Crews survey the site of an emergency repair triggered by a culvert failure along Interstate 70 east of Vail, Colo. Costs to replace this culvert totaled $4.2 million. Photo: Colorado DOT
Crews survey the site of an emergency repair triggered by a culvert failure along Interstate 70 east of Vail, Colo. Costs to replace this culvert totaled $4.2 million. Photo: Colorado DOT

These comments are in response to the article “Good culverts gone bad” on page 38 of the March 2005 issue of PUBLIC WORKS.

I would like to thank you for bringing attention to North America culvert failures in the article. It is important to raise awareness of the crumbling infrastructure in our nation. With that said, I was disappointed in the manner with which the material was presented and particularly concerned with the misrepresentation the article gave to corrugated high-density polyethylene (HDPE) pipe.

One of the topics mentioned in your article and the Transportation Research Board presentation was the determination of culvert service life. Perhaps the biggest question with regard to service-life determination is to define exactly what is considered a failure. For example, are leaking joints failures? They can be, if they would cause a sinkhole that leads to a collapse of a roadway or parking lot. Yet, this factor is often not addressed in service-life predictions, nor was it addressed in the article. Corrugated HDPE pipe has a superior joint system that virtually eliminates leakage of joints and the resulting potential for road failure due to sinkholes.

Other factors that affect service life include environmental considerations of the effluent such as pH and chemical content. In fact, the American Association of State Highway and Transportation Officials' Highway Drainage Guidelines, Volume 14, “Culvert Inspection, Material Selection, and Rehabilitation Guideline,” makes the following statement for both PVC and HDPE materials: “Both are unaffected by the chemical and corrosive elements typically found in soils. In addition, both types have exhibited excellent abrasive resistance, particularly where acidic or alkaline conditions also are present…the data that is available suggests that plastic materials will provide equivalent service life in a potentially broader range of conditions than either metal or concrete.”

The service life estimates that were mentioned in the article were misrepresentative or inaccurate. For instance, an intensive protocol was recently implemented which will allow corrugated HDPE usage for 100-year service-life applications in the state of Florida.

I echo the report's plea for culvert inspections and documentation. Proper inspection and follow-up is key to ensuring the product is performing according to its intended design.

Rich Gottwald, president, Plastics Pipe Institute

It was with great disappointment the members of the National Corrugated Steel Pipe Association (NCSPA) received the March 2005 issue of PUBLIC WORKS during our 2005 national meeting. The article, “Good culverts gone bad,” was filled with inaccuracies and misleading photos.

While the article did point out one, indisputable fact—all culverts, regardless of material, need to be inspected, maintained, and rehabilitated as they approach maximum service life or they will fail—it also, through selective listing of service life, photos, and statistical data, inferred that metal pipe culverts were more prone to failure than culverts of other materials. This is simply wrong.

When designed to appropriate service life for the given environmental parameters and properly installed, metal pipe culverts perform as well, if not better, than other materials such as concrete and plastic.