Glen Canyon: Nesting Season, Habitat Destruction, and Pesticide

The nesting season is in full swing, now, and pictures of baby owls and other baby wildlife are beginning to hit the Internet. Glen Canyon is – or has been – an exceptionally good nesting area, with many kinds of habitat, undisturbed thickets for protected breeding spots, and easy access to food and water.

But the Natural Areas Program doesn’t appear to have registered this. We reported on this last year, and they’re doing it again – breaking down thickets and spraying pesticides, despite the obvious risk of disturbing birds and other wildlife. An observer wrote us: “… a group of four individuals with picks and axes are at it in the mid section of the park.”

Spraying pesticides in Glen Canyon March 2013

“This is way back in the park which we had hoped to keep wild. They’ve already removed much of the understory and now they are poisoning. ”

It’s no use to ask the staff to look out for nests. Birds, especially small ones, hide their nests as thoroughly as they can. They’re difficult to find even if you know what to look for. Some are very tiny: a hummingbird’s nest is the size of a quarter. Even with the best will in the world, these workers would find it impossible to guard against disturbing or destroying nests or dens.

2013-03-14 (2)

What is it?  A tank mix of Aquamaster and Milestone, apparently. Aquamaster is glyphosate, the same stuff that goes in Roundup. And Milestone is the pesticide that doesn’t go away (and is therefore banned in New York, which fears it will get into its waterways). The Natural Areas Program has steadily increased its use of pesticides since 2009, and Milestone use has increased particularly sharply in 2012.  It looks like 2013 is off to a good start.  (For more information about the pesticide applications and the pesticides themselves, read SF’s Natural Areas Program Uses Even More Pesticides.)

SF’s Natural Areas Program Uses Even More Pesticides

The 2012 final data are in, and it’s official: In 2012, the Natural Areas Program (NAP) used more pesticides than in any year from 2008 (the first year for which we have data provided by the City). This is true by any measure, as the graphs below indicate. [Note: Graph edited to indicate units]

[Edited to Add: NAP also used more Tier I pesticide – the most toxic – than the rest of SF RPD areas together. HERE]

pesticide use number n vol 2008 to 2012

Depending on the measure you choose, usage has increased anywhere from 12% to 40% from 2011. It’s between 3 and 4 times the usage in 2008.


What pesticides have they been using?

The same as before: Tier II and Tier I pesticides, defined as more hazardous and most hazardous. (For a detailed discussion of these chemicals, click HERE:  Natural Areas Program’s Pesticides: Toxic and Toxic-er.

  • Aquamaster/ Roundup (Glyphosate). (Tier II)  This is one of the world’s most widely used herbicides, but in vitro research has linked these chemicals to changes to human cells, some of which are of the kind that could cause birth-defects. The EPA is studying whether it is an endocrine disruptor. The fact that it’s widely used gives us little comfort; a different widely used herbicide has just been declared unacceptably toxic to bees.
  • Garlon (Triclopyr). (Tier I) To NAP’s credit, they have reduced the use of this extremely toxic herbicide since the peak in 2010. It’s a Tier I pesticide, and associated with numerous diseases in humans, and potential kidney impacts on dogs.
  • Polaris (Imazapyr). This Tier II herbicide is a problem because it spreads (it doesn’t stay where it’s applied) and it persists (it doesn’t break down easily). It’s a relatively new herbicide, and we don’t know quite what it does – though its breakdown product  is neuro-toxic. It’s banned in Europe, and neighbors are fighting against its use in privately owned forests in Northern California.
  • Milestone (Amino-pyralid). This Tier I toxic chemical sticks around even more persistently than imazapyr. It was banned for a time in the UK because if animals eat and excrete it, the excreta are still poisonous – as is the manure made from it. It’s banned in New York state because they aren’t sure it won’t poison the water. NAP’s used it in Lake Merced, Pine Lake, Glen Canyon, and Mount Davidson, all of which are areas where water contamination is possible. [Edited to Add: In 2013, Milestone was reclassified as a Tier II chemical.]


Of course these chemicals are not good for people, and one would think that in a city that is so conscious of organic and green produce and products, wild lands would be one area that we’d try to keep organic. Not so. We even found evidence of blackberry bushes being sprayed – during the fruiting season when children and adults, birds and animals feast on the bonanza of berries.

Recent research indicates that both triclopyr and imazapyr are potentially toxic to butterflies – but NAP continues to use both Garlon and Polaris on Twin Peaks, where NAP are also struggling to re-introduce the endangered Mission Blue butterfly. Glyphosate is known to be dangerous to amphibians; but NAP uses Aquamaster around Lake Merced, Pine Lake, and in Glen Canyon – all near water-courses.

Finally, we have another problem with this use: it may be glorifying chemical solutions. A few months ago, a “volunteer” in Glen Canyon was found applying an unapproved pesticide to an area near a trail, without posting any notices or keeping any record of amounts or conditions. He believed he was doing a good thing for the environment. We have heard since of many other instances of random herbicide application in Natural Areas.


Furthermore, the list of plants on which it’s used also keeps expanding. It’s currently around 30, up from under 2 dozen a year ago. Some of the plants being sprayed aren’t on the list of the California Invasive Plants Council or USDA noxious plants lists.

We ask SF Recreation and Parks Dept  to stop using Tier I and Tier II pesticides in the Natural Areas. An escalating use of herbicides is bad for the environment and the people, pets and wildlife using these parks;  sends a damaging message about priorities; and indicates a lack of success.

The Natural Areas Program and Pesticides: Volumes and Numbers

We talked about pesticide use in the Natural Areas a number of times, and particular of the increasing volumes of the “Fearsome Four” pesticides they use most:

  • Glyphosate (Roundup or Aquamaster);
  • Triclopyr (Garlon or Garlon 4 Ultra);
  • Imazapyr (Polaris or Habitat); and
  • Amino-pyralid (Milestone).

[Read more about the effects of these herbicides HERE: SaveSutro’s article Toxic and Toxic-er.]

We got San Francisco’s Natural Areas Program pesticide use records under the Sunshine Act, and used them to create a graph of the number of applications by year. We’ve shown this graph at some of our presentations.

Recently someone spoke to us about the graph. “I asked NAP about it, and they said that possibly the number of applications has gone up, but the amount of pesticide use has gone down because they use less in each application.”

Possibly.  And possibly not.


What we found when we looked was that volumes have increased even more. (This is based again on the data provided us under the Sunshine Act.)

  • Between 2010 and 2011 the number of applications went up 21%. The volume of pesticide (in fluid ounces) used went up by 25%.
  • Between 2009 and 2010, the number of applications went up 184%. The volume of pesticide used went up by 365%.

So here’s that graph:

(Milestone doesn’t show up here because until now, the volume of applications has been small. Possibly, given its persistence, we should count it cumulatively?)

[Click HERE for more about ” Milestone” – aminopyralid.]

Edited to Add: For those interested in details of NAP’s pesticide use, calculated four different ways (number of applications; volume; active ingredient; and “acid equivalent”) here’s an article with details:

Click here for SaveSutro’s article: Measuring Pesticide Use by the Natural Areas Program

This graph that summarizes it by comparing pesticide use on various measures to 2008 levels. Pesticide use went down in 2009, then increased sharply in 2010 by all measures. In 2011, it rose in volume terms and number of applications, and declined very slightly when measured by active ingredient or acid equivalent.


[Edited to replace with the more precise and detailed calculation, above.]

Edited to Add (for those with a technical bent): SF RPD used various formulations of glyphosate over the years. Technically, to compare them you need to calculate “Acid Equivalents” of the various formulations. We did this exercise,  converted them to Aquamaster equivalents, and adjusted the numbers. It made no significant difference. Between 2010 and 2011 the number of applications went up 21%. The adjusted volume of pesticide used went up 52%. Between 2009 and 2010, the number of applications went up 184%. The adjusted volume of pesticide used went up 264%.

“Milestone” Pesticide in Glen Canyon (and Why New York Prohibits It)

This article is being reproduced, with permission and minor changes, from Death of a Million Trees.  “Milestone” (Aminopyralid) is one of the “Fearsome Four” pesticides the Natural Areas Program uses.

[Click HERE for an article on the “Fearsome Four” major pesticides and HERE for “Toxic and Toxic-er”  about each of these herbicides.]

The notice in this picture comes from Glen Canyon Park. As this article points out, this chemical is prohibited in New York; persists in the environment;  shouldn’t be used in watershed areas – and its use here may be violating the San Francisco’s Integrated Pest Management Policy.



Recently visitors to Glen Canyon Park in San Francisco spotted a Pesticide Application Notice in their park, which states that Milestone herbicide was used on “sweet pea.”  Sweet pea is not classified as an invasive plant by the California Invasive Plant Council.  Milestone herbicide is classified as Tier I “Most Hazardous” pesticide by San Francisco’s IPM program because it persists in the ground for a long time.  The City’s IPM policy states that it is approved for use on “invasive species.”  Since sweet pea is not an invasive plant, we assume this pesticide application violated San Francisco’s IPM policy.


The federally mandated Material Safety Data Sheet (MSDS) for Milestone advises users to, “Prevent [Milestone] from entering into soil, ditches, sewers, waterways and/or groundwater.”  The MSDS also says that Milestone “is not readily biodegradable according to OECD/EEC guidelines.”

Kid playing in Glen Canyon Park

For these reasons, the manufacturer of Milestone herbicide withdrew its application to sell Milestone in the State of New York, after the State of New York determined, “The [New York State] Department [of Environmental Conservation] could not ensure that the labeled use of aminopyralid [the active ingredient in Milestone] would not negatively impact groundwater resources in sensitive areas of New York State.” 

[Click HERE to read that finding.]

In other words, the sale of Milestone herbicide is banned in the State of New York.

Since Glen Canyon is a watershed to Islais Creek, we believe it is irresponsible to use Milestone in that park. [Islais Creek is the stream that runs through the bottom of Glen Canyon Park.]  And clearly there is no justification for using this persistent herbicide on a plant as benign as sweet peas.  Since Glen Canyon park is the home of a year-round day care center as well as a summer camp which leads children throughout the park, it is outrageous that these pointless risks were taken there.


As we celebrate the 50th anniversary of Rachel Carson’s ground-breaking book, Silent Spring, there is renewed media interest in this issue.  We welcome this reminder that Rachel Carson informed the public in 1962 that DDT was having a devastating impact on wildlife.  DDT had been used for about 20 years, but it took that long for us to notice that some species of birds had been poisoned nearly to extinction.  And it took another 10 years for DDT to finally be banned in 1972.

Rachel Carson was vilified for her revelations, just as critics of the so-called Natural Areas Program are being vilified by supporters of that program.  We have been called “chemophobes” and “anti-chemical crazies.”

Frank Graham, editor of Audubon Magazine, recently wrote an article for Yale University’s “environment 360” blog about the abuse that Rachel Carson endured after the publication of Silent Spring.

[Click HERE to read that article.]

He recounts several anecdotes about the attacks on her character.  For example, “An official with the federal Pest Control Review Board drew laughter from his audience when he remarked, ‘I thought she was a spinster.  What’s she so worried about genetics for?’”

Forty years after DDT was banned in the United States we have a local example of the persistence of this dangerous chemical in our environment.  From 1947 to 1966, several companies on the harbor in Richmond, California formulated, packaged, and shipped pesticides, including DDT.  The site was designated a State Superfund site in 1982, and in 1990 the EPA placed the site on a national priorities list for clean up.  “Remedial actions took place on the site from 1990 to 1999.”  Twelve years later, the EPA tells us, “Although actions were taken to reduce the risk from the pesticides found on site…sediments and the water [in that location] are still contaminated with pesticides, primarily DDT and dieldrin.

In other words, we fouled our water with dangerous pesticides; we then spent many years and probably a lot of money trying to clean up after ourselves, and 40 years later we are still living with the consequences of our foolishness.

What have we learned from that experience?  Now we are using a very persistent chemical (Milestone) on a benign plant (sweet pea) in our public parks.  We have learned nothing.  And those who have some economic gain from poisoning our parks—or are clueless about the risks they are taking—are defending the use of pesticides and trying to shut us up, just as they tried to shut Rachel Carson up 50 years ago.  We are proud to be in her company and we are inspired by her leadership.


Peaches at “Organic U-Pick” (Photo Credit: Arnita Bowman)

We prefer to end our stories on a positive note when we can, so we turn to a book we read recently about a fruit farmer in California’s Central Valley.  David Mas Masumoto wrote Epitaph for a Peach to tell us about his transition from the traditional farming methods used by his father to organic methods.  He has abandoned rigorous weed and pest control and he is learning to live in harmony with his orchards rather than fighting against nature.  He tells us about the difficult decision to quit using pesticides:

“I am reminded that in some valley wells they have found traces of a chemical called DBCP in ground water aquifers.  DBCP was linked to sterility in males and is now banned in the United States.  My dad used some DBCP years ago…No one knew it would contaminate drinking water.  Neighboring city folks are angry with farmers for damaging their water supply.  ‘How could you farmers poison the water?’ they ask.  My dad didn’t choose to pollute the water table.  He did nothing illegal.  He simply trusted the chemical company and the governmental regulatory agencies.

Mr. Masumoto has learned from bitter experience.  What we know about pesticides today is not necessarily what we will learn about them tomorrow.  We often look back on our use of pesticides with regret.  So, shouldn’t we at least avoid using them when we don’t need to—such as on flowers just because they aren’t native—or in places where the risks are great—such as public parks occupied by children?

Let’s turn that rhetorical question into the affirmative statement that it deserves to be:  We should not be using pesticides in our public parks or on plants that aren’t doing any harm.  We will live to regret it when we do.  And let’s express our gratitude to Rachel Carson for inspiring us to keep informing the public of the needless risks that are being taken in their parks.

Natural Areas Pesticides: The Fearsome Four

Three of the Four on Mt Davidson

The Natural Areas Program (NAP) uses four herbicides classified as “Most Hazardous” (Tier I) or “More Hazardous” (Tier II) by San Francisco’s Department of the Environment (DoE):

  • Garlon 4 Ultra (triclopyr)
  • Roundup or Aquamaster (glyphosate)
  • Polaris or Habitat (imazapyr)
  • Milestone (aminopyralid)

All these chemicals have serious problems: they’re associated with birth-defects and pregnancy failures; they’re endocrine disruptors; they poison animals, especially amphibians but also reduce bird-nesting success; and/or they’re persistent – they stick around.

For details of the risks associated with each one, read the article Natural Areas Program’s Pesticides: Toxic and Toxic-er.

We often get questions about this, especially from people who have heard about NAP from its supporters.

Source: (derived from from SF City records)

Q:  They hardly ever use pesticides, right? Just once every few years?

A:  NAP applied pesticides 86 times in 2011, up from 71 the year before. (We’re relying on City records here. There may be gaps.)

Q: But maybe they used less in each application?

A: The amounts used went up in proportion.

Q: Don’t they use very small amounts? Doesn’t the dose makes the poison?

A: In 2010, NAP used more Tier I herbicides than any comparable park department. (We don’t have compiled data for 2011 for other parks departments.)  Anyway, “the dose makes the poison” isn’t always true. Here’s what the American Chemical Society said in its Public Policy Statement, Testing for Endocrine Disruption:

Endocrine disruption is the alteration of the endocrine system that causes adverse health effects in an intact organism, or its progeny, or (sub)populations. Endocrine hormones naturally act at ultra-low concentrations and certain chemicals are suspected of altering endocrine function at similarly low concentrations, which sometime occur in the environment. A large and growing body of environmental health literature shows that endocrine disrupting substances have complicated dose-response curves that do not fit the central tenet of regulatory toxicology, namely, that the ‘dose makes the poison.’

Q: But aren’t they herbicides… don’t they act only on plants?

A:  They act differently on plants and on animals, but they still can – and do – impact animals (and people).  They may use different bio-chemical pathways in animals and in plants, and thus have different effects. None of these effects is good. The city of San Francisco subscribes to the “Precautionary Principle” – if you don’t know the effects, don’t use it. The natural areas are where children explore, people walk, and pets are exercised. This is not a risk they should take.

West Portal Monthly: Clearcut Case of Overkill at Mt Davidson Park

The West Portal Monthly today published an article by Jacquie Proctor explaining the problem of the NAP specifically at Mt Davidson and generally throughout the city.  The plan seeks to destroy at least 1600 trees on Mt Davidson alone. Read on:

Three Poisons on Mt Davidson: Garlon, Aquamaster, Milestone Pesticides

Recently, someone sent the San Francisco Forest Alliance this Pesticide Notice. It’s for Mount Davidson, for the end of January/ early February 2012. We found it shocking. Why?

It plans on using three of the most toxic pesticides San Francisco permits on Mount Davidson: Garlon 4 Ultra (Triclopyr); Milestone VM (Aminopyralid) and Aquamaster (Glyphosate). In several years of reviewing pesticide use on Natural Areas, we have not seen anything like this.

Garlon 4 Ultra and Milestone VM are Tier I chemicals, rated as “Most Hazardous” by San Francisco’s Department of the Environment. Their use is “Most Limited: justify use at public hearing.” Aquamaster, which has the same active ingredient as Roundup, is Tier II, More hazardous. (We have never seen the Natural Areas Program – NAP – use Tier III, Least Hazardous chemicals.)

Until now, we have not seen a situation where NAP uses two Tier I and a Tier II chemical in the same location.


1)  Garlon 4 Ultra, according to the guidelines published by San Francisco’s Department of the Environment (SFDoE) can be used as follows: “Use only for targeted treatments of high profile or highly invasive exotics via dabbing or injection. May use for targeted spraying only when dabbing or injection are not feasible, and only with use of a respirator. HIGH PRIORITY TO FIND ALTERNATIVE”  (The capitals are in the original guidelines.)

  • Garlon “causes severe birth defects in rats at relatively low levels of exposure.” Baby rats were born with brains outside their skulls, or no eyelids. Exposed adult females rats also had more failed pregnancies.
  • Rat and dog studies showed damage to the kidneys, the liver, and the blood.
  • About 1-2% of Garlon falling on human skin is absorbed within a day. For rodents, its absorbed twelve times as fast. It’s unclear what happens to predators such as hawks that eat the affected rodents.
  • Dogs  may be particularly vulnerable; their kidneys may not be able to handle Garlon as well as rats or humans.  Dow Chemical objected when the Environmental Protection agency noted decreased red-dye excretion as an adverse effect, so now it’s just listed as an “effect.”

2)  Milestone VM, also a Tier I chemical, has this note in the SFDoE guidelines:  “For invasive species in natural areas where other alternatives are ineffective, especially for invasive legumes and composites such as yellow star thistle and purple star thistle. Listed as Tier I due to persistence but toxicity & potential exposure are very low.

It deserves that Tier I ranking. Dow had to withdraw it from the UK because it was poisoning the compost.

It seems that this chemical is so persistent that if it’s sprayed on plants, and animals eat those plants, it still doesn’t break down. They excrete the stuff in their droppings. If those are composted — it still doesn’t break down the chemical. So now the compost’s got weedkiller in it, and it doesn’t nourish the plants fertilized with the compost, it kills them.

The manufacturer sees this as  a benefit. “Because of its residual activity, control can last all season long, or into the season after application on certain weed species,” says the Dow AgroSciences FAQ sheet.

What it means on Mt Davidson is that the chemical will be there for years. And, incidentally, none of the targeted plants – oxalis, erhata grass or Cape Ivy – are the “invasive legumes” or the star or purple thistle mentioned in the SFDoE guidelines.

3)  Aquamaster is a Tier II chemical. Here the SFDoE has made a recent change to its guidelines allowing terrestial use.

“Terrestrial uses: Spot application of areas inaccessible or too dangerous for hand methods, right of ways, utility access, or fire prevention. Use for cracks in hardscape, decomposed granite and edging only as last resort. OK for rennovations (sic) but must put in place weed prevention measures.”  The NAP reached a “last resort” 38 times last year (i.e. 2011).

Glyphosate has been associated with pregnancy problems and birth defects. A 2005 article published in the journal of the National Institutes of Health noted that glyphosate was toxic to placental cells (and Roundup was even more so):

“… glyphosate is toxic to human placental JEG3 cells within 18 hrs with concentrations lower than those found with agricultural use, and this effect increases with concentration and time or in the presence of Roundup adjuvants.”

In addition, it’s an endocrine disruptor.  French scientists published an article in the journal Toxicology titled, “Glyphosate-based herbicides are toxic and endocrine disruptors in human cell lines.”

For more about these and other pesticides the NAP uses, see The Natural Areas Program’s Pesticides: Toxic and Toxic-er on the Save Sutro Forest website.