The Health Department follows a comprehensive plan to prevent the spread of the West Nile virus, as recommended by federal, state and local public health and environmental agencies and experts. Activities include continuous monitoring of mosquito test pool results, using larvicide along creeks and in stagnant bodies of water to prevent mosquito eggs from developing into adults, abating or eliminating stagnant water, and public education efforts. The Health Department also conducts spraying to control the adult mosquito population to prevent the spread of the West Nile virus.

To report a stagnant swimming pool in your neighborhood, please call the Health Department at 972-744-4080 during regular business hours, or send us an e-mail at any time HERE.

Trucks used by the Health Department and its contractors are equipped with GPS-based controllers that vary the volume of chemical released based on the truck’s speed, up to about 30 mph. The volume of spray is calibrated to release the amount of chemical that has proven most effective at killing mosquitoes and conforms to standards set by the Environmental Protection Agency.

Most people who are exposed to this virus will experience no symptoms of illness or they may experience only mild flu-like illness, such as fever, muscle aches, stiffness in the neck, headache or swollen lymph glands. The incubation period typically ranges from 3 to 15 days. Only in rare cases does this virus cause serious illness. Although this illness can affect people at any age, it tends to be most severe in the elderly, the very young or those with chronic illnesses or weakened immune systems. Persons experiencing severe symptoms should consult their personal physician promptly.

The Health Department uses pesticide in order to help prevent the spread of mosquito-borne disease transmitted by adult mosquitoes. The most concerning of these is the spread of the West Nile and Zika viruses that are proven to be harmful and even deadly in some cases. The pesticide used to help control the mosquito populations is applied by using a truck-mounted ultra-low volume (ULV) sprayer that puts out only small amount of pesticide. ULV sprayers dispense extremely small droplets that stay airborne as long as possible and drift through an area above the ground killing the mosquitoes in the air on contact. The small droplet size makes the pesticide more effective, which means less pesticide is used to better protect people and the environment.

The City utilizes an ultra-low volume fogger that disperses pesticide, following Centers for Disease Control (CDC) and Environmental Protection Agency (EPA) guidelines, which is effective at reducing mosquito populations and is sensitive to the environment.

Spraying is typically conducted using ground-based foggers mounted in trucks. However, in certain emergency situations aerial-based spraying is considered a safe and effective way to control mosquitoes in larger geographical areas.

The City uses a product called Aqualuer 20-20, a water-soluble synthetic permethrin. Aqualuer 20-20 is an effective yet environmentally sensitive product, and equipment is calibrated in keeping with the pesticide's label for application requirements as required by law. Pesticides that are used for mosquito control have been judged by the EPA not to pose an unreasonable risk to human health. People who are concerned about exposure to a pesticide, such as those with chemical sensitivity or breathing conditions such as asthma, can reduce their potential for exposure by staying indoors during the application period.

The Health Department schedules spraying events during overnight hours to limit exposure to people who may wish to avoid contact with the pesticide used to control mosquito populations. Spraying events begin at 9 p.m. with the goal of ending by 4 a.m., depending upon the size of the spray area.

Use an EPA-registered pesticide that is proven as one of the fastest and best options to control mosquito populations. The Environmental Protection Agency (EPA) reports the chemical used by health workers has been fully evaluated by EPA researchers and it does not pose a risk to people or the environment in the way that it is applied. Extensive scientific research has been conducted by academia, industry, and government agencies to identify the appropriate droplet sizes used to ensure public safety, and the equipment nozzles used also undergo rigorous testing to properly distribute the mist when used.

Truck mounted ground level spraying is just one way the city controls the mosquito population. Spraying does not eradicate all mosquitos, but leading scientists at the Centers for Disease Control and Prevention (CDC), the Entomological Society of America and the Mosquito Control Association all support spraying and say it is an effective way to reduce mosquito numbers and control the spread of disease such as West Nile Virus.

The product used is a pesticide formulated for control of mosquitos. It is diluted with water and applied with an Ultra Low Volume Sprayer. While the city cannot guarantee that non-target pests will not be affected, steps are taken to minimize the chances of this happening. Spraying occurs overnight, when insects such as bees and dragonflies are least active. The application equipment is calibrated specifically to control insects the size of mosquitos minimizing impact to larger insects. Also, since the chemical does not leave a residual and must come in direct contact with the insect to be effective, insects that are active after spraying has occurred will not be affected.

The Health Department schedules spraying events during overnight hours to limit exposure to people who may wish to avoid contact with the pesticide used to control mosquito populations. Spraying events begin at 9 p.m. with the goal of ending by 4 a.m., depending upon the size of the spray area.

The Health Department schedules mosquito spraying based on positive findings of West Nile virus in mosquito traps placed around the city. Once located, the area around the positive finding is targeted for spraying on back to back nights (weather permitting) to help limit the spread of disease. Spraying is only one measure to help limit exposure, and health workers urge people to maintain vigilance in protecting themselves when going outside.

Trucks used by the Health Department and its contractors are equipped with GPS-based controllers that vary the volume of chemical released based on the truck’s speed, up to about 30 mph. The volume of spray is calibrated to release the amount of chemical that has proven most effective at killing mosquitoes and conforms to standards set by the Environmental Protection Agency.

The City uses several communication tools to inform the public about planned spraying events. News releases are sent to local media and posted on the City website; information is sent electronically to homeowners associations and neighborhood associations, as well as to subscribers of the Week In Review/City News e-notification list; and information is posted on the Richardson Today Facebook page and the Richardson Today Twitter account. Additionally, ‘Mosquito Spraying Tonight’ notification signs are placed at strategic points in each neighborhood that is be sprayed.

Health Department staff sprays only targeted areas. Targeted areas include areas where West Nile Virus has been isolated in a mosquito sample or if a case of illness is suspected or confirmed in humans. Since spraying does not eliminate all mosquitoes, it is important that citizens do what they can to protect themselves and that mosquito breeding sources around the home be eliminated. If spraying is indicated, the Health Department applies an EPA- approved pesticide with a low toxicity. Spraying events begin at 9 p.m. with the goal of ending by 4 a.m., depending upon the size of the spray area.

Use insect repellants (25% DEET for adults and 10% for children as recommended by the American Academy of Pediatrics); products containing picaridin and oil of lemon eucalyptus (a plant-based repellant) also offer protection.

Wear long sleeves and long pants when outdoors, and avoid being out of doors from dusk to dawn when many biting mosquitoes are active.

Mosquitoes need water in order to breed and grow into adults. Eliminating any standing water can help to control the population. Here are some tips:

Tip #1: Repair leaky plumbing such as dripping faucets and sprinklers. Don't over water the lawn as this can cause pockets of stagnant water to develop, particularly in low lying or poorly drained areas of the yard.

Tip #2: Don't allow birdbaths, swimming pools, pet watering dishes, flowerpots and saucers or other vessels to hold water and become stagnant. Wading pools, buckets in the sand box or a child's wagon can hold enough water for a mosquito to lay her eggs, so store these properly.

Tip #3: Keep your lawn mowed and tall grass and weeds trimmed.

Eliminating potential breeding areas (standing water) remains the most effective way to control mosquitoes. If the source cannot be eliminated and mosquitoes develop, there are effective products available to homeowners that target mosquito larva. These can be purchased through nurseries or lawn and garden stores. Bacillus Thuringiensis Israelensis (BTI) is a commonly used product that is easy to use and environmentally friendly. It is extremely important for consumers to carefully read and then follow the label instructions on any products before applied. Additionally, commercially available pesticides applied to bushes, ground cover, and other shaded or protective areas where adult mosquitos harbor can reduce the population of adult mosquitos in the immediate area around your home.

The pesticide used degrades rapidly in the environment, and there is no accumulative or residual effect. However, for people concerned about exposure during aerial spraying, health officials suggest the following precautions:

Tip #1: Minimize exposure. Avoid being outside, close windows and consider keeping pets inside while spraying occurs.

Tip #2: If skin or clothes are exposed, wash them with soap and water.

Tip #3: Rinse homegrown fruits and vegetables with water as a general precautionary measure.

Tip #4: Cover small ornamental fish ponds.

Tip #5: Because the chemical breaks down quickly in sunlight and water, no special precautions are suggested for outdoor swimming areas.