SU0004126 - Laserfiche WebLink

Home Browse Search

The presence of the observed nitrate concentrations is likely related to both the historical agricultural land use in the area prior to the commencement of aggregate mining by Teichert Aggregates and also continuing farming practices. This includes the nitrate concentration increases in the Brown's#1 well. Copper, iron,and zinc concentrations in shallow groundwater samples are typically low and frequently below their respective reporting limits. For example, the record(65 monitoring events) for the Hall well shows one copper detection (100 µg/l- in May 1999 sample), two iron detections(70 to 80 gg/L),and five zinc detections (30 to 130 gg/L). To date,manganese has not been detected in the Hall well. In samples retrieved from the Faulkner well, copper and manganese concentrations have always been nondetect; iron and zinc concentrations have ranged from<10 to 160 µg/L and from <20 to 220 pg/L, respectively. As in shallow groundwater samples, traces of copper concentrations in most deep groundwater samples are rarely detected. In contrast, iron,manganese and zinc are frequently detected in most deep wells;and variability is high. Most frequently, these metals were detected in samples retrieved from the Brown's New well and the Brown's #1 well. These metals are also present in well water more recently retrieved from the Granite #3 well. Metal detections in the South Tracy#1 well are few. In the South Tracy#3 well,copper, iron, manganese, and zinc concentrations have been nondetect to date(with the exception of two low iron detections). Lastly,total coliform bacteria have been absent from the domestic wells with few exceptions. Most recently,total coliform bacteria were reported at the reporting limit of 1.1 MPN/100 mL in the August 2008 sample retrieved from the Hall well. Fecal coliform organisms were absent. The sporadic presence of coliform bacteria can be due to sample contamination at the time of collection,the introduction of coliform bacteria to the well structure during well and pump maintenance work, or the detachment of bacterial biofilm from the well structure in combination with naturally occurring coliform organisms. ©LL.F EX PFF � SCALMUNINI CONSULTING ENGINEERS 7