U.S. Department of the Interior

U.S. Geological Survey

USGS Fact Sheet 007-99

August 1999

Colorado

Abandoned-Mine Lands

Many abandoned or inactive mines

are on or adjacent to public lands.

Wastes from many of these abandoned mine lands affect resources on

public lands. In 1995, a Federal

interdepartmental strategy was

developed to address remediation of

affected areas on public lands. The

strategy uses a watershed approach,

and is focused on developing methods

to understand the processes that

release and transport acid and metals

to streams and the subsequent response of biologic communities. The

U.S. Geological Survey (USGS) is

working closely with the Federal

land-management agencies, State

agencies, and local watershed groups

to develop efficient and cost-effective

methods to evaluate effects and

formulate plans for remediation.

The USGS is studying the upper

Animas River basin in southwestern

Colorado to identify metals and other

substances in water from these

abandoned mine lands. Scientists are

determining the toxicity of metals and

studying their movement through

food webs, which will help determine

the effects of mining waste on critical

high-altitude habitats. Preliminary

results show that water becomes

acidic when surface water reacts with

altered rock surrounding mineral

deposits and waste rock from mining

activities. Metals from stream waters

attach to sediments and are deposited

on the streambed, which affects

aquatic habitat and the food chain.

Contaminant Characterization and

Remediation

The USGS Mine Waste Characterization Project is an interdisciplinary

research project to develop methods

for characterizing weathered, solid

mine waste (fig. 1). Potential metal

release and acid production from the

waste depend on the mineralogical,

chemical, and physical characteristics

of the mine waste as well as geochemical and microbial processes.

Scientists from numerous disciplines

are working together in Silverton and

Leadville to evaluate characterization

methods and to understand processes

in solid mine-waste systems. The

Bureau of Reclamation and the U.S.

Environmental Protection Agency

(EPA) have asked the USGS to

develop rapid, cost-effective methods

for locating potential sources of

acidic mine drainage so that they

might expedite and streamline the

remediation process.

The USGS, in cooperation with local,

State, and Federal agencies, is

conducting studies to characterize soil

and water contamination caused by

the past production, storage, or

destruction of chemical agents,

munitions, radioactive materials,

fuels, and solvents. The studies

characterize the hydrology of the

sites, define the extent of contamination, evaluate monitoring networks,

determine contaminant transport

mechanisms, and model the fate of

contamination. The USGS is assessing the potential of zero-valence iron

for passive remediation of contaminants in ground water at several sites

that have different hydrogeologic

settings and contaminants.

Contamination from nonpoint sources

such as agriculture, mining, and

urban land uses can degrade the

quality of water for drinking, irrigation, and recreational use and can

affect the biota of streams, lakes, and

wetlands (fig. 2). Population growth

and residential development in the

mountains have increased demands

on ground-water supplies, increased

septic-system effluent returning to the

ground-water system, and heightened

public concern about the adequacy

and quality of ground water. USGS

scientists are evaluating nitrate

contamination in soil and ground

water from confined, animal-feeding

operations, assessing the effectiveness

of bioremediation to reduce nitrate

concentrations in ground water, and

Figure 2. Contaminated stream.

Figure 1. Collecting samples from a

mine waste dump.
science for a changing world

assessing the effects on ground water

and soil of treated-sewage-sludge

applications.

Front Range Infrastructure

Resources

Rehabilitation of existing infrastructure and development of new infrastructure to support human populations require the use of natural

resources, including natural aggregate

(stone, sand, and gravel) and water,

and energy resources. Urban expansion often hinders acquisition and use

of these essential raw materials by

making them less accessible or by

affecting their quality. Competing

land uses and mandates by Federal,

State, and local governments preclude

obtaining or using these resources in

some areas. The goal of the USGS

Front Range Infrastructure Resources

Project is to provide decision makers

and the public with objective information about the location and characteristics of land, natural aggregate,

water, energy resources, and biological resources and their relations to the

development of infrastructure resources.

A regional inventory of resources is

planned to define the basic physical

resource limitations and quality of

available resources and to relate

resource extraction to potential

effects on the environment. Streamside habitats and their potential to

support diverse groups of mammals,

birds, reptiles, and amphibians are

being classified. Methods for restoring streamside habitats and for

controlling undesirable exotic species

are being examined. Newly developed

data and data on natural aggregate

previously compiled by the Colorado

Geological Survey are integrated in

geographic information systems for

use by State and local agencies and

the producers and users of infrastructure resources. Interaction with these

groups ensures a focus on the highest

priority issues and the relevance of

project products.

Rocky Mountain Ecological

Research

Alpine and subalpine ecosystems on

the Front Range of Colorado are

among the most sensitive in North

America to atmospheric deposition of

nitrogen. Emissions of nitrogen

compounds to the air are likely to

increase because of population

growth, agricultural activity, and

energy development in the region.

Collaborative research by the USGS,

other Federal agencies, and universities is examining nitrogen-cycling

processes that control retention and

release of nitrogen in sensitive

terrestrial and aquatic ecosystems.

These findings are used to assess the

current status and predict changes in

ecosystem function that may result

from changes in emissions or climate.

Policymakers and regulators use this

information to make decisions on

permits for new sources and cleanup

of existing sources of nitrogen

emissions.

Whirling Disease In Trout

Whirling disease has been implicated

in declines of wild trout populations

in five major rivers in Colorado. The

disease is caused by a parasite

introduced from Europe that destroys

the cartilage in the bodies of young

trout, which causes them to become

deformed, to swim erratically, and,

eventually, to die from predation or

starvation. To understand this disease

and its potential management, USGS

scientists at the Colorado Cooperative

Fish and Wildlife Research Unit are

working closely with the Colorado

Division of Wildlife to develop

management options to deal with the

disease. The potential link between

management actions and the distribution and spread of whirling disease is

being examined. High-altitude lakes

stocked with fish suspected of having

the disease are being tested to determine if the disease can spread to wild

fish in these unique, pristine waters

(fig. 3). In another study, degraded

habitats are being examined to

determine how human influence on

watersheds contributes to the spread

of the parasite. The role of a headwater reservoir and a fish hatchery in

the persistence of the disease also is

being examined.

National Water-Quality

Assessment Program

The National Water-Quality Assessment (NAWQA) Program is designed

to describe the status and trends of

the quality of the Nation’s water

resources and to improve information

about the natural and human factors

that affect water quality. The building

blocks of the national NAWQA

program are more than 50 Study

Units. All or part of four Study Units

are within Colorado (fig. 4). The

South Platte River and the Rio

Grande studies began in 1991, and

the Upper Colorado River study

began in 1994. Part of the High Plains

Regional Ground-Water study, which

began in 1998, is in Colorado.

Figure 3. High-altitude lake where fish

may be affected by whirling disease.
Colorado

Information exchange and coordination through multiagency Study-Unit

liaison committees ensure that the

water-quality information produced

by the Program is relevant to regional, local, and national interests.

Energy Resources

The USGS National Coal Resource

Assessment, conducted in cooperation with the Colorado Geological

Survey and the Bureau of Land

Management, provides information

on the distribution and quality of coal

in the Colorado Plateau. Unlike

previous assessments, the geologic

and geographic data are in digital

format that can be updated easily with

new information. The geology, coal

quality, resources, and mining history

are being summarized for 11 major

coal units. A coal-quality database is

available for selected coal fields. Five

priority areas will have detailed

stratigraphic analysis of coal and coal

quality, a resource estimate, a stratigraphic database, and digital maps in

a geographic information system.

Sites were selected on the basis of

areas where significant mineral

ownership is federally administered,

areas that have active coal mining,

areas that have coalbed methane

production, and areas that have high

resource potential (fig. 5).

The USGS National Oil and Gas

Assessment Project assesses the

natural gas resources of the United

States. Eighteen priority provinces,

including the Uinta-Piceance (partly

in Colorado), are estimated to contain

90–95 percent of the known and

suspected natural gas resources of the

United States. The petroleum systems

and geologic assessment units in the

Uinta-Piceance basin will be defined,

and the suspected natural gas resources, including conventional and

continuous resources, will be assessed.

Water Availability And Quality

Water demands associated with the

rapid population growth in Colorado

in recent years emphasize the need

for current, reliable information on

water quantity, water quality, and

water use. This information can be

used to improve land-use and watermanagement practices, to protect

existing resources, and to identify and

address current and future waterquantity and -quality concerns. To

that end, the USGS, in cooperation

with several counties, will determine

the current quantity and quality of

surface and ground water within

those counties.

Changes in land and water use in the

Arkansas River Valley have caused

concerns about ground water that are

being addressed by local, State, and

Federal agencies. As part of this

effort, the USGS is determining the

areal extent of high ground-water

levels that are damaging structures

and crops in some parts of the valley.

The USGS also is evaluating whether

or not septic systems are affecting the

quality of shallow ground water.

In the Rio Grande basin, the State of

Colorado has identified the need for a

Decision Support System to improve

understanding and management of

water resources in the basin. The Rio

Grande Decision Support System is

being developed with the assistance

of an advisory committee composed

of numerous public and private

entities, including the USGS.

River/Watershed Processes

In mountain valleys along U.S.

Interstate 70, and in the hills and

mountains above valley floors,

geologic hazards include landslides,

debris flows, erosion, unstable

bedrock and surficial deposits, and

Figure 5. Detailed coal analysis.

i70

i25

i76

Durango San Juan Basin

Grand

Junction

Denver

Danforth Hills

Lower

White

River

Yampa

Coal-bearing areas

Priority coal projects

Study area

0 50 Miles

Southern Piceance

Upper

Colorado

Rio

Grande

South

Platte

High Plains

Figure 4. National Water-Quality

Assessment Study Units in Colorado.

Figure 6. Flooding and erosion in a

mountain valley.
Printed on recycled paper

USGS office locations USGS State Representative

The USGS has 1892

employees in Colorado

Boulder

Arvada Commerce City

Denver

Durango

Fort Collins

Grand

Junction

Golden

Lakewood

Pueblo

Meeker

Timnath

Bldg. 53, Denver Federal Center

Mail Stop 415, Box 25046

Lakewood, CO 80225

(303) 236-4882, ext. 258

Fax: (303) 236-4912

USGS Home Page

http://www.usgs.gov

Reports and products

1-888-ASK-USGS

flooding (fig. 6). The geology of 18

quadrangles along a segment of

Interstate 70 is being mapped by the

USGS. This mapping and the cooperative mapping by the Colorado

Geological Survey provide the public

with information on geologic hazards

that is intended to facilitate informed

land-use decisions and decrease

conflict between development and

these natural hazards.

Channel reconfiguration to mitigate

riverine problems has become an

important issue in the Western United

States. Reasons cited for channel

reconfiguration include restoration to

more natural or historical conditions,

improved water conveyance in floodprone areas, mitigation of unstable

reaches, increased sediment transport,

and enhancement of streamside

habitat. Reconfiguration of stream

and river channels by using designs

based on different approaches has

been undertaken at numerous locations in Colorado. However, few

assessments have been done of

channel response to these modifications over time. The USGS is monitoring and assessing selected river

reaches that have undergone such

reconfigurations to assess the effectiveness of these modifications over

time and to evaluate the downstream

effects of channel modifications.

Amphibian Population Decline

Amphibian populations in the intermountain regions of the Western

United States, including Colorado,

are declining or disappearing in areas

where they formerly were abundant.

Solar ultraviolet (UV) radiation from

ozone depletion may be causing this

decline because populations are

declining in relatively pristine

mountainous areas. To understand

why the populations are declining,

USGS scientists are measuring UV

radiation in the aquatic habitats of

these amphibians (fig. 7). Laboratory

studies are using a unique solar

simulator to determine the sensitivity

and effects of UV radiation on early

lifestage amphibians. Recent findings

indicate that increases in habitat

water clarity will significantly

increase UV exposure. Some amphibians, such as the endangered boreal

toad, can tolerate the upper UV range

currently measured in their habitats.

Other amphibians, however, such as

the tiger salamander or the Pacific

tree frog, are at their limits of tolerance to UV and show delayed development and symptoms of immune

suppression from exposure. Laboratory studies indicate that the interaction of UV and environmental

contaminants is a significant hazard

to amphibians. The toxicity of a

common pesticide, carbaryl, increased twelvefold to gray tree-frog

tadpoles in the presence of low UV

radiation, and a distilled petroleum

product was four times more toxic to

southern leopard-frog tadpoles in the

presence of UV radiation. Contaminants and UV can interact in a range

of amphibian intermountain habitats,

including nutrient-rich and turbid

sites, and could be a critical factor in

the loss of amphibians.

National Hydrography Dataset

The National Hydrography Dataset

(NHD) is a newly compiled geographic information systems database

that has been developed from the EPA

River Reach files and the USGS

Digital Line Graph (DLG) hydrography files. The objective of developing

the NHD is to provide a comprehensive, nationally accurate, highresolution, geographic digital dataset

at 1:100,000 scale. The NHD will be

distributed to the public, and it can be

used for computer modeling, analysis,

and mapping applications. The

Colorado National Hydrography

Dataset Densification Project is a new

innovative partnership between the

USGS and the Colorado Division of

Wildlife. The objective of this project

is to collect and incorporate into the

NHD finer resolution data (1:24,000

scale) from nearly 1,500 DLG

hydrography files, thereby improving

the spatial accuracy of the NHD

dataset.

Figure 7. Scientists measure

ultraviolet radiation in the aquatic

habitat of amphibians.