Is My Company’s Waste Hazardous? Reviewing California (Non-RCRA) Toxicity (Part Two of a Two-Part Series)

Most states are authorized to implement some or all of the RCRA hazardous waste requirements. State RCRA programs must be at least as stringent as the federal program, but states also can adopt more stringent requirements and in some cases, such as California, state requirements are much more stringent, especially the California definition of the toxicity characteristic. California regulates more metals (17, instead of just 8) and regulates those metals at lower levels. For example, California established hazardous waste standards for the total amount of regulated material in the waste (referred to as “total threshold limit concentration” or TTLC) and also created a more stringent version of the TCLP called the “waste extraction test” or WET. After WET extraction, samples are analyzed and the results are compared to the “soluble threshold leachate characteristic” (STLC) thresholds found in Title 22, California Code of Regulations, section 66261.24 (which are lower than the TCLP thresholds). In addition to the TTLC/STLC standards for metals, California has additional standards for acute toxicity criteria as well as limits for specific chemicals but the final standard that California added is the acute aquatic toxicity assay, also called the “fish tox test”. This test determines if wastes are harmful to the environment by preparing and placing an amount of the waste into 10-liter fish tanks along with 20 fish (rainbow trout, fathead minnow or golden shiner). Fish mortality is evaluated after 96 hours and waste is considered hazardous by aquatic toxicity if a 96-hour LC50 is less than 500 mg/liter. This is a “functional test” that is based only on results, as opposed to the other state and federal criteria that are based on specific levels of regulated substances. For the fish tox test, all that matters is whether the waste shows aquatic toxicity, not what is in the waste. This “functional” aspect is particularly relevant for wastes with low levels of hazardous contamination, such as wipes, rags, small containers, absorbent and similar debris. In most cases, the low levels of contamination are not enough for the waste to exhibit other hazardous waste characteristics but the presence of low levels of contamination might be enough to exhibit aquatic toxicity. The wastes could be tested, but this type of debris waste is inherently variable so test results from one container may not be predictive for others. As a consequence, many California waste generators make the conservative assumption that this type of debris waste will fail the aquatic toxicity assay and manage these wastes as hazardous waste. Wastes that fail any of the California criteria but do not fail RCRA criteria are referred to as “Non-RCRA” hazardous wastes. Even though they would not be considered hazardous waste outside the state, they still must be managed as hazardous waste within California. Hazardous waste toxicity determination can become very complicated. Evaluation based on federal criteria requires specialized testing and there are several additional criteria for California generators that can lead to non-RCRA hazardous waste that is only hazardous in California. If you have any questions about hazardous waste toxicity or any other hazardous waste regulatory compliance issues, please request a free review. We would love to help. – brought to you by the ACTenviro consulting team – your EH&S compliance experts