REP29398

• Permit No: C1982057
• IBM Index Class Name: Report
• Doc Date: 11/20/1989
• Doc Name: SENECA IIW C-82-057 1988 AHR
• From: MLRD
• To: CARL MOUNT
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

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STATE OF COLORADO
Roy Romer, Gove
DEPARTMENT OFNATURAL RESOURCES
MINED LAND RECLAMATION DIVISION
FRED R. BANTA, Director
DATE: November 20, 1989
T0: Carl Mount
FROM: J.M. Clayton
RE: Seneca IIW, C-82-057, 1988 AHR
Historic water monitoring was greatly altered in 1986 because of numerous
uncertain results from the wells on the mine site. In 1987 twelve new wells
were drilled to be used in conjunction with several wells retained from the
earlier sampling scheme in Section VI of the 1986 AHR. Current water levels
for wells drilled prior to August, 1987 are measured in April-June,
July-August, and October-November. All new wells measured monthly from April
to November. During 1988 alluvial wells GW-SZW-6A1, 6A2, 6A3 and 6A4 were not
monitored. This was blamed on the lack of an access agreement with the
landowner.
Seasonal water levels in wells closely mirror precipitation patterns. In
general water levels are several feet lower because of lower snow covers in
the last two years.
Alluvial water quality from Watering Trough Gulch and HubbedSGulch indicates a
calcium bicarbonate type. Iron and manganese standards are exceeded in Well
G-W-SZW-7AZ. In the Wadge overburden, Temple Well No. 1 flows the year round
usually and is used by livestock. This has a magnesium sulfate water with TDS
levels averaging 2347 mg/1. Because of dry conditions there was no flow in
the fall of 1987 and the summer of 1988.
There is no pumping for irrigation around the Seneca IIW mine plan area.
Nearby domestic well are reported to be in aquifers not impacted by proposed
mining.
The surface water runoff rates have been lower for the past two years. There
have been minimal disturbances on the site and thette are largely due to
access roads. Dry Creek has shown occasional exceedences in total iron,
sulfates and dissolved manganese. There levels indicate natural background
levels. For all surface water sample periods, Site SW-SZW-FG-1 shows sulfate
exceedences. TDS values range from 736 to 2006 mg/l.
This review shows no adverse impacts to the surrounding environment from the
Seneca IIW mine site.
JMC/yjb
1494E
215 Centennial Building, 1313 Sherman Street Denver, Colorado 80203-2273 Tel. [phone]