HomeMy WebLinkAboutMINUTES - 03122013 - C.90RECOMMENDATION(S):
Accept the 2013 Annual Report on the Integrated Pest Management (IPM) Program.
FISCAL IMPACT:
None.
BACKGROUND:
The County Board of Supervisors adopted an Integrated Pest Management (IPM) Policy in November 2002. The
Board adopted the policy in response to a report published in March 2001 by the County’s Public and Environmental
Health Advisory Board (PEHAB). An Integrated Pest Management Task Force was established to look at the
County’s use of pesticides and ways of reducing them through the use of IPM. In January 2009, an IPM Coordinator
was hired and in November 2009 the Task Force was dissolved and the IPM Advisory Committee was formed to take
its place.
APPROVE OTHER
RECOMMENDATION OF CNTY ADMINISTRATOR RECOMMENDATION OF BOARD COMMITTEE
Action of Board On: 03/12/2013 APPROVED AS RECOMMENDED OTHER
Clerks Notes:
VOTE OF SUPERVISORS
AYE:John Gioia, District I Supervisor
Candace Andersen, District II
Supervisor
Mary N. Piepho, District III
Supervisor
Karen Mitchoff, District IV
Supervisor
Federal D. Glover, District V
Supervisor
Contact: Tanya Drlik,
335-3214
I hereby certify that this is a true and correct copy of an action taken and entered on the minutes of the Board
of Supervisors on the date shown.
ATTESTED: March 12, 2013
David Twa, County Administrator and Clerk of the Board of Supervisors
By: June McHuen, Deputy
cc: Tasha Scott, D Gary, T Drlik
C.90
To:Board of Supervisors
From:William Walker, M.D.
Date:March 12, 2013
Contra
Costa
County
Subject:Annual Report on the Integrated Pest Management Program
CLERK'S ADDENDUM
Speakers: Maude Devictor; Shirley Shelangoski, Parents for a Safer Environment (PFSE); Michael Sullivan,
PSFE; Susan Junfish, PFSE.
ATTACHMENTS
G:\NON CONTRACTS\2012 IPM ANNUAL REPORT FINAL for BOS, 2-15-13.pdf
G:\NON CONTRACTS\2012 IPM Annual Report Appendix A--Ground Squirrel Rpt.pdf
G:\NON CONTRACTS\2012 IPM Annual Report Attachment A. General Pest Mgmt Dec Tree.pdf
:\NON CONTRACTS\2012 IPM Annual Report Attachment B. Decision Documentation Tree.pdf
G:\NON CONTRACTS\2012 IPM Annual Report Attachment C. IPM Priority Assessment Tool.pdf
G:\NON CONTRACTS\2012 IPM Annual Report Attachment D. CCC Posting Policy, revised 10-22-12.pdf
G:\NON CONTRACTS\2012 IPM Annual Report Attachment E. Ground Squirrel Trap Rpt.pdf
IPM Annual Report 1 January 31, 2013
Contra Costa County Integrated Pest Management Advisory Committee
2012 Annual IPM Program Status Report
to the
Transportation, Water, and Infrastructure Committee of the Contra Costa Board of Supervisors
EXECUTIVE SUMMARY
This year, the IPM Advisory Committee explored how pest management decisions are being made in the County
and how to make the IPM Program more transparent, especially in the area of pesticide use. The Committee also
worked on a comprehensive method for evaluating the County’s IPM Program. It was felt that pounds of pesticide
used is not the only or the best metric for evaluating the IPM program.
The IPM Advisory Committee produced a generic decision tree to document how County staff currently make
pest management decisions. The Committee also developed a form for the Departments to use in documenting the
details of specific pest management decisions. The Committee provided input to the IPM Coordinator on updating
the County’s IPM webpages and adding more information about pesticide use. In 2013 the County will launch
online posting of pesticide use in the areas where posting is required by the County’s pesticide posting policy. The
IPM Committee also developed an IPM priority assessment tool for assessing implementation of elements of an
IPM program and for prioritizing work on IPM implementation.
The Committee recommended, and the Departments agreed, that each Departmental IPM program will choose a
priority that is not fully implemented, determine appropriate metrics, and commit to improving implementation of
the priority in 2013. The Departments also agreed to identify a priority pesticide or pest management activity and
complete the form for documenting management decisions to demonstrate their decision-making process.
The County’s use of pesticide continues to decrease. Overall, County operations have decreased their pesticide
use by about 65% since FY 2000/01. Use of pesticides that are either known or probable carcinogens,
reproductive or developmental toxicants, cholinesterase inhibitors, known groundwater contaminants, or of high
acute toxicity has decreased by 99%. Twenty-two of the 31 pesticides in these categories that have been used over
the years have been phased out.
Bed bugs remain a serious issue in the County, especially for those citizens who are least able to cope with the
problem, such as the elderly, the disabled, and those with little means. The IPM Coordinator is working to provide
information to these citizens about what they can do to prevent bites and reduce the numbers of bed bugs.
The Agriculture Department continued its noxious weed management program. The Department surveyed over
216,000 acres of public and private land and treated 235 net acres of weeds. This year Department staff found and
eliminated small infestations of two weeds that are new to Contra Costa County.
In the Public Works Department, the Facilities Division continues to repair structural deficiencies in buildings to
prevent the entry of pests. These deficiencies are prioritized and the backlog is addressed as time and resources
allow. The County’s structural IPM contractor continues to provide excellent service. The Grounds Division has
switched to organic fertilizer and has purchased new equipment to make their work more efficient. All prunings
are now being chipped on site and used as mulch. The Roadside and Creeks Divisions participated in an annual
refresher training in habitat assessment for endangered and threatened species in order to comply with the
Department’s Routine Maintenance Agreement with the California Department of Fish and Game. The
Department is continuing its multi-year study comparing herbicide with sheep or goat grazing. In addition to this
study, the Department grazed 76 acres to manage weeds. The data being collected on grazing will help the
Department to determine, where, when, and how much to use grazing as a weed management tool.
IPM Annual Report 2 January 31, 2013
HISTORY
From 2002 to 2009, an informal IPM Task Force met to coordinate implementation of the IPM Policy that was
adopted by the Board of Supervisors in November 2002. A formal body, the Integrated Pest Management (IPM)
Advisory Committee, was created by the Board of Supervisors in November 2009. This report is the fourth annual
status report from the IPM Advisory Committee.
BACKGROUND
Purpose of the IPM Advisory Committee
The purpose of the Committee is to:
1. Protect and enhance public health, County resources, and the environment;
2. Minimize risks and maximize benefits to the general public, staff, and the environment as a result of
pest control activities conducted by County staff and contractors;
3. Promote a coordinated County-wide effort to implement IPM in the County in a manner that is
consistent with the Board-adopted IPM Policy;
4. Serve as a resource to help the Agriculture and Public Works Departments and the Board of
Supervisors review and improve existing pest management programs and the processes for making
pest management decisions;
5. Make policy recommendations upon assessment of current pest issues and evaluation of possible IPM
solutions; and
6. Provide a forum for communication and information exchange among members in an effort to
identify, encourage, and stimulate the use of best or promising pest management practices.
Members of the IPM Advisory Committee
Currently the Committee has a total of 13 seats consisting of voting and non-voting members.
The 8 voting members include
• One representative from Contra Costa Health Services
• One representative from the County Storm Water Program
• One representative from the County Public and Environmental Health Advisory Board
• One representative from the County Fish and Wildlife Committee
• One representative from an environmental organization
• Three at-large members of the public.
The 4 non-voting members include
• A representative from the Agriculture Department
• Two representative from the Public Works Department (Facilities Division and Maintenance
Division)
• One representative from the County’s pest management contractor
The Committee also has one public member alternate who only votes if one or more of the three at-large public
members is absent from a meeting.
IPM Annual Report 3 January 31, 2013
COMMITTEE PRIORITIES FOR 2012
In January of this year, the IPM Advisory Committee decided to focus its work on the following three aspects of
an IPM program and to develop recommendations for the Departments of Agriculture and Public Works around
these three topics:
A. IPM decision-making—how pest management decisions can be clarified and documented
B. Data management/IPM program evaluation—what data should be collected and how to evaluate it
C. IPM program transparency—how information and data should be presented to increase transparency
The Committee formed three subcommittees to work on these priorities.
2012 ACCOMPLISHMENTS OF THE IPM ADVISORY COMMITTEE AND THE IPM
COORDINATOR
Accomplishments of the IPM Committee
The IPM Advisory Committee (the Committee) held six regular meetings during 2012 and the subcommittees
held a total of 20 meetings to address the above priorities. The IPM Coordinator serves as staff to the Committee
and the three subcommittees. The accomplishments of the IPM Committee and its subcommittees are as follows:
Priority A: IPM Decision-Making
Through the work of the subcommittee, the IPM Advisory Committee
1. Gained an understanding of the complexities involved in making pest management decisions
2. Documented an existing Departmental decision-making process
a. Produced a specific weed management decision tree for the Public Works Department
b. Produced a detailed, annotated decision path for a specific weed problem on a roadside,
and from this began developing a form for the Departments to use
3. Prepared a generic pest management decision tree
The Committee recommends to the Departments that they
1. Accept the generic decision tree (see Attachment A) as documentation of how pest management
decisions are currently made
2. Use the Decision Documentation Tree (see Attachment B) as a method for documenting
management decisions for new pests, new sites/situations, and for using new pesticides
Priority B: Data Management/IPM Program Evaluation
Through the work of the subcommittee, the IPM Advisory Committee
1. Developed a tool (see Attachment C) to assess the implementation of the elements of an IPM
program, and to prioritize those elements
2. Worked with each Department to complete the tool
3. Verified that the vast majority of the data that needs to be collected is already being collected
The Committee recommends to the Departments that they:
1. Use the IPM Priority Assessment tool for assessing implementation of elements of an IPM
program and as a method for prioritizing work on IPM implementation
2. Have each Departmental IPM Program work with the Data Management subcommittee to choose
one priority that is not fully implemented, determine appropriate metrics, and commit to
improving implementation of the priority in 2013
3. Have each Departmental IPM program identify a priority pesticide or pest management activity
and fill out the Decision Documentation Tree (Attachment B) for that pesticide or activity
IPM Annual Report 4 January 31, 2013
Priority C: IPM Program Transparency
Through the work of the subcommittee, the IPM Advisory Committee
1. Provided input to the IPM Coordinator to update the IPM webpages on the Health Services
website and add more information about pesticide use and notification of use
2. Developed the format for a permanent posting sign that can be used in conjunction with current
posting methods
3. Developed a method for web posting of pesticide use
4. Revised the County’s pesticide use posting policy to accommodate web posting and the use of
permanent signs (see Attachment D)
The Committee recommends to the Departments that they:
1. Accept the revised pesticide use posting policy
2. Begin using the web posting method in 2013
3. Evaluate the web posting process after one year
Accomplishments of the IPM Coordinator
In addition to working on each subcommittee, the IPM Coordinator accomplished the following:
Bed Bugs
The common bed bug continues to be one of the most serious pests in the County, a pest that has provoked
citizens to misuse pesticides to an alarming extent. Pesticides do not solve the problem, and in many cases
make the problem worse. We increasingly see bed bugs affecting the citizens of Contra Costa who have the
fewest resources to combat them.
There is a sense that the bed bug problem is increasing in the County, but the County has not been collecting
data that can verify that assumption. We are working to remedy this.
This past year a single bed bug was found in the Contra Costa Regional Medical Center. It appears to have
entered the facility on a child’s car seat. Fortunately, it was quickly spotted and killed, and no others were
found after a thorough search of the area. This kind of bed bug introduction is likely to occur more frequently
in the future.
In an effort to educate County staff and the public about bed bugs, the IPM Coordinator
• Continued to organize and staff the County’s Bed Bug Task Force; the Task Force meets monthly and
advocates for increasing public awareness of bed bug problems and for developing sound bed bug
management policy throughout the County
• Joined forces with Alameda County Vector Control and the University of California Cooperative
Extension to widen the scope and effectiveness of the Bed Bug Task Force
• Began work with the new Bed Bug Task Force partners to design a study of the efficacy of IPM methods
versus conventional methods for controlling bed bugs in multi-family dwellings; the site of the study will
be Contra Costa County
• With the help of the Bed Bug Task Force, investigated (by telephone) a number of bed bug infestations
that came to the attention of the Health Services Department
• Began developing a specific bed bug prevention protocol for the County’s Head Start programs; once
complete this protocol can be used in private child care/pre-school settings across the County
• Presented a training in the use of the County’s bed bug prevention protocols to the County’s Brookside
homeless shelter staff
• Presented a bed bug awareness talk to the staff and clients of the Ambrose Senior Nutrition Center in Bay
Point; developed a notebook of laminated photos for distribution to other senior facilities
• Presented a bed bug awareness training to the Northern California Entomology Club
IPM Annual Report 5 January 31, 2013
• Developed and presented a bed bug awareness training to around 90 parents at Meadow Homes
Elementary School in Concord. Nati Flores from the Michael Chavez Center was a co-presenter. We hope
to train teachers and administrators at the school as well.
• Worked with Mara Gold in Supervisor Mitchoff’s office and Betsy Burkhart, Director of the County
Office of Communications and Media, on increasing bed bug awareness in the County
Outreach/Advising
• Organized a meeting of the Bay Area IPM Coordinators group to network and share new ideas
• Agreed to provide on-going advice along with review of educational materials for IPM training in child
care settings as part of a project of the Center for Environmental Research and Children’s Health at U.C.
Berkeley
• Agreed to participate in a committee developing IPM standards of practice for the Healthy Homes
Alliance in Alameda County; these standards, which include many more areas than just pest management,
will be directly applicable to Contra Costa County and will become part of a manual for in-home visitors
in a wide range of professions
• Worked with the Cities of San Pablo, El Cerrito, Walnut Creek, and Richmond on IPM issues in the cities
• Responded to a number of requests for pest management information from County staff and citizens
Pesticide Hazard Identification
• Met with Department staff to continue work on developing a pesticide hazard identification process for
the County
• This will be completed and presented to the IPM Advisory Committee at the beginning of the new year.
Responding to Public Records Requests
• From June 1 to September 24, spent 51.25 hours (9% of working hours) responding to public records
requests from Parents for a Safer Environment
2012 DEPARTMENT IPM PROGRAM HIGHLIGHTS AND CHALLENGES
Agriculture Department
IPM Program Highlights
• The Department actively worked on all three subcommittees of the IPM Advisory Committee and has
agreed to the Committee’s recommendations to the Departments.
• All historically treated noxious weed sites were surveyed and treated again this year
In order to achieve eventual eradication of target noxious weeds, all sites that have not been declared
eradicated must be surveyed each year and treated if necessary. Significant progress was made in the
Department’s eradication and control effort this year. The department program involves 18 target
terrestrial noxious weed species. This is two more than last year, because this year the Department found
two species new to Contra Costa. The Department surveys and/or spot-treats weeds on more than 580
sites that range from one acre to more than 5,000 acres in size. This year the Department surveyed over
216,000 acres (almost 2 ½ times as many acres as last year) and only treated 235 net acres (two-thirds of
what was treated last year).
Treatment involved hand removal, mechanical removal and targeted treatment with low toxicity
herbicides. With rare exception, pesticide treatment involved highly focused spot spraying using
backpack sprayers. In some newly treated areas, treatment involved focused area spray using a vehicle
mounted sprayer. The program involved over 4,000 hours of direct field time by staff. Of this,
approximately 90-95% of the time was spent in surveying and monitoring with the remainder being spent
on pesticide application.
IPM Annual Report 6 January 31, 2013
• One new Japanese dodder (Cuscuta japonica) site found this year
Japanese dodder is a very aggressive parasitic plant that has the potential to severely alter the composition
and function of riparian areas. It also affects ornamental plantings and agricultural crops. It is native to
Southeast Asia and was first discovered in the county in spring of 2004.
One new site involving two adjacent residential properties was discovered this year by Department staff
detection specialists. All the landscaping that was infested with Japanese dodder was manually removed
and buried at a land fill. No pesticides were used. Staff will continue to monitor the site for a minimum of
three years until eradication can be declared.
Forty-four of the 48 historically infested properties in the county have been free of Japanese dodder for
three or more years, which meets the criteria for eradication on these properties.
• Red sesbania (Sesbania punicea) removal
This was the seventh year of red sesbania removal at the primary infestation site of Kirker Creek, Dow
Wetlands. This small tree has a high potential for environmental damage by displacing native plants and
wildlife in riparian areas. Red sesbania is an exotic invasive weed that is native to South America, and is
poisonous to humans, livestock, and many native vertebrates.
All historic sites were surveyed, and a total of 4,293 plants were removed this year. Staff removed 2,838
plants in 2011; 1,899 in 2010; 2,059 in 2009; 492 in 2008; 833 in 2007 and 878 in 2006. A few individual
red sesbania plants were removed in Grayson Creek and lower Walnut Creek by County Public Works.
Two new infestations were discovered on residential properties and abated this year. The fact that more
plants were removed this year than any previous year demonstrates that red sesbania seeds are long-lived,
and that the seed bank is healthy and persistent.
Infestations are located on three wildland and 11 residential properties. With the exception of the eight
established plants on the two new properties, all plants removed were seedlings that germinated from the
existing seed bank. Removal of red sesbania is performed mechanically or by hand pulling.
• Kangaroo thorn (Acacia paradoxa) removal
The County has one site infested with kangaroo thorn. The removal of the existing infestation in 2005
involved 52 hours of staff time. At that time the infestation covered a little less than one net acre. This
year, it took only 5.5 hours of staff time to accomplish the surveying and seedling removal. Only small
seedlings of less than one foot in height were found, and the infested area totaled less than one hundredth
of an acre.
Each year the Department removes by hand pulling all new seedlings sprouting from the old seed bank.
• Smooth Distaff Thistle (Carthamus baeticus)
There is only one known smooth distaff thistle infestation site in the county. It originated from the
movement of a tractor from Fallon, Nevada to the site off Christie Road in Martinez. The small
infestation was first discovered in 2005 by one of the Department’s biologists. For six years, the
Department spot-sprayed this area. This year the infestation had been suppressed to the extent that staff
were able to accomplish removal of all plants without the use of herbicide. The Department hopes to
continue working toward eradication using only mechanical or hand pulling on this species.
• Two new noxious weed species found: Japanese knotweed and woolly distaff thistle
Two very small infestations of Japanese knotweed (Fallopia japonica) were found in the county by staff
biologists. One is in Lafayette and one in El Sobrante. These are first recorded occurrences of this species
in Contra Costa County. Japanese knotweed spreads by tenacious rhizomes from which small pieces can
break and form a new plant. The weed is a particular threat in riparian areas where it can survive floods
and quickly colonize scoured streambanks. The plant can form very dense patches that shade out all other
vegetation. The rhizomes produce bamboo-like shoots that can penetrate through two inches of asphalt.
After considerable research and study, and after formally documenting the decision-making process, the
Department treated both Japanese knotweed sites with the herbicide active ingredient imazapyr. The
product called Stalker® was used in El Sobrante, but the product Habitat® was used in Lafayette because
IPM Annual Report 7 January 31, 2013
it is labeled for aquatic use, and there was a creek nearby, although no herbicide was used in or near the
creek.
Two woolly distaff thistle (Carthamus lantanis) plants were found by a staff biologist on CalTrans right-
of-way on Highway 4 at the Highway 680 overcrossing. The biologist removed the plants by hand. This is
the first recorded occurrence in the county. This noxious weed occurs in Nevada, and it is very likely that
the source of the infestation was thistle seed falling off a vehicle carrying infested hay or equipment. This
noxious weed can form dense monocultures that displace native plants and reduce the availability and
value of forage. The plant does not produce rhizomes.
• Departmental IPM plan updated
The Department performed a detailed review and revision of the Department’s IPM plan.
• Work on pesticide screening process continued
The Deputy Agricultural Commissioner met regularly with the Public Works Vegetation Manager and the
IPM Coordinator to work on developing a screening process for pesticides used in the County.
• Critical infrastructure protection continued
The Department continues to protect critical infrastructure including levees, earthen dams, railroad beds
and roadways from damage by ground squirrels.
This past summer the Department experimented with live trapping ground squirrels along 1,200 linear
feet of roadway. The project involved the use of 12 Black Fox® traps that were inspected daily.
Unfortunately this method proved to be very costly. Data from the field trial show that live trapping cost
23 times that of the Department’s traditional diphacinone bait treatment. In addition, there were a number
of other problems identified with live trapping. This technique may be useful in sensitive situations,
especially if ground squirrels are threatening infrastructure damage in an area inhabited by an endangered
vertebrate species. (See Attachment E and the Appendix A for the final report on this in-house field trial
of live trapping.)
• South American Spongeplant (Limnobium laevigatum)
AB1540 (Buchanan) was signed by the governor in September. The Department, with endorsement from
the Board of Supervisors, worked with the Assembly Member and her staff to develop this legislation that
mandates control of this serious aquatic invasive weed by the Department of Boating and Waterways.
This is a major accomplishment in protection of fragile Delta resources.
Agriculture Department Challenges
• Ground squirrel control alternatives
The department continues to search for alternatives to treated grain bait. Unfortunately, raptor perches and
live trapping of ground squirrels have proved to be ineffective and/or too costly.
• Finding alternatives to herbicides
Although in field operations the Department uses only least toxic “Caution” labeled herbicides, staff are
continually trying to find safer and more effective materials and methods for noxious weed control. This
includes evaluating the feasibility of mechanical or hand removal as well as new herbicides that may be
more efficacious and of reduced toxicity.
Public Works Facilities Division
IPM Program Highlights
• The Division assisted as needed in the work of the three subcommittees of the IPM Advisory Committee
and has agreed to the Committee’s recommendations to the Departments
IPM Annual Report 8 January 31, 2013
• Pestec, the structural IPM contractor, is providing excellent service
The Division hired Pestec IPM Providers in December 2009 for the County’s structural pest management.
They continue to do an outstanding job in the County and are very responsive to the County’s needs.
Pestec has an excellent relationship with their customers in County buildings.
• IPM awareness among County employees
Last year Pestec was still encountering employees who were unaware of the County’s IPM Policy and
were confused about how structural pest problems are handled in the County. This has changed in the past
year, and the process for handling pest problems is running smoothly. Building occupants are really
starting to understand the purpose of the IPM program and to recognize the benefits of finding and
treating the source of the problem without using a pesticide (or by occasionally spot-treating with a least
toxic pesticide).
• Correcting structural deficiencies in buildings continues
Pestec regularly reports on conditions conducive to pests (“deficiencies”) in County buildings. Correcting
these deficiencies is the key to pest prevention in County buildings. It has been difficult in the past for the
Division to keep up with the repairs because of lack of budget and staff, but this year the Division was
able to hire a lead carpenter, fill two other positions and hire two temporary workers. The Division has
been making progress installing doorsweeps, sealing cracks, screening windows, sealing pipe entries, and
screening off areas under steps going to buildings.
• Owls in downtown Martinez
Pestec discovered an extensive “boneyard” on the roof of the County Administration building at 651 Pine
in Martinez. It appears to be the remains of hundreds of meals taken by owls nesting on the roof. These
bones are most likely from small rodents like rats and mice, as well as birds such as starlings. Dr. Jim
Hale, wildlife biologist and member of the IPM Advisory Committee, will be collecting samples of the
bones for a study he is doing on prey taken by owls in Contra Costa County.
• Structural IPM program pesticide use remains low
In FY 09/10, 17 lbs. of pesticide active ingredients were used in the approximately 2.75 million sq. ft. of
County structures. In FY 10/11, only 9 lbs. of active ingredients were used in County buildings. These
pesticides are almost exclusively deployed as baits in bait stations or in cracks and crevices. Pestec
continues to successfully manage rats and mice exclusively with traps.
• Uptick in service calls involving ants, mice, bees and yellowjacket
In FY 11/12, the Facilities Division received 126 additional calls for service for various pest problems.
These are calls for service that are outside the regularly scheduled monitoring service of the pest control
contractor. This is a large increase over the 40 calls received last year. Nearly three-quarters of the 126
calls were for ants, mice, spiders, and bees/yellowjackets. The increase in ants and mice invading
buildings is probably weather related. The increase in yellowjacket nests near buildings may also be
weather related. The very dry winter meant that County buildings with irrigated vegetation were havens
for these creatures amidst very dry surroundings. The majority of ant and mice problems were in Head
Start buildings which by their nature often have more food and habitat available.
Two bee hives were found in the ancient olive trees at the Contra Costa Regional Medical Center in
Martinez. The trees are very large and have many cavities that are perfect for hives. Another hive has
actually been in one of the olive trees for many years. It is 8 to 10 ft. from the ground where the bees are
unlikely to impact any people, so that hive is left undisturbed. The other two hives, which were near the
ground with flight paths across a sidewalk in the front of the building, had to be exterminated. There was
no way to remove them without destroying the trees.
• Bed bugs in the County
Both the Concord and Brookside homeless shelters have instituted the bed bug prevention protocols
developed last year by the IPM Coordinator. So far, there have been no bed bug problems at Brookside.
The Concord shelter had an ongoing problem for several years, but the prevention protocols combined
with staff vigilance and cleaning drastically reduced the numbers of bed bugs found daily.
IPM Annual Report 9 January 31, 2013
The Concord shelter received a $10,000 gift to help buy new metal beds and new encased mattresses that
are easier to clean and provide far fewer hiding places for bed bugs than did the old wooden beds. The
new beds were installed in September. The staff performed a thorough cleaning of the sleeping areas
when the beds were installed, and with all the prevention measures in place, staff have not seen any bed
bugs since September. The shelter has had to reduce staff time devoted to bed inspections and cleaning,
but is now involving clients in this process.
It is unlikely that the facility will remain free of bed bugs because the chances for new introductions are
so high with the daily influx of new clients, but any new introductions will be quickly found.
Facilities Division Challenges
• Pest exclusion in County buildings
This continues to be a challenge, but the Facilities Division is making steady progress.
• Pest exclusion in leased buildings
Reducing pest intrusions into leased buildings continues to be more of a challenge since the responsibility
often falls to the landlord.
• Bed bugs in County buildings
Bed bugs are particularly difficult and costly to control. As bed bugs become more prevalent, it is very
likely that more County buildings will be affected. At this point, awareness and prevention are critical,
but the amount of work to outreach to all the County Departments and staff that need information is
daunting.
Public Works Grounds Division
IPM Program Highlights
• The Division participated in various aspects of the work undertaken by the three subcommittees of the
IPM Advisory Committee and has agreed to the Committee’s recommendations to the Departments
• The Division switched to organic fertilizer
In January 2012, the Division stopped using synthetic fertilizer and switched to organic fertilizers. Staff
have seen a significant difference in the quality and health of the turf they manage. There were a number
of complaints about the smell of the product at some of the health clinics, but the manufacturer is
remedying this problem.
• New equipment purchased
The staff are better equipped now than they have been for the last 10 years. The Division purchased a
power sweeper to clean up acacia seeds which are the source of a perennial weed problem at a number of
sites. They also purchased a stump grinder and a chipper. Now all prunings are chipped on site and put
back on the soil as mulch.
Grounds is now using MP Rotators as sprinkler heads. These deliver multiple streams (rather than a
spray) of water at a slow, steady rate. This slower application rate allows water to soak into the soil
without running off. Irrigation is more efficient and the Division has seen a huge savings in water. All
new irrigation systems will use these heads, and as old sprinkler heads fail, they are being replaced with
MP Rotators which can be snapped onto existing equipment. The spray from the old sprinkler heads is
very susceptible to wind and large amounts of water are lost to hardscapes and other areas that should not
be irrigated.
• Hidden Pond Special District
This year a new irrigation system and many new plants were installed in the frontage landscape at Hidden
Pond Rd. and Reliez Valley Rd. Recently a flock of turkeys moved in and began digging up plants and
scattering mulch. The Division is going to experiment with two different scare tactics used in vineyards to
chase away the turkeys. One is a kite that is shaped and colored to look like an osprey and is tethered to a
IPM Annual Report 10 January 31, 2013
flexible pole. It can be lifted by even a gentle breeze. The other device is a bird scare windmill that
combines reflected light and sound to repel birds.
• Eucalyptus at the West County Detention Center
In preparation for a new park going in next to the Detention Center, Grounds has been dealing with
Eucalyptus stumps from trees cut down last year. Staff decided not to use herbicides and have cut all the
suckers by hand using machetes. They have used a flail mower to cut the sprouts once more since then
and will continue to mow new sprout until they can grind the stumps out.
• Grounds Division staff training
Kevin Lachapelle, Grounds Division Manager, and Jerry Tourte, Lead Gardener, attended trainings to
fulfill the continuing education requirements for the licenses they hold from the Department of Pesticide
Regulation (DPR). One more staff member is studying to pass the DPR licensing exam. All staff
participated in the annual pesticide safety training.
• Pesticide use
Pesticide use by the Grounds Division increased this year as the Division tries to improve the condition of
many of the County’s properties. For a number of years the lack of funding made it impossible to
properly manage weed problems around County buildings and in the Special Districts the Division is
responsible for. Weeds that are left unmanaged provide huge amounts of seed that make the weed
problem increasingly worse. The combination of inadequate funding and labor, and the intense weed
pressure makes it necessary to resort to more herbicide use, which is cheaper than other management
methods.
• Contracting out hand weed abatement
The Department continues to contract with Anka Behavioral Health for hand weed abatement around the
County. This year they cleared weeds by hand from a large number of acres, and the Grounds Crew
chipped the material and left it on site.
Grounds Division Challenges
• Inadequate funding for landscape maintenance in the County
This year the Division was allowed to hired 4 temporary workers, but this is still not enough labor to
adequately maintain County property. In the past several years the main problem was one of having
adequate funds at each site to perform needed landscape maintenance. This year the funding has been
increased at some sites, but the Division does not have enough staff to use the increased hours that are
allotted. Grounds does as much work as they possibly can and continues to explore new ways to reduce
the maintenance costs at sites around the County.
• Inadequate funding to license all grounds staff
It would be ideal to have all members of the grounds crew licensed by the Department of Pesticide
Regulation; however, it would be extremely difficult to pay for the fees and their time to attend
continuing education classes to maintain their licenses. Currently, staff that are not licensed must apply
pesticides under the supervision of one of the two licensed staff members.
Public Works Department Roadside and Creeks Divisions
IPM Program Highlights
• The Divisions participated in various aspects of the work undertaken by the three subcommittees of the
IPM Advisory Committee and have agreed to the Committee’s recommendations to the Departments
• Staff participated in annual habitat assessment refresher training
A large number of Public Works Maintenance crew members attended annual refresher training in habitat
assessment for endangered and threatened species in order to comply with the California Department of
IPM Annual Report 11 January 31, 2013
Fish and Game (CDFG) Routine Maintenance Agreement (RMA). The RMA stipulates that before work
can commence in an area, an assessment must be conducted to identify endangered species habitat. This
year crews trained to identify potential habitat spent a total of 359 hours performing habitat assessments.
As habitats are identified, they are reported to CDFG, which then provides County staff with guidelines to
move forward with work. These guidelines may include full time monitoring of the jobsite by a licensed
biologist.
• Buffer zones for certain pesticides enjoined by the courts have been implemented
Several lawsuits brought by environmental organizations against the EPA have been temporarily settled
by the delineation of buffer zones in and around habitat for a number of endangered or threatened species
in the Bay Area. The Department continues to work within the guidelines of the injunctions to assess
work sites and implement buffer zones before using any of the enjoined pesticides.
• Departmental IPM Plans revised
The Department completed a detailed IPM Plan for Roads, Flood Control Facilities, and Real Property in
2010 and the plans were reviewed and updated as needed in 2012.
• Multi-year grazing study continues
The County Flood Control District is conducting a streambank vegetation management study comparing
currently used herbicide application methods with grazing of sheep and/or goats. The study is examining
the safety, costs, and efficacy of each method to meet the District’s vegetation management goals for
streambanks. Data are being collected on erosion, water quality, and reduction of vegetation, in addition
to costs. There are two study sites: Reach 1 of Walnut Creek, which is between Monument Blvd. and the
I-680 and SR-242 split, and Reach 2 of Walnut Creek, which is between Willow Pass Rd. and SR-242.
Herbicides were applied in designated plots in March. Sheep and goats grazed their designated plots in
June.
• Grazing used for weed abatement
In addition to the grazing study mentioned above, goats and sheep were used to abate weeds at 23 other
sites in the County. A total of 76 acres of weeds were grazed with livestock, and records were kept on
costs and outcomes. The Department will use this data along with data from the grazing study to make
decisions about where, when, and how much to use grazing as an additional vegetation management tool.
Roadside and Creeks Divisions Challenges
• Cost implications of regulations
Compliance with RMA requirements has considerable cost implications. As mentioned above, work
within CDFG jurisdiction requires a habitat assessment prior to start of work so endangered species are
not harmed. Our crews identified endangered species at a couple of job sites and consultation with CDFG
resulted in using alternative work methods that were more costly.
• Staffing
In 2012 a long term county employee with the Vegetation Management Crew was promoted to fill the
vacant Vegetation Management Supervisor position and a new Senior Vegetation Management
Technician was hired. Even with these additions, the crew is still understaffed with only four personnel as
compared to a staff of 6 three years ago.
• Weather
Mowing, as well as the application of herbicides, to manage weeds is highly dependent upon weather
conditions. Weather can substantially alter the size of the weed load or its distribution over time. The
Department has a limited capacity to use mowing because of a number of factors including staff vacancies
in vegetation management staff, the Department’s limited budget for weed abatement, and the limited
number of tractor mowers (two). The Department faces a continued challenge of balancing the use of
herbicides to control weed growth with the Department’s capacity to mow or graze with goats or sheep
within the confines of our budget and timeline in order to prevent fires.
IPM Annual Report 12 January 31, 2013
PESTICIDE USE BY THE COUNTY OF CONTRA COSTA
Starting in FY 00/01, the IPM Task Force annually reported pesticide use data to the Transportation, Water, and
Infrastructure Committee for the County departments involved in pest management. The IPM Coordinator has
continued this task.
Table 1, below, compares figures for FY 00/01, FY 10/11, and FY 11/12.
Table 1. Comparison of Pesticide Use in FY 00/01, FY 10/11 and FY 11/12
Program Total Lbs. of
Active Ingredient
used in
FY 00/01
Total Lbs. of
Active Ingredient
used in
FY 10/ 11
Total Lbs. of
Active Ingredient
used in
FY 11/12
Reduction in Use from
Beginning of IPM Program
(FY 00/01) to FY 11/12
Public Works Roadsides and
Creeks
16,591 6439 5713 65.5 %
Agriculture Noxious Weeds and
Ground Squirrels
1,421 795 539 61.8%
Public Works Grounds 927 113 378 59.2%
Public Works Facilities FY 07/08 21 5 9 57.1%
Public Works Special Districts FY 07/08 11 45 7 36.4%
*The IPM Program did not tabulate pesticide use data for Facilities and Special Districts until FY 07/08.
Concern about “Bad Actor” Pesticides
There has been concern in the community and within the County about the use of “Bad Actor” pesticides by
County departments. “Bad Actor” is a term coined by the Pesticide Action Network and Californians for Pesticide
Reform to identify a “most toxic” set of pesticides. These pesticides are at least one of the following: known or
probable carcinogens, reproductive or developmental toxicants, cholinesterase inhibitors, known groundwater
contaminants, or pesticides with high acute toxicity.
The County’s use of these particular pesticides has decreased dramatically since FY 00/01 as shown in Table 2,
below. Of the 31 “Bad Actor” pesticides used by the County since 2000, 22 have been phased out and one more is
in the process of being phased out. In addition, two other pesticides that are not designated as “Bad Actors” by the
Pesticide Action Network are being phased out because the County feels they are particularly problematic.
Table 2. Comparison of “Bad Actor” Pesticide Use in FY 00/01 and FY 11/12
Department Total Lbs. of “Bad
Actor” Active
Ingredients used in
FY 00/01
Total Lbs. of “Bad
Actor” Active
Ingredients used in
FY 11/12
Reduction in
Use
Public Works 5240 7 99%
Agriculture 56 5 91%
Public Works Grounds 649 0 100%
Trends in Pesticide Use
A change in pesticide use from one year to the next does not necessarily indicate a long-term trend. Long-term
trends are more meaningful than short-term changes. It is important to understand that pesticide use can increase
and decrease depending on the pest population, the weather, the invasion of new and perhaps difficult to control
IPM Annual Report 13 January 31, 2013
pests, the use of new products that contain small percentages of active ingredient, the use of chemicals that are
less hazardous but not as effective, the addition or subtraction of new pest management projects to a department’s
workload, and cuts to budgets or staff that make it difficult or impossible to use alternate methods of control.
The County’s pesticide use trend follows a trend typical of other pollution reduction programs. Early reductions
are dramatic during the period when changes that are easy to make are accomplished. When this “low-hanging
fruit” has been plucked, it takes more time and effort to investigate and analyze where additional changes can be
made. The County is entering this period, and if further reductions in pesticide use are to be made, it will require
time for focused study and additional funding for implementation.
DEPARTMENTAL INTEGRATED PEST MANAGEMENT PRIORITIES FOR 2013
Agriculture Department Priorities for 2013
• Continue the County’s highly effective Noxious Weed Program
Noxious, invasive weeds cost Californians at least $82 million per year in monitoring, control, and
outreach. Every year, invasive weeds ruin thousands of acres for recreation and agriculture and for native
California plant and animal habitat. Some noxious weeds increase the fuel load in urban and rural areas,
and some suck up prodigious amounts of scarce water. Early detection and control of these weeds greatly
reduces their impact and the cost to manage them.
Contra Costa’s highly effective Noxious Weed Program has been in operation for 33 years. A major
objective of the Agriculture Department is to continue to monitor and treat targeted noxious weeds on all
historic sites before the weeds set seed. Preventing seed set is the most important factor in reducing weed
populations and in depleting existing seed banks. By doing this, the hours of labor needed and amounts of
herbicides applied in successive years to a particular area will be reduced. These reductions allow the
department to add previously untreated sites to the noxious weed program bringing local eradication of
the targeted weed species one year closer.
• Continue work on the pesticide screening process
The Department will work with the IPM Coordinator to screen all pesticides used by the Department.
• Continue attending IPM training and sharing the information with other Departments
The Agriculture Department will continue to have staff attend outside IPM seminars and training sessions
given on a variety of pest management issues. The Department will develop a training database so that
personnel who return from IPM seminars and workshops can store training and outreach materials in a
way that will be easily accessible to other County staff members. In addition, each staff person involved
with pest management attends annual pesticide safety training.
Public Works Department Priorities for 2013
Facilities Division
• Continue working to fix structural deficiencies in County buildings
• Continue monitoring the bed bug situation in County buildings and providing awareness training if
necessary
IPM Annual Report 14 January 31, 2013
Grounds Division
• Collect cost and efficacy data on sheet mulching at 2530 Arnold Drive in Martinez (Summit Center) over
the next several years
The landscaping at this site was completely inappropriate for the amount of money available to maintain
it. Over the last couple years, the Division has intentionally killed a great deal of the vegetation at this site
in order to have a hope of maintaining some of the landscaping properly. Wood chips have been
stockpiled at the site and because there is a small amount of extra money available for this site, the crew
can sheet mulch a portion of the entrance to the site. The Division will try both synthetic weed fabric and
cardboard underneath the woodchips and monitor the installations over time to determine which is more
acceptable in the long run.
• Continue diverting as much green waste as possible from the landfill by chipping prunings and using the
material in place
• Continue hand weed abatement at various sites using Anka Behavioral Services
• Continue preparation of the site next to the West County Detention Facility for a new park that will be
completed next year
The goal is to prepare the site without having to use herbicides.
Roadside and Creeks Divisions
• Continue work on the pesticide screening process
The Department will continue to work with the IPM Coordinator to develop a hazard screening process
for all pesticides used by the Department.
• Continue to collect data from the two spray trucks equipped with data collectors and analyze data to
ensure accuracy and usability of information.
• Continue grazing study
The Creeks Division will continue its multi-year study of grazing and chemical weed control methods.
• Continue to refine IPM practices
The Vegetation Manager will continue to refine the Department’s IPM practices and investigate new
methods of weed control. The Divisions will continue to expand the use of wood chips generated from
their tree trimming operations as mulch to control weed growth. In addition the Vegetation Manager will
explore the feasibility of reseeding areas such as roadside shoulders and creek banks with low growing
grasses such as rye or Bermuda in an effort to choke out fire prone weeds such as oats.
Appendix A
1
APPENDIX A of Ground Squirrel Live Trapping Report
Table 1: Live Trapping for Ground Squirrel Spermophilus beecheyi
Trap Apparatus Trap # 8/6/12 8/7/12
8/8/12
Day/Evening 8/9/12 8/10/12
Total
(Trap) Comment
Plywood+Rocks+Under Tree 1 2 4 1/0 0 7 14
Squirrels digging underneath cage;
trap adjusted; 8/8: Cage found
open
Plywood 2 0 2 3/0 1 5 11
Plywood 3 1 0 1/0 0 2 4 8/8/12 1 GS found deceased
possibly due to heat exposure
No Cover-1st 2 days then
Plywood added 4 2 1 5/0 2 3 13
Plywood Cover added 8/7/12;
8/7/12: 1 GS found deceased
possibly due to heat exposure or
fighting
No Cover-1st 2 days then
Plywood added 5 1 0 2/1 1 1 6 Plywood Cover added 8/7/12
Plywood +Rocks 6 2 1 1/0 2 2 8
Plywood 7 4 2 3/1 1 4 15
Plywood 8 1 0 2/1 2 3 9
Plywood 9 3 1 3/0 2 1 10 8/8/12 Cage found open during
evening
Disc Cover + Rocks/Plywood
added on 3rd day 10 3 2 4/0 7 5 21
Rock Apparatus drew more ground
squirrels due to trap appearing
more natural
Disc Cover/Plywood added on
3rd day 11 5 1 2/0 2 2 12 8/6/12 2 GS found deceased due
to heat exposure or fighting
Disc Cover + Plywood 12 5 8 7/1 4 5 30
Trap on edge of buffer barrier
bringing in higher yields of ground
squirrels
Total (Day) 28 22 38 24 40 152 Total (Week)
Table 1: The table exhibits traps #1-12 and its description. The efficacy of each trap and its’ ground squirrel counts. Traps #1-12 were placed on a 1200-foot
buffer zone (each trap 100 feet from each other) along Empire Mine Road, Antioch, California.
Appendix A
2
Figure 1: The figure displays traps #1-12 in order along Empire Mine Road, Antioch, California. The trap area consisted of stretch of twelve unique traps along a
1200-linear foot roadside area. Two 1500 feet untreated control areas were at either end of the trapping area.
Appendix A
3
Figure 2: The figure displays the areas of diphacinone 0.01% treatment (2.5 miles), untreated control (1,500ft), and the live trapped area (1,200ft).
Appendix A
4
Error!
Ground Squirrel Spermophilus
beecheyi
Empire Mine Rd Antioch, CA
28
22
38
24
40
0
5
10
15
20
25
30
35
40
45
8/6/12 8/7/12 8/8/12 8/9/12 8/10/12
Day Ground
Squirrel
Count
Figure 3: The figure displays the number of Ground Squirrels Spermophilus beecheyi caught via live trapping over a period of five days in a 1,200 foot trapped
area. The total number of squirrels caught for the week totaled 152. However, the impact on reducing the population of ground squirrels via live trapping was
insignificant.
Appendix A
5
Figure 4: The figure displays the Ground Squirrel Traps #4 and #5. The graph shows the reported number of ground squirrels caught each day. A trap
adjustment was made on 8/8/12 in which a plywood cover was added to reduce heat exposure, predatory animals, and increase coverage.
Uncovered
Catch Rate 2/day
(Mon/Tues)
Covered
Catch Rate 5/day
(Wed/Thurs/Fri)
Appendix A
6
Empire Mine Road, Antioch, CA 94509
Week Temperature
August 6, 2012-August 10,2012
92
89
98
103
100
80
85
90
95
100
105
8/6/12 8/7/12 8/8/12 8/9/12 8/10/12
Day Figure 5: The figure displays the average high temperatures August 6, 2012-August 10, 2012 at Empire Mine Road, Antioch, CA. The temperatures recorded
display that a significant amount of shade coverage was necessary for squirrels to survive while in the cages. In addition, the cages would require more man-
hours in order to create each individual shaded cage habitat.
Appendix A
7
Appendix A
8
Appendix A
9
Appendix A
10
Appendix A
11
Appendix A
12
Appendix A
13
Appendix A
14
Appendix A
15
General Pest Management Decision Tree
START HERE
No
Yes
No Yes SEE
INSERT
No No Yes
No
Yes
Yes
No
Yes
No
Note that this pest management decision tree documents the current practices of Contra Costa County staff.
Yes
The overall goal of this process is to choose the least-hazardous
management method that is effectve and economically viable.
Monitor site
Pest
present?
Population
high enough
to require
control?
Assess sensitivity
of site
Consider cultural controls
Consider physical controls
Consider chemical controls
Choose mgmt. method based on
hazard, risk, environmental
conditions, efficiency, efficacy,
labor, budget, legal/regulatory
constraints
Implement mgmt
technique.
Evaluate
management
Was it safe/
effective?
Consider
strategies
for future
prevention
of pest
problems.
Evaluate reason
for failure
Alter mgmt.
method, chemical,
timing, or training,
as necessary.
Consider
strategies to
prevent failure in
future and to
prevent future
pest problems.
Evaluate damage.
Damage due
to mgmt. or
Damage due
to timing or
Damage due
to employee
training?
Unforeseen
damage to non-
target spp./
environment?
Identify
mgmt
goals for
site.
If any exotic
invasive pests
present, alert
County
Department of
Agriculture.
Identify pest
Consider biological control
Check weather conditions
prior to implementation
Check list for Cultural Controls Check list for Bio Controls
• Is it possible to use education to alter sensitivity to or spread of pest problem?• Is an organism available for the target pest?
• Is it possible to use education to alter habitat and availability of food for pest?• Is it effective for the target pest (consider theoretical and historical)?
• Is it possible to use education to prevent pest entry?• Are there time constraints on the management of the target pest?
• Are the plants with pest problems suitable for landscape site?• How compatible is the organism with other management techniques?
• Is it possible to alter plant care to reduce or eliminate pests?• What is the cost of implementation?
• Is it possible to replace or completely remove plants with pest problems?• Can the budget accomodate this management technique?
• Is it possible to modify the environment to improve plant health?• Is staff/equipment available for implementation?
• Is it possible to modify the environment to reduce or eliminate pests?• What is the proper timing for releasing this organism?
Check list for Physical Controls Check list for Chemical Controls:
• Is it effective for target pest (consider theoretical and historical)?• Is it effective for target pest (consider theoretical and historical)?
• Is it suitable for the site and life stage of pest? • What is the toxicology of the pesticide?
• What are the risks to staff safety of implementing the technique?• What are the label restrictions?
• Can the budget accomodate this management technique?• Is the time of year/weather compatible with use of the chemical?
• Is staff/equipment available for implementation? • Is it suitable for the site and life stage of pest?
• Is this technique appropriate for the time of year/weather? • What is the proximity of sensitive sites, such as water, E/T spp. habitat, parks, schools?
• Is there potential for damage to non-target plant spp.?• What is the environmental persisitence of chemical?
• Is there potential for damage to non-target animal spp.?• Is there potential for damage to non-target plant spp.?
• Is there endangered spp habitat present and will the technique affect that?• Is there potential for damage to non-target animal spp.?
• Is there a potential for intro or spread of noxious weeds by using this technique?• Can the problematic aspects of the chemical be mitigated or eliminated?
• Is there a potential for erosion? • Are any new chemicals available?
• Are there time constraints on the management of the target pest?• Can the budget accomodate the use of this chemical?
• What is the role of chemical in herbicide resistance mgmt?
Other factors to consider:
• Where do physical (and possibly cultural) controls make the most sense?
• Where is it most cost effective to use physical controls?
• Where can herbicide use be reduced the most by substituting physical controls?
• Where can grazing save wear and tear on employees?
• Are there areas where using physical controls makes it possible to treat a larger area more efficiently than with chemicals?
• Where and under what conditions is it most dangerous for employees to work?
Note that these choices are evaluated for planning purposes as much as 1 or 2 yrs. in advance. Some things require considerable lead time.
Things to consider when evaluating management:
• Were fire regulations met on time?
• Did mgmt increase air pollution?
• Did mgmt increase/decrease
fire/flood hazards?
erosion?
biodiversity?
herbicide resistance?
customer complaints?
INSERT for Public Works Road and Flood Weed Control Decision Tree
INSERT
START HERE
Yes
Yes
No
No
Yes Yes
No No
Yes
No
Yes
No
Yes
No
Is this a
"Highly
Sesitive
Location" ?
Is site under
RMA with Fish
and Game?
Contact Certified
Biologist to assess
impact of work at
site.
Conduct a Habitat
Assessment before
any work begins.
Determine
spp./habitat and
consult injunction
text and tables.
Determine spp. and
habitat.
Review & comply
w/any special
restrictions and/or
considerations for
work/treatment at
the site.
Is site a known or
potential habitat
for any E/T spp.?
Is site under a
court-ordered
injunction?
Assess sensitivity of site.
Were live spp. of concern
found?
Did Biologist
find
spp./habitat of
concern?
Was habitat of concern found?
Review & comply
w/any buffer zones
for the particular
pesticide used and
the particular
spp./habitat.
STOP!
Contact Fish &
Game. No work
can be done w/o
approval.
Review & comply
w/any special
restrictions and/or
considerations for
work/treatment at
the site.
Review & comply
w/any special
restrictions and/or
considerations for
work/treatment at
the site.
Return to Main
Decision Tree
ATTACHMENT B.
DECISION DOCUMENTATION TREE
WEED MANAGEMENT
Date: _______________________________________
Department: _________________________________
Location: ___________________________________________________________
Situation: _________________________________________________________________
__________________________________________________________________________
What are the
management goals for the
site or weed?
Was the site monitored
and what was found?
Weeds have been
identified as the following:
Are populations high
enough to require control?
Explain
Is this a sensitive site? Is this a “highly sensitive site” as defined by PWD Environmental staff? Yes No
Is this under the RMA with Fish and Game? Yes No
Is this part of any of the court-ordered injunction? Yes No
Is this a known or potential habitat for any endangered or threatened species? Yes No
Is it on or near an area where people walk or children play? Yes No
Is it near a drinking water reservoir? Yes No
Is it near a creek or flood control channel? Yes No
Is it near crops? Yes No
Is it near desirable trees or landscaping? Yes No
Is the soil highly permeable, sandy, or gravelly? Yes No
Is the ground water near the surface? Yes No
Which cultural controls
were considered?
Mulching
Weed Barrier
Planting Desirable Species
CONCLUSIONS:
.
Which physical controls
were considered?
Pruning for line of sight
Mowing by hand
Mowing by machine
Grazing
CONCLUSIONS:
Which biological controls
were considered?
Biological controls available:
CONCLUSIONS:
Which chemical controls
were considered?
Attach PCA
recommendation
Pre-emergent (residual) herbicide?
Post emergent (contact) herbicide?
Possible herbicide choices (include estimated cost/acre):
CONCLUSIONS:
Which herbicide
application methods are
available for this
chemical?
Methods available:
CONCLUSIONS:
What factors were
considered in the
choosing the pesticide
application method?
What weather concerns
must be checked prior to
application?
Pesticide Profile for: _(Product Name)___________________________________________
Active Ingredient
Injunction
Restrictions
Signal Word
Federally, State, or
Locally Restricted Use
Material
Cancer
Prop 65
DPR Groundwater
Protection List
Mammalian Hazard
Bird Hazard
Aquatic Organism
Hazard
Bee Hazard
Persistence
Soil Mobility
Lbs of a.i. used in FY
10-11 by the Public
Works Dept.
Use in County
Method of Application
Cautions •
Rate Used in Co. •
Sources Label, MSDS, EPA registration and re-registration documents, carcinogen lists from EPA, International Agency for
Research on Cancer, National Toxicology Program, Prop. 65, California Department of Pesticide Regulation,
Oregon State University Pesticide Properties Database, Triclopyr Technical Fact Sheet from the National Pesticide
Information Center (Oregon State), Thurston Co., WA Triclopyr TEA Review, European Union, University of
Hertfordshire, U.K. Pesticide Properties Database
Attachment C. CCC IPM Priority Assessment Tool--Master
1 Revised 10/24/12
Date:____Department_______________
IPM Best Management Practices
Percent Imple-
mentation
Dept. 2012
Priority
L = low
M= med H=
high
IPM Comm.
2012 Priority
L = low
M= med H=
high
Notes
Pest Mgmt.
Data/Info Inventory pesticide stock annually
Record location of chemical use
Record size of area treated with chemicals
Track chemical use by cost (labor + materials)
Record location of non-chemical mgmt
Record size of area treated non-chemically
Track non-chemical mgmt by cost (labor & equipment)
Note target species
Make information available to public upon request
Make information available to public on the Web
IPM Plan Have written IPM Plan
Develop and maintain pest and/or site specific IPM Plans
Record explicit mgmt goals for each pest/site/kind of site
Develop metrics to evaluate the extent to which goals are
met
Record the extent to which goals are met
List explicit tolerance levels for pest/site/kind of sites (can
be set at 0)
Describe pest management decision-making process
Monitoring Monitor areas under management regularly for pest/damage
detection, identification, and population estimates
Monitor areas under management regularly for evaluation of
mgmt efforts
Document monitoring activities
IPM Decision-
making
Process
Document preventive measures considered and reason(s)
for use or rejection
Document non-chemical strategies considered and
reason(s) for use or rejection
Document chemical strategies considered and reason(s) for
use or rejection
Document potential impacts to human health, and the
environment, including "no impact"
Note costs and ability of staff to implement
Schedule mgmt activities for optimal effect
IPM Research Conduct on-going research into new, alternative options for
pest mgmt
Budget or seek other funds for design and implementation
of field trials for evaluating new, alternative treatment
strategies
Conduct field trials of new strategies
Attachment C. CCC IPM Priority Assessment Tool--Master
2 Revised 10/24/12
Date:____Department_______________
IPM Best Management Practices
Percent Imple-
mentation
Dept. 2012
Priority
L = low
M= med H=
high
IPM Comm.
2012 Priority
L = low
M= med H=
high
Notes
Document potential improvements/projects that could be
implemented if there were resources, and document
resource needs (tools, equipment, training, staff, budget,
etc.)
Training Conduct annual IPM safety training
Conduct training in BMPs for pests and sites
Provide all staff involved in pest management with at least
yearly professional development training
Provide training for other entities
Program
Administration Adopt and implement County IPM Posting Policy
Report annually on IPM program
Track pest management budget
Environmental
Compliance
Conduct environmental assessment & monitoring to comply
with Public Wrks RMA
Conduct environmental training for staff (relating to pest
mgmt activities)
Comply with Municipal Regional Permit for Stormwater
Discharge
Follow court-mandated pesticide injunctions
Regulatory
Compliance Report pesticide use monthly to Ag Dept.
Comply with state and federal permit requirements
Comply with fire regulations for vegetation
Comply with flood control certification requirements
Comply with water conservation laws
Comply with Health Department regulations
Comply with pesticide safety regulations
Comply with OSHA worker safety regulations
Safety Provide employees with written policies on worker safety in
regard to pest management activities, pesticide
emergencies, and pesticide clean-up
Conduct regular worker safety trainings
Track incidents related to safety in pest management (both
for chemicals and alternatives)
Contra Costa County Pesticide Posting Policy Revised 10-22-12
Attachment D. CONTRA COSTA COUNTY PESTICIDE USE POSTING AND NOTIFICATION
POLICY
General Provisions
This policy applies only to land owned by the County of Contra Costa.
Any County Department that uses or authorizes the use of a pesticide shall comply with the following posting
and notification procedures:
• Signs shall be posted at least three (3) days before application of the pesticide and remain posted at least
four (4) days after application. In specific situations/locations, permanent signs may also be used. See
provisions below under “Exemptions” and “Other Uses of Permanent Signs”.
• Application information shall be posted on the County website’s pesticide posting page at least three (3)
days before the application. If the application is postponed or changed, information on the website must be
updated.
• If treatment is in an enclosed area, signs shall be posted at all major public and employee entry points.
• If treatment is in an open area, signs shall be posted at highly visible location(s).
• Posting signs for rat and mouse bait stations shall be posted at eye level on the wall or other structure
above the bait station.
• Exceptions to these provisions are listed below under “Exemptions”.
Contents of Signs
The signs shall be of a standardized design, easily recognizable by the public and County employees and shall
contain the following information:
1. Name of pesticide product
2. Active ingredient(s) in the product
3. United States Environmental Protection Agency or California State registration number
4. Target pest
5. Signal word on the product label indicating the toxicity category of the pesticide product
6. Date of posting
7. Date(s) of anticipated use; a window of time for anticipated use is acceptable
8. Date of re-entry for staff and the public to the treated area, if applicable
9. Name and contact number of County Department responsible for the application
10. Website address for more information
Exemptions
Departments shall not be required to post signs in accordance with the provisions above
1. in rights-of-way or other areas that the general public does not use for recreation or pedestrian purposes.
Recreation is defined as any activity where significant physical contact with the treated area is likely to
occur.
Note: Each department that uses pesticides in such locations shall provide a public access telephone
number for information about pesticide applications. The public access telephone number shall be posted
in a prominent location at the department’s main office building. Information provided shall include all
items listed under “Contents of Signs”, above.
2. in or around County-owned or -leased buildings, if the pesticide is on a list agreed to by the IPM Advisory
Committee.
Note: Each County building shall post a permanent sign in a prominent location with a list of
pesticides that may be used in or around the structure without individual postings. Pesticides not on
this list must be posted in accordance with the provisions above. The permanent signs shall contain the
following:
a. Name of the pesticide product
Contra Costa County Pesticide Posting Policy 2 Revised 10-17-12
b. Active ingredient(s) in the product
c. Signal word on the product label indicating the toxicity category of the pesticide product
d. Areas inside or outside the building where the pesticide might be used
e. Name and contact number of County Department responsible for applications
Any pesticide granted an emergency exemption for public health emergencies or other urgent situations by the
County IPM Coordinator shall not be required to be posted prior to treatment. However, all other requirements
for posting, as set forth above, shall be followed.
Use of any pesticide listed by the Organic Materials Research Institute or of any products on the FIFRA 25(b)
list or in California Code of Regulations Section 6147 may be posted on the day of application. All other
provisions listed above apply.
The County IPM Coordinator may, at his or her discretion, grant necessary exemptions to the posting
requirements.
Other Uses of Permanent Signs
In addition to the provisions above regarding permanent signs in and around buildings, permanent signs are
acceptable in areas away from county-owned or –leased buildings where pesticide applications are a regular,
periodic occurrence. The following provisions apply:
1. The permanent sign must contain, at minimum, the following information
a. Target pest(s)
b. Reason for treatment
c. Name and contact number of County Department responsible for the application
d. Website address for more information
2. At least three (3) days before any pesticide application, the application information must be posted on
the County website’s pesticide posting page. If the application is postponed or changed, information on
the website must be updated.
3. On the actual day of the pesticide application, a paper sign with the information listed above under
“Contents of Signs” must be affixed to the permanent sign and remain for at least four (4) days.
DRAFT
GROUND SQUIRREL
SPERMOPHILUS BEECHEYI
LIVE TRAP VERSUS TREATED
GRAIN BAIT GROUND SQUIRREL
CONTROL METHODS
EMPIRE MINE ROAD ANTIOCH, CALIFORNIA
AUGUST 6-10, 2012
Contra Costa
County
Department Of
Agriculture
1
Ferbruary 8, 2013
Contra Costa County Agriculture Department
Ground Squirrel Spermophilus beecheyi
Empire Mine Road Antioch, California
August 6-10, 2012
Authors: Vince Guise, Gene Mangini, and Mortay Mendoza
Abstract:
This field trial was undertaken to compare the efficacy of live trapping with the use of
diphacinone treated bait. The study site was along Empire Mine Road located in the agricultural
rangeland area of Antioch, California. This area supports a moderate to high population of
ground squirrels and is t ypical of areas treated by our department. The area is open grassland
prairie with oak woodland grassland mix. This 3.3 mile road is closed to vehicles and has
minimal foot traffic. Twelve live traps were placed equidistant along a 1,200 linear foot stretch
of roadway with a 1,500-linear foot non-trapped/non-treated control area on each side. Oat grain
bait treated with 0.01% diphacinone was used to treat both extremities of Empire Mine Road
outside of the live trap test area. A total of 152 ground squirrels were captured and dispatched
using the live trapping method over a period of one work week (five days) in the 1,200-foot test
area. Live trapping costs equated to $7,311.85 per linear mile ($5,074.36 when adjusted for
efficiencies) and did not result in an acceptable level of control to provide protection of the
roadway from ground squirrel damage. Those areas of Empire Mine Road treated with 0.01%
diphacinone treated bait in a 12 foot swath broadcast at 10 pounds (0.016 ounces diphacinone)
per acre (2-3 kernels per square foot) equated to a cost of $220.40 per linear mile and did provide
the desired level of control. Though live trapping was 23 times more costly, it may provide a
viable alternative control in highly sensitive areas where treated bait use is not desired or allowed
such as in certain endangered species habitat areas or in areas of low population isolated squirrel
colonies. It was also found that live trapping was not the humane method that we expected. Trap
vandalism, which was experienced during the study, presents a danger to the public through
exposure to possible bites, scratches and zoonotic disease.
2
Ferbruary 8, 2013
Introduction:
The California ground squirrel Spermophilus beecheyi is native to Contra Costa County.
Its burrows provide positive effects on soil, habitat for burrowing owls and tiger salamanders,
and the squirrel itself is a food source for many native predators. In certain situations it is
considered a pest that can cause damage to public roadways and culverts, railroad beds, and
other infrastructure, including earthen dams, levees and bridge abutments. Ground Squirrel
burrowing can result in washouts, erosion, gully formation, undermining and weakening of
levees and other structures and can lead to catastrophic structural failure. In addition, ground
squirrel soil excavation can lead to injury of horses and cattle, and people walking and using
playgrounds. Ground squirrel feeding can cause economic damage to crops, and to vegetation in
parks and recreational areas. Individual burrows can extend up to 135 feet or more [4]. It is the
department’s goal to provide a relatively ground squirrel-free buffer of 100 to 200 feet adjacent
to or around sensitive structures. The baiting strategy used by the department takes advantage of
the ground squirrel’s natural behavior of foraging up to 300 feet from its burrow. A 12-foot wide
swath of ground around the structure to be protected is treated with 0.01% diphacinone treated
bait. The department does not treat ground squirrel populations that are generally present
beyond this buffer.
Aside from infrastructure protection, there is one area our department treats that involves human
health risk. A buffer area is treated along a community pool and playground that are adjacent to
an open space area on the side of Mount Diablo that has a very high ground squirrel population.
The ground squirrels had infested the community area where small children and a community
swim team utilize the facilities frequently. Besides the direct health concerns of children being
in close proximity to ground squirrels, there is a high population of rattlesnakes feeding on
squirrels in this area. There were many sightings at the pool and playground area, and removing
the prey from that area has eliminated snake sightings.
Control methods for removing ground squirrels from designated areas have brought forth some
concern as to what is most cost effective, and more importantly, what is safest for public health
and the environment. This experiment was conducted to determine the effectiveness and cost of
3
Ferbruary 8, 2013
live trapping in a moderate to high population of ground squirrels as compared to the use of
diphacinone 0.01% treated bait. Also considered in this study were the hazards of handling the
rodents, public health concerns, likelihood of effects on non target species, and humaneness of
control methods.
The California ground squirrel can transmit a number of diseases including bubonic plague,
Colorado tick fever, Lyme disease, Rocky Mountain spotted fever, tularemia, leptospirosis,
anaplasmosis, babeosis, relapsing fever, and tick paralysis [2, 18, 24, 25]. California’s plague
surveillance system regularly finds ground squirrels that are positive for plague in multiple
California counties [2]. This is a cause for concern to biologists, field assistants, and other
individuals who may come into close or direct contact with the animal or it ectoparasites that
may transmit disease to humans. Live trapping of ground squirrels requires direct contact
between people and the animals. Since ground squirrels carry diseases and are agricultural pests,
California Fish and Game Code specifies it is illegal to release ground squirrels elsewhere
without a written permit [11, 18, 20].
Diphacinone is a first generation anticoagulant. It is an organic compound that consists solely of
carbon, oxygen and hydrogen atoms. Breakdown of the compound occurs naturally with
sunlight and soil microbial action [22]. It requires multiple feedings for effective control and
breaks down relatively rapidly in animal tissues when compared to second generation
anticoagulants [5, 7]. It has not been found to contaminate surface or ground water and would
not be expected to do so [7, 17]. First generation anticoagulants are often confused with and
blamed for anticoagulant secondary poisoning that is the result of second generation
anticoagulant use. Second generation anticoagulants, sometimes referred to “one feeding kill”
rodenticides; include brodifacoum, bromadialone or difethialone. They are the active ingredient
in most common home use mouse and rat bait products such as D-Con. These products are more
persistent in animal tissue and though one feeding provides a lethal dose, the animal does not die
for two to five days or more. After receiving a lethal dose these animals also have a tendency to
stay above ground prior to dying versus the tendency with the first generation anticoagulants of
the animal to die in their burrow. Secondary poisoning of non target species from second
4
Ferbruary 8, 2013
generation anticoagulants is prevalent and is becoming a real problem. A study was done by
Lima and Salmon to determine the presence of anticoagulants in raptors in urban San Diego and
agricultural central valley counties of Fresno, Kern and Tulare. In all four counties there was
state-reported use of diphacinone in amounts very similar to the amount used in Contra Costa.
There was also prevalent use of all three second generation anticoagulants with especially high
amounts of reported use of bromadialone in San Diego and Fresno counties. Ninety-two percent,
or 49 of the 53 raptors tested in San Diego County for second generation anticoagulants were
positive. Sixty-nine or 34 of the 43 raptors tested in the central valley agricultural areas tested
positive for second generation anticoagulants. Of the 96 raptors tested, none were found to have
diphacinone contamination, two were found to contain trace levels of the first generation
material chlorophacinone, and 83 had detectable levels of second generation anticoagulants
present in their liver tissues [3].
In a Cornell University study involving a 56-day secondary poisoning trial with diphacinone
0.005% bait (50mg active ingredient/kg) revealed no hazard to sparrow hawks under conditions
likely to be encountered in nature [6]. In addition, diphacinone is less toxic to birds as it is less
persistent in the tissues of primary feeders, and must be eaten over a period of several days to
cause mortality in comparison to second generation rodenticides such as brodifacoum,
bromodialone and bromethalin [6, 7].
Another study involved an ecological risk assessment on coyotes, American kestrel, burrowing
owl, golden eagle, red-tailed hawk and the common raven from the use of diphacinone broadcast
and spot treatment. This study concluded that this method “will not cause unreasonable adverse
effects on coyote populations or those of other predators/scavengers that feed on squirrel
carcasses” [23].
Diphacinone degrades fairly rapidly with a half-life of 44 days, and vitamin K is antidotal in
cases of needed treatment [14]. Vitamin K1 can be found in plants and Vitamin K2 can be
synthesized by specific bacteria and is an essential cofactor for activating Vitamin K dependent
proteins in the liver [14]. Prothrombin is dependent on vitamin K in order to execute its primary
function in coagulation of blood. Prothrombin is another alternative that can aid in accidental
5
Ferbruary 8, 2013
consumption of diphacinone. Diphacinone application is most effective and safe when allowing
one day between each application because it allows the anticoagulant to work better over time
and reduces the consumption by the squirrel reducing secondary poisoning. Diphacinone does
not kill other species that may cohabit with ground squirrels in their burrows.
Rolled or flattened grain is used as the diphacinone carrier. The flattening makes the bait less
attractive to birds. The bait is also dyed blue. This makes it less attractive to non target species.
It need also be noted that direct feeding on diphacinone by domestic dogs and other canines will
produce toxic effects. That is why it is so important to properly use the treated bait by
broadcasting the bait at a rate of only a few grains per square foot and immediately cleaning up
any bait spillage that may occur around bait stations or with the broadcast material. Misuse of
this material would include “piling” the bait or throwing “handfuls” of the bait down or at
ground squirrel burrows. As an added precaution there are use restrictions in areas of
endangered kit fox habitat in our county.
Objectives
The objectives of this study were to compare the effectiveness and costs of live trapping
versus broadcast treatment of 0.01% diphacinone treated bait on a moderate to high ground
squirrel population. Also, it was our desire to gain direct experience with live trapping to gain
knowledge of possible benefits and problems. This study is consistent with our departmental
integrated pest management (IPM) goal of evaluating the feasibility of control methods that
involve potentially least toxic or lower toxicity alternatives. This study is not intended as an
official scientific study but as a departmental evaluation. Through this study we also want to
address concerns that have been expressed by the public with our program.
Procedure:
1) Photos were taken of area to be trapped and of the control and baited areas. Twelve
[Black Fox] traps were set at 100 ft spacing, and 1,500 feet of un-trapped and un-baited
control area was left on either side of the trapped area. Initially traps were wired open
6
Ferbruary 8, 2013
and untreated rolled oats were placed inside and scattered around the outside of the
trap.
2) Each trap was covered with a non-transparent/non-cloth material (i.e., plywood) to
provide adequate protection from predators and the heat. Note: Traps #4 & #5 were left
uncovered for the first two days to check the difference in catch rate between
uncovered/covered and to identify other differences. Plywood was placed under some
of the traps where grounds squirrels were found digging under the trap to obtain and
consume the bait.
3) Each trap was identified by a number from 1 to 12.
4) Labels were placed on the traps to inform the public that an experiment was underway
and to warn them to stay away.
5) The wired open traps were pre-baited over at least a two-day period using clean
untreated rolled oats.
6) Pre-baited with clean rolled oats prior to treating with Diphacinone 0.01% bait.
7) Time spent setting traps out and pre-baiting was documented.
8) After the pre-baiting period, the traps were set early in the afternoon (~2 p.m.) in order
to minimize the number of captured squirrels that would be in traps overnight to lessen
stress for the squirrels and attractiveness to nocturnal predators that may tamper with
the squirrel(s) and traps. Clean untreated rolled oats were again placed inside the trap.
9) Traps were checked and serviced at least once in a 24-hour period.
10) Captured squirrels were euthanized according to Institutional Animal Care and Use
Committee (IACUC) and American Veterinary Medical Association (AVMA)
guidelines [1]. We determined the flow rate necessary for the size of the CO2 chamber
so as to induce anesthetic effects rapidly, prevent distress to the animal and achieve
respiratory arrest within 5 minutes.
7
Ferbruary 8, 2013
11) Squirrels were euthanized using the proper personal protective equipment to avoid
exposure to fleas, which may carry an array of diseases (minimizing the time of human
exposure to the ground squirrels is imperative).
12) The number of ground squirrels in each trap was recorded.
13) Once the traps were emptied, they were reset.
14) The time spent live trapping and diphacinone baiting was recorded.
15) Step 5 through 14 was repeated as applicable. Diphacinone pre-baiting was conducted
only on Day 1. The application of diphacinone treated bait was done on Day 3 and 5.
16) The following week staff returned to survey the effects in the area of live trapping
versus that of the diphacinone 0.01% treated area.
Materials and Costs:
Live Trapping
Materials Cost Reusable Unit
Total
Cost
Actual
Cost
(prorated) Comment
Traps $54.75 X 1 cage $657 $33.73
Cages 3 year life | 8 weeks of use per year 8/52
weeks in a year=0.154, cost for this application
Re-bar $4.47 X 15 ft $22.35 $7.45
3 ft/piece | 24 pieces needed for 12 cages – 3year
life
Hammer $19.98 X
small
sludge $19.98 $6.66 3 year life
Flags Markers $5.5 X 100 flags $0.66 $0.22 Used one flag per trap site – 3 year life
Untreated
Rolled Oats $20.57 50 lbs $82.28 $82.28 Four 50 pound bags used
8
Ferbruary 8, 2013
Table 1: The table displays the material cost for live trapping at the site of Empire Mine Road, Antioch.
*Adjustments for efficiencies (see below text) bring this to $5,074.36/linear mile.
Gas Chamber $200 X 1 chamber $200 $40 9 cubic feet gas chamber | 5 year life
CO2 Tank +
CO2 $169.93 X 20 lb tank $169.93 $49.99 Tank $149.94 + CO2 $19.99 (per refill) |5 year life
Plywood $31.36 X 1 sheet $94.08 $31.36
3 sheets needed to cover 12 cages top and
bottom – 3 year life
Labor $19.94 1 hour $867.39 $867.39 Labor + Workers Comp Benefits | | 43.5 hrs total
Overtime
Labor $27.13 1 hour $298.43 $298.43 OT Labor @ Base Salary X1.5 (11 Total OT hours)
Rubber
Gloves $3.48 1 pair $13.92 $13.92 2 pairs per week
Cable Ties $3.98 20 ties $4.78 $4.78 2 cables per trap | 12 traps in experiment
Pliers $7.58 X 1 plier $7.58 $2.53
Modify traps if necessary i.e. trap door stuck shut
| 3 year
Labels $21.17 100 sheets $2.54 $2.54 Only 12 labels needed
Pressure
Washer $599 X
washer +
gas $603 $52
1 pressure washer + 1/2 gallon for fuel | $50/day
rental
Vehicle Cost $231.76
$0.555/per
mile $231.76 $177.15
$0.555/mile includes vehicle use and fuel (42.6 mi
round trip+3.0 mile stretch to and from Trap
Location on Empire Mine Road x 7 trips x 0.555
for one vehicle used)
Total Cost Per
Site $1,670.43 Total Cost per 1200 ft (live trapping)
$7,311.85*
Total Cost/Linear Mile (Minus
Reusable Items live trapping)
$10.99
Total Cost Per Squirrel per 1200 ft (152
ground squirrels)
9
Ferbruary 8, 2013
Diphacinone Bait Broadcast Treatment
Materials Cost Reusable Unit
Total
Cost
Actual
Cost Comment
Diphacinone
0.01% 63.50 50 lbs $401.96 $401.96
Broadcast 3.3 mile stretch of Empire Mine Road
(CDFA Research Surcharge @$0.50/LB) + Cost of
Treated Bait (6.33 bags used)
Labor 19.94 1 hour $119.64 $119.64
Cost per week for Empire Mine 1 day Untreated
(placebo) Grain plus 2 days Diphacinone treated
grain bait (6 hours total)
Untreated
Rolled Oats 20.57 50 lbs $82.28 $82.28
Cost for Broadcast 3.3 mile stretch of Empire Mine
Road (4 bags)
Seed
Spreader 710.00 X 1 Hopper $710.00 $14.20
Spreader 5 year life (1/10) use | (Spreader +
Rheostat)
Vehicle Cost 0.555 Per Mile $109.22 $109.22
$0.555/mile | 42.6 mi roundtrip + 6.6 miles
for Empire Mine Rd X 4 trips (one for trap
placement and placebo; three days for
treatment/survey)
Total Cost
Per Site $1,589.14 $727.30
Total Cost for 3.3 mile stretch of Empire Mine
Road
$481.56 $220.40
Total Cost per mile (treated bait) on
Empire Mine Road
Table 2: The displays the material cost for spreading treated bait on Empire Mine Road Antioch.
RESULTS AND FINDINGS:
Cost Analysis:
Total live trapping cost in our experiment, not including any additional supervisory or clerical
time, was $7,311.85 on a per linear mile basis. When adjusted for efficiencies (see below) this
totaled $5,074.36 per linear mile. The cost for the directed strip broadcast method using
diphacinone treated bait was $220.40 per linear mile. This is more than a 23 fold cost difference.
The high cost of live trapping was due to increased labor and handling time, equipment costs,
trap maintenance, and a higher number of site visits relative to where treated bait was used.
10
Ferbruary 8, 2013
These costs are documented in Tables 1 & 2 above. We did not include travel time, mileage or
other expenses for the USDA Wildlife Specialist that assisted with the euthanizing of the ground
squirrels, however, we did include the actual start to finish time of euthanizing at the hourly rate
of our staff because this part of his time would have been spent by our staff had he not assisted.
We did not include time or expense for trap set up help from staff other than the two core
employees that ran the experiment nor did we count time or expense of two post trapping surveys
that staff performed. Also not included in the total cost of the live trapping is added supervision
and clerical time required to support additional staff that would be needed if the live trapping
method were to be used more extensively.
With that being said there were certain efficiencies that could be realized that would bring the
cost down from that of the experiment. For the experiment we had two staff members involved
with the actual trapping. This could be done by one person with an estimated time savings of
about 25%. Thus the hours needed would be reduced from 43.5 to 31.625 actual hours or 139.15
hours on the per linear mile basis. Also, the evening check of the traps that was done on
overtime could be eliminated. This would also reduce the number of round trips from seven to
six resulting in a mileage cost reduction of $25.31. The total savings of these efficiencies would
result in a cost of $5,074.36 per linear mile (still not including costs of additional supervision or
clerical). With these efficiencies live trapping for five days plus the one day set up/placebo is a
little more than 23 times more costly than bait treatment. We feel this is not a wise or efficient
use of public funds with which we are entrusted.
For comparison purposes, quotes were obtained from commercial pest control operators that
could treat using non chemical live traps or other methods. The quotes ranged from $90 to
$125/hr plus mileage for nonchemical ground squirrel control using live traps or other methods.
At 139.15 hours per linear mile for the five days of trapping this would amount to $12,523.50 to
$17,393.75 per linear mile plus mileage. We also received two quotes of $20 and $25/ground
squirrel captured. These quotes on the per squirrel basis convert to a per linear mile rate of
$13,360 and $16,700 respectively considering that 668 squirrels were captured on a per linear
mile basis.
11
Ferbruary 8, 2013
These finds are consistent with other studies that found "trapping and mechanical devices to
control ground squirrels will rarely be used as part of the IPM program due to the inefficiencies,
expense and incompatibility with facility structures." [27]
Effectiveness:
Table 1 shows 152 ground squirrels were caught in the 1,200 foot test area. This supports that
our methods were very effective in capturing ground squirrels in the study area. Per linear mile,
this would equate to 668 squirrels trapped. Although the live trapping was effective, the survey
of the trapped area on the Monday following the five days of live trapping found a significant
and unacceptably high amount of ground squirrel activity in the trapped area. The activity
included ground squirrel use of burrows that were in the trapped area close to and immediately
adjacent to the roadway as well as significant foraging activity in the intended buffer area
adjoining the road (see Appendix A, pages 12 and 13). Failure of live trapping to adequately
reduce the population of ground squirrels was predicted by the lack of a decline in the daily catch
rate over the five day trapping period (see Appendix A, Figure #3, page 4). In fact the last
trapping day had the highest number caught at forty squirrels trapped. The lack of significant
reduction in population is consistent with reports from a local pest control operator (PCO) who
experienced the same outcome using live trapping. This same operator also reported vandalism
to traps and numerous catches of non-target skunks. It was fortunate for us that we did not
capture skunks as they are difficult to safely release from live traps and may require euthanizing.
Euthanization is how the PCO dealt with the situation. Conversely, significant and acceptable
reductions of ground squirrels were found in the areas of the roadside that were treated with
diphacinone 0.01% away from the live trap and control study area.
As previously stated on the Monday following the completion of the live trapping
experiment, numerous ground squirrels were observed using empty burrows as well as roadside
burrows located in the live trap buffer. This ground squirrel occupation of empty burrows in the
live trapped area was not anticipated as it does not occur in diphacinone 0.01% treatment areas
even though ground squirrel populations remain high beyond the treated buffer area. We
speculate that in treated areas the squirrels do not use these burrows for an extended time due to
12
Ferbruary 8, 2013
the treated squirrels that die in the burrows. This seems to act as a deterrent in bait treated areas.
This deterrent effect helps with our departmental goal of providing a squirrel free, or nearly
squirrel free, buffer area adjacent to the critical infrastructure that we are trying to protect. The
lack of acceptable control with 5 days of active live trapping resulted in the need to treat the live
trapped area the next week following the study.
There is the possibility that live trapping for longer periods of time, possibly two or three weeks
or more, would have resulted in creating the desired buffer. However, this would greatly
increase the cost. There is also a possibility that live trapping at a different time of year may
give different results. Live trapping in the winter would likely not be effective because of
hibernation. In late winter/spring the finding an acceptable bait to draw in the ground squirrels
into the trap would be a challenge because they are typically consuming grasses at this time and
would not be interested in the grain bait.
Concerns
Observations:
In Appendix A, figure 4 the graph displays an increase in the number of ground squirrels caught
due to the addition of plywood covering the trap. We initially used only metal discs on these
traps to provide weight, to keep predators from moving the traps and to provide shade. We were
concerned with heat radiating off this disc and therefore adding to the stress to the captured
squirrels. To remedy this we added total plywood coverage to the top of the trap. This increased
the catch rate in these two traps from 2/day to 5/day. The cover apparently made the squirrels
more comfortable in entering the traps.
The weather was hot in the afternoons, especially toward the end of the week (Appendix A,
Figure 5, page 6). This did not seem to significantly affect the catch rate, though on Wednesday
of the trapping week we checked the traps twice, once at about 2PM and again at dusk, about
8PM and found only four of the 38 captured that day were caught in the afternoon (Appendix A,
Table 1, page 1).
13
Ferbruary 8, 2013
Disposal of trapped squirrels presented a hazard to staff, and were required to wear protective
gloves and take precautions necessary to protect them from the spread of diseases via flea and
tick vectors on the ground squirrels. These precautions were necessary when handling dead
squirrels, especially those found dead in the traps.
Though not required, we had certified personnel to apply CO2 to the squirrels for proper
euthanization.
Traps consistently needed modification and maintenance in order to attract the ground squirrels.
We also found cleaning of cages at completion of the experiment to be imperative. At the end of
the study cages contained the dry residue of blood from the squirrels as well as a strong odor. As
we conducted the experiment the squirrels were observed to be frightened and would therefore
gnaw on the metal cages causing their mouths to bleed. Further observation throughout the week
supports the behavior of squirrel territorialism. Ground squirrels were observed fighting and
wounding each other in the traps. There were four dead squirrels in traps through the duration of
the study, their deaths probably due to fighting within the trap and heat stress. Deceased
squirrels lose body heat after all bodily functions cease and therefore fleas leave the host looking
for another warm-blooded animal. In addition, the deceased squirrels tend to emit an unpleasant
odor in the surrounding area. The presence of open wounds and blood further presented the
health issue of blood borne pathogens.
We also experienced trap vandalism. Two traps were found with the tops open in an apparent
attempt to free captured squirrels. This occurred even though the traps were clearly labeled as a
live trap experiment. This vandalism leads to great concern about the exposure of the public to
bites, scratches and transmissible diseases.
Observations made from the experiment indicate that the live trapping method would not be well
accepted by the public and would result in concerned citizens and complaints.
On the other hand ground squirrels controlled with treated bait alleviated most of the
observations mentioned above because we have found that the squirrels with rare exception will
14
Ferbruary 8, 2013
die in their burrows using this method. All areas treated with diphacinone 0.01% are surveyed
by our staff at the end of the treatment specifically for the presence of squirrels that have died
above ground. The entirety of the 2012 treatment season involved a total of 925 treated linear
miles. The department performs a carcass survey of all diphacinone treated areas. In the areas
treated by the department for ground squirrels during the 2012 season, these surveys found 6
ground squirrel carcasses above ground. No non target species were found during these surveys.
A Ventura County study found no carcasses above ground during broadcast baiting trials [27].
Though it is acknowledged that these surveys will not find all above ground carcasses, we
estimate above ground kills to be an extremely small percentage of ground squirrels affected
with the rest dying in the burrow. This is consistent with what is expected of first generation
anticoagulant rodenticides and is consistent with the results found in the previously mentioned
raptor studies.
An additional survey of Empire Mine Road was performed on September 14th, 2012, roughly one
month after treatment. The survey found no ground squirrel activity in the treated buffer area
though high activity beyond it. No evidence of deceased squirrel carcasses or non target species
was found.
Live trapping may be effective in highly sensitive areas that are known to be inhabited by
endangered species, such as the San Joaquin Kit Fox, or in other sensitive areas of small, isolated
colonies.
The timing and attractant bait for live trapping is an important consideration to effectiveness.
Our experiment was done in August in a rangeland situation where the ground squirrels were
readily taking grain bait. In the winter and spring it is unlikely that we would have had the level
of success in trap numbers because during those seasons ground squirrels in range land areas are
foraging on green grasses. Other baits that are more specific to the squirrels current diet may be
necessary for success in crop land areas. These baits may be almonds, melon or other food items
and may require trial and error to find successful bait. Also ground squirrels tend to hibernate in
the winter and success with live trapping will be reduced. In the heat of the summer ground
squirrels will often aestivate (summer equivalent to hibernation) and success may be reduced.
15
Ferbruary 8, 2013
Although in our study this was not a problem even though there were two days with afternoon
temperatures in excess of 100oF. There was reduced squirrel activity in the afternoon but not an
indication of aestivation during our study.
Other Control Method Options Used and Considered By the Department:
Burrow fumigation using carbon monoxide producing gas cartridges is a method that is
sometimes used by the department. This method produces positive results when conditions and
circumstances are right. Soil moisture is necessary to provide a seal to sufficiently hold the
carbon monoxide. Because of this, the use of gas cartridges is usually limited to the springtime.
Also vitamin K, the antidote for anticoagulants, is found in green grasses that are foraged by
ground squirrels in springtime and diphacinone baits are not effective during this season if the
squirrels are feeding on green grasses. With gas cartridges there is no chance of secondary
poisoning. However, there are drawbacks. The use of gas cartridges involve added staff time
and treatment cost. Gas cartridges are ineffective when squirrels are hibernating or aestivating
due to the squirrel internally plugging their burrow at these times. There is also the possibility of
direct primary kill to non target organisms and endangered species if gas cartridges are not
properly used. Endangered California tiger salamanders and California red-legged frogs cohabit
in active ground squirrel borrows. The endangered species act prohibits gas cartridge use in
California tiger salamander habitat and though not restricted by the act, we will not use this
method in red legged frog habitat. Endangered burrowing owls only inhabit abandoned ground
squirrel burrows. Our staff is trained to recognize and to not treat these burrows. Fire danger is
another issue to consider when using gas cartridges when grasses or other material is dry. Due
care to follow any special use restrictions and precautions, including in some cases no use, must
be taken by staff. It also must be noted that in some areas of the county and under certain
climatic events hibernation and aestivation may not occur. For example we have found minimal
hibernation on south west facing slopes in certain areas of East County. Evaluation may justify
burrow fumigation in the winter in some of these areas.
16
Ferbruary 8, 2013
O2/propane is an effective control measure. It works by injection of the gas mixture into the
burrow system the igniting which causes an explosion. This method has an added benefit of
partial burrow destruction. The department has attended demonstrations of this method. We
have chosen not to use the method mainly because it also kills other non-target organisms that
may be in the burrow, it presents a danger from flying material that may harm the applicator or
by-standers and can possibly cause damage nearby structures. It also attracts attention from the
public that may be in earshot of the applications.
CO2 is also used as a burrow fumigant. Our department does not have experience with this
material, though we would expect similar results as to gas cartridges though we expect that
efficacy would be less due to difficulty in finding burrow escape holes. With gas cartridges
these burrow system escape holes are rapidly apparent because of the smoke that the cartridges
produce. They holes are plugged by our staff to prevent loss of carbon monoxide thus giving
effective control. This may not be an issue with CO2 on flat ground because it is heavier than
air, but could be an issue in hilly or sloped areas. We also have concerns with non-target kills in
the burrows and the extra weight that our applicators would need to carry. The California
Department of Pesticide Regulation requires that the material (CO2) or the treatment device be
registered. On checking neither are so legal use of this method is pending registration.
Aluminum phosphide is another legal burrow fumigant. This material is highly toxic if not used
properly. It requires a restricted use pesticide permit. Non-target and efficacy concerns are very
similar to that of CO2. We choose not to use this fumigant in our ground squirrel program
because safer alternatives such as the gas cartridges are available.
Zinc phosphide treated bait is similar to the diphacinone bait in usage as a broadcast of treated
bait. Ten or more years ago we did use small amounts of this material but have decided since to
no longer use it as diphacinone is a less toxic and safer material to use. Zinc phosphide is
labeled “Warning” because it is moderately toxicity category as compared to diphacinone which
is labeled “Caution” or least toxic. There is a greater risk of direct non target kill and a greater
hazard to our applicators. The risk of secondary poisoning is less because the moisture in the
animal tissues rapidly converts zinc phosphide to phosphine gas which kills the animal.
17
Ferbruary 8, 2013
Phosphine gas dissipates rapidly reducing the potential of secondary non target kill. Bait
acceptance by ground squirrels in our county was also found to be lower than that of diphacinone
bait.
Bait stations containing anticoagulant bait is another method that is used by the department in
certain instances. This usually involves high damage areas where the broadcast method is not
allowed or desirable. This method can provide a satisfactory reduction in ground squirrel
populations in a buffer area near a sensitive site. Bait station use involves greater staff time and
cost. The PVC pipe type bait stations that we use exclude access by non target species and the
design prevents bait kick-out by the squirrels. Our staff is trained to clean up spillage that may
lead to concentrations of bait and unintentional poisoning of non-target animals. The bait
stations, though properly marked, present a danger to children. Tampering may also result in
concentrations of bait spilled outside of the bait station which will present a danger to non-target
animals. Control using bait stations is slower due to attractiveness to individual squirrels that
come to the bait station versus taking advantage of the natural foraging habit of the squirrel.
Squirrels in the immediate area come first to the stations and as they die out squirrels remote to
the bait stations find their way to them. This process can take two to three weeks or more as
compared to the four to six days that the broadcast method requires for a similar level of control.
Ground squirrels that come to bait stations also have a tendency to load up on more bait than
those that are foraging which can contribute to higher levels of toxicant if taken by non target
predators. In one study in Ventura County the pounds of bait used in bait stations was about ten
times as much as that used for similar control when treating by the broadcast method [27]. Bait
in bait stations that is ruined by moisture or mold must be handled as hazardous waste. This can
add to expense.
Raptor perches have been used in experimental areas by our department. They have not proved
to be successful in reducing ground squirrel populations. Three species of raptors in our area are
large enough to take ground squirrels, the red-tailed hawk, the red-shouldered hawk and the
golden eagle. Unfortunately of the 20 perches that our department put up in three different
locations, only a few have been rarely used by these species. On numerous occasions our staff
18
Ferbruary 8, 2013
has observed red-tailed hawks being chased away from the perches by kestrels, which are a small
territorial hawk. Ground squirrels have borrowed against some of the concrete filled post holes
used to place the perch. This is consistent with a ground squirrels affinity to borrow at the edge
of concrete and asphalt apparently because this makes them feel more protected from predators.
Owl Boxes Do not work for ground squirrel control for two basic reasons. One is that the
biology of the owl as a night time hunter and that of the ground squirrel that is active only during
the day make it such that the two do not cross paths. The other reason is that none of our native
owls are large enough to take a ground squirrel with the exception of the great horned owl. Very
rarely a great horned owl is found to have feed on a ground squirrel, likely one that was out at
dusk which is much later than normal for a ground squirrel to be out.
Kill Traps have not been used by the department. These will only capture one ground squirrel at
a time and may be effective in small light population areas. There are many kinds of traps.
However, use of kill traps will present potential to non-target animal capture and are of concern
in any area where there is the possibility of children coming into contact with them. They are
also very time consuming and therefore costly to implement.
Summary:
The experiment supported the following data and observations:
Negative Findings:
• Five consecutive days of live trapping was not effective in sufficiently reducing the
ground squirrel population to an acceptable level.
• Live trapping was over 23 times more expensive than treated grain bait application.
$5,074.36/linear mile compared to $220.40/ linear mile.
19
Ferbruary 8, 2013
• Our program in 2012 involved treating 925 linear miles. Besides the additional cost
in time and materials of live trapping, this method would require a substantial
increase in staff, the number of trucks needed to accomplish the workload, and
administrative time.
• The number of ground squirrels trapped in the test area as evidenced by the number
live trapped (152 or 668/linear mile) in one work week of trapping was not sufficient
to reduce the population and establish a buffer area to a desired level.
• A significant portion of squirrels that were live trapped were injured and bloodied
from squirrels fighting within the trap.
• Four squirrels died in the traps, though the traps were checked a minimum of once per
day. The deaths were apparently due to fighting, heat or other stresses or
combination of stresses.
• Trapped ground squirrels were observed heavily bleeding from the gums due to
chewing on trap wire in an apparent attempt to escape from the trap.
• Disposal of fumigated wounded and non-open wounded squirrel carcasses involved
reaching into the cages increasing the chance of operator exposure to disease and
ectoparasites and blood borne diseases.
• Uncovered traps were not as effective in attracting ground squirrels. The catch rate of
uncovered traps was 2/day whereas the catch rate of the same traps when covered was
5/day.
• Vandalism of traps by people occurred to two traps despite conducting the experiment
in a remote area with very little foot traffic and no vehicle traffic. This is cause for
great health concern to the public due to the possibility of bites, scratches and
exposure to transmissible disease.
Positive Findings:
20
Ferbruary 8, 2013
• The study showed that with the methods used a high number of ground squirrels can
be trapped.
• Live trapping may be an effective method at protecting small sensitive areas where
treated bait is not allowed and ground squirrel reduction is needed.
• Live trapping may also prove to be effective in a small area if it is desirable to
remove an isolated colony of ground squirrels.
• Using the broadcast method of treating with 0.01% diphacinone bait (a first
generation rodenticide) results in a very low rate of above ground squirrel death.
• Broadcast is generally better than the use of bait stations for treated bait in the risk to
children and to direct non-target species affects.
This experiment may serve as a foundation for future experiments to develop further
information on secondary poisoning or explore other cost effective or least toxic methods to
reducing ground squirrel populations.
References
1) AVMA Guidelines on Euthanasia. American Veterinary Medical Association.
https://www.avma.org/KB/Policies/Documents/euthanasia.pdf. June 2007
2) California Department of Public Health. Flea Borne Diseases. California Plague Surveillance.
http://www.calsurv.org/book/export/html/6. 2012
3) Lorin L. Lima and Terrel P. Salmon, Assessing Some Potential Environmental Impacts from
Agricultural Anticoagulant Uses
21
Ferbruary 8, 2013
Proceedings from the 24th Vertebrate Pest Control Conference (2010), Published at
University of California, Davis, pages 199-203
4) Grinnel, J. and J. Dixon, Natural history of the ground squirrels of California, California State
Commission of Horticulture Monthly Bulletin 7:597-708
5) Rodenticide Use - California Department of Fish and Game
http://www.dfg.ca.gov/education/rodenticide/
6) Diphacinone (Ramik, Promar)- Chemical Profile 1/85
http://pmep.cce.cornell.edu/profiles/rodent/rodent_A_L/diphacinone/diphac_prf_0185.ht
ml2012
7) Environmental Protection Agency. R.E.D. Rodenticide Cluster.
http://www.epa.gov/oppsrrd1/REDs/factsheets/2100fact.pdf.2012
8) Google Maps. Empire Mine Road, Antioch, CA.
http://maps.google.com/.2012
9) Neogen Corporation. Product List. Material Safety and Data Sheet.
http://www.neogen.com/AnimalSafety/AS_R_Product_List.asp?Catagory_ID=9a. 2012
10) Secondary Poisoning Concerns with Rodent Baits.
http://www.doyourownpestcontrol.com/secondarypoison.htm. 2012
11) The Home Depot. Hardware Cost.
http://www.homedepot.com/h_d1/N-5yc1vZbu0h/h_d2/Navigation?langId=-
1&storeId=10051&catalogId=10053. 2012.
12) United States Department of Agriculture. Animal and Plant Health Inspection Service.
http://www.aphis.usda.gov/wildlife_damage/. 2012
13) University of California Agricultural and Natural Resources.
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7438.html. 2012.
22
Ferbruary 8, 2013
14) Vermeer, C., Roberts, H., Stafford, D. Vitamin K supplementation during oral
anticoagulation: cautions. Blood, April 15, 2007. Volume 109, Number 8.
http://bloodjournal.hematologylibrary.org/content/109/8/3607.1.full.pdf+html
15) Whisson, Desley.A, and Salmon, Terrel.P. Effect of Diphacinone on blood coagulation in
Spermophilus beecheyi as a basis for determining optimal timing on field bait
applications. Pest Management Science. Volume 58. p. 736-738. 6/6/2002.
16) Wildlife Damage Control.
http://www.wildlifedamagecontrol.com/.2012
17) Results of Laboratory Testing for Diphacinone in Sea Water, Fish, Invertebrates, and Soil
following Aerial Application of Rodenticide on Lehua Island, Kauia County, Hawaii,
United States Geolocical Service, US Fish and Wildlife Service, Department of Interior
http://pubs.usgs.gov/of/2009/1142/pdf/OF2009_1142.pdf
18) Loredo-Prendeville, Ivette; Van Duren, Dirk; Kuenzi, Amy J.; and Morrison, Michael L.,
“California Ground Squirrels at Concord Naval Weapons Station: Alternatives for
Control and the Ecological Consequences” (1994). Proceedings of the Sixteenth
Vertebrate Pest Conference (1994), paper 32
http://digitalcommons.unl.edu/vpc16/32
19) Horn, Everett E. and Fitch, Henry S., “Trapping the California Ground Squirrel” (1946).
Journal of Mammology, Vol. 27, No. 3 (August 1946, ppg 220-224
http://www.jstor.org/stable/1375430
20) O’Connel, Ross A., “Trapping Ground Squirrels as a Control Method” (1994). Proceedings
of the Sixteenth Vertebrate Pest Conference (1994). Paper 43.
http://digitalcommons.unl.edu/vpc16/43
21) Salmon, Terrell P, and Schmidt, Robert H., “An Introduction Overview to California to
Ground Squirrel Control” (1984). Proceedings of the Eleventh Vertebrate Pest
Conference (1984). Paper 30.
http://digitalcommons.unl.edu/vpc11/30
22) Extension Toxicology Network; Pesticide Information Profile – Diphacinone
23
Ferbruary 8, 2013
http://extoxnet.orst.edu/pips/diphacin.htm
23) Siberhorn, Eric M., Schnabel, Duane L. and Salmon, Terrell, P. “Ecological Risk
Assessment for Use of Agricultural Rodenticides in California (2006). Proceedings of
the 22nd Vertebrate Pest Conference pages 458-462
24) Common Co-Infections Associated with Lyme Disease
http://www.lyme-symptoms.com/CoInfections.html. 2012
25) Internet Center for Wildlife Damage Management
http://icwdm.org/handbook/damage/WildlifeDiseases.asp. 2012
26) Baldwin, Roger A.; Salmon, Terrill P. “The Facts about Rodenticides, Understanding a
Valuable Tool in Integrated Pest Management” UC-IPM
27) Rodent Control for Flood Control Facility Protection, Ventura County Watershed Protection
District, December 12, 2006
http://portal.countyofventura.org/portal/page/portal/PUBLIC_WORKS/Watershed_Prote
ction_District/Programs_and_Projects/ApprovedIPMfinal.12.06.pdf
28) Rodent Control for Flood Control Facility Protection, 2007 Field Trial, Ventura County
Watershed Protection District, April 2007
http://portal.countyofventura.org/portal/page/portal/PUBLIC_WORKS/Watershed_Prote
ction_District/Programs_and_Projects/FinalTrialReport_4.10.08.pdf