Effects of Fluvial Tailings Deposits on Receiving Waters in the Upper Arkansas River Basin, Lake County, Colorado

Science Center Objects

Fluvial tailings deposits stored in the floodplain of the upper Arkansas River represent a potential nonpoint source of contamination to surface and ground waters. The U.S. Geological Survey has been cooperating with the U.S. Environmental Protection Agency to monitor a lowcost, insitu remediation technique for the deposits. Remediation of selected sites occurred in 1998 through 2000 by amending the sites with a mixture of biosolids, compost, and lime or limestone, incorporating the mixture into surficial soils, and reseeding the areas. Water quality beneath the sites is being monitored to detect improvements resulting from the remediation.


  1. Monitor long-term (6 year) changes in water quality in the saturated and unsaturated zone beneath one remediated site to detect changes that are related to the remediation.   Monitoring at this site had been active prior to remediation in 1998.
  2. Initiate monitoring at a new site where remediation involved a different amendment mixture than was used at the long-term site.
  3. Assess differences in water quality at the two sites that may be related to the different remediation amendments used at each site.