Dificultades y limitaciones para el estudio

For the Beaver Watershed, there was only one sample taken (Table 6). This sample was taken in Shenango Township in April of 2013. This sample was a

groundwater sample taken in 2013 (Figure 16). Since there was only one sample within

the Beaver Watershed no plots were made for this watershed, though chemical ratio graphs were created.

Figure 16-Samples within the Beaver Watershed, sorted into groundwater and surface water samples (PASDA, USDA)

In the Kiskiminetas Watershed 9 samples were taken, all of which were groundwater samples (Table 6). All of these samples were taken in Westmoreland County, most in Allegheny Township. One sample was taken in 2012, two in 2013, two during 2014, and five of the samples were taken during 2015 (Figure 17).

Figure 17-Samples within the Kiskiminetas Watershed, sorted into groundwater and surface water samples (PASDA, USDA)

Only 3 samples were taken in the Shenango watershed (Figure 18). All of these samples were groundwater samples (Table 6). No surface water samples were taken.

These samples were all taken on February 5^th of 2016 in Lawrence County.

Figure 18-Samples within the Shenango Watershed, sorted into groundwater and surface water samples (PASDA, USDA)

In the Upper-Ohio Wheeling Watershed 6 total samples were taken, 4

groundwater samples, and 2 surface water samples (Table 6) (Figure 19). Four of these samples were taken in Washington County, while the other two were taken in Greene County. Most of the samples were taken in 2012, but two were taken in 2015, and one was taken in 2013.

Figure 19-Samples within the Upper Ohio-Wheeling Watershed, sorted into groundwater and surface water samples (PASDA, USDA)

4.3 Field Measurements

4.3.1 Connoquenessing Watershed

Fifteen percent (44) of groundwater samples in the Connoquenessing Watershed were outside of the SMCL range set by the EPA for pH. Most samples were below the SMCL range with 34 (13% of the total samples) samples below the SMCL range, and only 7 (3%) samples above the SMCL range. The mean pH for groundwater samples in the Connoquenessing Watershed was 7.1, which is within the SMCL range (Figure 20).

Of the 265 groundwater samples, 45 (17%) samples were above the SMCL for total dissolved solids. Most of these samples were within a few hundred mg/L of the SMCL, but three were above 1,000 mg/L. The average TDS for these groundwater samples was 319 mg/L, well below the SMCL (Figure 21).

Figure 20-Box plot of pH levels for groundwater samples in all watersheds, mean shown with hollow circles, Secondary Maximum Contaminant Level (SMCL) shown in dark blue

4.0 5.0 6.0 7.0 8.0 9.0 10.0

pH

Watershed

SMCL Mean

Figure 21-Box plot of TDS levels for groundwater samples in all watersheds, mean shown with hollow circles, Secondary Maximum Contaminant Level (SMCL) shown in dark blue

Out of the six surface water samples taken within the Connoquenessing

Watershed, only one sample was outside of the SMCL range for pH. This sample had a pH of 9.4, well above the limit of 8.5 (Figure 22). None of the surface water samples had TDS levels above the SMCL, and the average TDS level was 140 mg/L for surface water (Figure 23).

0 500 1000 1500 2000 2500

TDS

Watershed

SMCL Mean

Figure 22-Box plot of pH levels for surface water samples in all watersheds, mean shown with hollow circles, Secondary Maximum Contaminant Level (SMCL) shown in dark blue

Figure 23-Box plot of TDS levels for surface water samples in all watersheds, mean shown with hollow circles, Secondary Maximum Contaminant Level (SMCL) shown in dark blue

4.3.2 Lower Allegheny Watershed

Out of the 58 groundwater samples taken within the Lower Allegheny Watershed, 12 (21%) of them were outside of the SMCL range for pH. Ten (17%) samples were below the SMCL range, and 2 samples were above the SMCL range for pH. The mean pH for groundwater within the Lower Allegheny Watershed was 7.1, which is within the SMCL range for pH (Figure 20). Twenty-two (38%) groundwater samples were above the SMCL for TDS in the Lower Allegheny Watershed, and the average TDS was 488 mg/L. Most samples were only a few hundred mg/L above the SMCL. However, three groundwater samples were over 1,000 mg/L (Figure 21).

There were considerably more surface water samples taken in the Lower

Allegheny Watershed than groundwater samples (Table 6), but only one of those samples was outside of the SMCL range for pH. This sample was just below the range at 6.49 pH.

All of the other surface water samples were within the 6.5 to 8.5 pH SMCL range set by the EPA. The mean pH of the surface water samples was above that of the groundwater samples at 7.4 pH (Figure 22). Though only one sample was outside of the range for pH, 20 (15%) surface water samples were above the SMCL for TDS. Though many samples were above the SMCL for TDS, the average for TDS was still below the SMCL at 332 mg/L. This is due to the considerable number of surface water samples with very low TDS (Figure 23).

4.3.3 Lower Monongahela Watershed

Forty-three groundwater samples were taken in the Lower Monongahela

Watershed. Of those samples, only three were outside of the SMCL range for pH, and all

three of those samples were below the bottom of the range. Similar to the groundwater samples in the Lower Allegheny Watershed, the mean pH of the groundwater samples was 7.1 (Figure 20). Eleven (26%) groundwater samples were above the SMCL for TDS, though most samples were just above the SMCL. However, one groundwater sample had a TDS of 1876 mg/L which is more than triple the SMCL. Though this sample increased the average TDS for groundwater, it was still below the SMCL at 461 mg/L.

Three of the 13 surface water samples had pH levels outside of the SMCL range.

Two samples were above the range, with the highest being 10.4 pH, and one sample was below the range at 5.8. However, the mean pH was 7.8, within the pH SMCL range (Figure 22). TDS levels were generally higher for the surface water samples than for the groundwater samples. Five surface water samples were above the SMCL for TDS, and the average TDS for surface water samples was 576 mg/L. This is also above the SMCL for TDS. This is due in large part to the large number of samples above the SMCL and specifically to two elevated samples above 1,000 mg/L TDS (Figure 23).

4.3.4 Upper Ohio Watershed

Out of the 60 groundwater samples that fall within the Upper Ohio Watershed, only 4 samples were outside of the SMCL range for pH. Three of these samples were below 6.5, the bottom of the range, and one was above 8.5, the top of the range. The mean pH for the groundwater samples was 7.2, similar to the mean pH for the groundwater samples for the Connoquenessing, Lower Allegheny, and Lower

Monongahela Watersheds (Figure 20). Thirteen (22%) groundwater samples had TDS levels above the SMCL range. Six of those samples were over 100 mg/L over the SMCL.

However, the average TDS level for groundwater was 437 mg/L, below the SMCL (Figure 21).

The mean pH level for surface water samples in the Upper Ohio Watershed was noticeably higher (7.7) than the mean for groundwater in other watersheds. However, none of the samples had pH level outside of the SMCL range. Most points were in the higher end of the range, which led to an elevated mean pH (Figure 22). Opposite of pH, the average TDS (322 mg/L) was lower than the groundwater samples for the Upper Ohio Watershed. Along with this, no surface water samples were above the SMCL for TDS (Figure 23).

4.3.5 Assorted Watersheds

For the one Beaver Watershed sample the pH was 6.6, within the range for the SDWS.

The Beaver Watershed sample had a TDS of 448, which is below the SDWS MCL (Table 1). Since there was only one sample taken in the Beaver Watershed, it was not included in the box plots for pH and TDS with the other watersheds.

Six of the nine groundwater samples taken in the Kiskiminetas Watershed were outside of the SMCL range for pH. This is a considerable number of samples to be outside of the pH range. All of these samples were below pH 6.5, the bottom of the SMCL range. The mean pH for all of the Kiskiminetas Watershed groundwater samples was 6.4, just below the SMCL range (Figure 20). TDS levels were above the SMCL for only one groundwater sample. The average TDS level for all groundwater samples was 209 mg/L, quite low considering the pH levels of the many of the samples (Figure 21).

Two of the three Shenango Watershed groundwater samples were below the SMCL for pH. However, these two points both had a pH of 6.49, which if rounded would be within the range for pH. These two lower points meant that the mean pH for

groundwater in the Shenango Watershed was only 6.6, just within the SMCL range (Figure 20). None of the three groundwater samples were above the SMCL for TDS, and the average TDS was 326 mg/L (Figure 21). There were no surface water samples taken within the Shenango Watershed.

None of the four groundwater samples in the Upper Ohio-Wheeling Watershed were outside of the SMCL range for pH. The mean pH was 7.4, which is higher than the pH of the groundwater samples in the other watersheds (Figure 20). There were also no groundwater samples over the SMCL for TDS. The average TDS for groundwater was 443 mg/L, similar to the averages of the other watersheds (Figure 21).

Of the two surface water samples taken in the Upper Ohio-Wheeling Watershed neither were outside of the SMCL range for pH. The mean pH for the two surface water samples was 7.2, which is similar to mean for other surface water samples (Figure 22).

The TDS levels for the two surface water samples were relatively low, 196 mg/L and 217 mg/L. Neither were above the SMCL and the TDS average was 206 mg/L, well below the 500 mg/L SMCL (Figure 23).

4.4 Anions

4.4.1 Connoquenessing Watershed

For groundwater in the Connoquenessing Watershed all anions measured (fluoride, chloride, nitrite, bromide, nitrate, phosphate, and sulfate) were detected in at

above the MCL. Bromide was detected in 101 (38%) of the samples taken, and phosphate was detected in 27 (10%) of the samples. Twenty-eight (10%) samples had fluoride levels above MCL, 6 had chloride levels above MCL, and 18 (7%) were above MCL for nitrate.

No samples were above MCL for sulfate, but 264 of the 265 (99.6%) samples had detectable levels of sulfate (Figure 24).

Figure 24-Box plot of anion concentrations for groundwater in the Connoquenessing Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

The surface water in the Connoquenessing Watershed did not have any bromide or phosphate detected. However, sulfate and nitrate were detected in all surface water samples. None of these samples were above the MCL. No samples were above the MCL for fluoride, chloride, or nitrite either (Figure 25).

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Figure 25-Box plot of anion concentrations for surface water in the Connoquenessing Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

4.4.2 Lower Allegheny Watershed

For the 58 groundwater samples, nitrite was the only anion not detected in any sample. Chloride and sulfate were detected in all of the groundwater samples, but only 10 of those samples were above the MCL for chloride, and none were above the MCL for sulfate. Five samples were over the MCL for fluoride, and four were above the MCL for nitrate. Bromide was detected in 19 (33%) of the samples, and phosphate in 1 of the samples (Figure 26).

Fluoride (6) Chloride (6) Nitrite (1) Bromide (1) Nitrate (6) Phosphate (6)

Figure 26-Box plot of anion concentrations for groundwater samples in the Lower Allegheny Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

Of the anions measured, all were detected in at least one of the surface water samples in the Lower Allegheny Watershed. All of the surface water samples had detectable levels of chloride, 131 (97%) nitrate, 132 (98%) sulfate, and 109 (81%) fluoride. Bromide was detected in only 4 of samples, and nitrite in only 2 of samples.

Eighteen (13%) samples had detectable levels of phosphate. Of the samples detected 9 were above the MCL for Chloride, and 3 were above the MCL for nitrate (Figure 27).

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Fluoride (41) Chloride (58) Nitrite (0) Bromide (19) Nitrate (54) Phosphate (1)

Figure 27-Box plot of anion concentrations for surface water samples in the Lower Allegheny Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

4.4.3 Lower Monongahela Watershed

Of the 43 groundwater samples taken in the Lower Monongahela Watershed nitrite was the only anion which was detected in none of the samples. Bromide was detected in 4 of samples, and phosphate in only 1 of samples. Two samples were over the MCL for fluoride, only 1 for chloride, 9 for nitrate, and only 1 for sulfate (Figure 28).

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Figure 28-Box plot of anion concentrations groundwater samples in the Lower Monongahela Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

Bromide and phosphate were not detected in any of the 13 surface water samples.

Chloride, nitrate, and sulfate were detected in all of the samples taken. However, no samples were over the MCL for chloride. Four samples were over the MCL for both nitrate and sulfate. Two samples had detectable levels over the MCL for nitrite (Figure 29).

Fluoride (20) Chloride (43) Nitrite (0) Bromide (4) Nitrate (42) Phosphate (1)

Figure 29-Box plot of anion concentrations for surface water samples in the Lower Monongahela Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

4.4.4 Upper Ohio Watershed

Of the seven anions measured, only nitrite was not present in any of the Upper Ohio Watershed groundwater samples. All of the samples had detectable levels of sulfate and chloride. Eight (13%) groundwater samples have nitrate levels above the MCL. Only 1 sample was measured above the MCL for fluoride, chloride, and sulfate (Figure 30).

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Fluoride (7) Chloride (13) Nitrite (2) Bromide (0) Nitrate (13) Phosphate (0)

Figure 30-Box plot of anion concentration for groundwater samples in the Upper Ohio Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

For the 166 surface water samples taken in the Upper Ohio Watershed, nitrite was not detected in any sample. All other anions were detected in at least one surface water sample. Only one sample over the MCL for nitrate. No samples were over the MCLs for fluoride, chloride, or sulfate. One-hundred sixty-five (99%) surface water samples had detectable levels of chloride, nitrate, and sulfate. There were 126 (76%) samples that had detectable levels of fluoride (Figure 31).

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Fluoride (22) Chloride (61) Nitrite (0) Bromide (4) Nitrate (60) Phosphate (4)

Figure 31-Box plot of anion concentrations for surface water samples in the Upper Ohio Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

4.4.5 Assorted Watersheds

Fluoride, chloride, nitrite, bromide, nitrate, phosphate, and sulfate were measured using Ion Chromatography. For the Beaver Watershed, there was only one sample taken. This sample was over the MCL for fluoride (Table 1), but below the MCL for all other anions.

No nitrate, nitrite, or phosphate were detected for the one Beaver Watershed sample.

For the nine samples taken in the Kiskiminetas Watershed, nitrite was the only anion not detected in any of the samples. Chloride, nitrate, and sulfate were detected in all of the samples. Three samples had detectable levels of fluoride, two had detectable levels of bromide, and only one had a detectable level of phosphate. Of these samples one was over the MCL for fluoride, and 5 were over the MCL for nitrate (Figure 32).

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Nitrite (0) Bromide (38) Nitrate (165) Phosphate (6) Sulfate (165)

mg/L

Anions

Mean PMCL SMCL

Figure 32-Box plot of anion concentrations for groundwater samples in the Kiskiminetas Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

No samples in the Shenango Watershed were above the MCL for the anions measured. Fluoride, chloride, nitrate, and sulfate were detected in all three of the Shenango Watershed samples. No samples had detectable levels of nitrite, bromide, or phosphate (Figure 33).

Fluoride (3) Chloride (9) Nitrite (0) Bromide (2) Nitrate (9) Phosphate (1)

Figure 33-Box plot of anion concentrations for groundwater samples in the Shenango Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

For the 4 groundwater samples taken in the Upper-Ohio Wheeling Watershed only one was over the MCL for fluoride. No groundwater samples were over the MCLs for chloride, nitrite, nitrate, or sulfate. There was no nitrite, bromide, or phosphate detected in any of the samples. Chloride was detected in all of the groundwater samples, as was nitrate, and sulfate. Two groundwater samples had detectable levels of fluoride (Figure 34).

Fluoride (3) Chloride (3) Nitrite (0) Bromide (0) Nitrate (3) Phosphate (0) Sulfate (3)

mg/L

Anions

Mean PMCL SMCL

Figure 34-Box plot of anion concentrations for groundwater samples in the Upper Ohio-Wheeling Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively

There were only two surface water samples taken in the Upper-Ohio Wheeling Watershed. Neither of those samples had detectable levels over MCL for any of the anions measured. Fluoride, chloride, nitrate, and sulfate were detected in both surface water samples. Phosphate was detected in one of the surface water samples.

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Fluoride (2) Chloride (4) Nitrite (0) Bromide (0) Nitrate (4) Phosphate (0)

Figure 35-Box plot of anion concentrations for surface water samples in the Upper Ohio-Wheeling Watershed with number of samples with detectable levels of each anion in parentheses, mean is marked as hollow circles, and Primary Maximum Contaminant Level (PMCL), and Secondary Maximum Contaminant Level (SMCL) are shown in orange and blue respectively