Wastewater Treatment Plant Aeration Basin Rehab

PROJECT TITLE: Wastewater Treatment Plant Aeration Basin Rehab

PROJECT LOCATION: Midwest

CLIENT: Meat Processing Plant

Problem

An aging aerobic digester system had developed restricted airflow, causing low oxygenation numbers in the basin. This kept the system from functioning properly and caused a backup in the entire plant’s wastewater treatment process.

Bulldog Diving specializes in working on this type of aerobic system, because we have devised a technique to do so without shutting down the airflow. Doing so could impact the wastewater treatment process so profoundly that it can potentially cause more problems than it solves.

In this particular project, we needed to rehabilitate portions of multiple different aeration grid systems in the same aeration basin, to improve air flow and increase water oxygenation. We did so while the air system was running, to avoid causing any process backups.

Solution

Aside from the typical challenges of commercial diving, the project parameters dictated that we had to also plan for limited to zero visibility in the plant flows; time and pressure issues; and, especially in aeration systems, heat concerns. All of these we would have to manage while working in these active systems with continuous airflow. This creates strong currents that push and pull the diver around, making repairs more difficult and time-consuming, as they are constantly needing to reposition themselves. This is also quite taxing physically on the divers, who must be in top physical condition to withstand such stresses.

After discussions with the client, our project planners made the decision to replace most poorly performing system components with replacement parts the client already had on site. Some new parts were brought in to complete other areas of the system rehabilitation. Some aeration laterals in disrepair were taken out of service and plugged off permanently, because the client determined that the resources required to bring them up to acceptable service weren’t worth the service they gave.

With a project of this size and covering multiple grid systems in the same basin, there are always additional minor issues that get discovered after the larger, main problems are solved. This project was no different, but our decades of experience have given us the insight to be prepared for this, and we were. Nothing arose that we couldn’t handle in the course of the work.

Result

The goal for this project was to increase airflow throughout the aeration basin system, and we achieved this goal. The repairs made by our crew have increased water oxygenation, which improves the wastewater treatment process. Much of our work involves helping to maintain and improve WWTP operations and throughput.