Cleaning Procedures for Acid Neutralization Tanks

An acid neutralization tank is a storage tank made of precast concrete that utilizes chips of limestone to counteract acid in waste water from laboratories such as those at hospitals and universities. Only trained professionals should clean acid neutralization tanks because the process can involve up to three individuals using heavy machinery to remove, haul away and dispose of old chips of limestone.

Clean the Tank

• Replace all used chips of limestone every two years. The limestone will crystallize from continued exposure to acid and lose its ability to neutralize acidity. Check with the Occupational Safety and Health Administration (OSHA) as to the proper safety requirements before cleaning the acid neutralization tank. Open all doors and windows near the tank if it is kept indoors to allow for ventilation before opening the tank. Vapors from solvents in the tank are toxic and flammable. Protect your body by wearing goggles, rubber gloves, rubber boots and a rubber apron. Remove the used chips of limestone and set them on heavy sheets of plastic polyethylene. Cover the used limestone chips with baking soda to neutralize any chemicals or acids remaining on the stones. Use water to wash the used chips of limestone. The used chips of limestone may still contain residual toxic chemicals. Hire a government-approved toxic waste disposal service to haul away and incinerate the used limestone chips.

Refill and Maintain

• Fill the acid neutralization tank with water up to the outlet fitting or lowest fitting. Spread the new limestone chips around the bottom of the tank to cover the entire area. Expect some water to displace and pour out of the outlet fitting. Check the condition of the new limestone chips every two months after cleaning the acid neutralization tank. The new limestone chips continue should cover the entire bottom of the tank. This ensures that enough limestone chips are available to neutralize the acid in the waste water. Use sediment interceptors in the acid neutralization tank to prevent the excessive buildup of oils, muck or other effluence that may clog pipelines.