 and Appendix D) . Impacts of pH-adjustment on aquifer solids (Chapter 6 and Appendix E) . Application of the computer code PHREEQC for simulating geochemical data from bench-scale experiments (Chapter 7 and Appendix F) In addition, the approach and results presented this thesis may be used to determine design and operation strategies for use in a full-scale field remediation project and simulate geochemical changes as a result of saltwater intrusion. 8.2 Recommendations for future work Recommendations for future work include, but are not limited to, the following: 1. Determine geochemical impacts of long term base-adjustment 2. Simulate pH-adjustment in a 2-dimensional aquifer model. 3. Simulate pH-adjustment in a 3-dimensional full-scale remedial system. 4. Couple the geochemical predictions with a model that includes hydrogeology and microbiology to simulate hydraulic transport and microbial grth as a function of pH and ion concentration. 5. Examine the impact of pH-adjustment on the presence and availability of trace metals required for microbial growth. 67 APPENDICIES 68 APPENDIX A 69 APPENDIX A EQUATIONS Table A-1. General carbonate equilibrium equations 1. Carbonic acid (HZCO3) H2CO3* = C02(g) + H20 log K -1.468 2. Bicarbonate (HCO3') H2CO3 = I‘I+ + HCO3- Log K -6.35 3. Carbonate (cof') HCO3' = H+ + C032- log K 40.329 4. Water (H20) H20 = OH- + HI log K - 14.0 5. pH pH = -log[H+] 70 APPENDIX A Table A-2. Selected carbonate equilibrium equations 1. Calcium carbonate (CaCO3) Ca2+ + co,” = CaCO3 log K 3.224 delta H 3.545 kcal 2. Calcium bicarbonate (CaHCOf) Ca2+ + HCO3' = CaHCO3+ log K 1.106 delta H 2.69 kcal 3. Magnesium carbonate (MgCO3) Mg2+ + CO32'= MgCO3 log K 2.98 delta H 2.713 kcal 4. Magnesium bicarbonate (MgHCOf) Mg2+ + HCO3’ = Mcho; log K 1.07 delta H 0.79 kcal 5. Sodium carbonate (NaCO3') Na+ + co,” = NaCO3' log K 1.27 delta H 8.91 kcal 6. Sodium bicarbonate (NaHCO3) Na“ + HCO3- = NaHCO3 log K -O.25 71 APPENDIX A Table A-3. Selected mineral equilibrium equations 1. Aragonite CaCO3 = Ca2* + cof‘ log K -8.336 2. Dolomite CaMg(CO3)2 = Ca2+ + Mg2+ + zoo,” log K -16.54 3. Calcite CaCO3 = Ca2+ + c032“ log K -8.48 4. Magnesite MgCO3 = Mg2+ + CO32' log K ~8.029 5. Anhydrite CaSO4 = Ca2+ + SO47" log K -4.36 6. Gypsum CaSO422HzO = Ca2+ + 3042' + ZHZO log K -4.58 7. Halite NaCl = Na+ + Cl' log K 1.582 8. Quartz 3102 + 2H20 = H4SIO4 log K -3.98 72 APPENDIX A Table A-4. Selected cation exchange equations 1. Calcium (CaXz) Ca” + 2X‘ = (2.2.x2 log K 0.8 2. Magnesium (Mng) Mg” + 2X‘ = ng2 log K 0.6 3. Hydrogen (HX) H+ + X' = HX log K 1.0 4. Sodium (NaX) Na+ + X' = NaX log K 0.0 5. Potassium (KX) K+ + X‘ = KX log K 0.7 73 APPENDIX A Table A-5. Chemical surface adsorption equations 1. Strong (Hfo_s) a. Hfo_sOH + H+ = Hfo_s(OH)2+ log K 7.29 # = pKal,int b. Hfo_sOH = Hfo_sO' + IE log K -8.93 # = -pKa2,int 2. Weak (Hfo_w) a. Hfo_wOH + If = Hfo_w(OH)2+ log K 7.29 # = pKal,int b. Hfo_wOH = Hfo_wO' + H+ log K -8.93 # = -pKa2,int 3. Calcium Hfo_sOH + Ca” = Hfo_sOHCa” log K 4.97 4. Magnesium Hfo_wOH + M g2+ = Hfo_wOMg+ + H+ log K -4.6 74 APPENDIX B 75 APPENDIX B PROPERTIES OF SCHOOLCRAF T AQUIFER SOLIDS Table B-1. Schoolcraft aquifer solids pH Depth pH in pH in Core ID Well (ft bg) Type DDW CaClz 2-3000 2 30.00 Medium sand 9.02 Lost 2-3208 2 32.67 Silty sand 9.19 8.19 2-3508 2 35.67 Fine sand 9.12 8.18 2-4000 2 40.00 Fine sand 9.07 8.21 2-4600 2 46.00 Fine sand 9.22 8.32 2-4608 2 46.67 Fine sand 9.24 8.43 2-5107 2 51.58 Medium sand 9.26 8.26 2-5404 2 54.33 Medium sand 9.35 8.24 2-6010 2 60.83 Medium sand 9.43 8.05 2-6608 2 66.67 Medium sand 9.47 8.47 2-7201 2 72.08 Medium sand 9.34 8.35 2-7404 2 74.33 Medium sand 9.33 8.38 2-7606 2 76.50 Coarse sand 9.39 8.11 4-3200 4 32.00 Fine sand 9.29 8.26 4-3406 4 34.50 Fine sand 9.07 8.16 4-3610 4 36.83 Fine sand 9.18 8.20 ~4-4200 4 42.00 Medium sand 9.35 8.23 ~4-4500 4 45.00 Medium sand 9.13 8.27 4-4706 4 47.50 Medium sand 9.40 8.37 4-5200 4 52.00 Medium sand 9.40 8.31 4-5406 4 54.50 Coarse sand 9.14 Lost 4-6206 4 62.50 Medium sand 9.39 8.26 4-6604 4 66.33 Medium sand 9.06 8.24 4-7206 4 72.50 Coarse sand 9.25 8.17 4-7604 4 76.33 Coarse sand 9.43 8.27 4-7810 4 78.83 Coarse sand 9.48 8.30 6-3111 6 31.92 Fine sand 9.25 8.22 6-3406 6 34.50 Fine sand 9.16 8.30 6-3702 6 37.17 Fine sand 9.21 8.19 6-4102 6 41.17 Medium sand 9.07 8.10 76 APPENDIX B Table B-1. (cont’d) Depth pH in pH in Core ID Well (ft bgs) Type DDW CaClz 6-4310 6 43.83 Medium sand 9.27 8.21 6-4604 6 46.33 Fine sand 9.09 8.20 6-5006 6 50.50 Medium sand 9.37 8.30 6-5302 6 53.17 Medium sand 9.24 8.30 6-5610 6 56.83 Coarse sand 8.46 7.89 6-5906 6 59.50 Coarse sand 9.27 8.30 6-6206 6 62.50 Medium sand 9.49 8.34 6-6500 6 65.00 Medium sand 9.42 8.25 6-6700 6 67.00 Fine sand 8.99 8.12 6-7206 6 72.50 Medium sand 9.51 8.24 6-8804 6 88.33 Coarse sand - - 8-3702 8 37.17 Fine sand 9.16 8.19 8-4104 8 41.33 Fine sand 9.13 8.12 8-4604 8 46.33 Medium sand 9.27 8.20 8-5010 8 50.83 Medium sand 9.36 8.29 8-5310 8 53.83 Medium sand 9.40 8.29 8-5610 8 56.83 Medium sand 9.48 8.22 8-6110 8 61.83 Medium sand 9.40 8.29 8-6508 8 65.67 Medium sand 9.17 8.11 8-7000 8 70.00 Coarse sand 9.42 8.32 8-7306 8 73.50 Coarse sand 9.35 8.14 8-7700 8 77.00 Coarse sand 9.31 8.06 8-8110 8 81.83 Coarse sand - - 8-8406 8 84.50 Coarse sand - - 10-3202 10 32.17 Fine sand 9.20 8.19 10-3511 10 35.92 Fine sand 9.34 8.09 10-3802 10 38.17 Fine sand 9.23 8.27 10-4206 10 42.50 Medium sand 9.34 8.10 10-4500 10 45.00 Fine sand 9.44 8.28 10-5008 10 50.67 Medium sand 9.41 8.30 10-5503 10 55.25 Medium sand 9.42 8.29 10-5802 10 58.17 Medium sand 9.49 8.35 10-6110 10 61.83 Medium sand 9.24 8.22 10-6406 10 64.50 Medium sand 9.41 8.29 77 APPENDIX B Table B-1. (cont’d) Depth pH in pH in Core ID Well (ft bgs) Type DDW CaClz 10-6710 10 67.83 Fine sand 9.29 8.08 10-7106 10 71.50 Coarse sand 9.43 Lost 10-7610 10 76.83 Coarse sand 9.56 8.24 10-8500 10 85.00 Very coarse - - 14-3111 14 31.92 Fine sand 9.13 8.17 14-3406 14 34.50 Fine sand 9.33 8.27 14-3706 14 37.50 Fine sand 9.29 8.27 14-4104 14 41.33 Fine sand 9.30 8.20 14-5310 14 53.83 Medium sand 9.27 8.22 14-5908 14 59.67 Medium sand 9.47 8.33 14-6206 14 62.50 Medium sand 9.32 8.22 14-6610 14 66.83 Medium sand 9.38 8.30 14-7706 14 77.50 Coarse sand 9.46 8.32 14-8004 14 80.33 Medium sand 9.36 8.17 14-8303 14 83.25 Coarse sand - - Average 9.28 :1: 0.16 8.23 :1: 0.09 No. Samples 74 71 78 APPENDIX B Table B-2. Schoolcraft aquifer solid base exchange capacity Depth Ca Mg K Total Core Well (ft bgs) (meq/100 g) (meq/100 g) (meq/100 g) (meq/100 g) 2-3000 2 30.00 0.70 0.13 < 0.02 0.85 2-3208 2 32.67 2.56 0.26 < 0.02 2.84 2-3508 2 35.67 3.60 0.29 < 0.02 3.91 2-4000 2 40.00 0.58 0.13 < 0.02 0.73 2-4600 2 46.00 3.37 0.27 < 0.02 3.65 2-4608 2 46.67 3.60 0.29 < 0.02 3.90 2-5107 2 51.58 3.05 0.28 < 0.02 3.33 2-5404 2 54.33 3.44 0.24 < 0.02 3.69 2-6010 2 60.83 2.95 0.22 < 0.02 3.17 2-6608 2 66.67 3.12 0.26 < 0.02 3.40 2-7201 2 72.08 2.81 0.25 < 0.02 3.07 2-7404 2 74.33 3.57 0.33 < 0.02 3.91 2-7606 2 76.50 3.44 0.25 < 0.02 3.70 4-3200 4 32.00 2.27 0.23 < 0.02 2.52 4-3406 4 34.50 3.21 0.35 0.03 3.58 4-3610 4 36.83 2.82 0.25 < 0.02 3.08 4-4200 4 42.00 4.68 0.29 < 0.02 4.99 4-4500 4 45.00 6.69 0.41 < 0.02 7.11 4-4706 4 47 .50 3.16 0.24 < 0.02 3.42 4-5200 4 52.00 2.96 0.23 < 0.02 3.20 4-5406 4 54.50 3.16 0.23 < 0.02 3.39 4-6206 4 62.50 2.73 0.21 < 0.02 2.94 4-6604 4 66.33 3.15 0.32 < 0.02 3.47 4-7206 4 72.50 1.73 0.22 < 0.02 1.96 4-7604 4 76.33 2.64 0.24 < 0.02 2.88 4-7810 4 78.83 3.53 0.28 < 0.02 3.82 6-3111 6 31.92 0.85 0.16 < 0.02 1.03 6-3406 6 34.50 2.63 0.27 0.02 2.92 6-3702 6 37.17 0.89 0.19 < 0.02 1.10 6-4102 6 41.17 5.52 0.32 < 0.02 5.85 64310 6 43.83 6.01 0.34 < 0.02 6.36 6-4604 6 46.33 6.00 0.42 < 0.02 6.43 6-5006 6 50.50 2.81 0.24 < 0.02 3.05 6-5302 6 53.17 4.51 0.26 < 0.02 4.77 79 APPENDIX B Table B-2. (cont’d) Depth Ca Mg K Total Core ID Well (ft bgs) (meq/100 ) (meq/100 g) (meq/100 g) (meq/100 g) 6-5610 6 56.83 5.36 1.34 < 0.02 6.72 6-5906 6 59.50 4.09 0.29 < 0.02 4.39 6-6206 6 62.50 3.29 0.20 < 0.02 3.50 6-6500 6 65.00 2.43 0.17 < 0.02 2.62 6-6700 6 67.00 4.02 0.43 < 0.02 4.47 6-7206 6 72.50 3.23 0.23 < 0.02 3.46 6-8804 6 88.33 4.31 0.35 < 0.02 4.67 8-3702 8 37.17 2.16 0.25 < 0.02 2.42 8-4104 8 41.33 5.59 0.33 0.02 5.94 84604 8 46.33 3.88 0.34 < 0.02 4.23 8-5010 8 50.83 3.76 0.26 < 0.02 4.04 8-5310 8 53.83 3.68 0.23 < 0.02 3.93 8—5610 8 56.83 3.55 0.25 0.02 3.82 8-6110 8 61 .83 3.80 0.28 < 0.02 4.09 8-6508 8 65.67 2.64 0.23 < 0.02 2.87 8-7000 8 70.00 3.59 0.29 < 0.02 3.88 8-7306 8 73.50 4.49 0.35 < 0.02 4.85 8-7700 8 77 .00 4.44 0.28 < 0.02 4.73 8-8110 8 81.83 3.84 0.31 < 0.02 4.15 8-8406 8 84.50 3.51 0.41 < 0.02 3.93 10-3202 10 32.17 0.88 0.18 < 0.02 1.07 10-3511 10 35.92 3.78 0.25 < 0.02 4.05 10-3802 10 38.17 6.82 0.38 0.03 7.23 10-4206 10 42.50 3.42 0.27 < 0.02 3.70 10-4500 10 45.00 5.35 0.34 < 0.02 5.70 10-5008 10 50.67 3.89 0.23 < 0.02 4.13 10-5503 10 55.25 3.08 0.23 < 0.02 3.32 10-5802 10 58.17 3.01 0.25 < 0.02 3.27 10-6110 10 61.83 3.19 0.26 < 0.02 3.45 10-6406 10 64.50 3.45 0.26 < 0.02 3.71 10-6710 10 67.83 1.48 0.37 < 0.02 1.87 10-7106 10 71.50 5.19 0.42 < 0.02 5.62 10-7610 10 76.83 3.93 0.25 < 0.02 4.20 10-8500 10 85.00 3.59 0.39 < 0.02 3.99 80 APPENDIX B Table B-2. (cont’d) Depth Ca Mg K Total Core ID Well (ft bgs) (meq/100g) (meq/100g) (meq/100 g) (meq/100 g_)_ 14-3111 14 31.92 1.95 0.23 < 0.02 2.20 14-3406 14 34.50 2.97 0.24 < 0.02 3.23 14-3706 14 37.50 4.50 0.33 0.02 4.85 14-4104 14 41 .33 6.27 0.39 0.02 6.69 14-5310 14 53.83 4.53 0.26 < 0.02 4.80 14-5908 14 59.67 3.00 0.23 < 0.02 3.23 14-6206 14 62.50 4.16 0.26 < 0.02 4.42 14-6610 14 66.83 3.69 0.25 < 0.02 3.95 14-7706 14 77 .50 3.41 0.22 < 0.02 3.63 14-8004 14 80.33 2.20 0.18 < 0.02 2.38 14-8303 14 83.25 2.27 0.26 < 0.02 2.55 Average 3.47 :t 1.29 0.28 i 0.13 < 0.02 3.77 :t 1.36 No. 79 79 7 > MDL 79 81 APPENDIX C 82 APPENDIX C SCHOOLCRAFT GROUNDWATER CHEMISTRY Table C-l. Historical properties of Schoolcraft groundwater Monitoring Wells Located Near Schoolcraft, Michiganl Property (unitS) Well 17 2 Well 18 2 Well 23 2 Alkalinity (mg/L as CaCO3) 203 142 170 Arsenic (pg/L) <1 <1 <1 Cadmium (pg/L) <10 <10 <10 Calcium (mg/L) 69 83 7O Chloride (mg/L) 7.2 13 ll Chromium (pg/L) <10 70 10 Copper (pg/L) <10 <10 <10 Fluoride (mg/L) 0.1 0.4 0.2 Hardness (mg/L as CaCO3) 280 320 170 Iron (pg/L) 70 320 220 Lead (pg/L) <100 <100 <100 Magnesium (mg/L) 27 28 23 Manganese (pg/L) 10 10 140 Nickel (pg/L) <100 <100 <100 Nitrate (mg/L as N) 0.01 0.01 0.02 pH (units) 7.65 7.73 7.3 Phosphate (mg/L) 0.01 0.01 0.01 Potassium (mg/L) 0.4 0.6 0.7 Silica (mg/L) 9.8 11 7.6 Sodium (mg/L) 2.7 3.9 3.5 Specific Conductance (uS/cm) 572 730 582 Strontium (11 g/L) 70 70 60 Sulfate (mg/L) 25 29 91 TDS-measured (mg/L) 282 418 308 Zinc (pg/L) 60 90 210 1 Geohydrology and Water Quality of Kalamazoo County, Michigan, 1986-88. US. Geological Survey. Water-Resources Investigations Report 90-4028. 2 Map showing location of wells is not included. 83 APPENDIX C Table C-2. Contract laboratory analysis of Schoolcraft groundwater Sample ID: MSU-MW34A Collected by: M. Dybas Collection date: March 17, 1997 Analysis method: ICP-AES Analysis by: Contract Laboratory Analysis date: March 28, 1997 Concentration Element Symbol (mg/L) Aluminum A1 < 0.050 Antimony Sb < 0.050 Arsenic As < 0.05 Barium Ba 0.059 Boron B 0.083 Cadmium Cd < 0.005 Calcium Ca 107 Chromium Cr < 0.010 Cobalt Co < 0.005 Copper Cu < 0.005 Iron Fe < 0.010 Lead Pb 0.009 Magnesium Mg 33.1 Manganese Mn < 0.005 Mercury Hg < 0.100 Molybdenum Mo < 0.020 Nickel Ni < 0.01 Phosphorus P < 0.100 Potassium K 6.80 Selenium Se 0. 100 Silicon Si 6.63 Sodium Na 35.2 Sulfur S 8.16 Thallium T1 < 0.10 Vanadium V < 0.005 Zinc Zn 0.018 84 APPENDIX C Table 03. Schoolcraft groundwater samples — May 09, 1997 Sample ID: MW34A (70 fi bgs) Collected by: M. Dybas Collection date: May 09, 1997 Analysis by: L. Warnick MW Charge Mass Component units Valance (mg/mmol) Value (meq/L) (mg/L) General Acidity mg/L as CaCO3 - - 32.0 - - Alkalinity mg/L as CaCO3 - - 383 - - Ph units - - 7.3 - - Conductivity umho - - 1,022 - - SiOz mg/L - 60.1 13.5 - 13.5 Total 13.5 Cations Ca2+ mg/L 2 40.1 131 6.5 131 Mg2+ mg/L 2 24.3 37.1 3.1 37.1 Na+ mg/L 1 23.0 35.7 1.6 35.7 1C mg/L 1 39.1 5.5 0.1 5.5 Total 11.3 209 Anions HCO3' mg/L 1 61.0 468 7.7 230 (31' mg/L 1 35.5 83.5 2.4 83.5 NO3' mg/L 1 62.0 32.6 0.5 32.6 3042' mg/L 2 96.1 27.1 0.6 27.1 Total 11.1 373 Charge Balance (meq/L) Solids Balance (mg/L) Total Cations 1 1.27 Silica 13.50 Total Anions 1 1.1 l Cations 209 Cation/Anion 1 .01 Anions 373 TDS (calc) 596 TDS (meas) 555 Calculated/Measured 1 .07 85 Table C-4. Schoolcraft groundwater samples - June 03, 1997 APPENDIX C Collected by: M. Dybas Collection date: June 03, 1997 Analysis by: L. Warnick a. Filtered Ca K Mg Na SiOz Well Sample‘ (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) MW34A Stagnant#1 63.0 6.2 37.1 25.3 8.6 MW34A Stagnant #2 63.3 6.5 37.5 24.6 8.6 MW34A Purge 15 min #1 124.0 5.7 37.3 41.4 14.1 MW34A Purge 15 min #2 124.9 5.2 36.3 40.6 13.7 MW34A Purge 1.25 hr #1 117.8 5.4 36.7 37.0 13.9 MW34A Purge 1.25 hr #2 89.6 5.4 37.4 35.6 14.0 EWS Stagnant #1 72.0 23.4 1.7 2.1 12.9 EWS Stagnant #2 70.9 23.6 2.0 2.3 12.8 EWS Purge 40-L #1 92.1 29.2 13.0 4.5 12.6 EWS Purge 40-L #2 94.3 29.3 13.0 4.7 12.8 EWS Purge 100-L #1 96.7 28.5 12.6 4.5 12.5 EWS Purge 100-L #2 96.5 30.0 12.6 4.8 12.9 b. Non-filtered Ca K Mg Na SiOz Well Sample' (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) MW34A Stagnant#1 62.9 6.2 36.0 23.9 8.3 MW34A Stagnant #2 62.2 6.5 36.6 24.4 8.1 MW34A Purge 15 min #1 124.0 6.1 37.2 40.8 13.9 MW34A Purge 15 min #2 105.8 5.4 36.5 41.7 13.9 MW34A Purge 1.25 hr #1 109.5 5.0 35.8 37.0 13.6 MW34A Purge 1.25 hr #2 78.9 5.4 36.3 36.6 13.8 EWS Stagnant #1 70.6 22.6 1.7 2.0 12.2 EWS Stagnant #2 72.0 23.3 1.7 2.2 12.5 EWS Purge 40-L #1 83.2 29.2 12.7 4 4.8 13.0 EWS Purge 40-L #2 34.7 28.5 13.0 4.5 12.7 EWS Purge lOO-L #1 51.9 28.7 12.4 4.6 12.6 EWS Purge lOO-L #2 68.9 29.4 12.7 4.6 13.4 86 APPENDIX C Table C-4. (cont’d) a. Filtered Al Ba Cd Co Cr Cu Well Sample' (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) MW34A 03/27/19972 < 0.04 0.241 < 0.004 < 0.007 < 0.007 < 0.006 MW34A Stagnant#1 <0.04 < 0.002 < 0.004 <0.007 <0.007 < 0.006 MW34A Stagnant #2 < 0.04 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 MW34A Purge 5 min #1 < 0.04 0.132 < 0.004 < 0.007 < 0.007 < 0.006 MW34A Purge 5 min #2 < 0.04 0.131 < 0.004 < 0.007 < 0.007 < 0.006 MW34A Purge 1.25 hr #1 < 0.04 0.116 < 0.004 < 0.007 < 0.007 < 0.006 MW34A Purge 1.25 hr #2 < 0.04 0.116 < 0.004 < 0.007 < 0.007 < 0.006 EWS Stagnant #1 < 0.04 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Stagnant #2 < 0.04 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Purge 40-L #1 0.944 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Purge 40-L #2 0.975 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Purge 100-L #1 0.340 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Purge 100-L #2 0.659 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 b. Non-filtered Al Ba Cd Co Cr Cu Well Sample‘ (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) MW34A Stagnant#1 < 0.04 < 0.002 < 0.004 <0.007 <0.007 < 0.006 MW34A Stagnant #2 <0.04 < 0.002 < 0.004 <0.007 <0.007 0.033 MW34A Purge 5 min #1 < 0.04 0.136 < 0.004 < 0.007 < 0.007 < 0.006 MW34A Purge 5 min #2 < 0.04 0.127 < 0.004 < 0.007 < 0.007 < 0.006 MW34A Purge 1.25 hr #1 < 0.04 0.111 < 0.004 < 0.007 < 0.007 < 0.006 MW34A Purge 1.25 hr #2 < 0.04 0.114 < 0.004 < 0.007 < 0.007 < 0.006 EWS Stagnant #1 < 0.04 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Stagnant #2 < 0.04 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Purge 40-L #1 < 0.04 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Purge 40-L #2 0.045 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Purge 100-L #1 < 0.04 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 EWS Purge 100-L #2 < 0.04 < 0.002 < 0.004 < 0.007 < 0.007 < 0.006 87 Table C-4. (cont’d) APPENDIX C a. Filtered Fe Mn Ni Pb Sr Zn Well Sample‘ (mg/L11mg/L) (mg/L) (mg/L) (mg/L) (mg/L) MW34A 03/27/19972 0.040 < 0.002 < 0.015 < 0.04 0.161 0.650 MW34A Stagnant #1 < 0.007 < 0.002 < 0.015 < 0.04 0.052 1.131 MW34A Stagnant #2 < 0.007 < 0.002 < 0.015 < 0.04 0.051 1.107 MW34A Purge 5 min #1 < 0.007 < 0.002 < 0.015 < 0.04 0.141 0.134 MW34A Purge 5 min #2 < 0.007 < 0.002 < 0.015 < 0.04 0.141 0.135 MW34A Purge 1.25 hr #1 < 0.007 < 0.002 < 0.015 < 0.04 0.139 0.060 MW34A Purge 1.25 hr #2 < 0.007 < 0.002 < 0.015 < 0.04 0.143 0.050 EWS Stagnant #1 < 0.007 < 0.002 < 0.015 < 0.04 0.151 < 0.002 EWS Stagnant #2 < 0.007 < 0.002 < 0.015 < 0.04 0.150 < 0.002 EWS Purge 40-L #1 1.130 0.019 < 0.015 < 0.04 0.163 < 0.002 EWS Purge 40-L #2 1.204 0.018 < 0.015 < 0.04 0.164 < 0.002 EWS Purge 100-L #1 0.502 0.010 < 0.015 < 0.04 0.164 < 0.002 EWS Purge 100-L #2 0.802 0.019 < 0.015 0.122 0.164 < 0.002 b. Non-filtered Fe Mn Ni Pb Sr Zn Well Sample‘ (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) MW34A Stagnant #1 < 0.007 < 0.002 < 0.015 < 0.04 0.052 1.202 MW34A Stagnant #2 0.021 < 0.002 < 0.015 < 0.04 0.054 1.668 MW34A Purge 5 min #1 < 0.007 < 0.002 < 0.015 < 0.04 0.141 0.285 MW34A Purge 5 min #2 < 0.007 < 0.002 < 0.015 < 0.04 0.141 0.162 MW34A Purge 1.25 hr #1 < 0.007 < 0.002 < 0.015 < 0.04 0.140 0.066 MW34A Purge 1.25 hr #2 < 0.007 < 0.002 < 0.015 < 0.04 0.141 0.047 EWS Stagnant #1 < 0.007 < 0.002 < 0.015 0.080 0.151 < 0.002 EWS Stagnant #2 < 0.007 < 0.002 < 0.015 < 0.04 0.151 < 0.002 EWS Purge 40-L #1 < 0.007 < 0.002 < 0.015 < 0.04 0.162 < 0.002 EWS Purge 40-L #2 < 0.007 < 0.002 < 0.015 0.495 0.165 < 0.002 EWS Purge 100-L #1 < 0.007 < 0.002 < 0.015 < 0.04 0.165 < 0.002 EWS Purge 100-L #2 < 0.007 < 0.002 < 0.015 < 0.04 0.165 < 0.002 1 Stagnant samples were collected to evaluate potential for trace metal contamination. 2 Sample collected on March 27, 1997. 88 APPENDIX C Table C-5. Schoolcraft groundwater samples — July 02, 1997 Collected by: M. Dybas Collection date: July 02-03, 1997 Analysis by: L. Warnick Analysis date: July 07, 1997 Collection pH Acidity Alkalinity SiOz Sample Depth Date (units) (meq/L) (meq/L) (mmol/L) SB-A-30.l 30 07/02/1997 7.47 0.43 7.22 0.25 SB-A-30.2 30 07/02/1997 7.70 0.56 6.92 0.27 SB-A-30.3 30 07/02/1997 7.48 0.56 7.16 0.27 SB-A-40 40 07/02/1997 7.60 0.59 7.42 0.26 SB-A-50 50 07/02/1997 7.54 0.61 7.04 0.25 SB-A-60 60 07/02/ 1997 7.48 0.62 6.54 0.26 SB-A-70.l 70 07/02/1997 7.58 0.51 6.16 0.25 SB-A-70.2 70 07/02/1997 7.57 0.50 6.16 0.25 SB-A-7 0.3 70 07/02/1997 7.64 0.45 6.26 0.29 SB-A-80 80 07/02/1997 7.52 0.58 6.46 0.27 SB-B-40 40 07/03/1997 7.41 0.84 6.54 0.23 SB-B-50 50 07/03/1997 7.33 0.74 7.14 0.29 SB-B-60 60 07/03/1997 7 .30 0.87 8.02 0.29 SB-B-70.1 70 07/03/1997 7.25 0.82 7.36 0.25 SB-B-70.2 70 07/03/1997 7.17 0.90 7.30 0.25 SB-B-70.3 70 07/03/1997 7.27 0.77 7.56 0.29 SB-B-80 80 07/03/1997 7.24 0.82 7.42 0.30 SB-B-90 90 07/03/1997 7.18 0.94 7.30 0.25 89 APPENDIX C Table C-5. (cont’d) Ca Mg Na K Cations Sample (meq/L) (meq/L) (meq/L) (meq/L) Total SB-A-30.l 5.72 2.63 1.43 0.26 10.13 SB-A-30.2 5.78 2.66 1.42 0.20 10.23 SB-A-30.3 5.74 2.66 1.46 0.18 10.20 SB-A-40 5.62 2.69 1.48 0.17 10.08 SB-A-SO 5.73 2.98 1.29 0.17 10.22 SB-A-60 6.14 3.12 0.76 0.08 10.17 SB-A-70.1 5.41 2.78 0.56 0.07 8.84 SB-A-70.2 5.37 2.76 0.56 0.08 8.85 SB-A-70.3 5.37 2.82 0.57 0.07 8.92 SB-A-80 5.81 3.17 0.61 0.04 9.67 SB-B-40 5.21 2.85 1.13 0.17 9.51 SB-B-SO 5.68 3.05 1.05 0.15 10.09 SB-B-60 6.47 3.26 0.91 0.22 1 1.05 SB-B-70.1 6.13 3.18 0.84 0.19 10.38 SB-B-70.2 6.14 3.18 0.86 0.18 10.40 SB-B-70.3 6.16 3.24 0.86 0.19 10.57 SB-B-80 6.52 3.46 0.97 0.11 11.12 SB-B-90 6.41 3.57 1.17 0.08 11.37 90 APPENDIX C Table C-5. (cont’d) HC03 Cl N03 804 Anions Cations/ Sample (meq/L) (meq/L) (meq/L) (meq/L) Total Anions SB-A-30.1 7.22 2.07 0.68 0.49 10.47 0.97 SB-A-30.2 6.92 2.10 0.68 0.51 10.21 1.00 SB-A-30.3 7.16 2.10 0.68 0.50 10.44 0.98 SB-A-40 7.42 1.97 0.58 0.53 10.50 0.96 SB-A-50 7.04 1.91 0.73 0.59 10.27 1.00 SB-A-60 6.54 1.92 0.84 0.60 9.91 1.03 SB-A-70.l 6.16 0.93 0.74 0.73 8.56 1.03 SB-A-70.2 6.16 0.93 0.74 0.75 8.58 1.03 SB-A-70.3 6.26 0.94 0.75 0.77 8.72 1.02 SB-A-80 6.46 1.14 0.95 0.78 9.33 1.04 SB-B-40 6.54 1.43 0.99 0.62 9.58 0.99 SB-B-50 7.14 1.34 1.03 0.70 10.21 0.99 SB-B-60 8.02 1.30 1.05 0.64 11.01 1.00 SB-B-70.l 7.36 1.10 1.16 0.70 10.32 1.01 SB-B-70.2 7.30 1.11 1.17 0.70 10.28 1.01 SB-B-70.3 7.56 1.14 1.15 0.69 10.53 1.00 SB-B-80 7.42 1.13 1.53 0.65 10.73 1.04 SB-B-90 7.30 1.88 0.14 1.71 11.03 1.03 91 APPENDIX C Table C-6. Baseline Schoolcraft groundwater - September 19, 1997 Collected by: M. Dybas Collection date: September 19, 1997 Analysis by: L. Warnick Collection pH SiOz Sample ID Well Depth Date (units) (mg/L) M5.45.1M M5 45 09/19/97 7.486 12.6 M5.55.1M M5 55 09/19/97 7.325 13.5 M5.65.1M M5 65 09/19/97 7.337 13.1 M5.75.1M M5 75 09/19/97 7.298 13.0 M6.45.1M M6 45 09/19/97 7.351 11.7 M6.55.1M M6 55 09/19/97 7.344 12.5 M6.65.1M M6 65 09/19/97 7.342 13.2 M6.75.1M M6 75 09/19/97 7.284 13.4 M7.45. 1M M7 45 09/19/97 7.311 12.3 M7.55.1M M7 55 09/19/97 7.346 12.6 M7.65.1M M7 65 09/19/97 7.321 12.8 M7.75.1M M7 75 09/19/97 7.325 13.2 M8.45.1M M8 45 09/19/97 7.279 13.7 M8.55.1M M8 55 09/19/97 7.344 12.5 M8.65.1M M8 65 09/19/97 7.318 13.1 M8.75.1M M8 75 09/19/97 7.376 13.8 M9.45.1M M9 45 09/19/97 7.314 11.6 M9.55.1M M9 55 09/19/97 7.412 11.3 M9.65.1M M9 65 09/19/97 7.318 13.4 M9.75.1M M9 75 09/19/97 7.321 15.6 M10.45.1M M10 45 09/19/97 7.318 13.0 M10.55.1M M10 55 09/19/97 7.316 10.3 M10.65.1M M10 65 09/19/97 7.328 12.8 M10.75.1M M10 75 09/19/97 7.323 10.7 M11.45.1M M11 45 09/19/97 7.353 12.8 M11.55.1M M11 55 09/19/97 7.359 12.6 Mll.65.1M M11 65 09/19/97 7.341 12.5 M11.75.1M M11 75 09/19/97 7.346 12.8 M12.45.1M M12 45 09/19/97 7.347 11.9 M12.55.1M M12 55 09/19/97 7.339 12.6 M12.65.1M M12 65 09/19/97 7.319 13.2 M12.75.1M M12 75 09/19/97 7.330 14.1 92 APPENDIX C Table C-6. (cont’d) Ca Mg Na K Sample 11) (mg/L) (mg/L) (mg/L) (mg/L) M5.45.1M 89.5 30.8 31.7 5.6 M5.55.1M 96.4 29.7 30.7 5.8 M5.65.1M 96.2 30.1 37.7 5.9 M5.75.1M 108.2 32.1 31.2 4.7 M6.45.1M 80.9 31.8 41.8 3.4 M6.55.1M 96.7 29.6 25.1 5.8 M6.65.1M 106.4 31.0 35.6 4.0 M6.75.1M 117.7 34.9 22.5 2.7 M7.45.1M 89.9 31.0 28.4 6.1 M7.55.1M 95.9 29.7 21.8 4.3 M7.65.1M 101.1 28.8 36.2 3.5 M7.75.1M 99.2 30.3 32.1 4.0 M8.45.1M 91.1 30.4 23.9 7.2 M8.55.1M 96.1 28.7 21.7 4.7 M8.65.1M 98.3 30.1 28.5 4.8 M8.75.1M 87.6 28.3 12.4 2.2 M9.45.1M 74.6 29.5 38.8 4.0 M9.55.1M 78.2 27.3 39.6 4.3 M9.65.1M 104.7 31.7 35.7 5.4 M9.75.1M 109.5 32.4 24.6 3.0 M10.45.1M 99.1 30.1 22.3 4.4 M10.55.1M 66.1 24.8 28.6 5.0 M10.65.1M 99.5 29.0 34.0 3.5 M10.75.1M 72.7 25.9 36.2 < 0.638 M11.45.1M 92.8 30.6 19.3 5.6 M11.55.1M 94.4 29.5 16.1 3.9 M11.65.1M 93.5 29.3 15.9 3.4 M11.75.1M 90.9 28.9 14.0 3.5 M12.45.1M 85.3 31.3 29.5 5.2 M12.55.1M 95.8 28.8 25.3 5.1 M12.65.1M 103.4 30.6 29.1 3.6 M12.75.1M 105.3 34.0 26.2 1.0 93 APPENDIX C Table C-6. (cont’d) HC03 C1 N03 804 Sample 11) (mg/L) (mg/L) (mg/L) (mg/L) M5.45.1M 412 74.1 53.8 29.5 M5.55.1M 427 65.3 56.0 29.1 M5.65.1M 445 77.6 50.6 28.6 M5.75.1M 447 83.5 42.3 27.9 M6.45.1M 387 80.0 47.1 29.1 M6.55.1M 435 50.1 52.5 28.6 M6.65.1M 462 87.7 47.4 28.4 M6.75.1M 465 76.2 47.1 28.6 M7.45.1M 410 56.8 57.7 27.5 M7.55.1M 416 45.0 61.1 29.0 M7.65.1M 442 60.6 57.6 28.6 M7.75.1M 436 59.2 55.2 27.3 M8.45.1M 412 61.1 49.5 26.0 M8.55.1M 403 55.5 37.5 28.6 M8.65.1M 424 61.9 48.2 27.1 M8.75.1M 372 43.6 54.1 33.8 M9.45.1M 395 77.2 42.5 31.0 M9.55.1M 419 69.7 48.4 25.6 M9.65.1M 450 81.5 46.8 29.4 M9.75.1M 387 38.7 63.1 31.1 M10.45.1M 416 42.7 71.1 28.3 M10.55.1M 400 48.9 64.3 29.0 M10.65.1M 441 65.8 56.9 29.0 M10.75.1M 447 58.1 56.8 32.0 M11.45.1M 397 57.1 50.7 29.5 M11.55.1M 387 48.2 37.9 30.1 M11.65.1M 395 40.4 59.1 30.0 M11.75.1M 380 41.5 55.0 32.3 M12.45.1M 392 61.5 57.7 28.8 M12.55.1M 424 51.7 65.4 28.0 M12.65.1M 439 71.7 51.0 30.2 M12.75.1M 421 59.2 62.8 29.7 94 APPENDIX C Table C-6. (cont’d) Al Ba Cu Fe Mn Sample 11) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) M5.45.1M 0.215 0.05 < 0.031 < 0.058 < 0.015 M5.55.1M 0.183 0.047 < 0.031 < 0.058 < 0.015 M5.65.1M 0.167 0.052 < 0.031 < 0.058 < 0.015 M5.75.1M 0.224 0.053 < 0.031 < 0.058 < 0.015 M6.45.1M 0.0709 0.0641 < 0.031 0.1262 0.0392 M6.55.1M 0.179 0.042 < 0.031 < 0.058 < 0.015 M6.65.1M 0.192 0.048 < 0.031 < 0.058 < 0.015 M6.75.1M 0.0263 0.043 < 0.031 < 0.058 0.036 M7.45.1M 0.216 0.044 < 0.031 < 0.058 < 0.015 M7.55.1M 0.204 0.043 < 0.031 < 0.058 < 0.015 M7.65.1M 0.194 < 0.008 < 0.031 < 0.058 < 0.015 M7.75.1M 0.216 0.05 < 0.031 < 0.058 < 0.015 M8.45.1M 0.171 0.048 < 0.031 < 0.058 < 0.015 M8.55.1M 0.2 0.043 < 0.031 < 0.058 < 0.015 M8.65.1M 0.185 0.048 < 0.031 < 0.058 < 0.015 M8.75.1M 0.147 0.033 < 0.031 < 0.058 < 0.015 M9.45.1M 0.0259 0.0634 < 0.031 < 0.058 < 0.015 M9.55.1M < 0.006 0.0597 < 0.031 < 0.058 0.0323 M9.65.1M 0.196 0.057 < 0.031 < 0.058 < 0.015 M9.75.1M 0.1314 0.071 < 0.031 < 0.058 0.0189 M10.45.1M 0.208 0.042 < 0.031 < 0.058 < 0.015 M10.55.1M < 0.006 0.0531 < 0.031 < 0.058 0.0284 M10.65.1M 0.204 0.044 < 0.031 < 0.058 < 0.015 M10.75.1M 0.0301 0.0478 < 0.031 0.2203 0.0169 M11.45.1M 0.192 0.041 < 0.031 < 0.058 < 0.015 M11.55.1M 0.173 0.033 < 0.031 < 0.058 < 0.015 M11.65.1M 0.159 0.037 < 0.031 < 0.058 < 0.015 M11.75.1M 0.173 0.039 < 0.031 < 0.058 < 0.015 M12.45.1M 0.192 0.04 < 0.031 < 0.058 < 0.015 M12.55.1M 0.201 0.041 < 0.031 < 0.058 < 0.015 M12.65.1M 0.193 0.048 < 0.031 < 0.058 < 0.015 M12.75.1M < 0.006 0.0603 < 0.031 < 0.058 < 0.015 95 APPENDIX C Table C-6. (cont’d) Ni Pb Sr Zn Sample 11) (mg/L) (mg/L) (mg/L) (mg/L) M5.45.1M < 0.018 0.085 0.087 0.049 M5.55.1M < 0.018 0.023 0.133 < 0.025 M5.65.1M < 0.018 < 0.008 0.149 0.031 M5.75.1M < 0.018 0.043 0.148 < 0.025 M6.45.1M < 0.018 0.1175 0.0846 0.0885 M6.55.1M < 0.018 < 0.008 0.133 0.037 M6.65.1M < 0.018 0.01 0.127 < 0.025 M6.75.1M < 0.018 < 0.008 0.123 < 0.025 M7.45.1M 0.019 0.009 0.093 < 0.025 M7.55.1M < 0.018 < 0.008 0.151 < 0.025 M7.65.1M < 0.018 < 0.008 0.117 0.027 M7 .75.1M 0.038 0.049 0.123 0.051 M8.45.1M < 0.018 < 0.008 0.132 0.053 M8.55.1M < 0.018 0.095 0.159 0.028 M8.65.1M < 0.018 0.056 0.152 < 0.025 M8.75.1M < 0.018 0.043 0.092 0.071 M9.45.1M < 0.018 0.1007 0.0801 0.0482 M9.55.1M < 0.018 0.2056 0.1191 0.0547 M9.65.1M < 0.018 0.071 0.15 0.041 M9.75.1M < 0.018 < 0.008 0.137 0.0482 M10.45.1M < 0.018 < 0.008 0.134 < 0.025 M10.55.1M < 0.018 0.1434 0.0905 0.0577 M10.65.1M < 0.018 0.026 0.116 < 0.025 M10.75.1M < 0.018 0.1503 0.0799 0.0534 M11.45.1M < 0.018 0.054 0.146 < 0.025 M11.55.1M < 0.018 0.046 0.133 0.035 M11.65.1M < 0.018 0.045 0.135 0.029 M11.75.1M <0.018 0.01 0.118 <0.025 M12.45.1M 0.057 0.037 0.081 < 0.025 M12.55.1M < 0.018 < 0.008 0.14 0.049 M12.65.1M < 0.018 < 0.008 0.121 0.031 M12.75.1M < 0.018 < 0.008 0.1041 < 0.025 96 APPENDIX C Table C-6. (cont’d) Collection pH SiOz Sample ID Well Depth Date (units) (mg/L) M13.45.1M M13 45 09/19/97 7.316 12.4 M13.55.1M M13 55 09/19/97 7.367 13.8 Ml3.65.1M M13 65 09/19/97 7.339 18.5 M13.75.1M M13 75 09/19/97 7.335 14.1 M14.50.1M M14 50 09/19/97 7.369 12.9 M14.60.1M M14 60 09/19/97 7.325 15.4 M14.80.1M M14 80 09/19/97 7.337 13.9 M14.90.1M M14 90 09/19/97 7.265 9.2 M15.30.1M M15 30 09/19/97 7.363 15.0 M15.40.1M M15 40 09/19/97 7.325 14.2 M15.50.1M M15 50 09/19/97 7.376 11.8 M15.60.1M M15 60 09/19/97 7.321 12.4 M15.70.1M M15 70 09/19/97 7.411 15.4 M15.80.1M M15 80 09/19/97 7.302 13.5 M15.90.1M M15 90 09/19/97 7.247 7 .7 M16.30.1M M16 30 09/19/97 7.404 14.6 M16.40.1M M16 40 09/19/97 7.291 11.3 M16.50.1M M16 50 09/19/97 7.353 12.5 M16.60.1M M16 60 09/19/97 7.342 14.2 M16.70.1M M16 70 09/19/97 7.386 12.6 M16.75.1M M16 75 09/19/97 7.341 12.8 M16.80.1M M16 80 09/19/97 7.353 15.1 M16.90.1M M16 90 09/19/97 7.295 16.4 M17.75.1M M17 75 09/19/97 7.330 13.4 M18.75.1M M18 75 09/19/97 7.270 13.1 M19.45.1M M19 45 09/19/97 7.337 14.3 M19.55.1M M19 55 09/19/97 7.346 15.1 M19.65.1M M19 65 09/19/97 7.279 13.2 M19.75.1M M19 75 09/19/97 7.261 16.9 M20.45.1M M20 45 09/19/97 7.286 12.3 M20.55.1M M20 55 09/19/97 7.341 11.4 M20.65.1M M20 65 09/19/97 7.362 12.8 M20.75.1M M20 75 09/19/97 7.356 18.7 97 APPENDIX C Table C-6. (cont’d) Ca Mg Na K Sample 11) (mg/L) (mg/L) (mg/L) (mg/L) M13.45.1M 90.7 29.4 20.0 7.3 M13.55.1M 99.1 32.0 21.7 3.0 Ml3.65.1M 98.5 32.6 39.4 3.4 M13.75.1M 100.0 31.3 16.9 2.4 M14.50.1M 85.4 30.6 29.3 5.0 M14.60.1M 115.9 36.1 33.3 4.9 M14.80.1M 103.9 33.2 19.7 1.5 M14.90.1M 101.3 35.1 21.8 3.4 M15.30.1M 103.3 33.5 38.0 5.8 M15.40.1M 101.4 31.2 32.6 6.8 M15.50.1M 64.2 25.1 37.2 1.2 M15.60.1M 94.8 30.2 11.5 3.7 M15.70.1M 112.9 34.1 22.9 1.7 M15.80.1M 97.6 32.4 12.7 2.0 M15.90.1M 80.5 31.3 21.4 0.9 M16.30.1M 95.7 29.9 30.8 4.9 M16.40.1M 70.1 26.0 35.9 4.1 M16.50.1M 84.1 31.1 24.6 4.3 M16.60.1M 100.7 31.6 17.2 2.7 M16.70.1M 87.1 27.8 7.2 2.4 M16.75.1M 87.7 26.7 14.3 1.6 M16.80.1M 101.6 34.5 18.0 1.4 M16.90.1M 113.2 40.3 10.8 3.0 M17.75.1M 94.9 29.8 23.0 5.6 M18.75.1M 102.5 32.1 24.4 5.4 M19.45.1M 95.9 37.8 45.9 4.6 M19.55.1M 107.4 34.6 38.3 4.3 M19.65.1M 108.9 31.7 29.9 3.3 M19.75.1M 131.5 43.3 34.5 1.7 M20.45.1M 87.9 28.8 19.1 6.9 M20.55.1M 79.6 26.5 24.3 1.8 M20.65.1M 98.1 29.2 39.7 3.2 M20.75.1M 99.2 32.7 20.7 2.4 98 APPENDIX C Table C-6. (cont’d) HCO3 CI N03 804 Sample 11) (mg/L) (mg/L) (mg/L) (mg/L) M13.45.1M 397 45.6 42.2 29.6 M13.55.1M 400 35.9 66.6 32.1 Ml3.65.1M 441 56.4 46.6 26.4 M13.75.1M 413 35.9 50.4 29.7 M14.50.1M 378 76.7 36.1 30.1 M14.60.1M 427 43.6 74.7 29.8 M14.80.1M 400 52.5 67.9 32.8 M14.90.1M 421 59.5 18.7 75.3 M15.30.1M 416 55.5 36.0 22.8 M15.40.1M 444 76.3 34.3 25.9 M15.50.1M 386 69.3 49.7 29.8 M15.60.1M 406 29.2 70.5 31.9 M15.70.1M 400 59.5 65.2 31.1 M15.80.1M 413 37.3 66.6 33.8 M15.90.1M 406 58.8 1.4 85.4 M16.30.1M 386 53.0 32.9 19.7 M16.40.1M 427 62.2 41.4 24.0 M16.50.1M 389 59.2 50.9 29.3 M16.60.1M 375 33.3 59.3 32.3 M16.70.1M 363 44.2 41.5 36.4 Ml6.75.1M 372 32.3 56.5 34.9 M16.80.1M 381 32.2 66.3 35.4 M16.90.1M 401 47.9 4.8 76.0 M17.75.1M 395 46.9 74.4 35.4 M18.75.1M 429 52.5 73.1 32.1 M19.45.1M 398 58.4 61.5 28.4 M19.55.1M 427 46.1 70.2 28.6 M19.65.1M 453 78.0 46.5 29.2 M19.75.1M 474 69.3 50.1 29.4 M20.45.1M 400 46.3 52.3 28.2 M20.55.1M 407 38.2 70.9 30.7 M20.65.1M 445 64.4 51.1 29.2 M20.75.1M 418 37.6 63.5 30.3 99 APPENDIX C Table C-6. (cont’d) Al Ba Cu Fe Mn Sample ID (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) M13.45.1M 0.209 0.046 < 0.031 < 0.058 < 0.015 M13.55.1M 0.0394 0.055 < 0.031 < 0.058 0.0217 Ml3.65.1M 0.224 0.046 < 0.031 0.076 0.078 M13.75.1M 0.21 0.041 < 0.031 < 0.058 0.032 M14.50.1M 0.168 0.045 < 0.031 < 0.058 < 0.015 M14.60.1M < 0.006 0.0867 < 0.031 < 0.058 < 0.015 M14.80.1M 0.1255 0.058 < 0.031 < 0.058 < 0.015 M14.90.1M 0.275 0.11 < 0.031 0.166 0.169 M15.30.1M 0.1028 0.064 < 0.031 < 0.058 < 0.015 M15.40.1M 0.196 0.051 < 0.031 < 0.058 < 0.015 M15.50.1M < 0.006 0.047 < 0.031 < 0.058 < 0.015 M15.60.1M 0.183 0.038 < 0.031 < 0.058 < 0.015 M15.70.1M 0.153 0.0693 < 0.031 < 0.058 < 0.015 M15.80.1M 0.225 0.04 < 0.031 < 0.058 < 0.015 M15.90.1M < 0.006 0.0972 < 0.031 < 0.058 0.1879 M16.30.1M 0.1009 0.0564 < 0.031 < 0.058 < 0.015 M16.40.1M 0.0396 0.0563 < 0.031 < 0.058 0.0396 M16.50.1M 0.2 0.042 < 0.031 < 0.058 < 0.015 M16.60.1M 0.15 0.0561 < 0.031 < 0.058 0.0198 M16.70.1M 0.165 0.032 < 0.031 < 0.058 < 0.015 M16.75.1M < 0.006 0.0511 < 0.031 < 0.058 0.0226 M16.80.1M 0.1425 0.0631 < 0.031 0.121 0.0551 M16.90.1M 0.384 0.084 < 0.031 0.485 0.484 M17.75.1M 0.175 0.056 < 0.031 < 0.058 < 0.015 M18.75.1M 0.186 0.053 < 0.031 < 0.058 < 0.015 M19.45.1M < 0.006 0.0688 < 0.031 < 0.058 < 0.015 Ml9.55.1M 0.0644 0.0777 < 0.031 < 0.058 < 0.015 M19.65.1M 0.189 0.045 < 0.031 < 0.058 < 0.015 M19.75.1M 0.1808 0.0756 < 0.031 < 0.058 < 0.015 M20.45.1M 0.155 0.043 < 0.031 < 0.058 < 0.015 M20.55.1M < 0.006 0.0482 < 0.031 < 0.058 < 0.015 M20.65.1M 0.209 0.046 < 0.031 < 0.058 < 0.015 M20.75.1M 0.215 0.043 < 0.03] < 0.058 0.038 100 Table C-6. (cont’d) APPENDIX C Sample ID Ni (mg/L) Pb (mg/L) Sr (mg/L) Zn (mg/L) M13.45.1M <0.018 0.042 0.117 < 0.025 M13.55.1M 0.0332 0.0693 0.1575 0.0615 Ml3.65.1M <0.018 0.062 0.123 0.03 M13.75.1M <0.018 0.044 0.102 < 0.025 M14.50.1M <0.018 < 0.008 0.08 < 0.025 M14.60.1M 0.0365 < 0.008 0.1819 0.0284 M14.80.1M <0.018 0.0209 0.1094 0.0695 M14.90.1M <0.018 < 0.008 0.102 0.032 M15.30.1M 0.0256 < 0.008 0.1935 0.0268 M15.40.1M <0.018 0.054 0.163 0.042 M15.50.1M 0.0196 0.1125 0.0671 0.0551 M15.60.1M 0.028 < 0.008 0.154 0.026 M15.70.1M <0.018 < 0.008 0.1113 0.0912 M15.80.1M <0.018 0.016 0.089 < 0.025 M15.90.1M <0.018 0.0779 0.0721 0.0344 M16.30.1M <0.018 < 0.008 0.1724 0.0855 M16.40.1M <0.018 0.1201 0.1343 0.0665 M16.50.1M <0.018 0.12 0.082 0.033 M16.60.1M 0.0242 < 0.008 0.1653 0.0517 M16.70.1M <0.018 0.054 0.111 0.033 M16.75.1M <0.018 < 0.008 0.0945 0.05 M16.80.1M 0.0181 0.1236 0.0919 0.073 M16.90.1M <0.018 0.078 0.089 0.097 M17.75.1M <0.018 < 0.008 0.14 0.053 M18.75.1M <0.018 < 0.008 0.147 0.054 M19.45.1M <0.018 0.0097 0.1042 0.0314 M19.55.1M 0.019 < 0.008 0.1618 0.0419 M19.65.1M <0.018 0.025 0.12 0.045 M19.75.1M <0.018 < 0.008 0.1273 0.0407 M20.45.1M <0.018 < 0.008 0.119 0.032 M20.55.1M <0.018 0.086 0.1385 0.0408 M20.65.1M <0.018 < 0.008 0.122 < 0.025 M20.75.1M <0.018 0.071 0.113 0.042 101 APPENDIX C Table C-6. (cont’d) Collection pH 8102 Sample ID Well Depth Date (units) (mg/L) M23.45.1M M23 45 09/19/97 7.319 11.8 M23.55.1M M23 55 09/19/97 7.335 12.4 M23.65.1M M23 65 09/19/97 7.302 14.7 M23.75.1M M23 75 09/19/97 7.239 14.4 M24.45.1M M24 45 09/19/97 7.374 13.4 M24.55.1M M24 55 09/19/97 7.344 15.8 M24.65.1M M24 65 09/19/97 7.342 13.3 M24.75.1M M24 75 09/19/97 7 .295 14.7 M25.45.1M M25 45 09/19/97 7.312 12.4 M25.55.1M M25 55 09/19/97 7.337 14.8 M25.65.1M M25 65 09/19/97 7.291 12.7 M25.75.1M M25 75 09/19/97 7.295 13.2 M26.45.1M M26 45 09/19/97 7.304 15.1 M26.55.1M M26 55 09/19/97 7.363 13.0 M26.65.1M M26 65 09/19/97 7.332 12.4 M26.75.1M M26 75 09/19/97 7.381 12.7 102 APPENDIX C Table C-6. (cont’d) Ca Mg Na K Sample ID (mg/L) (mg/L) (mg/L) (mg/L) M23.45.1M 82.6 29.8 28.6 5.4 M23.55.1M 95.6 29.0 21.9 4.0 M23.65.1M 117.4 34.5 36.0 2.4 M23.75.1M 112.7 34.6 19.7 2.3 M24.45.1M 89.5 29.3 18.3 2.4 M24.55.1M 107.6 33.6 54.8 3.1 M24.65.1M 92.7 29.4 10.1 3.8 M24.75.1M 97.1 34.9 29.8 7.3 M25.45.1M 89.2 29.2 26.3 5.0 M25.55.1M 106.1 34.1 31.8 4.2 M25.65.1M 103.1 29.6 28.8 2.7 M25.75.1M 102.5 31.9 31.7 2.3 M26.45.1M 105.6 36.8 32.2 16.8 M26.55.1M 89.8 28.8 9.1 3.6 M26.65.1M 98.9 29.3 35.8 2.9 M26.75.1M 87.6 29.0 16.7 2.4 103 Table C-6. (cont’d) APPENDIX C HCO3 Cl N03 804 Sample 11) (mg/L) (mg/L) (mg/L) (mg/L) M23.45.1M 395 56.1 61.4 28.6 M23.55.1M 416 47.6 61.7 28.7 M23.65.1M 444 75.1 55.3 29.8 M23.75.1M 471 69.9 56.1 29.3 M24.45.1M 400 34.1 66.7 32.2 M24.55.1M 445 69.9 50.2 28.7 M24.65.1M 383 31.7 72.7 33.1 M24.75.1M 401 55.4 47.9 27.7 M25.45.1M 392 46.6 63.7 27.7 M25.55.1M 413 37.4 78.4 29.1 M25.65.1M 430 68.6 60.4 29.3 M25.75.1M 467 58.4 64.6 29.9 M26.45.1M 401 57.4 46.4 27.8 M26.55.1M 383 35.5 60.1 34.0 M26.65.1M 441 93.2 20.0 27.7 M26.75.1M 389 44.6 53.0 33.4 104 APPENDIX C Table C-6. (cont’d) Al Ba Cu Fe Mn Sample ID (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) M23.45.1M 0.16 0.039 < 0.031 < 0.058 < 0.015 M23.55.1M 0.155 0.037 < 0.031 < 0.058 < 0.015 M23.65.1M < 0.006 0.0695 < 0.031 < 0.058 < 0.015 M23.75.1M 0.243 0.04 < 0.031 < 0.058 < 0.015 M24.45.1M 0.174 0.029 < 0.031 < 0.058 < 0.015 M24.55.1M 0.0916 0.0717 < 0.031 < 0.058 0.0304 M24.65.1M 0.178 0.033 < 0.031 < 0.058 < 0.015 M24.75.1M 0.0918 0.0775 < 0.031 < 0.058 < 0.015 M25.45.1M 0.0628 0.0598 < 0.031 < 0.058 < 0.015 M25.55.1M 0.1016 0.0614 < 0.031 < 0.058 < 0.015 M25.65.1M 0.201 0.042 < 0.031 < 0.058 < 0.015 M25.75. 1M 0.205 0.041 < 0.031 < 0.058 < 0.015 M26.45.1M 0.0522 0.0828 < 0.031 < 0.058 < 0.015 M26.55.1M 0.167 0.034 < 0.031 < 0.058 < 0.015 M26.65.1M 0.197 0.045 < 0.031 < 0.058 < 0.015 M26.7S.1M 0.177 0.033 < 0.031 < 0.058 < 0.015 105 APPENDIX C Table C-6. (cont’d) Ni Pb Sr Zn Sample ID (mg/L) (mg/L) (mg/L) (mg/L) M23.45.1M < 0.018 0.042 0.086 0.033 M23.55.1M < 0.018 0.092 0.132 0.057 M23.65.1M < 0.018 0.0288 0.1262 0.0769 M23.75.1M < 0.018 0.044 0.103 0.043 M24.45.1M < 0.018 0.046 0.09 < 0.025 M24.55.1M < 0.018 < 0.008 0.1406 0.0517 M24.65.1M < 0.018 < 0.008 0.147 < 0.025 M24.75.1M 0.021 < 0.008 0.1575 0.0295 M25.45.1M < 0.018 0.1303 0.0982 0.0621 M25.55.1M < 0.018 0.0131 0.1565 0.0583 M25.65.1M 0.043 0.013 0.11 < 0.025 M25.75.1M < 0.018 0.058 0.097 0.047 M26.45.1M < 0.018 < 0.008 0.1596 0.0574 M26.55.1M < 0.018 0.144 0.146 0.035 M26.65.1M 0.048 < 0.008 0.131 < 0.025 M26.75.1M < 0.018 0.023 0.088 < 0.025 106 APPENDIX C Table C-7. Trace metals concentration when exposed to aquifer solids Sample location: MW34A Analysis by: L. Warnick Analysis date: June 07,1997 Before Exposure After Exposure No. Samples Average No. Samples Average Element > MDL (ppm) > MDL (ppm) Al 3 0.019 :t 0.007 3 0.212 t 0.211 As 0 < 0.05 0 < 0.05 Ba 3 0.097 i 0.004 0 < 0.002 Cd 0 < 0.004 0 < 0.004 Co 0 < 0.007 0 < 0.007 Cr 0 < 0.007 0 < 0.007 Cu 0 < 0.006 1 0.002 Fe 0 < 0.007 3 0.395 i 0.291 Mn 0 < 0.002 0 < 0.002 Ni 0 < 0.015 2 0.016 :1: 0.007 Pb 0 < 0.040 0 < 0.040 Sr 3 0.146 :1: 0.001 3 0.092 i 0.001 Zn 3 0.727 i 0.106 1 0.003 Batch experiments (10 mL Schoolcraft groundwater, l g solids, time: 3 days) 107 APPENDIX D 108 APPENDIX D BENCH-SCALE COLUMNS Table D-l. Effluent chemistry for 1-D column (B4) Absolute Ca Mg Na K PVE pH (meq/L) (meq/L) (meq/L) (meq/L) 0.00 7.56 4.50 2.87 1.31 0.18 0.83 7.74 3.14 1.74 3.02 0.16 1.67 7.89 2.13 1.22 3.88 0.15 2.50 7.96 2.10 1.35 4.07 0.16 3.33 8.10 - - - - 4.17 8.16 1.41 2.15 4.08 0.17 5.00 8.23 - - - - 5.83 8.28 0.95 2.51 3.96 0.17 6.67 8.30 - - - - 7.50 8.32 0.91 2.71 3.99 0.18 8.33 8.33 0.90 2.81 4.03 0.18 9.17 8.33 0.88 2.84 4.10 0.18 10.00 8.34 0.87 2.88 4.24 0.18 10.83 8.35 0.88 2.86 4.15 0.19 11.67 8.36 - - - - 12.50 8.39 - - - - 13.33 8.37 0.86 2.79 4.12 0.19 109 APPENDIX D Table D-l. (cont’d) Absolute SiOz HCO3 Cl N03 804 PVE pH (mmol/L) (meq/L) (meq/L) (meq/L) (meq/L) 0.00 7.56 0.24 10.05 1.60 0.32 0.42 0.83 7.74 0.21 8.50 1.79 0.37 0.47 1.67 7.89 0.21 - 1.56 0.33 0.40 2.50 7 .96 0.22 7.35 1.78 0.37 0.45 3.33 8.10 - - - - - 4.17 8.16 0.22 8.40 1.95 0.36 0.44 5.00 8.23 - - - - - 5.83 8.28 0.23 7.55 1.77 0.37 0.45 667 8.30 - - - - - 7.50 8.32 0.22 7.85 - - - 8.33 8.33 0.22 - - - - 9.17 8.33 0.23 8.40 - - - 10.00 8.34 0.23 - 1.77 0.37 0.45 10.83 8.35 0.23 7.90 1.76 0.37 0.45 11.67 8.36 - - - - - 12.50 8.39 - - - - - 13.33 8.37 0.22 7 .25 1.73 0.37 0.45 110 Table D-2. Effluent pH for twenty l-D columns (C-l to C-20) APPENDIX D 111 C-1 C-2 C-3 C-4 C-5 C-6 C-7 Sample pH pH pH pH pH pH pH 1 7.55 7.57 7.6 7.55 7.71 7.61 7.6 2 7.72 7.55 7.79 7.53 7.88 7.85 7.81 3 7.94 7.54 7.95 7 .55 7.97 7.96 7.92 4 8.09 7.55 8.08 7.55 8.02 8.01 7.98 5 8.19 7.53 8.17 7.53 8.04 8.05 8.01 6 8.25 7.55 8.22 7.52 8.07 8.05 8.02 7 8.28 7.55 8.29 7.53 8.07 8.09 8.04 8 8.29 7.55 8.3 7.53 8.07 8.09 8.06 9 8.31 7.54 8.31 7.54 8.12 8.11 8.1 10 8.32 7.57 8.33 7.54 8.06 8.03 8.03 C-8 C-9 C-10 C-ll C-12 C-l3 C-14 Sample pH pH pH pH pH pH pH 1 7.55 7.54 7.55 7.51 7.45 7.54 7.51 2 7.84 7.73 7.74 7.71 7.58 7.78 7.78 3 7 .94 7.87 7.9 7.84 7.77 7.92 7.92 4 8.01 7.94 8.03 7 .94 7.84 8.06 8.07 5 8.02 8.1 8.14 8.03 7.86 8.18 8.16 6 8.06 8.19 8.22 8.13 7.95 8.22 8.22 7 8.06 8.23 8.27 8.18 8.03 8.25 8.25 8 8.11 8.24 8.28 8.22 8.06 8.28 8.29 9 8.13 8.26 8.29 8.26 8.09 8.29 8.3 10 8.08 8.28 8.31 8.29 8.13 8.29 8.31 C-15 C-l6 C-l7 C-18 C-19 C-20 Sample pH pH pH pH pH pH 1 7.69 7.54 7.48 7.68 7.67 7.64 2 7.78 7.68 7.67 7.8 7.85 7.86 3 7.9 7.79 7.84 7.88 7.95 8.04 4 7.94 7.85 7.94 7.94 8.05 8.16 5 8.02 7.92 8.03 7.98 8.14 8.21 6 8.1 7.97 8.09 8.04 8.19 8.25 7 8.15 8 8.15 8.08 8.23 8.28 8 8.21 8.05 8.2 8.12 8.25 8.31 9 8.24 8.06 8.22 8.19 8.27 8.33 10 8.27 8.1 8.24 8.22 8.28 8.34 APPENDIX D Table D-3. Effluent chemistry for l-D column (C-29) Ca Mg Na K Column Sample pH (meq/L) (meq/L) (meq/L) (meq/L) 029 1 7.45 3.77 3.13 1.31 0.14 C-29 2 7.65 2.94 1.92 1.61 0.10 029 3 7.81 2.49 1.90 1.78 0.11 C-29 4 7.93 2.06 2.53 1.81 0.12 C-29 5 8.03 1.76 2.83 1.79 0.13 C-29 6 8.13 1.63 2.91 1.77 0.13 029 7 8.19 1.63 3.02 1.75 0.13 C-29 8 8.26 1.63 2.99 1.79 0.13 C-29 9 8.24 1.56 3.04 1.74 0.12 029 10 8.28 1.54 3.02 1.77 0.13 C-29 11 8.28 - - - - C-29 12 8.31 - - - - C-29 13 8.32 - - - - C-29 14 8.32 - - - - C-29 15 8.33 - - - - 4.0 3-4 3.5 «- 8.3 A .. 8.2 E‘ 30 1 . +_Ca .- 8.1 g, 2.5 e I i—fi—Mg' -- 8'0? .3 2.0 . A V... _- —)(—Na + 7.9 i g 1.5 - +K *' Z: a. 1: + H 1“ ° 8 1.0 . l _L___P ._ 7.6 0.5 “ W 75 0.0 7.4 Figure D-1.Effluent chemistry for 1-D column (C-29) 0123456789101112131415 Pore volumes exchanged (PVE) 112 APPENDIX D Table D-4. Effluent chemistry for l-D column (C-30) Ca Mg Na K Column Sample pH (meq/L) (meq/L) (meq/L) (meq/L) C-30 1 7.47 1.95 2.82 1.27 0.11 030 2 7.66 1.73 1.71 1.52 0.09 030 3 7.77 1.66 1.45 1.76 0.09 C-30 4 7.86 1.97 1.71 1.71 0.10 C-30 5 7.94 1.56 2.23 1.70 0.10 C-30 6 8.06 1.39 2.41 1.72 0.11 C-30 7 8.13 1.41 2.64 1.75 0.10 C-30 8 8.18 1.43 2.61 1.75 0.11 C-30 9 8.21 1.29 2.66 1.91 0.13 030 10 8.25 1.39 2.69 1.75 0.11 C-30 11 8.27 1.33 2.57 1.67 0.12 030 12 8.29 1.36 2.78 1.76 0.11 030 13 8.29 1.31 2.59 1.67 0.12 C-30 14 8.3 1.30 2.60 1.70 0.11 C-30 15 8.32 1.31 2.63 1.74 0.10 3.0 8.4 I“ ‘3‘.“ 8.3 A 2'5 ‘ " _ 8.2 E- 20 y +Ca 4e 8.1 E; ‘ _ A" +Mg' 8.0 33 § 1.5 — Vfi' g-X—Na 1- 7.9 g «2 ++K . ._ 7.8 In E 1"" '+pI-Il -. 7.7 U 0.5 q - 7.6 -- 7.5 0.0 .fi-,,.r... .T. .,....7.4 0123456789101112131415 Pore volumes exchanged (PVE) Figure D-2. Effluent chemistry for l-D column (C-30) 113 APPENDIX D Table D-5. Effluent chemistry for 1-D column (C-35) Ca Mg Na K Column Sample pH (meq/L) (meq/L) (meq/L) (meq/L) C-35 1 7.41 1.42 2.70 1.34 0.13 C-35 2 7.58 1.90 1.74 1.47 0.11 C-35 3 7.73 1.95 1.45 1.67 0.09 035 4 7.8 1.49 1.78 1.97 0.13 035 5 7.85 1.73 2.29 1.70 0.12 C-35 6 7.88 1.47 2.39 1.67 0.13 C-35 7 7.95 1.33 2.49 1.68 0.13 C-35 8 7.97 1.33 2.53 1.66 0.12 035 9 8.02 1.30 2.57 1.71 0.13 035 10 8.01 1.36 2.58 1.88 0.13 C-35 11 8.09 - - - - C-35 12 8.07 - - - - C-35 13 8.11 - - - - C-35 14 8.14 - - - - C-35 15 8.12 - - - - 3.0 8.2 t 8.1 2.5 « 3 «e 8.0 3 2.0 . "“ ' .1 7.9 E +Ca A g 1.5 . ’v’f’ +Mg‘ I 7'8 g g i-x—Na 7.7 E § 1.0. l-x-k +7.6 ‘7 8: +1011 1 7.5 0.5 . --_ — -1 7.4 0.0 . g. 7.3 0123456789101112131415 Pore volumes exchanged (PVE) Figure D-3.Effluent chemistry for 1-D column (C-35) 114 APPENDIX E 115 APPENDIX E BASE-ADJUSTED AQUIF ER SOLIDS Table E-l. Base exchange capacity of aquifer solids l-D Ca Mg Ca+Mg Sample Column Type (meq/100 g) (meq/100 g) (meq/100 g) 2-6608-1 1 pH-adjusted 0.87 0.18 1.05 2-6608-2C 2 Control 1.06 0.1 1 1.18 4-7810-3 3 pH-adjusted 2.02 0.25 2.29 4-7810—4C 4 Control 1 .49 0.16 1 .66 6-31 1 1-5 5 pH-adjusted - - - 6-31 1 1-5C 5 Control 2.48 0.22 2.71 2-5405-6 6 pH-adjusted 1 .5 1 0.22 1.75 2-5405-6C 6 Control 1.24 0.15 1.39 4-7604-7 7 pH-adjusted l .52 0.26 1.79 4-7604-7C 7 Control 1.64 0.17 1.82 2-6010-8 8 pH-adjusted 1 .60 0.22 1 .83 2-6010-8C 8 Control 1.04 0.13 1.18 14-7706-9 9 pH-adjusted 1.47 0.21 1.69 14-7706-9C 9 Control 1.60 0.15 1.76 10-6406-10 10 pH-adjusted 1.28 0.24 1.53 10-6406-10C 10 Control 2.13 0.19 2.33 4-5200-1 1 l 1 pH-adjusted 1.65 0.24 1.91 4-5200-1 1C 1 1 Control 1.75 0.16 1.92 4-3406-12 12 pH-adjusted 1 .84 0.37 2 .24 4-3406-12C 12 Control 1.81 0.20 2.03 6-6500-13 13 pH-adjusted 1.63 0.25 1.89 6-6500-13C 13 Control 1.14 0.13 1.28 10-5503-14 14 pH-adjusted 2.27 0.27 2.55 10-5503-14C 14 Control 2.73 0.19 2.93 D10-4500 15 Core 2.83 0.21 2.83 15 15 pH-adjusted 2.44 0.34 2.44 15C 15 Control 2.02 0.19 2.02 116 APPENDIX E Table E-l. (cont’d) l-D Ca Mg Ca+Mg Sample Column Type (meq/100 g) (meq/100 g) (meq/100 g) D44706 16 Core 1.25 0.12 1.25 16 16 pH-adjusted 2.42 0.32 2.42 16C 16 Control 2.39 0.20 2.39 D4-4500 17 Core 2.76 0.21 2.76 17 17 pH-adjusted 2.99 0.27 2.99 17C 17 Control 3.18 0.20 3.18 D10-3202 18 Core 0.74 0.15 0.74 18 18 pH-adjusted 1 .64 0.47 1 .64 18C 18 Control 0.57 0.17 0.57 D4-6604 19 Core 2.15 0.23 2.15 19 19 pH-adjusted 1 .29 0.16 1 .29 19C 19 Control 1.71 0.16 1.71 D14-6206 20 Core 2.67 0.17 2.67 20 20 pH-adjusted 1.53 0.21 1.53 20C 20 Control 1.83 0.15 1.83 D14-4104 21 Core 4.87 0.26 4.87 21 21 pH-adjusted 3.67 0.26 3.67 21C 21 Control 3.47 0.18 3 .47 D8-8110 22 Core 2.72 0.17 2.72 22 22 pH-adjusted 1 .92 0.19 1 .92 22C 22 Control 2.84 0.17 2.84 D4-6206 23 Core 1.77 0.13 1.77 23 23 pH-adjusted 1.81 0.16 1.81 23C 23 Control 1.88 0.11 1.88 D8-5010 24 Core 3.14 0.19 3.14 24 24 pH-adjusted 2.32 0.27 2.32 24C 24 Control 2.38 0.25 2.38 D2-4600 25 Core 4.85 0.25 4.85 25 25 pH-adjusted 0.44 0.16 0.44 25C 25 Control 0.52 0.10 0.52 117 APPENDIX E Table E-l. (cont’d) l-D Ca Mg Ca+Mg Sample Column Type (meq/100 g) (meq/100 g) (meq/100 g) D8-8406 26 Core 2.32 0.23 2.32 26 26 pH-adjusted 1 .99 0. 19 1 .99 26C 26 Control - - - D4-3610.l 27 Core 3.48 0.23 3.48 D4-3610.2 27 Core 3.39 0.22 3.39 D4-3610.3 27 Core 2.58 0.23 2.58 27.1 27 pH-adjusted 1.33 0.31 1.33 27.2 27 pH-adjusted 1.63 0.33 1.63 27.3 27 pH-adjusted 1.46 0.34 1.46 27C.1 27 Control 1.24 0.20 1.24 27C.2 27 Control 1.27 0.18 1.27 27C.3 27 Control 1.33 0.18 1.33 D14-6610.1 28 Core 3.13 0.18 3.13 D14-6610.2 28 Core 3.17 0.19 3.17 D14-6610.3 28 Core 2.71 0.19 2.71 28.1 28 pH-adjusted 1.03 0.22 1.03 28.2 28 pH-adjusted 1.53 0.18 1.53 28.3 28 pH-adjusted 1.83 0.19 1.83 28C.1 28 Control 2.09 0.14 2.09 28C.2 28 Control 1.99 0.13 1.99 28C.3 28 Control 2.02 0.15 2.02 D4-5406.1 29 Core 1.45 0.15 1.45 D4-5406.2 29 Core 1.23 0.13 1.23 D4-5406.3 29 Core 1.35 0.12 1.35 29.1 29 pH-adjusted 1.08 0.17 1.08 29.2 29 pH-adjusted 1.19 0.16 1.19 29.3 29 pH-adjusted 1.71 0.18 1.71 29C.1 29 Control 1.14 0.11 1.14 29C.2 29 Control 1.17 0.09 1.17 29C.3 29 Control 1.19 0.11 1.19 118 APPENDIX E Table E-l. (cont’d) l-D Ca Mg Ca+Mg Sample Column Type (meq/100 g) (meq/100 g) (meq/100 g) D6-5006.1 30 Core 1.70 0.15 1.70 D6-5006.2 30 Core 1.69 0.15 1.69 D6-5006.3 30 Core 1.59 0.16 1.59 30.1 30 pH-adjusted 0.97 0.23 0.97 30.2 30 pH-adjusted 1.14 0.29 1.14 30.3 30 pH-adjusted 1.34 0.25 1.34 30C.1 30 Control 1.44 0.13 1.44 30C.2 30 Control 1.57 0.15 1.57 30C.3 30 Control 1.14 0.23 1.14 D6-3702.1 31 Core 0.91 0.16 0.91 D6-3702.2 31 Core 0.99 0.17 0.99 D6-3702.3 31 Core 0.99 0.17 0.99 31.1 31 pH-adjusted 0.86 0.24 0.86 31.2 31 pH-adjusted 0.79 0.24 0.79 31.3 31 pH-adjusted 0.69 0.25 0.69 31C.1 31 Control 0.74 0.14 0.74 31C.2 31 Control 0.79 0.15 0.79 31C.3 31 Control 0.81 0.13 0.81 D4-7206.1 32 Core 1.56 0.17 1.56 D4—7206.2 32 Core 1.63 0.16 1.63 D4-72063 32 Core 1.57 0.15 1.57 32.1 32 pH-adjusted 0.97 0.24 0.97 32.2 32 pH-adjusted 0.93 0.24 0.93 32.3 32 pH-adjusted 0.86 0.33 0.86 32C.1 32 Control 0.89 0.12 0.89 32C.2 32 Control 0.89 0.11 0.89 32C.3 32 Control 1.12 0.12 1.12 119 Table E-2. Composition of dissolved pH-adjusted aquifer solids APPENDIX E Cores after l-D exchanges in 15 cm column Dissolution of minerals using 1 N HNO3 Extracted concentrations (mg/ g solids) l-D Si Mn Fe Mg Al Ca K Sample Column Type mg/g mg/g mg/g mg/g mg/g mg/g mg/g D4-3610.1 27 Core 0.26 0.05 0.38 6.0 0.08 23.4 0.23 D4-3610.2 27 Core 0.39 0.04 0.43 6.5 0.16 24.7 0.67 D4-3610.3 27 Core 0.31 0.04 0.39 5.8 0.08 22.2 0.22 27.1 27 pH-adjusted 0.23 0.03 0.36 6.2 0.18 24.2 0.39 27.2 27 pH-adjusted 0.21 0.03 0.35 6.3 0.17 22.8 0.35 27.3 27 pH-adjusted 0.27 0.03 0.41 6.4 0.12 24.1 0.33 27C.1 27 Control 0.39 0.04 0.38 6.4 0.15 24.6 0.56 27C.2 27 Control 0.20 0.03 0.36 6.2 0.14 22.3 0.38 27C.3 27 Control 0.24 0.03 0.37 6.3 0.18 23.6 0.48 D14-6610 28 Core 0.15 0.01 0.28 5.3 0.22 19.8 0.57 28 28 pH-adjusted 0.15 0.02 0.23 4.7 0.13 17.5 0.35 28C 28 Control 0.15 0.01 0.28 5.9 0.21 20.9 0.50 D4-5406 29 Core 0.19 0.02 0.23 4.2 0.13 18.2 0.34 29 29 pH-adjusted 0.17 0.02 0.23 3.9 0.14 17.7 0.35 29C 29 Control 0.10 0.02 0.21 3.3 0.13 18.0 0.16 D6-5006 30 Core 0.18 0.03 0.29 5.0 0.11 21.2 0.12 30 30 pH-adjusted 0.20 0.00 0.31 5.6 0.28 20.8 0.87 30C 30 Control 0.15 0.02 0.26 4.9 0.20 20.0 0.49 D6-3702 31 Core 0.24 0.04 0.46 8.8 0.17 27.8 0.41 31 31 pH-adjusted 0.35 0.04 0.44 9.5 0.00 30.8 0.54 31C 31 Control 0.28 0.05 0.45 9.6 0.00 31.1 0.32 D4-7206 32 Core 0.23 0.03 0.34 6.4 0.13 21.5 0.26 32 32 pH-adjusted 0.13 0.01 0.23 5.3 0.14 18.4 0.49 32C 32 Control 0.11 0.00 0.16 3.4 0.16 15.4 0.40 120 APPENDIX F 121 APPENDIX F PHREEQC MODELING Table F—l. PHREEQC input file TITLE Simulation of Schoolcraft Column Experiments PHASES F ixed _pH H+ = H+ log_K 0.0 END SOLUTION 0 Displacing solution pH 8.39 temp 25.0 ~units ppm Ca 17 .1 Mg 33.9 Na 94.7 K 7.3 Alkalinity 442 C] 61.4 N(5) 22.8 S(6) 21.5 Si 13.5 END SELECTED_OUTPUT -file 1 10803.pun -totals Ca Mg Na K -si Calcite Dolomite Quartz END SOLUTION 1 Initial solution in pore volume pH 7.56 temp 25.0 -units ppm Ca 90.1 Mg 34.9 Na 30.2 K 7.0 122 APPENDIX F Table F—l. (cont’d) Alkalinity 613 C1 56.8 N(5) 20.12 S(6) 20.2 Si 14.2 EXCHANGE 1 # Exch. Amount CaX2 0.0055 MgX2 0.0011 USE exchange none SURFACE 1 # Surf. Amount Area Mass Hfo_w 0.0025 600. 30. USE surface none END TRANSPORT -cells 1 -shifis 15 END 123 APPENDIX F Table F-2. PHREEQC saturation indices for pore solution Phase SI log IAP log KT Formula Anhydrite -2.54 -6.9 -4.36 CaSO4 Aragonite 0.68 -7.66 -8.34 CaCO3 Brucite -4.81 12.03 16.84 Mg(OH)2 Calcite 0.82 -7.66 -8.48 CaCO3 Chalcedony -0.08 -3.63 -3.55 Si02 Chrysotile -3.37 28.83 32.2 Mg3Si205(OH)4 Clinoenstatite -2.94 8.4 1 1.34 MgSiO3 CO2(g) -1.72 -19.87 -18.15 C02 Cristobalite -0.04 -3.63 -3.59 Si02 Diopside -2.91 16.99 19.89 CaMgSiZO6 Dolomite 1.59 -15.5 -17.09 CaMg(CO3)2 Dolomite(d) 1.04 -15.5 -16.54 CaMg(CO3)2 Epsomite -4.95 -7.09 -2.14 M gSO4z7H20 Fixed _pH -7.56 -7.56 0 H+ Forsterite -7.88 20.43 28.31 Mg2SiO4 Gypsum -2.32 -6.9 -4.58 CaSO4z2H20 H2( g) -23. 12 -23. 12 0 H2 Halite -7.37 -5 .79 1.58 NaCl Huntite -1.21 -31.18 -29.97 CaMg3(CO3)4 Magadiite -6.47 -20.77 -14.3 NaSi70l3(OH)3:3H20 Magnesite 0.19 -7.84 -8.03 MgCO3 Nahcolite -4.37 -15.25 ~10.88 NaHCO3 Natron -9.31 - 10.62 - 1 .31 Na2CO3: 10H20 Nesquehonite -2.22 -7.84 -5.62 MgCO3:3H2O 02( g) 36.88 46.24 83.12 02 Portlandite -10.59 12.21 22.8 Ca(OH)2 Quartz 0.35 -3.63 -3.98 Si02 SiOZ(a) -0.92 -3 .63 -2.71 Si02 Talc 0.18 21.58 21.4 Mg3Si4O 10(OH)2 Thenardite -9.69 -9.87 -0. 18 Na2SO4 Thermonatrite - 10.75 - 10.62 0.12 Na2CO3 :HZO 124 APPENDIX F Table F-3. PHREEQC saturation indices for displacing solution Phase SI log IAP log KT Formula Anhydrite -3. 17 -7.53 -4.36 CaSO4 Aragonite 0.64 -7.7 -8.34 CaCO3 Brucite -3. 15 13.69 16.84 Mg(OH)2 Calcite 0.78 -7 .7 -8.48 CaCO3 Chalcedony -0.1 1 -3 .66 -3 .55 Si02 Chrysotile 1.53 33 .73 32.2 Mg3SiZOS(OH)4 Clinoenstatite -1.32 10.02 1 1.34 MgSiO3 C02(g) -2.7 -20.85 -18.15 C02 Cristobalite -0.08 -3.66 -3.59 Si02 Diopside -0.3 8 19.51 19.89 CaMgSiZO6 Dolomite 2.23 -14.86 -17.09 CaMg(CO3)2 Dolomite(d) 1.68 - 14.86 - 16.54 CaMg(CO3 )2 Epsomite -4.86 -7 -2. 14 MgSO4:7H20 Fixed _pH -8.39 -8.39 0 H+ F orsterite -4.6 23 .71 28.31 Mg2SiO4 Gypsum -2.95 -7.53 -4.58 CaSO4z2HZO H2( g) -24.78 -24.78 0 H2 Halite -6.83 -5 .25 1.58 NaCl Huntite 0.78 -29. 19 -29.97 CaMg3(CO3 )4 Magadiite -5.39 -19.69 -14.3 NaSi70l3(OH)3:3HZO Magnesite 0.87 -7. 16 -8.03 MgCO3 Nahcolite -4.02 -14.89 -10.88 NaHCO3 Natron -7.63 -8.94 -1.31 Na2CO3:10H20 Nesquehonite -1.54 -7.16 -5 .62 MgCO3 :3H20 02(g) -33.56 49.56 83.12 02 Portlandite -9.65 13. 15 22 . 8 Ca(OH)2 Quartz 0.32 -3.66 -3.98 8102 Si02(a) -0.95 -3 .66 -2.71 S102 Talc 5 26.4 21.4 Mg3 Si4O 10(OH)2 Thenardite -8.6 -8.78 -0. 18 Na2SO4 Thermonatrite -9.07 -8.94 0.12 Na2CO3 :HZO 125 APPENDIX F Table F-4. PHREEQC selected output file Calcite Dolomite Quartz step ph Ca Mg Na K _si _si _si -99 7.560 2.25E-03 1.44E-03 1.31E-03 1.79E-04 0.824 1.593 0.354 1 7.987 1.02E-03 4.70E-04 3.54E-03 1.02E-04 0.792 1.387 0.327 2 8.020 9.95E-04 7.00E-04 4.06E-03 1.52E-04 0.805 1.598 0.326 3 8.083 8.75E-04 8.35E-04 4.11E-03 1.70E-04 0.809 1.740 0.325 4 8.143 7.85E-04 9.41E-04 4.11E-03 1.79E-04 0.819 1.860 0.324 5 8.197 7.15E-04 1.03E-03 4.12E-03 1.83E-04 0.829 1.960 0.323 6 8.242 6.61E-04 1.10E-03 4.12E-03 1.85E-04 0.837 2.041 - 0.321 7 8.279 6.18E-04 1.16E-03 4.12E—03 1.85E-04 0.842 2.102 0.320 8 8.307 5.82E-04 1.20E-03 4.12E-03 1.86E-04 0.843 2.148 0.319 9 8.329 5.54E-04 1.24E-03 4.12E-03 1.86E-04 0.841 2.180 0.319 10 8.345 5.30E-04 1.27E-03 4.12E-03 1.86E-04 0.837 2.201 0.318 11 8.357 5.11E-04 1.30E-03 4.12E-03 1.86E-04 0.831 2.215 0.318 12 8.366 4.95E-04 1.32E-03 4.12E-03 1.87E-04 0.826 2.224 0.317 13 8.372 4.83E-04 1.33E-03 4.12E-03 1.87E-04 0.820 2.229 0.317 14 8.377 4.72E-04 1.34E-03 4.12E-03 1.87E-04 0.815 2.232 0.317 15 8.380 4.64E-04 1.35E-03 4.12E-03 1.87E-04 0.810 2.234 0.317 126 REFERENCES APHA, AWWA, and WEF. 1992. 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