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Part 1. DESCRIPTION OF THE VECTOR CONTROL DISTRICT 

Budget 

Fiscal Year (FY) 08/09 – $1,335,104.00 

Fiscal Year (FY) 09/10 - $1,269,127.00 * 

*Estimated at time of report creation. For more information see www.co.multnomah.or.us/budget 

Size of district

457 square miles – Multnomah County 

3.63 square miles – City of Durham and surrounding sites 

Combined size of treatment area in square miles 

457 square miles (maximum) – Multnomah County 

3.63 square miles (maximum) - City of Durham and surrounding sites 

Training goals of each pesticide applicator, supervisor and dates of training 

# of attendees Event

1 Child abuse training – 4-22-08 

5 Respiratory protection refresher – 5-22-08 

9 All Staff policies review and e-policies – 2-18-09 

3 Multnomah County media training – 1-29-09 

9 Dealing with difficult operators - Oct & Nov – 2008 

2 Multnomah County Climate Change Workshop – Feb. 6th 

1 Oregon Native Turtle Conservation Forum 3/20/2009 

1 Target Annual Fall Workshop, Portland – Nov. 6th 2008 

1 Oregon Vector Control Association Recertification Workshop – 

Nov.7th 2008 

1 6th International Integrated Pest Management Symposium 3/25/2009 

1 Washington State Department of Health, Zoonotic and Vector-borne 

Disease Workshop 3-2008 

5 Oregon State University Chemical Applicator Short Course – 1-2009 

1 Mapping Oregon Communities – 8-14-2008 

1 Northwest Mosquito and Vector Control Assn Conference – 10-9 and 

10-10-2008 

1 Society for Vector Ecology Conference – 9/28/2008 through 10/2/2008 
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Annual Report 

Mosquito Control (1-1-2008 through 12-31-2008) 

 Control – 5690 acres 

 Complaints – 0 

 Inspections – 44 

 Gambusia affinis distributed –1,273 individual fish 

Mosquito Surveillance (1-1-2008 through 12-31-2008) 

 Number of Mosquito pools submitted for testing using RT-PCR = 250 

 Total number of Mosquito pools tested (various methods incl. RT-PCR{160} and 

RAMP{90}) = 250 

 Number of Dead Birds Tested - 141 

Rodent Control (1-1-2008 through 12-31-2008) 

 Complaints – 1025 

 Inspections – 967 

Part 11. MAPPING 

All maps applicable to program were submitted in the 1999 and the 2000 pesticide use 

plans on file with both OHD and ODFW. 

PART III. USE OF SURVEILLANCE TO DEFINE THE PROBLEM AND DETERMINE PESTICIDE 

CHOICE 

1.1 Sampling pre-treatment: to determine if treatment is needed 

Routine mosquito larval surveillance is conducted prior to an application using 400mL 

dippers. Mosquito larvae are initially field identified and counted and samples are 

collected for specific identification at the Multnomah County Vector and Nuisance 

Control (MCVNC) lab. A threshold instigating a control application is exceeded when 

one or more mosquito larva with known potential vector capacity of mosquito-borne 

disease and or effects community livability, randomly sampled, is collected. This 

conservative larval threshold is based upon multiple factors including reproductive 

potential, host preference and avoidance, migratory potential and local population 

densities. 

Applications to control mosquitoes may be initiated if a mosquito larva is found. Many 

other factors are taken into account which may delay or prevent application of larvicides 

to the site which include; predator/larvae population, hydrology of site, time of year, 

weather, species, flight range of mosquito, location of site, community livability, 

vectorial capacity of species, and arboviral disease presence. 

1.2 Sampling post treatment after treatment 

Routine mosquito larval surveillance is conducted after an application using 400mL 

dippers. Post application surveillance of larvae is completed to review efficacy of 

suppression method implemented. 

1.3 To evaluate efficacy of treatment 
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MCVNC currently conducts efficacy of suppression methods under the following 

circumstances: 

 When larvicide stock materials, held over from previous year(s) are applied 

 When the site is yielding +20 mosquitoes/per 400mL dip prior to initial treatment 

to determine if population(s) are high enough to justify re-application. Bacillus 

sphaericus (e.g. Vectolex cg) performs better when numbers are high. 

 When new formulations or products of larvicide materials are applied, on trial 

basis, according to label, for viability in MCVNC program. 

Due to the redundancy of results, MCVNC does not conduct routine efficacy checks 

when known larvicide materials are used at different mosquito breeding sites, unless 

there are unique characteristics of the mosquito breeding site that would alter the 

outcomes of the material’s effect on control (i.e. B.t.i. and high organic content in water). 

 

1.4 To determine effect on non-target species 

MCVNC relies upon an integrated vector management plan that considers and 

implements multiple strategies for vector management by also balancing and considering 

affects on both non-targets and the local ecosystem. The MCVNC staff are regulated by 

Oregon Department of Agriculture and are licensed public applicators. The activities of 

MCVNC are reviewed and approved by Oregon Department of Fish and Wildlife, 

Oregon Department of Human Services, and Multnomah County Health Department. 

The MCVNC program manager routinely reviews peer reviewed literature on vector and 

pertinent public health preventions and applies that science and methodology to the 

vector control program. There is a plethora of peer-reviewed literature that shows that 

bacterial larvicides have no effect on non-targets other than Culicidae and some 

Chironomidae and Simuliidae. Additionally the carrier of the bacterium has no chemical 

affect on non-target organisms or the ecology of the local environment. When 

conducting post-application efficacy checks, staff may also note any effects on non-target 

species as applicable and work with appropriate parties to investigate as necessary. 

MCVNC works with local wildlife managers to assure vector control activities do not 

further impact local organisms protected under the Endangered Species Act of 1973, 

Migratory Bird Treaty Act of 1918, Bald Eagle Protection Act of 1940, United States 

Wildlife Service National Bald Eagle Management Guidelines May 2007, and 

information acquired from the Oregon and the Washington Bald Eagle Survey. Any 

aquatic or benthic non-targets collected during pre or post larviciding activities or routine 

larval collection are identified to minimum Order. This non target information is 

recorded on hardcopy and retained in a database which links the date of collection, 

location, and relative matching mosquito information and control activities for a 

particular location. As of 2006, MCVNC and Oregon Fish and Wildlife have developed 

and implemented a Mosquito Control Plan for the Sauvie Island Wildlife area to 

minimize impacts to non-target populations. Moreover as of 1995, MCVNC and the 

United States Department of Agriculture, Forest Services, Pacific Northwest Region, 

Columbia River Gorge National Scenic Area have developed and implemented a 

mosquito control plan for floodwater mosquitoes as part of the Sandy River Delta Plan 

and associated Environmental Impact Statement. Additionally as opportunities arise to 

partner with experts, MCVNC would defer to local wildlife managers for their expertise 

for non-target species monitoring other than humans or vector populations. In 2008, 
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Oregon Fish and Wildlife has agreed to perform some post monitoring of wildlife 

population(s) on Sauvie Island after a ULV-adulticide application by MCVNC for 

mosquito control. The methods and materials are yet to be determined by ODFW and 

MCVNC at this time. Please see the Sensitive Areas section for more detail. 

1.5 Document all sampling results for inclusion in the annual report 

We have a database containing species identification and numbers sampled. Additionally 

we record “field observations” when performing vector control activities around 

migratory birds, particularly Bald Eagle Haliaeetus leucocephalus and Osprey Pandion 

haliaetus. Any aquatic or benthic non-targets collected during pre or post larviciding 

activities or routine larval collection are identified to minimum Order. This non target 

information is recorded on hardcopy and retained in a database which links the date of 

collection, location, and relative matching mosquito information and control activities for 

a particular location. 

.1 Employ the use of landing rates, light traps, phone complaints (verified by trap 

samples). Require that complaints be made formally in writing. 

MCVNC does not normally use landing rates as a means of adult surveillance as this 

increases the risk for acquisition of a mosquito-borne disease by MCVNC staff. Instead, 

when necessary, MCVNC will utilize a sweep net for 30 seconds in place of landing 

counts. 

MCVNC occasionally uses New Jersey (light traps) for surveillance purposes. If average 

per night mosquito numbers experience a sharp rise, or are excessive in relation to nearby 

EVS traps then this data may be used to guide further surveillance and/or adult mosquito 

control efforts. There are other methods for mosquito collection that are used by 

MCVNC including gravid, modified Encephalitis Virus Surveillance (EVS), Bioagents 

Sentinel (BGS), attractants, etc for improved sample collection as necessary. 

MCVNC does accept phone call intake of adult mosquito complaints from Multnomah 

County residents. Complaints are taken via internet electronic complaints forms @ 

www.mchealthinspect.org or by phone at 503-988-3464. Complaints are investigated by 

trained field staff employees either licensed directly or working under the supervision of 

a public pesticide license holder administered by the Oregon Department of Agriculture. 

This information may additionally be used to locate the larval breeding site(s) as 

applicable. 

2.2(2.1) Sampling pre-treatment to determine species 

MCVNC regularly uses EVS traps for adult mosquito and arboviral disease surveillance 

throughout a large portion of the county. If it is determined that there are high numbers 

of known vector capable mosquitoes in a trap area then this data can be used to assist us 

and support the need to control mosquitoes such as adulticides. In most cases 

adulticiding would not occur based on the presence of certain mosquito species, but 

rather on a combination of factors including disease presence, and mosquito populations 

of vector capable mosquitoes. If however the presence of arboviral disease(s) existed, 

mosquito species data would be gathered and used to guide any adulticiding. 
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2.2(2.2) Sampling pre-treatment to determine population density 

MCVNC regularly uses EVS traps for adult mosquito and arboviral disease surveillance 

throughout a large portion of the county. If it is determined that there are high numbers 

of known vector capable mosquitoes in a trap area then this data would support the need 

to adulticide, and it would assist us in guiding our control efforts. Typically risk 

associated with the presence of an arboviral disease and other factors would be additional 

factors in deciding to treat high numbers of adult mosquitoes. 

2.2(2.3) Sampling pre-treatment to determine need for control 

Under normal situations, where there is no risk or a very low risk of human infection 

from mosquito-borne disease, MCVNC does not use adult collection traps for pretreatment sampling to determine need for control because adulticide applications are 

generally not performed. The primary goal of our EVS trapping program is to test for 

presence of arboviruses in local mosquito population(s). 

In the event, that a single mosquito pool tests positive for arbovirus in an area with other 

criteria such as positive bird or mosquito pool was found, known competent vector 

mosquito populations, and there are/are not no large die-offs of birds (specifically 

corvids) reported, MCVNC would use pre-treatment sampling to determine need for 

control determine the best course of action for a temporary adulticiding program. Under 

an IPM program, MCVNC would apply pesticides at appropriate times of the day when 

adult mosquitoes are most active with ULV output to minimize the quantity of active 

ingredient applied. 

2.3(3.1) Sampling after treatment to evaluate efficacy 

MCVNC would use cage tests to evaluate efficacy of adulticides applied. A set number 

of cages containing a set number of wild-caught or lab-reared species-targeted 

mosquitoes would be placed at set intervals along the spray route to determine treatment 

efficacy. This would provide the most accurate reading of our application efficacy 

without contamination from newly hatched or migrating mosquitoes. Initially however, 

post-treatment adult trapping would likely be done as an additional gauge of our success. 

This will usually be done with EVS traps, but also supplemented in certain areas where 

applicable by a permanent NJ light trap if already in place. 

2.3(3.2) Sampling after treatment to detect possible pesticide resistance 

Currently, MCVNC plans on conducting resistance tests, resource dependent, using bottle 

bioassays on wild caught mosquitoes from the areas where we adulticide. This will 

provide a method to check for pesticide resistance in our local mosquito species 

populations. 

2.3(3.3) Sampling after treatment to determine in-migration 

As described earlier, there will be some post-treatment trapping to determine the remnant 

mosquito population. Depending on the dynamics of the area, an increase in the number 

of traps and/or the duration in which the traps are set is likely. Such areas could include, 

but are not limited to those along the Columbia River—Sauvie Island, Kelly Point, and 

the Gorge. These are areas where traps in previous years have pointed to large influxes 
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of mosquitoes “blowing” in or migrating in from outside the area, particularly from Clark 

County. 

2.3(3.4) Sampling after treatment to determine if any effect on non-target species 

Adulticides, by chemical nature, are a broad spectrum product. Under an IPM program, 

MCVNC would apply adulticides when adult mosquitoes are most active (e.g. ULV and 

barrier applications) to minimize the quantity of active ingredient applied and minimize 

the risk to non-target species. Additionally as opportunities arise to partner with experts, 

MCVNC would defer to local wildlife managers for their expertise for non-target species 

monitoring other than humans or vector populations. In 2008, Oregon Fish and Wildlife 

has agreed to perform some post monitoring of wildlife population(s) on Sauvie Island 

after a ULV-adulticide application by MCVNC for mosquito control. The methods and 

materials are yet to be determined by ODFW and MCVNC at this time but will include 

monitoring of other pest or mosquito control activities adjacent to the mosquito control 

activities of Multnomah County where there may be an overlapping effect on non-targets. 

2.4 Document all sampling results for inclusion in the annual reports

MCVNC actively used EVS traps for adult mosquito collection and includes this data in 

year-end reports when requested. 

3 Choice of pesticides. Use the above information to explain your choices of 

pesticides. 

Larvicide Rationale

MCVNC primarily uses larval sampling results to determine the pesticide selection 

before application. Biorationals are not effective on late 4th instars and pupae and are not 

used as a control product in areas where those life stages are present. Instead, MCVNC 

will use alternate products such as oils and films (e.g. GBO) on those sites with those 

specific life stages present. MCVNC is aware that Bacillus sphaericus is inefficient at 

killing Anopheles spp. and would instead opt to use a B.t.i. product as a suppression tool. 

In situations where an MCVNC staff person is justified in applying control products for 

mosquito suppression and the mosquito breeding site mosquito population has 

metamorphosed beyond the effectiveness of biorationals, MCVNC may choose to use 

other larvicides such as GBO, MMF, or Abate, situationally dependent such as late instar; 

non-feeding stage, shorter residual life, polluted waters, and applications of larvicide due 

to low temperature when other bacterium biorationals are ineffective. For more 

information on Bacillus thuringiensis var. israelensis or B. sphaericus see Attachment 1 

and 2. 

Adulticide Rationale

In the event of a health emergency due to the detection of an arbovirus found present in a 

vector population in Multnomah County and specific criteria is met, MCVNC would 

initiate a local adulticiding program. Under an IPM program, MCVNC would apply 

pesticides at appropriate times of the day when adult mosquitoes are most active with 

ULV output to minimize the quantity of active ingredient applied. MCVNC may use 

barrier sprays for work in areas with elevated public exposure. MCVNC may use 

synthetic pyrethroid for application, as described upon label, to residences, agricultural 

areas, etc. MCVNC may use synthetic pyrethroids for application by ULV by ground 
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including areas such as green spaces. With appropriate resources and infrastructure, 

MCVNC anticipates monitoring resistance long term of chemical application(s) of 

adulticides in mosquito populations. Additionally as opportunities arise to partner with 

experts, MCVNC would defer to local wildlife managers for their expertise for non-target 

species monitoring other than humans or vector populations. In 2008, Oregon Fish and 

Wildlife has agreed to perform some post monitoring of wildlife population(s) on Sauvie 

Island after a ULV-adulticide application by MCVNC for mosquito control. The 

methods and materials are yet to be determined by ODFW and MCVNC at this time but 

will include monitoring of other pest or mosquito control activities adjacent to the 

mosquito control activities of Multnomah County where there may be an overlapping 

effect on non-targets. Please see the Sensitive Area section for more detail.

 

Mosquito Source Reduction Rationale

This section is not required in this report but MCVNC believes that it is a critical 

component of an integrated vector management plan. Source reduction is a term used to 

describe a variety of prevention-based activities that reduce or limit the population 

increase of vectors. Some examples of this may be vegetation management, water 

management, hydrology management, sanitation management, food storage 

manipulation, waste tire collection and disposal, etc. When appropriate after consultation 

with land manager(s) and or owner, MCVNC may remove a select beaver dam to 

discourage stagnant water at the discretion, permission or direction of the land manager 

and or owner, particularly when the beaver dam, silt or other riparian vegetation impedes 

managed wetlands or water control structures. 

Part IV. PEST CONTROL AND MANAGEMENT

1.1 Larval control - Physical elimination through mechanical modification of 

problem areas. 

MCVNC, under an IPM, makes recommendations and performs abatement with local, 

state and federal agencies and property owners of Multnomah County to alter, reduce, or 

limit practices such as vegetation, water and animal management that create or maintain 

mosquito breeding habitat. 

1.2 Biological agents 

MCVNC uses biological control agents as one control tool in an IPM. Biological control 

agents are effective on the immature stages of Culicidae.

1.2(2.1) Gambusia affinis 

MCVNC stocks mosquito fish, Gambusia affinis, by permit of Oregon Fish and Wildlife, 

in storm-water detention ponds (SDF) ponds, swales and other closed water systems not 

fed or drained by natural waterways including creeks, streams, and sloughs after 

assessment of potential release from stocked pond, potential for fish survival and 

reproduction, and risk to native fish, if applicable. In addition, mosquito fish are 

available, by permit of Oregon Fish and Wildlife to Multnomah County residents to be 

used in permanent backyard ponds not fed or drained by natural waterways including 
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creeks, streams, and sloughs. Mosquito fish are not distributed by MCVNC. Multnomah 

County will no longer collect fish from various “natural” locations throughout 

Multnomah County for distribution into permitted storm-water detention ponds (SDF) 

ponds, swales and other closed water systems not fed or drained by natural waterways 

including creeks, streams, and sloughs due to increase concerns over fish pathogens 

including infectious hematopoietic necrosis disease. Instead fish will be collected from 

Multnomah County managed breeding ponds or purchased from an approve Oregon 

Department of Fish and Wildlife Fish Hatchery and transported using a current Oregon 

Department of Fish and Wildlife (ODFW) “Permit to Transport Live Fish or Eggs” 

permit. ODFW and Oregon vector control districts and local health departments are 

expected to update the ODFW “Backgrounder” on mosquito fish in 2008. 

1.2(2.2) Bacillus thuringiensis var. israelensis (Bti) 

MCVNC uses the biorational control agent Bti for suppression of immature mosquitoes 

in their first through third instar larval life stages. Some formulations of Bti, such as 

Vectobac G, are preferred because it targets a wide range of mosquito species (Cq 

perturbans is an exception). For more information on Bacillus thuringiensis var. 

israelensis or B. sphaericus see Attachment 1 and 2. 

1.2(2.2) Bacillus sphaericus (Bs)

MCVNC uses the biorational control agent Bs for suppression of immature mosquitoes in 

their first through third instar larval life stages. This material is used throughout the 

county and is the primary control agent for the Culex spp. This material is ineffective at 

controlling Anopheles spp. For more information on Bacillus thuringiensis var. 

israelensis or B. sphaericus see Attachment 1 and 2. 

1.2(2.3) Methoprene (insect growth regulators) 

MCVNC uses the biorational Methoprene in specific sites such as catch basins, roadside 

ditches and small ponds. If surveillance results yielded mosquitoes with oxidase-based 

resistance, MCVNC would limit continued use of Methoprene to avoid resistance. 

However, there has been no evidence of resistance in our pre- and post-treatment larval 

sampling. This active ingredient is found in various formulations. 

1.3(3.1) Golden Bear Oil (GBO) 

MCVNC uses surface film products as a last resort due to the broad spectrum of 

organisms that potentially can be affected. GBO is used in areas where control efforts 

have begun to late to effectively apply bacterial larvicides for immature mosquito control. 

1.3(3.3) Other products – Vapona Strip 

MCVNC anticipates using Vapona Strips to assist with the curation of entomological and 

vertebrate taxidermy samples in museum curation. 

Other chemicals – see past list submitted 

2 Adult Control 
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VECTOR AND NUISANCE CONTROL – ADMINISTRATIVE GUIDELINES 

SUBJECT: FIELD POLICIES AND PROCEDURES NUMBER: 1115(1)

TITLE: APPLICATION OF ADULTICIDES ABSENCE OF WEST NILE VIRUS 

EFFECTIVE: 01/08/02 LAST REVIEWED DATE: 09/09/05

APPROVED: Christopher M. Wirth PAGE: 1 OF 3

POLICY STATEMENT 

Mosquito Control in the Absence of WNv (for example): 

 Local mosquito species that are not vectors of human disease 

 Exotic mosquito species with unknown vector competence 

 Local mosquito species with suspected but unknown vector competence for WNV 

 Local mosquito species with vector competence for endemic mosquito-borne 

disease (i.e. WEE, SLE, and malaria) 

PROCEDURE 

Prior to any program changes made as a result of the IPM Advisory Group, mosquito 

control in the absence of WNv on private and public lands will operate as follows:

(NOTE: All MCVNC private or public land applications include efficacy evaluation) 

 Complaint-driven system for Private Land (~60% of historical adulticide use, 

primarily barrier application), in which MCVNC will: 

o respond to mosquito complaints 

o offer advice to mitigate mosquito problems 

o recommend effective non-adulticide alternatives 

o present adulticide use as an option when other effective control measures 

are not available; options counseling; MCVNC will not recommend 

adulticides. 

o apply adulticides at the landowner’s request only when MCVNC judges 

application to be appropriate and likely to be effective (e.g. when adult 

traps exceed 100 or more mosquitoes in an 8 hour period) (Note: When 

there is WNv in the community, actions will be guided by WNv Policy) 

o not use aerial application of adulticides 

o maintain current program scope 

 Complaint-driven system for Public Lands 

o MCVNC will respond to complaints and offer routine control and 

surveillance as specified by any existing contracts 

o MCVNC will offer comprehensive recommendations to mitigate 

mosquitoes (as for private lands) 
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o MCVNC will present adulticide use as an option when other effective 

control measures are not available; MCVNC will not recommend 

adulticides. 

o Any application of adulticide will be at the total discretion of the land 

steward when there is no WNv in the community (Note: When there is 

WNV in the community, actions will be guided by WNv Policy) 

o MCVNC will not use aerial application of adulticides 

 Contracts for public lands (Note: No contracts exist or would be entered into 

between MCVNC and private land owners.) 

o Note: This issue area requires further discussion/development. All public 

land contracts are subject to the parameters set forth above in the 

complain-driven public lands section (i.e. range of control options without 

specific recommendations to use adulticides). Contracts do not include 

acreage amounts for adulticides. All work is based on the mosquito 

ecology and population dynamics of a given season, and again, is subject 

to the total discretion of the land steward. 

o Recommendations on contracts from the Spring 2004 WNv Task Force 

Small Group were: 

 No new contracts that include possible use of adulticides for 

nuisance control 

 No expansion of acreage that include possible use of adulticides 

for nuisance control in existing contracts 

 No new areas of adulticide use within lands covered by existing 

contracts – i.e., no “swapping” of old lands where adulticide was 

allowed for new lands where adulticide was not previously used 

ADDITIONAL CONSIDERATIONS 

For application of adulticides should include, at a minimum the following; 

 Best adulticide active ingredient choice and other label requirements 

 Best application of adulticide including timing of application and 

equipment used to apply product. 

 General ecology of the area such as key habitat types and the presence of 

natural barriers (i.e. large rivers) 

 Flight or migrational range of the affected/infected hosts (birds, mammals, 

etc) 

 Flight range of vectors known or believed to be of importance in the area 

 Population density and age proportion of parous females, those females 

with ability to produce offspring, potential. 

 Human population at risk in relationship to locality (i.e. urban vs. rural) 

 Human population at risk and the perception of the relative risk of use of 

adulticides for control 

 Human population at risk and the age demographics within the locality 

 Evidence of persistent transmission activity detected by the surveillance 

program 

 Season of the year and its relationship to the vector 
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 Other relative surveillance data specific to mosquito-borne disease of 

concern 

VECTOR AND NUISANCE CONTROL – ADMINISTRATIVE GUIDELINES 

SUBJECT: FIELD POLICIES AND PROCEDURES NUMBER: 1126(1)

TITLE: WEST NILE VIRUS RESPONSE PLAN FOR 2006-07 MOSQUITO SEASON 

EFFECTIVE: 03/01/07 LAST REVIEWED DATE: 02 13 07

APPROVED: Gary Oxman PAGE: 1 OF 17 

OVERVIEW 

Includes the following components of the Multnomah County Health Department, 2007 

Mosquito Season West Nile Virus Response Plan; 

 PLAN INTRODUCTION – Introduction/Purpose 

 PRINCIPLES 

 SUMMARY 

 RISK ASSESSMENT TOOL 

 RESPONSE GUIDELINES 

 GLOSSARY 

 

PLAN INTRODUCTION - Introduction/Purpose

This West Nile Virus Response Plan describes how Multnomah County Health Department will manage the 

problem of West Nile Virus (WNV) during 2007. The Plan consists of four parts: 

 Plan Introduction– This gives background on how the plan was developed and the thinking behind the 

plan. 

 Plan Summary – This gives a brief overview of the main features of the plan and how it will work. 

 Response Guidelines – This describes how the Health Department will respond to various degrees of 

the threat posed by West Nile Virus. 

 Human Health Risk Assessment Tool – This describes the methods the Health Department will use to 

assess the risk to human health posed by WNV as circumstances change through the mosquito season. 

Although the number of people in Multnomah County likely to suffer serious illness from this mosquitoborne disease is small, the Health Department is committed to minimizing the risks and impacts of WNV. 

It will do this through a comprehensive prevention-based plan that emphasizes public education and control 

of mosquitoes before they are able to fly and spread WNV. 

This Plan was developed during the Spring of 2004 with the assistance of the Health Department’s WNV 

Task Force made up of stakeholders with a wide range of knowledge, interests and values. 

The primary purpose of this West Nile Virus Response Plan is to provide guidance to decision makers in 

Multnomah County Health Department. Staff at all levels will use this Plan as they anticipate and respond 

to the potential human health impacts of West Nile Virus (WNV) in Multnomah County in 2007. 

This Plan was developed before the arrival of WNV in Multnomah County. It is based on “best practices” 

for managing the human health impacts of WNV developed by the Centers for Disease Control and 
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Prevention (CDC) and selected state and local health departments across the country. It is a “mainstream” 

plan; it is consistent with CDC’s recommendations, and is similar to the plans of many communities across 

the US. Because the Plan was developed before WNV arrived in our community, it does not benefit from 

local experience in managing WNV. 

The Health Department intends to follow this Plan closely in managing the impacts of WNV in Multnomah 

County. The Department recognizes its responsibility to use professional judgment in applying this Plan to 

deal with specific WNV-related situations that threaten the public’s health. 

PRINCIPLES 

This West Nile Virus Response Plan is based in the best available science and also embodies several 

important principles and beliefs: 

 The human health impacts of WNV can be reduced but not entirely avoided. Thus, the goal of the 

Plan is to ensure that the Health Department and our community takes appropriate and reasonable 

actions to reduce the impacts of WNV. 

 WNV infection and disease is likely to be with us for the foreseeable future. Therefore, prevention and 

response activities must be effective, and environmentally and economically sustainable over a long 

period of time. 

 WNV is carried to humans as part of a larger cycle of infection that primarily involves birds and 

mosquitoes. To be effective, WNV prevention and control activities must decrease the potential for 

infected flying adult mosquitoes to bite people. This is best accomplished by consistently applying 

long-term preventive actions that reduce populations of mosquitoes that can transmit WNV, and that 

engage the public in reducing mosquito breeding habitat and in protecting themselves. 

 Multnomah County Health Department utilizes Integrated Pest Management (IPM) as its approach to 

controlling mosquito populations. IPM is an integrated strategy that uses multiple methods to achieve 

long-term control of mosquito populations, and has been proven to be the most effective approach. In 

using IPM to address WNV, the Department will target its mosquito control activities at specific areas 

and situations that clearly contribute to the risk of transmitting WNV. 

 Some actions to reduce WNV infection in people can have unintended negative consequences on 

people and the environment. Thus, reducing WNV impacts involves balancing the risks and benefits 

of these control activities with their potential negative consequences. 

 Multnomah County Health Department is committed to using the least harmful interventions that are 

likely to be effective in a given situation. The Department is also committed to choosing and targeting 

its interventions based on reliable scientific information to the maximum extent that is practical. 

SUMMARY 

This section is a summary of Multnomah County Health Department’s West Nile Virus Response Plan for 

the 2007 mosquito season. The original Plan was based on recommendations made by the Department’s 

West Nile Virus Task Force in 2004. The 2007 plan was made available to the Vector and Nuisance 

Advisory Committee on March 20, 2007. The Department is committed to evaluating the effectiveness of 

this Plan at the end of each mosquito season, and will revise the Plan as necessary. 

While the number of people likely to suffer serious illness from this mosquito-borne disease is small, the 

Health Department is committed to minimizing the risks of WNV and its serious impacts (brain/nervous 

system infection). 

The Plan is based on the risk of human West Nile virus disease as periodically assessed by the West Nile 

Virus Human Health Risk Assessment Tool included in this Plan. The Tool defines four risk levels 

representing a range from no risk to high risk of acquiring infection locally. To ensure that decision-
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making about intervention is appropriate to the situation at a given point in time, the risk level is reset to 

Level A (no local risk) at the end of each adult mosquito season (typically November 1st). Level A will 

apply until there is evidence of WNV activity in the greater Portland metropolitan area that justifies a 

change in risk level. 

 

This Multnomah County Health Department West Nile Virus Response Plan focuses on reducing the 

potential human health impacts of WNV. At the same time, Health Department will continue to respond to 

residents’ concerns related to nuisance mosquitoes. However, when WNV is detected in the greater 

Portland metropolitan area priority will be given to area wide disease prevention rather than nuisance 

control. 

The Department’s typical response to nuisance mosquitoes will be based on an inspection of property to 

determine mosquito activity. Response activities may include small group and public education utilizing 

direct contact, printed materials, and other methods as appropriate. Use of chemical adulticides to control 

adult nuisance mosquitoes will be done only with the permission of the property owner, using application 

methods that minimize spread of these materials off the property. 

This plan has supporting documents that explain how activities described in the Plan will be carried out. 

Additional supporting documents and plans will be developed as needed each mosquito season. These will 

explain activities included in the County’s comprehensive approach to vector control. 

Two elements make up the heart of the plan. They are used together to classify and respond to the risk of 

human infection with WNV as the situation changes over the season. 

 West Nile Virus Human Health Risk Assessment Tool 

 West Nile Virus Response Guidelines 

West Nile Virus Human Health Risk Assessment Tool

The Assessment Tool was adapted from a model used by the state of California. The Tool considers eight 

different factors that reflect the risk of people in our community getting West Nile Virus infection. Each 

factor is given a score from 1 to 5. The scores for individual factors are averaged to give an overall 

measure of the risk of people becoming infected with West Nile Virus. The Assessment Tool uses two 

scales: 

1) A Seasonal Human Health Risk Scale to represent risk over the course of 2007 season. This scale 

provides information to guide surveillance, public education, and control activities other than spraying 

intended to reduce adult mosquito populations. 

2) A Short Term Human Health Risk Scale to reflect human health risk in the short-run (i.e., over a 

period of days or a few weeks). This will be used to guide short-term response activities, including the 

possibility of spraying intended to reduce adult mosquito populations. 

The scores of the two scales are “semi-quantitative.” Larger numbers mean that there is more risk, but (for 

example) a value of 4 cannot be interpreted as being twice as risky as a value of 2. The table below shows 

the relationship between response scores and response levels. 

Level Description Seasonal Risk 

Score 

Short Term 

Risk Score 

Level A No WNv In Community 1.0 – 2.5 

Level B WNv in community, Low Human Health Risk 2.6 – 4.5 

Level C Human Health Risk in Localized Area(s) 4.6 – 4.7 

Level D Human Health Risk in Multiple Areas or Throughout 

the County 

 4.8 or higher 

West Nile Virus Response Guidelines

The West Nile Virus Response Guidelines use four risk levels based on the results of the Assessment Tool at 

a given time. The levels (A-D) represent increasing human health risk from WNV. The risk levels are 
14

defined by Assessment Tool scores, and presence (or absence) of WNV in the County. Each level includes 

specific response actions that the Health Department can take. Each level builds on the activities of the 

previous level(s). 

The Response Guidelines utilize a comprehensive prevention-oriented approach. This approach 

emphasizes public education and control of mosquitoes before they are able to fly and spread WNV. Use 

of Ultra Low Volume (ULV) chemical insecticides to reduce adult mosquitoes populations is reserved for 

special high-risk situations. 

Level A: No WNv in the Community

The response in Level A establishes basic monitoring, public education and mosquito control activities. It 

emphasizes targeted, user-friendly public education that is culturally appropriate and does not invoke fear. 

It realistically describes the risk of getting WNV, how it is spread, what members of the public can do to 

reduce their own risk, and what they can do to help mosquito control efforts. Level A also features 

extensive monitoring to detect the arrival of WNV, and decrease the potential for its spread in coming 

months. This is done by reducing mosquito habitat, and applying biologic materials to prevent immature 

mosquitoes from hatching and becoming flying adults. In Level A, there can also be attempts to create 

assistance for low-income high-risk individuals and communities to decrease their WNV risk. Approaches 

could include promoting community clean-ups, and finding subsidies for window screens and other simple 

preventive steps. 

Level B: WNv in the Community, Low Human Health Risk

The response in Level B maintains most of the prevention and control activities in Level A. It increases 

public education though outreach and use of the mass media. Messages emphasize personal protection 

steps, and updates on the current risk situation. At Level B, there are increased efforts to reduce the 

sources of mosquitoes, and reduce immature mosquito populations. The Health Department will also start 

to actively look for infection in people. 

Level C: Human Health Risk in Localized Area(s)

In the response to Level C, public education is intensified and further focused on communities at increased 

risk of WNV exposure (for example, communities near sites where there are large numbers of infected 

mosquitoes). At Level C, the Health Department may choose to spray ULV insecticides to reduce adult 

mosquito populations. This would be done only when the Department has good reason to judge that 

spraying is likely to be effective in reducing the risk of WNv infection in humans in a given situation. In 

addition, the Health Department would have to address an extensive list of factors to ensure that spraying 

could be done in a way that is as safe as possible for people and the environment. ULV applications will 

only be done in a defined area that is targeted at controlling adult populations of a WNv carrying mosquito. 

No aerial applications of adulticides will be done. Only the County Health Officer will have the authority to 

approve ULV spraying for control of WNV. 

Level D: Human Health Risk in Multiple Areas or Throughout the County

At Level D, the Response Guidelines call for a shift towards further public education about self-protection. 

There would also be an emphasis on communications to keep the risk of WNV in context, and reduce 

unreasonable fears. Monitoring activities would be re-focused to track harmful mosquito populations, and 

assure that human cases are identified. Use of adulticides would likely be reduced for two reasons: 1) The 

development of widespread infection in the face of adulticide use suggests that further adulticide use 

would not be effective. 2) County resources could be better applied to promoting effective personal 

protection in the short-term. It is also possible that the Department would act to cancel outdoor activities 

that present an unreasonable risk of WNv transmission. 
WEST NILE VIRUS HUMAN HEALTH RISK ASSESSMENT 

Multnomah County Health Department 

West Nile Virus (WNv) Response Plan 

2007 Mosquito Season 

WNv Surveillance Factor 

Value Benchmark 

1. Environmental Conditions Environmental conditions that favor WNv transmission in Oregon are unknown. Based on findings elsewhere, high temperatures are associated with increased risk. 

1

2 3 4 5 

Temperature well below averageTemperature below average Temperature average Temperature above average Temperature well above average 

2. Abundance* of adult mosquito species with known ability to increase WNv infection in birds (amplification vectors) or transmit WNv to humans (bridge vectors) (examples: Aedes vexans, Coquillettidia perturbans, Culex pipiens, Culex tarsalis, Culex territans, Culiseta inornata)  * Relative to previously documented levels 

1

2 3 4 5 

Vector abundance well below average Vector abundance below average Vector abundance average Vector abundance above average Vector abundance well above average [NOTE: Specific measures of abundance for the 2004 

season are being developed]
WNv Surveillance Factor Value Benchmark 

3. Virus isolation in adult mosquito species with known competence to serve as a bridge or amplification vector of WNv (see #2 above for species definitions)

1

3 4 5 

No WNv infection detected in vector-competent species 

WNv infection detected in 1-4 pools of vector-competenspecies (either localized or geographically dispersed) WNv infection detected in 5 or more pools of vectorcompetent species (geographically dispersed in a way that indicates intense localized WNv activity) WNv infection detected in 5 or more pools of vectorcompetent species (geographically dispersed in a way that indicates widespread WNv activity) 

4. WNv Testing of Sentinel Chickens. 

Number of chickens in a flock that show laboratory evidence of new infection with WNv 

1

2 3 4 5 

No new positive tests among sentinel chickens in Oregon

New positive tests among sentinel chickens in Oregon or SW Washington but outside the 6 county Metropolitan area One new positive test in one Multnomah County flock One new positive test in two or more Multnomah County flocks Two or more new positive tests per flock in one or more Multnomah County flocks 
WNv Surveillance Factor Value Benchmark 

5. Dead bird infection

Includes zoo collections; excludes sentinel chickens NOTE: Interest is in bird populations whose characteristics (including local residence time and ranges in the Portland Metropolitan area) make it likely that the population(s) will contribute to WNv transmission and amplification. 

1

2 3 4 5 

No WNv positive dead birds in Oregon

WNv positive dead bird in Oregon, Washington, but nonin 6 county Portland metropolitan area One confirmed WNv positive dead bird in a Portland metropolitan area county other than Multnomah County One confirmed WNv positive dead bird reported in Multnomah County Multiple confirmed WNv positive dead birds in MultnomCounty 

6. Horse (equine) cases NOTE: Includes only horse cases that have been investigated and classified as locally-acquired 

1

3 4 5 

No horse cases in 6 county Portland metro area

One horse case in 6 county Portland metro area One horse case in Multnomah County Multiple horse cases in Multnomah County 

7. Human cases NOTE: Includes only human neuroinvasive cases that have been fully investigated by the appropriate health department and classified as locally-acquired 

1

2 3 4 5 

No human cases in Oregon One human case in Oregon or SW Washington outside th6 county Metropolitan area (i.e., none within the Metro area) One human case in the 6 county Metropolitan area One human case in Multnomah County Multiple human cases in Multnomah County (geographically dispersed in a way that suggests either intense localized WNv activity or widespread WNv activ
WNv Surveillance Factor Value Benchmark 

8. Proximity of virus activity to populated areas (scored only if virus activity is detected) 

1

3 5 

Virus activity detected primarily in unpopulated areas 

beyond usual flight range of infected human-biting species Virus activity detected in areas of low population density that are within usual flight range of infected species Virus activity detected in areas of high population density that are within usual flight range of infected species 

TOTAL OF FACTOR SCORES NUMBER OF FACTORS SCORED OVERALL SCORE (TOTAL/Number of Factors Scored) 

Level Description Seasonal Risk 

Score 

Short Term 

Risk Score 

Level A No WNv In Community 1.0 – 2.5Level B WNv in community - Low Human Health Risk 2.6 – 4.5Level C Human Health Risk from WNv in Localized 

Area(s) 

4.6 – 4.7 

Level D Human Health Risk from WNv in Multiple Areas 

or Throughout the County 

4.8 or higher 
WEST NILE VIRUS RESPONSE GUIDELINES 

Multnomah County Health Department 

West Nile Virus (WNv) Response Plan 

2007 Mosquito Season 

RESPONSE LEVEL A

NO WNv DETECTEDCriteria: 

 Seasonal and Short-Term Human Health Risk Assessment Score 1.0 – 2.5 

AND

 NO WNv activity detected in Multnomah County or elsewhere in the 6 county Portland metropolitan area (Clackamas, Columbia, 

in Oregon and Clark, and Skamania Counties in Washington) 

Basic Public Information and 

other Communication Actions Basic Surveillance and Control Actions 

 Emphasize coordinated public education that: 

o is user friendly & does not invoke fear; o is culturally and time appropriate; o targets at-risk populations; o describes the relative risk of the disease; o includes importance of ecology; o describes how mosquito-borne diseases are spread, 

and the public’s role in reducing the risk of transmission and in identifying WNv in the community; 

o includes information describing the County’s IPM and 

source reduction activities. 

 Track dead bird reporting by the public and agencies’ personnel.  Collect and test appropriate sample dead birds for WNv.  Continuously collect and test adult & larval mosquitoes per 

established protocols to assess abundance of mosquito species and presence of WNv. 

 Test sentinel chickens for WNv.  Land managers identify ecologically sensitive areas.  Assess County demographics to assess sizes, locations and 

characteristics of at-risk populations 

 Perform passive surveillance for WNv infection in humans & 

horses. 
 Conduct proactive media campaign that introduces “No 

Spray” option for the public, and that distinguishes between adulticide and aerial larvicide applications with language such as “spraying for adult mosquitoes.” 

 Begin public education at least one month prior to 

mosquito season. 

 Routinely communicate with state and local health 

departments re: WNv surveillance findings. 

 Conduct targeted larvicide applications based on assessment of 

local populations of immature mosquitoes that have significant potential to carry and transmit WNv. Larvicide applications will consider and reflect and land managers’ sensitive area designations. 

 Promote source reduction activities by the public and personnel in 

appropriate agencies. 

 Monitor effectiveness of mosquito control activities.  Monitor human health impacts of mosquito control activities.  Collaborate with land managers to monitor environmental impacts 

of mosquito control activities. 
RESPONSE LEVEL B: 

WNv IN THE COMMUNITY, LOW HUMAN HEALTH RISK Criteria: 

 Seasonal and Short-Term Human Health Risk Assessment Score: 2.6 – 4.5 

WITH

 WNv activity detected in Multnomah County or elsewhere in Portland Metropolitan AreaNOTE: All actions described in RESPONSE LEVEL A can be used in RESPONSE LEVEL B appropriate and do not conflict with LEVEL B activities. 

Additional Public Information and other 

Communication Actions at This Level Additional Surveillance and Control Actions at This Level 

 Notify mass media via news release re: positive WNv surveillance 

finding(s) utilizing public education guidelines in Level A. 

 Initiate local information hotline.  Enhance public education as appropriate (e.g., through links with 

communities/organizations, outreach workers, community health nurses in course of regular duties, posters/flyers, web updates). 

 Assure communication of vector surveillance data among 

Oregon’s local and state health departments. 

 Enhance education to address factors related to biology of 

mosquito species of concern (as identified by current local surveillance data). 

 Intensify public education on personal protection measures, 

including via mass media news releases. 

 Provide direct updates to affected communities.  Update information on WNv on Health Department web site. 

 Intensify source reduction efforts as appropriate.  Intensify targeted larvicide applications as appropriate in 

light of surveillance findings. 

 Institute active human surveillance if: 

o any human cases are detected, 

OR

o multiple indicators of infection in birds/mosquitoes 

are positive, 

OR 

o positive indicators of infection in birds/mosquitoes are 

widely dispersed. 

 Adjust surveillance on dead birds/sentinel chickens to 

assure these activities provide significant information about the extent and intensity of WNv infection in the community. 
RESPONSE LEVEL C:

HUMAN HEALTH RISK FROM WNv IN LOCALIZED AREA(S) Criterion: 

 Short-Term Human Health Risk Assessment Score: 4.6 – 4.7 NOTE: All actions described in RESPONSE LEVELS A and B can be used in RESPONSE LEare appropriate and do not conflict with LEVEL C activities. 

Additional Public Information 

and other Communication 

Actions at This Level 

Additional Surveillance and 

Control Actions at This Level Additional Assessment and Action Option

 Intensify public education, 

emphasizing preventive measures public can take to reduce transmission. 

 Publicize Health Department’s 

determination of Human Health Risk in Localized Areas(s) though mass media news releases. 

 Provide direct updates to 

affected communities using risk communication techniques to allay undue fear and anxiety. 

 Include appropriate 

notification re: ULV spraying as part of public information approach. 

 Intensify surveillance for 

infected mosquitoes in localized area(s) of concern 

 Intensify targeted larvicide 

applications as appropriate in light of surveillance findings. 

 Local Health Officer is directly involved in: 

o Evaluation of all relevant data related to human heo Decision-making related to ULV use, acting as the 

 Health Department may consider focused ULV applica

transmission to humans. 

 Health Department will take into account at least the fo

possible ULV use in this situation: o Potential effectiveness of ULV application in light 

mosquito ecology, mosquito population abundanceand adulticide resistance as determined by data fro

o Time of year;o Proximity of virus activity to at-risk human populao Concerns of specifically impacted communities; o Potential human health risks associated with ULV 

strategies to mitigate these risks; 

o Potential environmental risks associated with ULV 

strategies to mitigate these risks; and 

o Applicable environmental regulations.

 The Department will undertake ULV applications only in 
o It can perform post-application evaluation of effec

evaluation data will be used to decide whether to c

o There is a system in place for tracking and respond

human health impacts; 

o It has notified wildlife/habitat area managers about 

those agencies and their partner agencies can collaDepartment in monitoring for environmental impac

 After considering the above factors, if the Health Depa

ULV applications it will develop an application plan spof concern. This plan will take into account:o Local geographic and topographic factors in the na

that could affect success of application (e.g., road p

etc.), 

o Weather and atmospheric conditions, o Access to equipment and materials to allow ULV a

enough that they are likely to be effective, and 

o Timing of application (i.e., time of day) to maximi

human exposure. 

 The localized ULV application plan will also 

notification and information to be provided in well as the broader community. 
RESPONSE LEVEL D: 

HUMAN HEALTH RISK FROM WNv IN MULTIPLE AREAS OR THROUGHOUT CCriterion: 

 Short-Term Human Health Risk Assessment Score: 4.8 or higherNOTE: All actions described in RESPONSE LEVELS A, B and C can be used in RESPONSE 

are appropriate and do not conflict with LEVEL D activities.

Additional Public Information and other 

Communication Actions at This Level 

Additional Surveillance and Control 

Actions at This Level 

Additional Assessment and 

at This Lev

 Shift public education to focus primarily on preventive 

actions public can take to reduce transmission, and personal protective measures. 

 Publicize Health Department determination of Human 

Health Risk in Multiple Areas or Throughout County though mass media news releases and other educational approaches. 

 Shift communication channels to emphasize: 

o Use of mass media appropriate to various 

communities, and 

o Use of specialized communication pathways to 

address communities that tend not to utilize mass media. 

 Use risk communication techniques to allay undue fear 

and anxiety. 

 Include appropriate notification re: adulticide spraying 

as part of public information approach. 

 Shift foci of surveillance to: 

o Monitoring overall mosquito 

population distributions and dynamics, 

o Identifying potential targets for 

feasible vector control interventions, and 

o Intensifying actions to identify 

and confirm human cases. 

 Health Department will de

but may consider focused to address localized areas transmission risk within tof human health risk. 

 Any such localized use of 

would follow procedures described in Level C.

 Health Department will co

community-level control acanceling outdoor public eunusual risk of WNv infec
WNV GLOSSARY Note: Multnomah County Health Department developed this Glossary to support the WNV Task Force as it created its recommendation to thcontents represent Multnomah County Health Department perspectives, ideas and definitions, but they are closely aligned with common TermsSentinel chickensFlocks of domestic chickens that are maintained in cages for the purpose of detecting transmission of mosquito-borne diseases. The coulocated at Sauvie Island, SE Portland, N Portland and SW Portland. Each flock has about 6 number] chickens. Blood is taken from the weeks, and is tested for signs of exposure to WNV and related viruses. Passive & active human and horse surveillance Surveillance is the process that public health agencies use to detect cases of disease in the community.  In passive surveillance, a health department establishes which diseases, conditions or events are reportable, and who (e.g., medical 

required to report them. The department then waits to receive reports. 

 In active surveillance, a health department periodically contacts selected providers or agencies and inquires whether they have note

identified reportable events. For example, for active surveillance of possible WNv in humans, a health department might call selec

specialists) every week during the summer to see if they have seen any patients with encephalitis symptoms. 

Adulticide Chemical insecticides that are used to kill adult mosquitoes. Multnomah County would depend on the following adulticides in 2007 – a

some include synergists.  Anvil 10+10 

 Pyronil 525  Scourge  ULV (Ultra Low Volume) application. Adulticides are sprayed into the air with the intent of killing mosquitoes that are flying or re

ULV application is typically done with truck-mounted sprayers, but can be done with aircraft. ULV produces very small droplets t

few hours. ULV application is done during atmospheric conditions that promote slow drift of the adulticide for a distance of a few path (or point) of application. By definition, ULV uses that smallest possible amount of adulticide that will kill adult mosquitoes. 

(“non-target”) insects. 

Larvicide Natural and synthetic insecticides that are used with the intent of killing immature mosquitoes during the phases of their life when they 

County depends on the following larvicides in 2004: 
 Biorationals 

o Altosid – various formulations 

o Bacillus thuringiensis var. israelensis (BTi) – various formulations o Bacillus sphaericus – various formulations 

 Surfactant 

o Golden Bear Oil 

Larvicides also kill immature forms of other (“non-target”) insects. There are two basic techniques used for applying larvicides:  Ground-based application. Larvicides are placed into bodies of water by vector control staff by hand or dispersed by backpack spr

 Aerial application. Granular larvicides (e.g., BTi on corn-cob granules) are broadcast into bodies of water by spraying them from a 

application has the benefits of being able to efficiently treat large areas or areas that are not accessible by Vector Control staff. 

Ecologically sensitive areas Areas that are maintained or preserved primarily for their habitat value, or that have local ecosystems that are particularly sensitive to dEnvironmental Impact Evaluation Environmental Impact Evaluation – a process using reasonable scientific judgment to:  Define potential adverse impacts of proposed mosquito control activities on an ecologically sensitive area, and  Identify necessary, appropriate and practical modifications to the proposed mosquito control activities. 

This process should be carried out cooperatively between Vector Control and the agency responsible for stewardship of the ecologically NOTE: An Environmental Impact Evaluation is not the same thing as an Environmental Impact Statement (EIS) such as those required 

Species Act. High Numerically-defined levels of immature or adult mosquitoes that are used as guidelines for control activities.  Larval – 1 larva per standard dip (random 400 mL dip in body of water)  Adult –more than 100 adult mosquitoes collected in an EVS (encephalitis viral surveillance), Gravid, or New Jersey Light trap in 8 Abundant Synonym for high Adjacent community The five counties adjacent to Multnomah County – Clackamas and Washington and Columbia Counties in Oregon, and Clark and SkamWashington 
Multiple More than one. When used in public health decision-making, the concept of multiple can also imply both the actual number of events aincreasing over time. 

Biorational 

Biorational pesticides are derived from a variety of biological sources, including bacteria, viruses, fungi and protozoa. They also includnaturally occurring biological chemicals such as pheromones and insect growth regulators (IGRs). These analogues are considered thirdthat are more environmentally sound and closely resemble or are identical to chemicals produced by insects and plants. Biorational pro

from conventional, broad-spectrum pesticides in that they are typically target-specific and have little to no acute impact on most non-taSynergist A substance added to a pesticide to enhance the effectiveness of the active ingredient. In adult mosquito control, synergists typically pr

adulticide by the mosquito. Chemical sensitivityThe experience of having adverse effects after exposure to a given chemical or chemical combination. Corvid Member of the family of birds including jays and crows Equine Horse Vector A species that is capable of carrying disease organisms to another species Competent vector A vector species that is relatively efficient as a vector for transmitting a particular disease-causing organism Bridge vector A vector species that has a relatively wide range of host species with which it interacts and can transmit disease-causing organisms. Bedifferent host specifies, bridge vectors can transmit disease among multiple host species (serving as a “bridge” between species). Amplification vector A vector that serves as a primary pathway for transmission of disease within a species or within narrow group of species. These vectorrange of host species to which it transmits disease-causing organisms. This results in increasing rates of infection within those hosts (“a
Lag time (for human or horse infections) The period of time between the actual transmission of a disease-causing organism (e.g., by a mosquito) and the occurrence and recogni

(e.g., a person). In a broader sense, lag time can be thought of as the period between the ecological phenomena that drive disease transmagency/societal recognition of significant disease transmission in a population. Example: The period between establishment of a high r

with WNV, and reporting of a human case to a health department. Lag time is important in considering targets and potential effectiven

interventions. 
Part V. PUBLIC EDUCATION AND AWARENESS: DESCRIBE PLAN AND DATES FOR EACH ACT

Notify the general public and facilities where special vulnerable populations are found: (2.1) Hospitals (2.2) Health care facilities (2.3) Facilities for the elderly (2.4) Schools (2.5) Daycare facilities (2.6) Kennels and other animal shelters (2.7) Other MCVNC does not routinely make wide scale/county-wide adulticide applications. As previously described in Paand Management Section 2 “Adult Control Rationale”, MCVNC would notify the above and other stakeholders, media. Mass media includes an extensive educational program, website (www.mchealthinspect.org), phone surg

educational printed materials. Additionally, MCVNC is a program within the Multnomah County Health Departability to use multiple methods of communication including the Oregon Health Alert Network (HAN) and varioudetailed information, see Communication Plan below. Note that the Communication addresses WNV, but also seother mosquito-borne disease communications. Communication Plan is as follows; 

Goal: To increase public awareness of West Nile Virus (WNV) including education on mosquito-borne disease

and prevention, and integrated pest management control techniques. Summary Using the media, presentations to community groups, and collaboration with community agencies and elected County Health Department and Public Affairs will increase public awareness of mosquito-borne disease risk, wlimit their risk and county government’s role in WNV surveillance and control. If surveillance data indicate in

humans, the application of pesticides to control adult mosquitoes will be required. In order to assure accurate aof these mosquito control activities, Public Affairs will work with the Health Department to provide the pu

schedules, the type of pesticides being used, and how to reduce their exposure to these pesticides. 
Phase 1: Normal Situation, No / Very Low Risk of Human Infection 

Messages The early messages are designed to provide a baseline of information about WNV and the county’s moscontrol efforts. The public is given the first messages on eliminating standing water around the home.  Mosquito monitoring system in place and control of floodwater mosquito populations  No evidence of West Nile Virus found in mosquitoes or birds  Shift from ground level applications of larvicide to more effective aerial applications in floodwater  Initial messages about household prevention measures Methods  Media releases during peak mosquito seasons  Identification of stakeholder groups  Preparation of materials for dissemination to public  Development of strategies to reach people with low reading levels and those whose primary language is n

Phase 2: Basic Public Education, Low Risk of Human Infection 

Messages The Multnomah County Health Department has a comprehensive plan to reduce the threat of WNV through mosquito management and control, and measures the public can take to reduce exposure to mosquitoes.  County’s prevention strategies and activities address threat and minimize necessity of pesticide applicatio

control. 

 Disease surveillance helps with early identification of WNV’s arrival in the area by testing larval a

sentinel chickens, and dead crows for WNV. Veterinarians are encouraged to report cases in horses. To 

birds, or horses with WNV have been identified in Oregon. 

 Mosquito management and control activities: public education on removing standing water and other 

larvicides, and flood water control by the county to reduce the number of mosquitoes. 

 Protective measures such as clothing, repair of window & door screens. Baseline education on repellents Public to report dead birds through telephone information line or online form. Proper handling and dispos
Methods  Develop fact sheets or Q/A sheets in multiple languages (adaptation of materials from other states as appr Develop a pictorial poster in multiple languages for populations that learn more effectively from gra

methods. This includes people with low reading levels as well as people from cultures where pictoriaused regardless of literacy level. 

 Update website.  Create a master database encompassing contacts in other jurisdictions, public health officials, and the sc

well as collaborators, associations, and community organizations. Communicate to stakeholders via email lists. 

 Brief elected officials including Multnomah County Board of Commissioners, City of Portland, Gres

Village, Troutdale, Maywood Park, etc. 

 Educate medical providers on encephalitis, meningitis, reporting requirements, and how to submit spec

Updates on WNV to reinforce reporting requirements. Utilize local and state Medical Society publicationgroups, and Oregon Department of Human Services’ Current Disease Summary. Email to Hospital inf

serve. 

 Distribute print material to community organizations, neighborhood associations, schools, senior cente

libraries, recreation centers, etc. 

 Brief Media, including editorial board visits. Provide periodic status reports as needed via media releases Presentations to a variety of organizations and presence at community fairs and other public gatherings as  Collaborate with business and other jurisdictions to disseminate prevention messages.  Communicate with Multnomah County employees via the MINT (county intranet). 

Phase 3: Surveillance Indicates Increased / Medium Disease Risk for Humans 

Messages The health department will actively involve veterinarians and human health providers in disease survei

intensify existing public education and outreach.  Provide information to Veterinarians to monitor encephalitis and other mosquito-borne disease among pe

 Publicize telephone hotline and website for information and to report standing water.  Encourage protective measures such as clothing, repair of window & door screens, and use of insect repe Educate medical providers on encephalitis, meningitis, reporting requirements, and how to submit spec
Provide monthly updates on WNV to reinforce reporting requirements. Possible Continuing Education with these activities as needed.) 

 In the event that pesticide application becomes necessary; the Health Department will make every attemp

impacts to the environment and human health. 

Methods  Dissemination of radio and television Public Service Announcement scripts and frequent media releases. 

 Provide frequent updates to Environmental Health website to reflect the most current information and 

describe geographic areas in which WNV has been identified. Website should have the ability to receireporting dead birds and standing water. 

 Use county Information and Referral line and Communicable Disease hotline with recorded messages.  Utilize local and state Medical Society publications, websites, fax, email groups. Oregon Departmen

Current Disease Summary. Email to Hospital infection control via list serve. 

 Elicit assistance from educators and health outreach workers to provide grassroots community education. 

 Communicate with Multnomah County employees via county-wide email.  Collaboration with other jurisdictions to disseminate messages. 

Phase 4: High Risk of Human Infection / Pesticide Application 

Messages The county health department will provide further public education on the signs and symptoms of WNV, an

on pesticides used on adult mosquitoes.  Public awareness of signs and symptoms of WNV.  Information on adulticides being used, including application schedules and locations, how to reduce exp

in the event of pesticide exposure. 

 Alert medical providers and Poison Control Hotline of potential for reporting of exposures to them. Ad

Poison Control Hotline and medical provider with any reported exposures. 

 Specific product information on pesticides will be made available to the public. Advise public not t

control around the home using retail pesticides. 

Methods 
Communication with health care providers, hospitals, to announce spraying is to occur.  Posting of spraying locations and schedules on website.  Dissemination of radio and television Public Service Announcement scripts and frequent media release Coordinate with public safety agencies to urge people to reduce or limit outdoor activities. 
WNV Communication Tree 

Initial call receiver 

(See list for specific names) 

HD Administration, HO, CD Manager, EH Manager, PIO, 

Vector Supervisor, PDS, Health Educator 

Health Department Administration 

CD/OHO 

Manager 

CD Lead 

Staff 

EH Manager Health 

Officer 

Vector 

Supervisor 

CD Team 

PIO 

EH 

CD Team 

Asst. HO 

& 

EMS 

Vector Team 

CD On-call 

Person 

EH 

Team 
35

2. Use multimedia resources to provide notification: 

(2.1) Newspaper 

(2.2) Television 

(2.6) Radio 

MCVNC works through the Multnomah County Public Affairs Office for coordinated 

and individual media response. MCVNC receives and responds to approx 50-150 media 

inquiries annually. Our departmental policy is as follows; 

Due to the nature of vector control work, most media inquiries are “non-routine” as 

defined in the Multnomah County Health Department Administrative Guidelines. These 

questions, by letter, fax, or telephone from a media group regarding a non-routine issue, 

are usually in the form of crisis situation or allegations. Some examples of this are health 

hazards and controversial public policy decisions 

IMPLEMENTING PROCEDURES

1) Relay media inquiry to appropriate MCVNC media liaison 

2) MCVNC media liaison is required to gather the following information; 

a) contact information of media party requesting interview 

b) date of media interview 

c) date of expected release of interview 

d) talking points of interview, in brief 

3) MCVNC media liaison will forward the information as described in #2 above, 

electronically in bulleted form, to the one of the two following groups of people 

based upon the content of the media inquiry. The groups are described as; 

a) for media inquiries that refer to standard practices of MCVNC forward 

information to: 

MCVNC supervisor 

EH manager 

Disease Prevention and Control Dept. manager 

Public Affairs contact 

b) for media inquiries that refer to controversial issues of MCVNC forward 

information to; 

MCVNC supervisor 

EH manager 

Disease Prevention and Control Dept. manager 

Public Affairs contact 

Public Health officer 

Director of Health Dept. 
36

4) If the nature of inquiry is sewer related, forward the request to Mark Braun, BES 

and synonymously notify the work site supervisor of the request. 

(2.3) Recorded Message 

MCVNC through direct input by Communicable Disease, Environmental Health, Food 

Handlers, and Vector and Nuisance Control (MCVNC) has cooperatively created a phone 

tree system to triage the anticipated phone call volume associated with West Nile virus 

(WNV) for Multnomah County and surrounding communities. This phone system will 

incorporate other vector related information as it surfaces in the future; active since 

3/1/03. 

(2.4) Mailers 

(2.5) Newsletters 

MCVNC regularly provides printed information to Multnomah County citizens and 

others in surrounding communities upon request. Printed materials typically are designed 

to target a general audience for source reduction and prevention of vectors. Materials are 

reviewed when necessary for current information and are available in several languages 

other than English. 

(2.7) Web page 

MCVNC web page is at www. healthinspect.org. Web pages are designed to target a 

general audience for source reduction and prevention of vectors but also include 

electronic complaints forms, dead bird reporting information and notification to spray. 

Additional materials are reviewed when necessary for current information and are 

available in several languages other than English. 

3. Presentations 

MCVNC will present educational presentations upon request as resources allow with the 

assistance of a community services team including a health educator and community 

outreach workers. 

4. Display educational materials at county fairs, health fairs, holiday events at City 

Hall, local museums, libraries and other community events and gathering places. 

MCVNC does present and post educational materials upon request or when necessary as 

resources allow. In 2007, we participated in and or hosted numerous educational 

outreach events. Some examples were a West Nile Virus Town Hall meeting and 

Columbia Slough Watershed Council presentation on WNV. 

5. Recruit local media to help educate the public about vector control practices and 

activities. 

MCVNC works through the Multnomah County Public Affairs Office for coordinated 

and individual media response. MCVNC receives and responds to approx 50-150 media 

inquiries annually. Our departmental policy is outlined above under “2. Use multimedia 

resources to provide notification: (2.1) Newspaper, (2.2) Television, (2.6) Radio”. 

6. Provide notification of vector control activities in other languages when needed. 
37

MCVNC does use the Multnomah County Language Services for translation of printed 

materials. To review our translated materials see www. healthinspect.org. MCVNC also 

has video media of rodent/rat control translated in Vietnamese and Spanish. Materials 

follow the recommendations of the April 2007 summary, Culturally-Specific Populations 

Emergency Communications Project for Clackamas, Clatsop, Columbia, Multnomah, 

Tillamook and Washington Counties Final Report Overview, Synthesis, 

Recommendations by Northwest Oregon Health Preparedness Organization (NW-HPO). 

7. Provide your Pesticide Use Plan (PUP) to all local wildlife agencies in your 

district. 

By Oregon Revised Statutes Chapter 452, MCVNC provides the PUP to all wildlife 

agencies 

8. Provide the public with phone numbers to call if they have questions or problems. 

MCVNC phone numbers provided on all of our informational materials. 

Vector control Pesticide Use Plan: District Name:Multnomah County Vector and Nuisance Control 

 Date:2008 

CONTROL AGENT WORKSHEET 

IMPORTANT: Complete One Worksheet for each Control Agent 

PRODUCT NAME: Altosid Pellets 

EPA REGISTRATION#:2724-448- 

ACTIVE INGREDIENTS:Methoprene (CAS #65733-16-6) @ 4.25%

 

TARGET PEST: 

Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp., and Anopheles spp. mosquito larvae 

RATE OF APPLICATION: (Give in units of pounds of active ingredient per acre and/or pounds 

of product per acre) 

0.1 to 0.4 lb. of active per acre 

APPLICATION METHOD: (Describe the application apparatus, product diluent, mixture, if 

any, and application process) 
38

Pellets are applied by hand or granule spreader to the mosquito larval habitat. Lower rates will be 

used in floodwater areas. Higher rates will be used in ditches, waste tires, artificial containers 

and waste-water areas. Power backpack blowers may be used in some situations. 

APPLICATION SITE: (Describe the types of pest habitat where the product will be applied) 

Floodwater habitat, ditches, waste tires, artificial containers and waster water areas. 

POUNDS OF ACTIVE INGREDIENT TO BE USED:estimated 6.008 lbs 

ACRES TO BE TREATED:estimated 38 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 7.85 lbs 

PRODUCT NAME: Altosid XR Extended Residual Briquets 

EPA REGISTRATION #: 2724-421 

ACTIVE INGREDIENTS: (S)-Methoprene [Isopropyl (2E, 4E, 7S)-11-methoxy-2,7,11-

trimethyl-2,4-dodecadienoate] 

TARGET PEST: Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp., and Anopheles spp. 

mosquito larvae 

RATE OF APPLICATION: per label "1 briquet per 1200 ft square" 

APPLICATION METHOD: manually placed by MCVNC staff person 

APPLICATION SITE: water-holding sites such as storm drains, catch basins, etc of a municipal 

water collection system 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 7623 briquets to be placed 

ACRES TO BE TREATED: estimated 35 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 14526 briquets placed 

PRODUCT NAME: FLIT 10 EC 

EPA REGISTRATION #: 4816-688-8329/Per PICOL 8329-67 

ACTIVE INGREDIENTS: Permethrin @ 10% 

TARGET PEST: Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp. and Anopheles spp. 

adult mosquitoes adult mosquitoes 

RATE OF APPLICATION: 8.75 fl oz. per acre (17.5 oz / acre diluted) 
39

APPLICATION METHOD: 1 part Flit 10EC will be dilluted with 1 part water. The diluted 

material will be applied as a barrier treatment using Maryuama Backpack Mist Blowers with a 

walking 

speed of 2mph 

APPLICATION SITE: Diluted material will be applied to foilage surrounding affected areas. 

Applications will take place when results of a single EVS Trap at the site reach a total 500 adult 

mosquitoes in a single night or landing rates exceed 20 per minute 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 0.2-0.3 gallons 

ACRES TO BE TREATED: estimated 17 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: - 0.217 gallons 

PRODUCT NAME: Abate 4-E 

EPA REGISTRATION #: 8329-15/ per PICOL 8329-60 

ACTIVE INGREDIENT: Temephos @ 4lbs per gallon 

TARGET PEST: Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp., Anopheles spp. 

mosquito larvae 

RATE OF APPLICATION: 0.016 to 0.047 lb. active / acre (0.5 to 1.5 fluid ozs. / acre) 

APPLICATION METHOD: This product is diluted in water at a maximum rate of 0.25 fluid 

ounces of product per gallon of finished spray. Six gallons of finished spray are used to cover an 

acre by backpack application. 

APPLICATION SITE: The main application is for control of Aedes spp. & Ochlerotatus spp. 

larvae in temporary woodland pools during cold weather. It is also used in waste tires, some 

roadside ditches, and sewage polluted sites. This product is not used in areas of special 

environmental concern. 

 POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 1.25 gallons 

ACRES TO BE TREATED: estimated 25 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0.756 gallons 

PRODUCT NAME: GB-1111 @ 98.7% 

EPA REGISTRATION #:8898-16 

ACTIVE INGREDIENT: Petroleum distillate CAS # 008002-05-9 

TARGET PEST: Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp., Anopheles spp. 

mosquito larvae and pupae 

RATE OF APPLICATION: 2.94 to 4.91 lbs. active / acre (3 to 5 gallons per acre) 

APPLICATION METHOD: This product is applied undiluted using backpack sprayers calibrated 

to deliver 4 gallons per acre. It is used primarily for the control of late fourth instar larvae and 

pupae which are not affected by most other materials. 

APPLICATION SITE: Habitats include floodwaters, catch basins and dead end sewer plant 

runways. 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 10 gallons 

ACRES TO BE TREATED: estimated 10 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0.1380 gallons 

PRODUCT NAME: VectoLex WDG @ 51.2% 

EPA REGISTRATION #: 275-135/ per PICOL 73049-57 

ACTIVE INGREDIENT: Bacillus Sphaericus Serotype H5a5b, strain 2362 dried concentrate @ 

51.2% 

TARGET PEST: Culex spp., Coquillettidia spp. Ochlertotatus spp., and Aedes spp. mosquito 

larvae 

RATE OF APPLICATION: .5 to 1.5 lbs per acre 
40

APPLICATION METHOD: VectolextobacVectobac WDG is diluted in water at a maximum 

rate of 4 ozs. per gallon of finished spray. Application is made using backpack sprayers 

calibrated to deliver 6 gallons of the suspension 

per acre. 

APPLICATION SITE: Habitats will include sludge lagoons, sewage lagoons, septic polluted 

ditches, sewage treatment plant still waters. Applications also will be made the floodplains of the 

Columbia and Willamette 

Rivers in areas where water has been trapped behind after the spring freshets. These type of 

applications will only be made if these areas are producing large hatches of Culex mosquitoes 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 4.224 lb 

ACRES TO BE TREATED: estimated 8 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0 lb 

PRODUCT NAME: Pyronyl Oil Concentrate #525 

EPA REGISTRATION #: 655-471 

ACTIVE INGREDIENT: Pyrethrins & Piperonyl Butoxide Technical @ 30% cumulative 

TARGET PEST: Aedes spp., Ochlerotatus spp., Coquillettidia spp., Culex spp., Culiseta spp. and 

Anopheles spp. adult mosquitoes 

RATE OF APPLICATION: maximum of 0.0025 lb of pyrethrins and 0.0125 lb of piperonyl 

butoxide per acre. 

APPLICATION METHOD: This product may be used as supplied or diluted with diluent such as 

light mineral oil or deodorized kerosene in ULV cold fogger calibrated to deliver 0.24 oz of 

material per acre with a median droplet size of 8 to 20 microns. Applications are made when a 

temperature inversion is present and wind speed is between 2 and 8 mph. If public access to 

treatment areas cannot be avoided during application, areas are posted 24 hours prior to treatment. 

APPLICATION SITE: Habitats include floodplains, industrial wastelands, woodlots, farmlands, 

large parks, and other areas where adult mosquitoes are harboring. Residential areas will only be 

treated in the event of 

mosquito-borne disease. 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 2.5 gallons 

ACRES TO BE TREATED: estimated 1121 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0 gallons 

 

PRODUCT NAME: Scourge Insecticide with SBP-1382/Piperonyl Butoxide 18% + 54% MF 

EPA REGISTRATION #: 432-667 

ACTIVE INGREDIENT: Resmethrin & Piperonyl Butoxide 

TARGET PEST: Aedes spp., Ochlerotatus spp., Coquillettidia spp., Culex spp., Culiseta spp. and 

Anopheles spp. adult mosquitoes 

RATE OF APPLICATION: 0.3 fluid ounces of Resmethrin / acre (0.0035 active per acre) 

APPLICATION METHOD: Scourge is mixed with either soybean oil or deodorized kerosene at 

the rate of one part Scourge to 2.33 parts diluent. The diluted material is released through a ULV 

cold fogger calibrated to deliver one ounce of material per acre with a median droplet size of 8 to 

20 microns. A minimum 600 foot buffer is provided between application sites and surface 

waters. Applications are made when a temperature inversion is present and wind speed is 

between 2 and 8 mph. If public access to treatment areas cannot be avoided during application, 

areas are posted 24 hours prior to treatment. 

APPLICATION SITE: Habitats include floodplains, industrial wastelands, woodlots, large parks, 

and other areas where adult mosquitoes are harboring. Residential areas will only be treated in 

the event of mosquitoborne disease. 
41

LBS OF ACTIVE INGREDIENT TO BE USED: estimated 0.0135 lbs 

ACRES TO BE TREATED: estimated 1280 acres 

LBS OF ACTIVE INGREDIENT USED LAST YEAR: 0 

 

PRODUCT NAME: Vectobac G 

EPA REGISTRATION #: 275-50/ per PICOL 73049-10 

ACTIVE INGREDIENT: Bacillus Thuringiensis Serotype H-14 @ 0.2% 

TARGET PEST: Aedes spp., Culex spp., Anopheles spp., Culiseta spp., Ochlerotatus spp, 

mosquito larvae 

RATE OF APPLICATION: 0.01 to 0.02 lbs. active / acre (5 to 10 lbs. product per acre) 

APPLICATION METHOD: This product is applied using power backpack granule blowers and 

may be applied by aerial application this season. Application rates will range from 5 to 10 

pounds per acre. 

APPLICATION SITE: This product is used for the majority of large scale treatments of 

floodwater areas. Examples are the floodplains of the Columbia and Willamette rivers as well as 

various other intermittently flooded wetlands. Applications of this material may also be made to 

control hatches of Anophele species in 

standing water left behind after the spring freshets. 

LBS OF ACTIVE INGREDIENT TO BE USED: estimated 112 lbs 

ACRES TO BE TREATED: estimated 7230 acres 

LBS OF ACTIVE INGREDIENT USED LAST YEAR: 76.61 lbs 

 

PRODUCT NAME: Vectolex CG 

EPA REGISTRATION #: 275-77/ per PICOL 73049-20 

ACTIVE INGREDIENT: Bacillus sphaericus Serotype H5a5b (50 B.S. ITU/mg) @ 7.5% 

TARGET PEST: Culex spp., Ochlerotatus spp., Aedes spp., Coquillettidia spp., mosquito larvae 

RATE OF APPLICATION: 0.75 to 1.50 lbs. active / acre (10 to 20 lbs. product per acre) 

APPLICATION METHOD: Applications will be made with a power backpack granule blower or 

a hand operated crank seeder. Equipment will normally be calibrated to deliver 10 lbs. per acre at 

walking speeds of 1 to 2.5 mph. Additionaly large scale applications to sites greater than 100 

acres in size may be made by aerial application. These large scale applications will be made at a 

rate of 5 to 10 pounds per acre to 

control large hatches of Culex spp. mosquitoes. 

APPLICATION SITE: Habitats will include sludge lagoons, sewage lagoons, septic polluted 

ditches, sewage treatment plant still waters. Applications also will be made the floodplains of the 

Columbia and Willamette Rivers in areas where water has been trapped behind after the spring 

freshets. These type of 

applications will only be made if these areas are producing large hatches of Culex spp. 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 860 lbs 

ACRES TO BE TREATED: estimated 2108 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR 898.05 lbs 

PRODUCT NAME: Vectobac CG 

EPA REGISTRATION #: 275-70/ per PICOL 73049-19 

ACTIVE INGREDIENT: Bacillus thuringiensis Serotype H-14 @ 0.2% 

TARGET PEST: Culex spp., Culiseta spp., Aedes spp., Ochlerotatus spp., Anopheles spp., 

mosquito larvae 

RATE OF APPLICATION: 0.01 to .02 lbs. active / acre (5 to10 lbs. product per acre) 

APPLICATION METHOD: Application will be made with a power backpack granule blowers at 

7.5 pounds per acre This material may be applied by aerial application to sites larger than 100 

acres. 
42

Rate of application for aerial work will be 5 to 10 pounds per acre and would be made to control 

large 

hatches of Anopheles spp. 

APPLICATION SITE: This is used for the majority of large scale treatments of floodwater areas. 

Examples are the floodplains of the Columbia and Willamette Rivers as well as other 

intermittently flooded wetlands 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 0.1 lbs 

ACRES TO BE TREATED: estimated 8 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0 lbs 

PRODUCT NAME: VectoLex WSP 

EPA REGISTRATION #: 73049-20 

ACTIVE INGREDIENTS: Bacillus sphaericus Serotype H5a5b, strain 2362 Technical Powder 

(670 BsITU/mg) @ 7.5% 

TARGET PEST: Aedes spp., Ochlerotatus spp, Culex spp., Coquillettidia spp., and Anopheles 

spp. mosquito larvae 

RATE OF APPLICATION: Per label "1 pouch/50 sq. ft." 

APPLICATION METHOD: Placing one soluable puch per 50 sq. ft. of treatment area with 

reapplication 1-4 weeks following as necessary. 

APPLICATION SITE: Stormwater and drainage systems, etc in non-crop sites. 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 2.47 lbs 

ACRES TO BE TREATED: estimated 3 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 20.41 lbs 

PRODUCT NAME: Vectobac 12AS 

EPA REGISTRATION #: 275-102/ per PICOL 37049-38 

ACTIVE INGREDIENT: Bacillus thuringiensis, subsp. israelensis @1.2 % 

TARGET PEST: Culex spp., Culiseta spp., Aedes spp., Ochlerotatus spp., Anopheles spp., 

mosquito larvae 

RATE OF APPLICATION: By ground 5-100 gallons/acre using backpack equipment. 

APPLICATION METHOD: Vectobac 12 AS is diluted in water at a maximum rate of 5.33 ozs. 

per gallon of finished spray. Application is made using backpack sprayers calibrated to deliver 6 

gallons of the suspension per acre. This is used for general purpose larvaciding. Application will 

be made with a power backpack granule blowers at 7.5 pounds per acre This material may be 

applied by aerial application to sites larger than 100 acres. 

APPLICATION SITE: The product may be used on a variety of larval habitats including 

floodwaters, roadside ditches, temporary pools, etc. It is used heavily, early in the season, for 

control of Aedes in rainwater pools. This is used for the majority of large scale treatments of 

floodwater areas. Examples are the floodplains of the Columbia and Willamette Rivers as well as 

other intermittently flooded wetlands 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 0.10 gallons 

ACRES TO BE TREATED: estimated 60 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0 gallons 

PRODUCT NAME: Anvil 10+10 ULV 

EPA REGISTRATION #: 1021-1688-8329 

ACTIVE INGREDIENTS: Sumithrin @ 10.00% CAS #026002-80-2 & Piperonyl Butoxide @ 

10.00% CAS #000051-03-6 (cum. 20%/gal) 

TARGET PEST: Aedes spp., Ochlerotatus spp., Coquillettidia spp., Culex spp., Culiseta spp. and 

Anopheles spp. adult mosquitoes 

RATE OF APPLICATION: Ground ULV & Aerial rates = 0.0024 oz active/acre; 
43

APPLICATION METHOD: Using a 300ft swath width, applied undiluted in ULV cold fogger 

calibrated to deliver 1.3 to 5.1 oz of material per acre, at a truck speed of 5-20 mph, with a 

median droplet size of 5 to 25 microns. For aerial application, 50 microns or less with no more 

that 2.5% exceeding 100 microns at 0.21-0.62 oz/per acre. Applications are made when a 

temperature inversion is present and wind speed is between 2 and 8 mph. If public access to 

treatment areas cannot be avoided during application, areas are posted 24 hours prior to treatment. 

APPLICATION SITE: residential and recreational areas where adult mosquitoes are present in 

parks, woodlands, swamps, marshes, etc 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 3.82 gallons 

ACRES TO BE TREATED: estimated 4000 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 1.59 gallons 

PRODUCT NAME: Aqua-Kontrol Concentrate 

EPA REGISTRATION #: 73748-8 

ACTIVE INGREDIENTS: Permethrin @ 20.0% and Piperyonyl Butoxide Technical @ 20.0% 

TARGET PEST: Aedes spp., Ochlerotatus spp., Coquillettidia spp., Culex spp., Culiseta spp. and 

Anopheles spp. adult mosquitoes 

RATE OF APPLICATION: Barrier Spray @ 0.00175/0.00175 # ai./acre 

APPLICATION METHOD: Using a 50 ft swath while walking @ 2 mph speed for large droplet 

partical application . 

APPLICATION SITE: residential and recreational areas where adult mosquitoes are present in 

parks and other locations as label states 

POUNDS OF ACTIVE INGREDIENT TO BE USED: 0 

ACRES TO BE TREATED: 0 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0 

PRODUCT NAME: Altosid XR-G 

EPA REGISTRATION #: 2727-451 

ACTIVE INGREDIENTS: (S)-Methoprene @ 1.5% 

RATE OF APPLICATION: 5-20 lbs per acre, species specific and when environment dictates 

otherwise as label specifies. 

APPLICATION METHOD: may be applied by aerial application or by ground with granular 

spreader. Does include clause for pre-hatch application as well 

APPLICATION SITE: crop and non-crop areas, including flood-land 

POUNDS OF ACTIVE INGREDIENT TO BE USED: 2.44 lbs 

ACRES TO BE TREATED: 9.25 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0 lbs 

PRODUCT NAME: MGK brand Pyrocide 7396 

EPA REGISTRATION #: 1021-1569 

ACTIVE INGREDIENT: Pyrethrins & Piperonyl Butoxide Technical @ 30% cumulative 

TARGET PEST: Aedes spp., Ochlerotatus spp., Coquillettidia spp., Culex spp., Culiseta spp. and 

Anopheles spp. adult mosquitoes 

RATE OF APPLICATION: maximum of 0.0025 lb of pyrethrins and 0.0125 lb of piperonyl 

butoxide per acre. 

APPLICATION METHOD: This product may be used as supplied or diluted with diluent such as 

light mineral oil or deodorized kerosene in ULV cold fogger calibrated to deliver 0.24 oz of 

material per acre with a median droplet size of 8 to 20 microns. Applications are made when a 

temperature inversion is present and wind speed is between 2 and 8 mph. If public access to 

treatment areas cannot be avoided during application, areas are posted 24 hours prior to treatment. 
44

APPLICATION SITE: Habitats include floodplains, industrial wastelands, woodlots, farmlands, 

large parks, and other areas where adult mosquitoes are harboring. Residential areas will only be 

treated in the event of 

mosquito-borne disease. 

POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 6.0 gallons 

ACRES TO BE TREATED: estimated 1893.7 acres 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0 gallons 

PRODUCT NAME: Talon-G 

EPA REGISTRATION #: $100-1050 

ACTIVE INGREDIENTS: CAS #56073-10-0 @ 0.005% a.i. brodifacoum; each pack weighs 

0.0055 lbs or 25 grams 

TARGET PEST: Norway & Roof rats 

RATE OF APPLICATION: per label "4-16 bait packs" 

APPLICATION METHOD: No rodenticides will be provided to citizens for their direct use. 

Citizens may elect to acquire and use rodenticides on their own. 

APPLICATION SITE: Habitats would include urban and residential areas. 

 POUNDS OF ACTIVE INGREDIENT TO BE USED: estimated 0 lbs 

ACRES TO BE TREATED: 0 

POUNDS OF ACTIVE INGREDIENT USED LAST YEAR: 0.0003982 lbs 

PRODUCT NAME: Contract Super-Size Blox 

EPA REGISTRATION: #12455-82 

ACTIVE INGREDIENTS: Bromadiolone @ 0.005% per 8 oz block 

TARGET PEST: Norway and Roof rats 

RATE OF APPLICATON: per label 1 or 2 bait blocks per placement 

APPLICATION METHOD: Contrac Blox are primarily used in severe baiting. They may be 

also used in tamper resistant bait stations for control of severe infestations in areas with no access 

for children and pets. Placement is always made in a manner that minimizes access of the bait to 

non-targets wildlife. In sewers, the blocks are secured in place above the normal water line with 

wire. Once feeding stops all unconsumed bait is removed. 

APPLICATION SITE: Habitats include urban and residential areas (primarily in 

sewers). Not used in areas of special environmental concern. 

LBS OF A.I TO BE USED: 0.00153 lbs 

ACRES TO BE TREATED: N/A 

LBS OF A.I. USED LAST YR: 0.015 lbs 

PRODUCT NAME: 5% Skeeter Abate 

EPA REGISTRATION: #8329-IL-0 

ACTIVE INGREDIENTS: Temephos @ 5% 

TARGET PEST: Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp., 

Anopheles spp. mosquito larvae 

RATE OF APPLICATON: 2-10 lbs per acre depending upon water quality 

APPLICATION METHOD: Product is in a gypsum pellet form and will be applied with 

motorized backpack sprayers or during spot or catch basin treatment applications made with 

measured spoons. This product is also labeled for pre-treating areas that will breed mosquitoes. 

APPLICATION SITE: Used in waste tires, some roadside ditches, sewage polluted sites, 

and as a spot treatment to catch basins and similar structures. This product will be used primarily 

to target Culex spp. mosquitoes and this product is not used in areas of special concern. 

LBS OF A.I TO BE USED: estimated 100 lbs 
45

ACRES TO BE TREATED: estimated 10 acres 

LBS OF A.I. USED LAST YR: 0 lbs 

PRODUCT NAME: AGNIQUE MMF-G 

EPA REGISTRATION: #53263-30 

ACTIVE INGREDIENTS: Poly (oxy-1,2-ethanediyl), (C16-20 branched and linear alkyl)-

-hydroxy) @ 100% 

TARGET PEST: Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp., 

Anopheles spp. mosquito larvae 

RATE OF APPLICATON: 11-21.5 lbs/acre (fresh and polluted) 

APPLICATION METHOD: by ground or aerial applications. 

APPLICATION SITE: fresh and brackish waters sites, storm waters structures, polluted 

waters. This product will not be used in sensitive ecosystems. 

LBS OF A.I TO BE USED: estimated 16 lbs 

ACRES TO BE TREATED: estimated 2.5 acres 

LBS OF A.I. USED LAST YR: 17.17 lbs 

PRODUCT NAME: ALTOSID PELLETS WSP 

EPA REGISTRATION: #2724-228 

ACTIVE INGREDIENTS: (S)-Methoprene: Isopropyl (2E, 4E, 7S)-11-mehtoxy-3,7,11-

trimethyl-2-4-dodecadienoate @ 4.25% 

TARGET PEST: Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp., 

Coquillettidia spp., Anopheles spp. mosquito larvae 

RATE OF APPLICATON: 1 pouch into 1 catch basin. For other sites, 1 pouch for up to 135 

square feet of surface area. 

APPLICATION METHOD: by ground, by hand. 

APPLICATION SITE: catch basins 

LBS OF A.I TO BE USED: 20 lbs 

ACRES TO BE TREATED: n/a 

LBS OF A.I. USED LAST YR: 0 lbs 

PRODUCT NAME: ALTOSID Liquid Larvicide 

EPA REGISTRATION: #2724-392 

ACTIVE INGREDIENTS: (S)-Methoprene: @ 0.43 lb/gal a.i. 

TARGET PEST: Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp., 

Coquillettidia spp., Anopheles spp. mosquito larvae 

RATE OF APPLICATON: 0.5 – 5 gallons of product/acre 

APPLICATION METHOD: by ground by spray application 

APPLICATION SITE: mosquito breeding areas 

LBS OF A.I TO BE USED: 21.5 lbs 

ACRES TO BE TREATED: 10 acres 

LBS OF A.I. USED LAST YR: 0 lbs 

PRODUCT NAME: V60035 CG/VectoMax CG, V60035 Water Soluable Pouch 

WSP, VectoMax WSP 

EPA REGISTRATION: #73049-429 

ACTIVE INGREDIENTS: Bacillus spahaericus Serotype H5a5b, strain 2362 Fermentation 

Solids, Spores, and Insecticidal Toxins and B. thuringiensis

subsp. israelensis Serotype H-14, Strain AM65-52, Fermentation 

Solids, Spores and Insecticidal Toxins @ 7.2% 
46

TARGET PEST: Aedes spp., Ochlerotatus spp., Culex spp., Culiseta spp., 

Coquillettidia spp., Anopheles spp. mosquito larvae 

RATE OF APPLICATON: 5-20lbs/acre; 0.5-2lbs/1000 sq. ft for waste tires 

APPLICATION METHOD: by ground or aerially applied by helicopter 

APPLICATION SITE: mosquito breeding areas 

LBS OF A.I TO BE USED: anticipated 90 lbs @ 12.5 lbs/acre 

ACRES TO BE TREATED: anticipated 100 acres 

LBS OF A.I. USED LAST YR: 0 lbs 

Document1 

VECTOR CONTROL PESTICIDE USE PLAN 

This is a multi-part form. Page three is a Target Pest Information worksheet that must be filled 

out for each pest for which a treatment is planned during the season. Page four is a Control 

Agent Worksheet. This information must be supplied for each pesticide product or biological 

control agent that the district intends to use. Attach additional sheets as needed. A form 

containing the specified information in another format may b substituted, but, please include all 

information indicated on these forms. 

District Name:Multnomah County Vector and Nuisance Control 

 Date:2008 

Applicator Information 

Name:Christopher M. Wirth 

Address:5235 N. Columbia Blvd. 

City/Zip:Portland 97203 

Telephone:503-988-3464, ext 222 

E-Mail:chris.m.wirth@co.multnomah.or.us 

Pesticide Applicator License#:170888 

Additional District Information (complete only if there is a contact person who should receive 

official correspondence in addition to pesticide applicator): 

District Contact Name/Title: 

District Address: 

District City/Zip: 

District Phone: FAX: 
47

PUBLIC NOTIFICATION METHOD (check all that apply): 

Newspaper Television Radio Mailer 

 

Newsletter Bulletin Board Notices Recorded Telephone 

Message 

 Other_website @ 

www.mchealthinspect.org_________________________________________________________

___________ 

PUBLIC NOTIFICATION INFORMATION (provide a short description of notification plan, 

i.e., timing, frequency, languages other than English, etc.): 

Multnomah County Vector Control (MCVNC) does not normally make routine wide 

spread/county-wide adulticide applications to areas occupied by people. In the event of 

mosquito-borne disease or for community livability reasons, aerosol adulticide applications may 

be made in areas of human habitation. Public notification would be coordinated with the 

appropriate stakeholders including County Health Officer and Oregon Department of Human 

Services. MCVNC has an public notification system including specific website information that 

covers distribution of information to the public and media. Larvicide applications are made in 

areas with little potential for human exposure and by methods that result in minimal drift. 

Rodenticide placements are made only with signed consent of the person or agency who 

occupies, owns, or controls the property. Educational pamphlets, video tapes, and a slide 

presentation are available to educate the public, media, schools, and agencies/organizations. 

When aerial applications of BTI are used to control floodwater mosquito larvae, MCVNC uses 

newspapers, radio and television to inform the public of our activities. MCVNC has a response 

plan for West Nile virus that includes a comprehensive communication plan and response 

guidelines for control. See previous sections of this document for more information on 

notification. 

Vector Control Pesticide Use Plan: District Name:Multnomah County Vector and Nuisance 

Control 

 Date:see above 

TARGET PEST INFORMATION 

IMPORTANT: COMPLETE ONE SHEET FOR EACH TARGET PEST 

Target Pest: Check only one target pest per worksheet. 
48

Mosquito Larvae Domestic Rat Domestic Fly 

 

Mosquito Adult Other Pest (specify) 

MONITORING METHOD/TREATMENT THRESHOLD 

(Indicate the monitoring method and threshold for treatment) 

Monitoring Method:Monitoring done by modified random 400 ML dipcount method. Dipping focused on 

specific habitat types but done randomly within those habitats. 

Treatment Threshold:An average of one larvae per dip in site or based on historical data for pre-hatch 

treatments. 

EFFICACY SAMPLING 

(Indicate which treatments will be followed by an evaluation of efficacy, and what method will be used for 

the evaluation)

All large scale (>1 acre) treatments are followed up with sampling by dipcount or (for methoprene 

treatments) with pupal hatch counts to determine efficacy or as needed. A representative number of 

smaller treatments are also followed up in this fashion. 

SURVEILLANCE FOR IMPACTS ON NON-TARGET SPECIES 

(List methods used to determine impacts on non-target species.) 

Resources severely limit our ability to do extensive monitoring for impacts on non-target insects. 

Observations are made of non-target invertebrates found while taking pre and post treatment dipcounts. Materials that appear to cause significant changes in invertebrate fauna are avoided in 

areas utilized by wildlife whenever possible. See prior sections of this document on non-target impact 

methods for more information.. 

TOTAL NUMBER OF AGENTS (PESTICIDES AND BIOLOGICAL CONTROLS) TO BE USED FOR 

CONTROL:= 11+ 

DISTRICT NAME: Multnomah County Vector and Nuisance Control 

DATE: see above 
49

 

TARGET PEST INFORMATION 

 

TARGET PEST: CIRCLE ONLY ONE TARGET PEST PER WORKSHEET 

Mosquito Adult 

 

MONITORING METHOD 

Surveillance of adults mosquitoes is primarly done in order of most frequently used methods to least 

frequently used methods includes EVS traps, gravid traps when applicable, light traps and aspiration, 

sweep nets, landing rate counts, followed up with specimen identification. 

 

 

TREATMENT THRESHOLD 

Application of adulticides to mosquito source areas not inhabited by people are planned when criteria 

threshold is breached. 

Application of adulticides to mosquito source areas inhabited by people will only be treated if a health 

emergency due to the detection of an arbovirus found present in a vector population in Multnomah 

County or adjacent or regional areas and specific surveillance criteria related to specific arbovirus is met 

and or community livability thresholds are breached, MCVNC would initiate an adulticiding control 

efforts. See previously mentioned policies. 

EFFICACY SAMPLING 

Adulticiding applications to be evaluated post treatment traps (e.g. EVS) and cage tests. 

 

SURVEILLANCE FOR IMPACTS ON NON-TARGET SPECIES 

Comprehensive monitoring for effects on non-target insects following adulticide applications is too 

costly for our program to accomplish. We rely on published studies about these effects when selecting 

materials and methods. Obvious effects such as bee kills would be noticed during post treatment 

sampling. See other sections of this document on non-target surveillance methods for more information. 

 

TOTAL NUMBER OF AGENTS (PESTICIDES AND BIOLOGICAL CONTROLS) TO BE USED FOR 

CONTROL = 5+ various formulations 

DISTRICT NAME: Multnomah County Vector and Nuisance Control 
50

DATE: see above 

TARGET PEST INFORMATION 

 

TARGET PEST: CIRCLE ONLY ONE TARGET PEST PER WORKSHEET 

Domestic Rat 

 MONITORING METHOD 

Monitoring is done through citizen complaints, sewer break reports, and visual evidence. 

Sewer-related rat problems are tracked by computer and illustrated in our map info program. 

Sewer baiting is targeted at areas with high numbers of sewer-related rat problems. MCNVC, through 

cooperative rodent surveillance work being conducted at Portland State University, anticipates increased 

information to enhance existing rodent programs including specific species diversity, population density 

and spatial information of those species found in Multnomah County in 2003-2004. 

 

TREATMENT THRESHOLD 

The treatment threshold has been reached when an inspection indicates an active rat infestation or rats 

have been sighted. Sewer baiting for rats has been contracted with the City of Portland. Sewers will be 

baited prior to any construction on the line, or after an investigation by our office identifies the need. 

Rodenticide placements have been greatly curtailed on private property and only when a short term 

solution is necessary for rodent control while property owner works to reduce rat attractants 

simultaneously. An inspection is made and advice/report and control tools are provided if necessary. If 

control tools include rodenticides, resident will sign agreement for rodenticide placement and be 

supplied with a tamper-resistant bait station. Rodenticides provided will be over-the-counter products 

with full label intact. Rodenticide placement may occur, at the direction and oversight of a MCVNC 

inspector on public property when necessary when a short term solution is necessary for rodent control 

while public property owner works to reduce rat attractants simultaneously. 

 

EFFICACY SAMPLING 

Applications to sewer systems are a rodenticide labeled specifically for sewer bait placement. All 

rodenticides used in sewer systems will be wired in place, and monitored approximately every two weeks 

for bait consumption and product shelf-life viability. Consumed bait will be replaced every two weeks, 

once consumption has stopped, all unconsumed bait will be removed and discared according to label 

instructions. All sewer systems baited will be mapped out on a mapping program. All rodenticide 

placements in other areas of public ownership will be rechecked to assure efficacy and disposition of 

excess rodenticide. 

 

SURVEILLANCE FOR IMPACTS ON NON-TARGET SPECIES 

We rely on client reports for impacts on non-target animals such as squirrels, pets, etc. Public and 

private property owners are made aware of the potential effects of rodenticides on non-targets. Bait 

placements are made to the best of MCVNC ability to reduce/prevent children, pets, and non-target 

wildlife from accessing the materials. See prior sections of this document on non-target surveillance for 

more information. 

 
51

TOTAL NUMBER OF AGENTS (PESTICIDES AND BIOLOGICAL CONTROLS) TO BE USED FOR 

CONTROL = 2+ various formulations/active ingredients 

Vector Control Pesticide Use Plan: District Name:Multnomah County Vector and Nuisance Control 

 Date:see above 

SENSITIVE AREAS AND SPECIES 

(Provide a description of sensitive areas. Map(s) that show sensitive areas, areas to be treated by larviciding 

and areas to be treated by adulticiding should be on file with ODFW. If new sensitive areas are identified 

include new maps with this application.) 

The term "sensitive area" and its criteria has not yet been defined in context of the State of Oregon 

Pesticide Use Plan. The following areas are identified for a wide variety of criteria to be considered when 

making IPM choices as a precautionary approach. MCVNC has taken the lead initiative and is working 

with various local wildlife managers on identifying areas that may be critical or sensitive for a variety of 

reason(s). Additionally, MCVNC will track the areas and recommendations by the Terrestrial Ecology 

Enhancement Strategy draft report 8-22-07 as it develops. It is noted that the many of the habitat anchors 

identified by this group thus far are already included in the MCVNC list of sensitive areas. Additionally, 

MCVNC has been and will continue to work with Oregon Fish and Wildlife to implement modification 

when compatible to both public health and local wildlife population(s) and ecosystem(s). Some examples 

of this ongoing work have already been described in other sections of this document. Additional examples 

include working closely to modify our actions as necessary to support the monitoring and success of the 

local turtle populations at Sensitive Area #9 for painted turtles, Chrysemys spp. . 

Sensitive Area - 1 

Sauvie Island Wildlife Management Area 

See previously attached maps for location 

mosquito control and surveillance according to policies and procedures described above 

Sensitive Area - 2 

 Pittock Bird Sanctuary 

See previously attached maps for location 

mosquito control and surveillance according to policies and procedures described above 

Sensitive Area - 3 

Oaks Bottom Wildlife Refuge 

See previously attached maps for location 
52

mosquito control and surveillance according to policies and procedures described above 

Sensitive Area - 4 

Sandy River Gorge 

See previously attached maps for location 

mosquito control and surveillance according to policies and procedures described above 

Sensitive Area - 5 

Columbia River Gorge National Scenic Area 

 See previously attached maps for location 

mosquito control and surveillance according to policies and procedures described above 

Sensitive Area - 6 

Forest Park 

See previously attached maps for location 

mosquito control and surveillance according to policies and procedures described above 

Sensitive Area - 7 

Bull Run Watershed 

See previously attached maps for location 

mosquito control and surveillance according to policies and procedures described above 

Sensitive Area - 8 

Smith & Bybee Lakes 

See previously attached maps for location 

mosquito control and surveillance according to policies and procedures described above 

Sensitive Area - 9 

Burlington Bottoms 

See previously attached maps for location 

mosquito control and surveillance according to policies and procedures described above. Specifically, 

services will be modified for Chrysemys spp.in locations identified by Oregon Department of Wildlife by 

the following methods: 1) decontamination of footgear and any aqueous equipment to avoid pathogens 

spreading from one wetland to another, 2) flexible control thresholds for Aedes spp and Ochlerotatus spp 

mosquito species in the designated water bodies with juvenile turtles present; typically through to June 1st

. 

Modifications may require some flexibility should adult mosquitoes be above average. 

 
53

Sensitive Area – 10 

“Fish Habitat” 

As regulated by Oregon Department of Fish and Wildlife by ORS 635-100-0130 through ORS 635-100-

0135, all Multnomah County water bodies as described in Federal Register, ESU, September 2, 2005 

(70FR52630-52858) for; 

 Lower Columbia River Steelhead 

 Lower Columbia River Chinook 

 Columbia River Chum 

 Upper Willamette River Chinook 

 Upper Columbia River Spring Chinook 

Specifically, a minimum 100-foot buffer will be maintained when applying adulticides by ground ULV or 

barrier application near fish-bearing waters for the above fish species, according to label, excluding Naled. 

EDUCATIONAL ACTIVITIES OF DISTRICT 

(Provide a brief description of educational outreach, including programs for source control in the 

community.) 
54

MCVNC educational outreach efforts combines best practices management with sound science and legal 

control measures for the prevention and control of mosquito, rat and other pests found in Oregon. 

MCVNC routinely provides educational presentation on various subject matters including pest biology, 

pest prevention and control methods, and departmental operating practices including intergrated pest 

management. Presentations are typically given, upon request to local and regional groups such as OHSU 

nursing students, local and regional city and governmental agencies, and other interested parties in 

Multnomah County and occassionally other areas of Oregon where overlap of education information 

messages would benefit State of Oregon residences. Supplemental educational printed and pictorial 

information is also made available to citizens of Multnomah County on pest biology, pest prevention and 

control methods and departmental operating practices including intergrated pest management strategies 

available in multiple languages other than English. All materials are designed to serve Multnomah County 

residents first but due to MCVNC understanding that many areas of Oregon are underserved by vector 

agencies, are made available, upon request to any interested party in State of Oregon. MCVNC works in 

cooperation to routinely evaluate educational messages to ensure appropriate viability of messages to 

diverse audiences. Furthermore, MCVNC works with local educational institutions such as PSU, OSU and 

other professionals to nuture and build in additional expertise in MCVNC programs. 

 

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