Click on the image below to view an interactive Story Map detailing EPA's progress at the Site.
Manila Lode is a
former mine/mill operation just outside the town of Montezuma, Colorado that
ran from the 1870s into the 1910s during the Colorado Silver Boom. Although the
mineral processing stopped operation well over a hundred years ago, the
remnants of the operation still impact the area today.
At the site today,
two large contiguous waste rock and mine tailing piles exist and present heavy
metal contamination threats to hikers/recreationists, the Upper Snake River and
the residence built adjacent to the site. In a site soil sampling event in 2018,
Trout Unlimited reported presence of aluminum, arsenic, cadmium, copper, iron,
lead, manganese and zinc. Lead concentrations in the pile range from 2,000 to
20,000 mg/kg. A subsequent Trout Unlimited water sampling event in 2019 found
that much of the heavy metal contamination was reaching the Upper Snake River
adjacent to the site.
Exposure routes to
heavy metal contamination from the pile include a county greenspace trail
traversing the site, a residence adjacent to the pile, and year round rainwater
run off/snow melt draining through the pile and to the Snake River via a
In April and May of
2021, an EPA removal team conducted a site assessment and made observations
consistent with the Trout Unlimited findings and deemed the site to be in need
of a removal action due to the threat to both the Upper Snake and the nearby residents.
In July of 2021 an
EPA removal team was dispatched to the site to conduct removal action that will
include five main objectives:
- Temporarily reroute storm
water drainage around the waste pile to allow for waste piles to be
reworked and a permanent drainage path to be constructed without the
inflow of water.
- Rework and regrade the waste
piles to eliminate void spaces within the piles and to eliminate the steep
slopes currently present. This will minimize water infiltration through
the piles as well as mitigate erosion.
- Construct a permanent lined
drainage channel to take water from the Toledo Tunnel across the waste
site to the wetland area without allowing direct contact with waste
- Install an
evapo-transpiration cover over the waste piles and establish proper
vegetation to promote stabilization and mitigate direct contact with the
metal laden rock.
- Provide institutional
controls, such as deed restriction or an environmental covenant.