United States 

Department of

Agriculture

Forest Service

Intermountain

Region

Caribou-Targhee 

National

Forest

Ashton / Island 

Park Ranger 

District

April 2012

Mack’s Inn

Wastewater Treatment

Plant

Land Application

Expansion Project

Environmental Assessment
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opportunity provider and employer.
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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Table of Contents

SUMMARY .....................................................................................................................ii

CHAPTER 1 – PURPOSE AND NEED ...........................................................................1

DOCUMENT STRUCTURE...................................................................................................... 1

BACKGROUND ........................................................................................................................ 1

PURPOSE AND NEED FOR ACTION..................................................................................... 3

PROPOSED ACTION ................................................................................................................ 4

DECISION FRAMEWORK....................................................................................................... 4

PUBLIC INVOLVEMENT ........................................................................................................ 4

ISSUES ....................................................................................................................................... 5

CHAPTER 2 – ALTERNATIVES.....................................................................................6

DESCRIPTION OF ALTERNATIVES...................................................................................... 6

Alternative 1 – No Action............................................................................................6

Alternative 2 – Proposed Action..................................................................................6

ALTERNATIVES CONSIDERED BUT ELIMINATED FROM DETAILED STUDY........... 9

COMPARISON OF ALTERNATIVES ..................................................................................... 9

CHAPTER 3 – ENVIRONMENTAL CONSEQUENCES ................................................13

VEGETATION RESOURCES ................................................................................................. 13

Existing Conditions....................................................................................................13

Environmental Effects ...............................................................................................13

WILDLIFE RESOURCES........................................................................................................ 14

Existing Conditions....................................................................................................14

Environmental Effects ...............................................................................................14

CULTURAL RESOURCES ..................................................................................................... 21

Existing Conditions....................................................................................................21

Environmental Effects ...............................................................................................21

RECREATIONAL ACCESS.................................................................................................... 21

Existing Conditions....................................................................................................21

Environmental Effects ...............................................................................................22

ECONOMIC IMPACTS........................................................................................................... 22

Existing Conditions....................................................................................................22

Environmental Effects ...............................................................................................22

WATER QUALITY AND HYDROLOGY.............................................................................. 23

Existing Condition .....................................................................................................23

Environmental Effects ...............................................................................................24

SOILS ....................................................................................................................................... 25

Existing Conditions....................................................................................................25

Environmental Effects ...............................................................................................25

VISUAL QUALITY ................................................................................................................. 25

Existing Conditions....................................................................................................25

Environmental Effects ...............................................................................................26

CHAPTER 4 – CONSULTATION AND COORDINATION.............................................28

ID TEAM MEMBERS.............................................................................................................. 28

FEDERAL, STATE, AND LOCAL AGENCIES..................................................................... 28

TRIBES..................................................................................................................................... 28

OTHERS................................................................................................................................... 28

REFERENCES.......................................................................................................................... 29
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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SUMMARY

The Caribou-Targhee National Forest is considering approval of a special use permit application 

submitted by Fremont County for expansion of the Mack’s Inn Waste Water Treatment Facility

(WWTF) effluent application system. The purpose of the special use permit application is to 

gain legal access and rights to install additional effluent application equipment on a 50-acre

parcel of NFS lands.

The project area is located on a 50-acre parcel in Township 14 North, Range 43 East, Section 25

just west of and contiguous to the existing WWTF at Township 14 North, Range 44 East, Section

30. The area is within the Ashton/Island Park Ranger District of the Caribou-Targhee National 

Forest in eastern Idaho. This action is needed because the Mack’s Inn WWTF effluent

application system is running at 95 percent capacity and treated effluent is being applied at near 

maximum capacity allowed by the Environmental Protection Agency and the Idaho Department 

of Environmental Quality (IDEQ).

The proposed action may affect grizzly bear and elk habitat. The application of an additional 

24.4 million gallons of water annually over the 50-acre expansion area has the potential to 

impact ground water quality. The routine monitoring required by IDEQ limits the possibilities of 

contamination but does not prevent them.

In addition to the proposed action, the Forest Service also evaluated the no action alternative. 

Under this alternative, the Forest Service would not issue a special use permit to Fremont County 

for the expansion of the land application area. The site would remain at its current capacity 

serving approximately 1,250 equivalent users. The no action alternative would hinder any 

further development of the currently platted subdivisions within the areas of Fremont County 

serviced by the Mack’s Inn WWTF.

Given the purpose and need, the District Ranger will review the alternatives in order to make the 

following decisions:

1. Whether the proposed action will proceed as proposed, as modified by design features, by 

an alternative, or not at all.

2. What mitigation measures and monitoring requirements will be required.

3. Whether a Forest Plan amendment is warranted.
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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CHAPTER 1 – PURPOSE AND NEED

DOCUMENT STRUCTURE

The United States Forest Service (Forest Service) has prepared this Environmental Assessment (EA) in 

compliance with the National Environmental Policy Act (NEPA) and other relevant Federal and State 

laws and regulations. This EA discloses the direct, indirect, and cumulative environmental impacts that 

would result from the proposed action and alternatives. The document is organized into four parts:

Purpose and Need: This chapter includes information on the history of the project proposal, the 

purpose of and need for the project, and the agency’s proposal for achieving that purpose and 

need. This chapter also details how the Forest Service informed the public of the proposal and 

how the public responded.

Alternatives: This chapter provides a more detailed description of the agency’s proposed action. 

At this time no additional alternatives are being considered. If public scoping identifies other 

alternatives that also address the purpose and need these may be considered. This discussion 

also includes possible mitigation measures. Finally, this chapter provides a summary of the 

environmental consequences associated with the no action and proposed action alternatives.

Environmental Consequences: This chapter describes the environmental effects of implementing 

the no action and proposed action alternatives. This analysis is organized by resource area; 

existing conditions are described first followed by the effects of each alternative.

Consultation and Coordination: This section provides a list of preparers and agencies consulted 

during the development of the EA.

Additional documentation, including more detailed analyses of project-area resources, may be found in 

the project planning record located at the Ashton/Island Park Ranger District Office in Ashton, Idaho.

BACKGROUND

Fremont County constructed a central wastewater collection and treatment facility on National Forest 

System (NFS) lands to serve the Mack’s Inn/Island Park Village area in 1982. That facility was 

constructed to mitigate problems of ground and surface water contamination. An additional lagoon cell 

was constructed in 1989 to increase storage capacity of the wastewater facility. Further modifications 

were made in 1998 when the snowfluent application towers were installed west of the treatment facility 

to allow winter application of treated water. In recent years the wastewater effluent application system 

has been running at 95 percent of capacity during peak use seasons, and is nearing the maximum rates of 

effluent application allowed by Idaho Department of Environmental Quality (IDEQ). The current 

wastewater facility is managed under a special use permit administered by the Caribou-Targhee National 

Forest. The area affected by this special use permit is in management prescription 8.1.

In March 2009 the Ashton/Island Park Ranger District received a request for a special use permit from 

Fremont County for the expansion of the Mack’s Inn Wastewater Treatment Facility (WWTF) land 

application area (Figures 1 and 2). The existing facility consists of a 2-acre main WWTF and a 58-acre 

land application area located on land managed by the Forest Service and operated under Special Use 

Permit ID: ISL1034. The County currently uses an underground irrigation sprinkler system to apply 

treated water from the Mack’s Inn WWTF to 58 acres of land located north of the settling ponds. The 

Mack’s Inn WWTF contains six monitoring wells used for routine sampling to insure compliance with 

standards and operating conditions regulated by IDEQ.
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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Figure 1. Existing Mack’s Inn Wastewater Treatment Facility Location (T14N, R44E, 

Sec 30) and Proposed Expansion Area (T14N, R43E, Sec 25).
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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Figure 2. Aerial view of project location.

PURPOSE AND NEED FOR ACTION

The Ashton/Island Park Ranger District is responding to an application submitted by Fremont County to 

obtain a special use permit for expansion of the Mack’s Inn WWTF effluent application system.

The existing treatment facility supports 981.9 equivalent users (1 equivalent user =450 gallons or 4.5 

people at 100 gal/day/person). These equivalent users include both residential and commercial 

properties. The County is currently permitted to apply 28.3 million gallons per growing season (May 1 

thru October 15 [168 days]), which is equivalent to 18 inches/acre per growing season. Currently the 

spray field is operated for one week out of each month during the growing season using an underground 

sprinkler system. During the peak use season, the Mack’s Inn WWTF effluent application system is 

running at 95 percent capacity and treated effluent is being applied at near maximum capacity allowed 

by Environmental Protection Agency (EPA) and IDEQ.

Population trends for the Island Park area are difficult to estimate because the majority of the homes are 

not year round residences. In 2009 Keller Associates analyzed the population information for the cities 

closest to the Island Park area (Keller 2009). They reported that populations in the general geographic 

area have been increasing at a rate of 1.5 percent annually since 1970. They concluded that populations 

in Fremont County would continue to increase over the next 30 years. A growth rate of 5 percent was 
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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selected for use by the Citizen’s Advisory Committee for the Island Park area (Keller 2009) to address 

infrastructure planning needs including estimating the life expectancy of the WWTF.

Residential and commercial properties which are currently platted for development but have yet to be 

developed would increase the level of use of the WWTF by 1,000 equivalent users. The treatment 

facility and settling ponds at the facility have the capacity to handle the increased volume of waste 

generated by these additional properties. However, the effluent application system is near capacity and 

thus approaching its limits for meeting the standards established by the EPA and IDEQ. The expansion 

of the effluent application area would allow the Mack’s Inn WWTF to accommodate approximately 

1,250 additional equivalent users which would double their current capacity. This expansion would 

provide for those properties already platted as well as for some additional growth of the community. 

This would also enable the facility to remain in conformance with the current agency standards.

The proposed project area is within an area managed under prescription 5.1. 3 (a) (timber management) 

(USFS 1997b p. III-137) as described in the 1997 Revised Forest Plan Targhee National Forest.

PROPOSED ACTION

The action being proposed by Fremont County is to acquire the special use permit needed to develop a 

50-acre parcel located west of and contiguous to the existing WWTF. This would allow for the increase 

in effluent application and maintain standards and requirements issued by the EPA and IDEQ. Two 

center pivot irrigation units would be installed on the new land application area and treated effluent 

would be applied in a full circle. The proposed action includes a 500-foot setback from private water 

sources as required by EPA regulation and installation of a fence to restrict access to the site.

A site specific non-significant forest plan amendment is proposed. The proposed action would change

the management prescription area from 5.1.3(a) (timber management) to 8.1 (concentrated development 

areas) (USFS 1997b p. III-157). This change would be applied to approximately 50 acres where new

effluent application area would be located.

DECISION FRAMEWORK

Given the purpose and need, the deciding official will review the proposed action and no action 

alternatives in order to make the following decisions:

1. Whether the proposed action will proceed as proposed, as modified by design features, by an 

alternative, or not at all.

2. What mitigation measures and monitoring requirements will be required.

3. Whether a Forest Plan amendment is warranted.

PUBLIC INVOLVEMENT

The proposal was listed in the Schedule of Proposed Actions beginning October 2010. The proposal 

was provided to the public, to other agencies, and to the Shoshone-Bannock Tribes for comment. In 

addition, as part of the public involvement process, the Forest Service and Fremont County held an open 

house meeting on September 8, 2011 at the Fremont County Emergency Medical Services (EMS)

Building on Library Road to inform the general public about the proposed expansion. The CaribouTarghee National Forest is currently seeking the public’s comments on this EA.
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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ISSUES

Issues serve to highlight effects or unintended consequences that may occur from the proposed action 

and no action alternatives, giving opportunities during the analysis to reduce adverse effects and

compare trade-offs for the decision maker and public to understand. The responsible official approved 

the following issues to be analyzed in depth in this analysis by the Interdisciplinary Team.

1. Area is currently open to cross country travel by vehicles with a < 50 inch wide wheel base 

(providing they do not cause resource issues); use of the site for land application may impact 

recreation use.

2. Various wildlife species use the area; use of the site may result in a loss of habitat connectivity in 

the corridor adjacent to Henry’s Lake Outlet.

3. Potential impacts to ground water quality in the area; use of the site for land application may 

have impacts on ground water quality.

4. Any issues associated with the Forest Plan amendment and changing from Management 

Prescription Area 5.1.3(a) to 8.1.
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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CHAPTER 2 – ALTERNATIVES

This chapter describes and compares the alternatives considered for the Mack’s Inn Wastewater 

Treatment Expansion Project. It includes a description of the alternatives considered. This section also 

presents the alternatives in comparative form, defining the differences between each alternative and 

providing a clear basis for choice among options by the decision maker and the public.

DESCRIPTION OF ALTERNATIVES

Alternative 1 – No Action

Under the no action alternative the Forest Service would not issue a special use permit to Fremont 

County for the expansion of the land application area. The site would remain at its current capacity 

serving approximately 1,250 equivalent users. This alternative would hinder any further development of 

currently platted subdivisions within the areas of Fremont County serviced by the Mack’s Inn WWTF.

Alternative 2 – Proposed Action

Under the proposed action alternative the Forest Service would issue a special use permit to Fremont 

County for the expansion of the land application area at the Mack’s Inn WWTF. The special use permit 

required for the proposed action would authorize the use of 50 acres of contiguous NFS lands for the 

expansion. The 50 acres would provide for the installation of two center pivot irrigation units (pivots) to 

apply the treated wastewater; a 500 foot buffer area between the land application area and residential 

structures as per IDEQ setback requirements; and a perimeter fence around the land application area to 

limit trespass in the area (Figure 3).

The perimeter fence constructed around the area used for the pivots would be a three strand smooth wire 

fence to facilitate wildlife movement through the area. The fence would be let down in late fall to allow 

winter wildlife passage, prevent damage to the fence associated with snow loads in the winter, and allow 

access by snowmobiles during snow months. The fence would be put back up in the non-snow months. 

Signage would be added to the fence during non-snow months to inform the public that the area is used 

for treated wastewater disposal. This would make the fence visible to the public using the adjacent NFS

lands for recreation.

To facilitate installation and operation of the pivots all the trees within the project area would be 

removed. The trees are primarily lodgepole pine (Pinus contortus) with an average age of 30 years. The 

County would cut the trees and then use a combination of piling the trees and then burning the piles 

along with some broadcast burning. The County will install erosion and sediment control methods until 

the site has stabilized. Once cleared, the vegetation communities within the land application area would 

be routinely maintained using mechanical treatment (i.e., chainsaw or front end loader dependent upon 

tree size) to prevent interference with the operation of the pivots.

Pivots would be connected to the WWTF via a buried pipeline. The pipeline would connect to a pump 

located at the treatment facility and be buried in an 18-inch wide trench approximately six feet below 

ground surface. The pipe would be an 8-inch PVC pipe, that would travel north through the existing 

land application field for approximately 1,000 feet and then turn west and cross Forest Service Road 

338, traveling 1,000 feet west to the first center pivot unit in the land application expansion area. After 

leaving the first irrigation unit, the pipe would travel the remaining 1,200 feet to the second center pivot 

unit. An electrical line would also be buried in the trench used for the pipeline to supply electricity to 

the irrigation systems. The irrigation units would be designed and installed to accommodate future 

growth. The expansion of the land application area would allow the Mack’s Inn WWTP the ability to 

distribute 24.4 million gallons of treated wastewater through the land application process.
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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Figure 3. Overview of Proposed Action Alternative.
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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A site specific forest plan amendment is proposed. The proposed action would change the 

management prescription area from 5.1.3(a) (timber management) to 8.1 (concentrated 

development areas) (USFS 1997b p. III-157). This change would be applied to approximately 50 

acres where the new effluent application area would be located. 

Design Features Associated with the Proposed Action Alternative

The land application expansion site would be designed in such a manner as to comply 

with all IDEQ standards and requirements. These include but are not limited to 

maximum hydraulic loading rates, buffer zones, seasons of use, ground water quality, 

fencing and posting, and odor management.

o Maximum hydraulic loading rates – 18 inches/acre per growing season. 

o Buffer zones– Distance to public access – 50 feet

– Distance to inhabited dwellings – 300 feet

– Distance to streams – 100 feet

– Distance to private water sources – 500 feet

– Distance to public water sources – 1,000 feet

– Single sample maximum total coliform level – 240/100ml.

o Seasons of use – growing season: May 1 thru October 15 (168 days).

o Ground water quality – ground water quality shall be in compliance with Idaho 

Ground Water Quality Rule IDAPA 58.01.11 and monitored with existing monitoring 

wells on site. If necessary new wells will be installed at the request of IDEQ.

o Sign posting – signs should read “Irrigated with Reclaimed Wastewater – Do Not 

Drink” or equivalent, to be posted every 500 feet and at each corner of the outer 

perimeter of the buffer zones of the site.

o Odor management – the WWTP and other operations associated with the facility shall 

not create a public health hazard or nuisance conditions, including odors. These 

facilities shall be managed in accordance with an IDEQ approved Odor Management 

Plan which shall be submitted to and approved by the Department as a part of the 

preliminary engineering report described in Section 411of IDAPA 58.01.16. The 

Water Environment Federation Guidance referenced in Section 008 of these rules 

provides guidance for use in developing an odor management plan that is inclusive of 

the facilities being designed.

If any historical sites are found during construction, work would be immediately stopped 

and the Forest Archeologist would be contacted.

All personnel involved with on the ground implementation of the project must comply 

with the food storage order, Order Number 04-15-0063, to protect grizzly bears. This 

order makes food unavailable to grizzly bears. 

Prior to commencement of activities, a nest survey would be conducted to determine if 

active goshawk nests are present. If nests are present and active, all activities would occur 

between October and February.
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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Any machinery used on site for construction or maintenance will be cleaned of invasive 

species seed or debris prior to working on site. The site would be monitored and treated 

for invasive plant species for up to five years following the initiation of the project. . 

Tree removal activities should result in edges which appear natural with irregular lines 

and shapes to the extent possible.

Areas where soils are disturbed would be re-seeded to an appropriate native plant mix

approved by the Forest Botanist.

The following Best Management Practices related to sanitation systems would be 

applicable to the project (U.S. Forest Service 2012):

o An operation and maintenance plan would be prepared and maintained for the waste 

treatment and disposal facilities (FSM 7410).

o Follow-up actions identified during inspections of the facility would be implemented 

as needed to ensure that the system is working properly.

o Procedures would be included in the operation and maintenance plan to contain or 

avoid releases of pollutants in floods or other emergencies.

o The waste treatment and disposal facilities authorized on NFS lands would be 

operated and maintained according to applicable regulations and direction.

ALTERNATIVES CONSIDERED BUT ELIMINATED FROM DETAILED STUDY

Two other alternatives were considered during the planning process, but have not been included 

in the EA for detailed study. These are described briefly below, along with the rationale for not 

considering them further.

Expanding the new land application area to the east of the existing land application area 

was considered. This alternative was dropped from further consideration because that 

location is dominated by mature timber stands (ages in excess of 100 yrs) and it 

represents important big game habitat associated with the Henry’s Lake Outlet. This area 

is also known to be commonly used by grizzly bears which are protected under the 

Endangered Species Act (ESA). If this alternative were selected, the project would have 

an adverse affect on grizzly bears. 

Connecting the WWTF to the sprinkler system at the Island Park Golf Course was 

considered. The connection of the facility to the golf course was assessed in 2007 and it 

was determined that in order to meet IDEQ Standards for the application of treated water 

on a golf course the Mack’s Inn Sewer Treatment Plant would have to change its 

treatment methods to a mechanical treatment system. At the time it was determined to be 

cost prohibitive and remains as such at the current time.

COMPARISON OF ALTERNATIVES

This section provides a summary of the effects of implementing each alternative. Information in 

Table 1 is focused on activities and effects where different levels of effects or outputs can be 

distinguished quantitatively or qualitatively among alternatives.

Implementation of the proposed action would result in a Forest Plan amendment to reflect the 

change in management for the area. Both alternatives follow directions listed in the 1997 
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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Revised Forest Plan Targhee National Forest; however, there would be a shift from management 

prescription 5.3 (a) (timber management) (USFS 1997b p. III-137) to 8.1 (concentrated 

development areas) (USFS 1997b p. III-157), for the acreage associated with the proposed 

action. The proposed action fulfills the request submitted by Fremont County. This would allow 

the County to expand the land application area to meet IDEQ standards.

The proposed location for the land application area is currently designated as open for cross 

country motorized travel to vehicles less than 50 inches in width. Installation of the land 

application area and associated perimeter fence would exclude the 50 acres of land from use by 

cross country motorized vehicle use in the summer or non-snow months. The fence would be 

put up soon after snow melt, typically late May or early June. The fence would be taken down 

the middle of October prior to snow accumulation and would not restrict use during the winter 

when the system would be dormant. Under the no action alternative there would be no effects to 

recreation use of the area.

The proposed location for the land application expansion area receives limited use by wildlife 

species. This site was selected because the timber stand that would be affected is relatively 

young in comparison to surrounding stands. The young age of the stand and its close proximity 

to human development causes the area to be less desirable than other areas in close proximity to 

the WWTF for use by species such as big game (i.e., elk and mule deer) as well as grizzly bear.

The application of an additional 24.4 million gallons of water annually over the 50 acre 

expansion area has the potential to impact ground water quality. Routine monitoring required by 

IDEQ limits the possibilities of contamination but does not prevent them. Under the no action 

alternative, no additional water would be applied to the area and thus there would be no impact 

on ground water.

Table 1. Comparison of Effects between Alternatives.

Indicator Alternative 1 

No Action

Alternative 2

Proposed Action

Requires an Amendment to the Forest Plan No Yes

Impacts to Recreation

(motorized travel during non-snow months)

No Yes

Wildlife No Yes

Result in economic impact to County Yes; greater than Alt 2. Yes

Ground water quality No Potential

The proposed action would require amending the current Forest Plan because of the site specific 

changes that would occur as a result of expanding the WWTF. Specifically, the proposed project 

area is within an area managed under prescription 5.3 (a) (timber management) (USFS 1997b p. 

III-137) as described in the 1997 Revised Forest Plan Targhee National Forest. Installation of 

the land application system would require a change in management to prescription 8.1 

(concentrated development areas) (USFS 1997b p. III-157). This would require a site specific 

Forest Plan amendment to reflect the change in acres managed under each category. Table 2 

presents the standards and guidelines for each prescription which are different to provide a 
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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comparison and identify where changes would occur in management associated with an

amendment to the forest plan.

Table 2. Differences in Standards and Guidelines for each forest prescription associated with the 

plan amendment.

Comparison of

Management 

Prescriptions

Timber Management

5.1.3(a)

Concentrated 

Development Areas

8.1

Changes in Standards 

and Guides associated 

with project 

implementation

Timber 

Management

Lands included in timber 

base, no clearcutting is 

allowed.

Lands are removed from 

the suitable timber base. 

They do not contribute to 

the Allowable Sale 

Quantity (ASQ).

Remove lands from 

suitable timber base.

Access Open for pedestrian, 

horse/pack stock, mtn. 

bike/mechanized, 

Motorized <50”wide, 

Winter nonmotorized, and 

snowmachine.

Open for pedestrian, 

horse/pack stock, mtn. 

bike/mechanized, Winter 

nonmotorized, and 

snowmachine.

Close the land for cross 

country travel for

Motorized vehicles 

<50”wide. However, the 

proposed action would not 

permit cross country travel 

during the snow free 

season due to IDEQ 

requirements which restrict 

access to the general 

public.

Fire/fuels Wildfires will normally be 

suppressed using control 

strategies during the fires 

season. Pre-and post-fire 

season strategies may 

include containment, 

confinement, and control.

All wildfires will be 

aggressively suppressed.

Increase wildfire 

suppression efforts.

Recreation –

Trails

Motorized trails should be 

developed using primarily 

local roads and trails not 

being actively used for 

commodity recovery.

Protect existing trails and 

wherever possible avoid 

development of trails in or 

near concentrated 

development sites. Where 

feasible move existing 

trails away from these 

areas.

Alter trail management.

Recreation –

Recreation 

Opportunity 

Spectrum (ROS)

Recreation is managed to 

provide a combination of 

semi-primitive 

nonmotorized to roaded 

natural opportunities.

Semi-primitive 

nonmotorized to urban.

Alter Recreation – ROS.

Recreation –

Visual Quality 

Objective (VQO)

Generally Partial Retention 

to Modification.

Generally Partial Retention 

to Maximum Modification.

Possibly change 

Recreation – VQO.
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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Comparison of

Management 

Prescriptions

Timber Management

5.1.3(a)

Concentrated 

Development Areas

8.1

Changes in Standards 

and Guides associated 

with project 

implementation

Range Livestock grazing may be 

allowed on transitory 

forage produced following 

timber harvest where and 

when that use will not 

conflict with regeneration 

efforts or other concerns.

No standard and guide for 

Range

Currently there is not a 

grazing allotment in this 

area so grazing is not 

affected by the proposed 

plan amendment. 
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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CHAPTER 3 – ENVIRONMENTAL CONSEQUENCES

This section summarizes the physical, biological, social and economic environments of the 

affected project area and the potential changes to those environments due to implementation of 

the alternatives. It also presents the scientific and analytical basis for comparison of alternatives 

presented in Table 1 above. Effects considered below include in those to the following:

Vegetation resources including sensitive, threatened, and endangered plants, noxious 

weeds, as well as general vegetation

Wildlife resources including sensitive, threatened, and endangered wildlife species, as 

well as general wildlife species

Cultural resources

Recreational access

Economic resources

Water quality and hydrology

Soils

Visual Quality

VEGETATION RESOURCES

Existing Conditions

The project area is a forested ecosystem. The overstory within the project area is primarily 

lodgepole pine, with scattered subalpine fir (Abies lasiocarpa) and juvenile quaking aspen 

(Populus tremuloides). The understory includes a mixture of shrub, grasses and forb species. 

These include snowberry (Symphoricarpos albus), pinegrass (Calamagrostis rubescens), elk 

sedge (Carex garberi), grouse whortleberry (Vaccinium scoparium), lupine (Lupinus 

parviflorus), arrowleaf balsamroot (Balsamorhiza sagittata), yarrow (Achillea millefolium), and 

kinnikinnick (Arctostaphylos uva-ursi).

The lodgepole pine within the project area regenerated following harvest activities in the early 

1970s. The trees within the project area averaged 6-8 inches diameter at breast height (dbh). 

The understory species appeared to be healthy. Aspen recruitment is sporadic and scattered 

throughout the project area and the forested habitats surrounding the project area.

No sensitive, rare, threatened or endangered plants or suitable habitat for them exists in the 

project area. There are no unique or difficult to replace plant communities within the area. Ute 

ladies’-tresses (Spiranthes diluvialis; threatened) and whitebark pine (Pinus albicaulis; 

candidate) are both identified on the U.S. Fish and Wildlife Service (USFWS) species list dated 

August 17, 2011 for Fremont County, Idaho. Neither of these plants occur in or near the project 

area, as described in the biological assessment (BA) prepared for this project that is on file at the 

Ashton/Island Park Ranger District Office.

The project area does not have any invasive plant species present.

Environmental Effects

Alternative 1 – No Action 

Direct and Indirect Effects: By not issuing the special use permit to Fremont County the

proposed wastewater treatment land application expansion would not occur in the project area. 

This would result in no impacts to vegetation within the project area.
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Alternative 2 – Proposed Action

Direct and Indirect Effects: The installation of the expanded application area would affect

vegetation. Expansion of the Mack’s Inn wastewater treatment land application area would 

result in the removal of all of the trees and tall brush species in the 50-acre project area changing 

a forested setting to a nonforested opening for as long as the facility remains in place.

No noxious or invasive weeds were observed during the environmental survey; however, 

disturbance activities often increase the risk of invasion of weedy vegetation species. All 

construction equipment will be washed prior to working on NFS lands in order to remove weed 

seed and invasive plant debris. Areas where soils are disturbed would be re-seeded to an 

appropriate native plant mix and monitored for any new weed infestations. Any new infestations 

would be treated to prevent additional spread or introduction of noxious weeds.

Cumulative Effects: No other projects are planned near the project area which would 

cumulatively impact vegetation resources. Continued maintenance of the new site will keep the 

trees from reaching maturity in a similar manner as the existing land application site.

WILDLIFE RESOURCES

Existing Conditions

Both a BA addressing species protected under the ESA and a biological evaluation (BE) 

addressing Forest Service special status species have been completed and are on file at the 

Ashton/Island Park Ranger District Office. These two documents were summarized and 

combined in a wildlife report which also included information on Forest Service management 

indicator species (MIS); this report is also on file at the District Office. Two threatened and 

three candidate wildlife species are described in the BA: Canada lynx (Lynx canadensis; 

threatened), grizzly bear (Ursus arctos horribilis; threatened), greater sage-grouse (Centrocercus 

urophasianus; candidate), North American wolverine (Gulo gulo; candidate), and yellow-billed 

cuckoo (Coccyzus americanus; candidate). No habitat for Yellowstone Cutthroat Trout is present 

in the project area, therefore this project will not affect the species or its habitat. 

Nineteen Forest Service sensitive species are addressed in the BE. Thirteen species were 

identified in the Wildlife Report as occurring in habitat types similar to those which are present 

within the project area.

Environmental Effects

Alternative 1 – No Action 

Direct and Indirect Effects: By not issuing the special use permit to Fremont County the 

proposed wastewater treatment land application expansion would not occur in the project area. 

This would result in no impacts to wildlife species.

Alternative 2 – Proposed Action

Direct and Indirect Effects: Of the 25 species addressed in the Wildlife Report it was 

determined that implementation of the proposed action has the potential to impact grizzly bear

and elk. An individual determination of effects of this project on threatened, endangered and 

sensitive species is described below for each species or group of species discussed in the wildlife 

BE, BA, and Wildlife Report in the project file.
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Summary of T&E Species

No critical habitat has been proposed or designated for any listed species anywhere on the 

Caribou-Targhee National Forest, therefore none would be affected.

Canada Lynx (Lynx canadensis): The Mack’s Inn wastewater spray field expansion project will 

be compliant with all management direction for the Canada lynx contained in the Canada Lynx 

Conservation Assessment and Strategy, the Canada Lynx Conservation Agreement, the Northern 

Rockies Lynx Management Direction, and the 1997 Revised Forest Plan for the Targhee 

National Forest. The proposed project area is located within Lynx Analysis Unit (LAU) #4. 

This LAU has a low but stable density of snowshoe hares and during past surveys (between 1999 

and 2001) using hair snare protocol no lynx were detected in the LAU. The LAU exceeds 

minimum requirements for denning habitat. Even though the risk of impacts are limited it was 

determined that the proposed land application expansion at the Mack’s Inn WWTP MAY 

AFFECT, but is NOT LIKELY TO ADVERSELY AFFECT Canada lynx.

Grizzly Bear (Ursus arctos horribilis): This project will be compliant with all management 

direction for the grizzly bear contained in the Final Conservation Strategy for the Grizzly Bear in 

the Greater Yellowstone Area and the 1997 Revised Forest Plan for the Targhee National Forest. 

The proposed project would not occur within the Primary Conservation Area (PCA). However, 

the project area is located within the Henry’s Lake BMU, Subunit #1. The project area is located 

within an area of the BMU which, due to the density of human development, discourages grizzly 

bear presence and factors contributing to their presence. Grizzly bears heavily use the area 

encompassing the project area along the Henry’s Fork in the Mack’s Inn area as an east-west 

movement corridor, and several collared grizzlies have traveled directly through the project area. 

The project would remove the area within the land application expansion field from open cross 

country travel which would help to reduce disturbance in the area. However, the project area 

falls within non-secure habitat (within 500 meters of open roads). The increased human activity 

during the removal of trees would open up the treed habitat reducing security cover which would 

have an impact on grizzly bears. The installation of the perimeter fence would restrict movement 

of individuals through the 50-acre project area causing them to go around the perimeter. 

Nonetheless, due to the close proximity to human development and existing disturbances these 

impacts are anticipated to be negligible. Therefore, it is determined that this project MAY 

AFFECT, but is NOT LIKELY TO ADVERSELY AFFECT the grizzly bear.

Greater Sage-Grouse (Centrocercus urophasianus): There is no suitable habitat for the greater 

sage-grouse within or adjacent to the proposed project area. The implementation of the proposed 

project would have no direct or indirect effects to the greater sage-grouse; therefore it is 

determined that this project will have NO EFFECT on the greater sage-grouse.

North American Wolverine (Gulo gulo luscus): This project would have no direct or indirect 

effects to the wolverine because the project area is currently not considered wolverine habitat

due to the lack of alpine habitat with persistent spring snow. The project area is not within the 

potential home range of a female or male wolverine, and the project will not impact the habitat of 

their prey. There have been no documented wolverines near the proposed project area; therefore 

it is determined that this project will have NO EFFECT on wolverines.

Yellow-billed Cuckoo (Coccyzus americanus): The Yellow-billed Cuckoo is a candidate species. 

Yellow-billed Cuckoos are neotropical migrants that breed in low-elevation (less than 6600 feet) 

cottonwood forests with a dense understory in southern Idaho. Population declines have been 
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severe in the West and the bird is now considered rare (IDFG, 2005). There is no habitat for this 

species on the Ashton-Island Park ranger district. Therefore, it is my determination that this 

project will have no effect on the Yellow-billed Cuckoo.

Summary of Forest Service Sensitive Species and Management Indicator Species

Trumpeter Swan (Cygnus buccinator): The proposed project area does not contain any open 

water habitat. The closest open water habitat is located approximately 1⁄2 mile south of the 

project area along the Henry’s Fork of the Snake River. This area is included in the annual 

winter survey area for trumpeter swans at the Big Springs/North Fork/Mack’s Inn stretch. The 

construction activities associated with the expansion of the spray field would not occur during 

the winter months. Therefore it is determined that this project will have NO IMPACT on 

trumpeter swans.

Common Loon (Gavia immer): There is no designated breeding or brood rearing habitat for the 

common loon within or near the project area (USFS 2006, USFS 1997a). Therefore, it is 

determined that this project will have NO IMPACT on the common loon.

Harlequin Duck (Histrionicus histrionicus): There is no nesting or brood rearing habitat for the 

harlequin duck within or near the project area (USFS 1997a). Therefore, it is determined that

this project will have NO IMPACT on the harlequin duck.

Northern Goshawk (Accipiter gentilis): Territories for northern goshawk are typically centered 

on the most recently active nest. The 1997 Revised Forest Plan for the Targhee National Forest 

considers a northern goshawk territory to be 6,000 acres, which encompasses, approximately, 

lands within a 1.7 mile radius of the nest. The nearest goshawk nest area and set of incidental 

sightings is almost 4.5 miles to the southeast. Activities anticipated with this project will not 

disrupt known nesting, fledging, or foraging home ranges of northern goshawk in the District. 

Therefore, it is determined that this project May Impact Individuals or Habitat, But Will Not 

Likely Contribute to a Trend Towards Federal Listing or Loss of Viability to the Population or 

Species on the northern goshawk.

American Peregrine Falcon (Falco peregrinus anatum): In 2007 a peregrine falcon nest was 

discovered in the Thirsty Creek area approximately 3.5 miles northeast of the project area 

(Moulton 2009). This nest has had unknown productivity in both 2007 and 2008 (Moulton 

2009). The 1997 Revised Forest Plan for the Targhee National Forest standards prohibit the use 

of herbicides and pesticides, which cause eggshell thinning, within 15 miles of a known 

peregrine falcon nest (USFS 1997a). Only Forest Service approved herbicides would be used 

during vegetation management at the project site. It is determined that this project will have NO 

IMPACT on the peregrine falcon.

Bald Eagle (Haliaeetus leucocephalus): Multiple bald eagle territories are located relatively 

nearby the project area (Lucky Dog, Flat Rock, and Coffee Pot). The nearest nest territories to 

the project are Lucky Dog and Flat Rock both of which are just over 2 miles east and west of the 

project area; therefore the project area lies inside of its Zone III Home Range (2.5 mile radius 

from a bald eagle nest) of both territories. This nest territory was occupied, but reproductively 

inactive in 2009. The next closest nest territory is Flat Rock which is over 2 miles west of the 

spray field expansion project area and also within the Zone III Home Range.

The following Standards (S) and Guidelines (G) from the 1997 Revised Forest Plan apply to the 

proposed project:
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1. Management within Home Ranges (Zone III) (S) (USFS 1997a, p.III-19). Zone III 

includes “...all potential foraging habitat within a 4 km (21⁄2 mi) radius of the nest. Areas 

within the 4 km (21⁄2 mi) radius of the nest that do not include potential foraging habitat 

may be excluded” (BLM 2003).

Response: The project area does not contain foraging habitat for bald eagles.

2. Herbicides and pesticides (S) (USFS 1997a, p.III-19).

Response: Only herbicides approved by the Forest Service will be used during 

vegetation management as needed within the project area.

3. Recreation activities and developments (G) (USFS 1997a, p.III-19).

Response: Recreation activities within the project area would be decreased by fencing 

the spray field as per IDEQ requirements. This would impact the open cross country offroad vehicle travel in the area which would lessen the potential for any possible conflict 

with bald eagle activity.

It is determined that this project will have NO IMPACT to the bald eagle. This determination is 

based on the lack of available nest sites within or adjacent to the project area due to tree size and 

the season of construction is outside of nesting season and before wintering season when the 

general geographic area may experience the presence of bald eagles.

Forest Owls: Forest owls on the Targhee National Forest include flammulated (Otus 

flammeolus), boreal (Aegolius funereus), and great gray owls (Strix nebulosa).

The young lodgepole pine habitat within the project area does not provide suitable nesting 

habitats for the flammulated owl. This is coupled with the scarce presence of individuals; the 

nearest documented sighting occurred 18 years ago over 4miles away in the Upper Coffee Pot 

Campground area. There are no foreseeable projects that may affect habitat in the area for this 

species. Therefore, it is determined that this project will have NO IMPACT on flammulated 

owls.

The lodgepole pine habitat which dominates the project area is not boreal owl nesting habitat, 

though these habitat types can be used as a part of individuals home range (i.e., roosting and

foraging) (Hayward and Verner 1994). No known boreal owls have been sighted incidentally in 

the project area. Cumulative effects in the area include disturbance from hunting, fishing, 

hiking, snowmobiling, and other recreational activities, as well as existing roads. There are no 

foreseeable projects in the area that would affect habitat for this species. Therefore, it is 

determined that this project will have NO IMPACT on boreal owls.

The lodgepole pine found within the project area is potential great gray owl nesting habitat; 

however there are very few snags present within the parcel and no stick nests were observed 

during the July 2010 biological survey of the area. The project area is not within either active or 

historic potential great gray owl territory and no nest stands have been identified anywhere in or 

adjacent to the project area. After the removal of the trees in the project area, the clearing of the 

project area would provide potential foraging area for the great gray owl.

The ability of the Island Park area to support great gray owl has not changed from pre-settlement 

times, so potential great gray owl populations are stable on the Targhee National Forest (USFS 
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2006b). Great gray owls are relatively adaptable to habitat alteration, perhaps due to their use of 

openings for foraging. Project activities are not anticipated to affect great gray owl.

Cumulative effects in the area include disturbance from hunting, fishing, hiking, snowmobiling, 

and other recreational activities, as well as existing roads. There are no foreseeable projects in

the area that would affect habitat for this species. Therefore, it is determined that this project 

will have NO IMPACT on great gray owls.

Primary Cavity Nesters: Primary cavity nesters on the Targhee National Forest include: rednaped sapsucker (Sphyrapicus nuchalis), Williamson’s sapsucker (Sphyrapicus thyroideus), 

Lewis’s woodpecker (Melanerpes lewis), downy woodpecker (Picoides pubescens), hairy 

woodpecker (Picoides villosus), American three-toed woodpecker (Picoides dorsalis), blackbacked woodpecker (Picoides arcticus), and northern flicker (Colaptes auratus). Though all 

eight species are considered MIS, only the American three-toed woodpecker is a Forest Service 

sensitive species. These species use a variety of forest habitat types from aspen to spruce-fir 

forests. These species predominantly utilize forests that are recently burned, insect infested, 

and/or composed of mature to over-mature stands.

The project area is associated with an area which was replanted with lodgepole pine trees 

following an extensive bark beetle infestation in the late 1960s which resulted in the loss of large 

areas of lodgepole pine stands in the Island Park area. Occasional natural disturbance, attrition, 

and wind throw may create random snags throughout the project area, but likely not in 

concentrations which would attract American three-toed woodpecker. American three-toed 

woodpeckers are tolerant of human activity; therefore disturbance due to activity at the project 

site is unlikely to affect possible local individuals (Leonard 2001). Project activities are not 

anticipated to affect American three-toed woodpeckers and cumulative effects to the American 

three-toed woodpecker population on the forest has been favorable (pine beetle outbreak, blister 

rust infections, Willow Creek fire of 2008). Therefore, it is determined that this project will have 

NO IMPACT on the American three-toed woodpecker.

The proposed project will not alter or remove any existing snags therefore, both snag availability 

and timber management is adequate for habitat for cavity nesting wildlife.

The proposed project will not alter any primary cavity nesting species habitat. The trees within 

the project area are smaller diameter trees which were replanted following the large bark beetle 

infestation in the late 1960s and early 1970s and have not reached a diameter preferred for 

nesting cavities. The removal of the trees within the project area would remove potential future 

habitat; however, it would not result in the forest not meeting snag requirement and biological 

potential standards for cavity nesters. There are no foreseeable projects in the area that would 

compound the impact to habitat for these species.

Migratory Birds: For a project analysis, only those migratory birds on one of the aforementioned 

USFWS lists that primarily breed in the habitat types found in and adjacent to the project area 

are discussed below (Idaho PIF 2000). The choices of habitat types found in the Idaho Bird 

Conservation Plan are as follows: alpine, high-elevation mixed conifer forest, low-elevation 

mixed conifer forest, lodgepole pine, cedar and hemlock forest, ponderosa pine forest, 

juniper/pinyon/mountain mahogany, aspen, mountain brush, sagebrush/salt desert scrub, 

grassland, non-riverine wetlands (marshes/lakes/ponds), riparian, and cliffs/rock outcrops/talus 

(Idaho PIF 2000 p.15).
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Only migratory birds that primarily breed in lodgepole pine habitat would need to be analyzed 

for the Mack’s Inn Wastewater Treatment Plant Land Application Expansion Project. Because 

none of the aforementioned 14 migratory birds use lodgepole pine as their primary breeding 

habitat, no migratory bird species are analyzed specifically for this project.

Columbian Sharp-Tailed Grouse (Tympanuchus phasianellus columbianus): Upon completion 

of the field assessment in July 2010 there was no suitable habitat present within the project area 

for Columbian sharp-tailed grouse lekking, nesting, brooding, or wintering. There are no known 

or designated Columbian sharp-tailed grouse leks or key habitat within 5 miles of the proposed 

project site (IDFG CDC 2009). There are no foreseeable projects in the area that would affect 

habitat for this species. Therefore this project will have NO IMPACT on Columbian sharp-tailed 

grouse.

Boreal Toad (Anaxyrus boreas boreas): There are no documented occurrences of boreal toads 

within a 3 mile radius of the project area. The existing lagoons located at the existing WWTF

have the potential to support amphibian habitat, however, the routine maintenance of the facility 

would likely disturb individuals at this location. The application of treated water within the 

project area would result in increased moisture levels in the area however the removal of trees 

and downed logs within the path of the irrigation system would also remove cover habitat, 

making the area less suitable for boreal toads. Therefore this project will have NO IMPACT on 

boreal toads.

Columbia Spotted Frog (Rana luteiventris): The project area does not contain any suitable 

habitat for the Columbia spotted frog. Therefore this project will have NO IMPACT on the 

Columbia spotted frog.

Spotted Bat (Euderma maculatum): No suitable spotted bat habitat occurs in the project area.

There are no foreseeable cumulative effects from any other projects. This project will have NO 

IMPACT on spotted bats.

Townsend’s Western Big-Eared Bat (Plecotus townsendii pallescens): There are no suitable 

maternal roosts or winter hibernacula in or adjacent to the project area, though some trees in the 

project area could provide single night roosting. The removal of these trees within the project 

area would remove potential nightly roost sites; however, it would also open potential foraging 

areas. Ample number of trees would remain around the facility which could act as nightly roost 

sites. There are no foreseeable cumulative effects from any other projects. Therefore, this 

project will have NO IMPACT on Townsend’s western big-eared bats.

Red Squirrel (Tamiasciurus hudsonicus): The removal of trees within the project area would 

remove foraging areas available to the red squirrel. However, a 500 foot buffer zone would be 

maintained between the land application area and any future developments protecting this habitat 

for the squirrels. Trees within the buffer zone would remain in place and not be removed under 

the installation and operation of the facility unless they pose a risk to human safety or operation 

of the facility. The project will have NO DETRIMENTAL IMPACT on red squirrel populations 

in the area.

Pygmy Rabbit (Brachylagus idahoensis): There is no suitable habitat within or adjacent to the 

project area. This project will have NO IMPACT on pygmy rabbits

American Marten (Martes americana): The young age of the forested stands within the project 

area are at a younger age class than those commonly used by the American marten. Therefore, 
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due to the lack of existing habitat and the proximity to human activity, this project will NOT 

LIKELY ADVERSELY IMPACT the American marten.

Fisher (Martes pennanti): Though the project area provides mesic, forested riparian habitat, it 

does not provide high canopy closure, large diameter trees, or hard packed snow that fisher 

require. These habitat characteristics are lacking in the project area and there are no known 

nearby fisher populations. Therefore this project will have NO IMPACT on fishers.

Gray Wolf (Canis lupus): The project area falls within the current home range of the Henry’s 

Lake pack territory. Recent sightings (2009 and 2010) identify wolf activity within 1.5 miles of 

the project area. The project will not impact denning or rendezvous habitat. Any wolves that 

may be using the area should not be negatively affected by the human activities associated with 

the project. Therefore, this project is NOT LIKELY TO JEOPARDIZE THE CONTINUED 

EXISTENCE of the gray wolf.

Elk (Cervus elaphus): Hunting and other forms of recreation will continue throughout the Island 

Park area. This will continue to have impacts on elk populations in the area. The impacts from 

recreation should be lessened by creating more secure area closures.

The project area is inside Watershed 008 (Henry’s Fork Headwaters), which had an Elk Habitat 

Effectiveness (EHE) of 0.57 as of the 1997 Revised Forest Plan for the Targhee National Forest

(USFS 1997b). The average EHE for the Targhee National Forest was 0.57. Cross-country 

travel restrictions and road closures for habitat security identified in the 1997 Revised Forest 

Plan were implemented beginning in 1998, changing the motorized access density in Watershed 

008 from 2.56 mi/mi2prior to 1997 to 1.15 mi/mi2in 2004 (USFS 2006). This improved the 

EHE from that listed in the 1997 Revised Forest Plan for this watershed to 0.62 in 2004 (USFS 

2006).

Hunter densities supplied by the Idaho Department of Fish and Game (IDFG) were figured when 

there was a general bull season. The high hunter density coupled with a high motorized access 

density resulted in an estimated 95 percent Elk Vulnerability (EV) prior to 1997. As of 2005, the 

EV dropped to 40 percent for this watershed, far below the 89 percent threshold set by the Forest 

Service and IDFG (USFS 1997a).

The project area serves mostly as migratory habitat as elk move between their wintering grounds 

in the Ashton-St. Anthony valley area to their summer habitat in the mountains surrounding 

Island Park and Yellowstone National Park. Clearing and construction of the irrigation system 

would take place in the late summer months before migration occurs and when elk are not using 

the area. Motorized access is the main factor that the Forest Service can control for both EHE 

and EV. Project implementation would remove cross country motorized activity during nonsnow months in the project area by the installation of the perimeter fence. However, this would 

not exclude elk from entering the project area. The majority of the migration activity occurs east 

of the project in areas which contain mature lodgepole pine habitats closer to the Henry’s Fork 

outlet. Impacts to elk are anticipated to be limited to seasonal migration periods. Due to the 

levels of development in close proximity to the project area, no negative impacts are anticipated 

to elk as a result of project implementation.

Bighorn sheep (Ovis canadensis): The project area is not suitable summer or winter habitat for 

bighorn sheep. Therefore this project will have NO IMPACT on bighorn sheep.
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CULTURAL RESOURCES

Existing Conditions

The cultural resource site survey for the area of potential effect (APE) was completed on July 12, 

2010 and reviewed by the Forest Archeologist. No historical sites were found. Concurrence of 

the no effect from the State Historic Preservation Office was given on February 17, 2012.

The APE is comprised of an undeveloped parcel of public land administered by the U.S. Forest 

Service and is the located in the Ashton/Island Park Ranger District of the Caribou-Targhee 

National Forest in Fremont County, Idaho. The APE is located on flat, wooded terrain just north 

of the Henry’s Fork River. The objective of the cultural resource inventory was to identify and 

evaluate cultural properties within the project’s APE in accordance with 36 CFR 800. 

Information pertaining to prehistoric cultures and European-American activities was researched.

All areas were examined using pedestrian transects spaced no more than 30 m apart. Ground 

visibility in open areas was approximately 10 to 30 percent due to vegetation.

Environmental Effects

Alternative 1 – No Action 

Direct and Indirect Effects: Under the no action alternative a special use permit would not be 

granted to Fremont County for the expansion of the land application system. By not installing 

the land application expansion the Mack’s Inn WWTF would continue to operate at near 

capacity. The adjacent 50 acres would not be disturbed so there would be opportunity to disturb 

any subsurface artifacts.

Alternative 2 – Proposed Action

Direct and Indirect Effects: No historic sites were discovered during the archaeological site 

survey. Under Conclusions and Recommendations in the Archaeological and Historical Survey 

Report - Archaeological Survey of Idaho any discovery of historical sites during the construction 

process would require halting of the project and consulting with the Forest Archeologist to 

determine how to proceed.

Cumulative Effects: No other projects are planned near the project area which would 

cumulatively impact historic sites. 

RECREATIONAL ACCESS

Existing Conditions

The area associated with the proposed land application expansion is currently designated as open 

for cross country travel for all vehicles with a wheel base less than 50 inches in width, twowheeled vehicles, hikers, and horseback riders during the summer months with all trails and 

roads open to all licensed vehicles. Cross country travel for vehicles with a wheel base wider 

than 50 inches is prohibited in the proposed project area. The area is open for cross country 

snow travel between the months of November 1 to June 1. A groomed snowmobile trail passes 

through the area of the expansion.

The project area is within IDFG Game Management Unit (GMU) 61 which provides opportunity 

for open and controlled hunts for big game species (elk, deer, bear, lion, and moose) as well as 
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multiple upland bird species and waterfowl. However, due to the close proximity to residential 

properties the area is anticipated to receive very little use by hunters.

Environmental Effects

Alternative 1 – No Action 

Direct and Indirect Effects: Under the no action alternative recreation use of the project area 

would continue. Use by ATVs and snowmobiles in the 50 acres would continue and use would 

not be impacted in anyway associated with this project.

Alternative 2 – Proposed Action

Direct and Indirect Effects: The development of the project area would remove the 50 acres of 

NFS lands from the areas designated as open for motorized cross country travel during non-snow 

months. It is anticipated that new motorized routes would be reestablished by ATV users along 

the outside edges of the application field, beyond the boundary fence. The exclusion of

motorized and non-motorized cross-country travel in this area during the snow-free season would 

result in a reduction of available acres of open terrain. A section of groomed snowmobile trail 

would be closed; an alternative route would be groomed in its place. 

Cumulative Effects: The Forest Service is currently updating the travel management plan for 

the Island Park area. As part of this process, ATV trails would be constructed and a number of 

user-created motorized trails are under consideration for closure. The 50-acres that would be 

closed to motorized vehicle use under this project could add to the total number of acres closed if 

the project area itself is not within one of the areas being considered for closure. The current 

WWTP has restricted ATV use within the 60-acres occupied by the main WWTF and the land 

application area. The expansion proposed in this project would further restrict ATV use in an 

additional 50 acres.

ECONOMIC IMPACTS

Existing Conditions

In 2009 Keller and Associates developed a Fremont County Wastewater Facilities Planning 

Study, Environmental Information Document which assessed the need for action associated with 

Fremont County’s WWTF in the Island Park area (i.e., Mack’s Inn WWTF and Last Chance 

Water Treatment Facilities). Following this assessment Fremont County selected Alternative 1-

No Action, which called for modification of the existing facilities rather than development of a 

new larger facility or additional smaller facilities as was proposed in Alternative 2-5. This 

alternative was selected due to minimal fee increase that would be required for County residence. 

The other alternative would have resulted in a substantial fee increase. No specific dollar figure 

was provided for comparison of the alternative within the Keller Associates planning study.

Environmental Effects

Alternative 1 – No Action 

Direct and Indirect Effects: Under the no action alternative a special use permit would not be 

granted to Fremont County for the expansion of the land application system. By not installing 

the land application expansion the Mack’s Inn WWTF would continue to operate at near capacity 

which would limit the development of the residential and commercial properties which are 
Caribou-Targhee National Forest Mack’s Inn Wastewater Treatment Expansion Project

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currently platted for development. This in turn would impact the economic growth of the 

community by restricting development.

Development of previously platted residential and commercial properties could occur if one of 

the additional alternatives identified in Keller Associates planning study, or an additional 

alternative is developed which would allow for the treatment of wastewater associated with these 

developments. Implementation of one of the additional alternatives presented by Keller 

Associates was determined to increase the cost of implementation, resulting in an increased cost 

to County residence through property taxes or other collection means (i.e., levies or grants).

Alternative 2 – Proposed Action

Direct and Indirect Effects: Implementation of the proposed action would not result in an

immediate increase in user fees. An increase in user fees may occur over time however Keller 

Associates planning study did not present an exact percentage of increase. This alternative was

chosen because it would have the least amount of increase to private residence and commercial 

businesses. The ability of the WWTF to accommodate increased growth in the area would 

increase the tax base of the County by allowing the currently platted sites to be developed.

Cumulative Effects: Development of the platted residential and commercial properties within 

the Island Park Area which is serviced by the Mack’s Inn WWTF would have a cumulative 

economic impact on the area. Without the expansion of the land application facility 

development of these platted properties may be restricted. However, the development of these 

properties would aid in reducing the cost associated with increased taxes by spreading the total 

cost over more users.

WATER QUALITY AND HYDROLOGY

Existing Condition

Ground water levels in the project area vary by season being shallower in the spring and early 

summer associated with snow melt and deeper in the late summer and fall months. During the 

spring and early summer ground water levels may rise as high as 12 inches above to 24 inches 

below ground surface, but is most often approximately 20-40 feet below ground surface. Most 

domestic wells within a 1 mile radius of the Mack’s Inn WWTF are bored to a depth of 75 to 150 

feet dependent upon geologic conditions. The rate of development in the Island Park Area by 

both residential and commercial developments has raised concern of potential shallow ground 

water and surface water degradation due to the installation of individual septic systems at these 

locations.

No surface water bodies are present within the proposed project area. The closest open surface 

water is the four storage lagoons located within the bounds of the existing water treatment 

facility. The closest flowing surface water is the Henry’s Fork located approximately 0.75 miles 

south of the project area.

IDEQ is currently the governing agency which has issued a permit to Fremont County for the 

operation of the existing WWTF. Under the operation permit, facility personnel are required to 

monitor and collect samples on a daily, weekly, monthly, and annual basis. Daily monitoring is 

required to assess the volume of water being treated (wastewater) and the volume of 

supplemental irrigation water being applied on the land application areas (snowfluent and 

existing land application area). A weekly sample is collected to test for total coliform within the 
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treated water. A monthly sample is collected to test for pH, nitrate, nitrite, nitrogen, total 

phosphorus, total dissolved solids (TDS), and Total Kjeldahl Nitrogen (TKN). An annual report 

is generated discussing the hydraulic management unit which includes acres, calculations of 

nitrogen and phosphorus applied in pounds per acre (lbs/acre) per year, and hydraulic loading 

associated with number of gallons/year applied through land application. An annual soil sample 

is collected to monitor the chemical properties of the soils within the treatment facility and a 

ground water sample is collected from the six monitoring wells located around the WWTF. 

These monitoring and sampling practices aid the County in remaining in compliance with state 

and federal water quality standards. If at any time levels of chemical properties within a water 

sample are found to be outside of the allowable range the facility manager takes immediate 

corrective actions to bring levels within acceptable standards.

Environmental Effects

Alternative 1 – No Action 

Direct and Indirect Effects: The facility would continue to operate at its current level under the 

no action alternative. Once the facility has reached capacity the County would be required to 

take actions which would lessen the flows to the facility or develop an additional facility to 

handle the excess wastewater. Implementation of this alternative is not anticipated to impact 

ground water or surface water quality in association with the operation of the treatment facility, 

due to the tight regulation imposed by IDEQ associated with the operation permit. However, if 

the facility is running at capacity and development continues, allowing individual septic systems 

to be installed would increase the risk of a degradation of water quality.

Alternative 2 – Proposed Action

Direct and Indirect Effects: The installation of the land application expansion would require 

some soil disturbance in association with the installation of the supply pipeline. Best 

management practices associated with heavy equipment operation (i.e., fuel storage, fueling 

procedures, spill prevention/clean-up kits present, and proper functioning of machinery) would 

be implemented to prevent spills which have the potential to impact water quality. As with the 

existing land application practice, the expansion area would fall under the same regulatory 

requirements which require daily, weekly, monthly, and annual monitoring, sampling, and 

reporting to IDEQ. The monitoring wells down-gradient of the snowfluent field are used to 

assess ground water quality in the area. These wells will be used to monitor water quality for the 

new land application site. Additional wells are not anticipated but could be requested by IDEQ 

if water quality concerns become an issue with population growth in the area and concomitant 

increases in wastewater application.

The increased land application rates associated with the expansion would allow the facility to 

better serve the platted developments in the project area. A WWTF which could support more 

development would likely reduce the number of new individual septic systems within 

undeveloped platted parcels reducing the risk of surface and shallow groundwater degradation.

The distance between the proposed land application expansion area and the Henry’s Fork would 

prohibit any contamination of that surface water in association with the installation and operation 

of the facility.

Cumulative Effects: No other projects are planned near the project area which would 

cumulatively impact water quality or the hydrology of the area.
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SOILS

Existing Conditions

The general soil map unit in the Mack’s Inn area shows Bootjack-Chickreek soils which are 

“very deep, nearly level, poorly drained soils formed in alluvium” (USDA NRCS 2011). Soils in 

the project area consist of ABLA/VASC, CARU Koffgo-PICO Perfa association, 2 to 30 percent 

slopes, which have a very limited filtering capacity (USDA NRCS 2011).

Environmental Effects

Alternative 1 – No Action 

Direct and Indirect Effects: Under the no action alternative the soils in the project area would

not be affected.

Alternative 2 – Proposed Action

Direct and Indirect Effects: The installation of the land application expansion would require 

some soil disturbance in association with the installation of the supply pipeline. No more than 

15% of the soils in the project area are anticipated to be detrimentally disturbed. Clearing the 

site of vegetation with heavy equipment would also result in some soil compaction on the 50-

acre site. Best management practices associated with heavy equipment operation (i.e., fuel 

storage, fueling procedures, spill prevention/clean-up kits present, and proper functioning of 

machinery) would be implemented to prevent contamination of soils and potential run-off of 

contaminants offsite.

Treated wastewater effluent would be sprayed onto the soils from the center pivot systems. Most 

of the wastewater would evaporate from the soil or transpire from grasses and forbs on the site. 

Any remaining water would percolate into the groundwater system. Water quality monitoring 

wells, described in the Water Quality section above, would be used to detect any contaminated 

waters in the groundwater system and allow corrective measures to occur. It should be noted 

that there are water quality sampling steps that take place before treated effluent is allowed to 

enter the center pivot system.

Cumulative Effects: No other projects are planned near the project area which would 

cumulatively impact soils. The current WWTP has previously impacted 60 acres of soils. The 

expansion proposed in this project would impact an additional 50 acres of soils in the area.

VISUAL QUALITY

Existing Conditions

The landscape of the project area is relatively flat and dominated by forested vegetation

comprised primarily of lodgepole pine with scattered subalpine fir and juvenile quaking aspen. 

US-20, a major north-south travel corridor for visitors to Yellowstone National Park, Island Park, 

Harriman State Park, and other locations, runs north-south about 1⁄4 mile west of the project area. 

Several homes are located approximately 1⁄4 mile north of the project area. The Henrys Fork of 

the Snake River is located over 1⁄2 mile south of the project area. Forested NFS lands lie between 

each of these locations and the proposed project area.

The proposed project is subject to the perceptions of the following three distinct viewer groups: 

motorists, residents, and recreationists. Motorists are those persons who would view the project 
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from a moving vehicle and may be drivers or passengers. Views of a project site from a roadway 

are typically limited and of short-duration for motorists. Residents are people whose homes 

and/or property are in close proximity to, and have a view of, the proposed project site or a 

portion of a site. The individual sensitivity of residents to aesthetics and changes within a 

viewshed is highly variable. Recreationists are members of the community or the general public 

who use the recreational resources available within or adjacent to the proposed project site. Like 

residents, recreational users are highly sensitive to the visual character of the area since most are 

drawn to the area by an appreciation of its scenic nature.

For the purposes of determining effects of the proposed project, US-20, the homes north of the 

project area, and the Henry’s Fork south of the project area are identified as viewpoints from 

which a representative group (i.e., residents, recreationists, or motorists) could view the project 

site.

The Mack’s Inn WWTF is within an area designated as a Partial Retention to Modification, 

Visual Quality Objective (VQO). VQO’s are described in the Forest Plan as a measurable goal 

for the management of visual resources; used to measure the amount of visual contrast with the 

natural landscape caused by human activity. Partial Retention VQO’s are defined as areas where 

“human activity may be evident but must remain subordinate to the characteristic landscape” 

(USFS 1997). Modification VQO’s are areas where “human activity may dominate the 

characteristic landscape but must, at the same time, follow naturally established form, line, color, 

and texture. The activity should appear as a natural occurrence when viewed in foreground or 

middleground” (USFS 1997). Partial Retention would apply to those areas that would be 

considered to be in the foreground – generally considered to be 1⁄4 mile away – from major roads, 

trails, or water ways.

Environmental Effects

Alternative 1 – No Action 

Direct and Indirect Effects: Under the No Action Alternative, the expanded land application 

facility would not be constructed. In the absence of construction, there would be no effect to 

vegetation or scenic resources. Overall scenic views on the site as viewed from the highway and 

surrounding areas would remain the same. The VQO’s for the project area would not be 

impacted.

Alternative 2 – Proposed Action

Direct and Indirect Effects: During implementation, short-term visual impacts could result 

from the presence of equipment, materials, and work crews. Expansion of the Mack’s Inn WWT 

land application area would result in the removal of all of the trees and tall brush species in the 

50-acre project area changing a forested setting to a nonforested opening for as long as the 

facility remains in place. Once cleared, the vegetation communities within the land application 

area would be routinely maintained using mechanical treatment (i.e., chainsaw or front end 

loader dependent upon tree size) to prevent interference with the operation of the pivots. 

Construction equipment and the cleared vegetation as well as the pivot system would present a 

contrast to the surrounding area.

The proposed tree removal and installation of the center pivot irrigation structure would be 

within the mixed Partial Retention to Modification VQO’s. Viewpoints within the foreground 

include the access road to the Mack’s Inn WWTF and adjacent residential areas. Middleground 
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vantage points would be areas such as Highway 20, and the Henry’s Fork River. It is anticipated 

that the irrigation system would not be visible from a background vantage point.

The dense stands of lodge pole pine which would exist within the buffer zones required by IDEQ 

would limit the visual impact to the general public in the foreground and middleground views. A 

buffer zone of 300 feet from inhabited dwellings which is vegetated by lodgepole pine forest aids 

in blocking the view of the project area from the residential properties. A narrow buffer zone of 

50 feet from public access (i.e., unnamed access road to the Mack’s Inn WWTF) would limit the 

visibility of the cleared area associated with the proposed expansion area. Because of 

intervening forested vegetation in the foreground of the project area, the expansion would in 

large part not be visible to residents, recreationists, or motorists. There may be a few locations 

along US-20 where gaps in forest cover allowed a partial line of site to the project area. In these 

instances, views of the project site from the roadway would be limited and of short-duration for 

motorists due to distance and screening provided by vegetation. 

Standard construction-related BMPs would be used to minimize dust generated during 

construction and disturbed areas would be stabilized as soon as practicable after construction. In 

addition, the edges of the tree removal area would be feathered to replicate a natural opening 

with irregular lines to the extent possible. Therefore, the visual impacts due to the project would 

be minor.

Cumulative Effects: No other projects are planned near the project area which would 

cumulatively impact visual quality. The current WWTP has previously impacted 60 acres of 

trees. The expansion proposed in this project would impact an additional 50 acres of trees in the 

area.
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CHAPTER 4 – CONSULTATION AND COORDINATION

The Forest Service consulted the following individuals, Federal, State, and local agencies, tribes 

and non-Forest Service persons during the development of this EA:

ID TEAM MEMBERS

Bill Davis, Recreation Program Manager

Sabrina Derusseau, Wildlife Biologist

Ali Abusaidi, Archeologist

Kara Green, Soil Scientist

Brad Higginson, Hydrologist

Rose Lehman, Botanist

FEDERAL, STATE, AND LOCAL AGENCIES

Fremont County

Idaho Department of Water Resources

Idaho Department of Fish and Game

U.S. Fish and Wildlife Service

TRIBES

Shoshone-Bannock Tribes

OTHERS

The Draft EA will be sent to a subset of Ashton/Island Park Ranger District mailing list. The 

complete list is in the project file 
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United States: A technical conservation assessment. Gen. Tech. Rep. RM-253. Fort Collins, 

CO: USDA, Forest Service, Rocky Mountain Forest and Range Experiment Station.

Idaho Department of Fish and Game Conservation Data Center. 2009. Species occurrence 

database information.

Idaho Partners in Flight. 2000. Idaho bird conservation plan: version 1.0. Hamilton, MT.

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