We are trying to get rid of impostor ladybugs that return every fall. They congregate on the warmer south side of the house…which happens to be over our household well. Can we use this product safely?
In general one must be careful when using any kind of pesticide around wells. But it’s important to understand what kind of wells are subject to contamination and what kind of applications are “risky” to do around a well. In other words, is the well deep or shallow and is the well housing or water pipes above ground or close to where you intend on treating? These are some of the conditions that will factor in when determining whether there is reason for concern; the following excerpt regarding good guidelines explains how to judge:
“…When considering the use of any pesticide on property that relies upon well water or has a well on their property present, certain factors that should be considered. First and foremost is the depth needed to reach the water in the well. Properties will high water tables – especially those where water is present just a few feet down under the ground – must be very cognizant of the well. In general, these properties will be limited in what can be applied to the turf for lawn care because of their well. But since most well water will be found a lot deeper and when the local water level is 50 feet or more deep, it’s not likely anything applied properly to the turf could leach enough to do any damage or pose a problem. In cases where contamination does happen to water that’s deep, it’s usually due to the liquid being applied finding a well housing pipe and if enough accumulates alongside the pipe, some can leak down alongside it and reach the water down below. To insure this doesn’t happen, you should stay at least 10 feet clear of any pump, well housing, well pipe etc. that you know of on your property and make sure treatments don’t run or pool down to the housing where the pipe is present.”
So does this apply to your well? That I cannot answer because even though you said the “warmer side of the house …happens to be over our household well”, you aren’t clear if you mean it’s on the side where the housing is located or where you think the bulk of the water is buried. So without knowing for sure, here is my suggestion.
First, read through our LADYBUG CONTROL ARTICLE where you learn the only application of CYPERMETHRIN should be done above ground, to the siding of the home, and not to the ground itself. This is important.
Second, if no water pipes or pump housing is present on the southside of your home but you suspect the well water lies mostly in this area and you know it’s quite deep (like 50 feet or more down), then treatments to the siding of your home will pose no hazard to the water when done properly. This would be true even with some of the treatment running down the siding and coming in contact with the ground. But if you have a well housing or pipe clearly visible on this side of the home AND it’s right alongside the house, care must be taken to avoid letting any treatment pool up on or adjacent to the pipe. As explained above, letting any material pool up alongside a well water pipe above ground is a sure way of letting the material trickle down to the water table. To insure this doesn’t I would suggest not spraying the siding for 10 feet on either side of the pipe IF it’s closer than 10 feet to the house. However, you can still treat this area; just don’t spray it with a PUMP SPRAYER or other device that’s likely to splatter product all around. Instead, use a paint roller with extension to “roll” the liquid onto your siding. When applied this way slowly, there should be no product dripping or splattering so the risk of any gathering alongside a close water pipe will be nil.
So in summary, depending on what you meant by the siding being “over our household well”, there could be a condition that may affect the treatment process. In other words, you may have to “roll” the Cypermethrin on instead of being able to freely spray it without care. But in the end there is no reason why you can’t safely use it even if the housing or water pipes are close to the house. Just be sure to follow the above listed suggestions and make sure you do so on a day when you don’t expect it to rain so the treatment can have plenty of time to dry.
Here are direct links to the information and products listed above:
Ladybug Control Article: http://www.asianladybug.com/asian-lady-bug-control
Well Water Guidelines Post: https://www.bugspray.net/safety-concerns/safe-to-use-around-well-water.html