Central Area Water System Water Quality Data (Cont.)

Aesthetics

Analyte Units  Groundwater  Concentrations Greenway Surface Water Concentrations Pyramid Peak Surface Water Concentrations EPA Limit MCL EPA Limit MCLG Sample Date Possible Sources
    Range Average Range Average Range Average        
Alkalinity mg/L 107-145 119 87-160 122 111-149 120 NA NA 2005 Naturally present.
Calcium  mg/L 14-71 46 57* 57* NA NA NA NA 2004 Erosion of natural deposits.
Geosmin µg/L NA NA ND ND ND-0.0032 0.0021 NA NA 2004 Naturally present.
Hardness Gr/gal 10 10 12* 12* NA NA NA NA 2004 Naturally present.
Iron mg/L 0.12* 0.12* NA NA ND ND NA 0.3 2001-05 Erosion of natural deposits.
Magnesium  mg/L 18* 18* 21* 21* ND ND NA NA 2003-05 Erosion of natural deposits.
Manganese mg/L ND ND NA NA NA NA NA 0.05 2004 Naturally present.
Methylisoborneol (MIB) µg/L NA NA ND ND ND-0.0426 0.0063 NA NA 2004 Naturally present.
pH SU 7.2-8.5 8.0 7.5-8.7 7.9 7.6 7.6 NA NA 2004-05 NA
Total Dissolved Solids mg/L 228-296 255.0 611* 611* 400-700 605 NA NA 2002-05 Naturally present.
Sulfate  mg/L 29-41 35 150* 150* 199* 199* NA 250 2005 Naturally present.
Sodium  mg/L 26-56 36 69* 69* NA NA NA NA 2004 Naturally present.
* Only one sample collected, as required.

Copper and Lead

Analyte Units 90th Percentile Reported Groundwater Maximum Concentrations Greenway       Surface Water Maximum  Concentrations Pyramid Peak Surface Water Maximum  Concentrations EPA Action Level mg/L EPA Limit MCLG Sample Date Possible Sources
Copper mg/L 0.33 ND NR 0.8 1.3

1.3

 2003-04 Erosion of natural deposits, home plumbing systems.
Lead mg/L ND ND ND NR 0.015

0

 2003-04 Erosion of natural deposits, home plumbing systems.

Samples were collected from 76 homes, primarily from homes built between 1980 and 1984. No samples exceeded the action levels.

Percentile reporting means the data is first organized from smallest to the largest. In the case of copper, there were 76 samples ranging from 0.01 to 0.33 mg/L. We then determine which sample to evaluate by taking 90% of 76, which is 68. We then pick the 68th data result from the smallest as the reporting level. In this case, 0.33 mg/L. Ninety percent of the data is below 0.33 mg/L while the remaining ten percent is above. For lead there were also 76 samples and the 90th percentile was ND, or no detection.

Turbidity

Surface Water Treatment Plant Analyte Units Level Found Range MCL MCLG Possible Sources
Greenway Turbidity NTU 0.11 NA TT=1 NTU 0 Soil Runoff
100% NA TT= % of samples <0.3 NTU 0 Soil Runoff
Pyramid Peak Turbidity NTU 0.3 NA TT=1 NTU 0 Soil Runoff
100% NA TT=% of samples <0.3 NTU 0 Soil Runoff

Turbidity has no health effects. However, turbidity can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease-causing organisms. These organisms include bacteria, viruses, and parasites that can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.
Pyramid Peak and Greenway tested for but did not find giardia or cryptosporidium.
 

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