Leo Foster was appalled when he saw a Department of Transportation crew spray herbicides near a group of bicyclists (and a herd of cows) at Point Sur. It wasn’t the first time he’d allegedly been exposed on Big Sur’s Highway 1: He recalls being trapped on the highway near Esalen as a crew sprayed directly across the road.

“It seems like there’s a lot of involuntary exposure,” says the Big Sur resident, who lives with his pregnant wife on a property next to the highway. “Even if there is some argument for the necessity of this program, they don’t seem to be trained to use the product safely, and they also seem to be over-applying to begin with.”

Herbicide spraying is routine maintenance along Highway 1, according to Caltrans spokeswoman Susana Cruz. In Big Sur, she says, the agency applies at least five defoliants: Goaltender (oxyfluorfen), Roundup Pro (glyphosate), Reward (diquat dibromide), Oust (sulfometuron methyl) and Garlon (triclopyr). The pesticides are sometimes mixed with other products to control drift and make the chemicals stick to vegetation.

Pesticides are classified under four acute hazard labels: none, caution, warning and danger. Most of Caltrans’ Highway 1 applications are in the “caution” category, Cruz says: “They’re kind of the lower end.”

Caltrans tracks its pesticide use by pounds of active ingredient rather than diluted mix. In the 2007-08 fiscal year, Cruz reports, the agency sprayed 910 pounds along Highway 1 from Carmel to Big Sur. In 2008-09 it used 555 pounds, reflecting a crew shortage from the state budget cuts. This year, Big Sur applications are back up to a more typical 745 pounds as of March 23. The agency usually sprays in the spring, Cruz adds; most of this year’s work is already done.

Cruz says the multi-agency Big Sur Coastal Highway Management Plan commits Caltrans to spray herbicides “wherever needed” for highway safety, sight distance, scenic highway features and fire danger. Caltrans also does some mowing, she adds; the herbicides are for hard-to-kill weeds like mustard, thistle, pampas grass, sweet anise and poison oak.

But Lee Otter, a planner with the California Coastal Commission, says the highway management plan is a not a mandate to spray: “The plan does not require them to do it.”

While the 2004 plan allows for some roadside spraying, it’s supposed to be phasing out, consistent with a Caltrans committment to reduce herbicide use 80 percent statewide by 2012.

In response to Foster’s complaint, Cruz says if an exposure occurred, it was an accident. Licensed pesticide applicators log 20 hours of training every two years, she says. They’re taught to look out for people within 200 feet of their spray sites and radio one another if bicyclists or hikers are nearby. “They’re not out to spray people,” she says. “I can’t say whether somebody was sprayed or not, but certainly if they see pedestrians they’re going to stop.”

Locals are split on the spraying.

“If it helps for fire I think it’s a great idea, but I don’t know what the impact is,” says Big Sur Volunteer Fire Brigade Chief Martha Karstens. “Is it any worse than me spraying Roundup on my poison oak?”

But Pelican Network founder Jack Ellwanger doesn’t like the practice. “I don’t think there’s any justification for that kind of spraying,” he says. “They have no regard for native plants or anything else. What kind of fires are they preventing?”