Underground Storage Tank Cleaning Process

An underground water tank can be cleaned without removing water when it is compatible with a submersible, remotely operated cleaning system. Bristola’s approach introduces an ROV through a specialized entry point, where it mobilizes and vacuums sediment through a hose to a selected processing option. This avoids traditional draining and human entry while allowing qualifying systems to remain operational.

The process begins with reviewing tank conditions, access, sediment accumulation, operating constraints, and solids-handling needs. A compatible robotic entry system is then prepared, and a submersible ROV is deployed to remove sludge from the tank floor. The collected material moves through a flexible hose to the facility’s chosen destination. Results inform future maintenance planning and cleaning intervals.

Robotic cleaning is designed to mobilize and remove accumulated sediment and sludge from qualifying liquid storage tanks. The ROV works on the tank floor and transfers removed material through a flexible hose to a processing option selected by the facility. The appropriate approach depends on the tank’s contents, access configuration, sediment characteristics, and site-specific material-handling requirements.

Bristola’s zero-human-entry system is designed to avoid placing personnel inside qualifying tanks during routine robotic cleaning. Instead, a remotely operated vehicle enters through a dedicated access arrangement and is controlled from outside the tank. This reduces worker exposure to confined-space hazards while still enabling sludge removal. Site conditions and access requirements are reviewed before a cleaning plan is established.

For qualifying tanks equipped for the system, robotic cleaning can be performed while the tank remains in use, reducing the need for operational shutdowns. New facilities can incorporate the hardware before entering production. Existing facilities generally require an initial preparation and installation phase, which may include manual cleaning to remove existing sediment before future live cleanings can be performed.

The system is applicable to a broad range of liquid storage environments, including anaerobic digesters, water and wastewater treatment tanks, food and beverage process tanks, industrial tanks, biogas digesters, and certain covered lagoons. Compatibility depends on tank design, access dimensions, contents, and operating conditions. Bristola reviews these details to determine a suitable cleaning and installation strategy.

Cleaning frequency should be based on sediment accumulation, tank function, process performance, operating history, and maintenance objectives. Rather than waiting for a disruptive cleanout, operators can use a preventive maintenance program to establish inspection and cleaning intervals. A planned approach helps facilities anticipate solids management, protect available capacity, and align maintenance with production priorities.

Yes. Bristola can retrofit existing liquid storage facilities by first preparing the tank and removing existing sediment, then installing the necessary hardware and system components. An entry portal can be adapted to manholes 24 inches in diameter or greater. Once installed, the access arrangement supports repeatable robotic entry for future servicing without traditional human-entry cleaning.