Compliance with BWON requires careful attention to the word “waste,” the essential term in the regulation's applicability and control provisions. It is important to understand that the BWON has a special definition of “waste.” Other definitions-from the RCRA regulation or an ordinary dictionary-have no bearing on a BWON compliance program. The BWON definition (§61.341) of “waste” is:
“Material resulting from industrial, commercial, mining, or agricultural operations, or from community activities that is discarded or is being accumulated, stored, or physically, chemically, thermally, or biologically treated prior to being discarded, recycled, or discharged.”
Two extracts from this definition reveal the wide range of materials that are considered BWON wastes:
“Material resulting from industrial ... operations ... that is discarded....” This extract is a normal definition of waste materials - for example, discharged wastewaters and sludges processed for off-site disposal."
“Material resulting from industrial ... operations ... that is accumulated, stored, or ... treated prior to being ... recycled....” This extract reveals how the definition can cause materials to be BWON wastes that would not otherwise be considered wastes. Importantly, the definition captures many hydrocarbons, including:
- Off-specification product
- Hydrocarbon associated with wastewaters, tank draws, spent caustic
- Hydrocarbon from turnarounds and maintenance activities
- Small-quantity hydrocarbon discharges, such as pump drips, samples, sight glass drainings, vessel draws
Certain regulatory provisions-notably the TAB quantification and the 6BQ alternative-emphasize aqueous wastes. The term “aqueous” means a waste with more than 10 percent water. Such a waste may be aqueous at its point of generation, or it may initially be pure hydrocarbon but become aqueous through subsequent mixing with water during its management as a waste. Other considerations when determining if a material is a BWON waste, are outlined further in this article.
Many hydrocarbon streams can be BWON wastes.
Hydrocarbons that are associated with wastewaters are considered to be aqueous wastes. For example, hydrocarbon undercarry associated with desalter brine is part of an aqueous waste. Furthermore, hydrocarbon that is a non-aqueous waste when generated, such as a product sample dropped to a sewer, can become aqueous when it joins the wastewater.
When does a material first become a BWON waste?
The regulatory answer to this question is that a material becomes a waste when it exits a piece of equipment that is not integral to the process. Often, it is a straightforward matter to identify such equipment. For example, a tank draw becomes a BWON waste when it leaves the tank being drawn. Sometimes, it can be more difficult to decide if, for BWON compliance purposes, a piece of equipment is integral to the process, given that virtually all of a facility's equipment contributes to processing functions.
For more difficult determinations, it is useful to ask if the process could operate without a specific piece of equipment, in which case that equipment is not integral to the process. For example, a crude unit requires the desalter to prepare the crude oil for fractionation. Since desalter brines often contain appreciable amounts of hydrocarbon undercarry (up to 1 or 2 percent of water flow rate), some refineries install desalter brine break tanks to capture the hydrocarbon before the brine enters the sewer system. In such a case, the crude unit can operate with or without the break tank (such issues as refinery efficiency are not part of this analysis). Therefore, the break tank is not integral to the process and the desalter brine becomes a BWON waste when it leaves the desalter.
When does a waste stop being a BWON waste?
The answer is when the waste is returned to the process. Typically, this issue concerns slop oil or some other hydrocarbon BWON waste, because these materials are re-processed they are not treated to remove benzene. For BWON compliance purposes, a waste is returned to the process when it enters a tank used to store process feed, intermediate, or product, unless the tank is used primarily to store waste. The italicized disclaimer ending the previous sentence means that a material sent to a tank is still a BWON waste (and the tank is still a BWON waste management unit) if the tank manages primarily BWON waste. Sometimes, BWON waste is sent directly to a feed pipe, in which case is stops being a waste when it enters the feed pipe.
Some BWON wastes are non-aqueous (for example, pipeline flushes). Like recovered groundwater, the non-aqueous wastes are not included in the TAB quantification, but they are subject to the control provisions.
Wastes can come from off site. If benzene-containing waste is accepted from off site, then it becomes the facility's BWON waste upon entering facility property.
The BWON regulation applies to any material meeting the definition of “waste,” which includes more than wastewaters. A material can be a waste even if it is not discharged to the sewer system. For example, maintenance clearance can be a BWON waste.
The inclusion of recycled materials expands the list of wastes beyond what most people consider to be typical wastes. If a material is stored, accumulated, or treated during its recycle loop, then it may be a BWON waste, even if it never leaves the process unit boundaries. If you have more questions on BWON waste or need further support with BWON compliance for your facility, please contact us at 713.552.1371, x209.