For Hong Kong, like other densely populated areas, handling sewage is a challenge, especially with an aging infrastructure. The network involves about 900 miles (1,448 km) of pipelines going to 280 treatment facilities, processing over 700 million gallons (2.6 billion L) of sewage per day. Maintenance is critical and ongoing.
Instead of patching existing problems or completely rebuilding manholes and other parts of the system, we proposed a long-term solution using our polyurea spray coating method to stop deterioration and strengthen walls. This entailed working with a contractor who did pipeline repair in the region.
To earn approval from government officials, Rob Anderson in our USA headquarters flew to Hong Kong to demonstrate the process and define results. While the contractor had air compressors and generators that were compatible with the local electrical systems, they did not have spraying units needed for this project. We retrofitted and shipped high-speed, high-pressure coating equipment and product from the U.S. facility. It required 380 volt, three-phase wiring and a transformer box. Everything was then mounted on a flatbed truck for mobility.
To accommodate the audience and make for easy inspection, Anderson cleaned and sprayed a large concrete box culvert used to divert storm water under the roads. Although the deterioration was not as extensive as brick and mortar manholes, the coating process was nearly the same.
The culvert results gave both the contractor and government officials the confidence to move to the next step. A second trip was scheduled to demonstrate the manhole coating process and train applicators. Anderson knew they would need to work around numerous challenges coming from both the sewer environment and complexity of the underground sanitation system.