Engineering report for Albertville Valley sand mine includes list of recommendations

By LeAnn R. Ralph

TOWN OF HOWARD  —  An engineering report about the proposed Albertville Valley sand mine includes a number of recommendations pertaining to incomplete sections of the mine license application.

The report was prepared by SCS Engineers Environmental Consultants and Contractors out of Madison for the proposed 1,300 acre Albertville Valley sand mine.

Northern Sands Wisconsin is proposing to develop a frac sand mine southeast of Colfax that would stretch north and south along the Chippewa County and Dunn County line directly east of the intersection of county Highway N and county Highway A.

The SCS Engineers report includes recommendations on permits, engineering plans, a groundwater monitoring plan, and implementation of the Phase I groundwater monitoring plan.

The report also recommends if the Town of Howard asks for revised maps and figures, Northern Sands should submit the revised information with a corresponding explanation in the mine license application.

The report also recommends that before construction or mining activity begins, Certified Survey Maps of the properties must be provided to the Town of Howard.

The Town of Howard’s mine licensing ordinance requires CSMs, but the maps were not provided with the application for a mine license.

The engineering report was posted on the Town of Howard’s website ahead of an October 8 public hearing on the application for a non-metallic mine license application.

The report makes specific recommendations for plans to control surface water and dust as well as plans for building berms to screen the operation; monitoring and protection of the groundwater quality and quantity along with impacts to surface water; and resource inventory maps.

Permits

Before a sand mine could operate in the Town of Howard, Northern Sands Wisconsin would have to obtain a variety of permits and provide copies of those permits to the Town of Howard.

The permits include a Wisconsin Department of Natural Resources construction site storm water discharge permit; a fugitive dust control plan as part of the DNR air emission permit; a high capacity well permit from the DNR and a Wisconsin Pollution Discharge Elimination System general permit.

Several plans also would be required, including a water conservation plan filed with Chippewa County;  a storm water pollution prevention plan; and a spill response plan.

Design plans

According to the engineering report, “the final design for the mining operations has not been completed, and methods for control of surface water, screening design, conveyance methods and other designs and operation element are not detailed in the license application.”

Sand conveyance — the design of the conveyance methods is not complete. The application indicates the sand will be transported by mechanical conveyor, but no specific information is included.

Surface water runoff — Northern Sands is planning to hire someone to design and install surface water management systems.

Screening — Northern Sands is planning to screen the sand mine operations with berms and by maintaining setbacks and through elevation differences. The mine license application does not include a plan for berms. SCS Engineers recommends the berms be as high as the eaves of residential homes.

Night lighting — In the mine license application, Northern Sands indicates the company will comply with ordinance requirements. The berms Northern Sands intends to construct to control night lighting are not yet designed.

Off-site noise — Northern Sands indicates the company will keep the noise level below 60 decibels. A noise level of 60 decibels is the equivalent of an air conditioning unit at one hundred feet; normal speech between two people also ranges from 50 to 60 decibels, according to information online.

Dust control and air monitoring — the township’s ordinance requires the use of all relevant dust control methods outlined in NR415.075. The application only notes wetting of on-site gravel roads to control dust.  NR415.075 also recommends a maximum speed of 10 miles per hour, covered trucks, wet drilling and wet conveyance. A dust control plan is required before construction begins.

Hours of operation — Northern Sands is requesting to operate the processing plant 24 hours per day. If an exception is not acceptable, the town board should require the ordinance be followed.

Groundwater

The reclamation plan approved by Chippewa County requires groundwater monitoring to establish the elevation and to monitor changes to the groundwater elevation and groundwater chemistry.

The reclamation plan requires a minimum ten-foot separation between the mine floor and the water table to help prevent leaks and spills of fuels, lubricants, flocculants and other chemicals from contaminating the groundwater.

Removing soil and rock removes the natural filter to help keep the groundwater clean, and groundwater chemistry may be affected by removing soil and rock and may cause metals such as arsenic, lead, iron and manganese to dissolve at higher concentrations.

Using large quantities of groundwater for mining operations could lower the water table enough so that private wells and surface waters are impacted.

Monitoring wells

Northern Sands has installed four water table monitoring wells, but Chippewa County requires a minimum of seven wells.

Three additional wells were installed in June of 2018 after Northern Sands submitted the application to the Town of Howard for a mine license.

Information about the three additional wells should be given to the Town of Howard.

Groundwater divide

The proposed mine site contains a groundwater divide, which means groundwater flows in two different directions and drains to different watersheds.

The four Phase I monitoring wells are located in the area of the groundwater divide about a half mile apart.

According to the report, “The spacing of the wells is not optimal for defining the position of the groundwater divide. Because of the divide, it would be beneficial to have more wells to estimate the flow direction in Phase I.”

The Northern Sands application also did not include information about geologic logs to evaluate the position of the well in the geologic column.

“The well screens need to be placed in the appropriate strata so that the water level measurements and water quality data are of the most use in monitoring the groundwater,” according to the report.

Piezometers are included in the monitoring plan, “but would be helpful to provide information about the vertical component of groundwater flow,” the report states.

All of the monitoring wells are “life of the mine” wells located outside of the area to be mined.

The engineering report recommends “monitoring wells, to monitor groundwater level only, be installed within the area to be mined.”

The report notes the proposed mine also is located on a surface water divide, and establishing groundwater flow directions is necessary to evaluate any impacts to quality associated with sand mining activities.

Northern Sands also plans to install a high capacity well in the Mt. Simon aquifer and conduct a pumping test to determine the effect on the shallower bedrock aquifer.

Baseline

The reclamation permit approved by Chippewa County requires a baseline hydrologic inventory, and according to a letter from Chippewa County dated March 13 of this year, Northern Sands is required to have completed the survey by October 1.

Northern Sands also is required to provide a hydrologic inventory map showing the location of seeps, springs, wetlands and surface water in the mine and on adjacent properties. The map is required to include streams with beds and banks.

The March 13 letter required a delineation of all wetlands in Phase I as well.

The wetland report was submitted to Chippewa County on July 22, and Chippewa County land conservation and the DNR will review the report.

Recommendation

The SCS Engineers report recommends approval of the mine license should be contingent upon a number of conditions. The plan Northern Sands submits to the Town of Howard for groundwater monitoring should include the following:

• Determining the depth to the groundwater and the directions of the groundwater flow, including the vertical components of the flow within the area to be mined.

• Evaluating groundwater quality in the sandstone that will be mined and in the aquifer being used for water supply.

• Defining the groundwater divide and where it is positioned.

• Determining the elevation of the water table in the areas where frac sand will be mined.

The plan should include documentation and evaluation of monitoring wells; groundwater contour maps based on high and low water levels and the elevations of springs, seepage areas, streams and intermittent streams and surface topography; geologic cross-sections showing major geologic units, locations of monitoring wells, position of the water table, locations of nearby private wells, and the proposed limits of excavation.

The plan also should include proposed locations for water table wells in the areas that will be mined for frac sand; the proposed location for piezometers in the areas to be mined; the proposed locations for water table sentinel wells down-gradient of the mining phases and the sand processing areas; tabulated groundwater elevation and depth for the seven monitoring wells and the observed trends in fluctuations; tabulated groundwater quality data; well construction forms for private wells within 200 feet of the mine property and a discussion of the local aquifer. 

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