State Moves Forward with NPDES General Permit 8, Allowing for the Surface Discharge of Test Water

EPA’s new underground storage tank (UST) system testing requirements have been at the forefront of PMCI’s regulatory advocacy efforts over the last several years.  Iowa plans to adopt EPA’s amendments later this year.  EPA’s 2015 UST amendments will require UST owner/operators to test containment sumps, under-dispenser containments, and spill buckets using a vacuum, pressure, or liquid test method no later than October 13, 2021.  At this time, PMCI believes that liquid testing is the most likely test method to be used by owner/operators to meet EPA’s upcoming testing requirements.

Liquid testing, commonly referred to as hydrostatic testing, requires the introduction of test water into each containment at a UST facility.  The test liquid levels are monitored for one hour to determine if the containment passes the test.  At the completion of the test, the test water must be removed from the containment and properly disposed of.

NPDES General Permit #8 (GP 8) serves to facilitate the disposal of hydrostatic test water generated at Iowa UST facilities.  GP 8 is free and allows hydrostatic test water to be disposed of to the ground surface of a facility or to a surface water of the state assuming the test water does not exceed certain toxicity characteristics for the following chemicals: pH1, Sulfate, Chloride, Total Suspended Solids, Oil and Grease, Iron, Benzene, Toluene, Ethylbenzene, Xylenes, Total Residual Chlorine, Aluminum, MTBE, and Lead. 

Although GP 8 is free and circumvents costly testing and disposal requirements for PMCI members, we urge our members to use caution before disposing of hydrostatic test water to the ground surface at your facility.  GP 8 covers discharges of test water to the ground surface or surface waters of Iowa and does not preempt applicable requirements for drinking water and corrective action requirements.  GP 8 allows for test water containing 0.510 mg/L of benzene to be disposed of under the permit.  EPA classifies test water containing 0.5 mg/L of benzene to be a hazardous waste for its toxicity characteristics pursuant to 40 CFR 261.24.  Additionally, benzene found at a level of 0.005 mg/L in drinking water or groundwater triggers corrective action requirements at your facility.

While widespread testing of containments and spill buckets is still three years away, PMCI urges its membership to use caution before proceeding with the disposal of petroleum contaminated test water under GP 8.  Prior to moving forward with disposal, please contact the PMCI office and your financial responsibility provider.