INSPEC22352

• Permit No: M1989120
• IBM Index Class Name: Inspection
• Doc Date: 8/19/2002
• Doc Name: Status of Groundwater Investigation
• From: DMG
• To: Golden West Farms
• Inspection Date: 5/30/2002
• Media Type: D
• Archive: No

S
STATE OF COLORADO
OFFICE OF THE STATE ENGINEER
Division of Water Resouroes
Department of Natural Resources.
1373 Sherman Street, Room 876
Denver, Colorado 80203
Phone [phone] ~ -
FAX [phone]
www,wateistaie.co.us
July 8; 2002
Mr, Stephan Brancucoi
Golden West Farms
1281 WCR 27
Brighton, CO $0601
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Bill Owens
Governor
Greg E. Watcher
ExeMive Director
Hal D. Simpson, P.E.
. State Engineer ~~, _
Re: Devltatering Activities at Aggregate Industries' Platte Valley Gravel Pit; Field .
Investigations on May 30, 2002 and June 17, 2002 -
Dear Mr. Brancucci: -
On May 30; 2002, Tom Schreiner of the Division of Minerals and Geology
(DMG), George VanSlyke from fhe Division of Water Resources (DWR), and I visited
--= • - Aggregate Industries' Platte Valley Pit. We also visited you and some of your neighbors.
- This was in response to your concern that the dewatering activities at the Platte Valley
Pit are affecting your irrigation wells. On June 17, 2002, Tom Schreiner and I followed
up with a second investigation of the gravel pit and we also spoke to you and Mr. Sasaki
on that day.
As you know from Tom Schreinel's correspondence, DMG has analyzed
operations'at the site-to ensure compliance with the mine plan, the Substitute Water
Supply Plan (SWSP), and the well permit. Aggregate Industries (Aggregate) currently.
has a valid SWSP and well permit. DMG and our office are currently evaluating their
compliance. There is also a pending issue with other wells with in the mining area.
Aggregate has apre-existirig agreement with those wells' owners.
_-- - - -.-----The-objective-o€GeorgeVanSlykeandl-durar~g-ou~vJsits-to-theme-iatte-ValleyP-it--,
and your wells' sites has been to better understand the current hydrologic condi4ions, to
better understand the dewatering operation, and finally to make a determination as to
whether the performance of the wells can be directly linked to dewatering at the gravel
pit. We observed that in the mined area, the water is being removed to a depth of
between 25 and 30 feet below the ground surface. Around the excavated area, water is
seeping into the pit at places from 2 - 5 feet higher than the dewatered depth.
Therefore, the water table at the immediate location of the pit appears to be 20 - 25 feet
below the ground surface.
On the mined site, there are settling ponds that are maintained at a level that is 5
-10 feet below the ground surface. There is also a lake across the highway from fhe
gravel pit whose depth is being artificially maintained by pumping the dewatered water
from the pit. The direction of flow of groundwater in the alluvium at that location is
understood to be generally from fhe southeast to the northwest. There are several
variables that affect the ground water table in the area of the wells. Those include, but
are not limited:
The distance form the gravel pit to the wells in question (approximately %:
mile)
The effect of recharge on the water table from settling ponds on the mine
site