EXECUTIVE SUMMARY

EXECUTIVE SUMMARY

EXECUTIVE SUMMARY

Proposed Action and Purpose and 

Need

The Bureau of Land Management (BLM), an agency of 

the U.S. Department of the Interior (USDOI), 

administers vegetation on approximately 247 million 

acres (public lands) in 17 states in the western U.S., 

including Alaska. Management of vegetation on public 

lands, including habitat enhancement and management 

to reduce the risk of wildfires, is an important function 

of this agency. One of the BLM’s highest priorities is to 

promote ecosystem health, and one of the greatest 

obstacles to achieving this goal is the rapid expansion of 

invasive plants across public lands. If not eradicated or 

managed, invasive plants can jeopardize the health of 

public lands and the activities that occur on them. 

Herbicides are one method employed by the BLM to 

manage these plants.

The BLM is proposing to add the herbicides 

aminopyralid, fluroxypyr, and rimsulfuron to its list of 

approved active ingredients for use on public lands. 

These herbicides have been selected based on their 

effectiveness at controlling invasive plant species and 

their suitability for the BLM’s treatment needs. The new 

herbicides would be integrated into the herbicide 

treatment activities that were assessed in the Vegetation 

Treatments Using Herbicides on Bureau of Land 

Management Land in 17 Western States Programmatic 

Environmental Impact Statement (2007 PEIS). The 

Record of Decision (ROD) for the 2007 PEIS allows the 

BLM to use 18 herbicide active ingredients for a full 

range of vegetation treatments in 17 western states. 

Therefore, the proposed action would increase the 

number of herbicide active ingredients available to the 

BLM from 18 to 21.

Proposed treatments using aminopyralid, fluroxypyr, 

and rimsulfuron would occur on public lands in the 

western U.S., subject to the restrictions on the 

individual label of the associated formulation of each 

active ingredient. Components of site-specific treatment 

programs, including herbicide application methods 

utilized, acres treated, and treatment locations, would be 

determined at the local level and by Congressional 

direction and funding. While the ROD for the 2007

PEIS makes no decisions regarding the number of acres 

that can be treated using herbicides, the maximum 

treatment acreage assumed in the 2007 PEIS—932,000 

acres annually—is being carried over to this action. 

The need for the proposed action is the ongoing spread 

of noxious weeds and other invasive plants, which 

degrade the health of public lands and affect resources 

such as wildlife, native plant communities, threatened 

and endangered species, soil, water, and recreation.

Some invasive vegetation acts as a hazardous fine fuel 

and contributes to the frequency, extent, and severity of 

wildfires. The BLM requires effective tools for control 

of invasive plants in order to prevent their spread into 

non-infested areas, restore desirable vegetation in 

degraded areas, and reduce wildfire risk. In particular, 

the BLM has identified the need for additional herbicide 

active ingredients that: 1) have less environmental and 

human health impacts than some of the currently 

approved herbicides (e.g., picloram); 2) increase options 

for management of invasive annual grasses; and 3) 

address potential herbicide resistance by certain species 

(e.g., kochia, marestail, and pigweed) to active 

ingredients currently used by the BLM.

The purpose of the proposed action is to improve the 

effectiveness of the BLM’s vegetation management

program by allowing herbicide treatments with 

aminopyralid, fluroxypyr, and rimsulfuron. This action, 

by increasing the number of active ingredients, would 

give the BLM increased flexibility and options when 

designing on-the-ground herbicide treatments.

Herbicide Active Ingredients 

Evaluated

The three new herbicides that the BLM proposes to use 

are registered and available for use by the general 

public. Aminopyralid, fluroxypyr, and rimsulfuron have 

been deemed effective in managing target vegetation, 

have minimal effects on the environment and human 

health if used properly, and are registered with the U.S. 

Environmental Protection Agency (USEPA).

All three of the new active ingredients would be used to 

help reduce the spread of noxious weeds and other 

invasive plants to reduce the buildup of hazardous fuels 

and risk of wildfire; reduce the loss of wildlife habitat; 

help stabilize and rehabilitate sites impacted by fire; and 

restore native plant communities.

BLM Vegetation Treatments Three New Herbicides ES-1 January 2016

Final Programmatic EIS
EXECUTIVE SUMMARY

Aminopyralid

Aminopyralid, primarily used for the management of 

broadleaf weeds, is a selective herbicide that is used to 

manage invasive annual, biennial, and perennial 

herbaceous species, along with woody species. Target 

plants include, but are not limited to: Russian

knapweed, musk thistle, spotted knapweed, yellow 

starthistle, Russian thistle, and tansy ragwort. These 

noxious weeds displace native plant species. 

Aminopyralid is registered under the USEPA’s reduced 

risk initiative. It may be used instead of picloram in 

certain situations. Although not currently registered for 

aquatic use, it is likely that aminopyralid will receive an 

aquatic registration in the near future that would allow 

for incidental overspray of this herbicide during 

treatment of vegetation within close proximity to 

wetland and riparian areas.

Fluroxypyr

Fluroxypyr is a selective herbicide that is used to 

manage certain annual and perennial weeds, including 

broadleaf species that are resistant to sulfonylurea 

herbicides, such as annual kochia. It can be used to 

manage invasive plants while maintaining native 

rangeland grass species, and can be tank-mixed with 

other active ingredients to improve its ability to manage 

difficult-to-control weeds such as invasive pricklypear 

cactus. Other weeds targeted by fluroxypyr include 

marestail and black henbane. The use of fluroxypyr can 

reduce the amount of other herbicide products used in 

treatments.

Rimsulfuron

Rimsulfuron is a selective, acetolactate synthaseinhibiting active ingredient that targets, among other 

species, annual grasses such as cheatgrass (downy 

brome) and medusahead rye. Rimsulfuron has been 

observed to be more effective than imazapic in certain 

areas and under certain conditions.

Alternative Proposals

Four program alternatives were developed for and 

evaluated in this PEIS, including the Preferred 

Alternative and the No Action Alternative. These 

alternatives were developed based on the alternatives 

presented in the 2007 PEIS. They address many of the 

concerns that were raised during scoping for the 2007

PEIS, as well as concerns raised during scoping for this 

PEIS. Alternatives were also developed to ensure that 

the BLM complies with federal, tribal, state, and local 

regulations. Under all alternatives, the goals of 

herbicide treatments would continue to be to reduce the 

risk of wildfire and to improve ecosystem health.

Alternative A – Continue Present 

Herbicide Use (No Action Alternative)

Under this alternative, the BLM would continue to treat 

up to 932,000 acres using herbicides annually. Only the 

18 active ingredients approved in the ROD for the 2007

PEIS would be available for use by the BLM in its 

vegetation treatment programs. The most widely used 

herbicides would be clopyralid, glyphosate, imazapic, 

tebuthiuron, and triclopyr. 

Alternative B - Allow for Use of Three 

New Herbicides in 17 Western States 

(Preferred Alternative) 

This alternative would allow the BLM to expand its 

vegetation management program by permitting the use 

of aminopyralid, fluroxypyr, and rimsulfuron, in 

addition to the 18 currently approved active ingredients. 

Therefore, a total of 21 active ingredients would be 

available for use. Herbicide treatments would continue 

to occur on up to 932,000 acres annually. It is estimated 

that aminopyralid would make up 10 percent, 

fluroxypyr would make up 1 percent, and rimsulfuron 

would make up 16 percent of the total herbicide use on 

BLM-administered lands. Use of other herbicides is 

expected to decrease, particularly glyphosate, imazapic, 

and picloram. 

Alternative C - No Aerial Application

of New Herbicides

Alternative C would allow the BLM to expand its 

vegetation management programs to include the use of 

aminopyralid, fluroxypyr, and rimsulfuron; however, 

the three new herbicides could only be applied using 

ground-based methods. Aerial application (by helicopter 

or fixed-wing aircraft) would not be allowed. With the 

addition of three new active ingredients, a total of 21 

active ingredients would be available for use. Herbicide 

treatments would continue to occur on up to 932,000 

acres annually. It is estimated that under Alternative C 

aminopyralid would make up 6 percent, fluroxypyr 

would make up less than 1 percent, and rimsulfuron 

would make up 3 percent of the total projected herbicide 

use on BLM-administered lands. Use of other 

herbicides would decrease—particularly glyphosate and 

BLM Vegetation Treatments Three New Herbicides ES-2 January 2016

Final Programmatic EIS
EXECUTIVE SUMMARY

imazapic—although not as much as under Alternative 

B. 

Alternative D – No Use of New

Acetolactate Synthase-Inhibiting 

Active Ingredients (No Rimsulfuron)

This alternative would allow the BLM to expand its 

vegetation management program to include only the 

two new herbicide active ingredients that do not belong 

to the sulfonylurea, or the acetolactate synthaseinhibiting, group of herbicide active ingredients. 

Aminopyralid and fluroxypyr would be approved for 

use, but rimsulfuron would not. With the addition of 

two new active ingredients, a total of 20 active 

ingredients would be available for use. Herbicide 

treatments would continue to occur on up to 932,000 

acres annually. It is estimated that under Alternative C, 

aminopyralid would make up 10 percent of the total 

projected herbicide use on BLM-administered lands, 

and fluroxypyr would make up 1 percent of the total 

herbicide use. 

Direct and Indirect Impacts

In general, potential direct and indirect adverse impacts 

and benefits would be similar under all of the 

alternatives. Treatment goals would be the same, and 

herbicides would be used on roughly the same land 

area, under all of the alternatives. The small differences 

among the alternatives would pertain to the relative use 

of the various active ingredients and the efficacy of 

treatments based on which active ingredients would be 

available for use. As aminopyralid, fluroxypyr, and 

rimsulfuron are of lower toxicity than some of the 

herbicides currently used by the BLM, toxicological 

risks associated with herbicide treatments would be 

lower under the action alternatives, particularly 

Alternatives B and C. 

Impacts from herbicide treatments on local and regional 

air quality would be minor for all alternatives. Air 

quality emissions are largely based on acres treated, 

which would be the same under all the alternatives 

(including the No Action Alternative). Emissions of 

criteria pollutants would occur at levels that correspond 

to minor, short-term impacts to regional air quality. 

None of the treatments would result in emissions that 

exceed Prevention of Significant Deterioration 

thresholds or National Ambient Air Quality Standards.

Greenhouse gas emissions would occur under all 

alternatives, at a fraction of a percent of the total 

greenhouse gas emissions for the western U.S. 

However, reductions in wildfire risk associated with 

herbicide treatments would result in an indirect 

reduction in greenhouse gas emissions.

Under all alternatives, impacts to soil would continue to 

be low. There is no evidence that the currently approved 

herbicides or new herbicides proposed for use result in 

significant adverse impacts to soil. Treatments would 

benefit soil by restoring natural fire regimes and 

slowing the spread of invasive plants, which should 

reduce soil erosion and improve soil productivity. Some 

treated lands could show a temporary increase in 

erosion as the target vegetation is killed, followed by an 

overall reduction in erosion as native vegetation that has 

more extensive root systems or year-round cover 

becomes established. Under all alternatives, herbicide 

use would continue to improve watershed function and 

water quality by reducing the risk of fire and post-fire 

sedimentation, and potentially contributing to 

stabilization of soils and a return to normal fire cycles.

Like the currently approved herbicides, the new 

herbicides pose risks to vegetation. All three of the new 

herbicides could adversely impact non-target 

vegetation. Accidental spills and herbicide drift from 

treatment areas could be particularly damaging to nontarget vegetation, and treatment design would need to 

consider special status species and populations. Buffer 

zones would be used to reduce the risks to vegetation 

from herbicide treatments under all alternatives. Longterm benefits could include a reduction in the spread of 

invasive plant species and a reduction in the risk of 

future wildfire in areas where the fire cycle is limiting 

the ability of native vegetation to establish. Under the 

action alternatives, the efficacy of some herbicide 

treatments could be improved through use of the new 

active ingredients, which may be more effective at 

managing target species than currently approved 

herbicides, and may improve control of populations of

invasive plant species that have developed a resistance 

to currently approved herbicides. 

Under all of the alternatives, herbicide treatments would 

continue to pose risks to fish and wildlife. Herbicides 

have the potential to kill or harm animals, or affect their 

health and behavior, through exposures such as direct 

spray, accidental spill, or ingestion of treated food 

items. Damage to non-target plants from herbicide use 

could adversely impact habitats used by fish and 

wildlife. Aminopyralid, fluroxypyr, and rimsulfuron 

have no to very low risk to fish and wildlife. In some 

circumstances they would be used instead of currently 

approved active ingredients with a greater risk. 

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Therefore, overall toxicological risks to fish and wildlife 

could be lower under the action alternatives 

(particularly Alternatives B and C) than under the No 

Action Alternative.

Under all alternatives, buffers would be used between 

aquatic habitats and treatments involving terrestrial 

herbicides to reduce risks to aquatic organisms 1

. 

Appropriate buffers would also be used between 

treatment areas and habitats of special status species.

Vegetation treatments would adhere to the most recent 

guidance for special status species, including land use 

plan decisions for sage-grouse as amended by pertinent

sage-grouse EISs, and interim management direction as 

outlined in Instruction Memorandum 2012-043

(Greater Sage-Grouse Interim Management Policies 

and Procedures). Long-term beneficial effects to fish 

and wildlife habitat through ecosystem enhancement 

and reduction in wildfire risk would be similar under all 

alternatives.

Herbicides would continue to have some risk for 

toxicological effects to livestock and wild horses and 

burros that graze in treated rangelands. These animals 

could be exposed to herbicides by an accidental spill, 

direct spray, herbicide drift, or by consuming herbicidetreated vegetation. The three new herbicides are of less 

toxicological risk to animals than some of the herbicides 

used now, which would likely decrease in usage under 

the action alternatives. Beneficial effects, which would 

include improvements to rangeland condition and the 

quality of forage, would be similar under all 

alternatives.

Under all alternatives, herbicide treatments could affect 

cultural or paleontological resources near or on the 

surface, but would be more likely to affect traditional 

cultural practices of gathering plants and the health of 

Native peoples. Cultural and paleontological resources 

could be impacted by equipment, and to a lesser extent

by the chemicals in herbicides. Based on the results of a

human health risk assessment, aminopyralid, 

fluroxypyr, and rimsulfuron have no to low risks to 

human health, and have less risk to human health than 

some of the currently approved herbicides. However, 

the herbicides that would decrease in usage under the 

action alternatives also have no to low human health 

risks. Standard operating procedures would help prevent 

1 It is likely that aminopyralid will receive an aquatic 

registration in the near future. If so, buffers associated with 

its use near aquatic habitats could be reduced.

exposures of Native peoples to herbicides. Therefore,

risks would be similar under all of the alternatives. 

Herbicide treatments could affect visual, wilderness, 

and recreation resources under all alternatives. The level 

of these effects would be similar under all the 

alternatives. Treatments would remove and discolor 

vegetation, making it less visually appealing. Over the 

long term, landscapes should be more appealing as 

native vegetation is restored. Treatments in wilderness 

and other special areas would detract from the 

“naturalness” of the area. Although use of mechanical 

equipment would be strongly discouraged in these 

areas, even limited use would create noise and reduce 

the wilderness experience, and would need to be 

authorized based on further site-specific analysis. 

Recreationists could be exposed to herbicides or

experience less visually-appealing landscapes. In 

addition, recreational areas could be closed for short 

periods of time after application to protect the health of 

visitors. Over the long term, herbicide treatments would 

be expected to benefit visual resources, wilderness, and 

recreation by helping to restore native plant 

communities and reducing the risk of wildfire. The 

degree of benefits from treatments would be similar 

under all the alternatives.

Under all alternatives, social effects would be minor at 

the scale addressed in this PEIS. Herbicide treatment 

programs would continue to benefit communities that 

supply workers, materials, or services in support of 

treatment activities. Some businesses, such as 

recreation-based businesses and ranching operations, 

could be adversely affected if treatments were to result 

in the closure of areas used for recreation or by 

domestic livestock for extended periods. There are 

potential environmental justice concerns because a large 

number of Native peoples and other minority groups 

live in the West and work in or visit public lands that 

may be treated with herbicides. The alternatives vary 

slightly in terms of how much the BLM would spend 

per herbicide treatment acre. These costs would be only 

slightly lower under the action alternatives than under 

the No Action Alternative, and would be lowest under 

Alternative B.

Based on human health risk assessments, there would 

be risks to humans (workers and the public) from 

exposure to herbicides. These risks would be similar 

under all the alternatives. The three new herbicides have 

no to very low risk to human health (with an 

unacceptable risk only predicted for one accidental 

exposure scenario involving rimsulfuron). All 

alternatives would be associated with a similar degree 

BLM Vegetation Treatments Three New Herbicides ES-4 January 2016

Final Programmatic EIS

 
EXECUTIVE SUMMARY

of benefit to human health associated with management

of invasive plants and reduction in wildfire risk.

Cumulative Impacts 

The cumulative effects analysis for the 2007 PEIS was 

for the BLM’s larger herbicide treatment program, and 

is applicable to future treatments with the new active 

ingredients. Addition of the new herbicides would result 

in an increase in the number of active ingredients being 

used on BLM lands.

Herbicide treatments contribute only minor amounts of 

pollutants to the air, and would reduce the abundance of 

fire-prone fuels and therefore emissions associated with 

wildfire, resulting in fewer pollutants accumulating than 

would occur without treatments. Treatments would 

contribute to short-term loss of soil functions, process, 

and productivity, which would be offset by watershedlevel restoration treatments. Water quality and 

hydrology in the western U.S. have been impacted by 

various human activities, and pollutants have been 

documented in surface water and groundwater 

resources. Use of the new herbicides would increase the 

number of potential pollutants used by the BLM, 

although use of herbicides with a greater risk to water 

resources would likely decrease as a result of 

availability of the new active ingredients. Treatments 

that reduce risk of wildfire and that aim to improve 

riparian habitats would benefit water resources on and 

near public lands. Treatments would improve wetland 

and riparian area functions and values and would slow 

erosion, which contributes to wetland degradation on 

public lands. With improvement in these areas, habitat 

for fish and other aquatic organisms would also 

improve. 

Increased fire frequency and the spread of invasive 

plants have altered plant communities and fire regime 

condition class on public land and have led to a 

cumulative loss of productivity. Herbicide treatments 

would control invasive plants, and repeated treatments 

followed by restoration would improve the condition of 

plant communities and ecosystem processes. 

Improvement in vegetation characteristics would benefit 

wildlife. Some species that have adapted to degraded 

ecosystems could lose habitat as a result of restoring 

native plant communities, but most species would 

benefit. Factors that have led to the loss of native 

vegetation and ecosystem health have adversely 

impacted rangelands used by domestic livestock and 

wild horses and burros. Treatments would improve 

rangelands for these animals, and increase the capacity 

for public lands to support viable populations of 

livestock and wild horses and burros.

Treatments could add to the cumulative loss of 

paleontological and cultural resources, but risks would 

be low. Treatments could impact plants used by Native 

peoples for traditional lifeway uses, and the health of 

Native peoples. However, the BLM would conduct pretreatment surveys to identify areas of cultural concern 

before conducting treatments to reduce the cumulative 

loss of these values. 

Treatments would result in some short-term and 

temporary loss of visual, recreational, and wilderness 

and other special area values due to vegetation being 

killed or discolored. In some cases, areas might be 

closed to visitors during and after treatments; however, 

these impacts would be short-term and any values 

affected would be restored within two growing seasons 

in most cases.

Treatments would benefit local communities by 

providing jobs and income, and by reducing the risk of 

wildfire that could harm people and destroy property. 

These gains would be minor in the context of the 

western economy, but would still be a cumulative 

benefit for many rural communities.

Treatments could harm the health of workers and the 

public. Most herbicides, however, would pose few risks 

to workers, and even fewer risks to the public, when 

applied at the typical application rate and in accordance 

with the label directions. New herbicides proposed for 

use pose no to very low risk to humans. If treatments 

restored natural fire regimes, reduced the risk of fire, 

and slowed the spread of invasive plants, human health 

would benefit.

Treatments could result in short-term loss of some 

resources, including, but not limited to, soil, vegetation, 

wildlife, and livestock forage opportunities. Over the 

long term, loss of resource values would be slowed, and 

in some cases, would be reversed. Short-term losses in 

resource functions would be compensated for by longterm gains in ecosystem health.

BLM Vegetation Treatments Three New Herbicides ES-5 January 2016

Final Programmatic EIS