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Environmental assessment and nationwide section 4(f) evaluation Canyon Ferry Road : STPS 430-1(5)1; CN 4480, Lewis and Clark County, Montana (Volume 2003) online

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section of the project corxidor.

The relatrvely fiat dramage features of the project area require subsurface disposal of storm
water. Subsurface disposal of storm water would be accomplishedby allowing ninoff to
infiltrate through a layer of gravel or soil or by direct discharge into a dry well. It rs important to
note that storm water would not be expected to pollute groundwater smce the water would be
"filtered" naturally as rt seeps tiirough subsurface materrals. Thrs would be similar to flie existing
situation since stoim watei ninoff is contained and filteied through the soil in isolated roadside



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Canyon Ferry Road; STPS 430-1(5) 1



Environmental Assessment



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From: Firm Panels #1542 and #1544




Figure 8:

Floodplains in Vicinity of

Canyon Ferry Road



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Canyon Ferry Road; STPS 430-1(5) 1 Environmental Assessment

ditches. This system would be expected to help preserve flows in streams, recharge groundwater,
reduce peak ninoff flows, and reduce sediment in area surface waters.

The Prefened Action would not promote or encourage development witliin the base floodplain or
inciease flood liability hazards fiom its construction. Therefore, the Canyon Feixy Road pioject
is considered to be in compliance with Executive Oidei 11988 and meet floodplam management
criteiia.

CUMULATIVE IMPACTS. The project would have no cumulative impacts on the floodplain
of tlie project area because of MDT's design considerations for the replacement bridges and road
reconstruction.

No cumulative floodplain impacts are anticipated &om tliis proposed pioject and the othei blown
or reasonably foreseeable development in tlie project area considered in tliis EA (see projects
identified in Section 13. Secondary and Cumulative Effects later in tliis Part). Tliis proposed
project and otlier development projects with floodplain encroachments must comply witli the
County's floodplain management giudelines and would be subject to leview and pemiitting by local
goveiTUTient. The issuance of a floodplam pennit by the County does not mean that tiiere would be
no unpacts to floodplains.

IMPACTS OF THE NO ACTION ALTERNATIVE. This alternative would have no new
effects ontiie pioject area floodplain. There are no risks of new flooding, no impacts on natural
and beneficial floodplain values, and no likelihood of mcompafible floodplain development.

Mitigation Measures (Floodplain Impacts)

The following nieasme will be implemented to minimize potential floodplain impacts in the
Canyon Feny Road project area.

■ MDT will obtain a floodplain Development Permit from Lewis and Clark County

for construction activities within the delineated floodplains of the project area.



5. AIR QUALITY IMPACTS



Existing Conditions. Air quality within flie project area can be described as good. No
violations of state or federal air quality standards aie known to have occurred wiflun tiie Canyon
Ferry Road coiiidor.

Violafions of federal and state air quality standards have occurred within the East Helena area
due to emissions fiom the Asaico smelter. The operafion of the smelter resulted in violations of
air quality standards for lead and sulfur dioxide. Aieas that violate fedeial or state air quahty
standards are designated nonattamment areas by the U.S. Environmental Protection Agency
(EPA). These violafions occurred vvdth sufficient fiequency and resulted in nonattamment area
designations beir^ for East Helena for lead and sulfiir dioxide emissions. Communifies with

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Canyon Ferry Road; STPS 430-1(5) 1 Environmental Assessment

nonattainment areas are responsible for developing air pollution control strategies to bring tlie
ai'ea into compliance with an quality standai'ds.

Canyon Feny Road IS located about 1.6 km (1 imle)noitliof the boundary of the federally
designated East Helena Lead Nonattainment Area, wliichincludestlie Town of East Helena and
its immediate sun'oundmgs. Additionally, a portron of the project area rs about 5.6 km (3.5
miles) nortli of the East Helena Sulfur Dioxide Nonattainment Area. The sulfur dioxide
nonattainment area covers a localized area southoftheTownof East Helena at the site of the
Asarco smelter.

Federal and state air quality standards have not been exceeded in tlie area since 1 996 and the
primary source of lead and sulfui' dioxide pollution in tlie area, the Asarco lead smelter, has smce
closed.

Other sources of air pollution in tlie area mclude dust generated by hafQc on unpaved roads in
the area, agricultural activities and &om occasional outside burning.

IMPACTS OF THE PREFERRED ACTION AND THE NO ACTION ALTERNATIVE.

Despite its proximity to tlie East Helena Lead and Sulfm' Dioxide nonattainment areas, this
proposed project is located in an "unclassifiable'Vattaimiient area of Montana for air quality
under 40 CFR 81.327 , as amended. As such, this proposed project is not covered under the
EPA's Final Rule of November 24, 1993 on Air Quahty conformity. Therefore, tins proposed
project complies vvdth Sector/ 176(c) of the CleanAir Act (42 V. S.C. 7521 (a)), as amended.

This road reconstruction project would mvolve actions whose mdividual and cumulative effects
would be minor and would not affect regional emissions. Neitlier tlie Preferred Action nor the
No Action Alternative would be expected to result m adverse air quality impacts.

Short-term au' quality impacts would be anticipated during construction of tlie proposed project
due to the disturbance of relatively large areas and operation of heavy equipment in work zones.
Road construction activities would result in emissions of particulate matter, volatile organic
compounds (VOCs), and odors as a result of ground disturbance, vehicle exliaust, and use of new
surfacir^ materials. These impacts would be mmor and limited to the conshTiction period.

CUMULATIVE IMPACTS, hiiproving traffic flow on Canyon Feny Road would help reduce
the cumulative impacts of automobile emissions in the area. Automobiles typically emit greater
amounts of carbon monoxide, volatile organic compounds and otiier pollutants when they are
running in idle.

Mitigation Measures (Air Quality)

The foUovvdng measure will be implemented to minimize any aii' quality impacts associated vvdth
tiie constiuction of MDT's proposed project.

■ MDTwill incorporate dust control measures into the plan's specifications for the

propose fl project.

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Canyon Ferry Road; STPS 430-1(5) 1 Environmental Assessment



6. IMPACTS TO VEGETATION



Existing Conditions. From tlie beginning of the project to Lake Helena Drive, tlie project
traverses a flat valley bottom that has undergone extensive residential and commercial
development over tlie past 20 years. Few-if-any native vegetative communities remain mtact
tliiough this aiea. Common roadside ditch species include crested wheatgiass, smootli brome,
Kentucky bluegrass, yellow sweet clover, common mull em, and spotted knapweed. Residential
landscaping tliiough tins section mcludes various omamental flowers, native and mtroduced
trees and shrubs, and manicmed bluegiass lawns. Species common along the nmiierous
irrigation ditches that flovv' under tlie roadway tliiough this section include milkweed, smootli
biome, yellow sweet clover, asparagus, rose, and various wetland plants.

Within the rural portion of the conidor, the highway traverses rolling terrain tlnough dry-land
crop and grazing land. Some native rangeland exists through this area, although a majority has
been disturbed by agricultural practices and on-going residential development. Alfalfa
pioduction is common near Lake Helena Drive and in the vicinity of Spokane Creek near the
project's eastern terminus. Wheat and hay production is common m the non-inigated land
tlirough much of tins segment. Nahve rangeland plant communities found m the project area are
comprised primarily of sagebRish, blue grama, Idaho fescue, wheatgrass, cheatgiass, licoiice,
and prickly pear. Crested wheatgiass and smooth brome are the dominant grasses found m
roadside ditches through the rural section of the project.

Near tlie projects eastern teniiinus, the highway crosses over Spokane Creek and an unnamed
spnng-fed drainage. Wetland plant species can be found along Spokane Creek and the spring-
fed drainage west of Spokane Creek. Nairow-leafed cottonwood, wild rose, and snowbeny
occur' along both drainages.

Threatened or Endangered Plants. The US. Fish and Wildlife Service (USFWS)hsts
water howellia and Uteladies'-tress orchid as tlueatened plant species m Montana under tlie
Endangered Species Act (16 U.S.C. 1531-1543). Habitat for water howelha does not occui' in the
pioject area. According to the Biological Resources Report, potential habitat for Ute ladies'
tresses exists in pioject area wetlands; however, tlie nearest known occuirence of this plant is
south of Tovmsend in Broadwater County.

Rare or Sensitive Plants. A search of tlie Montana Natural Heritage Program
(MNHP) database revealed two known occurrences of plant species of concein within 8 km (5
miles) of the project (MNHP 2001). These include wedge-leaved saltbush and small yellow
lady's slipper and were for locations over 3 km (2 miles) from this proposed action. These plants
were not identified in tlie Canyon Feny Road conidor during field studies performed for this
project.

Invasive/Noxious Plants. Executive Order 13112, Invasive Species, signed on February 3,
1999, addresses federal agency responsibihhes with respect to invasive specres (noxious weeds).
As a partially federally frinded action, tlie project is subject to the provrsions of the Executive

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Canyon Ferry Road; STPS 430-1(5) 1 Environmental Assessment

Order. According to the Invaders Database System (2001), 15 noxious weeds have been
identified in Lewis and Clark County over tlie last 20 years including: hoary cress, diffiise
knapweed, spotted knapweed, Russian knapweed, oxeye daisy, Canada thistle, field bindweed,
hoimd's-tongue, leafy spurge, orange hawkweed, dalmation toadflax, sulfiir cinquefoil, tall
buttercup, tarnarix, and common tansy. Most of tiiese weeds are Category 1 noxious weeds as
defined by the Montana Department of Agrt culture. Orange hawkweed and tarnarix are
Category 2 noxious weeds.

Spotted knapweed, Russian knapweed, hoary cress, and Canada thistle were identified in the
project area by MDT's consulting biologrsts during field vrsits. Only individual plants or small
infestatrons of tiiese weeds were noted along much of the project.

IMPACTS OF THE PREFERRED ALTERNATIVE. The proposed lirghway improvements
would result in the permanent loss of vegetation where the roadway rs realigned or widened. The
vegetation lost due to tiirs proposed project would primarily involve non-native grasses species
and resrdential landscaping on both sides of the road in the commercial/resrdential section of the
corxidor. At some locations, reconstructron would impact or even result in tiie removal of some
ornamental flowers and shrubs, lavms, and intioduced tiees at residences along thrs portion of
tire corridor.

Within the rural section, the extent of vegetation lost would be greater due to the proposed mmor
shift in the location of Canyon Ferry Road. Minor amounts of natrve rangeland, cropland
supportir^ alfalfa, wheat and hay production, grazing land, and riparian and wefland vegetation
would be lost due to road reconstiuction.

Virtiially all of the proposed construction would occur in areas immediately adjacent to the
exrsting road already subjected to other sources of human disturbances, includmg residential,
recreational, and agricultural (farming, grazing) activities. Consequentiy, tiie overall effects of
the proposed project on vegetation communrtres would be mmor.

The proposed hrghway reconstruction project would not affect Ute ladies' tresses (a federally-
listed threatened specres) or any rare and sensitive plants.

Temporary distiirbances would occur where vegetation is cleared fiom the right-of-way permit
or easement areas, at staging areas for construction equrpment and at borrow sites. Many noxious
weed species gain a foothold after ground disturbances; tiierefore the potential for tire spread of
noxrous weeds is a concern due to the extent of the disturbances associated vvdth the proposed
projects. Once noxious weeds become estabhshed, they are often extremely difficult and very
expensrve to eradicate or contiol. Invasive noxious weeds can reduce the value of an area for
rangeland, wildhfe habrtat, or other uses.

In accordance witii Executive Order No. 1 3 1 1 2, MDT would implement measures with this
project to help prevent the intioduction of invasive species into the Canyon Ferry Road coriidor.
These measures would include coordinating tiie projects with tiie Lewis and Clark County Weed
Control District, prompfly reseeding disturbed areas, and requiring MDT's contiactor(s) to
follow procedures to prevent the spread of noxious weeds.



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Canyon Ferry Road; STPS 430-1(5) 1 Environmental Assessment

CUMULATIVE IMPACTS. Ground distuibing activities from the proposed road reconstruction
and other present and flituie development m the project area and other portions of the Helena
Valley could result in the loss of minor amounts of native vegetation and offer tlie potential for
the spread of noxious weeds.

IMPACTS OF THE NO ACTION ALTERNATIVE. This Alternative would cause no fiirtlier
impacts on vegetation witliin tlie project area.

Mitigation Measures (Vegetation Impacts)

The foUovvdng measures will be implemented to mmimize vegetation unpacts and reduce the
potential for the spread of noxious weeds in tlie project area.

■ Clearing and grubbing operations will be restricted to the minimuni area
necessary to acconitiiodate the planned reconstruction activities and
improvements and utility relocations.

■ Disturbed areas will be reseeded as quickly as possible.

■ A revegetation plan will be developed for this project to be followed by the
contractor. The plan will include specifications on seeding methods, seeding
dates, types and amounts of mulch and fcrtilizer, and seed mix components. The
plan will also be submitted to the Lewis and Clark County Weed Control District
for review.

■ The contractor must also follow the requirements of the County Noxious Weed
Management Act and all county and contract noxious weed control provisions.

■ Construction equipment must be cleaned prior to beginning work and after the
completion of work in the project area to avoid the unintentional introduction of
noxious weed seed from other sites.

■ Mulch used for revegetation will be certified as weed-free.



7. IMPACTS TO WETLANDS



Existing Conditions. Land & Water Consulting, Inc. delineated wetlands in tlie project area
during September 2001 according to criteria and methods outlined m the U.S. Army Corps of
Engineers (COE) 1987 Wetlands Delineation Manual (Environmental Laboratory, 1987). The
manual provides guidance for determining the presence of jurisdictional wetlands based on
obseiTations of vegetation, soils, and hydrology. Wetland location maps, found plant species
lists, and COE Routine Wetland Determination foinis were completed for wetland sites
identified witlim the comdoi. Addihonally, MDT Field Evaluation forms were completed to
assess the many fiuictions and values attributable to wetlands. These materials are mcluded in
tlie Biological Resources Report piepaied for this project.

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Canyon Ferry Road; STPS 430-1(5) 1 Environmental Assessment

The wetlands evaluation was conducted for all wetlands in tlie preliminary right-of-way corridor
of MDT's cmrently proposed alignment for Canyon Ferry Road. Six primary wetland areas (Sites
1 through 6) were delineated in the analysis area adjoining the present highway.

Wetland Sites 1 through 4 aie associated with either the Helena Valley Canal or other irrigation
ditches in the valley west of Lake Helena Drive and consist of narrow (less than 1 m (3 feet)
wide) fiinges occuiiing along tlie banks of the ditches. These fiinge wetlands are dominated by
emergent and wet meadow species including meadow foxtail, reed canary grass, and ledtop.
Wetland Site 5 is located in the vicinity of No Name Spring Creek (RP 8.68) and consists of a
large spring-fed wetland complex witli a defined channel and mixture of emergent marsli, wet
meadow and forested wetland habitats. Dominant species witliin tins site mclude reed
canarygrass, field horsetail, beaked sedge, bulrusli, broad-leafed cattail, foxtail barley, redtop,
meadow foxtail, and other common wetland species. Wetland Site 6 is directly associated vvdth
tlie active Spokane Creek channel and fioodplain near RP 9.0. The site consists of a narrow
wetiand fiinge along the banks of the creek and supports wetiand vegetation similar to that in
Site 5. Mature cottonwood tiees can be found in botii Sites 5 and 6.

A total of 3.18 ha (7.84 acres) of wetlands were delineated at the wetiand sites vvdthin the
Canyon Feny Road project comdor. The majority of tiiese wetlands are rated Category IV
according to MDT's Wetiand Assessment Method. This means that most wetlands in the project
area provide httle in the way of wildlife habitat, suiface water storage, flood attenuation,
production export/food cham support and groundwater discharge. Wetiands associated with Site
5 and witii Site 6 are primarily rated as Category 111 wetiands.

IMPACTS OF THE PREFERRED ACTION. ConstiTictionofthe proposed highway
improvements would result in unavoidable encroacliments mto wetlands, stieams and irrigation
canals at some locations in the Canyon Ferry Road corridor. These encroachments would result
fiom realignments, road widening, slope flattening, new bridge or culvert installations over
stieams and canals and associated detours around bridge or culvert mstallations. Wetland
vegetation would be removed and hydric soils would be covered witii the roadbed and fill slopes
in impacted aieas. The preliminary design of the proposed liighway project has been developed
to minimize encroacliment mto wetiands. However, at some locations wetlands exist on both
sides of the highway making it impossible to improve tiie road or replace bridges and culverts
witiiout encroaching on wetiands.

Based on preliminary design plans for tliis project, the amount of wetlands that would be diiectiy
impacted by tire proposed reconstruction of Canyon Ferry Road would be about 0.60 ha (1 .5
acres).

The "jurisdictional" status of affected wetiands m the area is an important consideration for this
pioposedpioject because of MDT's mitigation requirements. Jurisdictional wetiands aietiiose
tiiat fall under tiie COE jurisdiction vvith respect to Section 404 of tiie ClkanWaterAct.
Generally, the COE maintains jurisdiction over non-isolated wetiands tiiat are hydiologically-
cliar'ged by irrigation seepage as long as the seepage is considered "normal circumstances" for tiie
wetiands created by tiie water source. The COE does not generally mamtain jurisdiction ovei
wetiands in artificially irrigated areas unless: the wetiand has additional hydrological sources; the
wetiand IS of significant regional or local value; or elimmationoftheiiiigationcouldnotbe

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Canyon Ferry Road; STPS 430-1(5) 1 Environmental Assessment

accomplished in tlie near flitiire.

According to 1995 published guidance, the COE generally did not consider ditches excavated on
diy land as jmisdictional "waters of the United States." However, the Omaha Distiict of the
COE recently issued guidance to the effect that excavated urigation and dramage ditches may be
considered jurisdictional if they have a downstream smface connection to other waters of the
U.S.

As a result of a January 9, 2001 U.S. Supreme Court decision, many isolated wetlands (those not
connected oi adjacent to other waters of the U.S.), wliich previously fell under COE jmisdiction,
are now uniegulated for Section 404 purposes.

Based on these considerations, MDT's consulting biologists concluded that wetlands withm the
pioject corridor associated witli the Helena Valley Canal or its associated laterals aie
jmisdictional for Section 404 purposes because water supphes aie amiually discontmued and there
are no naturally flowing stieams that contiibute directly to flows m the canal. Wetlands associated
with No Name Spring Creek and Spokane Creek are "jmisdictional" wetlands.

Minor, short-term impacts to wetlands would occm in the vicimty of No Name Spring Creek and
Spokane Creek due to the need to provide detours and temporary stream crossings during the
installation of new culverts. Detoms during the constniction of new bridges across the Helena
Valley Canal would also result in similar impacts to fiinge wetlands alor^ the canal.

CUMULATIVE IMPACTS. The potential exists for other highway reconstniction projects and
developments in the Helena area and adjoining counties to impact wetlands. However, cumulative
impacts to wetlands would be minimized if efforts are taken to avoid wetlands or to adequately
mitigate for wetlands affected by ongoing and flitme development activities.

IMPACTS OF THE NO ACTION ALTERNATIVE. This alternative would cause no hirther
impacts to most wetlands within tlie project area. However, impacts to tlie stream ciossing at No
Name Spring Creek are foreseeable in the near future. This would result &om MDT's obligatory
maintenance to replace tlie structurally deficient bridge with a laige diameter culvert. This
would result m the placement of mmor amounts of fill mto Wetland Site 5.

Mitigation Measures (Wetland Impacts)

The 1 990 Memorandum of Agreement Between the Environmental Protection Agency and the
Department of the Army Concerning the Determination of Mitigation Under the Clean Water Act
Section 404(h} (1) Guidelines reqmies that wetland mitigation be addressed m tire following
sequence:

(1) Avoid potential impacts to the maximum extent piacticable.

(2) Minimize miavoidable impacts to the extent appropriate and practicable.

(3) Compensate for miavoidable adverse impacts tiiat remam after all appropriate and
piacticable minimization has been required.

■ Avoidance and Minimization. To the extent possible, the proposed alignment for tins

reconstruction project has been developed to avoid impacts on wetland sites. However,

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Canyon Ferry Road; STPS 430-1(5) 1



Environmental Assessment



since the existing roadway is located adjacent to and crosses wetlands, totally avoiding
wetlands is not possible. Roadside development tliioiigh much of the conidor has
established the ahgnment of this road and MDT's proposed reconshuchon would occur
on or very near the existmg alignment over most of the project's length.

Steepening roadside fill slopes is one measure tliat can be employed to reduce impacts to
wetlands. Although MDT's design is only m the preliminary stage, the use of steepened
slopes in the vicinity of wetlands will be considered and incorporated mto tlie project
where possible . The greatest benefits of usir^ steepened fill slopes would be in the
vicinity of wetland Sites 5 and 6.

■ Compensation. Compensatory mitigation for the projected wetland loss will be required

and developed m comphance with the 1 996 MDT Interagency Wetland Group operating
procedures. Although no specific wetland mihgation sites have been identified yet at this
early stage of the project, wetland creation/restorahon opportunities may exist on private
lands near Sites 5 and 6. MDT may also have sufficient wetland "credits" fiom past
mitigation efforts m the watershed tliat could be apphed to this project.

The foUovvdng measures will be implemented to mmimize impacts to wetlands in the project
com dor.

■ The design for the proposed highway improvements project will be developed to
avoid or minimize encroachment into wetlands.

■ MDT will seek to mitigate unavoidable wetland impacts in the ifiimediate vicinity
of this proposed project.


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Online LibraryRobert Peccia & AssociatesEnvironmental assessment and nationwide section 4(f) evaluation Canyon Ferry Road : STPS 430-1(5)1; CN 4480, Lewis and Clark County, Montana (Volume 2003) → online text (page 8 of 19)