Oil and gas usually take center stage when it comes to battles over mining in the West, but gravel has become the new enemy in Colorado’s St. Vrain Valley. Martin Marietta Materials, a company with operations throughout the U.S. and Canada, is planning to mine for gravel in Hygiene between Lyons and Longmont. The proposed operation would cause massive increases in water contamination, air pollution, noise pollution, light pollution and traffic (trucks and trains). The air and noise pollution from this mine would be devastating.
Boulder County includes parts of Rocky Mountain National Park, which set an attendance record with 4.5 million visitors in 2016. And last year’s visitation number spiked an 8.68 percent increase over the previous annual record set in 2015, itself a 32 percent increase over 2014, and a 40 percent increase since 2012. The current permit allows for one truck every three minutes and three trains a day. Traffic to the park will be significantly impacted, as will the air quality and the pastoral views. The experience of heading into the mountains will become vastly more industrial, potentially discouraging visitors.
There’s also worry about dangerous crystalline silica dust. The St. Vrain Valley can be extremely windy, which makes it impossible to control fugitive dust events and airborne toxins from a mining operation which will in turn poison local wildlife and residents.
Flooding in the St. Vrain Valley is a natural phenomenon that has been occurring for tens of thousands of years.
I witnessed the flood of 2013. I heard the roar of the river and watched it destroy ponds that were left from old mining operations in the area. Near 61st and Hygiene Road, the river jumped its track, destroying more mining ponds, and it swept that water east with great force. When the water breached the mining ponds at Pella Crossing, there was a massive swell of water and debris crashing into unsuspecting neighborhoods in Longmont.
The 2014 St.Vrain Creek Watershed Master Plan states, “During the flood, large split flow paths cascaded through the reclaimed gravel mining ponds. One split channel resulted in flooding outside of the 100-year floodplain and affected neighborhoods downstream in the City of Longmont. Although the adjacent floodplain has been historically connected to the channel, sand and gravel mining operations have altered the natural floodplain function for a majority of this reach.
If you go to Pella Crossing, 61st or Hygiene Road, you can see how the power of the floodwater blew out the mining ponds, adding to the catastrophe. The devastation is evidence of the knowledge that mining ponds should not be on a floodplain.
But, Martin Marietta Materials intends to mine between Hygiene Road and Colo. 66. Mining will leave behind even more mining ponds. Shouldn’t the valley’s floodplain be left alone? The valley is appropriate for open space, recreation and agriculture, but more mining will devastate the area- leaving wildlife and residents without clean drinkable water and poison in the air for many years to come.
Martin Marietta Materials’ intention to mine more than 400 acres in the St. Vrain floodplain.
Proposed gravel mining operations by Martin Marietta in the St. Vrain Valley between Lyons and Hygiene have serious groundwater ramifications for the residents of the valley.
35-acre parcels of land may be open-pit mined for aggregate in the special-use permit mining area between Hygiene Road and Colorado 66. Approximately 20 percent of the valley will be converted from forage land to gravel-pit mining operations. During the 10-year mining operation (there are 10 years left on the 30-year 1998 special-use permit) the groundwater will be drawn down around the mining pits in order to provide for dry-pit mining. Surface mines of 30 acres will necessitate massive dewatering around the pits to allow for heavy equipment to remove the gravel in a dry environment.
The mining pits may be as deep as 30 feet, which will mean that the water table in the area of the pits will have to be lowered more than 30 feet. Since the proposed mining operation is within the St. Vrain aquifer, groundwater will have to be pumped from the aquifer and diverted around the mining pits with the area of influence of the dewatering drawdown greatly exceeding the surface area of the gravel pits. Many of the residents and agricultural operations in the St. Vrain Valley depend on the aquifer for potable water for their homes, garden irrigation, agriculture, and stock watering.
During the possible 10-year mining operations, the residents of the St. Vrain Valley will have to seek other sources of potable water for their homes, gardens, agriculture, and livestock. When Lafarge was mining gravel in the valley several years ago, artesian springs dried up as well as shallow wells. Options for providing potable water to those affected by the water drawdown during previous gravel-mining operations included trucked-in water, a pipeline to Longmont to access city of Longmont water, or deep wells.
Trucked-in water requires that each homeowner has to have adequate water storage facilities to contain several days’ water use. A pipeline to Longmont will require homeowners to purchase Longmont city water at ever-increasing rates where now they pay only for the electricity for their well pumps. Deep wells miss the sweet water of the St. Vrain aquifer and the water requires substantial treatment before it can be used as potable household water. Irrigation with deep-well water is not advised as per water sample analysis by Colorado State University in Fort Collins. Deep-well water approaches the maximum limit of dissolved solids allowed for livestock water.
Please help bring this issue to light and help us stop this mine from killing the local wildlife, residents and environment.