PERMFILE42740 - Laserfiche WebLink

Home Browse Search

j 1 1 ~I 1.0 Introduction 1.1 Scope and Purpose A common requirement of open pit gravel mining operations is to insure that groundwater conditions in the area surrounding the site are not adversely affected by dewatering or water quality contamination. Often "monitoring" is the preferred method of determining whether any damage has occurred. However, it can be difficult to discern either the existing condition of the groundwater or any impact of mining operations simply by measuring conditions, even if done on a relatively frequent and regular basis. A great deal of data can be collected with time and expense but little useable information is created from it. The result is that a mining operator may mitigate perceived damages when none have occurred, or likewise, not have any clear direction to correct actual damages as needed. Both can have a dangerous and undesirable effect for an operator, creating undue Lability and expense. Clearly it would be valuable to create information that has definable margin of error and provides divection to an operator as to whether damages are occurring due to mining or not. Unfortunately, a monitoring program cannot easily answer that question, even with appropriate measurement and analysis methods. However, proper monitoring can describe the existing condition and whether a change has occurred over time. It may be very difficult to determine whether a detected change is a direct result of mining activities. The purpose of this Protocol is to remove from debate the question of what the groundwater level is like now, what it is like once mining operations have begun, and whether these are significantly different. 1.2 Project Location and Description Specifically, Western Mobile Northern, Inc., a subsidiary of Lafazge Corporation (hereafter referred to as Lafarge) is currently in the process of permitting a gravel mining site in Larimer County, on County Road 19, just north of Fort Collins, Colorado. There is a vicinity map included as Figure 1. This site is referred to as the North Taft Hill Expansion site. Lafarge already has a relatively large operation active in the vicinity of this site, often referred to as the Home Office. This site is over a gravel deposit associated with the Cache La Poudre River. Lafarge intends to begin mining operations 3 to 4 years from now, and complete mining and reclamation in approximately 7 yeazs from the start of mining. Based on anecdotal evidence and groundwater modeling completed by Tuttle Applegate, a great deal of water flows in the relatively permeable sand and gravel of the alluvial 1