Item 4ECITY OF
SOUTHLAKE
MEMORANDUM
May 7, 2013
To: Shana K. Yelverton, City Manager
From: Kyle Taylor, Assistant to the Director/Emergency
Management Coordinator
Subject: Item 4E: Approve City of Southlake's West Nile Virus
Action Plan
Action
Requested: Approve City of Southlake's West Nile Virus Action Plan.
Background
Information: The purpose of this item is to obtain approval for the City of
Southlake's West Nile Action Plan. This plan, which was
presented to City Council during the April 16, 2013
Worksession, has been developed in accordance with the
lessons learned while combating the threat of West Nile
Virus in 2012.
The Southlake West Nile Action plan contains provisions
relating to the response areas of Public Education, Source
Reduction, Surveillance and Monitoring, Larviciding and
Adulticiding. Also included in the plan is a tiered response
guide that defines the plan's response in easy to understand
risk levels that escalate based on the conditions observed in
the City. This plan presents a proactive approach to
managing the threat of West Nile Virus that empowers
stakeholders to prevent the virus before it becomes a
problem.
Financial
Consideration: There is no financial consideration included with the
approval of this plan. Any financial commitments needed to
supplement the City's response to West Nile Virus will be
pursued independently of the West Nile Virus Action Plan.
Strategic Link: Performance Management and Service Delivery; Safety and
Security; C1, Achieve the highest standards of Safety and
Security; B1, Achieve Best in Class Status in all City
Disciplines; B4, Provide High Quality Customer Service; B5,
Improve Performance of Delivery and Operational
Processes;
4E- i
City Council Meeting
Meeting Date — May 7, 2013
Page 2 of 2
Citizen Input/
Board Review: N/A
Legal Review: N/A
Alternatives: Council may approve, modify or deny this item.
Supporting
Documents: City of Southlake West Nile Virus Action Plan
Staff
Recommendation: Staff recommends the approval of the City of Southlake
West Nile Virus Action Plan.
4E - 2
CITY OF
SOUTH Al<,,,E
WEST NILE VIRUS ACTION PLAN
TABLE OF CONTENTS
Introduction....................................................................................................................................................3
West Nile Virus Response Team.........................................................................................................3
PublicEducation.........................................................................................................................................3
PublicInformation............................................................................................................................3
PersonalResponsibility....................................................................................................................4
EmployeeSafety..............................................................................................................................5
Sourcereduction.........................................................................................................................................5
Mosquito Surveillance and Monitoring............................................................................................6
Traps................................................................................................................................................ 6
MosqutioControl Methods.....................................................................................................................7
Larvicide........................................................................................................................................... 7
Adulticide.......................................................................................................................................... 7
Ris k Levels.....................................................................................................................................................9
NormalConditions............................................................................................................................9
RiskLevel One.................................................................................................................................9
RiskLevel Two.................................................................................................................................9
RiskLevel Three............................................................................................................................10
RiskLevel Four..............................................................................................................................10
Attachment A: Surveillance Map.......................................................................................................11
2
INTRODUCTION
The objective of the West Nile Virus Action Plan (the "Plan") is to attain an efficient and effective
mosquito control operation that will provide the best results possible, and be consistent with all
ecological aspects and the best interests of the City of Southlake. The Plan outlines strategies
for the prevention and control of mosquito -borne diseases that pose a threat to public health.
The City's immediate priority is to prepare for, and take preventive measures to reduce the
potential of the West Nile Virus (WNV) and other mosquito -borne diseases.
The Plan emphasizes a coordinated Integrated Pest Management (IPM) approach to minimize
the public health threat from mosquito -borne diseases, by utilizing proven sound mosquito
control techniques recommended by the Centers of Disease Control and Prevention (CDC). IPM
utilizes a variety of control techniques and evaluation procedures that includes:
• Public education
• Personal responsibility
• Source reduction
• Surveillance and monitoring
• Chemical control (larvicide and adulticide).
WEST NILE VIRUS RESPONSE TEAM
The West Nile Virus Response Team is a team of City staff members tasked with directing the
City's response to arbovirus. The team will meet as needed during the arboviral season to
discuss current response tactics, communication efforts and other mosquito related concerns.
The team also serves as the guiding body for the development and implementation of the Plan.
The team is composed of personnel from the following departments:
• City Manager's Office
• Departments of Public Safety
• Department of Public Works
• Department of Community Services
• Department of Planning and Development Services
PUBLIC EDUCATION
Public education during an arboviral outbreak
risks of the disease and what can be done foi
year, the City will engage in a public education
media, signs, displays and presentations.
Public Information
helps residents and visitors to understand the
personal protection. Beginning in April of each
campaign via the usage of City websites, social
The City will identify potential partners to assure a continuous flow of consistent information.
Additionally, the City will also utilize the CDC's "Fight the Bite" campaign to supplement its
public information efforts. Effective risk communication campaigns are successful because they
provide accurate, clear, and timely information. The prevention of any mosquito -borne disease
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is most efficiently accomplished by ensuring that prompt and accurate information reaches the
public. If the appropriate information reaches the public in a timely manner, personal protective
measures may be implemented without panic and confusion.
The City will provide continuous information on the City's website concerning arbovirus/disease
frequently asked questions (FAQs), disease symptoms, personal preventative measures, and
points of contact for additional information. If a sampled mosquito pool tests positive for
arbovirus/diseases, information describing the location of the sampling event, the date, and
other pertinent information will be provided.
Information dissemination methods may include the following:
• Utilization of the City's website to post information on positive human cases, mosquito
abatement activities, maps, surveillance reports, mosquito FAA's, personal protection
best practices, and mosquito control website links.
• Utilization of the City's Connect CTY system to alert the community of any potential virus
threat and adulticide control applications.
• Adding mosquito control tips on utility water bills.
• Letters, pamphlets, brochures, and/or door hangers to be distributed to residents,
shopping areas, schools, and faith based organizations within the community.
• Presentations to community groups and target populations concerning mosquito
breeding reduction and related activities.
• Press releases describing WNV response activities.
Personal Responsibility
All citizens must be active in personal protection and do their part to aid in the abatement
process to protect themselves, their family, their homes, and their community. Providing the
public with the most updated information is only one part in the prevention of mosquito breeding
and disease prevention. Since much of the land within Southlake is private property, the City will
stress the importance of personal protection responsibility through its public information
campaign year-round. It is important for the residents to know that the majority of mosquito
breeding sites are developed due to the creation of artificial breading sites around their homes.
The following information will assist the residents and help them to become more aware of
mosquito breeding sites to prevent the spread of mosquito -borne diseases.
The key component of the City's public information campaign to promote personal responsibility
will focus on the 4 D's:
• Dusk / Dawn: Dusk and dawn are the times of the day when mosquitoes are most
active. During peak mosquito season, individuals will be encouraged to stay indoors if
possible or limit outdoor activity during these periods.
• DEET: Individuals will be encouraged to use repellants that contain DEET as the active
ingredient for treating exposed skin areas.
• Dress: Individuals will be encouraged to dress to keep skin covered as much as
possible by wearing loose, long sleeved shirts and long pants
• Drain: Residents will be encouraged to drain any standing water on their property. This
includes water from flower pots, bird baths, rain gutters, rain barrel, and pet dishes at
least once a week.
0
Source reduction is another key component of the City's public information campaign. Source
reduction focuses on eliminating breeding sites for larvae by:
• Reducing all standing water around the property that provides breeding sites.
• Checking the irrigation system to prevent excessive -watering of lawns and plant beds.
• Repairing leaky pipes and outside faucets.
• Cleaning gutters every three (3) to four (4) months.
• Emptying outside pet bowls when not in use.
• Cleaning and adding fresh water to birdbaths once a week.
• Emptying plastic wading pools weekly and storing indoors when not in use.
• Using mosquito fish in decorative ponds and fountains.
• Filling holes or depressions in trees with sand or mortar, or draining them after each rain
by drilling holes into the tree. .
• Distributing larvicidal dunks for use by residents on private property
The public will also be encouraged to reduce exposure to adult mosquito populations through
the following actions:
• Mow tall grass or reduce the amount of brush and other foliage on the property to reduce
the resting sites for adult mosquitoes.
• For temporary relief in yards or high traffic areas, use organic and /or EPA approved fog
treatments or surface treatments of insecticides that are labeled for that use, and apply
them following the directions on the product label.
• Use screening in homes and pet kennels. Keep door and window screens in good repair,
and be sure that they are properly sealed around the frames
• Protect pets with drugs that eliminate heartworm.
Employee Safety
During peak mosquito season, City employees working in the field need to take steps to fight
the bite. Mosquito repellent containing DEET will be made available to employees at all City
facilities. When feasible, employees should take steps to cover arms and legs to minimize
contact with mosquitoes.
If an employee is bitten by a mosquito during work time and begins to experience symptoms,
their supervisor should be notified. A First Report of Injury form needs to be submitted as soon
as possible.
SOURCE REDUCTION
The elimination or modification of mosquito breeding sites is critical, and typically, the most
effective and economical solution for long-term mosquito control.
The normal habitat for mosquito larvae in the community is produced by just about anything that
holds water. Plastic containers, tree holes, down -spouts, depressions in streets, storm drains,
drainage ditches and meter boxes are a few of the breeding grounds identified in Southlake in
recent years. Small pools of water that are created by lawn irrigation or any rainfall during the
summer produce most of our nuisance species of mosquitoes. Almost anything, whether natural
or artificial, that will hold water for about a week or more, may breed mosquitoes. Mosquitos
have adapted to a wide variety of larval habitats, and it is important to check for larvae in any
pools of standing water.
The most common carrier of West Nile Virus in the Dallas -Fort Worth region is the species
Culex quinquefasciatus, also known as the southern house mosquito. This species' breeding
habitat are waters heavily polluted with organic materials such as ditches, down spouts, and
storm drains receiving grass clippings, leaves, septic tank overflow, and other organic materials
and polluted waters. This mosquito will also breed in artificial containers. The southern house
mosquito, although advantageous and lay eggs just about anywhere, will less likely breed in
flowing or pooled streams and other waterways, especially with the presence of predators such
as small fish.
City staff will practice source reduction year round by inspecting public facilities, infrastructures,
and equipment to remove any potential mosquito breeding site.
Staff will perform source reduction on public property that will include, but not limited to:
• Draining and/or filling of areas where shallow stagnant water can accumulate such as
gutters, potholes, and drainage ditches.
• Proper storage of outdoor equipment;
• Continue to enforce current City water conservation codes and ordinances;
• Monitoring the Parks irrigation systems for proper watering operations;
• Treat culverts, catch basins, fountains, manhole covers, storm water inlets, and
discharge areas.
MOSQUITO SURVEILLANCE AND MONITORING
The City's surveillance and monitoring program will be used during mosquito season to pinpoint
large mosquito populations in the community. The City will survey and monitor adult mosquitoes
using gravid traps. The captured mosquitoes will be taken to Tarrant County Public Health for
testing.
The information obtained from these surveillance efforts will be used to map mosquito
populations, provide public information, and determine the occurrence of any mosquito -borne
disease. All surveillance data and results will also be published on the City's website.
The City will use mosquito surveillance and monitoring by collecting adult mosquitoes to
determine what control measures are to be used, and evaluate the potential for any arboviral
disease outbreak within the community. The objective of the surveillance and monitoring
program is to:
• Assess the threat of arboviral exposure to residents.
• Identify high risk adult mosquito population areas.
• Identify larval habitats that are in need of targeted control.
• Monitor the effectiveness of control measures.
• Determine what level of control methods need to be implemented.
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Typically, surveillance programs are conducted May through November, though dates will be
adjusted based on seasonal trends
Traps
The City will utilize six gravid traps to conduct mosquito surveillance. Five of these traps will be
kept in static locations across the city, and one trap will be moved to different locations in the
City depending on surveillance results and positive human cases. See Attachment A for the
City's Surveillance Map.
The purpose of using traps is to determine the relative human health threat by detecting the
presence of arboviral agents in female mosquitoes, primarily of the Culex species. Upon
collection, the mosquitoes will be sent to Tarrant County for identification and arbovirus
isolation. The information obtained from these surveillance efforts will determine the need for
various control measures, assess the extent of the problem, and potentially gauge the
effectiveness of control measures.
MOSQUITO CONTROL METHODS
The CDC recommends that chemical control applications should be dependent on set threshold
levels. This means that a certain defined risk needs to exist before particular chemical control
measures are implemented.
The most commonly used chemical control treatments are larvicide and adulticide. Larviciding
and adulticiding is recognized by the CDC and other federal health authorities as critical
program elements in reducing public health threats from mosquito -borne diseases. Larviciding
would only help reduce populations of future generations, but would not affect existing adult
mosquitoes, which are infected or could be infected. It is acknowledged that source reduction
and Iarviciding cannot completely eliminate adult mosquito populations in the City. Given the
relative importance and capabilities of source reduction and Iarviciding to reduce the breeding of
mosquitoes, such activities will be undertaken before adulticiding. Should surveillance data
indicate increased mosquito population(s) and/or the presence of an arbovirus that poses a risk
to public health, adulticiding can help reduce such populations over a large area in a relatively
short period.
Larvicide
The City will utilize organic larvicides as well as EPA approved larvicides that will be applied
according to the manufacturer's directions. Larviciding is an important control mechanism since
the objective of Iarviciding is to control the immature stages at the breeding sties before adult
populations have had a chance to disperse, and to maintain populations levels at which the risk
of arbovirus transmission is minimal
Staff will utilize a Iarviciding program year round in combination with surveillance and source
reduction to control mosquito larvae before they develop into biting adults. Staff will inspect (on
a continual basis throughout the year) locations that are known to have the potential to hold
water and breed mosquitoes.
7
This strategy is the most effective, economical, and safest method for mosquito control because
mosquito larvae are minimized, thus reducing the need for adult mosquito control, and
subsequently reducing the impacts of control measures on non -target organisms. Using
larvicide controls also minimizes the chance of pesticide resistance in mosquito populations
because the product is either organic, a naturally occurring compound, or structurally identical to
a naturally occurring compound.
As recommended by the Texas Department of State Heath Services (DSHS) , the earliest
larvicide agents will be applied to water identified to contain mosquito larvae is three (3) days
after a rain event when the water stops flowing. Therefore, because of their organic properties, it
is recommended that larvicide agents are to be used as a primary source for mosquito control
within the City.
Adulticide
Adulticiding is the application of pesticides to kill adult mosquitoes. It will be standard procedure
for the City to only use pesticides meant for adult mosquitoes as a last resort to control adult
mosquito populations. The City will only use adulticiding chemicals that have been tested,
registered, and approved by the EPA. The City's consideration to use pesticides will be based
the CDC's recommendation that mosquito adulticiding should only be used in situations where
surveillance data indicates that it is necessary to reduce the density of adult mosquito
populations quickly to lower the risk of WNV or other mosquito -borne diseases.
Thresholds for consideration include:
• When a particular trap location has over 50 female mosquitoes in one night of trapping.
• When a mosquito pool (one trap's catch of mosquitoes) has tested positive for either
arbovirus.
• When Tarrant County or Denton County reports a human case of arbovirus in the City.
• On the recommendation by Tarrant County, Denton County or the DSHS for any public
health reason.
The City will use the following guidelines when applying adulticides:
• Spraying shall be conducted between the hours of 10:00 p.m. and 6:00 a.m.
• Notification to citizens in the areas being sprayed must occur 24 hours prior to any
application.
• Spraying areas will be published on the City's websites and social media accounts.
• Only the areas where a positive result was recorded will be sprayed.
• The areas where spraying takes places shall be treated three times in three consecutive
nights, depending on weather conditions.
• Spraying will not take place if the wind speed is below 1 MPH, or exceeds 10 MPH;
• Keep a copy of the pesticide label and MSDS in the spray truck.
• Spray truck emergency lights must be operating while spraying
The CDC has reported that many mosquito control programs have relied heavily upon using
chemical agents for mosquito control. Those mosquitoes that are exposed constantly to
chemical applications are genetically able to resist higher pesticide concentrations. Eventually,
the pesticide becomes less effective as resistance increases in the mosquito populations. The
CDC states the onset of resistance can be minimized through:
• Using doses that are no lower than the lowest level rate to avoid genetic selection;
• Using less frequent applications;
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• Using chemicals of short environmental persistence;
• Avoiding the use of slow release formulations;
• Avoiding using the same class of pesticides to control both adults and immature stages;
and
• Applying pesticides to only hot spots.
The effects on human health are primary factors considered in the regulation of adulticides. The
CDC reports that pesticides that can be used for mosquito control and have been approved by
the EPA do not to pose an unreasonable risk to human health. The CDC recommends people
who are concerned about exposure to chemicals, such as those with chemical sensitivity, or
breathing conditions such as asthma, can reduce their potential for exposure by staying indoors
during the application period.
RISK LEVELS
The CDC and the DSHS recommends that a mosquito control program should be supplemented
with a risk response plan designed for mosquito -borne disease outbreaks. The response plan is
not intended to replace a mosquito control plan, but to define human disease risk levels with
specific recommended responses in accordance with the principles of IPM and threshold
management criteria. The following response plan has been developed in accordance with the
risk levels outlined by Tarrant and Denton County.
NORMAL CONDITIONS
Conditions: No evidence of mosquito or arboviral activity.
Probability of Human Outbreak: None.
Surveillance Response:
• Develop and refine West Nile Virus response plan.
Public Education Response:
• Initiate community outreach and public education programs.
Vector Control Response:
• Prepare and secure vector control resources for use if risk level escalates.
RISK LEVEL ONE
Conditions: Normal mosquito activity with little or no evidence of arboviral activity.
Probability of Human Outbreak: Low
Surveillance Response:
• Conduct mosquito surveillance in the City's six traps on a weekly basis.
• Transport mosquitoes collected in the traps to Tarrant County for testing.
Public Education Response:
• Focus on risk potential, personal protection and residential source reduction.
• Begin targeted community presentations.
• Communicate via City website and social media accounts.
Vector Control Response:
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Focus on source reduction on public and private property.
Conduct larviciding operations on public property.
Distribute larvicide to citizens.
RISK LEVEL TWO
Conditions: Arboviral activity detected in surveillance samples.
Probability of Human Outbreak: Moderate.
Surveillance Response:
• Increase mosquito surveillance in areas where positive samples are collected.
Public Education Response:
• Communicate to the public that arboviral activity has been detected in the City.
• Communicate disease symptoms and advocate personal protection.
• Continue to emphasize source reduction.
• Continue targeted community presentations.
• Continue communicating through City websites and social media accounts.
Vector Control Response:
• Consider ground -based adulticide application around positive sample location.
• Conduct larviciding around positive sample locations.
• Continue to conduct larviciding operations on public property.
• Continue to distribute larvicide to citizens.
• Continue to promote source reduction on public and private property.
RISK LEVEL THREE
Conditions: Arbovirus detected in multiple mosquito samples collected at different times from
different locations. One or more confirmed human cases of arbovirus.
Probability of Human Outbreak: High
Surveillance Response:
• Monitor the spread of the arbovirus through continued surveillance operations.
Public Education Response:
• Communicate the ongoing public health threat and any advisories from Denton or
Tarrant County.
• Communicate disease symptoms and advocate personal protection activities.
• Continue to emphasize source reduction.
• Continue targeted community presentations.
• Continue communicating through the City websites and social media accounts.
Vector Control Response:
• Consider ground -based adulticide application around areas with confirmed human cases
and confirmed positive samples.
• Consider ground -based adulticide application around areas with positive samples.
• Continue to conduct larviciding operations around positive samples.
• Continue larviciding operations on public property.
• Continue to distribute larvicide to citizens.
• Continue to promote source reduction on public and private property.
10
RISK LEVEL FOUR
Conditions: Multiple human cases confirmed with continued widespread arboviral activity
detected by positive surveillance samples.
Probability of Human Outbreak: Outbreak in progress
Surveillance Response:
• Monitor the spread of the arbovirus through continued surveillance operations.
Public Education Response:
• Communicate the ongoing public health threat and any advisories from Denton or
Tarrant County.
• Communicate disease symptoms and advocate personal protection activities.
• Continue to emphasize source reduction.
• Continue targeted community presentations.
• Continue communicating through the City websites and social media accounts.
Vector Control Response
• Prepare to discuss aerial spraying should either County offer it as a vector control
option.
• Consider ground -based adulticide application around areas with confirmed human cases
and confirmed positive samples.
• Consider ground -based adulticide application around areas with positive samples.
• Continue to conduct larviciding operations around positive samples.
• Continue larviciding operations on public property.
• Continue to distribute larvicide to citizens.
• Continue to promote source reduction on public and private property.
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ATTACHMENT A: SURVEILLANCE MAP
SOUTHLAICE Static Mosquito
Surveillance �-
Locations o�
■ Static Trap Locations �, - # 4, Woodland Qr.
■ Static Traps Outside Southlake 1 Y 32.98564•-97.14810
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I J.- .
# 3, Shady Oaks
32.97025,-97.16014 114 ` ,�- f'
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# 5, Shady Ln
� I
32.95196,-97.11404
# 2, Meadowlark Ln
32.94111,-97.18286
a� $1
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12
J
# 1, Greymoor PI
32.93635,-97.14067