REP00790 - Laserfiche WebLink

Home Browse Search

Hydrology File - Foidel Creek Mine - 4 - GROUNDWATER Bedrock Wells The 1986 AHR compiled data for five bedrock wells. Foidel Creek Mine Bredrock Formation Twentymile Sandstone 1986 HMP 006-81-30 006-82-48A Wadge Overburden 006-81-31 006-82-38 006-82-48 Trout Creek Sandstone None fers Monitorino Wells 1987 HMP 006-BRDH7 006-82-48A May 27, 1987 009-79-4 006-82-74C 006-82-48 006-87-001 or 006 001-83-107 006-83-48C Energy Fuels Well A11 but two of these wells are being replaced for the following reasons. The Twentymile Sandstone well 006-81-30 is a partially uncased well, Wadge well 006-82-38 is also uncased and is open for 1015 feet (BARS at this site have increased dramatically in the last year). Wadge well 006-81-31 is contaminated with grout (1986 pH averaged 12) and will be replaced by well 006-87-006 during mid-1987. Replacement well 009-79-4 is currently in the C-81-071 permit monitoring plan and has been contaminated by the surface mine. Its function in this plan will be to monitor dewatering. The 006-82-48 series are currently being blown with nitrogen: The pH of these wells has risen and sulfate and sodium concentrations seem to be rising. It appears that the integrity of the wells may be impacted by this evacuation method, and it is not clear at this time whether the well construction or the sampling technique is responsible: The Twentymile Sandstone water from well 006-82-48A is currently a sodium sulfate water of low hardness. The TDS of this well increased five times during 1986 going from a historical average of 145 mg/1 to 744 mg/1. The SAR has also increased five times from 0.73 to 3.71. The April, 1986, sample showed substantially higher values of manganese and iron, which had not been observed in the past nor were replicated in the October sampling. The Wadge water from well 006-82-48 is currently a sodium sulfate water of very low hardness. The water has low concentrations of iron and manganese (less than 0.05 mg/1 and less than 0.068 mg/1 respectively) and the historical TDS is approximately 250 mg/1 and steady. During 1986, SAR levels increased from a previous historical average of 0:73 to 3.71.