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DRAFT ENVIRONMENTAL ASSESSMENT
Logan Landfill Expansion Project
Logan, Montana
Solid Waste Section
PO Box 200901
Helena MT 59620-0901
January 5, 2022
Class II Logan Landfill Expansion Project 2 Draft Environmental Assessment
Table of Contents
1. PURPOSE AND NEED FOR PROPOSED ACTION ........................................................................ 7
1.1. Summary .......................................................................................................................... 7
1.2. Background ....................................................................................................................... 8
1.3. Purpose, Need, and Benefits .......................................................................................... 12
1.4. Location Description and Study Area ............................................................................. 12
1.5. Authorizing Action ......................................................................................................... 13
1.6. Public Participation ........................................................................................................ 15
2. DESCRIPTION OF ALTERNATIVES ........................................................................................... 16
2.1. Introduction.................................................................................................................... 16
2.2. DEQ Alternative 1 – NO ACTION ALTERNATIVE ............................................................. 16
2.3. DEQ Alternative 2 – PROPOSED ACTION ........................................................................ 17
2.3.1 Landfill Design and Construction ............................................................................ 17
2.3.1.1 Landfill Features ................................................................................................. 17
2.3.1.2 Landfill Liner System Design ............................................................................... 18
2.3.1.3 Liner System Components.................................................................................. 19
2.3.2 Leachate Collection and Removal Systems Design ................................................. 22
2.3.3 Landfill Unit Construction ....................................................................................... 25
2.3.4 Stormwater Control Construction .......................................................................... 26
2.3.5 Soil Stockpiles ......................................................................................................... 29
2.3.6 Partial and Final Closure ......................................................................................... 29
2.3.7 Post-Closure Care .................................................................................................... 30
2.3.8 Financial Assurance ................................................................................................. 31
2.3.9 Landfill Operations .................................................................................................. 35
2.3.9.1 Personnel ............................................................................................................. 35
2.3.9.2 Operating Hours ................................................................................................ 35
2.3.9.3 Site Access ......................................................................................................... 35
2.3.9.4 Landfill Equipment ............................................................................................. 36
2.3.9.5 Acceptable and Prohibited Wastes ................................................................... 36
2.3.9.6 Waste Screening ................................................................................................ 37
Class II Logan Landfill Expansion Project 3 Draft Environmental Assessment
2.3.9.7 Composting ........................................................................................................ 38
2.3.9.8 Asbestos ............................................................................................................ 39
2.3.9.9 Waste Placement ............................................................................................... 39
2.3.9.10 Waste Compaction and Cover ......................................................................... 40
2.3.9.11 Severe Weather Operations ............................................................................ 41
2.3.9.12 Dust Control ..................................................................................................... 42
2.3.9.12 Litter Control.................................................................................................... 42
2.3.9.13 Recordkeeping ................................................................................................. 43
2.3.9.14 Fire and Safety Plan ......................................................................................... 44
2.3.9.15 Partial and Final Closure .................................................................................. 44
3. AFFECTED ENVIRONMENT AND IMPACT ANALYSIS BY RESOURCE ....................................... 44
3.1. Affected Environment and Study Area .......................................................................... 44
3.2. Evaluation and Summary of Potential Impacts to the Physical and Human
Environment in the Area Affected by the Proposed Project .................................................... 45
3.3. Impacts ........................................................................................................................... 46
3.3.1 Wildlife and Habitats .............................................................................................. 48
3.3.2 Threatened and Endangered Species ..................................................................... 49
3.3.3 Species of Concern .................................................................................................. 50
3.3.4 Geology ................................................................................................................... 51
3.3.5 Surface Water ......................................................................................................... 55
3.3.6 Groundwater ........................................................................................................... 56
3.3.7 Soils and Vegetation ............................................................................................... 61
3.3.8 Air Quality ............................................................................................................... 64
3.3.9 Industrial, Commercial, and Agricultural Activities ................................................ 69
3.3.10 Human Health and Safety ....................................................................................... 69
3.3.11 Recreational and Wilderness Activities .................................................................. 70
3.3.12 Population and Housing .......................................................................................... 70
3.3.13 Property Values ....................................................................................................... 70
3.3.14 Traffic and Utilities .................................................................................................. 71
3.3.15 Aesthetics ................................................................................................................ 72
Class II Logan Landfill Expansion Project 4 Draft Environmental Assessment
3.3.16 Demands for Government Services ........................................................................ 73
3.3.17 Cultural Uniqueness and Diversity .......................................................................... 73
3.3.18 Socioeconomics ...................................................................................................... 73
3.4. Cumulative Impacts ........................................................................................................ 74
3.5. Unavoidable Impacts ...................................................................................................... 75
4. REGULATORY RESTRICTIONS ................................................................................................. 76
5. FINDINGS ............................................................................................................................... 76
6. OTHER GROUPS OR AGENCIES CONTACTED OR CONTRIBUTING TO THE EA ....................... 77
7. AUTHORS ............................................................................................................................... 78
8. REFERENCES ........................................................................................................................... 78
Tables
Table 1: Facility Life ................................................................................................................. 7
Table 2: Applicable Regulatory Activities .............................................................................. 14
Table 3: Impacts..................................................................................................................... 46
Table 4: Federally Established Species List ............................................................................ 49
Table 5: Montana Recognized Species of Concern List ......................................................... 50
Table 6: USDA-NRCS, Custom Soil Resource Report, 2021 ................................................... 63
Table 7: Precipitation and Temperature Information in Belgrade, Montana ....................... 69
Figures
Figure 1: Topographic Location Map of the active Logan Landfill and Site .......................... 10
Figure 2: Aerial Photo of the Site .......................................................................................... 11
Figure 3: Features of the active Logan Landfill and the Site ................................................. 20
Figure 4: Liner, Leachate Collection Laterals, Final Leachate Sump, and Temporary Leachate
Removal Penetration Systems ............................................................................................... 21
Figure 5: Permanent Leachate Collection Sump and Leachate Storage Pond Systems ........ 24
Figure 6: Storm Water Detention Pond Design ..................................................................... 28
Class II Logan Landfill Expansion Project 5 Draft Environmental Assessment
Figure 7: Closure Final Cover Plan, Profile, and Drainage Swales ......................................... 33
Figure 8: Phased Sequence of Cell Fill and Partial Closure within the Class II Unit ............. 34
Figure 9: Surface Water Resources ....................................................................................... 56
Figure 10: Geologic Map of Surrounding Area* ................................................................... 54
Figure 11: Groundwater Production Well Locations and Flow Directions ............................ 59
Figure 12: Groundwater Monitoring Well Locations ............................................................ 60
Figure 13: Soil Resource Map ............................................................................................... 62
Figure 14: Wind Rose for Bozeman Area............................................................................... 68
Class II Logan Landfill Expansion Project 6 Draft Environmental Assessment
List of Acronyms & Terms
ACWM – Asbestos-Containing Material
waste containing any amount of asbestos
ADU – Asbestos Disposal Unit
AMSL – Above Mean Sea Level
ARM – Administrative Rules of Montana
CAA – Clean Air Act of Montana
Active Cell – Area within a landfill unit
where disposal is occurring, not to exceed
more than 19.98 acres at a time
Cell Life - Approximate duration a particular
landfill cell is active from construction to
closure.
CFR – Code of Federal Regulations
Class II Unit – 300-acre Class II landfill for
disposal of Group II waste
CP – Closure plan
CQA/CQC – Construction Quality Assurance
and Construction Quality Control
DEQ – Montana Department of
Environmental Quality
District – Gallatin County Solid Waste
Management District
Draft EA – draft environmental assessment
EA – Environmental Assessment
EIS – Environmental Impact Statement
EPA – Environmental Protection Agency
FA – Financial Assurance
Facility Life – Approximate duration of the
Proposed Action, not to exceed 162 years.
FWP – Montana Department of Fish,
Wildlife, and Parks
GCCS – Gas Collection and Control System
GWIC – Ground Water Information Center
IWMA – Integrated Waste Management Act
License – Yearly renewable legal document
from DEQ necessary for the operation of a
waste management facility at a particular
fixed site
LEL – Lower Explosive Limit
Logan Landfill – Gallatin County Class II
Solid Waste Management System
LOGO – Local Government Option
MBMG – Montana Bureau of Mines and
Geology
MNHP – Montana Natural Heritage Program
MPDES – Montana Pollutant Discharge
Elimination System
NOD – Notice of Deficiency
NOI – Notification of Intent
NRCS – Natural Resource Conservation
Service
O&M – Operation and Maintenance
PCB – Polychlorinated Biphenyls
PCP – Post closure plan
PPE – Personal Protective Equipment
RCRA – Resource Conservation and
Recovery Act
SAP – Sampling and Analysis Plan
Site – new 543.8 acres including features
associated with operations of the 300-acre
Class II landfill unit, 9-acre asbestos disposal
unit, and 8.8-acre gatehouse/scale entry
SHPO – State Historic Preservation Office
SWMA – Solid Waste Management Act
SWMS – Solid Waste Management System
TSCA – Toxic Substance Control Act
Unit – Contiguous landfill disposal structure
USFWS – United States Fish and Wildlife
Service
USGS – United States Geological Survey
WQA – Water Quality Act
WSR – Waste Shipment Record
Class II Logan Landfill Expansion Project 7 Draft Environmental Assessment
1. PURPOSE AND NEED FOR PROPOSED ACTION
1.1. Summary
This draft environmental assessment (Draft EA) was prepared for the proposed expansion of the
Gallatin County Class II Landfill (Logan Landfill) in accordance with the Montana Environmental
Policy Act (MEPA). The Gallatin County Solid Waste Management District (District) is currently
licensed (License #158) to operate a 127-acre Class II Solid Waste Management System (SWMS)
near Logan, Montana. On October 28, 2020, the District applied to the Department of
Environmental Quality (DEQ) for a license boundary expansion of operations at the active Logan
Landfill. The application was deemed complete on July 6, 2021. The application proposes to
expand the Logan Landfill by 543.8 acres, which includes an 8.8-acre parcel for the scale/office,
a 300-acre Class II Unit, and a 9-acre asbestos disposal unit, increasing SWMS waste disposal
capacity by 45,353,200 total cubic yards for up to 162 years (Proposed Action, Table 1).
Financial assurance (FA) would be guaranteed through a local government option according to
DEQ-approved cost estimates for closure and post-closure care of the Site.
Table 1: Facility Life
NO
GROWTH(1)
2% GROWTH(2) 5% GROWTH(3)
PHASE 5 6.3 YEARS 5.6 YEARS 4.9 YEARS
PHASE 6 5.7 YEARS 4.8 YEARS 4.0 YEARS
PHASE 7 4.0 YEARS 3.3 YEARS 2.6 YEARS
PHASE 8 5.3 YEARS 4.1 YEARS 3.2 YEARS
PHASE 9 10 YEARS 7 YEARS 5.0 YEARS
ENTIRE
SITE
162 YEARS 69 YEARS 41 YEARS
Notes:
1. Life based on 180,000 tons/year for the Facility Life
2. Life based on 194,000 tons/year starting in 2025 (180,000 tons/year in 2021)
3. Life based on 219,000 tons/year starting in 2025 (180,000 tons/year in 2021)
Source: Great West Engineering
Logan Landfill’s Facility Life is affected by four variables:
1. Total waste volume available
2. Population served
3. Rate of waste acceptance
4. Rate of population growth
Rate of waste acceptance varies at the same rate that the population varies because each
person is assumed to generate the same amount of waste (based on current data) per year.
Total waste volume available at the landfill is “fixed” based on the landfill design and the
Class II Logan Landfill Expansion Project 8 Draft Environmental Assessment
industry standard waste-to-soil ratio (WSR) of 4.3:1. Estimates of the Logan Landfill Facility Life,
as calculated by Great West Engineering, are provided in Table 1. These estimates illustrate
three scenarios for population growth in Gallatin County, resulting in an estimated Facility Life
ranging from 41 to 162 years. The formula below illustrates the calculation of Facility Life
Remaining (FLR) based on Total Waste Present (TWP) and current waste acceptance rates.
FLR = (Total Waste Volume - TWP) / Current Waste acceptance rate
TWP = sum of all previous yearly tonnages
It is important to note that the Facility Life range presented is purely an estimate based on the
best available information available today and projections of population growth. Potential
future developments, such as changes in waste diversion (composting, recycling, and resource
recovery), major fluctuations in population growth, or changes to the District’s waste receiving
area could all impact the estimates presented in Table 1. DEQ’s Solid Waste Program does not
have rules regulating facility life. Rather, facility life remaining is a useful tool for landfill
planners and gives DEQ a general sense of the potential duration of the Proposed Action.
Landfills are constructed in phases with discrete areas or “cells” (not to exceed 19.98 acres)
actively receiving waste (Active Cell). The Cell Life for several of the Logan Landfill’s proposed
cells (phases 5-9) is estimated in Table 1. Cell Life is the approximate duration that a particular
landfill cell is active, from construction to closure (Figure 8).
1.2. Background
The existing and active solid waste management system license for the Logan Landfill was
originally issued by the Department of Health and Environmental Sciences (DHES), DEQ’s
predecessor agency, to the District in 1975 and encompasses 127 acres of District-owned
property. The District has now acquired a lot that encompasses an entirely new disposal
project study area, which consists of 535 acres situated immediately east and south of the
existing facility (Figure 1). The District intends to license the entire lot to site a Class II SWMS
facility, but only 309 acres would contain a new Class II Landfill Unit for waste disposal, with the
remaining property serving as a buffer zone around the disposal unit. The existing compost
operation would eventually be relocated over the closed southwest portion of the Class II Unit.
Another 9-acre Asbestos Disposal Unit (ADU) is proposed southwest of the 300 acres (Figure 1).
The District would also license the existing 8.8-acre office and scale found at the entry to the
Site.
Logan Landfill has accepted waste since approximately 1970. Depending on the rate of future
utilization of the landfill with respect to waste volumes and the average waste density
achieved, the 127-acre active Logan Landfill would reach capacity sometime in 2025. In
preparation of reaching the existing landfill’s approved capacity, the District is initiating the
permitting steps needed to license and expand the landfill into the adjacent District-owned
property. Construction of the first phase of the proposed expansion area and commencement
of waste placement within the Phase-1 cell is proposed for winter of 2025.
Class II Logan Landfill Expansion Project 9 Draft Environmental Assessment
DHES originally issued the Logan Landfill license after its review, mitigation, and approval of the
District’s submitted design, operation, monitoring, and financial assurance documents for their
equivalence to all requirements (some of them performance-based criteria) for a Montana-
licensed Class II SWMS. As with the Proposed Action, DEQ solid waste licensing reviews
typically address proposed design, operation, and maintenance of associated landfill disposal
units (Units) where liner, leachate, final cover, and stormwater control systems are monitored to
meet performance standards. Class II SWMS licensing may involve DEQ evaluation of methane
control systems, extended ground water corrective action, composting, soil landfarming
systems, or immediate response to and management of landfill fires.
The District accepts approximately 160,000 tons of waste per year and services Gallatin County,
including the West Yellowstone/Hebgen Lake Refuse District, the cities of Belgrade, Three Forks,
Bozeman, and the town of Manhattan. The existing Logan Landfill receives waste from Jefferson
County, Broadwater County, Madison County, Park County, and Yellowstone National Park. The
existing Logan Landfill services approximately 120,000 persons.
DEQ is authorized by the U.S. Environmental Protection Agency (EPA) for independent licensing
and regulation of Municipal Solid Waste (MSW) activities. The District’s complete application
requires DEQ to evaluate the District’s proposed Class II SWMS operations based on their
potential environmental effects on the District property and the surrounding environment. This
document summarizes the results of DEQ’s environmental review of potential impacts.
DEQ’s solid waste authority extends to management of Group III and IV wastes, petroleum
contaminated soils, compost, and special wastes such as biohazardous wastes, TENORM, and
asbestos. Description and evaluation of the District’s proposed management of some of those
wastes is included herein. The District’s operations at the Site and DEQ’s approval of the
Proposed Action fall under the Montana Solid Waste Management Act (SWMA) and the
Administrative Rules of Montana (ARM). Other Montana laws and rules apply to some DEQ-
regulated landfill elements of the Proposed Action (e.g., potential effects on air and water
resources).
Class II Logan Landfill Expansion Project 10 Draft Environmental Assessment
Figure 1: Topographic Location Map of the active Logan Landfill and Site
Source: Great West Engineering, 2020 (NOT TO SCALE)
Class II Logan Landfill Expansion Project 11 Draft Environmental Assessment
Figure 2: Aerial Photo of the Site
(Active Logan Landfill in green; scale house and Site in red.)
Source: Great West Engineering 2020 and ArcGIS 2021 (NOT TO SCALE)
Gatehouse Scale
EAST
EXPANSION
LANDFILL
GALLATIN RIVER
MADISON
RIVER
Class II Logan Landfill Expansion Project 12 Draft Environmental Assessment
1.3. Purpose, Need, and Benefits
The District applied to DEQ for expansion of their current Class II solid waste
management facility. DEQ’s purpose and need in conducting the environmental review is
to act upon the District’s application to expand its SWMS.
The District must first obtain a license boundary expansion approval from DEQ for the
Proposed Action before it may build and operate the new Class II Unit or other features
proposed for the Site. Consequently, DEQ’s decision to approve or deny the Proposed
Action depends upon compliance and consistency (i.e., “equivalence”) of the SWMS
application with:
Applicable tenants of the SWMA, Clean Air Act of Montana (CAA), and Montana Water
Quality Act (WQA) established by Montana Code Annotated (MCA); and
Applicable solid waste management criteria as required in ARM.
ARM 17, Chapter 50, establishes the minimum requirements for the licensing of all
SWMS proposals. DEQ’s final decision to license any SWMS proposed for Logan Landfill
must be validated by the Gallatin County health officer within 15 days of its issuance.
The District’s purpose and need of the proposed actions is the construction and
operation of the solid waste management system as proposed. The application
proposes to expand the Logan Landfill by 543.8 acres total which includes an 8.8-acre
parcel for the scale/office, a 300-acre Class II Unit, and a 9-acre asbestos disposal unit,
increasing SWMS waste disposal by 45,353,200 total cubic yards. The District accepts
approximately 160,000 tons of waste per year and services Gallatin County, including the
West Yellowstone/Hebgen Lake Refuse District, the Cities of Belgrade, Three Forks,
Bozeman, and the Town of Manhattan. The facility also receives waste from Jefferson
County, Broadwater County, Madison County, Park County, and Yellowstone National
Park. The facility services approximately 120,000 persons. As stated in paragraph 1.2, the
current landfill will reach capacity in 6 years, at which time the District must expand the
landfill to continue to serve these communities.
1.4. Location Description and Study Area
The Site would occupy the 543.8-acres of District-owned property approximately two
miles southeast of the town of Logan in Gallatin County (Figures 1 and 2). The Site is
accessed via Two Dog Road from the Logan exit off I-90. The Site would occupy portions
of Section 6, Township 1 North, Range 3 East, excluding parts of the northeast and
northwest corners. Most of the northwest corner contains the active Logan Landfill and
a small segment of the northeast corner of Section 6 is located on the opposite side of I-
90 from the Site. The Site would join with the east and south boundaries of the active
Logan Landfill on the northwest.
Of the 535 total acres designated for solid waste management, only 300 acres are
planned for landfilling of Group II and IV wastes in contiguous cells that define each
Class II Logan Landfill Expansion Project 13 Draft Environmental Assessment
constructed phase of the proposed Class II Unit. The District proposes to landfill
asbestos in a 9-acre area and license the 8.8-acre scale house (Figure 1). The natural Site
rises gently southward from elevation 4225 to 4325 in the Camp Creek Hills on currently
undeveloped prairie grassland which has been intermittently used for grazing livestock.
The study area is defined in Section 3.1. The study area for each resource is unique and
described in each subsection under Section 3.3.
1.5. Authorizing Action
MONTANA ENVIRONMENTAL POLICY ACT (MEPA)
DEQ prepared this Draft EA in accordance with requirements of MEPA to disclose the
potential impacts to the human environment that may result from the agency action. A
MEPA document does not result in a certain decision, but rather serves to identify the
potentials effects of a state action within the confines of the existing regulations
governing such proposed activities so that agencies make balanced decisions. MEPA
does not provide regulatory authority beyond the authority explicitly provided in
existing regulations.
Among the several purposes an EA may serve, it may be used to determine the need to
prepare an EIS through an initial evaluation and determination of the significance of
impacts associated with the proposed action. ARM 17.4.607(2)(c). An EA may also be
used to ensure the fullest appropriate opportunity for public review and comment on
proposed actions, including alternative and planned mitigation, where the residual
impacts do not warrant the preparation of an EIS. ARM 17.4.607(2)(d). This document
may disclose impacts over which DEQ has no regulatory authority.
GENERAL LICENSING
DEQ is responsible for issuing SWMS licenses under the SWMA and associated ARM. The
license application must contain a plan of design and operations stating the type of
disposal techniques that would be used to encapsulate the Group II waste at the Site. It
must also include a detailed closure and post-closure care plan to allow DEQ to
determine whether requirements of the SWMA would be satisfied.
DEQ is also responsible for protecting air quality under the CAA, and water quality and
quantity under the WQA. The options that DEQ has for decision-making upon
completion of the EA are:
(1) Denying the application if the Proposed Action would violate SWMA, the CAA,
or the WQA.
(2) Approving the application as submitted.
(3) Approving the application with agency mitigations.
Class II Logan Landfill Expansion Project 14 Draft Environmental Assessment
(4) Determining the need for further environmental review.
Table 1 provides a listing of any state, local, or federal agencies that may have
overlapping or additional jurisdiction or environmental review responsibility for the
Proposed Action and the permits, licenses and other authorizations required. All
necessary permits and approvals must be attained prior to implementation of the
Proposed Action.
Table 2: Applicable Regulatory Activities
(List of agencies involved and their respective or licensing requirements)
Applicable Regulatory Activities
Agencies Responsibilities
DEQ – Waste and Underground Tank
Management Bureau
SWMS license
DEQ – Air Quality Bureau Air quality permitting
DEQ – Water Protection Bureau Montana Pollutant Discharge
Elimination System (MPDES) permit
Gallatin County health officer SWMS license validation by county
health officer
Gallatin County
County road construction and
maintenance, land use, and weed
plan approval
CONTINUAL FACILITY REVIEW AND LICENSE RENEWAL
All licensed SWMS facility operations must conform with the standing adopted rules and
statutes pertaining to solid waste management. If rules or statutes are adjusted or
changed, operations would need to adjust accordingly. When a SWMS is initially
approved and licensed, it becomes subject to a series of regular licensing and
operational reviews by DEQ, as follows:
SWMS License Renewal Applications Review: Annual
Class II Logan Landfill Expansion Project 15 Draft Environmental Assessment
The license renewal form includes waste volumes for the previous year and FA cost
estimate updates. DEQ uses reported waste volumes to estimate remaining facility life
as needed. A license is renewed if all renewal information is supplied, and the facility is
able to demonstrate an ongoing ability to operate in compliance with applicable rules
and statutes.
SWMS Inspections and Site Visits: Annual to Semi-Annual
DEQ staff visit licensed SWMS facilities to verify compliance with applicable rules and
statutes. Prior to inspections, staff review the facility’s approved operation &
maintenance (O&M) plan. During inspections, staff review operations and engineering
system performance (run-on/run-off, leachate collection, methane, and groundwater
monitoring) on-site. Compliance assistance is an emphasis for staff. However, failure to
follow the approved O&M plan or to meet the requirements of applicable rules and
statutes may result in a violation requiring corrective actions.
O&M Plan Review: At least every five years
Facilities are required to update O&M plans at least every five years. When no updates
are needed, facilities may notify DEQ that operations have not changed. Whenever
significant operational changes are expected, facilities must notify DEQ in advance by
submitting an updated plan for review and approval prior to implementation. All
changes must comply with all applicable rules and statutes during the period in which
the plan is reviewed.
Engineering Plans Review: Approximately every five years
As cells are filled, designs for the construction of subsequent cells must first be
submitted to and approved by DEQ. Construction of future cells must comply with
applicable rules and statutes during the period in which the engineering plan is
reviewed.
1.6. Public Participation
Pursuant to ARM 17.4.610(3), DEQ is responsible for providing opportunities for public
participation. Common methods of accomplishing public participation include, but are
not limited to:
News releases or legal notices to announce the availability of an EA,
summarizing its content and soliciting public comment.
Public meetings or hearings.
Mailing lists of persons interested in a particular action or type of action.
Notification of availability of EAs on such actions.
Distribution of EAs for review and comment.
Class II Logan Landfill Expansion Project 16 Draft Environmental Assessment
Logan Landfill serves Gallatin County where development and waste production has
continued to rapidly increase for more than four decades. DEQ determined that public
participation is warranted for this action and is conducting a 30-day public comment
period for this Draft EA, which began upon publication of this document. The public
comment period ends on February 4, 2022. Notification was sent to adjacent
landowners and other interested parties that requested to be notified. A public notice
announcing the Draft EA’s availability was published in the Bozeman Chronicle and
posted at: https://deq.mt.gov/public/publiccomment.
The District’s application and associated documents are public record and may be
requested via a records request at: Support Home Page (govqa.us).
2. DESCRIPTION OF ALTERNATIVES
2.1. Introduction
This section describes the Proposed Action and reasonable alternatives to the District’s
Proposed Action, including the No Action alternative. MEPA requires state agencies to
consider the No Action and reasonable alternatives to a proposed action that are
available and prudent to consider. The alternate approach or course of action must
accomplish the same objectives as the Proposed Action, and must be realistic,
technologically available, and must have a logical relationship to the Proposed Action.
Section 75-1-220, MCA, states that for a project that is not a state-sponsored project, an
alternatives analysis does not include an alternative facility or an alternative to the
proposed project itself. Therefore, DEQ only considered alternatives applicable to the
proposed facility at the proposed location.
2.2. DEQ Alternative 1 – NO ACTION ALTERNATIVE
Under the No Action alternative, the license expansion would not be approved, and the
Site would not be constructed. Operations at the currently active Logan Landfill would
continue for approximately six years or until reaching final waste capacity. Upon closure
of the existing facility, all wastes generated in Gallatin County would need to be hauled
for disposal to another licensed location.
Final cover would be installed over the existing Class II unit according to ARM, and
completion of final closure of the existing Logan Landfill would initiate the 30-year post-
closure care period (Section 2.3.9).
If the Proposed Action is not approved, and upon closure of the currently active Gallatin
County Logan landfill within approximately four years. Gallatin County would be
required to either transport the growing municipal and rural waste stream from Gallatin
County to another nearby active landfill (e.g., in Helena or Butte) or seek to license
another SWMS to ensure availability of airspace for continued waste disposal.
Class II Logan Landfill Expansion Project 17 Draft Environmental Assessment
2.3. DEQ Alternative 2 – PROPOSED ACTION
Under the Proposed Action, solid waste disposal at the active Logan Landfill would
relocate and continue in the Class II Unit and ADU for up to 162 years, or until final
landfill capacity is reached. A vegetated final cover would be installed upon closure of
the expansion and the post closure care, leachate collection and removal, monitoring,
and maintenance of the closed facility would continue for at least 30 years. Any
necessary continuance of ongoing corrective actions and FA would be required. Design
for the proposed ADU area would be submitted prior to approval.
No alternate locations were considered or investigated by the District.
2.3.1 Landfill Design and Construction
The Site’s design involves required SWMS criteria addressing the phased
construction of a single Class II Unit with support features that include a
composite liner, leachate collection and removal systems with sumps and storage
ponds, stormwater control systems with detention ponds, final cover systems
and revegetation, methane control systems, roads, soil stockpiles, and fencing.
Elevation of the Class II Unit final cover would vary from 4450 to 4200 feet above
mean sea level (amsl). The total Class II Unit airspace of 57,838,600 cubic yards
(cy) would yield 45,353,150 cy of waste volume at density 1280 lbs./cy and
waste-soil-ration of 4.3 to 1.
The Site would include a fenced and gated disposal area consisting of the
following waste management elements (Figure 3):
1. Access to existing shop and entry roads
2. Capture of the existing gate, gatehouse, scale, and office on 8.8 acres
3. Use of existing E-waste collection shed and a new compost management
area
4. Class II Unit and ADU
5. Two leachate storage ponds
6. Cover soil stockpiles
7. Stormwater control structures and two detention ponds
Haul trucks delivering Group II or IV or asbestos wastes to the Site would enter
the active Logan Landfill via Two Dog Road, then follow the northern or southern
exterior roads leading east to the perimeter road of the Class II Unit or ADU.
2.3.1.1 Landfill Features
The Site design and operation would include construction of the
following features (Figure 3):
Scale house
Class II Logan Landfill Expansion Project 18 Draft Environmental Assessment
Interior and exterior roads
Phased waste disposal cells 5 through 27
Composite base liner
Leachate management system
Groundwater monitoring system
Methane monitoring wells
Soil stockpiles
Stormwater control system and pond
Final cover
8- to 10-ft chain link perimeter fence, berms, ditches,
warning signs
2.3.1.2 Landfill Liner System Design
The Class II Unit would overlie mixed alluvium deposits of variable
moisture content. The highest elevation on the base excavation
would be 4328 feet on the central rib and maximum waste
thickness would be in the range of approximately 150-180 feet.
The combined landfill cells 5 through 27 would expand in 23
phases that would -initially develop by constructing cells 5
through 9 within the southwest corner of the unit (Figure 8).
Excavation plans for this initial 68-acre development indicate that
construction would provide 13,867,100-cy of soil stockpiled for
use in roads, berms, and daily or intermediate covers (waste to
soil volume ratio 4.3 to 1), and final covers. The soil budget for
initial construction of those first 6 cells, including support roads,
ponds, berms, and ditches, would yield 1,331,830-cy excess soil
from a maximum cut that varies in the range of 60- to 33-ft deep
for the cells. Completion of the entire Class II Unit excavation
would yield an excess of 1,331,830-cy upon completion of the
final cover over the entire unit. This would be stockpiled in the
buffer area surrounding the Class II Unit.
The floor grades of the base liner are divided into east and west
aspects by a centralized north-to-south lined crest and would
slope from 2- to 5% northwest and northeast to leachate
collection toe sumps on the northwest and northeast corners,
respectively (Figure 3). The western half would be expanded
northward in a series of consecutive phases (5 to 15) before later
expansion of the liner in the same manner within the eastern half
(phases 16 to 27), both separated by the central crest (Figure 8).
A break in slope (ratio 5:1 or 5 feet horizontal to 1 foot vertical),
heading essentially north-to-south azimuth, would also divide the
west side of the floor as earliest phases 5 to 15 develop northward
Class II Logan Landfill Expansion Project 19 Draft Environmental Assessment
therein from the south margin of the Class II Unit. Liner side
slopes circumscribing the Class II Unit would also be 5:1 grade.
2.3.1.3 Liner System Components
An alternative composite liner substituting a Geosynthetic Clay
Liner (GCL) for the 2-ft compacted clay layer saturated hydraulic
conductivity (Ks ≤ 1x10-7 cm/s), typical of the “prescriptive
standard” liner, was previously approved for the existing Logan
Landfill by DEQ [ARM 17.50.1204(1)(a)] by referencing equivalent
cell demonstrations (Phase 3, 2006 and Phase 4, 2018). Although
thinner, the saturated hydraulic conductivity (Ks 1x10-9 cm/s) of
the GCL basal component is consistently 100 times less than the
typical base “clay-layer standard”. Thus, the rate of flow of liquids
through the GCL is likewise very much lower than the 15-in
leachate collection gravel (or “protective layer” Ks 1x10-2 cm/s)
that would be installed over the liner’s uppermost geotextile to
rapidly drain collected leachate off the liner to the leachate
sumps. The same type of demonstration has been completed and
approved for this alternative GCL liner component at Logan
Landfill and throughout Montana. DEQ has approved this
approach and associated documents are incorporated by
reference to the submittal. The use of a GCL to replace the
standard liner clay layer has been widely accepted and advocated
by the U.S. Environmental Protection Agency (US EPA Fact Sheet
#EPA530-F-97-002, 2001). During liner construction for the
Proposed Action, the contractors would be using the same
alternative GCL liner components as in the prior demonstrations
(2/23/2016), in a similar situation and geometry, coupled with
similar leachate collection systems.
Installation of the composite base and slope liner (Figures 4D, 4E)
would involve placement of the following components (listed top
to bottom):
15-in Granular (passing diameter 2-in minus pit run)
leachate collection and protective layer on base (use 2-ft
native soil on side slopes)
16-oz Nonwoven geotextile cushion
60-mil High Density Polyethylene (HDPE) geomembrane
textured both sides (white preferred)
GCL needle punched (Bentomat DN equivalent)
Class II Logan Landfill Expansion Project 20 Draft Environmental Assessment
Figure 3: Features of the active Logan Landfill and the Site
Excavation of the Class II Unit (5-ft base liner contours) and associated features of the Site (compare to Figure 1 and 8)
southwest of the active Logan Landfill (upper right). Red arrows leachate flow to NW and NE sumps
LINER BASE
CONTOURS
CLASS II
UNIT
NW
Sump
NE
Sump
CENTRAL
CREST
Class II Logan Landfill Expansion Project 21 Draft Environmental Assessment
Figure 4: Liner, Leachate Collection Laterals, Final Leachate Sump, and Temporary Leachate Removal Penetration Systems
Internal features of the liner and leachate control systems for the Class II Unit of the Proposed Project.
Source: Great West Engineering, 2020
A
B
C
D E
Class II Logan Landfill Expansion Project 22 Draft Environmental Assessment
2.3.2 Leachate Collection and Removal Systems Design
A cross-slope network of slotted or perforated 8-in HDPE leachate collection
lateral pipes, with side-slope cleanouts, would be installed in 12-in recessed vee-
trenches in the base liner. This leachate collection pipe network would be
expanded over the floor liner in phases by placing the leachate laterals inside a
toe berm at the downslope margin during each phase of cell construction (Figure
4B). The temporary toe berm system lowers head on the liner of the connected
cells and allows temporary drainage of all leachate as the lateral network
expands to a series of the temporary lined leachate ponds. This network of
perforated or slotted leachate collection lateral pipes (Figure 8) would be bedded
2 inches above the liner in 1.5-in (minus) washed gravel mounded in windows
10-ft wide and flush with the adjacent 15-in thick gravel drainage (protection)
layer (Ks 1x10-2 cm/s) covering the entire floor liner (Figure 4E). The leachate
lateral network on the floor would also connect to a continuous, perforated, or
slotted, 8-in HDPE leachate pipe (toe-drain) placed along the bottom of all landfill
side slopes, including the central crest (Figure 3). The continuous toe drain
would thereby provide rapid direct transmission of leachate away from the outer
slopes and across the outer edge of the sloping floor to both leachate sumps at
the northern corners of the unit.
The temporary sump and leachate removal system designs (Figure 4A, 4B) would
be matched in every phase of the proposed Class II Unit liner expansion to
transmit collected leachate from each active cell. A temporary toe berm would
be constructed along the downslope liner termination, below and parallel to the
vee-trench lateral collection pipe (Figure 4B) where a tee allows the double
walled 8x16-in leachate drainage pipe to connect with the lateral and exit the
unit through a liner penetration (Figure 4A). The leachate drainage pipe enters
an external trench for gravity drainage and transmission to the nearby temporary
leachate pond constructed downslope during unit excavation. This toe berm,
lateral collection pipe, and penetration system would be relocated and replaced
at the lowest corner in the next adjacent cell, where the same temporary
leachate management system is constructed downslope at the termination of
leachate lateral extensions from the previous cell. The entire system of phased
cell liner and leachate collection expansion combine with the temporary leachate
drainage and removal system to allow regular partial closure of the Class II Unit
as disposal progresses downslope in each cell (Figure 8).
The District has used the HELP Model in previous designs for cells 1 through 4 at
the active Logan Landfill for estimating annual and total landfill leachate volumes
expected over the life of a chosen Class II landfill design (1/11/ 2007, 2/25/2011,
2019). The District has measurements of the actual annual volume of leachate
stored on site from 15 years of data acquired at the existing leachate pond for
gravity drainage from the Class II unit, phases 1, 2, 3, and 4 at the active Logan
Class II Logan Landfill Expansion Project 23 Draft Environmental Assessment
Landfill. The annual amount of leachate produced has remained very low for
very similar designs. DEQ has approved this data-based approach as the
preferred current alternative and has adopted by reference associated
documents for determining the necessary design capacity for the leachate
collection pipe system, sumps, and leachate ponds. Each 8-in leachate collection
system lateral would carry 300 gallons per minute to provide a large factor of
safety in the design for the peak gravity flow circumstances (e.g., early open liner
before waste and soil would entirely cover the cell base) at the Site when
draining leachate into the sumps for leachate removal pumping.
The construction of the final leachate removal systems at the toe of the Class II
Unit and connection of the two permanent leachate sumps (Figure 5A) to the
two permanent leachate ponds (Figure 5B) would complete the transition of
waste disposal to the Site from the currently active Logan unit. Each of the
matching NE and NW leachate collection sumps would consist of doubled
composite liner GCLs below an HDPE geomembrane and upper geotextile that
both match the base liner configuration. The solid 18-in HDPE leachate removal
slope riser connects at bottom over the enhanced composite liner to an elbow
and 14-ft perforated 18-in HDPE collection pipe bedded in a 2-ft deep by 15-ft
long by 14-ft wide sump filled with 1.5-in (minus) washed gravel aggregate that
laterally rise 1-ft higher than the connecting 15-in base collection gravel blanket
grade. The large side slope riser would sleeve the leachate pump and 2-in HDPE
carrier pipe that exits the riser near the surface through a manhole into a trench.
The manhole provides a connection to the pump station at the surface for
removing leachate from the permanent sump and allow gravity transmission of
the pumped leachate into a 2” HDPE pipe that drains into the lined leachate
storage ponds. Two 18-in side slope risers would provide twinned access for
installing an emergency or replacement pump if problems develop.
Both the temporary and permanent double-lined leachate storage ponds (Figure
5B) would be constructed in a similar manner with 3:1 side slope and a 1% base
grade directed to the monitoring sump and riser. As noted for the leachate
collection system, previous leachate storage pond designs are well documented
in the as built (or Record) drawings for the active Logan Landfill (2012). The
expansion area again utilizes similarly reliable design concepts for the leachate
ponds. The double liner for the leachate storage ponds would separate the
primary composite base (identical with the final sump liner) from the secondary
HDPE single-component liner with a geo-composite drainage net. A 12-in HDPE
collection riser pipe, terminated with slots at bottom, would be bedded within
the geonet composite for detecting leakage of the pond primary liner to facilitate
timely repairs. A scrap of the geonet is placed beneath the slotted termination
after the riser elbow to cushion the base liner components.
Class II Logan Landfill Expansion Project 24 Draft Environmental Assessment
Figure 5: Permanent Leachate Collection Sump and Leachate Storage Pond Systems
Internal features of the Leachate Collection Sump and Leachate Storage Pond Systems for the Class II Unit
Source: Great West Engineering, 2020
A
B
Class II Logan Landfill Expansion Project 25 Draft Environmental Assessment
2.3.3 Landfill Unit Construction
Seismic activity in the area was the only location restriction concern for the Class
II Unit and leachate collection, removal, and storage systems. When affected by
repeated seismic activity from single isolated large earthquakes (ARM
17.50.1007), these structures could be affected. A geotechnical report to
evaluate liner strengths for potential failure from a single selected large
earthquake that could cause internal slippage was submitted and approved by
DEQ. Shear strength of interfaces in the proposed stack of composite liner
materials was tested and passed pseudo-static digital models for seismic
displacement within the liner. The results showed that motion along liner
component interfaces was limited in the range of 1 to 7 cm when subjected to a
synthetic 0.36g seismic acceleration given models using the proposed liner slope
geometry and mass of the overlying waste. Ongoing studies have shown that
actual displacements of liner, leachate systems, and final covers within the 10- to
20-cm range have been found acceptable at landfills built in California seismic
zones after their impact by similar large earthquake events.
The friction along HDPE liner interfaces is controlled by the level of roughness
(“asperity height”) of the textured HDPE geomembrane. Samples taken from
GCL, HDPE liner, and geotextile rolls delivered onsite by the contractors, and
samples of onsite soils at the landfill, must be fully lab tested by wet “Direct
Shear” methods for interface strengths before use during liner construction on
site. Their acceptance is based on conformance with residual shear strengths
provided in the DEQ-approved geotechnical analysis report on site-specific
seismic stability. A wet composite sandwich test of all the stacked and floating
liner components is also required to pass at the same small displacement
residual shear strengths for each interface. All vertical (“normal”) loads on the
direct shear mechanism and strain rates during testing must conform to those
provided in the report (Great West, 2021).
The landfill cell and leachate collection system final design documents would be
completed prior to construction of each cell and submitted before construction
to DEQ for approval. Drawings and engineering certifications for cell
construction would be documented as part of the operating record for the
District. For example, composite liner components (e.g., GCL and HDPE
geomembrane) must be placed on a certified and surveyed subsurface interface
with the following characteristics:
Smooth and properly wetted
At least 2% grade
Proven subgrade with experienced handling and documentation
Properly overlapped and sealed GCL panels
Class II Logan Landfill Expansion Project 26 Draft Environmental Assessment
Double-fusion open channel welds between HDPE geomembrane
sheets tested for continuity
Rapid placement of flat geomembrane in contact with GCL
Proper spreading of gravel layer over geomembrane
All activities would be based on DEQ approved final construction booklets
including design plans, specifications, manufacturer’s manuals, and DEQ
approved Construction Quality Assurance and Construction Quality Control
(CQA/CQC) program documents. DEQ must be notified two days before
adjustments for an approved liner subdrain would be necessary in areas where
significant groundwater seepage could be discovered. An onsite engineer
documents and supervises construction.
Regardless of the life of the Site, final as-built drawings and a certified CQA/CQC
report would be submitted to DEQ for approval of each cell construction project.
DEQ would receive engineering reports annually to verify volume disposed,
available, and remaining landfill life.
2.3.4 Stormwater Control Construction
Elevations within the Class II Unit area vary from 4225 to 4325 feet above mean
sea level (amsl). A run-on control ditch and a run-off drainage ditch would follow
the outside and inside of the gravel access road that surrounds the proposed
Class II Unit. The run-on ditches would collect clean stormwater draining from
native ground and topography uphill, and off the exterior access roads, to divert
it away from the Class II Unit and ADU operations areas (Figures 3 and 8).
Internal clean stormwater run-off, from outside the waste and working face
areas, would be routed to two detention ponds strictly for clean sediment
capture (Figure 6A). The ponds provide an underdrain and valve (Figure 6B) for
the release of clean stormwater to the adjacent coulees, if necessary. The
notices for the ultimate discharge of stormwater into State waters would be
managed for pollutants and volumes under the existing SWPPP and MPDES
General Permit for Industrial Activities (No. MTR 00358) issued by the Montana
Water Quality Bureau.
The stormwater pond capacities and flow diversion structures for the Proposed
Action were based on precipitation studies for all four previous phases of design
and construction and would at least capture the maximum volume of internal
runoff for the 25-yr, 24-hr storm event as required. DEQ has approved this
approach and incorporates all associated documents into this submittal by
reference. Stormwater controls would maintain the necessary separation from
leachate controls as required (ARM 17.50.1109 & -10). Run-on controls would
protect the landfill units and the leachate and stormwater ponds from potential
erosional damage while also controlling release of sediment from the facilities.
Class II Logan Landfill Expansion Project 27 Draft Environmental Assessment
The detention ponds are not necessary after final cover is installed to shed clean
runoff from vegetated swales onto surrounding native ground.
Class II Logan Landfill Expansion Project 28 Draft Environmental Assessment
Figure 6: Stormwater Detention Pond Design
Internal features of the Stormwater Pond Systems for the Proposed Action
Source: Great West Engineering, 2020
A
B
Class II Logan Landfill Expansion Project 29 Draft Environmental Assessment
2.3.5 Soil Stockpiles
Soils excavated to construct all disposal cells would be stockpiled on native
ground within the large buffer area surrounding the Class II and ADU operations
and extending to the proposed license boundary if the expansion is approved by
DEQ. The construction plans submitted for DEQ approval prior to the
construction of each cell specify the location of soil stockpiles in the buffer zone.
Soils excavated to construct the cells would be properly segregated to provide
the select borrow needed for construction of the alternative store-and-release
final cover of both Class II landfill units upon closure of the Site.
2.3.6 Partial and Final Closure
The Class II Unit design provides for the progressive partial closure of the landfill
as each cell is filled and reaches final grade after it is tied into adjacent disposal
cells (Figure 8). The topsoil initially removed during construction of each cell and
stockpiled onsite would be used to construct the final cover (Figure 7A) that
would include a select composite soil barrier of adequate thickness placed
beneath a sufficiently revegetated and maintained growth layer. The final cover
proposed for all closure of all Class II Units at the active Logan Landfill is analyzed
and developed in the previous Gallatin County Logan Landfill Alternative Final
Cover Demonstration document (Great West Engineering, 2008). DEQ has
approved this same approach and incorporates all associated documents by
reference into the current expansion submittal. The alternative final cover
design relies on soil storage and evapotranspiration (store-and-release) of
moisture to prevent percolation of moisture into the waste mass.
The final cover system for the Proposed Action would consist of a 4-ft thick soil
cover constructed of native soil materials. From top to bottom the proposed
composite alternative soil cover consists of the following components (Figure
7B):
1-ft thick layer of native sand with 6-in topsoil augmented with compost
2-ft thick layer of select native silt material
1-ft thick layer of native sand
The key to the final cover design is the select silt/clay material. This material
needs to be selectively stockpiled for future use in the final cover whenever
encountered in excavations. If the District runs out of suitable materials during
the life of the Site to construct all the phases of final closure work, an alternative
closure design would be provided to DEQ for approval.
All topsoil would be stripped and selectively stockpiled to be reused as the top
growth layer for revegetation. Final grade for the landfill units would be shaped
to provide positive drainage from all covered areas and would be drained by a
Class II Logan Landfill Expansion Project 30 Draft Environmental Assessment
spiral series of parallel vegetated swales at maximum slope 5% (Figure 7B). The
alternative final cover would provide 4:1 side slope and a minimum top deck
slope of at least 5%. Erosion would be controlled by sustained revegetation and
by planting a DEQ approved USDA Natural Resource and Conservation Service
(NRCS) native seed mix, as specified in the Closure Plan.
As noted in the 2008 DEQ approval for the Logan Alternative Final Cover (AFC)
Demonstration, a method for monitoring the actual AFC drainage achieved onsite
must still be proposed for DEQ approval to show compliance with the predicted
performance standard for the cover soil storage, thickness of soil, vegetative cover,
and average site precipitation.
As currently approved, a 50-in thick alternative final cover would be installed as
described in Section 2.3.1. To provide the soil needed for installing the final
cover growth layer for revegetation, the topsoil initially removed and stockpiled
during construction of the Class II Unit cells would be used. A six-inch topsoil
layer and specified seed mix would provide for sufficient revegetation by native
plant species within one year. The final cover would be crowned with minimum 2
percent slope and drainage channels would route stormwater toward perimeter
control ditches and the two stormwater collection ponds on northeast and
northwest margins of the Class II Unit (Figure 8). All partial or full closure
construction (and DEQ final approval) would proceed in conformance with a
previously approved Construction Quality Assurance and Construction Quality
Control (CQA/CQC) Plan. The District submitted a draft copy of the deed notation
for the entire property that includes the Proposed Action.
2.3.7 Post-Closure Care
The Post Closure Plan (PCP) identifies the inspection, maintenance, and
monitoring activities that would be completed during the 30-year post-closure
care period and identifies the frequency for conducting these activities. The
final use of the Class II Unit would be rangeland.
According to the PCP, detailed inspections of the closed Class II Unit would be
conducted yearly during the 30-year post-closure care period, as required in ARM
17.50.1404, and would include the following:
Evaluation of the final cover for settlement, erosion, drainage swale
system function, and quality of vegetation
Inspection of drainage control facilities (berms, ditches, catch basins,
piping, culverts, outlets, and ponds) for erosion, damage, blockage, or
accumulation of sediment
Function and repair of the leachate and methane control systems
Condition and functionality of ground water and methane monitoring
wells
Class II Logan Landfill Expansion Project 31 Draft Environmental Assessment
General site conditions (gates, locks, fencing, survey monuments, etc.)
Evaluation of the financial assurance
If damage or degradation to the final cover, leachate or methane control systems,
drainage control facilities, monitoring systems, or general site features is noted,
timely maintenance would be completed by the owner. Maintenance activities,
described in the PCP, would follow manufacturer’s specifications as necessary,
and would meet all approved CQA/CQC procedures. The nature of the
maintenance completed would be noted on the inspection form, which would be
added to the operating record. Erosional damage to the cap shall be repaired by
regrading and seeding the affected areas. Areas which continually erode shall be
repaired with riprap or erosion blankets. Ponding areas caused by differential
settlement shall be filled and regraded to ensure the 5% minimum final grade
A report describing the inspections, conditions observed, corrective actions,
maintenance activities, monitoring activities performed, and annual FA
adjustments needed for the closed Class II Unit would be submitted to DEQ
annually and entered into the operating record. Routine ground water and
methane monitoring would be performed by the licensee during the post-closure
care period in accordance with the DEQ-approved ground water and methane
monitoring plans. Necessary adjustments to the PCP (resulting from annual
inspections or 5-year PCP review) would be submitted to DEQ for approval.
2.3.8 Financial Assurance
In accordance with ARM 17.50.540 and ARM 17.50.1118(1)(d), DEQ’s approval of
a Class II landfill expansion requires the licensee to provide and maintain a
Financial Assurance (FA) mechanism to cover costs associated with Class II Unit
closure, corrective action, and post-closure care. FA ensures that work
associated with the Class II Unit closure, corrective action, and post-closure care
is completed in the event the District cannot or would not do so on its own
accord. Gallatin County already maintains the Local Government Option (LOGO)
FA for the Logan Landfill. The FA required is based upon the calculated maximum
costs associated with third-party closure of the maximum exposed landfill area,
completion of corrective action, and the performance of post-closure care
activities. If the Class II Unit is approved, the 2020 total cost estimate for FA is
$19,818,000 and includes projected 2020 closure costs of $18,711,000 and
annual post-closure costs of $36,900, or $1,107,000 total for the 30-year post-
closure care period.
The LOGO and cost estimates for the Logan Landfill FA would be increased to
properly cover the new Class II Unit. DEQ would be the fund beneficiary and
would control all release of money from the LOGO. Annual FA payments are
required for facilities proposing to utilize the trust fund mechanism. Because the
District proposes to utilize the LOGO, annual payments are not required. The
Class II Logan Landfill Expansion Project 32 Draft Environmental Assessment
regulations require all Class II facilities to update the FA cost estimates annually,
including adjustments for inflation. Annual costs to the LOGO FA would be
adjusted for DEQ review to ensure that it is adequately funded. The County has
already deposited the yearly cash amount necessary per these cost estimates
into a closure and post-closure enterprise fund that has been audited for more
than 15 years to cover FA obligations for the active landfill. Annual growth of the
enterprise funds and DEQ annual review of the LOGO mechanism would
continue as necessary for the additional cost of the proposed Class II Unit.
Class II Logan Landfill Expansion Project 33 Draft Environmental Assessment
Figure 7: Closure Final Cover Plan, Profile, and Drainage Swales
Internal features of the Alternative Final Cover System (5-ft final grade contours) for the Class II Unit
Source: Great West Engineering, 2020
A
B
Class II Logan Landfill Expansion Project 34 Draft Environmental Assessment
Figure 8: Phased Sequence of Cell Fill and Partial Closure within the Class II Unit
The combined landfill cells 5 through 27 would expand downslope in 23 phases within the Class II Unit. Initial cells 5 through 9
occupy the 68-acre SW corner. Leachate lateral pipes carry flow down red along cell margins.
Source: Great West Engineering, 2020
FLOW
DIVIDE
Class II Logan Landfill Expansion Project 35 Draft Environmental Assessment
2.3.9 Landfill Operations
2.3.9.1 Personnel
Personnel at the Site would include, but are not limited to, the
following:
District manager
Household hazardous waste and safety coordinator
Office manager
Accountant
Scale house operator and operational support
Site foreman and lead equipment operator
Four full-time equipment operators
Compost operator and site maintenance
Lead mechanic and mechanics
Consultants
2.3.9.2 Operating Hours
Summer hours would be Monday through Friday from 7:00 am to
5:00 pm, and Saturday from 7:00 am to 4:30 pm, from May 1st to
October 31st.
Winter hours would be Monday through Saturday from 7:30 am to
4:30 pm, from November 1st to April 30th.
The Site would be closed on Sundays and the following holidays:
Christmas Day
New Year’s Day
Memorial Day
July 4th
Labor Day
Thanksgiving Day
A sign indicating hours of operation is currently located at the
main access gate at the corner of the junction at I-90 eastbound.
2.3.9.3 Site Access
Access to the Site is via Two Dog Road south and parallels I-90.
The Site has a paved access road beyond the scales to the
entrance to the active Logan Landfill. This road would be
extended to the new cells at the Site.
Class II Logan Landfill Expansion Project 36 Draft Environmental Assessment
Site controls include mechanical and lockable entrance gates and a
perimeter fence around the Site. There is a camera security
system and access to buildings is controlled through a card-
reading system.
2.3.9.4 Landfill Equipment
The District has the following equipment onsite for waste
management:
Two compactors
Motor grader
Haul truck
Excavator
Loader with bucket, forks, and brush
Two dozers
Tractor
Compost turner
Alternative daily cover sprayer
Service truck
Roll-off/hook truck
Water truck
Litter vacuum
In the event of equipment breakdown, the District has sufficient
equipment to continue operations until the broken equipment is
fixed. The District would request the temporary use of County
Road Department equipment for certain operations when needed.
2.3.9.5 Acceptable and Prohibited Wastes
Acceptable wastes would include, but are not limited to:
Groups II-IV wastes
Contaminated soil
Waste oil
Mobile structures (mobile homes, camp trailers, etc.)
Household hazardous waste
Conditionally exempt small quantity generator (CESQG)
hazardous waste
Friable and non-friable asbestos
Yard waste
Clean wood waste
Mortality (dead animals)
Class II Logan Landfill Expansion Project 37 Draft Environmental Assessment
Biosolids
Tires
Prohibited wastes would include, but are not limited to:
Regulated hazardous waste
Bulk liquids
Regulated asbestos-containing material
Technologically enhanced naturally occurring radioactive
material (TENORM)
2.3.9.6 Waste Screening
The Site would have a multi-tiered waste screening program that
includes the following:
Waste Acceptance Policy
Visual screening at the scale via TV cameras
Questioning by the scale operators
Waste Tracking Forms
Inspection of the waste by the dozer operator
Inspection of the waste by the compactor operator
Random load inspections
Waste Rejection Form
Random load inspections would be initiated at the scale house.
The scale house operator would notify the operators of the
vehicle description by radio. The scale operator would randomly
select a load for inspection every 300th user that enters the Site.
This would ensure a minimum of 1% of commercial and industrial
vehicles are inspected. The record of random load inspections,
including photos, would be maintained in the operating record.
Landfill operators would survey the waste during spreading and
compaction. They would be trained to identify hazardous,
prohibited, or suspicious wastes (Section 2.3.8.5). Any suspicious
wastes are quarantined, and the area is cordoned off until the
wastes are properly identified. The Waste Screening Program
outlines actions that would be taken by staff and management in
the event of hazardous or prohibited items being discovered. The
Waste Screening Program contains a list of contacts and phone
numbers for any potentially hazardous waste incident.
Class II Logan Landfill Expansion Project 38 Draft Environmental Assessment
2.3.9.7 Composting
The District would compost the following materials onsite:
Yard waste
Mortality (dead animals)
Biosolids
Yard waste composting would be done in a static pile
approximately 8 feet wide and six feet high. The feedstock would
be ground brush combined with grass cuttings and leaves. Brush
would be accumulated and periodically ground. Leaves and grass
would be mixed with the ground brush in a 50:50 ratio. Piles
would be monitored for moisture content and water would be
added accordingly. Temperatures would be recorded and placed
in the operating record. Once compost would be finished, the
material would be used onsite for cover, berms, or other onsite
reclamation uses.
Mortality composting would occur in a long, self-aerating,
windrow. A two-foot bed of wood chips from the brush grindings
would be laid out eight-feet wide to accept the animals. A one-
foot layer of previously composted material would be placed on
the animals. Animals would be covered with at least two feet of
additional brush grindings. A second layer of animals may be
placed over the first if they are deer or hog-sized animals before
the additional layer of two-feet of chips. The final pile would be
between four and six feet high. The material would be screened
to remove oversized bones from the processed material. The
bones would either be returned to the next compost pile for
further degradation or placed on the working face.
Biosolids composting would occur in windrows. The City of
Bozeman generates about 10-12 cubic yards of aerobically
digested, dewatered biosolids and/or waste activated sludge per
day. The City would transport the biosolids in a sealed 20-yard
container daily. The biosolids would be placed on a bed of ground
wood waste. The biosolids and the wood chip pre-mix would be
thoroughly blended using the front-end loader. Biosolids would
be mixed within two hours of delivery. The mix would be placed
on the chip bed for the windrow five feet high and ten feet wide
and covered with six inches of course, previously composted
material. The yard waste blend would then be mixed with the
biosolids. Covering the piles with a compost biofilter would help
Class II Logan Landfill Expansion Project 39 Draft Environmental Assessment
eliminate odor generation problems while the windrows are being
constructed.
All compost would be monitored for moisture content and water
is added accordingly. Temperatures would be recorded and
placed in the operating record. Once compost is finished, the
material would be used onsite for cover, berms, or other onsite
reclamation uses.
2.3.9.8 Asbestos
The District would accept only non-friable asbestos, non-
Regulated Asbestos Containing Materials (ACM) at the Site. The
District’s goal is to provide a safe and reasonable work
environment for its employees. Waste haulers, contractors,
businesses, and homeowners would be required to complete and
submit a waste tracking form for approval prior to disposal of non-
regulated ACM at the Site. Inspection reports and analytical
reports would be required from any entity generating this waste
from non-exempt residential dwelling units or commercial
buildings.
As this material arrives, the scale operator would notify the site
foremen or equipment operator that this material arrived. An
appropriately sized hole would be excavated in the working face to
receive the material. The customer would be required to deposit
the load as close to the hole as possible. Once the customer
leaves, the operators would push the material into the working
face and cover with a minimum of two feet of loose municipal
solid waste before resuming normal operations.
2.3.9.9 Waste Placement
When a new phase of the Class II Unit is opened, waste fill is
initiated at the head of the unit and filled in a down gradient
direction. Progression of fill in a down gradient direction allows
the fill to be graded in a manner that prevents ponding of
stormwater in the active cell areas. The initial waste placement in
the cell is designed to cover the bottom of the cell as rapidly as
possible with waste.
Because the cell has a complete leachate collection and removal
system in place, all precipitation that enters the leachate
collection system is considered leachate after the first load of
waste is placed in the cell.
Class II Logan Landfill Expansion Project 40 Draft Environmental Assessment
The new cells are initially footprinted with about four to six feet of
waste that is relatively uncompacted. This waste layer and the
intermediate cover over it absorb the precipitation that falls on
the cell and reduces the amount of leachate that must be pumped
to the leachate pond. The lack of compaction of this first lift
wouldn’t pose a problem because the weight of the refuse
subsequently placed on over this footprint layer will significantly
consolidate it. This method of waste placement further prevents
inadvertent damage to the liner system by keeping machinery well
above the liner
2.3.9.10 Waste Compaction and Cover
Equipment operators typically place the waste in approximately
15-foot-thick lifts. Daily waste cells are placed with a working face
slope of approximately 5H:1V. The cells are normally 50 to 75 feet
wide. Waste is then compacted with a compactor to maximum
density. Waste is finally covered at the end of the workday with
six inches of daily cover soil or with one of the DEQ-approved
alternative daily covers (ADC). Daily cover controls vectors, litter,
odors, and other landfill nuisances. Daily cover also helps reduce
stormwater contamination and the production of leachate.
An excavator and haul truck would be used for excavating and
hauling daily and intermediate cover from the soil stockpile and
borrow areas to the fill area. The wheel loader and the tracked
dozers would be used to place and spread weekly and
intermediate soil cover. Several standard compaction procedures
are used on site. These procedures include compacting the waste
in thin lifts (less than two feet thick) with multiple equipment
passes and compacting each lift in two directions perpendicular to
each other. At the end of the day, the tracked dozer would clean,
repair, and grade the tipping floors in the active disposal areas.
If asbestos-contaminated material (non-friable) enters the Site,
the scale operator would notify the site foreman or equipment
operator that the material has arrived with approximate volume.
An appropriately sized hole would be excavated in the working
face to receive the material. The customer would be required to
deposit the waste as close to the excavation as reasonably
possible. Once the customer has departed, the operator will
gently push the material into the excavated working face and
cover it with a minimum of two feet of cover before resuming
normal activities.
Class II Logan Landfill Expansion Project 41 Draft Environmental Assessment
Topcoat and Posi-Shell have been approved by DEQ as ADC. These
materials greatly reduce the amount of soil placed within the
landfill. They have proven to be reliable covers and save more air
space than soil cover. ADC would be utilized on all days that the
wind and weather allow deployment. When the weather
prohibits the use of ADC, the crew will cover the waste with soil to
meet the daily cover requirements. When soil cover is used on
the working face, the thickness should never exceed six inches.
Topcoat is shipped as a dry product and mixed on-site. Topcoat is
a hydro-mulch of recycled paper blended with proprietary
binders. Topcoat is used as a true daily cover. It is used in areas
that will receive waste the next day. The material is sprayed on
with the hydro-seeder thick enough that litter is controlled, and
birds and other vectors are discouraged from the working face.
When applied in accordance with the manufacturer’s instructions,
it meets all requirements for an ADC. DEQ requires the landfill to
cover any areas that use ADC with soil on a weekly basis. Areas of
exposed Topcoat ADC are inspected daily and re-covered with
Topcoat as needed. Landfill staff would maintain records of each
ADC application and follow-up inspections.
Intermediate cover of 12 inches (minimum) soil cover would be
placed on the intermediate top elevation as the lift progresses
across the landfill cell. The material is placed on the top of the lift
with the haul truck and is spread and track packed by the dozer.
When the next lift starts over the top of refuse with intermediate
cover, landfill staff would use the intermediate cover from the lift
as a tipping floor for the next lift of waste. This practice saves the
landfill air space. Landfill staff would keep records of daily waste
tonnage and daily and intermediate cover soil and ADC used. This
information would be used with periodic topographic surveys of
the fill area once annually to determine the compacted waste
density, waste-to-soil ratio, and overall volume per ton ratio. The
District would continue its procedure of tracking cover soil usage
including separate numbers for loads excavated from borrow
areas, stockpiles and loads imported into the cells for cover. The
District would also continue to keep detailed records of tonnage
accepted on-site.
2.3.9.11 Severe Weather Operations
The District has a policy that stops delivery of waste if winds reach
a sustained speed of 35 mph for ten minutes based on readings
Class II Logan Landfill Expansion Project 42 Draft Environmental Assessment
from the office anemometer, or wind gusts to 45 mph. If the
winds exceed these speeds, the District has the discretion to close
the landfill.
The District has a Severe Weather Closure Policy in place at the
active Logan Landfill and would implement it at the Site.
2.3.9.12 Dust Control
Dust becomes a nuisance at the working face, daily cover
excavation area, and along access roads.
Dust control measures to be utilized at the working face include:
Careful movement of dusty waste and soil
Prompt covering of light, powdery wastes
Orientation of the working face into the wind when
possible
Minimizing earth-moving activities during windy periods
Installation and maintenance of sealed cab with filters in
air systems of the compactor, dozers, excavators, haul
trucks, and loaders
Intermediate cover with compost and vegetative seeding
Spray applied to woody, straw, and mulch cover material
Dust control measures to be utilized on access roads include:
Gravel surfacing on new roads
Water spraying
Grading fine soils from roads during wet periods
Controlling vehicle speeds
Cleaning dirt from asphalt roads leading to the front
entrance after wet periods
Magnesium chloride application on non-paved road
surfaces
2.3.9.12 Litter Control
There is a litter control plan in place at the active Logan Landfill
that would be implemented at the Site. The Site would be
surrounded by a series of litter control fences and would utilize
portable litter screens and berms to control litter around the
working face. These screens are moved as necessary to provide
the best defense against the wind depending on wind direction.
Class II Logan Landfill Expansion Project 43 Draft Environmental Assessment
Litter would be regularly removed from these fences and access
roads by staff. The District utilizes litter picking crews from
Gallatin County Detention Center Work Program on a regular
basis.
The equipment available to pick litter would include:
Litter vacuum
Bobcat Tool Cat with IES litter collection attachment
Hand operated trash picking tools
All loads entering the Site must be covered before entry. The
District would stop waste delivery when wind speeds are
sustained at 35 miles per hour for ten minutes based on readings
from the office anemometer, or when wind gusts reach 45 miles
per hour. If necessary, local law enforcement agencies would be
utilized to prevent littering and indiscriminate dumping at the
entrance and along access roads.
2.3.9.13 Recordkeeping
The following records of all activities at the landfill would be kept
in the office onsite:
Annual license posted in the office
Annual renewal report forms and license fee records
Landfill design plans, QA/QC plans, reports, and
certifications
Operation and maintenance plan and addendums
Daily vehicle counts
Tonnage records (tracked by computer)
Daily and intermediate soil cover volumes
DEQ inspection reports and other local agency inspection
reports
Groundwater, leachate, and methane gas monitoring data
Logs of special events, including fires, earth slides, floods,
accidents, and other unusual events
Closure and post-closure plans
Financial assurance documents
Personnel training records
Inspection records for random and hazardous waste
screening
Freon removal certifications
Class II Logan Landfill Expansion Project 44 Draft Environmental Assessment
DEQ must be notified of recordkeeping changes and locations.
The O&M Plan would be updated and submitted for DEQ approval
as necessary based on annual inspections or 5-yr review as
required.
2.3.9.14 Fire and Safety Plan
Fires would be handled in a preventive as well as corrective
manner. Operators would inspect for hot loads. However, any hot
loads would be isolated and extinguished before they are placed
in the Site. If a fire were to occur in the working area, the
operators would use their equipment to push the burning waste
away from the working area if they can do so safely. Once the
waste is isolated, landfill operators and equipment would
extinguish the fire. In the event of a larger or more persistent fire,
the local fire department would be summoned. In the event of a
larger fire, the District would notify the DEQ and the engineer of
record for the facility.
2.3.9.15 Partial and Final Closure
Full or partial closure of the Class II Unit would proceed according
to the existing approved Closure Plan (CP). Partial closure would
progress in cycles when cover is placed over portions of each
landfill cell as disposal in each phase proceeds to reach final
grade. Runoff from final cover on partially closed areas would be
captured by stormwater control features (swales and down-
drains) for selective routing to the stormwater ponds as
revegetation develops. The quantity of leachate developed in
each cell would be significantly reduced by these closure
activities. Prior to full closure, the District would first place a
notice of intent to close the Class II Unit in the operating record.
Final closure activities would begin no later than 30 days after the
date of final disposal of Group II waste. Full or partial closure
must be completed within 180 days following the initiation of
closure construction. DEQ may grant an extension beyond 180
days if the necessity and the ability to prevent threats to human
health and the environment are demonstrated.
3. AFFECTED ENVIRONMENT AND IMPACT ANALYSIS BY RESOURCE
3.1. Affected Environment and Study Area
The Site would occupy the 543.8-acres of District-owned property approximately two
miles southeast of the town of Logan in Gallatin County. The Site is accessed via Two
Class II Logan Landfill Expansion Project 45 Draft Environmental Assessment
Dog Road from the Logan exit off I-90. The Site would include most of Section 6,
Township 1 North, Range 3 East, excluding parts of the northeast and northwest corners
(Figure 1 and Section 1.4).
Except where noted in specific resource sections, the study area for the impact analysis
includes all lands and resources located within Section 6 surrounding the 300-acre Class
II Unit. The study area may vary based on the predicted locations of direct and
secondary impacts that could result from the Proposed Action and are noted in each
impact analysis.
3.2. Evaluation and Summary of Potential Impacts to the Physical and Human
Environment in the Area Affected by the Proposed Project
The impact analysis will identify and evaluate direct and secondary impacts, which are as
follows:
Direct impacts: Impacts that occur at the same time and place as the
action that triggers the effect.
Secondary impacts: Impacts those that occur at a different location or
later time than the action that triggers the effect.
Direct impacts are those that occur at the same time and place as the action
that triggers the effect. Secondary impacts mean “a further impact to the human
environment that may be stimulated or induced by or otherwise result from a direct
impact of the action.” ARM 17.4.603(18). Where impacts are expected to occur, the
impacts analysis estimates the duration and intensity of the impact.
The severity of an impact is measured using the following:
No impact: There would be no change from current conditions.
Negligible: An adverse or beneficial effect would occur but would be at
the lowest levels of detection.
Minor: The effect would be noticeable but would be relatively small and
would not affect the function or integrity of the resource.
Moderate: The effect would be easily identifiable and would change the
function or integrity of the resource.
Major: The effect would alter the resource.
Class II Logan Landfill Expansion Project 46 Draft Environmental Assessment
3.3. Impacts
Table 2 shows a summary of the impacts of the Proposed Action.
Table 3: Impacts
Resource Alternative 1 – NO ACTION Alternative 2 – Proposed Action
Wildlife and
Habitats
No impacts (See Section 3.3.1). Minor impacts. As with the active
Logan Class II Landfill, wildlife
would inhabit the available habitats
surrounding the Class II Unit for no
longer than the Cell Life over the
span of the Facility Life. (See
Section 3.3.1)
Geology No impacts (See Section 3.3.4). No impacts. (See Section 3.3.4)
Surface Water No impacts (See Section 3.3.5). Minor impacts. If a discharge of
stormwater to State waters occurs,
minor impacts could result (See
Section 3.3.5)
Groundwater Minor to moderate impacts
(See Section 3.3.6).
Minor to moderate impacts.
Geologic maps (Vuke 2002) show
Willow Creek Fault system cutting
northeast through the Site area
which could influence groundwater
occurrences and offsets. (See
Section 3.3.6).
Soils and
Vegetation
No impacts (See Section 3.3.7). No impacts. The Proposed Action
would remove surface soils to allow
landfilling of solid waste. Removed
soils would be stockpiled onsite for
use as cover. (See Section 3.3.7)
Class II Logan Landfill Expansion Project 47 Draft Environmental Assessment
Air Quality No impacts (See Section 3.3.8). Minor impacts. Fugitive dust and
fire safety would be mitigated. (See
Section 3.3.8)
Industrial,
Commercial, and
Agricultural
Activities
No impacts (See Section 3.3.9).
No impacts. (See Section 3.3.9)
Human Health
and Safety
No impacts (See Section
3.3.10).
No impacts. (See Section 3.3.10)
Recreational and
Wilderness
Activities
No impacts (See Section
3.3.11).
No impacts. (See Section 3.3.11)
Population and
Housing
No impacts (See Section
3.3.12).
Minor impact. The Site wouldn’t
allow for further development or
construction of new homes. (See
Section 3.3.12)
Property Values (See Section 3.3.13) (See Section 3.3.13)
Traffic and Utilities No impacts (See Section
3.3.14).
Minor impact. Operations would
continue at the active Logan
Landfill until transition to the Site.
A similar level of traffic would
continue to access the Site for an
additional 162 years or when
landfill reaches capacity. Traffic
volumes would resemble current
conditions. (See Section 3.3.14)
Aesthetics No impacts (See Section
3.3.15).
Minor impacts. Impacts to visuals,
noise, litter, and odors are noted.
(See Section 3.3.15)
Class II Logan Landfill Expansion Project 48 Draft Environmental Assessment
Demand for
Government
Services
Minor impacts. Gallatin
County would have to find
another location for waste
disposal. If a new location is
proposed, DEQ would conduct
environmental review and
analysis on the new location
(See Section 3.3.16).
Minor impact. DEQ and the
Gallatin County sanitarian would
conduct periodic inspections at the
Site. (See Section 3.3.16)
Cultural
Uniqueness and
Diversity
No impacts (See Section
3.3.17).
No impacts. (See Section 3.3.17)
Socioeconomics Minor impacts. Closure and
post-closure activities would
solicit temporary and minor
increase in employment.
Gallatin County expenditures
to acquire a new landfill
location (See Section 3.3.18).
Minor impacts. There would be a
temporary and minor increase in
employment during construction at
the Site. (See Section 3.3.18)
3.3.1 Wildlife and Habitats
The affected environment and study area includes all lands and resources located
within Section 6 surrounding the 300-acre Class II Unit.
Under the No Action Alternative, no additional impacts are expected. The active
Logan Landfill would close in 2025. Closure and post-closure activities would
commence at this time (see Sections 2.3.6 and 2.3.7). The land would be
revegetated to resemble the surrounding area. Wildlife could graze on the
closed Logan Landfill at that time.
Minor impacts to wildlife and habitat are expected due to the Proposed Action.
Transient wildlife, other than generalist species which thrive in proximity to
human beings, tends to avoid landfills due to human scent and activities.
Montana Fish, Wildlife & Parks (FWP) manages the overall wildlife populations of
the region. Species of fish, amphibians, and aquatic plants are not included on
the following lists because landfill activities would not impact nearby perennial
Class II Logan Landfill Expansion Project 49 Draft Environmental Assessment
waters based on requirements for minimum setbacks, run-on and runoff
controls, and the District’s SWPPP (see Sections 2.3.1 and 3.2.4.1).
The applicant does not plan to expand the Site beyond the boundaries described
in the application. Therefore, no habitats outside the Site would be impacted.
The Site is currently covered by native grasses. Lands adjacent to the existing
Logan Landfill and the Site and to the east are primarily used for agricultural
purposes. Riparian areas along the Gallatin and Madison Rivers and their
tributary drainages provide habitat corridors connecting to the foothills and
higher elevations of the Bridger, Madison, and Gallatin Ranges.
Transient wildlife that are displaced from the Site by the Proposed Action may
affect wildlife adjacent to the Site, which wouldn’t be directly impacted.
Displacement would occur on the Active Cell for the Cell Life over the span of the
Facility Life. The surrounding area provides plentiful additional wildlife habitat to
support displacement.
3.3.2 Threatened and Endangered Species
The affected environment and study area is Gallatin County, as guided by U.S.
Fish and Wildlife Service’s (USFWS) online databases.
Under the No Action Alternative, no additional impacts are expected. The active
Logan Landfill would close in 2025. Closure and post-closure activities would
commence at this time (see Sections 2.3.6 and 2.3.7). The land would be
revegetated to resemble the surrounding area. No expansion of landfilling
activities would occur, and the surrounding area doesn’t provide necessary
habitat to sustain threatened or endangered species.
No impacts to threatened or endangered species are expected due to the
Proposed Action.
The USFWS species and status listings for Gallatin County are shown in Table 3.
Table 4: Federally Established Species List
SCIENTIFIC NAME COMMON NAME STATUS
Lynx canadensis Canada lynx Threatened
Spiranthes diluvialis Ute ladies’-tresses Threatened
Aquila chrysaetos Golden eagle Species of concern
Centrocercus urophasianus Greater sage-grouse Resolved taxon
Anthus spragueii Sprague’s pipit Resolved taxon
Ursus arctos horribilis Grizzly bear Threatened
Charadrius montanus Mountain plover Resolved taxon
Canis lupus Gray wolf Recovery
Class II Logan Landfill Expansion Project 50 Draft Environmental Assessment
Haliaeetus leucocephalus Bald eagle Recovery
Pinus albicaulis Whitebark pine Candidate
Gulo gulo luscus North American wolverine Resolved taxon
Danaus plexippus Monarch butterfly Candidate
The Site does not provide the habitat necessary to independently sustain the
listed species. Suitable habitat for these species exists in the region’s mountain
ranges, upland foothills, and riparian areas.
3.3.3 Species of Concern
The affected environment and study area includes all lands and resources located
within Section 6 surrounding the 300-acre Class II Unit.
Under the No Action Alternative, no additional impacts are expected. The active
Logan Landfill would close in 2025. Closure and post-closure activities would
commence at this time (see Sections 2.3.6 and 2.3.7). The land would be
revegetated to resemble the surrounding area. No expansion of landfilling
activities would occur.
No impacts to species of concern are expected due to the Proposed Action.
Designation as a species of concern is not a statutory or regulatory classification.
Instead, these designations provide a basis for resource managers and regulators
to make proactive decisions regarding species conservation.
The Montana Natural Heritage Program’s (MNHP) online databases were
accessed for listed species (MNHP, 2021). The MNHP species and status listing
for Township 1 North, Range 3 East is shown in Table 4.
Table 5: Montana Recognized Species of Concern List
SCIENTIFIC NAME COMMON NAME STATUS GRANK/SRANK
Myotis lucifugus Little brown myotis Species of concern G3/S3
Ursus arctos Grizzly bear Species of concern G4/S2
The MNHP uses a standardized ranking system developed by The Nature
Conservancy and maintained by NatureServe. Each species is assigned two
ranks; one represents its global status (GRank), and one represents its status in
the state (SRank). The scale is 1-5; 5 means common, widespread, and
abundant; 1 means at high risk. Species with a GRank 5 are not included in Table
4.
The Site is not located within a Core Area or any other recognized habitat level
for sage grouse, as designated by the Department of Natural Resources and
Conservation (DNRC).
Class II Logan Landfill Expansion Project 51 Draft Environmental Assessment
3.3.4 Geology
The resource study area for geology includes the Site and the surrounding area
(beyond a mile) as provided by the full extent of the geologic map in Figure 10.
Discussion of regional geology, largely based upon published reports, is provided.
The analysis methods included review of Montana Bureau of Mines and
Geology’s (MBMG) digital maps, reports, and other sources from the United
States Geological Survey (USGS), the latest geologic maps of the Bozeman
quadrangle and Montana by MBMG (Vuke, et al. 2002 and 2007), a M.S. Thesis
on the Lower Belt Supergroup of the area (Anderson, 2017), topographic maps,
and prior fieldwork.
Under the No Action Alternative, no additional impacts are expected. The active
Logan Landfill would close in 2025. Closure and post-closure activities would
commence at this time (see Sections 2.3.6 and 2.3.7). The land would be
revegetated to resemble the surrounding area.
No impacts to geology are expected due to the Proposed Action.
The excavation necessary to construct the base of the Class II Unit would not
significantly affect the thickness or character of shallow Tertiary sediments found
by reconnaissance (pits and drill holes) at the Site. The Tertiary formations are
widespread and well-exposed in the region surrounding the Site. These
sedimentary layers are shown to contain interbedded ash layers at various levels
that can resist the passage of liquids (like landfill leachate) into the deeper
subsurface to protect groundwater aquifers at depth. Geotechnical evaluations
submitted in the District’s application predict that the proposed landfill liner
stability is sufficient to withstand a high-magnitude earthquake event.
The complexity, number, and range in ages of geologic units identified and listed
on the geologic map for the study area (Figure 10) are significant. Their current
state and landforms evolved from the coincidence of three major tectonic events
in the study area over eons of time. The older rocks outcropping within the
elevated areas adjacent to the Gallatin River, on the northern portion of the
geologic map, exist at depth in the valley beneath the Site and were most
affected by the following two major events:
1. Formation of the ancient Proterozoic Belt Basin during early crustal rifting
of the continents and Precambrian cratons that existed at that time; and
2. The younger Upper Cretaceous to Early Tertiary Sevier-Laramide overthrust
and folded mobile belt caused by subduction oceanic crust along the
Montana to Mexico margin during Cordillera/Rocky Mountains orogenesis.
Class II Logan Landfill Expansion Project 52 Draft Environmental Assessment
Both plate tectonic events were affected by and modified the long-standing
embayment feature of the Montana Transverse Zone (MTZ), likely a plate suture
zone, and possibly a transform fault-related structure. It cuts across, truncates,
and juxtaposes several varied geologic terranes and passes from southwest near
Dillon to northeast through the Bozeman region. The local Willow Creek Fault
(WCF) system appears to locally follow and be involved in the larger MTZ activity
over a long period. It passes through the study area near Logan (Vuke et al.,
2002) and possibly near the active Logan Landfill.
Consequently, only pertinent aspects of the latest MTZ and WCF tectonics are
addressed herein because it most affects the Site given the earlier plate tectonic
settings summarized above. The effects of ongoing tectonic activities along the
west coast of North America continue to affect current evolution of the northern
Rocky Mountains within the active MTZ that passes through Logan to Bozeman
and beyond. The WCF fault system activity in the Logan area does not appear to
show surface displacement (E.G., scarps) during the Holocene, thereby avoiding
the restriction for location of the Logan Landfill to an offset greater than 200 feet
(ARM 17.50.1006) from any surface rupture.
The older intermontane basin fill found within valleys near the Three Forks
region and extending beneath and surrounding the Site predates the current
Gallatin Valley [see Tscmv in Figure 10]. The basin was initially formed by prior
stretching of continental crust in the Helena-to-Bozeman embayment during the
late stages of Cordillera (Early Rockies) mountain building, possibly due to
isostatic settlement of the highly elevated range, in the Early Tertiary (Eocene).
These older, deformed, highly variable sediments, and partly cemented Tertiary
basin rocks are typically divided into two age groups separated by an
unconformity (break in rock ages) in the Bozeman area (Vuke et al., 2002).
The oldest and first Paleogene(?) tectonic basin-fill sedimentary rocks (Tscmv in
Figure 10), largely found at depth, were rich in eroded volcanic debris and airfall
ash, both likely derived from Elkhorn Mountains volcanism to the west. The
younger second phase of Pliocene to Pleistocene (?) deposition (Tab in Figure 10)
overlaid the first and was later covered by various Pleistocene to Quaternary
alluvium and glacial deposits. These youngest sediments, now found at the
surface in the modern Gallatin Valley just beyond the Site, are composed of
various largely unconsolidated gravels (Qalo, Qab, and Qal in Figure 10) that
form a veneer by reworking and partly covering the two previous Tertiary
sedimentary units exposed at the time. This relatively recent rejuvenated valley
was formed last by reactivated motion within the embayment as crust dropped
to the north on the Willow Creek fault zone to sculpt the landscape seen today in
the embayment.
Class II Logan Landfill Expansion Project 53 Draft Environmental Assessment
The Site (Figure 10) is located west of Manhattan between the Gallatin and
Madison Rivers in the broad Gallatin Valley. The study area today lies within the
active seismic zone known as the Intermountain Seismic Belt of the northern
Rocky Mountains, likely caused by ongoing tensional stresses across the region
associated with ongoing block valley development. Extension continues today
with many earthquakes partly following subsidence along the normal faults at
the margins of the basin-and-range style block valleys separating the many
mountain ranges in southwest Montana that extend mostly north to south. A
geotechnical report, analyzing the potential effect of a typical peak seismic event
in the region surrounding the Site, proved the stability of landfill features. Active
hot springs are also found along the southwest to northeast MTZ today (e.g., at
Whitehall, Norris, and Bozeman). The three forks of the modern Missouri River
join today west of the Site at the confluence of the Jefferson, Madison, and
Gallatin rivers in the Gallatin Valley. Most valley runoff is absorbed as shown by
few coulees.
Class II Logan Landfill Expansion Project 54 Draft Environmental Assessment
Figure 9: Geologic Map of Surrounding Area*
(Active Logan Landfill green; Site red)
Symbols: Qal – Alluvium/ Qc – Colluvium/Qaf – Alluvial fan (Holocene & Pleistocene); Qab/Qabo/Qalo – Alluvial, braided bouldery plain, or landslide, und
(Pleistocene?); Tscmv – Loose to consolidated congl, ss, slt, volcanic ash, und. (Miocene-Pliocene?); Trdv – Rhyolite to dacite, vitrophyric (Pliocene);
Kk – Kootenai Fm (U. Cretaceous); Jme – Morrison Fm & Ellis Grp (Jurassic); PPvMps – Park Shale; Mmc – Mission Canyon/Ml – Lodgepole (Mississippian);
MDt – Three Forks Shale (Miss.-Devonian); Dj – Jefferson Limestone (Devonian); €p – Park Shale/€pi – Pilgrim Limestone/€m – Meagher Limestone/
€w – Woolsey Shale/€f – Flathead quartzite (Cambrian); Yla – LaHood Fm (Mesoproterozoic)
* Miss Mississippian, Fm formation, Grp Group, und undivided, Congl conglomerate, ss sandstone, slt siltstone. Bold black lines or dashes faults where thrusts have teeth on
upper slabs; thin purple lines fold axes. Gallatin River flows north of the site and I-90 westward to confluence with the Madison and Jefferson rivers at the headwaters of the
Missouri River near Three Forks. Blue stars springs, fine squiggly arrows show blue surface water flows and brown irrigation canals. Sources: MBMG web map application and
Montana Geologic Map 62 (2007); ESRI ArcGIS web.
Trdv
PǀPMps
Kk Jme
€w
Qal
Qab
€pi
€p Dj
MDt
Ml
Class II Logan Landfill Expansion Project 55 Draft Environmental Assessment
3.3.5 Surface Water
The study area for surface water is the hydrologic unit code (HUC) 12 watershed.
The Site is located within the City of Manhattan-Gallatin River watershed, HUC
100200081401. An unnamed ephemeral stream flows near the east edge of the Site
(Figure 9). Water from this stream flows north to its outlet at the Gallatin River,
approximately 1.25 miles north of the Site (Figure 9). The mainstem Gallatin River is
currently impaired by flow regime modification due to crop irrigation within the
watershed. The Proposed Action is not anticipated to impact the Gallatin River’s flow.
The Federal Emergency Management Agency’s flood zone map shows the 100-year flood
boundary for the Gallatin River is 0.7 miles away from the northern edge of the Site’s
boundary at its nearest point.
A man-made reservoir on the east side of the unnamed ephemeral stream is located less
than a quarter mile upstream of the Site’s southeast corner. The reservoir is used to
hold water for farmland irrigation and receives seasonal flow from areas upstream of the
Site. A topographically low spot lies between the southeast edge of the existing active
landfill and the western extent of the Site’s proposed boundary. This potential drainage
is not known to contain water other than during periods of excessive precipitation and is
not known to flow. The potential drainage mirrors the direction of the unnamed
ephemeral stream on the Site’s proposed eastern boundary.
Based on the USFWS National Wetlands Inventory map, no wetlands are located within
or adjacent to the Site’s boundaries, other than the unnamed ephemeral stream. A
buffer zone would be designated to the west of the ephemeral stream to ensure no
wetlands are impacted. Therefore, no wetlands would be impacted by the Proposed
Action.
Under the No Action Alternative, no additional impacts are expected. The active Logan
Landfill would close in 2025. Closure and post-closure activities would commence at
that time (see Sections 2.3.6 and 2.3.7), ensuring that the landfill would be capped with
a vegetated cover to minimize any potential erosion and surface water runoff.
Potential impacts to surface waters resulting from the Proposed Action are anticipated
to be minor because the following proactive mitigation strategies would be employed to
manage run-on and runoff:
Prior to commencing the construction phase of each landfill cell, best
management practices would be employed and constructed in accordance with
the Storm Water Pollution Prevention Plan (SWPPP). The SWPPP would include
specific plans for run-on and runoff controls during the construction phase based
on the unique positioning and topography of each cell.
Prior to operating an active cell and receiving waste, construction of stormwater
ditches around the perimeter of the cell would be completed to re-route run-on
water away from the active cell and off-Site.
Precipitation encountering refuse in the active cell would be routed through the
facility’s leachate collection and removal system (see Section 2.3.2 and 2.3.3) and
Class II Logan Landfill Expansion Project 56 Draft Environmental Assessment
managed through evaporation and (when necessary) pumping for treatment at a
publicly owned treatment works.
Any discharge of stormwater from the Site into State surface waters would be managed
for pollutants and volumes under the existing SWPPP and MPDES General Permit for
Industrial Activities (No. MTR 00358) issued by the Montana Water Quality Bureau (see
Section 2.3.4). A discharge of stormwater from the Site could have a minor impact on
downstream water resources. Under normal operating conditions, if no discharge of
stormwater occurs, no impact to surface water is expected due to the Proposed Action.
Periodic inspections by DEQ would evaluate the Site’s run-on and runoff controls (see
Section 2.3.4), as well as ensuring required setbacks are met. Minimum requirements
for run on controls, run-off controls, setbacks, and water quality standards regarding
surface water are established in ARM by DEQ’s Water Quality Bureau and are addressed
in the application and SWPP.
Figure 10: Surface Water Resources
(flow direction arrows in blue, Site outlined in red)
Source: ESRI and USGS
3.3.6 Groundwater
Under the No Action Alternative and the Proposed Action, minor to moderate impacts
could be expected.
Groundwater monitoring and sampling activities began at the active Logan Landfill in
1990, just prior to the initiation of Subtitle D requirements. Since then, groundwater
Class II Logan Landfill Expansion Project 57 Draft Environmental Assessment
monitoring has been conducted semi-annually in accordance with ARM 17.50.1306,
Detection Monitoring Program (Detection Monitoring). Detection Monitoring requires
that the District determine if there is a statistically significant increase over background
levels at the designated downgradient (point-of compliance or RPOC) groundwater
monitoring wells. All groundwater monitoring and reporting follow the SWP approved
Logan Landfill Sampling and Analysis Plan, Groundwater Monitoring (GWE, 2016).
Since the inception of groundwater monitoring in 1990, low levels of volatile organic
compounds (VOCs) have been detected and reported in downgradient monitoring wells.
In 2000, a Corrective Measures Assessment (CMA) was conducted for the existing Logan
Landfill and presented to DEQ in the report titled Logan Landfill, Assessment of
Additional Corrective Measures, Gallatin County, Montana, August 2006 (GWE, 2006).
The groundwater monitoring and reporting approach for the active Logan Landfill is
intended to satisfy the substantive intent of Detection Monitoring relying upon a
focused set of indicator parameters (pH, specific conductance, chloride, sulfate, and
nitrate-nitrite), while also providing ongoing VOC data to support the CMA process
(GWE, 2021). As such, the current monitoring and reporting approach for the active
landfill is a combination of both detection and assessment phase data evaluations.
The existing groundwater monitoring well network is comprised of 14 wells (Logan
Wells) (Figure 11). The locations of the Logan Wells and public production wells listed by
the MBMG’s Ground Water Information Center (GWIC) appear as Figure 10. In general,
subsurface materials encountered during drilling and installation of the Logan Wells soil
boring logs describing them as highly variable alternating unconsolidated to semi-
consolidated zones comprised of fine sands, silty sands, sandstones, siltstones with
interbedded clays, occasional limestones and wet to saturated zones consisting of fine to
coarse sands and gravels. Heavy gravels are reported to exist suggesting a confining
layer at depths of 166 to 175 feet bgs in well LMW-3, which is located near the
northwest perimeter (Figure 11). However, the lateral extent of the confining layer is
unknown, suggesting that it pinches out or maybe faulting has occurred in the past by
forces responsible for the creation of the Willow Creek fault described by Vuke (2002
and 2007).
Groundwater flow direction is generally to the north-northwest. Groundwater wells
located along the north perimeter of the active Logan Landfill show a groundwater flow
direction generally to the north at a steeper gradient, which is consistent with data
collected, and fits with the conceptual model of the landfill location’s relative flow or
discharge toward the Gallatin River alluvial groundwater system to the north (Figure 11).
Groundwater flow velocities typically range from 0.5 to 2 feet/day, with higher velocities
seen to the northeast area near spring/seeps. As described in the 2018 annual report
(Great West), the spring levels are relatively ‘low water’ whereas the fall levels are ‘high
water’ period. This phenomenon is inverse of a typical shallow surface water or alluvial
groundwater systems with rapid response to spring recharge, and thus suggests that
recharge to the Logan groundwater system is relatively distant from the landfill itself and
not derived from localized rapid infiltration of excess precipitation or surface runoff.
Given these characteristics in the site hydrography, it is believed that groundwater
recharge could be attributed to a more distant regional groundwater source, and/or
Class II Logan Landfill Expansion Project 58 Draft Environmental Assessment
possible groundwater recharge from a relatively deep geothermal source(s) or both
(GWE, 2018).
The Proposed Action would allow the development of a multi-unit Class II landfill facility.
There exists lateral continuity of the semi-consolidated, largely alluvial, older Tertiary
geologic strata beneath the Site and the area beneath the active Logan Landfill.
Groundwater investigations and monitoring at the active Logan Landfill has validated the
complexity of these strata and variations in both the level and extent of near-surface
saturated zones.
The landfill’s bottom liner system (see Section 2.3.1.3) would mitigate against potential
vertical migration of leachate into the uppermost groundwater aquifer. However, there
is potential for minor to moderate long-term impacts (potentially up to or exceeding
Facility Life) to result due to the Site’s proximity to the active Logan Landfill. Laterally
connected permeability zones could allow migration of groundwater and landfill gas
(LFG) between the contiguous existing Class II cells established at the active Logan
Landfill and active cells described in the Proposed Action. See Section 3.4 for a
discussion of potential cumulative affects to groundwater in the uppermost aquifer
beneath the Site due to contamination currently released into the subsurface at the
active Logan Landfill. Geologic maps (Vuke 2002) show Willow Creek Fault system
cutting northeast through the Site area which could influence groundwater occurrences
and offsets.
Class II Logan Landfill Expansion Project 59 Draft Environmental Assessment
Figure 11: Groundwater Production Well Locations and Flow Directions
(blue arrows show direction, GWIC wells in blue circles, 1-mile radius yellow shaded circle, Active Logan Landfill in green; Site in red)
Source: ESRI/ArcGIS and GWIC/MBMG (NOT TO SCALE)
Class II Logan Landfill Expansion Project 60 Draft Environmental Assessment
Figure 12: Groundwater Monitoring Well Locations
(blue circles show well locations and groundwater elevations (amsl), flow directions with blue arrows)
(NOT TO SCALE)
Class II Logan Landfill Expansion Project 61 Draft Environmental Assessment
3.3.7 Soils and Vegetation
Under the No Action Alternative, no impacts are expected. The active Logan Landfill
would close in 2025. Closure and post-closure activities would commence at this time
(see Sections 2.3.6 and 2.3.7). The land would be restored and revegetated to resemble
the surrounding area. Soils would be improved because of revegetation. Erosion would
be mitigated due to native grasses being established and soil health would be enhanced.
No expansion of landfilling activities would occur.
The impact of the Proposed Action to soils and vegetation would be minor.
The US Department of Agriculture (USDA) Natural Resources Conservation Service’s
(NRCS) National Cooperative Soil Survey databases were accessed for information about
the shallow subsurface soils at the Site and surrounding area (Figure 13 and Table 5).
Class II Logan Landfill Expansion Project 62 Draft Environmental Assessment
Figure 13: Soil Resource Map
(Soil unit with delineation in orange, approximate Site in red, Section 6 in green)
.
Source: USDA, Natural Resources Conservation Service (NRCS), 2021 (NOT TO SCALE)
Class II Logan Landfill Expansion Project 63 Draft Environmental Assessment
Table 6: USDA-NRCS, Custom Soil Resource Report, 2021
The US Department of Agriculture (USDA) Natural Resources Conservation Service’s
(NRCS) National Cooperative Soil Survey databases were accessed for information about
the shallow subsurface soils at the Site and surrounding
Site soils are from the Chinook and Kalstead loam classes. The ratings shown in Table 5
are based on the soil properties that affect trafficability and the risk of pollution which
could result from the Proposed Action. "Not limited" indicates that a soil type has
characteristics which are favorable for the specified use. Good performance and low
maintenance can be expected. "Somewhat limited" indicates that a soil type has
characteristics which are moderately favorable for the specified use. "Very limited"
indicates that a soil type has one or more characteristics which are unfavorable for the
specified use (NRCS, 2021).
The Site is currently covered by native grasses. The MNHP online databases were also
accessed for listed plant species in the Township 1 North, Range 3 East study area
(MNHP, 2021). Two species of concern with GRank 5 were listed and are not included in
this assessment. No impact on plant species of concern is anticipated to result from the
Proposed Action.
The Proposed Action would remove surface soils to allow landfilling of solid waste.
Removed soils would be stockpiled onsite for use as cover. The Site’s final cover would
consist of a one-foot-thick layer of native sand, a two-foot layer of select native silt
material, and a one-foot-thick layer of native sand and topsoil augmented with
compost. Topsoil would be fertilized and seeded to provide a vegetated surface cover.
Upon closure of the Site, it would be used as range land. Soil removal, and cell and road
construction activities would occur near and on the Active Cell for the Cell Life over the
span of the Facility Life. Soil removal activities and ground disturbances may result in
the potential of noxious weed growth at the Site. Any approval of weed plans or
mitigation would fall to Gallatin County.
MAP UNIT
SYMBOL
MAP UNIT NAME SOIL RATING
38B Chinook fine sandy loam, 4 to 8 percent slopes Somewhat limited
438D Chinook-Kalstead sandy loams, 8 to 15 percent slopes Somewhat limited
35C Kalstead sandy loam, 4 to 8 percent slopes Somewhat limited
38C Chinook fine sandy loam, 4 to 8 percent slopes Somewhat limited
Class II Logan Landfill Expansion Project 64 Draft Environmental Assessment
3.3.8 Air Quality
Under the No Action Alternative, no impacts are expected. The active Logan Landfill
would close in 2025. Closure and post-closure activities would commence at this time
(see Sections 2.3.6 and 2.3.7). The land would be revegetated to resemble the
surrounding area. No expansion of landfilling activities would occur. Landfilling
activities would cease, therefore eliminating fugitive dusts due to traffic, fire probability,
and methane generation.
Impacts to Air Quality would be minor due to the Proposed Action.
Air quality impacts would occur near and on the Active Cell for the Cell Life over the
span of the Facility Life.
Fugitive dust from the landfill can be minimized through best management practices
and use of abatement techniques that include applying water and chemical dust
suppressants during construction, excavation, and on roads, storage piles and the active
landfill. Landfill gas emissions would be controlled when required with a GCCS system
when NMOC emissions from the landfill exceed the NSPS Subpart XXX threshold.
Annual air quality impacts from the Proposed Action are not expected to change
significantly from the current Logan Landfill impacts. The impacts would continue
longer with the extended life of the landfill in the Proposed Action. Therefore, DEQ
expects no appreciable change to the air quality impacts to the analysis area should the
Proposed Action be approved.
Air quality impacts for the Proposed Action includes fugitive dust generated from
construction, excavation, vehicle traffic, day-to-day operations, and closure activity.
Landfill gas emissions cause another air quality impact that is generated from the
biological breakdown of waste. Landfill gas is mainly a mixture of methane and carbon
dioxide, but can also include nitrogen dioxide, oxygen, ammonia, sulfides, hydrogen,
and other volatile organic compounds released within each cell of an MSW landfill.
Landfill gas is generated as soon as waste is deposited in the landfill. Gas continues to
be generated through the operation of the landfill and after the landfill is closed, until all
the waste is degraded. Although rare, another source of air quality impact comes from
landfill fires. The District attempts to prevent landfill fires through waste inspections and
proper landfill waste deposits.
Fugitive dust is created from disturbing the ground, moving dirt, and vehicle activity
during construction and excavation activities. Blowing winds increase fugitive dust from
these activities and can pick up additional material from stockpiles and the daily cover
over the waste. If fugitive dust from construction, excavation and placement of cover
material becomes a problem, dust control measures, such as watering the work surfaces
before commencing working shall be initiated. Watering work surfaces is required
during construction activities such as road construction. During closure of the landfill,
more cover material is placed on the waste pile which generates fugitive dust from the
movement of the material and vehicles used to place the cover material. The Logan
Class II Logan Landfill Expansion Project 65 Draft Environmental Assessment
Landfill intends to control dust at the working face of the landfill using the following
measures:
Carefully moving dusty wastes and soils
Promptly covering light, powdery wastes with other wastes
Orienting working face into wind if feasible
Minimizing earthwork activities during windy periods
Applying intermediate cover with compost and vegetative seeding
Spraying woody/straw/mulch cover material
Dirt roads can generate fugitive dust emissions, particularly during dry and windy times.
Dirt can be carried onto paved roads from vehicles leaving dirt roads. Once this dirt
becomes dry on the paved roadway, it may be entrained into the air from vehicles
driving over it and when strong winds occur.
The Two Dog Road access road is paved from the interstate to the main access road into
the landfill and the District has paved the main road from the access road, past the
scales and to the entrance to the existing Logan Landfill. The District plans to expand
this paved road to service the new cells of the Proposed Action. Since the main
entrance is paved to the scales and beyond, there should be no change to the carry-over
of dirt deposited on Two Dog Road from the Proposed Action.
Internal access roads within the landfill parcel would be graveled roads maintained by
landfill staff. These roads are planned to be accessible year-round for access to all
operational areas. Other roads would be dirt roads and would be used strictly for soil
transportation by large equipment and would also be maintained by landfill staff.
Fugitive dust is to be controlled through the following measures:
Gravel surfacing of new roads
Application of water or chemical dust suppressants
Grading fine soils from roads during wet periods
Controlling vehicle speeds
Cleaning dirt from asphalt roads leading to the front entrance after wet periods
The impact of fugitive dust is affected by local meteorological conditions.
Meteorological data is collected by the National Weather Service at the Bozeman
Yellowstone International Airport. This meteorological station is about 14 miles
southeast of the landfill and is in Belgrade, MT. The data as shown in Figure 13, shows
wind in the area generally blows from the southeast. The average wind speed is 5.5
mph with gusts well above 21 mph at times. Temperature and precipitation data from
the nearby the Belgrade Airport from 1981 through 2010. Some landfills request air
quality burn permits which allow for the burning of untreated wood waste that reduces
the volume of material to be landfilled. The District application did not mention plans
for open burning at the Site.
Class II Logan Landfill Expansion Project 66 Draft Environmental Assessment
All facilities are required to comply with applicable Montana air quality requirements.
These include restrictions on particulate matter emissions to not exceed an opacity of
20 percent or more averaged over 6 consecutive minutes, whether from fugitive dust
sources or from combustion sources, per ARM 17.8.304 and ARM 17.8.308. ARM
17.8.308 also requires that facilities take reasonable precautions to control emissions of
airborne particulate matter from the production, handling, and storage of any material
and to apply reasonable precautions to any street, road, or parking lot. As described
above, the District proposes to control fugitive dust by using applications of water
and/or chemical dust suppressant on roadways. Watering of roads is an effective
method for reducing fugitive dust emissions during construction and operations.
Federal Prevention of Significant Deterioration regulations have classified states and
local areas to let state’s plan for local land use. Each classification allows for different
amounts of development and changes to the ambient air quality. Areas designated
Class I are the most restrictive and allow for the least amount of change to the ambient
air. Class II areas can accommodate normal, well-managed industrial growth. Areas
designated as Class I include our national parks, several of the wilderness areas and
certain native American Indian reservations. All other areas in the region are Class II
areas, which includes the location of the existing Logan Landfill and proposed
expansion. The nearest Class I area to the Proposed Action is Yellowstone National Park,
about 55 miles to the south. As described earlier, winds generally blow from the
southeast. Air quality impacts from the Proposed Action would not reach Yellowstone
National Park 55 miles away.
DEQ operates a regulatory monitor at Bozeman High School that monitors particulate
matter of 2.5 microns in diameter and less (PM2.5). This is the nearest monitor to the
landfill and is 20 miles to the southeast. The high school is in downtown Bozeman and
has the monitoring objective of reporting population exposure to PM2.5. Bozeman, and
the landfill meet the current Montana and national ambient air quality standards
(NAAQS)for all regulated pollutants. In 2020, the maximum daily PM2.5 monitored
value was 17 micrograms per cubic meter (µg/m3) and the average was 5.4 µg/m3.
These values are below the PM2.5 annual NAAQS value of 35 µg/m3 and the 24-hour
NAAQs of 12 µg/m3.
Montana has several areas that are designated as nonattainment areas by EPA, which
meaning they have experienced air quality impacts above the NAAQS. Although many
areas have not exceeded the NAAQS in years, they still carry the nonattainment
designation. The nearest nonattainment area is Ronan, MT. Ronan is about 140 miles
northwest of the Proposed Action and is designated ‘nonattainment’ for the particulate
matter of 10 microns or less (PM10) NAAQS. Air quality impacts from the Proposed
Action would not reach the Ronan community given their distance from the landfill.
The ARM 17.8.743 requires a facility to obtain a Montana air quality permit (MAQP)
before constructing a facility that has the potential to emit 25 tons per year (tpy) of a
regulated air pollutant or installing an incinerator, such as a landfill flare from a gas
collection and control system (GCCS). The District currently does not hold an MAQP
Class II Logan Landfill Expansion Project 67 Draft Environmental Assessment
because Logan Landfill does not exceed the emissions threshold limit or operate an
GCCS with a flare.
Title V operating permits are state and federally enforceable and are required for major
sources of air pollution and some area sources of air pollution. At this time, the Logan
Landfill has not met the applicability requirements for an Operating Permit. However,
upon commencement of construction for the Proposed Action, the District identified in
its Class II Solid Waste Management System License Application that the landfill would
be an affected source under the New Source Performance Standards (NSPS) of 40 Code
of Federal Regulations (CFR) Part 60 Subpart XXX because the combined Proposed
Action and existing Logan Landfill design capacity would be equal to or greater than the
qualifying design thresholds for applicability of 2.5 million cubic meters and 2.5 million
metric tons. Subparts XXX requires the installation of a gas collection and control
system (GCCS) if the non-methane organic compound (NMOC) emission rate is 34 metric
tons per year or more. Many, but not all GCCS systems include a flare to achieve the
required combustion efficiency.
Fires are infrequent events at landfills in Montana. If a fire were to occur, the fire would
contribute to poor air quality near the Proposed Action. Since fires at landfills are
infrequent and active measures are used to extinguish the fire, it would be a short-term
impact to air quality.
Landfill fires are typically attributable to the placement of a hot load in the working face.
It is important to note that the different landfill dynamics, characteristics, and
regulations, and the fires that occur in them, require different tactics to extinguish
them. Efforts would vary depending upon the waste characteristics, a surface fire
versus an underground fire, the depth of the fire if it’s an underground fire, and the
fire’s ignition source.
Fires would be handled in a preventive as well as corrective manner. Operators would
inspect for hot loads. Hot loads would be isolated and extinguished before they are
placed in the landfill. If a fire were to occur on the active fill, the operators would use
their equipment to push the burning waste away from the active landfill if they can do
so safely. Once the waste is isolated, landfill operators and equipment would extinguish
the fire. In the event of a larger or more persistent fire, the local fire department would
be summoned. In the event of a larger fire, the landfill would notify the DEQ and the
landfill engineering consultant.
Class II Logan Landfill Expansion Project 68 Draft Environmental Assessment
Figure 14: Wind Rose for Bozeman Area
Source: DEQ’s Air Quality Bureau; National Weather Service
Class II Logan Landfill Expansion Project 69 Draft Environmental Assessment
Table 7: Precipitation and Temperature Information in Belgrade, Montana
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual
Mean Max.
Temperature
(F)
35.9 39.5 49.6 59.2 68.3 77.2 87.8 87.2 75.1 61.2 44.9 33.3 60.1
Mean
Temperature
(F)
23.5 27.2 36.5 45.1 53.6 61.6 69.4 68.2 57.8 45.9 32.2 21.3 45.3
Mean Min.
Temperature
(F)
11.1 14.9 23.4 31 39 45.9 51.1 49.2 40.5 30.6 19.5 9.3 30.5
Mean
Precipitation
(in.)
0.51 0.45 0.94 1.6 2.46 2.46 1.12 1.08 1.1 1.1 0.77 0.51 14.1
Source: Western Regional Climate Center
3.3.9 Industrial, Commercial, and Agricultural Activities
Under the No Action Alternative, no additional impacts are expected. The active Logan
Landfill would close in 2025. Closure and post-closure activities would commence at this
time (see Sections 2.3.6 and 2.3.7). The land would be revegetated to resemble the
surrounding area. No expansion of landfilling activities would occur.
No impacts to industrial, commercial, or agricultural activities are expected due to the
Proposed Action.
There are no industrial, commercial, or agricultural activities taking place at the Site.
The Proposed Action would not impact any existing agricultural or commercial activities
located near the Site. The active Logan Landfill would be closed simultaneous to
implementation of the Proposed Action. Current staff would assume operations at the
Site once construction is complete.
3.3.10 Human Health and Safety
Under the No Action Alternative, no additional impacts are expected. The active Logan
Landfill would close in 2025. Closure and post-closure activities would commence at this
time (see Sections 2.3.6 and 2.3.7). No expansion of landfilling activities would occur.
Landfilling would cease at this location and Gallatin County would have to find another
location for waste disposal.
No impacts to human health and safety are expected due to the Proposed Action.
Mitigation for resources including surface water, groundwater, soils and vegetation, and
all resources noted in Section 3.3 would alleviate potential to human health and safety.
Class II Logan Landfill Expansion Project 70 Draft Environmental Assessment
Additionally, no hazardous waste sites are within Section 6, Township 1 North, Range 3
East, so construction of the Site wouldn’t further any potential exposure.
The District would implement a safety program for staff to ensure protection from
damage or injury. Such items in the safety program would include, but are not limited
to, the following:
Accident prevention training
First aid and CPR/AED training
Access to First Aid kits
Access to a list of emergency numbers
3.3.11 Recreational and Wilderness Activities
Under the No Action Alternative, no additional impacts are expected. The active Logan
Landfill would close in 2025. Closure and post-closure activities would commence at this
time (see Sections 2.3.6 and 2.3.7). The land would be revegetated to resemble the
surrounding area. No expansion of landfilling activities would occur.
No impacts to recreation are expected due to the Proposed Action.
The Site is owned by Gallatin County. The Site is not currently allotted for recreational
activities and does not contain any designated wilderness areas. The Proposed Action
would prevent future recreational activities from occurring at the Site but would not
hinder current recreational opportunities in the area. All landfilling activities would be
limited to the Site and would not exceed the Facility Life (see Section 1.1 and Table 1).
3.3.12 Population and Housing
Under the No Action Alternative, no additional impacts are expected. The active Logan
Landfill would close in 2025. Closure and post-closure activities would commence at this
time (see Sections 2.3.6 and 2.3.7). The land would be revegetated to resemble the
surrounding area. No expansion of landfilling activities would occur. The Site could be
utilized for potential future development or construction of new homes.
Minor impacts to population and housing are expected due to the Proposed Action.
The Proposed Action would accommodate for the increasing population of Gallatin
County by providing a waste management option for the area. The Site wouldn’t
impede on population growth, but it would impede on further development or
construction of new homes at the Site.
3.3.13 Property Values
In the past 30 years, various research has been done on the effects of landfills on
property values. These studies have yielded inconsistent results. Typically, hedonic
regression models have been used to try to isolate the effects of landfills on property
values holding all other variables constant. Surveys have also been used in studies.
Some studies show statistically significant adverse effects of landfills on property values.
Class II Logan Landfill Expansion Project 71 Draft Environmental Assessment
Generally, larger effects on property values are seen from larger landfills, less modern
landfills, landfills that accept hazardous waste or pose health risks, areas with negative
perceptions of landfills, landfills that are more visible, and higher end properties.
However, even these effects are not robust across all studies and not all these effects
were studied in every study. A study by Bouvier, RA., et al. entitled, "The Effect of
Landfills on Rural Residential Property Values: Some Empirical Evidence," does not
provide grounds for broad generalization about the effect of rural landfills on property
values (2000, The Journal of Regional Analysis & Policy). It finds that in five of the
landfills studied (in rural to semi-rural areas), no statistically significant evidence of an
effect from landfills was found. In the remaining case, evidence of an effect was found,
indicating that houses near this landfill suffered an average loss of about six percent in
value. This significant case was a landfill that was unlined and uncapped and is on EPA's
"potential health risk" list. Bouvier suggests that each landfill be studied on a case-by-
case basis. A study by C.P. Cartee, entitled "A Review of Sanitary Landfill Impacts on
Property Values," found that while it generally is believed that landfills negatively impact
property values, in some cases, the development of a sanitary landfill may enhance a
property's value (1989, Real Estate Appraiser and Analyst). It finds that the introduction
of new roads, utilities, and drainage may stimulate development and lead to increases in
land values.
The study area encompasses the Site and abutting properties.
Any impacts to property values are expected to be minor due to the Proposed Action.
The surrounding properties are agricultural in nature. The active Logan Landfill would
close prior to commencing landfilling activities at the Site. The Proposed Action will not
increase waste acceptance. All active landfilling would be limited to the Cell Life on the
Active Cell, not to exceed Facility Life (see Section 1.1 and Table 1).
3.3.14 Traffic and Utilities
Under the No Action Alternative, no additional impacts are expected. The active Logan
Landfill would close in 2025. Closure and post-closure activities would commence at this
time (see Sections 2.3.6 and 2.3.7). The land would be revegetated to resemble the
surrounding area. No expansion of landfilling activities would occur, and Gallatin County
would have to find another location for waste disposal. Landfilling activities would cease
at this location. Traffic due to landfilling activities would be eliminated.
Minor impacts to traffic and utilities are expected due to the Proposed Action.
Traffic would continue to access the Site via Two Dog Road. Existing public traffic
patterns, bridges, or culverts would not be impacted. No additional traffic is anticipated
due to the Proposed Action. The only traffic patterns that would change would be
within the Site. Traffic impacts would occur for the Facility Life (see Section 1.1 and
Table 1).
Class II Logan Landfill Expansion Project 72 Draft Environmental Assessment
3.3.15 Aesthetics
Under the No Action Alternative, no additional impacts are expected. The active Logan
Landfill would close in 2025. Closure and post-closure activities would commence at this
time (see Sections 2.3.6 and 2.3.7). The land would be revegetated to resemble the
surrounding area. No expansion of landfilling activities would occur, and Gallatin County
would have to find another location for waste disposal.
Under the No Action Alternative, no impacts are expected.
Minor impacts to aesthetics are expected due to the Proposed Action.
The Site would be immediately adjacent to the active Logan Landfill. Visual impacts
would be limited to vehicular traffic travelling eastbound on I-90 and looking south
toward the Site. The current landscape is not unique as large expanses of similar terrain
and land cover exist in all directions. Visual impacts of landfilling activities would be
temporary as landfilling would occur in phases. As the cells are filled and capped, they
would be closed, revegetated, and would mimic the surrounding grassland. Before
construction of the Site, District staff would plant trees along the north edge of the
property to further obstruct public view of the Site.
As noted in Section 2.3.9.11, litter control methods include berms, litter fences, and
portable litter screens. Staff would use various litter collection equipment to manage
and properly dispose of litter.
The Site would be located near the interstate and away from neighbors. Department of
Labor and Industries imposes noise limitations for employees’ safety from hearing loss.
Activities to take place at the Site would resemble current operations occurring at the
active Logan Landfill and other agricultural activities in the area. A slight increase in
noise would be anticipated during construction of the Site. Operations at the active
Logan Landfill would cease once the Site becomes operational. Movement into the Site
would increase the buffer zone between operations and the surrounding affected area.
The following measures would be implemented at the Site to minimize noise:
Maintain proper mufflers on vehicles and operating equipment
Periodic monitoring of equipment decibel levels of each machine
Provide ear protection devices for operators
Provide annual hearing tests and training per the Hearing Conservation Program
Maintain perimeter buffer zones
Limit operating hours
Potential odors would be generated from the Class II Unit and the composting area.
Daily cover would greatly reduce odors from the Class II Unit. The District would use
various odor control methods in the compost area, including use of a biofilter,
maintaining proper moisture contents, and monitoring temperatures to assure the
composting process is upheld.
Class II Logan Landfill Expansion Project 73 Draft Environmental Assessment
3.3.16 Demands for Government Services
Under the No Action Alternative, minor impacts are expected. The active Logan Landfill
would close in 2025. Closure and post-closure activities would commence at this time
(see Sections 2.3.6 and 2.3.7). The land would be revegetated to resemble the
surrounding area. No expansion of landfilling activities would occur. Gallatin County
would have to find another location for waste disposal. If a new location is proposed,
DEQ would conduct environmental review and analysis on the new location.
Minor impacts to demands for government services are expected due to the Proposed
Action.
DEQ currently conducts inspections at the active Logan Landfill. If approved, DEQ would
inspect the Site concurrently with the active Logan Landfill, which is anticipated to close
in no more than six years. Once the active Logan Landfill closes, operations and
inspections would continue at the Site. The Gallatin County sanitarian would conduct
periodic inspections as needed. District employees would oversee operations.
3.3.17 Cultural Uniqueness and Diversity
Under the No Action Alternative, no additional impacts are expected. The active Logan
Landfill would close in 2025. Closure and post-closure activities would commence at this
time (see Sections 2.3.6 and 2.3.7). The land would be revegetated to resemble the
surrounding area. No expansion of landfilling activities would occur. No previously
recorded sites are present within the area.
No impacts to cultural uniqueness and diversity are expected due to the Proposed
Action.
The SHPO conducted a resource file search for Section 6, Township 1 North, and Range 3
East, which indicated there have been no previously recorded sites within the area.
Based upon ground disturbances in Section 6, Township 1 North, and Range 3 East
associated with active Logan Landfill operations, agricultural activities, and residential
development in the area, SHPO determined that there is a low likelihood that cultural
properties would be impacted.
3.3.18 Socioeconomics
Under the No Action Alternative, minor impacts are expected. The active Logan Landfill
would close in 2025. Closure and post-closure activities would commence at this time
(see Sections 2.3.6 and 2.3.7). Closure and post-closure activities would solicit a minor
increase in temporary jobs. This would result in a minor and temporary beneficial
impact to the local tax base. No expansion of landfilling activities would occur. Gallatin
County would have to find another location for waste disposal. Gallatin County
expenditures to acquire a new landfill location would include, but are not limited to:
Engineering and consulting costs
Application fees
Construction costs
Class II Logan Landfill Expansion Project 74 Draft Environmental Assessment
Equipment costs
Staff costs
Impacts to socioeconomics are expected to be minor due to the Proposed Action.
During construction activities, there would be a minor increase in temporary jobs. This
would result in a minor beneficial impact to the local tax base. Staff currently employed
would assume responsibilities at the Site once it is fully operational. Revenue generated
from the Proposed Action would resemble current revenue from the active Logan
Landfill.
3.4. Cumulative Impacts
Cumulative impacts are the collective impacts on the human environment when a specific
action is considered in conjunction with other past, present, and future actions by location and
type. Cumulative impact analysis under MEPA requires an agency to consider all past and
present state and non-state actions. Related future actions must also be considered when these
actions are under concurrent consideration by any state agency through pre-impact statement
studies, separate impact statement evaluation, or permit processing procedures. Cumulative
impact analyses help to determine whether an action, combined with other activities, would
result in significant impacts. The only potential cumulative impacts noted would be to wildlife,
groundwater, and air quality.
A minor cumulative impact to wildlife and habitats is expected due to the Proposed Action.
Wildlife avoidance of the Site would occur because of the Proposed Action in conjunction with
the active Logan Landfill. The active Logan Landfill will be closed and capped in approximately
six years. Because of the nature of the Proposed Action and its conjunction with the active
Logan Landfill and its closure, cumulative impacts are expected to be minor.
The Proposed Action could have minor to moderate cumulative impacts to groundwater.
Narrative regarding groundwater is described in Section 3.2.6 of this EA. Diffusion of volatile
organic compounds through the composite liner would develop over time as widely shown by
landfill gas monitoring of landfills throughout the U.S. The Proposed Action groundwater and
methane monitoring networks would partly be an extension of the groundwater detection
monitoring network of the active Logan Landfill--- now circumscribing the outermost perimeter
of the two combined onsite Class II Units--- intended to detect contaminant releases beyond the
combined facility Relevant Point of Compliance (RPOC, not more than 150 meters or 500 feet
from the margin of each unit). However, the Class II Unit, with a coulee on its western flank, is
separated more than 500 feet from the active Logan Landfill Class II units where the uppermost
groundwater contains dissolved contaminate and, in part, landfill gas derived plumes. Thus, any
groundwater wells located at the flanks of one unit would essentially define the RPOC for the
other unit, so that neither unit may contaminate the subsurface below the other one.
Given the multi-unit Logan Class II Landfill facility that would result from approval of the
Proposed Action, two wells would be initially installed, at the margin of the active Class II Unit,
to investigate and monitor the potential for lateral migration of dissolved contamination and/or
contaminated landfill gas into the interunit subsurface between the active and proposed Class II
Units. The interunit lateral continuity of the uppermost aquifer for the Proposed Action with
Class II Logan Landfill Expansion Project 75 Draft Environmental Assessment
the deeper uppermost aquifer for the existing Logan Landfill has not yet been demonstrated.
Any detection of the migration of either contaminant plume into the interunit subsurface zone,
located between the active Logan Landfill and the Site, could potentially allow contamination of
the groundwater monitoring wells in the monitoring network of the Proposed Action, and must
be further investigated at that time.
Minor cumulative impacts to air quality may be expected due to the Proposed Action.
Construction activities would be occurring simultaneous to operations at the active Logan
Landfill. Further, emissions from the active Logan Landfill after closure in conjunction with
operations at the Site could impose a minor cumulative impact at the Site.
According to Gallatin County, no other projects are anticipated within the vicinity of the active
Class II Unit. Landfilling activities would continue in the currently active Class II Unit for
approximately six years, or until landfill capacity is reached. Potential impacts on the
environment from the Logan Landfill after the transfer of operations to the proposed Class II
Unit would likely at least resemble current conditions resulting from the active Logan Landfill
Class II unit. The Proposed Action is designed to accommodate the growing demand anticipated
for management of Group II, III and IV wastes in Gallatin County and the surrounding service
area. As the population grows, demands on the landfill may increase if reduction in waste
generation is not possible. Besides a visible increase in size of the landfill from I-90, the
resulting Logan Landfill operations may cause a minor increase in dust and noise at the Class II
Unit that combines with other ongoing local increases in human activities with population
increase. Dust would be mitigated according to the approved O&M plan.
3.5. Unavoidable Impacts
Residual impacts from the Proposed Action would include the loss of developed soil and
vegetation from approximately 317.8 acres of the 543.8-acre Site for use on roads, cover soil,
and construction of berms and other landfill features. Topsoil would be placed as part of the
cap construction during final closure of the active Logan Landfill (see Section 2.3.6 and 2.3.7).
Topsoil would be reseeded with native vegetation. Some sediment control structures would
remain, and the capped landfill units would appear as manmade features across the landscape.
Post-closure land use would be restricted to animal grazing. No structures that require the
placement of footings or foundations are allowed over the closed landfill units. Any disturbance
of the closed landfill final cover for construction of any structure would have to be approved in
advance by DEQ.
Plant communities dominated by native plants would be replaced by reclaimed plant
communities on the Site. Noxious weeds would increase from the soil disturbance, but weeds
would be treated to ensure revegetation by native local grasses occurs as required by the
Gallatin County’s weed control program. The disturbed areas would be reclaimed, reseeded,
revegetated, and a program implemented to inventory and treat noxious weeds would be
implemented.
Class II Logan Landfill Expansion Project 76 Draft Environmental Assessment
4. REGULATORY RESTRICTIONS
MEPA requires state agencies to prepare a Regulatory Restriction Analysis whenever the agency prepares
an EA or an EIS for a proposed action on private property that appears to restrict the use of the private
property. If the agency has discretion on the implementation of state of federal laws, the agency must
include: a description of the impact of the restriction on the use of private property; an analysis of
reasonable alternatives that reduce, minimize, or eliminate the restriction on the use of private property
while satisfying state and federal laws; and the agency’s rational for decisions concerning the regulatory
restriction analysis (75-1-201(1)(b)(iv)(D), MCA).
The proposed expansion of the Logan Landfill is located on public lands owned by Gallatin County. The
alternatives being evaluated would neither include the use of private property nor result in effects on
private property. As such, a regulatory restrictions analysis is not required.
5. FINDINGS
The depth and breadth of the project are typical of a landfill. DEQ’s analysis of potential impacts from the
Proposed Action are appropriate for the complexity, environmental sensitivity, degree of uncertainty, and
mitigating factors provided by the Rules for each resource considered.
To determine whether preparation of an EIS is necessary, DEQ is required to determine the significance of
impacts associated with the Proposed Action. The criteria that DEQ is required to consider in making this
determination are set forth in ARM 17.4.608(1)(a) through (g):
(a) The severity, duration, geographic extent, and frequency of occurrence of the impact.
(b) The probability that the impact will occur if the Proposed Action occurs; or conversely,
reasonable assurance in keeping with the potential severity of an impact that the impact will not occur.
(c) Growth-inducing or growth-inhibiting aspects of the impact, including the relationship or
contribution of the impact to cumulative impacts.
(d) The quantity and quality of each environmental resource or value that would be affected,
including the uniqueness and fragility of those resources or values.
(e) The importance to the state and to society of each environmental resource or value that would
be affected.
(f) Any precedent that would be set because of an impact of the Proposed Action that would
commit DEQ to future actions with significant impacts or a decision in principle about such future
actions.
(g) Potential conflict with local, state, or federal laws, requirements, or formal plans.
The Site’s location is described in Section 1.4 of this EA. The Site would partly occupy the 543.8-acres of
District-owned property approximately two miles southeast of the town of Logan in Gallatin County
(Figures 1 and 2). The Site is accessed via Two Dog Road from the Logan exit off I-90. The Site would
occupy portions of Section 6, Township 1 North, Range 3 East, excluding parts of the northeast and
northwest corners. The Proposed Action may occur for up to 162 years for the disposal of Group II and
Class II Logan Landfill Expansion Project 77 Draft Environmental Assessment
Group IV solid wastes, although the active life of the proposed facility could be much shorter depending on
population growth and rate of waste acceptance. The facility is not within sage grouse core habitat, general
habitat, or connectivity area. It has no special agricultural designation. Operations would not adversely
affect any threatened or endangered species.
Impact to soils and vegetation at the Site would be minor. The Proposed Action would remove surface soils
to allow landfilling of solid waste. Removed soils would be stockpiled onsite for use as cover. The Site’s
final cover would consist of a one-foot-thick layer of native sand, a two-foot layer of select native silt
material, and a one-foot-thick layer of native sand plus 6-in topsoil augmented with compost. Topsoil
would be fertilized and seeded to provide a vegetated surface cover. Upon closure of the Site, it would be
used as range land.
The Proposed Action may have a minor impact on surface water resources. Landfill designs, including
drainage ditches and detention ponds, should control stormwater and prevent surface water
contamination, as described in Sections 2.3.4 and 3.3.5 of this EA. The controlled release of stormwater
from any onsite stormwater detention ponds would not contain suspended sediment loads that naturally
impacts coulees during heavy precipitation or snowmelt events. Therefore, in the event of a controlled
stormwater release, the quality of the stormwater could be better than the stormwater that would
naturally flow from the Class II Unit or ADU.
Impact to groundwater at the Site could be minor to moderate. Narrative regarding ground water is
described in Section 3.2.6 of this EA. There exists lateral continuity of the semi-consolidated, largely
alluvial, older Tertiary geologic strata beneath the Site and the area beneath the active Logan Landfill.
Groundwater investigations and monitoring at the active Logan Landfill has validated the complexity of
these strata and variations in both the level and extent of near-surface saturated zones. Therefore, there
also exists potential for laterally connected porosity and/or permeability zones via fingers that could allow
migration of groundwater and landfill gas (LFG) within the subsurface between the contiguous Class II units
already established at the active Logan Landfill and the proposed Class II Unit. Geologic maps (Vuke 2002)
show Willow Creek Fault system cutting northeast through the Site area which could influence
groundwater occurrences and offsets.
DEQ has not identified any growth-inducing or growth-inhibiting aspects of the Proposed Action. DEQ’s
approval is not a decision regarding, in principle, any future actions that DEQ may perform. Furthermore,
approval doesn’t set any precedent or commit DEQ to any future action. Finally, the Proposed Action does
not conflict with any local, state, or federal laws, requirements, or formal plans.
The Proposed Action meets the requirements of the SWMA and associated rules. Based on the
consideration of all criteria outlined in ARM 17.4.608, adherence to the solid waste, water, and air quality
regulations, along with the District’s approved O&M plan, will mitigate the potential for harmful releases,
and impacts to human health and the environment due to the Proposed Action. Therefore, an EIS is not
required.
6. OTHER GROUPS OR AGENCIES CONTACTED OR CONTRIBUTING TO THE EA
Montana Natural Heritage Program
State of Montana Historic Preservation Office
Arrowhead Engineering, Inc.
CDM Federal
Class II Logan Landfill Expansion Project 78 Draft Environmental Assessment
Volpe National Transportation Center
U.S. Environmental Protection Agency
U.S. Geological Survey
Montana Bureau of Mines and Geology
U.S. Department of Agriculture - Natural Resource Conservation Service
Montana Department of Transportation
Gallatin County Environmental Health
7. AUTHORS
EA prepared by:
Tim Stepp: Solid Waste Program Engineer
Fred Collins: Solid Waste Environmental Science Specialist
Mike Eder: Solid Waste Hydrologist
Andy Ulven: Solid Waste Environmental Science Specialist
Julie Ackerlund: Air Quality Permitter
Brandon McGuire: Atmospheric Science Specialist
Julie Merkel: Air Quality Permitting Services Section Supervisor
Date: January 5, 2022
8. REFERENCES
Logan Landfill Expansion---Class II Solid Waste Management System: License Application, Solid Waste
License #158, September 2020, and NOD response May 2021
Montana Department of Environmental Quality (MDEQ), 2010. Administrative Rules of Montana (ARM)
Title 17, Chapter 50, Solid Waste Management,
https://rules.mt.gov/gateway/chapterhome.asp?chapter=17%2E50
Montana Tech of the University of Montana, MBMG, Ground Water Information Center, July 26, 2019,
http://mbmggwic.mtech.edu/
USDA NRCS, Web Soil Survey, 2021, http://websoilsurvey.nrcs.usda.gov/app/HomePage.htm
USGS Professional Paper 231, Physiography and Geology of Western Montana and Adjacent Areas, W. C.
Alden, 1953
Great West, 2014. Hydrogeological and Soils Investigation, Gallatin County Logan Landfill.
Great West, 2018. Gallatin Solid Waste Management District – Logan Landfill – Class II Landfill Expansion,
Phase 4 Alternative Liner Demonstration (License #158).
Great West, 2006. Gallatin Solid Waste Management District – Logan Landfill – Class II Landfill Expansion,
Phase 3 Alternative Liner Demonstration and HELP Model (License #158).
Vuke et. al., 2007. Geologic Map of Montana, MBMG, Map 62.
Class II Logan Landfill Expansion Project 79 Draft Environmental Assessment
Vuke, S.M., et al., Preliminary Geologic Map of The Bozeman 30’ X 60’ Quadrangle Southwestern Montana,
Montana Bureau of Mines and Geology Open File Report MBMG 469, 2002
http://www.mbmg.mtech.edu/pdf_100k/bozeman-text.pdf
Hackett et. al, 1960. Geology and Ground-Water Resources of the Gallatin Valley, Gallatin County,
Geological Survey Water-Supply Paper 1482.
United States Fish & Wildlife Service, 2021. National Wetlands Inventory (Map) of Study Area. Web search
National Wetlands Inventory Map via NMI Web Viewer.
MBMG, Open File Report No. 469.
Fetter, 1984. Applied Hydrogeology, Third Edition.
MBMG, Web Mapping Application https://mbmg.mtech.edu/main.asp
Anderson, C.J, Stratigraphic Framework and Provenance Of The Lower Belt (Newland Formation), Belt
Supergroup, Helena Embayment, Central Montana, M.S. Thesis, Montana State University, 2017,
https://scholarworks.montana.edu/xmlui/bitstream/handle/1/15326/AndersonC1217.pdf?sequ
ence=6&isAllowed=y
Alt, David D., and Donald Hyndman, Roadside Geology of Montana, Mountain Press Publishing, 1986
Walker, J.D., Geissman, J.W., Bowring, S.A., and Babcock, L.E., compilers, 2018, Geologic Time Scale v. 5.0:
Geological Society of America, CTS005R3C, 2018, https://doi.org/10.1130/2018
Montana Tech of the University of Montana, Montana Bureau of Mines and Geology (MBMG), Ground
Water Information Center, http://mbmggwic.mtech.edu/
United States Department of the Interior, Geological Survey Professional Paper 174, Physiography and
Glacial Geology of Eastern Montana and Adjacent Areas, William C. Alden, 1932
United States Fish & Wildlife Service, Environmental Conservation Online System, 2021
https://ecos.fws.gov/ecp/report/species-listings-by-current-range-county?fips=30031
Montana Natural Heritage Program, 2021, http://mtnhp.org/default.asp
Montana Cadastral, http://svc.mt.gov/msl/mtcadastral
Manhattan, Montana Weather Averages Summary
https://www.weatherbase.com/weather/weather.php3?s=226042&cityname=Manhattan-
Montana-United-States-of-America
Average Pan Evaporation Data by State
https://wrcc.dri.edu/Climate/comp_table_show.php?stype=pan_evap_avg
Montana State University Extension Service, https://www.msuextension.org/