2015-06-12_REVISION - C1981014 (2)

Home Browse Search

addition to using the nitrogen injection (see blow-out protection devise explained in the next paragraph). The Nitrogen Generators used on site are the less expensive means of adding nitrogen to the driller's compressed air for the drilling operation as compared to using pressurized nitrogen storage vessels. The rental time/cost for the nitrogen generators and the required accompanying technician starts from the time the generator leaves their home base until they return to the home base. The cost estimate for the Southfield project for the nitrogen generators is from the Grand Junction, Colorado location. There is no "standby time" cost estimate included for these generators in case there is a break -down of the drilling equipment, foul weather or some other unintended delay to the operation potentially increasing the excessive expense for drilling into the mine workings. BLOW-OUT PROTECTION (BOP): In addition to using nitrogen gas as a safety feature, it is necessary to secure a `rotating head' on the well casing at the ground surface to allow the rotating drill through the head and to also facilitate the installation of a blow-out protection device (BOP). The BOP serves as a seal via the rotating head at the top of the well casing and diverts any potential explosion or fire through a conduit to the side of the drill site rather than up into the drill rig and personnel. In short, drilling into the Southfield mine workings is high in risk of safety and is economically unreasonable for the limited information that is thought to be gained. MONITORING WELL MW -NW: EFCI maintains the position that MW -NW is functional for water monitoring in its current condition. MW -NW has been and is currently monitored on a semi-annual basis as approved in the Southfield Water Monitoring Program since the well was approved for water monitoring in 2003. When the well casing failed and the partial obstruction occurred in the casing is unknown. With the well being dry since it was approved for monitoring and the electronic well monitoring probe only responding when the probe contacts water, if water is contacted, the well is then measured for depth to water. There was no reason to suspect that the probe was not reaching the full depth of the well. It is reasonable to expect that the earlier monitoring of MW -NW (pursuant to 2003) was reaching the bottom of the well and the "dry" monitoring readings recorded are considered as viable monitoring data for the hydrologic records. At a later date (early 2012), the adjacent landowner questioned the integrity of MW -NW and in response, EFCI lowered a weight into the well to measure the total depth. The partial obstruction was encountered at 354 feet of depth in the well casing. (DRMS later determined that the partial obstruction was at 353 feet of depth). As previously reported, two well "flow" tests were performed (2012 & 2014) from which it was determined that the well casing was open to flow to the Southfield mine workings at a flow rate of 100+ gallons per minute (100+ GPM). The issue involved with MW -NW focuses on the bottom section of the well concerning the vertical distance from the partial obstruction to the roof of the Southfield mine workings which is less than 20 vertical feet, a mere 5% of the total 375 feet of the well depth to the mine workings. In an earlier hydrologic review, the Division stated that if water was present in the mine workings at the location of MW -NW, the water would not rise up the well casing. EFCI reiterates that the Division's opinion is in error, confusing confinement and non -confinement, and that the water would indeed rise up the well casing, to the same level as the surrounding pool if/when water level raises in the mine workings.