2025-03-14_PERMIT FILE - M2025016 ‎(29)‎

• Permit No: M2025016
• IBM Index Class Name: Permit File
• Doc Date: 3/14/2025
• Doc Name Note: Exhibit G - Groundwater Monitoring Plan
• Doc Name: Application
• From: Raptor Materials LLC
• To: DRMS
• Email Name: JR2
• Email Name: AME
• Email Name: EL1
• Media Type: D
• Archive: No

AWES, LLC
3

GROUNDWATER MONITORING WORK PLAN
RAPTOR PIT 125 MINE PROJECT
WELD COUNTY, COLORADO

1.0 INTRODUCTION

This Groundwater Monitoring Plan (Plan) has been prepared by AWES, LLC on behalf of Raptor Materials, LLC
(Raptor) for the proposed Pit 125 mine project located in Weld County, Colorado (Figure 1). The current
mining plan includes dry mine gravel extraction from four pits that will encompass approximately 196 acres.
This plan will be submitted to the Division of Reclamation, Mining and Safety (Division) as part of Raptor’s
mine permit application.

1.1 Objectives
The objectives of this Plan are to identify potential liabilities with the extraction of aggregate under semi-
saturated conditions. Specific objectives for the Raptor project are described below.

• To determine the aerial extent of drawdown associated with mine dewatering;
• To determine the effects of dry mine aggregate extraction on local hydrology and water quality;
• To generate predictive models on possible adverse drawdown in adjacent domestic wells; and
• To determine the effects of lined pit reclamation on the local groundwater flow regime.

1.2 Background Information
The proposed gravel quarry is located in section 29 of Township 3 North, Range 67 West of the 6th
Principal Meridian. The surrounding land use consists of agricultural, rural residential and oil and gas
gathering. The proposed mine area occupies an estimated 196 acres. The anticipated extraction depth
will vary between 23 and 50 feet below grade.

Information provided by geotechnical investigations, monitoring well water level data and water
resource evaluation reports document the local and regional hydrogeology. In August 2023, 6 soil
borings were drilled from ground surface to bedrock to determine the potential aggregate mass within
the proposed mine boundary. These borings were completed as one-inch groundwater monitoring wells
and the well locations are depicted on Figure 2. The depth to bedrock within the proposed mine pit
boundaries varied between 23 and 50 feet below ground surface. In general soil conditions consist of
less than one to six feet of top soil and sandy clay underlain by sand and gravel with occasional clay and
poorly graded sand lenses. The coarse alluvial deposits are underlain by bedrock which consists of
siltstone, sandstone and claystone.

2.0 GROUNDWATER MONITORING

2.1 Monitoring Well Installation
As mentioned in August 2023, DrillPro, Inc. of Denver, CO drilled six soil borings from ground surface to
bedrock using hollow stem auger techniques and completed the borings as one-inch groundwater
monitoring wells. Boring logs are presented in Appendix A.