2022-09-06_REPORT - C1982056 (3)

Home Browse Search

Foidel Creek Mine C-82-056 2021 Annual Hydrology Report report period ranged from 780 to 4990 mg/L. This is approximately 1500 pmhos/cm higher than the prior maximum measured in September 2016. The high field conductivity measured at Foidel Creek site 900 (upstream of 29 but downstream of Foidel Creeks sediment basins) on September 9, 2021, was probably related to low flow conditions. 3.4 Spoil Spring Monitoring Generally, groundwater migrates along bedding planes, faults, joints, or fracture zones. Given adequate head pressure, if these zones of water migration intercept the surface, a spring or seep results. The TC spoil spring monitoring program was initiated in 1986 and is conducted annually. In accordance with the approved plan, the annual mine wide survey is conducted during May, with springs measured for flow and field parameters. If a spring is discharging at or above 35 gallons per minute, it is monitored for the next year in accordance with the monitoring plan. A few samples are typically collected each year even when the 35 GPM mark is not met. Two spoil spring sites, 7 (Twentymile Pit Pond) and 303 (in Fish Creek Tipple area), require monitoring under Exhibit 14- 10. Site 7 is more properly termed a mine water discharge point and is discussed in Section 3.5. The 303 spring series (303-1 through 303-3) is monitored semi-annually for field parameters and water quality. Field parameters include flow, temperature, pH, and conductivity. Water quality parameters include TDS, TSS, dissolved calcium, dissolved magnesium, dissolved sodium, bicarbonate, carbonate, sulfate, total recoverable cadmium, total recoverable mercury, total recoverable selenium, total recoverable silver, total recoverable iron, total recoverable manganese, total recoverable molybdenum, total recoverable zinc, nitrate and nitrite, ammonia, and orthophosphorus. In 2021, site 303-1 was sampled on April 20th and September 12th. Spring points 303-2 and 303- 3 remained dry in 2021. These points stopped flowing in 2012 after the Fish Creek Tipple area was reclaimed. Table 3-4 shows the number of samples collected at each spoil spring site during the 2021 report period. Report period data including flow data, water quality statistics, and graphs of Laboratory TDS and Field Conductivity are included in Attachment 4. 24