Land Use, Sustainability,
and Resilience Committee
TO: LAND USE, SUSTAINABILITY, AND DATE: JANUARY 8, 2024
RESILIENCE COMMITTEE MEMBERS
FROM: PUBLIC WORKS DEPARTMENT WARDS: ALL
SUBJECT: USE OF GLYPHOSATE-BASED PRODUCTS FOR WEED ABATEMENT - UPDATE ISSUE:
Receive an update from the Public Works Department on the use of glyphosate-based products for weed abatement purposes.
RECOMMENDATION:
That the Land Use, Sustainability, and Resilience Committee receive and file an update from the Public Works Department regarding the use of glyphosate.
BACKGROUND:
Glyphosate is commonly referred to interchangeably with the commercial label Roundup. Glyphosate is considered a systemic herbicide, which acts by killing the entirety of a weed, including its root system, to minimize regrowth and recurrence of the weed issue. Controlling weed growth not only helps to maintain the aesthetics of our community, but also helps to maintain accessibility along pedestrian paths and bicycle lanes, reduces potential damage to infrastructure, and keep vehicle sight distances clear.
In April 2019, the City Manager implemented a temporary glyphosate moratorium in response to public concern regarding the City’s use of this herbicide. The City Council received an update on the temporary moratorium in January 2020 (Attachment 1), and in February 2021 the City Council ultimately approved rescinding the temporary moratorium (Attachment 2), allowing the resumption of glyphosate use on City-maintained properties and facilities.
On May 8, 2023, the Public Works Department presented an update to the Land Use, Sustainability and Resilience Committee detailing its use of glyphosate and current industry practices. The Committee requested that Public Works return to the Committee with a suite of options for weed abatement activities.
DISCUSSION:
Current Riverside Public Works Practice
The Public Works Department and its contractors make use of glyphosate, under the label of Roundup, for weed control in parkways, medians and other City maintained areas. City personnel are certified through the California Department of Pesticide Regulation (CDPR) in the application of herbicides, including Roundup, and are recertified annually. City contractors are also required to maintain current certification and licensure through the CDPR, which helps assure the City that its contractors are knowledgeable on current practices.
City staff and City contractor use of Roundup is also monitored through the Riverside County Agricultural Commission (County). The County conducts storage location and field inspections during the application of Roundup, checks tags on containers, and reviews records maintained by City staff. The Public Works Department has not been found out of compliance during County inspections. The County Agricultural Commissioner helps to ensure that glyphosate is applied correctly in the field and that it is stored properly when not in active use.
City staff use several best practices when applying Roundup, including:
Roundup is typically applied by hand either using a backpack or a hose connected to a slow-moving vehicle. Hand application helps to eliminate the potential for over-spraying.
In large areas, Roundup may be applied using a truck-mounted sprayer. This application method complies with regulations and is consistent with industry practices.
The City notifies daycares and schools located in the vicinity of the work prior to the application of Roundup and coordinates spraying times with the faculty. As a best practice, Public Works typically schedules spraying near schools on days when schools are not in session On days when wind speeds exceed 5 MPH, Roundup application is suspended The City uses a 1% solution of Roundup, meaning that for every 100 gallons of mix sprayed, only 1 gallon is Roundup.
Roundup is applied to any given area on an as-needed basis.
A dye is added to hand-applied Roundup to serve as a visual marker of its location of application.
These, amongst other requirements as stipulated by the aforementioned regulatory agencies, help to reduce the general public’s exposure to glyphosate. While the CDPR does not restrict the use of glyphosate, it carries the following label warning within the State of California:
“CALIFORNIA PROPOSITION 65 WARNING: Using this product can expose you to glyphosate. The International Agency for Research on Cancer classified glyphosate as probably carcinogenic to humans. US EPA has determined that glyphosate is not likely to be carcinogenic to humans; other authorities have made similar determinations. A wide variety of factors affect your potential risk, including the level and duration of exposure to the chemical. For more information, including ways to reduce your exposure, go to www.P65Warnings.ca.gov/glyphosate.” Importantly, this warning acknowledges that the EPA, among other authorities, has determined that “glyphosate is not likely to be carcinogenic to humans.” City of Irvine
The City of Irvine has implemented an Integrated Pest Management Program which primarily relies on alternative means of weed control. Their program details the use of steam, layering mulch, biological control (use of other species) and mechanical removal, including Fraze mowing operations, noting, “the process is expensive and labor intensive.” (Attachment 3) The City of Riverside experienced an increase of more than 7% in contract costs during the temporary moratorium on Roundup, and the effectiveness of its weed abatement programs suffered significantly.
If a spray must be applied to the weed, the City of Irvine requires that the chemical be organic. Identifying an inexpensive and effective organic herbicide is a challenge. Notably, one of the primary Roundup alternatives used within community and neighborhood parks during Irvine’s 2021 reporting period was “Whack Out Weeds.” The CDPR later warned that this product is known to contain glyphosate and that it was incorrectly labeled as organic. (Attachment 4) Options
A map of medians and parkways, and Victoria Avenue, where Public Works applies Roundup is attached to this report.
Medians and Parkways
Public Works is responsible for weed abatement in street medians that are not accessible to the public and see little foot traffic and where there is minimal exposure to the public following an herbicide application. Public Works also maintains parkways which may be adjacent to public sidewalks. These areas represent over 400 acres of City-maintained area and are spot-treated with glyphosate as-needed either by a team of two City staff using a truck-mounted sprayer or by a contractor using a backpack sprayer in most medians. Current contract cost to apply Roundup in medians and parkways is approximately $192,000 annually.
Victoria Avenue Walking Trail and Public Sidewalks
Public Works is responsible for landscape maintenance along both sides and the center median of Victoria Avenue between Myrtle Avenue and La Sierra Avenue, which represents approximately 60 acres of landscape maintenance area. Weed abatement along Victoria Avenue is performed by a landscape contractor on an as-needed basis during their working hours of 7:00 am and 3:00 pm Monday – Friday through a combination of glyphosate for grassy weeds and an alternate product, Cheetah Pro, around the Ragged Robin roses that is selective to avoid harming the roses’ root system at an estimated cost of $50,000 per year. Glyphosate with colored dye added to make the treated locations very noticeable is applied along the length of the center median by workers walking behind a truck-mounted trailer or on foot with a backpack sprayer. This method allows for a more precise application of glyphosate. The glyphosate label does not have a re-entry restriction as it dries within minutes of application. Volunteers also assist with occasional weed abatement in garden areas along the Avenue.
Public Works staff is preparing cost estimates to mulch the center median along the entire length of Victoria Avenue. Mulch will help control weeds and reduce the need for herbicides. Staff will be bringing this item to City Council in February 2024.
The Public Works Department ended its practice of spraying along public sidewalks over 10 years ago. Weedy areas along curbs & gutters are the responsibility of the property owner and may be referred to Code Enforcement for follow-up when maintenance is needed. Landscape contractors use string trimmers to remove weeds along sidewalks in their maintenance areas.
Alternatives to Glyphosate
Use of glyphosate is an effective method of weed control as it is a non-selective postemergence herbicide that goes to the root system, meaning it will kill any plant it is applied to typically with one application. Weeds typically targeted by staff for abatement are perennial weeds (regrow season after season, such as grassy weeds like bermudagrass and crabgrass, and Sahara mustard) or annual weeds (such as tumbleweeds that germinate in the spring and flower in the summer or fall).
Manual removal. Hand weeding will always be performed to some extent in landscaped areas. To be effective, this method requires removal of weeds before they have a chance to establish a root system and go to seed. Manual weed removal is most effective if done frequently, about every two weeks, and is most suitable for small scale maintenance. For context, to maintain Victoria Avenue, a contracted landscape company would likely assign 10-12 maintenance staff to perform daily manual weed removal year-round. Current contract rates for this type of work would be approximately $25/hour per person, which translates to approximately $625,000 for full-time weed abatement labor cost.
Public Works Weekend Work Release Crews perform only manual weed abatement using shovels or string trimmers. These crews target large areas such as along Mission Inn Avenue near Redwood to the city limits and along Central Avenue near the 215 Freeway (Sycamore Canyon Boulevard to Lochmoor Drive).
Thermal weed control. Heat can be used to kill seedling weeds. Flame weeding is effective on seedling weeds growing in hardscape areas (e.g. expansion joints or cracks in concrete areas), but should not be performed in areas where flammable mulch or plants or structures are present.
Where flammable materials are present, steam or hot foam may be used. Specialized equipment to produce pressurized steam or hot water with a biodegradable foaming agent is required and the output from the devices is very hot and can cause severe burns. The foaming agent may be slippery following application and can take up to 36 hours to completely dissipate. Thermal weed control may not be appropriate for City-owned public property. Flame, steam or hot-foam weeding may be effective weed control methods appropriate for small areas such as a closed school campus or other similar controlled environment.
Current contractors do not offer this service and would need to invest in start-up costs such as new equipment and staff training.
Postemergence herbicide alternatives. Other non-selective herbicides are available for use in landscaped areas, such as acid- or salt-based products (for example brand names include Scythe or Finale XL). These products may be organic or inorganic. These are contact herbicides that do not kill the root system like glyphosate, so additional applications are needed to be effective.
Organic herbicides are pesticides made of compounds found in nature. In recent years, more attention has been focused on using organic herbicides but there has been limited information on their efficacy. In March 2023, University of California Agriculture and Natural Resources (UCANR) published an article with the results of efficacy tests comparing organic herbicides to glyphosate and found that organic herbicides controlled weeds effectively for about 14 days. Glyphosate typically provides weed control for about 35 days. Use of organic herbicides will require reallocating resources to account for increased applications, lower dilution rates, and higher application volumes. City contractors used products including Scythe and Finale XL during the City’s glyphosate moratorium. During this time Public Works experienced approximately a 400% cost increase for weed control. Based on the current contract rates, we estimate that costs would increase to approximately $800,000 per year for use of alternative products in medians and parkways, due to increased application frequency.
It is important to note that organic herbicides can be toxic to the applicator and product labels must be followed closely for person protective equipment (PPE) and application requirements. Vinegar is commonly cited as an alternate herbicide to glyphosate. In order be effective for weed control, the percent of acetic acid should be 10% to 20%, which is more concentrated than household vinegar’s acetic acid content of 5%. Acetic acid concentrations over 11% can cause burns upon skin contact.
Hardscape. Replacing landscaped areas with hardscape such as pavers, concrete, stabilized decomposed granite (DG), or river rock can be effective at controlling weeds. In order to convert landscaped medians, spray-type irrigation systems need to be replaced with drip or bubblers, and plant material and soil need to be removed. The total cost to convert to hardscape is estimated at about $40 per square foot.
STRATEGIC PLAN ALIGNMENT:
This item contributes to Strategic Priority 2 – Community Well-Being and Goal 2.3 - Strengthen neighborhood identities and improve community health and the physical environment through amenities and programs that foster an increased sense of community and enhanced feelings of pride and belonging citywide.
This item aligns with each of the five Cross-Cutting Threads as follows:
Community Trust – The City complies with County and State regulations related to the use of glyphosate to ensure the safety of the community.
Equity – The City applies glyphosate on an as-needed basis across our various medians, parkways, and properties to maintain the physical environment and aesthetic beauty of our neighborhoods.
Fiscal Responsibility – The City applies glyphosate prudently and only in areas where abatement is needed. Roundup is a more economical alternative to costly hand removal and alternative herbicides as it can be applied with reduced labor and material cost.
Innovation – The City continues to apply industry best practices in its use of glyphosate.
Sustainability & Resiliency – Clean and accessible walkways encourage active transportation within the City of Riverside.
FISCAL IMPACT:
There is no fiscal impact associated with this update.
Prepared by: Jim Lowery, Senior Field Operations Manager Approved by: Gilbert Hernandez, Public Works Director
Certified as to
availability of funds: Kristie Thomas, Finance Director/Assistant Chief Financial Officer Approved by: Kris Martinez, Assistant City Manager
Approved as to form: Phaedra A. Norton, City Attorney
Attachments:
Public Works Landscape Maintenance Map
UCANR March 2023 Article
City of Irvine IPM Program
CDPR Whack Out Weeds Warning
Presentation
Update on Glyphosate Based Products for Weed Abatement Page 3