2010-09-23_HYDROLOGY - M1999120

• Permit No: M1999120
• IBM Index Class Name: HYDROLOGY
• Doc Date: 9/23/2010
• Doc Name: Letters from Mr. Ross Bachofeer Regarding Flooding of Property
• From: Deere & Ault
• To: L.G. Everist
• Permit Index Doc Type: Hydrology Report
• Email Name: ECS
• Media Type: D
• Archive: No

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Re: Letters from Mr. Ross Bachofr Regarding Flooding of Pr- oerty East of the South
l? attever near the Everist Fort Lupton Mine; D&A Job No. CG-0201.003.00
Mr. Jim Sittner
L.G. Everist
7321 East 88th Avenue, Suite 200
Henderson Colorado 80640
Dear Mr. Sittner:
As requested, we have reviewed letters from Mr. Ross Bachofer to the Colorado Division of Mine
Reclamation and Safety, the Colorado Division of Water Resources, the City of Aurora Water
Department, and the Weld County Public Works regarding flooding of Mr. Bachofer's property. Mr.
Bachofer's property is east of and adjacent to the South Platte River, south of Weld County Road 18.
The L.G. Everist Fort Lupton Gravel Mine with several mining cells is directly west and across the
river from Mr. Bachofer's property. Figure 1 shows the location of Mr. Bachofer's property and
L.G. Everrist's mine, as well as existing slurry walls and monitoring wells maintained by L.G.
Everist.
We have also reviewed a document referenced by Mr. Bachofer, USGS Scientific Investigation
Report 2010-5019, Land-Use Analysis and Simulated Effects of Land-Use Change and Aggregate
Mining on Groundwater Flow in the South Platte River Valley, Brighton to Fort Lupton, Colorado,
2010.
Mr. Bachofer's basic contention is that the slurry walls at L.G. Everist has constructed at their Fort
Lupton mine to create lined water storage reservoirs from the mined cells are responsible for the
South Platte River flooding parts of his low lying property on the east side of the river. He further
contends that USGS Scientific Report 2010-5019 explains how the slurry walls cause the flooding.
In our professional opinion, Mr. Bachofer's problems with flooding of his land are in no way related
to or caused by L.G. Everist's mining operations or construction of slurry walls. This opinion is
supported by the following facts:
1. In accordance with regulations, L.G. Everist's mining operations have not altered the
floodplain of the South Platte River.
2. The South Platte River lies between the L.G. Everist property and the Bachofer property.
Hydrologically the river creates (and would be modeled as) a no-flow boundary between the
L.G. Everist property and the Bachofer property. Measureable impacts to the alluvial aquifer
from the mining and slurry wall construction are hydrologically limited to the west side of
the river.
600 S. Airport Road, Building A, Suite 205
Longmont, CO 80503
Phone: [phone] • Fax: [phone]