Large Tank (AST) Cleaning and Degassing

BioSolve® Pinkwater is a highly “lipophilic” (oil-loving) nonionic surfactant formulation for oil tank cleaning.

Rapid turnaround is essential for oil or fuel storage tank cleaning prior to inspection or scheduled maintenance.  The process of stripping a tank can become protracted by the presence of high vapor levels and unpumpable sludge, which could take weeks to eliminate.  Over the past 30 years, BioSolve® Pinkwater has proven to be an effective, worker-friendly solution to these challenges.

BioSolve® Pinkwater is a highly “lipophilic” (oil-loving) nonionic surfactant formulation for oil tank cleaning that works in two ways when forcefully applied with high pressure spraying systems:

  • Pinkwater solubilizes hydrocarbons, stripping them from tank walls, internal structures, and concrete retaining walls as well as stripping oil from sludge.
  • Pinkwater encapsulates hydrocarbons in a water-based solution known as an emulsion that dramatically reduces vapor pressure, thereby lowering VOC levels and LEL readings.


  • Minimize down time for AST cleaning
  • Ensure safe working conditions
  • Eliminate use of hazardous products (solvents, caustic)
  • Minimize waste handling and treatment

The BioSolve® Advantage

  • Final decontamination and tank degassing in one step reduces time to prepare for manned entry.
  • Water-based system is easy-to-use and increases worker safety.
  • Particularly effective with lighter, more volatile fuels

Application Guidelines

For general cleaning and degassing, apply a 4% - 6% solution of Pinkwater with a high pressure, course spray from a water cannon or other automated cleaning jet.  As a guideline, plan on 1 gallon of Pinkwater concentrate for each 20 gallons of hydrocarbons in the tank.  Hot water or steam systems can greatly increase effectiveness with sludge.

For Final Cleaning and Degassing

  • Apply Pinkwater solution using an automated pressure washing system (such as a water canon or rotary impingement system) to loosen and solubilize residual sludge and to rinse hydrocarbons from the walls, roof, floor, sump and internal structures.
  • Cleaning and degassing with Pinkwater will eliminate the source of vapors and may reduce, but not completely eliminate existing vapors in the tank.
  • Test for LELs; repeat as necessary

For Sludge Removal

  • For sludge with about 40% or more water, Pinkwater concentrate can be mixed directly with water in the tank using an eductor system as part of the circulation loop. Effective tank sludge removal requires good circulation throughout the tank to achieve uniform mixing.
  • Adding a heat exchanger to the circulation loop will improve results.
  • Once the sludge is dissolved, use a frac tank to residual oil from water and solids.

Small Oil Storage Tank Cleaning, Fuel Storage Tank Cleaning and Degassing

Tanks less than 50,000 gallons

BioSolve® Pinkwater is a proven tool used in the process of cleaning and repairing or decommissioning and removing fuel storage tanks of all sizes.  Pinkwater is best known for its unmatched performance for fuel tank degassing to suppress flammable and hazardous vapors that are present when working on both AST and UST projects.

Pinkwater can also be effectively used for tank sludge removal when applied with a high pressure spraying system to loosen the sludge.

Major oil companies, as well as small tank removal contractors, find working with Pinkwater to be safe, easy, effective and worker friendly as compared to other oil tank cleaning chemicals and alternative approaches to tank cleaning and degassing.


Safely and reliably remove residual fuel and reduce LELs before removing or performing maintenance on fuel storage tanks.

The BioSolve® Advantage

  • BioSolve® Pinkwater is unsurpassed for suppression of dangerous volatile fuel vapors.
  • Proven effective through continuous use for past 30 years.
  • Pinkwater is water-based; there are no difficult-to-handle or hazardous materials required.
  • Used by major oil companies and terminals for AST cleaning and tank degassing on storage tanks as large as 300 ft (91 meters) in diameter.

Application Guidelines

  • Follow all established procedures for tank venting, testing, entry and removal.
  • Inspect tank, verify contents and drain as much as possible.
  • Prepare 5% solution of BioSolve® Pinkwater. Allow about 1 pail (5 U.S. gallons/19 Liters) of Pinkwater concentrate for each 10,000 gallons (38,000 Liters) of tank capacity.
  • Apply Pinkwater solution through a power washer or rotary impingement cleaning system, being sure to spray ALL internal surfaces in the tank. Use of hot water (up to 190oF/88oC) solution will improve performance.
  • Recover effluent for treatment; repeat for tanks with heavy sludge.

Always test for LEL’s before performing “hot work” or any manned entry.

FIELD APPLICATIONS Pinkwater Clear Activator Hydrovent
Surfactant Enhanced Aquifer Remediation
Aerobic Biodegradation of Impacted Soil
Insitu Spill Remediation
Land Farming & Biopiles
Industrial Maintenance
UST & AST Cleaning/Degassing
Subfloor/Interstitular Decomntamination
Vapor/Odor Control
MGP Site & Brownfield Remediation
Excavation in Impacted Soil
Hydrocarbon Spill Response
Spill Clean-Up
Equipment Decontamination