2009-09-01_PERMIT FILE - M2009018 (9)

Home Browse Search

Varra Companies, Inc. concurs with this opinion. Since the monitoring well in the northern portion of the operation will be removed by extraction activity, the monthly monitoring of the Haley well should be added to the monitoring routine. Given that an extensive time frame would be required prior to potential impacts to one nearby well (Haley), the applicant does not believe the gathering of baseline information should delay the onset of dewatering for nearly a year and one-quarter as the potential impacts on adjacent wells in the face of a reasonable protocol is considerably diminished. The applicant is more than willing to submit the monthly monitoring records commencing the month following approval of the application. 14. Please identify any land uses within 1,000 feet of the affected land that rely on subirrigation. Also, characterize the impacts to these land uses that may result from the dewatering activities. Consistent with our discussion of 4 August 2009, the potential for groundwater impacts lies within the designated cone of depression determined in the CGRS report of 29 June 2009, as previously submitted. For vegetated areas where groundwater fluctuations may occur to within four feet of the surface; or the common root zone for trees which would be among the first to suffer impacts proportionately within the root zone. Wetlands require surface waters to be within one foot of the surface; therefore, impacts to trees would pre-stage any impacts to wetlands or other subirrigated plants at the four foot level. We have evaluated the elevation differences of the surface relative to USGS cartography and known or measured groundwater levels, in conjunction with aerial photographs and subsequent ground truth verification, over the area of interest as reflected in the revised map included with this submittal (see Exhibit C-1: Existing Conditions Map ii -1:250 scale). The data from area wells shown in Part 11, above, suggests that impacts from discharge will not affect groundwater elevations influencing the root zone within four feet of the surface within the anticipated cone of depression - or extending 1,000 feet from the designated permit boundary. Measured groundwater elevations do not come closer than four (4) feet from the surface. Many of the surrounding trees comprise silver maple, Chinese elm, green ash, mature cottonwood, and honey locust. Many are located on lands affected by surface waters, such as ditch waters. For example; an approximate fifty (50f) inch diameter cottonwood tree exists just outside the northwest boundary of the project area and is watered by an unlined segment of the Last Chance Ditch. This is a common condition for a majority of the surrounding trees visible in the attending aerial image. A majority of the observed crops appear irrigated. Fields to the north, west and south of the project area are predominantly corn and alfalfa. To the west irrigated pastures are more common. All conditions for the observed vegetation uses are surface water influenced. Varra Companies, Inc. correspondence of 1 September 2009 to the Colorado Office of Mined Land 9 Reclamation (Office) in reply to Office correspondence of 27 July 2009 - Heintzelman Project - M2009-018.