Laserfiche WebLink
' dissolved iron concentrations have risen compared with prior data, but are still within <br />historical concentrations of previous sampling events. Manganese concentrations in TR-4 <br />' have risen from 2003 to the 2007 sampling season. Once again, this may be due to the well <br />repairs conducted in the spring of 2003. The lowest dissolved iron concentration in 2007 was <br />recorded at monitoring well TCS-1 in October with a value of <0.02 mg/L and the high was <br />recorded at monitoring well TR-3 in May with a value of 1.24 mg/L. The lowest manganese <br />concentration in 2007 was recorded at monitoring well TCS-1 during numerous months with a <br />' value of 0.015 mg/L and the high was recorded at monitoring well TR-4 in July with a value <br />of 3.89 mg/L. <br /> 4.2.7 Ground Water Orthophosphate and Nitrite <br /> Charts 34 and 35 show orthophosphate and nitrite concentrations for the monitoring <br />' wells TR-1.5, TR-3, TR-4, WR-1 and TCS-1 for the period of record. Historically, <br /> orthophosphate and nitrite values obtained over the period of record have been low with most <br /> being below detection limits. Elevated orthophosphate readings occurred in the summers of <br />' 1998 through 2000, at up-gradient well TR-1.5, possibly due to nearby agricultural activity. <br /> In 2001, concentrations of orthophosphate returned to historically low levels. Site TR-4 had a <br /> slight rise in orthophosphate concentration during the 2005 monitoring period, but decreased <br />' to levels similar to previous sampling events during the past few years. Nitrite concentrations <br /> were again elevated at TR-1.5 in May 2000 and May 2001 and at WR-1 in May 2001, but <br /> decreased to historical levels as the year progressed. Nitrite levels remained at historical <br /> levels in the 2007 monitoring period. The lowest orthophosphate concentration in 2007 was <br /> recorded at numerous monitoring wells during numerous events with a value of <0.01 mg/L <br /> and the high was recorded at monitoring well TR-1.5 in May with a value of 0.05 mg/L. The <br /> lowest nitrite concentration in 2007 was recorded at numerous monitoring wells during <br /> numerous events with a value of <0.01 mg/L and the high was recorded at momtormg well <br /> TR-4 in July with a value of 0.04 mg/L. <br /> 4.2.8 Ground Water Chloride and Potassium <br /> Charts 36 and 37 show chloride and potassium concentrations for the monitoring wells <br /> TR-1.5, TR-3, TR-4, WR-1 and TCS-1 for the period of record. Chloride and Potassium were <br />' added to the parameters list in 1994. Potassium levels increased in TR-4 over the course of <br /> 2003, but have leveled off over the last few years. Chloride at TR-4 spiked in both October <br /> 2004 and May 2005, however concentrations returned to historical levels over the past few <br /> monitoring periods. Chloride has risen over the past 3 monitoring seasons at TCS-1. The <br /> lowest chloride concentration in 2007 was recorded at monitoring well TR-3 in July and <br /> October with a value of 2 mg/L and the high was recorded at monitoring well TCS-1 in May <br />' with a value of 85 mg/L. The lowest potassium concentration in 2007 was recorded at <br /> monitoring well TR-3 in May with a value of 1 mg/I. and the high was recorded at monitoring <br /> well WR-1 in May with a value of 10 mg/I.. <br />' 13 <br />