At a special meeting of the Pasadena City Council on March 27, Los Angeles County Public Works Director Mark Pestrella confirmed that county officials sprayed a controversial weed killer in Hahamongna Watershed Park as part of a sediment removal project, but insisted that it presented no danger to city workers or local residents.

“There have been no signs or health indicators that have indicated that glyphosate was a molecule for cancer-causing up to this point,” Pestrella said, speaking of the popular herbicide Roundup, which contains glyphosate. The signature ingredient of the widely used herbicide has been linked to cancer. Currently, hundreds of court cases are wending their way through the judicial system by cancer patients claiming the weed killer caused their illnesses.

Hours after Pestrella’s comment at the special meeting, a judge ordered Bayer, makers of Roundup, to pay Edward Hardeman $75 million, after a jury ruled Hardeman contracted non-Hodgkin lymphoma due to exposure to glyphosate. The 70-year old used Roundup for 26 years.

In August, a state civil court jury found that Roundup was responsible for a school groundskeeper’s terminal cancer. Dewayne Johnson was spraying the chemical 20 to 30 times a year while working at a school district near San Francisco.

According to Pestrella, the county has been using about 3,000 gallons of Roundup mixed with water annually.

The revelation came during an 8 a.m. special meeting of the City Council with Los Angeles County Supervisor Kathryn Barger.

Weed Abatement

The herbicide was being used to destroy invasive weeds that can kill native plants in the habitat restoration part of the county’s Big Dig project in Hahamongna Watershed Park. The project includes removing 1.7 million cubic yards of sediment over the next three to five years, in part to free up compromised spillways in Devil’s Gate Dam which they say could be blocked by sediment during a major storm. Such blockage could cause the dam to overflow into the Arroyo Seco, which includes the Rose Bowl and Brookside Park.

The Pasadena Weekly reported last month that Roundup was being sprayed by county workers at a heliport in Northeast Pasadena. County officials began meeting to evaluate the use of the herbicides and pesticides after the newspaper spoke to several officials.

“As a cancer survivor I am hypersensitive to this issue,” Barger said at Wednesday’s meeting. “There are people who have had immune systems compromised, who are more susceptible.”

Barger was scheduled to meet with local resident Darian Donner on Monday to discuss the county’s use of the popular herbicide.

“They keep doing it until somebody stops them,” said Donner, who told the Pasadena Weekly last month that she saw county workers spraying the weed killer in Northeast Pasadena, Donner’s complaint eventually led to Barger’s county moratorium.

“We need to analyze the area to make sure we are protecting it for our future generations,”  Donner said.

Like Donner, Altadena Town Council member Dorothy Wong also saw county workers spraying Roundup, this time in Hahamongna.

“I asked them what they were using and they said Roundup,” Wong said. “This is before it became big news, and they said it’s safe, but I went home and looked it up online and saw the stories. The crew wasn’t wearing any safety equipment. I couldn’t believe it was happening. It’s a watershed. It is definitely not the place to be using herbicides.”

Test the Water

At that meeting, City Councilman Gene Masuda called on City Manager Steve Mermell to have the city’s water wells tested.

“First of all, we are talking about a very dangerous chemical that I understand as being extremely harmful to the environment and to our health,” Masuda told the PW. “This poison can seep into our water system and cause negative health impacts to humans and animals.”

Two weeks ago, the county Board of Supervisors unanimously passed a motion for a 30-day moratorium on the use of Roundup in LA County while several departments study its use.

“It’s common knowledge that there have been serious concerns about Roundup, or glyphosate,” City Council member John Kennedy told Pestrella. “A number of juries have made a direct causal connection between that substance and cancer, so you can understand why some residents in the area would be concerned about the whole issue of transparency, given the fact that it took you some time to recognize that this was not a prudent way in which to remove invasive plants.”

The use of Roundup by the city of Pasadena was stopped in 2017 in areas where people recreate and congregate, and discontinued its use altogether last year, said City Manager Steve Mermell.

Plugging the Nozzle

Communities in 13 states, including California, have placed restrictions or bans on Roundup.

In 2017, the city of Los Angeles’ Recreation and Parks Department stopped spraying the weed killer within 100 feet of children’s play areas, recreation centers and dog parks. Burbank discontinued the use of Roundup in city parks for one year, and the Burbank Unified School District, ceased using the herbicide due to cancer concerns. Carlsbad adopted a policy that makes organic pesticides the preferred method for killing weeds. Nearby beach city Encinitas has banned the use of Roundup and other glyphosate-based weed killers in city parks.

Irvine has stopped spraying Roundup and other glyphosate-based herbicides, and Thousand Oaks has a ban on glyphosate use on public golf courses. Petaluma officials are considering a ban on glyphosate for use in public parks, according to, and Richmond has banned the use of glyphosate for all weed abatement activities conducted by the city. Roundup can be purchased at most hardware stores, despite calls to ban the product.

According to the Department of Agriculture, in 2014, approximately 240 million pounds of glyphosate were sprayed in the US. As a result of widespread spraying, glyphosate has now been found to contaminate air, water and soil across vast expanses of the country.

Biomonitoring studies have found glyphosate in the bodies of children and pregnant women in the Midwest. Women who were more heavily exposed to glyphosate during pregnancy were more likely to give birth to premature babies who weighed less than average.

In 2018, researchers with the US Geological Survey (USGS) investigated 51 streams in nine Midwestern states, finding glyphosate in 18 of the streams.

The high occurrence in the Midwest where crops are grown is not surprising. Glyphosate is regularly applied to genetically modified corn and soybeans in small doses just before harvest as a drying agent. Glyphosate kills the crop, drying it out so it can be harvested earlier than if the plant were allowed to die and dry naturally.

According to testing performed last year, glyphosate has been found in popular oat-based cereals and other oat-based food marketed to children, including several cereals and breakfast bars made by General Mills and Quaker Oats.

“I am glad the supervisor’s motion stopped it while they study it,” Wong said. “This is really an opportunity for the county to rethink this project and things like Roundup that are harmful to our community.”