The community of Topanga has been embroiled in a debate over maintaining a chemical-free watershed in recent months, following accusations by residents that Caltrans broke an agreement with the community not to use chemicals to maintain the shoulders of Topanga Canyon Boulevard (State Route 27).
The conflict began in late spring, when residents witnessed Caltrans workers spraying herbicides along the road once in late April and again in early May. The incidents quickly inflamed the environmentally conscious community, where residents insisted they had a long-standing agreement with the state agency to hand-cut vegetation along the road rather than use weed killers so as not to pollute Topanga Creek.
Caltrans agreed to halt the spraying amid community backlash. In a letter to residents, Caltrans official Daniel Freeman said reductions in Caltrans’ Los Angeles maintenance workforce from a high of 1,390 in 2002 to a projected 700 in 2013 had accelerated the agency’s need to use weed-killers rather than hand-cut vegetation, which is slower and more labor-intensive.
The two sides are currently negotiating a new agreement to ensure no chemical products are used to maintain roadsides in Topanga. But the issue brings to the fore questions about Malibu and the policies of the agencies that maintain its road maintenance.
Based on research, it appears that herbicides are used some in Malibu, although fairly infrequently.
Caltrans manages PCH in Malibu and has used herbicides, according to spokesman Patrick Chandler, between Puerco Canyon and Webb Way in late May. Chandler said the agency used the herbicides Roundup and Milestone VM, which he called typical weed killers sold in stores. Chandler said the herbicides were used properly.
“We follow what’s on the label. We are well within policy,” Chandler said, referring to the label on the container reading the Environmental Protection Agency’s rules.
Roundup and Milestone VM are widely used, posing minimal harm to animals and people, according to EPA Life Scientist Patti L. TenBrook.
But both do have drawbacks. Roundup’s ingredient glyphosate can harm plants other than the ones meant to be sprayed, and Milestone’s ingredient aminopyralid can linger in some types of soil for years.
Roads in unincorporated Malibu fall under the jurisdiction of Los Angeles County Public Works, which contracts the Department of Agricultural Commissioner Weights and Measures to maintain them. The agency uses Roundup on roadsides once or twice a year, spokesman Kerjon Lee wrote in an email.
Otherwise, Public Works harnesses weed whackers, sending workers including traffic controllers, to fight the brush.
In a later email, Ray Smith, Deputy Director of Department of Agricultural Commissioner Weights and Measures, addressed the herbicide use.
“As biologists, our decision to use herbicides along roadsides is based on science and experience,” Smith wrote. “It is the safest, most efficient and cost-effective method and also the least disruptive to the environment.”
Malibu’s city-owned streets are maintained without herbicides, a policy which will change under no circumstances, according to Arthur Aladjadjian, Public Works Superintendent. City documents show Malibu has paid Burns Pacific Construction at least $31,448 for clearing weeds this year.
To maintain Malibu’s parks, such as Legacy Park, Malibu does contract with property management company CAM Services, which used herbicides in the past three and a half years, Bob Stallings, Director of Parks and Recreation, wrote in an email.
CAM Services has used Roundup, Speed Zone, another herbicide, Dimension, a weed preventer, as well as Fumitoxin to control burrowing animals like gophers and ground squirrels. And city documents show Malibu has paid the contractor at least $288,662 since late July 2006.
Nonetheless, CAM Services sprays herbicides as a last resort, said Park Supervisor Drew Belter.
“It’s rare that we use herbicides,” Belter said.
When clearing Malibu’s parks, the workers mainly target non-indigenous, invasive plants. They control these weeds by watering the parks just enough to treat the native plants, but not enough to preserve the non-native ones.
This works by the staff examining the next day’s weather and entering it into the sprinkler system daily. The next day, the sprinklers will spray only the water needed for that day’s weather.
Melina Watts is the Santa Monica Mountains watersheds coordinator for the Resource Conservation District of the Santa Monica Mountains, which works with cities and citizen groups on local watershed issues. Watts says the issue over herbicide use is difficult but worth exploring.
“Very few places in the world today are [herbicide-free],” Watts wrote in an email. “Due to the community’s concern about water quality, I think there is a growing sensitivity to the importance of reducing and eliminating, when possible, herbicide use in both home gardens and in agricultural use; both Malibu City and local agencies are continuing to consider when and how much to use herbicides.”