I want to comment briefly on Jon Houseknecht’s letter (“Flies a Good Thing?”, Onsite Installer, April 2011). In Cochise County, Ariz., these flies are pervasive. The county inspects our trucks yearly, and part of the inspection is that we have proper caps on our suction and dump hoses for this very reason — not to spread these pesky critters.
So they know they are transmitted by our hoses. These flies are capable of spreading disease, although I have not seen any documentation of that. Our county also has a grant from Homeland Security for a vector inspector. He is constantly checking for infiltration or breach on the border for anything that would cause a health issue to us from draconian sources.
I would never introduce or think of introducing an insect that has a diet from feces. They are neither normal nor healthy. However, the larvae do feast on organic matter — scum. They have to be out of the water sitting on the scum or, as I have found, on floating plastic debris. In the tanks I have looked into, they are making no headway eating the massive scum, and the end result is more flies.
Yes, they can come in from a roof vent, although that is yet to be proven, at least to my knowledge. Until my comments about filters, I never heard mention of the problem at least in our industry (pumping and installing).
If they stay in the tank, so be it, but when they migrate up the line into the kitchen — not good. When they plug filters in less than two months — not good. Yes, 6-inch filters would defer the plugging for longer periods. When a filter plugs, the tank overloads, and the effluent level rises and falls, causing debris to be pushed into the second chamber. When this happens, there will be shorter and shorter intervals of filter cleanings. I fully explain all my recommendations to customers so they can make an intelligent decision about their maintenance and my part of that.
Most of our residents do not know they have a filter in their tank, and it does not become evident until they have a catastrophic backup. The rule was introduced in 2001, and installers in our part of the country were told the filters could go years before you had to worry about them. The homeowners were never told that they had filters in their tanks.
When I get a call on the phone with trouble, the first question I ask is, “How old is your system?” If it was installed in 2001 or later, the second question is, “Do you know that you have a filter?” Only within the last two years have I received one or two answers in the affirmative.
My goal in any investigation is to help my customers, and it is not always an easy, practical, or conventional solution. Maybe someday there will be a solution to being rid of these flies in septic systems. We always appreciate the information that we read in COLE publications.
Dawn Long
American Septic Service
Sierra Vista, Ariz.
