San Juan Ridge Mine and the history of the Grizzly Hill school wells
December 5, 2012
The San Juan Mining Corporation, with headquarters in Nevada City, has submitted an application for a use permit to reopen the idle San Juan Ridge Gold Mine located on 1,440 acres of private property on the San Juan Ridge, north of Nevada City.
Siskon Corp. operated the mine from 1993 to 1997 when falling gold prices, coupled with higher than expected operating costs, closed the operation. The proposal has stirred up considerable controversy with residents near the project with a particular concern about water issues.
The prior mining operation in 1995 hit a fault in bedrock that contained high-pressure water. The fault was cemented off some four months later, but a total of 14 homeowner wells were affected, including the Grizzly Hill School well. New wells, deepened wells, were drilled at the operator’s expense.
Residents near the project are concerned this could happen again. The previous incident happened because the fault was undetected from exploration drilling. It was a vertical crack in the bedrock 4 inches wide and all the vertical drill holes missed it.
The history of the Grizzly Hill School water system is a long and complicated one.
The current proposed plan will include horizontal drill holes that cannot miss a vertical fault. If a fault or water is detected, the area will be avoided or sealed off.
The purpose of this article is to try to provide some background on the Grizzly Hill School wells, not to trivialize the impacts to wells from the prior operation. As a result of diligent efforts on the part of the community, there was a “Remedial Water Supply Plan” negotiated with Siskon as part of the prior operations use permit.
Cash bonding was put in place by Siskon to insure prompt action if there were water impacts. The bonding amounts were adequate to cover the deepened, replaced wells and the new treatment system for the school.
It has been proven by water-quality testing, performed since at least the early 1980s, that high concentrations of iron and manganese and high and low pH values are present in the groundwater of the San Juan Ridge. The Grizzly Hill School wells and associated drinking water system are a prime example.
To get a better picture of the Grizzly Hill School well history, there have been three wells, including the one currently in service, since the school was built in 1979. Well 1 had very high iron and low yield. It failed and was replaced with Well 2 (10 years prior to the mine construction). Well 2 was impacted by the 1995 event described herein and was replaced by Siskon with Well 3. Well 3 was eventually deepened by Siskon and continues in operation today.
In a letter dated July 31, 1985 (nearly 10 years prior to the Siskon operation), the Nevada County Environmental Health Department (NCEHD) informed the North San Juan Union School District that ‘unfortunately, we are unable to issue a Certificate of Operation or final the construction of the water and sewage systems at Grizzly Hills School because their well exceeds the maximum contaminate level for turbidity and iron.”
An Aug. 22, 1985, letter (years before Siskon operation) from the NCEHD to the school district also required that an iron removal system for drinking water be installed, that the turbidity problem be corrected as required
Due to the increased iron/manganese from the deepened Well 3, Siskon paid $55,000 to install a better, higher capacity treatment system in 2001. That plant provides drinking water for students and faculty today.
In summary, the history of the Grizzly Hill School water system is a long and complicated one. The prior operation did impact the school well level and the new, deeper well paid for by Siskon does have higher concentrations of iron and manganese than the original well; however, the original school well also had high concentrations of iron and manganese that were above the secondary drinking water standards. Water treatment was required to remove these contaminants well before the Siskon operation.
The simple fact is that since the 1980s (years before the Siskon operation), the Grizzly Hill School water has stained fixtures orange, tasted bad and required treatment. The same problems exist today, and the water still requires treatment to be drinkable as it always has.
Please visit http://www.sanjuanminingcorp.com for more detail on this issue.
Tim Callaway is CEO of the San Juan Mining Corporation.