Roadside -Herbecide - Pesticide

Collin County, Texas, manages roadside vegetation through scheduled herbicide applications. According to the Collin County Roadway Policy, the Public Works department treats all county right-of-ways twice per year with contact herbicides at required or allowable rates. The County as contracted with various companies, like Edko, LLC, and Opterra Solutions, Inc., for these services. For precise information on the herbicides employed, it would be best to contact the Collin County Public Works Department directly.

The Texas Department of Transportation (TxDOT) employs a comprehensive vegetation management program to maintain roadside safety and aesthetics. This program integrates mowing and the application of approved herbicides to control undesirable vegetation. Integrated Roadside Management Manual Transportation Library Doc TxDOT Herbicide Manual Transportation Research Library: Integrated Roadside Management Manual
Full Guidelines: https://onlinemanuals.txdot.gov/TxDOTOnlineManuals/TxDOTManuals/ope/vegetation_management.htm?

Sample Chemicals Used: (contact authorities & companies as above for up to date details)

Opterra Solutions utilizes a range of herbicides tailored to specific vegetation management needs. Some of the herbicides they employ include:

Interline Non-Selective Herbicide: Designed for use on glufosinate-tolerant crops like corn, cotton, canola, and soybeans, it effectively controls glyphosate-resistant weeds. shop.opterrasolutions.com
Oust Extra Forestry Management Herbicide: Provides long-lasting control of woody vines, troublesome brush, and broadleaf weeds in forestry and industrial sites.
Bromacil 80 WG Non-Selective Vegetation Management Herbicide: Offers broad-spectrum control of grasses, broadleaf weeds, and brush in non-crop areas.
Garlon 4 Ultra Herbicide: Used for basal bark, cut-stump, and dormant stem treatments, effective against a variety of woody plants.
RoundUp Custom: Provides non-selective aquatic weed control for nearly 200 species of emerged weeds, including broadleaf weeds and sedges. shop.opterrasolutions.com

For a comprehensive list of herbicides and detailed information, you can visit Opterra Solutions' official website. https://opterrasolutions.com

While specific herbicide formulations can vary based on regional vegetation types and management goals, some herbicides that have been utilized by TxDOT in the past include:

Escort (metsulfuron methyl): Used for broad-spectrum weed control.ROSA P
Oust (sulfometuron methyl): Applied to manage a variety of grasses and broadleaf weeds.
Rodeo and Roundup (glyphosate): Non-selective herbicides effective against many plant species.
Arsenal (imazapyr): Employed for controlling woody plants and broadleaf weeds.
Pathfinder II (triclopyr): Utilized for woody plant and brush control.

Transline (clopyralid): Targets certain broadleaf weeds.

Human Health Risks

Many herbicides used on roadsides not only harm pollinators and wildlife, but also have documented links to human health risks, including cancer, especially with long-term or repeated exposure. Here’s a breakdown:

⚠️ Known or Suspected Carcinogens Used in Roadside Herbicide Sprays

1. Glyphosate (Roundup, Rodeo)

Linked to: Non-Hodgkin’s lymphoma (NHL)
Classified by WHO's IARC: “Probably carcinogenic to humans” (Group 2A)
Numerous lawsuits have led to multi-billion dollar settlements over cancer claims.
Still heavily used by cities, counties, and DOTs, including in Texas.

2. Triclopyr (Pathfinder II, Garlon)

Suspected link: Liver and kidney toxicity; some studies show mutagenic properties.

Not officially classified as a carcinogen by EPA, but concerns remain due to its persistence and bioaccumulation potential.

3. Imazapyr (Arsenal)

Limited human data, but long-term exposure studies in animals show organ toxicity.
Not officially listed as carcinogenic, but caution is recommended due to potential groundwater contamination and plant uptake.

4. 2,4-D (used by some municipalities)

Classified as “possibly carcinogenic” (IARC Group 2B)
Some links to soft tissue sarcoma and non-Hodgkin lymphoma.
Often used in mixes with glyphosate or other herbicides.

5. Sulfometuron-methyl / Metsulfuron-methyl

Not listed as carcinogenic, but concerns exist around endocrine disruption and long-term exposure risks—especially to applicators or residents near sprayed areas.

👨‍👩‍👧 Community Exposure Risks

Drift from roadside spraying can travel hundreds of feet—affecting nearby homes, pets, gardens, and even schoolyards.
Children and pregnant women are especially vulnerable.
Groundwater and runoff contamination may affect drinking water and aquatic systems.

🐝 A Double Hit: Pollinators, Crops, Vineyards - See Below Details.

Pollinators like bees, butterflies, and dragonflies act as early warning systems—when they’re affected, it’s a red flag for ecosystem and human health alike.

Pollinators Health Impact:

👉 If a chemical is harmful to humans, it's very likely to be harmful to pollinators, especially insects like bees, butterflies, and dragonflies whose systems are far more sensitive to toxins. Here's why:

🧠 1. Size and Sensitivity

Pollinators are tiny — even a microdose of a chemical can shut down their nervous system, confuse navigation, or prevent reproduction.

Insects metabolize chemicals differently than humans and often can’t detox like we can.

🧬 2. Neurotoxic Effects

Many herbicides and insecticides (like glyphosate or neonicotinoids) affect acetylcholine receptors, disrupting brain and muscle function.
In bees, this causes:

Disorientation
Poor hive return rates
Death in flight or at the hive

🌺 3. Indirect Exposure Through Plants May:

Destroy the native plants pollinators rely on (milkweed for monarchs, clover for bees, etc.)
Make the landscape a food desert
Pesticide-laced nectar or pollen can poison larvae inside hives.

🧪 4. Chemical Synergy

Even if a chemical alone seems “non-lethal,” combining multiple herbicides, insecticides, and fungicides (which is common in road sprays) leads to synergistic effects — multiplying toxicity.
This is barely studied, but field tests show bee mortality skyrockets when exposed to these mixes.

💧 5. Environmental Persistence

Some chemicals persist in soil and water for months or years.
Pollinators drink surface water, lick dew off grass, or absorb through feet and antennae.

If something is toxic to humans — especially neurotoxic, endocrine disrupting, or carcinogenic — it is almost guaranteed to be even more harmful to small-bodied, fragile species like bees and butterflies. The difference is, they die quietly… and no one sues.

Various Studies - Articles:

Chemicals

Glyphosate:

Pollin & Nector Contamination: Glyphosate used as desiccant contaminates plant pollen and nectar of non-target plant species - ScienceDirect Cell.com Glyphosate Contaminates PubMed
Cognitive and Sensory Impairment: Research indicates that glyphosate negatively affects honey bees' associative learning and sensory abilities, leading to delays in brood development. PubMed PMC
Gut Microbiota Disruption: Exposure to glyphosate has been shown to alter the gut microbiota of honey bees, impacting their survival rates. British Ecological Society Journals+ Pub Med
Colony Thermoregulation Issues: A study revealed that glyphosate impairs bumblebees' ability to regulate nest temperature, which is crucial for colony health. The Guardian

Triclopyr:

Butterfly Development: Role of herbicides in decline of butterfly population and species. Exposure to triclopyr has been linked to reduced adult emergence in butterfly species, indicating potential developmental hindrances. PubMed
Larval Pesticide Exposure impacts monarch butterfly performance 6 chemicals tested - PubMed

Neoniconoid Insecticides

Experimental field evidence shows milkweed contaminated with a common neonicotinoid decreases larval survival of monarch butterflies - PubMed
Pollen and Nectar Contamination:Plant protection product residues in plant pollen and nectar: A review of current knowledge - ScienceDirect
Worldwide Samples: A worldwide survey of neonicotinoids in honey 75% various compounds | Science

Imazapyr:

Butterfly Pupation: Similar to triclopyr, imazapyr exposure has been associated with decreased pupation success in butterflies. Xerces ProjectXerces Project

Clopyralid:

Residue in Nectar and Pollen: When applied to crops like oilseed rape, clopyralid residues can be present in nectar and pollen, exceeding levels - bee farmers could not sell their honey. Also, it potentially exposed foraging bees. ScienceDirect+ Dept of Minn

Sulfometuron-methyl:

Data Deficiency: While specific studies on its impact on pollinators are limited, there is an acknowledgment of potential risks, leading to calls for more comprehensive research. EPS limited studies 

Chemical Residues Soil - Compost - Water:

🌎 Soil Residues & Uptake by Native Plants
Pollin - Nector - Leaves Contamination Residue listed above

Xerces Society Reports on Soil Persistence:

Herbicides applied to rights-of-way or roadsides can linger in the soil and be absorbed by nearby native plants, including those restored for pollinators. 📄 PDF: Rethinking Weed Management at Home (Xerces)

Compost & Manure: Aminopyralid and Clopyralid in Compost:

These herbicides can survive composting and manure, ending up in gardens and pollinator plots.

📖 Study: NC State Education - Herbicide Carryover in Manure and Compost NC State Education

💧 Chemical Residues in Water & Runoff

USGS National Water-Quality Assessment (NAWQA):

Found glyphosate and other herbicides in over 50% of sampled streams in agricultural areas, especially after rainfall. 📖 Link: USGS NAWQA Glyphosate in Streams 2020 Herbicide glyphosate prevalent in U.S. streams and rivers |Science Direct Study

Imazapyr and Triclopyr in Surface Water:

These are commonly detected in urban and roadside runoff, especially after spraying vegetation near roads or utilities.📖 EPA Risk Assessment: Imazapyr Ecological Risk PDF

Herbicide Runoff and Wetlands:

Multiple stressor effects of herbicide; Wetlands downstream from treated areas accumulate herbicides like sulfometuron-methyl and triclopyr, affecting aquatic invertebrates and amphibians. 📖 Study: Wetland Impact Study – Triclopyr

These findings underscore the importance of evaluating herbicide use and considering alternative vegetation management strategies to protect pollinator health.

🏞️ Road Runoff Pollutants & Their Effects ⚠️

🧪 1. Common Pollutants in Road Runoff:

Glyphosate and its metabolites: Found in runoff from roadside spraying (especially after rain). It can contaminate pasture plants and water sources.
Neonicotinoids: Persistent in the environment, especially if applied near roadsides; toxic to bees even in trace amounts.
Road salts (sodium chloride): High levels of salinity can disrupt plant growth and harm freshwater ecosystems.
Heavy metals: From vehicle exhaust (e.g., lead, copper), which accumulate in runoff, impacting soil quality and plant health.

🌧️ Road Runoff Oil Pollution:

When it rains, motor oil, fuel, lubricants, grease, brake and tire dust, and other petroleum-based substances that have built up on road surfaces are washed into:

Storm drains
Nearby soils and crops
Creeks, rivers, and groundwater

This runoff contains polycyclic aromatic hydrocarbons (PAHs), heavy metals, and toxic organic compounds.

🚱 2. Water Pollution

Road runoff can carry harmful chemicals directly into local rivers, streams, and ponds that farmers and ranchers rely on for livestock water or irrigation.

Eutrophication (algal blooms) in water bodies, decreasing oxygen and suffocating aquatic life.
Contaminated drinking water for humans, pets, and livestock.
Road Salts A Fresh Look at Road Salt: Aquatic Toxicity and Water-Quality Impacts on Local, Regional, and National Scales - PMC
Controlling Runoff from Roads, Highways and Bridges | Polluted Runoff (Nonpoint Source Pollution) | US EPA

🌾 3. Damage to Agricultural Land If runoff accumulates, chemicals from the road can affect soil health and the quality of crops and pasture grasses.

Herbicides: For example, herbicides in runoff can prevent the germination of seeds in the field. Over time, it reduces soil fertility and disrupts microbial communities crucial for plant growth.
2. Soil and Crop Contamination: Hydrocarbons, oils etc bind to soil particles and persist long-term, affecting: Soil microbial health and Nutrient uptake in crops.

3. Food safety (for vineyards, vegetables, etc.)🔗 Study:
"Petroleum Hydrocarbon Contamination and Its Impact on Agricultural Soil" – Journal of Environmental Science

🐢 4. Threats to Sensitive Habitats & Aqualife

Wetlands near roadsides are often polluted by runoff, disrupting native plant growth and harming the invertebrate population that pollinators feed on.
These disruptions lead to loss of habitat for species like turtles, frogs, and beetles — vital parts of the food chain that support pollinators.

🌍 Steps for Mitigating Runoff Damage

🐝 1. Pollinator-Friendly Vegetation Management:

Alternatives to roadside herbicides:

Use of native plants that require less pesticide intervention.
Mechanical or manual weed control.
Controlled burns or prescribed grazing to manage vegetation without chemicals.

💧 2. Rainwater Harvesting & Buffer Zones:

Create buffer zones of native plants or grasses along roadsides to absorb runoff and filter pollutants before they reach fields or waterways.
Use rain gardens and swales to direct runoff away from vulnerable areas.

🛣️ 3. Runoff Regulation

Road salt reduction programs or alternatives (like sand or calcium magnesium acetate) to reduce contamination.
Better management of herbicide spraying programs (i.e., spraying during dry periods, avoiding spraying near water sources).

🍇 Impacts on Vineyards and Farms

Grape vines are sensitive to soil contamination and changes in microbial communities.
Long-term exposure can alter terroir and grape flavor.
PAHs can accumulate on leaf surfaces and affect photosynthesis.
🔗 Study: "Impact of Urban Runoff on Agriculture" - European Journal of Agronomyhttps://doi.org/10.1016/j.eja.2020.126102

🐝 Buffer Zones

Beehives: Keep 300–1000 feet away from major roadways to reduce exposure to pollutants.
500-1,000 feet or more is ideal, especially in areas with high traffic or frequent chemical applications. A greater distance is needed if the prevailing wind direction blows road pollutants toward the hives, or if there are concerns about road runoff affecting water sources and foraging plants. Employing buffer zones and alternative foraging areas can further help mitigate the risk of contamination.
Water and Road Runoff Buffer:Road runoff containing harmful chemicals, heavy metals, or salts can directly impact bees by contaminating nearby water sources or affecting the plants they pollinate. A buffer of at least 300 feet can help prevent contamination of water sources that bees may visit for drinking or foraging.
Crops/Vineyards: Establish vegetated buffer strips of 100 feet with grasses or hedgerows to absorb runoff and trap oil particles.

Study of Vehicular Pollutants on Plants: PDF
Study Pollutants Ecologic etc PDF

If Road Construction is Inevitable - have them install proper barriers, drainage, water guards and get properly compensated on all aspects.

Vegetative Barriers:

Planting windbreaks or buffer strips of native grasses, shrubs, or trees can help protect crops from pesticide drift, air pollution, and road runoff.
These barriers act as a filter for airborne contaminants and prevent runoff from reaching crops.

Proper Drainage Management:

Installing swales, drainage ditches, oil-grit separators in storm drains, or rain gardens between the road and the crops can help capture and filter harmful pollutants from runoff before they reach the crops.
This helps reduce the contamination of soil and water used by the crops.

Water Quality Monitoring:

Regular testing of irrigation water for pollutants (e.g., salts, heavy metals, pesticides) will help ensure that the crops are not being affected by road runoff.

Site Selection:

When possible, select sites for planting that are naturally protected from road runoff, such as sloping areas where water naturally moves away from the field.

🌱 How to Protect Local Farms, Pollinators, and Communities

Soil and Conservation: Test Soil and water samples before and after road constructions.
Advocate for better roadside management to reduce chemical use.
Push for pollinator-friendly farming practices and government regulation to protect natural habitats from road runoff.
Encourage community programs to plant buffer zones or reduce the harmful use of de-icing chemicals.

If Road Construction is Inevitable - have them install proper barriers, drainage, water guards and get properly compensated on all aspects.

📚 Additional Resources

EPA – Polluted Runoff: Nonpoint Source Pollution https://www.epa.gov/nps
USGS – Road Runoff Contaminants and Effects on Water Quality U.S. Geological Survey Open-File Report 99-240
NRDC – Stormwater Runoff and Urban Pollution https://www.nrdc.org/stories/stormwater-runoff-101