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7B - West Nile Virus Mosquito Control Program Update4 CITYOFBOULDER PARKS AND RECREATION ADVISORY BOARD AGENDAITEM MEETING DATE: May 24, 2004 (Agenda Item Preparation Date: May 14, 2004) AGENDA TITLE: West Nile Virus Mosquito Control Program Update REQUESTING DEPARTMENT: Jan Geden, CPRP, Director of Parks and Recreation Ahce Guthrie, Crty IPM Coordmator FISCAL IMPACT: Costs of the Wesl N~le V~rus mosquito control program will be paid from General Fund Reserves. The amount budgeted is $285,000, but staff is revieing the budget in light of Council guidance on adult mosquito spraying and potential additional control efforCS on private 1and. EXECUTIVE SUMMARY: CiYy staff is updating the Paiks and Recreation Adv~sory Board (PRAB) on the status of West Nile Virus (WNV) mosquito conlrol efforCs Comments from the PRAB, the Environmental Advisory Board (EAB) and the Open Space Board of TrusCees (OSBT) will be presented Co the City Council on June l The West Nile V~rus Mosquito Control Plan focuses on prevention and ]arval mosquito controi as the most effective means of control Additional education and outreach to residents will be provided this year, as well as momtormg and treatmenY of all ciry-owned land for disease-vector mosquito larvae City Council has d~rected that emergency adult mosyuito conCrol should be utihzed when thresholds for spraying have been reached Staff has coordmated with lhe Boulder Pubhc Health Department and the Center for Disease Control (CDC) to develop an index (0 75) that would tngger adult mosquito spraymg. The index is based on number of disease vector mosqurtoes trapped (Culex spp) times lhe West Nile Virus mfection iate m the trapped mosqurtoes Fiscal Imnacts: Budgetary. $285,000 has been budgeted for larval momtormg and control, public ouCreach and education Without trap dala from specific locations, il is difficult to est~mate the cost far spraymg. If spraymg were required throughout the city of Boulder, the cost is AGENDA ITF,M # V~~~JJ : PAGE 1 est~mated at $27,000 for each apphcation event, based on a cost per lmear mile of $58 with 3801inear miles of sCreets and alleys m Boulder ($22,040), plus additional costs for advertismg and other notit"ication, as well as hoChne monitoring Staff ~s re-evaluatmg the budget for the June 1 Couneil meetmg Staff Time. The city's Inlegrated Pest Management Coordinator will be the pro~ect manager Staff from C~ty Manager's Office, Open Space/Mountam Parks, Parks and Recreation, Pubhe Affa~rs, Transportation and Utilrties will also be involved m the project Board and Commission Feedback: The Environmental Advisory Board (EAB) unanimously passed a resolution on March 10 supportmg the 2003 West Nile V~rus mosquito contiol approach of larval control only, which did not mclude spraying for adult mosqurtoes, aud contmuation of the same approach for 2004 At the EAB meeting on May 12, they further discussed adult mosquito spraymg and made the followmg recommendations to Coune~l: 1) undertake a mid- season evaluation of the spray progrlm, 2) if a deteimmed number of homes m a neighborhood "opt ouY' of spraying, the entire ne~ghbarhood would not be sprayed, 3) consider fundmg additional data collection to aid fu~ure decision-making. Staff will update the Open Space Board of Trustees (OSBT) at theii retreat on May 22 and will report on the~r discussion Public Feedback: Members of the public have been callmg and e-mailing staff advocatmg different points of view with regard lo spraymg One neighborhood has submitted a petriion requestmg that the neighborhood be sprayed for mosquito control. Last year, approx~mately 500 residents requested to be ]tsted on a"no spray" l~st ~P the city sprayed foi adult mosquilo control Staff Recommendation: Not applicable ANALYSIS The PRAB received an update in the packet foi the April 26 meetmg that mcluded background mformat~on on the WNV program for 2003 and plans for 2004. Please refei to that memo far deta~ls on the program. Education and outreach The Boulder County Public Health DeparYment has developed an education message that is d~fferent firom the one m 2003 They have prepaied mateiials far all the commumties m Boulder County to distribute to residents. C~ty stafP has requested posters, brochures and mserts fbr distribution to Boulder residents via several outlets - the Boulder Creek Fest (Parks and Recreation and Open Space/Mountain Parks booths), cny facilrties, city parke and trailheads, Farmei's Market, utility bill mserts, targeted maihngs, direct contact m specific areas and other means throughout the season If the materials are ava~lable, sCaff will have some aC Che PRAB meetmg on May 24 Larval inosquito control On April 22, the Plannmg Board approved a Weflands Permit to use Bacillus thurengaensas israeleensas (Bta) in city-regulated wetlande Por conCrol of Culex spp. laivae. They did not approve the use of native fish for control, statmg that they thought it was a good idea m concept but not well-enough researched to approve for 2004 They requested that staff conduct more monitormg on the impacts of Bta and the use of naCive fish AGENDA I1TM #V II-g; PAGE 2 The Plannmg Department is conductmg a project to re-map c~ty-regulated wetlande In conjunction with that pro~ect, sCaff offered wetland properry owners an opportunity to have their property evaluaYed for Culex habitat and receive mformation abouC larval mosquito control. To date, over 40 property owners have reyuested an evaluation. The city's contractor, OCtertail Environmental, is schedulmg and conducting Che evaluations. A workshop for property management companies and home owner's assoc~ations is scheduled for June 3. Information on how to manage ponds and wetlands to reduce the potential for Culex mosqu~to habitat wdl be presented. Bti briquettes or dunks are also bemg ordered and will be distributed lo residents. Adult mosquito control Staff has coordinaCed wrth the Boulder County Pubhc Health Department (BCPH) to develop an emergency adult mosquito spraying protocol for the city of Boulder At the May 4 City Counc~l meetmg staff presented options for deciding when emergency adult mosqurto control would be conducted. An index developed by Dr. Roger Nasci, research entomologist for the Center for Disease Control (CDC), located m Fort Collins, was discussed, and Council asked staff to relurn to Council at the June 1 business meeting to further explain the mdex and the protocol for emergency spraying. The index considers the number of Culex mosquitoes as well as the West Nile V~rus infection rate in the mosquiCOes. Issues that staff will address include the followmg: The number and generallocations of adult mosqurto traps necessary to adequately cover the Crty of Boulder. Currently, sCaff is workmg with Boulder County Pubhc Heath (BCPH) lo finahze adult trap locations and the radms around the trap that could potenually be sprayed. A map that ~llusirates the options will be presented at the May 24 meetmg. Staff is also coordinatmg wrth BCPH on adult trap locations m areas wheie city lands abut Che Boulder County Mosquito Control D~snict 2. The criteria used to determine placement of traps City staff worked with BCPH staff to locaYe in-city adult mosquito tiaps to provide coverage throughout the urban area, as well as to cover areas where human cases occurred m 2003. Adult trap locations are dependent upon smtable "harborage" for adult mosyuitoes One iecommendation from the CDC is that adult tiaps not be placed close to larval breedmg sites 3. Detailed explanation of the threshold to determme when spraying would occur (the 0.75 mdex) Staff wdl review the mdex with the PRAB at the meetmg The mdex developed by Dr Roger Nasci uses number of Culex species mosquitoes t~mes the WNV infection rate of the mosqurioes. Here is an example to aid m understandmg how the mdex would be used For example, mosquitoes would be collected from Trap A The techmcians would count the total mosqurtoes (200) and then speciate them (62 Culex species). They would then AC~ENDA ITEM # v I I•8 ; PAGE 3 send the Culex mosquitoes to the State of Colorado laboratory to be tested far the presence of West Nile V~rus. The information from the laboratory would be returned to the BCPH and the city and the mfection rate in the mosquitoes would be calculated (1°~0). In this example, the mdex would be calculated by lhe number of Culex mosquitoes (62) X infection rate ( O1), and would equal0 68 Based on usmg 0.75 as the threshold far emergency adult moeqmto spraymg, no spraymg would occur, but residents would be advised Lo take addiCional precautions to prevent exposure. Outdoor evenls and actrvities m~ght be cancelled. 4. Informahon on the city's education campaign. See information presented m the Edueation and outreach section above 5. Information on how Che ciry's West Ntle Virus Mosquito control program is m altgnment wrth lhe crty's Integrated Pest Management Program The city's Integrated PesY Management (IPM) Policy has been m place for over ten years It does not prohibit the use of pesCicides, but describes a decision-makmg piocese to use fot determinmg when pesticide use is warranted The ciYy's IPM policy was followed in the development of the West Nile V~rus Mosquito Control Plan in 2003, whieh meant that the plan would evaluate several methods of control and thresholds, and recommend the least impactful method and threshold The plan mcludes using Bacallus thurangaensis israelaensis (Bta) and estabhshes a threshold of one Culex larvae as the treatment threshold Preveretion is the first tenet of the IPM pohcy and that message has been stressed m all outreach materials to the community, as well as wrth cily staff. Cultural and mechanacal control methods have also been uCilized to some extent (such as filling m t~re rnts and eliminatmg other areas of standmg water), but in many cases the habitat for the Culex mosquitoes is in regulaled wetlands Baologacal control of the mosquito larvae has been the mosl widespread method used, (Bti), although it is not withoul ~mpacts Yo other genera m the order Diptera. However, il is widely accepted that Yhe ~mpacts to the human population and the environment from Bta are less than from other conCrol methods. Chemical control is a method of last resort The City Council has authonzed spraymg insecticide for adult mosquito control and the details of the condiCions under which spraymg would occur are now bemg discussed Long-Term Strategy Council has requested that staff work on a long-term strategy for West N~le Viius mosquiYo control Concerns have been exptessed about the potential long-term effects of Bacallus thurangaensis israelaensis (Bti) on wetlands and the impacts of long-term mosquito control on non-target orgamsms, such as birds and bals. The question of whether the city should Porm a mosquiCo abatement d~strict has also been raised. Staff will be developing options for a long-term West Nile Virus mosqurto control strategy and brmg them to the appropnale boards befare presentmg to Council before February 2005 AGF,NDA ITEM #U~~'g : PAGE 4