At the Leading Edge of Storm Water Infrastructure
Southeast Culvert, Inc. is a manufacturer of quality storm drainage products and accessories located in Winder, Georgia. The company was founded in 1981 by Doyle Johnson and his partner Eddie Stowers as a corrugated steel pipe manufacturer operating on five acres of land in Lawrenceville, Georgia.
By 1999, Southeast Culvert had outgrown that facility and moved to Winder in order to expand its operations. Shortly thereafter, the company expanded its offering by incorporating the manufacture of high-density polyethylene (HDPE) plastic pipe products into its portfolio, making Southeast Culvert one of a very few companies that manufacture both steel and plastic storm water products.
In 2010, Doyle Johnson’s two sons, Wallace and Michael Johnson, took over the company. It’s seen a great deal of success throughout the course of its history, having won a number of Project of the Year awards from the National Corrugated Steel Pipe Association, and having built an outstanding reputation for quality products, and quality service. The company operates out of Winder, Georgia on two parcels of land just northeast of Atlanta. One of the most challenging aspects Southeast Culvert has experienced while working within the storm water drainage industry is the negative perception of corrugated metal pipe because of problems with galvanized steel pipe in Georgia. Galvanized corrugated steel pipe is one of the oldest products in the storm drainage industry, having been available since 1898. It’s a very reliable pipe material when used properly, and can survive many years under the proper conditions. Unfortunately, galvanized corrugated steel pipe has frequently been used improperly, for applications and environments outside the recommendations of the corrugated steel pipe industry. As a result, it will often corrode sooner than the expected 50 year average service life for the product.
The durability problems of galvanized steel pipe have created a perception problem for all corrugated steel pipe products. Today’s corrugated steel pipe industry has more choices for protective coatings than was available during most of the 20th century. These coatings are capable of performing well in more aggressive drainage applications, including low pH conditions and higher levels of abrasion.
Many State DOT’s in regions of the country that commonly have low pH conditions have modified their stormdrain pipe specifications to increase the role of aluminized type 2 corrugated steel pipe and polymer coated corrugated steel pipe on their projects.
Aluminized type 2 corrugated steel pipe has a similar visual appearance to galvanized steel pipe because both products use metallic coatings. Galvanized steel has a zinc coating that protects the base steel from corrosion, but that coating is sensitive to both low pH (<6.0) conditions and the presence of soft water. Aluminized type 2 has an aluminum coating that is much more stable in low pH conditions and is unaffected by the presence of soft water. The aluminized type 2 corrugated steel pipe product has an expected minimum service life of 75 years for 16 gauge steel and 100 year minimum service life for 14 gauge steel when installed in the appropriate environmental conditions (4.5 < pH < 9.0). Polymer coated corrugated steel pipe is visually very different than galvanized or aluminized type 2 corrugated steel pipe. The pipe has a heavy gauge protective polymer coating that has a black, shiny appearance. Polymer coated metal pipe has the widest range of allowable applications for any corrugated steel pipe product. The coating is highly abrasion resistant and durable in very acidic conditions (3.0 > pH).
The problems with galvanized corrugated steel pipe have created a negative perception among many private and municipal engineers for all corrugated metal pipe even though the newer coating options have provided reliable performance all over the country through decades of usage.
“The unfavorable perception some have of corrugated steel pipe,” says Wallace Johnson, President of Southeast Culvert, “was created by a lot of misuse of the product. It has presented challenges for corrugated steel pipe products in numerous locations throughout the United States. You can put a lot of information out there, but if people already have a preconceived idea of what they think about a product, it’s awfully hard to change that.”
Changing perceptions is a challenge, but one that Southeast Culvert, with its involvement in the National Corrugated Steel Pipe Association (NCSPA), has been very successful in facing. The NCSPA has shown a great commitment toward pushing the industry forward and is very invested in research being done related to existing coating technologies and technologies that are being developed. “When we say a product is going to give you 75 to 100 years’ service life,” says Johnson, “we have a lot of science and data to back that up.”
This science includes a study on aluminized type 2 corrugated steel pipe that has been ongoing since 1952, right after the product was developed by AK Steel. The study was most recently updated in 2014, so it included sites that have been studied for more than 60 years. The results of the study demonstrated that the product could be relied upon to provide a 75 year minimum service life. The study can been found on the National Corrugated Steel Pipe Association’s website.
The NCSPA also studied the performance of aluminized type 2 corrugated steel pipes installed in the Atlanta area. The study includes more than 100 pipe installations, most of which have been installed for more than 20 years and some of which are almost 40 years old. The findings of the study exceed the industry recommendation of a 75 year minimum service life for the product. It also demonstrates that the aluminized product can perform well in a region like north Georgia, which commonly has low pH environments and soft water conditions. The study can be found on Southeast Culvert’s website.
Polymer coated steel pipe performance has also been studied in locations all across the country. Multiple studies can be found on the NCSPA website. The gathered data across multiple studies and decades of performance supports a 100 year minimum service life for the product in most applications.
Educating people on the proper applications for specific products, as well as helping customers select the right product for their specific needs, is a very challenging aspect of the work that Southeast Culvert performs. Fighting the uphill battle of reshaping a public perception that has been formed over many decades is a major hurdle, but one that the company is turning into an opportunity through a dedication to research and a data-driven approach to educating the public.
Based on the research cited above and their own experience with these products, Georgia DOT upgraded both aluminized type 2 corrugated steel pipe and polymer coated steel pipe in 2016 to allow their use under larger roadways. The products were upgraded from roads with an expected daily traffic of 1,500 ADT to roads with an expected daily traffic of 5,000 ADT. GDOT also differentiates between galvanized metal pipe and these newer coating technologies (galvanized is not allowed under any road). Additionally, Georgia DOT allows corrugated HDPE pipe under roads with an expected daily traffic of 15,000 ADT. The allowed stormdrain pipe products and appropriate environmental conditions for GDOT projects can be found in this chart.
Despite the many challenges facing the storm water drainage industry, Southeast Culvert has risen above and found a great deal of success manufacturing products that represent the leading edge of storm water pipes. Beyond the manufacture of these products, the company also offers engineering services.
The engineers at Southeast Culvert specialize in designing underground detention systems using corrugated steel pipe, corrugated HDPE pipe, and stormwater detention chamber products.
One such project was the North Cobb High School project, which included an underground detention system with more than 2000’ of 10’ diameter corrugated steel pipe. A short video of the system being installed can be found on YouTube.
Another large project was the underground detention under the parking lot of the Gwinnett Braves Stadium in Lawrenceville. The system consists of more than 1 mile of 12’ diameter corrugated steel pipe.
Southeast Culvert’s products have also been used to repair aging infrastructure, such as the stormdrain pipe underneath a Norfolk Southern rail line in Lovick, Alabama. Relining the existing pipe with 9’ diameter corrugated steel pipe instead of removing and replacing it allowed the rail line to function without interruptions and greatly reduced the cost of the repair project.
The engineers at Southeast Culvert also design proprietary water quality treatment systems using Hydro International devices. These systems provide water quality treatment for stormwater drainage including 80 percent TSS removal as required by Georgia EPD and the reduction of other stormwater pollutants.
Over the course of its history, Southeast Culvert has made a substantial impact on the storm water drainage industry. Through a dedication to furthering research and collecting data on stormwater products, the company’s contribution has had a significant effect on the quality of stormwater regulations and infrastructure. Southeast Culvert is committed to investing in research and using that research to further inform the public, engineers, and government leadership – and, in time, to fix an aging infrastructure.