The Cotter/Lincoln Park Community Advisory Group together with the CDPHE and the EPA and Colorado Legacy Land (owner of the superfund listed property) continues stepping through the federal CERCLA cleanup process at the Lincoln Park/Cotter Superfund Site. The Remedial Investigation phase is in full swing now. This is the step that identifies gaps in the data about the extent and location of the radioactive contamination and how it moves in the environment.
Local CAG speakers at the November meeting of the CAG revealed four important items:
1. location of some seeps and springs in the area north and south of the Arkansas,
2. a 1929 oil well in Cotter's old tailings pond footprint,
3. a potential connection of the Chandler and Wolf Park inactive mine workings
4. analysis of the geology and hydrogeology at the site, that mapped the reach of the geologic formations some distance under the Arkansas River.
CAG member Carol Dunn cited two reports in her slide presentation. First: the 1986 Cotter Remedial Investigation Executive Summary regarding groundwater emerging in seeps and springs in lower Sand Creek (which flows into the Arkansas River). Second: the 2007 Technical Advisory Grant publication by Dr. Charles Patterson that states “The Chandler airshaft, 1 mile east of the mill, flows 10 gals/minute to groundwater, and this water may be contaminated, possibly with subsurface connection to the Wolf Park Shaft. (…) Testing that water would be the definitive proof of the deep path.”
CAG Vice-chairwoman Jeri Fry presented her mapping of 11 seeps and springs north, east and west of the Cotter/CLL site including spring-fed lakes like Sells Lake and others on private property. Her field research showed there was a lot of water running in Sand Creek where it crosses Willow. She is curious where all the water comes from as the ditches are shut off in early October and Sand Creek is dammed at the SCS Dam up stream on the Cotter site. Sand Creek still drains the larger geologic formation under the Cotter/CLL footprint. Fry also mentioned the site of the old women's prison on Grandview where springs damaged the structure and ran down the steps. The CAG would like to see the waters in the seeps and springs characterized to learn whether they are contaminated.
CAG Chairperson Emily Tracy presented findings of retired Geologist, Bob Kirkham, whom the CAG met with at the County Planning Department to research maps of coal mines in the area. She noted that historic maps of the mine workings do not agree with each other about a connection between Wolf Park Mine (under the Cotter site) and the Chandler Mine (to the east of the Cotter site). A connection between the two mines would mean a pathway for water to move from one mine to the other. Eight shafts belonging to the Wolf Park Mine are noted on the map. One known as the Littell Shaft surfaced in Cotter's old tailings pond area. More detail is needed on how the Littell Shaft was closed. More detail is also needed on the other 7 shafts in the same vicinity.
Tracy reported that Kirkham found a mapped oil well that was drilled in 1929 by the Wolf Park Coal Mine company. It was drilled nearly 4,000 feet down from the surface, and though it purposefully avoided the coal mine workings, it did go through the coal beds, through the Trinidad Sandstone formation and into the Pierre Shale formation. The oil well is located in the place that became Cotter's original tailings ponds area in 1959 where contaminated waste was dumped on the ground or in unlined ponds. Details are not known about the casing or the annular space between the drill hole and the casing. The significance of the discovery of the oil well is that the shaft or drilled hole could be another potential path for contaminated water to reach deeper layers of sandstone providing a route for the contamination to flow into areas farther from the mill site.
Lifelong resident, Gus Slanovich, owner of the Chandler Mine and most of the land around the Cotter/CLL site presented his 2003 research analysis paper “The Other Path.” Slanovich's petroleum engineering degree is from the Colorado School of Mines. His work presented maps and diagrams showing each of the formations, by thickness and composition, which form the nested bowl shaped geological system that dips deepest beneath the Cotter mill site.
Slanovich described the Trinidad sandstone as a “prolific aquifer.” He traced the Trinidad formation to and under the Arkansas River, where he noted the Trinidad is shielded from the river's water by the Vermejo formation which also reaches under the Arkansas River and thus the Trinidad is able to dump water on the north side of the river without interacting with Arkansas River water. He believes waters from the Trinidad show up in springs in areas around the prison and in the Mackenzie area north of the Arkansas River. Water that enters into the Trinidad sandstone is able to travel the formation for a long distance until it can escape, in this case, north of the river.
The November 2021 CAG meeting was recorded on Facebook Live and can be viewed on the Lincoln Park/Cotter CAG Facebook Page.
The Cotter/Lincoln Park Community Advisory Group, established in 2005, is comprised of 14 Fremont County citizens who donate their time and service in work toward the best possible clean-up of the Cotter/ Lincoln Park Superfund Site. These volunteers work with the Colorado Department of Public Health and Environment (CDPHE) and Region 8 Environmental Protection Agency (EPA). Currently the process is in the Remedial Investigation phase of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) commonly known as Superfund, enacted by Congress on Dec. 11, 1980.
Those who would like more information or wish to serve, contact the CDPHE at (303) 692-3421.