Aerial Application of Herbicide, Shadow Cliffs: Week of February 29


Weather permitting, the East Bay Regional Park District will be applying by helicopter Milestone™ herbicide to their pasturelands sometime during the week of February 29. Milestone in the early spring can prevent the growth and germination of yellow star thistle, a highly invasive, non-native annual. Yellow star thistle degrades the Bay Area’s valuable (and diminishing) rangelands while creating a nuisance for recreation.  Yellow Star thistle alters the functioning of the ecosystem, outcompeting annual grasses and native plants, reducing available forage for livestock and using water reserves deep in the soil.  If left unmanaged, these plants have been observed to grow to dense monocultures, excluding all other types of vegetation and habitat utilized by many other species. 

The Milestone application is under the guidance of a licensed Pest Control Advisor and its efficacy is based on research results from the University of California Cooperative Extension. This herbicide treatment is part of an overall integrated Pest Management (IPM) approach to control invasive species at Briones Regional Park.

Will Milestone stay where it is sprayed?
Because of its formulation, Milestone is essentially non-volatile (i.e. non evaporative). Precautions will be taken to ensure that spray drift does not occur. It is applied at a very low rate, so there is little potential for runoff.

Do livestock need to be removed from the treated area?
No. There are no grazing restrictions for any class of livestock or wildlife.

What is the environmental impact of Milestone?
Milestone is registered under the EPA’s Reduced Risk Pesticide initiative, and is frequently used for environmental restoration projects. Because of its non-volatile formulation and its low-volume application rates, Milestone provides effective control with reduced exposure for people and for the environment. When applied in a responsible manner in accordance with the label directions, there should be no harm to persons, pets, property or the environment beyond the intended weed control activity of the pesticide.

Is notification required?
No. Pesticide applicators are required by law to apply pesticides in a safe and effective manner and ensure that no harm is caused to persons, property or wildlife outside of the targeted application site. Notification is only required by law to persons who are likely to enter the treated area. However, this notification is being provided to you by the property operator in good faith to alleviate concerns you may have about this application.

Casey Brierley
(510) 544-2343