Geological anomalies; a term some use to describe “sinkholes.” Just the facts Ma’am. State law, as specified by the FDOT (Florida Department of Transportation), allows the use of spiral ribbed aluminum storm pipe (SRASP) as well as galvanized steel pipe, in storm water drainage systems. Further, the FDOT has conducted life span studies on the various materials used for storm water drainage pipes. These studies clearly show a significant reduction in life span of metal pipes when exposed to certain environmental conditions, such as varying soil PH and exposure to chemicals.
As an example, a metal storm pipe designed for a 50 year life span could have its life span cut in half (to 25 years) depending upon environmental and chemical exposure. These studies are available for review by anyone. Most residents have a number of annual lawn treatments with chemicals, which leach through the storm water drainage system into area ponds.
Additionally, ponds in the golf courses in The Villages are relatively free of weeds, algae and related growth. This is directly related to chemicals intentionally introduced to these ponds to keep them free of algae and related growth. One particular chemical, copper sulfate, is very effective on algae growth. It is used for keeping water free of algae and is usually extremely corrosive to metal storm water drainage pipes. Storm water drainage pipes are continuously flooded with water and are in constant exposure to chemically treated water. Constant exposure of chemically contaminated water accelerates corrosion and creates a pathway for downward hydraulic pressure through the clayey confining beds, eroding soils down to the upper and lower aquifers.
Another interesting fact is that municipal projects (at least in Marion County) will not be constructed from materials other than reinforced concrete pipe (RCP) or high density polyethylene storm pipe (HDPE). Marion County Engineers told me they will not use metal storm pipe for county projects because of its predictably short life span. So, if you ever hear the term “geological anomaly”, when sinkholes occur over or near metal storm water drainage systems, it is to direct residents away from the most likely root cause; exposure of metal pipes to environmental variables described here. And, even a really bad engineer can look down into a sinkhole, observe metal storm water pipes that look like Swiss Cheese from corrosion, and determine the root cause of a sink hole.
Jeff Musante is a resident of the Village of Calumet Grove.
