Both the City and County of San Diego are moving to ultimately ban the use of weed-killers suspected of causing cancer in public parks in favor of using safer, organic alternatives.
A case in point is glyphosate, the primary ingredient in Monsanto’s popular weed killer Roundup, which has been linked to liver disease in animals. 
Discovered in 1970 by Monsanto chemist John E. Franz, glyphosate is an herbicide used to kill weeds that inhibits plant enzymes. Monsanto brought it to market for agricultural use in 1974 under the trade name Roundup.
In a new, first-of-its-kind study, researchers at UC San Diego School of Medicine have reported an association between the herbicide and negative effects on the human liver.
“We’re making progress on a pesticide-proof pilot park program here in Liberty Station to ensure more of our parks are pesticide-free in 2020,” said District 2 Councilmember Dr. Jen Campbell in her January State of the District address.
In a February memo, Andrew Field, director of City Parks and Recreation, noted that a 150-day phase-out, which began Sept. 1, 2019, was in effect in the parks department for use of Roundup and other glyphosate-based materials in all park locations.
“The Parks and Recreation Department has sought to sustainably manage pest issues that arise in its parks,” said Field in the memo. “Since 1999, the Integrated Pest Management Program has focused on mechanical means — hand-pulling, hoeing, weed whipping, brush mowing/fuel reduction — to be used before requests for pesticide application are made. Pesticides are used only after monitoring indicates that they (pesticides) are needed.”
However, noted Field, “Open space and golf operations are exempt from participating in the phase-out effort, as well as areas which are maintained by contractual vendors (until contract renewal).”
Field noted City parks has initiated a one-year pilot to use organics at three trial sites. One of which is at Liberty Station, the former Naval Training Center. 
The alternative pilot program is being conducted along with nonprofit Farmers Footprint, an organization with the expertise to measure the effectiveness of organic alternatives to weed-killers.
“Results of the pilot will be used to evaluate the abilities of alternatives,” said Field’s memo. “These sites were selected because of their varying levels of maintenance needs, which will serve as an ideal testing ground for emerging technologies.”
The County Board of Supervisors also recently took a first step toward banning the use of weed-killers, like Roundup, that has been linked to certain cancers, on County properties and infrastructure.
The board unanimously voted to direct its CAO to identify a plan that includes organic alternatives to herbicides and come back with a report in 120 days.
“I’m all for killing weeds, but we should do it in the most responsible way, without using toxic chemicals,” said Supervisor Nathan Fletcher who, along with colleague Dianne Jacob, proposed the County herbicide ban.
Environmental activist Ann Jackson Hefti said she was “excited and hopeful” about the non-toxic weed abatement program being piloted by the City, the County and also now by some San Diego schools.
A year ago, Jackson Hefti and friend Amy Ryan were walking their dogs in Sunset Cliffs Natural Park, and claim they were exposed to wind-drift toxic herbicide sprayed by workers there.
The incident motivated them to create “Campaign Non-Toxic San Diego.” The pair are now lobbying the City and County of San Diego to adopt an integrative pest management strategy, similar to one in Irvine, Calif., which replaces commonly used herbicides and pesticides containing cancer-linked glyphosate with other, safer organic products.