Industrial Wastewater MythBusters Part 2

Friday, April 28, 2017

Wastewater myths can negatively impact compliance and operating costs at industrial facilities. This article is part of a series that dispels myths related to pretreatment, surcharges, sampling, and complex pollutants.

PRETREATMENT

“If we install pretreatment, it will solve our compliance issue.”

While this certainly should be true, it isn’t always that simple.  Installing treatment does not guarantee compliance.  In fact, many facilities have spent hundreds of thousands of dollars on complicated technology to resolve a compliance issue, only to have it resurface months after startup.  This is usually due to a lack of operator training, improper treatment chemical usage, or a misapplication of the technology.

WASTEWATER VALUE

“Our wastewater has no value, so it isn’t worth thinking about.”

Depending on your process, your wastewater could be very valuable.  There is likely value from a compliance standpoint, but there could also be economic value from surcharge fees paid for organic components that contribute to BOD levels.  There may even be product or raw material value to your wastewater, so improving the efficiency of process equipment and cleaning operations may increase company profitability.  This is particularly true in the food processing industry.  For example, every pound of BOD discharged from a dairy processing facility represents a gallon of whole milk product wasted.  Is your facility flushing profits down the drain?

pH

“We need to install an expensive pH neutralization system because of our upper compliance limit.”

This may not be true, especially for facilities in small- to mid-sized towns and cities.  Often times, these POTWs make industry pH limits very stringent out of fear or a lack of understanding of the risks/benefits.  Although federal requirements prohibit lower pH limits from being less than 5.0 s.u., upper pH limits are a different story.  Many POTWs have upper pH limits set at 12.0 or 12.5, and some do not have upper limits at all.  These POTWs can be referenced as precedents to help justify raising overly stringent upper pH limits.  There are also technical justifications for increasing upper pH limits, including sewer infrastructure, POTW treatment process, and health/safety benefits that are all documented.  By showing your POTW “what’s in it for them,” you may be able to convince them to raise the upper pH compliance limit.

OIL & GREASE

“We generate oil & grease, but all we will need for compliance is a grease trap.”

While this is generally true for restaurants, food processing facilities may not be able to rely on this method alone.  Facility cleaning operations that involve washing process tanks and piping with heated caustic solutions can actually turn fat/grease into soap through the process of saponification.  This can result in O&G passing through the grease trap and may even result in previously accumulated fat/grease being discharged.  Other industrial facilities that use emulsified oils in their process will also struggle to comply with O&G limits using only a grease trap.  In these situations, a more active treatment technology such as dissolved air flotation (DAF) is typically necessary.