Highway Expansion Water Quality Impacts

Highway Expansion - Creating Tomorrows Problems Today

CDOT chose the most environmentally damaging
alternative (highway expansion) as the "Preferred"
alternative in the Draft PEIS.  This decision not only
ignores the huge water quality impacts to Black Gore
Creek and Clear Creek from the current I-70 facility,
but ignores water quality impact as a decision criteria
that most rational people would expect might be used
in an Environmental Impact Statement, in selecting the
"Preferred" alternative. 

Ultimately it would appear that CDOT's not so hidden
agenda of selecting highway expansion as the "Preferred"
outcome of the PEIS process is more important than
protecting Colorado's wonderful natural environment
including the drinking water supply for the 350,000 residents
in the downstream jurisdictions of Black Hawk, Westminster, 
Thornton, Northglenn and Golden and the Coors Brewing 
Company, that will be affected by I-70 highway expansion
impacts to Clear Creek.  The residents and visitors of Vail 
will also be affected by highway expansion impacts to Black
Gore Creek which provides a portion of their water supply.  

I-70 in the mountain corridor runs through river and

stream valleys and is often located in very close

proximity to these waterways.  The current highway

is adjacent to Clear Creek for 29 miles in Clear Creek

County.  CDOT is today the single biggest polluter to

Clear Creek in Clear Creek County.  Pollution results

from a mixture of storm water runoff and contaminants

caused by normal highway use and maintenance activities. 

Surface and structural erosion, resurfacing and highway

improvements, vehicle and tire wear, oil and grease

deposits, traction sand and chemical de-icers all

represent typical highway runoff pollution. 

Traction sand is a considerable problem in winter

environments such as the mountain corridor.  Traction

gravel alone does not cause any chemical contamination

of roadsides or receiving streams, however applied at the

rate of several tons of gravel per linear mile of highway

and because it is not typically swept up until the end of

the application season, the gravel accumulates on road

edges, physically smothering grass and other vegetation. 

When snow melts or rains fall, the gravel is carried by

runoff into nearby stream channels. Such gravel has a

very deleterious effect on fish habitat in high altitude

streams. The sediment physically smothers stream beds

with small particles that do not serve as a good substrate

habitat for aquatic insects or as good habitat for fish eggs.

In addition, because riparian zones of gravel impacted

streams tend also to be smothered by gravel, the food

source for any remaining aquatic insects is also reduced.

The insects and their food source are the bottom of the

game fish food chain.

Traction gravel applied to the roadway surface during winter

months is gradually moved downstream by water flow to the

nearest reservoir or ditch collection point and causes a

reduction in function to those facilities by filling them up

or blocking them. Some examples of traction gravel-impacted

streams in the Summit County area are Straight Creek near

Dillon and Black Gore Creek near Vail. Many thousands of

federal, state and local dollars are being spent to prevent

traction gravel from entering those streams after-the-fact

and restore some of the streams’ biological functions.

A final impact of traction gravel use is air pollution,

especially in high traffic volume areas. As traffic grinds over

the gravel, the traffic comminutes it to such a degree that

fine particles of gravel are suspended in air for a long time.

The small particles contribute to haze and also pose a hazard

to human lungs because the particles are sharp and insoluble.

The traction gravel plus salt mixture mitigates some of

the physical damage caused by traction gravel, but adds

a chemical pollution problem from the added salt. Most

of the salt applied eventually gets into surface waters

where the excess sodium ion content can pose a long

term risk to those drinking it who suffer from kidney

problems or high blood pressure. There are apparently

also some subtle effects on aquatic life. Most of the

streams affected by traction sand runoff are used as

drinking water supplies for either corridor communities

or Front Range communities.

The chloride anion of sodium chloride promotes the

corrosion of iron and steel objects. Although most road

salts contain proprietary corrosion inhibitors, it appears

that such inhibitors are not completely effective in preventing

corrosion. Those who live in the eastern U.S., where road salt

is applied liberally, know that cars don’t last as long there as

here in Colorado.

Road salts can also affect roadside vegetation by depositing

as aerosols on the trees’ needles or leaves and affecting the

exchange of water or air with the environment, to such a

degree that it can kill the leaves or needles. In the case of

pines, affected needles usually turn reddish-brown. The added

salt can also change the structure of the roadside soil and

may make it less permeable to water, thus starving the tree

of water.

Magnesium Chloride is also a salt and is the primary

component in the liquid de-icers used by CDOT on I-70. 

Magnesium Chloride has deleterious effects on streams

and trout in particular.  Magnesium Chloride is believed

to adversely affect riparian vegetation, stunting overall

growth and decreasing leaf cover that this vegetation

provides.  Magnesium Chloride affects roadside vegetation

in the same way as hard road salts, by depositing as an

aerosol on the trees’ needles or leaves and affecting the

exchange of water or air with the environment to a degree

that can kill the leaves or needles. The liquid salt can also

change the structure of the roadside soil and may make it

less permeable to water, thus starving the tree of water

and nutrients.

Some macro-invertebrates use riparian vegetation in their

reproductive cycles and any diminishment of plants can

adversely affect reproduction rates. Riparian vegetation

also provides shading to streams thereby controlling water

temperatures. This is particularly important during the later

parts of the summer when flows are generally down but

daytime temperatures are still high, heating the water.

Trout prefer water in the high 40's to mid 50's and begin

to become stressed when temperatures get into the 60's. 

Lack of vegetative cover can push stream temperatures

into the 60’s and higher.

Magnesium Chloride also corrodes metal on vehicles. 

Per pound applied, approximately 25% more chloride

ions (i.e. the corrosion-inducing ones) are applied with

magnesium chloride than with sodium chloride (hard road

salt).  To enhance de-icing and traction without gravel,

considerably more pounds of liquid magnesium chloride are

added per mile than sodium chloride in traction sand. 

Logically more roadside tree impacts from soil alternation

and from aerosols affecting leaf and needle air and water

exchange functions, and more vehicle corrosion and corrosion

of roadside metal objects, occur with the use of magnesium

chloride than with traction sand and salt mixtures.

Traction sand, chemical de-icer, copper from brake linings,

tire compounds, plus the occasional hazardous material spill

all contribute to pollution to the water courses adjacent to

highways.  The pollutants of concern are suspended solids,

chloride, phosphorous, copper and zinc, all of which are

projected to increase by at least 17 percent as a result of

I-70 highway expansion to six lanes.

Simply put, more lanes mean more impervious surface for

storm water runoff and more sand, more salt, more liquid

de-icer and more hazardous material spills into the adjacent

streams, creeks and rivers.

On average, 670 tons per mile of traction sand are applied

to I-70 annually in the Clear Creek drainage basin on the

current 4 lane facility (mp 213 to 255).  A six lane highway

in the same area would require on average between 1,050

and 1,100 tons per mile of traction sand annually, an

increase of between 58 and 62 percent.

On average, 13,772 gallons per mile of Liquid de-icer are

applied to I-70 annually in the Clear Creek drainage basin

on the current 4 lane facility (mp 213 to 255).  A six lane

highway in the same area would require on average between

19,400 and 20,000 gallons per mile annually, an increase of

between 41 and 45 percent.

Clearly, the greatest impacts on water resources in the

Clear Creek watershed would result from implementation

of the Six Lane Highway Alternatives or combinations

including the six lane highway alternatives.  The Advanced

Guideway System as a completely elevated alternative that

would not require traction sands or liquid de-icers, would

clearly be the least harmful action alternative in terms of

water quality impacts.

But Clear Creek is not the only affected water course in

the mountain corridor.  Phosphorous loading in water

supply reservoirs receiving runoff from the I-70 Mountain

Corridor include Standley Lake, Bear Creek Reservoir and

Dillon Reservoir.  Straight Creek and Black Gore Creek have

been put on EPA/CDPHE's 303 (d) list as water quality

impaired due almost entirely to sedimentation from I-70

runoff.

On average, 1,035 tons per mile of traction sand are

applied to I-70 annually in the Eagle River drainage area

of the current 4 lane facility (mp 133 to 190).  The Draft

PEIS six lane highway alternatives in the same area would

require on average between 1,200 and 1,250 tons per mile

of traction sand annually, an increase of between 17 and

19 percent.

On average, 9,697 gallons per mile of Liquid de-icer are

applied to I-70 annually in the Eagle River drainage area

of the current 4 lane facility (mp 133 to 190).  The Draft

PEIS six lane highway alternatives in the same area require

on average between 11,150 and 11,450 gallons per mile

annually, an increase of between 15 and 18 percent.

On average, 1,078 tons per mile of traction sand are applied

to I-70 annually in the Blue River drainage area of the current

4 lane facility (mp 190 to 213).  The Draft PEIS six lane

highway alternatives in the same area would require on

average 1,155 tons per mile of traction sand annually, an

increase of 7 percent.

On average, 12,652 gallons per mile of Liquid de-icer are

applied to I-70 annually in the Blue River drainage area of

the current 4 lane facility (mp 190 to 213).  The Draft PEIS

six lane highway alternatives in the same area require on

average 13,665 gallons per mile annually, an increase of

8 percent.

 

I-70 Traverses a mineralized zone and EPA Superfund Study Area

in Clear Creek County containing many Superfund sites.  Minerals

found in this zone are gold, silver, copper, lead, cadmium, zinc,

manganese, iron and aluminum.  The Superfund Sites located

within CDOT Right of Way are some of the most hazardous in

the county due to the historic location of mill sites along the

Clear Creek Valley (the current location of I-70).  

Mills at one time used mercury and cyanide as leaching agents

for gold and traces of these highly toxic substances can be found

under the current highway.  Significant disturbance of the existing

highway could mobilize not only the leaching agents in the mill

waste, but also other heavy metals in the mill and mine tailings

that were used as sub base for the current highway.   In addition,

new or substantially larger rock cuts necessary for highway

expansion will intercept highly mineralized zones, surface mine

wastes and mill tailings which will create additional metal

transport and loading in Clear Creek.

Six Lane Highway Expansion in Clear Creek County will cause:

-  Extensive Disturbance to Clear Creek including possible

   relocation in sections

-  Extensive Disturbance to Mine Works & Tailings within

   CDOT Right of Way

-  Extensive Disturbance to Mill Tailings within

   CDOT R.O.W.

-  High potential for heavy metals (cadmium, cyanide, lead,

   mercury, iron, copper and zinc) to enter the creek and

   significantly degrade water quality for the 350,000 plus

   residents in the downstream jurisdictions of Black Hawk,

   Westminster, Thornton, Northglenn and Golden, including 

   the Coors Brewing Company

The use of I-70 traction sand on Vail Pass today is creating significant sedimentation problems in Black Gore Creek.  The proposed climbing/descending lanes (auxiliary lanes) will no doubt aggravate an already difficult problem.  Mitigation of the current sedimentation problems in Black Gore Creek should be addressed prior to any highway expansion. The Environmental process used for the Vail Pass Auxiliary lanes will demonstrate CDOT's commitment to both the Context Sensitive Solutions process and their Environmental Stewardship policy.

Roadway Water Pollution Costs

For information on I-70 highway expansion impacts to Air Quality
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For information on I-70 highway expansion impacts to Human Health
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For information on I-70 highway expansion impacts to Visual Values
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For information on I-70 highway expansion impacts relating to Noise
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